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Panda A, Halder K, Debnath D, De S, Dasgupta S. Thermodynamics of the Association of Aminoglycoside Antibiotics with Human Angiogenin. Protein Pept Lett 2023; 30:92-101. [PMID: 36281865 DOI: 10.2174/0929866530666221021111823] [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: 02/16/2022] [Revised: 04/12/2022] [Accepted: 04/13/2022] [Indexed: 12/28/2022]
Abstract
BACKGROUND The body needs to maintain a firm balance between the inducers and inhibitors of angiogenesis, the process of proliferation of blood vessels from pre-existing ones. Human angiogenin (hAng), being a potent inducer of angiogenesis, is a cause of tumor cell proliferation, therefore its inhibition becomes a vital area of research. Aminoglycosides are linked ring systems consisting of amino sugars and an aminocyclitol ring and are in use in clinical practices for a long time. These compounds have found clinical uses as antibacterial agents that inhibit bacterial protein synthesis. OBJECTIVE Gentamycin C1, Kanamycin A, Neomycin B, Paromomycin I, and Streptomycin A are commonly used aminoglycoside antibiotics that have been used for the present study. Among these, Neomycin has reported inhibitory activity against angiogenin-induced angiogenesis on the chicken chorioallantoic membrane. This study focuses on the thermodynamic parameters involved in the interactions of these antibiotics with hAng. METHODS Agarose gel-based assay, Fluorescence quenching studies and Docking studies. RESULTS Anti-ribonucleolytic effect of the antibiotics was observed qualitatively using an agarose gelbased assay, which shows that Neomycin exhibits the most efficient inhibition of hAng. Fluorescence quenching studies at different temperatures, using Stern-Volmer and van't Hoff equations provide information about the thermodynamics of binding, which furthermore highlights the higher binding constant of Neomycin. Docking studies showed that the antibiotics preferably interact with the nuclear translocation site, except Streptomycin, which shows affinity towards the ribonucleolytic site of the protein with very less affinity value. CONCLUSION The study has shown the highly spontaneous formation of Neomycin-hAng complex, giving an exothermic reaction with increase in the degree of freedom of the protein-ligand complex.
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Affiliation(s)
- Atashi Panda
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Krishna Halder
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Debkumar Debnath
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Soumya De
- School of Bioscience, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Swagata Dasgupta
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
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Hung SW, Li Y, Chen X, Chu KO, Zhao Y, Liu Y, Guo X, Man GCW, Wang CC. Green Tea Epigallocatechin-3-Gallate Regulates Autophagy in Male and Female Reproductive Cancer. Front Pharmacol 2022; 13:906746. [PMID: 35860020 PMCID: PMC9289441 DOI: 10.3389/fphar.2022.906746] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 05/17/2022] [Indexed: 11/29/2022] Open
Abstract
With a rich abundance of natural polyphenols, green tea has become one of the most popular and healthiest nonalcoholic beverages being consumed worldwide. Epigallocatechin-3-gallate (EGCG) is the predominant catechin found in green tea, which has been shown to promote numerous health benefits, including metabolic regulation, antioxidant, anti-inflammatory, and anticancer. Clinical studies have also shown the inhibitory effects of EGCG on cancers of the male and female reproductive system, including ovarian, cervical, endometrial, breast, testicular, and prostate cancers. Autophagy is a natural, self-degradation process that serves important functions in both tumor suppression and tumor cell survival. Naturally derived products have the potential to be an effective and safe alternative in balancing autophagy and maintaining homeostasis during tumor development. Although EGCG has been shown to play a critical role in the suppression of multiple cancers, its role as autophagy modulator in cancers of the male and female reproductive system remains to be fully discussed. Herein, we aim to provide an overview of the current knowledge of EGCG in targeting autophagy and its related signaling mechanism in reproductive cancers. Effects of EGCG on regulating autophagy toward reproductive cancers as a single therapy or cotreatment with other chemotherapies will be reviewed and compared. Additionally, the underlying mechanisms and crosstalk of EGCG between autophagy and other cellular processes, such as reactive oxidative stress, ER stress, angiogenesis, and apoptosis, will be summarized. The present review will help to shed light on the significance of green tea as a potential therapeutic treatment for reproductive cancers through regulating autophagy.
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Affiliation(s)
- Sze Wan Hung
- Department of Obstetrics and Gynaecology, The Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
| | - Yiran Li
- Department of Obstetrics and Gynaecology, The Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
| | - Xiaoyan Chen
- Department of Obstetrics and Gynaecology, The Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
- Department of Obstetrics and Gynaecology, Shenzhen Baoan Women’s and Children’s Hospital, Shenzhen University, Shenzhen, China
| | - Kai On Chu
- Department of Ophthalmology and Visual Sciences, Hong Kong Eye Hospital, The Chinese University of Hong Kong, Hong Kong, China
| | - Yiwei Zhao
- Department of Obstetrics and Gynaecology, The Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
- Department of Obstetrics and Gynecology, School of Medicine, Renji Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Yingyu Liu
- Department of Obstetrics and Gynaecology, The Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
- Department of Obstetrics and Gynaecology, Shenzhen Baoan Women’s and Children’s Hospital, Shenzhen University, Shenzhen, China
| | - Xi Guo
- Department of Obstetrics and Gynaecology, The Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
| | - Gene Chi-Wai Man
- Department of Obstetrics and Gynaecology, The Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
- Department of Orthopaedics and Traumatology, The Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
- *Correspondence: Gene Chi-Wai Man, ; Chi Chiu Wang,
| | - Chi Chiu Wang
- Department of Obstetrics and Gynaecology, The Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
- Li Ka Shing Institute of Health Sciences; School of Biomedical Sciences; and Chinese University of Hong Kong-Sichuan University Joint Laboratory in Reproductive Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
- *Correspondence: Gene Chi-Wai Man, ; Chi Chiu Wang,
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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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Filippini T, Malavolti M, Borrelli F, Izzo AA, Fairweather-Tait SJ, Horneber M, Vinceti M. Green tea (Camellia sinensis) for the prevention of cancer. Cochrane Database Syst Rev 2020; 3:CD005004. [PMID: 32118296 PMCID: PMC7059963 DOI: 10.1002/14651858.cd005004.pub3] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND This review is an update of a previously published review in the Cochrane Database of Systematic Reviews (2009, Issue 3).Tea is one of the most commonly consumed beverages worldwide. Teas from the plant Camellia sinensis can be grouped into green, black and oolong tea, and drinking habits vary cross-culturally. C sinensis contains polyphenols, one subgroup being catechins. Catechins are powerful antioxidants, and laboratory studies have suggested that these compounds may inhibit cancer cell proliferation. Some experimental and nonexperimental epidemiological studies have suggested that green tea may have cancer-preventative effects. OBJECTIVES To assess possible associations between green tea consumption and the risk of cancer incidence and mortality as primary outcomes, and safety data and quality of life as secondary outcomes. SEARCH METHODS We searched eligible studies up to January 2019 in CENTRAL, MEDLINE, Embase, ClinicalTrials.gov, and reference lists of previous reviews and included studies. SELECTION CRITERIA We included all epidemiological studies, experimental (i.e. randomised controlled trials (RCTs)) and nonexperimental (non-randomised studies, i.e. observational studies with both cohort and case-control design) that investigated the association of green tea consumption with cancer risk or quality of life, or both. DATA COLLECTION AND ANALYSIS Two or more review authors independently applied the study criteria, extracted data and assessed methodological quality of studies. We summarised the results according to diagnosis of cancer type. MAIN RESULTS In this review update, we included in total 142 completed studies (11 experimental and 131 nonexperimental) and two ongoing studies. This is an additional 10 experimental and 85 nonexperimental studies from those included in the previous version of the review. Eleven experimental studies allocated a total of 1795 participants to either green tea extract or placebo, all demonstrating an overall high methodological quality based on 'Risk of bias' assessment. For incident prostate cancer, the summary risk ratio (RR) in the green tea-supplemented participants was 0.50 (95% confidence interval (CI) 0.18 to 1.36), based on three studies and involving 201 participants (low-certainty evidence). The summary RR for gynaecological cancer was 1.50 (95% CI 0.41 to 5.48; 2 studies, 1157 participants; low-certainty evidence). No evidence of effect of non-melanoma skin cancer emerged (summary RR 1.00, 95% CI 0.06 to 15.92; 1 study, 1075 participants; low-certainty evidence). In addition, adverse effects of green tea extract intake were reported, including gastrointestinal disorders, elevation of liver enzymes, and, more rarely, insomnia, raised blood pressure and skin/subcutaneous reactions. Consumption of green tea extracts induced a slight improvement in quality of life, compared with placebo, based on three experimental studies. In nonexperimental studies, we included over 1,100,000 participants from 46 cohort studies and 85 case-control studies, which were on average of intermediate to high methodological quality based on Newcastle-Ottawa Scale 'Risk of bias' assessment. When comparing the highest intake of green tea with the lowest, we found a lower overall cancer incidence (summary RR 0.83, 95% CI 0.65 to 1.07), based on three studies, involving 52,479 participants (low-certainty evidence). Conversely, we found no association between green tea consumption and cancer-related mortality (summary RR 0.99, 95% CI 0.91 to 1.07), based on eight studies and 504,366 participants (low-certainty evidence). For most of the site-specific cancers we observed a decreased RR in the highest category of green tea consumption compared with the lowest one. After stratifying the analysis according to study design, we found strongly conflicting results for some cancer sites: oesophageal, prostate and urinary tract cancer, and leukaemia showed an increased RR in cohort studies and a decreased RR or no difference in case-control studies. AUTHORS' CONCLUSIONS Overall, findings from experimental and nonexperimental epidemiological studies yielded inconsistent results, thus providing limited evidence for the beneficial effect of green tea consumption on the overall risk of cancer or on specific cancer sites. Some evidence of a beneficial effect of green tea at some cancer sites emerged from the RCTs and from case-control studies, but their methodological limitations, such as the low number and size of the studies, and the inconsistencies with the results of cohort studies, limit the interpretability of the RR estimates. The studies also indicated the occurrence of several side effects associated with high intakes of green tea. In addition, the majority of included studies were carried out in Asian populations characterised by a high intake of green tea, thus limiting the generalisability of the findings to other populations. Well conducted and adequately powered RCTs would be needed to draw conclusions on the possible beneficial effects of green tea consumption on cancer risk.
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Affiliation(s)
- Tommaso Filippini
- University of Modena and Reggio Emilia, Research Center in Environmental, Nutritional and Genetic Epidemiology (CREAGEN), Department of Biomedical, Metabolic and Neural Sciences, Via Campi 287, Modena, Italy, 41125
| | - Marcella Malavolti
- University of Modena and Reggio Emilia, Research Center in Environmental, Nutritional and Genetic Epidemiology (CREAGEN), Department of Biomedical, Metabolic and Neural Sciences, Via Campi 287, Modena, Italy, 41125
| | - Francesca Borrelli
- University of Naples 'Federico II', Department of Pharmacy, School of Medicine and Surgery, Via D Montesano 49, Naples, Italy, 80131
| | - Angelo A Izzo
- University of Naples 'Federico II', Department of Pharmacy, School of Medicine and Surgery, Via D Montesano 49, Naples, Italy, 80131
| | | | - Markus Horneber
- Paracelsus Medical University, Klinikum Nuremberg, Department of Internal Medicine, Division of Oncology and Hematology, Prof.-Ernst-Nathan-Str. 1, Nuremberg, Germany, D-90419
| | - Marco Vinceti
- University of Modena and Reggio Emilia, Research Center in Environmental, Nutritional and Genetic Epidemiology (CREAGEN), Department of Biomedical, Metabolic and Neural Sciences, Via Campi 287, Modena, Italy, 41125
- Boston University School of Public Health, Department of Epidemiology, 715 Albany Street, Boston, USA, MA 02118
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Guimarães R, Calhelha RC, Froufe HJC, Abreu RMV, Carvalho AM, Queiroz MJRP, Ferreira ICFR. Wild Roman chamomile extracts and phenolic compounds: enzymatic assays and molecular modelling studies with VEGFR-2 tyrosine kinase. Food Funct 2016; 7:79-83. [PMID: 26446815 DOI: 10.1039/c5fo00586h] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Angiogenesis is a process by which new blood vessels are formed from the pre-existing vasculature, and it is a key process that leads to tumour development. Some studies have recognized phenolic compounds as chemopreventive agents; flavonoids, in particular, seem to suppress the growth of tumor cells modifying the cell cycle. Herein, the antiangiogenic activity of Roman chamomile (Chamaemelum nobile L.) extracts (methanolic extract and infusion) and the main phenolic compounds present (apigenin, apigenin-7-O-glucoside, caffeic acid, chlorogenic acid, luteolin, and luteolin-7-O-glucoside) was evaluated through enzymatic assays using the tyrosine kinase intracellular domain of the Vascular Endothelium Growth Factor Receptor-2 (VEGFR-2), which is a transmembrane receptor expressed fundamentally in endothelial cells involved in angiogenesis, and molecular modelling studies. The methanolic extract showed a lower IC50 value (concentration that provided 50% of VEGFR-2 inhibition) than the infusion, 269 and 301 μg mL(-1), respectively. Regarding phenolic compounds, luteolin and apigenin showed the highest capacity to inhibit the phosphorylation of VEGFR-2, leading us to believe that these compounds are involved in the activity revealed by the methanolic extract.
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Affiliation(s)
- Rafaela Guimarães
- Centro de Investigação de Montanha, Escola Superior Agrária, Campus de Santa Apolónia, apartado 1172, 5301-854 Bragança, Portugal. and Centro de Química da Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal
| | - Ricardo C Calhelha
- Centro de Investigação de Montanha, Escola Superior Agrária, Campus de Santa Apolónia, apartado 1172, 5301-854 Bragança, Portugal. and Centro de Química da Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal
| | - Hugo J C Froufe
- Centro de Investigação de Montanha, Escola Superior Agrária, Campus de Santa Apolónia, apartado 1172, 5301-854 Bragança, Portugal.
| | - Rui M V Abreu
- Centro de Investigação de Montanha, Escola Superior Agrária, Campus de Santa Apolónia, apartado 1172, 5301-854 Bragança, Portugal.
| | - Ana Maria Carvalho
- Centro de Investigação de Montanha, Escola Superior Agrária, Campus de Santa Apolónia, apartado 1172, 5301-854 Bragança, Portugal.
| | | | - Isabel C F R Ferreira
- Centro de Investigação de Montanha, Escola Superior Agrária, Campus de Santa Apolónia, apartado 1172, 5301-854 Bragança, Portugal.
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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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Hoffman A, Baxter R, Nasar A, Gardner TR, Kumara S, Cordon-Cardo C, Ahmed A, Newman RA, Zmora O, Whelan RL. Perioperative polyphenon E, a green tea extract, does not affect the wound complication rate in mice after sham laparotomy yet has an inhibitory effect on wound healing. Surg Innov 2012; 19:399-406. [PMID: 22431911 DOI: 10.1177/1553350612436565] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Major surgery is associated with physiologic alterations that may promote tumor growth, and catechins in green tea may inhibit tumor growth. This study's aim was to assess the impact of a green tea extract on laparotomy wound healing in mice. METHODS Mice were randomized to daily oral catechins solution (n = 25) or placebo (n = 20), underwent sham laparotomy after 10 days, and were sacrificed on postoperative day 7 or 21. The peak force and total energy required to rupture the abdominal wall wound, wound collagen content, and histology were assessed. RESULTS There were no wound complications in either group, and mean peak wound rupture forces and collagen concentration were similar. Mean energy was lower and more fibroblast proliferation was found in the treatment group on postoperative day 21. CONCLUSIONS These results suggest that catechins has only mild clinically significant adverse effect on wound healing, and its perioperative use warrants further study.
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Chen CM, Li SC, Chen CYO, Au HK, Shih CK, Hsu CY, Liu JF. Constituents in purple sweet potato leaves inhibit in vitro angiogenesis with opposite effects ex vivo. Nutrition 2011; 27:1177-82. [DOI: 10.1016/j.nut.2011.01.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Revised: 12/27/2010] [Accepted: 01/15/2011] [Indexed: 10/18/2022]
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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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Lee UL, Choi SW. The chemopreventive properties and therapeutic modulation of green tea polyphenols in oral squamous cell carcinoma. ISRN ONCOLOGY 2011; 2011:403707. [PMID: 22084729 PMCID: PMC3197077 DOI: 10.5402/2011/403707] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Accepted: 03/20/2011] [Indexed: 11/23/2022]
Abstract
Chemoprevention is a relatively novel and promising approach for controlling cancer that uses specific natural products or synthetic agents to suppress, reverse, or prevent premalignancy before transformation into invasive cancer. Oral cavity squamous cell carcinoma (OCSCC) represents a large, worldwide health burden with approximately 274,000 cases diagnosed annually worldwide. Smoking and alcohol consumption are major inducers of OCSCC. Recently, the human papilloma virus was also shown to potentially be an etiologic factor. Due to its easily identifiable risk factors and the presence of premalignant regions, oral cancer makes a good candidate for chemoprevention. Green tea is the most widely consumed beverage in the world, and it has received considerable attention because of its abundant, scientifically proven, beneficial effects on human health. In this review, we discuss the role of green tea in oral cancer chemoprevention with regard to the multiple molecular mechanisms proposed in various in vitro, in vivo, and clinical trials.
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Affiliation(s)
- Ui-Lyong Lee
- Tooth Bioengineering National Research Lab, BK21, and Dental Research Institute, School of Dentistry, Seoul National University, Seoul 110-749, Republic of Korea
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The Chick Embryo Chorioallantoic Membrane as an In Vivo Assay to Study Antiangiogenesis. Pharmaceuticals (Basel) 2010; 3:482-513. [PMID: 27713265 PMCID: PMC4033966 DOI: 10.3390/ph3030482] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Revised: 01/29/2010] [Accepted: 03/02/2010] [Indexed: 12/15/2022] Open
Abstract
Antiangiogenesis, e.g., inhibition of blood vessel growth, is being investigated as a way to prevent the growth of tumors and other angiogenesis-dependent diseases. Pharmacological inhibition interferes with the angiogenic cascade or the immature neovasculature with synthetic or semi-synthetic substances, endogenous inhibitors or biological antagonists.The chick embryo chorioallantoic membrane (CAM) is an extraembryonic membrane, which serves as a gas exchange surface and its function is supported by a dense capillary network. Because its extensive vascularization and easy accessibility, CAM has been used to study morphofunctional aspects of the angiogenesis process in vivo and to study the efficacy and mechanism of action of pro- and anti-angiogenic molecules. The fields of application of CAM in the study of antiangiogenesis, including our personal experience, are illustrated in this review article.
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Boehm K, Borrelli F, Ernst E, Habacher G, Hung SK, Milazzo S, Horneber M. Green tea (Camellia sinensis) for the prevention of cancer. THE COCHRANE DATABASE OF SYSTEMATIC REVIEWS 2009. [PMID: 19588362 DOI: 10.1002/14651858.cd005004.pub2.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND Tea is one of the most commonly consumed beverages worldwide. Teas from the plant Camellia sinensis can be grouped into green, black and oolong tea. Cross-culturally tea drinking habits vary. Camellia sinensis contains the active ingredient polyphenol, which has a subgroup known as catechins. Catechins are powerful antioxidants. It has been suggested that green tea polyphenol may inhibit cell proliferation and observational studies have suggested that green tea may have cancer-preventative effects. OBJECTIVES To critically assess any associations between green tea consumption and the risk of cancer incidence and mortality. SEARCH STRATEGY We searched eligible studies up to January 2009 in the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Amed, CancerLit, Psych INFO and Phytobase and reference lists of previous reviews and included studies. SELECTION CRITERIA We included all prospective, controlled interventional studies and observational studies, which either assessed the associations between green tea consumption and risk of cancer incidence or that reported on cancer mortality. DATA COLLECTION AND ANALYSIS At least two review authors independently applied the study criteria, extracted data and assessed methodological quality of studies. Due to the nature of included studies, which were mainly epidemiological, results were summarised descriptively according to cancer diagnosis. MAIN RESULTS Fifty-one studies with more than 1.6 million participants were included. Twenty-seven of them were case-control studies, 23 cohort studies and one randomised controlled trial (RCT).Twenty-seven studies tried to establish an association between green tea consumption and cancer of the digestive tract, mainly of the upper gastrointestinal tract, five with breast cancer, five with prostate cancer, three with lung cancer, two with ovarian cancer, two with urinary bladder cancer one with oral cancer, three further studies included patients with various cancer diagnoses.The methodological quality was measured with the Newcastle-Ottawa scale (NOS). The 9 nested case-control studies within prospective cohorts were of high methodological quality, 13 of medium, and 1 of low. One retrospective case-control study was of high methodological quality and 21 of medium and 5 of low.Results from studies assessing associations between green tea and risk of digestive tract cancer incidence were highly contradictory. There was limited evidence that green tea could reduce the incidence of liver cancer. The evidence for esophageal, gastric, colon, rectum, and pancreatic cancer was conflicting. In prostate cancer, observational studies with higher methodological quality and the only included RCT suggested a decreased risk in men consuming higher quantities green tea or green tea extracts. However, there was limited to moderate evidence that the consumption of green tea reduced the risk of lung cancer, especially in men, and urinary bladder cancer or that it could even increase the risk of the latter. There was moderate to strong evidence that green tea consumption does not decrease the risk of dying from gastric cancer. There was limited moderate to strong evidence for lung, pancreatic and colorectal cancer. AUTHORS' CONCLUSIONS There is insufficient and conflicting evidence to give any firm recommendations regarding green tea consumption for cancer prevention. The results of this review, including its trends of associations, need to be interpreted with caution and their generalisability is questionable, as the majority of included studies were carried out in Asia (n = 47) where the tea drinking culture is pronounced. Desirable green tea intake is 3 to 5 cups per day (up to 1200 ml/day), providing a minimum of 250 mg/day catechins. If not exceeding the daily recommended allowance, those who enjoy a cup of green tea should continue its consumption. Drinking green tea appears to be safe at moderate, regular and habitual use.
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Affiliation(s)
- Katja Boehm
- Medizinische Klinik 5-Schwerpunkt Onkologie / Haematologie, Klinikum Nord, Prof.-Ernst-Nathan-Str. 1, Nuernberg, Germany, D-90419
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Boehm K, Borrelli F, Ernst E, Habacher G, Hung SK, Milazzo S, Horneber M. Green tea (Camellia sinensis) for the prevention of cancer. Cochrane Database Syst Rev 2009; 2009:CD005004. [PMID: 19588362 PMCID: PMC6457677 DOI: 10.1002/14651858.cd005004.pub2] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND Tea is one of the most commonly consumed beverages worldwide. Teas from the plant Camellia sinensis can be grouped into green, black and oolong tea. Cross-culturally tea drinking habits vary. Camellia sinensis contains the active ingredient polyphenol, which has a subgroup known as catechins. Catechins are powerful antioxidants. It has been suggested that green tea polyphenol may inhibit cell proliferation and observational studies have suggested that green tea may have cancer-preventative effects. OBJECTIVES To critically assess any associations between green tea consumption and the risk of cancer incidence and mortality. SEARCH STRATEGY We searched eligible studies up to January 2009 in the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Amed, CancerLit, Psych INFO and Phytobase and reference lists of previous reviews and included studies. SELECTION CRITERIA We included all prospective, controlled interventional studies and observational studies, which either assessed the associations between green tea consumption and risk of cancer incidence or that reported on cancer mortality. DATA COLLECTION AND ANALYSIS At least two review authors independently applied the study criteria, extracted data and assessed methodological quality of studies. Due to the nature of included studies, which were mainly epidemiological, results were summarised descriptively according to cancer diagnosis. MAIN RESULTS Fifty-one studies with more than 1.6 million participants were included. Twenty-seven of them were case-control studies, 23 cohort studies and one randomised controlled trial (RCT).Twenty-seven studies tried to establish an association between green tea consumption and cancer of the digestive tract, mainly of the upper gastrointestinal tract, five with breast cancer, five with prostate cancer, three with lung cancer, two with ovarian cancer, two with urinary bladder cancer one with oral cancer, three further studies included patients with various cancer diagnoses.The methodological quality was measured with the Newcastle-Ottawa scale (NOS). The 9 nested case-control studies within prospective cohorts were of high methodological quality, 13 of medium, and 1 of low. One retrospective case-control study was of high methodological quality and 21 of medium and 5 of low.Results from studies assessing associations between green tea and risk of digestive tract cancer incidence were highly contradictory. There was limited evidence that green tea could reduce the incidence of liver cancer. The evidence for esophageal, gastric, colon, rectum, and pancreatic cancer was conflicting. In prostate cancer, observational studies with higher methodological quality and the only included RCT suggested a decreased risk in men consuming higher quantities green tea or green tea extracts. However, there was limited to moderate evidence that the consumption of green tea reduced the risk of lung cancer, especially in men, and urinary bladder cancer or that it could even increase the risk of the latter. There was moderate to strong evidence that green tea consumption does not decrease the risk of dying from gastric cancer. There was limited moderate to strong evidence for lung, pancreatic and colorectal cancer. AUTHORS' CONCLUSIONS There is insufficient and conflicting evidence to give any firm recommendations regarding green tea consumption for cancer prevention. The results of this review, including its trends of associations, need to be interpreted with caution and their generalisability is questionable, as the majority of included studies were carried out in Asia (n = 47) where the tea drinking culture is pronounced. Desirable green tea intake is 3 to 5 cups per day (up to 1200 ml/day), providing a minimum of 250 mg/day catechins. If not exceeding the daily recommended allowance, those who enjoy a cup of green tea should continue its consumption. Drinking green tea appears to be safe at moderate, regular and habitual use.
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Affiliation(s)
- Katja Boehm
- Klinikum NordMedizinische Klinik 5‐Schwerpunkt Onkologie/HaematologieProf.‐Ernst‐Nathan‐Str. 1NuernbergGermanyD‐90419
| | - Francesca Borrelli
- University of Naples 'Federico II'Department of Experimental PharmacologyVia D Montesano 49NaplesItaly80131
| | - Edzard Ernst
- Peninsula Medical School, University of ExeterComplementary Medicine DepartmentExeterUK
| | - Gabi Habacher
- Small Animal HospitalFeline CentreDepartment of Veterinary Clinical SciencesUniversity of BristolLangfordUK
| | - Shao Kang Hung
- Peninsula Medical School, Universities of Exeter and PlymouthComplementary Medicine25 Victoria Park RoadExeterUKEX2 4NT
| | - Stefania Milazzo
- Paracelsus Medical University, Klinikum NuernbergDepartment of Internal Medicine, Division of Oncology and HematologyProf.‐Ernst‐Nathan‐Str. 1NuernbergGermanyD‐90419
| | - Markus Horneber
- Paracelsus Medical University, Klinikum NurembergDepartment of Internal Medicine, Division of Oncology and HematologyProf.‐Ernst‐Nathan‐Str. 1NurembergGermanyD‐90419
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Shrubsole MJ, Lu W, Chen Z, Shu XO, Zheng Y, Dai Q, Cai Q, Gu K, Ruan ZX, Gao YT, Zheng W. Drinking green tea modestly reduces breast cancer risk. J Nutr 2009; 139:310-6. [PMID: 19074205 PMCID: PMC2646205 DOI: 10.3945/jn.108.098699] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Green tea is a commonly consumed beverage in China. Epidemiological and animal data suggest tea and tea polyphenols may be preventive against various cancers, including breast cancer. Catechol-O-methyltransferase (COMT) catalyzes catechol estrogens and tea polyphenols. The COMT rs4680 AA genotype leads to lower COMT activity, which may affect the relationship between green tea consumption and breast cancer risk. We evaluated whether regular green tea consumption was associated with breast cancer risk among 3454 incident cases and 3474 controls aged 20-74 y in a population-based case-control study conducted in Shanghai, China during 1996-2005. All participants were interviewed in person about green tea consumption habits, including age of initiation, duration of use, brew strength, and quantity of tea. Odds ratios (OR) and 95% CI were calculated for green tea consumption measures and adjusted for age and other confounding factors. Compared with nondrinkers, regular drinking of green tea was associated with a slightly decreased risk for breast cancer (OR, 0.88; 95% CI, 0.79-0.98). Among premenopausal women, reduced risk was observed for years of green tea drinking (P-trend = 0.02) and a dose-response relationship with the amount of tea consumed per month was also observed (P-trend = 0.046). COMT rs4680 genotypes did not have a modifying effect on the association of green tea intake with breast cancer risk. Drinking green tea may be weakly associated with a decreased risk of breast cancer.
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Affiliation(s)
- Martha J. Shrubsole
- Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt School of Medicine, Nashville, TN 37232; Department of Epidemiology, Shanghai Cancer Institute, Shanghai 200032, People's Republic of China; and Shanghai Center for Disease Prevention and Control, Shanghai 200032, People's Republic of China
| | - Wei Lu
- Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt School of Medicine, Nashville, TN 37232; Department of Epidemiology, Shanghai Cancer Institute, Shanghai 200032, People's Republic of China; and Shanghai Center for Disease Prevention and Control, Shanghai 200032, People's Republic of China
| | - Zhi Chen
- Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt School of Medicine, Nashville, TN 37232; Department of Epidemiology, Shanghai Cancer Institute, Shanghai 200032, People's Republic of China; and Shanghai Center for Disease Prevention and Control, Shanghai 200032, People's Republic of China
| | - Xiao Ou Shu
- Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt School of Medicine, Nashville, TN 37232; Department of Epidemiology, Shanghai Cancer Institute, Shanghai 200032, People's Republic of China; and Shanghai Center for Disease Prevention and Control, Shanghai 200032, People's Republic of China
| | - Ying Zheng
- Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt School of Medicine, Nashville, TN 37232; Department of Epidemiology, Shanghai Cancer Institute, Shanghai 200032, People's Republic of China; and Shanghai Center for Disease Prevention and Control, Shanghai 200032, People's Republic of China
| | - Qi Dai
- Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt School of Medicine, Nashville, TN 37232; Department of Epidemiology, Shanghai Cancer Institute, Shanghai 200032, People's Republic of China; and Shanghai Center for Disease Prevention and Control, Shanghai 200032, People's Republic of China
| | - Qiuyin Cai
- Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt School of Medicine, Nashville, TN 37232; Department of Epidemiology, Shanghai Cancer Institute, Shanghai 200032, People's Republic of China; and Shanghai Center for Disease Prevention and Control, Shanghai 200032, People's Republic of China
| | - Kai Gu
- Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt School of Medicine, Nashville, TN 37232; Department of Epidemiology, Shanghai Cancer Institute, Shanghai 200032, People's Republic of China; and Shanghai Center for Disease Prevention and Control, Shanghai 200032, People's Republic of China
| | - Zhi Xian Ruan
- Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt School of Medicine, Nashville, TN 37232; Department of Epidemiology, Shanghai Cancer Institute, Shanghai 200032, People's Republic of China; and Shanghai Center for Disease Prevention and Control, Shanghai 200032, People's Republic of China
| | - Yu-Tang Gao
- Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt School of Medicine, Nashville, TN 37232; Department of Epidemiology, Shanghai Cancer Institute, Shanghai 200032, People's Republic of China; and Shanghai Center for Disease Prevention and Control, Shanghai 200032, People's Republic of China
| | - Wei Zheng
- Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt School of Medicine, Nashville, TN 37232; Department of Epidemiology, Shanghai Cancer Institute, Shanghai 200032, People's Republic of China; and Shanghai Center for Disease Prevention and Control, Shanghai 200032, People's Republic of China
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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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Carlson JR, Bauer BA, Vincent A, Limburg PJ, Wilson T. Reading the tea leaves: anticarcinogenic properties of (-)-epigallocatechin-3-gallate. Mayo Clin Proc 2007; 82:725-32. [PMID: 17550753 DOI: 10.4065/82.6.725] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Green tea is an extremely popular beverage worldwide. Derivatives of green tea, particularly (-)-epigallocatechin-3-gallate (EGCG), have been proposed to have anticarcinogenic properties based on preclinical, observational, and clinical trial data. To summarize, clarify, and extend current knowledge, we conducted a comprehensive search of the PubMed database and other secondary data sources, as appropriate, regarding the chemopreventive potential of EGCG. Apparently, EGCG functions as an antioxidant, preventing oxidative damage in healthy cells, but also as an antiangiogenic agent, preventing tumors from developing a blood supply needed to grow larger. Furthermore, EGCG may stimulate apoptosis in cancerous cells by negatively regulating the cell cycle to prevent continued division. Finally, EGCG exhibits antibacterial activity, which may be implicated in the prevention of gastric cancer. Although in vitro research of the anticarcinogenic properties of EGCG seems promising, many diverse and unknown factors may influence its in vivo activity in animal and human models. Some epidemiological studies suggest that green tea compounds could protect against cancer, but existing data are inconsistent, and limitations in study design hinder full interpretation and generalizability of the published observational findings. Several clinical trials with green tea derivatives are ongoing, and further research should help to clarify the clinical potential of EGCG for chemoprevention and/or chemotherapy applications.
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Ghosh KS, Maiti TK, Mandal A, Dasgupta S. Copper complexes of (−)-epicatechin gallate and (−)-epigallocatechin gallate act as inhibitors of Ribonuclease A. FEBS Lett 2006; 580:4703-8. [PMID: 16884715 DOI: 10.1016/j.febslet.2006.07.054] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2006] [Accepted: 07/12/2006] [Indexed: 11/17/2022]
Abstract
Green tea polyphenols, which have the ability to inhibit angiogenesis, form complexes with Cu(II), a known potent stimulator of blood vessel proliferation. Copper complexes of (-)-epicatechin gallate and (-)-epigallocatechin gallate were found to inhibit the enzymatic activity of Ribonuclease A (RNase A) as revealed by an agarose gel based assay and urea denatured gel electrophoresis. The copper complexes were found to be non-competitive inhibitors of RNase A with inhibition constants in the micromolar range. Changes in the secondary structure of the protein are found to occur due to the interaction as revealed from Fourier transform infrared and circular dichroism studies.
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Affiliation(s)
- Kalyan Sundar Ghosh
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India
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Stoclet JC, Chataigneau T, Ndiaye M, Oak MH, El Bedoui J, Chataigneau M, Schini-Kerth VB. Vascular protection by dietary polyphenols. Eur J Pharmacol 2005; 500:299-313. [PMID: 15464042 DOI: 10.1016/j.ejphar.2004.07.034] [Citation(s) in RCA: 351] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/01/2004] [Indexed: 11/19/2022]
Abstract
Consumption of polyphenol-rich foods, such as fruits and vegetables, and beverages derived from plants, such as cocoa, red wine and tea, may represent a beneficial diet in terms of cardiovascular protection. Indeed, epidemiological studies demonstrate a significant inverse correlation between polyphenol consumption and cardiovascular risk. Among the numerous plausible mechanisms by which polyphenols may confer cardiovascular protection, improvement of the endothelial function and inhibition of angiogenesis and cell migration and proliferation in blood vessels have been the focus of recent studies. These studies have indicated that, in addition to and independently from their antioxidant effects, plant polyphenols (1) enhance the production of vasodilating factors [nitric oxide (NO), endothelium-derived hyperpolarizing factor (EDHF) and prostacyclin] and inhibit the synthesis of vasoconstrictor endothelin-1 in endothelial cells; and (2) inhibit the expression of two major pro-angiogenic factors, vascular endothelial growth factor (VEGF) and matrix metalloproteinase-2 (MMP-2) in smooth muscle cells. The mechanisms of these effects involve: (1) in endothelial cells, increased Ca(2+) level and redox-sensitive activation of the phosphoinositide 3 (PI3)-kinase/Akt pathway (leading to rapid and sustained activation of nitric oxide synthase and formation of EDHF) and enhanced expression of nitric oxide synthase; and (2) in smooth muscle cells, both redox-sensitive inhibition of the p38 mitogen-activated protein kinase (p38 MAPK) pathway activation (leading to inhibition of platelet-derived growth factor (PDGF)-induced VEGF gene expression) and redox-insensitive mechanisms (leading to inhibition of thrombin-induced MMP-2 formation). The current evidence suggests that all these mechanisms are triggered by polyphenols with specific structures, although the structural requirements may be different from one effect to the other, and that they all contribute to the vasoprotective, anti-angiogenic, anti-atherogenic, vasorelaxant and anti-hypertensive effects of acute or chronic administration of plant polyphenols found in vivo in animals and in patients.
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Affiliation(s)
- Jean-Claude Stoclet
- Pharmacologie et Physico-Chimie des Interactions Cellulaires et Moléculaires, UMR CNRS 7034, Faculté de Pharmacie, Université Louis Pasteur de Strasbourg, B. P. 60024, 74 route du Rhin, F 67401 Illkirch, France.
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McCarty MF. Targeting multiple signaling pathways as a strategy for managing prostate cancer: multifocal signal modulation therapy. Integr Cancer Ther 2005; 3:349-80. [PMID: 15523106 DOI: 10.1177/1534735404270757] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The aberrant behavior of cancer reflects upregulation of certain oncogenic signaling pathways that promote proliferation, inhibit apoptosis, and enable the cancer to spread and evoke angiogenesis. Theoretically, it should be feasible to decrease the activity of these pathways-or increase the activity of pathways that oppose them-with noncytotoxic agents. Since multiple pathways are dysfunctional in most cancers, and cancers accumulate new oncogenic mutations as they progress, the greatest and most durable therapeutic benefit will likely be achieved with combination regimens that address several targets. Thus, a multifocal signal modulation therapy (MSMT) of cancer is proposed. This concept has already been documented by researchers who have shown that certain combinations of signal modulators-of limited utility when administered individually-can achieve dramatic suppression of tumor growth in rodent xenograft models. The present essay attempts to guide development of MSMTs for prostate cancer. Androgen ablation is a signal-modulating measure already in standard use in the management of delocalized prostate cancer. The additional molecular targets considered here include the type 1 insulin-like growth factor receptor, the epidermal growth factor receptor, mammalian target of rapamycin, NF-kappaB, hypoxia-inducible factor-1alpha, hsp90, cyclooxygenase-2, protein kinase A type I, vascular endothelial growth factor, 5-lipoxygenase, 12-lipoxygenase, angiotensin II receptor type 1, bradykinin receptor type 1, c-Src, interleukin-6, ras, MDM2, bcl-2/bclxL, vitamin D receptor, estrogen receptor-beta, and PPAR-. Various nutrients and phytochemicals suspected to have potential utility in prostate cancer prevention and therapy, but whose key molecular targets are still unknown, might reasonably be incorporated into MSMTs for prostate cancer; these include lycopene, selenium, green tea polyphenols, genistein, and silibinin. MSMTs can be developed systematically by testing various combinations of signal-modulating agents, in concentrations that can feasibly be achieved and maintained clinically, on human prostate cancer cell lines; combinations that appear promising can then be tested in xenograft models and, ultimately, in the clinic. Some signal modulators can increase response to cytotoxic drugs by upregulating effectors of apoptosis. When MSMTs fail to raise the spontaneous apoptosis rate sufficiently to achieve tumor stasis or regression, incorporation of appropriate cytotoxic agents into the regimen may improve the clinical outcome.
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Ghosh KS, Maiti TK, Dasgupta S. Green tea polyphenols as inhibitors of ribonuclease A. Biochem Biophys Res Commun 2005; 325:807-11. [PMID: 15541362 DOI: 10.1016/j.bbrc.2004.10.116] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2004] [Indexed: 11/24/2022]
Abstract
Ribonucleases (RNases), which are essential for cleavage of RNA, may be cytotoxic due to undesired cleavage of RNA in the cell. The quest for small molecule inhibitors of members of the ribonuclease superfamily has become indispensable with a growing number exhibiting unusual biological properties. Thus, inhibitors of RNases may serve as potential drug candidates. Green tea catechins (GTC), particularly its major constituent (-)-epigallocatechin-3-gallate (EGCG), have reported potential against cell proliferation and angiogenesis induced by several growth factors including angiogenin, a member of the RNase superfamily. This study reports the inhibition of bovine pancreatic ribonuclease A (RNase A) by EGCG and GTC. This has been checked qualitatively by an agarose gel based assay. Enzyme kinetic studies with cytidine 2',3' cyclic monophosphate as the substrate have also been conducted. Results indicate substantial inhibitory activity of a noncompetitive nature with an inhibition constant of approximately 80 microM for EGCG and approximately 100 microM for GTC measured in gallic acid equivalents.
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Affiliation(s)
- Kalyan Sundar Ghosh
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India
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Oak MH, El Bedoui J, Schini-Kerth VB. Antiangiogenic properties of natural polyphenols from red wine and green tea. J Nutr Biochem 2005; 16:1-8. [PMID: 15629234 DOI: 10.1016/j.jnutbio.2004.09.004] [Citation(s) in RCA: 128] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2004] [Revised: 09/20/2004] [Accepted: 09/30/2004] [Indexed: 10/26/2022]
Abstract
Epidemiological studies have indicated that regular consumption of red wine and green tea is associated with a reduced risk of coronary heart disease and tumor progression. The development of tumors and of atherosclerosis lesions to advanced plaques, which are prone to rupture, is accelerated by the formation of new blood vessels. These new blood vessels provide oxygen and nutrients to neighboring cells. Therefore, recent studies have examined whether red wine polyphenolic compounds (RWPCs) and green tea polyphenols (GTPs) have antiangiogenic properties. In vitro investigations have indicated that RWPCs and GTPs are able to inhibit several key events of the angiogenic process such as proliferation and migration of endothelial cells and vascular smooth muscle cells and the expression of two major proangiogenic factors, vascular endothelial growth factor (VEGF) and matrix metalloproteinase-2, by both redox-sensitive and redox-insensitive mechanisms. Antiangiogenic properties of polyphenols have also been observed in the chick embryo chorioallantoic membrane since the local application of RWPCs and GTPs strongly inhibited the formation of new blood vessels. Moreover, intake of resveratrol or green tea has been shown to reduce corneal neovascularization induced by proangiogenic factors such as VEGF and fibroblast growth factor in mice. The ability of RWPCs and GTPs to prevent the formation of new blood vessels contributes, at least in part, to explain their beneficial effect on coronary heart disease and cancer. This review focuses on the antiangiogenic properties of natural polyphenols and examines underlying mechanisms.
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Affiliation(s)
- Min-Ho Oak
- Pharmacologie et Physico-Chimie des Interactions Cellulaires et Moléculaires, UMR CNRS 7034, Faculté de Pharmacie, Université Louis Pasteur de Strasbourg, F-67401 Illkirch, France
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