• Title/Summary/Keyword: Cyclooxygenase pathway

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Effect of saccharin on inflammation in 3T3-L1 adipocytes and the related mechanism

  • Kim, Hye Lin;Ha, Ae Wha;Kim, Woo Kyoung
    • Nutrition Research and Practice
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    • v.14 no.2
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    • pp.109-116
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    • 2020
  • BACKGROUND/OBJECTIVES: Excessive intake of simple sugars induces obesity and increases the risk of inflammation. Thus, interest in alternative sweeteners as a sugar substitute is increasing. The purpose of this study was to determine the effect of saccharin on inflammation in 3T3-L1 adipocytes. MATERIALS/METHODS: 3T3-L1 preadipocytes were differentiated into adipocytes. The adipocytes were treated with saccharin (0, 50, 100, and 200 ㎍/mL) for 24 h. Inflammation was induced by exposure of treated adipocytes to lipopolysaccharide (LPS) for 18 h and cell proliferation was measured. The concentration of nitric oxide (NO) was measured by using Griess reagent. Protein expressions of nuclear factor kappa B (NF-κB) and inhibitor κB (IκB) were determined by western blot analysis. The mRNA expressions of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin 1β (IL-1β), interleukin 6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), and tumor necrosis factor-α (TNF-α) were determined by real-time PCR. RESULTS: Compared with the control group, the amount of NO and the mRNA expression of iNOS in the LPS-treated group were increased by about 17.6% and 46.9%, respectively, (P < 0.05), and those parameter levels were significantly decreased by saccharin treatment (P < 0.05). Protein expression of NF-κB was decreased and that of IκB was increased by saccharin treatment (P < 0.05). Saccharin decreased the mRNA expression of COX-2 and the inflammation cytokines (IL-1β, IL-6, MCP-1, and TNF-α) (P < 0.05). CONCLUSIONS: The results of this study suggest that saccharin can inhibit LPS-induced inflammatory responses in 3T3-L1 adipocytes via the NF-κB pathway.

Protective role of oligonol from oxidative stress-induced inflammation in C6 glial cell

  • Ahn, Jae Hyun;Choi, Ji Won;Choi, Ji Myung;Maeda, Takahiro;Fujii, Hajime;Yokozawa, Takako;Cho, Eun Ju
    • Nutrition Research and Practice
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    • v.9 no.2
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    • pp.123-128
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    • 2015
  • BACKGROUND/OBJECTIVES: Natural products or active components with a protective effect against oxidative stress have attracted significant attention for prevention and treatment of degenerative disease. Oligonol is a low molecular weight polyphenol containing catechin-type monomers and oligomers derived from Litchi chinensis Sonn. We investigated the protective effect and its related mechanism of oligonol against oxidative stress. MATERIALS/METHODS: Oxidative stress in C6 glial cells was induced by hydrogen peroxide ($H_2O_2$) and the protective effects of oligonol on cell viability, nitric oxide (NO) and reactive oxygen species (ROS) synthesis, and mRNA expression related to oxidative stress were determined. RESULTS: Treatment with oligonol inhibited NO and ROS formation under cellular oxidative stress in C6 glial cells. In addition, it recovered cell viability in a dose dependent-manner. Treatment with oligonol also resulted in down-regulated mRNA expression related to oxidative stress, nuclear factor kappa-B (NF-${\kappa}B$) p65, cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS), compared with the control group treated with $H_2O_2$. In particular, expression of NF-${\kappa}B$ p65, COX-2, and iNOS was effectively reduced to the normal level by treatment with $10{\mu}g/mL$ and $25{\mu}g/mL$ of oligonol. CONCLUSIONS: These results indicate that oligonol has protective activity against oxidative stress-induced inflammation. Oligonol might be a promising agent for treatment of degenerative diseases through inhibition of ROS formation and NF-${\kappa}B$ pathway gene expression.

Black soybean anthocyanins attenuate inflammatory responses by suppressing reactive oxygen species production and mitogen activated protein kinases signaling in lipopolysaccharide-stimulated macrophages

  • Kim, Jin Nam;Han, Sung Nim;Ha, Tae Joung;Kim, Hye-Kyeong
    • Nutrition Research and Practice
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    • v.11 no.5
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    • pp.357-364
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    • 2017
  • BACKGROUND/OBJECTIVES: Oxidative stress is closely related with inflammation and development of many diseases. Black soybean seed coat contains high amount of anthocyanins, which are well-known for free radical scavenging activities. This study investigated inflammatory response and action mechanism of black soybean anthocyanins with regard to antioxidant activity in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. MATERIALS/METHODS: RAW 264.7 cells were treated with anthocyanins extracted from black soybean seed coats in a concentration range of 12.5 to $100{\mu}g/mL$. The production of reactive oxygen species (ROS), secretion of pro-inflammatory mediators and cytokines, and the signaling in the mitogen activated protein kinases (MAPKs) pathway were examined. RESULTS: Black soybean anthocyanins significantly decreased LPS-stimulated production of ROS, inflammatory mediators such as nitric oxide (NO) and prostaglandin $E_2$, and pro-inflammatory cytokines, including tumor necrosis factor ${\alpha}$ and interleukin-6, in a dose-dependent manner without cytotoxicity (P < 0.001). Black soybean anthocyanins downregulated the expression of inducible NO synthase and cyclooxygenase-2 in LPS-stimulated RAW 264.7 cells (P < 0.001). Moreover, black soybean anthocyanins inhibited LPS-induced phosphorylation of MAPKs, including extracellular signal-regulated kinase, c-Jun N-terminal kinase, and p38 (P < 0.001). CONCLUSION: These results suggest that black soybean anthocyanins exert anti-inflammatory activity by inhibiting ROS generation and subsequent MAPKs signaling, thereby inhibiting inflammatory responses.

Effects of Isatidis Radix and it's Active Component, Tryptanthrin on the Production of Inflammatory Mediators in Lipopolysaccharide-activated Raw264.7 Cells (LPS로 활성화된 Raw264.7 cell에서 판람근 및 Tryptanthrin의 염증매개물질억제효과)

  • Park, Sook-Jahr;Lee, Jong-Rok;Jo, Mi-Jeong;Park, Sang-Mi;Buyn, Sung-Hui;Cho, Il-Je;Kim, Sang-Chan
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.24 no.1
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    • pp.64-77
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    • 2011
  • Objectives : 판람근(板藍根)은 십자화과에 속하는 대청(大靑) 또는 숭남의 근(根)을 건조한 것이다. 본 연구는 판람근(板藍根)이 청열해독(淸熱解毒)함에 근거하여, LPS로 활성화된 Raw264.7 cell에서 판람근(板藍根)과 그 성분중의 하나인 tryptanthrin이 염증매개물질에 미치는 효과를 살펴보고자 하였다. Methods : 세포생존율은 MTT, nitric oxide (NO)는 Griess reagent를 사용하여 측정하였으며, 각 단백질의 발현량은 Western blot 방법을 사용하였으며, cytokine 및 cyclooxygenase-2 (COX-2)는 ELISA방법을 사용하여 측정하였다. Results : LPS는 NO 및 prostaglandin E2 (PGE2)를 유의하게 상승시켰으며, 판람근(板藍根)추출물 (IRE) 및 tryptanthrin 은 이들을 유의하게 억제하였다. 그러나 판람근(板藍根)의 또 다른 성분인 indigo는 유의한 결과를 나타내지 못하였다. IRE와 tryptanthrin은 inhibitory kappa B alpha의 인산화를 억제하여, nuclear factor-${\kappa}$B (NF-${\kappa}$B)의 핵으로의 전위(轉位)를 억제하여, iNOS 및 cytokine을 억제하였다. IRE와 tryptanthrin의 PGE2 억제는, COX-2의 발현억제에서가 아니라, COX-2의 활성을 억제함에서 기인하였다. Conclusion : 이러한 결과는 판람근(板藍根)이 NF-${\kappa}$B pathway를 경유하여 iNOS의 발현 및 COX-2의 활성을 억제함을 나타내며, 이러한 판람근(板藍根)의 항염증효능은 일부 tryptanthrin의 작용에서 기인함을 시사한다.

Src Kinase Regulates Nitric Oxide-induced Dedifferentiation and Cyc1ooxygenase-2 Expression in Articular Chondrocytes via p38 Kinase-dependent Pathway

  • Yu, Seon-Mi;Lee, Won-Kil;Yoon, Eun-Kyung;Lee, Ji-Hye;Lee, Sun-Ryung;Kim, Song-Ja
    • IMMUNE NETWORK
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    • v.6 no.4
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    • pp.204-210
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    • 2006
  • Background: Nitric oxide (NO) in articular chondrocytes regulates dedifferentiation and inflammatory responses by modulating MAP kinases. In this study, we investigated whether the Src kinase in chondrocytes regulates NO-induced dedifferentiation and cyclooxygenase-2 (COX-2) expression. Methods: Primary chondrocytes were treated with various concentrations of SNP for 24 h. The COX-2 and type II collagen expression levels were determined by immunoblot analysis, and prostaglandin $E_2\;(PGE_2)$ was determined by using a $PGE_2$ assay kit. Expression and distribution of p-Caveolin and COX-2 in rabbit articular chondrocytes and cartilage explants were determined by immunohistochemical staining and immunocytochemical staining, respectively. Results: SNP treatment stimulated Src kinase activation in a dose-dependent manner in articular chondrocytes. The Src kinase inhibitors PP2 [4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo(3,4-d)pyrimidine], a significantly blocked SNP-induced p38 kinase and caveolin-1 activation in a dose-dependent manner. Therefore, to determine whether Src kinase activation is associated with dedifferentiation and/or COX-2 expression and $PGE_2$ production. As expected, PP2 potentiated SNP-stimulated dedifferentiation, but completely blocked both COX-2 expression and $PGE_2$ production. And also, levels of p-Caveolin and COX-2 protein expression were increased in SNP-treated primary chondrocytes and osteoarthritic and rheumatoid arthritic cartilage, suggesting that p-Caveolin may playa role in the inflammatory responses of arthritic cartilage. Conclusion: Our previously studies indicated that NO caused dedifferentiation and COX-2 expression is regulated by p38 kinase through caveolin-1 (1). Therefore, our results collectively suggest that Src kinase regulates NO-induced dedifferentiation and COX-2 expression in chondrocytes via p38 kinase in association with caveolin-1.

Nitric Oxide as a Pro-apoptotic as well as Anti-apoptotic Modulator

  • Choi, Byung-Min;Pae, Hyun-Ock;Jang, Seon-Il;Kim, Young-Myeong;Chung, Hun-Taeg
    • BMB Reports
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    • v.35 no.1
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    • pp.116-126
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    • 2002
  • Nitric oxide (NO), synthesized from L-arginine by NO synthases, is a small, lipophilic, diffusible, highly reactive molecule with dichotomous regulatory roles in many biological events under physiological and pathological conditions. NO can promote apoptosis (pro-apoptosis) in some cells, whereas it inhibits apoptosis (anti-apoptosis) in other cells. This complexity is a consequence of the rate of NO production and the interaction with biological molecules such as metal ion, thiol, protein tyrosine, and reactive oxygen species. Long-lasting overproduction of NO acts as a pro-apoptotic modulator, activating caspase family proteases through the release of mitochondrial cytochrome c into cytosol, up-regulation of the p53 expression, and alterations in the expression of apoptosis-associated proteins, including the Bcl-2 family. However, low or physiological concentrations of NO prevent cells from apoptosis that is induced by the trophic factor withdrawal, Fas, $TNF{\alpha}$/ActD, and LPS. The anti-apoptotic mechanism is understood on the basis of gene transcription of protective proteins. These include: heat shock protein, hemeoxygenase, or cyclooxygenase-2 and direct inhibition of the apoptotic executive effectors caspase family protease by S-nitrosylation of the cysteine thiol group in their catalytic site in a cell specific way. Our current understanding of the mechanisms by which NO exerts both pro- and anti-apototic action is discussed in this review article.

Anti-Inflammatory Effect of Rosa rugosa Flower Extract in Lipopolysaccharide-Stimulated RAW264.7 Macrophages

  • Tursun, Xirali;Zhao, Yongxin;Talat, Zulfiya;Xin, Xuelei;Tursun, Adila;Abdulla, Rahima;AkberAisa, Haji
    • Biomolecules & Therapeutics
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    • v.24 no.2
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    • pp.184-190
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    • 2016
  • Rosa rugosa Thunb, a deciduous shrub of the genus Rosa, has been widely used to treat stomach aches, diarrhoea, pain, and chronic inflammatory disease in eastern Asia. In recent years, our research team has extensively studied the Rosa rugosa flower extract, and specifically undertook pharmacological experiments which have optimized the extraction process. Our methods have yielded a standard extract enriched in phenolic compounds, named PRE. Herein, we expand our efforts and evaluated the anti-inflammatory activity of PRE on lipopolysaccharide (LPS)-induced inflammation in RAW 264.7 macrophages. PRE significantly inhibited production of nitric oxide (NO), prostaglandin $E_2(PGE_2)$, tumor necrosis factor (TNF)-${\alpha}$, interleukin (IL)-6, and interleukin $1{\beta}$ (IL-$1{\beta}$), as well as expression of their synthesizing enzymes, inducible nitric oxide synthase (iNOS) and cyclooxygenase2 (COX-2). Furthermore, PRE inhibited activity of mitogen-activated protein kinases (MAPK) as well as nuclear factor-kappa B (NF-${\kappa}B$) signaling pathway. Our findings are the first to explain the anti-inflammatory mechanism by PRE in LPS-stimulated macrophages. Given these results, we propose that PRE has therapeutic potential in the prevention of inflammatory disorders.

Anti-inflammatory activity of the water extract of Polygala tenuifolia Willd (원지(遠志)의 항염증 작용에 대한 연구)

  • Oh, Hyun-Suk;Kim, Byoung-Woo
    • The Journal of Internal Korean Medicine
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    • v.34 no.2
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    • pp.204-214
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    • 2013
  • Objectives : This study was designed to investigate the cellular and molecular mechanisms of anti-inflammatory activity of the water extract of Polygala tenuifolia Willd. (Pt-WE). Methods : Using lipopolysaccharide (LPS)-stimulated murine RAW264.7 cells, we examined inflammatory mediators such as nitric oxide (NO), inducible NO synthase (iNOS), cyclooxygenase (COX)-2 and prostaglandin $E_2$ ($PGE_2$). Also, the inhibitory effect of Pt-WE on the activity of activator protein 1 (AP-1) and upstream signaling molecules was evaluated. To assess the protective effect of Pt-WE on hydrochloride/ethanol (HCl/EtOH)-induced gastric ulcer in mice, we compared Pt-WE (200 mg/kg) with ranitidine (50 mg/kg) treated mice's gastric mucosa, based on gross observations. Results : Pt-WE inhibited LPS-induced production of NO, $PGE_2$ in a dose-dependent manner, without causing cytotoxicity. Pt-WE suppressed AP-1 activation by reducing generations of both c-Jun and c-Fos. In addition, Pt-WE inhibited the p-MKK 4/7 (mitogen-activated protein kinase kinase 4/7) and p-JNK (c-Jun N-terminal kinase) 1 in LPS-stimulated RAW264.7 cells. HCl/EtOH-induced gastric ulcer lesions were inhibited by pre-treatment of Pt-WE based on gross observations. In addition, Pt-WE decreased the phosphorylation level of JNK. Conclusions : These results demonstrate that Pt-WE has anti-inflammatory and gastroprotective effects. Thus, Pt-WE may be used widely in treatment of not only neurodegenerative diseases but also inflammatory diseases.

Protective Effects of Cardiotonic Pills(CP) on Neuroglia Cells Against Oxidative Stress and the Effects on Regional Cerebral Blood Flow in Normal Rats (심적환(心適丸)이 산화적 손상에 따른 신경교세포 보호효과 및 국소 뇌혈류량 변화에 미치는 영향)

  • Kwon, Tae-Woo;Son, Young-Soo;Cho, Su-In;Kim, Young-Kyun
    • The Korea Journal of Herbology
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    • v.23 no.4
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    • pp.71-79
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    • 2008
  • Objectives: SimJeok-Hwan(CP, Cardiotonic Pills) was made to treat patients with coronary arteriosclerosis, angina pectoris and hyperlipidemia. This study was designed to investigate the effects of CP on Proliferation rates neuroglia cells and protective effect of CP against oxidative stress, and also investigate the effects on regional Cerebral Blood Flow(rCBF) in normal rats. Methods: In this experiment, effects of CP on proliferation rates of neuroglia cells were measured using modified MTT methods. Oxidative stress was induced by treatment with 200 mM of hydrogen peroxide for 2 hr. rCBF and MABP were measured using Laser doppler flowmeter. Results: Treatment with CP elevated proliferation rates in C6 cells. In addition, CP protected cell death of C6 cells induced by oxidative stress. In results, rCBF was elevated by treatment with CP in normal rats. But, Mean Arterial Blood Pressure(MABP) did not affected by CP. In addition, the elevation of rCBF was blacked by pre-treatment with 1 mg/kg of indomethacin effectively. On the other hand, pre-treatment with 0.01 mg/kg of methylene blue did not affect rCBF level in normal rats. Conclusions: In conclusion, these results suggest that CP can act as anti-oxidant to protect neuroglia cells and also suggest that CP can elevate rCBF, which are involved in cyclooxygenase pathway.

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Anti-inflammatory effect of ozonated krill (Euphausia superba) oil in lipopolysaccharide-stimulated RAW 264.7 macrophages

  • Kim, Hong-Deok;Lee, Soo-Bin;Ko, Seok-Chun;Jung, Won-Kyo;Kim, Young-Mog;Kim, Seon-Bong
    • Fisheries and Aquatic Sciences
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    • v.21 no.6
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    • pp.15.1-15.9
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    • 2018
  • Background: Inflammation has been known to associate with many human diseases. The objective of this study was to evaluate an anti-inflammatory effect of ozonated krill (Euphausia superba) oil, which was prepared by the treatment of krill oil using ozone gas. The anti-inflammatory activity was evaluated in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Results: Ozonated krill oil significantly inhibited nitric oxide (NO) production and suppressed the mRNA and protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in LPS-stimulated RAW 264.7 macrophages. Ozonated krill oil also reduced the mRNA expression of inflammatory cytokines such as interleukin (IL)-$1{\beta}$, IL-6, and tumor necrosis factor (TNF)-${\alpha}$ in LPS-stimulated RAW 264.7 macrophages. To elucidate the mechanism underlying the anti-inflammatory activity of ozonated krill oil, we evaluated the effects of ozonated krill oil on the activation of mitogen-activated protein kinases (MAPKs) pathway. Ozonated krill oil suppressed the LPS-stimulated phosphorylation of p38 MAPK and c-Jun N-terminal kinases (JNK). Conclusion: This study revealed that the ozonated krill oil exhibited an anti-inflammatory effect in LPS-stimulated RAW 264.7 macrophages. To the best of our knowledge, this is the first report that ozonated krill oil suppressed pro-inflammatory mediator and cytokine expression in LPS-stimulated RAW 264.7 macrophages by inhibiting the phosphorylation of p38 MAPK and JNK.