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Research J. Topical and Cosmetic Sci. 6(1): Jan. – June 2015
1
ISSN 0976- 2981 (Print) www.anvpublication.org
2321-5844 (Online)
RESEARCH ARTICLE
Tea Polyphenols for Skin Care
Karishma Rajbhar, Himanshu Dawda and Usha Mukundan
Plant Biotechnology Laboratory, Ramniranjan Jhunjhunwala College, Ghatkopar, Mumbai, India.
*Corresponding Author E-mail: karishmarajbhar@rjcollege.edu.in
ABSTRACT:
Dietary polyphenols of tea show antioxidant, anti-ageing, anti-wrinkle, anti-acne, anti-microbial, anti-
inflammatory and skin lightening properties which are beneficial for dermal tissue. This article explores the
potential of topical application of polyphenols from tea in skin care. The use of tea polyphenols as a topically
applied plant extract which can penetrate in the dermis has been well documented. The findings of these studies
indicate that tea polyphenols when used in an appropriate way and amount can be used to prevent skin related
problems.
KEYWORDS: Tea, polyphenols, UV radiation, skin restoration, topical application.
INTRODUCTION:
Polyphenols are plant secondary metabolites and are
commonly found in almost all plants. The phenolic
components of most polyphenols have a common
structural feature of an aromatic ring with at least one
hydroxyl substituent [1]. Three phenolics compounds
important for humans are phenolic acids, flavonoids and
polyphenols [2]. Phenolic acid is divided into
hydroxycinnamic and hydroxybenzoic acids [3].
Flavonoids are a group of compounds with low
molecular weight, and are derivatives of benzo-y-pyrone.
Polyphenols are compounds with high molecular weights
divided into two groups- first is condensed group made
up of polymers of catechins and epicatechins, and
second is a hydrolysable group made up of polymers of
gallic and egllagic acids [2]. Polyphenols in plants
provides chemical defence against predators and ultra-
violet radiation [3].
Received on 22.02.2015 Accepted on 05.03.2015
©A&V Publications all right reserved
Research J. Topical and Cosmetic Sci. 6(1):Jan.–June 2015 page 1-6
DOI:
Tea is prepared from leaves and leaf buds of Camellia
sinensis from the family Theaceae. Types of tea like
white tea, green tea, oolong and black tea and others are
all harvested from this species, but are processed
differently to attain different levels of oxidation. The
infusion of tea leaves is a beverage which is widely
consumed second only to water [4]. The brew of one tea
bag in one cup of water produces a solution of 0.35%
w/w solids [5].
The composition of an infusion of Green tea or Black tea
is listed below [5].
Components %wt/wt Solids
Catechins 9%-30%,
Theaflavins 4%,
Simple polyphenols 2%- 3%,
Flavonols 1%-2%
Other polyphenols 6% -23%,
Theanine 3%
Amino acids 3%
Peptides and protein 6%
Organic acids 2%,
Sugars 7%
Other carbohydrates 4%
Lipids 3%
Caffeine 3%,
Other methyl xanthines <1%
Potassium 5%
Other minerals and ash 5%
Trace of aroma -
Research J. Topical and Cosmetic Sci. 6(1): Jan. – June 2015
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On the basis of the extent of enzymatic reactions which
occur during the manufacture, tea is classified into the
following types: green tea (non-fermented), black tea
(fermented) and oolong tea (specially treated and semi
fermented). The oxidized polyphenols in black tea are
responsible for briskness, strength, colour, taste and
astringency of the black tea infusion [6].
The polyphenols found in tea are more commonly
known as flavanols or catechins like epicatechin,
epicatechin-3-gallate, epigallocatechin, and
epigallocatechin-3-gallate (EGCG), with the latter being
the highest in concentration [7]. The principal
constituents are caffeine, tannins and essential oils.
Tannins comprise of a variety of polyphenolic
compounds - most important of these are flavonoids
called catechins [6]. Green tea contains higher amounts
of catechin derivatives, such as (-)-epicatechin (EC), (-)-
epigallocatechin (EGC) and their gallates (ECG and
EGCG). During the production of black tea, some of the
catechins are converted to theaflavins (TF) and
thearubigins (TR) by enzymatic oxidation and coupling
reactions (Roy; 2001). Catechins and their derivatives
are known to contribute towards the flavour of tea while
the aroma is dependent on the presence of different
volatile compounds. Theaflavins (TF) are responsible for
briskness and brightness while thearubigins (TR) for
colour and body or strength (mouth feel). Caffeine is
responsible for the stimulating effect of tea and the
cancer chemopreventive action of tea is mainly due to its
polyphenolic content [6].
UV RADIATION AND ITS EFFECTS ON SKIN
The part of electromagnetic spectrum of the wavelength
between 200nm to 400nm is ultra-violet (UV) radiation.
It is divided into long wave UVA (320nm-400nm),
medium wave UVB (280nm-320nm) and short wave
UVC (200nm-280nm) [8]. The longer wave is called
aging ray which penetrates deep in the epidermis and
dermis of skin. UVA is thousand times effective in
tanning effect than UVB. Tanning is caused by melanin
darkening in epidermis. Long term UVA exposure burns
sensitive skin and if last prolonged than can damage
inner structure of corium and results in premature photo-
aging of the skin. UVA induces endogenous
photosensitization responses in cells. Necrosis of
endothelial cells is caused by UVA injury and leads to
dermal blood vessel damage. UVA injury damage
structural DNA. Impair immune system and causes 67%
of malignant melanoma [9].
UVB radiation is called burning ray and makes up 4.5%
of UV light. UVB is less but most active in solar light,
UVB is thousand times stronger than UVA causing
sunburn. UVB is more genotoxic than UVA. UVB acts
in epidermal basal cell of skin; it’s directly or indirectly
induces adverse biological effects, like formation of
pyrimidine, photoproducts, isomerisation of trans to cis
urocanic acid, induction of ornithine decarboxylase
activity, stimulation of DNA synthesis, free radical
production in the skin, cell cycle growth arrest,
photoaging and photocarcinogenesis.
For showing biological effects UV must be absorbed by
cellular chromophore which transforms the energy into
biochemical signals. Nucleic acid and proteins are major
cellular chromophores absorbing radiation in the UVB
wavelength range. A DNA lesion is seen if DNA absorbs
UVB. Lesions like cyclobutane-pyrimidine dimers and
pyrimidine-pyrimidine photoproducts. DNA
photoproduct formation leads to the activation of p53
protein that induces apoptosis of irradiated keratinocytes
by blocking RNA transcription. Damage occurring in S-
phase of cell cycle might lead to mutagenesis resulting in
mainly cytosine to thymine substitution. On the other
hand more UV exposure results keratinocytes to lose
their ability to undergo the apoptotic process. Amino
acids like tryptophan, tyrosine and biomolecules like
NADH, quoins, flavins, porphyrins, 7-
dehydrocholesterol and urocanic acid absorbs UVB
radiations [9, 10].
SKIN DAMAGE BY UV RADIATION
Skin damage can be caused by UV radiation even if
exposed for 2 hours. Keratinosomes decrease is an
indicator of skin damage which forms dyskeratotic cells,
16 hours to 18 hours exposure results in intracellular
edema whereas 30 hours to 48 hours intercellular edema
which develops around damaged keratinocytes.
Degeneration of keratinocytes cause mitochondrial
swelling and rupture, cytoplasm condensation and
pyknotic nuclei appears which is caused by 48 hours to
72 hours of total UV range exposure. This also results
into Reactive Oxygen Species (ROS) largely seen in
keratinocytes and fibroblasts and is taken out by non-
enzymatic enzymatic antioxidants. ROS active
metabolites like hydroxyl radical, superoxide active
anion and peroxyl radicals and most active ones are
single oxygen, hydrogen peroxide and ozone. Reactive
Nitrogen Species (RNS) are nitric oxide and nitric
dioxide. Free radicals modulate progressive deterioration
of cellular structure function resulting loss of cellular
integrity by DNA modification and abnormal expression
of cellular genes [10].
UV radiation cause skin pigmentation on exposure,
melanocytes increase the production of intracellular
nitric oxide, triggering the signal transduction cascades
to initiate melanogenesis by tyrosinase. Melanogenesis is
influenced through a paracrine regulation process
involving the keratinocytes [11].
Research J. Topical and Cosmetic Sci. 6(1): Jan. – June 2015
3
POLYPHENOLS PROTECTIVE ACTION
AGAINST OXIDATION AND UV RADIATION
Antioxidant activity of herbal phenolic acids and
flavonoids such as quercetin, luteolin and catechins are
better antioxidants than the nutrients vitamin C, vitamin
E and β-carotene [2, 5]. Phenolics may be beneficial in
preventing UV-induced oxygen free radical generation
and lipid peroxidation, i.e. events involved in
pathological states such as photoaging and skin cancer.
This review is a summary of the findings of the pho-
toprotective effects of tea polyphenols in studies of the
skin damage induced by UV irradiation [12].
Flavonoids are antioxidant molecules. They absorb UV
light and modulate signalling pathways which influences
cellular function which can be beneficial for skin health.
UV radiation shows negative effects on skin like
erythema, edema, sunburned cells, hyperplasia,
inflammation, immune-suppression, photoaging and
photocarcinogenesis. Certain flavonoids can minimize
the adverse skin reactions, demonstration on cell culture,
animals, and humans have been proved. Green tea
polyphenols shows immense effect when used as
chemoprevention and it is most potent at suppressing the
carcinogenic activity of UV radiation. Green tea
polyphenols are photoprotective on cellular, molecular
and biochemical mechanisms in both in vitro and in vivo
systems [8, 10].
Polyphenols have been extensively studied as potential
chemopreventive agents that could act against external
inflammatory stimuli including tumour promoting agents
and solar ultraviolet (UV) radiation. Catechin,
epicatechin, epigallocatechin, epicatechin gallate and
epigallocatechin gallate, are effective free radical
scavengers, chain-breaking antioxidants and scavengers
of reactive nitrogen species. The tea polyphenols have
been attributed both antioxidant properties as scavengers
of reactive oxygen species and the activation of phase II
detoxifying enzymes [12].
Epigallocatechin (EGC) and epigallocatechin gallate
(EGCG) are the predominant catechins in tea protect
against UVB-induced skin carcinogenesis in mice
projected that reactive oxygen species generated by
UVB play a fundamental role in the process of
carcinogenesis and that tea polyphenols acted by
quenching such oxidant species . UVA component of
solar radiation exerts its biological effects primarily by
oxidative and antioxidants like the water-soluble
ascorbic acid, and the lipophilic K-tocopherol and
butylated hydroxytoluene are believed to act as photo-
protective agents by their ability to scavenge reactive
oxygen species generated during UVA irradiation. Tea
polyphenols may have a pro-oxidant role leading to the
generation of hydrogen peroxide in human cancer cell
lines, regulation of UVA-activated stress response genes
in human skin cells. EGC can modulate the expression of
haem oxygenase-1 (HO-1), cyclooxygenase-2 (Cox-2)
and metalloproteinase-1 (MMP-1) in UVA-irradiated
dermal and transformed epidermal keratinocytes [12].
Tea polyphenols are powerful antioxidants and
anticarcinogenic compounds, specifically the catechins
epigallocatechin-3-gallate (EGCG), epigallocatechin
(EGC), and epicatechin-3-gallate (ECG), which account
for 30-40 percent of the extractable solids of tea leaves,
are believed to mediate many of the cancer
chemopreventive effects. Mechanisms of action may
include antioxidant and free-radical scavenging activity,
and stimulation of detoxification systems through
selective induction or modification of phase I and phase
II metabolic enzymes. Tea inhibits biochemical markers
of tumour initiation and promotion, including the rate of
cell replication and thus inhibition of the growth and
development of neoplasms. Tea may serve to protect
against skin cancer. Tea consumption inhibited the
formation of tumours associated with the exposure to
UVB sunrays. Where UVB tumours already existed, tea
drinking slowed their growth and in some cases, actually
decreased their size [3, 12].
EGCG reactivated dying skin cells when exposed during
growth of the cells. The skin consists of three layers: the
epidermis (outer layer), dermis (middle layer) and
hypodermis (inner layer). Tea polyphenols are not
absorbed beyond the epidermis, so some benefits are
restricted to that outer layer of skin. But EGCG may be a
fountain of youth for skin cells as when exposed to
EGCG; the old cells found in the upper layers of the
epidermis appear to start dividing again as they make
DNA and produce more energy and the cells reactivated.
EGCG accelerates the differentiation process among new
cells. These two effects of EGCG on skin cells in
different layers of the epidermis could be potential
benefits for skin as diverse as aphthous ulcers, psoriasis,
rosacea, wrinkles and wounds. Possibly scar tissue could
be prevented from forming with EGCG therapy and
diabetics patients with slow healing wounds may benefit
from EGCG supplementation [12].
Caffeic acid (3,4-dihydroxycinnamic acid) and ferulic
acid (4-hydroxy-3-methoxycinnamic acid) have been
demonstrated to protect phospholipidic membranes from
UV-induced peroxidation by inhibiting propagation of
the lipid peroxidative chain reaction and to react with
nitrogen oxides and proved effective in protecting
human skin from UVB-induced erythema. Ferulic acid,
shown to be a strong UV absorber, is employed as a
photoprotective agent in a number of skin lotions and
sunscreens [3].
Research J. Topical and Cosmetic Sci. 6(1): Jan. – June 2015
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Quercetin (3, 5, 7, 3’, 4’-pentahydroxyflavon) a
powerful antioxidant and metal ion chelator, is believed
capable of preventing the harmful effects of UV light or
at least of reducing the damage. Quercetin protected skin
antioxidant systems, namely glutathione peroxidase,
glutathione reductase, catalase and superoxide dismutase
activities, against UVA irradiating damage in rats to a
considerable degree. Oral intake of quercetin prevented
UVB-induced immune suppression in SKH-1 hairless
mice. In vitro, quercetin and its semi-synthetic
derivatives (quercetin 3-O-acetate, quercetin 3-O-
propionate, and quercetin 3-O-palmitate) were found to
inhibit UVC radiation-induced peroxidation in liposomal
membranes [3].
TOPICAL APPLICATION ON SKIN
Photoprotective effects of green tea polyphenols,
catechins and others have been demonstrated on humans
by both oral supplementation and topical application.
Plant extracts is dissolved in solvent so that only plant
extracts remains on the dermal tissues. Although
delivery is an issue as they cannot penetrate and function
on human skin as the market commercial product do.
Large influence is exerting by flavonoids because of
their specific and nonspecific affinity for different types
of proteins throughout the cell. Flavonoids physically
block UV penetration, influence DNA repair, attenuate
the inflammatory response, preserve immune function
and induce cytoprotective pathways have been proved.
Mechanisms by which flavonoids protect skin from
harmful effects of UV radiation are still under
investigation. Topical application of EGCG may prevent
UV-B induced immune suppression and precancerous
cell changes after UVB exposure. Anti-inflammatory
and anticancer property of EGCG and green tea
polyphenols can be used to control onset and growth of
skin tumours [8, 9].
Antioxidant properties of tea show beneficial effect of
tea. Green and white tea shows protection against
detrimental effects of UV on cutaneous immunity. UV is
not absorbed by topical applied tea products or sunscreen
as both have presence of sun protection factor of one.
Green and white teas are potential photoprotective agent
which can be used in conjunction for sun protection
methods. Skin carcinogenesis is result of UV irradiation,
thus green tea extract can be used. Green tea extract
show reduction of UV induced erythema, DNA damage,
formation of radical oxygen species and down regulation
of numerous factors related to apoptosis, inflammation,
differentiation and carcinogenesis. Green tea extract s
chemicals stability and staining properties are unstable.
High concentration limits the usability of high green tea
extracts in cosmetic products. Low concentration green
extracts can be photochemopreventive to skin if doses
are taken regularly. Topical green tea extracts also
reduces UVB mediated epithelial damages [13].
SKIN RESTORATIVE PROPERTIES OF TEA
POLYPHENOLS
1. Antioxidant properties
EGCG is at least 100 times more effective than vitamin
C and 25 times better than vitamin E at protecting cells
and their genetic material DNA from damage, believed
to be linked to cancer, heart disease and other fatal
illness. EGCG carries twice the antioxidant potential of
resveratrol. It induces inhibition of soyabean
lipoxygenase, inhibits TPA and induces oxidative DNA
base modification in HeLa cells. It also inhibits Cu2+
mediated oxidation of low density lipoprotein (LDL) and
reduces tertiary butyl hydro peroxide which creates lipid
peroxidation and blocks the production of reactive
oxygen species derived from NADPH-cytochorme P450-
mediated oxidation of the cooked meat carcinogen i.e 2-
amino-3- methylimidazole (4-5-f) quinoline. Green tea
water soluble therefore excessive amounts of
antioxidants are excreted out by body. Antioxidant
activity of EGCG helps tremendously to combat post
exercise muscle soreness [8].
2. Anti-ageing and anti-wrinkle properties
Free radicals promote oxidation of nucleic acids,
proteins, and lipids and can damage intracellular
structures including DNA by regulating transcription
factors, such as activator protein 1 (AP-1) and nuclear
transcription factor-kappa B (NF-kB). Polyphenols
inhibit collagenase activity by two mechanisms first by
binding of the essential Zn2+ in the enzyme active site
and second by conformational changes on the enzyme
due the ability of phenolic compounds to interact with
proteins. Metalloproteinases are produced by AP-1
which breaks existing collagen, contributing to skin
wrinkling. It is the sum of NF-kB transcription of
proinflammatory mediators interleukin (IL)-1, IL-6, IL-
8, and tumor necrosis factor-alpha acting through the cell
surface responsible for skin aging. Tea polyphenols and
EGCG in addition are effective free-radical scavengers,
down-regulate UV-induced expression of AP-1 and NF-
kB and suppress metalloproteinase and age-related
collagen cross-linking in mice. Tea polyphenols inhibit
the activity of collagenase and increases collagen
biosynthesis rate of human fibroblasts. EGCG topical
treatments influence HIF-1α induction and VEGF
(vascular endothelial growth factor) expression and may
serve as a potential agent in the prevention of
telangiectasia (spider veins) [11, 14].
Research J. Topical and Cosmetic Sci. 6(1): Jan. – June 2015
5
3. Anti-acne properties
Acne vulgaris is the most common skin condition
resulting from the effects of hormones. Androgens such
as dihydrotestosterone (DHT) and testosterone, the
adrenal precursor dehydroepiandrosterone sulfate
(DHEAS), estrogens such as estradiol, and other
hormones, including growth hormone and insulin-like
growth factors (IGFs), could be important in acne. It is
being studied whether hormones are taken by serum of
sebaceous gland or produced locally within the gland or
whether a combination of these processes is involved.
Hormonal therapy is an option in women with acne not
responding to conventional treatment or with signs of
endocrine abnormalities. Study depict potential effects of
stable formulation (water in oil emulsion), containing
3% tea extract on skin sebum production for a period of
8 weeks. A statistically significant (p < 0.5%) decrease
was found in skin sebum production after long term
application of the formulation [15]. EGCG inhibits
lipogenesis. Epigallocatechin-3-gallate (EGCG)
decreases inflammation induced by SEB-1 sebocytes
stimulated by heat-inactivated Propionibacterium acnes
through the inhibition of NF-jB and activator protein 1
(AP-1) pathways. Biochemical, genetic, and cellular
studies indicate that modulation of AMPK–SREBP-1
and NF-kB/ activator protein 1 (AP-1) signalling
pathways mediates the sebosuppressive and anti-
inflammatory effects of EGCG [16].
4. Skin lightening properties
Natural skin lightening products containing tyrosinase
blockers like phenols and polyphenols, and non-
tyrosinase blockers like α- MSH, melanosome
transferase and cytokine inhibitors. Gallic acid
derivatives of hydroxyflavanols had been isolated from
tea as they are identified as strong tyrosinase inhibitors.
EGCG and hydroxyflavanols are not only tyrosinase
inhibitors, but also decreased MITF (Microphthalmia-
associated transcription factor) production in cells.
Ellagic acids (EA) polyphenol found in tea with strong
antioxidative properties and tyrosinase inhibition.
Chelating copper at the active site of tyrosinase to reduce
its activity and inhibition of proliferation of melanocytes
and melanin synthesis results in skin lightening by EA.
EA also show antioxidative and ROS-scavenging
activities which contribute to its skin lightening effect [9,
11].
5. Anti-viral properties
Microbial agents, viruses or bacteria attack skin and
cause local inflammation. Inflammation can be due to
internal elements such as autoimmune diseases that are
associated with damage to the skin, resulting in skin
lesions, rash, and altered appearance. Tea polyphenols
have been recognized for prevention of infection by a
range of viruses, such as adenovirus, Epstein-Barr virus
and influenza virus. Studies shows that EGCG
inactivated HSV (Herpes simplex virus) projecting that
the antiviral properties of polyphenols are due to their
influential protein binding capacity, follow-on tight
binding to the viral coat proteins, and their ability to
transform the dynamics of the cell plasma membrane,
preventing the entry of viral particles into the cells [8,
11].
6. Anti-Inflammatory properties
The conversion of arachidonic acid into various
proinflammatory agents, including leukotrienes is
catalyzed by the dioxygenase enzyme. Epicatechin
inhibits the dioxygenase and LTA 2 synthase activities
of 5-LOX. Epicatechin has also been shown to inhibit
15-LOX-1 [17].
SIDE EFFECTS AND TOXICITY
Tea is generally considered a safe, non-toxic beverage
and its consumption is usually without side effects. The
average cup of tea contains from 10-50 mg of caffeine,
and over-consumption may cause irritability, insomnia,
nervousness, and tachycardia. Because studies on its
possible teratogenic effect are inconclusive, caffeine
consumption is contraindicated during pregnancy.
Lactating women should also limit caffeine intake to
avoid sleep disorders in infants [7].
CONCLUSION:
Human skin is constantly exposed to the UV irradiation
present in sunlight which induces a number of
pathobiological cellular changes. Tea polyphenol
becomes one of the favourite ingredients for cosmetic
preparations as although the effects may be small, they
are significant and do meaningfully improve skin feel
and appearance with continued use. Also the component
are beneficial by being stable in production, storage, and
use, be nontoxic to the consumer and have activity at the
target site once applied. The development of novel
defensive and beneficial strategies can be studied by
molecular mechanism of UV-damage and plant
phenolics effects for prevention of the unpleasant effects
of UV radiation on the skin and improving skin
penetration of this bioactive cosmetic by enhancing
delivery into the skin.
ACKNOWLEDGEMENTS:
The authors would like to thank HUL (Hindustan
Unilever) for financial assistance for the collaborated
Research Project and the fellowship provided to the first
author.
Research J. Topical and Cosmetic Sci. 6(1): Jan. – June 2015
6
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