| EGCG Health Benefits and Side Effects |
The compound (-)-epigallocatechin-3-gallate (EGCG) is the major catechin
found in green tea [Camellia sinensis L. Ktze. (Theaceae)]. This
polyphenolic compound and several related catechins are believed to be
responsible for the health benefits associated with the consumption of
green tea. Increasing evidence has suggested that EGCG exhibits
anti-inflammatory, anti-oxidant and immunosuppressive effects. [4] The
potential health benefits ascribed to green tea and EGCG include
antioxidant effects, cancer chemoprevention, improving cardiovascular
health, enhancing weight loss, protecting the skin from the damage caused
by ionizing radiation, and others. [6] Nagle DG at The University of
Mississippi pointed out that a few well-designed double-blinded controlled
clinical studies demonstrated the efficacy of green tea extracts and purified
EGCG products in patients. [6]
What are the recent scientific suggestions for health
benefits of (-)-epigallocatechin-3-gallate (EGCG)?
EGCG MAY BENEFIT BONE HEALTH
Researchers from University of Toronto proposed the benefits of
epigallocatechin-3-gallate (EGCG)on bone health. In the study,
epigallocatechin-3-gallate (EGCG)at concentrations of 1-5 muM caused a
dose-dependent increase in the number and area of mineralized bone
nodules. [1]
EGCG MAY HAVE BENEFITS IN DIABETES
Researchers from University of Dundee, Scotland commented the
insulin-like glucose-lowering properties of epigallocatechin gallate (EGCG)
in mammals. EGCG is known to act at least in part by repression of
gluconeogenic genes such as phosphoenolpyruvate carboxykinase. Their
study shows EGCG exerts its insulin mimetic effects at least in part by
phosphorylation of the FOXOs through a mechanism that is similar but not
identical to insulin and IGF-1 induced FOXO phosphorylation.
Researchers from other group administrated rats with subtotal nephrectomy
plus streptozotocin injection with(-)-epigallocatechin 3-O-gallate (ECGG).
After a 50-day administration period, EGCG treated groups showed
suppressed hyperglycemia, proteinuria, and lipid peroxidation, though there
were only weak effects on the levels of serum creatinine and glycosylated
protein. These results suggest that EGCG ameliorates glucose toxicity and
renal injury, thus alleviating renal damage caused by abnormal glucose
metabolism-associated oxidative stress involved in renal lesions of diabetic
nephropathy. [8]
EGCG MAY HAVE BENEFITS IN CANCER
Green tea and its major constituent epigallocatechin gallate (EGCG) have
been extensively studied as a potential treatment for various cancers.
Epidemiological data have suggested that EGCG may provide protective
effects against hormone related cancers, namely breast or prostate cancer.
Extensive in vitro investigations using both hormone responsive and
non-responsive cell lines have shown that EGCG induces apoptosis and
alters the expression of cell cycle regulatory proteins that are critical for cell
survival and apoptosis. [3]
In a study, pretreatment of HEY and OVCA 433 ovarian carcinoma cell lines
with green tea and EGCG inhibited endothelin-1/ET(A)R expression,
endothelin(A)R-mediated COX-1/2 mRNA expression, and COX-2 promoter
activity. These effects were associated with a significant reduction in the
COX-1/2-derived prostaglandin E2 (PGE2) production. Thus, EGCG may
have benefits in ovarian carcinoma. [12]
Later, Spinella F and co-workers further suggested that EGCG inhibited
ovarian cancer cell growth and induced apoptosis that was associated with
a decrease in Bcl-X(L) expression and activation of caspase-3. Treatment
with green tea or EGCG inhibited endothelin A receptor
(ET(A)R)/endothelin-1 (ET-1) expression and reduced the basal and
endothelin-1-induced cell proliferation and invasion. [10]
Tan M and co-workers at University of Mississippi proposed the direct
administration of EGCG alone or in combination with thymoquinone can limit
PANC-1 cell proliferation in their in vitro studies. [10]
Researchers from Harvard Medical School evaluated the potential health
benefits of (-)- epigallocatechin-3-gallate (EGCG) in multiple myeloma
(MM). Basically, they found that EGCG induced both dose- and time-
dependent growth arrest and subsequent apoptotic cell death in multiple
myeloma cell lines including IL-6 dependent cells and primary patient cells;
without significant effect on the growth of peripheral blood mononuclear
cells (PBMC) and normal fibroblasts. [11]
EGCG MAY HAVE BENEFITS IN INFLAMMATIONS
HEPATITIS
Researchers pretreated mice with (-)-Epigallocatechin-3-gallate (EGCG)
before concanavalin A injection, and then measured alanine
aminotransferase (ALT) levels in plasma, inflammatory infiltration and
hepatocyte apoptosis in liver. They found that mice pretreated with EGCG
exhibited much less increased ALT levels in plasma, reduced inflammatory
infiltration and hepatocyte apoptosis in liver compared with control mice
pretreated with vehicle solutions.[4]
ARTHRITIS
Ahmed S and colleagues at University of Michigan Medical School found
that EGCG was nontoxic to RA synovial fibroblasts and treatment with
EGCG may be of potential benefits in inhibiting joint destruction in
rheumatoid arthritis. [6]
EGCG MAY HAVE BENEFITS IN NEURONAL DISORDER
Huntington's disease is a progressive neurodegenerative disorder for which
only symptomatic treatments of limited effectiveness are available.
Preventing early misfolding steps and thereby aggregation of the
polyglutamine (polyQ)-containing protein huntingtin (htt) in neurons of
patients may represent an attractive therapeutic strategy to postpone the
onset and progression of such disease. Here, researchers demonstrated
that polyphenol (-)-epigallocatechin-3-gallate (EGCG) potently inhibits the
aggregation of mutant htt exon 1 protein in a dose-dependent manner. [5]
EGCG MAY HAVE BENEFITS IN ANXIETY
Vignes M and co-workers at University of Montpellier II, France observed
that (-)-epigallocatechin gallate (EGCG) reversed GABA(A) receptor
negative modulator methyl beta-carboline-3-carboxylate (beta-CCM)
inhibition on GABA currents in a concentration dependent manner.
Behavioral tests in mice indicated that EGCG exerted both anxiolytic and
amnesic effects just like the benzodiazepine drug, chlordiazepoxide. [7]
EGCG MAY HAVE BENEFITS IN FUNGAL DISEASES
Japanese compared the antifungal activities of epigallocatechin 3-O-gallate
(EGCG)with six antifungal agents, amphotericin B (AMPH), fluconazole
(FLCZ), flucytosin (5FC), itraconazole (ITCZ), micafungin (MCFG), and
miconazole (MCZ)and concluded that EGCG has a comparable antifungal
actvities on some strains than some of these antifugal agents. [9]
Are there any side effects or interactions of EGCG?
Green tea is generally free of side effects. However, large amounts of
green tea consumption may lead to insomnia, anxiety, and other symptoms
caused by the caffeine content. It may also inhibit iron absorption.
On September 18, 2006, I found more than 500 scientific articles related to
the health benefits of epigallocatechin gallate. I summarized only a few
interesting of the most recent articles to demonstrate its potential health
benefits. Moreover, most of the studies are either in animals or in vitro.
THIS ARTICLE IS FOR YOUR INFORMATION ONLY. YOU SHOULD CONSULT WITH YOUR DOCTOR
IF YOU HAVE ANY QUESTIONS. ALL RIGHTS RESERVED 2006 ZHION.
References [1] Vali B, et al, Epigallocatechin-3-gallate increases the formation of mineralized bone
nodules by human osteoblast-like cells. J Nutr Biochem. 2006 Sep 7[2] Anton S,et al,
Epigallocatechin gallate (EGCG) mimics insulin action on the transcription factor FOXO1a and
elicits cellular responses in the presence and absence of insulin.Cell Signal. 2006 Jul 25[3] Stuart
EC et al, Role of epigallocatechin gallate (EGCG) in the treatment of breast and prostate cancer.Life
Sci. 2006 Aug 5 [4] Wang Y et al, (-)-Epigallocatechin-3-gallate protects mice from concanavalin
A-induced hepatitis through suppressing immune-mediated liver injury.Clin Exp Immunol. 2006
Sep;145(3):485-92.[5] Ehrnhoefer DE, et al, Green tea (-)-epigallocatechin-gallate modulates early
events in huntingtin misfolding and reduces toxicity in Huntington's disease models.Hum Mol Genet.
2006 Sep 15;15(18):2743-51. Epub 2006 Aug 7.[6] Nagle DG et al, Epigallocatechin-3-gallate
(EGCG): Chemical and biomedical perspectives.Phytochemistry. 2006 Sep;67(17):1849-55. Epub
2006 Jul 31. [6] Ahmed S et al, Regulation of interleukin-1beta-induced chemokine production and
matrix metalloproteinase 2 activation by epigallocatechin-3-gallate in rheumatoid arthritis synovial
fibroblasts.Arthritis Rheum. 2006 Aug;54(8):2393-401. [7] Vignes M et al, Anxiolytic properties of
green tea polyphenol (-)-epigallocatechin gallate (EGCG). Brain Res. 2006 Jul 19. [8] Yamabe N, et
al, Therapeutic Potential of (-)-Epigallocatechin 3-O-gallate on Renal Damage in Diabetic
Nephropathy Model Rats.J Pharmacol Exp Ther. 2006 Jul 11. [9] Park BJ, et al, Antifungal
susceptibility of epigallocatechin 3-O-gallate (EGCg) on clinical isolates of pathogenic
yeasts.Biochem Biophys Res Commun. 2006 Aug 25;347(2):401-5. Epub 2006 Jun 15.[10] Spinella F
et al, Green tea polyphenol epigallocatechin-3-gallate inhibits the endothelin axis and downstream
signaling pathways in ovarian carcinoma.Mol Cancer Ther. 2006 Jun;5(6):1483-92.[10] Tan M, et al,
Effects of (-)epigallocatechin gallate and thymoquinone on proliferation of a PANC-1 cell line in
culture.Biomed Sci Instrum. 2006;42:363-71. [11] Shammas MA, et al, Specific killing of multiple
myeloma cells by (-)- epigallocatechin-3-gallate extracted from green tea: biological activity and
therapeutic implications.Blood. 2006 Jun 29. [12]Spinella F, et al, Antitumor effect of green tea
polyphenol epigallocatechin-3-gallate in ovarian carcinoma cells: evidence for the endothelin-1 as
a potential target.Exp Biol Med (Maywood). 2006 Jun;231(6):1123-7.
found in green tea [Camellia sinensis L. Ktze. (Theaceae)]. This
polyphenolic compound and several related catechins are believed to be
responsible for the health benefits associated with the consumption of
green tea. Increasing evidence has suggested that EGCG exhibits
anti-inflammatory, anti-oxidant and immunosuppressive effects. [4] The
potential health benefits ascribed to green tea and EGCG include
antioxidant effects, cancer chemoprevention, improving cardiovascular
health, enhancing weight loss, protecting the skin from the damage caused
by ionizing radiation, and others. [6] Nagle DG at The University of
Mississippi pointed out that a few well-designed double-blinded controlled
clinical studies demonstrated the efficacy of green tea extracts and purified
EGCG products in patients. [6]
What are the recent scientific suggestions for health
benefits of (-)-epigallocatechin-3-gallate (EGCG)?
EGCG MAY BENEFIT BONE HEALTH
Researchers from University of Toronto proposed the benefits of
epigallocatechin-3-gallate (EGCG)on bone health. In the study,
epigallocatechin-3-gallate (EGCG)at concentrations of 1-5 muM caused a
dose-dependent increase in the number and area of mineralized bone
nodules. [1]
EGCG MAY HAVE BENEFITS IN DIABETES
Researchers from University of Dundee, Scotland commented the
insulin-like glucose-lowering properties of epigallocatechin gallate (EGCG)
in mammals. EGCG is known to act at least in part by repression of
gluconeogenic genes such as phosphoenolpyruvate carboxykinase. Their
study shows EGCG exerts its insulin mimetic effects at least in part by
phosphorylation of the FOXOs through a mechanism that is similar but not
identical to insulin and IGF-1 induced FOXO phosphorylation.
Researchers from other group administrated rats with subtotal nephrectomy
plus streptozotocin injection with(-)-epigallocatechin 3-O-gallate (ECGG).
After a 50-day administration period, EGCG treated groups showed
suppressed hyperglycemia, proteinuria, and lipid peroxidation, though there
were only weak effects on the levels of serum creatinine and glycosylated
protein. These results suggest that EGCG ameliorates glucose toxicity and
renal injury, thus alleviating renal damage caused by abnormal glucose
metabolism-associated oxidative stress involved in renal lesions of diabetic
nephropathy. [8]
EGCG MAY HAVE BENEFITS IN CANCER
Green tea and its major constituent epigallocatechin gallate (EGCG) have
been extensively studied as a potential treatment for various cancers.
Epidemiological data have suggested that EGCG may provide protective
effects against hormone related cancers, namely breast or prostate cancer.
Extensive in vitro investigations using both hormone responsive and
non-responsive cell lines have shown that EGCG induces apoptosis and
alters the expression of cell cycle regulatory proteins that are critical for cell
survival and apoptosis. [3]
In a study, pretreatment of HEY and OVCA 433 ovarian carcinoma cell lines
with green tea and EGCG inhibited endothelin-1/ET(A)R expression,
endothelin(A)R-mediated COX-1/2 mRNA expression, and COX-2 promoter
activity. These effects were associated with a significant reduction in the
COX-1/2-derived prostaglandin E2 (PGE2) production. Thus, EGCG may
have benefits in ovarian carcinoma. [12]
Later, Spinella F and co-workers further suggested that EGCG inhibited
ovarian cancer cell growth and induced apoptosis that was associated with
a decrease in Bcl-X(L) expression and activation of caspase-3. Treatment
with green tea or EGCG inhibited endothelin A receptor
(ET(A)R)/endothelin-1 (ET-1) expression and reduced the basal and
endothelin-1-induced cell proliferation and invasion. [10]
Tan M and co-workers at University of Mississippi proposed the direct
administration of EGCG alone or in combination with thymoquinone can limit
PANC-1 cell proliferation in their in vitro studies. [10]
Researchers from Harvard Medical School evaluated the potential health
benefits of (-)- epigallocatechin-3-gallate (EGCG) in multiple myeloma
(MM). Basically, they found that EGCG induced both dose- and time-
dependent growth arrest and subsequent apoptotic cell death in multiple
myeloma cell lines including IL-6 dependent cells and primary patient cells;
without significant effect on the growth of peripheral blood mononuclear
cells (PBMC) and normal fibroblasts. [11]
EGCG MAY HAVE BENEFITS IN INFLAMMATIONS
HEPATITIS
Researchers pretreated mice with (-)-Epigallocatechin-3-gallate (EGCG)
before concanavalin A injection, and then measured alanine
aminotransferase (ALT) levels in plasma, inflammatory infiltration and
hepatocyte apoptosis in liver. They found that mice pretreated with EGCG
exhibited much less increased ALT levels in plasma, reduced inflammatory
infiltration and hepatocyte apoptosis in liver compared with control mice
pretreated with vehicle solutions.[4]
ARTHRITIS
Ahmed S and colleagues at University of Michigan Medical School found
that EGCG was nontoxic to RA synovial fibroblasts and treatment with
EGCG may be of potential benefits in inhibiting joint destruction in
rheumatoid arthritis. [6]
EGCG MAY HAVE BENEFITS IN NEURONAL DISORDER
Huntington's disease is a progressive neurodegenerative disorder for which
only symptomatic treatments of limited effectiveness are available.
Preventing early misfolding steps and thereby aggregation of the
polyglutamine (polyQ)-containing protein huntingtin (htt) in neurons of
patients may represent an attractive therapeutic strategy to postpone the
onset and progression of such disease. Here, researchers demonstrated
that polyphenol (-)-epigallocatechin-3-gallate (EGCG) potently inhibits the
aggregation of mutant htt exon 1 protein in a dose-dependent manner. [5]
EGCG MAY HAVE BENEFITS IN ANXIETY
Vignes M and co-workers at University of Montpellier II, France observed
that (-)-epigallocatechin gallate (EGCG) reversed GABA(A) receptor
negative modulator methyl beta-carboline-3-carboxylate (beta-CCM)
inhibition on GABA currents in a concentration dependent manner.
Behavioral tests in mice indicated that EGCG exerted both anxiolytic and
amnesic effects just like the benzodiazepine drug, chlordiazepoxide. [7]
EGCG MAY HAVE BENEFITS IN FUNGAL DISEASES
Japanese compared the antifungal activities of epigallocatechin 3-O-gallate
(EGCG)with six antifungal agents, amphotericin B (AMPH), fluconazole
(FLCZ), flucytosin (5FC), itraconazole (ITCZ), micafungin (MCFG), and
miconazole (MCZ)and concluded that EGCG has a comparable antifungal
actvities on some strains than some of these antifugal agents. [9]
Are there any side effects or interactions of EGCG?
Green tea is generally free of side effects. However, large amounts of
green tea consumption may lead to insomnia, anxiety, and other symptoms
caused by the caffeine content. It may also inhibit iron absorption.
On September 18, 2006, I found more than 500 scientific articles related to
the health benefits of epigallocatechin gallate. I summarized only a few
interesting of the most recent articles to demonstrate its potential health
benefits. Moreover, most of the studies are either in animals or in vitro.
THIS ARTICLE IS FOR YOUR INFORMATION ONLY. YOU SHOULD CONSULT WITH YOUR DOCTOR
IF YOU HAVE ANY QUESTIONS. ALL RIGHTS RESERVED 2006 ZHION.
References [1] Vali B, et al, Epigallocatechin-3-gallate increases the formation of mineralized bone
nodules by human osteoblast-like cells. J Nutr Biochem. 2006 Sep 7[2] Anton S,et al,
Epigallocatechin gallate (EGCG) mimics insulin action on the transcription factor FOXO1a and
elicits cellular responses in the presence and absence of insulin.Cell Signal. 2006 Jul 25[3] Stuart
EC et al, Role of epigallocatechin gallate (EGCG) in the treatment of breast and prostate cancer.Life
Sci. 2006 Aug 5 [4] Wang Y et al, (-)-Epigallocatechin-3-gallate protects mice from concanavalin
A-induced hepatitis through suppressing immune-mediated liver injury.Clin Exp Immunol. 2006
Sep;145(3):485-92.[5] Ehrnhoefer DE, et al, Green tea (-)-epigallocatechin-gallate modulates early
events in huntingtin misfolding and reduces toxicity in Huntington's disease models.Hum Mol Genet.
2006 Sep 15;15(18):2743-51. Epub 2006 Aug 7.[6] Nagle DG et al, Epigallocatechin-3-gallate
(EGCG): Chemical and biomedical perspectives.Phytochemistry. 2006 Sep;67(17):1849-55. Epub
2006 Jul 31. [6] Ahmed S et al, Regulation of interleukin-1beta-induced chemokine production and
matrix metalloproteinase 2 activation by epigallocatechin-3-gallate in rheumatoid arthritis synovial
fibroblasts.Arthritis Rheum. 2006 Aug;54(8):2393-401. [7] Vignes M et al, Anxiolytic properties of
green tea polyphenol (-)-epigallocatechin gallate (EGCG). Brain Res. 2006 Jul 19. [8] Yamabe N, et
al, Therapeutic Potential of (-)-Epigallocatechin 3-O-gallate on Renal Damage in Diabetic
Nephropathy Model Rats.J Pharmacol Exp Ther. 2006 Jul 11. [9] Park BJ, et al, Antifungal
susceptibility of epigallocatechin 3-O-gallate (EGCg) on clinical isolates of pathogenic
yeasts.Biochem Biophys Res Commun. 2006 Aug 25;347(2):401-5. Epub 2006 Jun 15.[10] Spinella F
et al, Green tea polyphenol epigallocatechin-3-gallate inhibits the endothelin axis and downstream
signaling pathways in ovarian carcinoma.Mol Cancer Ther. 2006 Jun;5(6):1483-92.[10] Tan M, et al,
Effects of (-)epigallocatechin gallate and thymoquinone on proliferation of a PANC-1 cell line in
culture.Biomed Sci Instrum. 2006;42:363-71. [11] Shammas MA, et al, Specific killing of multiple
myeloma cells by (-)- epigallocatechin-3-gallate extracted from green tea: biological activity and
therapeutic implications.Blood. 2006 Jun 29. [12]Spinella F, et al, Antitumor effect of green tea
polyphenol epigallocatechin-3-gallate in ovarian carcinoma cells: evidence for the endothelin-1 as
a potential target.Exp Biol Med (Maywood). 2006 Jun;231(6):1123-7.
