RESUMO
Although the presence of nitro groups in chemicals can be recognized as structural alerts for mutagenicity and carcinogenicity, nitroaromatic compounds have attracted considerable interest as a class of agents that can serve as source of potential new anticancer agents. In the present study, the in vitro cytotoxicity, genotoxicity, and mutagenicity of three synthetic ortho-nitrobenzyl derivatives (named ON-1, ON-2 and ON-3) were evaluated by employing human breast and ovarian cancer cell lines. A series of biological assays was carried out with and without metabolic activation. Complementarily, computational predictions of the pharmacokinetic properties and druglikeness of the compounds were performed in the Swiss ADME platform. The MTT assay showed that the compounds selectively affected selectively the cell viability of cancer cells in comparison with a nontumoral cell line. Additionally, the metabolic activation enhanced cytotoxicity, and the compounds affected cell survival, as demonstrated by the clonogenic assay. The comet assay, the cytokinesis-block micronucleus assay, and the immunofluorescence of the γ-H2AX foci formation assay have that the compounds caused chromosomal damage to the cancer cells, with and without metabolic activation. The results obtained in the present study showed that the compounds assessed were genotoxic and mutagenic, inducing double-strand breaks in the DNA structure. The high selectivity indices observed for the compounds ON-2 and ON-3, especially after metabolic activation with the S9 fraction, must be highlighted. These experimental biological results, as well as the theoretical properties predicted for the compounds have shown that they are promising anticancer candidates to be exploited in additional studies.
Assuntos
Ativação Metabólica , Antineoplásicos , Sobrevivência Celular , Dano ao DNA , Humanos , Sobrevivência Celular/efeitos dos fármacos , Antineoplásicos/toxicidade , Antineoplásicos/farmacologia , Antineoplásicos/química , Dano ao DNA/efeitos dos fármacos , Linhagem Celular Tumoral , Testes para Micronúcleos , Mutagênicos/toxicidade , Ensaio Cometa , Testes de Mutagenicidade , Feminino , Nitrobenzenos/toxicidade , Nitrobenzenos/química , Neoplasias da Mama/patologia , Neoplasias da Mama/tratamento farmacológico , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/tratamento farmacológico , Relação Dose-Resposta a DrogaRESUMO
Selective photocatalytic oxidation of benzyl alcohol to benzaldehyde and reduction of nitrobenzene to aniline reactions are investigated by using SiO2@TiO2 spheres produced in a simple route using chitosan as a template. The spheres are predominantly macroporous and, the XRD points out an amorphous crystallographic profile suggesting the uniform distribution of TiO2. Under low-power lighting for 4 hours, the conversions achieved was of the order of 49% and 99% for benzyl alcohol and nitrobenzene, respectively, with selectivity to benzaldehyde and aniline of 99% in both reactions. The study also follows the effects of the solvent and the presence of O2.
Assuntos
Álcool Benzílico , Dióxido de Silício , Benzaldeídos , Nitrobenzenos/química , Compostos de AnilinaRESUMO
In the present work, we describe the preparation of two diastereomers from the enantioselective Michael addition of furan-2(5H)-one to (E)-(2-nitrovinyl)benzene catalyzed by a dinuclear Zn-complex. The relative configurations of the diastereomeric products were assigned by comparing nuclear magnetic resonance (NMR) experimental chemical shift data with those computed by density functional theory (DFT) methods. Corrected mean absolute error (CMAE) and CP3 analyses were used to compare the data sets. The absolute configuration of each diastereomer was initially assigned by analysis of electronic circular dichroism (ECD) data, which was consistent with that of the known X-ray crystallographic structure of the product of a related reaction, namely, (R)-5-((R)-1-(4-chlorophenyl)-2-nitroethyl)furan-2(5H)-one.
Assuntos
4-Butirolactona/análogos & derivados , Nitrobenzenos/química , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Dicroísmo Circular , Espectroscopia de Prótons por Ressonância Magnética , EstereoisomerismoRESUMO
Considering the lack of effective and safe therapy for the treatment of Chagas disease, the antihypertensive drug manidipine (MDP) was in vitro evaluated against Trypanosoma cruzi. The bioenergetics of trypomastigotes was studied in the presence of the drug using fluorimetric and luminescent assays. Manidipine showed a potent antiparasitic activity, with IC50 values of 0.1 µM (intracellular amastigotes) and 3 µM (trypomastigotes), resulting in a promising selectivity index against the amastigotes (>1459). Using fluorimetric analysis, the drug showed depolarisation of the electric potential of the plasma membrane with no alteration of the permeability. A decrease in ATP levels suggested a bioenergetic alteration of the mitochondria, which was confirmed by the depolarisation of the mitochondrial membrane potential and a slight increase of the ROS levels. This is the first study to show the promising in vitro effectiveness of the antihypertensive MDP against T. cruzi, which may represent a candidate for future investigations in animal models.
Assuntos
Anti-Hipertensivos/farmacologia , Di-Hidropiridinas/farmacologia , Reposicionamento de Medicamentos , Nitrobenzenos/farmacologia , Piperazinas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Linhagem Celular , Macaca mulatta , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Tripanossomicidas/farmacologia , Trypanosoma cruzi/metabolismoRESUMO
We aimed to elucidate the effects of PGE2 and PGF2α on the in vitro maturation (IVM) of bovine oocytes. First, cumulus-oocyte complexes were matured in the media supplemented with or without PGE2, PGF2α, or PGE2 plus PGF2α for the final 24, 12, or 6 h of culture. Then, the cumulus-oocyte complexes were matured in the absence or presence of a PG endoperoxide synthase 2 (PTGS2) enzyme inhibitor (NS398) supplemented with PGE2, PGF2α, or PGE2 plus PGF2α. Finally, the expression of genes associated with PGs activity in cumulus cells (PTGS2, PG E-synthase-1 [PTGES1], and aldo-keto reductase 1 [AKR1B1]) or oocytes (receptors for PGE2 [PTGER2] and PGF2α [PTGFR]) of different competencies was quantified. Supplementation of the IVM medium with PGs did not improve in vitro embryo production or embryo quality (P > 0.05). During maturation, the relative abundance of PTGS2 transcripts increased (P < 0.05) only in the less-competent group, whereas those of PTGES1 increased in the less-competent and in the more-competent groups. Conversely, AKR1B1 expression decreased only in the less-competent group (P < 0.05). Receptors for the PGE2 and PGF2α genes were very low or undetectable in oocytes. In conclusion, PGE2 and PGF2α are not recommended for media supplementation during maturation because they have no effect on embryo development. Although genes related to PGs activity are differentially expressed in cumulus cells of cumulus-oocyte complexes of different competence during maturation, the expression of PGE2 and PGF2α receptor genes was either not detectable or was detected at low levels in oocytes.
Assuntos
Dinoprosta/farmacologia , Dinoprostona/farmacologia , Técnicas de Maturação in Vitro de Oócitos/veterinária , Oócitos/efeitos dos fármacos , Animais , Bovinos , Técnicas de Cultura Embrionária/veterinária , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Nitrobenzenos/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Sulfonamidas/farmacologiaRESUMO
Canine leishmaniasis (CanL) is caused by the intracellular parasite Leishmania infantum. Prostaglandin E2 (PGE2 ) exerts potent regulatory effects on the immune system in experimental model Leishmania infection, but this influence has not yet been studied in CanL. In this study, PGE2 and PGE2 receptor levels and the regulatory effect of PGE2 on arginase activity, NO2 , IL-10, IL-17, IFN-γ, TNF-α and parasite load were evaluated in cultures of splenic leucocytes obtained from dogs with CanL in the presence of agonists and inhibitors. Our results showed that splenic leucocytes from dogs with CanL had lower EP2 receptor levels than those of splenic leucocytes from healthy animals. We observed that NO2 levels decreased when the cells were treated with a PGE2 receptor agonist (EP1/EP2/EP3) or COX-2 inhibitor (NS-398) and that TNF-α, IL-17 and IFN-γ cytokine levels decreased when the cells were treated with a PGE2 receptor agonist (EP2) or PGE2 itself. The parasite load in splenic leucocyte cell cultures from dogs with CanL decreased after stimulation of the cells with PGE2 . We conclude that Leishmania infection of dogs modulates PGE2 receptors and speculate that the binding of PGE2 to its receptors may activate the microbicidal capacity of cells.
Assuntos
Citocinas/imunologia , Dinoprostona/metabolismo , Doenças do Cão/tratamento farmacológico , Leishmania infantum/imunologia , Leishmaniose/veterinária , Receptores de Prostaglandina E/metabolismo , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Inibidores de Ciclo-Oxigenase 2/farmacologia , Dinoprostona/agonistas , Dinoprostona/antagonistas & inibidores , Doenças do Cão/imunologia , Doenças do Cão/parasitologia , Cães , Leishmaniose/tratamento farmacológico , Leishmaniose/imunologia , Óxido Nítrico/análise , Nitrobenzenos/farmacologia , Carga Parasitária , Receptores de Prostaglandina E/agonistas , Receptores de Prostaglandina E/fisiologia , Sulfonamidas/farmacologia , Fator de Necrose Tumoral alfa/imunologiaRESUMO
Dichloronitrobenzenes (DCNB) are intermediates in the production of dichloroanilines, which are key feedstocks for synthesis of diuron and other herbicides. Although DCNB is a major contaminant at certain chemical manufacturing sites, aerobic DCNB biodegradation is poorly understood and such sites have not been candidates for bioremediation. When a bench-scale aerobic fluidized- bed bioreactor was inoculated with samples from a DCNB contaminated site in Brazil 2,3-DCNB, 3,4-DCNB, 1,2-dichlorobenzene (o-DCB), and chlorobenzene (CB) were biodegraded simultaneously. Biodegradation of the mixture was complete even when the reactor was operated at high flow rates (1.6â¯h hydraulic residence time), and bacteria able to degrade the individual contaminants were isolated from the reactor by selective enrichment. The enrichments yielded 2 strains of bacteria able to degrade 3,4-DCNB and one able to degrade 2,3-DCNB. The isolates released nitrite during growth on the respective DCNB isomers under aerobic conditions. The draft genome sequence of Diaphorobacter sp. JS3050, which grew on 3,4-DCNB, revealed the presence of putative nitroarene dioxygenase genes, which is consistent with initial attack by a dioxygenase analogous to the initial steps in degradation of nitrobenzene and dinitrotoluenes. The results indicate clearly that the DCNB isomers are biodegradable under aerobic conditions and thus are candidates for natural attenuation/bioremediation.
Assuntos
Aerobiose , Biodegradação Ambiental , Nitrobenzenos/química , Poluentes Químicos da Água/química , Reatores Biológicos , Brasil , Catálise , Clorobenzenos/química , Comamonadaceae/metabolismo , DNA Bacteriano/genética , Genoma Bacteriano , Água Subterrânea , Nitritos/química , Esgotos , Purificação da Água/métodosRESUMO
Fluorescent probes are employed to investigate natural and model membranes. It is important to know probe location and extent of perturbations they cause into the lipid bilayer. Förster Resonance Energy Transfer (FRET) is a useful tool to investigate phenomena involving plasma membranes, and reports in literature used relatively large fluorophores like 1,6-diphenylhexatriene, located at the center of the hydrophobic region, 4-aminophthalimide-based molecules located at lipid/water interfaces and BODIPY-labeled phosphatidylcholine. In this work we explored FRET process in 1,2-dimyristoyl-L-α-GPC large unilamellar vesicles, in gel and fluid phase, using as donor the very small group o-Abz bound to hexadecyl chain (2-amino-N-hexadecyl-benzamide - AHBA) and 7-nitro-2-1,3-benzoxadiazol-4-yl (NBD) labeled lipids as acceptor. From the intensity decay of donor in presence of acceptors, the FRET efficiency was calculated, and used to fit the model proposed by Fung and Stryer to that efficiency. Using lipid bilayer structural data, the procedure allowed the determination of Förster distance for each donor-acceptor pair in vesicles, without imposing any value for the orientational factor κ2. From distance distributions between o-Abz in AHBA and NBD in lipid bilayer obtained using the program CONTIN, we obtained donor-acceptor populations having different separation distances. The populations reflect the occurrence of FRET involving probes in the same or in opposite leaflet. A dynamic picture emerged showing how relative position of the probes is dependent on the structural thermal phase of the DMPC bilayer. The results emphasize the need of careful analysis in order to understand processes involving fluorescent probes in model membranes.
Assuntos
Azóis/química , Benzamidas/química , Bicamadas Lipídicas/química , Nitrobenzenos/química , Azóis/metabolismo , Membrana Celular/química , Membrana Celular/fisiologia , Transferência Ressonante de Energia de Fluorescência/métodos , Corantes Fluorescentes/química , Bicamadas Lipídicas/metabolismo , Metabolismo dos Lipídeos , Lipídeos , Membranas , Nitrobenzenos/metabolismo , Fosfatidilcolinas/química , Fosfatidiletanolaminas/química , Espectrometria de FluorescênciaRESUMO
Natural products have an important role as prototypes in the synthesis of new anticancer drugs. Piperine is an alkaloid amide with antitumor activity and significant toxicity. Then, the N-(p-nitrophenyl)acetamide piperinoate (HE-02) was synthesized, and tested for toxicological and antitumor effects. The toxicity was evaluated in vitro (on RAW 264.7 cells and mice erythrocytes) and in vivo (acute toxicity in mice). The Ehrlich ascites carcinoma model was used to evaluate the antitumor activity of HE-02 (6.25, 12.5 or 25 mg/kg, intraperitoneally, i.p.), as well as toxicity. HE-02 induced only 5.01% of hemolysis, and reduced the viability of RAW 264.7 cells by 49.75% at 1000 µg/mL. LD50 (lethal dose 50%) was estimated at around 2000 mg/kg (i.p.). HE-02 reduced Ehrlich tumor cell viability and peritumoral microvessels density. There was an increase of Th1 helper T lymphocytes cytokine profile levels (IL-1ß, TNF-α, IL-12) and a decrease of Th2 cytokine profile (IL-4, IL-10). Moreover, an increase was observed on reactive oxygen species and nitric oxide production. Weak in vivo toxicological effects were recorded. Our data provide evidence that the piperine analogue HE-02 present low toxicity, and its antitumor effect involves modulation of immune system to a cytotoxic Th1 profile.
Assuntos
Acetamidas/farmacologia , Alcaloides/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Benzodioxóis/farmacologia , Carcinoma de Ehrlich/tratamento farmacológico , Sistema Imunitário/efeitos dos fármacos , Imunomodulação , Piperidinas/farmacologia , Alcamidas Poli-Insaturadas/farmacologia , Equilíbrio Th1-Th2/efeitos dos fármacos , Acetamidas/química , Acetamidas/uso terapêutico , Alcaloides/química , Alcaloides/uso terapêutico , Animais , Antineoplásicos/uso terapêutico , Benzodioxóis/química , Benzodioxóis/uso terapêutico , Sobrevivência Celular/efeitos dos fármacos , Eritrócitos/efeitos dos fármacos , Feminino , Hemólise/efeitos dos fármacos , Camundongos , Nitrobenzenos/química , Piperidinas/química , Piperidinas/uso terapêutico , Alcamidas Poli-Insaturadas/química , Alcamidas Poli-Insaturadas/uso terapêutico , Células RAW 264.7RESUMO
Glutathione transferases (GSTs) perform several catalytic and non-catalytic roles in the defense against toxicities of electrophile compounds and oxidative stress, and therefore are involved in stress-response and cell detoxification. Previously, we have provided evidence indicating that EgGST2 and EgGST3, two phylogenetically distant Echinococcus granulosus GSTs, can naturally form a heterodimeric structure (EgGST2-3). In the present work, the recombinant heterodimer GST (rEgGST2-3) is characterized. Hence, rEgGST2-3 was able to conjugate GSH to three substrates: 1-chloro-2,4-dinitrobenzene (CDNB, general substrate for GSTs), 1,2-dichloro-4-nitrobenzene (specific substrate for mammalian Mu class) and trans,trans-deca-2,4-dienal (reactive carbonyl). The canonical activity was considerably reduced by all the conventional inhibitors (cybacron blue, triphenylthin chloride and bromosulfophthalein) and by other inhibitors (ellagic acid, alizarin and chenodeoxycholic acid). Besides this, rEgGST2-3 activity was inhibited by a number of anthelmintic drugs, where the halogenated phenolic drugs (mainly bithionol and hexachlorophene) acted as stronger inhibitors, suggesting they may bind to the EgGST2-3. Moreover, rEgGST2-3 exhibited glutathione-peroxidase activity, and its specific constant (kcat/KM) was calculated. Finally, rEgGST2-3 displayed the ability to bind non-substrate molecules, particularly anthelmintic drugs, suggesting that ligandin activity may have potential to act as a passive protection parasite mechanism. Overall, the rEgGST2-3 behavior was shown to be both complementary and redundant to that reported for rEgGST1, another characterized GST from E. granulosus. It would be appropriate that different enzymes in the same organism do not have exactly the same functional properties to develop a better adaptation to life in the host.