The physiologically advantageous aspects of green tea have been identified recently and green tea has been a favorite drink of many people. Due to the increased awareness of green tea’s positive effects on human health, the demand for foods containing green tea has increased. This has led to the development of diverse green tea-related beverages; thereby many companies in Korea have put a wide variety of manufactured green tea beverages on the market. However, the components within green tea beverages have not been examined in Korea yet. In this study, we investigated the contents of the physiologically functional materials found in green tea, such as catechin, catechin gallate, epicatechin, epicatechin gallate, epigallocatecin gallate, gallocatechin gallate and caffeine. Fifty-six green tea products purchased from the local grocery stores and cafes were analyzed using high performance liquid chromatography (HPLC) analysis. As a result, all tested products contained catechin and caffeine, although the amount of each component was largely different. The total amount of catechin derivatives in the manufactured green tea beverages purchased from cafes was 263.17 mg/L, while they were 61.99 mg/L in the beverages purchased from the local grocery stores. And, to the almost samples the amount of caffeine was proportional to the amount of catechin.

녹차카테킨은 다양한 생리활성을 지닌 것으로 알려지고 있다. 본 실험에서는 사염화탄소와 갈락토사민으로 유발된 간독성에 대한 녹차카테킨의 간기능보호효과가 연구되었다. 녹차카테킨(50 mg/kg와 100 mg/kg)은 사염화탄소(0.5 ml/kg)와 갈락토사민(400 mg/kg)이 투여되기 전 그리고 투여 후 3일동안 흰쥐에 경구투여되었고, 간기능지표로 AST와 ALT를 측정하였다. 녹차카테킨(50 mg/kg)은 사염화탄소 처리된 랫드에서 상승된 혈중 AST와 ALT활성을 전투여군(262±11, 80±19 에서 153±33, 55±25로)과 후투여군(156±40, 105±3에서 106±22, 55±9로)모두 감소시켰다. 또한 갈락토사민으로 유도한 경우에도 AST와 ALT 수치는 전투석군(576±24, 276±68에서 236±13. 115±13로) 후 투여군(233±54, 137±11에서 119±23, 44±17로)에서 모두 유의성있게 감소된 결과를 나타내었다 또한 간 조직학적 검사에서도 사염화탄소와 갈락토사민으로 유도된 간경변을 유의성있게 억제하였다. 이상의 결과로 볼 때 녹차카테킨은 간독성에 의한 병변을 예방 및 치료할 수 있는 신약후보물질로서의 가능성을 시사한다.

The main constituent of green tea, catechins have been reported to have numberous biological activites 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 dosal area of SHK-1 hairless mouse daily for 2 weeks. UVB (100 mJ/㎠) 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 against UVB-induced skin damages, and these effects could contribute to the antitumor promotors activity.

The purpose of this study was to determine the optimum re-extraction conditions of ethanol from catechin in Korean green tea (Camellia sinensis L.) using response surface methodology (RSM). The experiments were carried out according to a five level and two variable central composite design (CCD). The two independent variables were solvent ratio to sample content (1, 4, 7, 10, 13 mL/g) and extraction temperature (-20, -10, 0, 10, 20℃) on the dependent variables including yield, epigallocatechin (EGC), epicathchin (EC), epigallocatechingallate (EGCG), epicatechingallate (ECG), total catechin and caffeine. ANOVA results showed that Coefficients of determination (R2) of estimated models for dependent variables were ranged from 0.9054~0.9778, while R2 of caffeine were estimated 0.8770. The optimum ranges for the maximized extraction including yield, EGC, EC, EGCG, ECG, caffeine and total catechin were 4.5~7.5 mL/g in ratio of ethanol to sample and -8~8℃ in extraction temperature. The actual values of yield, EGC, EC, EGCG, ECG, caffeine and total catechin, respectively, at the optimized conditions were 35.02%, 13.31%, 3.978%, 19.11%, 4.29%, 5.30% and 40.68%

The present study was conducted to investigate the translocation of polyphenols, especially catechin derivatives, from mushroom medium mixed with green tea residues into fruiting body of Pleurotus eryngii. Pleurotus eryngii was grown on the media incorporated by mixing or surface-treated with dry materials including leaf petioles and young stems or leaves of green tea. The dry materials treated in medium did not affect plant height and fresh weight of Pleurotus eryngii body. From the samples of Pleurotus eryngii, the eight main catechin derivatives (-)-gallocatechin(GC), (+)-catechin (C), (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epigallocatechin gallate (EGCG), (-)-gallocatechin gallate (GCG), (-)-epicatechin gallate (ECG), and (-)-catechin gallate (EGCG), and caffeine were analyzed quantitatively by HPLC. The results showed that EGC in Pleurotus eryngii was 45% more detected, when incorporated with the dry materials, than untreated control. Especially, content of EGCG was increased in surface-treated Pleurotus eryngii up to 3.2 ppm, while it was not detected or reduced in control and other treatments. Caffeine content was greatly increased regardless of treatment method, compared with control (0.1ppm), showing 44 fold-amount in Pleurotus eryngii at early growth stage when incorporated with the dry materials into medium. The results indicates that functional catechin derivatives of green tea would be partly translocated into Pleurotus eryngii throught incorporation and surface treatment with residues of green tea plants.