• Title/Summary/Keyword: nitric oxide synthase activity

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Vasoactive Intestinal Polypeptide Inhibits Pacemaker Activity via the Nitric Oxide-cGMP-Protein Kinase G Pathway in the Interstitial Cells of Cajal of the Murine Small Intestine

  • Kim, Byung Joo;Lee, Jae Hwa;Jun, Jae Yeoul;Chang, In Youb;So, Insuk;Kim, Ki Whan
    • Molecules and Cells
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    • v.21 no.3
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    • pp.337-342
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    • 2006
  • Interstitial cells of Cajal (ICCs) are pacemaker cells that activate the periodic spontaneous depolarization (pacemaker potentials) responsible for the production of slow waves in gastrointestinal smooth muscle. The effects of vasoactive intestinal polypeptide (VIP) on the pacemaker potentials in cultured ICCs from murine small intestine were investigated by whole-cell patch-clamp techniques. Addition of VIP (50 nM-$1{\mu}M$) decreased the amplitude of pacemaker potentials and depolarized resting membrane potentials. To examine the type of receptors involved in ICC, we examined the effects of the $VIP_1$ agonist and found that it had no effect on pacemaker potentials. Pretreatment with $VIP_1$ antagonist ($1{\mu}M$) for 10 min also did not block the VIP (50 nM)-induced effects. On the other hand exposure to 1H-(1,2,4)oxadiazolo(4,3-A)quinoxalin-1-one (ODQ, $100{\mu}M$), an inhibitor of guanylate cyclase, prevented VIP inhibition of pacemaker potentials. Similarly KT-5823 ($1{\mu}M$) or RP-8-CPT-cGMPS ($10{\mu}M$), inhibitors of protein kinase G (PKG) blocked the effect of VIP (50 nM) on pacemaker potentials as did N-nitro-L-arginine (L-NA, $100{\mu}M$), a non-selective nitric oxide synthase (NOS) inhibitor. These results imply that the inhibition of pacemaker activity by VIP depends on the NO-cGMP-PKG pathway.

Effects of Root Extracts from Angelica gigas and Angelica acutiloba on Inflammatory Mediators in Mouse Macrophages

  • Yoon, Tae-Sook;Cheon, Myeoung-Sook;Lee, Do-Yeon;Moon, Byeong-Cheol;Lee, Hye-Won;Choo, Byung-Kil;Kim, Ho-Kyoung
    • Journal of Applied Biological Chemistry
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    • v.50 no.4
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    • pp.264-269
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    • 2007
  • Root extracts of Angelica gigas and A. acutiloba have been used traditionally for the treatment of gynecological diseases, as well as anemia, blood stasis, and inflammatory pain, as blood tonics in Oriental medicine. In the present study, we investigated the effects of A. gigas and A. acutiloba on inflammatory mediators in mouse macrophages and compared their activities. Many studies suggest that prostaglandin $E_2$ ($PGE_2$) biosynthesis and nitric oxide (NO) production play important roles in the processes of both inflammation and carcinogenesis. Ethanolic extracts from the roots of both species exhibited significant inhibitory effects on $PGE_2$ generation in lipopolysaccharide-stimulated RAW 264.7 cells. In particular, the extract from A. gigas was more effective than that from A. acutiloba. Although neither inhibited NO generation, the extract from A. acutiloba stimulated NO generation. Our results suggest that the roots of A. gigas might possess more anti-inflammatory and/or cancer chemopreventative activity than that of A. acutiloba due to the suppression of cyclooxygenase-2 (COX2)-mediated $PGE_2$ production. In addition, A. acutiloba might exert anti-tumor activity through an increase in macrophage-produced NO.

The Change of Vascular Reactivity in Rat Thoracic Aorta 3 Days after Acute Myocardial Infarction (흰쥐에서 급성심근경색 3일 후 흉부 대동맥 혈관 반응성의 변화)

  • Lee, Sub;Roh, Woon-Seok;Jang, Jae-Seok;Bae, Chi-Hoon;Park, Ki-Sung;Lee, Jong-Tae
    • Journal of Chest Surgery
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    • v.42 no.5
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    • pp.576-587
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    • 2009
  • Background: The up-regulation of the nitric oxide (NO)-cGMP pathway might be involved in the change of vascular reactivity in rats 3 days after they suffer acute myocardial infarction. However, the underlying mechanism for this has not been clarified. Material and Method: Acute myocardial infarction (AMI) was induced by occluding the left anterior descending coronary artery (LAD) for 30 min (Group AMI), whereas the sham-operated control rats were treated similarly without LAD occlusion (Group SHAM), The concentration-response relationships for phenylephrine (PE), KCl, acetylcholine (Ach) and sodium nitroprusside (SNP) were determined in the endothelium intact E(+) and endothelium denuded E(-) thoracic aortic rings from the rats 3 days after AMI or a SHAM operation. The concentration-response relationships of PE in the E(+) rings from the AMI rats were compared with those relationships in the rings pretreated with nitric oxide synthase (NOS) inhibitor $N{\omega}$-nitro-L-arginine methyl ester (L-NAME) or the cyclooxygenase inhibitor indomethacin. The plasma nitrite/nitrate concentrations were checked via a Griess reaction. The cyclic GMP content in the thoracic aortic rings was measured by radioimmunoassay and the endothelial nitric oxide synthase (eNOS) mRNA expression was assessed by real time PCR. Result: The mean infarct size (%) in the rats with AMI was $21.3{\pm}0.62%$. The heart rate and the systolic and diastolic blood pressure were not significantly changed in the AMI rats. The sensitivity of the contractile response to PE and KCl was significantly decreased in both the E(+) and E(-) aortic rings of the AMI group (p<0.05). L-NAME completely reversed these contractile responses whereas indomethacin did not (p<0.05). Moreover, the sensitivity of the relaxation response to Ach was also significantly decreased in the AMI group (p<0.05). The plasma nitrite and nitrate content (p<0.05), the basal cGMP content (p<0.05) and the eNOS mRNA expression (p=0.056) in the AMI rats were increased as compared with the SHAM group. Conclusion: Our findings indicate that the increased eNOS activity and the up-regulation of the NO-cGMP pathway can be attributed to the decreased contractile or relaxation response in the rat thoracic aorta 3 days after AMI.

Antioxidant Activity and Physiological Function of the Anomala albopilosa Extracts (청동풍탱이(Anomala albopilosa)추출물의 항산화성 및 생리기능)

  • Yoon, Weon-Jong;Lee, Jung-A;Kim, Ji-Young;Kim, Sang-Bum;Park, Soo-Yeong
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.36 no.6
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    • pp.670-677
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    • 2007
  • We analyzed antioxidant and physiological activities to investigate the functional effects of ethanol extracts of Anomala albopilosa imago and A. albopilosa larva. In order to effectively screen for anti-inflammatory agents, we first investigated the antioxidant activities such as DPPH radical scavenging capacity, superoxide radical scavenging capacity, xanthine oxidase inhibitory activity, and nitric oxide scavenging capacity of the A. albopilosa extracts. By the screening system, we found that A. albopilosa extracts had antioxidant activity which increased with increments of the extract concentration. Moreover, we examined the inhibitory effect of the A. albopilosa extracts on the production of anti-inflammatory factors that the nitric oxide (NO), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and prostaglandin $E_2\;(PGE_2)$ production activated with LPS ($1{\mu}g/mL$) in murine macrophage cell line RAW 264.7. A. albopilosa extracts potentially inhibited the iNOS and COX-2 in a dose-dependent manner. The inhibition of iNOS activity was correlated with the decrease in nitrite levels. Additionally, the $PEG_2$ production is markedly inhibited after a treatment with the A. albopilosa extracts.

Effects of Fucoidan on Nitric Oxide Production and Activator Protein-1 Activation in Lipopolysaccharide-Stimulated Porcine Peripheral Blood Mononuclear Cells (LPS로 자극한 돼지 말초혈액 단핵구세포의 Nitric Oxide (NO) 생산 및 Activator Protein-1 (AP-1) 활성화에 있어 Fucoidan의 효과)

  • Park, Jongchan;Ahn, Changhwan;Kang, Byeong-Teck;Kang, Ji-Houn;Jeung, Eui-Bae;Yang, Mhan-Pyo
    • Journal of Veterinary Clinics
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    • v.32 no.4
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    • pp.289-294
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    • 2015
  • Fucoidan which is sulfated polysaccharide extracted from brown seaweed has a wide variety of internal biological activities. The objectives of this study were to examine the effect of fucoidan on nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated porcine peripheral blood mononuclear cells (PBMCs) and to investigate whether this effect is involved in the expression of inducible nitric oxide synthase (iNOS) and the activation of activator portein-1 (AP-1). The levels of NO production and AP-1 activity in the culture supernatants from porcine PBMCs were measured by the enzyme-linked immunosorbent assay and the levels of iNOS and AP-1 mRNA were determined by real time polymerase chain reaction. Fucoidan in LPS-naïve PBMCs has no effects on the production of NO and activity of AP-1. Expressions of iNOS and AP-1 mRNA in LPS-naïve PBMCs were also not affected by treatment of fucoidan. However, NO production, AP-1 activity and expressions of iNOS and AP-1 mRNA were dramatically increased in PBMCs stimulated with LPS. Enhancing effects of NO production and AP-1 activity in PBMCs induced by LPS were reduced by addition of fucoidan. Fucoidan also inhibited an increase in expressions of iNOS and AP-1 mRNA in LPS-stimulated PBMCs. These results suggested that fucoidan exerts anti-inflammatory effect by down-regulating production of NO via suppressing expression of iNOS and activity of AP-1 in LPS-stimulated porcine PBMCs.

Immunostimulation of C6 Glioma Cells Induces Nitric Oxide-Dependent Cell Death in Serum-Free, Glucose-Deprived Condition

  • Shin, Chan-Young;Choi, Ji-Woong;Ryu, Jae-Ryun;Ryu, Jong-Hoon;Kim, Won-Ki;Kim, Hyong-Chun;Ko, Kwang-Ho
    • Biomolecules & Therapeutics
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    • v.8 no.2
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    • pp.140-146
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    • 2000
  • Recently, we reported that immunostimulation of primary rat cortical astrocyte caused stimulation of glucose deprivation induced apoptotic cell death. To enhance the understanding of the mechanism of the potentiated cell death of clucose-deprived astrocyte by immunostimulation, we investigated the effect of immunostimulation on the glucose deprivation induced cell death of rat C6 glioma cells. Co-treatment of C6 glioma cells with lipopolysaccharide (LPS, $1\;{\mu}\textrm{g}/ml$) and interferon ${\gamma}(IFN{\gamma},\;100U/ml)$ is serum free condition caused marked elevationo f nitric oxide production ($>50\;{\mu}M$). In this condition, glucose deprivation caused significant release of lactate dehdrogenase (LDH) from C6 glioma cells while control cells did not show LDH release. To investigate whether elevated level of nitric oxide is responsible for the enhanced LDH release in glucose-deprived condition, C6 glioma cells were treated with 3-morphorinosydnonimine (SIN-1) and it was observed that SIN-1 caused increase in LDH release from glucose-deprived C6 glioma cells. Treatment of C6 glioma cells with $25\;{\mu}M$ of pyrrolidinedithiocarbamate (PDTC) which inhibit Nuclear factor kB (NF-kB) activation, caused complete inhibition of nitric oxide production. Treatment of C6 glioma cells with NO synthase inhibitors, $N^{G}$-nitro-L-arginine (NNA) or L-$N{\omega}$-nitro-L-arginine methyl ester (L-NAME), caused inhibition of nitric oxide production and also glucose deprivation induced cell death of cytokine-stimulated C6 glioma cells. In addition, diaminohydroxypyrimidine (DAHP, 5 mM) which inhibits the synthesis of tetrahydrobiopterine (BH4), one of essential cofactors for iNOS activity, caused complete inhibition of NO production from immunostimulated C6 glioma cells. The results from the present study suggest that immunostimulation causes potentiation of glucose deprivation induced death of C6 glioma cells which is mediated at least in part by the increased production of nitric oxide. The vulnerability of immunostimulated C6 glioma cells to hypoglycemic insults may implicate that the elevated level of cytokines in various ischemic and neurodegenerative diseases may play a role in their pathogenesis.

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Antioxidant and anti-inflammatory activity of parts of Rhus javanica L. (붉나무의 부위 별 항산화 및 항염증 활성)

  • Choi, Ji-Soo;Han, Sang-Don;Jang, Tae-Won;Lee, Seung-Hyun;Park, Jae-Ho
    • Journal of Applied Biological Chemistry
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    • v.62 no.2
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    • pp.195-202
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    • 2019
  • Rhus javanica L. is Anacardiaceae plant distributed in East Asia. We evaluated the antioxidant activity and antiinflammatory effect of leaf, branch, root of ethyl acetate fraction from R. javanica. To confirm effective each extraction, The antioxidant activity was evaluated using 1,1-Diphenyl-2-picryl-hydrazyl and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) scavenging activity assays, and the anti-inflammatory activity was evaluated based on inhibitory activities on the protein and mRNA expression of iNOS and COX-2 in LPS-induced RAW264.7 cells. The phenolic compounds content of each extract was analyzed with Folin reagents and HPLC/PDA method. The gallic acids were identified and quantified. The roots of R. javanica showed strong antioxidant activity. Its total phenolic compounds content were higher than the orders. In addition, anti-inflammatory activity inhibited the protein and mRNA expression of nitric oxide production factor, following the same pattern as contents of phenolic compounds included gallic acid and its antioxidant activity. In conclusion, R. javanica showed effective antioxidant and anti-inflammatory activity. Especially, the roots were evaluated to be highly valuable as a natural resource for reducing inflammation.

Antioxidant activity and anti-inflammatory activity of ethanol extract and fractions of Doenjang in LPS-stimulated RAW 264.7 macrophages

  • Kwak, Chung Shil;Son, Dahee;Chung, Young-Shin;Kwon, Young Hye
    • Nutrition Research and Practice
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    • v.9 no.6
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    • pp.569-578
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    • 2015
  • BACKGROUND/OBJECTIVES: Fermentation can increase functional compounds in fermented soybean products, thereby improving antioxidant and/or anti-inflammatory activities. We investigated the changes in the contents of phenolics and isoflavones, antioxidant activity and anti-inflammatory activity of Doenjang during fermentation and aging. MATERIALS/METHODS: Doenjang was made by inoculating Aspergillus oryzae and Bacillus licheniformis in soybeans, fermenting and aging for 1, 3, 6, 8, and 12 months (D1, D3, D6, D8, and D12). Doenjang was extracted using ethanol, and sequentially fractioned by hexane, dichloromethane (DM), ethylacetate (EA), n-butanol, and water. The contents of total phenolics, flavonoids and isoflavones, 2,2-diphenyl-1 picryl hydrazyl (DPPH) radical scavenging activity, and ferric reducing antioxidant power (FRAP) were measured. Anti-inflammatory effects in terms of nitric oxide (NO), prostaglandin (PG) E2 and pro-inflammatory cytokine production and inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 expressions were also measured using LPS-treated RAW 264.7 macrophages. RESULTS: Total phenolic and flavonoid contents showed a gradual increase during fermentation and 6 months of aging and were sustained thereafter. DPPH radical scavenging activity and FRAP were increased by fermentation. FRAP was further increased by aging, but DPPH radical scavenging activity was not. Total isoflavone and glycoside contents decreased during fermentation and the aging process, while aglycone content and its proportion increased up to 3 or 6 months of aging and then showed a slow decrease. DM and EA fractions of Doenjang showed much higher total phenolic and flavonoid contents, and DPPH radical scavenging activity than the others. At $100{\mu}g/mL$, DM and EA fractions of D12 showed strongly suppressed NO production to 55.6% and 52.5% of control, respectively, and PGE2 production to 25.0% and 28.3% of control with inhibition of iNOS or COX-2 protein expression in macrophages. CONCLUSIONS: Twelve month-aged Doenjang has potent antioxidant and anti-inflammatory activities with high levels of phenolics and isoflavone aglycones, and can be used as a beneficial food for human health.

The Effect of Polyphenols Isolated from Cynanchi wilfordii Radix with Anti-inflammatory, Antioxidant, and Anti-bacterial Activity

  • Jeong, Sunyoung;Lee, Sunwoo;Choi, Woo Jin;Sohn, Uy Dong;Kim, Wonyong
    • The Korean Journal of Physiology and Pharmacology
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    • v.19 no.2
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    • pp.151-158
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    • 2015
  • Recently, Cynanchi wilfordii Radix has gained wide use in Asian countries as a functional food effective for relieving fatigue, osteoporosis, and constipation, particularly in menopausal disorders. However, its anti-inflammatory and anti-microbial activities have not been explored in detail to date. The anti-inflammatory, antioxidant, and anti-bacterial properties of the Cynanchi wilfordii Radix extracts obtained with water, methanol, ethanol, and acetone were compared. All 4 polyphenol-containing extracts exhibited anti-inflammatory and antioxidant effects. The ethanol extract was found to elicit the most potent reduction of nitric oxide (NO), prostaglandin $E_2$ ($PGE_2$), and cytokine (IL-$1{\beta}$, IL-6, IL-10, and TNF-${\alpha}$) levels, as well as inhibit the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in a concentration-dependent manner. The evaluation of antioxidant activity also revealed the ethanol extract to have the highest free radical scavenging activity, measured as $85.3{\pm}0.4%$, which is equivalent to 99.9% of the activity of ${\alpha}$ -tocopherol. In the assessment of anti-bacterial activity, only ethanol extract was found to inhibit the growth of the Bacillus species Bacillus cereus and Bacillus anthracis. These results show that polyphenols of Cynanchi wilfordii Radix have anti-inflammatory, antioxidant, and anti-bacterial properties that can be exploited and further improved for use as a supplementary functional food, in cosmetics, and for pharmaceutical purposes.

Anti-Oxidant Activity and Anti-Inflammatory Effects of Spiraea fritschiana Schneid Extract (참조팝나무 추출물의 항산화 활성 및 항염증 효과)

  • Choi, Eun Yeong;Heo, Seong Il;Kwon, Yong Soo;Kim, Myong Jo
    • Korean Journal of Medicinal Crop Science
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    • v.24 no.1
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    • pp.31-37
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    • 2016
  • Background : We studied the anti-oxidant activity and anti-inflammatory effects of Spiraea fritschiana Schneid extract (SFSE). Methods and Results : The SFSE was prepared using methanol and was evaluated for its total phenol and flavonoid content, DPPH (1,1-diphenyl-2-picrylhydrazyl) free-radical scavenging activity, reducing power, and effect on nitric oxide (NO) production, and cell viability by using real-time polymerase chain reaction (PCR). The total phenol content was $212.78{\mu}g{\cdot}galli$c acid equivalent (GAE)/mg and the total flavonoid content was $66.84{\mu}g{\cdot}quercetin$ equivalent (QE)/mg. The extract showed antioxidant activity (DPPH free-radical scavenging activity) with $RC_{50}$ value of $76.61{\mu}g/m{\ell}$. The reducing power of the extract was Abs 0.58 at $250{\mu}g/m{\ell}$. Cell viability was determined using the MTT 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. To evaluate anti-inflammatory activity, we examined the inhibitory effects on lipopolysaccharide-(LPS)-induced NO production in RAW 264.7 cells. The NO inhibition rate was 90% at $200{\mu}g/m{\ell}$ SFSE. At the same concentration, the expression of pro-inflammatory genes such as inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 also decreased. Conclusions : Our results suggest that SFSE is a novel resource for the development of foods and drugs that possess anti-oxidant and anti-inflammatory activity.