• Journal of Life Science
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• v.32 no.1
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• pp.63-69
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• 2022

The thioredoxin reductase (TrxR) system is essential for cell survival and function by playing a pivotal role in maintaining homeostasis of cellular redox and regulating signal transduction pathways. The TrxR system comprises thioredoxin (Trx), TrxR, and nicotinamide adenine dinucleotide phosphate. Trx reduced by the catalytic reaction of the TrxR enzyme reduces downstream proteins, resulting in protection against oxidative stress and regulation of cell differentiation, growth, and death. Cancer cells survive by improving their intracellular antioxidant capacity to eliminate excessively generated reactive oxygen species (ROS) due to infinite cell proliferation and a high metabolic rate. Therefore, cancer cells have high dependence and sensitivity to antioxidant systems, suggesting that focusing on TrxR, a representative antioxidant system, is a potential strategy for cancer therapy. Several studies have revealed that TrxR is expressed at high levels in various types of cancers, and research on anticancer activity targeting the TrxR system is increasing. In this review, we discuss the feasibility and value of the TrxR system as a strategy for anticancer activity research by examining the relationship between the function of the intracellular TrxR system and the development and progression of cancer, considering the anticancer activity and mechanism of TrxR inhibitors.

• Journal of Marine Life Science
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• v.5 no.2
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• pp.51-57
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• 2020

Disinfection and maintenance of rearing water in aquaculture is an essential element for the prevention of fish diseases. This is especially important in recirculating aquaculture systems (RAS) in which fish are reared at high density using recycled water. In this study, tilapia was reared in two different RAS (one with plasma generator - PW system, another without plasma generator - No PW system). In plasma treated group, UVT% of water was improved clearly, and the number of heterotrophic bacteria decreased significantly after 40 days. Total weight gain of tilapia in PW system was significantly higher, and other growth indicators were also relatively higher although not statistically significant. In addition, the fish in PW system had a 100% survival rate, and there were no histological differences between fish from both systems. Fish did not seem to be affected by the toxicity of ROS. In conclusion, it is expected that plasma water can effectively deactivate fish pathogens and improve the quality of rearing water.

• The Korea Journal of Herbology
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• v.32 no.4
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• pp.53-60
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• 2017

Objectives : Collagen decrease of Skin appears through various path ways. One of causes may be the Advanced glycation endproducts (AGEs) that combine formation of glucose and protein. The aim of this study was to explore the prevent wrinkle formation of Paeoniae radix (PR) and heated Paeoniae radix (HPR) via AGEs path way. Methods : AGEs formation inhibitory activities of PR and HPR measured using bovine serum albumin, glucose, and fructose. To evaluate the protective effects of PR and HPR in diabetic rats induced with streptozotocin (STZ) and methyl glyoxal (MGO), SD rat were distributed into four groups. Normal rats (Nor), AGEs-induced rats (Con), AGEs-induced rats treated with 100 mg/kg PR(PR), AGEs-induced rats treated with 100 mg/kg HPR (HPR). To induce AGEs, streptozotocin (50 mg/kg) was administered intraperitoneally and after 3 days administrated 100mM methyl glyoxal for 3 weeks. Results : The oral administration of HPR inhibited AGEs in skin tissues compared with PR. The increased reactive oxygen species (ROS) levels in the serum were diminished by HPR treatment. The analyses of kidney and skin tissues proteins indicated that HPR treatment effectively reduced AGEs related protein levels as compared to that by PR treatment. Also, HPR decreased anti-oxidant related protein levels in skin tissues such as catalase, glutathione peroxidase. Moreover, it inhibited the reduction of COL1A2 by decreasing MMP-1. Conclusion : Based on these results, it was suggested that PR and HPR could have Improving effects on wrinkle formation. These evidences provide useful information for the development wrinkle formation treated agent.

• The Korea Journal of Herbology
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• v.37 no.5
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• pp.63-74
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• 2022

Objective : Gastritis refers to an inflammatory disease of the gastric mucosa. Alcohol is one of the main aggression factors, causing bleeding and inflammation in the gastric mucosa and it is known to not only increase lipid peroxide levels, but also deplete key antioxidant factors. The purpose of this study was to determine the effect of Uncariae Ramulus et Uncus water extract (URW) in alcohol-induced gastritis. Methods : The total polyphenol and flavonoid contents of URW were confirmed through an in vitro experiment. Also, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging activity and ferric reducing antioxidant power (FRAP) activity were confirmed. For in vivo experiments, mice were divided into 4 groups (n=8). Also, 1 hr after oral administration of each drug, 50% ethanol was orally administered to induce gastritis. Results : As a result of in vitro experiments, URW showed excellent antioxidant activity. In alcohol-induced gastritis, URW alleviated the damage to the gastric mucosa caused by alcohol. Also, URW decreased reactive oxygen species (ROS) and malondialdehyde (MDA) levels in serum and gastric tissues, and significantly decreased the expression of NADPH oxidases in gastric tissues. In addition, it significantly modulated the nuclear factor erythroid-derived 2-related factor 2 (Nrf2) and nuclear factor-𝜅B p65 (NF-𝜅B) pathways as well as significantly increased the expression of anti-inflammatory proteins. Conclusions : These results suggest that URW not only reduces oxidative stress through excellent antioxidant activity but also relieves gastric mucosal inflammation as a regulator of Nrf2 and NF-𝜅B pathways.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.3
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• pp.184-190
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• 2016

We investigated the antioxidative and protective effects of corn silk (Zea mays L.) ethanol extracts on human HaCaT cells and erythrocytes. The NICS-2 fraction, extracted from corn silk, exhibited favorable 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) radical scavenging activities with $IC_{50}$valuesof$13.3{\pm}0.3{\mu}g/mL$ and $14.2{\pm}0.1{\mu}g/mL$ when compared with those of ${\alpha}$-tocopherol, a positive control, with $IC_{50}=10.4{\pm}02.2$ and $22.2{\pm}3.6{\mu}g/mL$, respectively. In addition, we investigated skin protection effects of NICS extracts of corn silk in HaCaT keratinocytes. To investigate the pharmacological potential of NICS-1 and NICS-2 extracts of corn silk on UV-B-induced damage in HaCaT cells, we measured the activity of interleukin (IL) 1a. Our results showed that all the corn silk extracts inhibited the UV-B-induced activity of IL-1a. In particular, NICS-1 extracts of corn silk significantly suppressed IL-1a activity in a dose-dependent manner without inducing cytotoxicity. These results indicate that the ethanol extracts of corn silk (Zea mays L.) could function as natural cytoprotective agents and antioxidants in biological systems, particularly the skin exposed to UV radiation, by protecting cellular membrane against reactive oxygen species (ROS).

• Korean Journal of Poultry Science
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• v.29 no.2
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• pp.141-148
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• 2002

Two experiments were conducted to investigate the effects of supplemental feather digests on the growth of broiler chicks and taurine content in the broiler meat. In experiment 1, a total of 40 broiler chickens(Ros $s_{R}$) were assigned to four dietary treatments: control(T1), regular feather meal(FM) diet(R-FM,T2), NaOH treated FM diet(NaOH-FM,T3), HNO) treated FM diet($HNO_{3}$ -FM, T4). In experiment 2, a total of 70 broiler chickens were assigned to seven dietary treatments: T1 to t4(same as those of Exp. 1), modified $HNO_{3}$ treated FM diet(M- $HNO_{3}$-FM, T5), hair meal diet(HM, T6) and 0.22% cystine supplemented diet(CYS, T7). Feather meals and hair meal were supplemented at the level of 5% in the diet. In experiment 1 and 2, weight gain of chicks frd with R-FM or NaOH-FM tended to be higher than control or $HNO_{3}$ -FM. In experiment 2, weight gain of chicks frd with CYS was the highest followed by R-FM, M-HN $O_3$-FM, NaOH-FM, control, HM and $HNO_{3}$ -FM. In experiment 1, taurine content in breast muscle of chicks fed NaOH-FM was sogmofocamtly higher(P<0.05) than control. In experiment 2, taurine content in breast muscle of chicks fed NaOH-FM and CYS tended to be higher than other groups. Taurine content in leg muscle was significantly different among treatments as NaOH-FM and R-FM being highest followed by M- $HNO_{3}$-FM, CYS, control, $HNO_{3}$ -FM and HM. Taurine content in the liver(Exp. 1 and 2) and heart(Exp. 2) were not significantly affected by the supplemental feather digests. These results indicated that 5% NaOH-FM in the diet was effective in increasing taurine content in breast and leg muscle of broiler chicks.s.

• Journal of Life Science
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• v.32 no.1
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• pp.11-22
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• 2022

N-methyl-D-aspartate (NMDA) receptors have received considerable attention regarding their involvement in glutamate-induced neuronal excitotoxicity. Resveratrol has been shown to exhibit neuroprotective effects against this kind of overactivation, but the underlying cellular mechanisms are not yet clearly understood. In this study, HT-22 neuronal cells were treated with NMDA in Mg²⁺-free buffer and subsequently used as an experimental model of glutamate excitotoxicity to elucidate the mechanisms of resveratrol-induced neuroprotection. We found that NMDA treatment causes a drop in MTT reduction ability, disrupts inside-negative transmembrane potential of mitochondria, depletes cellular ATP levels, and stimulates intracellular ROS production. Double fluorescence imaging studies demonstrated an increased formation of mitochondrial permeability transition (MPT) pores accompanied by apoptotic cell death, while cobalt protoporphyrin and bilirubin showed protective effects against NMDA-induced mitochondrial injury. On the other hand, zinc protoporphyrin IX significantly attenuated the protective effects of resveratrol which was itself shown to enhance heme oxygenase-1 (HO-1) mRNA and protein expression levels. In cells transfected with HO-1 small interfering RNA, resveratrol failed to suppress the NMDA-induced effects on MTT reduction ability and MPT pore formation. The present study suggests that resveratrol may prevent mitochondrial injury in NMDA- treated HT-22 cells and that enhanced expression of HO-1 is involved in the underlying cellular mechanism.

• Journal of Life Science
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• v.29 no.3
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• pp.325-331
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• 2019

Lettuce (Lactuca sativa L.) is one of the most popular green leafy vegetables, and it contains various beneficial components including polyphenolic compounds and has been known to possess various biological functions such as anti-microbial, anti-oxidative, and anti-inflammatory activities. In the present study, we prepared ethanol extract of dried lettuce (DLE) and investigated its anti-inflammatory activity. To evaluate the anti-inflammatory activity of DLE, nitric oxide (NO) production was measured in LPS-activated mouse macrophage RAW 264.7 cells. DLE significantly suppressed NO production in these cells without affecting cell viabilities while resveratrol was used as a positive control. DLE dramatically decreased the expression of pro-inflammatory genes such as iNOS and COX-2 at the mRNA and protein levels and reduced the expression of several cytokines including $IL-1{\alpha}$, $IL-1{\beta}$, IL-1F6, $TNF-{\alpha}$, CSF2 and CXCL10. In addition, DLE suppressed phosphorylation of MAPKs and the nuclear translocation of $NF-{\kappa}B$ p65 indicating DLE shows its anti-inflammatory activity via regulating MAPKs pathway and $NF-{\kappa}B$ pathways. And also, DLE reduced the production of reactive oxygen species in a dose-dependent manner. DLE increased HO-1 protein expression, and also increased the nuclear translocation of Nrf2. Overall, our results suggest that lettuce down-regulate various pro-inflammatory genes and have its anti-inflammatory activity via regulating MAPKs, $NF-{\kappa}B$, and Nrf2/HO-1 pathways.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.1
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• pp.135-143
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• 2009

There is currently increased interest in the identification of antioxidant compounds that are pharmacologically potent and have low or no side effects. Plants produce significant amounts of antioxidants to prevent the oxidative stress caused by photons and oxygen, therefore they represent a potential source of new compounds with antioxidant activity. Moutan Root Sark (MRS) has been frequently used as analgesic. antispasmodic, anti-inflammatory and remedies for female diseases. In this study. the antioxidant activity of extract from MRS was studied in vitro methods by measuring the antioxidant activity by TEAC, measuring the scavenging effects on reactive oxygen species (ROS) [superoxide anion, hydroxyl radical] and on reactive nitrogen species (RNS) [nitric oxide and peroxynitrite] as well as measuring the inhibitory effect on $Cu^{2+}$ induced human LDL oxidation and the inhibitory effect on collagen induced platelet aggregation. The MRS extracts were found to have a potent scavenging activity, as well as an inhibitory effect on LDL oxidation and on platelet aggregation. In conclusion, the MRS extracts have anti-oxidative and anti-atherosclerotic effects in vitro system, which can be used for developing pharmaceutical drug against oxidative stress and atherosclerosis.

• Journal of Arbitration Studies
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• v.20 no.1
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• pp.109-131
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• 2010

Investment Agreement is to be a part of FTA, as negotiating together both trade and investment. For example, it has a separate chapter about investment in KORUS FTA contract and is more detailed and inclusive than BIT contents which are traditional investment provisions. It is called to the investment norm of FT A. The investment agreement lures a foreign investment by providing the environment which is stable to the foreign investors. Hence, it plans in goal for the economic development of the home country. In international investment, the arbitration award cases are coming out to be divided into two parts applying MFN provisions in investor protective principles and dispute resolution process; the tendency of broad interpretation and the tendency of limited interpretation. In the case of RosInvest Co UK Ltd v. the Russian Federation awarded in 2007, the arbitration tribunal interprets that the application scope of MFN provisions contain the more lucrative dispute provision than other BITs without limitations in entity right of the investor. This judgment is the same view as arbitration tribunal position of Maffezini case. The arbitration tribunal of Plama case has kept out an assertion magnifying the arbitration tribunal's jurisdiction. That is, for applying more inclusive investor-nation resolution method from different treaty, tribunal mentioned that MFN provision had to see clearly a point of applying the investor-nation dispute resolution method. Dispute resolution process providing inclusive MFN provision has both the tendency of broad interpretation and the tendency of limited interpretation. It needs ceaselessly to do the monitoring about cases of arbitration award. In conclusion, the point where MFN provisions are applied conclusively is recognized, but it is still controversial whether or not to magnify the jurisdiction of arbitration tribunal applying MFN provisions. Therefore, it does not exist clear principle in the theory or in the award eases about the application scope for entity protection provision of MFN. Hence, The Korean government of Korea and local autonomous entities needs to keep their eyes on the trend of the international arbitration award cases in relation to the investment dispute for the future. Also, Korean government or local self-governing group must consider MFN provisions when they make a contract of international investment treaty such as writing concretely the application of MFN provisions from KORUS FTA.