• Title/Summary/Keyword: anti oxidant

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A Study on Seaweed Sea Staghorn(Codium fragile) Ethanol Extract for Antioxidant (해조류 청각(Codium fragile) 에탄올 추출물의 항산화에 관한 연구)

  • Lee, Ju-Hee;Kim, Bo-Ae
    • The Journal of the Convergence on Culture Technology
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    • v.5 no.4
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    • pp.467-472
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    • 2019
  • Seaweeds are rich in in minerals, vitamins, proteins, and fiber, and are classified as green algae, and they are distributed on the coasts of Korea, East Asia, Oceania, etc. and are used as a health function material as well as food ingredients in our countries and countries. In this study, Codium fragile was extracted from ethanol and concentrated to confirm DPPH radical scavenging activity, SOD activity, FRAP and ABTS cation radical scavenging ability. As a result, DPPH scavenging activity was 0.83, 22.83, 38.27, 40.93, 45.60% at 6.25, 12.50, 25, 50 and $100{\mu}g/mL$, SOD-like activity were 23.13, 33.63, 33.93, 44.07 and 59.07%. FRAP and ABTS showed antioxidant activity in a concentration-dependent manner, as in the previous experiment. Therefore, this study confirmed that it can be used as a cosmetic material using Codium fragile, a natural material.

Analysis of Ar Plasma Effects for Copper Nitride Passivation Formation via Design of Experiment (실험계획법을 통한 구리 질화물 패시베이션 형성을 위한 아르곤 플라즈마 영향 분석)

  • Park, Hae-Sung;Kim, Sarah Eunkyung
    • Journal of the Microelectronics and Packaging Society
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    • v.26 no.3
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    • pp.51-57
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    • 2019
  • To protect the Cu surface from oxidation in air, a two-step plasma process using Ar and $N_2$ gases was studied to form a copper nitride passivation as an anti-oxidant layer. The Ar plasma removes contaminants on the Cu surface and it activates the surface to facilitate the reaction of copper and nitrogen atoms in the next $N_2$ plasma process. This study investigated the effect of Ar plasma on the formation of copper nitride passivation on Cu surface during the two-step plasma process through the full factorial design of experiment (DOE) method. According to XPS analysis, when using low RF power and pressure in the Ar plasma process, the peak area of copper oxides decreased while the peak area of copper nitrides increased. The main effect of copper nitride formation in Ar plasma process was RF power, and there was little interaction between plasma process parameters.

In vitro antioxidant activity of black tea (Camellia sinensis L.) residue extract (홍차박 추출물의 in vitro 항산화 활성)

  • Kim, Dong Chung
    • Journal of Applied Biological Chemistry
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    • v.62 no.3
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    • pp.281-286
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    • 2019
  • A black tea (Camellia sinensis L.) residue extract (BTRE) was prepared by 30% ethanol extraction to evaluate its in vitro antioxidant activity. The yield and polyphenol content of BTRE were $22.4{\pm}1.18%$ and $23.2{\pm}1.02{\mu}g$ gallic acid equivalents/mg-extract, respectively. Antioxidant activity of BTRE proportionally increased as BTRE concentration increased. $IC_{50}$ values of BTRE for cation radical, free radical and nitrite scavenging were 141.8, 108.1, and $397.2{\mu}g/mL$, respectively. Also $IC_{50}$ value of BTRE for ferric reducing anti-oxidant power was $97.8{\mu}g/mL$. BTRE effectively inhibited linoleic acid peroxidation. These results imply that BTRE possessed potent antioxidant activity, thus being utilized as a physiologically active material.

Neuroprotective mechanisms of dieckol against glutamate toxicity through reactive oxygen species scavenging and nuclear factor-like 2/heme oxygenase-1 pathway

  • Cui, Yanji;Amarsanaa, Khulan;Lee, Ji Hyung;Rhim, Jong-Kook;Kwon, Jung Mi;Kim, Seong-Ho;Park, Joo Min;Jung, Sung-Cherl;Eun, Su-Yong
    • The Korean Journal of Physiology and Pharmacology
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    • v.23 no.2
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    • pp.121-130
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    • 2019
  • Glutamate toxicity-mediated mitochondrial dysfunction and neuronal cell death are involved in the pathogenesis of several neurodegenerative diseases as well as acute brain ischemia/stroke. In this study, we investigated the neuroprotective mechanism of dieckol (DEK), one of the phlorotannins isolated from the marine brown alga Ecklonia cava, against glutamate toxicity. Primary cortical neurons ($100{\mu}M$, 24 h) and HT22 neurons (5 mM, 12 h) were stimulated with glutamate to induce glutamate toxic condition. The results demonstrated that DEK treatment significantly increased cell viability in a dose-dependent manner ($1-50{\mu}M$) and recovered morphological deterioration in glutamate-stimulated neurons. In addition, DEK strongly attenuated intracellular reactive oxygen species (ROS) levels, mitochondrial overload of $Ca^{2+}$ and ROS, mitochondrial membrane potential (${\Delta}{\Psi}_m$) disruption, adenine triphosphate depletion. DEK showed free radical scavenging activity in the cell-free system. Furthermore, DEK enhanced protein expression of heme oxygenase-1 (HO-1), an important anti-oxidant enzyme, via the nuclear translocation of nuclear factor-like 2 (Nrf2). Taken together, we conclude that DEK exerts neuroprotective activities against glutamate toxicity through its direct free radical scavenging property and the Nrf-2/HO-1 pathway activation.

The Evaluation of Exogenous Melatonin Administration in Supraspinatus Overuse Tendinopathy in an Experimental Rat Model

  • Kocadal, Onur;Pepe, Murad;Akyurek, Nalan;Gunes, Zafer;Surer, Hatice;Aksahin, Ertugrul;Ogut, Betul;Aktekin, Cem Nuri
    • Clinics in Shoulder and Elbow
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    • v.22 no.2
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    • pp.79-86
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    • 2019
  • Background: Increased oxidative stress and inflammation play a critical role in the etiopathogenesis of chronic tendinopathy. Melatonin is an endogenous molecule that exhibits antioxidant and anti-inflammatory activity. The aim of this study was to evaluate the biochemical and histopathological effects of exogenous melatonin administrations in supraspinatus overuse tendinopathy. Methods: Fifty rats were divided into the following four groups: cage activity, melatonin treatment, corticosteriod therapy, and control. Melatonin (10 mg/kg, intraperitoneal; twice a day) and triamcinolone (0.3 mg/kg, subacromial; weekly) were administered to the treatment groups after the overuse period. Biochemical and histopathological evaluations were performed on serum samples and biopsies obtained from rats. Plasma inducible nitric oxide synthase (iNOS), vascular endothelial growth factor (VEGF), total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) levels were evaluated biochemically. Results: The TAS, TOS, OSI, iNOS, and VEGF values were significantly lower than the pre-treatment levels in rats receiving exogenous melatonin treatment (3 or 6 weeks) (p<0.05). TOS, iNOS, VEGF, and OSI values after 3 weeks of triamcinolone administration, and TOS, VEGF, and OSI levels after 6 weeks of triamcinolone application, were significantly lower than the pre-treatment levels (p<0.05). Conclusions: Exogenous melatonin application in overuse tendinopathy reduces oxidative stress and inflammation. Melatonin might be an alternative potential molecule to corticosteroids in the treatment of chronic tendinopathy.

Persulfate Oxidation of 2,4-D: Effect of Hydroxylamine and Chelating Agent (과황산을 이용한 2,4-D의 산화: 하이드록실아민, 킬레이트제의 영향)

  • Choi, Jiyeon;Yoon, Na Kyeong;Shin, Won Sik
    • Journal of Soil and Groundwater Environment
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    • v.26 no.1
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    • pp.54-64
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    • 2021
  • The chemical warfare agents (CWAs) have been developed for offensive or defensive purposes and used as chemical weapons in war and terrorism. The CWAs are exposed to the natural environment, transported through the water system and then eventually contaminate soil and groundwater. Therefore, effective decontamination technology to remediate CWAs are needed. The CWAs are extremely dangerous and prodution is strictly prohibited, therefore, it is difficult to use CWAs even in experimental purpose. In this study, 2,4-dichlorophenoxyacetic acid (2,4-D) was chosen as a model representative CWA because it is a simulant of anti-plant CWAs and one of the major component of agent orange. The optimum degradation conditions such as oxidant:activator ratio were determined. The effects of hydroxylamine and chelating agents such as citric acid (CA), oxalic acid (OA), malic acid (MA), and EDTA addition to increase Fe2+ activation were also investigated. Scavenger experiments using tert-butyl alcohol (TBA) and ethanol confirmed that although both sulfate (SO4•-) and hydroxyl radical (•OH) existed in Fe2+-persulfate system, sulfate radical was the predominant radical. To promote the Fe2+ activator effect, the effect of hydroxylamine as a reducing agent was investigated. In chelating agents assisted Fe2+-persulfate oxidation, the addition of 2 mM of CA and MA enhanced 2,4-D degradation. In contrast, EDTA and OA inhibited the 2,4-D removal due to steric hindrance effect.

LAB Fermentation Improves Production of Bioactive Compounds and Antioxidant Activity of Withania somnifera Extract and Its Metabolic Signatures as Revealed by LC-MS/MS

  • Yu, Jinhui;Geng, Yun;Xia, Han;Ma, Deyuan;Liu, Chao;Wu, Rina;Wu, Junrui;You, Shengbo;Bi, Yuping
    • Journal of Microbiology and Biotechnology
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    • v.32 no.4
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    • pp.473-483
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    • 2022
  • In this study we investigated the effect of lactic acid bacteria (LAB) fermentation on the ingredients and anti-oxidant activity of Withania somnifera extract. Four strains of LAB could proliferate normally in medium containing W. somnifera extract after the pH reached 3.1~3.5. LAB fermentation increased the content of alcohols and ketones, endowing the extract with the characteristic aroma of fermentation. Compared to the control, the DPPH and ABTS free radical scavenging rates in the fermented samples were significantly improved, ranging from 48.5% to 59.6% and 1.2% to 6.4%. The content of total phenols was significantly increased by 36.1% during the fermentation of mixed bacteria. Moreover, the original composition spectrum of the extract was significantly changed while the differentially accumulated metabolites (DAMs) were closely related to bile secretion, tryptophan metabolism and purine metabolism. Therefore, LAB fermentation can be used as a promising way to improve the flavor and bioactivity of the extracts of W. somnifera, making the ferments more attractive for use as functional food.

Nutritional and Sensory Quality of Prepared Tomato (Solanum lycopersicum) Leather

  • Chhetri, Arun Jung;Dangal, Anish;Shah, Rajesh;Timsina, Prekshya;Bohara, Ebika
    • Analytical Science and Technology
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    • v.35 no.4
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    • pp.169-180
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    • 2022
  • Tomato has a limited shelf life and is highly perishable due to its high moisture content. As fruit leather, is a traditional food of Nepal, it can be beneficial to move towards value addition and diversification of the traditional product. The main aim was to analyze the nutritional values and phytochemicals of the tomato pulp and prepared leather, and sensory evaluation of prepared tomato leather. Five samples A, B, C, D and E were prepared with 80:20, 72.5:27.5, 95:5, 87.5:12.5 and 65:35 fruit pulp: sugar ratio respectively. Analysis of raw tomato pulp and all the five samples was performed. Sensory quality of the product sample A was found superior to that of other samples but chemical and phytochemical properties of product sample C was found superior than that of other prepared samples. Therefore, we had two best products, in terms of sensory properties and in terms of nutritional properties. The best product on the basis of nutrients (sample C) had acidity (%), TSS (°Bx), pH, total ash content (%), crude protein (%), crude fat (%), crude fiber (%), carbohydrate (%), vitamin C (mg/100 g), total energy (Kcal/100 g), TPC (mg GAE/g of dry extract), TFC (mg QE/g of dry extract), DPPH scavenging activity (% of inhibition) and lycopene content (mg/100 g) was found to be 3.70.1, 20 ± 0.02, 3 ± 0.1, 2.30 ± 0.05, 2.69 ± 0.04, 0.87 ± 0.02, 5.46 ± 0.01, 69.68 ± 0.02, 25.17 ± 1.25, 297.31 ± 0.01, 85.35 ± 0.02, 65.39 ± 0.02, 59.23 ± 0.03 and 98.57 ± 0.02 respectively. A tasty and nutritious product of tomato, leather can be prepared which can be more appealing to the consumer.

The Protective Effects of Dioscoreae Rhizoma on the Exposure to UVA of MEF cells (산약의 Mouse embryonic fibroblast cell에 대한 자외선 손상 방어효과)

  • Jin, Yong-Jae;Sung, Jung-Seok;Kim, Dong-Il
    • The Journal of Korean Obstetrics and Gynecology
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    • v.22 no.3
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    • pp.36-50
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    • 2009
  • Purpose: This study was to determine the protective effects of Dioscoreae Rhizoma on the Mouse Embrio Fibroblast (MEF) cells exposed to the ultraviolet rays(UVA). Methods: The samples were assigned randomly to five groups; control group without any treatments, UVA group exposed only to UVA, DR group exposed only to the Dioscoreae Rhizoma, UVA-DR group exposed to UVA before being treated with the Dioscoreae Rhizoma, and DR-UVA group treated with the Dioscoreae Rhizoma before being exposed to UVA. The survival rate of cells, metabolic rate of cells, transformation of nucleus within cells, alteration of cell cycle, effects on the apoptosis, the change of the amount of protein related to cell cycle were measured in order to determine the cell protective effects of the Dioscoreae Rhizoma on each group. Results: 1. DR-UVA group has more cell protective effects compared to the UVA group in all experiments, indicating that the Dioscoreae Rhizoma protects skin from UVA physically and chemically. 2. UVA-DR group shows more efficiency compared to UVA group in rapid recovery of damaged cell and leading highly damaged cells to apoptosis, preventing the expression of abnormal cells. Conclusions: Dioscoreae Rhizoma has effects of protecting MEF cells from UVA, of recovering cells damaged by UVA, and of prohibiting the expression of abnormal cells.