Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.248
Filtrar
1.
J Hazard Mater ; 442: 130051, 2023 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-36179627

RESUMO

Biodegradable plastics (BDP) are increasingly applied; however, there has been of concerns about their environmental safety, especially from nondegradable additive compositions. Until now, data of ecotoxicity of BDP additives is scarce. Here, nematode C. elegans was used to comparatively evaluate toxicity of an isocyanate additive, i.e., Hexamethylene diisocyanate (HDI), a maleic anhydride, i.e., Diallyl maleate (DIM), and other four BDP organic additives. These additives caused lethality of nematodes at µg L-1 level, of lowest LC50 value of HDI/DIM. Uniform exposure to these additives resulted in various degrees of inhibitions in body volumes and longevity, indicating developmental toxicity. Moreover, BDP additives induced significant elevations of gst-4 expression, especially mean 123.54 %/234.29 % increase in HDI/DIM group, but reduced ges-1 expression, which indicates oxidative damages and mitochondrial dysfunction. BDP additives further caused inhibition in locomotor and food intake/excretion behavior, and related damages of glutamatergic neurons and GABAergic neurons, indicating their neurotoxicity. We found HDI and DIM presented relatively strong effects on susceptible endpoints including lethality, gst-4, mean lifespan, food intake and excretion behavior. Overall, this study suggests prominent ecotoxic risk of isocyanates and maleic anhydrides as BDP additives, which is significant for the selection of environmentally friendly BDP additives.


Assuntos
Plásticos Biodegradáveis , Caenorhabditis elegans , Animais , Anidridos Maleicos , Plásticos Biodegradáveis/farmacologia , Isocianatos/farmacologia , Maleatos/farmacologia
2.
Eur J Med Chem ; 246: 114993, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36495631

RESUMO

Solubility-driven optimization of the salts of nitro benzothiopyranone 1, which targets DprE1, led to an antimycobacterial preclinical candidate 2. Five pharmaceutically acceptable salts, including the maleate (2), fumarate (3), citrate (4, 5), and l-malate (6) of compound 1, were prepared via the salt formation reaction and evaluated for their physicochemical and pharmacokinetic properties. Compared with 1, all the target salts exhibited greatly increased aqueous solubility and improved oral bioavailability in mice. Maleate salt 2, which displayed higher chemical stability and lower log P, showed substantially improved bioavailability in rats and a much better in vivo effect compared with free base 1 at the same dose. The X-ray crystal structure of 2 revealed that the exposed hydrophilic piperazine-maleate moiety in the crystal structure cell may be critical in increasing the solubility of 2. Thus, this maleate salt 2 overcame the poor druggability of benzothiopyranone derivatives and was identified as a promising preclinical candidate for treating tuberculosis.


Assuntos
Mycobacterium tuberculosis , Animais , Camundongos , Ratos , Maleatos/química , Maleatos/farmacologia , Piperazina/farmacologia , Sais/química , Solubilidade , Fumaratos/química , Fumaratos/farmacologia
3.
Nihon Yakurigaku Zasshi ; 157(4): 244-247, 2022.
Artigo em Japonês | MEDLINE | ID: mdl-35781453

RESUMO

Brain injury causes temporary or permanent impairment of brain function due to an accident or circulation disorders. Even after rehabilitation training, there are often persistent functional impairments. Recent advances in our understanding of the repair mechanisms of neural circuits after brain injury have led to the possibility that these mechanisms may offer potential therapeutic targets for drugs that promote functional recovery after brain injury. Neuroplasticity is believed to be important for the recovery process after brain injury in the brain regions associated with injured region for compensation. The effectiveness of drugs for restoring brain function after stroke investigated in a variety of animal models and clinical trials has been focused on drugs that act on the monoamine system to modulate neuroplasticity, as well as other targets such as NMDA receptors and CCR5. Recently, we focused on novel small compound, edonerpic maleate, as a drug which facilitates experience-dependent synaptic delivery of AMPA receptor. We found that edonerpic maleate binds to Collapsin-response mediator protein 2, a downstream molecule of Semaphorin and enhance synaptic plasticity by facilitating synaptic delivery of AMPA receptors, thereby promoting functional recovery in a rehabilitation-dependent manner after brain injury in rodents and non-human primates. Further investigations is needed to seek more appropriate drug targets from both preclinical animal studies and clinical trials, and to translate preclinical results into successful clinical trials.


Assuntos
Lesões Encefálicas , Fármacos Neuroprotetores , Animais , Encéfalo , Lesões Encefálicas/reabilitação , Maleatos/farmacologia , Maleatos/uso terapêutico , Plasticidade Neuronal/fisiologia , Recuperação de Função Fisiológica/fisiologia
4.
Nat Metab ; 4(5): 534-546, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35655026

RESUMO

Although the immunomodulatory and cytoprotective properties of itaconate have been studied extensively, it is not known whether its naturally occurring isomers mesaconate and citraconate have similar properties. Here, we show that itaconate is partially converted to mesaconate intracellularly and that mesaconate accumulation in macrophage activation depends on prior itaconate synthesis. When added to human cells in supraphysiological concentrations, all three isomers reduce lactate levels, whereas itaconate is the strongest succinate dehydrogenase (SDH) inhibitor. In cells infected with influenza A virus (IAV), all three isomers profoundly alter amino acid metabolism, modulate cytokine/chemokine release and reduce interferon signalling, oxidative stress and the release of viral particles. Of the three isomers, citraconate is the strongest electrophile and nuclear factor-erythroid 2-related factor 2 (NRF2) agonist. Only citraconate inhibits catalysis of itaconate by cis-aconitate decarboxylase (ACOD1), probably by competitive binding to the substrate-binding site. These results reveal mesaconate and citraconate as immunomodulatory, anti-oxidative and antiviral compounds, and citraconate as the first naturally occurring ACOD1 inhibitor.


Assuntos
Fumaratos/farmacologia , Interferons , Macrófagos , Maleatos/farmacologia , Antivirais/metabolismo , Antivirais/farmacologia , Carboxiliases , Catálise , Humanos , Inflamação/metabolismo , Macrófagos/metabolismo , Estresse Oxidativo
5.
Chem Pharm Bull (Tokyo) ; 70(6): 427-434, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35418544

RESUMO

In the present study, four novel ginsenosides fatty acid and aromatic acid derivatives were designed and synthesized, and their cytotoxic effects on human ovarian carcinoma cells (SKOV3) were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. The results demonstrated that all derivatives inhibited SKOV3 cell growth, and Compound 3 showed the most outstanding anti-proliferative effect on SKOV3 cells. The IC50 value of Compound 3 was 33.8 ± 2.21 µM, less than half of that of cis-platinum (70.1 ± 7.64 µM). Subsequent analysis revealed that Compound 3 could promote SKOV3 cell apoptosis, and the percentage of apoptotic cell population increased with increasing Compound 3 concentrations. In addition, the expression ratios of Bax/Bcl-2, cleaved-Caspase-3/Caspase-3 and cleaved-Caspase-9/Caspase-9 were gradually elevated in Compound 3-treated SKOV3 cells compared with control cells. Furthermore, translocation of Bax to mitochondria was associated with the release of Cytochrome C. Molecular docking analysis revealed three hydrogen-bonds existed in Compound 3 with poly(ADP-ribose)polymerase (PARP) receptor (PDB code: 5DSY), which may be the target of the anti-ovarian cancer effect of Compound 3. Altogether, our study indicates that Compound 3 induces SKOV3 cell apoptosis via reactive oxygen species (ROS)-dependent mitochondrial pathway, and can serve as an anti-cancer agent for treating ovarian carcinoma.


Assuntos
Mitocôndrias , Neoplasias Ovarianas , Sapogeninas , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Caspase 9/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Humanos , Maleatos/farmacologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Simulação de Acoplamento Molecular , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/patologia , Sapogeninas/farmacologia , Proteína X Associada a bcl-2/metabolismo
6.
Sci Rep ; 12(1): 3532, 2022 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-35241773

RESUMO

Extraction of integral membrane proteins with poly(styrene-co-maleic acid) provides a promising alternative to detergent extraction. A major advantage of extraction using copolymers rather than detergent is the retention of the lipid bilayer around the proteins. Here we report the first functional investigation of the mammalian insulin receptor which was extracted from cell membranes using poly(styrene-co-maleic acid). We found that the copolymer efficiently extracted the insulin receptor from 3T3L1 fibroblast membranes. Surprisingly, activation of the insulin receptor and proximal downstream signalling was detected upon copolymer extraction even in the absence of insulin stimulation. Insulin receptor and IRS1 phosphorylations were above levels measured in the control extracts made with detergents. However, more distal signalling events in the insulin signalling cascade, such as the phosphorylation of Akt were not observed. Following copolymer extraction, in vitro addition of insulin had no further effect on insulin receptor or IRS1 phosphorylation. Therefore, under our experimental conditions, the insulin receptor is not functionally responsive to insulin. This study is the first to investigate receptor tyrosine kinases extracted from mammalian cells using a styrene-maleic acid copolymer and highlights the importance of thorough functional characterisation when using this method of protein extraction.


Assuntos
Detergentes , Receptor de Insulina , Insulina , Ligantes , Maleatos/farmacologia , Fosforilação , Polímeros , Poliestirenos
7.
Acta Ophthalmol ; 100(7): 788-796, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35080812

RESUMO

PURPOSE: Tyrosine kinase inhibitors inhibit VEGF receptors. If delivered to the retina, they might inhibit oedema and neovascularization such as in age-related macular degeneration and diabetic retinopathy. The aim of this study was to formulate cediranib maleate, a potent VEGF inhibitor, as γ-cyclodextrin nanoparticle eye drops and measure the retinal delivery and overall ocular pharmacokinetics after a single-dose administration in rabbits. METHODS: A novel formulation technology with 3% cediranib maleate as γ-cyclodextrin micro-suspension was prepared by autoclaving method. Suitable stabilizers were tested for heat-stable eye drops. The ophthalmic formulation was topically applied to one eye in rabbits. The pharmacokinetics in ocular tissues, tear film and blood samples were studied at 1, 3 and 6 hr after administration. RESULTS: γ-cyclodextrin formed complex with cediranib maleate. The formation of γ-cyclodextrin nanoparticles occurred in concentrated complexing media. Combined stabilizers prevented the degradation of drug during the autoclaving process. Three hours after administration of the eye drops, treated eyes showed cediranib levels of 737 ± 460 nM (mean ± SD) in the retina and 10 ± 6 nM in the vitreous humour. CONCLUSIONS: Cediranib maleate in γ-cyclodextrin nanoparticles were stable to heat in presence of stabilizers. The drug as eye drops reached the retina in concentrations that are more than 100 times higher than the 0.4 nM IC50 value reported for the VEGF type-II receptor and thus, presumably, above therapeutic level. These results suggest that γ-cyclodextrin-based cediranib maleate eye drops deliver effective drug concentrations to the retina in rabbits after a single-dose administration.


Assuntos
Ciclodextrinas , Nanopartículas , gama-Ciclodextrinas , Administração Tópica , Animais , Ciclodextrinas/metabolismo , Ciclodextrinas/farmacologia , Indóis , Maleatos/metabolismo , Maleatos/farmacologia , Soluções Oftálmicas , Inibidores de Proteínas Quinases/farmacologia , Quinazolinas , Coelhos , Retina/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , gama-Ciclodextrinas/farmacocinética
8.
Plant Dis ; 106(3): 960-965, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34705489

RESUMO

Since the protective activity of the Bordeaux mixture against plant disease caused by oomycetes was discovered, copper compounds have been used for more than a century as an effective plant protection strategy. However, the application of excessive copper can cause adverse effects through long-term heavy metal accumulation in soils. Therefore, it is necessary to develop new strategies to reduce or replace copper in pesticides based on organic and low-input farming systems. Organic acids are eco-friendly. In this study, we tested the antifungal and anti-oomycete activity of maleic acid (MA) and copper sulfate (CS) against 13 plant pathogens. Treatment with a mixture of MA and CS showed strong anti-oomycetes activity against Phytophthora xcambivora, P. capsici, and P. cinnamomi. Moreover, the concentration of CS in the activated mixture of MA and CS was lower than that in the activated CS only, and the mixture showed synergy or partial synergy effects on the anti-oomycete activity. Application of a wettable powder formulation of MA and CS mixture (MCS 30WP; 26.67% MA and 3.33% CS) had excellent protective activity in pot experiments with control values of 73% Phytophthora blight on red pepper, 91% damping-off on cucumber, and 84% Pythium blight on creeping bentgrass, which are similar to those of the CS wettable powder formulation (6.67% CS) containing two times the CS content of MCS 30WP. These observations suggest that the synergistic effect of the MA and CS combination is a sustainable alternative for effective management of destructive oomycete diseases.


Assuntos
Sulfato de Cobre , Phytophthora , Sulfato de Cobre/farmacologia , Maleatos/farmacologia , Phytophthora/fisiologia , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle
9.
Sci Rep ; 11(1): 20029, 2021 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-34625595

RESUMO

Inhibiting sprouting of potatoes is an interesting subject needed for potato storage and industry. Sprouting degrades the quality of tuber along with releasing α-solanine and α-chaconine, which are harmful for health. Sprout suppressants, available in the market, are either costly or toxic to both health and environment. So, there is a need for developing countries to explore new sprouting suppressant compound which is cheap, non-toxic and reasonably efficient in comparison to commercial ones. We have established that simple maleic acid and L-tartaric acid are effective sprout suppressing agents. Both can hinder sprouting up to 6 weeks and 4 weeks post treatment respectively at room temperature in dark. These do not affect the quality parameters, retain the moisture content and maintain the stout appearance of the tubers along the total storage period. Thus maleic acid and L-tartaric acid would qualify as alternative, cheap, efficient sprout suppressant for potato storage and processing.


Assuntos
Armazenamento de Alimentos/métodos , Maleatos/farmacologia , Tubérculos/crescimento & desenvolvimento , Solanina/análogos & derivados , Solanum tuberosum/crescimento & desenvolvimento , Tartaratos/farmacologia , Tubérculos/efeitos dos fármacos , Tubérculos/metabolismo , Solanina/metabolismo , Solanum tuberosum/efeitos dos fármacos , Solanum tuberosum/metabolismo
10.
Molecules ; 26(12)2021 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-34207832

RESUMO

Triple-negative breast cancer (TNBC) is a heterogeneous subtype of tumors that tests negative for estrogen receptors, progesterone receptors, and excess HER2 protein. The mainstay of treatment remains chemotherapy, but the therapeutic outcome remains inadequate. This paper investigates the potential of a duocarmycin derivative, tafuramycin A (TFA), as a new and more effective chemotherapy agent in TNBC treatment. To this extent, we optimized the chemical synthesis of TFA, and we encapsulated TFA in a micellar system to reduce side effects and increase tumor accumulation. In vitro and in vivo studies suggest that both TFA and SMA-TFA possess high anticancer effects in TNBC models. Finally, the encapsulation of TFA offered a preferential avenue to tumor accumulation by increasing its concentration at the tumor tissues by around four times in comparison with the free drug. Overall, the results provide a new potential strategy useful for TNBC treatment.


Assuntos
Antineoplásicos/farmacologia , Alcaloides Indólicos/farmacologia , Nanopartículas/química , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Animais , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Feminino , Humanos , Alcaloides Indólicos/química , Maleatos/química , Maleatos/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Micelas , Poliestirenos/química , Poliestirenos/farmacologia , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/patologia
11.
Chem Commun (Camb) ; 57(56): 6919-6922, 2021 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-34155490

RESUMO

We demonstrate an intrinsic antitumor effect of polymer nanoparticles (P-NPs), which could re-program tumor-associated macrophages to pro-inflammatory phenotype. The intrinsic effect of P-NPs on macrophage repolarization and its combination with other therapies provide new ideas for drug delivery, macrophage regulation and immunotherapy in cancer treatment.


Assuntos
Antineoplásicos/farmacologia , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Maleatos/farmacologia , Nanopartículas/química , Poliestirenos/farmacologia , Polivinil/farmacologia , Animais , Antineoplásicos/química , Antineoplásicos/toxicidade , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Maleatos/química , Maleatos/toxicidade , Camundongos , Nanopartículas/toxicidade , Poliestirenos/química , Poliestirenos/toxicidade , Polivinil/química , Polivinil/toxicidade
12.
Expert Opin Ther Targets ; 25(5): 401-414, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34110944

RESUMO

INTRODUCTION: Autophagy is a cellular catabolic mechanism that helps clear damaged cellular components and is essential for normal cellular and tissue function. The sigma-1 receptor (σ-1R) is a chaperone protein involved in signal transduction, neurite outgrowth, and plasticity, improving memory, and neuroprotection. Recent evidence shows that σ-1R can promote autophagy. Autophagy activation by the σ-1Rs along with other neuroprotective effects makes it an interesting target for the treatment of Alzheimer's disease. AF710B, T-817 MA, and ANAVEX2-73 are some of the σ-1R agonists which have shown promising results and have entered clinical trials. These molecules have also been found to induce autophagy and show cytoprotective effects in cellular models. AREAS COVERED: This review provides insight into the current understanding of σ-1R functions related to autophagy and their role in alleviating AD. EXPERT OPINION: We propose a mechanism through which the activation of σ-1R and autophagy could alter amyloid precursor protein processing to inhibit amyloid-ß production by reconstituting cholesterol and gangliosides in the lipid raft to offer neuroprotection against AD. Future AD treatment could involve the combined targeting of the σ-1R and autophagy activation. We suggest that future studies investigate the link between autophagy the σ-1R and AD.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Terapia de Alvo Molecular , Receptores sigma/agonistas , Doença de Alzheimer/fisiopatologia , Animais , Autofagia/efeitos dos fármacos , Furanos/farmacologia , Humanos , Maleatos/farmacologia , Receptores sigma/metabolismo , Compostos de Espiro/farmacologia , Tiazolidinas/farmacologia , Tiofenos/farmacologia
13.
Intern Med ; 60(15): 2385-2394, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-33612668

RESUMO

Objective Evidence concerning the safety and efficacy of indacaterol maleate in a real-life setting is limited. The objective of this post-marketing surveillance was to evaluate the real-life safety and efficacy of indacaterol maleate in Japanese patients with chronic obstructive pulmonary disease (COPD). Methods This was a 52-week post-marketing surveillance conducted between April 2012 and December 2018. The safety endpoints included the incidence of adverse events (AEs), serious adverse events (SAEs), and adverse drug reactions (ADRs). The efficacy endpoints included the physician-reported global evaluation of treatment effectiveness (GETE), change from baseline in the COPD assessment test (CAT) results, forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and %FEV1 following 4, 12, 26, and 52 weeks of indacaterol administration. Results Of the 1,846 enrolled patients, 1,726 were included in the safety and efficacy analyses. The mean age of the patients was 72.5 years old. Cough, pneumonia and COPD worsening were the most common AEs reported, while pneumonia (1.04%) was the most common SAE, and cough (1.68%) was the most common ADR. GETE showed that 69.70% of patients achieved an excellent/good/moderate response following indacaterol treatment. The CAT score decreased, and lung function parameters (FVC, FEV1 and %FEV1) improved across all the COPD stages following treatment with indacaterol. Conclusion Indacaterol showed a favorable safety and tolerability profile in Japanese patients with COPD without new safety signals observed in real-life settings. These findings demonstrated that indacaterol is an effective maintenance treatment in real-life practice for Japanese patients with COPD.


Assuntos
Agonistas de Receptores Adrenérgicos beta 2 , Doença Pulmonar Obstrutiva Crônica , Agonistas de Receptores Adrenérgicos beta 2/efeitos adversos , Broncodilatadores/efeitos adversos , Método Duplo-Cego , Volume Expiratório Forçado , Humanos , Indanos/efeitos adversos , Japão/epidemiologia , Maleatos/farmacologia , Maleatos/uso terapêutico , Vigilância de Produtos Comercializados , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Quinolonas , Resultado do Tratamento
14.
Mol Cell Biol ; 41(2)2021 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-33168698

RESUMO

Our body responds to environmental stress by changing the expression levels of a series of cytoprotective enzymes/proteins through multilayered regulatory mechanisms, including the KEAP1-NRF2 system. While NRF2 upregulates the expression of many cytoprotective genes, there are fundamental limitations in short-read RNA sequencing (RNA-Seq), resulting in confusion regarding interpreting the effectiveness of cytoprotective gene induction at the transcript level. To precisely delineate isoform usage in the stress response, we conducted independent full-length transcriptome profiling (isoform sequencing; Iso-Seq) analyses of lymphoblastoid cells from three volunteers under normal and electrophilic stress-induced conditions. We first determined the first exon usage in KEAP1 and NFE2L2 (encoding NRF2) and found the presence of transcript diversity. We then examined changes in isoform usage of NRF2 target genes under stress conditions and identified a few isoforms dominantly expressed in the majority of NRF2 target genes. The expression levels of isoforms determined by Iso-Seq analyses showed striking differences from those determined by short-read RNA-Seq; the latter could be misleading concerning the abundance of transcripts. These results support that transcript usage is tightly regulated to produce functional proteins under electrophilic stress. Our present study strongly argues that there are important benefits that can be achieved by long-read transcriptome sequencing.


Assuntos
Processamento Alternativo , Proteína 1 Associada a ECH Semelhante a Kelch/genética , Fator 2 Relacionado a NF-E2/genética , RNA Mensageiro/genética , Transcriptoma , Linhagem Celular Transformada , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/genética , Núcleo Celular/metabolismo , Perfilação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch/química , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Linfócitos/citologia , Linfócitos/efeitos dos fármacos , Linfócitos/metabolismo , Maleatos/farmacologia , Modelos Moleculares , Fator 2 Relacionado a NF-E2/química , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo , Isoformas de Proteínas/química , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Estrutura Secundária de Proteína , RNA Mensageiro/classificação , RNA Mensageiro/metabolismo
15.
Int J Biol Macromol ; 167: 620-632, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33279560

RESUMO

Many restoring formulations for damaged hair keratin have been developed. Some patents claim that the hair repair occurs through the reconstruction of disulfide bridges of keratin, through α,ß-unsaturated Michael acceptors, such as shikimic acid and bis-aminopropyl diglycol dimaleate. To gain more insights into the possible repairing mechanism, this study is aimed at assessing, by IR and Raman spectroscopies coupled to scanning electron microscopy (SEM), the structural changes induced in keratin from bleached hair by the treatment with commercial reconstructive agents as well as shikimic acid and dimethyl maleate, chosen as model compounds. Vibrational spectroscopy revealed that shikimic acid- and maleate-based restoring agents interacted with hair fibers modifying both their cortex and cuticle regions. None of the investigated treatments induced an increase in the SS disulfide bridges content of the hair cortex, although it cannot be excluded that this phenomenon could have occurred in the cuticle. SS rearrangements were found to occur. None of our results can be interpreted as direct evidence of the sulfa-Michael reaction/cross-linking. From a morphological point of view, beneficial effects of the restoring agents were observed by SEM analyses, in terms of a more regular hair surface and more imbricated scales.


Assuntos
Cabelo/efeitos dos fármacos , Queratinas Específicas do Cabelo/metabolismo , Maleatos/farmacologia , Ácido Chiquímico/farmacologia , Dissulfetos/química , Cabelo/metabolismo , Cabelo/ultraestrutura , Humanos , Queratinas Específicas do Cabelo/química , Maleatos/química , Microscopia Eletrônica de Varredura , Ácido Chiquímico/química , Análise Espectral Raman
16.
Int J Biol Macromol ; 165(Pt B): 2528-2540, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-33098901

RESUMO

A new sponge-type hydrogel was obtained by cross-linking hyaluronic acid (HA) and poly(methylvinylether-alt-maleic acid) P(MVE-alt-MA) through a solvent-free thermal method. The sponge-type hydrogel was characterized and checked as a support for cell growth. The influence of concentration and weight ratio of polymers on the morphology and hydrogel stability was investigated. The total polymers concentration of 3% (w/w) and the weight ratio of 1:1 were optimal for the synthesis of a stable hydrogel (HA3P50) and to promote cell proliferation. The swelling measurements revealed a high-water absorption capacity of the hydrogel in basic medium. Diphenhydramine (DPH), lidocaine (Lid) and propranolol (Prop) were loaded within the hydrogel as a model drugs to investigate the ability of drug transport and release. In vitro studies revealed that HA3P50 hydrogel promoted the adhesion and proliferation of human hepatocellular carcinoma cell line HepG2, providing a good support for 3D cell culture to obtain surrogate tumor scaffold suitable for preclinical anti-cancer drug screening.


Assuntos
Proliferação de Células/efeitos dos fármacos , Ácido Hialurônico/química , Hidrogel de Polietilenoglicol-Dimetacrilato/farmacologia , Hidrogéis/farmacologia , Carcinoma Hepatocelular/tratamento farmacológico , Ciclo Celular/efeitos dos fármacos , Difenidramina/farmacologia , Células Hep G2 , Humanos , Ácido Hialurônico/farmacologia , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Hidrogéis/química , Lidocaína/farmacologia , Neoplasias Hepáticas/tratamento farmacológico , Maleatos/química , Maleatos/farmacologia , Propranolol/farmacologia
17.
J Med Entomol ; 57(6): 1992-1996, 2020 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-32484559

RESUMO

Aedes aegypti (L.) is the primary vector of Zika, dengue, yellow fever, and chikungunya viruses. Insecticides used in mosquito control can help prevent the spread of vector-borne diseases. However, it is essential to determine insecticide resistance (IR) status before control measures are undertaken. Only the most effective insecticides should be used to avoid ineffective control and/or promotion of IR. Pyrethroids and organophosphates are the most commonly used insecticides for mosquito control. Here, the efficacy of two active ingredients (AIs; permethrin [pyrethroid], chlorpyrifos [organophosphate]), two formulated products (FPs; Biomist [AI: permethrin]) and (Mosquitomist [AI: chlorpyrifos]), and three synergists (piperonyl butoxide, diethyl maleate, S-S-S-tributyl phosphorotrithioate) was evaluated in two Ae. aegypti colonies (pyrethroid resistant and susceptible). Mosquitomist was most effective against the pyrethroid-resistant colony (100% mortality at diagnostic time). Pre-exposure to synergists did not increase the efficacy of AIs against the pyrethroid-resistant colony. Further research is needed to discover how synergists may affect the efficacy of insecticides when used on pyrethroid-resistant mosquitoes.


Assuntos
Aedes/efeitos dos fármacos , Resistência a Inseticidas , Inseticidas/farmacologia , Maleatos/farmacologia , Organotiofosfatos/farmacologia , Sinergistas de Praguicidas/farmacologia , Butóxido de Piperonila/farmacologia , Aedes/fisiologia , Animais , Clorpirifos/farmacologia , Feminino , Longevidade , Permetrina/farmacologia
18.
Molecules ; 25(11)2020 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-32526905

RESUMO

Affibody molecules are the most studied class of engineered scaffold proteins (ESPs) in radionuclide molecular imaging. Attempts to use affibody molecules directly labelled with radiometals for targeted radionuclide therapy were hampered by the high uptake and retention of radioactivity in kidneys. Several promising strategies have been implemented to circumvent this problem. Here, we investigated whether a pharmacological approach targeting different components of the reabsorption system could be used to lower the uptake of [99mTc]Tc-ZHER:2395 affibody molecule in kidneys. Pre-injection of probenecid, furosemide, mannitol or colchicine had no influence on activity uptake in kidneys compared to the control group. Mice pre-injected with maleate and fructose had 33% and 51% reduction in the kidney-associated activity, respectively, compared to the control group. Autoradiography images showed that the accumulation of activity after [99mTc]Tc-ZHER2:2395 injection was in the renal cortex and that both maleate and fructose could significantly reduce it. Results from this study demonstrate that pharmacological intervention with maleate and fructose was effective in reducing the kidney uptake of affibody molecules. A presumable mechanism is the disruption of ATP-mediated cellular uptake and endocytosis processes of affibody molecules by tubular cells.


Assuntos
Quelantes/química , Frutose/farmacologia , Rim/metabolismo , Maleatos/farmacologia , Compostos de Organotecnécio/farmacocinética , Compostos Radiofarmacêuticos/farmacocinética , Proteínas Recombinantes de Fusão/farmacocinética , Animais , Inibidores Enzimáticos/farmacologia , Feminino , Rim/diagnóstico por imagem , Rim/efeitos dos fármacos , Camundongos , Imagem Molecular , Compostos de Organotecnécio/química , Cintilografia , Compostos Radiofarmacêuticos/química , Proteínas Recombinantes de Fusão/química , Edulcorantes/farmacologia , Distribuição Tecidual
19.
Int J Food Microbiol ; 324: 108614, 2020 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-32371237

RESUMO

Organic acids such as fumarate are commonly used as antimicrobials in foods. Apart from the classical mechanism of intracellular dissociation, weak acids are active through important additional mechanisms which are not well-defined. Fumarate, based on its low dissociation constants is expected to have a low antimicrobial activity which is not the case, suggesting additional antimicrobial effects. Previously, fumarate has been shown to inhibit the GAD system of E. coli and therefore, we investigated for first time how it affects this system in Listeria monocytogenes. We found that fumarate is highly antimicrobial towards L. monocytogenes under acidic conditions. We also show that in cell lysates and similarly to E. coli, fumarate inhibits the GAD system of L. monocytogenes. However, despite the inhibition and in contrast to E. coli, L. monocytogenes is able to counteract this and achieve a higher extracellular GAD output (measured by GABA export) in the presence of fumarate compared to its absence. The latter is achieved by a dramatic 9.44-fold increase in the transcription of gadD2 which is the main component of the extracellular GAD system. Interestingly, although maleate, the cis-isomer of fumarate results in a more dramatic 48.5-fold gadD2 upregulation than that of fumarate, the final GADe output is lower suggesting that maleate might be a stronger inhibitor of the GAD system. In contrast, the GADe removes more protons in the presence of fumarate than in the presence of HCl at the same pH. All the above suggest that there are additional effects by fumarate which might be associated with the intracellular GAD system (GADi) or other acid resistance systems. We assessed the GADi output by looking at the intracellular GABA pools which were not affected by fumarate. However, there are multiple pathways (e.g. GABA shunt) that can affect GABAi pools and we cannot conclusively suggest that GADi is affected. Furthermore, similarly to maleate, fumarate is able to eliminate L. monocytogenes in biofilms under acidic conditions. Overall, fumarate is a good candidate for L. monocytogenes decontamination and biofilm removal which is not toxic compared to the toxic maleate.


Assuntos
Antibacterianos/farmacologia , Inibidores Enzimáticos/farmacologia , Fumaratos/farmacologia , Glutamato Descarboxilase/antagonistas & inibidores , Listeria monocytogenes/efeitos dos fármacos , Proteínas de Bactérias/antagonistas & inibidores , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Glutamato Descarboxilase/genética , Glutamato Descarboxilase/metabolismo , Concentração de Íons de Hidrogênio , Listeria monocytogenes/genética , Listeria monocytogenes/metabolismo , Maleatos/farmacologia
20.
Biochim Biophys Acta Biomembr ; 1862(9): 183314, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32304757

RESUMO

α-Synuclein (αsyn) is a cytosolic intrinsically disordered protein (IDP) known to fold into an α-helical structure when binding to membrane lipids, decreasing protein aggregation. Model membrane enable elucidation of factors critically affecting protein folding/aggregation, mostly using either small unilamellar vesicles (SUVs) or nanodiscs surrounded by membrane scaffold proteins (MSPs). Yet SUVs are mechanically strained, while MSP nanodiscs are expensive. To test the impact of lipid particle size on α-syn structuring, while overcoming the limitations associated with the lipid particles used so far, we compared the effects of large unilamellar vesicles (LUVs) and lipid-bilayer nanodiscs encapsulated by diisobutylene/maleic acid copolymer (DIBMA) on αsyn secondary-structure formation, using human-, elephant- and whale -αsyn. Our results confirm that negatively charged lipids induce αsyn folding in h-αsyn and e-αsyn but not in w-αsyn. When a mixture of zwitterionic and negatively charged lipids was used, no increase in the secondary structure was detected at 45 °C. Further, our results show that DIBMA/lipid particles (DIBMALPs) are highly suitable nanoscale membrane mimics for studying αsyn secondary-structure formation and aggregation, as folding was essentially independent of the lipid/protein ratio, in contrast with what we observed for LUVs having the same lipid compositions. This study reveals a new and promising application of polymer-encapsulated lipid-bilayer nanodiscs, due to their excellent efficiency in structuring disordered proteins such as αsyn into nontoxic α-helical structures. This will contribute to the unravelling and modelling aspects concerning protein-lipid interactions and α-helix formation by αsyn, paramount to the proposal of new methods to avoid protein aggregation and disease.


Assuntos
Lipídeos de Membrana/química , Polímeros/farmacologia , Lipossomas Unilamelares/química , alfa-Sinucleína/química , Alcenos/química , Alcenos/farmacologia , Humanos , Proteínas Intrinsicamente Desordenadas/química , Bicamadas Lipídicas/química , Maleatos/química , Maleatos/farmacologia , Proteínas de Membrana/química , Polímeros/química , Agregados Proteicos/efeitos dos fármacos , Conformação Proteica em alfa-Hélice/efeitos dos fármacos , Dobramento de Proteína/efeitos dos fármacos , Estrutura Secundária de Proteína/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...