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1.
Curr Pharm Des ; 29(24): 1939-1957, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37592794

RESUMO

BACKGROUND: Myricitrin is a flavonol glycoside possessing beneficial effects on obesity, a rising global health issue that affects millions of people worldwide. However, the involving target and mechanism remain unclear. OBJECTIVE: In the present study, the anti-obesity targets and molecular mechanisms of Myricitrin, along with another flavanol Epigallocatechin gallate (EGCG), were explored through network pharmacology, bioinformatics, and molecular docking. METHODS: The potential targets for Myricitrin and EGCG were obtained from Pharmmaper, SwissTargetPrediction, TargetNet, SEA, Super-PRED, TCMSP, and STICH databases. Meanwhile, DEG targets were retrieved from GEO datasets, and obesity targets were collected from DrugBank, TTD, DisGeNet, OMIM, GeneCards, PharmGKB, and CTD databases. GO and KEGG pathway enrichment analyses were conducted through Metascape online tool. Protein-protein interaction (PPI) networks were also constructed for compound, DEG, and obesity targets to screen the core targets through MCODE analysis. The further screened-out key targets were finally verified through the compound-target-pathway-disease network, mRNA expression level, target-organ correlation, and molecular docking analyses. RESULTS: In total, 538 and 660 targets were identified for Myricitrin and EGCG, respectively, and 725 DEG targets and 1880 obesity targets were retrieved. GO and KEGG analysis revealed that Myricitrin and EGCG targets were enriched in the pathways correlating with obesity, cancer, diabetes, and cardiovascular disease. Furthermore, the intersection core targets for Myricitrin and EGCG function mainly through the regulation of responses to hormones and involving pathways in cancer. Above all, androgen receptor (AR), cyclin D1 (CCND1), early growth response protein 1 (EGR1), and estrogen receptor (ERS1) were identified as key targets in the compound-target-pathway-disease network for both Myricitrin and EGCG, with significant different mRNA expression between weight loss and control groups. Target-organ correlation analysis exhibited that AR and CCND1 showed high expression in adipocytes. Molecular docking also revealed good binding abilities between Myricitrin and EGCG, and all four receptor proteins. CONCLUSION: The present research integrated network pharmacology and bioinformatics approach to reveal the key targets of Myricitrin and EGCG against obesity. The results provided novel insights into the molecular mechanism of Myricitrin and EGCG in obesity prevention and treatment and laid the foundations for the exploitation of flavonoid-containing herbal resources.


Assuntos
Flavonoides , Farmacologia em Rede , Humanos , Simulação de Acoplamento Molecular
2.
J Mol Biol ; 435(7): 167996, 2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-36754343

RESUMO

Mobile genetic elements (MGEs) such as bacteriophages and their host prokaryotes are trapped in an eternal battle against each other. To cope with foreign infection, bacteria and archaea have evolved multiple immune strategies, out of which CRISPR-Cas system is up to now the only discovered adaptive system in prokaryotes. Despite the fact that CRISPR-Cas system provides powerful and delicate protection against MGEs, MGEs have also evolved anti-CRISPR proteins (Acrs) to counteract the CRISPR-Cas immune defenses. To date, 46 families of Acrs targeting type I CRISPR-Cas system have been characterized, out of which structure information of 21 families have provided insights on their inhibition strategies. Here, we review the non-canonical inhibition strategies adopted by Acrs targeting type I CRISPR-Cas systems based on their structure information by incorporating the most recent advances in this field, and discuss our current understanding and future perspectives. The delicate interplay between type I CRISPR-Cas systems and their Acrs provides us with important insights into the ongoing fierce arms race between prokaryotic hosts and their predators.


Assuntos
Archaea , Bactérias , Bacteriófagos , Sistemas CRISPR-Cas , Sequências Repetitivas Dispersas , Proteínas Virais , Archaea/genética , Archaea/virologia , Bactérias/genética , Bactérias/virologia , Bacteriófagos/genética , Bacteriófagos/metabolismo , Sistemas CRISPR-Cas/genética , Evolução Molecular , Proteínas Virais/química , Proteínas Virais/genética , Conformação Proteica
3.
J Biol Chem ; 298(7): 102124, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35697070

RESUMO

Prokaryotes evolved clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) proteins as a kind of adaptive immune defense against mobile genetic elements including harmful phages. To counteract this defense, many mobile genetic elements in turn encode anti-CRISPR proteins (Acrs) to inactivate the CRISPR-Cas system. While multiple mechanisms of Acrs have been uncovered, it remains unknown whether other mechanisms are utilized by uncharacterized Acrs. Here, we report a novel mechanism adopted by recently identified AcrIF23. We show that AcrIF23 interacts with the Cas2/3 helicase-nuclease in the type I-F CRISPR-Cas system, similar to AcrIF3. The structure of AcrIF23 demonstrated a novel fold and structure-based mutagenesis identified a surface region of AcrIF23 involved in both Cas2/3-binding and its inhibition capacity. Unlike AcrIF3, however, we found AcrIF23 only potently inhibits the DNA cleavage activity of Cas2/3 but does not hinder the recruitment of Cas2/3 to the CRISPR RNA-guided surveillance complex (the Csy complex). Also, in contrast to AcrIF3 which hinders substrate DNA recognition by Cas2/3, we show AcrIF23 promotes DNA binding to Cas2/3. Taken together, our study identifies a novel anti-CRISPR mechanism used by AcrIF23 and highlights the diverse mechanisms adopted by Acrs.


Assuntos
Bacteriófagos , Proteínas Associadas a CRISPR , Bacteriófagos/genética , Bacteriófagos/metabolismo , Proteínas Associadas a CRISPR/metabolismo , Sistemas CRISPR-Cas , DNA/metabolismo , Endonucleases/metabolismo
4.
Nat Commun ; 13(1): 1931, 2022 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-35411005

RESUMO

CRISPR-Cas systems are prokaryotic adaptive immune systems and phages use anti-CRISPR proteins (Acrs) to counteract these systems. Here, we report the structures of AcrIF24 and its complex with the crRNA-guided surveillance (Csy) complex. The HTH motif of AcrIF24 can bind the Acr promoter region and repress its transcription, suggesting its role as an Aca gene in self-regulation. AcrIF24 forms a homodimer and further induces dimerization of the Csy complex. Apart from blocking the hybridization of target DNA to the crRNA, AcrIF24 also induces the binding of non-sequence-specific dsDNA to the Csy complex, similar to AcrIF9, although this binding seems to play a minor role in AcrIF24 inhibitory capacity. Further structural and biochemical studies of the Csy-AcrIF24-dsDNA complexes and of AcrIF24 mutants reveal that the HTH motif of AcrIF24 and the PAM recognition loop of the Csy complex are structural elements essential for this non-specific dsDNA binding. Moreover, AcrIF24 and AcrIF9 display distinct characteristics in inducing non-specific DNA binding. Together, our findings highlight a multifunctional Acr and suggest potential wide distribution of Acr-induced non-specific DNA binding.


Assuntos
Bacteriófagos , Proteínas Associadas a CRISPR , Bacteriófagos/genética , Bacteriófagos/metabolismo , Proteínas Associadas a CRISPR/metabolismo , Sistemas CRISPR-Cas , DNA/metabolismo , Proteínas Virais/metabolismo
5.
RNA Biol ; 18(sup2): 562-573, 2021 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-34606423

RESUMO

Phage infection is one of the major threats to prokaryotic survival, and prokaryotes in turn have evolved multiple protection approaches to fight against this challenge. Various delicate mechanisms have been discovered from this eternal arms race, among which the CRISPR-Cas systems are the prokaryotic adaptive immune systems and phages evolve diverse anti-CRISPR (Acr) proteins to evade this immunity. Until now, about 90 families of Acr proteins have been identified, out of which 24 families were verified to fight against subtype I-F CRISPR-Cas systems. Here, we review the structural and biochemical mechanisms of the characterized type I-F Acr proteins, classify their inhibition mechanisms into two major groups and provide insights for future studies of other Acr proteins. Understanding Acr proteins in this context will lead to a variety of practical applications in genome editing and also provide exciting insights into the molecular arms race between prokaryotes and phages.


Assuntos
Bacteriófagos/fisiologia , Sistemas CRISPR-Cas , Interações Hospedeiro-Patógeno , Proteínas Virais/química , Proteínas Virais/metabolismo , Animais , Sítios de Ligação , Proteínas Associadas a CRISPR/química , Proteínas Associadas a CRISPR/metabolismo , DNA Bacteriano/química , DNA Bacteriano/metabolismo , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Ativação Enzimática , Edição de Genes , Humanos , Interações Microbianas , Modelos Moleculares , Conformação Proteica , Domínios e Motivos de Interação entre Proteínas , Relação Estrutura-Atividade
6.
Nucleic Acids Res ; 49(17): 10178-10191, 2021 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-34432044

RESUMO

CRISPR-Cas systems are bacterial adaptive immune systems, and phages counteract these systems using many approaches such as producing anti-CRISPR (Acr) proteins. Here, we report the structures of both AcrIF14 and its complex with the crRNA-guided surveillance (Csy) complex. Our study demonstrates that apart from interacting with the Csy complex to block the hybridization of target DNA to the crRNA, AcrIF14 also endows the Csy complex with the ability to interact with non-sequence-specific dsDNA as AcrIF9 does. Further structural studies of the Csy-AcrIF14-dsDNA complex and biochemical studies uncover that the PAM recognition loop of the Cas8f subunit of the Csy complex and electropositive patches within the N-terminal domain of AcrIF14 are essential for the non-sequence-specific dsDNA binding to the Csy-AcrIF14 complex, which is different from the mechanism of AcrIF9. Our findings highlight the prevalence of Acr-induced non-specific DNA binding and shed light on future studies into the mechanisms of such Acr proteins.


Assuntos
Sistemas CRISPR-Cas/genética , Proteínas de Ligação a DNA/metabolismo , DNA/metabolismo , Endodesoxirribonucleases/metabolismo , Pseudomonas aeruginosa/genética , Bacteriófagos/genética , Bacteriófagos/crescimento & desenvolvimento , Proteínas Associadas a CRISPR/metabolismo , DNA/genética , Proteínas de Ligação a DNA/antagonistas & inibidores , Conformação Proteica , Pseudomonas aeruginosa/virologia , Proteínas Virais/genética , Proteínas Virais/metabolismo
7.
Mol Cell ; 80(3): 512-524.e5, 2020 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-33049228

RESUMO

CRISPR-Cas systems are bacterial anti-viral systems, and phages use anti-CRISPR proteins (Acrs) to inactivate these systems. Here, we report a novel mechanism by which AcrIF11 inhibits the type I-F CRISPR system. Our structural and biochemical studies demonstrate that AcrIF11 functions as a novel mono-ADP-ribosyltransferase (mART) to modify N250 of the Cas8f subunit, a residue required for recognition of the protospacer-adjacent motif, within the crRNA-guided surveillance (Csy) complex from Pseudomonas aeruginosa. The AcrIF11-mediated ADP-ribosylation of the Csy complex results in complete loss of its double-stranded DNA (dsDNA) binding activity. Biochemical studies show that AcrIF11 requires, besides Cas8f, the Cas7.6f subunit for binding to and modifying the Csy complex. Our study not only reveals an unprecedented mechanism of type I CRISPR-Cas inhibition and the evolutionary arms race between phages and bacteria but also suggests an approach for designing highly potent regulatory tools in the future applications of type I CRISPR-Cas systems.


Assuntos
Proteínas Associadas a CRISPR/antagonistas & inibidores , Sistemas CRISPR-Cas/fisiologia , Proteínas Virais/metabolismo , ADP-Ribosilação/fisiologia , Proteínas de Bactérias/genética , Bacteriófagos/genética , Proteínas Associadas a CRISPR/genética , Proteínas Associadas a CRISPR/metabolismo , Sistemas CRISPR-Cas/genética , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Microscopia Crioeletrônica/métodos , DNA/metabolismo , Modelos Moleculares , RNA Bacteriano/metabolismo , Proteínas Virais/genética
8.
Sci Rep ; 10(1): 4808, 2020 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-32179776

RESUMO

Morus and Broussonetia trees are widely used as food and/or feed. Among 23 phenolics identified from leaves of five Moraceae species using UPLC-QTOF-MS/MS, 15 were screened using DPPH/ABTS-guided HPLCs, including seven weak (flavonoids with one hydroxyl on B-ring) and eight strong (four caffeoylquinic acids and four flavonoids, each with a double hydroxyl on B-ring) antioxidants. We then determined the activity and synergistic effects of individual antioxidants and a mixture of the eight strongest antioxidants using DPPH-guided HPLC. Our findings revealed that (1) flavonoid glucuronide may have a more negative effect on antioxidant activity than glucoside, and (2) other compounds in the mixture may exert a negative synergistic effect on antioxidant activity of the four flavonoids with B-ring double hydroxyls but not the four caffeoylquinic acids. In conclusion, the eight phenolics with the strongest antioxidant ability reliably represented the bioactivity of the five extracts examined in this study. Moreover, the Morus alba hybrid had more phenolic biosynthesis machinery than its cross-parent M. alba, whereas the Broussonetia papyrifera hybrid had significantly less phenolic machinery than B. papyrifera. This difference is probably the main reason for livestock preference for the hybrid of B. papyrifera over B. papyrifera in feed.


Assuntos
Antioxidantes , Broussonetia/química , Flavonoides/análise , Flavonoides/farmacologia , Moraceae/química , Fenóis/análise , Fenóis/farmacologia , Extratos Vegetais/química , Folhas de Planta/química , Árvores/química , Benzotiazóis , Compostos de Bifenilo , Cromatografia Líquida de Alta Pressão/métodos , Radicais Livres , Picratos , Relação Estrutura-Atividade , Ácidos Sulfônicos , Espectrometria de Massas em Tandem/métodos
9.
Int J Mol Sci ; 20(21)2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31683574

RESUMO

Daxueteng, the liana stem of Sargentodoxa cuneata, is a widely used Traditional Chinese Medicine facing the overflow of its commercial adulterants. A method for discriminating adulterants and screening potential candidate alternatives of S. cuneata was thus established. Total phenols and flavonoids of S. cuneata and its six adulterants and their abilities to scavenge DPPH• and ABTS•+, to absorb peroxyl radicals (ORAC), and to inhibit AAPH-induced supercoiled plasmid DNA strand scission were comprehensively assessed. Polygonum cuspidatum and Bauhinia championii, two of the six adulterants of S. cuneate, shared considerably higher antioxidant activities as well as phenolic contents and, therefore, were considered as potential candidate alternatives. Phenolic compositions of the two potential candidate alternatives and S. cuneata itself were further determined by UPLC-QTOF-MS/MS. Totally 38 phenolics, including four hydroxybenzoic acids, two tyrosols, two caffeoylquinic acids, seven flavanol or its oligomers, two lignans, three hydroxycinnamic acids, six stilbenes, seven anthraquinones, and five flavanones were determined from three species. Furthermore, contents of different phenolic categories were semi-quantified and the major antioxidant contributors of S. cuneata and the two potential candidate alternatives were subsequently determined. It is concluded that tyrosols and caffeoylquinic acids were unique categories making great antioxidant contributions in S. cuneata and thus were considered as effective biomarkers in distinguishing its potential candidate alternatives.


Assuntos
Antioxidantes/análise , Contaminação de Medicamentos/prevenção & controle , Medicamentos de Ervas Chinesas/análise , Medicina Tradicional Chinesa/normas , Fenóis/análise , Ranunculales/química , Cromatografia Líquida/métodos , Medicamentos de Ervas Chinesas/classificação , Flavonoides/análise , Lignanas/análise , Medicina Tradicional Chinesa/estatística & dados numéricos , Extratos Vegetais/análise , Ácido Quínico/análogos & derivados , Ácido Quínico/análise , Espectrometria de Massas em Tandem
10.
Molecules ; 24(5)2019 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-30857315

RESUMO

Dried flower buds of Lonicera japonica and L. macranthoides have long been used as herbs in numerous Chinese traditional medicines. Comparisons of three phenolic fractions (i.e., free, esterified, and insoluble-bound phenolics) in three different organs (i.e., flower, leaf, and stem) of the two species revealed that the free phenolics were the highest in terms of total phenol and total flavonoid content, composed of the most numerous phenolics and flavonoids; thus, they exhibited the most excellent antioxidant activities (2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonate) (ABTS), and oxygen radical absorbance capacity (ORAC)), as well as protective effects on DNA damage induced by free radicals. In identical free and esterified phenolics of a same organ, higher contents and bioactivities were observed in L. macranthoides than in L. japonica. Phenolics identified by ultra-performance liquid chromatography with a diode array detector, alongside tandem mass spectrometry coupled with a quadrupole time-of-flight mass spectrometer (UPLC-DAD⁻QTOF-MS/MS) mainly included chlorogenic acid and its five derivatives, three flavonoids that were only found in the free phenolic fraction and closely correlated with its bioactivity, and caffeic acid that was the major contributor to antioxidant activity of the esterified and insoluble-bound phenolic fractions. It was, thus, concluded that, like L. japonica, L. macranthoides, which was underestimated since being separately listed by the 2010 edition of the Chinese Pharmacopoeia, is also a good (and better) herbal medicine.


Assuntos
Lonicera/química , Fenóis/química , Antioxidantes/química , Compostos de Bifenilo/química , Cromatografia Líquida de Alta Pressão , Dano ao DNA/genética , Picratos/química
11.
Inflammopharmacology ; 27(5): 1055-1069, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30689101

RESUMO

To characterise bioactive phenolics and confirm anti-inflammatory indicators in Porana sinensis stem, 23 phenolics were identified by UPLC-QTOF-MS/MS from crude extract (CE) prepared optimally with 80% methanol. Further fractionalisation using D101 macroporous resin resulted in predominant enrichment of total phenols and flavonoids into Fr.II. Correspondingly, the bioactive components-enriched Fr.II exhibited the lowest IC50 for scavenging DPPH and ABTS and the highest oxygen radical absorbance capacity or ORAC followed by Fractions Fr.I + Fr.II, CE and Fr.I, implying that certain phenolics possessing lower antioxidant activity completely remained in CE. Anti-inflammatory tests with LPS-stimulated RAW264.7 cells showed that CE possessed the highest inhibition of NO-production followed by Fr.II and Fr.I, meaning that CE might contain compounds that expressed higher anti-inflammatory but lower antioxidant activities or possessed synergistic interactions but were not fractionated together. Quantitative determination of nine major phenolics revealed that caffeic acid and 3-, 4- and 5-caffeoylquinic acids were concentrated into Fr.I, whereas scopolin, scopoletin and 3,5-, 3,4- and 4,5-dicaffeoylquinic acids were enriched into Fr.II. Further experiments with three selected major phenolics reduced the proposed synergistic interactions. Anti-inflammatory tests of the nine major phenolics evidenced that caffeic acid and the six caffeoylquinic acids produced higher, and the three dicaffeoylquinic acids at 140 µΜ showed even more significant activities in suppressing NO-production and mRNA expression of iNOS, TNF-α, COX-2, and IL-6, suggesting that these three dicaffeoylquinic acids could be indicators of the anti-inflammatory potential of P. sinensis stem. These findings provided novel insights for potential use of P. sinensis or liana, as an important source of natural antioxidants, against inflammation.


Assuntos
Anti-Inflamatórios/farmacologia , Convolvulaceae/química , Fenóis/farmacologia , Animais , Antioxidantes/farmacologia , Ácidos Cafeicos/farmacologia , Linhagem Celular , Cromatografia Líquida de Alta Pressão/métodos , Flavonoides/farmacologia , Lipopolissacarídeos/farmacologia , Camundongos , Extratos Vegetais/farmacologia , Ácido Quínico/análogos & derivados , Ácido Quínico/farmacologia , Células RAW 264.7 , Espectrometria de Massas em Tandem/métodos
12.
R Soc Open Sci ; 5(6): 180364, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30110480

RESUMO

This study aimed to investigate effects of thermal treatments on major phenolics and their antioxidant contributions in Acer truncatum leaves and flowers (ATL and ATF, respectively). With ultra performance liquid chromatography-diode array detector-quadrupole time-of-flight-mass spectrometer/mass spectrometer, phenolic compositions of ATF were first characterized and compared with those of ATL. An optimized high performance liquid chromatography fingerprint was then established, and 10 major phenolics existing in both ATL and ATF were quantified. Gallic acid derivatives and flavonol-3-O-glycosides were found to be their dominant phenolic constituents, with the former being key constituents which was affected by thermal treatments and further influencing the variations of total phenols. Moreover, the mechanism underlining the changes of phenolics in ATL and ATF by the treatments was characterized as a thermolhydrolysis process. During thermal treatments, polymerized gallotannins were hydrolysed to 1,2,3,4,6-pentakis-O-galloyl-ß-d-glucose, ethyl gallate and gallic acid, resulting in more than fivefold and twofold increase of their contents in ATL and ATF, respectively. By contrast, contents and antioxidant contributions of flavonol-3-O-glycosides gradually decreased during the process.\absbreak Overall, this is, to our knowledge, the first report on the effects of thermal treatments on phenolics and their antioxidant contributions in ATL and ATF, and the three gallic acid derivatives with potentially higher bioactivity could be efficiently achieved by thermal treatments.

13.
Chem Cent J ; 12(1): 82, 2018 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-30003449

RESUMO

A flavonoids-rich extract of Scutellaria baicalensis shoots and its eight high content flavonoids were investigated for their inhibitory effects against α-glucosidase and α-amylase. Results show that abilities of the extract in inhibiting the two enzymes were obviously higher than those of acarbose. Moreover, inhibitory abilities of all the eight individual flavonoids against the two enzymes show exactly a same order (i.e., apigenin > baicalein > scutellarin > chrysin > apigenin-7-O-glucuronide > baicalin > chrysin-7-O-glucuronide > isocarthamidin-7-O-glucuronide), and their structure-activity relationship could be well-interpretated by the refined assign-score method. Furthermore, based on the inhibitory abilities and their contents in the extract, it was found that the eight flavonoids made predominant contributions, among which baicalein and scutellarin played roles as preliminary contributors, to overall inhibitory effects of the extract against the two enzymes. Beyond these, contributions of the eight flavonoids to the overall enzyme inhibitory activity were compared with those to the overall antioxidant activity characterized in our recent study, and it could be inferred that within the basic flavonoid structure the hydroxyl on C-4' of ring B was more effective than that on C-6 of ring A in enzyme inhibitory activities while they behaved inversely in antioxidant activities; scutellarin and apigenin contributed more to the overall enzyme inhibitory activity, and baicalin and scutellarin, to the overall antioxidant activity of the extract; and flavonoids of the extract, apart from directly inhibiting enzymes, might also be conducive to curing type 2 diabetes via scavenging various free radicals caused by increased oxidative stresses.

14.
Molecules ; 23(5)2018 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-29710864

RESUMO

Our previous reports showed that crude extract prepared with 50% ethanol (ethanol crude extract, ECE) from Mongolian oak cups possessed excellent in vitro antioxidant capacities as well as inhibitory activities against α-glucosidase, α-amylase and protein glycation caused by its enrichment in phenolics, including mainly ellagic acid, kaempferol and their derivatives. Nevertheless, few in vivo studies on antidiabetic activities of these phenolics were conducted. The present study investigated hypoglycemic effects with normal and diabetic rats being administrated orally without or with ECE at 200 and 800 mg/kg for 15 days. In normal rats, no significant differences were exhibited after ECE administration in body weight, fasting blood glucose level, levels of cholesterol, triglyceride, LDL and AST in serum, organ indexes, and levels of GSH and MDA in organs. In diabetic rats, the fasting blood glucose level, indexes of heart and liver, and levels of cholesterol and triglyceride in serum and MDA in heart tissue were significantly decreased. Moreover, HDL levels in serum and SOD activities in the four organs of diabetic rats were significantly improved after ECE administration at 800 mg/kg. Thus, in addition to inhibiting α-glucosidase, α-amylase and protein glycation reported previously, oak cups might contain novel dietary phytonutrients in preventing abnormal changes in blood glucose and lipid profile and attenuating oxidant stress in vivo. The results also implied that it is ellagic acid, kaempferol and their derivatives enriched in ECE that might play vital roles in managing type 1 as well as type 2 diabetes.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/química , Fenóis/administração & dosagem , Fenóis/química , Quercus/química , Administração Oral , Aloxano , Animais , Glicemia/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Colesterol/sangue , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/metabolismo , Ácido Elágico/administração & dosagem , Ácido Elágico/farmacologia , Hipoglicemiantes/farmacologia , Quempferóis/administração & dosagem , Quempferóis/farmacologia , Camundongos , Fenóis/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Triglicerídeos/sangue
15.
Molecules ; 22(2)2017 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-28165408

RESUMO

This study is the first to report the use of response surface methodology to improve phenolic yield and antioxidant activity of Acer truncatum leaves extracts (ATLs) obtained by ultrasonic-assisted extraction. The phenolic composition in ATLs extracted under the optimized conditions were characterized by UPLC-QTOF-MS/MS. Solvent and extraction time were selected based on preliminary experiments, and a four-factors-three-levels central composite design was conducted to optimize solvent concentration (X1), material-to-liquid ratio (X2), ultrasonic temperature (X3) and power (X4) for an optimal total phenol yield (Y1) and DPPH• antioxidant activity (Y2). The results showed that the optimal combination was ethanol:water (v:v) 66.21%, material-to-liquid ratio 1:15.31 g/mL, ultrasonic bath temperature 60 °C, power 267.30 W, and time 30 min with three extractions, giving a maximal total phenol yield of 7593.62 mg gallic acid equivalent/100 g d.w. and a maximal DPPH• antioxidant activity of 74,241.61 µmol Trolox equivalent/100 g d.w. Furthermore, 22 phenolics were first identified in ATL extract obtained under the optimized conditions, indicating that gallates, gallotannins, quercetin, myricetin and chlorogenic acid derivatives were the main phenolic components in ATL. What's more, a gallotannins pathway existing in ATL from gallic acid to penta-O-galloylglucoside was proposed. All these results provide practical information aiming at full utilization of phenolics in ATL, together with fundamental knowledge for further research.


Assuntos
Acer/química , Antioxidantes/química , Antioxidantes/farmacologia , Extração Líquido-Líquido , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Ondas Ultrassônicas , Cromatografia Líquida de Alta Pressão , Extração Líquido-Líquido/métodos , Fenóis/química , Compostos Fitoquímicos/química , Solventes , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Temperatura , Fatores de Tempo
16.
Molecules ; 20(3): 3758-75, 2015 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-25723850

RESUMO

Ischemia-Reperfusion (I/R) injury causes ROS overproduction, creating oxidative stress, and can trigger myocyte death, resulting in heart failure. Tyrosol is an antioxidant abounded in diets and medicine. Our objective was to investigate the protective effect of tyrosol on I/R-caused mortality in H9c2 cardiomyocytes through its influence on ROS, Hsp70, ERK, JNK, Bcl-2, Bax and caspase-8. A simulated I/R model was used, myocytes loss was examined by MTT, and ROS levels were measured using DCFH-DA. Nuclear condensation and caspase-3 activity were assessed by DAPI staining and fluorometric assay. Phosphorylated ERK and JNK were determined by electrochemiluminescent ELISA, and Hsp70, Bcl-2, Bax and caspase-8 were examined by Western blotting. Results show that tyrosol salvaged myocyte loss, inhibited nuclear condensation and caspase-3 activity dose-dependently, indicating its protection against I/R-caused myocyte loss. Furthermore, tyrosol significantly inhibited ROS accumulation and activation of ERK and JNK, augmenting Hsp70 expression. Besides, tyrosol inhibited I/R-induced apoptosis, associated with retained anti-apoptotic Bcl-2 protein, and attenuated pro-apoptotic Bax protein, resulting in a preservation of Bcl-2/Bax ratio. Finally, tyrosol notably decreased cleaved caspase-8 levels. In conclusion, cytoprotection of tyrosol in I/R-caused myocyte mortality was involved with the mitigation of ROS, prohibition of the activation of ERK, JNK and caspase-8, and elevation of Hsp70 and Bcl-2/Bax ratio.


Assuntos
Apoptose/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , MAP Quinase Quinase 4/metabolismo , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Miócitos Cardíacos/efeitos dos fármacos , Álcool Feniletílico/análogos & derivados , Espécies Reativas de Oxigênio/metabolismo , Animais , Antioxidantes/farmacologia , Proteínas Reguladoras de Apoptose/metabolismo , Células Cultivadas , Citoproteção , Immunoblotting , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/patologia , Miócitos Cardíacos/metabolismo , Álcool Feniletílico/farmacologia , Fosforilação/efeitos dos fármacos , Ratos , Transdução de Sinais/efeitos dos fármacos
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