Synthetic Analogs of Green Tea Polyphenols as Proteasome Inhibitors

Smith, David M.; Wang, Zhigang; Kazi, Aslamuzzaman; Li, Lian Hai; Chan, Tak Hang; Dou, Q. Ping

doi:10.1007/bf03402019

Cited by 113 publications

(125 citation statements)

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“…Green tea and the risk of adult leukaemia M Zhang et al significant dose -response relationships, the first such evidence, although a US hospital-based case -control study recently reported a negative association between black tea and AML in women (Li et al, 2006). Our findings are consistent with experimental evidence that green tea polyphenols inhibited proteasome and induced apoptosis in leukaemic cells (Smith et al, 2002).…”

Section: Number Of Cupssupporting

confidence: 88%

Possible protective effect of green tea intake on risk of adult leukaemia

Zhang

Zhao

et al. 2007

Br J Cancer

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In a case -control study of 107 adults with leukaemia and 110 orthopaedic controls in China, a reduced risk was found with longer duration, higher quantity, and frequency of green tea intake. Tea is one of the most frequently consumed beverages in the world (Graham, 1992). Different processing of tea leaves yields green, black, or Oolong tea. If tea leaves are immediately heated, then the enzymes that oxidise catechins are inactivated and the result is green tea; if crushed and allowed to undergo enzyme-mediated oxidation, the process results in black tea with its characteristic colour and taste. Oolong tea results from partially oxidised tea leaves (Graham, 1992).There is some evidence of a protective effect of green tea consumption on certain cancers (Zhang et al, 2002;2004;2007;Cabrera et al, 2006), but no epidemiological data are available on the effect of green tea on adult leukaemia. We therefore conducted a case -control study of the question in southeast China. MATERIALS AND METHODSA hospital-based case -control study was conducted in Hangzhou, southeast China. Eligible cases were defined as Chinese, over 15 years old and resident in Zhejiang Province with leukaemia, histopathologically confirmed according to the haematological standards (Zhang, 1998). They were identified by daily searching of medical records in haematology wards at two teaching hospitals of Zhejiang University in 2005 -2006; all medical records and laboratory reports were also reviewed to ensure complete ascertainment of cases. A total of 107 patients aged 16 -81 years were recruited, most (83.2%) were recent and were interviewed within 12 months of diagnosis. During the same period of data collection, 110 orthopaedic patients without leukaemia or other malignancy were randomly selected as controls to match the cases by age using a daily update of the list of cases. The project received approval from the hospital authorities and from the Human Research Ethics Committee of The University of Western Australia.Subjects were briefed regarding the aims of the study and confidentiality issues. After obtaining their consent, a face-to-face interview was conducted in the hospitals using a structured, validated questionnaire on (a) demography and lifestyle; (b) tea consumption; (c) hazard exposure and family history of malignancy. Most cases were recent patients interviewed within 3 -6 months of diagnosis. Details of leukaemia subtype and stage were retrieved from hospital records.Tea consumption was measured using a questionnaire adapted from our previous studies, its reproducibility evaluated in a testretest study where the intraclass correlation coefficient was 0.83 for tea (Zhang et al, 2005). Information was sought on preparation method, type of tea drank, duration of each type, frequency of cups (350 -400 ml), frequency of new batches of tea brewed, quantity of dried tealeaf consumed per year (in liang, equivalent to 50 g), and date of cessation. Frequency of cups was categorised as never or seldom, once a month, 2-3 times a month, once a...

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Section: Number Of Cupssupporting

confidence: 88%

Possible protective effect of green tea intake on risk of adult leukaemia

Zhang

Zhao

et al. 2007

Br J Cancer

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“…Various potential mechanisms contributing to the anticancer effects of (À)-EGCG have been described, including suppression of Wnt signaling (8), blockade of methylation (9), and inhibition of matrix metalloproteinase (10) and the proteasome (11)(12)(13)(14)(15)(16).…”

Section: Biologically Active Components Of Green Tea Include Polyphenmentioning

confidence: 99%

A Novel Prodrug of the Green Tea Polyphenol (−)-Epigallocatechin-3-Gallate as a Potential Anticancer Agent

et al. 2007

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“…Other structure-activity relationship studies evidenced that the A ring and the gallate ester/amide bond are involved in the mechanism of proteasome inhibition [132]. Similar effects have been described for two synthetic enantiomeric analogs of natural GTCs in PCa cells [133]. The observed accumulation of short-lived proteins, normally addressed to proteosomal degradation such as p21, p27, Bax and ikΒα, in PCa cells after EGCG or GTCs treatment indirectly confirms, that GTCs exert inhibitory effect on the proteasome activity [98,134].…”

Section: Proteasome Inhibitionmentioning

confidence: 53%

Green Tea Catechins for Prostate Cancer Prevention: Present Achievements and Future Challenges

Naponelli¹,

Ramazzina²,

Lenzi³

et al. 2017

Preprint

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Green Tea Catechins (GTCs) are a family of chemically related compounds usually classified as antioxidant molecules. Epidemiological evidences, supported by interventional studies, highlighted a more than promising role for GTCs in human Prostate Cancer (PCa) chemoprevention.In the last decades many efforts have been made to gain new insights into the mechanism of action of GTCs. Now it is clear that GTCs anticancer action can no longer be simplistically limited to their direct antioxidant/pro-oxidant properties. Recent contributions to the advancement of knowledge in this field have shown that GTCs specifically interact with cellular targets including, cell surface receptors, lipid rafts and endoplasmic reticulum, modulate gene expression through direct effect on transcription factors or indirect epigenetic mechanisms, interfere with intracellular proteostasis at various levels. Many of the effects observed in vitro are dose and cell context dependent and take place at concentration that cannot be achieved in vivo.Poor intestinal absorption together with an extensive systemic and enteric metabolism influence GTCs bioavailability through still poor understood mechanisms. Recent efforts to develop delivery systems that increase GTCs overall bioavailability, by mean of biopolymeric nanoparticles, represent the main way to translate preclinical results in a real clinical scenario for PCa chemoprevention.

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Synthetic Analogs of Green Tea Polyphenols as Proteasome Inhibitors

Cited by 113 publications

References 45 publications

Possible protective effect of green tea intake on risk of adult leukaemia

Possible protective effect of green tea intake on risk of adult leukaemia

A Novel Prodrug of the Green Tea Polyphenol (−)-Epigallocatechin-3-Gallate as a Potential Anticancer Agent

Green Tea Catechins for Prostate Cancer Prevention: Present Achievements and Future Challenges

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