• Journal of Microbiology and Biotechnology
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• 제33권10호
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• pp.1317-1328
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• 2023

Green tea (GT) polyphenols undergo extensive metabolism within gastrointestinal tract (GIT), where their derivatives compounds potentially modulate the gut microbiome. This biotransformation process involves a cascade of exclusive gut microbial enzymes which chemically modify the GT polyphenols influencing both their bioactivity and bioavailability in host. Herein, we examined the in vitro interactions between 37 different human gut microbiota and the GT polyphenols. UHPLC-LTQ-Orbitrap-MS/MS analysis of the culture broth extracts unravel that genera Adlercreutzia, Eggerthella and Lactiplantibacillus plantarum KACC11451 promoted C-ring opening reaction in GT catechins. In addition, L. plantarum also hydrolyzed catechin galloyl esters to produce gallic acid and pyrogallol, and also converted flavonoid glycosides to their aglycone derivatives. Biotransformation of GT polyphenols into derivative compounds enhanced their antioxidant bioactivities in culture broth extracts. Considering the effects of GT polyphenols on specific growth rates of gut bacteria, we noted that GT polyphenols and their derivate compounds inhibited most species in phylum Actinobacteria, Bacteroides, and Firmicutes except genus Lactobacillus. The present study delineates the likely mechanisms involved in the metabolism and bioavailability of GT polyphenols upon exposure to gut microbiota. Further, widening this workflow to understand the metabolism of various other dietary polyphenols can unravel their biotransformation mechanisms and associated functions in human GIT.

• 한국약용작물학회지
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• 제14권6호
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• pp.322-328
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• 2006

Green tea is of particular source as it has been found to have strong antioxidant activities. The extracts of green tea during the commercial harvest seasons from April, 2003 to August, 2003 were compared. The purpose of this study was to determine the correlation between the polyphenol content of green teas and its antioxidant activities. The con-tent of total polyphenols was analyzed and several antioxidant testings were performed. The levels of total polyphenols were higher in the green teas (e.g. Woojeon, Sejak) harvested during very early spring and lower in the green teas harvested late(eg. Ipha, Yepcha). In particular, the free radical scavenging, the inhibition of LDL oxidation, the cytoprotective effect and the inhibition of DNA damage were correlated with the total polyphenol contents of green tea extracts harvested early spring such as Woojeon, Sejak and Jungjak. The results obtained here show that all extracts of green teas including purified green tea catechin, GTC, have strong antioxidant activities on oxidative stress in vifrθ. The variation in polyphenol content and antioxidant activities among various types of green tea by the harvesting time may provide critical information for investigators and consumers using tea in purposes of nutrition and chemoprevention.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• 제18권1호
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• pp.85-89
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• 2005

This study was conducted to examine the effects of green tea polyphenols (GTP) and fructo-oligosaccharides (FOS) supplement on performance, counts of caecal microflora and its metabolites production. In female broiler chickens fed on semi-purified diets from 28 to 42 d of age, dietary green tea polyphenols (GTP) and fructo-oligosaccharides (FOS) significantly reduced mortality (p<0.05). Dietary GTP significantly decreased the total count of caecal microflora, each colonic population count and caecal flora metabolites contents when compared to other groups (p<0.05). Dietary FOS did not influence the total count of caecal flora but it selectively increased Bifidobacteri and Eubacteria counts (p<0.05) and decreased the count of other microflora and concentrations of caecal phenols and indole (p<0.0.5). These results suggest that GTP and FOS in semi-purified diets can decrease mortality and change the caecal colonic flora population, but GTP shows antibiotic-like effects of non-selectively decreasing all colonic flora and then metabolites, and FOS acts selectively by increasing profitable microflora and decreasing production of caecal microflora metabolites besides volatile fatty acids.

• 한국식품영양과학회지
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• 제24권1호
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• pp.160-168
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• 1995

Desmutagenicities against 2-amino-1-methyl-6-phenylimidazo[4, 5-b] pyridine(PhIP) and 2-amino-3, 8-dimethylimidazo[4, 5-f]quinoxaline(MelQx) of tea extracts (steamed green tea, roasted green tea, oolong tea and black tea) were investigated. All the fractions obtained from tea extracts showed strong desmutagenic activity against PhIP and MeIQx toward S. typhimurium TA 98 in the presence of the S-9 mix. The crude catechin fraction exhibited the strongest desmutagenic activity. Among these tea extracts, black tea especially exhibited the strongest desmutagenic activity and the activity was 70.9~91.0% against PhIP and 92.2~98.8% against MelQx at a concentration(0.5~1.0mg/plate) for drinking. The activity of authentic catechins of (-)-EGC, (-)-EGCg, (-)-ECg and (-)-EC were 79.5%, 60.2%, 46.1% and 43.5% against PhIP, and were 52.3%, 11.6%, 8.2% and 22.1% against MelQx by addition of 1.0mg/plate, respectively. The desmutagenic activity was supposedly due to the (-)-EGCg, (-)-EGC and (-)-EC in tea polyphenols, and the browning materials. The desmutagenicity was stronger when mutagens were preincubated with S-9 mix after reaciton with black tea extracts than when preincubated with them after reaction with S-9 mix. The desmutagenicity of tea extracts was rather expressed by reacting directly with mutagens than by deactivating the activated forms of mutagens.

• Asian Pacific Journal of Cancer Prevention
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• 제13권8호
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• pp.4107-4112
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• 2012

4-Nitroquinoline 1-oxide (4-NQO) a potent oral carcinogen, widely used for induction of oral carcinogenesis, has been found to induce lipid peroxidation in vivo and in vitro. Green tea contains a high content of polyphenols, which are potent antioxidants. Thus green tea polyphenols (GTP) might be expected play a protective role against 4-NQO induced lipid peroxidation and bone marrow toxicity. In the present study, a dose of 200 mg of GTP/kg b.wt/day was given orally for a week, simultaneously animals received 0.2 ml of 0.5% 4-NQO in propylene glycol (5 mg/ml) injected intramuscularly for three times/week. Oxidants and antioxidants such as malendialdehyde (MDA) and thiols, glutathione peroxidase (GPx), glutathione reductase (GR), superoxide dismutase (SOD) and catalase (CAT) were significantly decreased in 4-NQO induced animals except MDA, and these parameters were brought back to near normalcy on treatment with GTP. The results suggest that GTP treatment offers significant protection against 4-NQO induced lipid peroxidation and bone marrow toxicity and might be a promising potential candidate for prevention of mutations leading to cancer.

• 대한화장품학회지
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• 제31권4호
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• pp.311-321
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• 2005

차(Camellia sinensis)는 세계적으로 애용되는 음료이다. 그 중, 아시아권에서 주로 소비되는 녹차는 다양한 생리활성을 가지고 있어 화장품, 기능성식품을 위한 기능성 소재로서 선호되고 있다. 녹차의 피부에 대한 활성은 세포보호에서부터 피부 기질 단백질의 합성까지 다양하게 나타난다. 녹차 폴리페놀(green tea polyphenols; GTPs)은 활성을 나타내는 주성분으로서 항산화 활성 이외에 항암, 항염증, 피부면역능 저하방지활성 등을 보이며, 세포내 신호전달 경로에도 관여한다 GTPs는 표피각질형성세포에서 자외선 조사에 의한 산화 스트레스를 감소시키고, 그에 따르는 mitogen-activated protein kinase (MAPK) 신호전달과 세포사멸을 억제한다. 또한, 같은 세포에서 tumor necrosis factor alpha $(TNF{\alpha})$나 다른 화학물질에 의해 cyclooxygenase-2(COX-2), interleukin-8 (IL-8) 및 vascular endothelial growth factor (VEGF) 같은 염증매개물질이 유발되는 것을 막아준다. 또한, GTPs는 등물실험에서 화학물질이나 자외선에 의한 피부암의 발생도 억제하는데, 경구투여 외에 경피투여로도 효과가 있었다. 피부보호작용 이외에도 GTPs는 각질형성세포의 분화촉진, 노화된 피부세포의 증식능 회복, 피부기질단백질의 분해억제 등의 기능이 있으며, 피부세포에서의 기질단백질 생합성을 직접적으로 촉진하기도 한다. 녹차성분이 보이는 이러한 피부에 대한 활성은, 제형 측면에서의 연구가 진행되어 감에 따라 보다 효과적인 피부를 위한 소재로서의 사용 가능성을 더욱 높여주고 있다.

• 미생물학회지
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• 제48권2호
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• pp.87-92
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• 2012

이 연구의 목적은 국산 녹차(Camellia sinensis L.)에서 추출한 차폴리페놀(tea polyphenols, TPP)에 노출된 Salmonella typhimurium의 여러 가지 세포반응을 조사하는 것이다. TPP는 S. typhimurium에 대하여 투여량에 비례한 살균효과를 보여주었다. TPP로 처리된 S. typhimurium 배양에서 세포막을 구성하는 포화 및 불포화 지방산은 조성에서 상당한 변화가 일어난 것으로 분석되었으며, 주사전자현미경 분석에서 아치사 농도의 TPP로 처리된 세포는 세포표면에 구멍이 나고, 속이 움푹 패인 불규칙한 모양으로 관찰되었다. TPP에 노출된 S. typhimurium 배양의 수용성 단백질 부분에 대한 이차원 폴리아크릴아미드 젤 전기영동에서 16개의 단백질이 TPP 노출에 의해 증가하는 것이 확인되었다. 항산화 및 chaperons, 전사 및 결합단백질, 에너지 및 DNA 대사 등에 수반되는 단백질을 포함하는 이들 유도된 단백질은 MALDI-TOF를 사용한 peptide mass fingerprinting에 의해 동정되었다. 이들 결과는 S. typhimurium에 대한 TPP 유도스트레스와 세포독성의 기작을 이해하는데 중요한 단서를 제공할 수 있다.

• Toxicological Research
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• 제30권4호
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• pp.283-289
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• 2014

Tea flavonoids and polyphenols are well known for their extraordinary antioxidant activity which is considered important for anti-aging processes in animals. This study evaluated the anti-wrinkle effects of three different kinds of tea (Camellia sinensis) water extracts (CSWEs) including green, white, and black teas using a photoaged hairless mouse model. Data showed that the CSWE-treatment greatly improved skin conditions of mice suffering from UVB-induced photoaging, based on the parameters including the skin erythema index, moisture capacity, and transepidermal water loss. In addition, the wrinkle measurement and image analysis of skin replicas indicated that CSWEs remarkably inhibited wrinkle formation. In histological examination, the CSWE-treated mice exhibited diminished epidermal thickness and increased collagen and elastic fiber content, key signatures for skin restoration. Furthermore, the reduced expression of MMP-3, a collagen-degradative enzyme, was observed in the skin of CSWE-treated animals. Interestingly, comparative data between green, white, and black tea indicated that the anti-wrinkle activity of white tea and black tea is equally greater than that of green tea. Taken together, these data clearly demonstrated that CSWEs could be used as an effective anti-wrinkle agent in photoaged animal skin, implying their extended uses in therapeutics.

• Nutritional Sciences
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• 제8권3호
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• pp.175-180
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• 2005

Green tea, which has high polyphenols amount, is thought to have hypocholesterolemic effects. The present study was performed to further examine the hypocholesterolemic action of green tea, especially (-) epigallocatechin gallate (EGCG) for its effect on diet-induced hypercholesterolemia in rats. Male Sprague-Dawley rats (n=15) were fed a green tea-free diet (control), $1.0\%$ green tea catechin (catechin) or $0.5\%$ green tea catechin EGCG for seven weeks. Hypercholesterolemia was induced by adding $1\%$ cholesterol and $0.5\%$ cholic acid to all diets. There was no difference in food intake and body weight gain among the groups. The green tea EGCG treatment led to a significant improvement in plasma levels of total cholesterol, low density lipoprotein (LDL)-cholesterol and high density lipoprotein (HDL)/LDL ratio (p<0.05). There was no significant effect on the plasma HDL-cholesterol level. The catechin treatment led to a 4.19-fold increase in the LDL-receptor mRNA level compared to the control, but the EGCG treatment did not affect the hepatic LDL-receptor mRNA level. Our results suggest that when blood cholesterol level is down-regulated by green tea EGCG, the LDL receptor gene-independent pathway may dominate the hypocholesterolemic action of EGCG.