21 |
Reactivity studies of antitumor active dirhodium compounds with DNA oligonucleotidesKang, Mijeong 25 April 2007 (has links)
The study of the mechanism of action of an antitumor active drug is essential for
improving the efficacy and reducing the side effects of the drug as well as for developing
better alternatives. In this vein, reactions of dirhodium compounds with DNA
oligonucleotides were investigated by the techniques of mass spectrometry, HPLC, and
NMR spectroscopic analytical methods.
The relative reactivities of three dirhodium compounds, namely Rh2(O2CCH3)4,
Rh2(O2CCF3)4, and [Rh2(O2CCH3)2(CH3CN)6](BF4)2, with DNA oligonucleotides were
studied and compared to the clinically used anticancer drugs cisplatin and carboplatin
using both MALDI and ESI mass spectrometric methods. The compound Rh2(O2CCF3)4
exhibits the highest reactivity among the dirhodium compounds, which is comparable to
cisplatin, followed by [Rh2(O2CCH3)2(CH3CN)6](BF4)2, and finally Rh2(O2CCH3)4
which is the least reactive.
Various dirhodium-oligonucleotide adducts were detected with both MALDI and
ESI methods, which involve substitution of different numbers of the original ligands of the given dirhodium compound. ESI MS was found to be a sufficiently soft ionization
method for detecting intact metal adducts, and CID MS-MS was useful for detecting
weakly bound species such as axial adducts [M+Rh2(O2CCH3)4] and for comparing the
relative bond strength between ligands in the metal adduct.
A combination of anion exchange HPLC purification and enzymatic digestion
studies of the adducts of Rh2(O2CCH3)4 with the 5'-CCTTCAACTCTC oligonucleotide
revealed that Rh2(O2CCH3)4 binds to the center or to the ends of the oligonucleotide
sequence by displacement of one or two acetate groups.
Kinetic products of the type [M+Rh2(O2CCH3)3] obtained from the reaction of
Rh2(O2CCH3)4 with 5'-CTCTCAACTTCC were separated by employing both reverse
phase and anion exchange HPLC methods. The adduct that involves binding of the
dirhodium unit to the exocyclic N4 atom of C5 and the N7 of A6 was found to be most
stable whereas other adducts involving binding of C3 or C12 residues are clearly less
stable.
Reaction of cis-[Rh2(DAP)(O2CCH3)3(CH3OH)](O2CCH3) (DAP = 1,12-
diazaperylene) with 5'-CTCTCAACTTCC produced a major adduct in which DAP
group intercalates between 6A and 7A in the double stranded adduct with the rhodium
atom that is not coordinated to the DAP group forming a covalent bond to the N7 atom
of 6A which lends stability to the adduct.
|
22 |
Antitumour MetallocenesMokdsi, George January 2000 (has links)
This thesis reports a study of the chemical stability and coordination chemistry of several antitumour metallocenes Cp2MCl2 (Cp = h5-C5H5; M = Ti 1, V 2, Nb 3, Mo 4), as well as derivatives of Cp2TiCl2 1, with nucleic acids, nucleic acid constituents and proteins. These studies were carried out in order to identify the biologically active species and more fully understand the molecular level mechanism of action of the antitumour metallocenes, in particular Cp2TiCl2 1, which is currently undergoing phase II clinical trials. The interactions of Cp2MoCl2 4 with four oligonucleotides were studied by 1H and 31P NMR spectroscopy. In 50 mM salt solutions of Cp2MoCl2 4, hydrolysis of the halide ligands occurred to give a solution with pD -2, containing a species in which both Cp rings remain metal bound for 24 h. At pD -7, partial hydrolysis of the Cp rings (-30percent) occurred after 24 h. Addition of an aqueous solution of Cp2MoCl2 4 in 50 mM salt to the self-complementary sequence d(CGCATATGCG)2, maintaining the pD at 6.0-7.0, showed no evidence for the formation of a metallocene-oligonucleotide complex and only peaks arising from hydrolysis of Cp2MoCl2 4 were detected. A similar result was obtained in titration experiments with the single stranded sequence d(ATGGTA) at pD 6.5-7.0. However, at pD 3.0, new signals assigned to a molybdocene-oligonucleotide complex(es), which was stable for hours at pD 3.0, were detected; while at pD -7 the complex is destabilised and only peaks arising from hydrolysis of Cp2MoCl2 4 were detected. Titration experiments at low pD with Cp2MoCl2 4 and the dinucleotide dCG were consistent with formation of a complex arising due to coordination of molybdenum to guanine N7 and/or cytosine N3. The results obtained showed that stable oligonucleotide adducts were not formed in 50 mM salt at pD -7 and hence it is highly unlikely that formation of molybdocene-DNA adducts in vivo is the primary action that is responsible for the antitumour properties of Cp2MoCl2 4. The rate of hydrolysis of the aromatic rings of Cp2TiX2 (X equals Cl 1, OCOCH2NH3Cl 27) and the dimethylsubstituted derivatives (MeCp)2TiX2 (X equals Cl 34, OCOCH2NH3Cl 41), in aqueous solutions at pD 2-8 was studied by 1H NMR spectroscopy. Rapid hydrolysis of both the halide/glycine and Cp ligands in Cp2TiX2 (X equals Cl 1, OCOCH2NH3Cl 27) occurred and predominantly gave a precipitate at pD -7. In contrast, under the same experimental conditions, the predominant species present in aqueous solutions of (MeCp)2TiX2 (X equals Cl 34, OCOCH2NH3Cl 41) at pH 2-8 contained both MeCp rings metal bound. At pD < 5, Cp2TiX2 (X equals Cl 1, OCOCH2NH3Cl 27) and (MeCp)2TiX2 (X equals Cl 34, OCOCH2NH3Cl 41) formed similar complex(es) with purine nucleotides. However, at pD >5, stable adducts between nucleotides and Cp2TiX2 (X equals Cl 1, OCOCH2NH3Cl 27) were not formed. In contrast, (MeCp)2TiX2 (X equals Cl 34, OCOCH2NH3Cl 41) formed complex(es) with 5'-dAMP or 5'-dGMP, which were stable for 24 h. These results suggest that formation of stable chelates between (MeCp)2TiX2 (X equals Cl 34, OCOCH2NH3Cl 41) and nucleic acid constituents in vivo is possible. However, the methyl substituted derivatives 34 and 41 did not show any antitumour activity against EAT in mice when administered in either 10percentDMSO/90percentsaline or in water at pH 6.2-6.4, which suggests that the labile Cp-Ti bond present in Cp2TiCl2 1 is required for antitumour activity. The synthesis of a range of Cp substituted titanocene derivatives was investigated in an attempt to prepare derivatives with modified Cp stability in comparison to the methyl substituted derivatives. The synthesis of derivatives (CpCH2Y)2TiCl2 where Y equals ?CHO 43, ?CONMe2 44, ?NO2 45, (RCp)2TiCl2 where R equals ?COMe 46, ?COOMe 47 or ?CONMe2 48, (CpNMe2)2TiCl2 62 and (Cp(CH2)2NMe2)2TiCl2 63 was unsuccessful, due to the presence of coordinating substituents on the Cp rings and poor stability in polar, protic solvents. Hence, these derivatives were excluded from further studies. The rate of hydrolysis of the Cp rings of Cp2TiX2 (X equals Cl 1, OCOCCl3 22 and OCOCH2NH3Cl 27) in aqueous solutions, 10percentDMSO/90percentD2O and 100percent DMSO was monitored by 1H NMR spectroscopy. Rapid hydrolysis of both the carboxylate and Cp ligands of Cp2TiX2 (OCOCCl3 22 and OCOCH2NH3Cl 27) occurred in DMSO to give biologically inactive species. The rate of these reactions were concentration dependent as dilution of these samples with saline or water to give the therapeutic conditions of 10percentDMSO/90percentD2O slowed the hydrolysis chemistry. In contrast, samples of Cp2TiX2 (X equals Cl 1 and OCOCH2NH3Cl 27) dissolved in water, gave solutions containing the presumed antitumour active species in which the halide or glycine ligands have been hydrolysed but the Cp rings remain metal bound. Thus, charged X ligands may be incorporated into Cp2TiX2 and will give comparable activity to Cp2TiCl2 1 provided the samples are administered in water. The antitumour metallocenes Cp2MCl2 (M equals Ti 1, V 2, Nb 3, Mo 4) and the inactive derivative (MeCp)2TiCl2 34 were found to inhibit the relaxation of supercoiled plasmid DNA pBR322 by human topoisomerase II in vitro. These results implicated the inhibition of topoisomerase II in the mechanism of antitumour activity although there was no direct correlation between the in vitro results with biological activity against EAT in vivo. UV spectroscopy confirmed that the metallocenes Cp2MCl2 (M equals Ti 1, Mo 4) became associated with and were stabilised to hydrolysis by calf thymus DNA but not with human serum albumin. ICP-AES was used to measure the amount of metal associated with either DNA or human serum albumin after incubation with Cp2MCl2 (M equals Ti 1, Nb 3, Mo 4) and dialysis of these solution. The results confirmed that DNA stabilises or becomes associated with the metallocenes. However, errors associated with the ICP-AES measurements did not allow these results to be quantified. 1H NMR spectroscopy was used to show that the antitumour metallocene Cp2MoCl2 4 formed an adduct with glutathione 72 in the pH range 3-7 through the sulfur donor group. In comparison, the antitumour metallocenes Cp2MCl2 (M equals Ti 1, Nb 3) showed limited adduct formation with glutathione 72 at pH -3 and no adducts were detected at pH > 5.5.
|
23 |
Translational studies of drug-induced tumor cell death /Hägg Olofsson, Maria, January 2006 (has links)
Diss. (sammanfattning) Stockholm : Karolinska institutet, 2006. / Härtill 6 uppsatser.
|
24 |
Caracterização química e avaliação da atividade biológica da própolis vermelha em células tumorais e não tumoraisFrozza, Caroline Olivieri da Silva 07 December 2012 (has links)
A própolis vermelha brasileira tem atraído interesses científicos e econômicos devido às suas variadas atividades biológicas. Este produto natural possui composição química diferente de acordo com a região na qual é encontrado, sendo necessária uma completa caracterização química para cada tipo de própolis, a fim de se elucidar os compostos presentes e possivelmente responsáveis por estas atividades. Dentre as atividades biológicas mais investigadas, destacam-se as atividades antioxidante e antitumoral. Neste
trabalho, buscou-se caracterizar quimicamente o extrato hidroalcoólico da própolis vermelha brasileira, avaliar as atividades antioxidantes e antitumorais, além de investigar o padrão proteico de células tumorais de laringe tratadas e não tratadas com extratos da própolis vermelha através da análise proteômica comparativa. A caracterização química realizada através de espectrometria de massas com ionização por electrospray mostrou que a própolis apresenta moléculas complexas, principalmente isoflavonoides, compostos com importantes atividades biológicas. Os extratos hidroalcoólicos obtidos a partir da própolis vermelha revelaram um significante conteúdo de polifenóis associados a uma habilidade de sequestrar radicais livres DPPH·. Os extratos também apresentaram atividades superóxido-dismutase-/ike e catalase-/ike, indicando que podem exercer um papel fundamental na manutenção fisiológica do equilíbrio redox quando em um organismo. A atividade citotóxica dos extratos da própolis foi avaliada nas linhagens tumorais Hep-2, HeLa e não tumoral Hek-293, sendo que os valores de IC50 foram menores para a linhagens tumorais em relação a não tumoral. Desta forma, sugere-se uma seletividade da própolis vermelha quanto às linhagens tumorais. A análise proteômica, usando eletroforese bidimensional associada à cromatografia líquida de alta eficiência acoplada a espectrômetro de massa, permitiu a comparação dos mapas proteicos da linhagem Hep-2, na ausência ou presença de extratos da própolis vermelha, nas concentrações 6 f.1g/mL (não citotóxica) e 120 f.lg/mL (IC50). A excisão manual de 325 spots foi efetuada nos géis 2D- SDS-PAGE, em que 177 proteínas foram identificadas. Estas proteínas foram relacionadas com diversos processos metabólicos e estruturais como produção e conversão de energia, transporte e metabolismo de carboidratos, modificação pós-traducional, reciclagem de proteínas e chaperonas, proteínas do citoesqueleto, proteínas de reparo, entre outros. Das proteínas identificadas com expressão diferencial, cinco apresentaram expressão reduzida na presença do extrato da própolis, este em sua maior concentração (120 f.lg/mL). Apenas duas proteínas identificadas neste estudo mostraram expressão aumentada na concentração não citotóxica (6 f.lg/mL) do extrato da própolis vermelha. Os resultados da proteômica comparativa mostram que a própolis interfere em um conjunto de eventos intracelulares e, assim, passa a ser uma candidata promissora para inibir o crescimento celular e contribuir para os diferentes passos relacionados com o processo de carcinogênese. Embora os mecanismos moleculares pelos quais a própolis vermelha interaja com o metabolismo das células permaneçam ainda desconhecidos, estudos adicionais servirão para melhor elucidar as atividades antioxidantes e antitumorais aqui observadas. / Submitted by Marcelo Teixeira (mvteixeira@ucs.br) on 2014-06-11T12:18:58Z
No. of bitstreams: 1
Dissertacao Caroline Olivieri da Silva Frozza.pdf: 43747 bytes, checksum: ca596fd367a149df47e208c279da85cb (MD5) / Made available in DSpace on 2014-06-11T12:18:58Z (GMT). No. of bitstreams: 1
Dissertacao Caroline Olivieri da Silva Frozza.pdf: 43747 bytes, checksum: ca596fd367a149df47e208c279da85cb (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Brazilian red propolis has attracted scientific and economic interests because of its varied biological activities. This natural product has different chemical compositions according to the region in which it is found, requiring a robust chemical characterization to elucidate the compounds responsible for the activities in each type of propolis investigated. So far antioxidant and antitumor properties are amongst the most studied biological activities. This study aimed to characterize chemically the hydroalcoholic extract of Brazilian propolis from the state of Sergipe, evaluate the antitumor and antioxidant activities, and to investigate the pattern o f proteins in tumor cells o f the larynx treated o r not with extracts of propolis through comparative proteomic analysis. The chemical characterization by mass spectrometry with electrospray ionization showed that propolis presents complex molecules, especially isoflavones, which has important biological and antioxidant capacity. The hydroalcoholic extracts obtained from propolis revealed a significant content of polyphenols associated with the ability to scavenge DPPH. radicais. The extracts also showed significant activities for superoxide dismutase-like and catalase-like, indicating an important role in maintaining physiological redox equilibrium, decreasing oxidative stress.
Cytotoxic activity was assessed for tumor cell !ines Hep-2, HeLa and non-tumor cell line Hek-293, showing IC50 values greater for Hek-293 compared to Hep-2 and HeLa cells, which suggests a selectivity of propolis for the tumor !ines. The proteomic analysis using two-dimensional electrophoresis associated with high performance liquid chromatography coupled with mass spectrometer allowed the comparison of the protein maps of Hep-2 cell line in the absence or presence of propolis extracts in concentrations of 6 f.lg/mL (not cytotoxic) and 120 f.lg/mL (IC50). 325 spots were manually excised from the gels 2D SDS-PAGE and 177 proteins were identified. These proteins have been linked to various structural and metabolic processes, such as production and energy conversion, transport and carbohydrate metabolism, post-translational modification, protein tumover and chaperones, cytoskeletal proteins, repair proteins, among others. From the identified proteins that showed differential expression five were downregulated in the presence of propolis extract in the highest concentration (120 J.lg/mL). Only . two proteins identified in this study showed increased expression in the no cytotoxic concentration (6 J.tg/mL) ofthe red propolis extract. The results of comparative proteomic showed that the propolis interacts with a series of intracellular events and hence becomes a promising candidate to inhibit cellular growth and contribute to the different steps related to the process of carcinogenesis. Although the molecular mechanisms by which propolis interacts with the metabolism of the cells remain unknown, additional studies will better elucidate the antitumor and antioxidant activities here observed.
|
25 |
Avalia??o das atividades antioxidante, anticoagulante e antiproliferativa de extratos aquosos de marsdenia megalanthaOliveira, Ruth Medeiros de 21 March 2011 (has links)
Made available in DSpace on 2014-12-17T14:03:36Z (GMT). No. of bitstreams: 1
RuthMO_DISSERT_partes_autorizadas.pdf: 1326808 bytes, checksum: b857ffe38a32dadfb7993ebe2bf2b79c (MD5)
Previous issue date: 2011-03-21 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The species of the genus Marsdenia, Apocynaceae, are widely used in folk
medicine of several countries. In Brazil is found several species belonging to this
genus. The in vitro antioxidant, anticoagulant and antiproliferative activities were
evaluated to aqueous extracts of stalk, leaf and root of Marsdenia megalantha. In
the total antioxidant capacity assay (expressed as ascorbic acid equivalents) the
stalk extract showed 76.0 mg/g, while leaf and root extracts 141.3 mg/g and 57.0
mg/g, respectively. The stalk and leaf extracts showed chelating activity around 40%
at 1.5 mg/mL, while root extract, at the same concentration showed, 17%. Only the
leaf extract showed a significant ability in superoxide scavenging (80% at 0.8
mg/mL). Any extract was able in scavenge hydroxyl, as well anticoagulant activity.
The antiproliferative activity of the extracts was evaluated against HeLa tumor cell
line. The extracts inhibited in a dose-dependent manner the cell growth. However,
the leaf extract showed 80% of inhibition at 1.0 mg/mL, while stalk and root extracts
inhibited 63% and 30%, respectively. To assess the mechanism of cell death caused
by the leaf extract in HeLa, was performed flow cytometry and western blot. The
results show that leaf extract induces cell death by apoptosis through an activation
caspase-independent pathway. These data indicate that stalk and leaf extracts
obtained have potential to be used as antioxidants and anticancer drugs / As esp?cies do g?nero Marsdenia, Apocynaceae, s?o bastante utilizadas na
medicina popular de v?rios pa?ses. No Brasil s?o encontradas v?rias esp?cies
pertencentes a esse g?nero. As atividades antioxidante, anticoagulante e
antiproliferativa foram avaliadas para os extratos de caule, folha e raiz de Marsdenia
megalantha. Na capacidade antioxidante total (expressa como equivalente de ?cido
asc?rbico), o extrato do caule apresentou 76,0 mg/g, enquanto os extratos da folha e
raiz apresentaram, respectivamente, 14,3 mg/g e 57,0 mg/g. Os extratos do caule e
da folha mostraram habilidade quelante em torno de 40% na concentra??o de 1,5
mg/mL, enquanto o extrato da raiz, na mesma concentra??o, apresentou 17%.
Apenas o extrato da folha apresentou uma capacidade significante em sequestrar
radicais super?xidos (80% em 0,8 mg/mL). Nenhum extrato mostrou capacidade em
seq?estrar radicais hidroxila, bem como atividade anticoagulante. A atividade
antiproliferativa dos extratos foi avaliada contra a linhagem tumoral HeLa. Os
extratos inibiram, de forma dose-dependente, o crescimento celular. Entretanto, o
extrato da folha foi capaz de inibir em 80% a prolifera??o celular na concentra??o de
1,0 mg/mL, enquanto os extratos de caule e raiz inibiram 63% e 30%,
respectivamente. Para avaliar o mecanismo de morte celular causada pelo extrato
da folha nas c?lulas HeLa, foi realizada citometria de fluxo e western blot. Os
resultados mostraram que o extrato da folha induz morte celular por apoptose
atrav?s de uma via de ativa??o independente de caspase. Estes resultados indicam
que os extratos de caule e folha obtidos t?m potencial para serem futuramente
utilizados como f?rmacos antioxidantes e antic?ncer
|
26 |
Estudo do Potencial AnticÃncer de um Derivado de Chalcona, 1-(4-Nitrofenil)-3-Fenilprop-2-En-1-Ona, In vitro e In vivo / In vitro and In vivo Study of the Anticancer Potential of a Chalcona Derived Substance, 1- (4-Nitrofenil)-3- fenilprop-2- en-1-onaKristiana Cerqueira Mousinho 22 October 2010 (has links)
CoordenaÃÃo de AperfeiÃoamento de NÃvel Superior / A substÃncia 1-(4-Nitrofenil)-3-fenilprop-2-en-1-ona (CG) Ã um derivado de chalcona, sintetizado a partir da reaÃÃo quÃmica entre a acetofenona e para-nitro benzaldeÃdo. Para avaliar o seu potencial anticÃncer foi realizado um estudo farmacolÃgico de suas propriedades antitumorais em vÃrios modelos biolÃgicos in vitro e in vivo. A CG apresentou potente atividade citotÃxica nas 5 linhagens tumorais testadas, inibindo a proliferaÃÃo das cÃlulas tumorais pelo ensaio do MTT e em cÃlulas mononucleares do sangue perifÃrico (PMCB) humano atravÃs do ensaio do Alamar blue. Todas as linhagens mostraram sensibilidade ao tratamento com a CG, e a CI50 variou de 1,18ÂM em HCT-8 a 3,32ÂM em SF-295. O composto apresentou fraca citotoxicidade (CI50 igual a 7,07ÂM) nas cÃlulas PBMC, com exposiÃÃo a CG em 72h, em relaÃÃo Ãs cÃlulas de HL-60, utilizada como modelo nos demais testes biolÃgicos. O tempo de encubaÃÃo com o composto foi de 24h na maioria dos experimentos. Adicionalmente, a CG nÃo induziu efeitos hemolÃticos. O ensaio de exclusÃo por azul de Tripan revelou diminuiÃÃo da viabilidade celular principalmente apÃs 24h na maior concentraÃÃo testada (4ÂM) com 58,4%. Para os testes de atividade antiproliferativa, LA/BE mostrou em sua morfologia cÃlulas em apoptose nas duas maiores concentraÃÃes, enquanto que o BrdU, apresentou incorporaÃÃo do mesmo nas concentraÃÃes testadas. A morfologia analisada por May-Grunwald-Giemsa mostrou reduÃÃo do volume celular, condensaÃÃo da cromatina e fragmentaÃÃo nuclear. Adicionalmente, a CG induziu apoptose em cÃlulas leucÃmicas HL-60, com participaÃÃo das vias intrÃnseca e maior estÃmulo da via extrÃnseca, de maneira concentraÃÃo-dependente, como observado na integridade da membrana citoplasmÃtica, aumento da fragmentaÃÃo do DNA e externalizaÃÃo da fosfatidilserina. Na anÃlise do ciclo celular, foi observado parada na fase G2/M, sendo ativada as caspases 3, 7, 8 e 9 (a Ãltima na maior concentraÃÃo e confirmada pelo teste do Western blot). NÃo houve ativaÃÃo do Citocromo c. A CG nÃo foi capaz de induzir processos genotÃxicos/ mutagÃnicos (testes do cometa e micronÃcleo in vitro). No ensaio de atividade antitumoral in vivo, observou-se inibiÃÃo tumoral nas doses testadas (25 e 50mg/Kg/dia, via oral) de 54,85 e 69,11% respectivamente. As doses de CG causaram tumefaÃÃo celular e o surgimento de focos inflamatÃrios no parÃnquima ou estroma hepÃtico/renal, necrose nefrotÃxica focal, esteatose microvesicular, pigmentos de hemossiderina, hiperplasia das cÃlulas de Kupffer, congestÃo da polpa vermelha e desorganizaÃÃo dos folÃculos linfÃides esplÃnicos. AlÃm disso, os Ãndices bioquÃmicos mostraram aumento do AST e diminuiÃÃo da urÃia (CG 25mg/Kg/dia), diminuiÃÃo do ALT (5-FU e CG 25mg/Kg/dia); as alteraÃÃes hematolÃgicas mostraram leucopenia e plaquetopenia (5-FU), aumento dos leucÃcitos totais (CG 50mg/Kg/dia), aumento de neutrÃfilos e linfÃcitos em todos os grupos tratados. Todos os resultados nos levam a enfatizar que a CG possui grande potencialidade como molÃcula promissora por suas propriedades anticÃncer. / The substance 1- (4-Nitrofenil)-3- fenilprop-2- en-1-ona (CG) is a chalcone derivative, synthesized from a chemical reaction between acetophenone and p-nitro benzaldehyde. To evaluate its anticancer potential a pharmacological study of its antitumor properties in selected biological models in vitro e in vivo. CG presented a powerful cytotoxic activity in the 5 tested tumor lines evaluated, inhibiting cell proliferation of the tumor lines in the MTT assay and human peripheral mononuclear blood cells (PMBC) through the Alamar Blue assay. All cell lines showed sensitivity to the treatment with the CG, and the IC50 varied from 1,18 ÂM in HCT-8 to 3,32 ÂM in SF-295. The sample presented weak cytotoxic effect (IC50 of 7,07 ÂM) in cells PMBC, with 72h exposure to CG, compared to HL-60 cells (leukemic cell line), used in the next biological tests. The sample was incubated with the cells during 24h for the majority of the experiments. Additionally, CG did not induce hemolytic effects. The Tripan Blue assay showed a decrease of the cellular viability especially after 24h of incubation of the higher tested concentration (4 ÂM) with 58,4%. In assays for antiproliferative activity, OA/BE showed in its morphology cells going under apoptosis in the two higher concentrations, whereas the BrdU assay, presented incorporation of the same in the tested concentrations. The morphology analyzed with the May-Grunwald-Giemsa stain showed a decrease of the cellular volume, chromatin condensation and nuclear fragmentation.CG induced apoptosis in HL-60 cells, with participation of the intrinsic pathway and major stimulation of the extrinsic pathway, in a concentration-dependent manner, as observed in the cytoplasmatic membrane integrity, increase of DNA fragmentation and outsourcing of phosphatidylserine. In the cellular cycle analysis, it was observed a stop in the G2/M phase, activating caspases 3, 7, 8 and 9 (the last one in the highest concentration and confirmed by the Western blot assay). It was not observed activation of Cytochrome c. CG was not capable to induce mutagenic/genotoxic processes (comet assay and micronucleus in vitro). In the in vivo antitumor activity assay, tumor inhibition was observed in the tested doses (25 and 50mg/Kg/day, oral intake) of 54,85 and 69,11%, respectively . The doses of CG caused cellular swelling and the arise of inflammatory focus in the parenchyma or hepatic/renal stroma, focal nephrotoxic necrosis, microvesicular steatosis, hemosiderin pigments, hyperplasia of Kupffer cells, congestion of the red pulp and disorganization of the splenic lymphoid follicles. Furthermore, the biochemical indices had shown increase of AST and reduction of urea (25mg/Kg/day of CG), reduction of ALT (25mg/Kg/day of 5-FU and CG); hematologic alterations showed leukopenia and thrombocytopenia (5-FU), increase of total leukocytes (50mg/Kg/day of CG), increase of neutrophils and lymphocytes in all treated groups. All results led us to emphasize that CG possesses great potential as a promising molecule for its anticancer properties.
|
27 |
ProspecÃÃo de substÃncias com potencial anticÃncer em microrganismos associados ao zoantÃdeo Protopalythoa variabilis (cnidaria, anthozoa) / Prospecting for substances with anticancer potential in microorganisms associated with the zoanthid Protopalythoa variabilis (cnidaria, anthozoa)Bianca Del Bianco Sahm 07 April 2014 (has links)
CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / Os produtos naturais apresentam um papel fundamental na descoberta de novos fÃrmacos. Nesse contexto, os produtos naturais marinhos apresentam um grande potencial quÃmico e farmacolÃgico. Resultados prÃvios demonstraram um potencial quÃmico e farmacolÃgico promissor do zoantÃdeo Protopalythoa variabilis encontrado no litoral cearense. Por outro lado, fortes indÃcios apontam que os microrganismos associados sejam os verdadeiros responsÃveis pelo elaborado arsenal de metabÃlitos secundÃrios isolados de invertebrados marinhos. Dessa forma surgiu o interesse em estudar o potencial biomÃdico da microbiota associada ao P. variabilis. Os esforÃos para isolar as bactÃrias renderam um total de 10 colÃnias. Destas, 3 apresentaram padrÃes morfolÃgicos tÃpicos de actinomicetos e 2 delas foram estudadas neste trabalho. A cepa BRA-035 foi identificada como pertencente ao gÃnero de actinomicetos Streptomyces, e seu extrato acetato de etila, resultante da fermentaÃÃo em meio A1, causou alta inibiÃÃo do crescimento celular contra a linhagem de carcinoma de prÃstata metastÃtico PC-3/M, com concentraÃÃo inibitÃria mÃdia (CI50 ) na ordem de pg/mL. O fracionamento bioguiado levou ao isolamento dos compostos glicopiericidina A, piercidina D, e piericidina A, sendo que esta Ãltima apresentou elevada atividade antiproliferativa em linhagens tumorais de cÃncer de ovÃrio (OVCAR-8), cÃncer de cÃlon (HCT-116) e PC-3/M, com CI50 encontradas na ordem de pico atà fento molar. Apesar de jà ter sido amplamente estudada, esta pode ser a primeira ocorrÃncia de atividade antiproliferativa de Piericidina A contra as linhagens testadas neste trabalho, assim como a ordem de grandeza de sua potÃncia. Outra cepa selecionada para estudo, a BRA-060, tambÃm foi identificada como pertencente ao gÃrero Streptomyces. Sua fermentaÃÃo foi otimizada em meio Marine Broth para produÃÃo de extrato acetato de etila com citotoxicidade contra a linhagem de leucemia promielocÃtica HL-60 em ng/mL. O fracionamento bioguiado deste extrato resultou no isolamento de trÃs dicetopiperazinas: a ciclo (L-Tyr-trans-L-Pro), a ciclo(L-Phe-cis-4-OH-D-Pro) e a ciclo(L-Phe-trans-4-OH-L-Pro). As dicetopiperazinas isoladas apresentaram potente atividade citotÃxica contra as linhagens de glioblastoma (SF-295), cÃncer de ovÃrio (OVCAR-8), HCT-116 e HL-60 e outra leceumia K-562, com valores de CI50 variando de nano a micro molar. Embora suas estruturas jà terem sido descritas pela literatura, nenhum trabalho foi feito quanto a suas atividades citotÃxicas, podendo este ser o primeiro relato sobre suas propriedades antitumorais. Esses resultados ressaltam a importÃncia da microbiota associada ao zoantÃdeo P. variabilis, encontrado no litoral cearense, como fonte de compostos com potencial anticÃncer. / Natural products exhibit a fundamental role in the discovery of new medicines. Marine natural products possess a huge chemical and pharmacological potential to yield new leads. Previous results support the promising chemical and pharmacological potential of the zoanthid Protopalythoa variabilis from the coast of Ceara State. On the other hand, strong evidences have indicated that associated microorganisms are the producers of the elaborate arsenal of secondary metabolites isolated from marine invertebrates. Then this study aimed to investigate the biomedical potential of associated microbiota to P. variabilis. The efforts to isolate associated bacteria yielded 10 different strains, and 3 of them showed typical actinomycete morphology. Here 2 of these actinomcetes had their anticancer potential studied. The strain BRA-035 belongs to the genus Streptomyces. BRA-035 culture using A1 broth yielded an acetate extract with potent cytotoxicity against a prostatic carcinoma cell line (PC-3/M), with inhibitory concetrantion mean (IC50) value in pg/mL. The bioguided fractionation led to the isolation of glucopiericidin A, piericidin D and piericidin A, and the later showed high antiprolifetative activity against ovarian cancer (OVCAR-8), colon cancer (HCT-116) and PC-3/M with IC50 values ranging from pico to fentomolar. Although Piericidin A has been widely studied, this might be the first report of cytotoxic activity against the lineages tested in this work, as well as the magnitude of its potency. Another strain selected for this study, BRA-060, was identified as belong to the genus Streptomyces also. The fermentation was optimized in marine broth to produce an acetate extract highly cytotoxic against a leukemia cell line (HL-60). The bioguided fractionation of these extracts yielded three diketopiperazines: cyclo (L-Try-trans-L-Pro); cyclo (L-Phe-cis-4-OH-D-Pro) and cyclo (L-Phe-trans-4-OH-D-Pro). The diketopiperazines isolated showed potent cytotoxic activity against glioblastoma (SF-295), ovarian cancer (OVCAR-8), HCT-116, HL-60 and another leukemia (K-562) The IC50 values ranging from nanomolar and micromolar. Althought their structures have already been described in the literature, there was no previous report of their cytotoxic acitivities. Altogether, these results emphasize the value of microbiota associated with the zoanthid P. variabilis, found on the coast of Cearà State, as a source of active compounds.
|
28 |
Avaliação do efeito antiproliferativo da apocinina e diapocinina em células de osteossarcoma humano / Evaluation of the antiproliferative effect of apocynin and diapocynin on human osteosarcoma cellsAdriana Arruda Matos 24 January 2018 (has links)
O osteossarcoma (OS) é o tumor maligno primário mais comum do tecido ósseo, caracterizado pela formação de osteócitos anormais. Apesar do avanço nas terapias convencionais (quimioterapia e retirada do tumor), essas não conseguem eliminar totalmente as células tumorais e impedir a progressão da doença. Recentemente, agentes derivados de fontes naturais ganharam considerável atenção por causa de sua segurança, eficácia e disponibilidade imediata. Nesse sentido, a apocinina, inibidor do complexo NADPH-oxidase, vem sendo estudada como agente antitumoral em alguns tipos de câncer como: pâncreas, próstata, pulmão e mama. Apocinina é um pró-fármaco e sua ação parece estar relacionada à sua conversão produzindo a diapocinina, a qual se mostrou mais efetiva do que a apocinina. Portanto, o objetivo desse estudo é avaliar, in vitro, o potencial antitumoral da apocinina e diapocinina em células de osteossarcoma humano. Para isso, foram utilizados osteoblastos humanos normais (HOb) e osteossarcoma humano imortalizadas (SaOS-2) tratados ou não com apocinina e diapocinina em diversas concentrações. Foram realizados os ensaios de viabilidade celular, alterações morfológicas, apoptose celular, produção de espécies reativas de oxigênio (EROs), formação de colônias, migração, invasão e expressão do fator indutor de hipóxia-1alfa (HIF-1). Também foram conduzidos ensaios para verificar a atividade de metaloproteinase de matriz (MMP) 2 e 9. Os resultados em SaOS-2 mostraram que o tratamento com apocinina nas concentrações de 1,5 e 3 mM; e diapocinina nas concentrações de 0,75 e 1,5 mM reduziram a viabilidade; aumentaram o número de células em apoptose e diminuíram a produção de EROs; sem causar danos às células HOb. Além disso, essas mesmas concentrações inibiram a migração e invasão celular; diminuíram a expressão de HIF-1; e reduziram a atividade de MMP-2 em SaOS-2. Considerando os resultados obtidos, concluímos que a apocinina e diapocinina podem atuar como possíveis moduladores de células tumorais, sendo que a diapocinina mostrou ser mais efetiva nos parâmetros testados. / Osteosarcoma (OS) is the most common primary malignant tumor of bone tissue, characterized by the formation of abnormal osteocytes. Despite advances in conventional therapies (chemotherapy and surgery) they cannot completely eliminate tumor cells and prevent the progression of the disease. Recently, agents derived from natural sources have achieved considerable attention because of their safety, efficacy and immediate availability of therapies. In this way, apocynin, an inhibitor of the NADPH-oxidase complex, has been studied as an antitumor agent in some types of cancer, such as pancreas, prostate, lung and breast. Apocynin is a prodrug and its action indicate to be related to its conversion to diapocynin, which has been shown to be more efficient than apocynin itself. Thus, the aim of this study is to evaluate, in vitro, the antitumor potential of apocynin and diapocynin in human osteosarcoma cells. For this, normal human osteoblasts (HOb) and immortalized human osteosarcoma cells (SaOS-2) were treated or no-treated with apocynin and diapocynin in various concentrations. Cell viability assay, morphological alterations, cellular apoptosis, reactive oxygen species (ROS) production, colony formation, migration, invasion and expression of hypoxia-inducible factor-1 alpha (HIF-1) were performed. We also performed assays to verify the activity of matrix metalloproteinase (MMP) 2 and 9. The results in SaOS-2 showed that treatment with apocynin at concentrations of 1,5 e 3 mM; and diapocynin at concentrations of 0,75 e 1,5 mM reduced cell viability; increased the number of cells in apoptosis and decreased the production of ROS; without damaging HOb cells. Moreover, these same concentrations inhibited cell migration and invasion; decreased HIF-1 expression; and reduced MMP 2 activity in SaOS-2. Considering the results, we suggest that apocynin and diapocynin may act as possible modulators of tumor cells, and diapocynin has been shown to be more effective.
|
29 |
Avaliação da citotoxicidade e genotoxicidade de extratos orgânicos e ácido barbático isolado do líquen Cladonia salzmannii (Nyl.)GONÇALVES, Joelma Pessoa 25 February 2015 (has links)
Submitted by Irene Nascimento (irene.kessia@ufpe.br) on 2016-07-11T18:08:29Z
No. of bitstreams: 2
license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5)
Dissertação- JOELMA PESSOA GONÇALVES.pdf: 1383537 bytes, checksum: 125450bea68880058f29778e9d89ead0 (MD5) / Made available in DSpace on 2016-07-11T18:08:29Z (GMT). No. of bitstreams: 2
license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5)
Dissertação- JOELMA PESSOA GONÇALVES.pdf: 1383537 bytes, checksum: 125450bea68880058f29778e9d89ead0 (MD5)
Previous issue date: 2015-02-25 / Capes / Os metabólitos secundários dos liquens são responsáveis pela maioria das suas atividades biológicas. Muitos destes compostos apresentam relevante atividade antineoplásica. O objetivo deste trabalho foi verificar as atividades citotóxica e genotóxica in vitro dos extratos orgânicos e do ácido barbático (BAR) purificado de Cladonia salzmannii Nyl. Os extratos orgânicos foram obtidos a partir do talo liquênico (22 g) previamente limpo e seco, com os solventes éter dietílico, clorofórmio e acetona, através do método de esgotamento a quente em aparelho de Soxhlet. O ácido barbático foi purificado a partir do extrato etéreo (1,3 g). A análise química dos extratos orgânicos e do BAR purificado foi realizada através de Cromatografia em Camada Delgada (CCD). A pureza do BAR purificado foi observada através de Cromatografia Líquida de Alta Eficiência (CLAE). A atividade citotóxica dos extratos orgânicos e do BAR purificado foi determinada através do Método do MTT [brometo de 3-(4,5-dimetiltiazol-2-il)-2,5-difeniltetrazólio] e do IPBC (Índice de Proliferação com Bloqueio da Citocinese). O potencial genotóxico dos extratos orgânicos e do BAR purificado foram determinados através do teste do micronúcleo e do ensaio cometa. O dimetilsulfoxido (DMSO) foi utilizado como solvente de diluição das amostras em todos os testes de atividade biológica. Os resultados referentes a CI50 demonstraram relevante potencial citotóxico para o extrato etéreo (Ext E) (50 μg/mL) frente as linhagens celulares NCI-H292 (CI50: 29,91 μg/mL), HEp-2 (CI50: 26,75 μg/mL) e HL-60 (CI50: 3,59 μg/mL), e para o BAR purificado (25 μg/mL) contra as linhagens HEp-2 (CI50: 15,79 μg/mL) e MCF-7 (CI50: 18,28 μg/mL). Porém, a avaliação da citotoxicidade considerando o Índice de Proliferação com Bloqueio de Citocinese (IPBC) demonstrou atividade citotóxica para o BAR purificado em todas as concentrações testadas (5, 10, 20 e 40 μg/mL) e para todos os extratos orgânicos (50 μg/mL) frente as células do Carcinoma de Ehrlich. Entretanto, para o Sarcoma 180 apenas o BAR purificado na concentração de 40 μg/mL e os extratos etéreo e clorofórmico (50 μg/mL) foram considerados citotóxicos. O teste do micronúcleo (MN) demonstrou que o BAR purificado na concentração de 5 μg/mL não apresentou potencial genotóxico em ambas as linhagens celulares tumorais. Além disso, o extrato clorofórmico e BAR purificado na concentração de 10 μg/mL não foram considerados genotóxicos para o Sarcoma 180. No ensaio cometa, todos os compostos testados induziram danos ao DNA em ambas as linhagens tumorais. Com base nos resultados, considera-se que os extratos orgânicos e o BAR purificado de C. salzmannii (Nyl). apresentam atividade citotóxica e genotóxica frente as linhagens celulares tumorais testadas. / The secondary metabolites of lichens are responsible for most of their biological activities. Many of these compounds exhibit significant antineoplastic activity. The objective of this study was to evaluate the in vitro cytotoxic and genotoxic activities of organic extracts and purified barbatic acid from Cladonia salzmannii Nyl. The organic extracts were obtained from liquenic thallus (22 g) previously cleaned and dried with the solvents diethyl ether, chloroform and acetone, through hot exhausted method in a Soxhlet apparatus. The barbatic acid was purified from the ether extract (1.3 g). Chemical analysis of the organic extracts and purified BAR was performed by Thin Layer Chromatography (TLC). The purity of purified BAR was observed by High Performance Liquid Chromatography (HPLC). The cytotoxic activity of the organic extracts and purified BAR was determined by the MTT method [3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide] and IPBC (Cytokinesis-Block Proliferation Index). The genotoxic potential of the organic extracts and purified BAR was determined by the micronucleus test and comet assay. Dimethyl sulfoxide (DMSO) was used as diluting solvent of the samples in all biological tests. The results for IC50 demonstrated significant cytotoxic potential to the ether extract (Ext E) (50 μg/mL) against the cell lines NCI-H292 (IC50: 29,91 μg/mL), HEp-2 (IC50: 26,75 μg/mL) and HL-60 (IC50: 3,59 μg/mL) and to the purified BAR (25 μg/mL) against the cell lines HEp-2 (IC50: 15,79 μg/mL) and MCF-7 (IC50: 18,28 μg/mL). However, the assessment of cytotoxicity considering the Cytokinesis-Block Proliferation Index (IPBC) showed cytotoxic activity for purified BAR at all concentrations tested (5, 10, 20 and 40 μg/mL) and for all organic extracts (50 μg/mL) against Ehrlich carcinoma cells. However, for Sarcoma 180 only BAR purified at a concentration of 40 μg/mL and ether and chloroform extracts (50 μg/mL) were considered cytotoxic. The micronucleus test (MN) showed that the purified BAR at a concentration of 5 μg/mL showed no genotoxic potential in both tumor cell lines. Furthermore, the chloroform extract and purified BAR at a concentration of 10 μg/mL were not considered genotoxic for Sarcoma 180. In the comet assay, all compounds tested induced DNA damage in both tumor lines. Based on the results, it is considered that the organic extracts and the BAR purified from C. salzmannii (Nyl). exhibit cytotoxic and genotoxic activity front of the tested tumor cell lines.
|
30 |
Síntese, comprovação estrutural e atividade antitumoral e antiparasitária de novos derivados benzodioxolicos / Síntese , caracterização estrutural e avaliação da atividade antitumoral e antiparasitária de novos derivados benzodioxolicosSILVA, Willams Leal 04 August 2016 (has links)
Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-04-25T13:06:43Z
No. of bitstreams: 2
license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5)
TESE CATALOGADA 19.pdf: 3608512 bytes, checksum: 1c5363a2c904d02f78a6ed3352207710 (MD5) / Made available in DSpace on 2017-04-25T13:06:43Z (GMT). No. of bitstreams: 2
license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5)
TESE CATALOGADA 19.pdf: 3608512 bytes, checksum: 1c5363a2c904d02f78a6ed3352207710 (MD5)
Previous issue date: 2016-08-04 / FACEPE / O câncer destaca-se como um importante problema de saúde pública, além de configurar uma
das principais causas de morte no mundo. Considerando que em 2012 houve cerca de 8,2
milhões de mortes. Este trabalho teve como objetivo a obtenção de novos derivados benzo1,3-dioxol
(NW), por estratégia de hibridação molecular a fim de reunir características
estruturais em uma única estrutura com propriedades farmacológicas mista, dual ou dupla. A
síntese consiste na reação em duas rotas paralelas partindo dos aldeídos benzo[d][1,3]dioxol4-carbaldeído
e benzo[d][1,3]dioxol-5-carbaldeído, seguida de reações de condensação com
tiossemicarbazidas para obtenção de tiossemicarbazonas que podem ser conduzidas a uma
ciclização com ácido monocloroácetico formando o anel 4-tiazolidina. Todos os compostos
tiveram suas estruturas comprovadas por RMN1H, RMN 13C, COSY, IV e pirólise acoplado a
espectrometria de massas. Os compostos benzodioxois (NW) obtidos foram testados a fim de
avaliar a atividade antiproliferativa in vitro utilizando-se o ensaio da sulforrodamina B (SBR)
para avaliação do crescimento celular frente várias linhagens tumorais. Para o teste
antitumoral realizado os resultados obtidos mostram um derivado promissor NW-03 com GI50
estabelecidas entre 2,9 a 14,4 μM, quando comparado ao controle positivo utilizado. Diante
dos resultados obtidos os derivados foram classificados como ativos e mostraram um perfil
citostático. Além disso, os resultados obtidos corroboram para uma associação de núcleos
viáveis por meio da hibridação molecular entre o benzo-1,3-benzodioxol e tiossemicarbazona
levando a resultados promissores. Posteriormente os compostos foram submetidos a ensaios
de citoxicidade e avaliação antiparasitária onde foi possível eleger os compostos promissores
NW-03, NW-06 e NW-11 com baixa toxicidade para esplenócitos e atividade antiparasitária.
Em relação à atividade tripanocida, o composto NW-13 (1-naftil) exibiu elevados níveis de
atividade contra epimastigota e tripomastigota (IC50 = 1,48 e 3,89 µM, respectivamente). Com
o estudo de docking foi possível estabelecer correlação do encaixe de compostos NW-02 E
NW-09 com o alvo cruzaína através de interações. O composto NW-03 foi avaliado como
possível inibidor de tirosinase através de experimento de titulação por técnica de
espectroscopia de ressonância magnética nuclear e espectrofotometria. / The cancer stands out as a major public health problem, and configure one of the leading
causes of death worldwide. Whereas in 2012 there were about 8.2 million deaths. This study
aimed to obtain new derivatives benzo-1,3-dioxole (NW), by molecular hybridization strategy
to gather structural features in a single structure with mixed pharmacological properties, dual
or double. The synthesis consists of two parallel routes reaction starting from the aldehydes
benzo [d] [1,3] dioxol-4-carbaldehyde and benzo [d] [1,3] dioxol-5-carbaldehyde, followed by
condensation reactions to tiossemicarbazidas obtaining thiosemicarbazone that can be
conducted with a cyclized with monochloroacetic acid to form the 4-thiazolidine ring. All
compounds had their structures evidenced by 1 H NMR, 13C NMR, COSY, IV and coupled
pyrolysis mass spectrometry. Benzodioxoles The compounds (NW) have been tested in order
to assess the antiproliferative activity in vitro using the sulforhodamine B assay (SBR) for
evaluation of cell growth across various tumor cell lines. For antitumor test performed the
results obtained show a promising derived NW-03 GI50 established between 2.9 to 14.4 uM
when compared to the positive control used. Results obtained derivatives were classified as
active and showed a cytostatic profile. Moreover, the results support an association of viable
nuclei by means of molecular hybridization between the benzo-1,3-benzodioxole
thiosemicarbazone leading to promising results. Later the compounds were subjected to
cytotoxicity testing and antiparasitic assessment where it was possible to elect the promising
compounds NW-03, NW 06 and NW-11 with low toxicity to splenocytes and antiparasitic
activity. Regarding trypanocidal activity, NW-13 compound (1-naphthyl) exhibited high
levels of activity against epimastigote and trypomastigote (IC50 = 1.48 and 3.89 uM,
respectively). With the docking study was possible to establish compounds fitting correlation
NW-02 and NW-09 with the target cruzain through interactions. NW-03 The compound was
evaluated as a possible inhibitor of tyrosinase by titration experiment for technical nuclear
magnetic resonance spectroscopy, and spectrophotometry.
|
Page generated in 0.0439 seconds