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1.
Food Chem ; 303: 125380, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31445175

RESUMO

Soybean Bowman-Birk trypsin inhibitor (BBTI), an antinutritional factor of soy products, could strongly inhibit the protein digestion. The inactivation effect and mechanism of BBTI induced by tea polyphenols (TPs) and its major components (EGCG and EGC), were investigated in this study using fluorescence, FTIR, CD spectroscopy, isothermal titration calorimetry (ITC) and molecular docking. EGCG and EGC interacted with BBTI via static quenching process and hydrophobic interaction, with binding constant (Ka) of 2.19 × 103 M-1 and 0.25 × 103 M-1 at 298 K, respectively. TPs, EGCG and EGC induced a transition of BBTI conformation from disorder to order. ITC analysis and molecular docking revealed the interaction of EGCG-BBTI and EGC-BBTI were spontaneous, and hydrophobic interactions and hydrogen bonds were the predominant forces. Overall, this study clearly suggested that EGCG could be a promising inactivating agent for BBTI, which could also improve the safety and nutritional value of soy products.


Assuntos
Catequina/análogos & derivados , Simulação de Acoplamento Molecular , Inibidor da Tripsina de Soja de Bowman-Birk/química , Catequina/química , Catequina/farmacologia , Fluorescência , Ligações de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Conformação Proteica , Termodinâmica , Inibidor da Tripsina de Soja de Bowman-Birk/efeitos dos fármacos , Inibidor da Tripsina de Soja de Bowman-Birk/metabolismo
2.
J Agric Food Chem ; 67(45): 12461-12471, 2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31613618

RESUMO

In this study, derivatization of epigallocatechin (EGC) by representative phytosterols (stigmasterol and ß-sitosterol) was performed employing Steglich esterification. The structural identity and purity of epigallocatechin ß-sitosterol (ESi) and epigallocatechin stigmasterol (ESt) were confirmed by NMR, FT-IR, and HPLC-MS. Further evaluation of ESi and ESt revealed their extraordinary antioxidant activities in O/W emulsion. Two different radical sources in oil or aqueous phase were applied to explore the antioxidant behavior in O/W emulsion. The mechanism was further investigated by fluorescent microscopy and transmission electron microscopy (TEM). Furthermore, incorporation of EGC with stigmasterol and ß-sitosterol notably enhanced the cholesterol-reducing activity. TEM studies suggested the hydrogen bonding of EGC strengthened the aggregation network of ESi and ESt in the bile salt micelle. The exceptional properties of ESi and ESt signified their intriguing utilization in the food industry.


Assuntos
Antioxidantes/química , Catequina/análogos & derivados , Colesterol/química , Fitosteróis/química , Catequina/química , Emulsões/química , Esterificação , Oxirredução , Sitosteroides/química , Estigmasterol/química
3.
Chem Biodivers ; 16(10): e1900347, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31532890

RESUMO

Catechins in green tea are well-known to be effective in reducing the risk of obesity. The purpose of this study was to elucidate the effects of catechins present in green tea on adipocyte differentiation and mature adipocyte metabolism. Treatment of 3T3-L1 mouse adipocyte during differentiation adipocytes with (-)-epigallocatechin (EGC) and gallic acid (GA) resulted in dose-dependent inhibition of adipogenesis. Specifically, EGC increased adiponectin and uncoupling protein 1 (UCP1) transcription in mature adipocytes. Transcription levels of adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL) were not significantly impacted by either of the compounds. These results suggest that the EGC is the most effective catechin having anti-obesity activity. Finally, EGC is an attractive candidate component for remodeling obesity.


Assuntos
Tecido Adiposo Marrom/efeitos dos fármacos , Fármacos Antiobesidade/farmacologia , Catequina/análogos & derivados , Células 3T3-L1 , Tecido Adiposo Marrom/metabolismo , Animais , Fármacos Antiobesidade/química , Fármacos Antiobesidade/isolamento & purificação , Catequina/química , Catequina/isolamento & purificação , Catequina/farmacologia , Diferenciação Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Camundongos , Estrutura Molecular , Relação Estrutura-Atividade , Chá/química
4.
J Agric Food Chem ; 67(40): 11108-11118, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31496243

RESUMO

A blood glucose level lowering effect is postulated for polyphenols (PPs), which is in part attributed to the inhibition of α-amylase. To estimate structure-effect relationships, chlorogenic acid (CA), phlorizin (PHL), epigallocatechin gallate (EGCG), epicatechin (EC), and malvidin-3-glucoside (Mlv-3-glc) were used as inhibitors in an enzyme assay, on the basis of the conversion of GalG2CNP by α-amylase. The detection of CNP was performed by UV/vis spectroscopy. The data reveal that the inhibitor strength decreases as follows: EGCG > Mlv-3-glc > EC > PHL ∼ CA. Detection of the substrate conversion by isothermal titration calorimetry supports these results. All PPs showed mixed inhibition, except for CA and EGCG wherein the competitive proportion was predominant. Investigations by saturation transfer difference NMR revealed interaction of PPs with α-amylase prevalently based on interactions with the aromatic or conjugated system. A correlation between the extent of the conjugated system and the IC50 of the PP could be found.


Assuntos
Antocianinas/química , Catequina/análogos & derivados , Catequina/química , Ácido Clorogênico/química , Inibidores Enzimáticos/química , Glucosídeos/química , alfa-Amilases Pancreáticas/antagonistas & inibidores , Florizina/química , Animais , Calorimetria , alfa-Amilases Pancreáticas/química , Suínos
5.
Int J Nanomedicine ; 14: 5017-5032, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31371944

RESUMO

Background: Epigallocatechin gallate (EGCG), the major anti-inflammatory compound in green tea, has been shown to suppress osteoclast (OC) differentiation. However, the low aqueous solubility of EGCG always leads to poor bioavailability, adverse effects, and several drawbacks for clinical applications. Purpose: In this study, we synthesized EGCG-capped gold nanoparticles (EGCG-GNPs) to solve the drawbacks for clinical uses of EGCG in bone destruction disorders by direct reduction of HAuCl4 in EGCG aqueous solution. Methods and Results: The obtained EGCG-GNPs were negatively charged and spherical. Theoretical calculation results suggested that EGCG was released from GNPs in an acidic environment. Cellular uptake study showed an obviously large amount of intracellular EGCG-GNPs without cytotoxicity. EGCG-GNPs exhibited better effects in reducing intracellular reactive oxygen species levels than free EGCG. A more dramatic anti-osteoclastogenic effect induced by EGCG-GNPs than free EGCG was observed in lipopolysaccharide (LPS)-stimulated bone marrow macrophages, including decreased formation of TRAP-positive multinuclear cells and actin rings. Meanwhile, EGCG-GNPs not only suppressed the mRNA expression of genetic markers of OC differentiation but also inhibited MAPK signaling pathways. Furthermore, we confirmed that EGCG-GNPs greatly reversed bone resorption in the LPS-induced calvarial bone erosion model in vivo, which was more effective than applying free EGCG, specifically in inhibiting the number of OCs, improving bone density, and preventing bone loss. Conclusion: EGCG-GNPs showed better anti-osteoclastogenic effect than free EGCG in vitro and in vivo, indicating their potential in anti-bone resorption treatment strategy.


Assuntos
Catequina/análogos & derivados , Ouro/farmacologia , Nanopartículas Metálicas/química , Osteogênese/efeitos dos fármacos , Animais , Células da Medula Óssea/citologia , Células da Medula Óssea/efeitos dos fármacos , Reabsorção Óssea/patologia , Catequina/farmacologia , Morte Celular/efeitos dos fármacos , Teoria da Densidade Funcional , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Ligantes , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Masculino , Nanopartículas Metálicas/ultraestrutura , Camundongos Endogâmicos BALB C , Modelos Biológicos , Ligante RANK/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Crânio/patologia , Transcrição Genética/efeitos dos fármacos
6.
J Sci Food Agric ; 99(15): 6922-6930, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31393601

RESUMO

BACKGROUND: The potential use of polyphenols to improve the functional characteristics of dairy products has gained much attention. However, the effects of the polyphenols on naturally occurring enzymes in milk have not been studied extensively. Excess plasmin activity in dairy products might result in several quality defects. The objective of this study was to assess the ability of polyphenols to inhibit plasmin in milk using a molecular and kinetic approach. RESULTS: Epicatechin gallate (ECG), epigallocatechin gallate (EGCG), quercetin (QUER), and myricetin (MYR) caused a significant decrease in plasmin activity by 60, 86, 65, and 90%, respectively. The inhibition rates were alleviated in the presence of milk proteins. EGCG, QUER, and MYR, exhibited noncompetitive inhibition against plasmin, whereas ECG caused a mixed-type inhibition. A decrease in the random structure of plasmin upon the complex formation with ECG, EGCG, QUER, and MYR was found. The other phenolics that were evaluated did not cause any significant changes in plasmin conformation. The observed inhibitory phenolic-plasmin interactions were dominated by H-bonds and electrostatic attractions. Green tea extract (GTE) rich in catechins also inhibited plasmin activity in the milk. CONCLUSION: Significant changes in the secondary structure of plasmin upon binding of ECG, EGCG, QUER, and MYR led to diminished plasmin activity both in the absence and presence of milk proteins. These flavonoids with promising plasmin inhibitory potential could be used in new dairy formulations leading to controlled undesired consequences of plasmin activity. © 2019 Society of Chemical Industry.


Assuntos
Antifibrinolíticos/química , Camellia sinensis/química , Leite/enzimologia , Extratos Vegetais/química , Polifenóis/química , Animais , Catequina/análogos & derivados , Catequina/química , Bovinos , Fibrinolisina/química , Cinética , Leite/química
7.
J Sci Food Agric ; 99(15): 6937-6943, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31414496

RESUMO

BACKGROUND: Non-volatile compounds play a key role in the quality and price of Keemun black tea (KBT). The non-volatile compounds in KBT samples from different producing areas normally vary greatly. The development of rapid methods for tracing the geographical origin of KBT is useful. In this study, we develop models for the discrimination of KBT's geographical origin based on non-volatile compounds. RESULTS: Seventy-two KBT samples were collected from five towns in Anhui province to determine 13 KBT compounds by high-performance liquid chromatography (HPLC). Analysis of variance showed that the content of 13 compounds in KBT indicated significant differences (P < 0.05) among five towns. Three multivariate statistical models including principal component analysis (PCA), soft independent modeling of class analogy (SIMCA), and linear discriminant analysis (LDA) were built to discriminate origin. Principal component analysis effectively extracted three principal components, namely theaflavins, galloylated catechins, and simple catechins. The high sensitivity (64.5%-99.2%) was achieved of SIMCA model. To establish the discriminant functions, six variables (gallic acid, (+)-catechin, (-)-epigallocatechin gallate, theaflavin-3-gallate, theaflavin-3,3'-di-gallate, and total theaflavins) were chosen from 13 variables, and LDA was applied. This gave a satisfactory overall correct classification rate (94.4%) and cross-validation rate (88.9%) for KBT samples. CONCLUSION: The results showed that HPLC analysis together with chemometrics is a reliable approach for tracing KBT and guaranteeing its authenticity. © 2019 Society of Chemical Industry.


Assuntos
Camellia sinensis/química , Biflavonoides/análise , Camellia sinensis/classificação , Catequina/análogos & derivados , Catequina/análise , Cromatografia Líquida de Alta Pressão , Análise Discriminante , Ácido Gálico/análogos & derivados , Ácido Gálico/análise , Modelos Estatísticos , Análise de Componente Principal , Chá/química
8.
Food Chem ; 301: 125294, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31382111

RESUMO

The interaction of copper complexed with (-)-epigallocatechin-3-gallate (EGCG) and bovine serum albumin (BSA) was investigated using fluorescence, circular dichroism (CD) spectroscopy, HPLC and protein-ligand docking. The fluorescence quenching efficiency of BSA by EGCG was enhanced after EGCG was complexed with copper, and the EGCG-Cu complex exhibited a higher apparent binding affinity (8.88 × 105 M-1) to BSA compared with EGCG alone (5.17 × 105 M-1). The CD experiment showed that both the EGCG-BSA and [EGCG-Cu]-BSA interactions resulted in the unfolding of the secondary structure of the protein. Results of competitive binding experiments confirmed that the location of EGCG and EGCG-Cu complex binding in BSA was site I. Furthermore, molecular modeling was used to identify the amino acid residue in site I and site II that play key roles in this binding interaction. The data suggest that most of the residues involved in the [EGCG-Cu]-BSA reaction belong to the subdomains IIa (site I) of BSA.


Assuntos
Catequina/análogos & derivados , Cobre/química , Soroalbumina Bovina/química , Ligação Competitiva , Catequina/química , Catequina/metabolismo , Cromatografia Líquida de Alta Pressão , Dicroísmo Circular , Complexos de Coordenação/química , Complexos de Coordenação/metabolismo , Cobre/metabolismo , Ligantes , Simulação de Acoplamento Molecular , Estrutura Secundária de Proteína , Soroalbumina Bovina/metabolismo , Espectrometria de Fluorescência
9.
Food Chem ; 301: 125301, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31387032

RESUMO

Novel delivery systems for epigallocatechin gallate (EGCG) were developed using broccoli by-products and their fractions as carriers. Puree and pomace from broccoli by-products had higher adsorption capacities for EGCG than juice at 25 °C (43.20 mg g-1, 39.47 mg g-1 and 25.22 mg g-1 dry weight for pomace, puree and juice respectively). Chemical sorption is the rate-controlling step for EGCG-broccoli interactions. Langmuir and Freundlich models well described the adsorption of EGCG onto puree and pomace. FTIR results indicated that EGCG-puree had stronger interaction than EGCG-pomace. When the same level of EGCG (∼26 mg) was added to different matrices, more EGCG (∼20%) was recovered from the in vitro digestion system of EGCG-loaded puree than from the EGCG-loaded pomace (14%) and neat EGCG (9%). The antioxidant capacity of the whole digesta was positively correlated with the EGCG levels. Broccoli by-products are promising carriers for delivering and stabilizing EGCG through gastrointestinal digestion.


Assuntos
Brassica/química , Catequina/análogos & derivados , Portadores de Fármacos/química , Adsorção , Antioxidantes/análise , Catequina/administração & dosagem , Catequina/química , Catequina/farmacocinética , Digestão , Sistemas de Liberação de Medicamentos/métodos , Espectroscopia de Infravermelho com Transformada de Fourier , Resíduos
10.
J Med Microbiol ; 68(10): 1552-1559, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31419210

RESUMO

Introductio n. Pseudomonas aeruginosa is an important Gram-negative pathogen that is intrinsically multidrug-resistant (MDR) and frequently associated with healthcare-associated outbreaks. With increasing resistance to antibiotics and with very few novel drugs under development, clinicians often use combinations to treat critically ill patients.Aim. The aim of this study was to evaluate the ability of epigallocatechin (EGCG) to restore the activity of aztreonam against clinical MDR strains of P. aeruginosa.Methodology. Checkerboard and time-kill kinetic assays were performed to assess synergy in vitro and the Galleria mellonella model of infection was used to test the efficacy of the combination in vivo. Accumulation assays were performed to gain insight into the mechanism of action.Results. The results demonstrate that synergy between aztreonam and EGCG exists [fractional inhibitory concentration indices (FICIs) 0.02-0.5], with the combination affording significantly (P=<0.05) enhanced bacterial killing, with a >3 log10 reduction in colony-forming units ml-1 at 24 h. EGCG was able to restore susceptibility to aztreonam to a level equal to or below the breakpoint set by the European Committee for Antimicrobial Susceptibility Testing. In G. mellonella, the combination was superior to monotherapy, with increased larval survival observed (94 % vs ≤63 %). We also demonstrated the relatively low toxicity of EGCG to human keratinocytes and G. mellonella larvae. Accumulation assay data suggest that the mechanism of synergy may be due to EGCG increasing the uptake of aztreonam.Conclusion. EGCG was able to restore the activity of aztreonam against MDR P. aeruginosa. The data presented support further evaluation of the aztreonam-EGCG combination and highlight its potential for use in clinical medicine.


Assuntos
Antibacterianos/farmacologia , Aztreonam/farmacologia , Catequina/análogos & derivados , Polifenóis/farmacologia , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/efeitos dos fármacos , Animais , Catequina/farmacologia , Farmacorresistência Bacteriana Múltipla , Sinergismo Farmacológico , Humanos , Larva/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Mariposas/efeitos dos fármacos , Pseudomonas aeruginosa/crescimento & desenvolvimento
11.
Food Chem ; 299: 125097, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31284242

RESUMO

The low solubility, instability, and low bioavailability of food bioactive compounds such as polyphenols and flavonoids, restrict their applications in the fields of food science and nutrition. Ferritin protein has received more and more attention in encapsulation and delivery of the bioactive compounds due to its nanosized shell-like structure and its reversible self-assembly character. After encapsulation, bioactive compounds can be functionalized by the ferritin vehicle to achieve stabilization, solubilization, and targeted delivery. In addition, the outer interfaces and the porous structure of ferritin are also artfully harnessed for encapsulation. This review focuses on the newest advances in the fabrication, characterization, and application of ferritin-based nano-carriers for bioactive compounds by the reversible self-assembly, outer-interface decoration methods, and the channel-directed approach. The functional improvements of food bioactive compounds, including their solubility, stability, and cellular uptake, are emphasized. The limitations that affect ferritin encapsulation are also examined.


Assuntos
Ferritinas/química , Ferritinas/farmacocinética , Alimentos , Nanoestruturas/química , Antocianinas/administração & dosagem , Antocianinas/química , Antocianinas/farmacocinética , Disponibilidade Biológica , Catequina/análogos & derivados , Catequina/química , Quitosana/química , Curcumina/administração & dosagem , Curcumina/química , Curcumina/farmacocinética , Humanos , Polifenóis/administração & dosagem , Polifenóis/química , Polifenóis/farmacocinética , Proantocianidinas/administração & dosagem , Proantocianidinas/química , Proantocianidinas/farmacocinética , Solubilidade , beta Caroteno/administração & dosagem , beta Caroteno/química , beta Caroteno/farmacocinética
12.
Bioengineered ; 10(1): 282-291, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31311401

RESUMO

Transforming growth factor (TGF)-ß1 plays a crucial role in the epithelial-to-mesenchymal transition (EMT) in many cancer types and in thyroid cancers. Epigallocatechin-3-gallate (EGCG), the most important ingredient in the green tea, has been reported to possess antioxidant and anticancer activities. However, the cellular and molecular mechanisms explaining its action have not been completely understood. In this study, we found that EGCG significantly suppresses EMT, invasion and migration in anaplastic thyroid carcinoma (ATC) 8505C cells in vitro by regulating the TGF-ß/Smad signaling pathways. EGCG significantly inhibited TGF-ß1-induced expression of EMT markers (E-cadherin reduction and vimentin induction) in 8505C cells in vitro. Treatment with EGCG completely blocked the phosphorylation of Smad2/3, translocation of Smad4. Taken together, these results suggest that EGCG suppresses EMT and invasion and migration by blocking TGFß/Smad signaling pathways.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Catequina/análogos & derivados , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica , Transdução de Sinais/efeitos dos fármacos , Células Epiteliais da Tireoide/efeitos dos fármacos , Fator de Crescimento Transformador beta1/antagonistas & inibidores , Antígenos CD/genética , Antígenos CD/metabolismo , Caderinas/antagonistas & inibidores , Caderinas/genética , Caderinas/metabolismo , Catequina/farmacologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Transição Epitelial-Mesenquimal/genética , Humanos , Fosforilação/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Proteína Smad2/genética , Proteína Smad2/metabolismo , Proteína Smad3/genética , Proteína Smad3/metabolismo , Proteína Smad4/genética , Proteína Smad4/metabolismo , Células Epiteliais da Tireoide/metabolismo , Células Epiteliais da Tireoide/patologia , Fator de Crescimento Transformador beta1/farmacologia , Vimentina/agonistas , Vimentina/genética , Vimentina/metabolismo
13.
J Food Sci ; 84(8): 2159-2164, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31329273

RESUMO

This study investigated the inhibitory effect of epigallocatechin gallate (EGCG), epigallocatechin (EGC), and gallic acid (GA) on the formation of N-nitrosodiethylamine (NDEA) in vitro. Results show that the three polyphenols are capable to block NDEA formation when the molar ratio of phenols to nitrite is higher than 0.8, and a more acidic environment is prone to promote the inhibitory potential of phenols. It is also found that the inhibitory effect tends to decrease in the order: EGCG, EGC, GA, which is in accordance with the order of their DPPH scavenging activity, suggesting that the inhibitory effect of polyphenols on NDEA formation may work through a free radical way. Kinetic study further revealed the three polyphenols react with nitrite at a much faster rate than diethylamine does (P < 0.05). By scavenging nitrite at a faster rate than the nitrosation of diethylamine, polyphenols at high concentration can significantly block NDEA formation. These observations may promote a possible application of polyphenol compounds to inhibit the formation of nitrosamines in food processing. PRACTICAL APPLICATION: The presence of N-nitrosamines in human diet should be an etiological risk factor for human cancers. This work may provide a useful guideline for phenolic compounds to inhibit the formation of nitrosamines in food processing, such as in the process of curing meats. Polyphenols have been proved to block NDEA formation under normal gastric juice condition, suggesting the intake of polyphenols is a potential way to prevent diseases caused by nitrite.


Assuntos
Catequina/análogos & derivados , Dietilnitrosamina/química , Ácido Gálico/química , Catequina/química , Dietilnitrosamina/antagonistas & inibidores , Radicais Livres/química , Cinética , Fenóis/farmacologia
14.
AAPS PharmSciTech ; 20(6): 250, 2019 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-31297635

RESUMO

Melanoma is regarded as the fifth and sixth most common cancer in men and women, respectively, and it is estimated that one person dies from melanoma every hour in the USA. Unfortunately, the treatment of melanoma is difficult because of its aggressive metastasis and resistance to treatment. The treatment of melanoma continues to be a challenging issue due to the limitations of available treatments such as a low response rate, severe adverse reactions, and significant toxicity. Natural polyphenols have attracted considerable attention from the scientific community due to their chemopreventive and chemotherapeutic efficacy. It has been suggested that poorly soluble polyphenols such as curcumin, resveratrol, quercetin, coumarin, and epigallocatechin-3-gallate may have significant benefits in the treatment of melanoma due to their antioxidant, anti-inflammatory, antiproliferative, and chemoprotective efficacies. The major obstacles for the use of polyphenolic compounds are low stability and poor bioavailability. Numerous nanoformulations, including solid lipid nanoparticles, polymeric nanoparticles, micelles, and liposomes, have been formulated to enhance the bioavailability and stability, as well as the therapeutic efficacy of polyphenols. This review will provide an overview of poorly soluble polyphenols that have been reported to have antimetastatic efficacy in melanomas.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Melanoma/tratamento farmacológico , Polifenóis/administração & dosagem , Polifenóis/química , Neoplasias Cutâneas/tratamento farmacológico , Animais , Antioxidantes/administração & dosagem , Antioxidantes/química , Antioxidantes/metabolismo , Disponibilidade Biológica , Catequina/administração & dosagem , Catequina/análogos & derivados , Catequina/química , Catequina/metabolismo , Curcumina/administração & dosagem , Curcumina/química , Curcumina/metabolismo , Humanos , Melanoma/metabolismo , Melanoma/prevenção & controle , Nanopartículas/administração & dosagem , Nanopartículas/química , Nanopartículas/metabolismo , Polifenóis/metabolismo , Quercetina/administração & dosagem , Quercetina/química , Quercetina/metabolismo , Resveratrol/administração & dosagem , Resveratrol/química , Resveratrol/metabolismo , Neoplasias Cutâneas/metabolismo , Solubilidade
15.
J Agric Food Chem ; 67(32): 9079-9087, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31353905

RESUMO

Organic anion transporting polypeptides (OATPs) 1B1 and 1B3 are two highly homologous transporters expressed in the human liver. However, epigallocatechin gallate (EGCG), which is the most predominant catechin in green tea, has opposite effects on the function of OATP1B1 and OATP1B3. In the present study, the critical structural domains and amino acid residues for the activation of OATP1B3 by EGCG have been determined by characterizing the function of a series of OATP1B3-derived chimeric transporters, site-directed mutagenesis, and kinetic studies. Our results showed that G45 and F555 in transmembrane domains 1 and 10 are the most important amino acid residues for OATP1B3 activation. Kinetic studies showed that the activation of OATP1B3 by EGCG at a low substrate concentration was due to its increased substrate binding affinity. However, EGCG caused increased Km and decreased Vmax for 1B3-G45A and 1B3-F555H. The flexibility at position 45 and aromaticity at position 555 might be important for OATP1B3 activation. While 1B3-G45A and 1B3-F555H could not be activated by EGCG, their transport activity for EGCG was comparable to that of wild-type OATP1B3. In conclusion, the present study elucidated the molecular mechanism for OATP1B3 activation by EGCG.


Assuntos
Catequina/análogos & derivados , Extratos Vegetais/metabolismo , Membro 1B3 da Família de Transportadores de Ânion Orgânico Carreador de Soluto/química , Membro 1B3 da Família de Transportadores de Ânion Orgânico Carreador de Soluto/metabolismo , Motivos de Aminoácidos , Camellia sinensis/química , Catequina/química , Catequina/metabolismo , Células HEK293 , Humanos , Cinética , Fígado/metabolismo , Transportador 1 de Ânion Orgânico Específico do Fígado/química , Transportador 1 de Ânion Orgânico Específico do Fígado/genética , Transportador 1 de Ânion Orgânico Específico do Fígado/metabolismo , Modelos Moleculares , Extratos Vegetais/química , Domínios Proteicos , Membro 1B3 da Família de Transportadores de Ânion Orgânico Carreador de Soluto/genética
16.
Molecules ; 24(11)2019 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-31174271

RESUMO

Gout is a chronic inflammatory disease evoked by the deposition of monosodium urate (MSU) crystals in joint tissues. The nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family pyrin domain containing 3 (NLRP3) inflammasome is responsible for the gout inflammatory symptoms induced by MSU crystals. We investigated whether epigallocatechin-3-gallate (EGCG) suppresses the activation of the NLRP3 inflammasome, thereby effectively preventing gouty inflammation. EGCG blocked MSU crystal-induced production of caspase-1(p10) and interleukin-1ß in primary mouse macrophages, indicating its suppressive effect on the NLRP3 inflammasome. In an acute gout mouse model, oral administration of EGCG to mice effectively alleviated gout inflammatory symptoms in mouse foot tissue injected with MSU crystals. The in vivo suppressive effects of EGCG correlated well with the suppression of the NLRP3 inflammasome in mouse foot tissue. EGCG inhibited the de novo synthesis of mitochondrial DNA as well as the production of reactive oxygen species in primary mouse macrophages, contributing to the suppression of the NLRP3 inflammasome. These results show that EGCG suppresses the activation of the NLRP3 inflammasome in macrophages via the blockade of mitochondrial DNA synthesis, contributing to the prevention of gouty inflammation. The inhibitory effects of EGCG on the NLRP3 inflammasome make EGCG a promising therapeutic option for NLRP3-dependent diseases such as gout.


Assuntos
Catequina/análogos & derivados , Gota/tratamento farmacológico , Inflamação/tratamento farmacológico , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Animais , Caspase 1/genética , Catequina/farmacologia , DNA Mitocondrial/biossíntese , DNA Mitocondrial/efeitos dos fármacos , Modelos Animais de Doenças , Gota/genética , Gota/patologia , Humanos , Inflamassomos/efeitos dos fármacos , Inflamassomos/genética , Inflamação/genética , Inflamação/patologia , Interleucina-1beta/genética , Macrófagos/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Espécies Reativas de Oxigênio/metabolismo , Ácido Úrico/toxicidade
17.
BMC Complement Altern Med ; 19(1): 129, 2019 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-31196040

RESUMO

BACKGROUND: Green tea has polyphenols like flavonoids and catechins; mainly epigallocatechin-3-gallate (EGCG), epicatechin gallate (ECG), epigallocatechin (EGC) and epicatechin (EC), out of which EGCG is of higher abundance. EGCG has shown preventive role in hypercholesterolemia. However, due to low oral bioavailability, a need arises to improve its membrane permeability and transporter-mediated intestinal efflux. Therefore, an attempt was made to enhance permeability and bioavailability of EGCG using curcumin to treat hyperlipidemia. Further, it was formulated in herbal tea bags to achieve patient compliance. METHODS: EGCG extracted from green tea leaves was confirmed by High Performance Thin Layer Chromatography. Green tea extract (GTE), curcumin and their mixtures were subjected to Fourier Transform Infra-Red spectroscopy and Differential Scanning Calorimetry for compatibility studies. Powder formulation was prepared comprising GTE, curcumin, sucralose and cardamom. RESULTS: Ex-vivo study was performed on everted goat intestine, analyzed by HPLC and demonstrated highest permeation of GTE:curcumin (220:50) (53.15%) than GTE (20.57%). Antihyperlipidemic activity was performed in rats for 15 days. Blood sample analysis of rats of test groups (formulation and GTE solution) fed on high fat diet showed (mg/dl):cholesterol 80 and 90, triglycerides 73.25 and 85.5, HDL 50.75 and 46, LDL 43.9 and 46, VLDL 14.65 and 17.1 respectively with significant lipid regulating effect. CONCLUSION: Curcumin enhanced permeability of EGCG. Therefore, P-glycoprotein pump inside intestine can be potential mechanism to enhance permeability of EGCG. Thus, EGCG-curcumin herbal tea bag is promising nutraceutical to treat hyperlipidemia in day-to-day life achieving patient compliance.


Assuntos
Antioxidantes/farmacocinética , Catequina/análogos & derivados , Curcumina/administração & dosagem , Hiperlipidemias/tratamento farmacológico , Animais , Antioxidantes/administração & dosagem , Disponibilidade Biológica , Catequina/administração & dosagem , Catequina/farmacocinética , Avaliação Pré-Clínica de Medicamentos , Sinergismo Farmacológico , Feminino , Masculino , Permeabilidade , Fitoterapia , Ratos Sprague-Dawley , Chá
18.
J Sci Food Agric ; 99(13): 5984-5993, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31215023

RESUMO

BACKGROUND: (-)-Gallocatechin gallate (GCG) shows multi-bioactivities. Its stability, however, has not been investigated systematically yet. Therefore, the objective of this study was to characterize the stability of GCG and to find ways to stabilize it in biological assays. Furthermore, the epimerization of the compound, its auto-oxidation and degradation were also analyzed by liquid chromatography mass spectrometry (LC-MS). RESULTS: The stability of GCG was concentration-dependent and was sensitive to pH, temperature, bivalent cations, and dissolved oxygen level. The results also showed that GCG was not stable in common buffers (50 mmol L-1 , pH 7.4, 37 °C) or in cell culture medium DMEM/F12 under physiological conditions (pH 7.4, 37 °C). Our experiments indicated that nitrogen-saturation and the addition of ascorbic acid (VC) could stabilize GCG in biological assays. In addition, LC-MS determination indicated that GCG was able to be epimerized to its epimer (-)-epigallocatechin gallate (EGCG). Meanwhile it was also able to be auto-oxidized to theasinensin and compound P2 and degraded to gallocatechin and gallic acid in pure water at 100 °C. CONCLUSION: The stability of GCG should be seriously considered in research on the bioactivity of it to avoid possible artifacts. Nitrogen-saturation and use of VC are good ways to make GCG stable in biological assays. © 2019 Society of Chemical Industry.


Assuntos
Catequina/análogos & derivados , Catequina/química , Cromatografia Líquida , Estabilidade de Medicamentos , Isomerismo , Cinética , Oxirredução , Espectrometria de Massas em Tandem , Temperatura Ambiente
19.
Environ Pollut ; 252(Pt B): 1318-1324, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31252129

RESUMO

The increase in ambient fine dust particles (FDP) due to urbanization and industrialization has been identified as a major contributor to air pollution. It has become a serious issue that threatens human health because it causes respiratory diseases and skin aging. In the present study, the protective effect of the green tea catechin, (-)-epigallocatechin gallate (EGCG), against FDP (ERM-CZ100)-stimulated skin aging in human dermal fibroblasts (HDFs) was investigated. The results demonstrate that EGCG significantly and dose-dependently scavenged intracellular reactive oxygen species (ROS) in and increased the viability of FDP-stimulated HDFs. In addition, EGCG dose-dependently recovered collagen synthesis and inhibited intracellular elastase and collagenase activities. Moreover, EGCG decreased the expression of human matrix metalloproteinases (MMPs) via regulation of nuclear factor kappa B (NF-κB), activator protein 1 (AP-1), and mitogen-activated protein kinases (MAPKs) signaling pathways in FDP-stimulated HDFs. This study suggests that EGCG is a potential anti-aging candidate that can be used for FDP-induced skin aging as a therapeutic agent itself or as an ingredient in pharmaceutical and cosmeceutical products.


Assuntos
Catequina/análogos & derivados , Sistema de Sinalização das MAP Quinases/fisiologia , NF-kappa B/metabolismo , Material Particulado/efeitos adversos , Envelhecimento da Pele/efeitos dos fármacos , Fator de Transcrição AP-1/metabolismo , Catequina/farmacologia , Linhagem Celular , Colagenases , Poeira/análise , Fibroblastos/efeitos dos fármacos , Humanos , Inibidores de Metaloproteinases de Matriz/farmacologia , Elastase Pancreática/antagonistas & inibidores , Espécies Reativas de Oxigênio/metabolismo , Pele/fisiopatologia , Envelhecimento da Pele/fisiologia , Chá/química
20.
Int J Pediatr Otorhinolaryngol ; 124: 106-110, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31176023

RESUMO

INTRODUCTION: That EGCG has strong antioxidant and anti-inflammatory activities as well as antibacterial activity against many streptococcus species suggests that it may be beneficial in the treatment of AOM. OBJECTIVE: Aim of the study is to reveal the molecular and biochemical effects of EGCG on LPS induced otitis media in rats. METHODS: Forty-two male albino Wistar rats were randomly divided into 7 groups. Inflammation was induced by administrating 50 µL of 1 mg/ml lipopolysaccharide (LPS). EGCG used 50 and 100 mg/kg/day and combined penicillin G (PENG) 48 h after LPS injection. RESULTS: The combined EGCG 50 and PENG group and the group with EGCG 50 alone showed the best anti-inflammatory effect on LPS-induced AOM. TNF-α and IL-1ß gene expression significantly down regulated EGCG 50 and combined with PENG compared to the otitis media group. The combination of PenG and EGCG 50 led to the best histopathological improvement. Both the inflammation and the membrane thickness of this group were at almost the same level as the healthy group and tympanum was seen normal. CONCLUSION: The results of this study make it clear that EGCG plays an important role in antioxidant and anti-inflammatory activity during AOM.


Assuntos
Antioxidantes/uso terapêutico , Catequina/análogos & derivados , Otite Média/tratamento farmacológico , Animais , Antibacterianos/uso terapêutico , Antioxidantes/farmacologia , Catequina/farmacologia , Catequina/uso terapêutico , Regulação para Baixo , Quimioterapia Combinada , Expressão Gênica/efeitos dos fármacos , Interleucina-1beta/genética , Lipopolissacarídeos , Masculino , Otite Média/induzido quimicamente , Otite Média/patologia , Penicilina G/uso terapêutico , Distribuição Aleatória , Ratos , Ratos Wistar , Fator de Necrose Tumoral alfa/genética , Membrana Timpânica/patologia
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