• Journal of Nutrition and Health
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• 제32권7호
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• pp.838-843
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• 1999

Antitumor effects of various teas have been studied for a long time. Among them, green tea is one of the most popular test and very close to our lives in Korea. However, precise effect and mechanism about antitumor effects of green tea were not estabilished. The present study investigated the antitumor effect of catechin, which is main component of green tea, which was produced in Korea, was used. In each group, morphological changes were observed induced severe cell damage and growth inhibition gradually until 24hours. Then catechin effect was found to be concentration-and time-dependent. EATC was injured abruptly at 100ug/ml catechin treatment for 6 hours and the effect lasted constantly until 24 hours. But in both of cell lines, cell damage and inhibition of proliferation did not show up apparently at concentration of 10 and 1ug/ml. In contrast, catechin led to little or no effect against HepG2 in all of concentrations and periods. These results suggest that catechin extracted from green tea had different effect on cancer cells as cell type, concentration and period. Therefore green tea would be helpful to cancer treatment as well as cancer prevention and this study would be the basic source for further research of green tea.

• 한국식품영양학회지
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• 제31권3호
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• pp.416-424
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• 2018

The physiologically advantageous aspects of green tea have been identified recently and green tea has been a favorite drink of many people. Due to the increased awareness of green tea's positive effects on human health, the demand for foods containing green tea has increased. This has led to the development of diverse green tea-related beverages; thereby many companies in Korea have put a wide variety of manufactured green tea beverages on the market. However, the components within green tea beverages have not been examined in Korea yet. In this study, we investigated the contents of the physiologically functional materials found in green tea, such as catechin, catechin gallate, epicatechin, epicatechin gallate, epigallocatecin gallate, gallocatechin gallate and caffeine. Fifty-six green tea products purchased from the local grocery stores and cafes were analyzed using high performance liquid chromatography (HPLC) analysis. As a result, all tested products contained catechin and caffeine, although the amount of each component was largely different. The total amount of catechin derivatives in the manufactured green tea beverages purchased from cafes was 263.17 mg/L, while they were 61.99 mg/L in the beverages purchased from the local grocery stores. And, to the almost samples the amount of caffeine was proportional to the amount of catechin.

• 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.

• 한국식품위생안전성학회지
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• 제17권3호
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• pp.117-123
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• 2002

시중에 유통되고 있는 녹차중의 catechin류에 대하여 열수추출 및 HPLC분석을 통하여 함량을 조사하고 이를 효율적으로 이용하기 위하여 pH조건이 녹차 catechin류의 안정성에 미치는 영향에 대하여 분석하였다. 시판 중인 전남 보성산 녹차의 catechin류 함량은 (+)-catechin>(-)-EGCg>(-)-EGC>(-)-EC>(-)-ECg순으로 추출되었고 Total catechin류의 함량은 103.72mg/g이었다. 녹차에서 분리·정제되어진 catechin류인 (+)-catechin, (-)-EC, (-)-ECg, (-)-EGCg를 pH 3∼11에 대한 안정성을 흡광도측정장치를 이용하여 측정하였다. 그 결과 catechin류의 pH에 대한 영향을 최대흡수파장 및 흡광도 변화로 보면 pH가 높을수록 (+)-catechin과 (-)-EC은 흡광도가 증가되었고 (-)-ECg와 (-)-EGCg는 최대흡수파장이 증가되었다. 또한 7일간 실온에서 저장하면서 기간에 따른 변화를 살펴본 결과에서 산성조건에서는 큰 변화가 없지만 알칼리조건에서는 흡광도가 증가되었다. (+)-catechin과 (-)-EC은 알칼리조건에서 흡수파장 400∼430 nm에서 저장기간이 길수록 흡광도가 증가되었다. 이는 녹차의 갈변과 관계가 있을 것으로 생각되었다. 이상의 결과로, 녹차 Catechin유도체의 pH 및 저장기간에 대한 영향은 ECg, EGCg에 gallic acid의 결합에 의한 것으로 생각되고, C, EC의 불안정은 중합반응으로 생각된다. 녹차 catechin류는 대부분 산성에서 저장기간이 길고 안정한 것으로 나타났으나 생리활성이 강한 (-)-EGCg는 산성에서도 불안정한 것으로 나타났다. 결론적으로 녹차의 기능성 성분을 효율적으로 이용하기 위해서는 pH를 낮게 유지하여야 할 것으로 사료되어진다.

• 한국식품영양과학회지
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• 제33권4호
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• pp.753-756
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• 2004

본 연구에서는 녹차 완제품에 원적외선을 처리한 후 물 추출물을 제조하여 항산화능 및 catechin류의 변화를 조사하였다. 녹차 물 추출물의 flavanol 함량은 무처리구(145 mg/g)에 비하여 원적외선을 10분간 처리한 경우 160 mg/g로 증가하였으나, 20분간 처리하였을 경우에는 90 mg/g으로 감소하였다. 또한, DPPH 라디칼 소거능의 경우 원적외선을 10분간 처리한 녹차 추출물의 경우 62.57%로서 무처리구의 61.58%에 비해 약간의 증가를 나타내었지만, 원적외선을 20분간 처리한 경우에는 59.98%로서 감소하였다. 한편, 녹차 추출물의 epicatechin류(EGC, EGCG, EC, ECG)의 함량은 원적 외선의 처리 시간이 증가할수록 감소하였으며, catechin류(GC, C, GCG, CG) 함량은 원적외선을 10분간 처리하였을 때 가장 높게 관찰되었다.

• 한국지역사회생활과학회지
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• 제19권1호
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• pp.55-61
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• 2008

This study was conducted to compare the nutrient and chemical contents of traditional Chungtaejeon tea with that of green tea which was harvested in Jangheung, Jeonnam district. Vitamin C, amino acids and total nitrogen contents of Chungtaejeon tea were lower than that of green tea by 0.30, 2.30 and 4.20g/100g, respectively. The tannin, caffeine, reducing sugar and chlorophyll contents in Chungtaejeon tea were the same as those in green tea. Comparing catechin contents, catechin (C), epicatechin (EC), and epigallocatechin (EGC) in Chungtaejeon tea were lower than those of green tea. However, gallocatechin (GC), epicatechin gallate (ECG), epigallocatechin gallate (EGCG) and catechin gallate (CG) showed no significant difference between Chungtaejeon tea and green tea. The flavonoid contents of Chungtaejeon tea and green tea showed higher quercetin and kaempferol contents in green tea, and higher myricetin content in Chungtaejeon tea. The measured amino acid contents for threonine and aspartic acid were lower, and for glutamic acid were higher in Chungtaejeon tea compared with those in green tea. However, free amino acid content in Chungtaejeon tea and green tea showed no significant difference. Potassium and magnesium contents in Chungtaejeon tea were lower compared to green tea but no significant difference was found for iron, manganese or calcium contents when comparing the two teas.

• 동의생리병리학회지
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• 제19권6호
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• pp.1580-1584
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• 2005

Antioxidative activities of catechin from green tea extracts were examined by the methods of 1,1-Diphenyl-2-picrylhydrazyl (DPPH) electron donating ability, hydroxy scavenging activity and the inhibitory effect on xanthine oxidase activity. The resulted demonstrated the fact that Catechin one (containing Green tea extracts plus catechin 51%) of green tea extracts product showed at 65.5% in electron donating activity on the DPPH. The electron donating ability on the DPPH of Catechin one was increased to 10% than purified catechin. Catechin one showed the activity at 64.5% in scavenging activity using hydroxy radical method. To the Catechin one provided to increase the hydroxy scavenging activity up to 3 fold. Inhibitory effects of the catechin one measured with xanthine oxidase method was 6.5%. Although the antioxidative activity of catechin (98% purified) was lower than that of Catechin one (containing Green tea extracts plus catechin 51%) in same catechin concentrations ($5{\mu}g$, respectively). Therefore, we may suggest that Catechin one can be used as a functional food additive possessing the potent antioxidative activity.

• 한국식품영양과학회지
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• 제21권4호
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• pp.386-389
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• 1992

녹차에 있어서 맛성분으로도 중요하고, 최근에는 그 약리작용의 연구과 활발히 연구되고 있는 catechin의 함량 분석을 국산 시판 녹차를 시료로 하여 시도하였다. 100mg의 시료 분말 녹차를 열수 출출한 후 $CHCl_3$를 가하여 시료 용액으로 부터 caffeine를 제거시키고 EtOAc를 가하여 catechin류를 추출 농축하여 5ml로 한 다음 $0.45\;\mu\textrm{m}$ membrane filter를 통과시킨 후 $2\;\mu\textrm{l}$을 HPLC에 주입시켰다. 4종류의 고순도 정량분석용 catechin류를 표준용액으로 한 검량선법에 의하여 시료중의 catechin 함량을 구하였다. 그 결과, EGCg의 함량(찐 1번차 : 7.54%, 볶은 1번차 : 7.88%)이 가장 많았고 EGC, ECg, EC의 순서로 그 함량이 감소하엿다. 수확시기가 늦은 2번차에서는 EGCg, ECg 와 같은 gallate는 증가하고 EGC는 약간 감소하는 경향을 나타내어 차의 맛에 영향을 주는것 같다.

• 동아시아식생활학회지
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• 제21권2호
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• pp.243-249
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• 2011

This study investigated the physiological and antioxidant activities of green, oolong, and black tea extracts. The crude catechin extract yields of green, oolong, and black tea were 4.9%, 3.4%, and 2.5%, respectively. Total phenol contents of green, oolong, and black tea were 40.9%, 43.0%, and 38.5%, respectively. The order of the electron donating abilities of green, oolong and black tea were green tea>oolong tea>black tea extracts. The SOD-like activities of green, oolong and black tea extracts at 5,000 ppm were 21.2%, 17.5% and 13.9%, respectively. The nitrite-scavenging abilities of green, oolong and black tea extracts were higher than that of ascorbic acid (p<0.05). Antioxidant activities in soybean oil substrates at 500 ppm were in the order of green tea>oolong tea>black tea${\geq}$BHT (200 ppm). Therefore these results showed that the physiological and antioxidant activities of green tea were better than those of oolong and black tea.

• 한국식품영양과학회지
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• 제33권1호
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• pp.47-51
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• 2004

본 연구는 녹차의 혈중 콜레스테롤 저하 효과 및 녹차 추출물인 catechin과 EGCG가 hypocholesterolemic 효과에 미치는 정도를 식이로 고콜레스테롤혈증을 유도한 흰쥐에서 평가하고자 수행하였다. 4주령의 수컷 SD계 흰쥐를 난괴법에 따라 각 군당 5마리씩 무녹차섭취군(대조군), 4% 녹차분말군(GTP), 1% 녹차 catechin군(Catechin),0.5% 녹차 EGCG군(EGCG)의 4군으로 7주간 사육을 하였다. 녹차 첨가군은 모두 0.5% EGCG를 함유하도록 녹차 첨가량을 결정하였으며 모든 식이는 고콜레스테롤혈증을 유도하기 위하여 1% cholesterol과 0.5% cholic acid를 첨가하였다. 식이섭취량은 각 군간에 유의적인 차이를 나타내지 않았다. 혈청 총 및 LDL-콜레스테롤 수준은 Catechin군이 189.2 mg/dL, 166 mg/dL, EGCG군에서는 161.4 mg/dL, 138 mg/dL로 나타나 대조군(245 mg/dL, 222 mg/dL)에 비하여 유의적으로 감소되었고 (p<0.05), EGCG군에서 그 효과는 더욱 크게 나타났다. 혈청의 중성지방농도는 녹차섭취군이 대조군보다 낮았으며 EGCG군에서 가장 낮게 나타났다. HDL-콜레스테롤 수준은 유의적이지는 않았지만 녹차섭취군이 대조군보다 높은 경향을 보였고, HDL/LDL-콜레스테롤 비율은 대조군에 비하여 녹차섭취군에서 증가하여 EGCG군에서 가장 높았다. 이와 같은 결과는 녹차의 섭취가 혈중 콜레스테롤 및 중성지방을 감소하고, HDL-콜레스테롤은 증가시킴으로써 동맥경화 위험을 줄일 수 있는 가능성을 반영하고 있다. 간에서의 CYP7Al활성과 유전자 발현정도는 Catechin군, EGCG군이 대조군에 비하여 높게 나타났으며, EGCG군에서 가장 많이 증가하여 혈청에서의 지질수준 감소 경향과 일치하였다. 이상의 본 연구 결과들은 녹차 섭취군에서의 혈중 콜레스테롤 저하작용 특히 EGCG군에서의 현저한 hypocholesterolemic 효과는 CYP7Al 유전자 발현 및 효소의 활성증가에 따른 콜레스테롤의 담즙산으로의 배설 증가에 기인하는 것으로 추측된다.