• Korean Journal of Food Science and Technology
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• v.38 no.1
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• pp.5-9
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• 2006

Method for separation and quantification of methylxanthins, catechins, and theaflavins in Korean commercial teas (green, oolong, and black teas) was developed using reversed phase high-performance liquid chromatography (HPLC). After extraction with hot water, tea compounds were separated on Inertsil ODS-3v $(5\;{\mu}m)$ column, eluted with gradient of 7% acetonitrile and 93% of 20 mM phosphate buffer mixture for 7 min. Column effluent was monitored at 270 nm. This technique was effective for analyses of m methylxanthins, catechins, and theaflavins in teas and biological samples. In green and oolong teas, two kinds of methylxanthins and 7 of catechins were identified, whereas 4 theaflavins were only identified in black tea. Among seven catechins in green and oolong teas, EGCG showed highest amount, whereas ECG was highest in black tea. (theaflavins were found only in black teas) In all teas, theobromine content was lower than that of caffeine.

• 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.

• Korean Journal of Food Science and Technology
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• v.42 no.1
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• pp.21-26
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• 2010

Microbial-fermented tea (MFT), which is made by microorganisms through fermentation, is a popular beverage in Asia, especially in the Yunnam province, China. In this study, changes of the chemical constituents and antioxidant activity during the manufacturing process of MFT were investigated. MFT were respectively prepared from fresh leaves of three different tea species (Yabukita, Daecha, and Korean wild cultivar) and a processed green tea (Korean wild cultivar). The color of the tea infusions gradually changed to red and yellow as a function of fermentation time. Total nitrogen and caffeine contents were not significantly changed. Whereas, the chlorophyll, tannin, and total catechins contents gradually decreased. Interestingly, the epicatechin and epigallocatechin contents increased up to 25 days of fermentation and then decreased. Change of the chemical constituents of all samples showed the same patterns. The antioxidant activity of MFT from Daecha and Yabukita slightly decreased as increasing fermentation time. However, the range over which the antioxidant activity of MFT from Korean wild cultivar and green tea were not changed. This research suggests that it may be possible to manufacturing possibility of MFT using Korean wild cultivar and processed green tea.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.2
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• pp.201-205
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• 2004

In these several years, as many people have been attracted by the functional cosmetics, there are a lot of study to enhance the stability of active ingredients for light, heat, oxygen, etc. in the academic and industrial field. Especially, catechin is well known as strong anti-oxidant, anti-inflammatory and reducing agent for oxidative stress but it is very unstable for light, heat, oxygen. etc. In this study, the stability and skin penetration of catechin are improved by 3-dimensional method. As I-dimension, porous silica is prepared using sol-gel method, and then catechin is adsorbed in pores of silica. As 2-dimension, solid lipid nanoparticles (SLN) are obtained using non-phospholipid vesicles. Finally 3-dimension is completion through lamellar phase self-organization that combines SLN catechin with skin lipid matrix. We used laser light scattering system, cyro-SEM, chromameter, HPLC and image analyzer to analyze our 3-dimentional systems. According to chromameter date, the color stability of 3-dimensional catechin is enhanced by 5-10 times compared with general liposome systems. We also confirmed through HPLC analysis that 3-dimensional catechin is more long lasting. The effect of skin penetration and wrinkle reduction are improved, too.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.1
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• pp.13-24
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• 2006

Neuronal apoptotic events, consequently resulting in neuronal cell death, are occurred in hypoxic/ischemic condition. This cell death has been shown to be accompanied with the production of reactive oxygen species (ROS), which can attack cellular components such as nucleic acids, proteins and phospholipid. However, the underlying mechanisms of apoptosis induced in hypoxic/ischemic condition and its treatment methods are unsettled. Cobalt chloride $(CoCl_2)$ has been known to mimic hypoxic condition including the production of ROS. Epigallocatechin gallate (EGCG), a green tea polyphenol, has diverse pharmacologial activities in cell growth and death. This study was aimed to investigate the apoptotic mechanism by $CoCL_2$ and effects of EGCG on $CoCl_2-induced$ apoptosis in PC12 cells. Administration of $CoCl_2$ decreased cell survival in dose- and time-dependent manners and induced genomic DNA fragmentation. Treatment with $100{\mu}M$ EGCG for 30 min before PC12 cells were exposed to $150{\mu}M$ $CoCl_2$, being resulted in the cell viability and DNA fragmentation being rescued. $CoCl_2$ caused morphologic changes such as cell swelling and condensed nuclei whereas EGCG attenuated morphologic changes by $CoCl_2$. EGCG suppressed the apoptotic peak and a loss of ${\Delta}{\psi}_m$ induced by $CoCl_2$. $CoCl_2$ decreased Bcl-2 expression but Bax expression was not changed in $CoCl_2$- treated cells. EGCG attenuated the Bcl-2 underexpression by $CoCl_2$. $CoCl_2$ augumented the cytochrome c release from mitochondria into cytoplasm and increased caspase-8, -9 and caspase-3 activity a marker of the apoptotic executing stage. EGCG ameliorated the incruement in caspase-8, -9 and -3 activity, and cytochrome c release by $CoCl_2$ NAC (N-acetyl-cysteine), a scavenger of ROS, attenuated $CoCl_2-induced$ apoptosis in consistent with those of EGCG. These results suggest that $CoCl_2$ induces apoptotic cell death through both mitochondria- and death receptor-dependent pathway and EGCG has neuroprotective effects against $CoCl_2-induced$ apoptosis in PC12 cells.

• Journal of Nutrition and Health
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• v.47 no.1
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• pp.1-11
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• 2014

Purpose: Several studies have proven that EGCG, the primary green tea catechin, and glucosamine-6-phosphate (PGlc) reduce triglyceride contents in 3T3-L1 adipocytes. The objective of this study is to evaluate the combination effect of EGCG and PGlc on decline of accumulated fat in differentiated 3T3-L1 adipocytes. Methods: EGCG and PGlc were administered for 6 day for differentiation of 3T3-L1 adipocytes. Cell viability was measured using the CCK assay kit. In addition, TG accumulation in culture 3T3-L1 adipocytes was investigated by Oil Red O staining. We examined the expres-sion level of several genes and proteins associated with adipogenesis and lipolysis using real-time RT-PCR and Western blot analysis. A flow cytometer Calibar was used to assess the effect of EGCG and PGluco on cell-cycle progression of differentiating 3T3-L1 cells. Results: Intracelluar lipid accumulation was significantly decreased by combination treatment with EGCG $60{\mu}M$ and PGlc $200{\mu}g/m$ compared with control and EGCG treatment alone. In addition, use of combination treatment resulted in directly decreased expression of $PPAR{\gamma}$, $C/EBP{\alpha}$, and SREBP1. In addition, it inhibited adipocyte differentiation and adipogenesis through downstream regulation of adipogenic target genes such as FAS, ACSL1, and LPL, and the inhibitory action of EGCG and PGlc was found to inhibit the mitotic clonal expansion (MCE) process as evidenced by impaired cell cycle entry into S phase and the S to G2/M phase transition of confluent cells and levels of cell cycle regulating proteins such as cyclin A and CDK2. Conclusion: Combination treatment of EGCG and PGlc inhibited adipocyte differentiation through decreased expression of genes related to adipogenesis and adipogenic and cell cycle arrest in early stage of adipocyte differentiation.

• Tuberculosis and Respiratory Diseases
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• v.66 no.3
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• pp.178-185
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• 2009

Background: Epigallocatechin-3-gallate (EGCG) is the major catechin in green tea, and has shown antiproliferative, antiangiogenic, antimetastatic and cell cycle pertubation activity in various tumor models. Hypoxia can be induced because angiogenesis is insufficient for highly proliferating cancer. Hypoxia-inducible factor-1$\alpha$ (HIF-1$\alpha$) and its downstream target, vascular endothelial growth factor (VEGF), are important for angiogenesis, tumor growth and metastasis. The aim of this study was to determine how hypoxia could cause changes in the cellular phenomena and microenvironment in a non-small cell culture system and to examine the effects of EGCG on a HIF-1$\alpha$ and VEGF in A549 cell line. Methods: A549 cells, a non-small cell lung cancer cell line, were cultured with DMEM and 10% fetal bovine serum. A decrease in oxygen tension was induced using a hypoxia microchamber and a $CO_2-N_2$ gas mixture. Gas analysis and a MTT assay were performed. The A549 cells were treated with EGCG (0, 12.5, 25, 50 ${\mu}mol/L$), and then examined by real-time-PCR analysis of HIF-1$\alpha$, VEGF, and $\beta$-actin mRNA. Results: Hypoxia reduced the proliferation of A549 cells from normoxic conditions. EGCG inhibited HIF-1$\alpha$ transcription in A549 cells in a dose-dependent manner. Compared to HIF-1$\alpha$, VEGF was not inhibited by EGCG. Conclusion: HIF-1$\alpha$ can be inhibited by EGCG. This suggests that targeting HIF-1$\alpha$ with a EGCG treatment may have therapeutic potential in non-small cell lung cancers.

• Tuberculosis and Respiratory Diseases
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• v.76 no.3
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• pp.114-119
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• 2014

Background: Epigallocatechin-3-gallate (EGCG), a major biologically active component of green tea, has anti-cancer activity in human and animal models. We investigated the schedule-dependent effect of EGCG and paclitaxel on growth of NCI-H460 non-small cell lung cancer cells. Methods: To investigate the combined effect of EGCG (E) and paclitaxel (P), combination indices (CIs) were calculated, and cell cycle analysis was performed. For the effect on cell apoptosis, western blot analysis was also performed. Results: CI analysis demonstrated that both concurrent and sequential E ${\rightarrow}$ P treatments had antagonistic effects (CIs >1.0), but sequential P ${\rightarrow}$ E had synergistic effects (CIs <1.0), on the growth inhibition of NCI-H460 cells. In the cell cycle analysis, although paclitaxel induced $G_2/M$ cell cycle arrest and increased the sub-G1 fraction, concurrent EGCG and paclitaxel treatments did not have any additive or synergistic effects compared with the paclitaxel treatment alone. However, western blot analysis demonstrated that sequential P ${\rightarrow}$ E treatment decreased the expression of Bcl-2 and procaspase-3 and increased poly(ADP-ribose) polymerase (PARP) cleavage; while minimal effects were seen with concurrent or sequential E ${\rightarrow}$ P treatments. Conclusion: Concurrent or sequential E ${\rightarrow}$ P treatment had opposite effects to P ${\rightarrow}$ E treatment, where P ${\rightarrow}$ E treatment showed a synergistic effect on growth inhibition of NCI-H460 cells by inducing apoptosis. Thus, the efficacy of EGCG and paclitaxel combination treatment seems to be schedule-dependent.

• Journal of agriculture & life science
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• v.44 no.5
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• pp.91-99
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• 2010

The objective of this work was to investigate the influence of ultrasonification on extraction yield and chemical properties of green tea infusion. Changes in total soluble matter(TSM), vitamin C, total phenolic compounds, flavonols, catechins, caffeine, free amino acids contents in green tea infusion(GTI) influenced by ultrasonification at $60^{\circ}C$ of extraction temperature for 1, 5, 30, and 60 min were investigated. The amount of infused TSM increased about 5.3% by ultrasonification for 60min. Vitamin C contents also increased 0.21, 0.16, 0.31 mg/g from 1 to 30 min by ultrasonification. However, vitamin C decreased from 2.47 to 2.22 mg/g at 60min. Total phenol compounds contents increased about 10~13 mg/g on all extraction times by ultrasonification. Flavonols such as, myricetin, quercetin, kaempferol were increased to doubled contents as an influence of ultrasonification. Catechins such as, EGCG, EGC, ECG, EC, (+)-C and caffeine contents showed same tendency as the results of vitamin C. On the other hand, result of free amino acids showed different tendency. All amounts of free amino acids did not increase by ultrasonification. Consequently, content of bioactive compounds such as, vitamin C, total phenolic, flavonols and catechins in green tea infusion were influenced by ultrasonification.

• Journal of Life Science
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• v.28 no.5
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• pp.615-620
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• 2018

Epigallocatechin-3-gallate (EGCG), one of catechins of green tea, has been known to possess anti-oxidation, anti-inflammation, and anti-cancer effects. The present study analyzed global gene expression changes in EGCG-treated HCT116 cells and p53-null HCT116 cells by oligo DNA microarray analysis. Among the differentially expressed genes in EGCG-treated HCT116 cells, four were selected that are known as tumor suppressor genes (activating transcription factor 3 [ATF3], cyclin dependent kinase inhibitor 1A [CDKN1A], DNA damage-inducible transcript 3 [DDIT3] and non-steroidal anti-inflammatory drug activated gene [NAG-1]) and their expression was compared to the expression of genes in p53-null HCT116 cells. We found that the expression of these genes was not dependent on their p53 status except for NAG-1, which was only up-regulated in HCT116. The results of RT-PCR and Western blot analysis showed that ATF3 up-regulation by EGCG was not affected by the presence of p53, whereas NAG-1 expression was not induced in p53-null HCT116 cells. We also detected ATF3 and NAG-1 expression changes through genistein and resveratrol treatment. Interestingly, genistein could not up-regulate ATF3 regardless of p53 status, but genistein could induce NAG-1 only in HCT116 cells. Resveratrol could significantly induce NAG-1 as well as ATF3 independent of p53 presence. These results indicate that EGCG, genistein and resveratrol may have different anti-cancer effects. Overall, the results of this study may help to increase our understandings of molecular mechanisms on anti-cancer activities mediated by EGCG, genistein and resveratrol in human colorectal cancer cells.