X-Message-Number: 31877
Date: Sun, 16 Aug 2009 08:33:51 -0700 (PDT)
From:
Subject: White Tea Could Keep You Healthy And Looking Young
[Below is some detective work attempting to account for the differences
betweem green and white tea extracts used in this test. I really wonder
what the effect would be of adding this tea to cryoprotectant solutions.]
White Tea Could Keep You Healthy And Looking Young
ScienceDaily (Aug. 14, 2009) aC” Next time youaC re making a cuppa, new research
shows it might be wise to opt for a white tea if you want to reduce your risk
of cancer, rheumatoid arthritis or even just age-associated wrinkles.
Researchers from Kingston University teamed up with NealaC s Yard Remedies to
test the health properties of 21 plant and herb extracts. They discovered all of
the plants tested had some potential benefits, but were intrigued to find white
tea considerably outperformed all of them.
Professor Declan Naughton, from the School of Life Sciences at Kingston
University in South West London, said the research showed white tea had
anti-ageing potential and high levels of anti-oxidants which could prevent
cancer and heart disease. aC WeaC ve carried out tests to identify plant
extracts that protected the structural proteins of the skin, specifically
elastin and collagen,aC he explained. aC Elastin supports the bodyaC s natural
elasticity which helps lungs, arteries, ligaments and skin to function. It also
helps body tissue to repair when you suffer wounds and stops skin from
sagging.aC Collagen is a protein found in connective tissues in the body and is
important for skin, strength and elasticity, he added.
Results showed white tea prevented the activities of the enzymes which breakdown
elastin and collagen which can lead to wrinkles that accompany ageing. These
enzymes, along with oxidants, are associated with inflammatory diseases such as
rheumatoid arthritis. Professor Naughton said: aC These enzymes and oxidants are
key components of normal body processes. However, in inflammatory conditions,
suppressing the activities of these excess components has been the subject of
decades of research. We were surprised to find such high activity for the white
tea extracts in all five tests that were conducted.aC
The researchers were blown away by exactly how well the white tea had performed.
aC We were testing very small amounts far less than you would find in a
drink,aC Professor Naughton, one of the countryaC s leading specialists on
inflammation, said. aC The early indicators are that white tea reduces the risk
of inflammation which is characteristic of rheumatoid arthritis and some cancers
as well as wrinkles.aC
Eight of the other plants and herbs analysed also helped protect against the
breakdown of both elastin and collagen. After white tea, bladderwrack performed
well followed by extracts of cleavers, rose, green tea, angelica, anise and
pomegranate.
Dr Pauline Hili, Technical Director for NealaC s Yard Remedies, said: aC We are
really excited by this research as it helps us to remain innovative and at the
cutting edge of natural skin care. Celebrating the plants used in the NealaC s
Yard Remedies products and understanding their specific actions on the skin is
what it is all about. The Kingston University research program helps us to
create safe, highly effective and cutting-edge products so itaC s an ideal
partnership for us.aC
Journal reference:
BMC Complement Altern Med. 2009 Aug 4;9(1):27. [Epub ahead of print]
Anti-collagenase, anti-elastase and anti-oxidant activities of extracts from 21
plants.
Thring TS, Hili P, Naughton DP.
ABSTRACT: BACKGROUND: Owing to their roles in tissue remodelling in health and
disease, several studies have reported investigations on plant extracts as
inhibitors of proteinases and as anti-oxidants. METHODS: The anti-ageing and
anti-oxidant properties of 23 plant extracts (from 21 plant species) were
assessed as anti-elastase and anti-collagenase activities and in selected
anti-oxidant assays along with phenolic content. RESULTS: Anti-elastase
activities were observed for nine of the extracts with inhibitory activity in
the following order: white tea (~89%), cleavers (~58%), burdock root (~51%),
bladderwrack (~50%), anise and angelica (~32%). Anti-collagenase activities were
exhibited by sixteen plants of which the highest activity was seen in white tea
(~87%), green tea (~47%), rose tincture (~41%), and lavender (~31%). Nine plant
extracts had activities against both elastase (E) and collagenase (C) and were
ranked in the order of white tea (E:89%, C:87%) > bladderwrack (E:50%, C:25%) >
cleavers (E:58%, C:7%) > rose tincture (E:22%, C:41%) > green tea (E:10%: C:47%)
> rose aqueous (E: 24%, C:26%) > angelica (E:32%, C:17%) > anise (E:32%, C:6%)
> pomegranate (E:15%, C:11%). Total phenolic content varied between 0.5 and 0.26
mg gallic acid equivalents (GAE)/mL with the exception of white tea (0.77 mg
GAE/mL). For anti-oxidant assessment, the Trolox equivalent anti-oxidant
capacity (TEAC) assay revealed activity for all extracts. White tea had the
highest activity equivalent to ~21 microM Trolox for a 6.25 microg aliquot. In
addition, seven extracts exhibited activities [greater than or equal to] 10
microM Trolox with witch hazel (6.25 microg = 13 microM Trolox) and rose aqueous
(6.25 microg = 10 microM Trolox) showing very high activities at low
concentrations. A high activity for white tea was also found in the superoxide
dismutase (SOD) assay in which it exhibited ~88% inhibition of reduction of
nitroblue tetrazolium. High activities were also observed for green tea
(86.41%), rose tincture (82.77%), witch hazel (82.05%) and rose aqueous
(73.86%). CONCLUSIONS: From a panel of twenty three plant extracts, some one
dozen exhibit high or satisfactory anti-collagenase or anti-elastase activities,
with nine having inhibitory activity against both enzymes. These included white
tea which was found to have very high phenolic content, along with high TEAC
and SOD activities.
PMID: 19653897
Free text>
http://www.biomedcentral.com/content/pdf/1472-6882-9-27.pdf
[In terms of skin antiaging activity, the exceptionally powerful
inhibitory effect on elastase shows the white tea used in this test to
be in a class by itself. Why this white tea is so effective is unknown,
since ECGC and green tea are much less active. Below I expound on a theory
to account for this difference.]
"In terms of anti-ageing, finding inhibitors of elastase enzymes can be useful
to prevent loss of skin elasticity and thus skin sagging. "
[Based on other research, the glycerine in the green tea extract is
unlikely to account for the relatively poor results for green tea in this
test.]
"In the case of the green tea extract used here, there is relatively low
activity compared to that of the white tea which may be due to the extract
supplied in glycerine as opposed to a pure aqueous extraction. "
[White tea is also much more effective than any of the 150 extracts used
in a previous test.]
"In a previous study, 150 methanolic plant extracts were tested against porcine
and human elastases and only six extracts showed inhibition of 65% or above
[17]. These extracts also only showed activity at IC50 values over 208 I g/mL.
In this study, aqueous extracts such as white tea and cleavers exhibited good
activity (89% and 58% respectively) at 25 I g final concentration for the same
concentration of substrate and units/mL enzyme."
[Best guess as to why white tea is so effective, may be due to its source
being a dried powder. Repeated drying of tea releases "massive" amounts
of gallic acid from ECGC, as well as flavonoids from their
glycosides. These alterations may account for the unusual effectiveness
of the white tea used in this test. Below a head to head comparison of
unprocessed white versus green tea which showed no difference in UV protection.]
J Agric Food Chem. 2008 Sep 10;56(17):7950-6. Epub 2008 Aug 16.
Massive accumulation of gallic acid and unique occurrence of myricetin,
quercetin, and kaempferol in preparing old oolong tea.
Lee VS, Dou J, Chen RJ, Lin RS, Lee MR, Tzen JT. Graduate Institute of
Biotechnology, National Chung-Hsing University, Taichung 402, Taiwan.
Old oolong tea, tasting superior and empirically considered beneficial for
human health, is prepared by long-term storage accompanied with periodic
drying for refinement. Analyzing infusions of three old and one newly
prepared oolong teas showed that significant lower (-)-epigallocatechin
gallate (EGCG) but higher gallic acid contents were detected in the old teas
compared to the new one. The possibility of releasing gallic acid from EGCG
in old tea preparation was supported by an in vitro observation of gallic
acid degraded from EGCG under heating conditions mimicking the drying
process. Moreover, three minor flavonols, myricetin, quercetin, and
kaempferol, that were undetectable in the new tea occurred in all of the
three old teas. Converting the new oolong tea into an old one by periodic
drying revealed the same characteristic observation, i.e., massive
accumulation of gallic acid presumably released from EGCG and unique
occurrence of flavonols putatively decomposed from flavonol glycosides.
PMID: 18707114
Z Naturforsch C. 2007 May-Jun;62(5-6):357-61.
Elastase release by stimulated neutrophils inhibited by flavonoids: importance
of the catechol group.
Kanashiro A, Souza JG, Kabeya LM, Azzolini AE, Lucisano-Valim YM.
Departamento de FA sica e QuA mica, Faculdade de CiAancias FarmacAauticas de
RibeirALo Preto da Universidade de SALo Paulo, Avenida do CafAC, s/n,
14040-903, RibeirALo Preto, SP, Brasil.
Pathogenesis of chronic inflammatory diseases is associated with excessive
elastase release through neutrophil degranulation. In the present study,
inhibition of human neutrophil degranulation by four flavonoids (myricetin,
quercetin, kaempferol, galangin) was evaluated by using released elastase as
a biomarker. Inhibitory potency was observed in the following order:
quercetin > myricetin > kaempferol = galangin. Quercetin, the most potent
inhibitor of elastase release also had a weak inhibitory effect on the
enzyme catalytic activity. Furthermore, the observed effects were highly
dependent on the presence of a catechol group at the flavonoid B-ring. The
results of the present study suggest that quercetin may be a promising
therapeutic agent in the treatment of neutrophil-dependent inflammatory
diseases.
PMID: 17708440
J Photochem Photobiol B. 2006 Jul 3;84(1):21-7. Epub 2006 Feb 21.
Protective effect of topical formulations containing quercetin against
UVB-induced oxidative stress in hairless mice.
Casagrande R, Georgetti SR, Verri WA Jr, Dorta DJ, dos Santos AC, Fonseca
MJ. Department of Pharmaceutical Science, Faculty of Pharmaceutical Sciences
of Ribeirao Preto - USP, Av. do CafAC s/n, CEP 14040-903, Ribeirao Preto,
SP, Brazil.
UV radiation-induced skin damages may result in pre-cancerous and cancerous
skin lesions, and acceleration of skin aging. It involves an imbalance of
the endogenous antioxidant system that leads to the increase of free radical
levels and inflammation. Therefore, antioxidant supplementation might
inhibit such imbalance. In this regard, quercetin is a promising drug, this
plant derived lipophilic flavonoid presents the higher antioxidant activity
among flavonoids and multiple antioxidant mechanisms. Thus, the present
study investigated the possible beneficial effects of topical formulations
containing quercetin to inhibit UVB irradiation-induced oxidative damages.
Quercetin was administered on the dorsal skin of hairless mice using two
formulations, formulation 1 (non-ionic emulsion with high lipid content) and
formulation 2 (anionic emulsion with low lipid content). The UVB
irradiation (0.31-3.69 J/cm(2)) induced a dose-dependent increase in the
myeloperoxidase (MPO) activity (4-2708%) and depletion of reduced
glutathione (GSH) (22-68%) in the skin of hairless mice after 6h. These
results demonstrated that the UVB doses are not excessive, and additionally,
they are lower than the doses used in other similar studies. Proteinases
secretion/activity, detected by the qualitative sodium dodecyl sulphate
polyacrylamide gel electrophoresis substrate-embedded enzymography
(zymography), was also enhanced in the same manner as MPO activity using the
UVB dose of 1.23J /cm(2). Formulations 1 and 2 inhibited the MPO activity
increase (62% and 59%, respectively), GSH depletion (119% and 53%,
respectively) and proteinases secretion/activity. To our knowledge, this is
the first study to demonstrate the effectiveness of topical formulations
containing quercetin to inhibit the UVB irradiation-induced skin damages.
Thus, these data suggest the possible usefulness of topical formulations
containing quercetin to prevent UVB radiation skin damages.
PMID: 16495072
Exp Dermatol. 2009 Jun;18(6):522-6.
Topical application of green and white tea extracts provides protection from
solar-simulated ultraviolet light in human skin.
Camouse MM, Domingo DS, Swain FR, Conrad EP, Matsui MS, Maes D, Declercq L,
Cooper KD, Stevens SR, Baron ED. Department of Dermatology, University
Hospitals Case Medical Center Cleveland, OH 44106, USA.
BACKGROUND: Tea polyphenols have been found to exert beneficial effects on
the skin via their antioxidant properties. AIMS: We sought to determine
whether topical application of green tea or white tea extracts would prevent
simulated solar radiation-induced oxidative damages to DNA and Langerhans
cells that may lead to immune suppression and carcinogenesis. METHODS: Skin
samples were analysed from volunteers or skin explants treated with white
tea or green tea after UV irradiation. In another group of patients, the in
vivo immune protective effects of green and white tea were evaluated using
contact hypersensitivity to dinitrochlorobenzene. RESULTS: Topical
application of green and white tea offered protection against detrimental
effects of UV on cutaneous immunity. Such protection is not because of
direct UV absorption or sunscreen effects as both products showed a sun
protection factor of 1. There was no significant difference in the levels of
protection afforded by the two agents. Hence, both green tea and white tea
are potential photoprotective agents that may be used in conjunction with
established methods of sun protection.
PMID: 19492999
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