• The Korean Journal of Physiology and Pharmacology
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• v.2 no.4
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• pp.479-491
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• 1998

In order to know the pathogenesis of adult respiratory distress syndrome (ARDS) in association with the oxidative stress by neutrophils, the role of platelet activating factor (1-0-alkyl-2-acetyl-snglycero-3-phosphocholine, PAF) was investigated during acute lung injury induced by interleukin- $1{\alpha}$ (IL-1) in rats. An insufflation of IL-1 into the rat's trachea increased the acetyltransferase activity in the lung and the increase of PAF content was followed. As evidences of acute lung injury by neutrophilic respiratory burst, lung leak index, myeloperoxidase activity, numbers of neutrophils in the bronchoalveolar lavage fluid, neutrophilic adhesions to endothelial cells and NBT positive neutrophils were increased after IL-1 treatment. In addition, a direct instillation of PAF into the trachea caused acute lung leak and the experimental results showed a similar pattern in comparison with IL-1 induced acute lung injury. For the confirmation of oxidative stress during acute lung leak by IL-1 and PAF, a histochemical electron microscopy was performed. In IL-1 and PAF treated lungs of rats, the deposits of cerrous perhydroxide were found. To elucidate the role of PAF, an intravenous injection of PAF receptor antagonist, WEB 2086 was given immediately after IL-1 or PAF treatment. WEB 2086 decreased the production of hydrogen peroxide and the acute lung leak. In ultrastructural study, WEB 2086 mitigated the pathological changes induced by IL-1 or PAF. The nuclear factor kappa B (NFkB) was activated by PAF and this activation was inhibited by WEB 2086 almost completely. Based on these experimental results, it is suggested that the PAF produced in response to IL-1 through the remodeling pathway has the major role for acute lung injury by neutrophilic respiratory burst. In an additional experiment, we can also come to conclude that the activation of the NFkB by PAF is thought to be the fundamental mechanism to initiate the oxidative stress by neutrophils causing release of proinflammatory cytokines and activation of phospholipase $A_2$.

• The Korean Journal of Physiology and Pharmacology
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• v.25 no.2
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• pp.97-109
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• 2021

Neonatal hypoxia/ischemia (H/I), injures white matter, results in neuronal loss, disturbs myelin formation, and neural network development. Neuroinflammation and oxidative stress have been reported in neonatal hypoxic brain injuries. We investigated whether Paeoniflorin treatment reduced H/I-induced inflammation and oxidative stress and improved white matter integrity in a neonatal rodent model. Seven-day old Sprague-Dawley pups were exposed to H/I. Paeoniflorin (6.25, 12.5, or 25 mg/kg body weight) was administered every day via oral gavage from postpartum day 3 (P3) to P14, and an hour before induction of H/I. Pups were sacrificed 24 h (P8) and 72 h (P10) following H/I. Paeoniflorin reduced the apoptosis of neurons and attenuated cerebral infarct volume. Elevated expression of cleaved caspase-3 and Bad were regulated. Paeoniflorin decreased oxidative stress by lowering levels of malondialdehyde and reactive oxygen species generation and while, and it enhanced glutathione content. Microglial activation and the TLR4/NF-κB signaling were significantly down-regulated. The degree of inflammatory mediators (interleukin 1β and tumor necrosis factor-α) were reduced. Paeoniflorin markedly prevented white matter injury via improving expression of myelin binding protein and increasing O1-positive olidgodendrocyte and O4-positive oligodendrocyte counts. The present investigation demonstrates the potent protective efficiency of paeoniflorin supplementation against H/I-induced brain injury by effectually preventing neuronal loss, microglial activation, and white matter injury via reducing oxidative stress and inflammatory pathways.

• Herbal Formula Science
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• v.11 no.2
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• pp.135-146
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• 2003

Objectives : Wolguk-whan has been used as a prescription of natural drug for the treatment of stress digestive system disease. Recently, we reported that Wolguk-whan methnol extract (WGWM) exerted a significant protective effect against oxidative damage to the liver of ICR mice. This study was purposed to investigate the effects of Wolguk-whan water extract (WGWW) on liver injury induced by oxidative stress. Methods : In order to investigate the effects of WGWW on acute liver injury, ICR mice were pretreated with WGWW for 6days, starved for 24hrs, and administerated acetamirtophen(500mg/kg, i.p.). In the liver homogenates, lipid peroxide and glutathione(GSH) levels were measured. In addition, activities of hepatic enzyme, such as catalase, glutathione peroxidase(GSH-Px), glutathione S-transferase(GST) were measured in the hepatic mitochondrial and cytosolic fractions. Results : In vivo administeration of WGWW showed effective inhibition of acetaminophen induced lipid peroxidation, and showed elevations of GSH level, catalase, GSH-Px, GST activities. Conclusions : These results suggested that WGWW might suppress the formation of oxidative metabolites, and prevent acetaminophen induced hepatotoxicity.

• The Korean Journal of Physiology and Pharmacology
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• v.13 no.3
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• pp.139-145
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• 2009

The purpose of this study was to evaluate the effects of the water extract of Samultang (SMT), a Chinese herb, on apoptotic cell death by $H_2O_2$-induced oxidative stress in SK-N-M C cells. A nuclear fragmentation was observed via fluorescence imaging 12 h after exposure to 30 ${\mu}M$ $H_2O_2$ and DNA laddering was detected via agarose electrophoresis gel. In addition, increases in sub-G1 phase and cleavage of the PARP protein were observed. However, treatment with SMT for 2 h prior to $H_2O_2$ exposure significantly reduced apoptotic cell death induced by incubation with 30 ${\mu}M$ $H_2O_2$ in SK-N-MC cells. Pre-incubation with water extract of SMT for 2 h prevented the $H_2O_2$-induced decrease in mitochondrial transmembrane potential. SMT also attenuated the increase in caspase-3 activity and the breakdown of PARP protein caused by $H_2O_2$-induced oxidative stress. These results suggest that the water extract of SMT provides inhibition of apoptotic cell death against oxidative injury in SK-N-MC cells.

• The Korea Journal of Herbology
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• v.20 no.3
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• pp.67-74
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• 2005

Objectives : This study was carried out to determine if Scutellariae Radix have protective effect against cell injury induced by various toxic agents in rat kidney slices. Methods : Water(SWe) and methanol(SMe) extracts were prepared for this experiment. Cell injury was estimated by measuring lactate dehydrogenase(LDH). Lipid peroxidation was examined by measuring malondialdehyde. Results : SMe prevented the LDH release by CCl4, menadione, tert-butyl hydroperoxide and mercury treatment in vitro in kidney slices, but SWe prevented the LDH release by CCl4 and mercury. SMe also prevented reduction in GSH by CCl4 and lipid peroxidation induced by mercury. Conclusions : Thus, SMe may have more powerful efficacy on anti-oxidative effects when compared with SWe. And further studies have to be followed concerned with procedure of extraction of SMe and its change of effects.

• Herbal Formula Science
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• v.25 no.2
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• pp.155-166
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• 2017

Objectives : Polygoni Multiflori Ramulus has been widely used as a traditional medicinal herb for the treatment of insomnia, limb pain and itch. The extract of Polygoni Multiflori Ramulus (PMRE) is known to have a modulatory effect of many inflammatory responses. This study was performed to investigate the hepatoprotective effect of PMRE against arachidonic acid (AA) + iron-induced oxidative stress on HepG2 cell and carbon tetrachloride ($CCl_4$)-induced liver injury on mice. Methods : The effects of PMRE on cell viability was assessed by MTT assay. And flow cytometric analysis was performed to estimate the effects on mitochondrial function. To investigate its underlying mechanism, apoptosis-related proteins were analysed by using immunoblot analysis. In addition, ICR mouse were administrated (po) with the PMRE (30, 100 mg/kg) for 3 days and then, injected (ip) with $CCl_4$ (0.5 ml/kg body weight) to induce acute liver damage. The level of pro-caspase-3 was measured. Results : Treatment of PMRE increased relative cell viability, prevented a cleavage of poly (ADP ribose) polymerase and pro-caspase-3, and also reduced mitochondrial membrane permeability against AA + iron-induced oxidative stress. In addition, PMRE treatment decreased liver injury induced by $CCl_4$, as evidenced by increases in pro-caspase-3 level. Conclusions : These results demonstrate that PMRE has an ability to anti-oxidant and hepatoprotective effect against AA + iron-induced oxidative stress and $CCl_4$-induced liver injury.

• BMB Reports
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• v.48 no.3
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• pp.184-189
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• 2015

Src homology 2-containing protein tyrosine phosphatase 2 (SHP-2) is known to protect neurons from neurodegeneration during ischemia/reperfusion injury. We recently reported that ROS-mediated oxidative stress promotes phosphorylation of endogenous SHP-2 in astrocytes and complex formation between caveolin-1 and SHP-2 in response to oxidative stress. To examine the region of SHP-2 participating in complex formation with caveolin-1, we generated three deletion mutant constructs and six point mutation constructs of SHP-2. Compared with wild-type SHP-2, binding of the N-SH2 domain deletion mutant of SHP-2 to p-caveolin-1 was reduced greatly, using flow cytometric competitive binding assays and surface plasmon resonance (SPR). Moreover, deletion of the N-SH2 domain of SHP-2 affected $H_2O_2$-mediated ERK phosphorylation and Src phosphorylation at Tyr 419 in primary astrocytes, suggesting that N-SH2 domain of SHP-2 is responsible for the binding of caveolin-1 and contributes to the regulation of Src phosphorylation and activation following ROS-induced oxidative stress in brain astrocytes.

• The Korean Journal of Physiology and Pharmacology
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• v.22 no.5
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• pp.567-575
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• 2018

Acute kidney injury (AKI), which is defined as a rapid decline of renal function, becomes common and recently recognized to be closely intertwined with chronic kidney diseases. Current treatment for AKI is largely supportive, and endoplasmic reticulum (ER) stress has emerged as a novel mediator of AKI. Since carbon monoxide attenuates ER stress, the objective of the present study aimed to determine the protective effect of carbon monoxide releasing molecule-2 (CORM2) on AKI associated with ER stress. Kidney injury was induced after LPS (15 mg/kg) treatment at 12 to 24 h in C57BL/6J mice. Pretreatment of CORM2 (30 mg/kg) effectively prevented LPS-induced oxidative stress and inflammation during AKI in mice. CORM2 treatment also effectively inhibited LPS-induced ER stress in AKI mice. In order to confirm effect of CO on the pathophysiological role of tubular epithelial cells in AKI, we used mProx24 cells. Pretreatment of CORM2 attenuated LPS-induced ER stress, oxidative stress, and inflammation in mProx24 cells. These data suggest that CO therapy may prevent ER stress-mediated AKI.

• BMB Reports
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• v.35 no.1
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• pp.67-86
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• 2002

Three routes have been identified triggering neuronal death under physiological and pathological conditions. Excess activation of ionotropic glutamate receptors cause influx and accumulation of $Ca^{2+}$ and $Na^+$ that result in rapid swelling and subsequent neuronal death within a few hours. The second route is caused by oxidative stress due to accumulation of reactive oxygen and nitrogen species. Apoptosis or programmed cell death that often occurs during developmental process has been coined as additional route to pathological neuronal death in the mature nervous system. Evidence is being accumulated that excitotoxicity, oxidative stress, and apoptosis propagate through distinctive and mutually exclusive signal transduction pathway and contribute to neuronal loss following hypoxic-ischemic brain injury. Thus, the therapeutic intervention of hypoxic-ischemic neuronal injury should be aimed to prevent excitotoxicity, oxidative stress, and apoptosis in a concerted way.

• BMB Reports
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• v.44 no.5
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• pp.312-316
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• 2011

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and its toxic metabolite 1-methyl-4-phenylpyridium ion (MPP$^+$) have been shown to induce Parkinson's disease-like symptoms as well as neurotoxicity in humans and animal species. Recently, we reported that maintenance of redox balance and cellular defense against oxidative damage are primary functions of the novel antioxidant enzyme cytosolic NADP$^+$-dependent isocitrate dehydrogenase (IDPc). In this study, we examined the role of IDPc in cellular defense against MPP$^+$-induced oxidative injury using PC12 cells transfected with IDPc small interfering RNA (siRNA). Our results demonstrate that MPP$^+$-mediated disruption of cellular redox status, oxidative damage to cells, and apoptotic cell death were significantly enhanced by knockdown of IDPc.