• Title, Summary, Keyword: Epigallocatechin-3-gallate

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Antitumor Evaluation of Epigallocatechin Gallate by Colorimetric Methods (비색분석법에 의한 Epigallocatechin Gallate의 항암효과평가)

  • Baek, Soon Ok;Kim, Il Kwang;Baek, Seung Hwa;Han, Du Seok
    • 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.

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Preventive Effects of a Major Component of Green Tea, Epigallocathechin-3-Gallate, on Hepatitis-B Virus DNA Replication

  • Karamese, Murat;Aydogdu, Sabiha;Karamese, Selina Aksak;Altoparlak, Ulku;Gundogdu, Cemal
    • 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.

Extraction and Purification of EGCG(Epigallocatechin Gallate) from Green Tea (녹차로부터 EGCG(Epigallocatechin Gallate)의 추출 및 정제)

  • Gang, Ji-Hun;Park, Yeong-Gwang;Jeong, Seong-Taek;No, Gyeong-Ho
    • 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.

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Inhibitory Effects of (-)Epigallocatechin Gallate and Quercetin on Phorbol 12-Myristate 13-Acetate-Induced Secretion of Metalloproteinase-2 and Metalloproteinase-9

  • Kang Sang-Wook;Choi Yean-Jung;Choi Jung-Suk;Kwon Hyang-Mi;Bae Ji-Young;Park Eun-Hee;Ji Geun-Eog;Kang Il-Jun;Kang Young-Hee
    • 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.

Antioidants of Theae Folium and Moutan Cortex (녹차와 목단피의 항산화 성분)

  • Boo, Yong-Chool;Jeon, Che-Ok
    • 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.

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Antibacterial Activities of Phenolic Components from Camellia sinensis L. on Pathogenic Microorganisms

  • Shin, Jung-Sook;Chung, Ha-Sook
    • 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.

Effects of Tea Constituents on Intracellular Level of the Major Tea Catechin, (-)-Epigallocatechin-3-gallate

  • Hong, Jun-Gil;Yang, Chung-S.
    • 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.

Isolation of a Novel Polyphenol from Oolong Tea and Its Effective Prevention of the Gout (우롱차로터 새로운 Polyphenol 분리 및 통풍 예방 효과)

  • An, Bong-Jeun;Lee, Jin-Tae;Bea, Man-Jong
    • Korean Journal of Food Science and Technology
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    • v.30 no.4
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    • pp.970-975
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    • 1998
  • Eighty percent of acetone extract were isolated from the leaves of Korean Oolong tea using Sephadex LH-20, MCI-gel, Fuji gel. The compound reacted the red and the blue with anisaldehyde and $FeCl_3$, respectively. Instrumental analysis of the derivatives of this compound showed that the chemical structure was decided to $epicatechin-(4{\beta}{\rightarrow}8)-epigallocatechin-3-O-gallate$ as a kind of dimeric proanthocyanidine, that bound with -(-)epicatechin and -(-)epigallocatechin-3-O-gallate, at the upper and the lower, respectively. Considering inhibition effect on xanthin oxidase by 62% levels at $50{\;}{\mu}mole$, this compound showed a possibility to be used as a new material for functional food.

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Effect of pH on the Stability of Green tea Catechins (녹차 카테킨류의 pH에 대한 안정성 연구)

  • 박영현;원은경;손동주
    • 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.

Green Tea Extract (CUMC6335), not Epigallocatechin Gallate, Cause Vascular Relaxation in Rabbits

  • Lim, Dong-Yoon;Baek, Young-Joo;Lee, Eun-Bang
    • Natural Product Sciences
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    • v.10 no.5
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    • pp.228-236
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    • 2004
  • The aim of the present study was to examine whether green tea extract (CUMC6335) affects the blood pressure and the isolated aortic contractility of the rabbit in comparison with one of the most powerful active catechins, epigallocatechin gallate (EGCG). The phenylephrine $(1-10\;{\mu}M)-induced$ contractile responses were greatly inhibited in the presence of CUMC6335 (0.3-1.2 mg/ml). Also, high potassium (56 mM)-induced contractile responses were depressed in high concentration (0.6-1.2 mg/ml), but not affected in low concentration CUMC6335 (0.3 mg/ml). However, epigallocatechin gallate $(EGCG,\;4-12\;{\mu}g/ml)$ did not affect the contractile responses evoked by phenylephrine and high $K^+$. The infusion of CUMC6335 with a rate of 20 mg/kg/30 min made a significant reduction in pressor responses induced by intravenous norepinephrine. However, EGCG (1 mg/kg/30 min) did not affect them. Collectively, these results obtained from the present study suggest that intravenous CUMC6335 causes depressor action in the anesthetized rat at least partly through the blockade of adrenergic ${\alpha}_1-receptors$. CUMC6335 also causes the relaxation in the isolated aortic strips of the rabbit partly via the blockade of adrenergic ${\alpha}_1-receptors$, in addition to the unknown direct mechanism. It seems that there is no species difference in the vascular effect between the rat and the rabbit.