• Journal of Nutrition and Health
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• v.14 no.2
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• pp.71-79
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• 1981

The purpose of this paper is to find out whether Du-chung tea and Du-chung tea added with Stevia leaves are suitable for everyday use of diabetics. For this purpose, states of diabetic rabbit, induced by giving alloxan to normal rabbit, were examined in two cases. One was to administer Du-chung tea sweetened by sugar to the above same animal and the other to apply Du-chung tea sweetened by Stevia leaves, instead of sugar, under the equal condition. A study was carried out to determine the effects on blood sugar level, contents of BUN (blood urea nitrogen) and total cholesterol, and GPT (glutamic pyruvate transaminase) activity in both groups. The following results were obtained. 1) Sweetness of Du-chung tea added with 0.3-0.5% Stevia leaves was never to the standard sweetness. 2) Sweetness of Du-chung tea with 2% sugar plus 0.2% Stevia leaves was the nearest to the standard sweetness. 3) Du-chung tea with 0.5% Stevia leaves was recognized as the most effective the next was Du-chung tea no sweetening, and the worst was Du-chung tea with sugar. Addition of 0.2% Stevia leaves without lessening sugar concentration of the above Du-chung tea showed the same result as Du-chung tea with sugar. 4) Du-chung tea with Stevia leaves and Du-chung tea without sweetening had the tendency of reducing the total cholesterol content in serum, while only Du-chung tea with Stevia leaves presented remarked difference after 4, 6 and 10 days, when they were compared with control group. 5) Degree of CPT, activity had in general the similar tendency- to that of total cholesterol content. 6) Taken Du-chung tea with Stevia leaves and Du-chung tea without sweetening, the BUN content showed reducing tendency in small quanity, but, having little defference from control group.

• Journal of Nutrition and Health
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• v.5 no.3
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• pp.109-125
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• 1972

According to the Sam-guk Sa-gi (History of three Kingdoms: Silla, Koguryo and Paeckje) tea was first brought into Korea by Kim Tae-ryeum, a diplomat, in 828 A.D. during the reign of king Hung-dot of Silla, and planted on the hill of Mt. Chi-ri. Afterwards, the tea trees were transplanted and cultivated by Buddists in many Buddist temples in southern provinces during the Silla and Koryo dynasties. People took much delight in drinking green tea, and specially the kings, buddist monks and nobilities of Silla and Koryo enjoyed drinking green tea. And eventually, the green tea became an indispensable part in all important ceremonies during the Koryo dynasty. After the Yi dynasty came into being, the dualistic philosophy of China was introduced and respected while buddist temples declined as a result of strong oppression by the ruling class. While temples were declined, the practice of drinking green tea was also declined. Nowadays we find many tea plants grow wild, which are seemed to be planted around buddist temples during the Koryo dynasty. Today, Korean people do not drink home made green tea. Instead, they like to take coffee, black tea and other tea products imported from foreign countries. Aa a result, Korea had to pay $ 520 thousand in 1969 to import foreign made tea and coffee. The natural conditions of southern provinces of Korea are very suitable in cultivating tea plants. If we develope the skill in producing good quality tea in Korea, we would be able to save the foreign exchanges that are being spent for importing foreign made tea products, and at the same time, we would be able to export our green tea to overseas. The quality of Korean green tea is as good as that of Japanese green tea. Green tea contains vitamin C while coffee and black tea do not contain it.

• Korean Journal of Agricultural Science
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• v.38 no.2
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• pp.295-299
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• 2011

The content of hesperidin in the mixed tea, which was composed of dried orange peel, laurel leaf, mulberry leaf, silver magnolia leaf, oriental melon tap, cassia seed, and licorice root, was determined by high performance liquid chromatography (HPLC). Hesperidin was quantified by a reverse phase column with gradient solvent system (watcr:acetonitrile = 80:20 to 35:65 for 30 min) and UV/VIS detection (280 nm). The How rate was kept constant at 1.0 ml/min. The content of hesperidin in the mixed tea was measured in depending on extraction time 1, 2, 3, and 4 min (29.07, 52.39, 52.45, and 88.35 mg/g, respectively).

• Toxicological Research
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• v.28 no.2
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• pp.113-116
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• 2012

Various kinds of positive effects of green tea extracts had been studied for long time which included anti-inflammation, anti-aging, and cardiometabolic effects. Although topical steroid and non-steroidal calcineurin inhibitors may control clinical symptoms of allergic contact dermatitis, some of patients also present allergic reaction to these topical agents. Therefore, we have tried green tea extracts for managing this skin disorder with expectation of anti-inflammatory effect without potential side effects including skin irritation and toxic responses. The toxicity test of green tea extract also did not show any sign of irritation in the skin throughout the test period. Moderate severity of allergic contact dermatitis presented satisfactory clinical outcome at second week follow-up which was final visit of outpatient. This result mean that green tea extract has a positive effect for managing allergic contact dermatitis but its potency and efficacy seem to be so not strong enough to control moderate severity allergy skin lesion. In this pilot study, we were able to conclude that green tea cell extracts might be applied for potential anti-inflammatory soaking without skin toxicity.

• 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.

• Journal of Nutrition and Health
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• v.56 no.1
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• pp.70-85
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• 2023

Purpose: Several studies have been conducted on the relationship between green tea intake and metabolic syndrome. However, compared to the studies carried out internationally, there is inadequate research on the relationship between domestic green tea consumption and metabolic syndrome. Therefore, in this study, the general characteristics of Koreans according to their green tea intake and its association with metabolic syndrome were examined. Methods: A total of 44,611 subjects were included in the study, and analysis was carried out using data from the Korean Genome and Epidemiology Study (KoGES) for Korean adults aged 40 or older. Green tea consumption was estimated using 106 verified food frequency questionnaires (FFQ). Metabolic syndrome was defined using the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) parameters. After adjusting for confounding variables by performing a Cox regression analysis, the association between green tea consumption and metabolic syndrome was confirmed through the hazard ratio (HR) and 95% confidence interval (CI). Results: The average incidence of metabolic syndrome was 18.7% (20.8% in men and 17.8% in women). Compared to those who drank almost no green tea, in subject groups consuming more than one cup of green tea a day, the metabolic syndrome incidence was significantly reduced by 15% (HR, 0.85; 95% CI, 0.74-0.96; p trend = 0.0200) among men and by 19% (HR, 0.81; 95% CI, 0.73-0.90; p trend < 0.0001) among women. In addition, the biomarkers related to metabolic syndrome also tended to decrease overall in these groups. Conclusion: This study concluded that as the intake of green tea increased, the incidence of metabolic syndrome and related indicators decreased. Therefore, green tea intake is believed to have a positive effect on the prevention and management of the metabolic syndrome.

• Preventive Nutrition and Food Science
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• v.4 no.2
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• pp.92-96
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• 1999

The effects of aqueous extracts from Korean commercial teas on excessive free radicals were examined utilizing spin trapping, 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical and lipid peroxidation. A potent scavenging effect of green tea and oriental senna tea was dound using sipin trapping. The most effective teasagainst the DPPH radical was green tea, followed inorder by pine leak tea, Chinese gutta percha tea and orietnal senna tea. Similar to the effects of DPPH radical , green tea, pine leaf tea, Chinese gutta percha tea and oriential senna tea had an inhibitory effect on lipid peroxidation. These findings predict that Korean tea is a promising material for scavenging free radicals, and for curing diseases related to free-radical reactions.

• Applied Biological Chemistry
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• v.31 no.3
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• pp.284-291
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• 1988

To establish the evaluation method of Korean green tea, the correlation between physicochemical characteristics and sensory scores by the expert panels were investigated using 15 kinds of green tea manufactured in 1985 from Korea, Taiwan and Japan. Tannin, caffeine and total free amino acid contents of Korean green tea are higher than foreign ones, but the chlorophyll content is the highest in Japanese high grade green tea. Sixteen free amino acids including theanine were identified, and theanine, glutamic acid, aspartic acid and arginine contents which affect the brothy taste of green tea infusion were highest in Korean green tea. Sensory score for the color of Korean green tea infusion were lower than Japanese tea, but the flavor and taste were the best. In multiple regression analysis, the quality affecting factors of the green tea were elucidated as the caffeine$(X_1)$, chlorophyll b$(X_2)$, total free amino acid contents$(X_3)$, and L value$(X_4)$ of green tea infusion. The regression equation was expressed as $Y=-21.5820+2.1691X_1+0.0130X_2+0.2314X_3-0.0001X_4$ and then $R^2$ was 0.8919.

• 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.

• Mycobiology
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• v.40 no.2
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• pp.124-128
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• 2012

Multiple treatment modalities, including topical and systemic corticosteroid and phototherapy, have been used in treatment of patients with atopic dermatitis. However, long-term corticosteroid therapy may have various adverse effects. The purpose of this study was to investigate the therapeutic efficacy and safety of bath therapy using green tea extracts for treatment of patients with atopic dermatitis. A total of four patients with atopic dermatitis were enrolled in this study. A Malassezia multiplex detection kit was used in performance of multiplex PCR on clinical isolates, which confirmed Malassezia sympodialis. Subjects underwent treatment with bath therapy using green tea extracts three times per wk for a period of 4 wk. Assessment using the scoring atopic dermatitis (SCORAD) index, the visual analogue scale for pruritus, and transepidermal water loss was performed weekly. Laboratory tests were performed before and after treatment. All patients showed marked improvement on the mean SCORAD and visual analogue scale, and a significant decrease in the mean values of serum eosinophil counts was observed after treatment. Bath therapy with green tea extract is an effective, safe, and nonsteroidal therapy for treatment of patients with atopic dermatitis associated with Malassezia sympodialis.