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Małecka M, Skoczyńska A, Goodman DM, Hartinger CG, Budzisz E. Biological properties of ruthenium(II)/(III) complexes with flavonoids as ligands. Coord Chem Rev 2021. [DOI: 10.1016/j.ccr.2021.213849] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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2
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Panda A, Karhadkar S, Acharya B, Banerjee A, De S, Dasgupta S. Enhancement of angiogenin inhibition by polyphenol-capped gold nanoparticles. Biopolymers 2021; 112:e23429. [PMID: 33851721 DOI: 10.1002/bip.23429] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 02/27/2021] [Accepted: 03/22/2021] [Indexed: 11/10/2022]
Abstract
Angiogenin (Ang), is a ribonucleolytic protein that is associated with angiogenesis, the formation of blood vessels. The involvement of Ang in vascularisation makes it a potential target for the identification of compounds that have the potential to inhibit the process. The compounds may be assessed for their ability to inhibit the ribonucleolytic activity of the protein and subsequently blood vessel formation, a crucial requirement for tumor formation. We report an inhibition of the ribonucleolytic activity of Ang with the gallate containing green tea polyphenols, ECG and EGCG that exhibits an increased efficacy upon forming polyphenol-capped gold nanoparticles (ECG-AuNPs and EGCG-AuNPs). The extent of inhibition was confirmed using an agarose gel-based assay followed by fluorescence titration studies that indicated a hundred fold stronger binding of polyphenol-capped gold nanoparticles (GTP-AuNPs) compared to the bare polyphenols. Interestingly, we found a change in the mode of inhibition from a noncompetitive type to a competitive mode of inhibition in case of the GTP-AuNPs, which is in agreement with the 'n' values obtained from the fluorescence quenching studies. The effect on angiogenesis has also been assessed by the chorioallantoic membrane (CAM) assay. We find an increase in the inhibition potency of GTP-AuNPs that could find applications in the development of anti-angiogenic compounds.
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Affiliation(s)
- Atashi Panda
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, India
| | - Siddhant Karhadkar
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, India
| | - Bidisha Acharya
- School of Bioscience, Indian Institute of Technology Kharagpur, Kharagpur, India
| | - Anwesha Banerjee
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, India
| | - Soumya De
- School of Bioscience, Indian Institute of Technology Kharagpur, Kharagpur, India
| | - Swagata Dasgupta
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, India
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Tripathy DR, Panda A, Dinda AK, Dasgupta S. Positional preferences in flavonoids for inhibition of ribonuclease A: Where "OH" where? Proteins 2021; 89:577-587. [PMID: 33423292 DOI: 10.1002/prot.26043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 12/16/2020] [Accepted: 12/31/2020] [Indexed: 11/09/2022]
Abstract
Flavonoids are a class of polyphenols that possess diverse properties. The structure-activity relationship of certain flavonoids and resveratrol with ribonuclease A (RNase A) has been investigated. The selected flavonoids have a similar skeleton and the positional preferences of the phenolic moieties toward inhibition of the catalytic activity of RNase A have been studied. The results obtained for RNase A inhibition by flavonoids suggest that the planarity of the molecules is necessary for effective inhibitory potency. Agarose gel electrophoresis and precipitation assay experiments along with kinetic studies reveal Ki values for the various flavonoids in the micromolar range. Minor secondary structural changes of RNase A were observed after interaction with the flavonoids. An insight into the specific amino acid involvement in the binding of the substrate using docking studies is also presented. The dipole moment of the flavonoids that depends on the orientation of the hydroxyl groups in the molecule bears direct correlation with the inhibitory potency against RNase A. The direct association of this molecular property with enzyme inhibition can be exploited for the design and development of inhibitors of proteins.
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Affiliation(s)
- Debi Ranjan Tripathy
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, India
| | - Atashi Panda
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, India
| | - Amit Kumar Dinda
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, India
| | - Swagata Dasgupta
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, India
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Interaction between an (−)-epigallocatechin-3-gallate-copper complex and bovine serum albumin: Fluorescence, circular dichroism, HPLC, and docking studies. Food Chem 2019; 301:125294. [DOI: 10.1016/j.foodchem.2019.125294] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 07/26/2019] [Accepted: 07/29/2019] [Indexed: 11/20/2022]
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Complex of EGCG with Cu(II) Suppresses Amyloid Aggregation and Cu(II)-Induced Cytotoxicity of α-Synuclein. Molecules 2019; 24:molecules24162940. [PMID: 31416122 PMCID: PMC6719089 DOI: 10.3390/molecules24162940] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 08/05/2019] [Accepted: 08/08/2019] [Indexed: 12/14/2022] Open
Abstract
Accumulation of α-synuclein (α-Syn) is a remarkable pathology for Parkinson’s disease (PD), therefore clearing it is possibly a promising strategy for treating PD. Aberrant copper (Cu(II)) homeostasis and oxidative stress play critical roles in the abnormal aggregation of α-Syn in the progress of PD. It is reported that the polyphenol (−)-epi-gallocatechin gallate (EGCG) can inhibit α-Syn fibrillation and aggregation, disaggregate α-Syn mature fibrils, as well as protect α-Syn overexpressed-PC12 cells against damage. Also, previous studies have reported that EGCG can chelate many divalent metal ions. What we investigate here is whether EGCG can interfere with the Cu(II) induced fibrillation of α-Syn and protect the cell viability. In this work, on a molecular and cellulaire basis, we demonstrated that EGCG can form a Cu(II)/EGCG complex, leading to the inhibition of Cu(II)-induced conformation transition of α-Syn from random coil to β-sheet, which is a dominant structure in α-Syn fibrils and aggregates. Moreover, we found that the mixture of Cu(II) and EGCG in a molar ratio from 0.5 to 2 can efficiently inhibit this process. Furthermore, we demonstrated that in the α-Syn transduced-PC12 cells, EGCG can inhibit the overexpression and fibrillation of α-Syn in the cells, and reduce Cu(II)-induced reactive oxygen species (ROS), protecting the cells against Cu(II)-mediated toxicity.
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Alhafez M, Kheder F, Aljoubbeh M. Synthesis, characterization and antioxidant activity of EGCG complexes with copper and zinc ions. J COORD CHEM 2019. [DOI: 10.1080/00958972.2019.1638510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Maysoon Alhafez
- Department of Chemistry, Faculty of Science, Damascus University, Damascus, Syria
| | - Fadi Kheder
- Department of Chemistry, Faculty of Science, Damascus University, Damascus, Syria
| | - Malak Aljoubbeh
- Department of Chemistry, Faculty of Science, Damascus University, Damascus, Syria
- Syrian Private University, Damascus, Syria
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Kayet A, Datta D, Das A, Dasgupta S, Pathak T. 1,5-Disubstituted 1,2,3-triazole linked disaccharides: Metal-free syntheses and screening of a new class of ribonuclease A inhibitors. Bioorg Med Chem 2018; 26:455-462. [DOI: 10.1016/j.bmc.2017.12.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 11/28/2017] [Accepted: 12/02/2017] [Indexed: 10/18/2022]
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8
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Liu Z, Nakashima S, Nakamura T, Munemasa S, Murata Y, Nakamura Y. (-)-Epigallocatechin-3-gallate inhibits human angiotensin-converting enzyme activity through an autoxidation-dependent mechanism. J Biochem Mol Toxicol 2017; 31. [PMID: 28544013 DOI: 10.1002/jbt.21932] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 04/06/2017] [Indexed: 11/07/2022]
Abstract
We investigated the molecular mechanisms involved in the angiotensin-converting enzyme (ACE) inhibition by (-)-epigallocatechin-3-gallate (EGCg), a major tea catechin. EGCg inhibited both the ACE activity in the lysate of human colorectal cancer cells and human recombinant ACE (rh-ACE) in a dose-dependent manner. Co-incubation with zinc sulfate showed no influence on the rh-ACE inhibition by EGCg, whereas it completely counteracted the inhibitory effect of ethylenediaminetetraacetic acid, a chelating-type ACE inhibitor. Although hydrogen peroxide was produced by the autoxidation of EGCg, hydrogen peroxide itself had little effect on the ACE activity. Conversely, the co-incubation of EGCg with borate or ascorbic acid significantly diminished the EGCg inhibition. A redox-cycling staining experiment revealed that rh-ACE was covalently modified by EGCg. A Lineweaver-Burk plot analysis indicated that EGCg inhibited the ACE activity in a non-competitive manner. These results suggested that EGCg might allosterically inhibit the ACE activity through oxidative conversion into an electrophilic quinone.
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Affiliation(s)
- Zhe Liu
- Graduate School of Environmental and Life Science, Okayama University, Okayama, 700-8530, Japan
| | - Sayaka Nakashima
- Graduate School of Environmental and Life Science, Okayama University, Okayama, 700-8530, Japan
| | - Toshiyuki Nakamura
- Graduate School of Environmental and Life Science, Okayama University, Okayama, 700-8530, Japan
| | - Shintaro Munemasa
- Graduate School of Environmental and Life Science, Okayama University, Okayama, 700-8530, Japan
| | - Yoshiyuki Murata
- Graduate School of Environmental and Life Science, Okayama University, Okayama, 700-8530, Japan
| | - Yoshimasa Nakamura
- Graduate School of Environmental and Life Science, Okayama University, Okayama, 700-8530, Japan
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Zhang L, Sahu ID, Xu M, Wang Y, Hu X. Effect of metal ions on the binding reaction of (−)-epigallocatechin gallate to β-lactoglobulin. Food Chem 2017; 221:1923-1929. [DOI: 10.1016/j.foodchem.2016.11.158] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Revised: 10/26/2016] [Accepted: 11/30/2016] [Indexed: 11/25/2022]
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Abstract
Polyphenols are a widely used class of compounds in dermatology. While phenol itself, the most basic member of the phenol family, is chemically synthesized, most polyphenolic compounds are found in plants and form part of their defense mechanism against decomposition. Polyphenolic compounds, which include phenolic acids, flavonoids, stilbenes, and lignans, play an integral role in preventing the attack on plants by bacteria and fungi, as well as serving as cross-links in plant polymers. There is also mounting evidence that polyphenolic compounds play an important role in human health as well. One of the most important benefits, which puts them in the spotlight of current studies, is their antitumor profile. Some of these polyphenolic compounds have already presented promising results in either in vitro or in vivo studies for non-melanoma skin cancer and melanoma. These compounds act on several biomolecular pathways including cell division cycle arrest, autophagy, and apoptosis. Indeed, such natural compounds may be of potential for both preventive and therapeutic fields of cancer. This review evaluates the existing scientific literature in order to provide support for new research opportunities using polyphenolic compounds in oncodermatology.
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Affiliation(s)
- Adilson Costa
- Department of Dermatology, Emory University School of Medicine, Atlanta Veterans Administration Medical Center, Winship Cancer Institute, 101 Woodruff Circle, Atlanta, GA, 30322, USA
| | - Michael Yi Bonner
- Department of Dermatology, Emory University School of Medicine, Atlanta Veterans Administration Medical Center, Winship Cancer Institute, 101 Woodruff Circle, Atlanta, GA, 30322, USA
| | - Jack L Arbiser
- Department of Dermatology, Emory University School of Medicine, Atlanta Veterans Administration Medical Center, Winship Cancer Institute, 101 Woodruff Circle, Atlanta, GA, 30322, USA.
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Chakraborty K, Dasgupta S, Pathak T. Carboxylated acyclonucleosides: synthesis and RNase A inhibition. Molecules 2015; 20:5924-41. [PMID: 25854756 PMCID: PMC6272279 DOI: 10.3390/molecules20045924] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 03/20/2015] [Accepted: 03/20/2015] [Indexed: 11/17/2022] Open
Abstract
Strategically designed carboxylated acyclonucleosides have been probed as a new class of RNase A inhibitors. Several experimental and theoretical studies have been performed to compile relevant qualitative and quantitative information regarding the nature and extent of inhibition. The inhibition constant (Ki) values were determined using a UV-based kinetics experiment. The changes in the secondary structure of the enzyme upon binding with the inhibitors were obtained from circular dichroism studies. The binding constants for enzyme-inhibitor interactions were determined with the help of fluorescence spectroscopy. Docking studies were performed to reveal the possible binding sites of the inhibitors within the enzyme. The cytosine analogues were found to possess better inhibitory properties in comparison to the corresponding uracil derivatives. An increment in the number of carboxylic acid groups (-COOH) in the inhibitor backbone was found to result in better inhibition.
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Affiliation(s)
- Kaustav Chakraborty
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, India.
| | - Swagata Dasgupta
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, India.
| | - Tanmaya Pathak
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, India.
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Datta D, Dasgupta S, Pathak T. Ribonuclease A inhibition by carboxymethylsulfonyl-modified xylo- and arabinopyrimidines. ChemMedChem 2014; 9:2138-49. [PMID: 25125220 DOI: 10.1002/cmdc.201402179] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Indexed: 11/10/2022]
Abstract
A group of acidic nucleosides were synthesized to develop a new class of ribonuclease A (RNase A) inhibitors. Our recent study on carboxymethylsulfonyl-modified nucleosides revealed some interesting results in RNase A inhibition. This positive outcome triggered an investigation of the role played by secondary sugar hydroxy groups in inhibiting RNase A activity. Uridines and cytidines modified with SO2 CH2 COOH groups at the 2'- and 3'-positions show good inhibitory properties with low inhibition constant (Ki ) values in the range of 109-17 μM. The present work resulted in a set of inhibitors that undergo more effective interactions with the RNase A active site, as visualized by docking studies.
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Affiliation(s)
- Dhrubajyoti Datta
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur (India), Fax: (+91) 3222-255303
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Franco-Luesma E, Ferreira V. Quantitative analysis of free and bonded forms of volatile sulfur compouds in wine. Basic methodologies and evidences showing the existence of reversible cation-complexed forms. J Chromatogr A 2014; 1359:8-15. [PMID: 25064535 DOI: 10.1016/j.chroma.2014.07.011] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 07/02/2014] [Accepted: 07/07/2014] [Indexed: 11/24/2022]
Abstract
This paper examines first some basic aspects critical to the analysis of Volatile Sulfur Compounds (VSCs), such as the analytical characteristics of the GC-pFPD system and the stability of the different standard solutions required for a proper calibration. Following, a direct static headspace analytical method for the determination of exclusively free forms of VSCs has been developed. Method repeatability is better than 4%, detection limits for main analytes are below 0.5μgL(-1), and the method dynamic linear range (r(2)>0.99) is expanded by controlling the split ratio in the chromatographic inlet to cover the natural range of occurrence of these compounds in wines. The method gives reliable estimates of headspace concentrations but, as expected, suffers from strong matrix effects with recoveries ranging from 0 to 100% or from 60 to 100 in the cases of H2S and the other mercaptans, respectively. This demonstrates the existence of strong interactions of these compounds with different matrix components. The complexing ability of Cu(2+) and to a lower extent Fe(2+) and Zn(2+) has been experimentally checked. A previously developed method in which the wine is strongly diluted with brine and the volatiles are preconcentrated by HS-SPME, was found to give a reliable estimation of the total amount (free+complexed) of mercaptans, demonstrating that metal-mercaptan complexes are reversible. The comparative analysis of different wines by the two procedures reveals that in normal wines H2S and methanethiol can be complexed at levels above 99%, with averages around 97% for H2S and 75% for methanethiol, while thioethers such as dimethyl sulfide (DMS) are not complexed. Overall, the proposed strategy may be generalized to understand problems caused by VSCs in different matrices.
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Affiliation(s)
- Ernesto Franco-Luesma
- Laboratory for Flavor Analysis and Enology, Aragón Institute of Engineering Research (I3A), Department of Analytical Chemistry, Faculty of Sciences, University of Zaragoza, 50009 Zaragoza, Spain
| | - Vicente Ferreira
- Laboratory for Flavor Analysis and Enology, Aragón Institute of Engineering Research (I3A), Department of Analytical Chemistry, Faculty of Sciences, University of Zaragoza, 50009 Zaragoza, Spain.
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Analysis of the Mechanism of Inhibition of Human Matrix Metalloproteinase 7 (MMP-7) Activity by Green Tea Catechins. Biosci Biotechnol Biochem 2014; 75:1564-9. [DOI: 10.1271/bbb.110257] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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15
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Comparison of the ribonucleolytic activity of the dityrosine cross-linked Ribonuclease A dimer with its monomer in the presence of inhibitors. Int J Biol Macromol 2014; 63:107-13. [DOI: 10.1016/j.ijbiomac.2013.10.033] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 10/24/2013] [Indexed: 11/18/2022]
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16
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Singha Roy A, Ghosh KS, Dasgupta S. An investigation into the altered binding mode of green tea polyphenols with human serum albumin on complexation with copper. J Biomol Struct Dyn 2013; 31:1191-206. [DOI: 10.1080/07391102.2012.729158] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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17
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Tripathy DR, Singha Roy A, Dasgupta S. Complex formation of rutin and quercetin with copper alters the mode of inhibition of Ribonuclease A. FEBS Lett 2011; 585:3270-6. [DOI: 10.1016/j.febslet.2011.09.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Revised: 08/19/2011] [Accepted: 09/04/2011] [Indexed: 10/17/2022]
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Pan MH, Chiou YS, Wang YJ, Ho CT, Lin JK. Multistage carcinogenesis process as molecular targets in cancer chemoprevention by epicatechin-3-gallate. Food Funct 2011; 2:101-10. [PMID: 21779554 DOI: 10.1039/c0fo00174k] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The consumption of green tea has long been associated with a reduced risk of cancer development. (-)-Epicatechin-3-gallate (ECG) or (-)-epigallocatechin-3-gallate (EGCG) are the major antioxidative polyphenolic compounds of green tea. They have been shown to exert growth-inhibitory potential of various cancer cells in culture and antitumor activity in vivo models. ECG or EGCG could interact with various molecules like proteins, transcription factors, and enzymes, which block multiple stages of carcinogenesis via regulating intracellular signaling transduction pathways. Moreover, ECG and EGCG possess pharmacological and physiological properties including induction of phase II enzymes, mediation of anti-inflammation response, regulation of cell proliferation and apoptosis effects and prevention of tumor angiogenesis, invasion and metastasis. Numerous review articles have been focused on EGCG, however none have been focused on ECG despite many studies supporting the cancer preventive potential of ECG. To develop ECG as an anticarcinogenic agent, more clear understanding of the cell signaling pathways and the molecular targets responsible for chemopreventive and chemotherapeutic effects are needed. This review summarizes recent research on the ECG-induced cellular signal transduction events which implicate in cancer management.
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Affiliation(s)
- Min-Hsiung Pan
- Department of Seafood Science, National Kaohsiung Marine University, No.142, Haijhuan Rd., Nanzih District, Kaohsiung 81143, Taiwan.
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Chakraborti S, Chatterjee T, Joshi P, Poddar A, Bhattacharyya B, Singh SP, Gupta V, Chakrabarti P. Structure and activity of lysozyme on binding to ZnO nanoparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:3506-3513. [PMID: 20000758 DOI: 10.1021/la903118c] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The interaction between ZnO nanoparticles (NPs) and lysozyme has been studied using calorimetric as well as spectrophotometric techniques, and interpreted in terms of the three-dimensional structure. The circular dichroism spectroscopic data show an increase in alpha-helical content on interaction with ZnO NPs. Glutaraldehyde cross-linking studies indicate that the monomeric form occurs to a greater extent than the dimer when lysozyme is conjugated with ZnO NPs. The enthalpy-driven binding between lysozyme and ZnO possibly involves the region encompassing the active site in the molecule, which is also the site for the dimer formation in a homologous structure. The enzyme retains high fraction of its native structure with negligible effect on its activity upon attachment to NPs. Compared to the free protein, lysozyme-ZnO conjugates are more stable in the presence of chaotropic agents (guanidine hydrochloride and urea) and also at elevated temperatures. The possible site of binding of NP to lysozyme has been proposed to explain these observations. The stability and the retention of a higher level of activity in the presence of the denaturing agent of the NP-conjugated protein may find useful applications in biotechnology ranging from diagnostic to drug delivery.
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Chen Z, Wang C, Zhou H, Sang L, Li X. Modulation of calcium oxalatecrystallization by commonly consumed green tea. CrystEngComm 2010. [DOI: 10.1039/b913589h] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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22
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Grazul M, Budzisz E. Biological activity of metal ions complexes of chromones, coumarins and flavones. Coord Chem Rev 2009. [DOI: 10.1016/j.ccr.2009.06.015] [Citation(s) in RCA: 180] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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23
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Ghosh KS, Debnath J, Pathak T, Dasgupta S. Using proton nuclear magnetic resonance to study the mode of ribonuclease A inhibition by competitive and noncompetitive inhibitors. Bioorg Med Chem Lett 2008; 18:5503-6. [DOI: 10.1016/j.bmcl.2008.09.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2008] [Revised: 09/02/2008] [Accepted: 09/04/2008] [Indexed: 10/21/2022]
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Ghosh KS, Sahoo BK, Jana D, Dasgupta S. Studies on the interaction of copper complexes of (−)-epicatechin gallate and (−)-epigallocatechin gallate with calf thymus DNA. J Inorg Biochem 2008; 102:1711-8. [DOI: 10.1016/j.jinorgbio.2008.04.008] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2008] [Revised: 04/21/2008] [Accepted: 04/25/2008] [Indexed: 10/22/2022]
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Cho KN, Sukhthankar M, Lee SH, Yoon JH, Baek SJ. Green tea catechin (-)-epicatechin gallate induces tumour suppressor protein ATF3 via EGR-1 activation. Eur J Cancer 2007; 43:2404-12. [PMID: 17764926 PMCID: PMC2174270 DOI: 10.1016/j.ejca.2007.07.020] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2007] [Revised: 07/12/2007] [Accepted: 07/20/2007] [Indexed: 01/03/2023]
Abstract
Epicatechin gallate (ECG) is the third major catechin component in green tea, but it shows strong biological activity in some aspects, including apoptosis, cell growth inhibition, and membrane transport system in various cells. We previously reported that ECG induces activating transcription factor 3 (ATF3), which is involved in pro-apoptosis in HCT-116 cells. In this report, we present a molecular mechanism by which ECG induces ATF3 expression at the transcriptional level. We found that Sp3 contributed to the basal expression of the ATF3 gene, whereas EGR-1 played an important role in ECG-induced ATF3 expression in HCT-116 cells, as assessed by EMSA and co-transfection experiments. These results suggested that EGR-1, a tumour suppressor protein, could substantiate ECG's role of ATF3 expression in human colorectal cancer cells. We also found that pro-oxidant activity of ECG contributed to ECG-induced ATF3 expression.
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Affiliation(s)
- Kyou-Nam Cho
- Laboratory of Environmental Carcinogenesis, Department of Pathobiology, College of Veterinary Medicine, University of Tennessee, 2407 River Drive, Knoxville, TN 37996, USA
| | - Mugdha Sukhthankar
- Laboratory of Environmental Carcinogenesis, Department of Pathobiology, College of Veterinary Medicine, University of Tennessee, 2407 River Drive, Knoxville, TN 37996, USA
| | - Seong-Ho Lee
- Laboratory of Environmental Carcinogenesis, Department of Pathobiology, College of Veterinary Medicine, University of Tennessee, 2407 River Drive, Knoxville, TN 37996, USA
| | - Joo-Heon Yoon
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Korea
| | - Seung Joon Baek
- Laboratory of Environmental Carcinogenesis, Department of Pathobiology, College of Veterinary Medicine, University of Tennessee, 2407 River Drive, Knoxville, TN 37996, USA
- * Corresponding author: Tel.: +1 865 974 8216; fax: +1 865 974 5616. E-mail: (S.J. Baek)
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Ghosh KS, Maiti TK, Debnath J, Dasgupta S. Inhibition of Ribonuclease A by polyphenols present in green tea. Proteins 2007; 69:566-80. [PMID: 17623866 DOI: 10.1002/prot.21484] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We report the effect of the natural polyphenolic compounds from green tea on the catalytic activity of Ribonuclease A (RNase A). The compounds behave as noncompetitive inhibitors of the protein with inhibition constants ranging from 80-1300 microM. The dissociation constants range from 50-150 microM for the RNase A-polyphenol complexes as determined by ultraviolet (UV) and circular dichroism (CD) studies. We have also investigated the changes in the secondary structure of RNase A on complex formation by CD and Fourier transformed infrared (FTIR) spectroscopy. The presence of the gallate moiety has been shown to be important for the inhibition of enzymatic activity. Docking studies for these compounds indicate that the preferred site of binding is the region encompassing residues 34-39 with possible hydrogen bonding with Lys 7 and Arg 10. Finally we have also looked at changes in the accessible surface area of the interacting residues on complex formation for an insight into the residues involved in the interaction.
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Affiliation(s)
- Kalyan S Ghosh
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India
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Fox JH, Kama JA, Lieberman G, Chopra R, Dorsey K, Chopra V, Volitakis I, Cherny RA, Bush AI, Hersch S. Mechanisms of copper ion mediated Huntington's disease progression. PLoS One 2007; 2:e334. [PMID: 17396163 PMCID: PMC1828629 DOI: 10.1371/journal.pone.0000334] [Citation(s) in RCA: 141] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2006] [Accepted: 03/06/2007] [Indexed: 12/11/2022] Open
Abstract
Huntington's disease (HD) is caused by a dominant polyglutamine expansion within the N-terminus of huntingtin protein and results in oxidative stress, energetic insufficiency and striatal degeneration. Copper and iron are increased in the striata of HD patients, but the role of these metals in HD pathogenesis is unknown. We found, using inductively-coupled-plasma mass spectroscopy, that elevations of copper and iron found in human HD brain are reiterated in the brains of affected HD transgenic mice. Increased brain copper correlated with decreased levels of the copper export protein, amyloid precursor protein. We hypothesized that increased amounts of copper bound to low affinity sites could contribute to pro-oxidant activities and neurodegeneration. We focused on two proteins: huntingtin, because of its centrality to HD, and lactate dehydrogenase (LDH), because of its documented sensitivity to copper, necessity for normoxic brain energy metabolism and evidence for altered lactate metabolism in HD brain. The first 171 amino acids of wild-type huntingtin, and its glutamine expanded mutant form, interacted with copper, but not iron. N171 reduced Cu2+in vitro in a 1∶1 copper∶protein stoichiometry indicating that this fragment is very redox active. Further, copper promoted and metal chelation inhibited aggregation of cell-free huntingtin. We found decreased LDH activity, but not protein, and increased lactate levels in HD transgenic mouse brain. The LDH inhibitor oxamate resulted in neurodegeneration when delivered intra-striatially to healthy mice, indicating that LDH inhibition is relevant to neurodegeneration in HD. Our findings support a role of pro-oxidant copper-protein interactions in HD progression and offer a novel target for pharmacotherapeutics.
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Affiliation(s)
- Jonathan H. Fox
- Department of Neurology, Harvard Medical School, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
| | - Jibrin A. Kama
- Department of Neurology, Harvard Medical School, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
| | - Gregory Lieberman
- Department of Neurology, Harvard Medical School, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
| | - Raman Chopra
- Department of Neurology, Harvard Medical School, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
| | - Kate Dorsey
- Department of Neurology, Harvard Medical School, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
| | - Vanita Chopra
- Department of Neurology, Harvard Medical School, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
| | - Irene Volitakis
- Oxidation Disorders Laboratory, Mental Health Research Institute of Victoria, and Department of Pathology, The University of Melbourne, Parkville, Victoria, Australia
| | - Robert A. Cherny
- Oxidation Disorders Laboratory, Mental Health Research Institute of Victoria, and Department of Pathology, The University of Melbourne, Parkville, Victoria, Australia
| | - Ashley I. Bush
- Genetics and Aging Research Unit, and Department of Psychiatry, Harvard Medical School, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
- Oxidation Disorders Laboratory, Mental Health Research Institute of Victoria, and Department of Pathology, The University of Melbourne, Parkville, Victoria, Australia
| | - Steven Hersch
- Department of Neurology, Harvard Medical School, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
- * To whom correspondence should be addressed. E-mail:
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