• Journal of the Korean Wood Science and Technology
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• v.42 no.5
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• pp.579-589
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• 2014

Atopic dermatitis (AD) syndrome is one of the most common and severe skin diseases in Korea; a large population has this disease. We examined the effects of the extract from the leaf and sprig of Camellia sinensis on the development of AD by using NC mice as a model of atopic dermatitis. Oral administration of the extract to NC/Nga mice treated with 2,4?dinitrochlorobenzene (DNCB) inhibited the development of AD-like skin lesions as shown by a significant decrease in the skin symptoms of the disease and a decrease in ear thickness and levels of immunoglobulin E (IgE) and thymus-and activation-regulated chemokine (TARC) level in the skin. Administration of the extract markedly suppressed the DNCB-induced mRNA expression of interleukin 4 (IL-4) and tumor necrosis factor ${\alpha}$ (TNF-${\alpha}$). The findings suggest that transdermal application of the extract may modulate in the skin of NC/Nga mice. The extract was effective for the prevention and treatment of AD.

• Journal of Applied Biological Chemistry
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• v.60 no.3
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• pp.199-205
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• 2017

To investigate the anti-inflammatory activity of natural products, we determined the anti-inflammatory activity of purified epigallocatechin (EGC) from Camellia sinensis leaves. In the present study, we found that EGC inhibited the production of proinflammatory mediators (IL-6, TNF-${\alpha}$, NO, and $PGE_2$) in lipopolysaccharide (LPS)-stimulated Raw 264.7 cells. Suppression of IL-6 seems to be at least partly attributable to the inhibitory effect of EGC. TNF-${\alpha}$ is a major cytokine produced by LPS-induced macrophages, and they have a wide variety of biological functions including regulation of inflammation. The inhibition of IL-6 and TNF-${\alpha}$ production by EGC may downregulate the acute-phase response to LPS, thereby reducing LPS-induced inflammation. In addition to IL-6 and TNF-${\alpha}$, EGC effectively reduced the production of other key inflammatory mediators, including NO and $PGE_2$. The inhibitory effect of EGC on NO and $PGE_2$ production was supported by the suppression of inducible nitric oxide synthase and COX-2 at protein levels. These results support the traditional use of EGC in the alleviation of various inflammation-associated diseases and suggest that EGC might be useful in the development of new functional foods for inflammatory diseases.

• The Korean Journal of Food And Nutrition
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• v.22 no.2
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• pp.279-285
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• 2009

Antioxidant and antimicrobial efficiency were investigated for: i) water extract of green tea(Camellia sinensis), ii) water extract of middle drying megmoondong(Liriope platyphylla Wang et Tang) and iii) water extract of drying megmoondong. The electron donating ability of the green tea(Camellia sinensis) and drying megmoondong(Liriope platyphylla Wang et Tang) extract were 88 and 79, respectively, while that of the middle drying megmoondong extract showed low levels. The relative inhibitory abilities against lipid peroxidase were: green tea(Camellia sinensis) extract > drying megmoondong(Liriope platyphylla Wang et Tang) extract > middle drying megmoondong extract. The green tea(Camellia sinensis) extract showed the strongest antimicrobial effect against Staphylococcus aureus. The middle drying(Liriope platyphylla Wang et Tang) and drying megmoondong extracts showed no antimicrobial effect against Staphylococcus aureus. The green tea(Camellia sinensis) extract had the strongest antimicrobial effect against Escherichia coli. The middle drying megmoondong(Liriope platyphylla Wang et Tang) and drying megmoondong extracts showed no antimicrobial effect against Escherichia coli.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.9
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• pp.1134-1139
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• 2007

This study was conducted to investigate the effects of four kinds of tea (Camellia sinensis) extracts on the antioxidant defense systems as well as the activities of alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) in ethanol administered ICR mice. According to the results, treatment with puerh tea significantly increased the superoxide dismutase activity and glutathion reductase activity in liver. In addition, the group treated with oolong tea exhibited higher superoxide dismutase activity and glutathion reductase activity in serum than those of puerh tea, green tea and black tea treated groups. The oolong tea and puerh tea also reduced malondealdehyde contents in both liver and serum. These results suggested that puerh tea and oolong tea were the most effective against alcohol-induced oxidative damage among the Camellia sinensis teas. On the other hand, in the measurement of alcohol break-down enzyme activities, the group treated with green tea exhibited the highest hepatic ADH and ALDH activities, suggesting that the group treated with green tea might be useful for alcohol down-regulation.

• The Korean Ginseng Research and Industry
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• v.10 no.1
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• pp.12-16
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• 2016

• Bulletin of Food Technology
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• v.19 no.2
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• pp.140-148
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• 2006

• Preventive Nutrition and Food Science
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• v.14 no.1
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• pp.49-53
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• 2009

Antioxidative activities of major pentacyclic terpenoids from the semi-fermented tea of Camellia sinensis L. were investigated. The free radical scavenging activities of triterpenoids $1{\sim}3$ were examined with of DPPH and superoxide anion radical scavenging activity. The $IC_{50}$ of compounds 1 and 2 for DPPH radical scavenging activities were 23.1 and $37.2{\mu}g/mL$ respectively, and for superoxide anion radical scavenging activities were 37.2 and $35.2{\mu}g/mL$, respectively. According to this result, compounds 1 or 2 in semi-fermented tea could be the candidates for bioactive material having antioxidant activity.

• The Plant Pathology Journal
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• v.16 no.3
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• pp.162-165
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• 2000

Screening of effective fungicides, determination of effective fungicide application time and investigation of the emergence of resistant isolates to fungicides were conducted to establish effective chemical control strategy of gray blight of tea (Camellia sinensis) in Korea. Systemic fungicides, such as bitertanol, were effective for controlling gray blight when the fungicides were sprayed within 3 days after cutting tea leaves for harvest. Sprayed immediately after cutting, contact fungicides such as chlorothalonil were also effective, but control efficacy rapidly decreased with lengthening of the intervals between cutting and spraying. Korean isolates of P. longiseta and P. theae were still sensitive to bitertanol or fluazinam. However, the isolates highly insensitive to copper hydroxide or thiophanate-methyl have already emerged in Korea. Therefore, careful attention should be paid to use of fungicides and spraying programs for the effective control of gray blight of tea in Korea.

• Plant Resources
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• v.6 no.3
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• pp.195-204
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• 2003

Genetic diversity of 45 tea accessions from Korea, Japan, China and Taiwan was investigated by using RAPD analysis. Out of the eighty primers screened, twenty primers generated 99 polymorphic bands with a polymorphic rate 87.0%. The size of the amplified fragments ranged from about 3,138 bp to 520 bp. By cluster analysis, all of the 45 accessions can be grouped into five groups. Over 90% of the 32 Korean accessions belonged to group II, III, IV and V. Moreover, newly developed Korean cultivars (accession no. 13, 14 and 15) belonged to very different group compared with any other Korean accessions. Among the Korean accessions, the minimum genetic similarity 0.500 was obtained between accession no. 17 and 37 and the largest genetic similarity 0.912 between no. 20 and 21.

• Proceedings of the Korean Society of Crop Science Conference
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• 2004.04a
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• pp.154-155
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• 2004