• 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.

• BMB Reports
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• v.40 no.5
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• pp.636-643
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• 2007

This study was designed to identify and characterize the mechanism of macrophage activation by AAP, an acidic polysaccharide fraction isolated from the roots of Angelica sinensis (Oliv.) Diels. As a result, AAP significantly enhanced nitric oxide (NO) production and cellular lysosomal enzyme activity in murine peritoneal macrophages in vitro and in vivo. Furthermore, L-NAME, a specific inhibitor of inducible nitric oxide synthase (iNOS), effectively suppressed AAP-induced NO generation in macrophages, indicating that AAP stimulated macrophages to produce NO through the induction of iNOS gene expression and the result was further confirmed by the experiment of the increase of AAP-induced iNOS transcription in a dose-dependent manner. To further investigate, AAP was shown to strongly augment toll-like receptor 4 (TLR4) mRNA expression and the pretreatment of macrophages with anti-TLR4 antibody significantly blocked AAP-induced NO release and the increase of iNOS activity, and tumor necrosis factor-$\alpha$ (TNF-$\alpha$) secretion.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.21 no.2
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• pp.54-70
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• 2008

Background and Object : This study was carried out to investigate the effects of GCSBPT (Gagam-Cheongsang BangPungTang) on the in vitro and in vivo anti-inflammatory reactions. Methods : Vascular permeability and Cyclooxygenase inhibition assay are examined in vitro and nitric oxide inhibition assay, radical scavenging activity test, $TNF-{\alpha}$, COX-2 inhibition test are examined in vivo. Results : GCSBPT showed inhibitory effects on vascular permeability and leukocyte migration in animal test. In cyclooxygenase 2 inhibition assay, an ethanol extract of GCSBPT inhibited prostaglandin E2 generation at a concentration of $10{\mu}g/ml$. Among the herbal ingredients of GCSBPT, ethanol extracts of Nepetae Spica exhibited potent inhibitory activities. Ethanol extract of GCSBPT inhibited the release of nitric oxide and the gene expression of inducible nitric oxide synthase in RAW 246.7 cells stimulated by lipopolysaccharide. Ethanol extract of GCSBPT exhibited radical scavenging activity of 54% at $100{\mu}g/ml$. Among the herbal ingredients of GCSBPT. Conclusions : According to the above results, I expected that GCSBPT was a potent anti-inflammatory prescription.

• Biomedical Science Letters
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• v.24 no.1
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• pp.50-54
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• 2018

N-nitroso-N-methylurea (NMU) and N-nitroso-N-ethylurea (NEU), direct alkylating chemical mutagens and carcinogens, are shown to be the upregulators of cellular $NF-{\kappa}B$, regulating various genes that mediate tumorigenesis and carcinogenesis. Nitric oxide (NO), a toxic reactive radical gas, has been known to induce programmed cell death or apoptosis in various cells. Therefore, the assessment of NO production was examined to elucidate the possible contribution of NO release to the chemical carcinogenic potency of NMU and NEU in human skin cells. NMU and NEU did not alter the NO production, but they caused a significant downregulation of the NO generation on lipopolysaccharide (LPS)-induced NO production at concentrations ranging from $2{\sim}5{\mu}M$. The degree of downregulation of NO by NMU and NEU decreased up to 15% and 20%, respectively, compared to the control. These results demonstrate that the LPS-inducible keratinocytes NO synthase is involved in modulating carcinogenic potency by NMU and NEU, and the regulation of the cellular $NF-{\kappa}B$ activity by NMU and NEU is negatively correlated with the level of LPS-induced NO production in human skin cells. The findings of this study suggest the hypothesis that NMU and NEU-induced carcinogenesis may be associated with the downregulation of NO production, and the inducible NO may play an important role in NMU and NEU-induced carcinogenicity in human epidermal keratinocytes.

• The Korean Journal of Physiology and Pharmacology
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• v.15 no.3
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• pp.123-128
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• 2011

Caesalpinia sappan (C. sappan) is a medicinal plant used for promoting blood circulation and removing stasis. During a screening procedure on medicinal plants, the ethylacetate extract of the lignum of C. sappan (CLE) showed inhibitory activity on arginase which has recently been reported as a novel therapeutic target for the treatment of cardiovascular diseases such as atherosclerosis. CLE inhibited arginase II activity prepared from kidney lysate in a dose-dependent manner. In HUVECs, inhibition of arginase activity by CLE reciprocally increased NOx production through enhancement of eNOS dimer stability without any significant changes in the protein levels of eNOS and arginase II expression. Furthermore, CLE-dependent arginase inhibition resulted in increase of NO generation and decrease of superoxide production on endothelium of isolated mice aorta. These results indicate that CLE augments NO production on endothelium through inhibition of arginase activity, and may imply their usefulness for the treatment of cardiovascular diseases associated with endothelial dysfunction.

• Journal of Ginseng Research
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• v.32 no.2
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• pp.89-98
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• 2008

There are increasing evidences in the literatures on the potential role of ginsenosides in treating cardiovascular diseases. In this article, current information about ginsenosides-mediated vascular relaxation are reviewed. From the published studies using isolated organs, cell culture systems and animal models, ginsenosides are shown to relax blood vessels and improve blood flow through diverse mechanisms, including nitric oxide release by activating eNOS phosphorylation via PI3K/Akt and/or ERK1/2 pathways in endothelial cells, induction of inducible nitric oxide synthase through activation of NF-${\kappa}$B, reducing the intracelluar Ca$^{2+}$ levels by activating Ca$^{2+}$-activated K$^{+}$ channels in vascular smooth muscle cells and reducing platelet aggregation by decreasing thromboxane A$_2$ formation and intracelluar Ca$^{2+}$in platelets. In addition, the relevant clinical trials regarding the effects of ginsenosides on the cardiovascular disease are summarized, particulary focusing on managing hypertension and improving thrombotic disorders. Finally, antagonistic effects of ginsenosides on the prostaglandin H$_2$ receptor and scavenging effects on the generation of oxygen-derived free radicals in spontaneously hypertensive rats (SHR) are discussed.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.5
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• pp.1295-1302
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• 2006

Our preliminary aim is to elucidate the pharmacokinetic features of the PNS(Panax notoginseng Buck F.H. Chen. (Arialiaceae) root). First, we assessed the prevention of neurtrophil functions. A Panax notoginseng inhibited neutrophil functions, including degranulation, superoxide generation, and leukotriene B4 production, without any effect on 5-lipoxygenase activity. This Panax notoginseng reduced nitric oxide (NO) and prostaglandin E2 production in mouse peritoneal macrophages stimulated with lipopolysaccharide, whereas no influence on the activity of inducible NO synthase, cyclo-oxygenase-2 or cyclo-oxygenase-1 was observed. Panax notoginseng significantly reduced mouse paw oedema induced by carrageenan. The results indicate that Panax notoginseng exerts anti-inflammatory effects related to the inhibition of neutrophil functions and of NO and prostaglandin E2 production, which could be due to a decreased expression of inducible NO synthase and cyclo-oxygenase-2.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.2
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• pp.198-206
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• 2008

갯쑥(Artemisia fukudo Makino, 일명 바다쑥)은 바닷가 염전 주변 습지에서 자라는 염생식물로 어린 갯쑥은 나물로 먹어왔으며, 민간에서 간에 좋다고 알려져 있다. 본 연구에서는 염생식물의 기능 성분을 탐색하는 연구의 일환으로 마우스유래 대식세포주인 RAW264.7세포를 이용하여 갯쑥의 nitric oxide(NO) 생성 억제 작용을 알아보고자 하였다. 갯쑥은 methanol 추출과 열수 추출한 후 농축하여 실험하였고, methanol 추출물은 다시 hexane, chloroform, ethylacetate, butanol, water로 순차 용매 분획하여 농축하여, 각각의 추출물을 RAW 264.7 세포에 농도별 분획별로 처리한 후 LPS와 interferon-${\gamma}$로 자극한 RAW 264.7 세 포주의 NO 생성을 측정하여 NO 생성 저해율을 구하였다. 갯쑥 methanol 추출물의 높은 NO 생성 저해율과 iNOS 활성 저해율을 나타내었으며(IR=90.7%과 IR=81.6%), 각각의 추출물중 분획물이 100${\mu}g/mL$ 농도에서 hexane 분획물이 가장 높은 NO 생성 저해 효과(IR=92.1%)와 iNOS 활성 억제 효과(IR=85.0%)를 나타내었다. 갯쑥의 methanol 추출물, hexane과 chloroform 분획물에서 높은 NO 생성 저해 효과를 나타내어 새로운 암 예방인자 물질로 기대되며, 따라서 본 연구 결과는 암 예방인자 분리를 위한 기초 자료가 될 것이며, 나아가 성분 분리 연구와 동물 실험을 통한 기전 연구가 수행되어야 할 것이다.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.1
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• pp.91-96
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• 1997

Lipocortin 1 has been proposed as a putative mediator of anti-inflammatory actions of glucocorticoids. We investigated the role of lipocortin 1 in the effect of dexamethasone using rat splenic leukocytes. Concanavalin A(ConA; 1 ${\mu}g/ml$) increased the leukocyte proliferation and nitric oxide(NO) generation, which were measured as $[^3H]-thymidine$ uptake by the cells and nitrite accumulation in the culture media, respectively. Dexamethasone suppressed ConA-induced cell proliferation, in a concentration-dependent manner with $EC_{50}$ around 50nM. The addition of anti-lipocortin l(Anti-LCl) reversed dexamethasone effects: 0.24, 1.2, 6 ${\mu}g/ml$ of Anti-LC1 reversed dexamethasone(50 nM)-induced suppression of thymidine uptake by $9{\pm}3%$, $16{\pm}3%$, $36{\pm}5%$, respectively; 0.24, 1.2, and 6 ${\mu}g/ml$ of Anti-LCI reversed dexa-methasone-induced decrease of nitrite concentration by $49{\pm}16%$, $61{\pm}20%$, $77{\pm}19%$, respectively. The present data indicate that lipocortin 1 mediates, at least in part, glucocorticoids-induced suppression of leukocyte proliferation and blockade of NO generation.

• Advances in Traditional Medicine
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• v.7 no.4
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• pp.341-347
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• 2007

Red seaweed (Callophyllis japonica) has long formed part of the diet of Asians, but the pharmacological properties of this plant have not been evaluated. In this study, we examined the effect of an ethanol extract of C. japonica on the generation of nitric oxide (NO) in RAW 264.7 cells. The C. japonica extract increased the generation of NO and tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$), which were detected by the Griess method and an enzyme-linked immunosorbent assay, respectively. The increased production of NO by C. japonica extract was inhibited by $N^G$-monomethyl-L-arginine ($100{\mu}M$), a specific inhibitor of NO production in the L-arginine-dependent pathway, and by the nuclear $factor-{\kappa}B$ ($NF-{\kappa}B$) inhibitor, pyrrolidine dithiocarbamate ($10-100{\mu}M$) in a dose-dependent manner. These findings demonstrate that C. japonica extract stimulates the production of NO and $TNF-{\alpha}$ in RAW 264.7 cells through the activation of $NF-{\kappa}B$ and that this extract might also inhibit the growth of the human leukemic cells.