• Journal of Applied Biological Chemistry
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• v.53 no.1
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• pp.56-59
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• 2010

An optimal manufacturing process was established for the mass-production of mulberry leaves tea. The produced tea contained abundant dietary fibers, $\beta$-carotenes, and calcium. Also the polyphenol content and antioxidant activity of mulberry leaves tea were higher than those of simply dried mulberry leaves. These results imply that this tea manufacturing process is effective to utilize the useful components of mulberry leaves.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.3751-3755
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• 2012

Aim: Tea polyphenols are known to play roles in critical steps of human lung carcinoma cell metastasis. For understanding the mechanisms whereby they inhibit tumor metastasis, the present study was conducted to investigate their effects on the adhesion of highly metastatic lung carcinoma cell lines (PG cells) to endothelial cells (EC cells) and adhesion molecule expression in vitro. Methods: The expression of CD44 or CD54 in the PG cells was detected by flow cytometry and adhesion of PG cells to EC cells was assessed by confocal microscopy double fluorescence staining. Results: The results showed that tea polyphenols: (1) inhibited the expression of CD44 and CD54, two important adhesion molecules in the PG cells in a dose-dependent manner; (2) significantly blocked the adhesion of PG cells to EC cells not only in a state of rest but also when active; and (3) influenced CD44 and CD54 expression during the adhesion process of PG cells to EC cells. Conclusions: The data indicated that the blocking role of tea polyphenols in the adhesion of PG cells to EC cells is related to CD44 and CD54. The mechanism of tea polyphenol prevention of human lung carcinoma metastasis might be through inhibiting adhesion molecule expression to block cancer cell adhesion.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.2
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• pp.293-298
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• 1995

Antimicrobial effect of tea extracts from green tea(steamed, roasted), oolong tea and black tea was investigated. Minimal inhibitory concentration(MIC) of tea extraxcts against 9 well known strains of foodborne pathogenic bacteria such as the Gram positive and Gram negative bacteria was determined at 37$^{\circ}C$. Significant antimicrobial activity was observed in the steamed green tea and the roasted green tea of the water-soluble fraciton, and the steamed green tea of the methanol-soluble fraction, and the steamed green tea, roasted green tea and the oolong tea of the crude catechin fraction. The MIC of these extracts against B. subtillis were 700$\mu\textrm{g}$/ml, 500$\mu\textrm{g}$/ml and 120 $\mu\textrm{g}$/ml, respectively. The crude catechin fraction possessed greater antimicrobial activity than did the other fractions. Among tea extracts, extracts of steamed green tea, roasted green tea and oolong tea showed higher antimicrobial activity than them of black tea. The MIC of the crude catechin fraction obtained from tea extracts against Gram-positive bacteria such as M. Iuteus, B. subtillis and S. mutans were 30~50$\mu\textrm{g}$/ml, 120~240$\mu\textrm{g}$/ml and 120~180$\mu\textrm{g}$/ml, and against Gram-negative bacteri such as e. aerogenes and V. parahaemolyticus were 50~60$\mu\textrm{g}$/ml and 60~70$\mu\textrm{g}$/ml in the broth medium, respectively. Especially, the MIC to Streptococcus mutans which has known as a causative bacteria of a decayed tooth were 120$\mu\textrm{g}$/ml, 140$\mu\textrm{g}$/ml, 180$\mu\textrm{g}$/ml and above 1,000$\mu\textrm{g}$/ml in steamed green tea, roasted green tea, oolong tea and black tea, respectively. Tea extracts had strong growth inhibition activity against foodborne pathogenic and dental bacteria.

• Journal of Life Science
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• v.26 no.6
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• pp.640-645
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• 2016

Microglial cells are immediately activated in the central nervous system in response to a variety of neuronal environmental changes, such as injuries or inflammation. In addition to the modulation of the intrinsic immune response, a key role of microglial cells is the phagocytosis of dying cells and cellular debris. In this study, the inhibitory effects of epigallocatechine-3-gallate (EGCG), a most abundant and active polyphenol component of green tea, on lipopolysaccharide (LPS)-induced microglial activation are determined. EGCG dose dependently suppressed LPS-induced nitric oxide production and the expression of inducible nitric oxide synthase (iNOS) in BV-2 microglial cells. EGCG are potent LPS-induced inhibitors of several pro-inflammatory cytokine expressions, such as TNF-α and IL-1β, in microglial cells. Furthermore, EGCG generally inhibits the induction of LPS-mediated microglial activation and potently inhibits the phagocytosis of LPS-stimulated BV2 microglia. Although the conditioned media from LPS-stimulated BV-2 cells caused the SN4741 cell death, that from the conditioned media of EGCG pretreated BV-2 cells did not diminish the viability of SN4741 cells. These results suggest EGCG, a green tea polyphenol, could be a promising available molecule for the modulation of harmful microglial activation.

• Biomolecules & Therapeutics
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• v.11 no.4
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• pp.238-244
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• 2003

Nicotine is one of the major hazardous components in cigarettc smoke. Nicotine deals a harmful effect to smokers and passive smokers due to its rapid conversion to various carcinogenic metabolites. Nitrosamine-4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is believed to cause lung cancers among the nicotine-derived carcinogens. Recent studies report that NNK synthesis can be inhibited by the metabolism pathway to produce a stable metabolite cotinine from nicotine. Tea polyphenols have been known to contain factors to prevent cancers and to retard progression of cancers. This study aims to correlate tea polyphenol's potential for cancer prevention with an accelerated formation of cotinine. The conversion from nicotine to cotinine in the presence of tea extracts or three polyphenols (Catechin, epicatechin gallate, epigallocatechin gallate) was measured in established cell lines and in Xenopus oocytes. Among three lines of cell used, PLC/PRF5 and HEK293 cells showed a fast turnover from nicotine to cotinine while HepG2 cell line showed a marginal difference between groups treated and non-treated with tea polyphenols. When Xenopus oocytes were microinjected with nicotine, tea polyphenols appear to accelerate the conversion of nicotine to cotinine. Among the polyphenols tested in this study, (＋)－catechin showed the best efficiency overall in accelerating conversion from nicotine to cotinine both in the cell lines and in the oocytes. In summary, the present study indicated that tea polyphenols have a positive effect on conversion of nicotine to cotinine.

• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.10
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• pp.1399-1404
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• 2006

Structured lipid (SL) containing conjugated linoleic and caproic acid was produced from soybean oil through lipase-catalyzed reaction, and its oxidative stability was compared. When heated at $60^{\circ}C\;or\;150^{\circ}C$, soybean oil as control was more susceptible to oxidation than SL. When the antioxidants, such as ascorbyl palmitate, tea polyphenol, alpha-tocopherol, and rosemary extract, were added in SL, the induction periods of each antioxidant treats in SL were increased. The tea polyphenol showed the most effective antioxidant activity among them. When the emulsion form with SL was heated from oxidation, its oxidation stability was reduced compared to SL. The oxidation stability were also observed in photooxidation of SL.

• The Korean Journal of Food And Nutrition
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• v.37 no.2
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• pp.100-109
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• 2024

This study examined the quality characteristics and antioxidant properties of sword bean tea available in domestic markets. Each product of sword bean tea had distinct appearance characteristics. The color, pH, brownness, and turbidity of the tea varied significantly across different products, with tea bags showing higher levels of brownness and turbidity. The total polyphenol content of hot water extraction ranged from 165.13 to 517.69 mg gallic acid equivalents (GAE)/100 g sample for pod tea, 999.36 to 2,054.74 mg GAE/100 g sample for tea bag tea, and 74.62 to 275.00 mg GAE/100 g sample for grain tea, respectively. Similarly, the total flavonoid content, measured in terms of catechin equivalents (CE), ranged from 39.51 to 65.00 mg CE/100 g sample for pod tea, 86.57 to 253.63 mg CE/100 g sample for tea bag tea, and 32.94 to 38.63 mg CE/100 g sample for grain tea, for hot water extraction. The DPPH and ABTS radical scavenging activities of pod tea were 95.68 to 276.19 mg TE/100 g sample and 270.87 to 804.21 mg trolox equivalents/100 g sample, respectively, for hot water extraction. These results suggest the need to establish quality standards to ensure consistent quality of sword bean tea.

• Journal of the Korean Society of Food Culture
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• v.22 no.4
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• pp.449-453
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• 2007

Using green tea(GT), oolong tea(OT), black tea(BT) and green tea bag(GTB) out of tea products in market, this study quantified polyphenol and catechins as anti-oxidant substances and analyzed their respective anti-oxidant capacities. As a result, more epigallocathechin(EGC) was found in GT and GTB as well as caffein(CAF) in GT and BT. GT contained more epigallocathechin gallate(EGCG) than other tea types. Both FRAP and ORAC, as two methods of analyzing anti-oxidant capacities, showed that GTB had highest anti-oxidant capacities, while OT had lowest of all. By brand, it was found that all the 3 brands of GT had similarly high anti-oxidant capacities, but there were differences in the anti-oxidant activities of GTB and BT depending on brand. Out of catechin components, it was found that epicatechin(EC), epicathechin gallate(ECG) and EGCG were major components affecting anti-oxidant capacities.

• Textile Coloration and Finishing
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• v.20 no.5
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• pp.7-13
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• 2008

In order to introduce new functions onto textile fabrics, nylon and cotton were treated with green tea extracts. And then the anti-oxidant activity of fabrics treated with the extracts was evaluated by Blois method using DPPH ($\alpha$, $\alpha$-diphenyl- $\beta$-picrylhydrazyl). The anti-oxidant activity was exhibited on the textile fabrics treated as well as by the extracts itself. The cotton fabric treated with 10% o.w.f. of extract appeared to have almost 90% of anti-oxidant activity and 95% was obtained for nylon.