• Title/Summary/Keyword: Transcription inhibition

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Padina boryana, a brown alga from the Maldives: inhibition of α-MSH-stimulated melanogenesis via the activation of ERK in B16F10 cells

  • Jayawardena, Thilina U.;Sanjeewa, K.K. Asanka;Kim, Hyun-Soo;Lee, Hyo Geun;Wang, Lei;Lee, Dae-Sung;Jeon, You-Jin
    • Fisheries and Aquatic Sciences
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    • v.23 no.3
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    • pp.8.1-8.9
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    • 2020
  • Background: The present study investigates the potent skin whitening ability of ethanol extract from the brown alga, Padina boryana (PBE) which was collected in the shores of Fulhadhoo Island, the Maldives, and its specific pathways of action. The effect of PBE which contains a rich amount of polyphenols was evaluated using B16F10 murine melanoma cells and provides insight to the underlying mechanisms with reference to the inhibition of melanin formation. Methods: Melanin synthesis and cellular tyrosinase inhibition were assessed in the α-MSH-stimulated melanocytes. Melanogenic pathway-related protein expressions were investigated via Western blotting. ERK 42/44 was particularly examined considering its involvement in the melanogenic pathway. Further, RT-qPCR techniques were involved in gene expression analysis. Results: PBE dose-dependently inhibited the cellular melanin synthesis and tyrosinase levels. Western blotting revealed the potential of PBE to downregulate microphthalmia-associated transcription factor (MITF), tyrosinase, and tyrosinase-related protein-1 and protein-2 (TRP-1 and TRP-2). Moreover, results explained the phosphorylation of ERK was sustained via PBE and hence declined the ultimate melanin synthesis. Gene expression analysis reinforced the results obtained. Conclusions: The study provides substantial evidence to express the potential of PBE to inhibit B16F10 melanoma cell melanin synthesis. Concisely, results suggest the ability of PBE to be involved in medicinal and cosmeceutical applications.

Inhibitiory Effects of Mixture of Atractylodes Macrocephala and Amomum Villosum Extracts on Adipocyte Differentiation in OP9 Cells (백출과 사인 추출 혼합물의 지방세포분화 억제 효과)

  • Kim, Ha Rim;Kwon, Yong Kwan;Choi, Bong Keun;Baek, Dong Gi
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.34 no.1
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    • pp.24-29
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    • 2020
  • In this study, we investigated the inhibition effects of mixtures of Atractylodes macrocephala (AM) and Amomum villosum (AV) water extracts on adipocyte differentiation. Treatment with mixtures of AM and AV extracts in a ratio of 3:1 for 24 and 48 hours did not show any cytotoxicity in OP9 cells. Mixtures of AM(3) and AV(1) extracts inhibited adipocyte differentiation, expression of peroxisome proliferator-activated receptor gamma (PPARγ) and CCAT/enhancer-binding protein alpha (C/EBPα), the major transcription factors of differentiation. It also inhibited the expression of lipoprotein lipase (LPL), adipocyte protein 2 (aP2), which are PPARγ-target genes in adipocyte. We also checked the inhibition effects on cell proliferation during the early stage of differentiation by treatment with mixtures of AM(3) and AV(1) extracts. It markedly inhibited adipocyte proliferation after 48 hours, and also the phosphorylation of ERK1/2 and Akt after 10 min or 3 hour. These results identify a possible mechanism of action of mixtures of AM(3) and AV(1) extracts, suggesting that the mixtures of AM(3) and AV(1) extracts-induced inhibition of ERK and Akt phosphorylation suppresses adipogenesis by inhibiting other signaling cascades that include PPARγ and C/EBPα during the process of OP9 adipocyte differentiation.

Inhibitory Effects of Panduratin A on Periodontitis-Induced Inflammation and Osteoclastogenesis through Inhibition of MAPK Pathways In Vitro

  • Kim, Haebom;Kim, Mi-Bo;Kim, Changhee;Hwang, Jae-Kwan
    • Journal of Microbiology and Biotechnology
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    • v.28 no.2
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    • pp.190-198
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    • 2018
  • Periodontitis is an inflammatory disease caused by microbial lipopolysaccharide (LPS), destroying gingival tissues and alveolar bone in the periodontium. In the present study, we evaluated the anti-inflammatory and anti-osteoclastic effects of panduratin A, a chalcone compound isolated from Boesenbergia pandurata, in human gingival fibroblast-1 (HGF-1) and RAW 264.7 cells. Treatment of panduratin A to LPS-stimulated HGF-1 significantly reduced the expression of interleukin-$1{\beta}$ and nuclear factor-kappa B (NF-${\kappa}B$), subsequently leading to the inhibition of matrix metalloproteinase-2 (MMP-2) and MMP-8 compared with that in the LPS control ($^{**}p$ < 0.01). These anti-inflammatory responses were mediated by suppressing the mitogen-activated protein kinase (MAPK) signaling and activator protein-1 complex formation pathways. Moreover, receptor activator of NF-${\kappa}B$ ligand (RANKL)-stimulated RAW 264.7 cells treated with panduratin A showed significant inhibition of osteoclastic transcription factors such as nuclear factor of activated T-cells c1 and c-Fos as well as osteoclastic enzymes such as tartrate-resistant acid phosphatase and cathepsin K compared with those in the RANKL control ($^{**}p$ < 0.01). Similar to HGF-1, panduratin A suppressed osteoclastogenesis by controlling MAPK signaling pathways. Taken together, these results suggest that panduratin A could be a potential candidate for development as a natural anti-periodontitis agent.

Fermented Unpolished Black Rice (Oryza sativa L.) Inhibits Melanogenesis via ERK, p38, and AKT Phosphorylation in B16F10 Melanoma Cells

  • Sangkaew, Orrarat;Yompakdee, Chulee
    • Journal of Microbiology and Biotechnology
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    • v.30 no.8
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    • pp.1184-1194
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    • 2020
  • Melanin is a major factor that darkens skin color as one of the defense systems to prevent the harmful effects of UV light. However, darkened skin from the localized or systemic accumulation of melanin is viewed in many cultures as an esthetic problem. Consequentially, searching for anti-melanogenic agents from natural sources is very popular worldwide. Previous screening of fermented rice products, obtained from various rice cultivars fermented with different sources of loog-pang (Thai traditional fermentation starter), revealed that the highest ability to reduce the melanin content in B16F10 melanoma cells was from unpolished black rice fermented with a defined starter mixture of microbes isolated from loog-pang E11. The aim of this study was to investigate the mechanism of the fermented unpolished black rice (FUBR) on the inhibition of melanogenesis in B16F10 melanoma cells. The strongest reduction of cellular melanin content was found in the FUBR sap (FUBRS). The melanin reduction activity was consistent with the significant decrease in the intracellular tyrosinase activity. The FUBRS showed no cytotoxic effect to B16F10 melanoma or Hs68 human fibroblast cell lines. It also significantly reduced the transcript and protein expression levels of tyrosinase, tyrosinase-related protein 1 (TYRP-1), TYRP-2, and microphthalmia-associated transcription factor. Furthermore, it induced a significantly increased level of phosphorylated ERK, p38 and Akt signaling pathways, which likely contributed to the negative regulation of melanogenesis. From these results, a model for the mechanism of FUBRS on melanogenesis inhibition was proposed. Moreover, these results strongly suggested that FUBRS possesses anti-melanogenesis activity with high potential for cosmeceutical application as a skin depigmenting agent.

Inhibition Effects of Lamellarin D on Human Leukemia K562 Cell Proliferation and Underlying Mechanisms

  • Zhang, Nan;Wang, Dong;Zhu, Yu;Wang, Jian;Lin, Hong
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.22
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    • pp.9915-9919
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    • 2014
  • Lamellarin D (LamD) is a marine alkaloid with a pronounced cytotoxicity against a large panel of cancer cells, affecting cell growth and inducing apoptosis. However, the molecular mechanisms of action of this compound are poorly understood. In this study, the anticancer efficacy of LamD was investigated in human leukemia K562 cells. The results showed suppressed cell proliferation and induction of G0/G1-phase arrest,while expression of CDK1, and activity of smad3 and smad5 were reduced, but that of p27, p53 and STGC3 was increased. LamD induced cell apoptosis through activation of caspases-8/-3, inhibition of survivin and Bcl-2, suggesting that this compound may also act through a caspase-independent pathway. Moreover, LamD inhibited the secretion of TGF-${\beta}$, IL-$1{\beta}$, IL-6, IL-8 and other inflammatory cytokines and the transcriptional activity of transcription factor NF-${\kappa}B$ in human leukemia K562 cells.Taken together, our results suggest that LamD-mediated inhibition of leukemia cell proliferation may be related to the induction of apoptosis and the regulation of cell cycle, tumor-related gene expression and cytokine expression, which may provide a new way of thinking for the treatment leukemia.

Inhibition of Trypsin-Induced Mast Cell Activation by Water Fraction of Lonicera japonica

  • Kang, Ok-Hwa;Choi, Yeon-A;Park, Hye-Jung;Lee, Joo-Young;Kim, Dae-Ki;Choi, Suck-Chei;Kim, Tae-Hyun;Nah, Yong-Ho;Yun, Ki-Jung;Choi, Suck-Jun;Kim, Young-Ho;Bae, Ki-Hwan;Lee, Young-Ml
    • Archives of Pharmacal Research
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    • v.27 no.11
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    • pp.1141-1146
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    • 2004
  • Lonicera japonica Thunb.(Caprifoliaceae) has long been known as an anti-inflammatory. In the present study, the effect of water fraction of Lonicera japonica (LJ) on trypsin-induced mast cell activation was examined. HMC-1 cells were stimulated with trypsin (100 nM) in the presence or absence of LJ (10, 100, and 1000 $\mu$ g/mL). TNF-$\alpha$ and tryptase production were measured by enzyme-linked immunosorbent assay (ELISA) and reverse transcription-PCR. Extracellular signal-regulated kinase (ERK) phosphorylation was assessed by Western blot. Trypsin activity was measured by using Bz-DL-Arg-p-nitroanilide (BAPNA) as substrate. LJ (10, 100, and 1000 $\mu$g/mL) inhibited TNF-$\alpha$ secretion in a dose-dependent manner. LJ (10, 100, and 1000 $\mu$g/mL) also inhibited TNF-$\alpha$ and tryptase mRNA expression in trypsin-stimulated HMC-1. Furthermore, LJ inhibited trypsin-induced ERK phosphorylation. However, LJ did not affect the trypsin activity even 1000 $\mu$g/mL. These results indicate that LJ may inhibit trypsin-induced mast cell activation through the inhibition of ERK phosphorylation than the inhibition of trypsin activity.

Anti-inflammatory Effects of Water Extract of Eucommia ulmoides OLIVER on the LPS-induced RAW 264.7 Cells (대식세포 Raw 264.7에서 두충의 항염증효과)

  • Kim, Young-Ock;Lee, Sang-Won;Sohn, Sang-Hyun;Kim, Seung-Yu;Oh, Myung-Sook;Kim, Su-Kang
    • Korean Journal of Medicinal Crop Science
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    • v.20 no.5
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    • pp.381-386
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    • 2012
  • Eucommia ulmoides OLIVER (EU) is a traditional Korean herbal used for the treatment of rheumatoid arthritis (RA). In the present study, the molecular pharmacology basis of its anti-inflammatory effect is revealed in this work, EU was studied in lipopolysaccharide (LPS)-activated macrophage cells (RAW 264.7) as an established inflammation model. After activation, nitric oxide (NO) production and iNOS mRNA were measured by using a colorimetric assay (Griess reagent), and reverse transcription polymerase chain reaction (RT-PCR), respectively. The change in the content of $PGE_2$, $TNF{\alpha}$, and IL-6 was concurrently monitored by ELISA. In results, we found that in the concentration range without showing cytotoxicity, EU produced a remarkable anti-inflammatory effect and showed a dose-dependent inhibition of LPSinduced NO production. Compared with indomethacin, EU has more potency and a specific action of NO inhibition, $PGE_2$, IL-6, and TNF-${\alpha}$ inhibition. These results suggest that EU may be a suitable herbal medicine to yield the greatest anti-inflammatory activity for food additives and medicine.

Protective effect of resveratrol on the oxidative stress-induced inhibition of gap junctional intercellular communication in HaCaT keratinocyte

  • Lee, J.C.;Lee, S.M.;Kim, J.H.;Ahn, S.M.;Lee, B.G.;Chang, I.S.
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 2003.11a
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    • pp.65-65
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    • 2003
  • The aim of this study was to investigate the effect of resveratrol on the oxidative stress-induced inhibition of gap junctional intercellular communication (GJIC) in HaCaT keratinocyte. Anti-oxidative activity of resveratrol was measured by a,a-diphenyl-b-picrylhydrazyl (DPPH) assay and dichlorodihydrofluorescein diacetate oxidation assay. GJIC of HaCaT keratinocyte was assessed using the scrape loading/dye transfer technique. Western blots and reverse transcription-polymerase chain reaction were also analyzed for Connexin 43 protein and mRNA expression, respectively. Resveratrol scavenged directly the stable DPPH radical over a concentration range of 4 mg/$\mell$ (78.2 $\pm$ 2.7% of control) to 500 mg/$\mell$ (29.9 $\pm$ 4.2% of control) and prevent to increase the intracellular fluorescence induced by oxidative stress significantly. Ultraviolet A irradiation (UVA) and 12-O-tetradecanoylphorbol-13-acetate markedly reduced GJIC, which was restored by resveratrol. There were no significant differences in the level of Connexin 43 protein and mRNA expression among any of the experimental groups. Our data suggests that resveratrol has the protective effect on the oxidative stress-induced inhibition of gap junctional intercellular communication in HaCaT keratinocyte and this protection is likely due to the scavenging of reactive oxygen species.

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5-Aminoisoquinolinone Reduces the Expression of Vascular Endothelial Growth Factor-C via the Nuclear Factor-kappa B Signaling Pathway in CT26 Cells

  • Wu, Wei-Qiang;Fauzee, Nilufer Jasmine Selimah;Wang, Ya-Lan
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.3
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    • pp.991-994
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    • 2012
  • Objective: VEGF-C has recently been identified as a key molecule which is involved in tumor lymphangiogenesis. The aim of this research was to investigate the role of PARP-1 inhibition in the regulation of VEGF-C expression in CT26 cells. Methods: CT26 cells were treated with or without the PARP-1 inhibitor 5-aminoisoquinolinone (5-AIQ). The expression of PARP-1, NF-kB, and VEGF-C proteins in CT26 cells was measured by Western blot analysis and the VEGF-C mRNA level was determined by reverse transcription polymerase chain reaction (RT-PCR). CT26-secreted VEGF-C was detected by enzyme-linked immunosorbent assay (ELISA). Results: The results of Western blot analysis showed that the expression levels of PARP-1, NF-kB, and VEGF-C were reduced in 5-AIQ treated CT26 cells and the levels of VEGF-C mRNA in 5-AIQ treated CT26 were significantly lower than t in 5-AIQ-untreated cells (P<0.05). The concentrations of CT26-secreted VEGF-C were also dramatically decreased (P<0.05). Conclusion: Here, we provide evidence for the first time that PARP-1 inhibition dramatically reduces VEGF-C expression via the nuclear factor NF-kB signaling pathway. We therefore propose that PARP-1 inhibition has an anti-lymphangiogenic effect and may contribute to the prevention of metastatic dissemination via the lymphatic system.

The Dose Dependent Effects of Ruxolitinib on the Invasion and Tumorigenesis in Gliomas Cells via Inhibition of Interferon Gamma-Depended JAK/STAT Signaling Pathway

  • Delen, Emre;Doganlar, Oguzhan
    • Journal of Korean Neurosurgical Society
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    • v.63 no.4
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    • pp.444-454
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    • 2020
  • Objective : Glioblastoma multiforme (GBM) is the most aggressive for of brain tumor and treatment often fails due to the invasion of tumor cells into neighboring healthy brain tissues. Activation of the Janus kinase-signal transducer and activator of transcription (JAK/STAT) signaling pathway is essential for normal cellular function including angiogenesis, and has been proposed to have a pivotal role in glioma invasion. This study aimed to determine the dose-dependent effects of ruxolitinib, an inhibitor of JAK, on the interferon (IFN)-I/IFN-α/IFN-β receptor/STAT and IFN-γ/IFN-γ receptor/STAT1 axes of the IFN-receptor-dependent JAK/STAT signaling pathway in glioblastoma invasion and tumorigenesis in U87 glioblastoma tumor spheroids. Methods : We administered three different doses of ruxolitinib (50, 100, and 200 nM) to human U87 glioblastoma spheroids and analyzed the gene expression profiles of IFNs receptors from the JAK/STAT pathway. To evaluate activation of this pathway, we quantified the phosphorylation of JAK and STAT proteins using Western blotting. Results : Quantitative real-time polymerase chain reaction analysis demonstrated that ruxolitinib led to upregulated of the IFN-α and IFN-γ while no change on the hypoxia-inducible factor-1α and vascular endothelial growth factor expression levels. Additionally, we showed that ruxolitinib inhibited phosphorylation of JAK/STAT proteins. The inhibition of IFNs dependent JAK/STAT signaling by ruxolitinib leads to decreases of the U87 cells invasiveness and tumorigenesis. We demonstrate that ruxolitinib may inhibit glioma invasion and tumorigenesis through inhibition of the IFN-induced JAK/STAT signaling pathway. Conclusion : Collectively, our results revealed that ruxolitinib may have therapeutic potential in glioblastomas, possibly by JAK/STAT signaling triggered by IFN-α and IFN-γ.