• Journal of the Korean Chemical Society
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• v.42 no.4
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• pp.411-415
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• 1998

In the present study, we were evaluated cytotoxic effects of epigallocatechin gallate in human skin melanoma cells such as HTB-69. The light microscopic study showed morphological changes of the treated cells. Disruptions in cell organelles were determined by colorimetric methods; 3-(4,5-dimethyl thiazol-2-yl)-2,5diphenyl-2H-tetrazolium bromide (MTT) assay, neutral red (NR) assay and sulforhodamine B protein (SRB) assay. These results suggest that epigallocatechin gallate retains a potential antitumor activity.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.10
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• pp.4199-4202
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• 2015

Background: Hepatitis B virus infection is one of the major world health problems. Epigallocatechin-3 gallate is the major component of the polyphenolic fraction of green tea and it has an anti-viral, anti-mutagenic, anti-tumorigenic, anti-angiogenic, anti-proliferative, and/or pro-apoptotic effects on mammalian cells. In this study, our aim was to investigate the inhibition of HBV replication by epigallocatechin-3 gallate in the Hep3B2.1-7 hepatocellular carcinoma cell line. Materials and Methods: HBV-replicating Hep3B2.1-7 cells were used to investigate the preventive effects of epigallocatechin-3 gallate on HBV DNA replication. The expression levels of HBsAg and HBeAg were determined using ELISA. Quantitative real-time-PCR was applied for the determination of the expression level of HBV DNA. Results: Cytotoxicity of epigallocathechin-3-gallate was not observed in the hepatic carcinoma cell line when the dose was lower than $100{\mu}M$. The ELISA method demonstrated that epigallocatechin-3 gallate have strong effects on HBsAg and HBeAg levels. Also it was detected by real-time PCR that epigallocatechin-3 gallate could prevent HBV DNA replication. Conclusions: The obtained data pointed out that although the exact mechanism of HBV DNA replication and related diseases remains unclear, epigallocatechin-3 gallate has a potential as an effective anti-HBV agent with low toxicity.

• KSBB Journal
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• v.14 no.5
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• pp.517-522
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• 1999

A green tea used in this experiment was cultivated at Bosung (Chonnam) and purchased from a domestic market. The extract at 5$0^{\circ}C$ water from the powder of green tea partitioned with chloroform and ethyl acetate. The resulting solution was further purified with a chromatographic column (4.6$\times$250 mm, 15${\mu}{\textrm}{m}$, Lichrospher 100RP-18). Finally separation was achieved on a $\mu$-Bondapak $C_18$(3.9$\times$300mm, 10${\mu}{\textrm}{m}$) column. The elution order of the catechin compounds contained in the green tea was EGC(Epigallocatechin, C(catechin), EC(Epicatechin), EGCG(Epigallocatechin Gallate) and ECG(Epicatechin Gallate). From the experimental results the mobile phase for isolating EGCG from the extract consisted of 0.1% acetic acid in water/acetonitrile, 87/13%(v/v). The flow rate of mobile phase was 1.0 $m\ell$/min, and UV wavelength was fixed at 280 nm. 121.3 mg of EGCG, higher than 98% of purity, was obtained from 5 g of dry green tea.

• Nutritional Sciences
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• v.9 no.3
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• pp.145-151
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• 2006

Matrix metalloproteinases (MMP) play an important role in the extracellular matrix (ECM) degradation undetphysiological and pathological conditions. The present study examined the influence of (-)epigallocatechin gallate and quercetin on phorbol-12-myristate 13-acetate (PMA)-induced secretion of MMP-2 and MMP-9, when human umbilical vein endothelial cells (HUVEC) were treated with (-)epigallocatechin gallate and quercetin at supraphysiological concentrations of $25{\mu}mol/L$. No cytotoxicity was observed by MIT assay in response to a treatment with PMA in the presence of (-)epigallocatechin gallate and quercetin. Western blot analysis and gelatin zymography revealed that exposure of HUVEC to PMA enhanced the levels and gelatinolytic activities of pro and active forms of MMP-2 and active form of MMP-9. (-)Epigallocatechin gallate attenuated PMA-stimulated secretion of active forms of MMP-2 and MMP-9 concomitantly with a loss of activities of these enzymes, which was related to the decreased mRNA levels of MMP. Quercetin was more potent than (-)epigallocatechin gallate in alleviating MMP-9 protein secretion and activity with a decrease in MMP-9 mRNA accumulation. Taken together, the results indicated that (-)epigallocatechin gallte and quercetin exhibited inhibitory effects on MMP activity and may qualify as chemopreventive and cardiovascular protective agents.

• Applied Biological Chemistry
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• v.36 no.5
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• pp.326-331
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• 1993

Three antioxidants were isolated: (-)-epigallocatechin and (-)-epigallo catechin gallate from Theae Folium generally called green tea, and gallic acid from Moutan Cortex. They inhibited $Fe^{3+}-ADP/ascorbate-induced$ lipid peroxidation in rat liver microsomal fraction, showing $IC_{50}$, the concentration of antioxidants which is required to inhibit 50% of the peroxidation for microsomal membranes at 1 mg protein/ml, to be $0.2\;{\mu}g/ml$, $0.4\;{\mu}g/ml$ and $2.5\;{\mu}g/ml$, respectively.

• Preventive Nutrition and Food Science
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• v.12 no.3
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• pp.135-140
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• 2007

Antibacterial activities of the major phenolic components from Camellia sinensis L. were investigated against several pathogenic microorganisms including Gram-positive strains like Staphylococcus aureus ATCC 29213 and Streptococcus pyogens 308A; and Gram-negative strains like Escherichia coli ATCC 25922, Escherichia coli 078, Pseudomonas aeruginosa 9027, and Enterobacter cloacae 1321E. The MIC values demonstrate that both (-)-epicatechin and (-)-epigallocatechin were more considerably toxic against Staphylococcus aureus ATCC 29213 than the other two catechins like (-)-epicatechingallate and (-)-epigallocatechin-3-gallate. (-)-Epicatechingallate and (-)-epigallocatechin-3-gallate were most inhibitory against Escherichia coli ATCC 25922. As a result, (-)-epicatechin showed predominant antibacterial activities among tea varieties. The contents of major polyphenolic components such as four catechins, theaflavin, and quercetin were different according to fermentation processes. The total contents of four catechins were ranged from 13.81 to 1.33%, with (-)-epigallocatechin-3-gallate being dominant among tea varieties; theaflavin was found the characteristic pigment in fully-fermented black tea.

• Food Science and Biotechnology
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• v.16 no.1
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• pp.167-170
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• 2007

(-)-Epigallocatechin-3-gallate (EGCG), a mai or tea catechin has been shown to have many interesting biological activities. In the present study, we studied the effects of green tea catechins, EGCG metabolites, and black tea theaflavins on accumulation of EGCG in HT-29 human colon cells. Intracellular levels of [$^3H$]-EGCG were not changed significantly in the presence of other tea catechins including (-)-epicatechin, (-)-epigallocatechin, and (-)-epicatechin-3-gallate. EGCG methyl metabolites and EGCG 4"-glucuronide did not affect cellular levels of [$^3H$]-EGCG. Black tea theaflavins and theasinensin A (TsA), an EGCG oxidative dimer, however, significantly decreased cellular accumulation of EGCG in HT-29 cells by 31-56%. This decrease was more pronounced when cells were incubated in the presence of theaflavin-3',3"-digallate (TFdiG) or TsA. When EGCG was added separately from TFdiG or TsA, the accumulation of EGCG in HT-29 cells was also significantly decreased regardless of when TFdiG or TsA was added during the uptake study (p<0.01). The results suggest that theaflavins and TsA may interrupt EGCG absorption through the gastrointestinal epithelium.

• Journal of Nutrition and Health
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• v.36 no.4
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• pp.382-388
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• 2003

(-)-Epigallocatechin-3-gallate (EGCG) is a polyphenolic compound found in peen tea leaves, and has been known to be one of the most potent catechin species which inhibits cell growth most possibly through an apoptotic cell death. We investigated the apoptotic activity of (-)-EGCG on the human myeloid leukemia cell line, HL-60. Our results of MTT test indicated that (-)-EGCG had a significant antiproliferation effect in HL-60 cells with $IC_{50}$/ (50% inhibition concentration) value of 65 $\mu$M. Giemsa statining of HL-60 cells treated with (-)-EGCG (100 $\mu$M) for 6hrs showed a typical apoptosis-specific morphological change including shrinkage of the cytoplasm, membrane blobbing and compaction of the nuclear chromatin. The DNA fragmentation was observed from the agarose gel electrophoresis of cells treated with (-)-EGCG for 3hrs or longer, and was progressed to a greater degree as treatment time increases. Treatment of the cells with (-)-EGCG (100 $\mu$M) resulted in a rapid release of mitochondrial cytochrome c into the cytosol, and a subsequent cleavage of caspase-3 to an active form in a treatment-time dependent manner. (-)-EGCG (100 $\mu$M) also stimulated proteolytic cleavage of poly-(ADP-ribose) polymerase (PARP) to an active form in HL-60 cells. Tlken together, (-)-EGCG appears to induce the apoptosis in human myeloid leukemia cells via a caspase-dependent pathway. These results suggest the possible application of (-)-EGCG, the major active compound in green tea, as an antiproliferative agent for cancer prevention.

• Journal of Food Hygiene and Safety
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• v.17 no.3
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• pp.117-123
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• 2002

The five main green tea catechin components such as (+)-catechin, (-)-epicatechin, (-)-epigallocatechin, (-)-epicatechin gallate, and (-)-epigallocatechin gallate were analyzed quantitatively from commercial green tea by HPLC. Amounts of catechins decreased in the following order : (+)-catechin > (-)-epigallocatechin gallate >(-)-epigallocatechin >(-)-epicatechin >(-)-epicatechin gallate. In this study, the stability of the following green tea catechins to pH in the range from 3 to 11 was studied using of ultraviolet spectroscopy : (+)-catechin, (-)-epicatechin, (-)-epicatechin gallate, and (-)-epigallocatechin gallate. This study demonstrated that green tea catechins were not stable at high pH and that the pH-, and time-dependent spectral alternatives were not reversible In conclusion, low pH is important to maintain the efficient utilization of green tea catechins.

• Environmental Mutagens and Carcinogens
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• v.18 no.2
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• pp.98-103
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• 1998

Epigallocatechin gallate (EGCG) was reported to exert weak cytotoxicity against normal healthy cells such as C3H10T1/2 cells, but profound inhibitory effects on the initiation or promotion stage of chemical carcinogenesis in mammary gland, blood and mouse skin. This study was carried out to develop antitumor agents with weak side effects and strong antitumor activity. Human skin melanoma cells (HBT 69) and human oral epitheloid carcinoma cells (OCL 17) were cultured in RPMI-1640 media containing 10% fetal bovine serum, antibiotic, and fungizone. After incubation for 24 hrs, the cells were treated with various amounts of (EGCG) for 48 hrs. The growth inhibitory effects of EGCG in human oral epitheloid carcinoma cells were evaluated by the 3- (4,5-djmethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT), neutral red (NR), and sulforhodamine B protein (SRB) assays of colorimetric methods. The light microscopic study was also carried out to observe morphological changes of the treated cells. These results obtained were as follows; 1. Significantly inhibitory effects of EGCG against cultured human oral epithelioid carcinoma cells. 2. Significantly inhibitory effects against cultured human skin melanoma cells treated with 50 $\mu$M EGCG, but decreased inhibitory effects in 100 $\mu$M EGCG. 3. Degenerative changes against cultured human oral epitheloid carcinoma cells. 4. Degenerative changes against human skin melanoma cells treated with 50 UM EGCG, but recovered degenerative changes in 100 $\mu$M EGCG.