The effects of green tea derived catechins upon adipocyte metabolism

Tea, from the plant Camellia Sinensis, is after water, the most consumed drink in the world. Green tea, produced by steaming freshly harvested leaves to prevent fermentation, is high in polyphenols known as catechins or flavanols. The major flavanols found in green tea include (-) epigallocatechin-3...

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Main Author: Mehra, Anisha
Format: Thesis (University of Nottingham only)
Language:English
Published: 2010
Subjects:
Online Access:https://eprints.nottingham.ac.uk/12115/
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author Mehra, Anisha
author_facet Mehra, Anisha
author_sort Mehra, Anisha
building Nottingham Research Data Repository
collection Online Access
description Tea, from the plant Camellia Sinensis, is after water, the most consumed drink in the world. Green tea, produced by steaming freshly harvested leaves to prevent fermentation, is high in polyphenols known as catechins or flavanols. The major flavanols found in green tea include (-) epigallocatechin-3-gallate (EGCG) and (-) epicatechin. Literature reports suggest that green tea flavanols have the potential to exert anti-obesity effects by modulating weight gain and other factors such as lipogenesis, β-oxidation and adipokine release. Key features of obesity and associated insulin resistance are adipokine dysregulation, decreased sensitivity of adipocytes to insulin and subsequently, changes in glucose uptake by cells. The aims of this thesis were firstly to establish an efficient system of differentiated adipocytes and secondly to use this to investigate the effects of the flavanols EGCG and epicatechin on physiological outcomes such as adipokine release and glucose uptake. Thirdly, the question of whether these processes might be regulated by the ERK1/2 pathway and what may be happening upstream of this was explored. Finally, the effect of flavanol treatment on adipocyte gene expression of genes known to be modulated in obesity was investigated. Using the well established cell culture model of 3T3-L1 adipocytes, the studies from this thesis show that EGCG and epicatechin are able to modulate the release of the adipokines adiponectin and resistin, dependent on the media glucose concentration. This modulation may be mediated by the ERK1/2 pathway, since flavanol treatment increased ERK1/2 phosphorylation. Uptake of glucose was not altered by any time or concentration of EGCG or epicatechin, and there were no significant changes in adipocyte gene expression following EGCG or epicatechin treatment. A thorough investigation of adipokine release, ERK signalling, glucose uptake and gene expression, under the influence of flavanol treatment, showed that although molecular changes occurred in the 3T3-L1 system, these did not translate into functional readouts. Therefore, it appears unlikely that these have major direct effects on adipocyte function.
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spelling nottingham-121152025-02-28T11:17:40Z https://eprints.nottingham.ac.uk/12115/ The effects of green tea derived catechins upon adipocyte metabolism Mehra, Anisha Tea, from the plant Camellia Sinensis, is after water, the most consumed drink in the world. Green tea, produced by steaming freshly harvested leaves to prevent fermentation, is high in polyphenols known as catechins or flavanols. The major flavanols found in green tea include (-) epigallocatechin-3-gallate (EGCG) and (-) epicatechin. Literature reports suggest that green tea flavanols have the potential to exert anti-obesity effects by modulating weight gain and other factors such as lipogenesis, β-oxidation and adipokine release. Key features of obesity and associated insulin resistance are adipokine dysregulation, decreased sensitivity of adipocytes to insulin and subsequently, changes in glucose uptake by cells. The aims of this thesis were firstly to establish an efficient system of differentiated adipocytes and secondly to use this to investigate the effects of the flavanols EGCG and epicatechin on physiological outcomes such as adipokine release and glucose uptake. Thirdly, the question of whether these processes might be regulated by the ERK1/2 pathway and what may be happening upstream of this was explored. Finally, the effect of flavanol treatment on adipocyte gene expression of genes known to be modulated in obesity was investigated. Using the well established cell culture model of 3T3-L1 adipocytes, the studies from this thesis show that EGCG and epicatechin are able to modulate the release of the adipokines adiponectin and resistin, dependent on the media glucose concentration. This modulation may be mediated by the ERK1/2 pathway, since flavanol treatment increased ERK1/2 phosphorylation. Uptake of glucose was not altered by any time or concentration of EGCG or epicatechin, and there were no significant changes in adipocyte gene expression following EGCG or epicatechin treatment. A thorough investigation of adipokine release, ERK signalling, glucose uptake and gene expression, under the influence of flavanol treatment, showed that although molecular changes occurred in the 3T3-L1 system, these did not translate into functional readouts. Therefore, it appears unlikely that these have major direct effects on adipocyte function. 2010-07-15 Thesis (University of Nottingham only) NonPeerReviewed application/pdf en arr https://eprints.nottingham.ac.uk/12115/1/523603.pdf Mehra, Anisha (2010) The effects of green tea derived catechins upon adipocyte metabolism. PhD thesis, University of Nottingham. Therapeutic use of green tea Catechin Fat cells Obesity prevention Adipocytes
spellingShingle Therapeutic use of green tea
Catechin
Fat cells
Obesity prevention
Adipocytes
Mehra, Anisha
The effects of green tea derived catechins upon adipocyte metabolism
title The effects of green tea derived catechins upon adipocyte metabolism
title_full The effects of green tea derived catechins upon adipocyte metabolism
title_fullStr The effects of green tea derived catechins upon adipocyte metabolism
title_full_unstemmed The effects of green tea derived catechins upon adipocyte metabolism
title_short The effects of green tea derived catechins upon adipocyte metabolism
title_sort effects of green tea derived catechins upon adipocyte metabolism
topic Therapeutic use of green tea
Catechin
Fat cells
Obesity prevention
Adipocytes
url https://eprints.nottingham.ac.uk/12115/