• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.162.1-162.1
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• 2015

The use of plasma has increased in bio-application field in recent years. Particularly, water treated by arc discharge or atmospheric pressure plasma has been actively utilized in bio-industry. In this study, we have developed a plasma activated water generating system. For this system, two kinds of plasma sources; dielectric barrier discharge (DBD) plasma and arc discharge plasma have been used. The discharge energy was calculated using the breakdown voltage and current, and the emission spectrum was measured to investigate the generated reactive species. We also analyzed the amount of reactive oxygen and nitrogen species in water using the chemical methods and nitric oxide sensor. Finally, the influence of plasma generated reactive species on the germination and growth of spinach (Spinacia oleracea) was investigated. Spinach is a green leafy vegetable that contains a large amount of various physiologically active organic compounds. However, it is characterized with a low seed germination rate.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.6
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• pp.322-330
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• 2003

The unicellular green alga Haematococcus pluvialis has recently attracted great inter-est due to its large amounts of ketocarotenoid astaxanthin, 3,3'-dihydroxy-${\beta}$,${\beta}$-carotene-4,4'-dione, widely used commercially as a source of pigment for aquaculture. In the life cycle of H. pluvialis, astaxanthin biosynthesis is associated with a remarkable morphological change from green motile vegetative cells into red immotile cyst cells as the resting stage. In recent years we have studied this morphological process from two aspects: defining conditions governing astaxanthin biosynthesis and questioning the possible function of astaxanthin in protecting algal cells against environmental stress. Astaxanthin accumulation in cysts was induced by a variety of environmental conditions of oxidative stress caused by reactive oxygen species, intense light, drought, high salinity, and high temperature. In the adaptation to stress, abscisic acid induced by reactive oxygen species, would function as a hormone in algal morphogenesis from veget ative to cyst cells. Furthermore, measurements of both in vitro and in vivo antioxidative activities of astaxanthin clearly demonstrated that tolerance to excessive reactive oxygen species is greater in astaxanthin-rich cysts than in astaxanthin-poor cysts or astaxanthin-less vegetative cells. Therefore, reactive oxygen species are involved in the regulation of both algal morph O-genesis and carotenogenesis, and the accumulated astaxanthin in cysts can function as a protective agent against oxidative stress damage. In this study, the physiological roles of astaxanthin in stress response and cell protection are reviewed.

• Journal of Nutrition and Health
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• v.49 no.5
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• pp.288-294
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• 2016

Purpose: The aim of this work was to investigate the beneficial effects of rhamnazin against inflammation, reactive oxygen species (ROS)/reactive nitrogen species (RNS), and anti-oxidative activity in murine macrophage RAW264.7 cells. Methods: To examine the beneficial properties of rhamnazin on inflammation, ROS/ RNS, and anti-oxidative activity in the murine macrophage RAW264.7 cell model, several key markers, including COX and 5-LO activities, $NO^{\cdot}$, $ONOO^-$, total reactive species formation, lipid peroxidation, $^{\cdot}O_2$ levels, and catalase activity were estimated. Results: Results show that rhamnazin was protective against LPS-induced cytotoxicity in macrophage cells. The underlying action of rhamnazin might be through modulation of ROS/RNS and anti-oxidative activity through regulation of total reactive species production, lipid peroxidation, catalase activity, and $^{\cdot}O_2$, $NO^{\cdot}$, and $ONOO^{\cdot}$ levels. In addition, rhamnazin down-regulated the activities of pro-inflammatory COX and 5-LO. Conclusion: The plausible action by which rhamnazin renders its protective effects in macrophage cells is likely due to its capability to regulate LPS-induced inflammation, ROS/ RNS, and anti-oxidative activity.

• Environmental Analysis Health and Toxicology
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• v.11 no.1_2
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• pp.49-57
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• 1996

The production of reactive oxygen species on addition of hexavalent chromium (potassium dichromate, $K_2Cr_2O_7$ ) to lung cells in culture was studied using flow cytometer analysis. A Coulter Epics Profile flow cytometer was used to detect the formation of reactive oxygen species after $K_2Cr_2O_7$ was added to A549 cells grown to confluence. The cells were loaded with the dye, 2',7'-dichlorofluorescein diacetate, after which cellular esterases removed the acetate groups and the dye was trapped intracellularly. Reactive oxygen species oxidized the dye, with resultant fluorescence. Increased doses of Cr(VI) caused increasing fluorescence (10-fold higher than background at 200 gM). Addition of Cr(III) compounds, as the picolinate or chloride, caused no increased fluorescence. Electron paramagnetic resonance (EPR) spectroscopic studies indicated that three (as yet unidentified) spectral "signals" of the free radical type were formed on addition of 20, 50, 100 and 200 gM Cr(VI) to the A549 cells in suspension. Two other EPR 'signals" with the characteristics of Cr(V) entities were seen at field values lower than the standard free radical value. radical value.

• Reproductive and Developmental Biology
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• v.39 no.1
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• pp.1-6
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• 2015

Luteolysis is a cyclical regression of the corpus luteum in many non-primate mammalian species. Prostaglandin $F_2{\alpha}$($PGF_2{\alpha}$) from the uterus and ovary induces functional and structural luteolysis in bovine. The action of $PGF_2{\alpha}$ is mediated by $PGF_2{\alpha}$ receptor located on the luteal steroidogenic and endothelial cell membranes. $PGF_2{\alpha}$ plays an important role in regulating nitric oxide production in endothelial cells of the bovine corpus luteum. Nitric oxide production and nitric oxide synthase activity are stimulated and induced by $PGF_2{\alpha}$ in luteal endothelial cells. Moreover, the reactive oxygen species inhibits progesterone secretion in bovine luteal cells and induces apoptosis. Thus, the interaction between $PGF_2{\alpha}$ and reactive oxygen species provides important aspects in physiology of the corpus luteum forfunctional and structural luteolysis.

• Biomolecules & Therapeutics
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• v.30 no.6
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• pp.479-489
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• 2022

5-Fluorouracil (5-FU) remains to be an important chemotherapeutic drug for treating several cancers when targeted therapy is unavailable. Chemoresistance limits the clinical utility of 5-FU, and new strategies are required to overcome the resistance. Reactive oxygen species (ROS) and antioxidants are balanced differently in both normal and cancer cells. Modulating ROS can be one method of overcoming 5-FU resistance. This review summarizes selected compounds and endogenous cellular targets modulating ROS generation to overcome 5-FU resistance.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.542-542
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• 2013

저온 플라즈마를 발생시키는 대기압 마이크로-플라즈마 젯(Micro-plasma jet)을 이용하여 플라즈마와 세포와의 상호작용에 대한 연구를 진행하였다. 세포의 대사과정에서 생성되는 활성산소 종(Reactive Oxygen Species, ROS)은 세포에 산화 스트레스를 유발시킨다. 이러한 스트레스는 세포 예정사(programmed cell death)의 원인이 된다. 플라즈마 형성 기체로 헬륨, 아르곤, 질소를 사용하여 각각의 기체에 따른 세포의 형태 변화 및 세포 내 활성 산소 종의 영향을 분석하였다. 실험에 사용된 세포는 인체의 폐암 세포[Human lung cancer cell, A549]이며 플라즈마 처리 후 Intracellular ROS assay를 통하여 플라즈마에서 발생되는 활성 산소 종(Reactive Oxygen Species, ROS)이 세포 내에 들어가 활성 산소 종을 증가시키는 것을 확인하였다. 이때, 플라즈마에서 발생되는 활성 산소 종(Reactive Oxygen Species, ROS)들은 광 방출 스펙트럼(Optical Emission Spectroscopy)로 분석하였고, 기체별로 비교하여 보았다. 또한, 이 때 발생되는 플라즈마의 전류-전압 특성에 따른 optical intensity를 비교하였다.

• Journal of the Korean institute of surface engineering
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• v.51 no.2
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• pp.133-137
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• 2018

Plasma devices such as jets, pencils, and torches have been developed as new tools that help penetration of target agents and applied to plasma medicine. However, these devices cannot be used in a large area. Therefore, we introduced a flexible plasma device, which can be treated of large area and designed as bendable plasma. In additional, in vitro model based on agarose gel was prepared that can be show effectiveness in the depth of penetration. Plasma treatment conditions such as power, time and distance can be optimized on the agarose gel wound model. The chemical structure of changed polysaccharides was predicted due to reactive excited atoms and molecules, UV photons, charged particles and reactive oxygen and nitrogen species (RONS).

• Toxicological Research
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• v.35 no.4
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• pp.303-310
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• 2019

We are exposed to numerous xenobiotic electrophiles on a daily basis through the environment, lifestyle, and dietary habits. Although such reactive species have been associated with detrimental effects, recent accumulated evidence indicates that xenobiotic electrophiles appear to act as signaling molecules. In this review, we introduce our findings on 1) activation of various redox signaling pathways involved in cell proliferation, detoxification/excretion of electrophiles, quality control of cellular proteins, and cell survival during exposure to xenobiotic electrophiles at low concentrations through covalent modification of thiol groups in sensor proteins, and 2) negative regulation of reactive sulfur species (RSS) in the modulation of redox signaling and toxicity caused by xenobiotic electrophiles.

• Proceedings of the PSK Conference
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• 2005.11a
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• pp.89-90
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• 2005