RESUMO
In this study, an electrospray synthesis approach was utilized in which a solution mixture of a sensitive bioactive agent, d-limonene (DL, R-(+)-Limonene), and a nature-inspired polymer, κ-carrageenan (κC) was applied to design DL-κC nanoparticles (NPs) in a one step process. The engineered DL-κC NPs displayed spherical morphology and the maximum encapsulation efficiency of NPs was about 97 % by altering the mass ratio of DL to κC. The developed DL-κC NPs showed a pH-dependent release manner in vitro. Both photostability and thermostability of DL were promoted by increasing the κC concentration, and >85 % of the original DL could be preserved following 120 min of UV-light exposure in the NPs with 0.5 % κC. The results demonstrated that electrosprayed κC NPs are promising candidates for the design of high-loading pH-sensitive NPs for encapsulation of highly sensitive bioactive agents.
Assuntos
Nanopartículas , Carragenina , PolímerosRESUMO
This study evaluated the effect of molecular weight of chitosan (3 kDa,150 kDa, 400 kDa, and 600 kDa) on zein-nisin-chitosan nanocomplexes. The formation mechanism, physicochemical and antibacterial properties of the nanocomplexes (ZNC0.3, ZNC15, ZNC40, and ZNC60) were assessed. The nanocomplexes were characterized by DLS, ζ-potential, atomic force microscopy, scanning electron microscopy, circular dichroism, fourier transform infrared and UV-Vis spectroscopy. The results showed that the lowest molecular weight chitosan (LMWC, 3 kDa) formed nanocomplexes with nisin and zein structurally differed from the higher molecular weights chitosan (HMWC, >3 kDa). LMWC was doped on the surface of the nanocomplexes. HMWC linked and formed a network to adsorb zein and nisin. The antibacterial activity against Staphylococcus aureus showed that the minimum inhibitory concentration of ZNC0.3, ZNC15, ZNC40, and ZNC60 was 7.0625, 14.125, 14.125, and 28.25 µg/mL. ZNC0.3 could be a suitable nisin delivery system for its high encapsulation efficiency (85.38%) and antibacterial properties.
Assuntos
Quitosana , Nisina , Zeína , Antibacterianos/química , Antibacterianos/farmacologia , Quitosana/química , Quitosana/farmacologia , Peso Molecular , Nisina/química , Nisina/farmacologiaRESUMO
In an attempt to optimize the anti- hyperlipidemic effect and reduce statins induced hepatotoxicity, Atorvastatin Calcium (ATC) transdermal proniosomal gel (PNG) was developed. Different non-ionic surfactants (NISs) (Spans, Tweens, Cremophor RH 40 and Brij 52) were incorporated in the vesicle's lipid bilayer, in combination with lecithin. PNG formulae were characterized for encapsulation efficiency percent (% EE), vesicle size, polydispersity index (PDI) and zeta potential (ZP). Ex-vivo permeation study was performed using full thickness rat skin measuring drug flux and skin permeability coefficients. The pharmacodynamic performance of optimized transdermal ATC- PNG on both lipid profile and liver biomarkers was assessed and compared to oral ATC administration in poloxamer 407-induced hyperlipidemic rats. The liver tissues were subjected to histological examination as well. The results revealed nano-size range vesicles with relatively high ATC entrapment efficiency. Ex-vivo results demonstrated the permeation superiority of ATC proniosomes over free drug. Pharmacodynamic study revealed that transdermal administration of ATC- PNG succeeded in retaining the anti-hyperlipidemic efficacy of orally administered ATC without elevating liver biomarkers. The histological examination signified the role of optimized ATC-PNG in hindering statin- induced hepatocellular damage. The obtained results suggested a promising, easy-to-manufacture and effective ATC proniosomal gel for safe treatment of hyperlipidemia.
Assuntos
Doença Hepática Induzida por Substâncias e Drogas , Hiperlipidemias , Administração Cutânea , Animais , Atorvastatina , Disponibilidade Biológica , Hiperlipidemias/induzido quimicamente , Hiperlipidemias/tratamento farmacológico , Poloxâmero , Ratos , Absorção CutâneaRESUMO
Simultaneous reduction in activity of fat destabilizing enzymes (lipase and lipoxygenase), contaminants heavy metals (As, Cd, Pb, and Hg), antinutrient phytic acid and hazardous coliforms in rice bran was investigated. Application of washing, soaking the washed sample at different pH values (2, 6 and 9) alone or in combination with ultrasonication were examined. While washing was beneficial, its low efficiency acquired further treatment, which was prevailed by application of acidic pH and ultrasound (28 kHz) treatments. Free fatty acids and peroxide value, as indicators of enzymes activity, implied the effectiveness of treatments with adverse impact of sonication on peroxide value. Remarkably, reduction of dominant heavy metals (As, Pb and Zn) and phytic acid were synergistically facilitated by sonication. Coliforms growth was inhibited at pH 2 even at the absence of ultrasonic treatment. Evidently, combination of acidic pH and ultrasound is a practical approach to improve rice bran stability and safety.
Assuntos
Análise de Alimentos , Lipase/análise , Lipoxigenase/análise , Metais Pesados/análise , Oryza/química , Ácido Fítico/análise , Concentração de Íons de Hidrogênio , Proteínas de Plantas/análiseRESUMO
Proniosomes are free-flowing powders composed of water-soluble carriers blended with surfactants, which form niosomes upon hydration. In this work, proniosomal formulations containing the natural antioxidant resveratrol (RSV) were prepared and fully characterized. A pre-formulation study on RSV-loaded niosomes was carried out to determine the most promising ratio between the two surfactants, Tween 20 and Span 60, in terms of entrapment efficiency and antioxidant activity. The optimized formulae were subsequently adapted to be prepared as proniosomes by the slurry method, including lactose or maltodextrin as carriers. The impact of surfactants and carriers properties on size, entrapment efficiency and release kinetics of proniosomes were evaluated. In vitro release of RSV in simulated gastric and intestinal media was determined, as well as the vesicular stability. Moreover, the biocompatibility of the formulations was determined on intestinal cells in vitro. Overall, the developed proniosomes provide promising nanoingredient for functional food, improving resveratrol stability and bioavailability.
Assuntos
Alimento Funcional , Lipossomos/química , Resveratrol/química , Resveratrol/farmacocinética , Antioxidantes/química , Disponibilidade Biológica , Hexoses/química , Humanos , Polissacarídeos/química , Polissorbatos/química , Pós , Tensoativos/químicaRESUMO
Starch nanoparticles (SNPs) are a promising choice for the strategic development of new renewable and biodegradable nanomaterials for novel biomedical and pharmaceutical applications when loaded with antibiotics or with anticancer agents as target drug delivery systems. The final properties of the SNPs are strongly influenced by the synthesis method and conditions being a controlled and monodispersed size crucial for these applications. The aim of this work was to synthesize controlled size SNPs through nanoprecipitation and microemulsion methods by modifying main operating parameters regarding the effect of amylose and amylopectin ratio in maize starches. SNPs were characterized by size and shape. SNPs from 59 to 118 nm were obtained by the nanoprecipitation method, registering the higer values when surfactant was added to the aqueous phase. Microemulsion method led to 35-147 nm sizes observing a higher particle formation capacity. The composition of the maize used influenced the final particle size and shape.
RESUMO
A nanoemulsion system was designed for Atorvastatin calcium (ATOR) transdermal delivery to overcome its poor bioavailability of (30%) resulting from the extensive first-pass effect and dissolution rate-limited in vivo absorption. Pseudo ternary phase diagrams were developed, and various NE formulae were prepared using oleic acid (OA), Tween 80 as surfactant and PEG 400 as cosurfactant, ethanol and limonene as permeation enhancers (PEs). NEs were characterized for morphology, droplet size, zeta potential and in vitro release. The optimized formulae were assessed for ex vivo transdermal permeation and in vivo pharmacodynamic/pharmacokinetic studies. Hypocholesterolemic effect after 7 days skin treatment was detected and compared to oral ATOR dispersion. Finally, blood plasma levels were measured for 24 h for rats received the selected transdermal NE and transdermal drug in OA. The obtained results suggested the low potentiality of NE systems in transdermal delivery of lipophilic drugs, only the addition of PEs is driving factor for increasing drug flux through full thickness rat skin. In the optimized formula, the presence of ethanol and PEG 400 disrupts SC lipids exhibiting rapid ex vivo release profile compared to other NEs and to ATOR in OA. In contrast, the optimized NE achieved a prolonged plasma profile. Transdermal NE was significantly more efficient than oral administration in lowering cholesterol plasma level and in increasing ATOR bioavailability. In conclusion, data revealed no correlation between ex vivo and in vivo studies explained by the collapse of the follicles in ex vivo skin permeation study, leaving only the lipoidal pathway for NE to pass through, thus only NE components, neither nanosizing nor other reported mechanisms, are the main influencing factors. In vivo experiments suggested that o/w NE changed ATOR pathway to follicular delivery leading to accumulation of NE in follicles and consequently a prolonged plasma profile.
Assuntos
Atorvastatina/administração & dosagem , Inibidores de Hidroximetilglutaril-CoA Redutases/administração & dosagem , Nanopartículas/administração & dosagem , Administração Cutânea , Animais , Atorvastatina/química , Atorvastatina/farmacocinética , Disponibilidade Biológica , Liberação Controlada de Fármacos , Emulsões , Inibidores de Hidroximetilglutaril-CoA Redutases/química , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacocinética , Nanopartículas/química , Ácido Oleico/administração & dosagem , Ácido Oleico/química , Polietilenoglicóis/administração & dosagem , Polietilenoglicóis/química , Polissorbatos/administração & dosagem , Polissorbatos/química , Ratos Wistar , Pele/metabolismo , Absorção Cutânea , SolubilidadeRESUMO
A water-soluble polysaccharide from Monostroma nitidum, designated MWS, was isolated using water extraction, anion-exchange and size-exclusion chromatography. MWS was a sulfated glucuronorhamnan consisting of â3)-α-l-Rhap-(1â, â4)-ß-d-GlcpA-(1â and â2)-α-l-Rhap-(1â units. Sulfate ester groups located at C-4/C-2 of â3)-α-l-Rhap-(1â and C-4/C-3 of â2)-α-l-Rhap-(1â units. In in vitro tests, it was proved that MWS possessed broad spectrum against different viruses, especially for enterovirus 71 (EV71) with nearly no toxicity in relation to cell lines used. MWS may largely inhibit EV71 infection before or during viral adsorption through binding to virus particles and block some early steps of virus life cycle by down-regulating host phosphoinositide 3-kinase /protein kinase B signaling pathway. Intramuscular injection of MWS markedly reduced viral titers in EV71-infected mice. The data demonstrated that MWS could have great promising to become an antiviral drug for prevention and therapy of EV71 infection.
Assuntos
Antivirais/uso terapêutico , Clorófitas , Enterovirus Humano A/efeitos dos fármacos , Infecções por Enterovirus/tratamento farmacológico , Mananas/uso terapêutico , Sulfatos/uso terapêutico , Animais , Antivirais/química , Antivirais/farmacologia , Chlorocebus aethiops , Cães , Infecções por Enterovirus/virologia , Feminino , Células Madin Darby de Rim Canino , Mananas/química , Mananas/farmacologia , Camundongos Endogâmicos ICR , Estrutura Molecular , Alga Marinha , Sulfatos/química , Sulfatos/farmacologia , Células VeroRESUMO
Considering the health risks of E. coli O157:H7 presence in food and water, an affordable and highly sensitive detection method is crucial. Herein, we report the first use of a single antibody-based fluorescent lateral flow immunoassay (FLFIA) depending on non-radiative energy transfer between graphene oxide and quantum dots for determination of E. coli O157:H7 in beef and river water. FLFIA showed a high sensitivity rate thousand-fold better than the conventional lateral flow (LF). In inoculated minced beef and river water samples, the limits of detection were 178 and 133â¯CFUâ¯g-1 or mL-1, respectively. Besides, it presented a high selectivity in the presence of other possible interfering bacteria. The single antibody approach reduced the assay cost to 60% less than the conventional LF. Alongside, the results could be read by portable LF readers or smartphones. These advantages offer FLFIA as a promising technology for pathogen detection in food and water.
Assuntos
Escherichia coli O157 , Microbiologia de Alimentos/instrumentação , Microbiologia de Alimentos/métodos , Imunoensaio/métodos , Carne Vermelha/microbiologia , Animais , Anticorpos , Bovinos , Desenho de Equipamento , Escherichia coli O157/imunologia , Corantes Fluorescentes/química , Microbiologia de Alimentos/economia , Grafite , Imunoensaio/economia , Imunoensaio/instrumentação , Óxidos , Pontos Quânticos , Rios/microbiologia , Sensibilidade e Especificidade , Smartphone , Microbiologia da ÁguaRESUMO
Surfactant and microwave assisted extraction (S-MAE) was used for pectin extraction from orange peel. First, we optimized the conditions of microwave assisted extraction (MAE), e.g., irradiation time, liquid-to-solid ratio (LSR), and pH on pectin yield (PY), galacturonic acid (GA) content, and degree of esterification (DE) using a Box-Behnken design. Under optimal conditions (pH 1.2, 7.0â¯min, and 21.5 v/w LSR), we obtained a PY of 28.0⯱â¯0.5%, which was close to the predicted value (31.1%). Second, we analyzed the effect of surfactant on microwave extraction of pectin. Among the surfactants investigated, Tween-80 (8â¯g/L, w/v) increased PY by 17.0%. Compared with conventional solvent extraction, S-MAE is a novel and efficient method for pectin extraction, which generated a higher (pâ¯<â¯0.05) PY (32.8%), GA content (78.1%), DE (69.8%), and Mw (286.3â¯kDa).
Assuntos
Citrus sinensis/metabolismo , Micro-Ondas , Pectinas/química , Tensoativos/química , Cromatografia Líquida de Alta Pressão , Esterificação , Ácidos Hexurônicos/química , Concentração de Íons de Hidrogênio , Pectinas/isolamento & purificação , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
Polysaccharide from Monostroma latissimum PML is a sulfated rhamnan, which consists of â3)-α-L-Rhap-(1â and â2)-α-L-Rhap-(1â residues with partial branches and sulfate groups at C-2 of â3)-α-L-Rhap-(1â and/or C-3 of â2)-α-L-Rhap-(1â. The anti-enterovirus 71 (EV71) activity in vitro of PML was assessed by cytopathic effect inhibition and plaque reduction assays, and the results showed that PML was non-cytotoxic and significantly inhibited EV71 infection. The mechanism analysis of anti-EV71 activity demonstrated that PML largely inhibited viral replication before or during viral adsorption, mainly by targeting the capsid protein VP1. PML may also inhibit some early steps of infection after viral adsorption by modulating signaling through the epidermal growth factor receptor (EGFR)/phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) pathway. Moreover, PML markedly improved survival and decreased viral titers in EV71-infected mice. The investigation revealed that PML has potential as a novel anti-EV71 agent targeting the viral capsid protein as well as cellular EGFR/PI3K/Akt pathway.
Assuntos
Antivirais/química , Antivirais/farmacologia , Clorófitas/química , Desoxiaçúcares/química , Desoxiaçúcares/farmacologia , Enterovirus Humano A/efeitos dos fármacos , Mananas/química , Mananas/farmacologia , Sulfatos/química , Animais , Antivirais/isolamento & purificação , Sequência de Carboidratos , Chlorocebus aethiops , Desoxiaçúcares/isolamento & purificação , Enterovirus Humano A/fisiologia , Mananas/isolamento & purificação , Camundongos , Células Vero , Carga Viral/efeitos dos fármacosRESUMO
The clinical use of paclitaxel as a chemotherapeutic agent is limited by the severe acute and chronic hypersensitivity caused when it is administered via intraperitoneal or intravenous routes. Thus far, evidence has suggested that transient receptor potential vanilloid-1 (TRPV1) has a key role in the chronic neuropathy induced by paclitaxel. Despite this, the role of TRPV1 in paclitaxel -related acute nociception, especially the development of visceral nociception, has not been evaluated. Thus, the goal of this study was to evaluate the participation of TRPV1 in a model of acute nociception induced by paclitaxel in rats and mice. A single intraperitoneal (i.p.) paclitaxel administration (1â¯mg/kg, i.p.) produced an immediate visceral nociception response 1â¯h after administration, caused mechanical and heat hypersensitivity, and diminished burrowing behaviour 24â¯h after administration. These nociceptive responses were reduced by SB-366791 treatment (0.5â¯mg/kg, i.p., a TRPV1 antagonist). In addition, TRPV1-positive sensory fibre ablation (using resiniferatoxin, 200⯵g/kg, s.c.) reduced visceral nociception and mechanical or heat hypersensitivity caused by paclitaxel injection. Similarly, TRPV1 deficient mice showed a pronounced reduction in mechanical allodynia to paclitaxel acute injection and did not develop heat hypersensitivity. Moreover, 24â¯h after its injection, paclitaxel induced chemical hypersensitivity to capsaicin (a TRPV1 agonist, 0.01 nmol/site) and increased TRPV1 immunoreactivity in the dorsal root ganglion and sciatic nerve. In conclusion, TRPV1 is involved in mechanical and heat hypersensitivity and spontaneous-pain behaviour induced 24â¯h after a single paclitaxel injection. This receptor is also involved in visceral nociception induced immediately after paclitaxel administration.
Assuntos
Nociceptividade/efeitos dos fármacos , Paclitaxel/efeitos adversos , Canais de Cátion TRPV/metabolismo , Dor Aguda/induzido quimicamente , Dor Aguda/metabolismo , Dor Aguda/fisiopatologia , Animais , Masculino , Camundongos , Ratos , Xantofilas/farmacologiaRESUMO
Snakebite envenoming is a major neglected disease related to poverty in developing countries. Treatment involves the administration of a specific antivenom serum and auxiliary therapies, if necessary. The improvement of antibodies is of great importance for the technological advancement of antivenom therapy and to reduce the morbidity and mortality associated with this medical burden. In the present study, adult hens were immunized nine times with 20µg of B. arietans or C. d. terrificus venoms at three-week intervals between immunizations. Developing antibodies presented increasing avidity and affinity to antigenic toxin epitopes along immunization, attaining a plateau after the seventh immunization. Pooled egg yolk-purified IgY antivenom antibodies, subjected to in vitro-in vivo lethality assay using Swiss adult mice, exhibited potent venom lethal neutralizing activity. Taken together, chickens under the described immunization schedule were considered alternative candidates for antivenom production. Lower maintenance costs, a simple antibody manufacturing process and immunization suffering restrictions are additional advantages.
Assuntos
Antitoxinas/imunologia , Venenos de Crotalídeos/imunologia , Imunoglobulinas/imunologia , Animais , Bothrops , Galinhas , Crotalus , Feminino , CamundongosRESUMO
Two field experiments were conducted over three growing seasons (2006-07, 2008-09 and 2009-10) to evaluate Se-enriched pasta through foliar fertilization at various rates and timing of application on 4 durum wheat varieties. Our findings confirm the effectiveness of foliar Se fertilization to increase Se concentrations in durum wheat grain, even at high Se rates (120gSeha(-1)). Se fortification was significant across different genotypes, with greater Se accumulation in landraces ('Timilia') and obsolete varieties ('Cappelli'), with respect to modern varieties. The Se content in the grain was increased by up to 35-fold that of the untreated control. The Se concentration decreased during milling (11%), while processing and cooking of pasta did not show significant decreases. This biofortification stategy had no effects on grain quality parameters, except for reduced gluten index in the high-gluten variety PR22D89, as well as for the sensorial properties of the spaghetti.
Assuntos
Grão Comestível/classificação , Alimentos Fortificados , Glutens/análise , Selênio/análise , Triticum/química , Culinária , Valor Nutritivo , Triticum/genéticaRESUMO
Tropomyosin (TM), a myofibrillar protein, is a major allergen in shrimp. The aim of this study was to evaluate the effect of transglutaminase (TGase)-catalyzed glycosylation on the potential allergenicity and conformational structure of TM in Metapenaeus ensis. Results showed that glycosylation of TM induced unfolding of the primary protein structure followed by loss of the secondary structure. Cleavage of certain free amino groups was observed during TGase-catalyzed glycosylation. The glycosylation rate correlated with reaction temperature. Western blotting and indirect ELISA with TM-specific polyclonal antibodies from rabbit and sera from patients allergic to shrimp demonstrated that antigenicity and potential allergenicity of TM decreased, which correlated well with the conformational changes in its structure. Considering TGase is widely utilized in the food industry, these results indicate that TGase-catalyzed glycosylation has the potential to serve as a mild method for reducing the allergenicity of shrimp products.
Assuntos
Penaeidae/química , Hipersensibilidade a Frutos do Mar/imunologia , Frutos do Mar/análise , Transglutaminases/metabolismo , Tropomiosina/química , Tropomiosina/imunologia , Alérgenos/imunologia , Animais , Western Blotting , Ensaio de Imunoadsorção Enzimática , Glicosilação , Humanos , Conformação Proteica , Estrutura Secundária de Proteína , CoelhosRESUMO
Oxidative stress aggravates renal fibrosis, a pathway involved in almost all forms of chronic kidney disease (CKD). However, the underlying mechanism involved in the pathogenesis of renal oxidative stress has not been completely elucidated. In this study, we explored the role and mechanism of hypochlorite-modified albumin (HOCl-alb) in mediating oxidative stress and fibrotic response in a remnant-kidney rat model. Five-sixths nephrectomy (5/6 NX) was performed on the rats and then the animals were randomly assigned to intravenous treatment with either vehicle alone, or HOCl-rat serum albumin (RSA) in the presence or absence of SS-31 (administered intraperitoneally). A sham-operation control group was set up concurrently. Compared with the control group, 5/6 NX animals displayed marked mitochondrial (mt) dysfunction, as evidenced by decrease of mitochondrial membrane potential (MMP), ATP production, mtDNA copy number alterations and manganese superoxide dismutase (MnSOD) activity, release of cytochrome C (Cyto C) from mitochondria to the cytoplasm, and increase of mitochondrial reactive oxygen species in renal tissues. They also displayed increased levels of HOCl-alb in both plasma and renal tissues. These changes were accompanied by accumulation of extracellular matrix, worsened proteinuria, deteriorated renal function, and a marked increase of macrophage infiltration along with up-regulation of monocyte chemoattractant protein (MCP)-1 and transforming growth factor (TGF)-ß1 expression. HOCl-alb challenge further exacerbated the above biological effects in 5/6 NX animals, but these adverse effects were prevented by administration of SS-31, a mitochondrial targeted antioxidant peptide. These data suggest that accumulation of HOCl-alb may promote renal inflammation and fibrosis, probably related to mitochondrial oxidative stress and dysfunction and that the mitochondrial targeted peptide SS-31 might be a novel therapy for renal fibrosis and chronic renal failure (CRF).
Assuntos
Antioxidantes/farmacologia , Ácido Hipocloroso/química , Rim/efeitos dos fármacos , Rim/patologia , Mitocôndrias/efeitos dos fármacos , Oligopeptídeos/farmacologia , Albumina Sérica/farmacologia , Animais , Biomarcadores/metabolismo , Citoproteção/efeitos dos fármacos , Matriz Extracelular/efeitos dos fármacos , Matriz Extracelular/metabolismo , Fibrose , Rim/metabolismo , Rim/fisiologia , Mitocôndrias/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ratos Sprague-Dawley , Albumina Sérica/química , Regulação para Cima/efeitos dos fármacosRESUMO
Vanillic acid grafted chitosan (Va-g-Ch) was evaluated as a new antioxidant wall material for microencapsulation of polyunsaturated fatty acid rich sardine oil. A high grafting ratio of 305mg vanillic acid equivalent/g of polymer was achieved using a free radical mediated grafting reaction. Oil in water emulsion was prepared with an optimised combination of Va-g-Ch and Tween 20 (3.2:1). Sardine oil loaded microparticles (SO-M) were produced (â¼75% yield) by spray drying. The average diameter and polydispersity Index (PDI) of the particles were found to be 2.3µ and 0.345. XRD spectra of SO-M showed reduction in crystallinity due to microencapsulation. After four weeks of storage, a moderate (â¼12%) decrease in the EPA and DHA content and a low PV of 5.5±0.51meq/kg oil in SO-M demonstrated good oxidative stability. Satisfactory encapsulation efficiency (84±0.84%) and loading efficiency (67±0.51%) values, also demonstrated the suitability of Va-g-Ch for microencapsulation of sardine oil.
RESUMO
Autophagy is a cell survival mechanism hijacked by advanced tumors to endure a rough microenvironment. Late autophagy inhibitors such as (hydroxy)chloroquine have been used clinically to halt tumor progression with modest success. However, given the toxic nature of these compounds and their lack of specificity, novel targets should be considered. We recently identified a benzotropolone derivative that significantly inhibited the essential autophagy protein ATG4B. Therefore, we synthesized and tested additional benzotropolone compounds to identify a promising ATG4B inhibitor that impairs autophagy both in vitro and in vivo. A compound library containing 27 molecules with a benzotropolone backbone was synthesized and screened for inhibition of recombinant ATG4B. Depending on the benzotropolone compound, inhibition of recombinant ATG4B ranged from 3 to 82%. Active compounds were evaluated in cellular assays to confirm inhibition of ATG4B and suppression of autophagy. Seven compounds inhibited processing of the autophagy protein LC3 and autophagosome formation. Compound UAMC-2526 was selected for further in vivo use because of its fair plasma stability. This compound abolished autophagy both in nutrient-deprived GFP-LC3 mice and in CD1-/- Foxn1nu mice bearing HT29 colorectal tumor xenografts. Moreover, addition of UAMC-2526 to the chemotherapy drug oxaliplatin significantly improved inhibition of tumor growth. Our data indicate that suppression of autophagy via ATG4B inhibition is a feasible strategy to augment existing chemotherapy efficacy and to halt tumor progression.
Assuntos
Adenocarcinoma/tratamento farmacológico , Antineoplásicos/uso terapêutico , Proteínas Relacionadas à Autofagia/antagonistas & inibidores , Autofagia/efeitos dos fármacos , Neoplasias do Colo/tratamento farmacológico , Inibidores de Cisteína Proteinase/uso terapêutico , Desenho de Fármacos , Tropolona/análogos & derivados , Adenocarcinoma/patologia , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Proteínas Relacionadas à Autofagia/genética , Proteínas Relacionadas à Autofagia/metabolismo , Proliferação de Células/efeitos dos fármacos , Neoplasias do Colo/patologia , Cisteína Endopeptidases/genética , Cisteína Endopeptidases/metabolismo , Inibidores de Cisteína Proteinase/química , Inibidores de Cisteína Proteinase/farmacologia , Estabilidade de Medicamentos , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Células HEK293 , Células HT29 , Humanos , Células Jurkat , Camundongos Knockout , Camundongos Transgênicos , Proteínas Associadas aos Microtúbulos/antagonistas & inibidores , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Compostos Organoplatínicos/uso terapêutico , Oxaliplatina , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Tropolona/química , Tropolona/farmacologia , Tropolona/uso terapêutico , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Four soluble dietary fiber (SDF) fractions characterized by major components of AXs, relatively narrow molecular weight distribution, different substituted ratio, and structure-sensitive parameter (ρ) were prepared from wheat bran. The fractions were added to wheat dough to determine the interactions between the dough's network and the SDF fractions relative to their physicochemical characteristics. Furthermore, a comprehensive study focusing on the dough texture characteristic, tensile properties, thermodynamic stability, and the microstructure was conducted by performing texture profile analysis (TPA), differential scanning calorimetry (DSC), and confocal laser scanning microscopy (CLSM) experiments. Additionally, an estimation function of the interactions parameters between the dough's network and the SDF fractions related to the factor molecular weight and ρ of the SDFs was established. The results indicated that the SDF fractions exhibiting a medium molecular weight, and a higher substitution degree and di-substituted ratio, were the most suitable fortifier providing benefits to the dough's qualities. Furthermore, the research methodology might support the high potential of SDF fractions as fortifier for flour-based products.
Assuntos
Fibras na Dieta/análise , Glutens/análise , Microscopia Confocal , Varredura Diferencial de Calorimetria , Farinha/análise , Peso Molecular , Triticum/químicaRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Type 2 diabetes mellitus (T2DM) is becoming a serious threat to human health. The fruit of Morus alba L. is widely used as a traditional Chinese medicine for the treatment of DM, dizziness, tinnitus, insomnia, and premature graying, as well as to protect the liver and kidneys. Several studies have demonstrated that the aqueous extracts of the roots bark, leaves, and ramuli of mulberry, which are known to contain polyphenols and polysaccharides, have antihyperglycemic and antihyperlipidemic activities. The aim of the present study was to further investigate the active polysaccharides from M. alba fruit by evaluating the antidiabetic activities of different fractions on T2DM rats and elucidate the mechanism underlying these activities. MATERIALS AND METHODS: Diabetic rats were treated with two fractions of M. alba fruit polysaccharides (MFP50 and MFP90). The disease models were induced by a high-fat diet and low dose injection of streptozotocin and were compared to normal rats and metformin-treated diabetic rats. After seven weeks, the fasting blood glucose (FBG), oral glucose tolerance test (OGTT), fasting serum insulin (FINS) levels, homeostasis model of assessment-insulin resistance (HOMA-IR), glycated serum protein (GSP), and serum alanine transaminase (ALT) levels, as well as serum lipid profiles and histopathological changes in the pancreas were measured. Next, the expressions of the insulin signaling pathway were measured by western blot analysis to elucidate the potential mechanism underlying these antidiabetic activities. RESULTS: After seven weeks of treatment, a significant reduction in the FBG levels, OGTT-area under the curve (OGTT-AUC), FINS, HOMA-IR, ALT, and triglyceride (TG) values of the MFP50 group was observed. On the other hand, in the MFP90 group, the FBG, OGTT-AUC, FINS, HOMA-IR, GSP, and TG levels were significantly reduced. The level of high-density lipoprotein cholesterol (HDL-c) and the proportion of HDL-c to total cholesterol (TC) significantly increased in the MFP50 group. Moreover, MFP50 and MFP90 induced repair of damaged pancreatic tissues of the diabetic rats. The hypoglycemic effect of MFP50 was more stable than MFP90, whereas the hypolipidemic effect of MFP90 was slightly better than MFP50. Moreover, the expression levels of InsR, IRS-2, Akt and GLUT4 in the MFP90 group significantly increased relative to that of the T2DM group. CONCLUSIONS: MFP50 and MFP90 have markedly antihyperglycemic and antihyperlipidemic effects and can clearly relieve diabetes symptoms in the T2DM rat model. The M. alba fruit polysaccharides may potentially be utilized as an effective treatment for T2DM. Further research into the structures of active M. alba fruit polysaccharides and their mechanisms in promoting antidiabetic effects are underway.