• Title/Summary/Keyword: scavenger effect

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Experimental Studies on the Effect of Gamibaegi-eum

  • Kim Won-Ill
    • The Journal of Korean Medicine
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    • v.25 no.4
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    • pp.61-78
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    • 2004
  • Objective : This study was undertaken to determine whether Gamibaegi-eum (BGU) in vitro and in vivo exerts a beneficial effect against cell injury induced by reactive oxygen species (ROS) in the human intestine. Methods : Effects of BGU in vitro on cell injury were examined using Caco-2 cells, cultured human intestinal cell line. Exposure of cells to H₂O₂ induced increases in the loss of cell viability in a time and dose-dependent fashion. Results : BGU prevented H₂O₂-induced cell death and its effect was dose-dependent over a concentration range of 0.05­1%. H₂O₂-induced cell death was prevented by catalase, the hydrogen peroxide scavenger enzyme, and deferoxamine, the iron chelator. However, the potent antioxidant DPPD did not affect H₂O₂-induced cell death. H₂O₂ increased lipid peroxidation, which was inhibited by BGU and DPPD. H₂O₂ caused DNA damage in a dose-dependent manner, which was prevented by BGU, catalase, and deferoxamine, but not DPPD. BGU restored ATP depletion induced by H₂O₂. BGU inhibited generation of superoxide and H₂O₂ and scavenged directly H₂O₂. Oral administration of mepirizole in vivo at a dose of 200mg/kg resulted in ulcer lesions in the stomach and the proximal duodenum. Pretreatment of BGU(0.1%/kg, orally) and catalase (800Units/kg, i.v.) significantly decreased the size of ulcers. Mepirizole increased lipid peroxidation in the mucosa of the duodenum, suggesting an involvement of ROS. Pretreatment of BGU and catalase significantly inhibited lipid peroxidation induced by mepirizole. Morphological studies showed that mepirizole treatment causes duodenal injury and its effect is prevented by BGU. Conclusion : These results indicate that BGU exerts a protective effect against cell injury in vitro and in vivo through antioxidant action. The present study suggests that BGU may playa therapeutic role in the treatment of human gastrointestinal diseases mediated by ROS.

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Effect of Nitric Oxide on Paraquat-Tolerance in Lettuce Leaves (상추잎의 Paraquat 내성에 미치는 Nitric oxide의 영향)

  • Lee, Jee-Na;Hong, Jung-Hee
    • Journal of Environmental Science International
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    • v.20 no.12
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    • pp.1509-1519
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    • 2011
  • The protective effect of nitric oxide (NO) on the antioxidant system under paraquat(PQ) stress was investigated in leaves of 8-week-old lettuce (Lactuca sativa L.) plants. PQ stress caused a decrease of leaf growth including leaf length, width and weight. Application of NO donor, sodium nitroprusside (SNP), significantly alleviated PQ stress induced growth suppression. SNP permitted the survival of more green leaf tissue preventing chlorophyll content reduction and of higher quantum yield for photosystem II than in non-treated controls under PQ exposure, suggesting that NO has protective effect on chloroplast membrane in lettuce leaves. Flavonoids and anthocyanin were significantly accumulated in the leaves upon PQ exposure. However, the rapid increase of these compounds was alleviated in the SNP treated leaves. PQ treatment resulted in lipid peroxidation and induced accumulation of hydrogen peroxide ($H_2O_2$) in the leaves, while SNP prevented PQ induced increase in malondialdehyde (MDA) and $H_2O_2$. These results demonstrate that SNP serves as an antioxidant agent able to scavenge $H_2O_2$ to protect plant cells from oxidative damage. The activities of two antioxidant enzymes that scavenge reactive oxygen species, superoxide dismutase (SOD) and catalase (CAT) in lettuce leaves in the presence of NO donor under PQ stress were higher than those under PQ stress alone. Application of 2-(4-carboxyphenyl)-4, 4, 5, 5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO), a specific NO scavenger, to the lettuce leaves arrested SNP mediated protective effect on leaf growth, photosynthetic pigment and antioxidant systems. However, PTIO had little effect on lettuce leaves under PQ stress compared with that of PQ stress alone. The obtained data suggest that the damage caused by PQ stress is in part due to increased generation of active oxygen by maintaining increased antioxidant enzyme activities and SNP protects plants from oxidative stress. From these results it is suggested that NO might act as a signal in activating active oxygen scavenging system that protects plants from oxidative damage induced by PQ stress and thus confer PQ tolerance.

Influence of Nitric Oxide on Steroid Synthesis, Growth and Apoptosis of Buffalo (Bubalus bubalis) Granulosa Cells In vitro

  • Dubey, Pawan K.;Tripathi, Vrajesh;Singh, Ram Pratap;Sastry, K.V.H.;Sharma, G.Taru
    • Asian-Australasian Journal of Animal Sciences
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    • v.24 no.9
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    • pp.1204-1210
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    • 2011
  • Objective of this study was to examine the effect of sodium nitroprusside (SNP), a nitric oxide (NO) donor on steroid synthesis, growth and apoptosis of buffalo granulosa cells (GCs) in vitro. Follicular fluid of antral follicles (3-5 mm diameter) was aspirated and GCs were cultured in 0 (control), $10^{-3}$, $10^{-5}$, $10^{-7}$, $10^{-9}\;M$ of SNP for 48 h. To evaluate whether this effect was reversible, GCs were cultured in presence of $10^{-5}\;M$ SNP+1.0 mM $N^{\omega}$-nitro-L-arginine methyl ester (L-NAME) a NO synthase (NOS) inhibitor or hemoglobin (Hb, $1.0{\mu}g$) as NO scavenger. Nitrate/nitrite concentration was evaluated by Griess method, progesterone and estradiol concentrations by RIA and apoptosis by TUNEL assay. SNP ($10^{-3}$, $10^{-5}$, $10^{-7}\;M$) significantly (p<0.05) inhibited estradiol and progesterone synthesis, growth, disorganized GCs aggregates and induced apoptosis in a dose dependent manner. However, $10^{-9}\;M$ SNP induced the progesterone synthesis and stimulated GCs to develop into a uniform monolayer. Combination of SNP $10^{-5}$ M+L-NAME strengthened the inhibitory effect while, SNP+Hb together reversed these inhibitory effects. In conclusion, SNP at greater concentrations ($10^{-3}$, $10^{-5}$ and $10^{-7}\;M$) has a cytotoxic effect and it may lead to cell death whereas, at a lower concentration ($10^{-9}\;M$) induced progesterone synthesis and growth of GCs. These findings have important implications that NOS derived NO are involved at physiological level during growth and development of buffalo GCs which regulates the steroidogenesis, growth and apoptosis.

Antioxidant Effects and Anti-inflammation Effects of Lophatheri Herba Water Extracts Via Reducing iNOS Synthesis Induced by LPS in RAW 264.7 Cell (담죽엽의 항산화 효과와 RAW 264.7 세포에서 LPS로 유도된 iNOS 발현에 미치는 영향)

  • Hwang, Sung-Yeoun;Lee, Sung-Won;Kwon, Kang-Beom;Choi, Won-Jong;Kim, Jae-Hyo;Ahn, Seong-Hun
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.24 no.6
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    • pp.976-982
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    • 2010
  • We studied to know the anti-inflammation effect on water extracts of Lophatheri Herba which was growing in every places in our country. We objected free radical scanvenger effect and nitrite eliminate effect of the Lophatheri Herba water extracts, and the cell viabillity, the effects of Lophatheri Herba water extracts on NO production, iNOS synthesis induced by LPS. Free radical scavenger effects were $27.91{\pm}0.12%$, $38.96{\pm}0.10%$, $46.22{\pm}0.15%$ depend on 0.5, 1.0, 2.0 mg/ml each dose of Lophatheri Herba water extracts. Nitrite eliminate effects were $9.86{\pm}0.3%$, $80.61{\pm}0.23%$, $97.62{\pm}0.56%$ in 0.1, 1.0, 2.0 mg/ml Lophatheri Herba water extracts on pH 1.2. NO production and iNOS synthesis induced by LPS were reduced in RAW 264.7 cell by Lophatheri Herba water extracts. As the above results, Lophatheri Herba water extracts have anti-inflammation effects via NO production decrease, iNOS synthesis decrease mechanism. So Lophatheri Herba water extracts will be used as the protection or treatment in chronic inflammation desease like a asthma, stomatitis etc.

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.

A Comparative Study of Memory Improving Effects of Stachys Rhizome and Lycopi Rhizome on Scopolamine-induced Amensia in mice (시판 초석잠 기원식물의 기억력개선효과 비교연구)

  • Lee, Shin Woo;Jung, Tae-Hong;Shin, Yong-Wook
    • The Korea Journal of Herbology
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    • v.28 no.5
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    • pp.69-77
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    • 2013
  • Objectives : The purpose of this study was to characterize the effect of the Ethanolic extract of Stachys sieboldii and Lycopus lucidus on the learning and memory impairments induced by scopolamine. Methods : The genetic difference of Stachys sieboldii and Lycopus lucidus were observed with RAPD analysis. The cognition-enhancing effect of Stachys sieboldii and Lycopus lucidus was investigated using a passive avoidance test, Y-maze test and the Morris water maze test in mice. Drug-induced amnesia was induced by treating animals with scopolamine (1 mg/kg, i.p.). Results : As a result of RAPD analysis, Stachys sieboldii and Lycopus lucidus Radix was found to be genetically different and The results of learning memory analysis showed that Stachys sieboldii extract-treated group (500 mg/kg, p.o.) and the tacrine-treated group (10 mg/kg, p.o.) significantly ameliorated scopolamine-induced amnesia based on the Passive avoidance Y-maze test and Water maze test. And these results are same manner in DPPH radical scavenger effect and Acetylcholineseterase inhibition effect. These results suggest that Stachys sieboldii extract maybe a useful cognitive impairment treatment, and its beneficial effects are depending on the origin plants. Conclusions : Commercially available Stachys sieboldii Radix consists of two original plant, one of them people misuse. To clarify the origin of the plant Memory tests were performed. These results suggest that 80% Ethanol extract of Stachys sieboldii showed significant anti-amnestic and cognitive-enhancing activities related to the memory processes, and these activities were parallel to treatment duration and dependent of the learning models.

ROS Scavenger, Ebselen, Has No Preventive Effect in New Hearing Loss Model Using a Cholesterol-Chelating Agent

  • Lee, Min Young;Kabara, Lisa L.;Swiderski, Donald L.;Raphael, Yehoash;Duncan, R. Keith;Kim, Young Ho
    • Journal of Audiology & Otology
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    • v.23 no.2
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    • pp.69-75
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    • 2019
  • Background and Objectives: The antioxidant ebselen will be able to limit or prevent the ototoxicity arising from 2-hydroxypropyl-β-cyclodextrin (HPβCD). Niemann-Pick Type C (NPC) disease is a disorder of lysosomal storage manifested in sphingolipidosis. Recently, it was noted that experimental use of HPβCD could partially resolve the symptoms in both animals and human patients. Despite its desirable effect, HPβCD can induce hearing loss, which is the only major side effect noted to date. Understanding of the pathophysiology of hearing impairment after administration of HPβCD and further development of preventive methods are essential to reduce the ototoxic side effect. The mechanisms of HPβCD-induced ototoxicity remain unknown, but the resulting pathology bears some resemblance to other ototoxic agents, which involves oxidative stress pathways. To indirectly determine the involvement of oxidative stress in HPβCD-induced ototoxicity, we tested the efficacy of an antioxidant reagent, ebselen, on the extent of inner ear side effects caused by HPβCD. Materials and Methods: Ebselen was applied prior to administration of HPβCD in mice. Auditory brainstem response thresholds and otopathology were assessed one week later. Bilateral effects of the drug treatments also were examined. Results: HPβCD-alone resulted in bilateral, severe, and selective loss of outer hair cells from base to apex with an abrupt transition between lesions and intact areas. Ebselen co-treatment did not ameliorate HPβCD-induced hearing loss or alter the resulting histopathology. Conclusions: The results indirectly suggest that cochlear damage by HPβCD is unrelated to reactive oxygen species formation. However, further research into the mechanism(s) of HPβCD otopathology is necessary.

ROS Scavenger, Ebselen, Has No Preventive Effect in New Hearing Loss Model Using a Cholesterol-Chelating Agent

  • Lee, Min Young;Kabara, Lisa L.;Swiderski, Donald L.;Raphael, Yehoash;Duncan, R. Keith;Kim, Young Ho
    • Korean Journal of Audiology
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    • v.23 no.2
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    • pp.69-75
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    • 2019
  • Background and Objectives: The antioxidant ebselen will be able to limit or prevent the ototoxicity arising from 2-hydroxypropyl-β-cyclodextrin (HPβCD). Niemann-Pick Type C (NPC) disease is a disorder of lysosomal storage manifested in sphingolipidosis. Recently, it was noted that experimental use of HPβCD could partially resolve the symptoms in both animals and human patients. Despite its desirable effect, HPβCD can induce hearing loss, which is the only major side effect noted to date. Understanding of the pathophysiology of hearing impairment after administration of HPβCD and further development of preventive methods are essential to reduce the ototoxic side effect. The mechanisms of HPβCD-induced ototoxicity remain unknown, but the resulting pathology bears some resemblance to other ototoxic agents, which involves oxidative stress pathways. To indirectly determine the involvement of oxidative stress in HPβCD-induced ototoxicity, we tested the efficacy of an antioxidant reagent, ebselen, on the extent of inner ear side effects caused by HPβCD. Materials and Methods: Ebselen was applied prior to administration of HPβCD in mice. Auditory brainstem response thresholds and otopathology were assessed one week later. Bilateral effects of the drug treatments also were examined. Results: HPβCD-alone resulted in bilateral, severe, and selective loss of outer hair cells from base to apex with an abrupt transition between lesions and intact areas. Ebselen co-treatment did not ameliorate HPβCD-induced hearing loss or alter the resulting histopathology. Conclusions: The results indirectly suggest that cochlear damage by HPβCD is unrelated to reactive oxygen species formation. However, further research into the mechanism(s) of HPβCD otopathology is necessary.

In vitro Free Radical Scavenging and Hepatoprotective Compound from Sanguisorbae Radix

  • An, Ren-Bo;Tian, Yu-Hua;Oh, Hyun-Cheol;Kim, Youn-Chul
    • Natural Product Sciences
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    • v.11 no.3
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    • pp.119-122
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    • 2005
  • In the course of searching for hepatoprotective agents from natural products, four compounds were isolated from the MeOH extract of Sanguisorbae Radix, as guided by their DPPH free radical scavenging activity. The structures were determined as 4,5-dimethoxy-3-hydroxybenzoic acid methyl ester (1), (+)-gallocatechin (2), methyl $6-O-galloyl-{\beta}-D-glucopyranoside$ (3), and pomolic acid $3-O-[{\alpha}-L-arabinopyranoside]-28-O-[{\beta}-D-glucopyranosyl]$ ester (ziyu-glycoside I) (4). Compounds 2 and 3 showed significant DPPH free radical scavenging effects, exhibiting $IC_{50}$ values of 11.4 and $13.0\;{\mu}M$, respectively. L-Ascorbic acid was used as a positive control and exhibited the $IC_{50}$ value of $50.3\;{\mu}M$. In evaluation of the hepatoprotective activity of the isolated compounds on drug-induced cytotoxicity, compound 2 showed the significant hepatoprotective effect with the $EC_{50}$ value of $91.84\;{\pm}\;11.0\;{\mu}M$ on tacrine-induced cytotoxicity in Hep G2 cells, while silybin, a positive control, exhibited $EC_{50}$ value of $122.4\;{\pm}\;12.5\;{\mu}M$.

The Study of DEP Degradation Properties by Combination US and UV Lamp of Different Wavelength (초음파 (US)와 다양한 파장범위의 자외선 (UV) 조사에 따른 DEP 분해특성에 관한 연구)

  • Na, Seung-Min;Cai, Jinhua;Shin, Dong-Hoon;Cui, Mingcan;Khim, Jee-Hyeong
    • Journal of Environmental Science International
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    • v.21 no.7
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    • pp.845-853
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    • 2012
  • Diethyl phthalate (DEP) is widely spread in the natural environment as an endocrine disruption chemicals (EDs). Therefore, in this study, ultrasound (US) and ultraviolet (UVC), including various applied power density (10-40 W/L), UV wavelengths (365 nm, 254 nm and 185 nm) and frequencies (283 kHz, 935 kHz) were applied to a DEP contaminated solution. The pseudo-first order degradation rate constants were in the order of $10^{-1}$ to $10^{-4}\;min^{-1}$ depending on the processes. Photolytic and sonophotolytic DEP degradation rate also were high at shortest UV wavelength (VUV) due to the higher energy of photons, higher molar absorption coefficient of DEP and increased hydroxyl radical generation from homolysis of water. Sonolytic DEP degradation rate increased with increase of applied input power and the dominant reaction mechanism of DEP in sonolysis was estimated as hydroxyl radical reaction by the addition of t-BuOH, which is a common hydroxyl radical scavenger. Moreover, synergistic effect of were also observed for sonophotolytic degradation with various UV irradiation.