ArticlePDF Available

Antimicrobial potential of epigallocatechin-3-gallate (EGCG): A green tea polyphenol


Abstract and Figures

The compounding problem of microbial resistance has become a global threat nowadays and demands urgent attention. Given the limited number of clinically proven drugs available, reversion towards compounds from natural resources have become renewed source of interest. Utilization of novel and potent antimicrobial agents with different targets can act as accessories to antibiotic therapy. Considerable amount of research has been conducted on the various advantages of secondary metabolites produced by different plants. Among these, polyphenols have come into sight over the past few decades as a potential source to promote human health. This article summarizes the various health benefits of EGCG, the major component of green tea polyphenols with more emphasis on the anti-microbial properties of EGCG.
Content may be subject to copyright.
S. Das et al. / Journal of Biochemical and Pharmacological Research, Vol. 2 (3): 167-174, September 2014
ISSN 2168-8761 print/ISSN 2168-877X online167
Antimicrobial potential of epigallocatechin-3-
gallate (EGCG): a green tea polyphenol
Shrayanee Das1, Jyoti Tanwar1, Saif Hameed*, Zeeshan Fatima*
Amity Institute of Biotechnology, Amity University Haryana, Gurgaon (Manesar)-122413, India
1Equal contribution
*To whom correspondence should be addressed: Dr. Zeeshan Fatima and Dr. Saif Hameed, Amity Institute of Biotechnology,
Amity University Haryana, Gurgaon (Manesar)-122413, India. Phone: +91-124-2337015, Ext: 1205.
(Received June 6, 2014; Revised June 25, 2014; Accepted June 27, 2014; Published online: July 5, 2014)
Abstract: The compounding problem of microbial resistance has become a global threat nowadays and
demands urgent attention. Given the limited number of clinically proven drugs available, reversion towards
compounds from natural resources have become renewed source of interest. Utilization of novel and potent
antimicrobial agents with different targets can act as accessories to antibiotic therapy. Considerable amount of
research has been conducted on the various advantages of secondary metabolites produced by different plants.
Among these, polyphenols have come into sight over the past few decades as a potential source to promote
human health. This article summarizes the various health benefits of EGCG, the major component of green tea
polyphenols with more emphasis on the anti-microbial properties of EGCG.
Keywords: EGCG, green tea, polyphenols, catechins
A huge amount of research has been conducted on the
various advantages of secondary metabolites produced by
different plants. Among these, polyphenols have come into
sight over the past few decades as a potential source to
promote human health. A number of clinical trials have
shown wide range of biological and pharmacological
properties of polyphenolic compounds such as anti-
microbial, anti-carcinogenic, anti-oxidative, anti-allergic,
anti-cardiovascular [1], anti-diabetic [2], anti-inflammatory
[3], anti-hypercholesterolemic (lipid clearance) [4], anti-
atherosclerosis, anti-hypertensive [1], anti-mutagenic [5],
anti-aging [6], decreased risk of osteoporotic fractures [7],
neuroprotective [8] and immunomodulatory effects [3].
Being an incredible source they are considered safer and
metabolize better than conventional pharmaceutical drugs
since these compounds are derived from natural food
products [9]. The development of resistance to various
commercial anti-microbial drugs drives the increased use of
these natural polyphenols in recent years. Polyphenols are
major dietary constituents of many food items and
beverages. Tea (Camellia sinensis, family Theaceae) is the
second most consumed plant-based (Table 1) beverage in the
world preceded by water and is cultivated in about 30
countries in the world [1, 5, 10]. On the basis of method of
post-harvest processing, tea can be divided into four
categories namely black tea (aerated or oxidized), green tea
(non-aerated), white tea and oolong tea (semi-aerated or
partially oxidized) [10]. The antimicrobial potential of
EGCG, the major component of green tea polyphenols, is the
focus of this article.
Chemical composition of green tea
Green tea in general refers to the product which is
derived from fresh tea leaves after some modifications like
steaming or drying at elevated temperature. The main
component of polyphenols is catechins and its oxidation is
avoided in the above processing [3]. The amount of
catechins is higher in green tea (Fig 1) in comparison to the
other varieties. Common green tea is rich source of dietary
flavonoids which are classified as catechins (C), (-)-
epigallocatechin-3-gallate (EGCG), (-)-epigallocatechin
(EGC), (-)-epicatechin-3-gallate (ECG) and (-)-epicatechin
(EC) [1] (Table 2). EGCG has been declared as safe
S. Das et al. / Journal of Biochemical and Pharmacological Research, Vol. 2 (3): 167-174, September 2014
Table 2. Chemical structures of different catechins in green tea.
Catechins in Green Tea Chemical Structure
Epigallocatechin -3-gallat e(EGCG)
Epigallocatechin (EGC)
Epicatech in-3-gal late (ECG)
Epicatech in (EC)
compound by the US Food and Drug Administration [12]
and it is the most active and characteristic component found
only in green tea. The natural product EGCG forms 50-80%
of catechins in green tea, representing 200–300 mg in a
brewed cup of green tea while other catechins are found in
lower abundance in green tea which includes catechin
gallate, gallocatechin, gallocatechin gallate, epigallocatechin
digallate, methylepicatechin and methyl EGC [3]. Some
flavanols such as quercetin, kaempferol, myricetin, and their
glycosides are also present in tea. Other component like
threonine which is responsible for the characteristic flavor, is
present 4-6% weight of dried tea [13].
Table 1. Phylogenetic classification of green tea
Kingdom Plantae
Order Ericales
Family Theaceae
Genus Camellia
Species C. sinensis [8]
Health promoting activities of EGCG
EGCG is the most abundant, potent polyphenol and
is responsible for most of therapeutic benefits (either
clinical, animal or cell culture studies) of green tea (Fig 2). It
has various medicinal potentialities which include anti-
microbial properties against resistant microorganisms on
which it acts by either disrupting the cell membrane,
inhibiting the biosynthesis of the cell constituents, cell
signaling or DNA damage (described in following sections).
The most important antioxidant property is very crucial in
treating chronic diseases which are related to oxidative
stress, cardiovascular, neurodegenerative diseases and
cancer. Research on this property revealed information about
its anti-cardiovascular and anti-hypertensive activity which
enables EGCG to prevent platelet aggregation, lower
cholesterol level and inhibit lipid peroxidation [14]. In vitro
studies of mouse model, it induces lowered risk of cancer
development by binding to various key proteins, thus
affecting the signaling pathways followed by growth
inhibition due to apoptosis or suppression of angiogenesis
and metastasis [1, 15]. EGCG is also beneficial for
preventing aging of brain and other neurodegenerative
diseases such as Alzheimer’s and Parkinson’s diseases as
depicted from mouse model studies [8, 14]. It also shows
anti-hypercholesterolemic (anti-obesity) activity and
promotes weight loss through fat oxidation [16]. Animal
studies have demonstrated that EGCG is an efficient agent in
preventing the development of diabetes, type 1 or type 2 [2].
EGCG increases lysosomal acidification, regulates
autophagy and lipid clearance in liver due to its anti-steatotic
property [4]. EGCG, in dose dependent manner can reduce
the release of cytokines/chemokines responsible for
inflammation showing anti-inflammatory property [3, 17].
Its anti-allergic property strongly inhibits activation of mast
cells and expression of high-affinity IgE receptor, which
produces an allergic reaction on exposure to certain foreign
antigens [18].
S. Das et al. / Journal of Biochemical and Pharmacological Research, Vol. 2 (3): 167-174, September 2014
Fig. 1. Percentage of different components of green tea [11].
Antimicrobial potent of EGCG
Natural products have emerged as rich sources of
antimicrobial agents efficient against a wide variety of
microorganisms. Tea polyphenol EGCG have broad
antimicrobial spectrum such as antifungal [Candida spp.(C.
albicans, C. glabrata), dermatophytes (Trichophyton
mentagrophytes, T. rubrum)], antibacterial (methicilllin
resistant Staphylococcus aureus and Stenotrophomonas
maltophilia, Mycobacterium tuberculosis, Helicobacter
pylori, Streptococci spp., Clostridium spp., Bacillus cereus,
Salmonella spp., Mycoplasma pneumonia) and antiviral
[Orthomyxoviridae (Influenza virus) and Flaviviridae
(hepatitis C), hepatitis B virus, herpes simplex virus, Human
Immunodeficiency Virus and adenovirus] effects. The
following section will review the various antimicrobial
potential of EGCG (Fig. 3).
Antifungal activity of EGCG
More than 600 different fungi are reported to cause
common to fatal infections in human. The increasing number
of immunosuppressed patients and advancements in the
medicinal fields contributes to the incidence of invasive
fungal infections. The effects of EGCG are generally studied
against yeast strains such as Candida spp. (C. albicans, C.
glabrata) and dermatophytes (Trichophyton mentagrophytes,
T. rubrum).
C. albicans is a polymorphic and commensal
organism found to be a member of human’s normal
microbial flora. Nosocomial infections or hospital acquired
infections (HAI) are the fourth most leading cause of
diseases and C. albicans is known to cause approximately
80% of fungal HAI which are major cause of morbidity and
mortality. About 90-100% of mucosal infections and 50-
70% of Blood Stream Infections (BSI) are generally caused
by C. albicans [19]. These fungal infections are generally
treated by antifungal mainly azoles such as fluconazole and
itraconazole which inhibits sterol biosynthetic pathway. In
antifungal therapy, these azoles have less toxicity against the
fungal strains, hence providing poor fungicidal activity with
increased side effects. Due to enhanced antimicrobial
resistance there is a need of developing effective natural
antifungal agents which are less toxic and safer [21].
Various in vitro studies using clinical isolates of C. albicans,
C. tropicalis, etc., indicated that EGCG shows antifungal
effects against resistant Candida species and might be an
alternative agent for treating candidal infections. The ability
of C. albicans to adhere to other cells, various hosts, medical
and surgical devices contributes to its colonization and
pathogenicity by biofilm formation which is highly resistant
to several antifungal agents. In an in vitro study, Evensen
and Braun [22] showed that at physiological concentration
(1 µmol/ml), green tea polyphenols cause metabolic
instability with EGCG being most potent among them.
Biofilm formation of C. albicans was impaired by EGCG
which contributed to both structural and metabolic
disruption [23]. Another common mechanism of action of
antifungal agents is that they physically bind to ergosterol,
disturbing the osmotic integrity and hence create pores. This
causes intracellular ions (potassium and magnesium) to leak
out, therefore killing the cell and EGCG is known to
enhance this activity due to its synergistic effect [24]. Some
research groups have shown even antifolic activity of EGCG
against dihydrofolate reductase (DHFR) by inhibition of this
crucial enzyme for the biosynthesis of purines, pyrimidines
and various amino acids resulting in disturbing the growth of
fungal cells [25]. In vitro study by Hirasawa & Takada [20]
showed the antifungal effects of EGCG both individually
and in combination with antimycotic drugs against C.
albicans. They found that EGCG has a pH dependent effect
shows more strong action at basic pH such that the microbial
inhibitory concentration was decreased by 10 times at higher
(~2.0 mg/L at 8.0 pH) than at lower (~1024 mg/L at 6.0 pH)
pH. The pH dependent effect holds true when it was used in
association with commercial antifungal drugs where it
enhanced their activity with lesser dose.
Dermatophytosis is another most common and
widespread infectious diseases that is yet to be solved. It is
caused by dermatophytes, particularly Trichophyton
mentagrophytes, T. rubrum which were shown to have
sensitivity to EGCG (MIC50, 2-4 µg/ml, MIC90, 4-8 µg/ml)
[26]. In vitro study by Toyoshima [27] showed antifungal
effects of EGCG against clinical isolates of T.
mentagrophytes. They reported that inhibition of
germination of conidia was followed by some morphological
changes like deformation, swelling, granular accumulation
and inhibited hyphal growth.
S. Das et al. / Journal of Biochemical and Pharmacological Research, Vol. 2 (3): 167-174, September 2014
allerg ic
inf lammato ry
protectiv e
carcinogen ic
Fig. 2. Health benefits of epigallocatechin-3-gallate (EGCG).
Antibacterial activity of EGCG
Bacterial infections are offering extensive challenge
to health care and a major cause of morbidity and mortality.
Due to bacterial resistance to antibiotics over the past
decade, treatment of these infections has become even more
challenging. The effects of EGCG are generally studied
against bacterial strains such as (methicillin resistant
Staphylococcus aureus and Stenotrophomonas maltophilia,
Mycobacterium tuberculosis, Helicobacter pylori,
Streptococci spp.).
Staphylococci species (methicillin resistant
Staphylococcus aureus) is major cause of severe, acute and
chronic HAI. The activity of β-lactams (antibiotics such as
methicillin) was found to be enhanced by EGCG. The
biological activity of EGCG was investigated against clinical
isolates of S. aureus and the in vitro study suggested that
binding of negatively charged EGCG to positively charged
lipids of the cell membrane, damages the membrane
structure or fragments the lipid bilayer causing
intramembranous leakage [28]. It has also been reported that
EGCG inhibited (MIC50, 10 µg/ml) the penicillinase activity
of peptidoglycan of bacterial cell membrane by binding to it
either directly or indirectly, hence keeping the penicillin
away from inactivation [29]. EGCG was also found to
decrease or inhibit biofilm production by S. aureus [30].
EGCG have been reported to inhibit the growth of Gram-
positive and Gram-negative bacteria. Stenotrophomonas
maltophilia is an environmental Gram-negative (multiple
drug resistant) organism which is commonly associated with
respiratory infections in humans. EGCG can lead to bacterial
cell death by inhibiting bacterial DNA gyrase, thus
preventing DNA supercoiling [31]. DHFR is a key enzyme
that reduces 7, 8-dihydrofolate (DHF) to 5, 6, 7, 8-
tetrahydrofolate (THF). This NADPH- dependent reduction
reaction is involved in nucleotide biosynthesis. EGCG
shows antifolate activity against DHFR and hence leads to
the disruption of DNA synthesis. An in vitro study on
mechanism of action of the EGCG against clinical isolates of
S. maltophilia (MIC range, 4 to 256 µg/ml) revealed that the
primary target of their anti-bacterial activity is phospholipids
of the bacterial membrane, hence kills the cell by membrane
disruption [32, 33].
S. Das et al. / Journal of Biochemical and Pharmacological Research, Vol. 2 (3): 167-174, September 2014
Fig. 3. Antimicrobial actions of EGCG.
Helicobacter pylori is known to be a major causative
agent of chronic gastritis, peptic ulcer and can also lead to
the development of gastric cancer. From in vitro studies, it
had been proved that EGCG is natural and safe having
physiochemical stability in stomach acid, which makes it an
effective alternative therapeutic agent for treatment of the
above mentioned gastric diseases at an inhibitory
concentration of 100 µg/ml against clinical isolates of H.
pylori [34]. EGCG blocks TLR-4 (toll like receptor)
glycosylation, stimulated by H. pylori infection, which
disturbs H. pylori- induced host cell signaling and protects
from gastric cytotoxicity [35]. Studies indicated that EGCG
is responsible for the inhibition of bacterial adhesion to
human cells by Streptococci species (S. mutans, S. pyogenes)
and induces cell death [36].
Tuberculosis (TB) is caused by Mycobacterium
tuberculosis (MTB) which is seventh leading cause of death
worldwide and is estimated to kill more than 2 million
people every year. Induction and activation of reactive
oxygen species (ROS) and pro-inflammatory cytokine TNF-
α (tumor necrosis factor) respectively is significant for
proliferation of MTB in host cells Peripheral Blood
Mononuclear cells (human monocytes). Fatima et al. [37,
38] in an in vitro study, revealed that due to its antioxidant
property, EGCG is an inhibitor of ROS and reactive nitrogen
intermediates (RNI) pathways. It also shows better
inhibition of TNF-α and MTB 85B gene expression (MIC, 5
µg/ml) than other first line antibiotics, thus proving EGCG
to be safe, economic and natural therapeutic agent for
treatment of TB.
Antiviral activity of EGCG
The effects of EGCG are generally studied against
bacterial strains such as (Hepatitis C Virus, Human Immuno
deficiency Virus, Influenza viruses, Hepatitis B virus,
S. Das et al. / Journal of Biochemical and Pharmacological Research, Vol. 2 (3): 167-174, September 2014
Enterovirus,Adenovirus, Epstein–Barr virus,Herpes
Simplex Virus). Hepatitis C Virus (HCV) is an RNA virus
which chronically infects about 160 million individuals. It is
a member of Flaviviridae family and is associated with life-
threatening diseases like cirrhosis, liver failure and
hepatocellular carcinoma [39]. HCV infection can be spread
via cell to cell transmission. Entry of virus is a multistep
process which involves endocytosis and fusion of the viral
membrane with the host membrane. EGCG can prevent this
cell-cell transmission due to a unique potential of inhibiting
the attachment of HCV and its entry into the host cell by
impairment of virus binding to the cell, thereby preventing
its RNA replication. Moreover, single dose concentration of
EGCG ranging from 50-1600 mg is sufficient to inhibit the
HCV and safe for human volunteers as reviewed by
Steinmann [23, 40, 41]. It is responsible of increasing the
lipid droplet formation and impairment of lipoprotein
secretion in hepatocytes, both of which are crucial for the
life cycle of HCV [42].
Human Immunodeficiency Virus-1(HIV-1) is a
lentivirus which is estimated to infect about 33 million
people worldwide. It is the major causative agent of AIDS
and belongs to the Retroviridae family. It is a major cause of
morbidity and in the absence of effective vaccine or cure,
antiretroviral treatment is the best option [43]. EGCG affects
each step of the HIV life cycle, from cell attachment, entry
of virus, replication cycle to the expression of mRNA. It also
interferes with the infectivity of the virus by binding to the
surface of viral envelope and deforming the phospholipids
followed by lysis of the virus particle [44, 45]. The
attachment of the gp120 envelope protein to the CD4
receptor on T-helper cells initiates the entry of HIV-1 into
the host. EGCG blocks the interaction of gp120 and CD4
and prevents the attachment of HIV-1 virions [46]. This tea
catechin inhibits reverse transcriptase (RT) which catalyses
the conversion of RNA into DNA and integrase enzyme
which splice synthesized DNA into host cell genome [11,
45]. EGCG also inhibits the viral production from infected
cells and the level of expression of viral mRNA.
Influenza viruses (Influenza virus A and B) are
members of Orthomyxoviridae family and are a major cause
of respiratory diseases in human. Influenza A viruses are
single stranded, segmented RNA viruses with envelope. The
various antiviral drugs used to treat diseases caused by this
organism are amantadine and rimantadine etc. However,
many viral strains have developed resistance to these drugs
and therefore, EGCG has emerged as a potent source of
antiviral agent. It was reported for the first time in 1993 that
EGCG was able to alter the physical integrity and
agglutinate the virus preventing them from adsorbing on
MDCK cells (Madin-Dardy Canine Kidney) [47]. It also
ceased the growth of influenza virus by inhibiting the
acidification of intracellular compartments like endosomes,
lysosomes etc. [48] and inhibited the entry by binding to
haemagglutinin [49]. Another virus against which EGCG
exerts its antiviral activity is Adenovirus of Adenoviridae
family, a non-enveloped virus composed of a nucleocapsid
and a double-stranded linear DNA genome. Approximately
5–10% of upper respiratory infections in children are caused
by this organism. Weber and co-workers [50] concluded that
EGCG inactivated adenoviruses and inhibited the viral
protease activity. It was found to be most effective during
the transition from early to late phase of the infection and
also inhibited the late stages of viral infection followed by
its intracellular growth. Enterovirus 71 is a single stranded
RNA virus belonging to Picornaviridae family and causes
life threatening hand, foot and mouth disease (HFMD),
cutaneous and neurological diseases. EGCG exerts its
antiviral activity by inhibiting the viral replication and
subsequent formation of progeny virus [51].
Hepatitis B, which affects over 300 million people all
over the world, is caused by Hepatitis B virus (HBV) which
is a small enveloped virus from the Hepadnaviridae family.
It can be transmitted parentally, sexually and perinatally
[52]. In a dose dependent manner, EGCG was capable of
reducing the expression of HBV specific antigens, the levels
of extracellular HBV DNA and inhibit the replication of
intracellular replicative intermediates resulting in a reduction
in cccDNA production (covalently closed circular DNA)
Analysis of antiviral effect of EGCG on Epstein–Barr
virus (EBV), a herpes virus of Herpesviridae family,
demonstrated that it inhibited the transcription of immediate-
early genes and expression of the lytic proteins, thus
blocking the EBV lytic cycle [54]. It is associated with
Burkitt’s lymphoma, nasopharyngeal carcinoma, T-cell
lymphoma and Hodgkin’s disease [55]. Another virus from
the Herpesviridae family, Herpes Simplex Virus (HSV)
causes a sexually transmitted Herpes simplex disease at 65-
90% rates all over the world [23]. As no vaccine is currently
available for treatment, EGCG was characterized against
HSV to study its antiviral effects in Vero cell lines and was
found to affect prior to infection, having no effect on the
viral production [12].
The recent research have reveal that green tea has
proved its potentials ranging right from antimicrobial to
antioxidant, neuroprotective to skin and hair care, and many
more, posing as a “natural boon to human being”. Despite
EGCG being safe in nature, it suffers with few limitations
viz. low absorption, poor membrane permeability, metabolic
transformations and unstability [56]. Moreover, even
antagonistic action of EGCG has been reported with
anticancer drugs [57]. However, with their unique
biochemical profiles, they have even managed to contribute
to the enhancement of the activity of different standard
drugs. This has not only grabbed the attention of common
people but also nailed its position as an alternative remedy
for different chronic life-threatening infections.
S. Das et al. / Journal of Biochemical and Pharmacological Research, Vol. 2 (3): 167-174, September 2014
S.H. thanks Science and Engineering Research Board
(SERB), New Delhi for the financial assistance in the form
of Young Scientist award (SR/FT/LS-12/2012). We thank
Prof. S.M. Paul Khurana, Dean, Faculty of Science,
Engineering & Technology for encouragement.
Conflict of interests
The authors declare no conflict of interest.
[1] Tachibana H. Green tea polyphenol sensing. Proc Jpn Acad
Ser B Phys Biol Sci. 2011;87:66-80.
[2] Babu PV, Liu D, Gilbert ER. Recent advances in
understanding the anti-diabetic actions of dietary flavonoids.
J Nutr Biochem. 2013;24:1777-89.
[3] Gu JW, Makey KL, Tucker KB, Chinchar E, Mao X, Pei I et
al. EGCG, a major green tea catechin suppresses breast
tumor angiogenesis and growth via inhibiting the activation
of HIF-1α and NFκB, and VEGF expression. Vasc Cell.
[4] Zhou J, Farah BL, Sinha RA, Wu Y, Singh BK, Bay BH et al.
Epigallocatechin-3-gallate (EGCG), a green tea polyphenol,
stimulates hepatic autophagy and lipid clearance. PLoS One.
[5] Schramm L. Going Green: The Role of the Green Tea
Component EGCG in Chemoprevention. J Carcinog
Mutagen. 2013;4:1000142.
[6] Cooper R, Morré DJ, Morré DM. Medicinal Benefits of
Green Tea: Part I. Review of Noncancer Health Benefits. J
Altern Complement Med. 2005;11:521-8.
[7] Shen CL, Yeh JK, Cao J, Wang JS. Green Tea and Bone
metabolism. Nutr Res. 2009;29: 437–456.
[8] Parmar N, Rawat M, Kumar VJ. Camellia Sinensis (Green
Tea): A Review. Glob J of Pharmacol. 2012;6:52-59.
[9] Kim HS, Quon MJ, Kim JA. New insights into the
mechanisms of polyphenols beyond antioxidant properties;
lessons from the green tea polyphenol, epigallocatechin 3-
gallate. Redox Biol. 2014; 2:187-195.
[10] Koech KR, Wachira FN, Ngure RM, Wanyoko JK, Bii CC,
Karori SM et al. Antimicrobial, synergistic and antioxidant
activities of tea polyphenols. In: Mendez-Vilas A, editor.
Microbial pathogens and strategies for combating them,
Spain. Formatex Research Centre. 2013;p:971-981.
[11] Anand J, Rai N, Kumar N, Gautam P. Green Tea: A Magical
Herb With Miraculous Outcomes. Int Res J of Pharm.
[12] de Oliveira A, Adams SD, Lee LH, Murray SR, Hsu SD,
Hammond JR et al. Inhibition of herpes simplex virus type 1
with the modified green tea polyphenol palmitoyl-
epigallocatechin gallate. Food Chem Toxicol. 2013;52:207-
[13] Kanwar J, Taskeen M, Mohammad I, Huo C, Chan TH, Dou
QP. Recent advances on tea polyphenols. Front Biosci (Elite
Ed). 2012;4:111-31.
[14] Sharangi A. Medical and therapeutic potentialities of tea
(Camellia sinensis L.) – A review. Food Res Int.
[15] Fujimura Y, Sunida M, Sugihara K, Tsukamoto S, Yamada K,
Tachibana H. Green tea polyphenol EGCG sensing motif on
the 67-kDa laminin receptor. PLoS One. 2012;7:e37942.
[16] Westerterp-Plantenga, M.S. Green tea catechins, caffeine and
body-weight regulation. Physiol Behav. 2010;100:42-46.
[17] Cavet ME, Harrington KL, Vollmer TR, Ward KW, Zhang
JZ. Anti-inflammatory and anti-oxidative effects of the green
tea polyphenol epigallocatechin gallate in human corneal
epithelial cells. Mol Vis. 2011;17:533-42.
[18] Yamamoto MM, Tachibana H. Anti-Allergic Action of O-
methylated EGCG in Green Tea Cultivar Benifuuki. J Food
Drug Anal. 2012;20:313-317.
[19] Tanwar J, Das S, Fatima Z, Hameed S. Crusade for
opportunity: Candida albicans from commensalism to
pathogenicity. J Hum Dis. 2013;112:160-167.
[20] Hirasawa M., Takada K. Multiple effects of green tea
catechin on the antifungal activity of antimycoticsagainst
Candidaalbicans. J Antimicrob Chemother.2004;53:2259.
[21] Neto JB, da Silva CR, Neta MA, Campos RS, Siebra JT,
Silva RA et al. Antifungal Activity of Naphthoquinoidal
Compounds In Vitro against Fluconazole-Resistant Strains of
Different Candida Species: A Special Emphasis on
Mechanisms of Action on Candida tropicalis. PLoS One.
[22] Evensen NA, Braun PC. The effects of tea polyphenols on
Candida albicans: inhibition of biofilm formation and
proteasome inactivation. Can J Microbiol. 2009;55:1033-9.
[23] Steinmann J, Buer J, Pietschmann T, Steinmann E. Anti-
infective properties of epigallocatechin-3-gallate (EGCG),
a component of green tea. Br J Pharmacol. 2013;168:1059-
[24] Ellis D. Amphotericin B: Spectrum and Resistance. J
Antimicrob Chemother. 2002;49:7-10.
[25] Navarro-Martinez MD, Garcia-Canovas F, Rodriguez-Lopez
JN. Tea polyphenol epigallocatechin-3-gallate inhibits
ergosterol synthesis by disturbing folic acid metabolism in
Candida albicans. J Antimicrob Chemother. 2006;57:1083–
[26] Park BJ, Taguchi H, Kamei K, Matsuzawa T, Hyon SH, Park
JC. In vitro antifungal activity of epigallocatechin 3-O gallate
against clinical isolates of dermatophytes. Yonsei Med J.
[27] Toyoshima Y, Okubo S, Toda M, Hara Y, Shimamura T.
Effect of catechin on the ultrastructure of Trichophyton
mentagrophytes. Kansenshogaku Zasshi. 1994;68:295–303.
[28] Ikigai H, Nakae T, Hara Y, Shimamura T. Bactericidal
catechins damage the lipid bilayer. Biochim Biophys Acta.
[29] Zhao WH, Hu ZQ, Hara Y, Shimamura T. Inhibition of
penicillinase by epigallocatechin gallate resulting in
restoration of antibacterial activity of penicillin against
penicillinase-producing Staphylococcus aureus. Antimicrob
Agents Chemother. 2002;46:2266–2268.
[30] Sudano Roccaro A, Blanco AR, Giuliano F, Rusciano D,
Enea V. Epigallocatechin-gallate enhances the activity of
tetracycline in staphylococci by inhibiting its efflux from
S. Das et al. / Journal of Biochemical and Pharmacological Research, Vol. 2 (3): 167-174, September 2014
bacterial cells. Antimicrob Agents Chemother.
[31] Gradisar H, Pristovsek P, Plaper A, Jerala R. Green tea
catechins inhibit bacterial DNA gyrase by interaction with its
ATP binding site. J Med Chem. 2007;50:264–71.
[32] Gordon NC, Wareham DW. Antimicrobial activity of the
green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG)
against clinical isolates of Stenotrophomonas maltophilia. Int
J Antimicrob Agents. 2010;36:129-31.
[33] Navarro-Martínez MD, Navarro-Perán E, Cabezas-Herrera
J, Ruiz-Gómez J, García-Cánovas F, Rodríguez-López JN.
Antifolate activity of epigallocatechin gallate against Stenotr
ophomonas maltophilia. Antimicrob Agents Chemother.
[34] Yanagawa Y, Yamamoto Y, Hara Y, Shimamura T. A
combintion effect of epigallocatechin gallate, a major
compound of green tea catechins, Helicobacter pylori growth
in vitro. Curr Nicrobiol. 2003;47:244-249.
[35] Lee KM, Yeo M, Choue JS, Jin JH, Park SJ, Cheong JY et al.
Protective mechanism of epigallocatechin-3-gallate against
Helicobacter pylori – induced gastric epithelialcytotoxicity
via the blockage of TLR-4 signaling. Helicobacter.
[36] Hull Vance S, Tucci M, Benghuzzi H. Evaluation of
the antimicrobial efficacy of green tea extract (egcg) against
streptococcus pyogenes in vitro - biomed 2011. Biomed Sci
Instrum. 2011;47:177-82.
[37] Fatima Z, Hameed S, Islam N. Green tea polyphenol
(EGCG) is a better inhibitor of TNF-α and MTB 85B antigen
in human monocytes than known antioxidants and
antibiotics. J. Infect Dis. 2013;112:131-137.
[38] Fatima Z, Hameed S, Islam N. Epigallocatechin-3-gallate
(EGCG), a green tea polyphenol suppresses bacilli-induced
augmented expression of Mycobacterium tuberculosis 85B
and proinflammatory TNF-α in human monocytes. Int J. Sci
Res Pub. 2012;2:1-6.
[39] Lavanchy D. Evolving epidemiology of hepatitis C virus.
Clin Microbiol Infect. 2011;17:107–115.
[40] Chen C, Qui H, Gong J, Liu Q, Xiao H, Chen XW et al. (-)-
Epigallocatechin-3-gallate inhibits the replication cycle of
hepatitis C virus. Arch Virol. 2012;157:1301-12.
[41] Calland N, Albecka A, Belouzard S, Wychowski C, Duverlie
G, Descamps V et al. (-)-Epigallocatechin-3-gallate is a new
inhibitor of hepatitis C virus entry. Hepatology. 2012;55:720-
[42] Li L, Stillemark-Billton P, Beck C, Bostrom P, Andersson L,
Rutberg M et al. Epigallocatechin gallate increases the
formation of cytosolic lipid droplets and decreases the
secretion of apoB-100 VLDL. J Lipid Res. 2006;47:67–77.
[43] Simon V, Ho DD, Abdool Karim Q. HIV/AIDS
epidemiology, pathogenesis, prevention, and treatment.
Lancet. 2006;368:489–504.
[44] Fassina G, Buffa A, Benelli R, Varnier OE, Noonan DM,
Albini A. Polyphenolic antioxidant (-)-epigallocatechin-3-
gallate from green tea as a candidate anti-HIV agent. AIDS.
[45] Yamaguchi K, Honda M, Ikigai H, Hara Y, Shimamura T.
Inhibitory effects of (-)-epigallocatechin gallate on the life
cycle of human immunodeficiency virus type 1 (HIV-1).
Antiviral Res. 2002;53:19-34.
[46] Kawai K, Tsuno NH, Kitayama J, Okaji Y, Yazawa K,
Asakage M et al. Epigallocatechin gallate, the main
component of tea polyphenol, binds to CD4 and interferes
with gp120 binding. J Allergy Clin Immunol. 2003;112:951–
[47] Nakayama M, Suzuki K, Toda M, Okubo S, Hara Y,
Shimamura T. Inhibition of the infectivity of influenza virus
by tea polyphenols. Antiviral Res. 1993;21:289–299.
[48] Imanishi N, Tuji Y, Katada Y, Maruhashi M, Konosu S,
Mantani N et al. Additional inhibitory effect of tea extract on
the growth of influenza A and B viruses in MDCK cells.
Microbiol Immunol. 2002;46:491–494.
[49] Song JM, Lee KH, Seong BL. Antiviral effect of catechins in
green tea on influenza virus. Antiviral Res. 2005;68:66–74.
[50] Weber JM, Ruzindana-Umunyana A, Imbeault L, Sircar S.
Inhibition of adenovirus infection and adenain by green tea
catechins. Antiviral Res. 2003;58:167–173.
[51] Ho HY, Cheng ML, Weng SF, Leu YL, Chiu DT. Antiviral
effect of epigallocatechin gallate on enterovirus 71. J Agric
Food Chem. 2009;57:6140–6147.
[52] Shepard CW, Simard EP, Finelli L, Fiore AE, Bell BP.
Hepatitis B virus infection: epidemiology and vaccination.
Epidemiol Rev. 2006;28:112–125.
[53] He W, Li LX, Liao QJ, Liu CL, Chen XL. Epigallocatechin
gallate inhibits HBV DNA synthesis in a viral replication –
inducible cell line. World J Gastroenterol. 2011;17:1507–
[54] Chang LK, Wei TT, Chiu YF, Tung CP, Chuang JY, Hung
SK et al. Inhibition of Epstein–Barr virus lytic cycle by (-)-
epigallocatechin gallate. Biochem Biophys Res Commun.
2003; 301:1062–1068.
[55] Bravender T. Epstein–Barr virus, cytomegalovirus, and
infectious mononucleosis. Adolesc Med State Art Rev.
[56]. Lecumberri E, Dupertuis YM, Miralbell R, Pichard C.
Green tea polyphenol epigallocatechin-3-gallate (EGCG) as
adjuvant in cancer therapy. Clin Nutr. 2013;32:894-903.
[57]. Chen D, Wan SB, Yang H, Yuan J, Chan TH, Dou QP.
EGCG, green tea polyphenols andtheir synthetic analogs and
prodrugs for human cancer prevention and treatment. Adv
Clin Chem. 2011;53:155-77.
... The results of EGCG are mainly studied against dermatophytes such as Trichophyton rubrum and Trichophyton mentagrophytes; and yeast strains such as Candida glabrate and Candida albicans (Das et al., 2014). In the case of catechins, pyrogallol catechin showcases greater antifungal activity against C. ...
... According to Farhad Mollashahi et al., (2015), the antifungal activity of green tea was based on time and its inhibitory action which did not reduce over time. Das et al., (2014) documented that the formation of biofilm by C. albicans was damaged by the EGCG. It also produces spores in the membrane by attaching to ergosterol and interrupting the osmotic integrity. ...
... Several antiviral drugs such as rimantadine and amantadine are used to treat this disease. However, numerous strains of viruses have generated resistance to these drugs and therefore, EGCG has been employed as an important source for influenza infection (Das et al., 2014). Matsumoto et al., (2011), registered about 197 eligible healthcare workers and arbitrarily allocated them to an intervention; 98 were allotted to get theanine/catechin capsules and the other 99 to placebo. ...
Full-text available
The Camellia sinensis plant provides a wide diversity of black, green, oolong, yellow, brick dark, and white tea. Tea is one of the majorly used beverages across the globe, succeeds only in the water for fitness and pleasure. Generally, green tea has been preferred more as compared to other teas due to its main constituent e.g. polyphenols which contribute to various health benefits. The aim of this updated and comprehensive review is to bring together the latest data on the phytochemistry and pharmacological properties of Camellia sinensis and to highlight the therapeutic prospects of the bioactive compounds in this plant so that the full medicinal potential of Camellia sinensis can be realised. A review of published studies on this topic was performed by searching PubMed/MedLine, Scopus, Google scholar, and Web of Science databases from 1999-2022. The results of the analysed studies showed that the main polyphenols of tea are the four prime flavonoids catechins: epigallocatechin gallate (EGCG), epicatechin gallate (ECG), epigallocatechin (EGC), and epicatechin (EC) along with the beneficial biological properties of tea for a broad heterogeneity of disorders, including anticancer, neuroprotective, antibacterial, antiviral, antifungal, antiobesity, antidiabetes and antiglaucoma activities. Poor absorption and low bioavailability of bioactive compounds from Camellia sinensis are limiting aspects of their therapeutic use. More human clinical studies and approaching the latest nanoformulation techniques in nanoparticles to transport the target phytochemical compounds to increase therapeutic efficacy are needed in the future.
... Otherwise, increased resistance in microorganisms to the current antimicrobials has motivated the search for and evaluation of other agents. This search for new sources of antimicrobial is undertaken by many research teams throughout the world on various plant species that are used with acceptable therapeutic index in traditional medicine [8][9][10][11][12][13][14] . So far, most efforts have been concentrated on extracts activity and the relationship between this activity and that of conventional drugs. ...
... Earlier, Mandalari et al. 24 observed that combined action of different groups of polyphenol could have either synergistic or antagonistic effect on microorganisms. Polyphenols in general were reported to interfere with the microbial cell functions by: causing leakage of the bacterial cell content like lipopeptides; impairing the supercoiling process of bacterial DNA like quinolones; acting as anti-metabolites like sulfonamides or inhibiting the sterol synthesis in fungal cell envelop like the azoles 11 . Although in the present investigation the raw product contained a variety of chemical compounds with no predictable interaction, its in vitro effectiveness on C. albicans and other bacterial isolates expressing varied resistance phenotypes can be, at least partially understood based on its multi-potential on the tested microbes. ...
... Endowed with inhibitory potential, aglycones can, therefore, modulate (either directly or indirectly) the activity of the gut microbial flora. Owing to the fact that this class of chemical is also abundant in foodstuff and has proven beneficial for human 11 , it can reasonably be anticipated that very high concentrations are required for significant adverse effects on the bacterial growth on one hand and/or that typical endogenous flora that have become adapted to this chemical group use some of them to be rid of invading microorganisms (most incriminated in microbe-related gastro-intestinal disorders). This assertion is consistent with Chung et al. 6 findings on the role of polyphenols in fruits protection against microbes. ...
Full-text available
The present works were conducted to screen and semi-quantify a few secondary metabolites from the stem bark of Erythropleum guineensis (G.Don) on one hand and test the antibacterial and antifungal potential of the crude hydro-alcoholic extract on the other. The investigated chemicals included alkaloids, polyphenols, coumarins, anthocyanes, flavonoids, saponosids, terpenoids, steroids, tannins, anthraquinones, phlobotannins, mucilages and resins. The antimicrobial activity was tested by standard macro-dilution and disk diffusion techniques on twelve microbial types. The parameters investigated were the minimal inhibitory concentration (MIC), the minimal lethal concentration (MLC) and the diameter of the zone of growth inhibition. About 64 % of the secondary metabolites investigated were detected. Also all germs were susceptible within the range of extract concentrations used (200-0.781 mg/mL). Susceptibility at the MIC was not Gram-type dependent and, close to 67% of the most susceptible at this concentration were ESBL-expressing isolates. In addition in these ESBL-positive isolates the MBC/MIC values were the highest like in C. albicans. The crude extract activity on multiple phenotype-expressing microbes suggested possible action on multiple microbial targets. Overall, this activity on both bacterial Gram types and C. albicans expressing a variety of resistance traits is a special asset that can be used to argue and promote the use of the improved version of the E. guineensis extract in the management of some infectious diseases; consistent with traditional practices, the advocacy of the WHO about the relevance of traditionally improved drugs in healthcare and the necessity to provide basic healthcare for all with available and affordable resources. Optimal use might, therefore, represent an alternative to many conventional drugs including some C 3 G, owing to its activity on ESBL-producing strains; but financial and motivated human resources are required for this goal to be achieved.
... In this study, the interactions between (-)-epigallocatechin-3-gallate, another popular flavonoid in the scientific world, and antibiotics were also evaluated, and extremely positive results were obtained. (-)-epigallocatechin-3-gallate is a flavonoid name of which is identified with green tea and has come to the fore with its health benefits, having antifungal, antibacterial, antiviral properties [24]. Hu et. ...
... We believe that catechins are responsible for the antibacterial effect of green tea extracts. According to the literature sources, the mechanism of antibacterial activity of catechins is underlying in inhibition the formation of biofilm [17], dehydrofolate reductase [18], and DNA gyrase [19], which in turn leads to a change in cell wall permeability, denaturation of proteins present in microbial cells and ultimately the death of bacteria [20]. ...
Full-text available
Introduction. Nowadays, there is high demand of phytochemical extracts with antioxidant and antibacterial properties due to increasing growth of drug-resistant pathogenies. Therefore, study antibacterial and antioxidant activities of green tea extracts is a topical and perspective topic for today. The aim of the work was determined the antioxidant and antibacterial activities of green tea leaves ethanolic and aqueous liquid extracts. Materials & methods. The object of the study was dry green tea leaves of spices Chun Myn were the object of the study, the raw material was collected in Anhui province (China) from March to May. The spectrophotometry was used for the quantitative determination of phenolic compounds, catechins, flavonoids and hydroxycinnamic acids; antioxidant activity was determined by potentiometric method. Results & discussion. Total content of phenolic compounds was 86.70±1.73 and 47.40±0.95 mg/mL, catechins – 84.00±1.68 and 52.50±1.05 mg/mL, flavonoids – 5.14±0.10 and 5.08±0.10 mg/mL and hydroxycinnamic acids – 7.75±0.16 and 4.79±0.10 mg/mL for ethanolic and aqueous extract, respectively. The antioxidant activity was 617.29 and 226.60 mmol-equiv./mres dry for ethanolic and aqueous extracts, respectively. Staphylococcus aureus bacteria was the most sensitive to the ethanolic and aqueous extracts (26.33 and 26 mm) whereas Proteus vulgaris was the most resistant to the ethanolic and aqueous extracts (21.33 and 19.67 mm). Obtained results showed that ethanolic extract had higher antioxidant and antibacterial activities than aqueous extract. Conclusions. In this study, we found that green tea leaves possess the high antioxidant and antibacterial activities. The results showed that ethanol is more appropriate solvent for obtaining the extract. Thus, green tea leaves extracts can prove beneficial in food and pharmaceutical industry as today, there is high demand of antioxidant and antimicrobial drugs. Key words: green tea leaves, antioxidant activity, antibacterial activity, analysis, liquid extracts
... Aliquots (1 mL) of the fermentation samples were centrifuged at 14,000 rpm, at 4 • C for 5 min and the supernatants removed. For EGCG containing samples, sterile water (1 mL) was added to wash the microbial to remove free EGCG as EGCG binds to DNA and enzymes [52,53], which would result in low yield of DNA extraction and would inhibit PCR amplification. The procedure was repeated to remove the supernatant, and the precipitation was collected for DNA extraction. ...
Full-text available
(-)-Epigallocatechin gallate (EGCG) and tuna oil (TO) are beneficial bioactive compounds. EGCG, TO or a combination of, delivered by broccoli by-products (BBP), were added to an in vitro anaerobic fermentation system containing human fecal inocula to examine their ability to generate short-chain fatty acids (SCFA), metabolize EGCG and change the gut microbiota population (assessed by 16 S gene sequencing). Following 24 h fermentation, EGCG was hydrolyzed to (-)-epigallocatechin and gallic acid. EGCG significantly inhibited the production of SCFA (p < 0.05). Total SCFA in facal slurries with BBP or TO-BBP (48–49 µmol/mL) were significantly higher (p < 0.05) than the negative control with cellulose (21 µmol/mL). EGCG-BBP and TO-EGCG-BBP treatment increased the relative abundance of Gluconacetobacter, Klebsiella and Trabulsiella. BBP and TO-BBP showed the greatest potential for improving gut health with the growth promotion of high butyrate producers, including Collinsella aerofaciens, Bacillus coagulans and Lactobacillus reuteri.
... Tanin biasanya digunakan sebagai bahan pembantu dalam farmaseutikal karena kemampuan antiseptiknya (Cowan, 1999). Sedangkan epigalokatekin galat yang merupakan komponen paling aktif di dalam teh hijau, memiliki kemampuan untuk mengganggu membran sel, menghambat biosintesis sel dan merusak DNA bakteri (Das, dkk, 2014). Alkaloid melakukan penghambatan dengan kemampuannya melakukan interkalasi pada DNA sel bakteri yang menyebabkan kematian pada sel bakteri (Cowan, 1999 (Voight, 1994). ...
... Inhibition of growth of Gram-negative and Gram-positive bacteria and pathogenic fungi, including C. albicans, by high-concentration solutions of trisodium citrate • Local anticoagulation properties by binding Ca 2+ [102] ascorbic acid Neuroprotective properties arising from the inhibition of protein fibrillation processes [108][109][110] tannic acid ...
Full-text available
The biocidal properties of silver nanoparticles (AgNPs) prepared with the use of biologically active compounds seem to be especially significant for biological and medical application. Therefore, the aim of this research was to determine and compare the antibacterial and fungicidal properties of fifteen types of AgNPs. The main hypothesis was that the biological activity of AgNPs characterized by comparable size distributions, shapes, and ion release profiles is dependent on the properties of stabilizing agent molecules adsorbed on their surfaces. Escherichia coli and Staphylococcus aureus were selected as models of two types of bacterial cells. Candida albicans was selected for the research as a representative type of eukaryotic microorganism. The conducted studies reveal that larger AgNPs can be more biocidal than smaller ones. It was found that positively charged arginine-stabilized AgNPs (ARGSBAgNPs) were the most biocidal among all studied nanoparticles. The strongest fungicidal properties were detected for negatively charged EGCGAgNPs obtained using (−)-epigallocatechin gallate (EGCG). It was concluded that, by applying a specific stabilizing agent, one can tune the selectivity of AgNP toxicity towards desired pathogens. It was established that E. coli was more sensitive to AgNP exposure than S. aureus regardless of AgNP size and surface properties.
... In general they interfere with the microbial cell functions by:1-causing leakage of the bacterial cell content like lipopeptides; 2-impairing the supercoiling process of bacterial DNA as quinolones do; 3-acting as anti-metabolites like sulfonamides or; 4-inhibiting the sterol synthesis in fungal cell envelop like the azoles. [37] The effectiveness recorded on bacteria expressing resistance to several conventional drugs might also let anticipate the multifactorial actions on these bacteria for which some conventional drug associations like the CAZ/FOX and CAZ/Imipenem were contra-indicated. [4] As the extract was effective on both major true bacteria Gram types with a relatively higher potential on Gram-positive, it might be tempting to associate the susceptibility pattern with the cell envelop chemical composition. ...
Full-text available
The present investigation focused semi-quantitative chemical screening and antibacterial potential of aqueous extracts from the stem bark and fruits of Tetrapleura tetraptera (T. tetreptera) grown in rain forest. Secondary metabolites targeted included alkaloids, anthocyans, anthraquinones, coumarins, flavonoids, saponins, tannins, glycosides, reducing sugars and polyphenols. The antimicrobial potential was tested on six Gram-positive and two Gram-negative multidrug-resistant common hospital hosts expressing inducible cephalosporinases (IC). The parameters regarded included the minimal inhibitory and bactericidal concentrations (MIC and MBC, respectively), the diameters of inhibition zones and the MBC/MIC ratios. All tests were performed according to previous protocols, with Gentamicin as reference for extract activity. Though not as rich as that from the stem bark and unlike it, extract from the fruits displayed effectiveness on all strains. The MICs and MBCs ranged from 12 mg/mL through 200 mg/mL, with global bactericidal effect at varying levels. This bactericidal potential on all strains substantiated the broad spectrum activity that precluded sets of resistance mechanisms including IC production. Though yet to be fully addressed, some interactions likely reduced overall effectiveness of the stem bark extract. It appears from the present findings that the fruits could be regarded as sources for antibacterials which could sustainably be used to improve on patient safety through surface hygiene with reduced resistance selection pressure Kwetche et al. World Journal of Pharmacy and Pharmaceutical Sciences acknowledged to develop with conventional cleaning in hospitals. Water as solvent would help associate cost-effectiveness and availability, but major challenges in this field remain the low output and standards for extraction and dosage.
Seaweed, an important food resource in several Asian countries, contains various metabolites, including sugars, organic acids, and amino acids; however, their content is affected by prevailing environmental conditions. This review discusses seaweed metabolomics, especially the distribution of primary and functional secondary metabolites (e.g., carotenoids, polyphenols) in seaweed. Additionally, the effects of global warming on seaweed metabolite profile changes are discussed. For example, high temperatures can increase amino acid levels in seaweeds. Overall, understanding the effects of global warming on seaweed metabolite profiles can be useful for evaluating the nutritional composition of seaweeds as food. This review provides an overview of recent applications of metabolomics in seaweed research as well as a perspective on the nutrient content and cultivation of seaweeds under climate change scenarios.
Full-text available
Flavonoids are some of the most precious phytochemicals, believed to be found largely in terrestrial plants. With the advancement of phytochemical research and marine bioprospecting, flavonoids have also been reported by the research of microalgae and macroalgae. High growth rate with minimal nutritional and growth requirement, saving arable land and rich metabolic profile make microalgae an excellent repertoire of novel anticancer compounds, such as flavonoids. In addition, marine algae, especially seaweeds contain different types of flavonoids which are assumed to have unique chemical structures and bioactivities than their terrestrial counterparts. Flavonoids are not only good antioxidants but also have the abilities to kill cancer cells by inducing apoptosis and autophagy. However, the study of the anticancer properties of flavonoids is largely limited to terrestrial plants. This review offers an insight into the distribution of different classes of flavonoids in eukaryotic microalgae, cyanobacteria and seaweeds with their possible anticancer activities. In addition, extraction and purification methods of these flavonoids have been highlighted. Finally, prospects and challenges to use algal flavonoids as anticancer agents have been discussed.
Full-text available
The anti-allergic effect of epigallocatechin-3-O-(3-O-methyl) gallate (EGCG3″Me) and epigallocatechin-3-O-(4-O-methyl) gallate (EGCG4″Me) isolated from Japanese or Taiwanese tea (Camellia sinensis L.) leaves. These catechins strongly inhibited mast cell activation and histamine release after FcepsilonRI cross-linking through the suppression of tyrosine phosphorylation (Lyn) of cellular protein kinase, and the suppression of myosin light chain phosphorylation and high-affinity IgE receptor expression via the binding to 67kDa laminin receptor. A double blind clinical study on subjects with Japanese cedar pollinosis was carried out. At the eleventh weeks after starting to intake, the most severe cedar pollen scattering period, symptoms i.e. blowing nose, itch of eyes were significantly relieved in Benifuuki group compared with placebo group. Over one consecutive month intake of Benifuuki green containing O-methylated catechin tea was useful for reduction of some symptoms derived from Japanese cedar pollinosis, and did not affect any normal immune response in the subjects with Japanese cedar-pollinosis. From the investigation that the effects of cultivars, tea seasons of crops and manufacturing methods, green or semi-fermented teas, made from fully-matured Benifuuki in second crop season, should be consumed. It is possible to develop functional articles such as beverage or food with this Benifuuki green tea.
Full-text available
In recent decades, the incidence of candidemia in tertiary hospitals worldwide has substantially increased. These infections are a major cause of morbidity and mortality; in addition, they prolong hospital stays and raise the costs associated with treatment. Studies have reported a significant increase in infections by non-albicans Candida species, especially C. tropicalis. The number of antifungal drugs on the market is small in comparison to the number of antibacterial agents available. The limited number of treatment options, coupled with the increasing frequency of cross-resistance, makes it necessary to develop new therapeutic strategies. The objective of this study was to evaluate and compare the antifungal activities of three semisynthetic naphthofuranquinone molecules against fluconazole-resistant Candida spp. strains. These results allowed to us to evaluate the antifungal effects of three naphthofuranquinones on fluconazole-resistant C. tropicalis. The toxicity of these compounds was manifested as increased intracellular ROS, which resulted in membrane damage and changes in cell size/granularity, mitochondrial membrane depolarization, and DNA damage (including oxidation and strand breakage). In conclusion, the tested naphthofuranquinones (compounds 1-3) exhibited in vitro cytotoxicity against fluconazole-resistant Candida spp. strains.
Full-text available
Green tea is rich in polyphenol flavonoids including catechins. Epigallocatechin 3-gallate (EGCG) is the most abundant and potent green tea catechin. EGCG has been extensively studied for its beneficial health effects as a nutriceutical agent. Based upon its chemical structure, EGCG is often classified as an antioxidant. However, treatment of cells with EGCG results in production of hydrogen peroxide and hydroxyl radicals in the presence of Fe (III). Thus, EGCG functions as a pro-oxidant in some cellular contexts. Recent investigations have revealed many other direct actions of EGCG that are independent from anti-oxidative mechanisms. In this review, we discuss these novel molecular mechanisms of action for EGCG. In particular, EGCG directly interacts with proteins and phospholipids in the plasma membrane and regulates signal transduction pathways, transcription factors, DNA methylation, mitochondrial function, and autophagy to exert many of its beneficial biological actions.
Full-text available
Epigallocatechin gallate (EGCG) is a major polyphenol in green tea that has been shown to have anti-inflammatory, anti-cancer, anti-steatotic effects on the liver. Autophagy also mediates similar effects; however, it is not currently known whether EGCG can regulate hepatic autophagy. Here, we show that EGCG increases hepatic autophagy by promoting the formation of autophagosomes, increasing lysosomal acidification, and stimulating autophagic flux in hepatic cells and in vivo. EGCG also increases phosphorylation of AMPK, one of the major regulators of autophagy. Importantly, siRNA knockdown of AMPK abrogated autophagy induced by EGCG. Interestingly, we observed lipid droplet within autophagosomes and autolysosomes and increased lipid clearance by EGCG, suggesting it promotes lipid metabolism by increasing autophagy. In mice fed with high-fat/western style diet (HFW; 60% energy as fat, reduced levels of calcium, vitamin D3, choline, folate, and fiber), EGCG treatment reduces hepatosteatosis and concomitantly increases autophagy. In summary, we have used genetic and pharmacological approaches to demonstrate EGCG induction of hepatic autophagy, and this may contribute to its beneficial effects in reducing hepatosteatosis and potentially some other pathological liver conditions.
Full-text available
Polyphenols are secondary metabolites produced by tea plant, which play multiple essential roles in plant physiology and have potential health properties on human health, mainly as antioxidants, anti-allergic, anti-inflammatory, anticancer, antihypertensive and antimicrobial agents. Microbial resistance has become an increasing global problem; there is a need to find out novel potent antimicrobial agents with alternative modes of action as accessories to antibiotic therapy. This study investigated the antimicrobial, synergistic and antioxidant properties of tea polyphenols. The synergistic effect of tea polyphenols in combination with conventional antimicrobial agents against clinical multidrug-resistant microorganisms has been investigated and valuable data generated on the potential synergistic properties of tea polyphenols.
Background Cancer cells are under greater oxidative stress than normal cells. Limited studies have showed that epigallocatechin-3-gallate (EGCG), a green tea antioxidant can afford protection against a variety of cancer types. The role of EGCG in breast cancer therapy is poorly understood. The present study tests the hypothesis that EGCG as an antioxidant can inhibit the activation of HIF-1α and NFκB, and VEGF expression, thereby suppressing tumor angiogenesis and breast cancer progression. Material and Methods: 16 eight-wk-old female mice (C57BL/6J) were inoculated with 10^6 E0771 (mouse breast cancer) cells in the left fourth mammary gland fat pad. 8 mice received EGCG at 50–100 mg/kg/d in drinking water for 4 weeks. 8 control mice received drinking water only. Tumor size was monitored using dial calipers. At the end of the experiment, blood samples, tumors, heart and limb muscles were collected for measuring VEGF expression using ELISA and capillary density (CD) using CD31 immunochemistry. Cultured E0771 cells were used for determining the direct effects of EGCG on proliferation (3H-thymidine incorporation), migration (Matrigel assay), VEGF expression (ELISA), the activation of HIF-1α and NFκB (motif binding assays, Active Motif). MCF-7 and MDA-MB-231 cells were also used for 3H-thymidine incorporation. Results: Oral EGCG treatment significantly reduced tumor weight over the control (0.37±0.15 vs. 1.16±0.30 g; P<0.01), tumor CD (109±20 vs. 156±12 capillary #/mm^2; P<0.01), tumor VEGF expression (45.72±1.4 vs. 59.03±3.8 pg/mg; P<0.01), respectively. EGCG treatment reduced plasma VEGF levels over the control mice (26.48±3.76 vs. 40.79±3.5 pg/ml; P<0.01). However, there were no differences in the body weight and heart weight between EGCG and the control groups. EGCG did not inhibit angiogenesis and VEGF expression in the heart and skeletal muscle of mice, compared to the control. EGCG at 50 mmol/L significantly inhibited the activation of HIF-1α (0.11±0.02 vs. 0.24±0.02; P<0.01) and NFκB (1.15±0.21 vs. 1.61±0.32; P<0.01) as well as VEGF expression (1752±49 vs. 2254±91 pg/mg; P<0.01) in cultured E0771 cells, compared to the control, respectively. EGCG caused a dose-related inhibition on the proliferation and migration in cultured E0771 cells. EGCG also caused a dose-related inhibition on the proliferation in cultured MCF-7 and MDA-MB-231 cells. Discussion: These findings support the hypothesis that EGCG, a green tea antioxidant, directly targets both tumor cells and tumor vasculature, thereby inhibiting tumor growth, proliferation, migration, and angiogenesis of breast cancer, which is mediated by the inhibition of HIF-1α and NFκB activation as well as VEGF expression. Interestingly, oral EGCG treatment has no effects on the body weight, heart weight, angiogenesis and VEGF expression in the heart and skeletal muscle of mice. This work will have important implications for translating EGCG therapy to human breast cancer treatment and prevention. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-17-07.
In response to the increased popularity and greater demand for medicinal plants, a number of conservation groups are recommending that wild medicinal plants be brought into cultivation. Green Tea is one of the most ancient and popular therapeutic beverages consumed around the world. This product is made from the leaf of the plant called "Camellia sinensis". It can be prepared as a drink, which can have many systemic health effects or an "extract" can be made from the leaves to use as medicine. Green tea is reported to contain thousands of bioactive ingredients which are almost contributed by polyphenols which plays a key role in prevention and treatment of many diseases. The aim of this literature review was to illustrate therapeutic properties of the plant "Green tea".
Catechins are the main ingredients of green tea extracts and have been shown to possess versatile biological activities, including antimicrobial. We determined that the catechins inhibit bacterial DNA gyrase by binding to the ATP binding site of the gyrase B subunit. In the group of four tested catechins, epigallocatechin gallate (EGCG) had the highest activity, followed by epicatechin gallate (ECG) and epigallocatechin (EGC). Specific binding to the N-terminal 24 kDa fragment of gyrase B was determined by fluorescence spectroscopy and confirmed using heteronuclear two-dimensional NMR spectroscopy of the EGCG-15N-labeled gyrase B fragment complex. Protein residues affected by binding to EGCG were identified through chemical shift perturbation. Molecular docking calculations suggest that the benzopyran ring of EGCG penetrates deeply into the active site while the galloyl moiety anchors it to the cleft through interactions with its hydroxyl groups, which explains the higher activity of EGCG and ECG.
Polyphenols are secondary metabolites produced by tea plant, which play multiple essential roles in plant physiology and have potential health properties on human health, mainly as antioxidants, anti-allergic, anti-inflammatory, anticancer, antihypertensive and antimicrobial agents. Microbial resistance has become an increasing global problem; there is a need to find out novel potent antimicrobial agents with alternative modes of action as accessories to antibiotic therapy. This study investigated the antimicrobial, synergistic and antioxidant properties of tea polyphenols. The synergistic effect of tea polyphenols in combination with conventional antimicrobial agents against clinical multidrug-resistant microorganisms has been investigated and valuable data generated on the potential synergistic properties of tea polyphenols.