• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2008.10a
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• pp.75-76
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• 2008

A standardization of evaluation method of anti-oxidant activity for fabrics was studied. And then 1mM of DPPH solution was the most suitable condition. Also, it is enough to react anti-oxidant reaction in approximately 90 minutes. So we studied anti-oxidant activity for nylon and cotton treated with green tea extracts. The cotton fabrics treated with 10% o.w.f. of extract appeared to have almost 90% of anti-oxidant activity and 95% was obtained for nylon.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.78.2-78.2
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• 2003

We have previously reported that green tea catechins (GTC) displayed anti-thrombotic activity, and that this might be due to anti-platelet rather than anti-coagulation effects. In the present study, we have studied the anti-platelet activity and mechanism of gallocatechin gallate (GCG), which is a component of GTC. GCG inhibited the collagen- and U46619-induced aggregation of rabbit platelets, with IC$\^$50/ values of 63.0 and 48.3 ${\mu}$M, respectively. GCG also inhibited collagen-induced serotonin release and TxB$_2$ formation in a similar manner of platelets aggregation. (omitted)

• Animal Bioscience
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• v.34 no.3_spc
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• pp.393-404
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• 2021

Objective: This study compared the catechin composition of different tea byproducts and investigated the effects of dietary supplementation with green tea byproducts on the accumulation of abdominal fat, the modulation of lipid metabolism, and the inflammatory response in red feather native chickens. Methods: Bioactive compounds were detected, and in vitro anti-obesity capacity analyzed via 3T3-L1 preadipocytes. In animal experiments, 320 one-day-old red feather native chickens were divided into 4 treatment groups: control, basal diet supplemented with 0.5% Jinxuan byproduct (JBP), basal diet supplemented with 1% JBP, or basal diet supplemented with 5×106 colony-forming unit (CFU)/kg Bacillus amyloliquefaciens+5×106 CFU/kg Saccharomyces cerevisiae (BA+SC). Growth performance, serum characteristics, carcass characteristics, and the mRNA expression of selected genes were measured. Results: This study compared several cultivars of tea, but Jinxuan showed the highest levels of the anti-obesity compound epigallocatechin gallate. 3T3-L1 preadipocytes treated with Jinxuan extract significantly reduced lipid accumulation. There were no significant differences in growth performance, serum characteristics, or carcass characteristics among the groups. However, in the 0.5% JBP group, mRNA expression of fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC) were significantly decreased. In the 1% JBP group, FAS, ACC and peroxisome proliferator-activated receptor γ levels were significantly decreased. Moreover, inflammation-related mRNA expression levels were decreased by the addition of JBP. Conclusion: JBP contained abundant catechins and related bioactive compounds, which reduced lipid accumulation in 3T3-L1 preadipocytes, however there was no significant reduction in abdominal fat. This may be due to a lack of active anti-obesity compounds or because the major changes in fat metabolism were not in the abdomen. Nonetheless, lipogenesis-related and inflammation-related mRNA expression were reduced in the 1% JBP group. In addition, dietary supplementation with tea byproducts could reduce the massive amount of byproducts created during tea production and modulate lipid metabolism and the inflammatory response in chickens.

• 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.34 no.2
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• pp.69-74
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• 2016

The main constituent of tea catechins, EGCG [(-)-Epigallocatechin-3-gallate], could inhibit the growth of various microorganisms and differently affect gram-positive and gram-negative bacteria. Antimicrobial activity of EGCG, a compound from green tea (Camellia sinensis) extract, against Cronobacter spp. and Salmonella spp. was studied to evaluate the possibility of using EGCG as a natural food additive in various dairy products. In pure TSB culture, the growth of Cronobacter spp. was suppressed below the detection limit (1 log CFU/mL) depending on EGCG concentration ($600{\sim}800{\mu}g/mL$), after 5~16 days at $4^{\circ}C$. Similarly, the growth of Salmonella spp. was suppressed below the detection limit (1 log CFU/mL) depending on EGCG concentration ($400{\sim}800{\mu}g/mL$), after 5~16 days at $4^{\circ}C$. Therefore, these results suggest that EGCG could be used as an effective additive to inhibit the growth of Cronobacter spp. and Salmonella spp. in various dairy products, such as yoghurt, cheese, dried infant powder, and so on.

• Biomolecules & Therapeutics
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• v.21 no.1
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• pp.54-59
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• 2013

In this study, we investigated the effect of (-)-epigallocatechin-3-gallate (EGCG), a major component of green tea catechins from green tea leaves, on activities of cyclooxygenase (COX)-1 and thromboxane synthase (TXAS), thromboxane $A_2$ ($TXA_2$) production associated microsomal enzymes. EGCG inhibited COX-1 activity to 96.9%, and TXAS activity to 20% in platelet microsomal fraction having cytochrome c reductase (an endoplasmic reticulum marker enzyme) activity and expressing COX-1 (70 kDa) and TXAS (58 kDa) proteins. The inhibitory ratio of COX-1 to TXAS by EGCG was 4.8. These results mean that EGCG has a stronger selectivity in COX-1 inhibition than TXAS inhibition. In special, a nonsteroid anti-inflammatory drug aspirin, a COX-1 inhibitor, inhibited COX-1 activity by 11.3% at the same concentration ($50{\mu}M$) as EGCG that inhibited COX-1 activity to 96.9% as compared with that of control. This suggests that EGCG has a stronger effect than that of aspirin on inhibition of COX-1 activity. Accordingly, we demonstrate that EGCG might be used as a crucial tool for a strong negative regulator of COX-1/$TXA_2$ signaling pathway to inhibit thrombotic disease-associated platelet aggregation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.1
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• pp.1-10
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• 2008

Oral squamous cell carcinoma (OSCC) is the most frequent form of oral cancer and holds the eighth position in the cancer incidence ranking. OSCC patients are treated by classical therapeutic modalities consisting of surgery, radiotherapy, and/or chemotherapy. But OSCC still shows significant mortality rates. Thus, new therapeutic approaches have been investigated and the most promising one is naturally acquired agents with known anti-cancer effects. Genistein is a compound extracted from soy bean. Its anti-cancer effect on breast cancer is well established now and it is investigated whether it has similar effect on OSCC. It inhibited the growth and invasive-ness of OSCC cells in vitro, but these effects did not work in living animals in vivo. Catechin is a compound from green tea and its anti-cancer effect on OSCC is known better than other agents. Catechin showed its anti-cancer effect in vitro via induction of apoptosis, cell cycle arrest, inhibition of growth, and down-regulation of invasion/metastasis. These effects were confirmed in vivo with mouse model. Cordycepin is one of major pharmacologically important components in Cordyceps Militaris and may exert its anti-cancer effect as an adenosine receptor agonist. In recent study, it inhibited the proliferation of OSCC cells via A3 adenosine receptor. But because there is very scarce evidence on this effect, more researches are needed on this theme.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.6
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• pp.1187-1193
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• 1997

The purpose of this study was to investigate the effects of green tea catechin on lipid metabolism in streptozotocin(STZ)-induced diabetic rats. Male Sprague-Dawley rats weighing 150$\pm$10gm were randomly assigned to one normal and three STZ-induced diabetic groups. Diabetic animals were fed catechin free diet(DM-0C group), 0.5% catechin diet(DM-0.5C group) and 1% catechin diet(DM-1C group). Diabetes was experimentally induced by intravenous injection of 55mg/kg body wt of STZ in citrate buffer(pH 4.3) after feeding of three experimental diets for 4 weeks. Animals were sacrificed at the 6th day of diabetic states. Levels of blood glucose were three fold higher in all three STZ-induced diabetic groups than that of the normal group. The levels of plasma insulin were markedly lower in three STZ-induced diabetic groups than that of the normal group. The levels of plasma cortisol were increased in DM-0C group compared with that of the normal group. Triglyceride, total-cholesterol and LDL-cholesterol levels in serum were increased in DM-0C groups compared with the normal group but were not significantly different between catechin diet groups and normal group. Serum HDL-cholesterol levels were reduced in DM-0C and DM-0.5C groups by 38% and 25%, respectively and had similar tendency in the DM-1C group compared with that of control group. Atherogenic index have shown same pattern as the result of total cholesterol. Activities of 3-hydroxy-3-methylglutaryl Co enzyme A(HMG-CoA) reductase were higher in DM-0C groups than those of the normal group but were not significantly different between catechin diet groups and the normal group. It is concluded that dietary catechins can modulate lipid levels of serum and liver HMG-CoA reductase activity in diabetic rats.

• Journal of Food Hygiene and Safety
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• v.16 no.2
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• pp.117-124
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• 2001

The main constituent of green tea, catechins have been reported to have numberous biological anti-vites including antimutagenic, antibacterial, hypocholesterolemic, antioxidant and antitumor properties. In the present study, we examined the protective effect of catechin on UVB-induced skin damage. Catechin (3 mg/mouse) was topically treated to dorsal area of SHK-1 hairless mouse daily for 2 weeks. UVB (100 mJ/$\textrm{cm}^2$) was also treated soon after application of catechin alone or with catechin for 2 weeks. Catechin reduced UVB-induced infiltration of inflammatory cells, fibrosis of cells and collagen-fiber formation. In addition, catechin also prevented UVB-induced DNA fragmentation and apoptosis cell number, but not changed p53 level. Furthermore catechin inhibited UVB-induced cell proliferation. There results showed that catechin have preventive effect aganinst UVB-induced skin damages. and these effects could contribute to the antitumor promoters activity.

• Korean Journal of Food Science and Technology
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• v.47 no.4
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• pp.525-533
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• 2015

The effect of the hot water extract of defatted green tea seed cake (GTSE) on lipid metabolism and the underlying mechanisms of lipolysis in mature 3T3-L1 adipocytes were investigated. In this study, we found that the naringenin content of GTSE was 5.5 mg/g; however, catechins were not detected. The intracellular lipid droplets were stained with Oil Red O dye and quantified. Compared to the control, lipid accumulation was significantly decreased by 52%, and intracellular triglyceride (TG) level was reduced by 33% after treatment with GTSE at a concentration of $40{\mu}g/mL$. To determine the mechanism of reduction in TG content, we determined the level of fatty acid synthase (FAS), phosphorylation of adenosine monophosphate-activated protein kinase (AMPK), and acetyl-coenzyme A carboxylase (ACC) in the cell model. Incubation of the 3T3-L1 adipocytes with GTSE stimulated AMPK and ACC phosphorylation in a dose-dependent manner, and decreased the expression of FAS.