• Journal of Nutrition and Health
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• v.28 no.1
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• pp.15-22
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• 1995

The antioxidant effects of aqueous green tea extracts with $\alpha$-tocopherol and lecithin dissolved in lard were investigated on the lipid metabolism in serum and liver of Sprague-Dawley male rats. Elderly male rats were fed for 8 weeks by different experimental diets containing 10% lard(w/w), 0.5% aqueous green tea extracts, 0.05% $\alpha$-tocopherol and 1.0% lecithin. By the addition of the mixture of the antioxidants, the level of total cholesterol. HDL-cholesterol and triglyceride in serum and liver were not changed. The activities of glutathione peroxidase were significantly increased in the case of addition of the antioxdant mixtures but the activities of superoxide dismutase and glutathione S-transferase were not affected.

• Textile Coloration and Finishing
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• v.11 no.3
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• pp.15-22
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• 1999

This study investigated the mordanting effect of natural mordants such as camellia ash, bean chaff ash and pyrolignite of iron(Iron(II) Acetate) on silk fabrics dyed with green tea extracts. Experimental variables include the conditions of extraction and dyeing, and types of natural mordants. Inorganic ion contents In natural mordants were analysed by Induced Coupled Plasma Atomic Emission Spectrometer. In the ash Al, Fe, Si and Mn were in % unit, Cr and Ni were detected in ppm unit, and in the aqueous extracts of the ash all the metal ions were in ppm unit. On the other hand, fairly high content of Al(2.13% ) in camellia ash extract and Fe(7.91% ) in the aqueous extracts of pyrolignite iron were detected. The absorbance intensity of green tea extracts in UV-Visible spectrum increased with the temperature and time of extraction. The maximum absorption wavelength of the extracts appeared at 272.5nm and 210.5nm. The US values of silk fabrics dyed with green tea extracts were increased with temperature and time of dyeing. Surface color of silk fabric dyed with green tea extracts was 9.1YR, but it was changed from 7.9YR to 7.5YR by camellia ash extract and 7.4YR to 6.4YR by bean chaff ash extract with increase in mordant concentration. Pre-mordanted and post-mordanted fabrics with pyrolignite of iron were changed from 1.4YR to 1.1R and 7.2P to 4.2P, respectively.

• Food Science and Preservation
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• v.16 no.3
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• pp.392-399
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• 2009

Recent studies indicate that green tea may have anticancer, antioxidant, and antihypertensive effects, and aids body weight control and the promotion of various desirable physiological functions. However, few studies have investigated the antimicrobial effects of green tea. We sought to determine the antimicrobial activity of green tea extract against food spoilage microorganisms. The extract showed remarkable antimicrobial effects against a wide spectrum of putrefactive and food spoilage microorganisms when used at concentrations greater than $500{\mu}g/ml$. The extract showed thermal and pH stability in the range of $40{\sim}150^{\circ}C$ and pH 3.11, respectively. Green tea extract seems to be an ideal natural antimicrobial, considering both efficacy and thermal and pH stabilities. Antimicrobial substances in green tea extract were investigated using electron microscopy and a $\beta$-galactosidase assay. The data showed that the extract contains several efficacious materials, and that their activities are not synergistic but are instead independent. Our data indicate that hydrophilic antimicrobial substances in green tea extract might control food spoilage microorganisms owing to perturbation of the microbial cell membrane.

• Korean Journal of Food Science and Technology
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• v.25 no.6
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• pp.759-763
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• 1993

The antioxidant effects of aqueous green tea extract(AGTE) obtained from green tea and its combinations with several synergists on lard were investigated to equalize with that of crude catechin in green tea. The antioxidant effect of crude catechin was about 3-fold higher than that of AGTE. The suitable synergists for AGTE were ${\delta}-tocopherol$ and lecithin, while the tendency of their synergistic effects was different from each other. Addition of ${\delta}-tocopherol$ within 0.05% dosage to lard showed significant synergistic effect, and its synergistic effect decreased with the concentration of AGTE over 0.1% dosage. In combination of AGTE and lecithin, they gradually enhanced synergistic effect on lard with increasing the concentration. The combinations of AGTE, ${\delta}-tocopherol$ and lecithin showed intense synergistic effects and the optimum level of the each component was 0.1% AGTE, 0.05% ${\delta}-tocopherol$ and 1% lecithin. By adding the optimum level of three components to lard, the induction period was lenghtened approximately 8-fold than that of the control owing to their synergism. Comparing the antioxidant effect between the AGTE with synergists and crude catechin, the former was 60% and 20% higher than the latter at 0.1% and 1% dosage respectively.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.47 no.4
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• pp.281-287
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• 2021

In this study, we analyzed the cosmetic applicability of extract from snow tea, native to Lijiang, Yunnan-province, China. After confirming the species as N. grossedentata through DNA analysis of Lijiang snow tea, experiments were conducted using representative tea, green tea, and a representative control group for each efficacy analysis. Both teas were extracted using 70% (v/v) ethanol aqueous solution. The polyphenol content in the Lijiang snow tea extract (gallic acid equivalent, 23.9 ± 3.2 mg/mL) was higher than that in green tea extract (16.4 ± 2.3 mg/mL). In contrast, the antioxidant (Radical scavenging, IC₅₀ 104 ㎍/mL), tyrosinase enzyme inhibitory (whitening agent, IC₅₀ 40.7 ㎍/mL), and Escherichia coli growth inhibitory (preservative) activities (IC₅₀ 2.85 mg/mL) were analyzed based on the solid content in the extract, and it was confirmed that the activities of Lijiang snow tea extract were superior to those of green tea extract (radical scavenging, IC₅₀ 234 ㎍/mL. It also showed similar efficacy to previously used active substances such as antioxidants (vitamin C, IC₅₀ 108 ㎍/mL), whitening agents (vitamin C, IC₅₀ 80㎍/mL), and preservatives (methylparaben, IC₅₀ 4.35 mg/mL). However, green tea was found to be better in collagenase inhibition activity (anti-wrinkle). Through this study, the cosmetic application potential of Lijiang snow tea is high.

• Korean Journal of Food Science and Technology
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• v.53 no.3
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• pp.267-277
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• 2021

To evaluate hepatoprotective effects, the antioxidant capacities of matcha green tea extract (Camellia sinenesis) were compared to those of green leaf tea and the anti-inflammatory activities in HepG2 cells were investigated. Evaluation of the total phenolic and total flavonoid content, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, and inhibitory effect on lipid peroxidation indicated that the aqueous extract of matcha green tea presented significant catechin content and antioxidant capacity compared to those of green leaf tea. In addition, the extract had considerable inhibitory effects on α-glucosidase, α-amylase, and advanced glycation end-products. The matcha green tea extract significantly increased cell viability and reduced reactive oxygen species in H₂O₂- and high-glucose-treated HepG2 cells. Furthermore, in response to oleic acid-induced HepG2 cell injury, treatment with matcha green tea aqueous extract inhibited lipid accumulation and regulated the expression of inflammatory proteins such as p-JNK, p-Akt, p-GSK-3β, caspase-3, COX-2, iNOS, and TNF-α. Matcha green tea could be used as a functional material to ameliorate hepatic lipid accumulation and inflammation.

• Korean Journal of Veterinary Service
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• v.33 no.3
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• pp.275-285
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• 2010

This study was designed to evaluated the nitrite scavenging activity and protective effect of the Puerariae Radix and green tea extract on lead acetate and cadmium-induced liver damage in mice. The quantitative analytical method for major antioxidants, isoflavones, puerarin, catechine and caffeine in galgun (Puerariae Radix) and green tera extract were established by HPLC. Contents of isoflavones, such as daidzin, genistin, daidzein and genistein were 4.23g/100g, 0.13g/100g, 0.07g/100g, and 0.03g/100g, and puerarin contents was 8.99g/100g, respectively. The total catechins and caffeine contents of green tea extract were 49.24g/100g and 6.53g/100g. The nitrite scavenging ability of galgun extract (pH 1.2, 100mg/ml) was 98.07% and it was higher than those of other extracts. It was the highest at the pH 1.2 and more than 64% in 25~100mg green tea extract, and was dependents on pH and concentration of the samples. The hepatoprotective effects of an aqueous extract from the root of gal gun and standard puerarin were evaluated against lead acetate and cadmium-induced liver damage in mice. Galgun extract and standard at a dose of 100mg/kg and 10mg/kg, 50mg/kg were administered orally once daily for successive 5 days and then a lead acetate and cadmium were orally at 3 hrs after the every day administration of galgun. The substantially elevated serum enzymatic activities of alanine and aspartate aminotransferase were due to lead acetate and cadmium treatment was dose dependently restored to the near normal level. In addition, galgun extract also significantly prevented the elevation of hepatic malon-dialdehyde formation in the liver of lead acetate and cadmium intoxicated mice in a dose-dependent manner. The results of this study clearly indicated that green tea and galgun extracts had nitrite scavenging ability and galgun extract had potent hepato-protective effects against lead acetate and cadmium-induced hepatic damage in mice and standard puerarin was also showed similar to the results of the galgun extracts.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.4
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• pp.608-613
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• 2011

The aqueous Green tea comes to be used with the Oriental medicine plant, it has the numerous health benefits, including antioxidant, anti-inflammatory, and anti- carcinogenic properties. Epidermal progenitor cells give rise to multiple skin lineages: hair follicle, sebaceous gland and the overlying interfollicular epidermis. Sebocytes are the cells of the sebaceous gland, which synthesize and accumulate lipid dropolets. In order to determine the effect of Green tea on lipid production, several experiments were performed in SZ95 cells (sebocytes). We found that Green tea increased lipid droplets compared with control in a dose-dependent manner. Human sebaceous glands produce sebum, a lipid mixture of squalene, wax esters, triglycerides, cholesterol esters, and free fatty acids that is secreted onto the skin. Therefore, to investigate the effects of Green tea on intracellular lipid levels, we treated SZ95 cells with Green tea, and then examined cholesterol and triglyceride levels. After treatment of the cells with Green tea, the cholesterol and triglyceride levels of SZ95 cells were increased significantly in a dose-dependent manner.

• Korean Journal of Food Science and Technology
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• v.42 no.1
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• pp.103-108
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• 2010

To obtain the best yield of the beneficial ingredients in green tea, such as catechins, green tea powder is most often prepared by ethyl alcohol extraction. However, the taste, cost and composition of ethyl alcohol extract is different from aqueous spray-dried green tea extract (aq-GTE). Specifically, aq-GTE has a better flavor, lower production costs and higher purity when compared to ethyl alcohol extract. In this study, we elucidated the effect of aq-GTE on diet-induced obesity in male C57BL/6J mice following dose-dependent oral administration of aq-GTE. After eight weeks, the body weight was reduced by 13-17% in mice fed 200 mg/kg bw aq-GTE ($12.468{\pm}0.45\;g$; p<0.05) and 20-25% in mice fed 400 mg/kg bw aq-GTE ($11.259{\pm}0.61\;g$; p<0.05) when compared with the high-fat diet (HFD) control group mice ($14.714{\pm}0.95\;g$; p<0.05). The correlation between epididymal fat accumulation and body weight also decreased by approximately 26.6% (p<0.05) in mice fed a HFD with aq-GTE 400 mg/kg bw. Finally, serum parameters such as the triglyceride, glucose and cholesterol levels in the HFD groups were reduced by the aq-GTE 400 mg/kg bw diet. Analysis on glutamic-pyruvic transaminase, blood urea nitrogen and development of hepatic steatosis revealed no histologic evidence of hepatotoxicity in HFD mice fed aq-GTE. Overall, our results imply that aq-GTE is able to regulate body weight and fat accumulation in mice.

• Korean Journal of Food Science and Technology
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• v.41 no.1
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• pp.82-86
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• 2009

The objective of this study was to evaluate the effect of various solvents on extraction of bioactive phenolics and to analyze the antioxidant capacity and contents of individual catechins in various grades of green teas organically grown in Boseong, Korea. The organic green teas, based on their harvest seasons, were categorized into five grades such as Woo-Jeon, Se-Jak, Jung-Jak, Dae-Jak, and coarse tea. Solvents used to extract phenolics from these teas included water at $23^{\circ}C$ and $70^{\circ}C$ as well as 80% (v/v) aqueous methanol and ethanol. In general, aqueous organic solvents of methanol and ethanol led to higher extraction yields of phenolics than water at $23^{\circ}C$ and $70^{\circ}C$. Total phenolics and antioxidant capacity of the teas extracted with the aqueous organic solvents were approximately 1.5 to 3.2 and 1.8 to 3.8 times higher than those with water at $23^{\circ}C$ and $70^{\circ}C$, respectively. Coarse tea, the lowest grade of green tea, showed approximately 30-60% lower total phenolics and antioxidant capacity compared with the higher grade ones. Reversed-phase HPLC analysis was performed quantitatively to identify individual catechins, gallic acid, and caffeine in teas extracted with 80% (v/v) aqueous methanol. Based on their dry weights, the organic green teas contained about 1.7 to 2.9% of caffeine. Content (mg/g dry weight) of tea catechins decreased in the following order: Woo-Jeon (155.4) > Se-Jak (147.7) > Jung-Jak (143.2) > coarse tea (135.1) > Dae-Jak (130.5). (-)-Epigallocatechin gallate was the most abundant among the catechins analyzed. The highest grade of green tea, Woo-Jeon, had the highest amount of (-)-epigallocatechin gallate at 77.4 mg/g dry weight. Overall, the higher grade of organic green teas tended to have the higher level of antioxidant capacity and catechins.