• KSBB Journal
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• 제14권5호
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• pp.517-522
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• 1999

실험에 사용된 녹차는 전남 보성에서 재배된 것으로 국내시장에서 구입하였다. 녹차 5g을 순수한 물 5$0^{\circ}C$에서 추출한 후 클로로포름과 에틸아세테이트로 분배하였다. 추출액을 크로마토그래픽 컬럼 (4.6$\times$250 mm, 15$\mu\textrm{m}$, Lichrospher 100RP-18)을 이용하여 정제하였다. 정제된 추출액으로부터 $\mu$-Bondapak $C_18$(3.9$\times$300mm, 10$\mu\textrm{m}$) 컬럼을 이용하여 녹차에 포함된 카테킨 화합물을 분리하였으며, EGC(Epigallocatechin, C(catechin), EC(Epicatechin), EGCG(Epigallocatechin Gallate) and ECG(Epicatechin Gallate)의 순으로 용출되었다. 본 연구의 결과로서는 목적물질인 EGCG를 분리하기 위해 이동상의 조성은 0.1%의 아세트산이 포함된 물/아세토나이트릴, 87/13 %(v/v)이었다. 유량은 1.0 $m\ell$/min, UV 검지기는 280nm로 고정하였다. 위의 실험조건으로 5g의 전남 보성산 녹차로부터 순도 98% 이상의 121.3mg EGCG를 얻을 수 있었다.

• Food Science and Biotechnology
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• 제16권1호
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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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• 제36권4호
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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.

• 한국환경성돌연변이발암원학회지
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• 제18권2호
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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.

• 한국식품영양학회지
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• 제25권4호
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• pp.855-862
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• 2012

Resveratrol (RVT) and epigallocatechin gallate (EGCG) individually inhibit adipogenesis in 3T3-L1 adipocytes. The objective was to examine the possibility of interaction between RVT and EGCG, resulting in enhanced inhibition of adipogenesis in 3T3-L1 adipocytes. Preadipocytes were treated with RVT and EGCG individually at 6.25 or $25{\mu}M$ (RVT6.25 or RVT25) and 12.5 or $50{\mu}M$ (EGCG12.5 or EGCG50) and in combination (RVT6.25 + EGCG12.5 and RVT25 + EGCG50). RVT25 as an individual compound decreased lipid accumulation in 3T3-L1 adipocytes by 24%, and RVT25 + EGCG50 further decreased lipid accumulation by 77%. In addition, exposure of 3T3-L1 adipocytes to RVT6.25 + EGCG12.5 and RVT25 + EGCG50 combinations resulted in an enhanced increase of adiponectin release and inhibition of leptin release. Quantitative analysis revealed that the combination of tested materials (RVT6.25 + EGCG12.5 and RVT25 + EGCG50) decreased the expression levels of C/EBP${\alpha}$, PPAR${\gamma}2$, and aP2. These results indicate that the combined treatments with RVT and EGCG produce synergistic effects on inhibiting adipogenesis in 3T3-L1 adipocytes. The overall results suggested that the combining RVT and EGCG might be more capable of exerting antiobesity effects than each individual compound by itself.

• Journal of Pharmaceutical Investigation
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• 제29권3호
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• pp.179-184
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• 1999

Phannacokinetics of epigallocatechin gallate(EGCG) was studied following i.v. bolus and oral administration in rats. The values of systemic clearance(CL) were $67.9{\pm}5.2$ and $26.5{\pm}1.4\;ml/min/kg$ following i.v. bolus administration of 1 mg and 5 mg EGCG, respectively. The values of volume of distribution at steady state (Vss) were $380{\pm}56$ and $835{\pm}84\;ml/kg$ after i.v. bolus administration of 1 mg and 5 mg EGCG, respectively. The decrease in the value of CL and the increase in the value of $V_{ss}$ as a function of EGCG dose (1 mg to 5 mg) suggest saturable mechanism(s) responsible for the distribution and elimination of EGCG. The fraction absorbed of EGCG after oral and intraduodenal administration of GTC were 13% and 22% of the dose, respectively. This result suggests a considerable degradation or elimination of EGCG in the gastrointestinal absorption after oral administration in rats.

• 한국식품영양과학회지
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• 제37권9호
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• pp.1114-1119
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• 2008

ECCG는 녹차 카테킨의 주요 성분으로 항산화작용으로 인한 항암작용이 보고되고 있다. 본 연구는 EGCG가 전이성이 강한 인체 유방암 세포인 MDA-MB-231의 세포사멸에도 영향을 주는지를 알아보고자 하였다. 인체 유방암 세포 배양액에 EGCG를 0, 5, 10, $20\;{\mu}M$로 첨가시켜, 세포사멸과 관련된 단백질들의 단백질과 mRNA 발현, caspase-3 활성을 관찰하였다. EGCG 첨가 농도가 $5\;{\mu}M$ 이상부터 세포사멸을 억제하는 단백질인 bcl-2의 단백질과 mRNA 발현이 감소하였으며, 세포사멸을 유도하는 단백질인 bax의 단백질과 mRNA 발현은 유의적으로 증가하여 결과적으로 EGCG 첨가에 따라 bcl-2/bax의 비율이 유의적으로 감소하였다. 또한 세포사멸의 마지막 단계인 caspase-3의 활성은 EGCG 농도가 증가할수록 유의적으로 증가하였다. 본 연구 결과를 종합해 보면 전이성이 강한 인체 유방암 세포 MDA-MB-231에서 EGCG는 암세포에서 bcl-2의 발현은 억제시키고 bax의 발현은 증가시키며, caspase-3의 활성을 증가시켜 세포사멸을 유도하는 것으로 확인하였다.

• 한국식품영양학회지
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• 제30권5호
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• pp.1035-1041
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• 2017

(-)-Epigallocatechin-3-gallate (EGCG) is a major catechin found in green tea. It is reported that EGCG possesses various health benefits including anti-cancer, antioxidant, anti-diabetes, and anti-obesity. The objective of this study was to investigate the effects of EGCG on adipogenesis via activation of AMP-activated protein kinase (AMPK) pathway in 3T3-L1 preadipocytes. In order to determine the effects of EGCG on adipogenesis, preadipocyte differentiation was induced in the presence or absence of EGCG ($0{\sim}100{\mu}M$) for a period of 6 days. EGCG significantly inhibited fat accumulation and suppressed the expression of adipogenic specific proteins including peroxisome proliferator-activated receptor (PPAR)-${\gamma}$. Also, EGCG markedly increased the activation of AMPK and acetyl-CoA carboxylase (ACC) and the production of intracellular reactive oxygen species (ROS). However, any pretreatment with a specific AMPK inhibitor, compound C, abolished the inhibitory effects of the EGCG on $PPAR{\gamma}$ expression. This study suggests that EGCG has anti-adipogenic effects through modulation of the AMPK signaling pathway and therefore, may be a promising antiobesity agent.

• 생약학회지
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• 제32권4호통권127호
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• pp.280-286
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• 2001

Epigallocathechin-3-gallate (EGCG), the main polyphenol component in green tea, inhibits angiogenesis, urokinase, and matalloproteinases, and EGCG also has the antioxidative property. Recent reports proposed that EGCG may modulate the immune response on allergy or asthma. Human nasal mucosal fibroblasts are a rich source of cytokines, inflammatory mediators, and chemokines. Chemokines are important for the recruitment of leukocytes to sites of infection, which is essential in host defense. The objective of this study was to investigate the effect of EGCG on the expression of the chemokines such as RANTES (regulated upon activation, normal T cell expressed and presumably secreted), eotaxin, and interleukin-8 (IL-8) in human nasal mucosal fibroblasts after stimulation with cytokines like IL-4, tumor necrosis $factor-{\alpha}\;(TNF-{\alpha})$, and $interferon-{\gamma}\;(IFN-{\gamma})$. To detect the expression of chemokine genes, RT-PCR was performed. Expressions of RANTES, eotaxin, and IL-8 mRNA stimulated with IL-4 and $TNF-{\alpha}$ were increased, respectively, while the expression of those genes incubated with $IFN-{\gamma}$ was similar pattern compared to control group. Analyses of chemokine genes of cells pretreated with EGCG showed that the expressions of eotaxin, and IL-8 genes stimulated $IFN-{\gamma}$ were higher compared with those not pretreated with EGCG.

• 한국식품위생안전성학회지
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• 제17권3호
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• pp.117-123
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• 2002

시중에 유통되고 있는 녹차중의 catechin류에 대하여 열수추출 및 HPLC분석을 통하여 함량을 조사하고 이를 효율적으로 이용하기 위하여 pH조건이 녹차 catechin류의 안정성에 미치는 영향에 대하여 분석하였다. 시판 중인 전남 보성산 녹차의 catechin류 함량은 (+)-catechin>(-)-EGCg>(-)-EGC>(-)-EC>(-)-ECg순으로 추출되었고 Total catechin류의 함량은 103.72mg/g이었다. 녹차에서 분리·정제되어진 catechin류인 (+)-catechin, (-)-EC, (-)-ECg, (-)-EGCg를 pH 3∼11에 대한 안정성을 흡광도측정장치를 이용하여 측정하였다. 그 결과 catechin류의 pH에 대한 영향을 최대흡수파장 및 흡광도 변화로 보면 pH가 높을수록 (+)-catechin과 (-)-EC은 흡광도가 증가되었고 (-)-ECg와 (-)-EGCg는 최대흡수파장이 증가되었다. 또한 7일간 실온에서 저장하면서 기간에 따른 변화를 살펴본 결과에서 산성조건에서는 큰 변화가 없지만 알칼리조건에서는 흡광도가 증가되었다. (+)-catechin과 (-)-EC은 알칼리조건에서 흡수파장 400∼430 nm에서 저장기간이 길수록 흡광도가 증가되었다. 이는 녹차의 갈변과 관계가 있을 것으로 생각되었다. 이상의 결과로, 녹차 Catechin유도체의 pH 및 저장기간에 대한 영향은 ECg, EGCg에 gallic acid의 결합에 의한 것으로 생각되고, C, EC의 불안정은 중합반응으로 생각된다. 녹차 catechin류는 대부분 산성에서 저장기간이 길고 안정한 것으로 나타났으나 생리활성이 강한 (-)-EGCg는 산성에서도 불안정한 것으로 나타났다. 결론적으로 녹차의 기능성 성분을 효율적으로 이용하기 위해서는 pH를 낮게 유지하여야 할 것으로 사료되어진다.