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1.
Biochemistry (Mosc) ; 85(7): 833-837, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33040727

RESUMO

Nrf2 is a key transcription factor responsible for antioxidant defense in many tissues and cells, including alveolar epithelium, endothelium, and macrophages. Furthermore, Nrf2 functions as a transcriptional repressor that inhibits expression of the inflammatory cytokines in macrophages. Critically ill patients with COVID-19 infection often present signs of high oxidative stress and systemic inflammation - the leading causes of mortality. This article suggests rationale for the use of Nrf2 inducers to prevent development of an excessive inflammatory response in COVID-19 patients.


Assuntos
Betacoronavirus , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/metabolismo , Citocinas/antagonistas & inibidores , Citocinas/metabolismo , Terapia de Alvo Molecular/métodos , Fator 2 Relacionado a NF-E2/metabolismo , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/metabolismo , Animais , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Catequina/análogos & derivados , Catequina/farmacologia , Catequina/uso terapêutico , Infecções por Coronavirus/virologia , Fumarato de Dimetilo/farmacologia , Fumarato de Dimetilo/uso terapêutico , Feminino , Humanos , Imunossupressores/farmacologia , Imunossupressores/uso terapêutico , Inflamação/metabolismo , Isotiocianatos/farmacologia , Isotiocianatos/uso terapêutico , Masculino , Camundongos , Estresse Oxidativo/efeitos dos fármacos , Pandemias , Pneumonia Viral/virologia , Síndrome do Desconforto Respiratório do Adulto/tratamento farmacológico , Síndrome do Desconforto Respiratório do Adulto/metabolismo , Síndrome do Desconforto Respiratório do Adulto/virologia , Resveratrol/farmacologia , Resveratrol/uso terapêutico , Transdução de Sinais/efeitos dos fármacos , Tiossulfatos/farmacologia , Tiossulfatos/uso terapêutico
2.
Int J Nanomedicine ; 15: 4969-4990, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32764930

RESUMO

Background: Polyphenols possess antioxidant, anti-inflammatory and antimicrobial properties and have been used in the treatment of skin wounds and burns. We previously showed that tannic acid-modified AgNPs sized >26 nm promote wound healing, while tannic acid-modified AgNPs sized 13 nm can elicit strong local inflammatory response. In this study, we tested bimetallic Au@AgNPs sized 30 nm modified with selected flavonoid and non-flavonoid compounds for wound healing applications. Methods: Bimetallic Au@AgNPs were obtained by growing an Ag layer on AuNPs and further modified with selected polyphenols. After toxicity tests and in vitro scratch assay in HaCaT cells, modified lymph node assay as well as the mouse splint wound model were further used to access the wound healing potential of selected non-toxic modifications. Results: Tannic acid, gallic acid, polydatin, resveratrol, catechin, epicatechin, epigallocatechin, epicatechin gallate, epigallocatechin gallate and procyanidin B2 used to modify Au@AgNPs exhibited good toxicological profiles in HaCaT cells. Au@AgNPs modified with 15 µM tannic acid, 200 µM resveratrol, 200 µM epicatechin gallate, 1000 µM gallic acid and 200 µM procyanidin B2 induced wound healing in vivo and did not lead to the local irritation or inflammation. Tannic acid-modified Au@AgNPs induced epithelial-to-mesenchymal transition (EMT) - like re-epithelialization, while other polyphenol modifications of Au@AgNPs acted through proliferation and wound closure. Conclusion: Bimetallic Au@AgNPs can be used as a basis for modification with selected polyphenols for topical uses. In addition, we have demonstrated that particular polyphenols used to modify bimetallic nanoparticles may show different effects upon different stages of wound healing.


Assuntos
Ouro/química , Nanopartículas Metálicas/química , Polifenóis/química , Polifenóis/farmacologia , Prata/química , Cicatrização/efeitos dos fármacos , Animais , Antioxidantes/química , Antioxidantes/farmacologia , Biflavonoides/química , Catequina/análogos & derivados , Catequina/química , Camundongos , Proantocianidinas/química , Taninos/química
3.
Chem Biol Interact ; 330: 109228, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32827518

RESUMO

This study aimed at exploring the potential mechanism of decreased in vivo exposure of the antiplatelet agent, ticagrelor and its active metabolite, AR-C124910XX, mediated by tea polyphenols, which was first revealed by our previous study, as well as predicting the in vivo drug-drug interaction (DDI) potential utilizing an in vitro to in vivo extrapolation (IVIVE) approach. The bidirectional transport and uptake kinetics of ticagrelor were determined using Caco-2 cells. Inhibition potency of major components of tea polyphenols, epigallocatechin gallate (EGCG) and epigallocatechin (EGC) were obtained from Caco-2 cells, human intestinal and hepatic microsomes (HIMs and HLMs) in vitro. A mean efflux ratio of 2.28 ± 0.38 and active uptake behavior of ticagrelor were observed in Caco-2 cell studies. Further investigation showed that the IC50 values of EGCG and EGC on the uptake of ticagrelor were 42.0 ± 5.1 µM (95% CI 31.9-54.8 µM) and 161 ± 13 µM (95% CI 136-191 µM), respectively. EGCG and EGC also displayed moderate to weak reversible inhibition on the formation of AR-C124910XX and the inactive metabolite, AR-C133913XX in HIMs and HLMs, while no clinically significant time-dependent inhibition was observed for either compound. IVIVE indicated a significant inhibition effect of EGCG on the uptake process of ticagrelor, while no potential DDI risk was found based on microsomal data. A 45% decrease in ticagrelor in vivo exposure was mechanistically predicted by incorporating intestinal and hepatic metabolism as well as intestinal absorption. This dual inhibition of tea polyphenols on ticagrelor revealed the underlying potential of transporter-enzyme interplay, in which the altered uptake process was more critical.


Assuntos
Modelos Teóricos , Polifenóis/farmacologia , Chá/química , Ticagrelor/antagonistas & inibidores , Adenosina/análogos & derivados , Adenosina/metabolismo , Transporte Biológico/efeitos dos fármacos , Células CACO-2 , Catequina/análogos & derivados , Catequina/farmacologia , Linhagem Celular Tumoral , Interações Medicamentosas , Humanos , Absorção Intestinal/efeitos dos fármacos , Cinética , Microssomos Hepáticos/metabolismo , Inibidores da Agregação de Plaquetas/farmacocinética , Antagonistas do Receptor Purinérgico P2Y/farmacocinética , Ticagrelor/metabolismo , Ticagrelor/farmacocinética
4.
J Oleo Sci ; 69(9): 1077-1085, 2020 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-32788520

RESUMO

There is growing research interest in the hypocholesterolemic effect of various food components such as polyphenols. In this study, we examined the effects of oligonol-a low-molecular weight polyphenol extracted from lychee fruit-on cholesterol metabolism in rats under short-term administration. Administration of oligonol for 3 days significantly increased cecum weight and decreased cecal n-butyric acid concentrations in rats. Oligonol also significantly lowered the levels of hepatic cholesterol and increased the levels of total neutral steroids excreted in the feces. It also increased fecal ß-muricholic acid significantly, whereas the levels of total acidic steroids remained unchanged. Gene expression of hepatic CYP7A1 (cytochrome P450 family 7 subfamily A member 1) significantly increased following the administration of oligonol. This increase could be ascribed to changes in the expression of farnesoid X receptor, small heterodimer partner, and fibroblast growth factor 15 in ileum. Our data suggest that oligonol induces hypocholesterolemic effects through the inhibition of biliary cholesterol absorption from the intestine and the upregulation of cholesterol catabolism in rats even following short-term administration. Therefore, oligonol may be an important food component for reducing cholesterol level.


Assuntos
Catequina/análogos & derivados , Colesterol/metabolismo , Litchi/química , Fenóis/isolamento & purificação , Fenóis/farmacologia , Animais , Butiratos/metabolismo , Catequina/administração & dosagem , Catequina/isolamento & purificação , Catequina/farmacologia , Colesterol 7-alfa-Hidroxilase/genética , Colesterol 7-alfa-Hidroxilase/metabolismo , Expressão Gênica/efeitos dos fármacos , Íleo/metabolismo , Fígado/metabolismo , Masculino , Peso Molecular , Fenóis/administração & dosagem , Polifenóis , Ratos Wistar , Receptores Citoplasmáticos e Nucleares/genética , Receptores Citoplasmáticos e Nucleares/metabolismo , Fatores de Tempo
5.
Life Sci ; 258: 118232, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32781066

RESUMO

AIMS: To elucidate the mechanism by which (-)-epigallocatechin-3-gallate (EGCG) mediates intracellular Ca2+ increase in androgen-independent prostate cancer (PCa) cells. MAIN METHODS: Following exposure to different doses of EGCG, viability of DU145 and PC3 PCa cells was evaluated by MTT assay and the intracellular Ca2+ dynamics by the fluorescent Ca2+ chelator Fura-2. The expression of different channels was investigated by qPCR analysis and sulfhydryl bonds by Ellman's assay. KEY FINDINGS: EGCG inhibited DU145 and PC3 proliferation with IC50 = 46 and 56 µM, respectively, and induced dose-dependent peaks of internal Ca2+ that were dependent on extracellular Ca2+. The expression of TRPC4 and TRPC6 channels was revealed by qPCR in PC3 cells, but lack of effect by modulators and blockers ruled out an exclusive role for these, as well as for voltage-dependent T-type Ca2+ channels. Application of dithiothreitol and catalase and sulfhydryl (SH) measurements showed that EGCG-induced Ca2+ rise depends on SH oxidation, while the effect of EGTA, dantrolene, and the PLC inhibitor U73122 suggested that EGCG-induced Ca2+ influx acts as a trigger for Ca2+-induced Ca2+ release, involving both ryanodine and IP3 receptors. Different from EGCG, ATP caused a rapid Ca2+ increase, which was independent of external Ca2+, but sensitive to U73122. SIGNIFICANCE: EGCG induces an internal Ca2+ increase in PCa cells by a multi-step mechanism. As dysregulation of cytosolic Ca2+ is directly linked to apoptosis in PCa cells, these data confirm the possibility of using EGCG as a synergistic adjuvant in combined therapies for recalcitrant malignancies like androgen-independent PCa.


Assuntos
Antioxidantes/farmacologia , Cálcio/metabolismo , Catequina/análogos & derivados , Líquido Intracelular/metabolismo , Neoplasias da Próstata/metabolismo , Catequina/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Relação Dose-Resposta a Droga , Humanos , Líquido Intracelular/efeitos dos fármacos , Masculino , Células PC-3
6.
Life Sci ; 258: 118136, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32726662

RESUMO

The endothelium is a critical regulator of vascular homeostasis, controlling vascular tone and permeability as well as interactions of leukocytes and platelets with blood vessel walls. Consequently, endothelial dysfunction featuring inflammation and reduced vasodilation are considered central to cardiovascular disease (CVD) pathogenesis and have become a therapeutic area of focus. Type II endothelial cell (EC) activation by stress-related stimuli such as tumor necrosis factor-α (TNF-α) initiates the nuclear factor-κB (NF-κB) signaling pathway, a master regulator of inflammatory responses. Because dysregulated NF-κB signaling has been tightly linked to several CVDs, EC-specific inhibition of NF-κB represents an attractive pharmacological strategy. As accumulating evidence highlights the clinical benefits of tea catechin for multiple diseases including CVDs, we sought to determine whether the tea catechin epigallocatechin gallate (EGCG) that displays antioxidative, anti-inflammatory, hypolipidemic, anti-thrombogenic, and anti-hypertensive properties offers protection against CVDs by suppressing the canonical NF-κB pathway. Our findings indicate that EGCG downregulates multiple components of the TNF-α-induced NF-κB signaling pathway and thereby reduces the consequent increase in inflammatory gene transcription and protein expression. Furthermore, EGCG blocked type II EC activation, evidenced by diminished EC leakage and monocyte adhesion in EGCG-treated cells. In summary, our study advances knowledge of EGCG's anti-inflammatory effects on the NF-κB pathway and hence its benefits on endothelial health, supporting its therapeutic potential for CVDs.


Assuntos
Catequina/análogos & derivados , Vasos Coronários/patologia , Células Endoteliais/patologia , Inflamação/tratamento farmacológico , Catequina/farmacologia , Catequina/uso terapêutico , Adesão Celular/efeitos dos fármacos , Permeabilidade da Membrana Celular/efeitos dos fármacos , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Humanos , Inflamação/genética , Inflamação/patologia , Mediadores da Inflamação/metabolismo , Monócitos/efeitos dos fármacos , Monócitos/patologia , NF-kappa B/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
7.
Int J Mol Sci ; 21(14)2020 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-32708322

RESUMO

Some coronavirus disease 2019 (COVID-19) patients develop acute pneumonia which can result in a cytokine storm syndrome in response to Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) infection. The most effective anti-inflammatory drugs employed so far in severe COVID-19 belong to the cytokine-directed biological agents, widely used in the management of many autoimmune diseases. In this paper we analyze the efficacy of epigallocatechin 3-gallate (EGCG), the most abundant ingredient in green tea leaves and a well-known antioxidant, in counteracting autoimmune diseases, which are dominated by a massive cytokines production. Indeed, many studies registered that EGCG inhibits signal transducer and activator of transcription (STAT)1/3 and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) transcription factors, whose activities are crucial in a multiplicity of downstream pro-inflammatory signaling pathways. Importantly, the safety of EGCG/green tea extract supplementation is well documented in many clinical trials, as discussed in this review. Since EGCG can restore the natural immunological homeostasis in many different autoimmune diseases, we propose here a supplementation therapy with EGCG in COVID-19 patients. Besides some antiviral and anti-sepsis actions, the major EGCG benefits lie in its anti-fibrotic effect and in the ability to simultaneously downregulate expression and signaling of many inflammatory mediators. In conclusion, EGCG can be considered a potential safe natural supplement to counteract hyper-inflammation growing in COVID-19.


Assuntos
Anti-Inflamatórios/uso terapêutico , Catequina/análogos & derivados , Infecções por Coronavirus/tratamento farmacológico , Síndrome da Liberação de Citocina/tratamento farmacológico , Pneumonia Viral/tratamento farmacológico , Antioxidantes/uso terapêutico , Doenças Autoimunes/tratamento farmacológico , Betacoronavirus/efeitos dos fármacos , Betacoronavirus/imunologia , Catequina/uso terapêutico , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/patologia , Síndrome da Liberação de Citocina/patologia , Humanos , NF-kappa B/antagonistas & inibidores , Pandemias , Extratos Vegetais/uso terapêutico , Pneumonia Viral/imunologia , Pneumonia Viral/patologia , Fibrose Pulmonar/tratamento farmacológico , Fibrose Pulmonar/prevenção & controle , Fator de Transcrição STAT1/antagonistas & inibidores , Fator de Transcrição STAT3/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos
8.
Int J Nanomedicine ; 15: 4417-4429, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32606686

RESUMO

Purpose: Currently, the clinical benefits of tea polyphenols have contributed to the development of efficient systemic delivery systems with adequate bioavailability and stability. In this study, we aimed to establish a nanoparticle model to overcome the shortcomings of epigallocatechin gallate (EGCG) in the treatment of lung cancer. Materials and Methods: Poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) loaded with EGCG were prepared by the oil-in-water emulsion solvent evaporation technique. The characteristics of NPs, entrapment efficiency, and in vitro release were systematically evaluated. The cellular uptake, cytotoxic activity, and the effect of the formulation on cellular apoptosis of free-from EGCG and the NPs were compared. The interaction between protein-NF-κB and EGCG was detected by bio-layer interferometry (BLI). NF-κB signaling was evaluated by Western blotting and q-RT-PCR. The efficacy of the optimized nanoformulation was evaluated using a patient-derived tumor xenograft (PDX) model. Results: EGCG-loaded NPs (175.8±3.8 nm in size) demonstrated its optimal efficacy, with approximately 86.0% of encapsulation efficiency and 14.2% of loading efficiency. Additionally, EGCG-encapsulated PLGA-NPs offered a 3-4-fold dose advantage compared to free EGCG in terms of exerting antiproliferative effects and inducing apoptosis at lower doses (12.5, 25 µM). Molecular interaction assays demonstrated that EGCG binds to NF-κB with high affnity (KD=4.8×10-5 M). EGCG-NPs were more effective at inhibiting NF-κB activation and suppressing the expression of NF-κB-regulated genes than free EGCG. Furthermore, EGCG-NPs showed superior anticancer activity in the PDX model than free EGCG. Conclusion: These findings indicated that the prepared EGCG-NPs were more effective than free EGCG in inhibiting lung cancer tumors in the PDX model.


Assuntos
Antineoplásicos/uso terapêutico , Catequina/análogos & derivados , Neoplasias Pulmonares/tratamento farmacológico , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Catequina/uso terapêutico , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Liberação Controlada de Fármacos , Endocitose/efeitos dos fármacos , Humanos , Neoplasias Pulmonares/patologia , NF-kappa B/metabolismo , Nanopartículas/química
9.
Food Chem ; 333: 127400, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32673949

RESUMO

The conjugate prepared from (-)-epigallocatechin gallate (EGCG) and soy protein isolate (SPI) under alkaline and aerobic conditions was analyzed using a Nano-LC-Q-Orbitrap-MS/MS technique. The sulfhydryl and free amino groups of SPI were involved in covalent binding. Fifty-one peptides were conjugated with EGCG. Fifty-nine modified sites were identified, located on Cys, His, Arg, and Lys, respectively. It is the first time to confirm that each of the two phenolic rings of EGCG contained a reactive site that bound to an amino acid residue. The amino acid residue reactivity, amino acid sequence and composition affected the EGCG binding site in SPI. Lys and Arg residues are the most likely sites for modification, and modification appears to reduce IgE binding. This study is helpful to elucidate the pattern of covalent binding of polyphenols to proteins in food systems and provides a theoretical basis for the directional modification of soy proteins with polyphenols.


Assuntos
Catequina/análogos & derivados , Imunoglobulina E/metabolismo , Proteínas de Soja/química , Proteínas de Soja/metabolismo , Aminoácidos/metabolismo , Sítios de Ligação , Catequina/química , Polifenóis/metabolismo , Ligação Proteica
10.
Arch Biochem Biophys ; 690: 108446, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32593678

RESUMO

A simple NMR method to analyze the data obtained by NMR titration experiment of amyloid formation inhibitors against uniformly 15N-labeled amyloid-ß 1-42 peptide (Aß(1-42)) was described. By using solution nuclear magnetic resonance (NMR) measurement, the simplest method for monitoring the effects of Aß fibrilization inhibitors is the NMR chemical shift perturbation (CSP) experiment using 15N-labeled Aß(1-42). However, the flexible and dynamic nature of Aß(1-42) monomer may hamper the interpretation of CSP data. Here we introduced principal component analysis (PCA) for visualizing and analyzing NMR data of Aß(1-42) in the presence of amyloid inhibitors including high concentration osmolytes. We measured 1H-15N 2D spectra of Aß(1-42) at various temperatures as well as of Aß(1-42) with several inhibitors, and subjected all the data to PCA (PCA-HSQC). The PCA diagram succeeded in differentiating the various amyloid inhibitors, including epigallocatechin gallate (EGCg), rosmarinic acid (RA) and curcumin (CUR) from high concentration osmolytes. We hypothesized that the CSPs reflected the conformational equilibrium of intrinsically disordered Aß(1-42) induced by weak inhibitor binding rather than the specific molecular interactions.


Assuntos
Peptídeos beta-Amiloides/química , Fenóis/química , Análise de Componente Principal/métodos , Amiloide/metabolismo , Peptídeos beta-Amiloides/genética , Catequina/análogos & derivados , Catequina/química , Cinamatos/química , Curcumina/química , Depsídeos/química , Escherichia coli/genética , Humanos , Espectroscopia de Ressonância Magnética , Isótopos de Nitrogênio/química , Conformação Proteica , Temperatura , Termodinâmica
11.
Toxicol Appl Pharmacol ; 401: 115100, 2020 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-32512070

RESUMO

(-)-Epigallocatechin-3-gallate (EGCG) is the main bioactive component in tea (Camellia sinensis) catechins, and exhibits potential antitumor activity against colorectal cancer (CRC). However, the underlying mechanisms are largely unclear. We investigated the effects of EGCG on activities of CRC cells and the exact molecular mechanism. We used human colon cancer cells (HT-29) and exposed them to EGCG at various concentrations. The MTT assay, flow cytometry, and TUNEL staining were used to study the underlying mechanisms of EGCG (proliferation, apoptosis, autophagy). Western blotting was used to measure expression of marker proteins of the cell cycle, apoptosis, and autophagy. Using a combined microarray-based transcriptomic and ultra-high-performance liquid chromatography coupled with quadrupole-time-of-flight tandem mass spectrometry (UHPLC-QTOF/MS)-based metabolomic approach, we investigated the perturbed pathways induced by EGCG treatment at transcript and metabolite levels. Transcriptomic analyses showed that 486 genes were differentially expressed between untreated and EGCG-treated cells. Also, 88 differentially expressed metabolites were identified between untreated and EGCG-treated cells. The altered metabolites were involved in the metabolism of glutathione, glycerophospholipids, starch, sucrose, amino sugars, and nucleotide sugars. There was substantial agreement between the results of transcriptomics and metabolomics analyses. Our data indicate that the anticancer activity of EGCG against HT-29 cells is mediated by induction of cell-cycle arrest, apoptosis, and autophagy. EGCG modulates cancer-cell metabolic pathways. These results provide a platform for future molecular mechanistic studies of EGCG.


Assuntos
Anticarcinógenos/farmacologia , Catequina/análogos & derivados , Neoplasias do Colo/genética , Neoplasias do Colo/metabolismo , Metabolômica/métodos , Transcriptoma/efeitos dos fármacos , Anticarcinógenos/uso terapêutico , Catequina/farmacologia , Catequina/uso terapêutico , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/fisiologia , Neoplasias do Colo/tratamento farmacológico , Células HT29 , Humanos , Transcriptoma/fisiologia
12.
Food Chem ; 331: 127355, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32593042

RESUMO

Ara h1 is a major allergen from peanut. We investigated the effect of covalent conjugation of Ara h1 and dietary polyphenols on allergenicity and functional properties of Ara h1. Enzyme-linked immunosorbent assay revealed that the covalent conjugation of dietary polyphenols significantly reduced the IgE binding capacity of Ara h1. Covalent binding of dietary polyphenols with Ara h1 reduced histamine release by 40% in basophils. The decreased IgE binding capacity of Ara h1 could be ascribed to changes in protein conformation. The IgE epitope of Ara h1 might be blocked by polyphenols at the binding site. Analysis of pepsin digestion of Ara h1-polyphenol conjugates indicated that the covalent binding increased pepsin digestibility and reduced IgE binding capacity. Furthermore, covalent conjugation of Ara h1 with polyphenols decreased denaturation temperature and increased antioxidant activity. Ara h1 conjugated with polyphenols may be a promising approach for reducing the allergenicity of Ara h1.


Assuntos
Antígenos de Plantas/química , Antígenos de Plantas/imunologia , Catequina/análogos & derivados , Ácido Clorogênico/química , Proteínas de Membrana/química , Proteínas de Membrana/imunologia , Hipersensibilidade a Amendoim/imunologia , Proteínas de Plantas/química , Proteínas de Plantas/imunologia , Antígenos de Plantas/farmacologia , Antioxidantes/química , Arachis/química , Basófilos/efeitos dos fármacos , Basófilos/imunologia , Basófilos/metabolismo , Catequina/química , Catequina/imunologia , Catequina/metabolismo , Epitopos/metabolismo , Histamina/metabolismo , Humanos , Imunoglobulina E/metabolismo , Proteínas de Membrana/farmacologia , Proteínas de Plantas/farmacologia , Conformação Proteica , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Espectroscopia de Infravermelho com Transformada de Fourier
13.
Pestic Biochem Physiol ; 167: 104588, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32527428

RESUMO

Methyl parathion (MP) is a commonly used organophosphorus insecticide in commercial farming. It is well known that MP exposure can affect the function of nervous, respiratory, cardiovascular and reproductive systems. In our previous report we have demonstrated that MP exposure results in poor oocyte maturation and defective embryo development which is mainly mediated through oxidative stress. The present investigation was designed to explore whether using a potent free radical scavenger like Epigallocatechin-3-gallate (EGCG) can help in reducing the detrimental effects of MP on the oocytes. For the study, germinal vesicle (GV) stage oocytes collected from the ovaries of adult Swiss albino mice were subjected to in vitro maturation (IVM) in the presence or absence of MP (100 µg/mL) and/or EGCG (0.25 µM). MP significantly reduced the nuclear maturation rate, and resulted in poor cytoplasmic organization which was evident from the altered distribution pattern of mitochondria, endoplasmic reticulum and abnormal spindle organization. These changes were associated with significant elevation in oxidative stress and expression of ER stress markers such as 78 kDa Glucose regulated protein (GRP78) as well as X-box binding protein-1 (XBP1) in the oocytes. Further, the oocytes exposed to MP had lower activation rate and developmental potential. Supplementation of EGCG during IVM not only improved the nuclear maturation rate but also reduced the cytoplasmic abnormalities. These beneficial effects appear to be due to mitigation of oxidative and ER stress in oocytes. In conclusion, results of our study indicate that EGCG can help in alleviating MP-induced oocyte abnormalities.


Assuntos
Metil Paration , Animais , Catequina/análogos & derivados , Estresse do Retículo Endoplasmático , Camundongos , Oócitos , Estresse Oxidativo
14.
Am J Chin Med ; 48(4): 1005-1019, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32468825

RESUMO

Harboring insulin-producing cells, the pancreas has more interstitial insulin than any other organ. In vitro, insulin activates both insulin receptor (IR) and insulin-like growth factor-1 receptor (IGF1R) to stimulate pancreatic cancer cells. Whether intra-pancreatic insulin nourishes pancreatic cancer cells in vivo remains uncertain. In the present studies, we transplanted human pancreatic cancer cells orthotopically in euglycemic athymic mice whose intra-pancreatic insulin was intact or was decreased following pretreatment with streptozotocin (STZ). In the next eight weeks, the tumor carriers were treated with one of the IR/IGF1R antagonists penta-O-galloyl-[Formula: see text]-D-glucose (PGG) and epigallocatechin gallate (EGCG) or treated with vehicle. When pancreatic tumors were examined, their fraction occupied with living cells was decreased following STZ pretreatment and/or IR/IGF1R antagonism. Using Western blot, we examined tumor grafts for IR/IGF1R expression and activity. We also determined proteins that were downstream to IR/IGF1R and responsible for signal transduction, glycolysis, angiogenesis, and apoptosis. We demonstrated that STZ-induced decrease in intra-pancreatic insulin reduced IR/IGF1R expression and activity, decreased the proteins that promoted cell survival, and increased the proteins that promoted apoptosis. These suggest that intra-pancreatic insulin supported local cancer cells. When tumor carriers were treated with PGG or EGCG, the results were similar to those seen following STZ pretreatment. Thus, the biggest changes in examined proteins were usually seen when STZ pretreatment and PGG/EGCG treatment concurred. This suggests that intra-pancreatic insulin normally combated pharmacologic effects of PGG and EGCG. In conclusion, intra-pancreatic insulin nourishes pancreatic cancer cells and helps the cells resist IR/IGF1R antagonism.


Assuntos
Catequina/análogos & derivados , Taninos Hidrolisáveis/farmacologia , Insulina/fisiologia , Neoplasias Pancreáticas/patologia , Receptor de Insulina/antagonistas & inibidores , Animais , Catequina/farmacologia , Linhagem Celular Tumoral , Expressão Gênica/efeitos dos fármacos , Humanos , Insulina/metabolismo , Fator de Crescimento Insulin-Like I/genética , Fator de Crescimento Insulin-Like I/metabolismo , Masculino , Camundongos Nus , Receptor de Insulina/genética , Receptor de Insulina/metabolismo , Estreptozocina/farmacologia
15.
Arch Oral Biol ; 114: 104727, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32361019

RESUMO

OBJECTIVE: This study was conducted to evaluate and compare the antimicrobial efficacy of green tea and its extract epigallocatechin-3-gallate (EGCG) as a mouthwash in children. DESIGN: The study group included 47 children aged 5-12 years at high caries risk and prevalence. Children selected were asked to rinse with one of the substances (EGCG, green tea, chlorhexidine and distilled water) for one min. A non-stimulated salivary sample (2 mL) was collected at baseline and after rinsing. The concentration of cariogenic microorganisms (mutans streptococci and lactobacilli) was determined before and after rinsing based on the count of colony-forming units (CFU). CFU were counted with the aid of a stereomicroscope through the perfunctory identification of the morphological characteristics of CFU. The microbial reduction percentage was then calculated. RESULTS: The analysis of the effectiveness of the treatments showed that there was a significant reduction in relation to the values obtained before and after the mouthwash, both for mutans streptococci (pCHX = 0.001; pEGCG = 0.001; pGreen Tea = 0.005; pDistilled Water = 0.018) and lactobacilli (pCHX = 0.001; pEGCG = 0.002; pGreen Tea = 0.008; pDistilled Water = 0.033). The percentage of microbial reduction of both cariogenic microorganisms caused by the EGCG solution was higher than green tea and distilled water, but less than CHX. The percentage of microbial reduction by the EGCG solution for mutans streptococci was 79.9%, green tea 68.3%, distilled water 50.6% and CHX 95.5%. For lactobacilli, the percentage reduction of all solutions was relatively lower when compared to mutans streptococci. For the EGCG solution it was 72.09%, followed by green tea 59.17% and distilled water 41.96%, but less than CHX 86.02%. CONCLUSION: Rinsing with EGCG solution reduced the levels of mutans streptococci and lactobacilli in the oral cavity of children. Although EGCG had better antimicrobial activity than green tea, this study supports the effectiveness of both as an antibacterial mouthwash option. Both EGCG and green tea could be used as alternatives to chlorhexidine-based mouthwashes.


Assuntos
Catequina/análogos & derivados , Microbiota , Antissépticos Bucais/uso terapêutico , Extratos Vegetais/uso terapêutico , Chá/química , Catequina/uso terapêutico , Criança , Pré-Escolar , Humanos , Lactobacillaceae , Boca/microbiologia , Streptococcus mutans
16.
Proc Natl Acad Sci U S A ; 117(21): 11788-11798, 2020 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-32393630

RESUMO

Down syndrome (DS) is the most common form of intellectual disability. The cognitive alterations in DS are thought to depend on brain regions critical for learning and memory such as the prefrontal cortex (PFC) and the hippocampus (HPC). Neuroimaging studies suggest that increased brain connectivity correlates with lower intelligence quotients (IQ) in individuals with DS; however, its contribution to cognitive impairment is unresolved. We recorded neural activity in the PFC and HPC of the trisomic Ts65Dn mouse model of DS during quiet wakefulness, natural sleep, and the performance of a memory test. During rest, trisomic mice showed increased theta oscillations and cross-frequency coupling in the PFC and HPC while prefrontal-hippocampal synchronization was strengthened, suggesting hypersynchronous local and cross-regional processing. During sleep, slow waves were reduced, and gamma oscillations amplified in Ts65Dn mice, likely reflecting prolonged light sleep. Moreover, hippocampal sharp-wave ripples were disrupted, which may have further contributed to deficient memory consolidation. Memory performance in euploid mice correlated strongly with functional connectivity measures that indicated a hippocampal control over memory acquisition and retrieval at theta and gamma frequencies, respectively. By contrast, trisomic mice exhibited poor memory abilities and disordered prefrontal-hippocampal functional connectivity. Memory performance and key neurophysiological alterations were rescued after 1 month of chronic administration of a green tea extract containing epigallocatequin-3-gallate (EGCG), which improves executive function in young adults with DS and Ts65Dn mice. Our findings suggest that abnormal prefrontal-hippocampal circuit dynamics are candidate neural mechanisms for memory impairment in DS.


Assuntos
Síndrome de Down/fisiopatologia , Hipocampo/fisiologia , Córtex Pré-Frontal/fisiologia , Reconhecimento Psicológico/fisiologia , Animais , Catequina/análogos & derivados , Catequina/farmacologia , Modelos Animais de Doenças , Função Executiva/efeitos dos fármacos , Feminino , Hipocampo/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Rede Nervosa/efeitos dos fármacos , Rede Nervosa/fisiologia , Fármacos Neuroprotetores/farmacologia , Córtex Pré-Frontal/efeitos dos fármacos , Reconhecimento Psicológico/efeitos dos fármacos
17.
Food Chem ; 326: 126963, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32413754

RESUMO

Neat epigallocatechin gallate (EGCG) has low bioavailability and tuna oil (TO) is prone to oxidation. Broccoli byproducts (BBP) were used for preparing TO-BBP (25% oil, dry basis) and TO-EGCG-BBP (20% oil and 20% EGCG, dry basis) powders. The gross composition and surface fat of powders and morphology of reconstituted emulsions were characterized. Oxipres® data (80 °C, 5 bar oxygen pressure) showed that the TO-EGCG-BBP formulation was more oxidatively stable [Induction period (IP) > 100 h] than TO-BBP (IP ~ 20 h). During in vitro digestion, 90% of EGCG was recovered in the whole intestinal digesta of the TO-EGCG-BBP formulation compared to 76% for the EGCG-BBP formulation and 66% for the neat EGCG. The use of BBP for co-delivering EGCG and TO increases oxidative stability of TO and improves EGCG stability during in vitro digestion. This study highlights the potential for formulating functional ingredient with BBP and contribute to food waste reduction.


Assuntos
Brassica , Catequina/análogos & derivados , Emulsões/química , Óleos de Peixe/administração & dosagem , Atum , Animais , Disponibilidade Biológica , Catequina/administração & dosagem , Catequina/química , Catequina/farmacocinética , Suplementos Nutricionais , Digestão , Óleos de Peixe/química , Óleos de Peixe/farmacocinética , Alimentos , Oxirredução , Pós , Eliminação de Resíduos , Resíduos
18.
J Nat Med ; 74(4): 673-679, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32472528

RESUMO

(-)-epigallocatechin-3-O-gallate (EGCG) is a bioactive polyphenol in green tea. Previous studies have demonstrated the beneficial effects of EGCG on muscle mass and muscle atrophy. In the current study, we investigated the mechanisms underlying effect of EGCG on muscle atrophy. It was demonstrated that EGCG suppressed muscle-specific ubiquitin ligase, muscle RING Finger 1 (MuRF1) expression through 67-kDa laminin receptor (67LR). Previous studies have shown that eriodictyol potentiates the anti-tumor activities of EGCG by amplifying 67LR signaling. Therefore, we investigated the effects of EGCG and eriodictyol on the MuRF1 expression in C2C12 myotubes. The combined treatment of EGCG and eriodictyol significantly suppressed MuRF1 expression in dexamethasone-treated C2C12 myotubes. Tail suspension was maintained for 10 consecutive days using C57BL6/J mice, and during this time EGCG and eriodictyol were orally administered. In the gastrocnemius muscle, the muscle mass loss was inhibited by the combination of EGCG and eriodictyol. Therefore, EGCG may prevent muscle atrophy by inducing 67LR signaling and eriodictyol amplifies this pathway.


Assuntos
Catequina/análogos & derivados , Flavanonas/metabolismo , Proteínas Musculares/metabolismo , Plantas/química , Receptores de Laminina/metabolismo , Proteínas com Motivo Tripartido/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Animais , Catequina/química , Regulação para Baixo , Camundongos , Transdução de Sinais
19.
J Appl Microbiol ; 129(3): 601-611, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32281733

RESUMO

AIMS: To study the mechanism of the antibacterial action of tea polyphenols such as catechins and theaflavins against Bacillus coagulans, and the interaction of epigallocatechin gallate (EGCg) or theaflavin 3,3'-di-O-gallate (TFDG) with the surface of B. coagulans cells was investigated. METHODS AND RESULTS: The antibacterial activities of EGCg and TFDG against B. coagulans cells were measured by counting of the viable cells after the mixing with each polyphenol. Bactericidal effect of TFDG was shown at the concentration of greater than or equal to 62·5 mg l-1 ; however, at the same concentration, EGCg did not. According to the results of two dimensional (2D)-electrophoresis analysis, TFDG seemed to interact with cytoplasmic membrane proteins. The activity of the glucose transporters of the cells decreased 40% following the treatment with TFDG of 62·5 mg l-1 ; however, this decrease was only slight in case of EGCg. This result was in accordance with the strength of their bactericidal activities. CONCLUSION: Our results suggest that the direct interaction between membrane proteins and TFDG is an important factor in the antibacterial activity of polymerized catechins, affecting their functions and leading to cell death. SIGNIFICANCE AND IMPACT OF THE STUDY: Tea polyphenols can effectively use the prevention of product spoilage in the food and beverage industry.


Assuntos
Antibacterianos/farmacologia , Bacillus coagulans/efeitos dos fármacos , Biflavonoides/farmacologia , Catequina/análogos & derivados , Bacillus coagulans/metabolismo , Biflavonoides/metabolismo , Catequina/metabolismo , Catequina/farmacologia , Membrana Celular/efeitos dos fármacos , Glucose/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Viabilidade Microbiana/efeitos dos fármacos , Polifenóis/química , Polifenóis/farmacologia , Chá/química
20.
Oncol Rep ; 43(6): 1885-1896, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32236585

RESUMO

Epigallocatechin­3­gallate (EGCG), a polyphenol present in green tea, exhibits anticancer effects in various types of cancer. A number of studies have focused on the effects of EGCG on lung cancer, but not ovarian cancer. Previous reports have implicated that EGCG suppressed ovarian cancer cell proliferation and induced apoptosis, but its potential anticancer mechanisms and signaling pathways remain unclear. Thus, it is necessary to determine the anti­ovarian cancer effects of EGCG and explore the underlying mechanisms. In the present study, EGCG exerted stronger proliferation inhibition on SKOV3 cells compared with A549 cells and induced apoptosis in SKOV3 cells, as well as upregulated PTEN expression and downregulated the expression of phosphoinositide­dependent kinase­1 (PDK1), phosphor (p)­AKT and p­mTOR. These effects were reversed by the PTEN inhibitor VO­Ohpic trihydrate. The results of the mouse xenograft experiment demonstrated that 50 mg/kg EGCG exhibited increased tumor growth inhibition compared with 5 mg/kg paclitaxel. In addition, PTEN expression was upregulated, whereas the expression levels of PDK1, p­AKT and p­mTOR were downregulated in the EGCG treatment group compared with those in untreated mice in vivo. In conclusion, the results of the present study provided a new underlying mechanism of the effect of EGCG on ovarian cancer and may lead to the development of EGCG as a candidate drug for ovarian cancer therapy.


Assuntos
Antineoplásicos Fitogênicos/administração & dosagem , Catequina/análogos & derivados , Neoplasias Ovarianas/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Células A549 , Animais , Antineoplásicos Fitogênicos/farmacologia , Catequina/administração & dosagem , Catequina/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Camundongos , Neoplasias Ovarianas/metabolismo , PTEN Fosfo-Hidrolase/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
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