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1.
Bioorg Chem ; 131: 106286, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36459778

RESUMO

In this work, new steroidal aromatase inhibitors (AIs) were designed, synthesized, and tested. In one approach, C-ring substituted steroids namely those functionalized at C-11 position with an α or ß hydroxyl group or with a carbonyl group as well as C-9/C-11 steroidal olefins and epoxides were studied. It was found that the carbonyl group at C-11 is more beneficial for aromatase inhibition than the hydroxyl group, and that the C-ring epoxides were more potent than the C-ring olefins, leading to the discovery of a very strong AI, compound 7, with an IC50 of 0.011 µM, better than Exemestane, the steroidal AI in clinical use, which presents an IC50 of 0.050 µM. In another approach, we explored the biological activity of A-ring C-1/C-2 steroidal olefins and epoxides in relation to aromatase inhibition and compared it with the biological activity of C-ring C-9/C-11 steroidal olefins and epoxides. On the contrary to what was observed for the C-ring olefins and epoxides, the A-ring epoxides were less potent than A-ring olefins. Finally, the effect of 7ß-methyl substitution on aromatase inhibition was compared with 7α-methyl substitution, showing that 7ß-methyl is better than 7α-methyl substitution. Molecular modelling studies showed that the 7ß-methyl on C-7 seems to protrude into the opening to the access channel of aromatase in comparison to the 7α-methyl. This comparison led to find the best steroidal AI (12a) of this work with IC50 of 0.0058 µM. Compound 12a showed higher aromatase inhibition capacity than two of the three AIs currently in clinical use.


Assuntos
Inibidores da Aromatase , Aromatase , Inibidores da Aromatase/farmacologia , Aromatase/metabolismo , Esteroides/farmacologia , Relação Estrutura-Atividade , Compostos de Epóxi
2.
Bioorg Med Chem ; 46: 116360, 2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34425478

RESUMO

Steroidal compounds were proven to be efficient drugs against several types of cancer. Oximes are also chemical structures frequently associated with anticancer activity. The main goal of this work was to combine the two referred structures by synthesizing steroidal oximes and evaluating them in several cancer cell lines. Compounds (17E)-5α-androst-3-en-17-one oxime (3,4 - OLOX), (17E)-3α,4α-epoxy-5α-androstan-17-one oxime (3,4 - EPOX), (17E)-androst-4-en-17-one oxime (4,5 - OLOX) and (17E)-4α,5α-epoxyandrostan-17-one oxime (4,5 - EPOX) were synthesized and their cytotoxicity evaluated in four human cancer cell lines, namely colorectal adenocarcinoma (WiDr), non-small cell lung cancer (H1299), prostate cancer (PC3) and hepatocellular carcinoma (HepG2). A human non-tumour cell line, CCD841 CoN (normal colon cell line) was also used. MTT assay, flow cytometry, fluorescence and hemocompatibility techniques were performed to further analyse the cytotoxicity of the compounds. 3,4 - OLOX was the most effective compound in decreasing tumour cell proliferation in all cell lines, especially in WiDr (IC50 = 9.1 µM) and PC3 (IC50 = 13.8 µM). 4,5 - OLOX also showed promising results in the same cell lines (IC50 = 16.1 µM in WiDr and IC50 = 14.5 µM in PC3). Further studies also revealed that 3,4 - OLOX and 4,5 - OLOX induced a decrease in cell viability accompanied by an increase in cell death, mainly by apoptosis/necroptosis for 3,4 - OLOX in both cell lines and for 4,5 - OLOX in WiDr cells, and by necrosis for 4,5 - OLOX in PC3 cells. These compounds might also exert their cytotoxicity by ROS production and are not toxic for non-tumour CCD841 CoN cells. Additionally, both compounds did not induce haemoglobin release, proving to be safe for intravenous administration. 3,4 - OLOX and 4,5 - OLOX might be the starting point for an optimization program towards the discover of new steroidal oximes for anticancer treatment.


Assuntos
Antineoplásicos/farmacologia , Desenho de Fármacos , Oximas/farmacologia , Esteroides/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Estresse Oxidativo/efeitos dos fármacos , Oximas/síntese química , Oximas/química , Esteroides/síntese química , Esteroides/química , Relação Estrutura-Atividade , Células Tumorais Cultivadas
3.
Can Assoc Radiol J ; 70(4): 344-353, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31522841

RESUMO

PURPOSE: The required training sample size for a particular machine learning (ML) model applied to medical imaging data is often unknown. The purpose of this study was to provide a descriptive review of current sample-size determination methodologies in ML applied to medical imaging and to propose recommendations for future work in the field. METHODS: We conducted a systematic literature search of articles using Medline and Embase with keywords including "machine learning," "image," and "sample size." The search included articles published between 1946 and 2018. Data regarding the ML task, sample size, and train-test pipeline were collected. RESULTS: A total of 167 articles were identified, of which 22 were included for qualitative analysis. There were only 4 studies that discussed sample-size determination methodologies, and 18 that tested the effect of sample size on model performance as part of an exploratory analysis. The observed methods could be categorized as pre hoc model-based approaches, which relied on features of the algorithm, or post hoc curve-fitting approaches requiring empirical testing to model and extrapolate algorithm performance as a function of sample size. Between studies, we observed great variability in performance testing procedures used for curve-fitting, model assessment methods, and reporting of confidence in sample sizes. CONCLUSIONS: Our study highlights the scarcity of research in training set size determination methodologies applied to ML in medical imaging, emphasizes the need to standardize current reporting practices, and guides future work in development and streamlining of pre hoc and post hoc sample size approaches.


Assuntos
Pesquisa Biomédica , Diagnóstico por Imagem/estatística & dados numéricos , Aprendizado de Máquina , Humanos , Tamanho da Amostra
4.
Bioorg Med Chem ; 24(12): 2823-31, 2016 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-27160054

RESUMO

In this work, new potent steroidal aromatase inhibitors both in microsomes and in breast cancer cells have been found. The synthesis of the 3,4-(ethylenedioxy)androsta-3,5-dien-17-one (12), a new steroid containing a heterocycle dioxene fused in the A-ring, led to the discovery of a new reaction for which a mechanism is proposed. New structure-activity relationships were established. Some 5ß-steroids, such as compound 4ß,5ß-epoxyandrostan-17-one (9), showed aromatase inhibitory activity, because they adopt a similar A-ring conformation as those of androstenedione, the natural substrate of aromatase. Moreover, new chemical features to increase planarity were disclosed, specifically the 3α,4α-cyclopropane ring, as in 3α,4α-methylen-5α-androstan-17-one (5) (IC50=0.11µM), and the Δ(9-11) double bond in the C-ring, as in androsta-4,9(11)-diene-3,17-dione (13) (IC50=0.25µM). In addition, induced-fit docking (IFD) simulations and site of metabolism (SoM) predictions helped to explain the recognition of new potent steroidal aromatase inhibitors within the enzyme. These insights can be valuable tools for the understanding of the molecular recognition process by the aromatase and for the future design of new steroidal inhibitors.


Assuntos
Androstanos/química , Androstanos/farmacologia , Androstenodiona/química , Androstenodiona/farmacologia , Inibidores da Aromatase/química , Inibidores da Aromatase/farmacologia , Aromatase/metabolismo , Neoplasias da Mama/enzimologia , Linhagem Celular Tumoral , Feminino , Humanos , Simulação de Acoplamento Molecular , Esteroides/química , Esteroides/farmacologia , Relação Estrutura-Atividade
5.
Food Chem ; 459: 140080, 2024 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-38986205

RESUMO

Cinnamic acids are aromatic acids primarily found in plants and plant-derived food. Phenolic cinnamic acids, with one or more hydroxyl groups in the aromatic ring, often contribute to the biological activities attributed to these compounds. The presence of hydroxyl groups and a carboxyl group makes cinnamic acids very hydrophilic, preventing them from crossing biological membranes and exerting their biological activities. To alleviate this condition, a panel of synthetic modifications have been made leading to a diverse set of phenolic cinnamic structures. In this review, an overview of the natural phenolic cinnamic acid derivatives and their plant sources (more than 200) is described. The synthetic approaches to obtain the referred derivatives (more than 200) namely esters and amides are reviewed. Further, their anti-inflammatory activity (more than 70 compounds) is scrutinized. Finally, future directions will be indicated to translate the research on phenolic cinnamic derivatives into potentially effective anti-inflammatory drugs.


Assuntos
Anti-Inflamatórios , Cinamatos , Fenóis , Cinamatos/química , Cinamatos/farmacologia , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Humanos , Animais , Fenóis/química , Fenóis/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Plantas/química , Estrutura Molecular
6.
Biochem Pharmacol ; 225: 116266, 2024 07.
Artigo em Inglês | MEDLINE | ID: mdl-38710333

RESUMO

Cancer continues to be a serious threat to human health worldwide. Lung, prostate and triple-negative breast cancers are amongst the most incident and deadliest cancers. Steroidal compounds are one of the most diversified therapeutic classes of compounds and they were proven to be efficient against several types of cancer. The epoxide function has been frequently associated with anticancer activity, particularly the 1,2-epoxide function. For this reason, three 1,2-epoxysteroid derivatives previously synthesised (EP1, EP2 and EP3) and one synthesised for the first time (oxysteride) were evaluated against H1299 (lung), PC3 (prostate) and HCC1806 (triple-negative breast) cancer cell lines. A human non-tumour cell line, MRC-5 (normal lung cell line) was also used. EP2 was the most active compound in all cell lines with IC50 values of 2.50, 3.67 and 1.95 µM, followed by EP3 with IC50 values of 12.65, 15.10 and 14.16 µM in H1299, PC3 and HCC1806 cells, respectively. Additional studies demonstrated that EP2 and EP3 induced cell death by apoptosis at lower doses and apoptosis/necrosis at higher doses, proving that their effects were dose-dependent. Both compounds also exerted their cytotoxicity by ROS production and by inducing double-strand breaks. Furthermore, EP2 and EP3 proved to be much less toxic against a normal lung cell line, MRC5, indicating that both compounds might be selective, and they also demonstrated suitable in silico ADME and toxicity parameters. Finally, none of the compounds induced haemoglobin release. Altogether, these results point out the extreme relevance of both compounds, especially EP2, in the potential treatment of these types of cancer.


Assuntos
Antineoplásicos , Compostos de Epóxi , Neoplasias Pulmonares , Neoplasias da Próstata , Humanos , Antineoplásicos/farmacologia , Antineoplásicos/química , Compostos de Epóxi/farmacologia , Compostos de Epóxi/química , Linhagem Celular Tumoral , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Masculino , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/patologia , Neoplasias da Próstata/metabolismo , Feminino , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Neoplasias da Mama/metabolismo , Apoptose/efeitos dos fármacos , Esteroides/farmacologia , Esteroides/química , Relação Dose-Resposta a Droga
7.
Arch Environ Contam Toxicol ; 64(2): 219-27, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23124167

RESUMO

The mining district of Molango in the Hidalgo State, Mexico, possesses one of the largest deposits of manganese (Mn) ore in the world. This research assessed the impacts of Mn mining activity on the environment, particularly the interactions among soil, plants, and arbuscular mycorrhiza (AM) at a location under the influence of an open Mn mine. Soils and plants from three sites (soil under maize, soil under native vegetation, and mine wastes with some vegetation) were analyzed. Available Mn in both soil types and mine wastes did not reach toxic levels. Samples of the two soil types were similar regarding physical, chemical, and biological properties; mine wastes were characterized by poor physical structure, nutrient deficiencies, and a decreased number of arbuscular mycorrhizal fungi (AMF) spores. Tissues of six plant species accumulated Mn at normal levels. AM was absent in the five plant species (Ambrosia psilostachya, Chenopodium ambrosoides, Cynodon dactylon, Polygonum hydropiperoides, and Wigandia urens) established in mine wastes, which was consistent with the significantly lower number of AMF spores compared with both soil types. A. psilostachya (native vegetation) and Zea mays showed mycorrhizal colonization in their root systems; in the former, AM significantly decreased Mn uptake. The following was concluded: (1) soils, mine wastes, and plant tissues did not accumulate Mn at toxic levels; (2) despite its poor physical structure and nutrient deficiencies, the mine waste site was colonized by at least five plant species; (3) plants growing in both soil types interacted with AMF; and (4) mycorrhizal colonization of A. psilostachya influenced low uptake of Mn by plant tissues.


Assuntos
Manganês/toxicidade , Mineração , Micorrizas/efeitos dos fármacos , Plantas/efeitos dos fármacos , Microbiologia do Solo , Poluentes do Solo/toxicidade , Monitoramento Ambiental , Resíduos Industriais , Manganês/análise , México , Micorrizas/fisiologia , Fenômenos Fisiológicos Vegetais , Plantas/microbiologia , Solo/química , Poluentes do Solo/análise
8.
HardwareX ; 16: e00493, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38045919

RESUMO

Although microparticles are frequently used in chemistry and biology, their effectiveness largely depends on the homogeneity of their particle size distribution. Microfluidic devices to separate and purify particles based on their size have been developed, but many require expensive cleanroom manufacturing processes. A cost-effective, passive microfluidic separator is presented, capable of efficiently sorting and purifying particles spanning the size range of 15 µm to 40 µm. Fabricated from Polymethyl Methacrylate (PMMA) substrates using laser ablation, this device circumvents the need for cleanroom facilities. Prior to fabrication, rigorous optimization of the device's design was carried out through computational simulations conducted in COMSOL Multiphysics. To gauge its performance, chitosan microparticles were employed as a test case. The results were notably promising, achieving a precision of 96.14 %. This quantitative metric underscores the device's precision and effectiveness in size-based particle separation. This low-cost and accessible microfluidic separator offers a pragmatic solution for laboratories and researchers seeking precise control over particle sizes, without the constraints of expensive manufacturing environments. This innovation not only mitigates the limitations tied to traditional cleanroom-based fabrication but also widens the horizons for various applications within the realms of chemistry and biology.

9.
Pharmaceutics ; 14(2)2022 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-35214047

RESUMO

Magnetite nanoparticles (MNPs) have gained significant attention in several applications for drug delivery. However, there are some issues related to cell penetration, especially in the transport of cargoes that show limited membrane passing. A widely studied strategy to overcome this problem is the encapsulation of the MNPs into liposomes to form magnetoliposomes (MLPs), which are capable of fusing with membranes to achieve high delivery rates. This study presents a low-cost microfluidic approach for the synthesis and purification of MLPs and their biocompatibility and functional testing via hemolysis, platelet aggregation, cytocompatibility, internalization, and endosomal escape assays to determine their potential application in gastrointestinal delivery. The results show MLPs with average hydrodynamic diameters ranging from 137 ± 17 nm to 787 ± 45 nm with acceptable polydispersity index (PDI) values (below 0.5). In addition, we achieved encapsulation efficiencies between 20% and 90% by varying the total flow rates (TFRs), flow rate ratios (FRRs), and MNPs concentration. Moreover, remarkable biocompatibility was attained with the obtained MLPs in terms of hemocompatibility (hemolysis below 1%), platelet aggregation (less than 10% with respect to PBS 1×), and cytocompatibility (cell viability higher than 80% in AGS and Vero cells at concentrations below 0.1 mg/mL). Additionally, promising delivery results were obtained, as evidenced by high internalization, low endosomal entrapment (AGS cells: PCC of 0.28 and covered area of 60% at 0.5 h and PCC of 0.34 and covered area of 99% at 4 h), and negligible nuclear damage and DNA condensation. These results confirm that the developed microfluidic devices allow high-throughput production of MLPs for potential encapsulation and efficient delivery of nanostructured cell-penetrating agents. Nevertheless, further in vitro analysis must be carried out to evaluate the prevalent intracellular trafficking routes as well as to gain a detailed understanding of the existing interactions between nanovehicles and cells.

10.
Front Bioeng Biotechnol ; 10: 947616, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35875496

RESUMO

Melanoma is an aggressive type of skin cancer that accounts for over 75% of skin cancer deaths despite comprising less than 5% of all skin cancers. Despite promising improvements in surgical approaches for melanoma resection, the survival of undetectable microtumor residues has remained a concern. As a result, hyperthermia- and drug-based therapies have grown as attractive techniques to target and treat cancer. In this work, we aim to develop a stimuli-responsive hydrogel based on chitosan methacrylate (ChiMA), porcine small intestine submucosa methacrylate (SISMA), and doxorubicin-functionalized reduced graphene oxide (rGO-DOX) that eliminates microtumor residues from surgically resected melanoma through the coupled effect of NIR light-induced photothermal therapy and heat-induced doxorubicin release. Furthermore, we developed an in silico model to optimize heat and mass transport and evaluate the proposed chemo/photothermal therapy in vitro over melanoma cell cultures.

11.
Acta Biotheor ; 59(3-4): 231-50, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21611886

RESUMO

Rift Valley Fever is a vector-borne disease mainly transmitted by mosquito. To gain some quantitative insights into its dynamics, a deterministic model with mosquito, livestock, and human host is formulated as a system of nonlinear ordinary differential equations and analyzed. The disease threshold [Formula: see text] is computed and used to investigate the local stability of the equilibria. A sensitivity analysis is performed and the most sensitive model parameters to the measure of initial disease transmission [Formula: see text] and the endemic equilibrium are determined. Both [Formula: see text] and the disease prevalence in mosquitoes are more sensitive to the natural mosquito death rate, d(m). The disease prevalence in livestock and humans are more sensitive to livestock and human recruitment rates, [Formula: see text] and [Formula: see text], respectively, suggesting isolation of livestock from humans is a viable preventive strategy during an outbreak. Numerical simulations support the analytical results in further exploring theoretically the long-term dynamics of the disease at the population level.


Assuntos
Interações Hospedeiro-Parasita , Modelos Teóricos , Febre do Vale de Rift/transmissão , Vírus da Febre do Vale do Rift/isolamento & purificação , Humanos
12.
Comput Math Methods Med ; 2021: 6647425, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33777169

RESUMO

A modeling approach to investigate the dynamics of COVID-19 epidemics coupled with fear is presented in this paper. The basic reproduction number R 0 is computed and employed in analysing the effect of initial transmission and the conditions for disease control or eradication. Numerical simulations show that whenever there is an outbreak coupled with fear, the disease is likely to persist in the first two months, and after that, it will start to slow down as the recovery rate from fear increases. An increase in the number of recovered individuals lead to a rise in the number of susceptibles and consequently set off a second wave of infection in the third month of the epidemic.


Assuntos
COVID-19/epidemiologia , COVID-19/psicologia , Epidemias , Medo , Algoritmos , Número Básico de Reprodução , COVID-19/diagnóstico , Simulação por Computador , Surtos de Doenças , Humanos , Controle de Infecções , Modelos Teóricos , Pandemias
13.
Micromachines (Basel) ; 12(11)2021 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-34832789

RESUMO

The discovery of new membrane-active peptides (MAPs) is an area of considerable interest in modern biotechnology considering their ample applicability in several fields ranging from the development of novel delivery vehicles (via cell-penetrating peptides) to responding to the latent threat of antibiotic resistance (via antimicrobial peptides). Different strategies have been devised for such discovery process, however, most of them involve costly, tedious, and low-efficiency methods. We have recently proposed an alternative route based on constructing a non-rationally designed library recombinantly expressed on the yeasts' surfaces. However, a major challenge is to conduct a robust and high-throughput screening of possible candidates with membrane activity. Here, we addressed this issue by putting forward low-cost microfluidic platforms for both the synthesis of Giant Unilamellar Vesicles (GUVs) as mimicking entities of cell membranes and for providing intimate contact between GUVs and homologues of yeasts expressing MAPs. The homologues were chitosan microparticles functionalized with the membrane translocating peptide Buforin II, while intimate contact was through passive micromixers with different channel geometries. Both microfluidic platforms were evaluated both in silico (via Multiphysics simulations) and in vitro with a high agreement between the two approaches. Large and stable GUVs (5-100 µm) were synthesized effectively, and the mixing processes were comprehensively studied leading to finding the best operating parameters. A serpentine micromixer equipped with circular features showed the highest average encapsulation efficiencies, which was explained by the unique mixing patterns achieved within the device. The microfluidic devices developed here demonstrate high potential as platforms for the discovery of novel MAPs as well as for other applications in the biomedical field such as the encapsulation and controlled delivery of bioactive compounds.

14.
Comput Math Methods Med ; 2020: 8972063, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33123216

RESUMO

A deterministic mathematical model for brucellosis that incorporates seasonality on direct and indirect transmission parameters for domestic ruminants, wild animals, humans, and the environment was formulated and analyzed in this paper. Both analytical and numerical simulations are presented. From this study, the findings show that variations in seasonal weather have the great impact on the transmission dynamics of brucellosis in humans, livestock, and wild animals. Thus, in order for the disease to be controlled or eliminated, measures should be timely implemented upon the fluctuation in the transmission of the disease.


Assuntos
Zoonoses Bacterianas/transmissão , Brucelose/transmissão , Brucelose/veterinária , Modelos Biológicos , Animais , Animais Domésticos , Animais Selvagens , Número Básico de Reprodução/estatística & dados numéricos , Biologia Computacional , Simulação por Computador , Suscetibilidade a Doenças/veterinária , Microbiologia Ambiental , Feminino , Humanos , Masculino , Conceitos Matemáticos , Estações do Ano , Tempo (Meteorologia)
15.
Antibiotics (Basel) ; 9(12)2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-33265897

RESUMO

One of the challenges of modern biotechnology is to find new routes to mitigate the resistance to conventional antibiotics. Antimicrobial peptides (AMPs) are an alternative type of biomolecules, naturally present in a wide variety of organisms, with the capacity to overcome the current microorganism resistance threat. Here, we reviewed our recent efforts to develop a new library of non-rationally produced AMPs that relies on bacterial genome inherent diversity and compared it with rationally designed libraries. Our approach is based on a four-stage workflow process that incorporates the interplay of recent developments in four major emerging technologies: artificial intelligence, molecular dynamics, surface-display in microorganisms, and microfluidics. Implementing this framework is challenging because to obtain reliable results, the in silico algorithms to search for candidate AMPs need to overcome issues of the state-of-the-art approaches that limit the possibilities for multi-space data distribution analyses in extremely large databases. We expect to tackle this challenge by using a recently developed classification algorithm based on deep learning models that rely on convolutional layers and gated recurrent units. This will be complemented by carefully tailored molecular dynamics simulations to elucidate specific interactions with lipid bilayers. Candidate AMPs will be recombinantly-expressed on the surface of microorganisms for further screening via different droplet-based microfluidic-based strategies to identify AMPs with the desired lytic abilities. We believe that the proposed approach opens opportunities for searching and screening bioactive peptides for other applications.

16.
J Med Chem ; 62(7): 3636-3657, 2019 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-30852901

RESUMO

C-6α and C-7α androstanes were studied to disclose which position among them is more convenient to functionalize to reach superior aromatase inhibition. In the first series, the study of C-6 versus C-7 methyl derivatives led to the very active compound 9 with IC50 of 0.06 µM and Ki = 0.025 µM (competitive inhibition). In the second series, the study of C-6 versus C-7 allyl derivatives led to the best aromatase inhibitor 13 of this work with IC50 of 0.055 µM and Ki = 0.0225 µM (irreversible inhibition). Beyond these findings, it was concluded that position C-6α is better to functionalize than C-7α, except when there is a C-4 substituent simultaneously. In addition, the methyl group was the best substituent, followed by the allyl group and next by the hydroxyl group. To rationalize the structure-activity relationship of the best inhibitor 13, molecular modeling studies were carried out.


Assuntos
Inibidores da Aromatase/química , Inibidores da Aromatase/farmacologia , Esteroides/farmacologia , Humanos , Simulação de Acoplamento Molecular , Esteroides/química , Relação Estrutura-Atividade
17.
J Steroid Biochem Mol Biol ; 171: 218-228, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28396197

RESUMO

The majority of breast cancer cases are estrogen receptor positive (ER+). Although, third-generation aromatase inhibitors (AIs) are used as first-line treatment in post-menopausal women, they cause endocrine resistance and bone loss, which limits their success. Therefore, there is a demand to discover new potent molecules, with less toxicity that can circumvent these drawbacks. Our group has previously demonstrated that new 7α-substituted steroidal molecules, 7α-(2ξ,3ξ-epoxypropyl)androsta-1,4-diene-3,17-dione (3), 7α-allylandrost-4-ene-3,17-dione (6), 7α-allylandrost-4-en-17-one (9), 7α-allyl-3-oxoandrosta-1,4-dien-17ß-ol (10) and 7α-allylandrosta-1,4-diene-3,17-dione (12) are potent AIs in placental microsomes. In this work, it was investigated their anti-aromatase activity and in vitro effects in sensitive and resistant breast cancer cells. All the steroids efficiently inhibit aromatase in breast cancer cells, allowing to establish new structure-activity relationships for this class of compounds. Moreover, the new AIs can inhibit breast cancer cell growth, by causing cell cycle arrest and apoptosis. The effects of AIs 3 and 12 on sensitive cells were dependent on aromatase inhibition and androgen receptor (AR), while for AI 9 and AI 10 were AR- and ER-dependent, respectively. In addition, it was shown that all the AIs can sensitize resistant cancer cells being their behavior similar to the sensitive cells. In summary, this study contributes to the understanding of the structural modifications in steroidal scaffold that are translated into better aromatase inhibition and anti-tumor properties, providing important information for the rational design/synthesis of more effective AIs. In addition, allowed the discovery of new potent 7α-substituted androstane molecules to inhibit tumor growth and prevent endocrine resistance.


Assuntos
Androstanos/farmacologia , Antineoplásicos Hormonais/farmacologia , Apoptose/efeitos dos fármacos , Inibidores da Aromatase/farmacologia , Neoplasias da Mama/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos , Androstanos/efeitos adversos , Androstanos/química , Antineoplásicos Hormonais/efeitos adversos , Antineoplásicos Hormonais/química , Aromatase/química , Aromatase/genética , Aromatase/metabolismo , Inibidores da Aromatase/efeitos adversos , Inibidores da Aromatase/química , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Feminino , Humanos , Concentração Inibidora 50 , Células MCF-7 , Proteínas de Neoplasias/química , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Receptores Androgênicos/metabolismo , Receptores de Estrogênio/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Relação Estrutura-Atividade
18.
J Mater Chem B ; 4(36): 6004-6011, 2016 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-32263489

RESUMO

This work presents an Electrospray Induced Surface Activation (EISA) method generalization for electrospinning. It allows an easy way to produce surface functionalized microfiber mats for infectious disease diagnostic purposes. We present the details of both the production and characterization of surface functionalized highly porous poly methyl methacrylate (PMMA) microfiber mats produced using dry (DS) and wet substrate (WS) configurations. The characterization was performed using high-resolution scanning electron microscopy (HRSEM), Size Exclusion Chromatography (SEC), X-ray photoelectron spectroscopy (XPS) and biological essays attaching both the recombinant auto-fluorescent green fluorescent protein (GFP) and the anti-human Ig protein containing a fluorescent reporter R-phycoerythrin (AbPE). The final biological application assay was performed by positively detecting HIV contaminated human samples.

19.
Carbohydr Polym ; 134: 775-83, 2015 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-26428185

RESUMO

Polyvinyl Alcohol (PVA)/guar gum (GG) membranes with different loads of paramagnetic iron oxide Fe3O4 nanoparticles were successfully electrospun using both non-alkaline and alkaline stock solutions. The nanoparticle homogeneity distribution was clearly enhanced in fibers obtained from alkaline stock solutions. This is mainly due to the interaction between GG and the metallic ion, which also leads to further dispersion of remained uncoated nanoparticles in the mixture. It was also noticed that GG favors nanoparticle stability in the mixture and contributes to nanoparticle encapsulation. X-ray results showed that all membranes were semi-crystalline. FTIR-ATR spectra showed that Fe-O absorption band intensity improved with increasing nanoparticle load, reaching saturation at 3.5mg/ml Fe3O4 concentration under alkaline conditions. VSM analyses showed that the nanoparticles are paramagnetic and were successfully incorporated by the fibers. In vitro biocompatibility tests using L929 cells indicates adequate levels of cytotoxicity and cell adhesion/proliferation assays for both membranes obtained from non-alkaline and alkaline stock solutions. Therefore, they have potential for biomedical applications as biodegradable wound dressing.


Assuntos
Eletricidade , Galactanos/química , Nanopartículas de Magnetita/química , Mananas/química , Membranas Artificiais , Gomas Vegetais/química , Álcool de Polivinil/química , Animais , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Concentração de Íons de Hidrogênio , Teste de Materiais , Camundongos , Álcool de Polivinil/toxicidade
20.
Food Chem ; 183: 235-58, 2015 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-25863633

RESUMO

In this paper, a review of the literature on the phenolic compounds with anticancer activity published between 2008 and 2012 is presented. In this overview only phenolic antioxidant compounds that display significant anticancer activity have been described. In the first part of this review, the oxidative and nitrosative stress relation with cancer are described. In the second part, the plant-derived food extracts, containing identified phenolic antioxidants, the phenolic antioxidants isolated from plants and plant-derived food or commercially available and the synthetic ones, along with the type of cancer and cells where they exert anticancer activity, are described and summarized in tables. The principal mechanisms for their anti-proliferative effects were also described. Finally, a critical analysis of the studies and directions for future research are included in the conclusion.


Assuntos
Anticarcinógenos/análise , Antioxidantes/análise , Fenóis/análise , Extratos Vegetais/química , Plantas Comestíveis/química , Humanos , Oxirredução
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