• Title/Summary/Keyword: Free radicals

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Neuroprotective Effects of Pinelliae Rhizoma Water-Extract by Suppression of Reactive Oxygen Species and Mitochondrial Membrane Potential Loss in a Hypoxic Model of Cultured Rat Cortical Cells. (배양대뇌신경세포 저산소증모델에서 유해산소생성억제 및 사립체막전위 소실방지에 의한 반하(半夏)의 신경세포사 억제 효능)

  • Kwon, Gun-Rok;Moon, Il-Soo;Lee, Won-Chul
    • Journal of Life Science
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    • v.19 no.5
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    • pp.598-606
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    • 2009
  • Oxidative stress by free radicals is a major cause of neuronal cell death. Excitotoxicity in hypoxia/ischemia causes an increase in reactive oxygen species (ROS) and a loss of mitochondrial membrane potential (MMP), resulting in dysfunction of the mitochondria and cell death. Pinelliae Rhizoma (PR) is a traditional medicine for incipient stroke. We investigated the effects of PR Water-Extract on the modulation of ROS and MMP in a hypoxic model using cultured rat cortical cells. PR Water-Extract was added to the culture medium at various concentrations (0.25${\sim}$5, 5.0 ${\mu}g/ml$) on day in vitro 12(DIV12), given a hypoxic shock (2% $O_2$/5% $CO_2$, $37^{\circ}C$, 3 hr), and cell viability was assessed on DIV15 by Lactate Dehydrogenase Assay (LDH assays). PR Water-Extract showed a statistically significant effect on neuroprotection (10${\sim}$15% increase in viability; p<0.01) at 1.0 and 2.5 ${\mu}g/ml$ in normoxia and hypoxia. Measurement of ROS production by $H_2DCF-DA$ stainings showed that PR Water-Extract efficiently reduced the number and intensity of ROS-producing neurons, especially at 1 hr post shock and DIV15. When MMP was measured by JC-1 stainings, PR Water-Extract efficiently maintained high-energy charged mitochondria. These results indicate that PR Water-Extract protects neurons in hypoxia by preventing ROS production and preserving the cellular energy level.

Effect of Water Extract of Cynanchi Wilfordii Radix in RANKL-induced Osteoclast Differentiation (백하수오(白何首烏) 물 추출물의 파골세포 분화에 미치는 영향)

  • Ahn, Yong-Hwan;Oh, Jae-Min;Lee, Myeung-Su;Jung, Jong-Hyuk;Chae, Soo-Uk;Moon, Seo-Young;Jeon, Byung-Hoon;Choi, Min-Kyu
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.26 no.2
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    • pp.160-165
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    • 2012
  • Osteoporotic fracture became a serious social problem, which related with mortality and morbidity in old age population. Osteoclast which is responsible for bone resorption is originated from hematopoietic cell line and plays a key role osteoporotic bone loss. Cynanchum wilfordii (Asclepiadaceae) roots have been used in Korean folk medicine for the treatment of diabetes mellitus and aging progression. Also, recent studies have shown that the extract and fractions of Cynanchi Wilfordii Radix have various pharmacological actions including scavenging free radicals, enhancing immunity, reducing high serum cholesterol, and anti-tumor activity. However, the effect of extract of Cynanchi Wilfordii Radix in osteoclast differentiation had not been reported. Thus, we evaluated the effect of Cynanchi Wilfordii Radix on receptor activator of nuclear factor-${\kappa}B$ ligand (RANKL)-induced osteoclast differentiation. Through our study, we found that Cynanchi Wilfordii Radix significantly inhibited osteoclast differentiation induced by RANKL. Cynanchi Wilfordii Radix suppressed the activation of p38 pathway and $NF{\kappa}B$ in bone marrow macrophages (BMMs) treated with RANKL. Also, Cynanchi Wilfordii Radix significantly inhibited the mRNA expression of c-Fos, tartrate-resistant acid phosphatase (TRAP), osteoclast-associated receptor (OSCAR), nuclear factor of activated T cells (NFAT)c1 and cathepsin K in BMMs treated with RANKL. Particularly, Cynanchi Wilfordii Radix inhibited the protein expression of c-fos and NFATc1. Taken together, our results demonstrated that Cynanchi Wilfordii Radix may be useful treatment option of bone-related disease such as osteoporosis leads to fracture of bone and rheumatoid arthritis.

In vitro Antioxidant Activity of Sanguisorbae Radix Ethanol Extracts (지유 에탄올추출물의 생체외 항산화 활성)

  • Rhim, Tae-Jin
    • Korean Journal of Plant Resources
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    • v.26 no.2
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    • pp.149-158
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    • 2013
  • The objective of this study was to investigate the antioxidative capacity of ethanol extracts from Sanguisorbae officinalis L. root (Sanguisorbae radix) in vitro. The concentration of Sanguisorbae radix extract at which DPPH radical scavenging activity was inhibited by 50% was 0.33 mg/mL, which was similar to $IC_{50}$ of ${\alpha}$-tocopherol (0.40 mg/mL), as compared to 100% by pyrogallol as a reference. Total antioxidant status was examined by total antioxidant capacity against ABTS radical reactions. Total antioxidant capacities of Sanguisorbae radix extract were significantly (p<0.05) higher than those of ${\alpha}$-tocopherol. Superoxide scavenging activities of Sanguisorbae radix extract were significantly (p<0.05) higher than those of catechin. Oxygen radical absorbance capacities of Sanguisorbae radix extract were significantly (p<0.05) higher than those of ascorbic acid. Cupric reducing antioxidant capacities of Sanguisorbae radix extract were significantly (p<0.05) higher than those of ${\alpha}$-tocopherol. Sanguisorbae radix extract prevented supercoiled DNA strand breakage induced by hydroxyl radical and peroxyl radical. Total phenolic contents of Sanguisorbae radix extract at concentrations of 0.5 and 5 mg/mL were 0.50 and 3.33 mM gallic acid equivalents, respectively. Sanguisorbae radix extract at concentration of 0.01, 0.1 and 0.5 mg/mL inhibited 0.2 mM tert-butyl hydroperoxide-induced cytotoxicity by 33.8, 79.1 and 96.9%, respectively, in HepG2 cell culture system. Thus, strong antioxidant and cytotoxicity-ihnibiting effects of Sanguisorbae radix extract seem to be due to, at least in part, the prevention from free radicals-induced oxidation as well as high levels in total phenolic contents.

Component Analysis and Comparison of Biological Activities of Salvia miltiorrhiza Bunge from Different Cultivation Regions (재배지역별 단삼의 성분 분석 및 생리활성 비교)

  • Yang, Eun Ju;Seon, Yoo Kyung;Seo, Ye-Seul;Shin, Bo Yeon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.46 no.8
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    • pp.929-936
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    • 2017
  • The purpose of this study was to compare the chemical components and biological activities of Salvia miltiorrhiza Bunge (SMB) from different cultivation regions (Gochang, Yeongyang, Jangheung, and China). Proximate compositions and contents of total polyphenols and flavonoids were measured. Depending on the cultivation region, proximate composition of SMB showed significant variations. Total polyphenol and total flavonoid contents were highest in Yeongyang SMB and Gochang SMB, respectively. We prepared hot water and 75% ethanol extracts of SMB from different cultivation regions and also investigated the biological effects of extracts on anti-oxidant, antibacterial, and anti-inflammatory activities. Extracts of Yeongyang SMB were the most effective at scavenging DPPH and ABTS free radicals, and hot water extract showed better scavenging activity than 75% ethanol extract. We observed that extracts of Yeongyang SMB exhibited the best antibacterial activity against Bacillus cereus, and 75% ethanol extract showed better antibacterial activity than water extract. Anti-inflammatory activities of SMB extracts from different cultivation regions were investigated through evaluation of their inhibitory effects on production of nitric oxide (NO) in lipopolysaccharides-induced RAW 264.7 cells. At $50{\mu}g/mL$, extract of China SMB showed the highest NO inhibitory activity of 34% among water extracts, and extract of Gochang SMB showed the highest NO inhibitory activity of 68% among 75% ethanol extracts. Salvianolic acid B level was the highest in extract of Yeongyang SMB with values of 110.59 mg/g for water extract and 111.93 mg/g for 75% ethanol extract.

Radical Scavenging Activities and Antioxidant Constituents of Oriental Melon Extract (참외 추출물의 라디칼소거활성과 항산화 성분)

  • Kim, Hye-Suk;Hong, Mi-Jeong;Kang, In-Yeong;Jung, Ji-Youn;Kim, Hye-Kyung;Shin, Yong-Seub;Jun, Ha-Joon;Suh, Jun-Kyu;Kang, Young-Hwa
    • Journal of Bio-Environment Control
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    • v.18 no.4
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    • pp.442-447
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    • 2009
  • Extracts from various parts of oriental melon were obtained and antioxidant property and antioxidant constituents including total phenol, total flavonoid, total vitamin C were examined. Free radical scavenging activity was measured by DPPH and ABTS method. Peel part of oriental melon showed the most potent scavenging activities against DPPH and ABTS radicals. The contents of total phenol, total flavonoid in peel were higher than other parts except vitamin C. The amount of vitamin C was the highest in placenta. The relationship between antioxidant activities and antioxidant constituents was determined and showed higher correlation coefficients between antioxidant activities and content of total phenol than other constituents. The above results suggest that phenolic compounds affect antioxidant activity of oriental melon and oriental melon has a good promise as functional food for enhancing health.

Comparison of Biological Activities of Extracts from Different Parts and Solvent Fractions in Cornus kousa Buerg (산딸나무의 부위별 추출물 및 용매 분획물의 생리활성 비교)

  • Kim, Young-Jung;Jeong, Jin-A;Kwon, Su-Hyun;Lee, Cheol-Hee
    • Korean Journal of Plant Resources
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    • v.21 no.1
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    • pp.28-35
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    • 2008
  • Several extracts of different parts and solvent fractions of Cornus kousa were obtained and their functional material contents, antioxidant activities and tyrosinase inhibition effects were determined. Content of total polyphenols and flavonoids contents in flower were 169.638 $mg{\cdot}g^{-1}$ and 25.418 $mg{\cdot}g^{-1}$, respectively, which were much higher than those of other parts. Also, flower extracts showed the strongest effects on DPPH and ABTS radicals scavenging and ferrous ion chelating. In flower, leaf, and stem extracts, inhibition effects on peroxidation of linoleic acid determined by ferric thiocyanate(FTC) method were higher than a synthetic antioxidant, BHT. Tyrosinase inhibition activities were shown only in flower extract. Flower and leaf extracts, showing high biological activities in various system, were successively reextracted with n-hexane, chloroform, ethylacetate and n-butanol. Total polyphenol contents of water fractions were higher than any other solvent fractions in both flower and leaf, 67.006 $mg{\cdot}g^{-1}$ and 67.739 $mg{\cdot}g^{-1}$, respectively. But total flavonoid contents were higher in ethyl acetate fraction for flower extract and butanol fraction for leaf extract. Among the solvent fractions, the highest efficiency of free radical scavenging activities was obtained in ethyl acetate fraction for flower extract and n-butanol fraction for leaf extract. Tyrosinase inhibition activities were higher in water fraction for both flower and leaf extracts, 49.24% and 31.8%, respectively.

Antioxidant and Alcohol Degradation Activities of Extracts from Acer tegmentosum Maxim. (벌나무 열수 및 에탄올 추출물의 항산화 활성 및 알코올 분해능)

  • Choi, Jun-Hyeok;Lee, So-Hee;Park, Yun-Hee;Lee, Sung-Gyu;Jung, Yung-Tae;Lee, In-Seon;Park, Jun-Hong;Kim, Hyun-Jeong
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.42 no.3
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    • pp.378-383
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    • 2013
  • The purpose of this study is to evaluate the antioxidant activities of extracts from Acer tegmentosum Maxim. (AT) and the ability of these extracts to reduce the serum alcohol concentration in rats administered alcohol. The total amount of polyphenols in hot water and ethanol extracts from AT were $71.93{\pm}2.2{\mu}g/mg$ and $152.69{\pm}1.25{\mu}g/mg$, respectively, while the total amount of flavonoids in hot water and ethanol extracts from AT were $7.51{\pm}1.34{\mu}g/mg$ and $5.01{\pm}0.83{\mu}g/mg$, respectively. FRAP values in AT extracts were $1.67{\sim}1.75{\mu}M/{\mu}g$. AT extracts were capable of directly scavenging DPPH and ABTS free radicals, with higher inhibitory activities for TBA. The hepatoprotective effect of hot water extracts from AT against ethanol-induced oxidative damage was investigated. Ethanol-induced damage on HepG2 liver cells were protected by hot water extracts from AT. Administration of hot water extracts from AT (200 mg/kg) had reduced serum alcohol levels in acute alcohol-treated rats. These results indicate that AT extracts can be protective against alcohol-induced toxicity, potentially through its antioxidant properties.

Quality and Antioxidant Characteristics of Roasted Maize Tea with Different Moisture Contents (수분함량을 달리하여 제조한 볶음 옥수수차의 품질 및 항산화 특성)

  • Lee, Ji Hae;Kim, Hyun-Joo;Kim, Mi Jung;Jung, Gun-Ho;Lee, Byong Won;Lee, Byoung Kyu;Woo, Koan Sik
    • The Korean Journal of Food And Nutrition
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    • v.30 no.6
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    • pp.1149-1156
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    • 2017
  • We investigated the quality characteristics and the antioxidant efficacy of roasted maize tea according to different moisture contents (9% to 14%) using the puffing system (PS) and the roasting system (RS). Compared with the RS, the PS caused higher turbidity (0.017 vs. 0.003 in PS-14% vs. RS-14%), brown color intensity (0.170 vs. 0.059 in PS-14% vs. RS-14%), a-values (0.20 vs. -0.44 in PS-14% vs. RS-14%), b-values (7.90 vs. 5.57 in PS-14% vs. RS-14%), and a lower L-value (19.67 vs. 21.03 in PS-14% vs. RS-14%). Total polyphenol and flavonoid contents of roasted maize tea were increased along with the moisture content and they were higher with the PS (polyphenol; 5.95 mg GAE/g, flavonoids; 1.27 CE/g in PS-14%) than with the RS (polyphenol; 5.39 mg GAE/g, flavonoids; 1.12 mg CE/g in RS-14%). The DPPH and ABTS radical scavenging effects of roasted maize tea were also increased along with the moisture content, and the scavenging efficacy was significantly higher with the PS (DPPH; 160 mg TE/100g, ABTS; 507 mg TE/100g in PS-14%) compared with the RS (DPPH; 120 mg TE/100g, ABTS; 362 mg TE/100g in RS-14%). The polyphenol levels were significantly correlated with turbidity, brown color intensity, and L, a, and b-values of the roasted maize tea. In addition, an increase of the total polyphenol content in roasted maize tea induced antioxidant activities. As a result, an increase in polyphenols during the roasting process induced antioxidant activities which could prevent damage from free radicals.

Effects of Methacrylamide Treatment on Silk Fibers III. Polymerization Behavior of Methacrylamide (견섬유에 대한 메타크릴아미드의 처리효과 III. 메타크릴아미드의 중합거동)

  • 신봉섭;남중희
    • Journal of Sericultural and Entomological Science
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    • v.34 no.2
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    • pp.32-40
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    • 1992
  • Many studies have been carried out on the graft finishing in order to improve the quality of silk fiber. Various vinyl monomers, for instance, styrene, methylmethacrylate, 2-hydroxyeth-ylmethacrylate and methacrylamide, have been used practically up to date. Among these monomers, methacrylamide has been applied as the most favourable monomer onto silk fibers in recent years. The polymerization mechanism about styrene- and methylmethacrylate-grafted silk fiber has been studied by many researchers. They proposed that free radicals were formed and vinyl monomers were polymerized in silk fibroin by graft polymerization mechanism, while active sites were varied by the types of monomer and initiator as well as by the reaction condition. In general. there is another Opinion that monomers are polymerized and impregnated in the internal side of the fiber by homopolymerization, which has not been proved experimentally yet More than 10 years have been passed since methacrylamide was applied on the silk fiber, and at the present time most finishings are being achieved by methacrylamide. However, no attention has been paid to the polymerization mechanism of the methacrylamide-treated silk fiber yeL In this paper, the treatments of methacrylamide on silk fibers were studied in aqueous solution using potassium persulfate as an initiator. The polymerization mechanism of the methacrylamide-treated silk fibers was investigated and analyzed on the basis of the results of infrared spectroscopy, amino acid analysis and scanning electron microscopy. From the results of these instrumental analyses, it can be suggested that polymerization mechanism about the methacrylamide-treated silk fibers is not performed by graft polymerization which has been accepted generally in styrene and methylmethacrylate-grafted silk fibers. The different mechanism is supposed to be due to the difference in monomer types, initiator types and treatment conditions.

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Neuronal injury in AIDS dementia: Potential treatment with NMDA open-channel blockers and nitric oxide-related species

  • Lipton, Stuart A.
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1996.04a
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    • pp.19-29
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    • 1996
  • The neurological manifestations of AIDS include dementia, encountered even in the absence of opportunistic superinfection or malignancy. The AIDS Dementia Complex appears to be associated with several neuropathological abnormalities, including astrogliosis and neuronal injury or loss. How can HIV-1 result in neuronal damage if neurons themselves are only rarely, if ever, infected by the vitus\ulcorner In vitro experiments from several different laboratiories have lent support to the existence of HIV- and immune-related toxins. In one recently defined pathway to neuronal injury, HIV-infected macrophages/microglia as well as macrophages activated by HIV-1 envelope protein gp120 appear to secrete excitants/neurotoxins. These substances may include arachidonic acid, platelet-activating factor, free radicals (NO - and O$_2$), glutamate, quinolinate, cysteine, cytokines (TNF-${\alpha}$, IL1-B, IL-6), and as yet unidentified factors emanating from stimulated macrophages and possibly reactive astrocytes. A final common pathway for newonal suscepubility appears to be operative, similar to that observed in stroke, trauma, epilepsy, and several neurodegenerative diseases, including Huntington's disease, Parkinson's disease, and amyotrophic lateral sclerosis. This mechanism involves excessive activation of N-methyl-D-aspartate (NMDA) receptor-operated channels, with resultant excessive influx of Ca$\^$2+/ leading to neuronal damage, and thus offers hope for future pharmacological intervention. This chapter reviews two clinically-tolerated NMDA antagonists, memantine and nitroglycerin; (ⅰ) Memantine is an open-channel blocker of the NMDA-associated ion channel and a close congener of the anti-viral and anti-parkinsonian drug amantadine. Memantine blocks the effects of escalating levels of excitotoxins to a greater degree than lower (piysiological) levels of these excitatory amino acids, thus sparing to some extent normal neuronal function. (ⅱ) Niuoglycerin acts at a redox modulatory site of the NMDA receptor/complex to downregulate its activity. The neuroprotective action of nitroglycerin at this site is mediated by n chemical species related to nitric oxide, but in a higher oxidation state, resulting in transfer of an NO group to a critical cysteine on the NMDA receptor. Because of the clinical safety of these drugs, they have the potential for trials in humans. As the structural basis for redox modulation is further elucidated, it may become possible to design even better redox reactive reagents of chinical value. To this end, redox modulatory sites of NMDA receptors have begun to be characterized at a molecular level using site-directed mutagenesis of recombinant subunits (NMDAR1, NMDAR2A-D). Two types of redox modulation can be distinguished. The first type gives rise to a persistent change in the functional activity of the receptor, and we have identified two cysteine residues on the NMDARI subunit (#744 and #798) that are responsible for this action. A second site, presumably also a cysteine(s) because <1 mM N-ethylmaleimide can block its effect in native neurons, underlies the other, more transient redox action. It appears to be at this, as yet unidentified, site on the NMDA receptor that the NO group acts, at least in recombinant receptors.

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