• Archives of Reconstructive Microsurgery
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• v.15 no.1
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• pp.1-9
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• 2006

The purpose of this study is to determine the effects of selective inducible nitric oxide synthase (iNOS) inhibitor N-[3-aminomethyl]benzyl]acetamidine (l400W) on the reperfused cremaster muscle. The extracellular superoxide dismutase knockout ($EC-SOD^{-/-}$) mice was used to make the experimental window for ischemia-reperfusion injury. The muscle was exposed to 4.5 h of ischemia followed by 90 min of reperfusion and the mice received either 3 mg/kg of 1400W or the same amount of phosphate buffered saline (PBS) subcutaneously at 10 min before the start of reperfusion. The results showed that 1400W treatment markedly improved the recovery of the vessel diameter and blood flow in the reperfused cremaster muscle compared to that of PBS group. Histological examination showed reduced edema in the interstitium and muscle fiber, and reduced nitrotyrosine formation (a marker of total peroxinitrite ($ONOO^-$) in 1400W-treated muscle compared to PBS. Our results suggest that iNOS and $ONOO^-$ products are involved in skeletal muscle I/R injury. Reduced I/R injury by using selective inhibition of iNOS is perhaps via limiting cytotoxic $ONOO^-$ generation, a reaction product of nitric oxide (NO) and superoxide anion ($O_2^-$). Thus, inhibition of iNOS appears to be a good treatment strategy in reducing clinical I/R injury.

• Biomolecules & Therapeutics
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• v.21 no.5
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• pp.371-380
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• 2013

Doxorubicin is still main drug in chemotherapy with limitation of use due to adverse drug reaction. Increased oxidative stress and alteration of nitric oxide control have been involved in cardiotoxicity of doxorubicin (DOX). A Disintegrin And Metalloproteinase (ADAMs) are transmembrane ectoproteases to regulate cell-cell and cell-matrix interactions, but role in cardiac disease is unclear. The aim of this study was to determine whether DOX activates peroxynitrite and ADAM 10 and thus ADAM and matrix metalloproteinase (MMP) induce cardiac remodeling in DOX-induced cardiomyopathy. Adult male Sprague-Dawley rats were subjected to cardiomyopathy by DOX (6 times of 2.5 mg/kg DOX over 2-weeks), and were randomized as four groups. Then followed by 3, 5, 7, and 14 days after cessation of DOX injection. DOX-injected animals significantly decreased left ventricular fractional shortening compared with control by M-mode echocardiography. The expressions of cardiac nitrotyrosine by immunohistochemistry were significant increased, and persisted for 2 weeks following the last injection. The expression of eNOS was increased by 1.9 times (p<0.05), and iNOS was marked increased in DOX-heart compared with control (p<0.001). Compared to control rats, cardiac ADAM10- and MMP 9- protein expressions increased by 20 times, and active/total MMP 9 proteolytic activity showed increase tendency at day 14 after cessation of DOX injection (n=10, each group). DOX-treated $H_9C_2$ cell showed increased ADAM10 protein expression with dose-dependency (p<0.01) and morphometric changes showed the increase of ventricular interstitial, nonvascular collagen deposition. These data suggest that activation of cardiac peroxynitrite with increased iNOS expression and ADAM 10-dependent MMP 9 expression may be a molecular mechanism that contributes to left ventricular remodeling in DOXinduced cardiomyopathy.

• The Korean Journal of Physiology and Pharmacology
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• v.3 no.4
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• pp.375-382
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• 1999

Growing evidence indicates that enhanced generation or actions of nitric oxide (NO) are implicated in the pathogenesis of hypertension in spontaneously hypertensive rats and diabetic nephropathy in streptozotocin (STZ)-induced diabetic rats. We investigated whether inducible nitric oxide synthase (iNOS) expression in STZ-induced diabetic rats is responsible for the alterations of vascular reactivity. Diabetic state was confirmed 28 days after injection of STZ (i.p) in rats by measuring blood glucose. In order to evaluate whether short term (4 weeks) diabetic state is related with altered vascular reactivity caused by iNOS expression, isometric tension experiments were performed. In addition, plasma nitrite/nitrate (NOx) levels and expression of iNOS in the lung and aorta of control and STZ-treated rats were compared by using Griess reagent and Western analysis, respectively. Results indicated that STZ-treated rats increased the maximal contractile response of the aorta to phenylephrine (PE), and high $K^+,$ while the sensitivity remained unaltered. Endothelium-dependent relaxation, but not SNP-mediated relaxation, was reduced in STZ-treated rats. Plasma nitrite/nitrates are significantly increased in STZ-treated rats compared to controls. The malondialdehyde (MDA) contents of liver, serum, and aorta of diabetic rats were also significantly increased. Furthermore, nitrotyrosine, a specific foot print of peroxynitrite, was significantly increased in endothelial cells and smooth muscle layers in STZ-induced diabetic aorta. Taken together, the present findings indicate that enhanced release of NO by iNOS along with increased lipid peroxidation in diabetic conditions may be responsible, at least in part, for the augmented contractility, possibly through the modification of endothelial integrity or ecNOS activity of endothelium in STZ-diabetic rat aorta.

• YAKHAK HOEJI
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• v.60 no.2
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• pp.92-99
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• 2016

Parkinson's disease (PD) is one of the representative neurodegenerative movement disorders with the selective loss of dopaminergic neurons in the substantia nigra. 6-Hydroxydopamine (6-OHDA) is widely used as an experimental model system to mimic PD and has been reported to cause neuronal cell death via oxidative and/or nitrosative stress. Therefore, daily intake of dietary or medicinal plants which fortifies cellular antioxidant capacity can exert neuroprotective effects in PD. In the present study, we have investigated the protective effect of Korean red ginseng (KRG) against 6-OHDA-induced nitrosative death in C6 glioma cells. Treatment of C6 cells with 6-OHDA decreased cell viability and increased expression of inducible nitric oxide synthase, production of nitric oxide as well as peroxynitrite, and formation of nitrotyrosine. 6-OHDA led to apoptotic cell death as determined by decreased Bcl-2/Bax, phosphorylation of JNK, activation of caspase-3, and cleavage of PARP. Conversely, pretreatment of C6 cells with KRG attenuated 6-ODHA-induced cytotoxicity, apoptosis, and nitrosative damages. To further elucidate the molecular mechanism of KRG protection against 6-OHDA-induced nitrosative cell death, we have focused on the cellular self-defense molecules against exogenous noxious stimuli. KRG treatment up-regulated heme oxygenase-1 (HO-1), a key antioxidant enzyme essential for cellular defense against oxidative and/or nitrosative stress via activation of Nrf2. Taken together, these findings suggest KRG may have preventive and/or therapeutic potentials for the management of PD.

• Nutrition Research and Practice
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• v.7 no.4
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• pp.302-308
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• 2013

The emerging role of endothelial inflammation in diabetes has stimulated research interest in the effects of nutrition on related indices. In the current study we investigated whether the nutrient composition of dietary formula as reflected in glycemic index (GI) may be predictive of postprandial endothelial inflammation in non-diabetic subjects. A double-blinded, randomized, crossover study was conducted in non-diabetic subjects (n = 8/group). Each subject consumed three types of diabetes-specific dietary formulas (high-fiber formula [FF], high-monounsaturated fatty acid (MUFA) formula [MF] and control formula [CF]) standardized to 50 g of available carbohydrates with a 1-week interval between each. The mean glycemic index (GI) was calculated and 3-hour postprandial responses of insulin, soluble intercellular adhesion molecule-1 (sICAM-1), nitrotyrosine (NT) and free fatty acids (FFA) were measured. The MF showed the lowest mean GI and significantly low area under the curve (AUC) for insulin (P = 0.038), but significantly high AUCs for sICAM-1 (P<0.001) and FFA (P < 0.001) as compared to the CF and FF. The FF showed intermediate mean GI, but significantly low AUC for NT (P<0.001) as compared to the CF and MF. The mean GI was not positively correlated to any of the inflammatory markers evaluated, and in fact negatively correlated to changes in FFA (r = -0.473, P = 0.006). While the MF with the lowest GI showed the highest values in most of the inflammatory markers measured, the FF with intermediate GI had a modest beneficial effect on endothelial inflammation. These results suggest that nutrient composition of dietary formula as reflected in the GI may differently influence acute postprandial inflammation in non-diabetic subjects.

• Journal of Ginseng Research
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• v.43 no.1
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• pp.10-19
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• 2019

Background: Frequent overdose of paracetamol (APAP) has become the major cause of acute liver injury. The present study was designed to evaluate the potential protective effects of ginsenoside Rk1 on APAP-induced hepatotoxicity and investigate the underlying mechanisms for the first time. Methods: Mice were treated with Rk1 (10 mg/kg or 20 mg/kg) by oral gavage once per d for 7 d. On the 7th d, allmice treated with 250mg/kg APAP exhibited severeliverinjury after 24 h, and hepatotoxicitywas assessed. Results: Our results showed that pretreatment with Rk1 significantly decreased the levels of serum alanine aminotransferase, aspartate aminotransferase, tumor necrosis factor, and interleukin-$1{\beta}$ compared with the APAP group. Meanwhile, hepatic antioxidants, including superoxide dismutase and glutathione, were elevated compared with the APAP group. In contrast, a significant decrease in levels of the lipid peroxidation product malondialdehyde was observed in the ginsenoside Rk1-treated group compared with the APAP group. These effects were associated with a significant increase of cytochrome P450 E1 and 4-hydroxynonenal levels in liver tissues. Moreover, ginsenoside Rk1 supplementation suppressed activation of apoptotic pathways by increasing Bcl-2 and decreasing Bax protein expression levels, which was shown using western blotting analysis. Histopathological observation also revealed that ginsenoside Rk1 pretreatment significantly reversed APAP-induced necrosis and inflammatory infiltration in liver tissues. Biological indicators of nitrative stress, such as 3-nitrotyrosine, were also inhibited after pretreatment with Rk1 compared with the APAP group. Conclusion: The results clearly suggest that the underlying molecular mechanisms in the hepatoprotection of ginsenoside Rk1 in APAP-induced hepatotoxicity may be due to its antioxidation, antiapoptosis, anti-inflammation, and antinitrative effects.

• Journal of Nutrition and Health
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• v.41 no.8
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• pp.691-700
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• 2008

One suggested mechanism underlying copper (Cu) deficiency teratogenicity is a low availability of nitric oxide (NO), signaling molecule which is essential in developmental processes. Increased superoxide anions secondary to decreased activities of Cu-zinc superoxide dismutase (Cu-Zn SOD) in Cu deficiency can interact with NO to form peroxynitrite, which can nitrate proteins at tyrosine residues. In addition, peroxynitrite formation can limit NO bioavailability. We previously reported low NO availability and increased protein nitration in Cu deficient (Cu-) embryos. In the current study, we tested whether Cu deficiency alters downstream signaling of NO by assessing cyclic GMP (cGMP) and phosphorylated vasodilator-stimulating phosphoprotein (VASP) levels, and whether NO supplementation can affect these targets as well as protein nitration. Gestation day 8.5 embryos from Cu adequate (Cu+) or Cu- dams were collected and cultured in either Cu+ or Cu- media for 48 hr. A subset of embryos was cultured in Cu- media supplemented with a NO donor (DETA/NONOate; 20 ${\mu}M$) and/or Cu-Zn SOD. Cu-/Cu- embryos showed a higher incidence of embryonic and yolk sac abnormalities, low NO availability, blunted dose-response in NO concentrations to increasing doses of acetylcholine, low mRNA expression of endothelial nitric oxide synthase (eNOS), increased levels of 3-nitrotyrosine (3-NT) compared to Cu+/Cu+ controls. cGMP concentrations tended to be low in Cu-/Cu- embryos, and they were significantly lower in Cu-/Cu- yolk sacs than in controls. Levels of phosphorylated VASP at serine 239 (P-VASP) were similar in all groups. NO donor supplementation to the Cu- media ameliorated embryonic and yolk sac abnormalities, and resulted in increased levels of cGMP without altering levels of P-VASP and 3-NT. Taken together, these data support the concept that Cu deficiency limits NO availability and alters NO/cGMP-dependent signaling in Cu- embryos and yolk sacs, which contributes to Cu deficiency-induced abnormal development.

• Herbal Formula Science
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• v.25 no.4
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• pp.509-526
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• 2017

Background and objectives : Soeumin Bojungykgi-tang (seBYTE) has been used to supplement qi in Korean medicine. It has been demonstrated to possess various biological functions such as anti-cancer, anti-aging and anti-inflammatory effects. The present study evaluated the protective roles of seBYTE in hepatotoxic in vitro and in vivo model. Methods : To investigate cytoprotective effect of seBYTE, HepG2 cells were pretreated with seBYTE and then subsequently exposed to $10{\mu}m$ AA for 12 h, followed by $5{\mu}m$ iron. Cell viability was examined by MTT assay, and expression of apoptosis-related proteins was evaluated by immunoblot analysis. For responsible molecular mechanisms, ROS production, GSH contents, and mitochondrial membrane potential were measured. In addition, hepatoprotective effect of seBYTE in vivo was assessed in $CCl_4$-induced animal model. Results : seBYTE prevented AA + iron-induced cytotoxicity in concentration dependent manner. In addition, ROS production, GSH depletion, and mitochondrial dysfunction induced by AA + iron were significantly reduced by seBYTE pretreatment. Furthermore, seBYTE recovered expression of the pro-apoptotic proteins such as PARP and pro-caspase-3. In animal experiment, plasma ALT and AST levels were significantly elevated in $CCl_4$ treatment, but seBYTE significantly decreased the ALT and AST levels. Moreover, seBYTE alleviated the numbers of histological activity index, percentages of degenerative regions, degenerated hepatocytes, infiltrated inflammatory cells, nitrotyrosine- and 4-hydroxynonenal-positive cells in liver. Conclusions : These results showed that hepatoprotective effect of seBYTE against on $CCl_4$-induced hepatic damages is partly due to antioxidative and anti-apoptotic process.

• Biomolecules & Therapeutics
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• v.9 no.3
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• pp.167-175
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• 2001

Recent studies have shown that cytokines are capable of modulating cardiovascular function and that some drugs used in the treatment of heart failure variably modulate the production of cytokines. Hige- namine, a positive inotropic isoquinoline alkaloid, has been used traditionally as cardiac stimulant, and reported to reduce nitric oxide (NO) and inducible nitric oxide synthase (iNOS) expression in LPS- and/or cytokine-activated cells in vitro and in vivo. Therefore, we investigated whether higenamine modulates the production of proinflammatory cytokines in myocardial infarction. In addition, effects of higenamine on antioxidant action and antioxidant enzyme expression (MnSOD) were studied. Myocardial infarction (MI) was confirmed by measuring left ventricular (LV) pressure after occlusion of the left anterior descending coronary artery (LAD) for 5 weeks in rats. Treatment of higenamine (10 mg/kg/day) reduced infarct size about 35 %, which accompanied by reduction of production TNF-$\alpha$, IL-6, but not IFN-${\gamma}$ and IL-1$\beta$ in the myocardium. The expression of TNF-$\alpha$ mRNA in infracted myocardium was significantly reduced by higenamine. Although iNOS mRNA was not detected, nitrotyrosine staining was significantly increased in myocardium of Ml compared to higenamine-treated one, Indicating that peroxynitrite-induced damage is evident in MI. Cytochrome c oxidation by peroxynitrite was concentration-dependently reduced by higenamine, an effect which was almost compatible to glutathion. Higenamine treatment did not affect the expression of MnSOD mRNA in myocardial tissues in MI. Taken together, higenamine may be beneficial in oxidative stress conditions such as ischemic-reperfusion injury and MI due to antioxidant action as well as modulation of cytokines.

• Herbal Formula Science
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• v.28 no.1
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• pp.1-13
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• 2020

Objectives : Present study investigated hepatoprotective effects of four types of Taraxaci Herba water extract (TL-F, Taraxaci Herba leaf originated from foreign country; TR-F, Taraxaci Herba root originated from foreign country; TL-K, Taraxaci Herba leaf originated from Korea; TR-K, Taraxaci Herba root originated from Korea) on carbon tetrachloride (CCl₄)-induced acute liver injury. Methods : Mice were administered orally with 200 mg/kg of TL-F, TR-F, TL-K, or TR-K for seven days, and intraperitoneally injected with 0.5 mL/kg of CCl₄ 1 h after last Taraxaci Herba treatment. Silymarin (100 mg/kg) was used as a positive drug. Body weight gain, relative liver weight, serum biochemistry, histopathological and immunohistochemical analyses, and hepatic antioxidant capacity were determined to investigate the hepatoprotective effect of four extracts. Results : Administration of four types of Taraxaci Herba extract increased body weight gain, and decreased relative liver weight in CCl₄-injected mice. As compared to CCl₄ group, TL-F and TR-F significantly decreased serum aspartate aminotransferase activity, while four extracts reduced CCl₄-induced alanine aminotransferase activity. In addition, TL-F and TR-F significantly decreased the numbers of degenerated hepatocytes, infiltrated inflammatory cells, cleaved caspase-3 positive cells, and cleaved PARP positive cells in hepatic tissues. Moreover, TL-F, TR-F, and TR-K administration reduced the lipid peroxidation and nitrotyrosine, and increased glutathione, superoxide dismutase, and catalase activities in hepatic tissues. There were no statistical differences between TL-F- and silymarin-treated group. Conclusion : Of four extracts tested, present results suggest that TL-F is the most favorable candidate against CCl₄-induced acute liver injury through enhancing antioxidant activity.