• Title/Summary/Keyword: inhibitory mechanism

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Four active monomers from Moutan Cortex exert inhibitory effects against oxidative stress by activating Nrf2/Keap1 signaling pathway

  • Zhang, Baoshun;Yu, Deqing;Luo, Nanxuan;Yang, Changqing;Zhu, Yurong
    • The Korean Journal of Physiology and Pharmacology
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    • v.24 no.5
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    • pp.373-384
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    • 2020
  • Paeonol, quercetin, β-sitosterol, and gallic acid extracted from Moutan Cortex had been reported to possess anti-oxidative, anti-inflammatory, and anti-tumor activities. This work aimed to illustrate the potential anti-oxidative mechanism of monomers in human liver hepatocellular carcinoma (HepG2) cells-induced by hydrogen peroxide (H2O2) and to evaluate whether the hepatoprotective effect of monomers was independence or synergy in mice stimulated by carbon tetrachloride (CCl4). Monomers protected against oxidative stress in HepG2 cells in a dose-response manner by inhibiting the generation of reactive oxygen species, increasing total antioxidant capacity, catalase and superoxide dismutase (SOD) activities, and activating the antioxidative pathway of nuclear factor E2-related factor 2/Kelch-like ECH-associated protein 1 (Nrf2/Keap1) signaling pathway. We found that the in vitro antioxidant capacities of paeonol and quercetin were better than those of β-sitosterol and gallic acid. Furthermore, paeonol apparently diminished the levels of alanine transaminase and aspartate aminotransferase, augmented the contents of glutathione and SOD, promoted the expressions of Nrf2 and heme oxygenase-1 proteins in mice stimulated by CCl4. In HepG2 cells, paeonol, quercetin, β-sitosterol, and gallic acid play a defensive role against H2O2-induced oxidative stress through activating Nrf2/Keap1 pathway, indicating that these monomers have anti-oxidative properties. Totally, paeonol and quercetin exerted anti-oxidative and hepatoprotective effects, which is independent rather than synergy.

The Inhibitory Effects of Ahnjeonbaekho-tang on FRTL-5 Cell Proliferation and Thyroxine Synthesis

  • Kang, Shin-Ik;Lee, Byung-Cheol;Ahn, Young-Min;Doo, Ho-Kyung;Ahn, Se-Young
    • The Journal of Internal Korean Medicine
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    • v.27 no.3
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    • pp.653-663
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    • 2006
  • Objective : Graves' disease, the most common cause of hyperthyroidism, is an autoimmune disorder associated with autoantibodies to the TSH receptor. The clinical features of Graves' disease are goiter and hypermetabolic symptoms induced by excessive hormones. Antithyroid drug therapy is the first-line treatment for Graves' disease in Korea, Japan and European countries. Yet in spite of a long period and high-dose of treatment, it is hard to achieve remission because of adverse effects, frequent recurrence and resistance to antithyroid drugs. Recently, it has been reported that the abnormal thyroid hormone and clinical symptoms of Graves' disease were reduced by Ahnjeonbaekho-tang (AJBHT). Methods : To investigate the effectiveness and action mechanism of AJBHT, we studied the influence of AJBHT on FRTL-5 thyroid cell proliferation, DNA synthesis and expression of T4, TSH, cAMP, Tg and TPO mRNA. Results : AJBHT significantly inhibited the FRTL-5 cell proliferation, DNA synthesis, T4 synthesis, cAMP production and the expression of Tg mRNA in comparison with control and MMI. Conclusions : These results suggest that AJBHT may inhibit the cell proliferation and DNA synthesis by regulating the cAMP, and suppress the T4 synthesis by modulating Tg mRNA expression and cAMP synthesis, and that it may be useful agent for treating the goiter and hormone abnormality of Graves' disease.

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Anti-inflammatory Effects of Cheongnoimyungshin-hwan in Microglia Cells (미세아교세포의 염증반응에 미치는 청뇌명신환의 영향)

  • Im, Yong-Gyun;Choi, Yung-Hyun;Hwang, Won-Deok
    • Journal of Oriental Neuropsychiatry
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    • v.25 no.4
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    • pp.423-434
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    • 2014
  • Objectives: Activated microglia cells play an important role in inflammatory responses in the central nervous system (CNS) which are involved in neurodegenerative diseases. We attempted to determine the anti-inflammatory effects of Cheongnoimyungshin-hwan (CNMSH) in microglia cells. Methods: We examined the effect of CNMSH on the inflammatory responses in BV2 microglia cells induced by lipopolysaccharide (LPS) and explored the mechanism underlying the action of CNMSH. Results: BV2 cells treated with LPS showed an up-regulation of nitric oxide (NO), prostaglandin $PGE_2(PGE_2)$ and interleukin $1{\beta}(IL-1{\beta})$ release, whereas CNMSH suppressed this up-regulation. CNMSH inhibited the induction of COX-2, iNOS and $IL-1{\beta}$ proteins in LPS-treated BV2 cells and blocked the LPS-induced phosphorylation and nuclear translocation of nuclear factor ${\kappa}B(NF-{\kappa}B$). Furthermore, CNMSH attenuated the LPS-induced phosphorylation of extracellular signal-regulated kinase and p38 mitogen activated protein kinase (MAPK), as well as the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway, but did not inhibit the LPS-induced phosphorylation of c-Jun amino terminal kinase. Conclusions: These results suggest that the inhibitory effect of CNMSH on the LPS-induced production of inflammatory mediators and cytokines in BV2 cells is associated with the suppression of the $NF-{\kappa}B$ and PI3KAkt signaling pathways.

Comparison of the Anti-inflammatory Effects of Water Fermented and Ethanol Fermented Extracts from Rhei Radix et Rhizoma (물추출 발효대황과 에탄올추출 발효대황의 항염증 효과에 관한 비교)

  • Kim, Nan-Young;Kim, Hae-Ja;Lee, Joo-Hee;Lee, Eun-Kyoung;Kang, Ok-Hwa;Kwon, Dong-Yeul;So, Hong-Seob;Lee, Ki-Nam;Chong, Myong-Soo
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.25 no.2
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    • pp.227-233
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    • 2011
  • Water Fermented and Ethanol Fermented Extracts from Rhei Radix et Rhizoma exhibit potent anti-inflammatory activity with an unknown mechanism. To elucidate the molecular mechanisms of W-FR and E-FR on pharmacological and biochemical actions in inflammation, we examined the effect of W-FR and E-FR on pro-inflammatory mediators in lipopolysaccharide (LPS)-stimulated macrophages. The investigation focused on whether FR inhibited nitric oxide (NO), tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), interleukin-6 (IL-6) and the expressions of iNOS, COX-2 in LPS-stimulated RAW 264.7 cells. We found that FR inhibited LPS-induced NO, TNF-${\alpha}$ and IL-6 productions as well as the expressions of iNOS and COX-2. These results suggest that W-FR and E-FR have inhibitory effects on LPS-induced TNF-${\alpha}$, NO, and IL-6 production, as well as the expressions of iNOS and COX-2 in the murine macrophage.

Effects of Chinemys reevesii on Lipopolysaccaride-indused Inflammatory Reactions (구판의 LPS로 유도된 염증 반응 억제 효과)

  • Baek, Young-Mi;Choi, Jung-Yen;Lee, Cheol-Woo;Jeon, Young-Seok;Han, Jin-Taek;Jang, Sung-Il;Yoo, Hwa-Seung
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.26 no.1
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    • pp.26-34
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    • 2012
  • This study is to investigate the effects of Chinemys reevesii (CR) on allergic inflammation mechanism related chronic dermatitis. To investigate the effects of CR, we study inhibitory effect of CR on the levels of pro-inflammatory cytokines released from RAW 264.7 cell stimulated with lipopolysaccaride (LPS), and EoL-1, THP-1, Jutkat cell stimulated with Dermatophagoides pteronyssinus (DP), and LPS induced acute inflammatory BALB/c mouse model. CR reduced the levels of IL-$1{\beta}$ released from RAW 264.7 cell stimulated with LPS at 20 ug/ml, 10 ug/ml concentration. CR significantly reduced the levels of MCP-1 released from EoL-1 cell, IL-6 from THP-1 cell, and IL-4, IL-5, TNF-${\alpha}$ from Jutkat cell stimulated with DP at all the concentration. CR significantly reduced the levels of TNF-${\alpha}$, IL-6, IL-$1{\beta}$, in LPS induced inflammatory BALB/c mouse model, in a dose-dependent manner. These results suggested that CR has suppressive effects on pro-inflammatory cytokines in various inflammation related cell lines through the regulation of immune system. CR could be a therapeutic agent for treatment of chronic inflammatory dermatitis in the future.

Inhibitory Effect of Scorpion MeOH Extract on Nitric Oxide and Cytokine Production in Lipopolysaccharide - Activated Raw 264.7 Cells (전갈 메탄올추출물이 LPS로 유도된 Raw 264.7 cell에서의 nitric oxide 및 cytokine에 미치는 영향)

  • Choi, Jun-Hyeok;Lee, Jong-Rok;Jee, Seon-Young;Kim, Sang-Chan
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.21 no.3
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    • pp.721-727
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    • 2007
  • Scorpion (SCP) has been clinically used for the treatment of endogenous wind to relieve convulsion, clearing away toxins, resolving hard masses and removing obstruction in the collaterals to relieve pain. Recent studies showed that scorpion toxins that affect the activating mechanism of sodium channels and indian black scorpion venom induced anti-proliferative and apoptogenic activity against human leukemic cell lines U937 and K562. There is lack of studies regarding the effects of SCP on the immunological activities. The present study was conducted to evaluate the effect of SCP on the regulatory effects of cytokines and nitric oxide (NO) for the immunological activities in Raw 264.7 cells. After the treatment of SCP MeOH extract dissolved in media for 1 h prior to the addition of lipopolysaccharide (LPS: 1 ${\mu}$g/ml), cell viability was measured by MTT assay, NO production was monitored by measuring the nitrite content in culture medium. Inducible nitric oxide synthase (iNOS) was determined by immunoblot analysis, and levels of cytokine were analyzed by sandwich immunoassays. As results, SCP inhibited the production of nitrite and nitrate (0.3 and 1.0 mg/ml), iNOS and p-$I_KB_{\alpha}$ protein, tumor necrosis factor-${\alpha}$ (0.3 and 1.0 mg/ml), interleukin-1${\beta}$ (0.3 and 1.0 mg/ml) and interleukin-6 (1.0mg/ml) in Raw 264.7 cells activated with LPS. These findings suggest that SCP can produce anti-inflammatory effect, which may play a role in adjunctive therapy in Gram-negative bacterial infections.

Anti-Cancer Effect of IN-2001 in MDA-MB-231 Human Breast Cancer

  • Min, Kyung-Nan;Joung, Ki-Eun;Kim, Dae-Kee;Sheen, Yhun-Yhong
    • Biomolecules & Therapeutics
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    • v.20 no.3
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    • pp.313-319
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    • 2012
  • In recent years, inhibition of HDACs has emerged as a potential strategy to reverse aberrant epigenetic changes associated with cancer, and several classes of HDAC inhibitors have been found to have potent and specific anticancer activities in preclinical studies. But their precise mechanism of action has not been elucidated. In this study, a novel synthetic inhibitor of HDAC, 3-(4-dimethylamino phenyl)-N-hydroxy-2-propenamide [IN-2001] was examined for its antitumor activity and the underlying molecular mechanisms of any such activity on human breast cancer cell lines. IN-2001 effectively inhibited cellular HDAC activity ($IC_{50}$ = 0.585 nM) inMDA-MB-231 human breast cancer cells. IN-2001 caused a significant dose-dependent inhibition of cell proliferation in estrogen receptor (ER) negative MDA-MB-231human breast cancer cells. Cell cycle analysis revealed that the growth inhibitory effects of IN-2001 might be attributed to cell cycle arrest at $G_0/G_1$ and/or $G_2$/Mphase and subsequent apoptosis in human breast cancer cells. These events are accompanied by modulating several cell cycle and apoptosis regulatory genes such as CDK inhibitors $p21^{WAF1}$ and $p27^{KIP1}$ cyclin D1, and other tumor suppressor genes such as cyclin D2. Collectively, IN-2001 inhibited cell proliferation and induced apoptosis in human breast cancer cells and these findings may provide new therapeutic approaches, combination of antiestrogen together with a HDAC inhibitor, in the hormonal therapy-resistant ER-negative breast cancers. In summary, our data suggest that this histone deacetylase inhibitor, IN-2001, is a novel promising therapeutic agent with potent antitumor effects against human breast cancers.

Inhibitory Effects of Polyphenol-Rich Fraction Extracted from Rubus coreanum M on Thoracic Aortic Contractility of Spontaneously Hypertensive Rats

  • Lim, Hyo-Jeong;Min, Seon-Young;Woo, Eun-Ran;Lim, Dong-Yoon
    • Biomolecules & Therapeutics
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    • v.19 no.4
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    • pp.477-486
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    • 2011
  • The purpose of the present study was to investigate whether polyphenol-rich fraction extracted from fruit wine of Rubus coreanum M (PCRC) can affect the contractility of the thoacic aortic strips isolated from spontaneously hypertensive rats (SHRs), and to clarify its mechanism of action. PCRC (200-800 ${\mu}g/mL$) concentration-depenedently blocked phenylephrine (10 ${\mu}M$)-induced contractile responses of the isolated aortic strips of SHRs. PCRC (400 ${\mu}g/mL$), added in to bath medium, also depressed the contractile active tension evoked by both phenylephrine (3 and 10 ${\mu}M$) and high potassium (25 and 56 mM). In the simultaneous presence of PCRC (400 ${\mu}g/mL$) and L-NAME (a selective inhibitor of NO synthase, 300 ${\mu}M$), the contractile responses evoked by phenylephrine and high $K^+$ were recovered to considerable level of the corresponding control contractility compared with those effects of PCRC-treatment alone. However, in the simultaneous presence of indomethacin (10 ${\mu}M$, a selective cyclooxygenase inhibitor) and PCRC (400 ${\mu}g/mL$), they were not affected. In the endothelium-denuded aortic strips by CHAPS-treatment, PCRC did not affect the contractile responses induced by phenylephrine or high potassium. Interestingly, PCRC (1.0, 3.0 and 10.0 mg/kg/30 min, i.v., respectively) dose-dependently suppressed norepiphrine-induced vasopressor responses in anesthetized SHRs. Collectively, we concluded that PCRC causes vasorelaxation in the thoracic aortic strips with intact endothelium of SHRs at least partly by the increased NO production through the activation of NO synthase of vascular endothelium, but not through the activation of cyclooxygenase. These results suggest that PCRC might be helpful to prevent or alleviate cardiovascular diseases, including hypertension.

Itch E3 Ubiquitin Ligase Positively Regulates TGF-β Signaling to EMT via Smad7 Ubiquitination

  • Park, Su-Hyun;Jung, Eun-Ho;Kim, Geun-Young;Kim, Byung-Chul;Lim, Jae Hyang;Woo, Chang-Hoon
    • Molecules and Cells
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    • v.38 no.1
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    • pp.20-25
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    • 2015
  • TGF-${\beta}$ regulates pleiotropic cellular responses including cell growth, differentiation, migration, apoptosis, extracellular matrix production, and many other biological processes. Although non-Smad signaling pathways are being increasingly reported to play many roles in TGF-${\beta}$-mediated biological processes, Smads, especially receptor-regulated Smads (R-Smads), still play a central mediatory role in TGF-${\beta}$ signaling for epithelial-mesenchymal transition. Thus, the biological activities of R-Smads are tightly regulated at multiple points. Inhibitory Smad (I-Smad also called Smad7) acts as a critical endogenous negative feedback regulator of Smad-signaling pathways by inhibiting R-Smad phosphorylation and by inducing activated type I TGF-${\beta}$ receptor degradation. Roles played by Smad7 in health and disease are being increasingly reported, but the molecular mechanisms that regulate Smad7 are not well understood. In this study, we show that E3 ubiquitin ligase Itch acts as a positive regulator of TGF-${\beta}$ signaling and of subsequent EMT-related gene expression. Interestingly, the Itch-mediated positive regulation of TGF-${\beta}$ signaling was found to be dependent on Smad7 ubiquitination and its subsequent degradation. Further study revealed Itch acts as an E3 ubiquitin ligase for Smad7 polyubiquitination, and thus, that Itch is an important regulator of Smad7 activity and a positive regulator of TGF-${\beta}$ signaling and of TGF-${\beta}$-mediated biological processes. Accordingly, the study uncovers a novel regulatory mechanism whereby Smad7 is controlled by Itch.

Hydrogen Peroxide-induced Alterations in Na+-phosphate Cotransport in Renal Epithelial Cells

  • Jung, Soon-Hee
    • Korean Journal of Clinical Laboratory Science
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    • v.41 no.2
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    • pp.83-92
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    • 2009
  • This study was undertaken to examine the effect of oxidants on membrane transport function in renal epithelial cells. Hydrogen peroxide ($H_2O_2$) was used as a model oxidant and the membrane transport function was evaluated by measuring $Na^+$-dependent phosphate ($Na^+$-Pi) uptake in opossum kidney (OK) cells. $H_2O_2$ inhibited $Na^+$-Pi uptake in a dose-dependent manner. The oxidant also caused loss of cell viability in a dose-dependent fashion. However, the extent of inhibition of the uptake was larger than that in cell viability. $H_2O_2$ inhibited $Na^+$-dependent uptake without any effect on $Na^+$-independent uptake. $H_2O_2$-induced inhibition of $Na^+$-Pi uptake was prevented completely by catalase, dimethylthiourea, and deferoxamine, suggesting involvement of hydroxyl radical generated by an iron-dependent mechanism. In contrast, antioxidants Trolox, N,N'-diphenyl-p-phenylenediamine, and butylated hydroxyanisole did not affect the $H_2O_2$ inhibition. Kinetic analysis indicated that $H_2O_2$ decreased Vmax of $Na^+$-Pi uptake with no change in the Km value. Phosphonoformic acid binding assay did not show any difference between control and $H_2O_2$-treated cells. $H_2O_2$ also did not cause degradation of $Na^+$-Pi transporter protein. Reduction in $Na^+$-Pi uptake by $H_2O_2$ was associated with ATP depletion and direct inhibition of $Na^+$-$K^+$-ATPase activity. These results indicate that the effect of $H_2O_2$ on membrane transport function in OK cells is associated with reduction in functional $Na^+$-pump activity. In addition, the inhibitory effect of $H_2O_2$ was not associated with lipid peroxidation.

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