• Journal of Applied Biological Chemistry
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• 제53권1호
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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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• 제13권8호
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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.

• 한국식품영양과학회지
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• 제24권2호
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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.

• 생명과학회지
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• 제26권6호
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• pp.640-645
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• 2016

본 연구에서는 녹차 유래 polyphenol 중의 하나인 epigallocatechine gallate (EGCG)를 이용한 신경염증 억제 효과를 확인하였다. LPS로 유도된 미세아교세포의 활성화로 분비되는 nitric oxide (NO)와 pro-inflammatory cytokine을 포함하여 iNOS, TNF-a와 IL-1b 유전자의 발현과 LPS 수용체인 TLR-4의 활성에 미치는 EGCG의 억제 효능을 확인하였다. Latex beads를 이용한 phagocytotic activity를 확인한 결과 LPS로 유도된 미세아교세포 활성에 의한 식균활성이 EGCG에 의해 억제되는 것을 볼 수 있었다. 뿐만 아니라, BV-2 미세아교세포 조건배지를 이용하여 도파민성 신경세포 SN4741의 세포 사멸확인에서도 EGCG에 의한 보호 효과를 확인하였다. 본 연구 결과는 녹차 유래 polyphenol인 EGCG의 신경염증 반응억제효능과 신경퇴행성 질환 제어 가능성을 확인하였다. 본 연구의 결과는 녹차 유래 polyphenol인 EGCG의 신경염증 반응과 그로 인한 신경 퇴행성 질환 제어 가능성을 제시하였다.

• Biomolecules & Therapeutics
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• 제11권4호
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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.

• 한국식품과학회지
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• 제30권4호
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• pp.970-975
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• 1998

약용 식물로부터 여러 효소의 저해제를 탐색 하였다. 한국산 우롱차엽으로부터 80%의 아세톤 추출물을 Sephadex LH-20, MCI-gel, Fuji gel 등을 사용하여 분리하였고 이 화합물은 Anisaldehyde 및 $FeCl_3$에 붉은색과 청색을 나타내었다. 이 화합물의 유도체화에 의한 기기분석 결과에서 상부는 -(-)epicatechin로 하부는 -(-)epigallocatechin 3-O-gallate 결합된 dimeric proanthocyanidin 종류인, $epicatechin-(4{\beta}{\rightarrow}8)-epigallocatechin{\;}3-O-gallate$로 화학 구조가 결정되었다. Xanthin oxidase 저해 효과에서는 $50{\;}{\mu}mole$에서 62%의 저해를 보여주어 앞으로 통풍 예방 기능성 식품 신소재로서의 이용이 가능하다는 것을 확인하였다.

• 한국식품영양과학회지
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• 제35권10호
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• pp.1399-1404
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• 2006

기능성식품 소재로 사용할 수 있는 재구성지질의 산화안정성을 검토하기 위하여 대두유, CLA와 caproic acid에 lipase를 가하여 반응시켜 합성한 재구성지질과 이의 유탁액에 각종 항산화제를 첨가하고 $60^{\circ}C,\;150^{\circ}C$의 열처리한 것과 광을 조사하면서 저장과정 중 POV, TBA값, AV를 측정한 결과는 다음과 같았다. 대두유와 재구성지질을 $60^{\circ}C$에서 열처리하였을 때 대두유가 재구성지질에 비하여 산화가 더 빠르게 진행되었으며 항산화제를 첨가한 재구성지질은 산화유도기간이 길어졌으나 10일이 지나면서 POV가 100 meq/kg에 도달해 식용이 불가능한 상태가 되었다. 재구성지질에 항산화제를 첨가하였을 때 산화억제 효과는 tea polyphenol extract>$\alpha-tocopehrol$>rosemary extract>ascorbyl palmitate의 순으로 tea polyphenol extract가 가장 우수하였으며 $150^{\circ}C$에서 열처리하였을 때에도 저장 3일에 대두유의 POV가 117 meq/kg, 재구성지질이 92 meq/kg로서 3일이 지나면서 식용이 불가하였으며 고온에서의 항산화제의 산화억제정도는 저온에서와 같은 경향이었다. 유지유탁액이 일반적인 유지 상태보다 산화속도가 빨랐으며 유탁액 상태에서도 항산화제의 산화억제효과는 가열처리 때와 유사하였다. 대두유와 재구성지질에 대하여 광을 조사하여 산화시킬 때 가열산화에서와 같이 재구성지질이 더욱 안정하였으며 조사기간이 길수록 신화정도는 차이가 심하였으며 유탁액 상태에서 더욱 불안전하였다.

• 한국식품영양학회지
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• 제37권2호
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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.

• 한국식생활문화학회지
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• 제22권4호
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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.

• 한국염색가공학회지
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• 제20권5호
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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.