• Title/Summary/Keyword: Chemical-induced inhibition

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Structure-Activity Relationship of Oleanane Disaccharides isolated from Akebia quinata on Both Cytotoxicity against Cancer Cells and NO inhibition against LPS-induced Macrophage 264.7

  • Jung, Hyun-Ju;Lee, Jung-Ok;Lee, Kyung-Tae;Choi, Jong-Won;Park, Hee-Juhn
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.371.3-372
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    • 2002
  • We have reported cytotoxicities based on several types of sugar linkage in saponins in addition to antitumor and antiinflammatory effects. In order to find further structure-activity relationship on the cytotoxicity of saponins. we intended to isolate oleanane disaccharides Irom the saponin-containing extract of Akebia Quinata (Lardizabalaceae). (omitted)

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Chemical Constituents from Buddleja officinalis and Their Inhibitory Effects on Nitric Oxide Production

  • Park, Tae Wook;Lee, Chul;Lee, Jin Woo;Jang, Hari;Jin, Qinghao;Lee, Mi Kyeong;Hwang, Bang Yeon
    • Natural Product Sciences
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    • v.22 no.2
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    • pp.129-133
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    • 2016
  • Bioactivity-guided fractionation of a methanolic extract of Buddleja officinalis led to the isolation of two monoterpenes, crocusatin M (1), crocusatin C (2), a flavonoid, acacetin (3), three lignans, lariciresinol (4), pinoresinol (5), and syringaresinol (6), and two triterpenoidal saponins, mimengoside B (7) and songarosaponin A (8). The structures of isolates were identified based on 1D-, 2D-NMR, and MS data analysis. All isolates were tested for their inhibition on LPS-induced NO production in RAW 264.7 cells. As a result, mimengoside B (7) and songarosaponin A (8) showed a mild inhibitory activity of NO production.

Enzymatic Characteristics of steroid $\Delta^1$-dehydrogenase from Arthrobacter simplex

  • Lee, Mi-Kyung;Bae, Moo
    • Journal of Microbiology and Biotechnology
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    • v.4 no.2
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    • pp.119-125
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    • 1994
  • Steroid $\Delta^1$-dehydrogenase purified from hydrocortisone-induced cells of Arthrobacter simplex converted various 3-ketosteroids into their corresponding $\Delta^1$-dehydrogenated products. The transformation efficiencies depend upon the chemical structure of the steroids, especially length of the side chain at 17 position and hydroxyl groups at 11 and 17 positions. The Km values for androstenedione, the most favorable substrate examined, and hydrocortisone were 74 ${\mu}M$ and 294 ${\mu}M$, respectively. The optimum temperature and pH of the enzyme reaction were 35$^{\circ}C$ and pH 9, respectively, and the enzyme was relatively stable at the range from 20 to 35$^{\circ}C$ and from pH 5 to 10 after one hour of incubation. The enzyme activity was markedly inhibited in the presence of $Cu^{2+},\;Fe^{3+},\;Hg^{2+},\;Mo^{6+}$ ions, and somewhat inhibited by $Zn^{2+}$ and $Fe^{2+}$. $\alpha,\alpha'$-Dipyridyl that inhibits 9$\alpha$-hydroxylase and accumulates 1,4-androstadiene-3,17-dione from sterols revealed no inhibitory effect on this enzyme. EGTA showed inhibitory effect. $\beta$-Estradiol competitively inhibited the enzyme activity. Chemical modifications of the enzyme were attempted with several reagents. p-Hydroxymer-curibenzoate showed inhibition of the enzyme activity and protection of the substrate. This suggests that cysteine residue may be involved in the active site of the enzyme.

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In vitro Antimutagenic Activity of Brown Rice and its Physico-Chemical Characteristics (현미의 in vitro 항돌연변이 활성 및 물리화학적 특성)

  • 전향숙;김인호
    • Journal of Food Hygiene and Safety
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    • v.10 no.3
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    • pp.133-138
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    • 1995
  • In vitro antimutagenic activity of methanol extract from brrwn rice and its physico-chemical characteristics were investigated using Salmonella typhimurium reversion assay and SOS chromotest. Methanol extracts of brown rice were not mutagenic compared with direct and indirect, mutagenicities of 4NQO (4-nitroquinoline oxide), 2NF(2-nitrofluorene), Trp-p-1(3-Amino-1,4-dimethyl-5H-pyrido-[4,3-b]indole), and Trp-p-2(3-Amino-1-methy-5H-pyrido-[4,3-b]indole). Antimutagenic activity against the indirect mutagenicties induced by Trp-p-1, Trp-p-2 and AFB1 (aflatoxin B1) was found in methanol extract. Even though antimutagenic activity showed dose-dependent, it remained constant at inhibition rate ranging 60~90% when the concentration was abov 3mg/plate in the S. typhimurium reversion assay and 0.2~0.6 mg/assay in the SOS chromotest. The antimutagenic activity of the methanol extracts was stable at various pH (2, 7 and 10), temperatures (60, 80 and 10$0^{\circ}C$)and heation times (2, 4, 6, 8, 10 min at 10$0^{\circ}C$).

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Anti-herpetic Activity of Various Medicinal Plant Extracts

  • Woo, Eun-Rhan;Kim, Hyoung-Ja;Jong, Hwan-Kwak;Lim, Young-Kwern;Park, Seong-Kyu;Kim, Hae-Soo;Lee, Chong-Kyo;Park, Hokoon
    • Archives of Pharmacal Research
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    • v.20 no.1
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    • pp.58-67
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    • 1997
  • In order to find antiviral compounds against Herpes simplex virus type I (HSV-1) and II (HSV2) from natural products, a convenient virus-induced cytopathic effect (CPE) inhibition assay was introduced. More than 300 fractions were prepared by solvent fractionation from sixty collected plants or purchased herbal medicines, and their anti-herpetic activities were evaluated. Among them, several medicinal plants showed potent anti-herpetic activity. Selective indexes (SI) of the EtOAc extract of Caraganae Radix (Caragana sinica) against HSV-1 and HSV-2 were more than 8.06 and 24.79, SI of the MeOH extract of Acer okamotoanum leaves were 3.92 and 3.51, SI of the $CH_{2}Cl_{2}$ extract of Veratri Rhizoma et Radix (Veratrum patulum) were 5.49 and 1.31 and SI of the MeOH extract of aerial part of Osmundae Rhizoma (Osmunda japonica) were more than 3.45 and 1.25, respectively.

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Antithrombotic Phenolics from the Stems of Parthenocissus tricuspidata Possess Anti-inflammatory Effect

  • Nguyen, Phi-Hung;Zhao, Bing Tian;Lee, Jeong Hyung;Kim, Young Ho;Min, Byung Sun;Woo, Mi Hee
    • Bulletin of the Korean Chemical Society
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    • v.35 no.6
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    • pp.1763-1768
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    • 2014
  • In the course of our program to search for antithrombotic and anti-inflammatory agents from plants, twelve phenolics (1-12) were isolated from the stems of Parthenocissus tricuspidata. Their structures were elucidated on the basis of spectroscopic (1D and 2D NMR, and MS) data analyses, and comparison with published data. At the concentration of $100{\mu}g/ml$, compounds 2, 4, 6 and 10 possessed potential effects on anti-blood coagulation, with inhibitory percentage of 216, 174, 148 and 225%, respectively; while aspirin used as positive control showed 181% inhibition at the same concentration. Furthermore, the anti-inflammatory activity of isolated compounds (1-12) was investigated on lipopolysaccharide (LPS)-induced murine macrophage cells (RAW264.7). Compounds 2, 4 and 6 also potential inhibited the production of nitric oxide, with $IC_{50}$ values of $11.9{\pm}0.3$, $2.9{\pm}0.2$ and $29.0{\pm}0.6{\mu}M$, respectively. Celastrol, the positive control used, gave an $IC_{50}$ value of $1.0{\pm}0.1{\mu}M$.

Effects of 5-Aza-2'-Deoxycytidine, Bromodeoxyuridine, Interferons and Hydrogen Peroxide on Cellular Senescence in Cholangiocarcinoma Cells

  • Moolmuang, Benchamart;Singhirunnusorn, Pattama;Ruchirawat, Mathuros
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.3
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    • pp.957-963
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    • 2016
  • Cellular senescence, a barrier to tumorigenesis, controls aberrant proliferation of cells. We here aimed to investigate cellular senescence in immortalized cholangiocyte and cholangiocarcinoma cell lines using five different inducing agents: 5-aza-2'deoxycytidine, bromodeoxyuridine, interferons ($IFN{\beta}$ and $IFN{\gamma}$), and hydrogen peroxide. We analyzed senescence characteristics, colony formation ability, expression of genes involved in cell cycling and interferon signaling pathways, and protein levels. Treatment with all five agents decreased cell proliferation and induced cellular senescence in immortalized cholangiocyte and cholangiocarcinoma cell lines with different degrees of growth-inhibitory effects depending on cell type and origin. Bromodeoxyuridine gave the strongest stimulus to inhibit growth and induce senescence in most cell lines tested. Expression of p21 and interferon related genes was upregulated in most conditions. The fact that bromodeoxyuridine had the strongest effects on growth inhibition and senescence induction implies that senescence in cholangiocarcinoma cells is likely controlled by DNA damage response pathways relating to the p53/p21 signaling. In addition, interferon signaling pathways may partly regulate this mechanism in cholangiocarcinoma cells.

Synthesis of Lysophosphatidylcholine Analogues Using D-Mannitol as a Chiral Template and Their Biological Activity for Sepsis

  • Heo, Hye Jin;Jung, Jun-Sub;Lee, Jung Ho;Han, Su Young;Bang, Hyun Bae;Song, Dong-Keun;Jun, Jong-Gab
    • Bulletin of the Korean Chemical Society
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    • v.27 no.8
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    • pp.1149-1153
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    • 2006
  • LPC analogues including natural and unnatural LPC, 3-L-2-PC, acetylated LPC and ethylene glycol derivative are prepared from D-mannitol using in convenient procedures by only changing the synthetic sequences, and their protective activities against cecal ligation and puncture (CLP)-induced severe sepsis are compared. The chirality at C2 position in LPC is found to be required as (S)-configuration for sepsis inhibition, comparing from the protection activity between LPC 6 and unnatural LPC 8. The hydroxyl functionality is also very important and required at C2 or C3 position as shown in the protection activities of ethylene glycol analogue 11 and 3-L-2-PC 9.

Synthesis and Biological Evaluation of Novel IM3829 (4-(2-Cyclohexylethoxy)aniline) Derivatives as Potent Radiosensitizers

  • Ahn, Jiyeon;Nam, Ky-Youb;Lee, Sae-Lo-Oom;Ryu, Hwani;Choi, Hyun Kyung;Song, Jie-Young
    • Bulletin of the Korean Chemical Society
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    • v.35 no.12
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    • pp.3623-3626
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    • 2014
  • Nuclear factor-erythroid 2-related factor 2 (Nrf2) regulates the expression of over 200 genes of antioxidant and phase II drug-metabolizing enzymes, and is highly expressed in non-small cell lung cancer (NSCLC). Nine derivatives of 4-(2-cyclohexylethoxy)aniline were designed. Our previous study demonstrated that IM3829 increases radiosensitivity of several lung cancer cells in vitro and in vivo. Here, biological effects of IM3829 derivatives (2a-2i) were evaluated. Compound 2g derivative effectively inhibits mRNA and protein expression of Nrf2 and HO-1. In addition, we observed over two fold enhancement in IR-induced cell death, from $2.90{\pm}0.22$ to $6.02{\pm}0.87$, in H1299 cancer cell-line. Among the nine derivatives, compound 2g derivative exhibited the highest enhancement of radiosensitizing effect via inhibition of Nrf2 activity.

Evolutionary Operation (EVOP) to Optimize Whey-Independent Serratiopeptidase Production from Serratia marcescens NRRL B-23112

  • Pansuriya, Ruchir C.;Singhal, Rekha S.
    • Journal of Microbiology and Biotechnology
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    • v.20 no.5
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    • pp.950-957
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    • 2010
  • Serratiopeptidase (SRP), a 50 kDa metalloprotease produced from Serratia marcescens species, is a drug with potent anti-inflammatory property. In this study, a powerful statistical design, evolutionary operation (EVOP), was applied to optimize the media composition for SRP production in shake-flask culture of Serratia marcescens NRRL B-23112. Initially, factors such as inoculum size, initial pH, carbon source, and organic nitrogen source were optimized using one factor at a time. The most significant medium components affecting the production of SRP were identified as maltose, soybean meal, and $K_2HPO_4$. The SRP so produced was not found to be dependent on whey protein, but rather was notably induced by most of the organic nitrogen sources used in the study and free from other concomitant protease contaminant, as revealed by protease inhibition study. In addition, experiments were performed using different sets of EVOP design with each factor varied at three levels. The experimental data were analyzed with a standard set of statistical formula. The EVOP-optimized medium, with maltose 4.5%, soybean meal 6.5%, $K_2HPO_4$ 0.8%, and NaCl 0.5% (w/v), gave a SRP production of 7,333 EU/ml, which was 17-fold higher than the unoptimized media. The application of EVOP resulted in significant enhancement of SRP production.