• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2004.04a
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• pp.296-301
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• 2004

We focused our research interests on the characteristic of silk fabrics dyed with green tea extracts and, moreover, revealed the catechin content of silk fabrics after dyeing with Korean tea extract by measuring the residues. Three kinds of green tea samples were taken between April and May, 2003, from Bosung(southern province in South Korea), in different terms as the first corp, the second corp, and the third corp. Before and after dyeing the silk fabrics with these extracts, catechins in the residue were analyzed by HPLC. Four kinds of Catechins, such as (-)-epicatechin(EC), (-)-epicatechin gallate(ECG), (-)-epigallocatechin (EgC), (-)-epigallocatechin gallate(EgCG) were isolated from Korean green tea extracts. Catechine contents in Korean green tea leaves depend on the making process such as heating and steaming, and the younger the richer. The absorbed catechins in sillk fabrics after dyeing followed in a decreasing order of EgCG>EgC>ECG>EC. We have found a 68% uptake of EgCG, and 116.8mg/g of EgCG in the silk fabrics after dyeing with 1% Korean green tea extracts.

• BMB Reports
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• v.38 no.5
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• pp.563-570
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• 2005

Tamoxifen citrate (TAM), is widely used for treatment of breast cancer. It showed a degree of hepatic carcinogenesis. The purpose of this study was to elucidate the antioxidant capacity of green tea (Camellia sinensis) extract (GTE) against TAM-induced liver injury. A model of liver injury in female rats was done by intraperitoneal injection of TAM in a dose of $45\;mg\;Kg^{-1}\;day^{-1}$, i.p. for 7 successive days. GTE in the concentration of 1.5%, was orally administered 4 days prior and 14 days after TAM-intoxication as a sole source of drinking water. The antioxidant flavonoid; epicatechin (a component of green tea) was not detectable in liver and blood of rats in either normal control or TAM-intoxicated group, however, TAM intoxication resulted in a significant decrease of its level in liver homogenate of tamoxifen-intoxicated rats. The model of TAM-intoxication elicited significant declines in the antioxidant enzymes (glutathione-S-transferase,glutathione peroxidase, superoxide dismutase and catalase) and reduced glutathione concomitant with significant elevations transaminase) levels. The oral administration of 1.5% GTE to TAM-intoxicated rats, produced significant increments in the antioxidant enzymes and reduced glutathione concomitant with significant decrements in TBARS and liver transaminases levels. The data obtained from this study speculated that 1.5% GTE has the capacity to scavenge free radical and can protect against oxidative stress induced by TAM intoxication. Supplementation of GTE could be useful in alleviating tamoxifen-induced liver injury in rats.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.11
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• pp.1501-1506
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• 2011

In this study, we optimized the reaction conditions for the bioconversion of green tea using tannase, and to evaluate its radical scavenging activities. Tea catechins such as (-)-epigallocatechin gallate (EGCG) or (-)-epicatechin gallate (ECG) were hydrolyzed by tannase to produce (-)-epigallocatechin (EGC) or (-)-epicatechin (EC), respectively, and a common product, gallic acid. The bioconversion of tea catechins by tannase was increased as enzyme concentration, substrate concentration and incubation time for enzyme dose. The results indicated the optimum reaction conditions for tannase were tannase 30 U/mL (enzyme concentration) on 1% green tea (substrate concentration) for 1 hr (incubation time for enzyme). Tannase enhanced the radical-scavenging properties of green tea; the 2,2-azinobis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals scavenging abilities were significantly (p<0.001) greater for the tannase-treated green tea extract compared to the untreated green tea extract. It is reported that ECG has the greatest antioxidant activity among the catechins in green tea, and the release of gallic acid is considered to be beneficial because of its significant antioxidant potency. The results of this study suggest that the tannase-treated green tea increases antioxidant activities under optimum reaction conditions.

• Fashion & Textile Research Journal
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• v.11 no.2
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• pp.344-349
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• 2009

Optimum dyeing conditions of green tea extracts were investigated toward nylon, cotton, rayon, and tencel fabrics. Affinity of green tea extracts was exhibited much higher onto nylon fabric than the other cellulosics. As for nylon, the adsorption was increased with the increase of dyeing temperature and optimum dyeing pH was around 4~6. Buildup property of green tea extract was good showing a linear relationship between concentration of the extracts and color strength of dyed fabrics within experimental range. Color fastnesses were good to excellent in general except to light.

• Food Science and Preservation
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• v.16 no.6
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• pp.924-928
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• 2009

Green tea has been shown to have multifunctional health-promoting properties including cholesterol level control an antidiabetic effect and anticancer, antioxidant, and antimicrobial properties, inboth in vivo and in vitro experiments.We earlier reported antifungal and antibacterial effects of green tea extract by investigating cell membrane functions. The purpose of the present study was to purify and identify antimicrobial substances from green tea extract. Such materials were extracted from green tea (Camellia sinensis. var. sinensis) and purified by high-performance liquid chromatography. The antimicrobial substances in the extract were identified as epicatechin gallate and epigallocatechin gallate by nuclear magnetic resonance spectrophotometry.

• Animal cells and systems
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• v.13 no.2
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• pp.133-139
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• 2009

Green tea seed was extracted with absolute ethanol,and the green tea seed extract(GTSE)was subjected to assays for toxicity, antioxidant ability, angiogenesis inhibitory effects and cell adhesion, as well as western blotting, and an in vivo experiment against 4 high-ranking adult cancers in Korea. Our series of experimental data demonstrated that GTSE has an antioxidant ability superior to that of EGCG in the green tea leaf, and also exhibits a profound high tumor growth inhibitory activity on a variety of cancer cell lines, as well as nude mice infected with cancer cells. GTSE was identified as a natural anticancer compound showing excellent angiogenesis inhibition and cancer cell suppression abilities. Our preliminary observations also indicate that GTSE may be another potential source of natural dietary antioxidants and also may be applicable as a novel natural anticancer agent.

• Textile Coloration and Finishing
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• v.11 no.3
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• pp.15-22
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• 1999

This study investigated the mordanting effect of natural mordants such as camellia ash, bean chaff ash and pyrolignite of iron(Iron(II) Acetate) on silk fabrics dyed with green tea extracts. Experimental variables include the conditions of extraction and dyeing, and types of natural mordants. Inorganic ion contents In natural mordants were analysed by Induced Coupled Plasma Atomic Emission Spectrometer. In the ash Al, Fe, Si and Mn were in % unit, Cr and Ni were detected in ppm unit, and in the aqueous extracts of the ash all the metal ions were in ppm unit. On the other hand, fairly high content of Al(2.13% ) in camellia ash extract and Fe(7.91% ) in the aqueous extracts of pyrolignite iron were detected. The absorbance intensity of green tea extracts in UV-Visible spectrum increased with the temperature and time of extraction. The maximum absorption wavelength of the extracts appeared at 272.5nm and 210.5nm. The US values of silk fabrics dyed with green tea extracts were increased with temperature and time of dyeing. Surface color of silk fabric dyed with green tea extracts was 9.1YR, but it was changed from 7.9YR to 7.5YR by camellia ash extract and 7.4YR to 6.4YR by bean chaff ash extract with increase in mordant concentration. Pre-mordanted and post-mordanted fabrics with pyrolignite of iron were changed from 1.4YR to 1.1R and 7.2P to 4.2P, respectively.

• Journal of Life Science
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• v.5 no.2
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• pp.20-20
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• 1995

The aroma components of commercial green teas picked inAugust were collected and identified. The extract of aroma compounds in green tea were accoimplished by a modified rotary evaporation. The concentrated wxtracts were analyzed and identified by GC and GC-MS. In GC analysis, T$_{R}$ value of GC represented bt KI value which standardized. The most abundant components of green teas picked in August were 1-Penten-3-ol, trans, trans-2, 4-heptadienal, linalool, $\beta$-ionone and nerolidol.

• Journal of Life Science
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• v.5 no.2
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• pp.76-80
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• 1995

The aroma components of commercial green teas picked inAugust were collected and identified. The extract of aroma compounds in green tea were accoimplished by a modified rotary evaporation. The concentrated wxtracts were analyzed and identified by GC and GC-MS. In GC analysis, T$_{R}$ value of GC represented bt KI value which standardized. The most abundant components of green teas picked in August were 1-Penten-3-ol, trans, trans-2, 4-heptadienal, linalool, $\beta$-ionone and nerolidol.

• Food Science and Biotechnology
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• v.15 no.6
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• pp.914-919
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• 2006

We investigated the catechin content in green tea leaf (GTL) and green tea seed (GTS), the antiproliferative and detoxifying phase II enzyme-inducing activities of the methanolic (80%, v/v) extracts from GTL and GTS. GTL and GTS contained $8,685{\pm}1,061$ and $108{\pm}32\;{\mu}g/g$ epigallocatechin gallate (EGCG), $11,486{\pm}506$ and $116{\pm}72\;{\mu}g/g$ epigallocatechin (EGC), $3,535{\pm}308$ and $821{\pm}95\;{\mu}g/g$ epicatechin gallate (ECG), and $1,429{\pm}177$ and $37{\pm}44\;{\mu}g/g$ epicatechin (EC), respectively. The methanolic extract of GTS showed a greater increase in quinone reductase activity and antiproliferation potential against mouse hepatoma cells than GTL extract did. GTS treatment resulted in the accumulation at sub-G1 phase of mouse hepatoma hepa1c1c7 cells as assessed by flow cytometry. Enhancement of phase II enzyme activity by GTS extract was shown to be mediated, directly or indirectly, via interaction with the antioxidant response element (ARE) sequence in the genes encoding the phase enzymes. As the catechin content in GTS was significantly lower than that in GTL, components other than catechins appear to be responsible for the anticarcinogenic activity of the seed. In summary, these results suggest that the 80% methanolic extract of GTS deserves further study to evaluate its potential as an anticarcinogenic agent and to investigate its mechanism of action.