• Journal of Food Hygiene and Safety
• /
• v.16 no.1
• /
• pp.41-47
• /
• 2001

The purpose of this study was to elucidate the effects of green tea catechins (GTC) on the lipid peroxidation and superoxide dismutase (SOD). GTC showed the high SOD activity, while sitgnificantly inhibited the peroxide value of linoleic acid (93%) and lipid peroxidation (84%) from rat liver microsomal fraction induced by Fe$^{2+}$ascorbate system. The effects of GTC on the SOD and catalase activities, and lipid peroxidation after oral administration were investigated. GTC (50 mg/kg) significantly increased SOD (62%) and catalase activities (75%), while significantly inhibited the lipid peroxidation (52%) of rat liver microsome in a dose-dependent manner. These results suggest that GTC has the antioxidative effect which is rotated to the prevention of aging and cancer.r.

• Journal of Food Hygiene and Safety
• /
• v.11 no.2
• /
• pp.83-87
• /
• 1996

The objective of this study is to investigate the direct effects of green tea catechins(GTC) on vascular smooth muscle tension and 45Ca2+ Uptake in rat aorta. The methods used in this study are isometric tension measurements using physiograph, Lanthanum method for 45Ca2+(2 uCi/ml) uptake measurement in rat aorta. GTC modified tension induced by 40 mM KCl or 1 uM norepinephrine in rat aorta. Low concentrations of GTC(<0.5mg/ml) increased tension by 40 mM KCl or 1 uM norepinephrine, individually. However, high conecentration of GTC(>0.5 mg/ml) inhibiited tension by 40 mM KCl or 1 uM norepinephrine, individually. GTC increased 45Ca uptake induced by 40 mM KCl in a dose-dependent manner. From these results, GTC has the dual actions in vascular smooth muscle in vitro. Low concentrations of GTC augments tension by K or norepinephrine. However, high concentrations of GTC inhibits tension by K or norepinephrine GTC may have Ca2+ channel activation, action, which may result in unphysiological vasodilation by Ca2+ overload in vascular smooth muscle.

• Journal of Food Hygiene and Safety
• /
• v.11 no.2
• /
• pp.77-82
• /
• 1996

Green tea catechins(GTC) were studied for its inhibitory effect on human platelet aggregation in vitro, for its antithrombotic effect in mice in viro, and bleeding and clotting time in rats. The catechins were isolated and purified from green tea, which were composed of (-)-epigallocatechin gallate, (-)-epigallocatechin, (-)epicatechin gallate and (-)-epicatechin, GTC produced a potent inhibition of human platelet aggregation in a dose-dependent manner against the stimulants such as ADP, collagen, epinephrine and ristocetin n vitro. GTC also prevented death due to the formation of pulmonary thrombosis by platelet aggregates in mice in a dose-de-pendent manner in viro. GTC increased the bleeding time, whole blood clotting time and plasma clotting time in rats, too. These results suggest that GTC is a promising antithrombotic agent.

• Korean Journal of Clinical Laboratory Science
• /
• v.46 no.2
• /
• pp.75-78
• /
• 2014

Green tea and tea polyphenols have been studied extensively as cancer chemopreventive agents in recent years. Epigallocatechin-3-gallate (EGCG) is widely recognized as a powerful antioxidant and a free radical scavenger. The purpose of this study was to evaluate the protective effects of green tea catechins (GTC) on the Bleomycin- and Cyclophosphamide-induced cytotoxicity. Cell viability was measured by MTT assay. In the protective effect of GTC, the cell viability was significantly increased by the treatment of GTC. Furthermore, GTC showed the higher protective effect than EGCG and vitamin E. These results suggest that GTC has the protective effect which is related to the prevention of cancer. Our studies show that the continuous presence of EGCG can reduce radical-induced DNA damage in Chinese hamster lung fibroblast cells (CHL cells).

• Korean Journal of Clinical Laboratory Science
• /
• v.46 no.4
• /
• pp.131-135
• /
• 2014

Over-consumption of alcohol leads to many side-effects such as malnutrition, liver disease, and neuronal disorders and many investigators have tried to identify methods for preventing the side-effects of drinking. This study was carried out to investigate the effect of the beverage contained green tea catechins (GTC) on the alcohol administered rats. We observed that blood alcohol concentration level decreased significantly in plasma. GTC (200 mg/kg) also reduced the aspartate aminotransferase (AST) and alanine aminotransferase (ALT) level of the intoxicated rats. These results suggest that GTC may be useful for the prevention and therapy of hepatotoxic pathogenesis.

• Biomolecules & Therapeutics
• /
• v.14 no.2
• /
• pp.96-101
• /
• 2006

Amyloid$\beta(A{\beta})$ has been reported have an effect on the induction of oxidative stress that involves the functional and structural abnormalities in Alzheimer's disease. As a role of a radical scavenger, a green tea treatment was found have some inhibitory effect on the neurodegenerative process. The aim of this study was to determine if green tea catechin (GTC) reduces in transgenic model. To test this, transgenic mice carrying neuronspecific enolase (NSE) controlled C-terminus (105) of APP (APP-C105) were created and treated them with a low ana high dose of GTC for 6 months. Herein, we conclude that transgenic mice expressing NSE/APP-C105 were successfully created and the GTC-treated group exhibited significant reduction in body weight. Thus, GTC might be a good prevention of obesity or good treatment for AD patient.

• YAKHAK HOEJI
• /
• v.45 no.1
• /
• pp.101-107
• /
• 2001

Green tea catechins (GTC) and its major component, (-)-epigallocatechin gallate (EGCG) were studied for their protective effects against reactive oxygen species (ROS)-induced oxidative stress. GTC and EGCG skewed the strong antioxidative effects on the lipid peroxidation of ethyl linolate with Fenton's reagent and free radical scavenging effect to DPPH radical generation. They also protected $H_2O$$_2$- or KO$_2$-induced cytotoxicity in CHL cells or mouse splenocytes. These results indicate that GTC and EGCG are capable of protecting the lipid peroxidation, flee radical generation and cytotoxicity induced by ROS. The mechanism of inhibition in ROS-induced cytotoxicity may be due to their antiofidative and free radical scavenging properties. Therefore, GTC and EGCG may be useful chemopreventive agents by protecting the free radical generation which are involved in cancer and aging.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
• /
• v.62
• /
• pp.55-86
• /
• 2014

Korea has become a member of the United Nations Convention on Contract of the International Sales of Goods (the 'CISG') effective since March 1, 2005. As, therefore, the governing law of the general terms and conditions (the 'GTC') in the Government Foreign Procurement Contract (the 'Contract') is mandatorily fixed to the Korean Law, the CISG, as an International Convention, now having an equivalent or even higher status to the Korean Law, unless expressly excluded, will be priorly applied to the Contract where a transaction occurs between its members. In this regard, this study focuses on how to find the way for the CISG to be a governing law of the GTC in order to eliminate legal uncertainties and lacks of foreseeability prevailed in the international trade. For that purpose, the legal aspects of GTC, and the Buyer's remedy for the Seller's breach of the Contract are analyzed in accordance with the comparative study between the CISG and the GTC including the relevant case studies. As a result of this study, the application of the CISG into the GTC is highly recommended in order to reflect into the Contract such features as fairly harmonized for the interest of both parties. Taking this opportunity, a GTC, amended from the existing one, or newly formed, within the perimeter of not conflicting with the provisions of the CISG, including but not limited to the Civil Law and Commercial Law, is required in order to evenly share each party's responsibilities and obligations where the breach or remedy of the Contract is, and, thus, which will ultimately contribute to an efficient conduct of the Contract.

• Journal of Food Hygiene and Safety
• /
• v.19 no.3
• /
• pp.105-111
• /
• 2004

Green tea catechin (GTC) is known to have a wide variety of pharmacological activites. In the present study, the effects of GTC on acute hepatotoxicity induced by carbon tetrachloride ($CCl_4$) and galactosamine were examined in rats. Two doses (50 or 100 mg/kg) of GTC were administered to rats orally for 3 days befor or after the induction of hepatotoxicity. A hepatotoxicity was induced by the inpraperitoneal injection of the $CCl_4$ (0.5 ml/kg) or galactosamine (400 mg/kg). GTC(50 mg/kg) reduced the aspartate aminotransferase (AST) and alanine aminotransferase (ALT) level of the $CCl_4$-intoxicated rats in the pre-treatment group (from 262${\pm}$11, 80${\pm}$19 to 153${\pm}$22, 55${\pm}$25), and also in the post-treatment group (from 156${\pm}$40, 105${\pm}$3 to 106${\pm}$22, 55${\pm}$9), respectively. And GTC (50 mg/kg) also reduced the levels of AST and ALT in both pre-treatment (from 576${\pm}$24, 276${\pm}$68 to 236${\pm}$13, 115${\pm}$13) and post-treatment (from 233${\pm}$54, 137${\pm}$11 to 119${\pm}$23, 44${\pm}$17) when induced by galactosamine. GTC also showed the inhibition of pathogenesis of hepatocyte of $CCl_{4^-}$ and galatosamine-intoxicated rat. These results suggest that green tea catechin (GTC) may be useful fur the prevention and therapy of hepatotoxic pathogenesis.

• Journal of Internet Computing and Services
• /
• v.18 no.5
• /
• pp.31-38
• /
• 2017

Recently with the rapid development of LBS (Location-based Services) technology, approaches of protecting user's location have gained tremendous attentions. For using LBS, users need to forward their real locations to LBS server. However, if the user sends his/her real location to LBS server, the server will have the all the information about user in LBS. Moreover, if the user opens it to LBS server for a long time, the trajectory of user may be released. In this paper, we propose GTC (Grid-based Trajectory Cloaking) method to address the privacy issue. Different from existing approaches, firstly the GTC method sets the predicting trajectory and divides the map into $2^n*2^n$ grid. After that we will generate cloaking regions according to user's desired privacy level. Finally the user sends them to LBS server randomly. The GTC method can make the cost of process less than sequential trajectory k-anonymity. Because of confusing the departure and destination, LBS server could not know the user's trajectory any more. Thus, we significantly improve the privacy level. evaluation results further verify the effectiveness and efficiency of our GTC method.