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1.
APMIS ; 128(1): 25-34, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31628820

RESUMO

Eradication failure of Helicobacter pylori infection could play a causal role in progression of gastric disorders. In this study, infection with H. pylori was followed in gastric biopsies of symptomatic adult patients at two phases during 1-year period. Analyses were done to show association of therapeutic regimens with the refractory infection, changes in sequence types (STs) and minimum inhibitory concentration (MIC) values, and progression of histopathological changes. Infection with H. pylori was confirmed in 32.3% (57/170) of the patients. Persistent infection with H. pylori was confirmed in 14 out of the 25 patients (56%) who participated at the second phase of the study. A difference between primary and secondary resistance rates to clarithromycin (49% vs 64.3%), metronidazole (76.36% vs 100%), and ciprofloxacin (45% vs 57.1%) was detected. Although the re-emerged strains in patients with refractory infection did not show alteration in STs, their MIC50 values showed twofold increases for clarithromycin and ciprofloxacin. While ciprofloxacin containing regimens were more successful, failure of metronidazole containing regimens was detected in 77% of the patients. Consequently, inappropriate medication has an impact on refractory H. pylori infection, which could cause to a rise in resistance levels to antibiotics and progression of pathological disorders.


Assuntos
Antibacterianos/uso terapêutico , Farmacorresistência Bacteriana Múltipla , Infecções por Helicobacter/tratamento farmacológico , Infecções por Helicobacter/patologia , Helicobacter pylori/efeitos dos fármacos , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/farmacologia , Técnicas de Tipagem Bacteriana , Biópsia , Ciprofloxacino/farmacologia , Claritromicina/farmacologia , Feminino , Seguimentos , Técnicas Histológicas , Humanos , Concentração Inibidora 50 , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Tipagem de Sequências Multilocus , Estômago/microbiologia , Estômago/patologia
2.
APMIS ; 128(1): 41-47, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31692136

RESUMO

Campylobacteriosis is one of the most frequently reported zoonoses worldwide. The well-documented increase in the ciprofloxacin resistance has increased the importance of rapid detection of the resistance. The incidence of ciprofloxacin resistance was investigated using real-time PCR. Identification of one hundred and fifty-eight strains was performed by PCR. Minimum inhibitory concentration (MIC) of ciprofloxacin was determined by Epsilometer test. Following the confirmation of the efficiencies of singleplex real-time PCR methods using two different probes, a cytosine to thymine point mutation at codon 86 was detected by allelic discrimination. Of the 158 strains, 114 (72.2%) were determined to be resistant to ciprofloxacin. The MIC50 and the MIC90 of ciprofloxacin were found to be 8 and ≥32 mg/L, respectively. By real-time PCR, the presence of the mutation was confirmed in all, but one, resistant strains and the absence of the mutation was demonstrated in all, but one, susceptible strains. The rate of resistance is high among C. jejuni strains and ciprofloxacin should not be used in the treatment of such infections in Turkey. A cytosine to thymine mutation is the most frequently detected mechanism for the resistance. Real-time PCR can be used for the quick screening of the resistance.


Assuntos
Antibacterianos/farmacologia , Campylobacter jejuni/efeitos dos fármacos , Campylobacter jejuni/genética , Ciprofloxacino/farmacologia , Farmacorresistência Bacteriana/genética , Mutação Puntual , Alelos , Infecções por Campylobacter/epidemiologia , Infecções por Campylobacter/microbiologia , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Eletroforese em Gel de Campo Pulsado , Humanos , Concentração Inibidora 50 , Testes de Sensibilidade Microbiana , Fenótipo , Prevalência , Turquia
3.
Phys Chem Chem Phys ; 21(39): 22103-22112, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31570909

RESUMO

Type III phosphatidylinositol 4 kinases (PI4KIIIs) are essential enzymes that are related to the replication of multiple RNA viruses. Understanding the interaction mechanisms of molecular compounds with the alpha and beta isoforms of PI4KIII (PI4KIIIα and PI4KIIIß) is of significance in the development of inhibitors that can bind to these two enzymes selectively. In this work, molecular dynamics (MD) simulations and binding free energy calculations were combined to investigate the binding modes of seven selected compounds to PI4KIIIα and PI4KIIIß. Analyses based on MD trajectories provide detailed interaction mechanisms of these compounds with PI4KIIIα and PI4KIIIß at the atomic level, and indicate that the selectivity of these compounds is mainly due to the structural difference of the binding pockets. It is expected that the detailed binding information found in this study can provide useful help for the structure-based design of selective inhibitors toward PI4KIIIα and PI4KIIIß.


Assuntos
1-Fosfatidilinositol 4-Quinase/antagonistas & inibidores , Simulação de Dinâmica Molecular , Inibidores de Proteínas Quinases/química , Sequência de Aminoácidos , Domínio Catalítico , Concentração Inibidora 50 , Estrutura Molecular , Ligação Proteica , Conformação Proteica , Transdução de Sinais , Relação Estrutura-Atividade , Termodinâmica
4.
Int J Nanomedicine ; 14: 7561-7581, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31571864

RESUMO

Introduction: This study was conducted to elucidate the chemopreventive potential, cytotoxic, and suppression of cellular metastatic activity of etodolac (ETD)-loaded nanocarriers. Methods: To esteem the effect of charge and composition of the nanovectors on their performance, four types of vectors namely, negative lipid nanovesicles; phosalosomes (N-Phsoms), positive phosalosomes (P-Phsoms), nanostructured lipid carriers (NLCs) and polymeric alginate polymer (AlgNPs) were prepared and compared. ETD was used as a model cyclo-oxygenase-2 (COX-2) inhibitor to evaluate the potency of these nanovectors to increase ETD permeation and retention through human skin and cytotoxicity against squamous cell carcinoma cell line (SCC). Moreover, the chemopreventive activity of ETD nanovector on mice skin cancer model was evaluated. Results: Among the utilized nanovectors, ETD-loaded N-Phsoms depicted spherical vesicles with the smallest particle size (202.96±2.37 nm) and a high zeta potential of -24.8±4.16 mV. N-Phsoms exhibited 1.5, and 3.6 folds increase in the ETD amount deposited in stratum corneum, epidermis and dermis. Moreover, cytotoxicity studies revealed a significant cytotoxic potential of such nanovector with IC50=181.76 compared to free ETD (IC50=982.75), correlated to enhanced cellular internalization. Its efficacy extended to a reduction in the relative tumor weight with 1.70 and 1.51-fold compared to positive control and free ETD, that manifested by a 1.72-fold reduction in both COX-2 and proliferating cell nuclear antigen mRNA (PCNA-mRNA) levels and 2.63-fold elevation in caspase-3 level in skin tumors relative to the positive control group with no hepato-and nephrotoxicity. Conclusion: Encapsulation of ETD in nanovector enhances its in-vitro and in-vivo anti-tumor activity and opens the door for encapsulation of more relevant drugs.


Assuntos
Quimioprevenção , Inibidores de Ciclo-Oxigenase 2/uso terapêutico , Ciclo-Oxigenase 2/metabolismo , Nanoestruturas/química , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/enzimologia , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Inibidores de Ciclo-Oxigenase 2/farmacologia , Inibidores de Ciclo-Oxigenase 2/toxicidade , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Etodolac/farmacologia , Etodolac/uso terapêutico , Feminino , Humanos , Concentração Inibidora 50 , Lipídeos/química , Camundongos , Nanoestruturas/ultraestrutura , Tamanho da Partícula , Estudos Prospectivos , Absorção Cutânea/efeitos dos fármacos , Neoplasias Cutâneas/patologia , Eletricidade Estática , Resultado do Tratamento
5.
Int J Nanomedicine ; 14: 7809-7822, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31576125

RESUMO

Introduction: Nanoparticles (NPs) can be toxic due to their nano-range sizes. Zinc oxide (ZnO) has good biocompatibility and is commercially used in cosmetics. Moreover, ZnO NPs have potential biomedical uses, but their safety remains unclear. Methods: A range of doped ZnO NPs was evaluated for antileishmanial activity and in vitro toxicity in brine shrimp and human macrophages, and N-doped ZnO NPs were evaluated for in vivo toxicity in male BALB/C mice. N-doped ZnO NPs were administered via two routes: intra-peritoneal injection and topically as a paste. The dosages were 10, 50, and 100 mg/kg/day for 14 days. Results: Topical administration was safe at all dosages, but intra-peritoneal injection displayed toxicity at higher doses, namely, 50 and 100 mg/kg/day. The pathological results for the i.p. dose groups were mild to severe degenerative changes in parenchyma cells, increases in Kupffer cells, disappearance of hepatic plates, increases in cell size, ballooning, cytoplasmic changes, and nuclear pyknosis in the liver. Kidney histology was also altered in the i.p. administration group (dose 100 mg/kg/day), with inflammatory changes in the focal area. We associate pathological abnormalities with the presence of doped ZnO NPs at the diseased site, which was verified by PIXE analysis of the liver and kidney samples of the treated and untreated mice groups. Conclusion: The toxicity of the doped ZnO NPs can serve as an essential determinant for the effects of ZnO NPs on environmental toxicity and can be used for guidelines for safer use of ZnO-based nanomaterials in topical treatment of leishmaniasis and other biomedical applications.


Assuntos
Anti-Helmínticos/farmacologia , Nanopartículas/toxicidade , Óxido de Zinco/farmacologia , Óxido de Zinco/toxicidade , Animais , Artemia/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Humanos , Concentração Inibidora 50 , Rim/efeitos dos fármacos , Rim/patologia , Leishmania/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/patologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Masculino , Camundongos Endogâmicos BALB C
6.
Pharm Res ; 36(12): 170, 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31654151

RESUMO

PURPOSE: Many bioactive molecules show a type of solution phase behavior, termed promiscuous aggregation, whereby at micromolar concentrations, colloidal drug-rich aggregates are formed in aqueous solution. These aggregates are known to be a major cause of false positives and false negatives in select enzymatic high-throughput screening assays. The goal of this study was to investigate the impact of drug-rich aggregates on in vitro drug screening metabolism assays. METHODS: Cilnidipine was selected as an aggregate former and its impact on drug metabolism was evaluated against rCYP2D6, rCYP1A2, rCYP2C9 and human liver microsomes. RESULTS: The cilnidipine aggregates were shown to non-specifically inhibit multiple cytochrome P450 enzymes with an IC50 comparable with the IC50 of potent model inhibitors. CONCLUSIONS: This newly demonstrated mode of "promiscuous inhibition" is of great importance as it can lead to false positives during drug metabolism evaluations and thus it needs to be considered in the future to better predict in vivo drug-drug interactions.


Assuntos
Sistema Enzimático do Citocromo P-450/química , Di-Hidropiridinas/química , Microssomos Hepáticos/metabolismo , Proteínas Recombinantes/química , Carvedilol/química , Carvedilol/metabolismo , Coloides/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Diclofenaco/química , Diclofenaco/metabolismo , Di-Hidropiridinas/metabolismo , Interações de Medicamentos , Ensaios de Triagem em Larga Escala/métodos , Humanos , Concentração Inibidora 50 , Cinética , Taxa de Depuração Metabólica/efeitos dos fármacos , Fenacetina/química , Fenacetina/metabolismo , Proteínas Recombinantes/metabolismo , Solventes/química , Tamoxifeno/química , Tamoxifeno/metabolismo
7.
Plant Dis ; 103(12): 3108-3116, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31657998

RESUMO

Wheat powdery mildew, caused by Blumeria graminis f. sp. tritici, is managed in the United States with cultivar resistance and foliar fungicides. Despite high levels of fungicide sensitivity in other cereal mildew populations, fungicide sensitivity of U.S. B. graminis f. sp. tritici has never been evaluated. Almost 400 B. graminis f. sp. tritici isolates were collected from 15 U.S. states over 2 years and phenotyped for sensitivity to two widely used demethylation inhibitor (DMI) fungicides, tebuconazole and prothioconazole. A large range of sensitivity to both DMIs was observed, with more insensitive isolates originating from the eastern United States (Great Lakes, Mid-Atlantic, and Southeast regions) and more sensitive isolates from central states (Plains region, Arkansas, and Missouri). Cross-resistance was indicated by a positive although weak association between tebuconazole and prothioconazole sensitivities at all levels of analysis (EC50 values, P < 0.0001). A possible fitness cost was also associated with prothioconazole insensitivity (P = 0.0307) when analyzed at the state population level. This is the first assessment of fungicide sensitivity in the U.S. B. graminis f. sp. tritici population, and it produced evidence of regional selection for reduced DMI efficacy. The observation of reduced sensitivity to DMI fungicides in the eastern United States underlines the importance of rotating between chemistry classes to maintain the effectiveness of DMIs in U.S. wheat production. Although cross-resistance was demonstrated, variability in the relationship of EC50 values for tebuconazole and prothioconazole also suggests that multiple mechanisms influence B. graminis f. sp. tritici isolate responses to these two DMI fungicides.


Assuntos
Ascomicetos , Farmacorresistência Fúngica , Fungicidas Industriais , Arkansas , Ascomicetos/efeitos dos fármacos , Fungicidas Industriais/farmacologia , Concentração Inibidora 50 , Missouri , Estados Unidos
8.
Exp Parasitol ; 206: 107730, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31494215

RESUMO

Phospholipids are the main component of membranes and are responsible for cell integrity. Alkylphospholipid analogues (APs) were first designed as antitumoral agents and were later tested against different cell types. Trypanosoma cruzi, the Chagas disease etiological agent, is sensitive to APs (edelfosine, miltefosine and ilmofosine) in vitro. We investigated the effect of synthetic ring substituted AP against epimastigotes, amastigotes and trypomastigotes. TCAN26, could inhibit the in vitro growth of epimastigotes and amastigotes with the 50% inhibitory concentrations (IC50) in the nanomolar range. Trypomastigotes lysis was also induced with 24-h treatment and a LC50 of 2.3 µM. Ultrastructural analysis by electron microscopy demonstrated that TCAN26 mainly affected the parasite's membranes leading to mitochondrial and Golgi cisternae swelling, membrane blebs, and autophagic figures in the different parasite developmental stages. While the Golgi of the parasites was significantly affected, the Golgi complex of the host cells remained normal suggesting a specific mechanism of action. In summary, our results suggest that TCAN 26 is a potent and selective inhibitor of T. cruzi growth probably due to disturbances of phospholipid biosynthesis.


Assuntos
Adamantano/farmacologia , Fosforilcolina/análogos & derivados , Fosforilcolina/farmacologia , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Adamantano/química , Animais , Antiprotozoários/química , Antiprotozoários/farmacologia , Autofagia/efeitos dos fármacos , Membrana Celular/efeitos dos fármacos , Doença de Chagas/tratamento farmacológico , Doença de Chagas/parasitologia , Relação Dose-Resposta a Droga , Citometria de Fluxo , Complexo de Golgi/efeitos dos fármacos , Concentração Inibidora 50 , Dose Letal Mediana , Macrófagos Peritoneais/efeitos dos fármacos , Camundongos , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Microscopia de Fluorescência , Microscopia Imunoeletrônica , Mitocôndrias/efeitos dos fármacos , Fosforilcolina/química , Tripanossomicidas/química , Trypanosoma cruzi/crescimento & desenvolvimento , Trypanosoma cruzi/ultraestrutura
9.
Int J Nanomedicine ; 14: 6971-6988, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31507319

RESUMO

Background and purpose: Ginsenoside Rg5 (Rg5), a triterpene saponin, extracted from the natural herbal plant ginseng, is one of the most potent anticancer drugs against various carcinoma cells. However, the therapeutic potential of Rg5 is limited by its low solubility in water, poor bioavailability, and nontargeted delivery. Therefore, we prepared folic acid (FA)-modified bovine serum albumin (BSA) nanoparticles (FA-Rg5-BSA NPs) to improve the therapeutic efficacy and tumor targetability of Rg5. Methods: Various aspects of the FA-Rg5-BSA NPs were characterized, including size, polydispersity, zeta potential, morphology, entrapment efficiency (EE), drug loading (DL), in vitro drug release, thermal stability, in vitro cytotoxicity, cell apoptosis, cellular uptake, in vivo antitumor effects and in vivo biodistribution imaging. Results: The FA-Rg5-BSA NPs showed a particle size of 201.4 nm with a polydispersity index of 0.081, uniform spherical shape, and drug loading of 12.64±4.02%. The aqueous solution of FA-Rg5-BSA NPs had favorable stability for 8 weeks at 4°C. The FA-Rg5-BSA NPs dissolved under acidic conditions. Moreover, the Rg5-BSA NPs and FA-Rg5-BSA NPs had advanced anticancer activity compared with Rg5 in MCF-7 cells, while poor cytotoxicity was observed in L929 cells. The FA-Rg5-BSA NPs facilitated cellular uptake and induced apoptosis in MCF-7 cells. In addition, in an MCF-7 xenograft mouse model, the in vivo antitumor evaluation revealed that FA-Rg5-BSA NPs were more effective in inhibiting tumor growth than Rg5 and Rg5-BSA NPs. The in vivo real-time bioimaging study showed that the FA-Rg5-BSA NPs exhibited superior tumor accumulation ability. Conclusion: The results suggested that FA-Rg5-BSA NPs could serve as a promising system to improve the antitumor effect of Rg5.


Assuntos
Ácido Fólico/química , Ginsenosídeos/uso terapêutico , Terapia de Alvo Molecular , Neoplasias/tratamento farmacológico , Soroalbumina Bovina/química , Animais , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Bovinos , Sobrevivência Celular/efeitos dos fármacos , Portadores de Fármacos , Liberação Controlada de Fármacos , Humanos , Hidrodinâmica , Concentração Inibidora 50 , Células MCF-7 , Camundongos , Nanopartículas/química , Nanopartículas/ultraestrutura , Tamanho da Partícula , Distribuição Tecidual/efeitos dos fármacos
10.
J Enzyme Inhib Med Chem ; 34(1): 1426-1438, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31401883

RESUMO

Anaplastic lymphoma kinase (ALK) has been recognised as a promising molecular target of targeted therapy for NSCLC. We performed SAR study of pyrazolo[3,4-b]pyridines to override crizotinib resistance caused by ALK-L1196M mutation and identified a novel and potent L1196M inhibitor, 10g. 10g displayed exceptional enzymatic activities (<0.5 nM of IC50) against ALK-L1196M as well as against ALK-wt. In addition, 10g is an extremely potent inhibitor of ROS1 (<0.5 nM of IC50) and displays excellent selectivity over c-Met. Moreover, 10g strongly suppresses proliferation of ALK-L1196M-Ba/F3 and H2228 cells harbouring EML4-ALK via apoptosis and the ALK signalling blockade. The results of molecular docking studies reveal that, in contrast to crizotinib, 10g engages in a favourable interaction with M1196 in the kinase domain of ALK-L1196M and hydrogen bonding with K1150 and E1210. This SAR study has provided a useful insight into the design of novel and potent inhibitors against ALK gatekeeper mutant.


Assuntos
Quinase do Linfoma Anaplásico/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Pirazóis/farmacologia , Piridinas/farmacologia , Quinase do Linfoma Anaplásico/metabolismo , Apoptose/efeitos dos fármacos , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Linhagem Celular Transformada , Proliferação de Células/efeitos dos fármacos , Cromatografia Líquida , Cristalografia por Raios X , Inibidores Enzimáticos/química , Humanos , Concentração Inibidora 50 , Simulação de Acoplamento Molecular , Espectroscopia de Prótons por Ressonância Magnética , Pirazóis/química , Piridinas/química , Transdução de Sinais/efeitos dos fármacos , Espectrometria de Massas por Ionização por Electrospray , Relação Estrutura-Atividade
11.
Chemistry ; 25(49): 11416-11421, 2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-31407832

RESUMO

Trypanothione reductase (TR) plays a key role in the unique redox metabolism of trypanosomatids, the causative agents of human African trypanosomiasis (HAT), Chagas' disease, and leishmaniases. Introduction of a new, lean propargylic vector to a known class of TR inhibitors resulted in the strongest reported competitive inhibitor of Trypanosoma (T.) brucei TR, with an inhibition constant Ki of 73 nm, which is fully selective against human glutathione reductase (hGR). The best ligands exhibited in vitro IC50 values (half-maximal inhibitory concentration) against the HAT pathogen, T. brucei rhodesiense, in the mid-nanomolar range, reaching down to 50 nm. X-Ray co-crystal structures confirmed the binding mode of the ligands and revealed the presence of a HEPES buffer molecule in the large active site. Extension of the propargylic vector, guided by structure-based design, to replace the HEPES buffer molecule should give inhibitors with low nanomolar Ki and IC50 values for in vivo studies.


Assuntos
Desenho de Drogas , Inibidores Enzimáticos/química , NADH NADPH Oxirredutases/antagonistas & inibidores , Proteínas de Protozoários/antagonistas & inibidores , Trypanosoma brucei brucei/enzimologia , Sítios de Ligação , Domínio Catalítico , Cristalografia por Raios X , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/metabolismo , Concentração Inibidora 50 , Ligantes , Simulação de Dinâmica Molecular , NADH NADPH Oxirredutases/metabolismo , Proteínas de Protozoários/metabolismo , Relação Estrutura-Atividade
12.
J Enzyme Inhib Med Chem ; 34(1): 1451-1456, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31409143

RESUMO

Herein, we report the effect of nine FDA approved protease inhibitor drugs against a new HIV-1 subtype C mutant protease, E35D↑G↑S. The mutant has five mutations, E35D, two insertions, position 36 (G and S), and D60E. Kinetics, inhibition constants, vitality, Gibbs free binding energies are reported. The variant showed a decreased affinity for substrate and low catalytic efficiency compared to the wild type. There was a significant decrease in the binding of seven FDA approved protease inhibitors against the mutant (p < .0001). Amprenavir and ritonavir showed the least decrease, but still significant reduced activity in comparison to the wildtype (4 and 5 folds, respectively, p = .0021 and .003, respectively). Nelfinavir and atazanavir were the worst inhibitors against the variant as seen from the IC50, with values of 1401 ± 3.0 and 685 ± 3.0 nM, respectively. Thermodynamics data showed less favourable Gibbs free binding energies for the protease inhibitors to the mutant.


Assuntos
Inibidores da Protease de HIV/farmacologia , Protease de HIV/efeitos dos fármacos , HIV-1/enzimologia , Termodinâmica , Protease de HIV/genética , Protease de HIV/metabolismo , Inibidores da Protease de HIV/química , Concentração Inibidora 50 , Cinética , Simulação de Acoplamento Molecular , Mutação
13.
J Enzyme Inhib Med Chem ; 34(1): 1439-1450, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31409157

RESUMO

Leishmaniasis is a tropical disease found in more than 90 countries. The drugs available to treat this disease have nonspecific action and high toxicity. In order to develop novel therapeutic alternatives to fight this ailment, pteridine reductase 1 (PTR1) and dihydrofolate reductase-thymidylate synthase (DHF-TS) have been targeted, once Leishmania is auxotrophic for folates. Although PTR1 and DHFR-TS from other protozoan parasites have been studied, their homologs in Leishmania chagasi have been poorly characterized. Hence, this work describes the optimal conditions to express the recombinant LcPTR1 and LcDHFR-TS enzymes, as well as balanced assay conditions for screening. Last but not the least, we show that 2,4 diaminopyrimidine derivatives are low-micromolar competitive inhibitors of both enzymes (LcPTR1 Ki = 1.50-2.30 µM and LcDHFR Ki = 0.28-3.00 µM) with poor selectivity index. On the other hand, compound 5 (2,4-diaminoquinazoline derivative) is a selective LcPTR1 inhibitor (Ki = 0.47 µM, selectivity index = 20).


Assuntos
Inibidores Enzimáticos/farmacologia , Leishmania infantum/enzimologia , Complexos Multienzimáticos/antagonistas & inibidores , Oxirredutases/antagonistas & inibidores , Timidilato Sintase/antagonistas & inibidores , Catálise , Cromatografia de Afinidade , Clonagem Molecular , Avaliação Pré-Clínica de Medicamentos , Eletroforese em Gel de Poliacrilamida , Escherichia coli/genética , Concentração Inibidora 50 , Complexos Multienzimáticos/genética , Complexos Multienzimáticos/isolamento & purificação , Complexos Multienzimáticos/metabolismo , Oxirredutases/genética , Oxirredutases/isolamento & purificação , Oxirredutases/metabolismo , Tetra-Hidrofolato Desidrogenase/genética , Tetra-Hidrofolato Desidrogenase/isolamento & purificação , Tetra-Hidrofolato Desidrogenase/metabolismo , Timidilato Sintase/genética , Timidilato Sintase/isolamento & purificação , Timidilato Sintase/metabolismo
14.
Int J Nanomedicine ; 14: 5503-5526, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31410001

RESUMO

Background and purpose: Glioma is one of the most aggressive primary brain tumors and is incurable. Surgical resection, radiation, and chemotherapies have been the standard treatments for brain tumors, however, they damage healthy tissue. Therefore, there is a need for safe anticancer drug delivery systems. This is particularly true for natural prodrugs such as thymoquinone (TQ), which has a high therapeutic potential for cancers but has poor water solubility and insufficient targeting capacity. We have tailored novel core-shell nanoformulations for TQ delivery against glioma cells using mesoporous silica nanoparticles (MSNs) as a carrier. Methods: The core-shell nanoformulations were prepared with a core of MSNs loaded with TQ (MSNTQ), and the shell consisted of whey protein and gum Arabic (MSNTQ-WA), or chitosan and stearic acid (MSNTQ-CS). Nanoformulations were characterized, studied for release kinetics and evaluated for anticancer activity on brain cancer cells (SW1088 and A172) and cortical neuronal cells-2 (HCN2) as normal cells. Furthermore, they were evaluated for caspase-3, cytochrome c, cell cycle arrest, and apoptosis to understand the possible anticancer mechanism. Results: TQ release was pH-dependent and different for core and core-shell nanoformulations. A high TQ release from MSNTQ was detected at neutral pH 7.4, while a high TQ release from MSNTQ-WA and MSNTQ-CS was obtained at acidic pH 5.5 and 6.8, respectively; thus, TQ release in acidic tumor environment was enhanced. The release kinetics fitted with the Korsmeyer-Peppas kinetic model corresponding to diffusion-controlled release. Comparative in vitro tests with cancer and normal cells indicated a high anticancer efficiency for MSNTQ-WA compared to free TQ, and low cytotoxicity in the case of normal cells. The core-shell nanoformulations significantly improved caspase-3 activation, cytochrome c triggers, cell cycle arrest at G2/M, and apoptosis induction compared to TQ. Conclusion: Use of MSNs loaded with TQ permit improved cancer targeting and opens the door to translating TQ into clinical application. Particularly good results were obtained for MSNTQ-WA.


Assuntos
Antineoplásicos/uso terapêutico , Benzoquinonas/uso terapêutico , Composição de Medicamentos , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Glioma/tratamento farmacológico , Nanopartículas/química , Dióxido de Silício/química , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Benzoquinonas/farmacologia , Materiais Biocompatíveis/química , Encéfalo/patologia , Varredura Diferencial de Calorimetria , Caspase 3/metabolismo , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Quitosana/química , Citocromos c/metabolismo , Difusão , Ativação Enzimática/efeitos dos fármacos , Humanos , Concentração de Íons de Hidrogênio , Concentração Inibidora 50 , Cinética , Nanopartículas/ultraestrutura , Porosidade , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria
16.
Int J Nanomedicine ; 14: 4741-4754, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31456635

RESUMO

Background: Ipomoea batatas (L.) Lam.(Ib) has high content of various beneficial nutrients which helps in improving and maintaining human health. It is well known as a functional food and also a valuable source of unique natural products. It contains various phenolic and flavonoid bioactive compounds. Methods: In this study, using the outer peel of two varieties of Ib : Korean red skin sweet potato and Korean pumpkin sweet potato, silver nanoparticles (AgNPs) were synthesized (termed Ib1-AgNps and Ib2-AgNps), respectively. Characterization of Ib1-AgNPs and Ib2-AgNPs was carried out through scanning electron microscopy, Fourier-transform infrared (FT-IR) spectroscopy, energy-dispersive X-ray analysis, X-ray powder diffraction and UV-Vis spectroscopy. Further, the bio-potential of the synthesized AgNPs was investigated by antidiabetic (α-glucosidase assay), antioxidant (free radical scavenging assays), antibacterial (disc diffusion method) and cytotoxicity assays (cell viability against HepG2 cells). Results: FT-IR spectroscopy revealed the contribution of bioactive compounds existing in Ib1 and Ib2 extracts, in the biosynthesis and equilibrium of the AgNPs. Although the Ib2-AgNPs had a higher atomic percentage of Ag in comparison with Ib1-AgNPs, in the antidiabetic assay, the inhibition percentage of α-glucosidase was higher for AgNPs of Ib1 than Ib2, at all three concentrations examined. From the cytotoxicity results, HepG2 cancer cells were more sensitive to the Ib1-AgNPs in comparison to the Ib2-AgNPs-treated HepG2 cells. The antioxidant prospective was higher in Ib2-AgNPs than Ib1-AgNPs. Moreover, the Ib2-AgNPs showed inhibitory action against all five tested pathogenic bacteria, producing an inhibition zone of 8.74-11.52 mm while Ib1-AgNPs had an inhibitory effect on four of them, with an 8.67-11.23 (mm) inhibition zone. Conclusions: Overall, the results concluded that the Ib2-AgNPs exhibited relatively higher functional activity than Ib1-AgNPs, which might be credited to the greater abundance of bioactive compounds existing in Ib2 extract that acted as reducing as well as capping agents in the synthesis of Ib2-AgNPs. Overall, the current study highlights a novel cost-effective and eco-friendly AgNPs synthesis using food waste peels with biocompatibility and could be potentially utilized in biomedical and pharmaceutical industries.


Assuntos
Antibacterianos/farmacologia , Antioxidantes/farmacologia , Ipomoea batatas/química , Nanopartículas Metálicas/química , Prata/farmacologia , Bactérias/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Células Hep G2 , Humanos , Hipoglicemiantes/farmacologia , Concentração Inibidora 50 , Nanopartículas Metálicas/ultraestrutura , Testes de Sensibilidade Microbiana , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X , alfa-Glucosidases/metabolismo
17.
Exp Parasitol ; 205: 107753, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31469986

RESUMO

Trypanosoma brucei causes human African trypanosomiasis and Nagana disease in cattle, imposing substantial medical and economic burden in sub-Saharan Africa. The current treatments have limitations, including the requirement for elaborated protocols, development of drug resistance, and they are prone to adverse side effects. In vitro screening of a library of 14 dinuclear-thiolato bridged arene ruthenium complexes, originally developed for treatment of cancer cells, resulted in the identification of 7 compounds with IC50 values ranging from 3 to 26 nM. Complex [(η6-p-MeC6H4Pri)2Ru2(µ2-SC6H4-o-Pri)3]Cl (2) (IC50 = 4 nM) and complex [(η6-p-MeC6H4Pri)2Ru2(µ2-SCH2C6H4-p-But)2(µ2-SC6H4-p-OH)]BF4(9) (IC50 = 26 nM) were chosen for further assessments. Application of complex 2 and 9 at 20 nM and 200 nM, respectively, for 4.5 h induced alterations in the trypanosome mitochondrion as evidenced by immunofluorescence employing an antibody against mitochondrial Hsp70 and Mitotracker labeling. Transmission electron microscopy of parasites taken at 2 and 4h of treatment demonstrated massive alterations in the mitochondrial ultrastructure, while other organelles and structural elements of the parasites remained unaffected. Complex 2 treated trypanosomes exhibited a distorted mitochondrial membrane, and the mitochondrial matrix was transformed into an amorphous mass with different degrees of electron densities. Complex 9 did not notably impair the integrity of the membrane, but the interior of the mitochondrion appeared either completely translucent, or was filled with filamentous structures of unknown nature. Dose- and time-dependent effects of these two compounds on the mitochondrial membrane potential were detected by tetramethylrhodamine ethyl ester assay. Thus, the mitochondrion and associated metabolic processes are an important target of dinuclear thiolato-bridged arene ruthenium complexes in T. brucei.


Assuntos
Potencial da Membrana Mitocondrial/efeitos dos fármacos , Compostos de Rutênio/farmacologia , Trypanosoma brucei brucei/efeitos dos fármacos , Tripanossomíase Africana/parasitologia , Animais , Relação Dose-Resposta a Droga , Imunofluorescência , Humanos , Concentração Inibidora 50 , Microscopia Eletrônica de Transmissão , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/ultraestrutura , Compostos de Rutênio/química , Fatores de Tempo , Trypanosoma brucei brucei/metabolismo , Trypanosoma brucei brucei/ultraestrutura , Tripanossomíase Africana/sangue
18.
Exp Parasitol ; 205: 107747, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31442454

RESUMO

Development of new chemotherapeutic agents is an essential issue in the treatment and control of a disease. This study aimed to evaluate the anti-leishmanial activity of amiodarone, an antiarrhythmic class III drug, against Leishmania major, the most prevalent etiological agent of cutaneous leishmaniasis in the old world. The proliferation of promastigotes and intracellular amastigotes in the absence or presence of amiodarone was estimated, in an in vitro study. For in vivo study, five weeks after infection of BALB/c mice with L. major, when the lesions appeared at the injection site, the mice were divided into four groups (n = 6 each); treatment was conducted for 28 consecutive days with vehicle, amiodarone at 40 mg/kg orally and glucantime at 60 mg/kg intraperitoneally. Therapy with amiodarone reduced the size of lesions compared to the untreated group after 12 days. Amiodarone decreased the parasite load and inflammatory responses, particularly the macrophages containing amastigotes, and enhanced granulation tissue formation in the dermis and subcutaneous area. The Tumor necrosis factor-α and Interleukin-6 levels were significantly lower in the cell culture supernatants of the inguinal lymph node in the amiodarone treated group compared to the vehicle and untreated groups. Amiodarone significantly increased the activity of glutathione peroxidase in comparison to the vehicle and untreated groups but did not affect the plasma levels of superoxide dismutase, malondialdehyde, adiponectin, and ferric reducing ability of plasma. Therefore, the anti- L. major activity and immunomodulatory effects of amiodarone reduced the parasitic load and enhanced wound healing in cutaneous leishmaniasis in BALB/c mice. Amiodarone reduced the lesion surface area, but it did not cure it completely.


Assuntos
Amiodarona/uso terapêutico , Antiprotozoários/uso terapêutico , Leishmania major/efeitos dos fármacos , Leishmaniose Cutânea/tratamento farmacológico , Adiponectina/sangue , Amiodarona/farmacologia , Animais , Antiarrítmicos/farmacologia , Antiarrítmicos/uso terapêutico , Antiprotozoários/farmacologia , Linhagem Celular , Feminino , Glutationa Peroxidase/metabolismo , Concentração Inibidora 50 , Interleucina-6/análise , Leishmania major/ultraestrutura , Leishmaniose Cutânea/parasitologia , Linfonodos/química , Linfonodos/imunologia , Macrófagos/parasitologia , Malondialdeído/sangue , Antimoniato de Meglumina/farmacologia , Antimoniato de Meglumina/uso terapêutico , Camundongos , Camundongos Endogâmicos BALB C , Carga Parasitária , Distribuição Aleatória , Pele/parasitologia , Pele/patologia , Pele/ultraestrutura , Superóxido Dismutase/metabolismo , Fator de Necrose Tumoral alfa/análise
19.
Exp Parasitol ; 205: 107738, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31442456

RESUMO

Leishmaniases, caused by Leishmania spp., are among the most prevalent infectious diseases in the world and their treatment may present high toxicity and side/adverse effects. This study evaluated the antileishmanial activity of the Hexanic Eluate subfraction from Maytenus guianensis bark (HEMg) incorporated in microparticles of PLGA. One batch of microparticles produced contained HEMg (HEMgP) and another contained the PLGA polymer alone (PCTE). The microparticles were characterized in regards to diameter, Zeta potential, encapsulation rate and morphology and their cytotoxicity was evaluated against J774 macrophages. The infection assay employing peritoneal macrophages witth L. amazonensis and cytokine dosages were performed on the cell supernatants. The groups of infected BALB/C mice were treated, euthanized and the parasite load and cytokine production were evaluated. The diameters and zeta potential were: 4 µm and -11.6 mV (PCTE) and 7.8 µm and -26.7 mV (HEMgP). The encapsulation rate was ≅ 15% and the morphology of the particles was spherical and homogeneous. In the infection assay, HEMgP inhibited the amastigotes by 70% (24 h) and 59% (48 h) and induced IL-12 and TNF-α production. HEMg in solution reduced the number of parasites in the lymph nodes by 50% and HEMgP administration increased the levels of IL-12 and TNF-α cytokines in lymph nodes and in the lesion site. When encapsulated, HEMg maintained its antileishmanial activity, but in a more attenuated and sustained form over time, showing promise as complementary/alternative therapy against cutaneous leishmaniasis.


Assuntos
Antiprotozoários/farmacologia , Leishmania mexicana/efeitos dos fármacos , Maytenus/química , Casca de Planta/química , Extratos Vegetais/farmacologia , Animais , Biodegradação Ambiental , Linhagem Celular , Micropartículas Derivadas de Células/química , Micropartículas Derivadas de Células/ultraestrutura , Concentração Inibidora 50 , Linfonodos/parasitologia , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/parasitologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Eletrônica de Varredura
20.
Int J Nanomedicine ; 14: 4413-4428, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31417252

RESUMO

Background: As part of our continuing quest to enhance the efficacy of bioactive phytochemicals in cancer therapy, we report an innovative green nanotechnology approach toward the use of resveratrol for the production of biocompatible resveratrol-conjugated gold nanoparticles (Res-AuNPs). Our overarching aim is to exploit the inherent pro-apoptotic properties of gold nanoparticles (AuNPs) through synergistic anti-tumor characteristics of resveratrol, with the aim of developing a new class of green nanotechnology-based phytochemical-embedded AuNPs for applications in oncology. Method: Resveratrol was used to reduce Au3+ to Au0 for the synthesis of Res-AuNPs at room temperature and gum arabic (GA) was used to further encapsulate the nanoparticulate surface to increase the overall stability of the AuNPs. This comprehensive study involves the synthesis, full characterization and in vitro stability of Res-AuNPs in various biological media for their ultimate applications as anti-cancer agents against human breast (MDAMB-231), pancreatic (PANC-1) and prostate (PC-3) cancers. Results: This strategy to systematically increase the corona of resveratrol on AuNPs, in order to gain insights into the interrelationship of the phytochemical corona on the overall anti-tumor activities of Res-AuNPs, proved successful. The increased resveratrol corona on Res-AuNPs showed superior anti-cancer effects, attributed to an optimal cellular uptake after 24-hour incubation, while GA provided a protein matrix support for enhanced trans-resveratrol loading onto the surface of the AuNPs. Conclusion: The approach described in this study harnesses the benefits of nutraceuticals and nanoparticles toward the development of Res-AuNPs. We provide compelling evidence that the increased corona of resveratrol on AuNPs enhances the bioavailability of resveratrol so that therapeutically active species can be optimally available in vivo for applications in cancer therapy.


Assuntos
Antineoplásicos/farmacologia , Neoplasias da Mama/patologia , Ouro/química , Nanopartículas Metálicas/química , Neoplasias Pancreáticas/patologia , Neoplasias da Próstata/patologia , Resveratrol/farmacologia , Linhagem Celular Tumoral , Forma Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Endocitose , Feminino , Humanos , Concentração Inibidora 50 , Masculino , Nanopartículas Metálicas/ultraestrutura , Tamanho da Partícula , Polifenóis/química , Polifenóis/farmacologia , Resveratrol/química , Espectrofotometria Ultravioleta , Resultado do Tratamento
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