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Farhan M, Rizvi A, Ali F, Ahmad A, Aatif M, Malik A, Alam MW, Muteeb G, Ahmad S, Noor A, Siddiqui FA. Pomegranate juice anthocyanidins induce cell death in human cancer cells by mobilizing intracellular copper ions and producing reactive oxygen species. Front Oncol 2022; 12:998346. [PMID: 36147917 PMCID: PMC9487716 DOI: 10.3389/fonc.2022.998346] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 08/17/2022] [Indexed: 02/05/2023] Open
Abstract
Anthocyanidins are the most abundant polyphenols in pomegranate juice. This class of molecules includes Delphinidin (Del), Cyanidin (Cya), and Pelargonidin (Pel). Using prostate, breast and pancreatic cancer cell lines PC3, MDA-MB-231, BxPC-3 and MiaPaCa-2, we show that anthocyanidins inhibit cell proliferation (measured by MTT assay) and induce apoptosis like cell death (measured by DNA/Histone ELISA). Copper chelator neocuproine and reactive oxygen species scavengers (thiourea for hydroxyl radical and superoxide dismutase for superoxide anion) significantly inhibit this reaction thus demonstrating that intracellular copper reacts with anthocyanidins in cancer cells to cause DNA damage via ROS generation. We further show that copper-supplemented media sensitizes normal breast epithelial cells (MCF-10A) to Del-mediated growth inhibition as determined by decreased cell proliferation. Copper supplementation results in increased expression of copper transporters Ctr1 and ATP7A in MCF-10A cells, which is attenuated by the addition of Del in the medium. We propose that the copper mediated, ROS-induced mechanism of selective cell death of cancer cells may in part explain the anticancer effects of anthocyanidins.
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Affiliation(s)
- Mohd Farhan
- Department of Basic Sciences, Preparatory Year Deanship, King Faisal University, Al-Ahsa, Saudi Arabia,*Correspondence: Mohd Farhan,
| | - Asim Rizvi
- Department of Kulliyat, Faculty of Unani Medicine, Aligarh Muslim University, Aligarh, India
| | - Ferasat Ali
- Department of Kulliyat, Faculty of Unani Medicine, Aligarh Muslim University, Aligarh, India
| | - Aamir Ahmad
- Interim Translational Research Institute, Academic Health System, Hamad Medical Corporation, Doha, Qatar
| | - Mohammad Aatif
- Department of Public Health, College of Applied Medical Sciences, King Faisal University, Al-Ahsa, Saudi Arabia
| | - Arshi Malik
- Department of Clinical Biochemistry, College of Medicine, King Khalid University, Abha, Saudi Arabia
| | - Mir Waqas Alam
- Department of Physics, College of Science, King Faisal University, Al-Ahsa, Saudi Arabia
| | - Ghazala Muteeb
- Department of Nursing, College of Applied Medical Sciences, King Faisal University, Al-Ahsa, Saudi Arabia
| | - Saheem Ahmad
- Department of Medical Laboratory Sciences, College of Applied Medical Sciences, University of Hail, Hail, Saudi Arabia
| | - Awal Noor
- Department of Basic Sciences, Preparatory Year Deanship, King Faisal University, Al-Ahsa, Saudi Arabia
| | - Farhan Asif Siddiqui
- Department of Laboratory and Blood Bank, King Fahad Hospital, Al Ahsa, Saudi Arabia
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CF3SOCl-promoted intramolecular cyclization of β-diketones: An efficient synthesis of flavones. Tetrahedron 2021. [DOI: 10.1016/j.tet.2021.132226] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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3
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Gogula T, Yerrabelly JR. Synthesis of Diverse Oxa-Carbocycle-Annulated Flavones Using the CombinedClaisenRearrangement and Ring-Closing Metathesis. Helv Chim Acta 2016. [DOI: 10.1002/hlca.201600028] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Thirupathi Gogula
- Department of Chemistry; Osmania University; Hyderabad Telangana 500007 India
| | - Jayaprakash Rao Yerrabelly
- Department of Chemistry; Osmania University; Hyderabad Telangana 500007 India
- Department of Chemistry; Telangana University; Nizamabad 503322 India
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4
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Microwave-assisted synthesis, molecular docking and antimicrobial activity of novel 2-(3-aryl,1-phenyl-1H-pyrazol-4-yl)-8H-pyrano[2,3-f]chromen-4-ones. Med Chem Res 2016. [DOI: 10.1007/s00044-016-1505-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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5
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Lu J, Zhang Z, Ni Z, Shen H, Tu Z, Liu H, Lu R. QM/MM–PB/SA scoring of the interaction strength between Akt kinase and apigenin analogues. Comput Biol Chem 2014; 52:25-33. [DOI: 10.1016/j.compbiolchem.2014.07.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 05/20/2014] [Accepted: 07/25/2014] [Indexed: 12/11/2022]
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6
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Lu J, Zhang Z, Ni Z, Shen H, Tu Z, Liu H, Lu R, Shi H. The non-additive contribution of hydroxyl substituents to Akt kinase–apigenin affinity. MOLECULAR SIMULATION 2014. [DOI: 10.1080/08927022.2014.913099] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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7
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Synthesis, antibacterial and antioxidant activities of new 1-alkyl-4-(1-alkyl-4-oxo-1,4-dihydroquinolin-2-yl)pyridinium bromides. Eur J Med Chem 2013; 69:348-55. [DOI: 10.1016/j.ejmech.2013.08.050] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 08/25/2013] [Accepted: 08/31/2013] [Indexed: 11/18/2022]
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8
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Ziyatdinova G, Labuda J. Biosensor with Protective Membrane for the Detection of DNA Damage and Antioxidant Properties of Fruit Juices. ELECTROANAL 2012. [DOI: 10.1002/elan.201200416] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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9
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A new synthesis of flavones and pyranoflavone by intramolecular photochemical Wittig reaction in water. Tetrahedron Lett 2011. [DOI: 10.1016/j.tetlet.2011.10.134] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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10
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Teimouri MB, Akbari-Moghaddam P, Golbaghi G. Pseudo-five-component reaction between 3-formylchromones, meldrum's acid, isocyanides and primary arylamines: diversity-oriented synthesis of novel chromone-containing peptidomimetics. ACS COMBINATORIAL SCIENCE 2011; 13:659-66. [PMID: 21919509 DOI: 10.1021/co200125a] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An efficient and practical method has been developed for the diversity-oriented synthesis of chromone-containing tripeptides via pseudo-five-component reaction between 3-formylchromones, Meldrum's acid, isocyanides and primary aromatic amines for the generation of a wide range of structurally interesting and pharmacologically significant compounds at ambient temperature. It is worth mentioning that in the course of this reaction, five new bonds (two C-C bonds, two C-N bonds and one C═O bond) are formed. In the present reaction three amide bonds are newly formed.
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Affiliation(s)
- Mohammad Bagher Teimouri
- Petrochemical Department, Iran Polymer and Petrochemical Institute, P.O. Box 14965-115, Tehran, Iran
| | - Peyman Akbari-Moghaddam
- Petrochemical Department, Iran Polymer and Petrochemical Institute, P.O. Box 14965-115, Tehran, Iran
| | - Golara Golbaghi
- Department of Chemistry, School of Sciences, Alzahra University, Vanak, Tehran, Iran
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Teimouri MB, Eskandari M. An Efficient Synthesis of Novel Chromone-Containing Furopyrimidines. JOURNAL OF CHEMICAL RESEARCH 2011. [DOI: 10.3184/174751911x13146322603355] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The one-pot three-component reaction of 1,3-disubstituted barbituric acid derivatives, 3-formylchromones and alkyl isocyanides proceed smoothly at room temperature to give the corresponding chromone-containing furopyrimidines derivatives in good yields within 10 minutes in DMF. This three-component reaction represents a facile and efficient route to the furo[2,3-d]pyrimidine derivatives, which have become synthetic targets for many organic and medicinal chemists. In the course of the creation of a fused furopyrimidine ring, three bonds (C=C, C–C and C–O bonds) are newly formed.
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Affiliation(s)
| | - Mehrdad Eskandari
- Faculty of Chemistry, Omidiyeh Branch, Islamic Azad University, Omidiyeh, Iran
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12
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Lv PC, Cai TT, Qian Y, Sun J, Zhu HL. Synthesis, biological evaluation of chrysin derivatives as potential immunosuppressive agents. Eur J Med Chem 2011; 46:393-8. [DOI: 10.1016/j.ejmech.2010.10.034] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2010] [Revised: 10/15/2010] [Accepted: 10/31/2010] [Indexed: 10/18/2022]
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Abstract
The interactions of gallic acid and tannic acid with purified brush border sucrase (EC 3.2.1.48) from mouse intestine have been studied. These findings indicate that both gallic acid and tannic acid inhibit sucrase activity, which is pH dependent. Kinetic analysis revealed that enzyme inhibition by gallic acid is a pure V effect at pH 5.0, which changes to mixed type at pH 7.2, and pure K effect at pH 8.5. In contrast, sucrase inhibition by tannic acid was a pure K effect at acidic pH and uncompetitive type in the alkaline pH range. Far-CD spectroscopic analysis revealed an increase in the helicity of the enzyme at acidic pH in the presence of tannic acid but no change at alkaline pH. Fluorescence spectra revealed a red shift in λmax of the enzyme, suggesting that tryptophan residues come to a more hydrophilic environment in the presence of polyphenols. These findings suggest that inhibition of mice sucrase by polyphenols is pH dependent, and is associated with conformational modifications of the enzyme.
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Pathak VN, Varshney B, Gupta R. A ‘one pot’ synthesis of 2‐aryl‐4
H
‐1‐benzopyran‐4‐ones under coupled microwave phase transfer catalysis (PTC) and ultrasonic irradiation PTC. J Heterocycl Chem 2009. [DOI: 10.1002/jhet.5570450246] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Vijai N. Pathak
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur 302 004, India
| | - Bindu Varshney
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur 302 004, India
| | - Ragini Gupta
- Department of Chemistry, Malaviya National Institute of Technology, Jaipur 302 017, India
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15
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Zambare AS, Sangshetti JN, Kokare ND, Shinde DB. Development of mild and efficient method for synthesis of substituted flavones using oxalic acid catalyst. CHINESE CHEM LETT 2009. [DOI: 10.1016/j.cclet.2008.10.042] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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16
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Peng SM, Zou XQ, Ding HL, Ding YL, Lin YB. Synthesis and promotion angiogenesis effect of chrysin derivatives coupled to NO donors. Bioorg Med Chem Lett 2009; 19:1264-6. [PMID: 19167219 DOI: 10.1016/j.bmcl.2008.12.116] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2008] [Revised: 10/28/2008] [Accepted: 12/06/2008] [Indexed: 11/17/2022]
Abstract
Two types of new chrysin derivatives were prepared by coupling NO donors of alkyl nitrate and furazan derivatives and were fully characterized by (1)H NMR and other techniques. These compounds were tested in human umbilical vein endothelial cells (HUVECs-12) and all the compounds exhibited cell proliferation. Notable effects of promoting angiogenesis were observed for all the modified compounds using chick chorioallantoic membrane (CAM) assay.
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Affiliation(s)
- Sheng-Ming Peng
- Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan, Hunan 411105, PR China
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Kgomotso T, Chiu F, Ng K. Genistein- and daidzein 7-O-β-D-glucuronic acid retain the ability to inhibit copper-mediated lipid oxidation of low density lipoprotein. Mol Nutr Food Res 2008; 52:1457-66. [DOI: 10.1002/mnfr.200800010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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18
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Cell death induced by flavonoid glycosides with and without copper. Food Chem Toxicol 2008; 46:2394-401. [DOI: 10.1016/j.fct.2008.03.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2007] [Revised: 03/05/2008] [Accepted: 03/19/2008] [Indexed: 11/17/2022]
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19
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Hanif S, Shamim U, Ullah M, Azmi AS, Bhat SH, Hadi S. The anthocyanidin delphinidin mobilizes endogenous copper ions from human lymphocytes leading to oxidative degradation of cellular DNA. Toxicology 2008; 249:19-25. [DOI: 10.1016/j.tox.2008.03.024] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2008] [Revised: 03/29/2008] [Accepted: 03/31/2008] [Indexed: 01/27/2023]
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20
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Lin CN, Chen HL, Yen MH. Flavonoids with DNA strand-scission activity from Rhus javanica var. roxburghiana. Fitoterapia 2008; 79:32-6. [PMID: 17855017 DOI: 10.1016/j.fitote.2007.07.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2006] [Accepted: 07/11/2007] [Indexed: 10/23/2022]
Abstract
The flavonoids isolated from the stems of Rhus javanica var. roxburghiana, taxifolin (1), fisetin (2), fustin (3), 3,7,4'-trihydroxyflavanone (4) and 3,7,4'-trihydroxyflavone (5) caused breakage of supercoiled plasmid pBR322 DNA in the presence of Cu(II). Cu(I) was shown to be an essential intermediate by using the Cu(I)-specific sequestering reagent neocuproine. The Cu(II)-mediated DNA scissions induced by 1, 2, 3 and 5 were inhibited by the addition of catalase and exhibited DNA strand break by the addition of KI and superoxide dimutase (SOD), while in the Cu(II)-mediated DNA scissions induced by 4 was inhibited by the addition of KI, SOD, and catalase. It is concluded that 1, 2, 3, and 5 can induce H2O2 and superoxide anion, while 4 can induce OH* and H2O2 and subsequent oxidative damage of DNA in the presence of Cu(II).
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Affiliation(s)
- Chun-Nan Lin
- School of Pharmacy, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
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21
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Letelier ME, Lagos F, Faúndez M, Miranda D, Montoya M, Aracena-Parks P, González-Lira V. Copper modifies liver microsomal UDP-glucuronyltransferase activity through different and opposite mechanisms. Chem Biol Interact 2007; 167:1-11. [PMID: 17274970 DOI: 10.1016/j.cbi.2006.12.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2006] [Revised: 12/20/2006] [Accepted: 12/21/2006] [Indexed: 11/26/2022]
Abstract
Treatment of hepatic microsomes with Fe(3+)/ascorbate activates UDP-glucuronyltransferase (UGT), a phenomenon totally prevented and reversed by reducing agents. At microM concentrations, iron and copper ions catalyze the formation of ROS through Fenton and/or Haber-Weiss reactions. Unlike iron ions, indiscriminate binding of copper ions to thiol groups of proteins different from the specialized copper-binding proteins may occur. Thus, we hypothesize that incubation of hepatic microsomes with the Cu(2+)/ascorbate system will lead to both UGT oxidative activation and Cu(2+)-binding induced inhibition, simultaneously. We studied the effects of Cu(2+) alone and in the presence of ascorbate on rat liver microsomal UGT activity. Our results show that the effects of both copper alone and in the presence of ascorbate were copper ion concentration- and incubation time-dependent. At very low Cu(2+) (25nM), this ion did not modify UGT activity. In the presence of ascorbate, however, UGT activity was increased. At higher copper concentrations (10 and 50microM), this ion led to UGT activity inhibition. In the presence of ascorbate, 10microM Cu(2+) activated UGT at short incubation periods but inhibited this enzyme at longer incubation times; 50microM Cu(2+) only inhibited UGT activity. Thiol reducing agent 2,4-dithiothreitol prevented and reversed UGT activation while EDTA prevented both, UGT activation and inhibition. Our results are consistent with a model in which Cu(2+)-induced oxidation of UGT leads to the activation of the enzyme, while Cu(2+)-binding leads to its inhibition. We discuss physiological and pathological implications of these findings.
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Affiliation(s)
- María Eugenia Letelier
- Laboratory of Pharmacology, Department of Pharmacological and Toxicological Chemistry, Chemical and Pharmaceutical Sciences School, Universidad de Chile, Olivos 1007, Independencia, Santiago, Chile.
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Shanafelt TD, Lee YK, Call TG, Nowakowski GS, Dingli D, Zent CS, Kay NE. Clinical effects of oral green tea extracts in four patients with low grade B-cell malignancies. Leuk Res 2005; 30:707-12. [PMID: 16325256 DOI: 10.1016/j.leukres.2005.10.020] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2005] [Revised: 09/07/2005] [Accepted: 10/22/2005] [Indexed: 11/21/2022]
Abstract
Green tea or its constituents have long been touted as a health promoting substance including claims it may have cancer prevention properties. We previously reported the in vitro ability of one tea polyphenol, epigallocatechin gallate (EGCG), to induce apoptotic cell death in the leukemic B-cells from a majority of patients with chronic lymphocytic leukemia (CLL). After the publication of our findings many patients with CLL and other low grade lymphomas began using over-the-counter products containing tea polyphenols despite the absence of evidence to suggest clinical benefit, definition of possible toxicities, or information on optimal dose and schedule. We have become aware of four patients with low grade B-cell malignancies seen in our clinical practice at Mayo Clinic who began, on their own initiative, oral ingestion of EGCG containing products and subsequently appeared to have an objective clinical response. Three of these four patients met criteria for partial response (PR) by standard response criteria. Although spontaneous remission/regression is occasionally observed in individuals with low grade B-cell malignancies, such events are rare. Several patients presented here had documented steady clinical, laboratory, and/or radiographic evidence of progression immediately prior to initiation of over-the-counter green tea products and then developed objective responses shortly after self-initiating this therapy. Such anecdotes highlight the need for clinical trials of tea polyphenols to define the optimal dosing, schedule, toxicities, and clinical efficacy before widespread use can be recommended. An NCI sponsored phase I/II trial of de-caffeinated green tea extracts for patients with asymptomatic, early stage CLL opened at Mayo Clinic in August 2005.
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Affiliation(s)
- T D Shanafelt
- Mayo Clinic College of Medicine, Division of Hematology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
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Seijas JA, Vázquez-Tato MP, Carballido-Reboredo R. Solvent-free synthesis of functionalized flavones under microwave irradiation. J Org Chem 2005; 70:2855-8. [PMID: 15787587 DOI: 10.1021/jo048685z] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[reaction: see text] Eco-friendly direct solvent-free synthesis of flavones is achieved by microwave irradiation of phloroglucinol and beta-ketoesters. Heating with microwaves versus under classical conditions was shown to be higher yielding, cleaner, and faster. The reaction goes through a cycloaddition of an alpha-oxo ketene intermediate followed by an uncatalyzed thermal Fries rearrangement.
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Affiliation(s)
- Julio A Seijas
- Departamento de Química Orgánica, Universidad de Santiago de Compostela, Facultad de Ciencias, Aptdo. 280, 27080-Lugo, Spain.
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25
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Azam S, Hadi N, Khan NU, Hadi SM. Prooxidant property of green tea polyphenols epicatechin and epigallocatechin-3-gallate: implications for anticancer properties. Toxicol In Vitro 2005; 18:555-61. [PMID: 15251172 DOI: 10.1016/j.tiv.2003.12.012] [Citation(s) in RCA: 256] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2003] [Accepted: 12/30/2003] [Indexed: 10/26/2022]
Abstract
It is believed that anticancer and apoptosis inducing properties of green tea are mediated by it's polyphenolic constituents particularly catechins. A number of reports have shown that green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) is among the most effective chemopreventive and apoptosis-inducing agents present in the beverage. Plant polyphenols are naturally occurring antioxidants but they also exhibit prooxidant properties. Over the last several years we have shown that various classes of plant polyphenols including flavonoids, curcuminoids and tannins are capable of catalyzing oxidative DNA cleavage particularly in the presence of transition metal ions such as copper and iron. With a view to understand the chemical basis of various pharmacological properties of green tea, in this paper we have compared the prooxidant properties of green tea polyphenols--EGCG and EC ((-)-epicatechin). The rate of oxidative DNA degradation as well as hydroxyl radical and superoxide anion formation was found to be greater in the case of EGCG as compared with EC. It was also shown that copper mediated oxidation of EC and EGCG possibly leads to the formation of polymerized polyphenols. Further, it was indicated that copper oxidized catechins were more efficient prooxidants as compared with their unoxidized forms. These results correlate with the observation by others that EGCG is the most effective apoptosis inducing polyphenol present in green tea. They are also in support of our hypothesis that prooxidant action of plant polyphenols may be an important mechanism of their anticancer properties. A model for binding of Cu(II) to EC has been presented where the formation of quinone and a quinone methide has been proposed.
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Affiliation(s)
- S Azam
- Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, U.P., India
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Castro GT, Blanco SE. Structural and spectroscopic study of 5,7-dihydroxy-flavone and its complex with aluminum. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2004; 60:2235-2241. [PMID: 15249011 DOI: 10.1016/j.saa.2003.11.022] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2003] [Accepted: 11/25/2003] [Indexed: 05/24/2023]
Abstract
The structure, stability and molar absorptivity of the complex formed between AlCl(3) and 5,7-dihydroxy-flavone in methanol were investigated using UV-Vis spectroscopy and the AM1 method. The molar ratio method and Job's method of continuous variation were applied to ascertain the stoichiometric composition of the complex in methanol at constant ionic strength. A 1:2 complex was indicated by both methods. The molar absorptivity and stability constant of the complex were determined using a simple and accurate procedure that requires solutions having the ligand and metal ion in the stoichiometric proportion. The high stability constant demonstrates that the complexation reaction is total. The structure of this complex, obtained by the quantum semi-empirical AM1 method, indicates that two classes of metal-ligand interactions are involved in the formation of the metal complex: (a) two simple covalent bonds between the aluminum atom and the oxygen atoms of o-hydroxyl groups of 5,7-dihydroxy-flavone; (b) two stronger Coulombic interactions between the aluminum atom and the carbonyl oxygen atoms of the ligand.
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Affiliation(s)
- G T Castro
- Area de Química-Física, Departamento de Química, Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, Chacabuco y Pedernera, 5700 San Luis, Argentina
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Uddin Q, Malik A, Azam S, Hadi N, Azmi AS, Parveen N, Khan NU, Hadi SM. The biflavonoid, amentoflavone degrades DNA in the presence of copper ions. Toxicol In Vitro 2004; 18:435-40. [PMID: 15130600 DOI: 10.1016/j.tiv.2003.12.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2003] [Accepted: 12/23/2003] [Indexed: 11/26/2022]
Abstract
Previous reports from this laboratory have shown that flavonoids including apigenin are capable of inducing oxidative DNA cleavage in the presence of copper ions. In the present report, we have examined the ability of amentoflavone, a biflavonoid which is a dimer of apigenin, to catalyze the degradation of DNA. Amentoflavone was found to degrade calf thymus DNA in the presence of Cu(II) at a rate almost twice that of apigenin. Amentoflavone was also shown to reduce Cu(II) to Cu(I) and to generate hydroxyl radicals in the presence of copper ions. In the presence of Cu(II), the absorption spectrum of amentoflavone undergoes a shift and a quenching effect indicating that the biflavonoid is capable of binding to copper ions. Amentoflavone and apigenin were isolated from Cycas rumphii and Trifolium alexandrinum, respectively. The results are discussed in relation to the putative chemopreventive mechanism of amentoflavone.
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Affiliation(s)
- Qamar Uddin
- Department of Chemistry, Natural Product Research Lab, Aligarh Muslim University, Aligarh 202002, UP, India
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Edenharder R, Grünhage D. Free radical scavenging abilities of flavonoids as mechanism of protection against mutagenicity induced by tert-butyl hydroperoxide or cumene hydroperoxide in Salmonella typhimurium TA102. Mutat Res 2003; 540:1-18. [PMID: 12972054 DOI: 10.1016/s1383-5718(03)00114-1] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mutagenicity induced by tert-butyl hydroperoxide (BHP) or cumene hydroperoxide (CHP) in Salmonella typhimurium TA102 was effectively reduced by flavonols with 3',4'-hydroxyl groups such as fisetin, quercetin, rutin, isoquercitrin, hyperoxide, myricetin, myricitrin, robinetin, and to a lesser extent also by morin and kaempferol (ID50=0.25-1.05 micromol per plate). With the exception of isorhamnetin, rhamnetin, morin, and kaempferol, closely similar results were obtained with both peroxides. Hydrogenation of the double bond between carbons 2 and 3 (dihydroquercetin, dihydrorobinetin) as well as the additional elimination of the carbonyl function at carbon 4 (catechins) resulted in a loss of antimutagenicity with the notable exception of catechin itself. Again, all flavones and flavanones tested were inactive except luteolin, luteolin-7-glucoside, diosmetin, and naringenin. The typical radical scavenger butylated hydroxytoluene also showed strong antimutagenicity against CHP (ID50=5.4 micromol per plate) and BHP (ID50=11.4 micromol per plate). Other lipophilic scavengers such as alpha-tocopherol and N,N'-diphenyl-1,4-phenylenediamine exerted only moderate effects, the hydrophilic scavenger trolox was inactive. The metal chelating agent 1,10-phenanthroline strongly reduced mutagenicities induced by CHP and BHP (ID50=2.75 and 2.5 micromol per plate) at low concentrations but induced mutagenic activities at higher concentrations. The iron chelator deferoxamine mesylate, however, was less effective in both respects. The copper chelator neocuproine effectively inhibited mutagenicity induced by BHP (ID50=39.7 micromol per plate) and CHP (ID50=25.9 micrommol per plate), the iron chelator 2,2'-dipyridyl was less potent (ID50=6.25 mmol per plate against BHP, 0.42 mmol per plate against CHP). In the absence of BHP and CHP, yet not in the presence of these hydroperoxides, quercetin, rutin, catechin, epicatechin, and naringenin induced strong mutagenic activities in S. typhimurium TA102. Radical scavenging activities of flavonoids against peroxyl radicals generated from 2,2'-azo-bis(2-amidinopropane)dihydrochloride (AAPH) as measured in the haemolysis test, confirmed that in general flavonoids with di- or trihydroxy hydroxyl functions especially in positions 3', 4', 5' are effective radical scavengers. In this test system, however, luteolin was the most potent compound, followed by epicatechin and eriodictyol. Again, isorhamnetin was a potent inhibitor of lysis of red blood cells despite the presence of a 3'-OCH3 function. Radical scavenging activities of flavonoids against the stable radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) in principle obeyed the rules outlined above. Flavanones, tamarixetin, and rhamnetin, however, were only weakly active against DPPH, while isorhamnetin was again a potent compound. From these results we conclude that in the Salmonella/reversion assay with strain TA102 antimutagenic activities of flavonoids against the peroxide mutagens CHP and BHP are mainly caused by radical scavenging effects.
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Affiliation(s)
- R Edenharder
- Department of Hygiene and Environmental Medicine, University of Mainz, Obere Zahlbacher Strasse 67, D-55131 Mainz, Germany.
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Labuda J, Bucková M, Heilerová L, Silhár S, Stepánek I. Evaluation of the redox properties and anti/pro-oxidant effects of selected flavonoids by means of a DNA-based electrochemical biosensor. Anal Bioanal Chem 2003; 376:168-73. [PMID: 12712310 DOI: 10.1007/s00216-003-1884-3] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2002] [Revised: 02/14/2003] [Accepted: 02/25/2003] [Indexed: 10/20/2022]
Abstract
Quercetin and rutin as well as catechin and epigallocatechin gallate were investigated, as widely distributed representatives of flavonols and flavanols, respectively, regarding their anti/pro-oxidant properties. The flavonoids are irreversibly oxidized at a dsDNA-modified screen-printed electrode within 0.368 to 0.449 V vs. SHE without binding to DNA. Using the DNA biosensor the detection scheme of a DNA prevention/degradation exploits the [Co(phen)(3)](3+) complex as an electrochemical DNA marker. Antioxidant activity of flavonoids was tested in a model cleavage mixture composed of 5 x 10(-7) mol L(-1) [Cu(phen)(2)](2+) as the catalyst, 1 x 10(-3) mol L(-1) ascorbic acid as the chemical reductant and atmospheric oxygen as the natural oxidant where reactive oxygen radicals are generated. The antioxidant activity increases with the concentration of flavonoids reaching a maximum where pro-oxidative behaviour becomes of importance. The pro-oxidant potency of flavonoids depends on the presence of atmospheric oxygen and follows the order quercetin>rutin>epigallocatechin gallate>catechin.
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Affiliation(s)
- Ján Labuda
- Department of Analytical Chemistry, Faculty of Chemical and Food Technology, Slovak University of Technology, 81237 Bratislava, Slovakia.
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Krizková L, Nagy M, Polónyi J, Dobias J, Belicová A, Grancai D, Krajcovic J. Phenolic acids inhibit chloroplast mutagenesis in Euglena gracilis. Mutat Res 2000; 469:107-14. [PMID: 10946247 DOI: 10.1016/s1383-5718(00)00059-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The mutagenicity (bleaching activity) of ofloxacin (43 microM) and acridine orange (AO) (13.5 microM) in Euglena gracilis is inhibited by plant phenolics. Caffeic acid (CA), p-coumaric acid (PCA), ferulic acid (FA) and gentisic acid (GA) (25, 50, 100 and 250 microM) exhibited a significant concentration-dependent inhibitory effect against ofloxacin-induced mutagenicity, which was very effectively eliminated by the highest concentration of all four of those phenolic acids. The mutagenicity of AO was also significantly reduced in the presence of CA, PCA and FA (25, 50, 100 and 250 microM). However, GA exhibited no significant activity, even at the concentration of 250 microM. Based on the UV spectrophotometric measurements, we suggest that the antimutagenic effect of CA, PCA, FA and GA resulted from the scavenging of reactive oxygen species (ROS) produced by ofloxacin. On the other hand, the reduction of AO-induced mutagenicity correlates with the binding capabilities of CA, PCA and FA, with the exception of GA.
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Affiliation(s)
- L Krizková
- Institute of Cell Biology, Faculty of Science, Comenius University, Odborárske nám. 5, 811 07, Bratislava, Slovak Republic.
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