• Journal of Nutrition and Health
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• 제45권5호
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• pp.443-451
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• 2012

We compared the effects of grapefruit seed extract (GFSE), green tea extract (GT) and their microencapsulated extract on anti-inflammatory activities in murine RAW 264.7 macrophages cell line. In order to protect the bioactive compounds in the extracts, they were microencapsulated with maltodextrin and $H_2O$. Nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), inducible nitric oxide synthase (iNOS) protein expression and thiobarbiturate reactive substances (TBARS) were analyzed in LPS activated RAW 264.7 macrophages. The green tea extract at the range of $100-600{\mu}g/mL$ inhibited NO, PGE2 production and iNOS protein expression without cytotoxicity in a dose-dependent manner. Grapefruit seed extract had strong inhibitory effects on NO and PGE production and iNOS protein expression at the range of $5-20{\mu}g/mL$ without cytotoxicity. Microencapsulation of green tea extract had further inhibitory effects on NO and PGE2 production and on iNOS protein expression, whereas microencapsulated GFSE did not show any further inhibitory effects on these parameters. Taken together, our results suggest that GSFE might be a promising candidate for preventing inflammation related diseases, such as cardiovascular disease, cancer or diabetes, and the microencapsulation of green tea extract could improve its bioactivity.

• 대한약침학회지
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• 제19권4호
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• pp.312-318
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• 2016

Objectives: Bacterial resistant infections have become a global health challenge and threaten the society's health. Thus, an urgent need exists to find ways to combat resistant pathogens. One promising approach to overcoming bacterial resistance is the use of herbal products. Green tea catechins, the major green tea polyphenols, show antimicrobial activity against resistant pathogens. The present study aimed to investigate the effect of catechins, green tea extract, and methylxanthines in combination with gentamicin against standard and clinical isolates of Staphylococcus aureus (S. aureus) and the standard strain of Pseudomonas aeruginosa (P. aeruginosa). Methods: The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) values of different agents against bacterial strains were determined. The interactions of green tea extract, epigallate catechin, epigallocatechin gallate, two types of methylxanthine, caffeine, and theophylline with gentamicin were studied in vitro by using a checkerboard method and calculating the fraction inhibitory concentration index (FICI). Results: The MICs of gentamicin against bacterial strains were in the range of $0.312-320{\mu}g/mL$. The MIC values of both types of catechins were $62.5-250{\mu}g/mL$. Green tea extract showed insufficient antibacterial activity when used alone. Methylxanthines had no intrinsic inhibitory activity against any of the bacterial strains tested. When green tea extract and catechins were combined with gentamicin, the MIC values of gentamicin against the standard strains and a clinical isolate were reduced, and synergistic activities were observed (FICI < 1). A combination of caffeine with gentamicin did not alter the MIC values of gentamicin. Conclusion: The results of the present study revealed that green tea extract and catechins potentiated the antimicrobial action of gentamicin against some clinical isolates of S. aureus and standard P. aeruginosa strains. Therefore, combinations of gentamicin with these natural compounds might be a promising approach to combat microbial resistance.

• 한국축산식품학회지
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• 제34권4호
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• pp.403-407
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• 2014

Changes in Maillard reaction of pidan white were monitored with $A_{294}$, fluorescence intensity, and browning intensity during pickling in the absence and presence of Chinese black tea extract (Camellia sinensis) at levels of 2% and 5% together with 0.2% $ZnCl_2$ or 0.2% $CaCl_2$ up to 3 wk, followed by ageing for another 3 wk. Browning intensity and $A_{294}$ of pidan white increased with increasing pickling/ageing, while fluorescence intensity decreased during ageing (p<0.05), irrespective of treatments. At wk 6, pidan white treated with 0.2% $ZnCl_2$ and 0.2% $CaCl_2$ showed slightly higher browning intensity, fluorescence intensity and $A_{294}$ than those treated with divalents together with Chinese black tea (p<0.05). Free amino group and sugar contents showed continuous decrease during pickling and ageing irrespective of tea and cations used. However, pidan treated without Chinese black tea extract showed significantly lower free amino group and sugar during the ageing of 6 wk (p<0.05). Thus, Chinese black tea extract had an inhibitory effect on the Maillard reaction during ageing of pidan white.

• Journal of Nutrition and Health
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• 제41권7호
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• pp.602-611
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• 2008

본 연구에서 pair feeding함으로서 사료 섭취량이 체중이나 지단백 대사에 미칠 요인을 제거한 상태에서 녹차분말이나 녹차추출물이 갖는 항 비만효과나 지질 강하효과를 비교 조사하였다. 녹차분말이나 추출물에서 증체 억제효과를 보였는데 이는 녹차성분이 소장에서의 지방흡수를 억제하거나 지방산화를 촉진하고 대사율을 올려 열량소비를 증가시킨다는 기존 연구결과와 이해를 같이 하는데, 예비실험에서 사료섭취량 자체가 억제됨을 감안 할 때 녹차 추출물이나 분말의 항비만 효과에 대해서 긍정적이다. 본 연구에서 녹차 추출물의 높은 콜레스테롤 흡수 억제력에도 불구하고 녹차의 콜레스테롤 강하효과는 나타나지 않았는데 이는 체 콜레스테롤 pool size에 강한 homeostasis 기질이 작용한 것이라고 생각할 수 있다. 식이 콜레스테롤과 지방의 흡수억제에 있어서 녹차분말과 녹차 추출물의 장내 유용성과 체 콜레스테롤의 합성과 담즙 생성에 있어서 EGCG를 포함한 차 카테킨 작용기전을 이해하기 위해서 보다 많은 연구가 필요하리라 생각된다. 녹차 분말과 추출물은 항산화 지표에도 정도에 다소 차이가 있으나 긍정적인 효과를 보였는데 녹차 카테킨은 수용성으로 bioavailability가 비교적 높은 polyphenol계 항산화 물질로서 녹차 잎의 건조중량 50% 이상이 카테킨이고 이중 80% 이상이 catechin gallate 형태로 강한 항산화 효력을 지닌 것으로 나타나 있다. 노화를 활성산소에 의한 세포의 손상과정이라 볼 때 식품으로서 녹차는 매우 중요한 입지에 있다. 차로 마시는 녹차의 섭취방법에서 분말이나 추출물로 섭취방법을 다양화하고 있는데 분말과 추출물의 영양적 효과를 비교해 볼 때 유리 (free)된 카테킨 형태로 추출물이 유리할 수 있지만 녹차분말이 식품으로서의 높은 선호도와 함께 HDL-콜레스테롤을 증가시키는 효과가 있다면 분말차의 섭취도 좋은 방법이다. 음료로서 따져 볼 때 일회 분량 2 g의 녹차를 3회 우려 마시는 경우 이로부터 섭취할 수 있는 항산화물질은 EGCG기준으로 $109{\sim}147\;mg$정도이고 이를 비타민 C 로 환산하는 경우 $142{\sim}168\;mg$이다. 천연의 항산화 물질을 자연스럽게 섭취하는 방법으로서 차의 음용을 생활화하는 것은 비만이나 퇴행성 또는 노화관련 질환의 예방차원에서 바람직하리라 본다.

• 한국식품영양학회지
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• 제18권3호
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• pp.219-224
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• 2005

녹차에 대한 보이차의 항산화력을 알아보기 위해 물 추출물과 메탄올 추출물의 항산화 효과를 비교$\cdot$조사하였다. 총 폴리페놀의 함량은 물 추출물의 경우 녹차와 보이차가 비슷하였으며 메탄올 추출물의 경우는 보이차의 함량이 녹차의 약 $58\%$정도 밖에 되지 않았다. 전자공여능은 물 추출물의 경우 녹차와 보이차가 거의 유사하였으며 메탄올추출물의 경우 보이차가 녹차의 $54\%$정도였다. SOD 유사 활성은 용매간에 많은 차이가 있었는데 물 추출물의 활성은 $13.46\~14.07\%$로 녹차와 보이차간에는 거의 차이가 없었으나 메탄올 추출물의 활성은 녹차가 $59.63\%$, 보이차가 $48.93\%$로 물 추출물보다 $3\~4$배 높았으며 또한 녹차가 활성이 높았다. 아질산염 소거능은 물 추출물의 경우 녹차와 보이차간에 거의 차이가 없었으며 메탄올 추출물은 보이차가 녹차보다 다소 효과가 높았다. ACE 저해 활성은 물 추출물의 경우 보이차가 녹차보다 약 $38\%$ 정도 활성이 높았으나 메탄올 추출물은 반대로 녹차가 보이차보다 활성이 높았다. 이상의 연구 결과 보이차의 물추출물 항산화력은 녹차와 비슷하였으나 오히려 ACE 저해활성만은 높은 값을 나타내었고 메탄올 추출물에서는 보이차는 녹차보다 항산화력이 전반적으로 낮았으나 아질산염 소거능만은 높았다.

• Natural Product Sciences
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• 제19권2호
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• pp.166-172
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• 2013

Caffeine and epigallocatechin gallate (EGCG) are major constituents of green tea, the leaves of Camellia sinensis (Theaceae). Although EGCG is well known for diverse beneficial effect, caffeine is sometimes harmful with adverse effects. Therefore, the extraction efficiency was investigated using different extraction method such as extraction solvent, extraction time, extraction method, and repeated extraction. The content of EGCG and caffeine in green tea extract was quantitated by HPLC analysis. The extraction condition exerted difference on the extraction yield. The content of EGCG was also affected by different extraction condition. Especially, the extraction solvent greatly affected the content of EGCG in the extract. However, the content of caffeine was less affected compared to that of EGCG. The inhibitory effect of green tea extract on pancreatic lipase was almost similar regardless of extraction condition. Taken together, optimization of extraction condition will provide best efficacy for further development of green tea as anti-obesity therapeutics.

• 한국환경성돌연변이발암원학회지
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• 제25권2호
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• pp.71-75
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• 2005

Green tea and their major constituents such as catechins are famous materials for their anti-oxidative and anti-carcinogenic activity, but many compounds with reducing power can promote the oxidation in their oxidized form or in the presence of metal ion. We investigated the pro-oxidative effect of the ethanol extract equivalent up to 30mg of dried weight of green tea leaves in four in vitro systems which could be used for detecting DNA damage. Although ethanol extract of green tea did not show significant mutagenicity in Salmonella typhimurium TA102, which is sensitive strain to oxidative stress, it degraded deoxyribose extensively in the presence of $FeCl_3-EDTA$ complex, promoted 8-oxoguanine formation in the live bacteria cell, Salmonella typhimurium TAI04, and cleaved super coiled DNA strand with the help of copper ion. It suggested that green tea, famous anti-oxidative material, can be pro-oxidant according to the condition of extraction or metal existence.

• 한국응용과학기술학회지
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• 제30권2호
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• pp.272-279
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• 2013

본 연구에서는 중국산 발효 보이차 잎을 고농축으로 추출하였다. 또한 이 추출물에 대한 항산화 활성 및 항노화 효과를 평가하여, 화장품 산업에 응용하고자 하였다. 발효보이차 추출물의 수득율은 17.9%이었으며, 총 폴리페놀량은 37.5%, 탄닌 7.5%, 다당체류 25%, 기타 22%, 수분 8%가 함유되어 있었다. 발효보이차 추출물의 항산화 (in-vitro)활성은 30mg/mL에서는 $33.7{\pm}1.8%$, 50mg/mL에서는 $39.4{\pm}2.2%$의 소거효과를 보였다. 비교군인 초산토코페롤과 녹차추출물 보다 높은 항산화 효과를 보였다. 발효보이차 추출물의 콜라겐 합성율(in-vitro)은 1 mg/mL에서는 $102.9{\pm}9.9%$, 5 mg/mL에서는 $111.5{\pm}9.9%$, 10 mg/mL에서는 $122.7{\pm}12.2%$, 30 mg/mL에서는 $131.5{\pm}13.7%$의 높은 합성능을 보였다 (*p-value£0.05, n=3). 8시간 후의 피부보습효과(in-vivo)는 비교군보다 38.5%의 높은 효과를 보였다. 이 보습력은 도포전보다 32.7% 상승하였다. 발효보이차 추출물은 화장품산업에서 보습효과를 가진 원료로 응용이 가능할 것으로 기대한다.

• Preventive Nutrition and Food Science
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• 제5권3호
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• pp.165-169
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• 2000

Kombucha beverages were made from sweetened tea by Oriental, European and Tibetan tea fungus starters. The hot water extracts o green tea, black tea, Gugija and Omija were mixed with white and/or brown sugar, and were fermented under a static culture at 3$0^{\circ}C$. Titrable acidity, pH, color and cellulose production in kombucha beverages were evaluated. All tea fungus starters showed a higher acid production in green/black tea extracts rather than Gugija and Omija extracts. In green/black tea extracts Oriental tea fungus produced a kombucha beverage with a higher titrable acidity and lower pH than those of European and Tibetan tea fungus starters. By the static fermentation of green/black tea extract for 18 days, Oriental, Tibetan and European tea fungus starters produced cellulose pellicles of 0.43g, 0.16g, and 0.19 g (dry weight) on the top in the culture, respectively. As a mother starter, the cellulose pellicle was more efficient in acid production compared with tea fungus broth. Oriental/Tibetan mixed tea fungus showed the best acid production in the green/black tea extract supplemented with brown sugar.

• Fibers and Polymers
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• 제7권3호
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• pp.255-261
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• 2006

There is increasing interest in the many beneficial aspects of green tea to human such as anti-carcinogenic, anti-aggregant, anti-allergic, anti-bacterial, anti-mutagenic, and anti-oxidant activities. Besides these beneficial aspects, it has been reported that green tea ingredients, especially polyphenolic families (i.e., catechin), have some UV protection property both in vivo and in topical applications. In this study, green tea extract was used as a dyeing stock for cotton and the UV protection property of the dyed cotton fabric was examined. To increase the affinity of cotton fiber to the polyphenolic components in the green tea extract, a natural biopolymer, chitosan, was used as mordanting agent. The effects of chitosan concentration in mordanting on the dyeing characteristics and the UV protection property were examined. Chitosan mordanted green tea dyed cotton showed better dyeing characteristic and higher UV protection property compared with the unmordanted green tea dyed cotton. As the chitosan concentration in mordanting increased, the dyeing efficiency and the UV protection property also increased. Therefore, adapting chitosan mordanting in green tea dyeing can increase the UV protection property of cotton fabrics to some extent.