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University of Manchester
1.
Owen, Elena.
Understanding interactions of mucins with flavour
compounds in tea.
Degree: 2019, University of Manchester
URL: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:318691 
► Mucin glycoproteins are the structural components of mucus barriers throughout the body. The polymeric gel forming mucins form disulphide bonded networks that govern mucus viscoelasticity…
(more)
▼ Mucin glycoproteins are the structural components
of mucus barriers throughout the body. The polymeric gel forming
mucins form disulphide bonded networks that govern mucus
viscoelasticity and thus its protective barrier properties.
Recently, there has been considerable interest in the interactions
between the mucus barrier and dietary components in terms of the
bioavailability of beneficial molecules. Black tea theaflavins are
considered potent antioxidants and have anticancer properties
however, their bioavailability is low. The consumption of tea
influences mouthfeel, causing dry, puckering sensation known as
astringency. The interactions between tea polyphenols and
components of the mucus barrier, including mucins, have been shown
to be responsible this mouthfeel. Previous studies have focused on
the green tea catechins, epicatechin (EC) and
epigallocatechin-3-gallate (EGCG) and have shown that EGCG
facilitates mucin cross-linking resulting in their aggregation.
Additionally, these studies have shown that EC does not cause mucin
reorganisation to the same extent, concluding that the galloyl
moiety is essential in this interaction. Here we investigated the
properties of the salivary mucins in the presence of black tea
theaflavins, aiming to elucidate whether they are able to
facilitate the same interactions as the green tea catechins. We
utilised electrophoretic and centrifugal separations to analyse the
effect of
theaflavin interaction with MUC5B and its subdomains.
Results suggest that there is a dramatic reorganisation of the
MUC5B network in, and purified from, human whole saliva upon
addition of the galloylated theaflavins. Infra-red analysis of the
theaflavins in the presence of MU5B suggested that the galloyl
group of the
theaflavin is essential in mediating mucin-polyphenol
interactions. Utilising recombinant mucin protein domains;
N-terminal, C-terminal and Cys7 we aimed to elucidate the site of
theaflavin interaction. We show that the theaflavins interact with
different regions of the mucin with differing affinities and that
this interaction is influenced by conditions such as pH and cation
content. Furthermore, milk is commonly added to black tea and is
shown to decrease the perception of astringency. Using the same
methods we show that the milk protein β-lactoglobulin is able to
sequester tea polyphenols which prevents mucin aggregation. From
this study we are able to build upon a previously suggested model
of polyphenol-mucin interactions. We conclude that the N-terminal
and Cys-rich regions of MUC5B associates first with the
theaflavin
further cross-linking the mucin polymers. As the local
concentration of the galloylated
theaflavin increases they interact
with C-terminal thus leading to the production of insoluble mucin
aggregates.
Advisors/Committee Members: GARDNER, PETER P, Thornton, David, Gardner, Peter.
Subjects/Keywords: MUC5B; Mucin; Saliva; Tea; Theaflavin
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APA (6th Edition):
Owen, E. (2019). Understanding interactions of mucins with flavour
compounds in tea. (Doctoral Dissertation). University of Manchester. Retrieved from http://www.manchester.ac.uk/escholar/uk-ac-man-scw:318691
Chicago Manual of Style (16th Edition):
Owen, Elena. “Understanding interactions of mucins with flavour
compounds in tea.” 2019. Doctoral Dissertation, University of Manchester. Accessed March 05, 2021.
http://www.manchester.ac.uk/escholar/uk-ac-man-scw:318691.
MLA Handbook (7th Edition):
Owen, Elena. “Understanding interactions of mucins with flavour
compounds in tea.” 2019. Web. 05 Mar 2021.
Vancouver:
Owen E. Understanding interactions of mucins with flavour
compounds in tea. [Internet] [Doctoral dissertation]. University of Manchester; 2019. [cited 2021 Mar 05].
Available from: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:318691.
Council of Science Editors:
Owen E. Understanding interactions of mucins with flavour
compounds in tea. [Doctoral Dissertation]. University of Manchester; 2019. Available from: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:318691
Durham University
2.
Hilton, Peter J. R.
Studies on the enzymic oxidation of catechins from the leaf of tea (Camellia sinensis L.).
Degree: PhD, 1970, Durham University
URL: http://etheses.dur.ac.uk/8837/
;
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.585965
Subjects/Keywords: 633.7; Theaflavin
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
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APA (6th Edition):
Hilton, P. J. R. (1970). Studies on the enzymic oxidation of catechins from the leaf of tea (Camellia sinensis L.). (Doctoral Dissertation). Durham University. Retrieved from http://etheses.dur.ac.uk/8837/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.585965
Chicago Manual of Style (16th Edition):
Hilton, Peter J R. “Studies on the enzymic oxidation of catechins from the leaf of tea (Camellia sinensis L.).” 1970. Doctoral Dissertation, Durham University. Accessed March 05, 2021.
http://etheses.dur.ac.uk/8837/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.585965.
MLA Handbook (7th Edition):
Hilton, Peter J R. “Studies on the enzymic oxidation of catechins from the leaf of tea (Camellia sinensis L.).” 1970. Web. 05 Mar 2021.
Vancouver:
Hilton PJR. Studies on the enzymic oxidation of catechins from the leaf of tea (Camellia sinensis L.). [Internet] [Doctoral dissertation]. Durham University; 1970. [cited 2021 Mar 05].
Available from: http://etheses.dur.ac.uk/8837/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.585965.
Council of Science Editors:
Hilton PJR. Studies on the enzymic oxidation of catechins from the leaf of tea (Camellia sinensis L.). [Doctoral Dissertation]. Durham University; 1970. Available from: http://etheses.dur.ac.uk/8837/ ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.585965
University of Manchester
3.
Owen, Elena.
Understanding interactions of mucins with flavour compounds in tea.
Degree: PhD, 2019, University of Manchester
URL: https://www.research.manchester.ac.uk/portal/en/theses/understanding-interactions-of-mucins-with-flavour-compounds-in-tea(18bc5a02-d506-4334-a985-838db133da97).html
;
https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.804089
► Mucin glycoproteins are the structural components of mucus barriers throughout the body. The polymeric gel forming mucins form disulphide bonded networks that govern mucus viscoelasticity…
(more)
▼ Mucin glycoproteins are the structural components of mucus barriers throughout the body. The polymeric gel forming mucins form disulphide bonded networks that govern mucus viscoelasticity and thus its protective barrier properties. Recently, there has been considerable interest in the interactions between the mucus barrier and dietary components in terms of the bioavailability of beneficial molecules. Black tea theaflavins are considered potent antioxidants and have anticancer properties however, their bioavailability is low. The consumption of tea influences mouthfeel, causing dry, puckering sensation known as astringency. The interactions between tea polyphenols and components of the mucus barrier, including mucins, have been shown to be responsible this mouthfeel. Previous studies have focused on the green tea catechins, epicatechin (EC) and epigallocatechin-3-gallate (EGCG) and have shown that EGCG facilitates mucin cross-linking resulting in their aggregation. Additionally, these studies have shown that EC does not cause mucin reorganisation to the same extent, concluding that the galloyl moiety is essential in this interaction. Here we investigated the properties of the salivary mucins in the presence of black tea theaflavins, aiming to elucidate whether they are able to facilitate the same interactions as the green tea catechins. We utilised electrophoretic and centrifugal separations to analyse the effect of theaflavin interaction with MUC5B and its subdomains. Results suggest that there is a dramatic reorganisation of the MUC5B network in, and purified from, human whole saliva upon addition of the galloylated theaflavins. Infra-red analysis of the theaflavins in the presence of MU5B suggested that the galloyl group of the theaflavin is essential in mediating mucin-polyphenol interactions. Utilising recombinant mucin protein domains; N-terminal, C-terminal and Cys7 we aimed to elucidate the site of theaflavin interaction. We show that the theaflavins interact with different regions of the mucin with differing affinities and that this interaction is influenced by conditions such as pH and cation content. Furthermore, milk is commonly added to black tea and is shown to decrease the perception of astringency. Using the same methods we show that the milk protein Î2-lactoglobulin is able to sequester tea polyphenols which prevents mucin aggregation. From this study we are able to build upon a previously suggested model of polyphenol-mucin interactions. We conclude that the N-terminal and Cys-rich regions of MUC5B associates first with the theaflavin further cross-linking the mucin polymers. As the local concentration of the galloylated theaflavin increases they interact with C-terminal thus leading to the production of insoluble mucin aggregates.
Subjects/Keywords: Theaflavin; Tea; MUC5B; Mucin; Saliva
Record Details
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Record Details
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Owen, E. (2019). Understanding interactions of mucins with flavour compounds in tea. (Doctoral Dissertation). University of Manchester. Retrieved from https://www.research.manchester.ac.uk/portal/en/theses/understanding-interactions-of-mucins-with-flavour-compounds-in-tea(18bc5a02-d506-4334-a985-838db133da97).html ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.804089
Chicago Manual of Style (16th Edition):
Owen, Elena. “Understanding interactions of mucins with flavour compounds in tea.” 2019. Doctoral Dissertation, University of Manchester. Accessed March 05, 2021.
https://www.research.manchester.ac.uk/portal/en/theses/understanding-interactions-of-mucins-with-flavour-compounds-in-tea(18bc5a02-d506-4334-a985-838db133da97).html ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.804089.
MLA Handbook (7th Edition):
Owen, Elena. “Understanding interactions of mucins with flavour compounds in tea.” 2019. Web. 05 Mar 2021.
Vancouver:
Owen E. Understanding interactions of mucins with flavour compounds in tea. [Internet] [Doctoral dissertation]. University of Manchester; 2019. [cited 2021 Mar 05].
Available from: https://www.research.manchester.ac.uk/portal/en/theses/understanding-interactions-of-mucins-with-flavour-compounds-in-tea(18bc5a02-d506-4334-a985-838db133da97).html ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.804089.
Council of Science Editors:
Owen E. Understanding interactions of mucins with flavour compounds in tea. [Doctoral Dissertation]. University of Manchester; 2019. Available from: https://www.research.manchester.ac.uk/portal/en/theses/understanding-interactions-of-mucins-with-flavour-compounds-in-tea(18bc5a02-d506-4334-a985-838db133da97).html ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.804089
Virginia Tech
4.
Sirk, Timothy Wayne.
A Molecular Dynamics Study on the Interaction of Tea Catechins and Theaflavins with Biological Membranes.
Degree: PhD, Mechanical Engineering, 2009, Virginia Tech
URL: http://hdl.handle.net/10919/26946
► Molecular dynamics simulations were performed to study the interactions of bioactive catechins and theaflavins commonly found in tea with lipid bilayers, as a model for…
(more)
▼ Molecular dynamics simulations were performed to study the interactions of bioactive catechins and theaflavins commonly found in tea with lipid bilayers, as a model for cell membranes. Previously, multiple experimental studies rationalized the anticarcinogenic, antibacterial, and other beneficial effects of these compounds in terms of physicochemical molecular interactions with cell membranes. To contribute toward understanding the molecular role of tea polyphenols on the structure of cell membranes, simulation results are presented for seven catechins and three theaflavins in lipid bilayer systems which are both pure (POPC) and representative of HepG2 cancer cells (POPC and POPE). Our simulations show that the catechins and theaflavins evaluated have a strong affinity for the lipid bilayer it{via} hydrogen bonding to the bilayer surface, with many of the catechins able to penetrate beneath the surface. Epigallocatechin-gallate (EGCG) and
Theaflavin-3,3'-digallate showed the strongest interaction with the lipid bilayers based on the number of hydrogen bonds formed with lipid headgroups. The simulations also provide insight into the functional characteristics of the tea compounds that distinguish them as effective compounds to potentially alter the lipid bilayer properties. The results on the hydrogen-bonding effects may contribute to a better understanding of proposed multiple molecular mechanisms of the action of catechins and theaflavins in microorganisms, cancer cells, and tissues.
Advisors/Committee Members: Huxtable, Scott T. (committee member), Bevan, David R. (committee member), Paul, Mark R. (committee member), Onufriev, Alexey V. (committee member), Brown, Eugene F. (committeecochair), Sum, Amadeu K. (committeecochair).
Subjects/Keywords: Bilayer; Molecular Dynamics; Polyphenol; Theaflavin; Catechin
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Sirk, T. W. (2009). A Molecular Dynamics Study on the Interaction of Tea Catechins and Theaflavins with Biological Membranes. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/26946
Chicago Manual of Style (16th Edition):
Sirk, Timothy Wayne. “A Molecular Dynamics Study on the Interaction of Tea Catechins and Theaflavins with Biological Membranes.” 2009. Doctoral Dissertation, Virginia Tech. Accessed March 05, 2021.
http://hdl.handle.net/10919/26946.
MLA Handbook (7th Edition):
Sirk, Timothy Wayne. “A Molecular Dynamics Study on the Interaction of Tea Catechins and Theaflavins with Biological Membranes.” 2009. Web. 05 Mar 2021.
Vancouver:
Sirk TW. A Molecular Dynamics Study on the Interaction of Tea Catechins and Theaflavins with Biological Membranes. [Internet] [Doctoral dissertation]. Virginia Tech; 2009. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/10919/26946.
Council of Science Editors:
Sirk TW. A Molecular Dynamics Study on the Interaction of Tea Catechins and Theaflavins with Biological Membranes. [Doctoral Dissertation]. Virginia Tech; 2009. Available from: http://hdl.handle.net/10919/26946
Freie Universität Berlin
5.
Kehrer, Alexandra Katrin Hertha.
Cardioprotective characteristics of teapolyphenols epigallocatechin-3-gallate
und theaflavin-3,3'-digallate.
Degree: 2010, Freie Universität Berlin
URL: http://dx.doi.org/10.17169/refubium-9706
► Cardiovascular diseases are the main cause of death worldwide. Oxidative Stress plays a major role in their pathogenesis. Epidemiological studies show a lower incidence of…
(more)
▼ Cardiovascular diseases are the main cause of death worldwide. Oxidative
Stress plays a major role in their pathogenesis. Epidemiological studies show
a lower incidence of cardiovascular disease in Asia. As a possible explanation
for this the widespread consumption of green tea is discussed. For that matter
numerous studies could proof the different beneficial effects of green tea. It
could be shown in this study, that both epigallocatechin-3-gallate (EGCG) from
green tea and
theaflavin-3,3'-digallate (TF3) from black tea protect cardiac
myocytes from oxidative stress: a pretreatment for one hour with 50 µmol/l
EGCG or 20 µmol/l TF3 resulted in a significantly lower LDH-release from
cardiac myocytes after induction of oxidative stress by incubation with
hydrogen peroxide. An extension of treatment time lead to a loss of
polyphenol-mediated cellprotection. In search of the underlying mechanisms a
transcriptional induction of heme oxygenase-1 by EGCG –but not TF3- could be
shown by RT-PCR. Further examined antioxidative enzymes - gluthathione
peroxidase, catalase and superoxide dismutase 1, remained unaffected in their
expression by treatment with polyphenols. In western blots an activation of
antiapoptotic signal cascades ERK 1/2, Akt and p38 MAPK after treatment with
EGCG and TF3 was demonstrated. Interestingly, the inhibition of these possible
mechanisms with pretreatment and simultaneous treatment with inhibitors of
heme oxygenase-1, protein- and RNA-synthesis as well as the above mentioned
signal cascades did not lead to loss of the cytoprotective characteristics of
the polyphenols. In contrast, measurement of fluorescence of H2DCFDA-marked
cardiac myocytes –a marker for reactive oxygen species (ROS) - showed
significantly reduced concentration of intracellular ROS after pretreatment
with teapolyphenols and subsequent treatment with hydrogen peroxide. Against
the background of the close time correlation between effectivity of the
polyphenols and their half-lives in the cell culture medium our results
suggest a direct ROS-scavenging effect of teapolyphenols as cause for their
mediated cardioprotection.
Advisors/Committee Members: w (gender), Prof. Dr. med. V Stangl (firstReferee), Priv.-Doz. Dr. med. R. Dechend, Priv.-Doz. Dr. habil. V.Böhm (furtherReferee).
Subjects/Keywords: oxidative stress; cardiac myocytes; epigallocatechin-3-gallate; theaflavin-3; 3´digallate; heme oxygenase 1; 600 Technik, Medizin, angewandte Wissenschaften::610 Medizin und Gesundheit
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Record Details
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Kehrer, A. K. H. (2010). Cardioprotective characteristics of teapolyphenols epigallocatechin-3-gallate
und theaflavin-3,3'-digallate. (Thesis). Freie Universität Berlin. Retrieved from http://dx.doi.org/10.17169/refubium-9706
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Kehrer, Alexandra Katrin Hertha. “Cardioprotective characteristics of teapolyphenols epigallocatechin-3-gallate
und theaflavin-3,3'-digallate.” 2010. Thesis, Freie Universität Berlin. Accessed March 05, 2021.
http://dx.doi.org/10.17169/refubium-9706.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Kehrer, Alexandra Katrin Hertha. “Cardioprotective characteristics of teapolyphenols epigallocatechin-3-gallate
und theaflavin-3,3'-digallate.” 2010. Web. 05 Mar 2021.
Vancouver:
Kehrer AKH. Cardioprotective characteristics of teapolyphenols epigallocatechin-3-gallate
und theaflavin-3,3'-digallate. [Internet] [Thesis]. Freie Universität Berlin; 2010. [cited 2021 Mar 05].
Available from: http://dx.doi.org/10.17169/refubium-9706.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Kehrer AKH. Cardioprotective characteristics of teapolyphenols epigallocatechin-3-gallate
und theaflavin-3,3'-digallate. [Thesis]. Freie Universität Berlin; 2010. Available from: http://dx.doi.org/10.17169/refubium-9706
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
. 
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