• Journal of Life Science
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• v.17 no.10
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• pp.1354-1360
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• 2007

Theaflavins (TF) and thearubigins (TR) are constituents of tea pigments which are polyphenols derived from Korean fermentation tea. After TF, TR and [(-) epigallocatechin-3-gallate](EGCG) have been applied to macrophage cell line (RAW264.7) nitric oxide (NO) synthesis and cytokines production were estimated. Cytokines production by enzyme linked immune-sorbent assay (ELISA) determined. NO production was increased by about 1.5-folds at the dose of $80\;{\mu}g/ml$ compared to control and lipopolysaccharide (LPS) stimulation when TF, TR and EGCG were applied to a RAW264.7 cell. Interleukin-6 (IL-6), Tumor necrosis factor ($TNF-{\alpha}$) and granulocyte-macrophage colony stimulating factor (GM-CSF) increased depended on concentrations of TF, TR and EGCG. The production of tumor necrosis $factor-{\alpha}$ increased highly in TR, TF and EGCG group with LPS. These results suggest that TF, TR and EGCG have immune-enhancement effect through the cytokine production. TF, TR and EGCG inhibited cancer cell viability, the anticancer effect of these polyphenols may explain the anti-tumor promotion action and antioxidant activity of these tea constituents.

• Molecules and Cells
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• v.41 no.2
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• pp.73-82
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• 2018

Cancer preventive activities of green tea and its main constituent, (-)-epigallocatechin gallate (EGCG) have been extensively studied by scientists all over the world. Since 1983, we have studied the cancer chemopreventive effects of EGCG as well as green tea extract and underlying molecular mechanisms. The first part of this review summarizes groundbreaking topics with EGCG and green tea extract: 1) Delayed cancer onset as revealed by a 10-year prospective cohort study, 2) Prevention of colorectal adenoma recurrence by a double-blind randomized clinical phase II trial, 3) Inhibition of metastasis of B16 melanoma cells to the lungs of mice, 4) Increase in the average value of Young's moduli, i.e., cell stiffness, for human lung cancer cell lines and inhibition of cell motility and 5) Synergistic enhancement of anticancer activity against human cancer cell lines with the combination of EGCG and anticancer compounds. In the second part, we became interested in cancer stem cells (CSCs). 1) Cancer stem cells in mouse skin carcinogenesis by way of introduction, after which we discuss two subjects from our review on human CSCs reported by other investigators gathered from a search of PubMed, 2) Expression of stemness markers of human CSCs compared with their parental cells, and 3) EGCG decreases or increases the expression of mRNA and protein in human CSCs. On this point, EGCG inhibited self-renewal and expression of pluripotency-maintaining transcription factors in human CSCs. Human CSCs are thus a target for cancer prevention and treatment with EGCG and green tea catechins.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.28 no.1
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• pp.42-57
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• 2002

본 연구는 널리 알려져 있는 항산화제들의 세포 수준에서의 anti-oxidative stress 효과 및 그 기작을 알아보기 위한 연구이다. 연구에 사용한 항산화제로는 지용성인 retinol, $\alpha$-tocopherol, propyl gallate(PG) 및 butylated hydroxy toluene(BHT)과 수용성인 ascorbic acid, $\alpha$-glucosyl rutin 및 green tea extract를 사용하였으며 이들 항산화제들의 시간별 세포 생존율을 NR assay 로 측정한 후 적정 농도에서 DCFH-DA(2', 7'-dichlorofluorescin-diacetate) 를 이용하여 항산화제들의 anti-oxidative stress 억제 효과를 시간별로 측정하였다. 또한 이들 항산화제의 항산화 기작을 알아보기 위하여 NBT(Nitro-blue-tetrazolium) 및 DPPH(Diphenyl-picry-hydrazl)도 병행하여 실시하였다. Anti-oxidative stress 실험에서 지용성 항산화제들은 전반적으로 수용성 항산화제에 비하여 세포에 대한 독성이 상대적으로 강하여 retinol 의 경우에는 0.01%에서 oxidative stress 억제 효과를 관할할 수 있었으며 1 시간경과 후 측정시 53.1%의 억제 효과를 보여 주었다. PG 의 경우에는 0.1%에서 2 시간 경과 후 측정시 50%의 oxidative stress 억제 효과를 보여주었다. 수용성 항산화제인 green tea extract 및 $\alpha$-glucosyl rutin의 경우에는 1%에서 1시간 경과 후 측정시 각 각 51.6% 및 69.7%의 oxidative stress 억제 효과를 관찰할 수 있었다. 또한 시료처리 후 자외선 조사시 oxidative stress 억제 효과의 경우 수용성 항산화제인 ascorbic acid, $\alpha$-glucosyl rutin 및 green tea extract 와 지용성 항산화제 중에서는 $\delta$-tocopherol 에서만 oxidative stress 억제 효과가 관찰되었으나 자외선을 조사 하지 않았을 때 보다 약 20%-40%까지 억제 효과가 감소되었다. 그리고 PG 및 retinol 의 경우에는 자외선 조사시 독성이 증가하여 oxidative stress 억제 효과를 측정할 수 없었다. NBT실험에서 $\alpha$-glucosyl rutin, $\alpha$-tocopherol 및 PG 1%에서 70%이상의 superoxide anion 생성 억제 효과를 보였으며 DPPH 실험에서는 ascorbic acid 와 PG 1%에서 98%의 hydroxyl radical 생성 억제 효과를 보여 주었다. 본 실험을 통하여 BHT 를 제외하고 전반적으로 세포 수준에서의 oxidative stress 에 대한 억제 효과를 확인해 볼 수 있었으며 특히 수용성 항산화제들에서 두드러진 효과를 보여 주었다.

• Korean Journal of Clinical Pharmacy
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• v.28 no.4
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• pp.342-346
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• 2018

Background: Green tea extracts are approved as nonprescription drug and available as health functional foods, health foods, and beverages. Clinical information on the products is lacking. Methods: Information about the products on green tea nonprescription drugs was obtained from the website of the Korea Pharmaceutical Information Center. The Naver, i.e., a top ranking online search portal, was used for compiling the list of the health functional food products using key words of 'green tea catechin' on August 23, 2018. The recommended daily dosages of catechins were calculated as 30% of the total dried mass of green tea and about 50% of the catechins were considered as epigallocatechin gallate (EGCG). Results: A total of two types of nonprescription drugs containing green tea powder or extracts, nine health functional food products, and three types of health foods were found. The regulatory requirements of the EGCG exceeding 800 mg were reported to be associated with adverse effects of elevated liver enzyme. If consumers take several green tea products concurrently, such as nonprescription drugs with health functional foods or health foods, it could exceed the recommended amount of EGCG. Conclusion: The concurrent use of green tea products as nonprescription drugs, health functional foods, and healthy foods may lead to an increased exposure to EGCG. Pharmacists should be aware the availability of various types of green tea products and the potential risk of liver toxicity due to excessive consumption of EGCG.

• Natural Product Sciences
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• v.28 no.3
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• pp.143-152
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• 2022

In our study, sixteen known phenolic compounds, including quercetin (1), methyl gallate (2), caesalpiniaphenol C (3), 8S,8'S,7'R-(-)-lyoniresinol (4), 7,3',5'-trihydroxyflavanone (5), sappanchalcone (6), sappanone A (7), taxifolin (8), fisetin (9), fustin (10), (+)-catechin (11), brazilin (12), 3,4,5-trimethoxyphenyl β-ᴅ-glucopyranoside (13), 1-(2-methylbutyryl)phloroglucinol-glucopyranoside (14), (+)-epi-catechin (15), and astragalin (16) and one mixture of two conformers of protosappanin B (17/18) were isolated from the stems of Caesalpinia decapetala var. japonica. Their structures were elucidated based on a comparison of their physicochemical and spectral data with those of literature. To the best of our knowledge, this represents the first isolation of compounds 3, 4, 8, 9, and 10 from C. decapetala and compounds 13 and 14 from the Caesalpinia genus. All the isolated compounds were evaluated for their inhibitory effect against the α-glucosidase enzyme. Among them, two flavonols (1 and 9), one chalcone (6), and one homoisoflavanone (7) exhibited an inhibitory effect on α-glucosidase action with an IC₅₀ range value of 5.08-15.01 μM, stronger than that of the positive control (acarbose, IC₅₀ = 152.22 μM). Kinetic analysis revealed that compounds 1 and 9 showed non-competitive α-glucosidase inhibition, while the inhibition type was mixed for compounds 6 and 7.

• Animal Bioscience
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• v.36 no.1
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• pp.53-62
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• 2023

Objective: In this study, metabolites that changed in the rumen fluid, urine and feces of dairy cows fed different feed ratios were investigated. Methods: Eight Holstein cows were used in this study. Rumen fluid, urine, and feces were collected from the normal concentrate diet (NCD) (Italian ryegrass 80%: concentrate 20% in the total feed) and high concentrate diet (HCD) groups (20%: 80%) of dairy cows. Metabolite analysis was performed using proton nuclear magnetic resonance (NMR) identification, and statistical analysis was performed using Chenomx NMR software 8.4 and Metaboanalyst 4.0. Results: The two groups of rumen fluid and urine samples were separated, and samples from the same group were aggregated together. On the other hand, the feces samples were not separated and showed similar tendencies between the two groups. In total, 160, 177, and 188 metabolites were identified in the rumen fluid, urine, and feces, respectively. The differential metabolites with low and high concentrations were 15 and 49, 14 and 16, and 2 and 2 in the rumen fluid, urine, and feces samples, in the NCD group. Conclusion: As HCD is related to rumen microbial changes, research on different metabolites such as glucuronate, acetylsalicylate, histidine, and O-Acetylcarnitine, which are related to bacterial degradation and metabolism, will need to be carried out in future studies along with microbial analysis. In urine, the identified metabolites, such as gallate, syringate, and vanillate can provide insight into microbial, metabolic, and feed parameters that cause changes depending on the feed rate. Additionally, it is thought that they can be used as potential biomarkers for further research on subacute ruminal acidosis.

• The Korea Journal of Herbology
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• v.34 no.6
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• pp.109-115
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• 2019

Objective : Herbal medicinal mixture (JMB) are consisted of Caryophylli Flos, Aucklandiae Radix, and Angelicae Dahuricae Radix. Each of these herbal medicines has studied on anti-aging effect in vitro. So this study was conducted to investigate efficacy and potency of JMB extract on dermal anti-aging and whitening. Methods : The JMB was extracted at room temperature by 80% ethanol. Collagenase and elastase inhibition activity in JMB ethanol extract were determined at 10, 50, 100, 500, 1000 mg/ml concentrations by colorimetric method. The toxic range of JMB ethanol extract was evaluated using MTT assay. Also, The inhibitory effect of JMB ethanol extract on tyrosinase activity and melanin contents in mouse melanoma cell line (B16F10 cell) was identified at 50, 100, 200 ㎍/㎖ levels by spectrometric assay. In each analysis, EGCG (epigallocatechin gallate) and Kojic acid were used as positive controls, respectively. Results : The elastase and collagenase inhibitory activity of JMB ethanol extract increased dose dependently. Also, The MTT assay showed that JMB, up to 400 ㎍/㎖ concentration, exhibited no toxic effect to the B16F10 cell. And following the JMB ethanol extract treat, cellular melanin contents and tyrosinase activity were dose-dependently decreased compared to those of control. Conclusion : These results suggest that JMB ethanol extract has effects to inhibitory activity on dermal wrinkle enzyme and melanogenesis. Therefore, JMB has applicable benefits for development of materials or products to have whitening and anti-aging functions on skin.

• Journal of Digestive Cancer Research
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• v.4 no.2
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• pp.64-76
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• 2016

The step-wise process of colorectal carcinogenesis from aberrant crypt foci, adenoma to adenocarcinoma, is relatively suitable for chemopreventive intervention. Accumulated evidences have revealed that maintaining an undifferentiated state (stemness), inflammation, and oxidative stress play important roles in this colon carcinogenesis process. However, appropriate molecular targets that are applicable to chemopreventive intervention regarding those three factors are still unclear. In this review, we summarized appropriate molecular targets by identification and validation of the prospective targets from a comprehensive overview of data that showed colon cancer preventive effects in clinical trials, epidemiological studies and basic research. We first selected a study that used aspirin, statins and metformin from FDA approved drugs, and epigallocatechin-gallate and curcumin from natural compounds as potential chemopreventive agents against colon cancer because these agents are considered to be promising chemopreventive agents. Experimental and observational data revealed that there are common target molecules in these potential chemopreventive agents: T-cell factor/lymphoid enhancer factor (TCF/LEF), nuclear factor-&B (NF-κB) and nuclear factor-erythroid 2-related factor 2(NRF2). Moreover, these targets, TCF/LEF, NF-κB and NRF2, have been also indicated to suppress maintenance of the undifferentiated state, inflammation and oxidative stress, respectively. In the near future, novel promising candidate agents for colon cancer chemoprevention could be identified by integral evaluation of their effects on these three transcriptional activities.

• Food Science and Preservation
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• v.16 no.6
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• pp.946-952
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• 2009

We investigated the physicochemical properties and antioxidant activities of green tea with respect to extraction conditions. The values of pH, and the L, a, and b Hunter parameters of green tea beverage 1 (GTB 1), green tea beverage 2 (GTB 2), and commercial green tea beverage (CGTB) were 6.22, 96.91, -1.06, and 7.77 5.40, 96.39, -1.73, and 13.68 and 6.20, 95.40, -4.75, and 25.51, respectively. The total free amino acid content of GTB 1 and 2, and CGTB, were 253.21, 262.65, and 58.36 mg/100 mL, and the major free amino acids were aminoadipic acid (102.56, 136.29, and 27.02 mg/100 mL), arginine (23.32, 30.75, and 7.31 mg/100 mL), and serine (18.22, 17.96, and 5.94 mg/100 mL). The levels of total phenolics and caffeine were higher in GTB 2 (852.58 and $225.51\;{\mu}g/mL$) than in GTB 1 (500.65 and $317.34\;{\mu}g/mL$) or CGTB (387.14 and $164.53\;{\mu}g/mL$). The catechin content of GTBs 1 and 2, and CGTB, were 294.8, 415.7, and $130.99\;{\mu}g/mL$, respectively. The major catechins of GTB 1 and 2, and CGTB were epigallocatechin, catechin, and epigallocatechin gallate, in that order, and the epigallocatechin contents were 186.50 in GTB 1, 268.10 in GTB 2, and $82.26\;{\mu}g/mL$ in CGTB. GTB 1 and 2 and CGTB showed substantial dose-dependent antioxidative activities. The DPPH radical-scavenging activities of GTB 1 and 2, and CGTB, were 85.48, 87.09, and 87.03%, respectively at a concentration of $125\;{\mu}g/mL$. The ferric reducing/antioxidant activities (FRAPs) of GTB 1 and 2 and CGTB were 2.66, 2.70 and 2.67 absorbance at a concentration of $1,000\;{\mu}g/mL$. Sensory evaluation tests revealed no significant differences among the three green tea beverages.

• Journal of Dairy Science and Biotechnology
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• v.27 no.2
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• pp.7-16
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• 2009

Appenzeller cheese samples were prepared by addition of 0.5, 1.0, and 2.0% green tea (Camellia sinensis, CS) powder and control cheese. We examined various quality characteristics of the novel cheese, such as viable-cell counts, pH, water-soluble nitrogen (WSN), non-casein nitrogen (NCN), non-protein nitrogen (NPN), and catechin level during maturation for 16 weeks at $14^{\circ}C$. To develop a Korean natural cheese containing green tea powder, we also analyzed the changes in the polyacrylamide gel electrophoresis pattern, chemical composition, and sensory qualities. The viable cell counts of the samples were not significantly different. Until the $3^{rd}$ week, the pH of the CS cheese decreased with an increase in the maturation time. However, the pH gradually increased by the $12^{th}$ week, while WSN, NCN, NPN also increased. The WSN, NCN, NPN, and catechin values for the CS cheese samples were significantly higher than the values for the control cheese. The polyacrylamide gel electrophoretic pattern of caseins for the CS cheese indicated that this cheese degraded more rapidly than the control cheese did. In the sensory evaluation, cheese with 1.0% CS powder showed the highest scores in taste and appearance and good scores in flavor and texture. These results indicate that 1.0% CS is the optimal value for addition to cheese, and cheese containing 1.0% CS shows good physiological properties and reasonably high overall sensory acceptability.