• 제목/요약/키워드: Transcription inhibition

검색결과 587건 처리시간 0.024초

Inhibition of LPS induced iNOS, COX-2 and cytokines expression by salidroside through the $NF{-\kappa}B$ inactivation in RAW 264.7 cells (Salidroside의 RAW 264.7 세포에서 $NF{-\kappa}B$ 불활성화를 통한 LPS에)

  • Won, So-Jung;Park, Hee-Juhn;Lee, Kyung-Tae
    • Korean Journal of Pharmacognosy
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    • 제39권2호
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    • pp.110-117
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    • 2008
  • In this study, we investigated the anti-inflammatory effects of salidroside (SAL) isolated from the MeOH extract of Acer tegmentosum Maxim heartwood in RAW 264.7 macrophage cells. SAL pretreatment significantly inhibited nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$) productions in the lipopolysaccharide (LPS)-induced RAW 264.7 cells. Western blot and RT-PCR analyses revealed that SAL inhibited the LPS-induced expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) at the protein and mRNA levels in a concentration-dependent manner. In addition, SAL reduced the release and the mRNA expressions of tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$) and interleukin-6 (IL-6). Furthermore, nuclear factorkappa B ($NF{-\kappa}B$) luciferase reporter assay was performed to know the involvement of SAL in the production of pro-inflammatory cytokines, we confirmed that LPS-induced transcription activity of $NF{-\kappa}B$ was inhibited by SAL. Taken together, our data indicate that anti-inflammatory property of salidroside might be the result from the inhibition of iNOS, COX-2, $TNF-{\alpha}$ and IL-6 expressions via the down-regulation of $NF{-\kappa}B$ activity.

Screening of Anti-cancer Compounds Originated from Filamentous Fungi (Monascus sp.) (사상성 곰팡이 (Monascus sp.) 유래 항암 물질의 탐색)

  • Sin, Yeong-Min;Park, Hae-Ryoun;An, Won-Gun
    • Journal of Physiology & Pathology in Korean Medicine
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    • 제19권3호
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    • pp.671-676
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    • 2005
  • In this study, we investigated the antioxidant effect of extract from Monascus pillosus, on the human wild-type p53 and p21 expressing A549 lung epithelial cell line and MCF-7 mammary adenocarcinoma cell line stimulated by NO. $P21^{waf/cip1}$ was identified as a gene induced in senescent cells. It is a cyclin-dependent kinase inhibitor and has been shown to cause cell cycle arrest and apoptosis. While p53-regulated stimulation of p21 appears to be central for the permanent growth-arrest, the role of p21 in p53-triggered cell death is unclear. Low dose of sodium nitroprusside (SNP) induced the development of senescence associated with increased expression of p53 and p21 in A549 cells. Inhibition of p21 transactivating activity requires high level correlates with the amount of p53 necessary to cause cell death. Association of p21 and p53 results in inhibition of p21-stimulated transcription. This requires a higher p53 level than is necessary for transcriptional activation of endogenous p53-responsive gene but correlates well with the level of p53 necessary to cause cell death. Exposure to W-1 inhibited oxidative stresses-induced senescence-like arrest, resulting in a significant reduction in p53 and p21 steady state levels. These results suggest that p53 and p21 play a central role in the onset of senescence. Thus, it is important to emphasize control of oxidative balance in tumor prevention and aging.

Inhibition of Telomerase Activity in U937 Human Monocytic Leukemia Cells by Compound K, a Ginseng Saponin Metabolite

  • Kang Kyoung-Ah;Lee Kyoung-Hwa;Chae Sung-Wook;Kim Jeong-Ki;Seo Jung-Yeon;Ham Yong-Ho;Lee Kee-Ho;Kim Bum-Joon;Kim Hee-Sun;Kim Dong-Hyun;Hyun Jin Won
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제11권1호
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    • pp.7-12
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    • 2006
  • Telomerase activation is detected in most cancerous cells; hence, telomerase is a highly selective target for cancer therapy, which plays an important role in the apoptotic process. We have previously reported that the ginseng saponin metabolite, Compound K (20-O-D-glucopyranosyl-20(S)-protopanaxadiol, IH901), inhibits cell proliferation by inducing apoptosis and cell cycle arrest at the $G_1$ phase. The present study investigated the regulation of telomerase activity in Compound K treated U937 cells. Compound K treatment caused a reduction in telomerase activity and down-regulated the human telomerase reverse transcriptase (hTERT) gene, resulting in the decreased expressions of its protein, and of the c-Myc and Spl proteins (transcription factors of hTERT). These results indicate that the anticancer activity of Compound K could be mediated by inhibition of the telomerase activity.

Ethanol Extract of Hippophae Rhamnoides L. Leaves Inhibits Adipogenesis through AMP-activated protein kinase (AMPK) Activation in 3T3-L1 Preadipocytes (비타민나무 잎 에탄올추출물의 AMPK 활성화를 통한 3T3-L1 지방전구세포의 adipogenesis 억제효과)

  • Jeong, Hyeon Ju;Park, Ju Hee;Kim, Myong-Jo
    • Korean Journal of Plant Resources
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    • 제28권5호
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    • pp.582-590
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    • 2015
  • In the present study, we investigated the effect of 70% EtOH extract from Hippophae Rhamnoides L. leaves (HRL) on the anti-obesity effect in 3T3-L1 cells. The effects of HRL on lipid accumulation in 3T3-L1 cells were examined using Oil Red O staining. In addition, we examined the gene expression levels by using RT-PCR and western blot. The results of this analysis showed that 100 ㎍/㎖ HRL significantly increased the inhibition of lipid accumulation by 82.25%; significantly decreased the mRNA expression of sterol regulatory element binding protein-1c (SREBP-1c), peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer binding proteins α (C/EBPα), and fatty acid synthase (FAS) in 3T3-L1 cells as well as the stimulated protein expression of AMP-activated protein kinase (AMPK); and suppressed the expression level of PPARγ. These results suggest that HRL can prevent adipogenesis through activation of AMPKα and inhibition of adipogenesis transcription factors.

Melanogenesis inhibition activity of floralginsenoside A from Panax ginseng berry

  • Lee, Dae Young;Lee, Jongsung;Jeong, Yong Tae;Byun, Geon Hee;Kim, Jin Hee
    • Journal of Ginseng Research
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    • 제41권4호
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    • pp.602-607
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    • 2017
  • Background: Panax ginseng is a traditional herb used for medicinal purposes in eastern Asia. P. ginseng contains various ginsenosides with pharmacological effects. In this study, floralginsenoside A (FGA), ginsenoside Rd (GRD), and ginsenoside Re (GRE) were purified from P. ginseng berry. Methods: Chemical structures of FGA, GRD, and GRE were determined based on spectroscopic methods, including fast atom bombardment mass spectroscopy, ID-nuclear magnetic resonance, and infrared spectroscopy. Inhibitory activities of these compounds on melanogenesis were studied by measuring the expression of protein and melanin content in the melan-a cell line. This inhibitory activity was confirmed by observing pigmentation and tyrosinase activities of zebrafish. Results: GRD, GRE, and FGA were not cytotoxic at concentrations less than $20{\mu}M$, $80{\mu}M$, and $160{\mu}M$ in melan-a cells, respectively. GRD, GRE, and FGA inhibited melanin biosynthesis in melan-a cells by 15.2%, 22.9%, and 23.9% at $20{\mu}M$, $80{\mu}M$, and $160{\mu}M$, respectively. FGA was observed to display the most potent inhibitory effect. In addition, FGA decreased microphthalmia-associated transcription factor protein expression in a dose-dependent manner. Moreover, FGA induced extracellular signal-regulated kinase phosphorylation level in melan-a cells. In addition, melanin pigment content and tyrosinase activity in zebrafish treated with FGA at $160{\mu}M$ were reduced. Conclusion: FGA showed the most potent inhibition of melanogenesis in both in vitro and in vivo studies. This study suggests that FGA purified from P. ginseng may be an effective melanogenesis inhibitor.

NF-kB and AP-1-regulatory Mechanism of Buthus Martensi Karsch Herbal Acupuncture Solution on Inflammatory Cytokine-induced Human Chondrocytes Dysfunction

  • Cho, Jae-Yong;Kim, Kyung-Ho;Cho, Hyun-Seok;Lim, Dae-Jung;Hwang, Ji-Hye;Kim, Kap-Sung
    • Journal of Acupuncture Research
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    • 제23권2호
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    • pp.61-72
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    • 2006
  • Objectives : Human chondrocytes co-treated with Buthus martensi Karsch herbal acupuncture solution(BMK-HAS) extract produced significantly less NO compared with chondrocytes stimulated with $IL-1{\beta}$ alone Methods : Activation and translocation of and NF-kB DNA binding activity were determined by Western blotting and specific enzyme-linked immunosorbent assay. Results : The inhibition of NO production correlated with the suppression of induction and expression of nuclear factor-kB (NF-kB) and activation protein-1 (AP-1)-dependent gene. BMK-HAS inhibited the activation and translocation of NF-kB to the nucleus, indicating that BMK-HAS inhibits the $IL-1{\beta}-induced$ production of NO in human chondrocytes by interfering with the activation of NF-kB through a novel mechanism. In addition, BMK-HAS reduced prostaglandin E2 (PGE2)production in mouse peritoneal macrophages stimulated with lipopolysaccharide, whereas no influence on the activity of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2) or cyclooxygenase-1 (COX-1) was observed. My data, therefore, suggest that BMK-HAS may be a therapeutically effective inhibitor of $IL-1{\beta}-induced$ inflammatory effects that are dependent on NF-kB activation in human OA chondrocytes. Conclusion : The results indicate that BMK-HAS exerts anti-inflammatory effects related to the inhibition of neutrophil functions and of NO and PGE2 production, which could be due to a decreased expression of iNOS and COX-2 through the transcription factors NF-kB and AP-1.

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Tissue-cultured Gymnema sylvestre Leaf Extract Enhance Anti-adipogenic Effects through Inhibition of C/EBP-${\alpha}$ Expression and Lipid Droplet Accumulation (조직배양된 Gymnema sylvestre 추출물의 C/EBP-${\alpha}$ 및 지방축적 억제에 따른 항비만 효과)

  • Park, Chang-Min;Joung, Min-Seok;Choi, Jong-Wan
    • Journal of the Society of Cosmetic Scientists of Korea
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    • 제35권2호
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    • pp.111-116
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    • 2009
  • Gymnema sylvestre, a traditional India medicine called a 'Gagaimogouip' in Korea, has been used to regulate sugar metabolism in patients with diabetes mellitus. First, we induced callus from Gymnema sylvestre leaf and mode extract from cultured callus. In this study, we investigated the anti-obesity effect of tissue-cultured Gymnema sylvestre leaf extract in 3T3-L1 cells. The tissue-cultured Gymnema sylvestre extract inhibited the cytoplasmic lipid accumulation as well as adipogenic differentiation of preadipocytes. The tissue-cultured Gymnema sylvestre extract inhibited insulin-induced predipocyte differentiation through the inhibition of expression of the early adipogenic transcription factor C/EBP-${\alpha}$ that regulate adipogenesis. These results indicate that tissue-cultured Gymnema sylvestre extract may be potential natural ingredient for slimming cosmetic products.

Cancer Prevention with Green Tea and Its Principal Constituent, EGCG: from Early Investigations to Current Focus on Human Cancer Stem Cells

  • Fujiki, Hirota;Watanabe, Tatsuro;Sueoka, Eisaburo;Rawangkan, Anchalee;Suganuma, Masami
    • Molecules and Cells
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    • 제41권2호
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    • pp.73-82
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    • 2018
  • Cancer preventive activities of green tea and its main constituent, (-)-epigallocatechin gallate (EGCG) have been extensively studied by scientists all over the world. Since 1983, we have studied the cancer chemopreventive effects of EGCG as well as green tea extract and underlying molecular mechanisms. The first part of this review summarizes groundbreaking topics with EGCG and green tea extract: 1) Delayed cancer onset as revealed by a 10-year prospective cohort study, 2) Prevention of colorectal adenoma recurrence by a double-blind randomized clinical phase II trial, 3) Inhibition of metastasis of B16 melanoma cells to the lungs of mice, 4) Increase in the average value of Young's moduli, i.e., cell stiffness, for human lung cancer cell lines and inhibition of cell motility and 5) Synergistic enhancement of anticancer activity against human cancer cell lines with the combination of EGCG and anticancer compounds. In the second part, we became interested in cancer stem cells (CSCs). 1) Cancer stem cells in mouse skin carcinogenesis by way of introduction, after which we discuss two subjects from our review on human CSCs reported by other investigators gathered from a search of PubMed, 2) Expression of stemness markers of human CSCs compared with their parental cells, and 3) EGCG decreases or increases the expression of mRNA and protein in human CSCs. On this point, EGCG inhibited self-renewal and expression of pluripotency-maintaining transcription factors in human CSCs. Human CSCs are thus a target for cancer prevention and treatment with EGCG and green tea catechins.

Inhibition of Escherichia coli O157:H7 Attachment by Interactions Between Lactic Acid Bacteria and Intestinal Epithelial Cells

  • Kim, Young-Hoon;Kim, Sae-Hun;Whang, Kwang-Youn;Kim, Young-Jun;Oh, Se-Jong
    • Journal of Microbiology and Biotechnology
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    • 제18권7호
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    • pp.1278-1285
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    • 2008
  • The intestinal epithelial cell (IEC) layer of the intestinal tract makes direct contact with a number of microbiota communities, including bacteria known to have deleterious health effects. IECs possess innate protective strategies against pathogenic challenge, which primarily involve the formation of a physicochemical barrier. Intestinal tract mucins are principal components of the mucus layer on epithelial surfaces, and perform a protective function against microbial damage. However, little is currently known regarding the interactions between probiotics/pathogens and epithelial cell mucins. The principal objective of this study was to determine the effects of Lactobacillus on the upregulation of MUC2 mucin and the subsequent inhibition of E. coli O157:H7 attachment to epithelial cells. In the current study, the attachment of E. coli O157:H7 to HT-29 intestinal epithelial cells was inhibited significantly by L. acidophilus A4 and its cell extracts. It is also important to note that the expression of MUC2 mucin was increased as the result of the addition of L. acidophilus A4 cell extracts (10.0 mg/ml), which also induced a significant reduction in the degree to which E. coli O157:H7 attached to epithelial cells. In addition, the mRNA levels of IL-8, IL-1$\beta$, and TNF-$\alpha$ in HT-29 cells were significantly induced by treatment with L. acidophilus A4 extracts. These results indicate that MUC2 mucin and cytokines are important regulatory factors in the immune systems of the gut, and that selected lactobacilli may be able to induce the upregulation of MUC2 mucin and specific cytokines, thereby inhibiting the attachment of E. coli O157:H7.

Human Cytomegalovirus Inhibition of Interferon Signal Transduction

  • Miller, Daniel M.;Cebulla, Colleen M.;Sedmak, Daniel D.
    • Journal of Microbiology
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    • 제38권4호
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    • pp.203-208
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    • 2000
  • Cytomegalovirus (CMV), a beta-herpesvirus with worldwide distribution, exhibits host persistence, a distinguishing characteristic of all herpesviruses. This persistence is dependent upon restricted gene expression in infected cells as well as the ability of productively infected cells to escape from normal cell-mediated anti-viral immunosurveillance. Type I (IFN-$\alpha$/$\beta$) and type II (IFN-γ) interferons are major components of the innate defense system against viral infection. They are potent inducers of MHC class I and II antigens and of antigen processing proteins. Additionally, IFNS mediate direct antiviral effects through induction effector molecules that block viral infection and replications such as 2', 5-oligoadenylate synthetase (2, 5-OAS). IFNS function through activation of well-defined signal transduction pathways that involve phosphorylation of constituent proteins and ultimate formation of active transcription factors. Recent studies have shown that a number of diverse viruses, including CMV, EBV, HPV mumps and Ebola, are capable of inhibiting IFN-mediated signal transduction through a variety of mechanisms. As an example, CMV infection inhibits the ability of infected cells Is transcribe HLA class I and II antigens as well as the antiviral effector molecules 2, 5-OAS and MxA I. EMSA studies have shown that IFN-$\alpha$ and IFN-γ are unable to induce complete signal transduction in the presence of CMV infection, phenomena that are associated with specific decreases in JAKl and p48. Viral inhibition of IFN signal transduction represents a new mechanistic paradigm for increased viral survival, a paradigm predicting widespread consequences in the case of signal transduction factors common to multiple cytokine pathways.

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