RESUMO
Herein, four silver(I) complexes bearing acetylated d-galactopyranoside-based N-heterocyclic carbene ligands were synthesized and fully characterized by elemental analysis, NMR, and X-ray photoelectron spectroscopy. All complexes were obtained with an anomeric ß-configuration and as monocarbene species. In this study, we investigated the biological effects of the silver(I) complexes 2a-d on the human rhabdomyosarcoma cell line, RD. Our results show concentration-dependent effects on cell density, growth inhibition, and activation of key signaling pathways such as Akt 1/2, ERK 1/2, and p38-MAPK, indicating their potential as anticancer agents. Notably, at 35.5 µM, the complexes induced mitochondrial network disruption, as observed with 2b and 2c, whereas with 2a, this disruption was accompanied by nuclear content release. These results provide insight into the utility of carbohydrate incorporated NHC complexes of silver(I) as new agents in cancer therapy.
Assuntos
Antineoplásicos , Proliferação de Células , Ensaios de Seleção de Medicamentos Antitumorais , Rabdomiossarcoma , Prata , Humanos , Acetilação , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Complexos de Coordenação/farmacologia , Complexos de Coordenação/química , Complexos de Coordenação/síntese química , Relação Dose-Resposta a Droga , Galactose/química , Galactose/farmacologia , Compostos Heterocíclicos/química , Compostos Heterocíclicos/farmacologia , Compostos Heterocíclicos/síntese química , Metano/química , Metano/análogos & derivados , Metano/farmacologia , Metano/síntese química , Estrutura Molecular , Rabdomiossarcoma/tratamento farmacológico , Rabdomiossarcoma/patologia , Prata/química , Prata/farmacologia , Relação Estrutura-AtividadeRESUMO
A new lectin from marine sponge Ircinia strobilina, denominated IsL, was isolated by combination of affinity chromatography in Guar gum matrix followed by size exclusion chromatography. IsL was able to agglutinate native and enzymatically treated rabbit erythrocytes, being inhibited by galactosides, such as α-methyl-D-galactopyranoside, ß-methyl-D-galactopyranoside and α-lactose. IsL hemagglutinating activity was stable at neutral to alkaline pH, however the lectin loses its activity at 40° C. The molecular mass determinated by mass spectrometry was 13.655 ± 5 Da. Approximately 40% of the primary structure of IsL was determined by mass spectrometry, but no similarity was observed with any protein. The secondary structure of IsL consists of 28% α-helix, 26% ß-sheet, and 46% random region, as determined by dichroism circular. IsL was a calcium-dependent lectin, but no significant variations were observed by circular dichroism when IsL was incubated in presence of calcium and EDTA. IsL was not toxic against Artemia nauplii and did not have antimicrobial activity against bacterial cells. However, the IsL was able to significantly inhibit the biofilm formation of Staphylococcus aureus and Staphylococcus epidermidis.
Assuntos
Lectinas , Poríferos , Animais , Coelhos , Lectinas/farmacologia , Galactose/metabolismo , Galactose/farmacologia , Cálcio/metabolismo , BiofilmesRESUMO
We, herein, investigated the in vitro effects of galactose on the activity of pyruvate kinase, succinate dehydrogenase (SDH), complex II and IV (cytochrome c oxidase) of the respiratory chain and Na+K+-ATPase in the cerebral cortex, cerebellum and hippocampus of 30-day-old rats. We also determined the influence of the antioxidants, trolox, ascorbic acid and glutathione, on the effects elicited by galactose. Galactose was added to the assay at concentrations of 0.1, 3.0, 5.0 and 10.0 mM. Control experiments were performed without galactose. Galactose, at 3.0, 5.0 and 10.0 mM, decreased pyruvate kinase activity in the cerebral cortex and at 10.0 mM in the hippocampus. Galactose, at 10.0 mM, reduced SDH and complex II activities in the cerebellum and hippocampus, and reduced cytochrome c oxidase activity in the hippocampus. Additionally, decreased Na+K+-ATPase activity in the cerebral cortex and hippocampus; conversely, galactose, at 3.0 and 5.0 mM, increased this enzyme's activity in the cerebellum. Data show that galactose disrupts energy metabolism and trolox, ascorbic acid and glutathione addition prevented the majority of alterations in the parameters analyzed, suggesting the use of antioxidants as an adjuvant therapy in Classic galactosemia.
Assuntos
Antioxidantes , Galactose , Ratos , Animais , Antioxidantes/farmacologia , Galactose/metabolismo , Galactose/farmacologia , Complexo IV da Cadeia de Transporte de Elétrons , Piruvato Quinase/metabolismo , Piruvato Quinase/farmacologia , Ratos Wistar , Ácido Ascórbico/farmacologia , Ácido Ascórbico/metabolismo , Metabolismo Energético , Encéfalo/metabolismo , Glutationa/metabolismo , Adenosina Trifosfatases/metabolismo , Adenosina Trifosfatases/farmacologiaRESUMO
Classic galactosemia is an inborn error of metabolism caused by deleterious mutations on the GALT gene, which encodes the Leloir pathway enzyme galactose-1-phosphate uridyltransferase. Previous studies have shown that the endoplasmic reticulum unfolded protein response (UPR) is relevant to galactosemia, but the molecular mechanism behind the endoplasmic reticulum stress that triggers this response remains elusive. In the present work, we show that the activation of the UPR in yeast models of galactosemia does not depend on the binding of unfolded proteins to the ER stress sensor protein Ire1p since the protein domain responsible for unfolded protein binding to Ire1p is not necessary for UPR activation. Interestingly, myriocin - an inhibitor of the de novo sphingolipid synthesis pathway - inhibits UPR activation and causes galactose hypersensitivity in these models, indicating that myriocin-mediated sphingolipid depletion impairs yeast adaptation to galactose toxicity. Supporting the interpretation that the effects observed after myriocin treatment were due to a reduction in sphingolipid levels, the addition of phytosphingosine to the culture medium reverses all myriocin effects tested. Surprisingly, constitutively active UPR signaling did not prevent myriocin-induced galactose hypersensitivity suggesting multiple roles for sphingolipids in the adaptation of yeast cells to galactose toxicity. Therefore, we conclude that sphingolipid homeostasis has an important role in UPR activation and cellular adaptation in yeast models of galactosemia, highlighting the possible role of lipid metabolism in the pathophysiology of this disease.
Assuntos
Galactosemias , Galactose/metabolismo , Galactose/farmacologia , Galactosemias/metabolismo , Humanos , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Esfingolipídeos/metabolismo , UTP-Hexose-1-Fosfato Uridililtransferase/metabolismoRESUMO
Erectile dysfunction (ED) is defined as the inability to achieve and/or maintain penile erection sufficient for satisfactory sexual relations, and aging is one of the main risk factors involved. The D-(+)-Galactose aging model is a consolidated methodology for studies of cardiovascular aging; however, its potential for use with ED remain unexplored. The present study proposed to characterize a new experimental model for ED, using the D-(+)-Galactose aging model. For the experiments, the animals were randomly divided into three groups receiving: vehicle (CTL), D-galactose 150 mg/kg (DGAL), and D-(+)-galactose 150 mg/Kg + sildenafil 1.5 mg/Kg (DGAL+SD1.5) being administered daily for a period of eight weeks. All of the experimental protocols were previously approved by the Ethics Committee on the Use of Animals at the Federal University of Paraíba n° 9706070319. During the treatment, we analyzed physical, molecular, and physiological aspects related to the aging process and implicated in the development of ED. Our findings demonstrate for the first time that D-(+)-Galactose-induced aging represents a suitable experimental model for ED assessment. This was evidenced by an observed hyper-contractility in corpora cavernosa, significant endothelial dysfunction, increased ROS levels, an increase in cavernous tissue senescence, and the loss of essential penile erectile components.
Assuntos
Envelhecimento , Disfunção Erétil/etiologia , Galactose/efeitos adversos , Envelhecimento/efeitos dos fármacos , Animais , Modelos Animais de Doenças , Estimulação Elétrica , Disfunção Erétil/metabolismo , Galactose/farmacologia , Masculino , Ereção Peniana , Pênis/patologia , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Citrato de Sildenafila/efeitos adversos , Citrato de Sildenafila/farmacologiaRESUMO
In the presence of galactose, lithium ions activate the unfolded protein response (UPR) by inhibiting phosphoglucomutase activity and causing the accumulation of galactose-related metabolites, including galactose-1-phosphate. These metabolites also accumulate in humans who have the disease classic galactosemia. Here, we demonstrate that Saccharomyces cerevisiae yeast strains harboring a deletion of UBX4, a gene encoding a partner of Cdc48p in the endoplasmic reticulum-associated degradation (ERAD) pathway, exhibit delayed UPR activation after lithium and galactose exposure because the deletion decreases galactose-1-phosphate levels. The delay in UPR activation did not occur in yeast strains in which key ERAD or proteasomal pathway genes had been disrupted, indicating that the ubx4Δ phenotype is ERAD-independent. We also observed that the ubx4Δ strain displays decreased oxygen consumption. The inhibition of mitochondrial respiration was sufficient to diminish galactose-1-phosphate levels and, consequently, affects UPR activation. Finally, we show that the deletion of the AMP-activated protein kinase ortholog-encoding gene SNF1 can restore the oxygen consumption rate in ubx4Δ strain, thereby reestablishing galactose metabolism, UPR activation, and cellular adaption to lithium-galactose challenge. Our results indicate a role for Ubx4p in yeast mitochondrial function and highlight that mitochondrial and endoplasmic reticulum functions are intertwined through galactose metabolism. These findings also shed new light on the mechanisms of lithium action and on the pathophysiology of galactosemia.
Assuntos
Galactose/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Lítio/farmacologia , Mitocôndrias/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Resposta a Proteínas não Dobradas/efeitos dos fármacos , Fatores de Transcrição de Zíper de Leucina Básica/genética , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Retículo Endoplasmático/metabolismo , Galactose/metabolismo , Galactosefosfatos/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/deficiência , Peptídeos e Proteínas de Sinalização Intracelular/genética , Consumo de Oxigênio , Proteínas Serina-Treonina Quinases/deficiência , Proteínas Serina-Treonina Quinases/genética , Splicing de RNA , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Proteínas de Saccharomyces cerevisiae/genéticaRESUMO
The brown seaweed Scytosiphon lomentaria produces moderate amounts of fucoidans. By cetrimide fractionation, typical heavily sulfated galactofucans are obtained, with no major signs of chemical heterogeneity, together with fractions with higher proportions of xylose, mannose and uronic acids. Anyway, fucose is the most important monosaccharide in most of the subfractions of the subsequent extracts. The fucan moieties appear to be mostly as 3-linked α-l-fucopyranosyl units, with several patterns of sulfate and branching. Galactose is mostly 6-linked, whereas mannose appears to be 2-linked, and xylose appears mostly as terminal stubs. Small amounts of 2-O-acetylated fucose units appear. A high and selective antiviral activity against HSV-1 and HSV-2 was determined for the galactofucan fractions whereas the uronofucoidans were inactive.
Assuntos
Antivirais/farmacologia , Fucose/farmacologia , Galactose/farmacologia , Herpesvirus Humano 1/efeitos dos fármacos , Herpesvirus Humano 2/efeitos dos fármacos , Polissacarídeos/farmacologia , Antivirais/química , Antivirais/isolamento & purificação , Configuração de Carboidratos , Fucose/química , Fucose/isolamento & purificação , Galactose/química , Galactose/isolamento & purificação , Testes de Sensibilidade Microbiana , Phaeophyceae/química , Polissacarídeos/química , Polissacarídeos/isolamento & purificaçãoRESUMO
Menopause is associated with bone loss. Prebiotics increase Ca, inorganic phosphorus (Pi), and Mg absorption, improving bone health. These increases would supply an extra amount of minerals, decreasing bone resorption and possibly reversing ovariectomy-induced bone loss. The present experimental study sought to evaluate the effect of adding a prebiotic GOS/FOS® mixture to a normal or a low Ca diet on Ca, Pi, and Mg absorption, in osteopenic rats. Four groups of n = 8 rats each were OVX, and 8 rats were SHAM operated. All rats were fed a commercial diet for 45 days. They were then fed one of the following diet for 45 days: C-0.5%: SHAM fed AIN 93 M containing 0.5%Ca; O-0.5% and O-0.3%: OVX rats fed AIN 93 M, containing 0.5% or 0.3%Ca, respectively; GF-0.5% and GF-0.3%: OVX rats fed AIN 93 M, containing 0.5% or 0.3%Ca+ 2.5% GOS/FOS®, respectively. At the end of the experimental time point, Ca, P, and MgAbs% was significantly higher in GF-0.5% and GF-0.3% as compared to the remaining groups (p < 0.01). Irrespective of diet Ca content, CTX decreased whereas femur Ca and P content, tibia BV/TV and GPC.Th, lumbar spine and proximal tibia BMD, bone strength, bone stiffness, and elastic modulus increased in the GF-0.5% and GF-0.3% groups as compared to O-0.5% and O-0.3%, respectively (p < 0.05). This prebiotic mixture would be a useful tool to prevent the increase in bone loss associated with menopause and aging.
Assuntos
Doenças Ósseas Metabólicas/metabolismo , Osso e Ossos/efeitos dos fármacos , Cálcio da Dieta , Dieta , Absorção Intestinal/efeitos dos fármacos , Oligossacarídeos/farmacologia , Animais , Densidade Óssea/efeitos dos fármacos , Doenças Ósseas Metabólicas/etiologia , Doenças Ósseas Metabólicas/patologia , Osso e Ossos/fisiologia , Cálcio/deficiência , Cálcio/metabolismo , Cálcio/farmacocinética , Cálcio da Dieta/administração & dosagem , Cálcio da Dieta/farmacocinética , Dieta/métodos , Suplementos Nutricionais , Feminino , Frutose/química , Frutose/farmacologia , Galactose/química , Galactose/farmacologia , Oligossacarídeos/administração & dosagem , Ovariectomia , Ratos , Ratos WistarRESUMO
Aging is a complex biological process. Epigenetic alterations have been related to both aging and memory decline. Included amongst these alterations is histone acetylation, which may play a crucial role in aging. Thus, the aims of the present study were to standardize the animal model of d-galactose (d-gal), and to evaluate the effects caused by sodium butyrate (SB), which is a histone deacetylase inhibitor on memory, the modulation of histone deacetylases (HDACs), and also DNA damage in 2, 6 or 16-month-old Wistar rats which were subjected to administrations of d-gal. To help choose the best dose of d-gal for the induction of the aging model, we performed a dose-response curve (100, 200 or 300â¯mg/kg). d-Gal was administered orally to the 2-month-old rats for a period of 30â¯days. After this, d-gal (200â¯mg/kg) or water were administered to the 2, 6 or 16-month-old rats for a period of 30â¯days. On the 24th day, treatment was started with SB (600â¯mg/kg) intraperitoneally, for a period of 7â¯days. SB was able to reverse the damage to habituation memory caused by d-gal in the 2 and 6-month-old rats, but was unable to reverse the damage in the 16â¯month-old animals. In addition, SB was able to reverse the damage caused by natural aging in the 16-month-old animals. In the inhibitory avoidance task, SB improved the damage caused by d-gal in the 2, 6 and 16-month-old animals and had the same result against the effects of natural aging in the 16-month-old rats. Moreover, d-gal caused an increase in the level of HDACs activity in the 16-month-old animals, and SB was able to reverse this effect in the frontal cortex and hippocampus. The 16-month-old animals showed an increase in the frequency of DNA damage in peripheral blood, and SB was able to reduce this damage. Moreover, d-gal caused an increase in the index and frequency of DNA damage in the 2 and 6-month-old animals, and treatment with SB was able to prevent this damage. Thus, the present study showed the protective effects of SB on the memory of naturally aged and d-gal induced aging in rats. Therefore, the present study shows new findings for the use of SB in aging.
Assuntos
Envelhecimento/efeitos dos fármacos , Ácido Butírico/farmacologia , Galactose/farmacologia , Inibidores de Histona Desacetilases/farmacologia , Memória/efeitos dos fármacos , Animais , Encéfalo/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Modelos Animais de Doenças , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Ratos , Ratos WistarRESUMO
A series of hybrids containing tacrine linked to carbohydrate-based moieties, such as d-xylose, d-ribose, and d-galactose derivatives, were synthesized by the nucleophilic substitution between 9-aminoalkylamino-1,2,3,4-tetrahydroacridines and the corresponding sugar-based tosylates. All compounds were found to be potent inhibitors of both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) in the nanomolar IC50 scale. Most of the d-xylose derivatives (6a-e) were selective for AChE and the compound 6e (IC50â¯=â¯2.2â¯nM for AChE and 4.93â¯nM for BuChE) was the most active compound for both enzymes. The d-galactose derivative 8a was the most selective for AChE exhibiting an IC50 ratio of 7.6 for AChE over BuChE. Only two compounds showed a preference for BuChE, namely 7a (d-ribose derivative) and 6b (d-xylose derivative). Molecular docking studies indicated that the inhibitors are capable of interacting with the entire binding cavity and the main contribution of the linker is to enable the most favorable positioning of the two moieties with CAS, PAS, and hydrophobic pocket to provide optimal interactions with the binding cavity. This finding is reinforced by the fact that there is no linear correlation between the linker size and the observed binding affinities. The majority of the new hybrids synthesized in this work do not violate the Lipinski's rule-of-five according to FAF-Drugs4, and do not demonstrated predicted hepatotoxicity according ProTox-II.