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Sample records for 1b inhibitory activity

  1. Natural products possessing protein tyrosine phosphatase 1B (PTP1B) inhibitory activity found in the last decades

    PubMed Central

    Jiang, Cheng-shi; Liang, Lin-fu; Guo, Yue-wei

    2012-01-01

    This article provides an overview of approximately 300 secondary metabolites with inhibitory activity against protein tyrosine phosphatase 1B (PTP1B), which were isolated from various natural sources or derived from synthetic process in the last decades. The structure-activity relationship and the selectivity of some compounds against other protein phosphatases were also discussed. Potential pharmaceutical applications of several PTP1B inhibitors were presented. PMID:22941286

  2. Insulin-mimetic selaginellins from Selaginella tamariscina with protein tyrosine phosphatase 1B (PTP1B) inhibitory activity.

    PubMed

    Nguyen, Phi-Hung; Zhao, Bing-Tian; Ali, Md Yousof; Choi, Jae-Sue; Rhyu, Dong-Young; Min, Byung-Sun; Woo, Mi-Hee

    2015-01-23

    As part of an ongoing search for new antidiabetic agents from medicinal plants, three new (2, 4, and 5) and two known selaginellin derivatives (1 and 3) were isolated from a methanol extract of Selaginella tamariscina. The structures of the new compounds were determined by spectroscopic data analysis. All isolates showed strong glucose uptake stimulatory effects in 3T3-L1 adipocyte cells at a concentration of 5 μM. Furthermore, these compounds were found to possess inhibitory effects on PTP1B enzyme activity with IC50 values ranging from 4.6 ± 0.1 to 21.6 ± 1.5 μM. Compound 2 showed the greatest potency, with an IC50 value of 4.6 ± 0.1 μM, when compared with the positive control (ursolic acid, IC50 = 3.5 ± 0.1 μM). Therefore, these selaginellin derivatives may have value as new lead compounds for the development of agents against type 2 diabetes.

  3. Protein tyrosine phosphatase 1B inhibitory activities of ursane- and lupane-type triterpenes from Sorbus pohuashanensis.

    PubMed

    Li, Dongxia; Li, Wei; Higai, Koji; Koike, Kazuo

    2014-04-01

    Protein tyrosine phosphatase 1B (PTP1B) is a non-transmembrane protein tyrosine phosphatase, and has received much attention as a molecular target for the treatment of insulin resistance diseases because of its critical roles in negatively regulating insulin- and leptin-signaling cascades. Six ursane-type triterpenes, 3β-acetoxy-urs-12-ene-28-oic acid (1), pomolic acid-3β-acetate (2), pomolic acid (3), ursolaldehyde (4), euscaphic acid (5) and 3β-acetoxy-urs-11-en-28,13-olide (6), and a lupane-type triterpene, betulinic acid (7), from the fruits of Sorbus pohuashanensis, exhibited significant PTP1B inhibitory activity, with IC50 values ranging from 3.5 to 54.8 μM. Kinetics analyses revealed that compounds 2, 3, and 7 are non-competitive PTP1B inhibitors, and compounds 1 and 6 are mixed-type PTP1B inhibitors.

  4. New sesquiterpenoids from the edible mushroom Pleurotus cystidiosus and their inhibitory activity against α-glucosidase and PTP1B.

    PubMed

    Tao, Qiao-Qiao; Ma, Ke; Bao, Li; Wang, Kai; Han, Jun-Jie; Zhang, Jin-Xia; Huang, Chen-Yang; Liu, Hong-Wei

    2016-06-01

    Nine new sesquiterpenoids, clitocybulol derivatives, clitocybulols G-O (1-9) and three known sesquiterpenoids, clitocybulols C-E (10-12), were isolated from the solid culture of the edible fungus Pleurotus cystidiosus. The structures of compounds 1-12 were determined by spectroscopic methods. The absolute configurations of compounds 1-9 were assigned via the circular dichroism (CD) data analysis. Compounds 1, 6 and 10 showed moderate inhibitory activity against protein tyrosine phosphatase-1B (PTP1B) with IC50 values of 49.5, 38.1 and 36.0μM, respectively.

  5. Extraction and PTP1B inhibitory activity of bromophenols from the marine red alga Symphyocladia latiuscula

    NASA Astrophysics Data System (ADS)

    Liu, Xu; Li, Xiaoming; Gao, Lixin; Cui, Chuanming; Li, Chunshun; Li, Jia; Wang, Bingui

    2011-05-01

    Previously, we had characterized several structurally interesting brominated phenols from the marine red alga Symphyocladia latiuscula collected from various sites. However, Phytochemical investigations on this species collected from the Weihai coastline of Shandong Province remains blank. Therefore, we characterized the chemical constituents of individuals of this species collected from the region. Eight bromophenols were isolated and identified. Using detailed spectroscopic techniques and comparisons with published data, these compounds were identified as 2,3-dibromo-4,5-dihydroxybenzyl methyl ether ( 1), 3,5-dibromo-4-hydroxybenzoic acid ( 2), 2,3,6-tribromo-4,5-dihydroxymethylbenzene ( 3), 2,3,6-tribromo-4,5-dihydroxybenzaldehyde ( 4), 2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether ( 5), bis(2,3,6-tribromo-4,5-dihydroxyphenyl)methane ( 6), 1,2-bis(2,3,6-tribromo-4,5-dihydroxyphenyl)-ethane ( 7), and 1-(2,3,6-tribromo-4,5-dihydroxybenzyl)-pyrrolidin-2-one ( 8). Among these compounds, 1 and 2 were isolated for the first time from S. latiuscula. Each compound was evaluated on the ability to inhibit protein tyrosine phosphatase 1B (PTP1B), which is a potential therapeutic target in the treatment of type 2 diabetes. Bromophenols 5, 6, and 7 showed strong activities with IC50 values of 3.9, 4.3, and 3.5 μmol/L, respectively. This study provides further evidence that bromophenols are predominant among the chemical constituents of Symphyocladia, and that some of these compounds may be candidates for the development of anti-diabetes drugs.

  6. Protein tyrosine phosphatase 1B inhibitory activity of Indonesian herbal medicines and constituents of Cinnamomum burmannii and Zingiber aromaticum.

    PubMed

    Saifudin, Azis; Kadota, Shigetoshi; Tezuka, Yasuhiro

    2013-04-01

    We screened water and methanol extracts of 28 Indonesian medicinal plants for their protein tyrosine phosphatase 1B (PTP1B) inhibitory activities. Nine water extracts, i.e., Alstonia scholaris leaf, Blumea balsamifera, Cinnamomum burmannii, Cymbopogon nardus, Melaleuca leucadendra, Phyllanthus niruri, Piper nigrum, Syzygium aromaticum, and Sy. polyanthum, exhibited ≥70 % inhibition at 25 μg/mL, whereas 11 methanol extracts, i.e., Als. scholaris, Andrographis paniculata, B. balsamifera, Ci. burmannii, Curcuma heyneana, Glycyrrhiza glabra, M. leucadendra, Punica granatum, Rheum palmatum, Sy. polyanthum, and Z. aromaticum, exhibited ≥70 % inhibition at 25 μg/mL. Water extracts of B. balsamifera (IC50, 2.26 μg/mL) and M. leucadendra (IC50, 2.05 μg/mL), and methanol extracts of Ci. burmannii (IC50, 2.47 μg/mL), Pu. granatum (IC50, 2.40 μg/mL), and Sy. polyanthum (IC50, 1.03 μg/mL) exhibited strong inhibitory activity, which was comparable with that of the positive control, RK-682 (IC50, 2.05 μg/mL). The PTP1B inhibitory activity of the constituents of Ci. burmannii and Z. aromaticum was then evaluated. 5'-Hydroxy-5-hydroxymethyl-4″,5″-methylenedioxy-1,2,3,4-dibenzo-1,3,5-cycloheptatriene (2; IC50, 29.7 μM) and trans-cinnamaldehyde (5; IC50, 57.6 μM) were the active constituents of Ci. burmannii, while humulatrien-5-ol-8-one (21; IC50, 27.7 μM), kaempferol-3,4'-di-O-methyl ether (32; IC50, 17.5 μM), and (S)-6-gingerol (33; IC50, 28.1 μM) were those of Z. aromaticum. These results suggest that these medicinal plants may contribute to the treatment and/or prevention of type II diabetes and/or obesity through PTP1B inhibition.

  7. Bioassay-guided isolation of an active compound with protein tyrosine phosphatase 1B inhibitory activity from Sargassum fusiforme by high-speed counter-current chromatography.

    PubMed

    Wang, Miao; Gu, Dongyu; Guo, Xinfeng; Li, Haoquan; Wang, Yi; Guo, Hong; Yang, Yi; Tian, Jing

    2016-11-01

    A rapid and efficient method using high-speed counter-current chromatography was established for the bioassay-guided separation of an active compound with protein tyrosine phosphatase 1B inhibitory activity from Sargassum fusiforme. Under the bioassay guidance, the ethyl acetate extract with the best IC50 value of 0.37 ± 0.07 μg/mL exhibited a potential protein tyrosine phosphatase 1B inhibitory activity, which was further separated by high-speed counter-current chromatography. The separation was performed with a two-phase solvent system composed of n-hexane/methanol/water (5:4:1, v/v). As a result, dibutyl phthalate (19.7 mg) with the purity of 95.3% was obtained from 200 mg of the ethyl acetate extract. Its IC50 was 14.05 ± 0.06 μM, which was further explained by molecular docking. The result of molecular docking showed that dibutyl phthalate enfolded in the catalytic site of protein tyrosine phosphatase 1B. The main force between dibutyl phthalate and protein tyrosine phosphatase 1B was the hydrogen bond interaction with Gln266. In addition, hydrogen bond, van der Waals force and hydrophobic interaction with the amino acids (Ala217, Ile219, and Gly220) were also responsible for the stable protein-ligand complex.

  8. New compounds from acid hydrolyzed products of the fruits of Momordica charantia L. and their inhibitory activity against protein tyrosine phosphatas 1B.

    PubMed

    Zeng, Ke; He, Yan-Ni; Yang, Di; Cao, Jia-Qing; Xia, Xi-Chun; Zhang, Shi-Jun; Bi, Xiu-Li; Zhao, Yu-Qing

    2014-06-23

    Four new cucurbitane-type triterpene sapogenins, compounds 1-4, together with other eight known compounds were isolated from the acid-hydrolyzed fruits extract of Momordica charantia L. Their chemical structures were established by NMR, mass spectrometry and X-ray crystallography. Compounds 1-7 and 9-12 were evaluated for their inhibitory activities toward protein tyrosine phosphatase 1B (PTP1B), a tyrosine phosphatase that has been implicated as a key target for therapy against type II diabetes. Compounds 1, 2, 4, 7 and 9 were shown inhibitory activities of 77%, 62%, 62% 60% and 68% against PTP1B, respectively. All of these tested compounds were exhibited higher PTP1B inhibition activities than that of the Na3VO4, a known PTP1B inhibitor used as positive control in present study. Structure activity relationship (SAR) analysis indicated that the inhibition activity of PTP1B was associated with the presence and number of -OH groups.

  9. Sesquiterpene Hydroquinones with Protein Tyrosine Phosphatase 1B Inhibitory Activities from a Dysidea sp. Marine Sponge Collected in Okinawa.

    PubMed

    Abdjul, Delfly B; Yamazaki, Hiroyuki; Takahashi, Ohgi; Kirikoshi, Ryota; Ukai, Kazuyo; Namikoshi, Michio

    2016-07-22

    Three new sesquiterpene hydroquinones, avapyran (1), 17-O-acetylavarol (2), and 17-O-acetylneoavarol (3), were isolated from a Dysidea sp. marine sponge collected in Okinawa together with five known congeners: avarol (4), neoavarol (5), 20-O-acetylavarol (6), 20-O-acetylneoavarol (7), and 3'-aminoavarone (8). The structures of 1-3 were assigned on the basis of their spectroscopic data. Compounds 1-3 inhibited the activity of protein tyrosine phosphatase 1B with IC50 values of 11, 9.5, and 6.5 μM, respectively, while known compounds 4-8 gave IC50 values of 12, >32, 10, 8.6, and 18 μM, respectively. In a preliminary investigation on structure-activity relationships, six ester and methoxy derivatives (9-14) were prepared from 4 and 5.

  10. Conformational Lability in Serine Protease Active Sites: Structures of Hepatocyte Growth Factor Activator (HGFA) Alone and with the Inhibitory Domain from HGFA Inhibitor-1B

    SciTech Connect

    Shia, Steven; Stamos, Jennifer; Kirchhofer, Daniel; Fan, Bin; Wu, Judy; Corpuz, Raquel T.; Santell, Lydia; Lazarus, Robert A.; Eigenbrot, Charles

    2010-07-20

    Hepatocyte growth factor activator (HGFA) is a serine protease that converts hepatocyte growth factor (HGF) into its active form. When activated HGF binds its cognate receptor Met, cellular signals lead to cell growth, differentiation, and migration, activities which promote tissue regeneration in liver, kidney and skin. Intervention in the conversion of HGF to its active form has the potential to provide therapeutic benefit where HGF/Met activity is associated with tumorigenesis. To help identify ways to moderate HGF/Met effects, we have determined the molecular structure of the protease domain of HGFA. The structure we determined, at 2.7 {angstrom} resolution, with no pseudo-substrate or inhibitor bound is characterized by an unconventional conformation of key residues in the enzyme active site. In order to find whether this apparently non-enzymatically competent arrangement would persist in the presence of a strongly-interacting inhibitor, we also have determined, at 2.6 {angstrom} resolution, the X-ray structure of HGFA complexed with the first Kunitz domain (KD1) from the physiological inhibitor hepatocyte growth factor activator inhibitor 1B (HAI-1B). In this complex we observe a rearranged substrate binding cleft that closely mirrors the cleft of other serine proteases, suggesting an extreme conformational dynamism. We also characterize the inhibition of 16 serine proteases by KD1, finding that the previously reported enzyme specificity of the intact extracellular region of HAI-1B resides in KD1 alone. We find that HGFA, matriptase, hepsin, plasma kallikrein and trypsin are potently inhibited, and use the complex structure to rationalize the structural basis of these results.

  11. Isolation of betulinic acid, its methyl ester and guaiane sesquiterpenoids with protein tyrosine phosphatase 1B inhibitory activity from the roots of Saussurea lappa C.B.Clarke.

    PubMed

    Choi, Ji Young; Na, Minkyun; Hyun Hwang, In; Ho Lee, Seung; Young Bae, Eun; Yeon Kim, Bo; Seog Ahn, Jong

    2009-01-08

    Activity-guided fractionation of a MeOH extract of the roots of Saussurea lappa C.B.Clarke (Compositae), using an in vitro protein tyrosine phosphatase 1B (PTP1B) inhibition assay, led to the isolation of four active constituents: betulinic acid (1), betulinic acid methyl ester (2), mokko lactone (3) and dehydrocostuslactone (4), along with nine inactive compounds. Our findings indicate that betulinic acid (1) and its methyl ester 2, as well as the two guaiane sesquiterpenoids 3 and 4 are potential lead moieties for the development of new PTP1B inhibitors.

  12. Competitive protein tyrosine phosphatase 1B (PTP1B) inhibitors, prenylated caged xanthones from Garcinia hanburyi and their inhibitory mechanism.

    PubMed

    Tan, Xue Fei; Uddin, Zia; Park, Chanin; Song, Yeong Hun; Son, Minky; Lee, Keun Woo; Park, Ki Hun

    2017-04-15

    Protein tyrosine phosphatase 1B (PTP1B) plays important role in diabetes, obesity and cancer. The methanol extract of the gum resin of Garcinia hanburyi (G. hanburyi) showed potent PTP1B inhibition at 10µg/ml. The active compounds were identified as prenylated caged xanthones (1-9) which inhibited PTP1B in dose-dependent manner. Carboxybutenyl group within caged motif (A ring) was found to play a critical role in enzyme inhibition such as 1-6 (IC50s=0.47-4.69µM), whereas compounds having hydroxymethylbutenyl 7 (IC50=70.25µM) and methylbutenyl 8 (IC50>200µM) showed less activity. The most potent inhibitor, gambogic acid 1 (IC50=0.47µM) showed 30-fold more potency than ursolic acid (IC50=15.5µM), a positive control. In kinetic study, all isolated xanthones behaved as competitive inhibitors which were fully demonstrated with Km, Vmax and Kik/Kiv ratio. It was also proved that inhibitor 1 operated under the enzyme isomerization model having k5=0.0751µM(-)(1)S(-)(1), k6=0.0249µM(-)(1)S(-)(1) and Ki(app)=0.499µM. To develop a pharmacophore model, we explored the binding sites of compound 1 and 7 in PTP1B. These modeling results were in agreement with our findings, which revealed that the inhibitory activities are tightly related to caged motif and prenyl group in A ring.

  13. Selective binding modes and allosteric inhibitory effects of lupane triterpenes on protein tyrosine phosphatase 1B

    PubMed Central

    Jin, Tiantian; Yu, Haibo; Huang, Xu-Feng

    2016-01-01

    Protein Tyrosine Phosphatase 1B (PTP1B) has been recognized as a promising therapeutic target for treating obesity, diabetes, and certain cancers for over a decade. Previous drug design has focused on inhibitors targeting the active site of PTP1B. However, this has not been successful because the active site is positively charged and conserved among the protein tyrosine phosphatases. Therefore, it is important to develop PTP1B inhibitors with alternative inhibitory strategies. Using computational studies including molecular docking, molecular dynamics simulations, and binding free energy calculations, we found that lupane triterpenes selectively inhibited PTP1B by targeting its more hydrophobic and less conserved allosteric site. These findings were verified using two enzymatic assays. Furthermore, the cell culture studies showed that lupeol and betulinic acid inhibited the PTP1B activity stimulated by TNFα in neurons. Our study indicates that lupane triterpenes are selective PTP1B allosteric inhibitors with significant potential for treating those diseases with elevated PTP1B activity. PMID:26865097

  14. Antiobesity and Antidiabetes Effects of a Cudrania tricuspidata Hydrophilic Extract Presenting PTP1B Inhibitory Potential

    PubMed Central

    Kim, Dae Hoon; Lee, Sooung; Chung, Youn Wook; Kim, Byeong Mo; Kim, Hanseul; Kim, Kunhong; Yang, Kyung Mi

    2016-01-01

    Diabetes and obesity represent the major health problems and the most age-related metabolic diseases. Protein-tyrosine phosphatase 1B (PTP1B) has emerged as an important regulator of insulin signal transduction and is regarded as a pharmaceutical target for metabolic disorders. To find novel natural materials presenting therapeutic activities against diabetes and obesity, we screened various herb extracts using a chip screening allowing the determination of PTP1B inhibitory effects of the tested compounds using insulin receptor (IR) as the substrate. Cudrania tricuspidata leaves (CTe) had a strong inhibitory effect on PTP1B activity and substantially inhibited fat accumulation in 3T3-L1 cells. CTe was orally administrated to diet-induced obesity (DIO) mice once daily for 3 weeks after which changes in glucose, insulin metabolism, and fat accumulation were examined. Hepatic enzyme markers (aspartate aminotransferase, AST, and alanine aminotransferase, ALT) and total fat mass and triglyceride levels decreased in CTe-treated mice, whereas body weight and total cholesterol concentration slightly decreased. CTe increased the phosphorylation of IRS-1 and Akt in liver tissue. Furthermore, CTe treatment significantly lowered blood glucose levels and improved insulin secretion in DIO mice. Our results strongly suggest that CTe may represent a promising therapeutic substance against diabetes and obesity. PMID:26989693

  15. Hepatitis C virus NS5A replication complex inhibitors. Part 6: Discovery of a novel and highly potent biarylimidazole chemotype with inhibitory activity toward genotypes 1a and 1b replicons.

    PubMed

    Belema, Makonen; Nguyen, Van N; Romine, Jeffrey L; St Laurent, Denis R; Lopez, Omar D; Goodrich, Jason T; Nower, Peter T; O'Boyle, Donald R; Lemm, Julie A; Fridell, Robert A; Gao, Min; Fang, Hua; Krause, Rudolph G; Wang, Ying-Kai; Oliver, A Jayne; Good, Andrew C; Knipe, Jay O; Meanwell, Nicholas A; Snyder, Lawrence B

    2014-03-13

    A medicinal chemistry campaign that was conducted to address a potential genotoxic liability associated with an aniline-derived scaffold in a series of HCV NS5A inhibitors with dual GT-1a/-1b inhibitory activity is described. Anilides 3b and 3c were used as vehicles to explore structural modifications that retained antiviral potency while removing the potential for metabolism-based unmasking of the embedded aniline. This effort resulted in the discovery of a highly potent biarylimidazole chemotype that established a potency benchmark in replicon assays, particularly toward HCV GT-1a, a strain with significant clinical importance. Securing potent GT-1a activity in a chemotype class lacking overt structural liabilities was a critical milestone in the effort to realize the full clinical potential of targeting the HCV NS5A protein.

  16. PTP1B inhibitory effects of tridepside and related metabolites isolated from the Antarctic lichen Umbilicaria antarctica.

    PubMed

    Seo, Changon; Choi, Yun-Hyeok; Ahn, Jong Seog; Yim, Joung Han; Lee, Hong Kum; Oh, Hyuncheol

    2009-10-01

    The selective inhibition of PTP1B has been widely recognized as a potential drug target for the treatment of type 2 diabetes and obesity. In the course of screening for PTP1B inhibitory natural products, the MeOH extract of the dried sample of the Antarctic lichen Umbilicaria antarctica was found to exhibit significant inhibitory effect, and the bioassay-guided fractionation and purification afforded three related lichen metabolites 1-3. Compounds 1-3 were identified as gyrophoric acid (1), lecanoric acid (2), and methyl orsellinate (3) mainly by analysis of NMR and MS data. These compounds inhibited PTP1B activity with 50% inhibitory concentration values of 3.6 +/- 0.04 microM, 31 +/- 2.7 microM, and 277 +/- 8.6 microM, respectively. Furthermore, the kinetic analysis of PTP1B inhibition by compound 1 suggested that the compound inhibited PTP1B activity in a non-competitive manner.

  17. Inhibitory effect of ganglioside GD1b on K+ current in hippocampal neurons and its involvement in apoptosis suppression.

    PubMed

    Chen, Xuesong; Chi, Shaopeng; Liu, Mingna; Yang, Wei; Wei, Taotao; Qi, Zhi; Yang, Fuyu

    2005-12-01

    Gangliosides are endogenous membrane components enriched in neuronal cells. They have been shown to play regulatory roles in many cellular processes. Here, we show for the first time that ganglioside GD1b plays an antiapoptotic role in cultured hippocampal neurons. GD1b inhibited the voltage-dependent outward delayed rectifier current (I(K)) but not the transient outward A-type current in a dose-dependent manner, with an IC50 value of 15.2 microM. This effect appears to be somehow specific, because GD1b, but not GM1, GM2, GM3, GD1a, GD3, or GT1b, was effective in inhibiting I(K). Intracellular application of staurosporine (STS; 0.1 microM) resulted in rapid activation of I(K), which was partially reversed upon addition of the K+ channel blocker tetraethylammonium (TEA; 5 mM) and GD1b (10 microM). Furthermore, GD1b (10 microM) attenuated STS-induced neuronal apoptosis by nearly the same amount as 5 mM TEA. In addition, GD1b suppressed the apoptosis-associated caspase 3 activation that was activated by STS. Collectively, these findings suggest that GD1b plays an antiapoptotic role in cultured hippocampal neurons through its inhibitory effect on the I(K) and caspase activity.

  18. Zinc ions modulate protein tyrosine phosphatase 1B activity.

    PubMed

    Bellomo, Elisa; Massarotti, Alberto; Hogstrand, Christer; Maret, Wolfgang

    2014-07-01

    Protein tyrosine phosphatases (PTPs) are key enzymes in cellular regulation. The 107 human PTPs are regulated by redox signalling, phosphorylation, dimerisation, and proteolysis. Recent findings of very strong inhibition of some PTPs by zinc ions at concentrations relevant in a cellular environment suggest yet another mechanism of regulation. One of the most extensively investigated PTPs is PTP1B (PTPN1). It regulates the insulin and leptin signalling pathway and is implicated in cancer and obesity/diabetes. The development of novel assay conditions to investigate zinc inhibition of PTP1B provides estimates of about 5.6 nM affinity for inhibitory zinc(II) ions. Analysis of three PTP1B 3D structures (PDB id: 2CM2, 3I80 and 1A5Y) identified putative zinc binding sites and supports the kinetic studies in suggesting an inhibitory zinc only in the closed and cysteinyl-phosphate intermediate forms of the enzyme. These observations gain significance with regard to recent findings of regulatory roles of zinc ions released from the endoplasmic reticulum.

  19. Coumarins from Angelica decursiva inhibit α-glucosidase activity and protein tyrosine phosphatase 1B.

    PubMed

    Ali, Md Yousof; Jannat, Susoma; Jung, Hyun Ah; Jeong, Hyong Oh; Chung, Hae Young; Choi, Jae Sue

    2016-05-25

    In the present study, we investigated the anti-diabetic potential of six natural coumarins, 4-hydroxy Pd-C-III (1), 4'-methoxy Pd-C-I (2), decursinol (3), decursidin (4), umbelliferone 6-carboxylic acid (5), and 2'-isopropyl psoralene (6) isolated from Angelica decursiva and evaluated their inhibitory activities against protein tyrosine phosphatase 1B (PTP1B), α-glucosidase, and ONOO(-)-mediated protein tyrosine nitration. Coumarins 1-6 showed potent PTP1B and α-glucosidase inhibitory activities with ranges of IC50 values of 5.39-58.90 μM and 65.29-172.10 μM, respectively. In the kinetic study for PTP1B enzyme inhibition, compounds 1, 5, and 6 were competitive, whereas 2 and 4 showed mixed type, and 3 displayed noncompetitive type inhibition. For α-glucosidase enzyme inhibition, compounds 1 and 3 exhibited good mixed-type, while 2, 5, and 6 showed noncompetitive and 4 displayed competitive type inhibition. Furthermore, these coumarins also effectively suppressed ONOO(-)-mediated tyrosine nitration in a dose-dependent manner. To further investigate PTP1B inhibition, we generated a 3D structure of PTP1B using Autodock 4.2 and simulated the binding of compounds 1-6. Docking simulations showed that different residues of PTP1B interacted with different functional groups of compounds 1-6 through hydrogen and hydrophobic interactions. In addition, the binding energies of compounds 1-6 were negative, suggesting that hydrogen bonding may stabilize the open form of the enzyme and potentiate tight binding of the active site of PTP1B, thereby resulting in more effective PTP1B inhibition. These results demonstrate that the whole plant of A. decursiva and its coumarins are useful as potential functional food ingredients for the prevention and treatment of type 2 diabetes.

  20. PTP1B Inhibitory and Anti-Inflammatory Effects of Secondary Metabolites Isolated from the Marine-Derived Fungus Penicillium sp. JF-55

    PubMed Central

    Lee, Dong-Sung; Jang, Jae-Hyuk; Ko, Wonmin; Kim, Kyoung-Su; Sohn, Jae Hak; Kang, Myeong-Suk; Ahn, Jong Seog; Kim, Youn-Chul; Oh, Hyuncheol

    2013-01-01

    Protein tyrosine phosphatase 1B (PTP1B) plays a major role in the negative regulation of insulin signaling, and is thus considered as an attractive therapeutic target for the treatment of diabetes. Bioassay-guided investigation of the methylethylketone extract of marine-derived fungus Penicillium sp. JF-55 cultures afforded a new PTP1B inhibitory styrylpyrone-type metabolite named penstyrylpyrone (1), and two known metabolites, anhydrofulvic acid (2) and citromycetin (3). Compounds 1 and 2 inhibited PTP1B activity in a dose-dependent manner, and kinetic analyses of PTP1B inhibition suggested that these compounds inhibited PTP1B activity in a competitive manner. In an effort to gain more biological potential of the isolated compounds, the anti-inflammatory effects of compounds 1–3 were also evaluated. Among the tested compounds, only compound 1 inhibited the production of NO and PGE2, due to the inhibition of the expression of iNOS and COX-2. Penstyrylpyrone (1) also reduced TNF-α and IL-1β production, and these anti-inflammatory effects were shown to be correlated with the suppression of the phosphorylation and degradation of IκB-α, NF-κB nuclear translocation, and NF-κB DNA binding activity. In addition, using inhibitor tin protoporphyrin (SnPP), an inhibitor of HO-1, it was verified that the inhibitory effects of penstyrylpyrone (1) on the pro-inflammatory mediators and NF-κB DNA binding activity were associated with the HO-1 expression. Therefore, these results suggest that penstyrylpyrone (1) suppresses PTP1B activity, as well as the production of pro-inflammatory mediators via NF-κB pathway, through expression of anti-inflammatory HO-1. PMID:23612372

  1. PTP1B, α-glucosidase, and DPP-IV inhibitory effects for chromene derivatives from the leaves of Smilax china L.

    PubMed

    Zhao, Bing Tian; Le, Duc Dat; Nguyen, Phi Hung; Ali, Md Yousof; Choi, Jae-Sue; Min, Byung Sun; Shin, Heung Mook; Rhee, Hae Ik; Woo, Mi Hee

    2016-06-25

    Two new flavonoids, bismilachinone (11) and smilachinin (14), were isolated from the leaves of Smilax china L. together with 14 known compounds. Their structures were elucidated using spectroscopic methods. The PTP1B, α-glucosidase, and DPP-IV inhibitory activities of compounds 1-16 were evaluated at the molecular level. Among them, compounds 4, 7, and 10 showed moderate DPP-IV inhibitory activities with IC50 values of 20.81, 33.12, and 32.93 μM, respectively. Compounds 3, 4, 6, 11, 12, and 16 showed strong PTP1B inhibitory activities, with respective IC50 values of 7.62, 10.80, 0.92, 2.68, 9.77, and 24.17 μM compared with the IC50 value for the positive control (ursolic acid: IC50 = 1.21 μM). Compounds 2-7, 11, 12, 15, and 16 showed potent α-glucosidase inhibitory activities, with respective IC50 values of 8.70, 81.66, 35.11, 35.92, 7.99, 26.28, 11.28, 62.68, 44.32, and 70.12 μM. The positive control, acarbose, displayed an IC50 value of 175.84 μM. In the kinetic study for the PTP1B enzyme, compounds 6, 11, and 12 displayed competitive inhibition with Ki values of 3.20, 8.56, and 5.86 μM, respectively. Compounds 3, 4, and 16 showed noncompetitive inhibition with Ki values of 18.75, 5.95, and 22.86 μM, respectively. Molecular docking study for the competitive inhibitors (6, 11, and 12) radically corroborates the binding affinities and inhibition of PTP1B enzymes. These results indicated that the leaves of Smilax china L. may contain compounds with anti-diabetic activity.

  2. The physiological concentration of ferrous iron (II) alters the inhibitory effect of hydrogen peroxide on CD45, LAR and PTP1B phosphatases.

    PubMed

    Kuban-Jankowska, Alicja; Gorska, Magdalena; Jaremko, Lukasz; Jaremko, Mariusz; Tuszynski, Jack A; Wozniak, Michal

    2015-12-01

    Hydrogen peroxide is an important regulator of protein tyrosine phosphatase activity via reversible oxidation. However, the role of iron in this reaction has not been yet elucidated. Here we compare the influence of hydrogen peroxide and the ferrous iron (reagent for Fenton reaction) on the enzymatic activity of recombinant CD45, LAR, PTP1B phosphatases and cellular CD45 in Jurkat cells. The obtained results show that ferrous iron (II) is potent inhibitor of CD45, LAR and PTP1B, but the inhibitory effect is concentration dependent. We found that the higher concentrations of ferrous iron (II) increase the inactivation of CD45, LAR and PTP1B phosphatase caused by hydrogen peroxide, but the addition of the physiological concentration (500 nM) of ferrous iron (II) has even a slightly preventive effect on the phosphatase activity against hydrogen peroxide.

  3. Overexpression and enhanced specific activity of aldoketo reductases (AKR1B1 & AKR1B10) in human breast cancers.

    PubMed

    Reddy, K Ashok; Kumar, P Uday; Srinivasulu, M; Triveni, B; Sharada, K; Ismail, Ayesha; Reddy, G Bhanuprakash

    2017-02-01

    The incidence of breast cancer in India is on the rise and is rapidly becoming the primary cancer in Indian women. The aldoketo reductase (AKR) family has more than 190 proteins including aldose reductase (AKR1B1) and aldose reductase like protein (AKR1B10). Apart from liver cancer, the status of AKR1B1 and AKR1B10 with respect to their expression and activity has not been reported in other human cancers. We studied the specific activity and expression of AKR1B1 and AKR1B10 in breast non tumor and tumor tissues and in the blood. Fresh post-surgical breast cancer and non-cancer tissues and blood were collected from the subjects who were admitted for surgical therapy. Malignant, benign and pre-surgical chemotherapy samples were evaluated by histopathology scoring. Expression of AKR1B1 and AKR1B10 was carried out by immunoblotting and immunohistochemistry (IHC) while specific activity was determined spectrophotometrically. The specific activity of AKR1B1 was significantly higher in red blood cells (RBC) in all three grades of primary surgical and post-chemotherapy samples. Specific activity of both AKR1B1 and AKR1B10 increased in tumor samples compared to their corresponding non tumor samples (primary surgical and post-chemotherapy). Immunoblotting and IHC data also indicated overexpression of AKR1B1 in all grades of tumors compared to their corresponding non tumor samples. There was no change in the specific activity of AKR1B1 in benign samples compared to all grades of tumor and non-tumors.

  4. Berberine inhibits PTP1B activity and mimics insulin action.

    PubMed

    Chen, Chunhua; Zhang, Yuebo; Huang, Cheng

    2010-07-02

    Type 2 diabetes patients show defects in insulin signal transduction that include lack of insulin receptor, decrease in insulin stimulated receptor tyrosine kinase activity and receptor-mediated phosphorylation of insulin receptor substrates (IRSs). A small molecule that could target insulin signaling would be of significant advantage in the treatment of diabetes. Berberine (BBR) has recently been shown to lower blood glucose levels and to improve insulin resistance in db/db mice partly through the activation of AMP-activated protein kinase (AMPK) signaling and induction of phosphorylation of insulin receptor (IR). However, the underlying mechanism remains largely unknown. Here we report that BBR mimics insulin action by increasing glucose uptake ability by 3T3-L1 adipocytes and L6 myocytes in an insulin-independent manner, inhibiting phosphatase activity of protein tyrosine phosphatase 1B (PTP1B), and increasing phosphorylation of IR, IRS1 and Akt in 3T3-L1 adipocytes. In diabetic mice, BBR lowers hyperglycemia and improves impaired glucose tolerance, but does not increase insulin release and synthesis. The results suggest that BBR represents a different class of anti-hyperglycemic agents.

  5. Design synthesis and evaluation of the inhibitory selectivity of novel trans-resveratrol analogues on human recombinant CYP1A1 CYP1A2 and CYP1B1

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A series of trans-stilbene derivatives containing 4’-thiomethyl substituent were synthesized and evaluated for inhibitory activities on human recombinant cytochrome P450(s): CYP1A1, CYP1A2, and CYP1B1. CYP1A2-related metabolism of stilbene derivatives was estimated by using NADPH oxidation assay. A...

  6. Triterpenoids from the leaves of Diospyros kaki (persimmon) and their inhibitory effects on protein tyrosine phosphatase 1B.

    PubMed

    Thuong, Phuong Thien; Lee, Chul Ho; Dao, Trong Tuan; Nguyen, Phi Hung; Kim, Wan Gi; Lee, Sang Jun; Oh, Won Keun

    2008-10-01

    Phytochemical study on a methanol-soluble extract of the leaves of persimmon (Diospyros kaki) resulted in the isolation of two new ursane-type triterpenoids, 3alpha,19alpha-dihydroxyurs-12,20(30)-dien-24,28-dioic acid (1) and 3alpha,19alpha-dihydroxyurs-12-en-24,28-dioic acid (2), together with 12 known ursane- and oleanane-type triterpenoids (3-14). Triterpenoids with a 3beta-hydroxy group were found to inhibit protein tyrosine phosphatase 1B (PTP1B) activity, with IC50 values ranging from 3.1+/-0.2 to 18.8+/-1.3 microM, whereas those with a 3alpha-hydroxy moiety were not active.

  7. The small GTPase Rap1b negatively regulates neutrophil chemotaxis and transcellular diapedesis by inhibiting Akt activation.

    PubMed

    Kumar, Sachin; Xu, Juying; Kumar, Rupali Sani; Lakshmikanthan, Sribalaji; Kapur, Reuben; Kofron, Matthew; Chrzanowska-Wodnicka, Magdalena; Filippi, Marie-Dominique

    2014-08-25

    Neutrophils are the first line of cellular defense in response to infections and inflammatory injuries. However, neutrophil activation and accumulation into tissues trigger tissue damage due to release of a plethora of toxic oxidants and proteases, a cause of acute lung injury (ALI). Despite its clinical importance, the molecular regulation of neutrophil migration is poorly understood. The small GTPase Rap1b is generally viewed as a positive regulator of immune cell functions by controlling bidirectional integrin signaling. However, we found that Rap1b-deficient mice exhibited enhanced neutrophil recruitment to inflamed lungs and enhanced susceptibility to endotoxin shock. Unexpectedly, Rap1b deficiency promoted the transcellular route of diapedesis through endothelial cell. Increased transcellular migration of Rap1b-deficient neutrophils in vitro was selectively mediated by enhanced PI3K-Akt activation and invadopodia-like protrusions. Akt inhibition in vivo suppressed excessive Rap1b-deficient neutrophil migration and associated endotoxin shock. The inhibitory action of Rap1b on PI3K signaling may be mediated by activation of phosphatase SHP-1. Thus, this study reveals an unexpected role for Rap1b as a key suppressor of neutrophil migration and lung inflammation.

  8. Prediction of enzyme inhibition and mode of inhibitory action based on calculation of distances between hydrogen bond donor/acceptor groups of the molecule and docking analysis: An application on the discovery of novel effective PTP1B inhibitors.

    PubMed

    Eleftheriou, P; Petrou, A; Geronikaki, A; Liaras, K; Dirnali, S; Anna, M

    2015-01-01

    PTP1B is a protein tyrosine phosphatase involved in insulin receptor desensitization. PTP1B inhibition prolongs the activated state of the receptor, practically enhancing the effect of insulin. Thus PTP1B has become a drug target for the treatment of type II diabetes. PTP1b is an enzyme with multiple binding sites for competitive and allosteric inhibitors. Prediction of inhibitory action using docking analysis has limited success in case of enzymes with multiple binding sites, since the selection of the right crystal structure depends on the kind of inhibitor. In the present study, a two-step strategy for the prediction of PTP1b inhibitory action was applied to 12 compounds. Based on the study of known inhibitors, we isolated the structural characteristics required for binding to each binding site. As a first step, 3D-structures of the molecules were produced and their structural parameters were measured and used for prediction of the binding site of the compound. These results were used for the selection of the appropriate crystal structure for docking analysis of each compound, and the final prediction was based on the estimated binding energies. This strategy effectively predicted the activity of all compounds. A linear correlation was found between estimated binding energy and inhibition measured in vitro (r = -0.894).

  9. 5-HT1B autoreceptor regulation of serotonin transporter activity in synaptosomes

    PubMed Central

    Hagan, Catherine E.; McDevitt, Ross A.; Liu, Yusha; Furay, Amy R.; Neumaier, John F.

    2012-01-01

    Serotonin-1B (5-HT1B) autoreceptors are located in serotonin (5-HT) terminals along with serotonin transporters (SERT), and play a critical role in autoregulation of serotonergic neurotransmission, and are implicated in disorders of serotonergic function, particularly emotional regulation. SERT modulates serotonergic neurotransmission by high-affinity reuptake of 5-HT. Alterations in SERT activity are associated with increased risk for depression and anxiety. Several neurotransmitter receptors are known to regulate SERT Km and Vmax, and previous work suggests that 5-HT1B autoreceptors may regulate 5-HT reuptake, in addition to modulating 5-HT release and synthesis. We used rotating disk electrode voltammetry to investigate 5-HT1B autoreceptor regulation of SERT-mediated 5-HT uptake into synaptosomes. The selective 5-HT1B antagonist SB224289 decreased SERT activity in synaptosomes prepared from wild-type but not 5-HT1B knockout mice, whereas SERT uptake was enhanced after pre-treatment with the selective 5-HT1B agonist CP94253. Furthermore, SERT activity varies as a function of 5-HT1B receptor expression—specifically, genetic deletion of 5-HT1B decreased SERT function, while viral-mediated overexpression of 5-HT1B autoreceptors in rat raphe neurons increased SERT activity in rat hippocampal synaptosomes. Considered collectively, these results provide evidence that 5-HT1B autoreceptors regulate SERT activity. Since SERT clearance rate varies as a function of 5-HT1B autoreceptor expression levels and is modulated by both activation and inhibition of 5-HT1B autoreceptors, this dynamic interaction may be an important mechanism of serotonin autoregulation with therapeutic implications. PMID:22961814

  10. PASylation technology improves recombinant interferon-β1b solubility, stability, and biological activity.

    PubMed

    Zvonova, Elizaveta A; Ershov, Alexander V; Ershova, Olga A; Sudomoina, Marina A; Degterev, Maksim B; Poroshin, Grigoriy N; Eremeev, Artem V; Karpov, Andrey P; Vishnevsky, Alexander Yu; Goldenkova-Pavlova, Irina V; Petrov, Andrei V; Ruchko, Sergey V; Shuster, Alexander M

    2017-03-01

    Recombinant interferon-β1b (IFN-β1b) is an effective remedy against multiple sclerosis and other diseases. However, use of small polypeptide (molecular weight is around 18.5 kDa) is limited due to poor solubility, stability, and short half-life in systemic circulation. To solve this problem, we constructed two variants of PASylated IFN-β1b, with PAS sequence at C- or N-terminus of IFN-β1b. The PAS-modified proteins demonstrated 4-fold increase in hydrodynamic volume of the molecule combined with 2-fold increase of in vitro biological activity, as well as advanced stability and solubility of the protein in solution as opposed to unmodified IFN-β1b. Our results demonstrate that PASylation has a positive impact on stability, solubility, and functional activity of IFN-β1b and potentially might improve pharmacokinetic properties of the molecule as a therapeutic agent.

  11. Cytochrome P450 CYP1B1 activity in renal cell carcinoma.

    PubMed

    McFadyen, M C E; Melvin, W T; Murray, G I

    2004-08-31

    Renal cell carcinoma (RCC) is the most common malignancy of the kidney and has a poor prognosis due to its late presentation and resistance to current anticancer drugs. One mechanism of drug resistance, which is potentially amenable to therapeutic intervention, is based on studies in our laboratory. CYP1B1 is a cytochrome P450 enzyme overexpressed in a variety of malignant tumours. Our studies are now elucidating a functional role for CYP1B1 in drug resistance. Cytochrome P450 reductase (P450R) is required for optimal metabolic activity of CYP1B1. Both CYP1B1 and P450R can catalyse the biotransformation of anticancer drugs at the site of the tumour. In this investigation, we determined the expression of CYP1B1 and P450R in samples of normal kidney and RCC (11 paired normal and tumour and a further 15 tumour samples). The O-deethylation of ethoxyresorufin to resorufin was used to measure CYP1B1 activity in RCC. Cytochrome P450 reductase activity was determined by following the reduction of cytochrome c at 550 nm. The key finding of this study was the presence of active CYP1B1 in 70% of RCC. Coincubation with the CYP1B1 inhibitor alpha-naphthoflavone (10 nM) inhibited this activity. No corresponding CYP1B1 activity was detected in any of the normal tissue examined (n=11). Measurable levels of active P450R were determined in all normal (n=11) and tumour samples (n=26). The presence of detectable CYP1B1, which is capable of metabolising anticancer drugs in tumour cells, highlights a novel target for therapeutic intervention.

  12. HTLV-1 bZIP Factor Impairs Anti-viral Immunity by Inducing Co-inhibitory Molecule, T Cell Immunoglobulin and ITIM Domain (TIGIT).

    PubMed

    Yasuma, Keiko; Yasunaga, Jun-ichirou; Takemoto, Keiko; Sugata, Kenji; Mitobe, Yuichi; Takenouchi, Norihiro; Nakagawa, Masanori; Suzuki, Yutaka; Matsuoka, Masao

    2016-01-01

    Human T-cell leukemia virus type 1 (HTLV-1) infects CD4+ T cells and induces proliferation of infected cells in vivo, which leads to the onset of adult T-cell leukemia (ATL) in some infected individuals. The HTLV-1 bZIP factor (HBZ) gene, which is encoded in the minus strand of HTLV-1, plays critical roles in pathogenesis. In this study, RNA-seq and ChIP-seq analyses using HBZ transduced T cells revealed that HBZ upregulates the expression and promoter acetylation levels of a co-inhibitory molecule, T cell immunoglobulin and ITIM domain (TIGIT), in addition to those of regulatory T cells related genes, Foxp3 and Ccr4. TIGIT was expressed on CD4+ T cells from HBZ-transgenic (HBZ-Tg) mice, and on ATL cells and HTLV-1 infected CD4+ T cells of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) in vivo. Expression of Blimp1 and IL-10 was upregulated in TIGIT+CD4+ cells of HBZ-Tg mice compared with TIGIT-CD4+ T cells, suggesting the correlation between TIGIT expression and IL-10 production. When CD4+ T cells from HBZ-Tg mice were stimulated with TIGIT's ligand, CD155, their production of the inhibitory cytokine IL-10 was enhanced. Furthermore, dendritic cells from HBZ-Tg mice produced high levels of IL-10 after stimulation. These data suggest that HBZ alters immune system to suppressive state via TIGIT and IL-10. Importantly, TIGIT suppressed T-cell responses to another HTLV-1 virus protein, Tax, in vitro. Blocking of TIGIT and PD-1 slightly increased anti-Tax T-cell activity in some HAM/TSP patients. These results suggest that HBZ-induced TIGIT on HTLV-1 infected cells impairs T-cell responses to viral antigens. This study shows that HBZ-induced TIGIT plays a pivotal role in attenuating host immune responses and shaping a microenvironment favorable to HTLV-1.

  13. [Activation and inhibitory mechanisms of blood platelets].

    PubMed

    Suzuki-Inoue, Katsue

    2014-07-01

    Exposure of platelets to subendothelial matrices initiates physiological hemostasis and pathological thrombosis. Under high shear stress, von Willebrand factor bridges newly exposed collagen to glycoprotein (GP) Ib on platelets. This initial tethering facilitates association between the collagen receptor GPVI and collagen, which generates tyrosine kinase-dependent activation signals, followed by release of secondary mediators and integrin activation. Activated integrin can bind to their ligands including fibrinogen. The released secondary mediators, ADP and thromboxane A2, activate integrin of flowing platelets, which enables formation of platelet thrombi by binding of activated flowing platelets and adhered platelets to collagen via binding between activated aIIbbeta3 integrin and fibrinogen. Platelets also have inhibitory mechanisms, which help to prevent unwanted platelet activation in vivo.

  14. The serine/threonine phosphatase PPM1B (PP2Cβ) selectively modulates PPARγ activity.

    PubMed

    Tasdelen, Ismayil; van Beekum, Olivier; Gorbenko, Olena; Fleskens, Veerle; van den Broek, Niels J F; Koppen, Arjen; Hamers, Nicole; Berger, Ruud; Coffer, Paul J; Brenkman, Arjan B; Kalkhoven, Eric

    2013-04-01

    Reversible phosphorylation is a widespread molecular mechanism to regulate the function of cellular proteins, including transcription factors. Phosphorylation of the nuclear receptor PPARγ (peroxisome-proliferator-activated receptor γ) at two conserved serine residue (Ser(112) and Ser(273)) results in an altered transcriptional activity of this transcription factor. So far, only a very limited number of cellular enzymatic activities has been described which can dephosphorylate nuclear receptors. In the present study we used immunoprecipitation assays coupled to tandem MS analysis to identify novel PPARγ-regulating proteins. We identified the serine/threonine phosphatase PPM1B [PP (protein phosphatase), Mg(2+)/Mn(2+) dependent, 1B; also known as PP2Cβ] as a novel PPARγ-interacting protein. Endogenous PPM1B protein is localized in the nucleus of mature 3T3-L1 adipocytes where it can bind to PPARγ. Furthermore we show that PPM1B can directly dephosphorylate PPARγ, both in intact cells and in vitro. In addition PPM1B increases PPARγ-mediated transcription via dephosphorylation of Ser(112). Finally, we show that knockdown of PPM1B in 3T3-L1 adipocytes blunts the expression of some PPARγ target genes while leaving others unaltered. These findings qualify the phosphatase PPM1B as a novel selective modulator of PPARγ activity.

  15. Altered motor activity of alternative splice variants of the mammalian kinesin-3 protein KIF1B.

    PubMed

    Matsushita, Masafumi; Yamamoto, Ruri; Mitsui, Keiji; Kanazawa, Hiroshi

    2009-11-01

    Several mammalian kinesin motor proteins exist as multiple isoforms that arise from alternative splicing of a single gene. However, the roles of many motor protein splice variants remain unclear. The kinesin-3 motor protein KIF1B has alternatively spliced isoforms distinguished by the presence or absence of insertion sequences in the conserved amino-terminal region of the protein. The insertions are located in the loop region containing the lysine-rich cluster, also known as the K-loop, and in the hinge region adjacent to the motor domain. To clarify the functions of these alternative splice variants of KIF1B, we examined the biochemical properties of recombinant KIF1B with and without insertion sequences. In a microtubule-dependent ATPase assay, KIF1B variants that contained both insertions had higher activity and affinity for microtubules than KIF1B variants that contained no insertions. Mutational analysis of the K-loop insertion revealed that variants with a longer insertion sequence at this site had higher activity. However, the velocity of movement in motility assays was similar between KIF1B with and without insertion sequences. Our results indicate that splicing isoforms of KIF1B that vary in their insertion sequences have different motor activities.

  16. The effect of organic anion-transporting polypeptides 1B1, 1B3 and 2B1 on the antitumor activity of flavopiridol in breast cancer cells.

    PubMed

    Brenner, Stefan; Riha, Juliane; Giessrigl, Benedikt; Thalhammer, Theresia; Grusch, Michael; Krupitza, Georg; Stieger, Bruno; Jäger, Walter

    2015-01-01

    The contribution of organic anion transporting polypeptides (OATPs) to the cellular uptake of flavopiridol was investigated in OATP1B1-, OATP1B3- and OATP2B1-expressing Chinese hamster ovary (CHO) cells. Uptake of flavopiridol into these cells showed typical Michaelis-Menten kinetics with much higher transport capacity for OATP1B3 compared to OATP1B1 and OATP2B1 (Vmax/Km, 33.9 vs. 8.84 and 2.41 µl/mg/min, respectively). The predominant role of OATPs was further supported by a dramatic inhibition of flavopiridol uptake in the presence of the OATP substrate rifampicin. Uptake of flavopiridol by OATPs also seems to be an important determinant in breast cancer cells. The much higher mRNA level for OATP1B1 found in wild-type compared to ZR-75-1 OATP1B1 knockdown cells correlated with higher flavopiridol initial uptake leading to 4.6-fold decreased IC50 values in the cytotoxicity assay (IC50, 1.45 vs. 6.64 µM). Cell cycle profile also showed a clear incidence for a stronger cell cycle arrest in the G2/M phase for ZR-75-1 wild-type cells compared to OATP1B1 knockdown cells, further indicating an active uptake via OATP1B1. In conclusion, our results revealed OATP1B1, OATP1B3 and OATP2B1 as uptake transporters for flavopiridol in cancer cells, which may also apply in patients during cancer therapy.

  17. In vitro and in silico PTP-1B inhibition and in vivo antidiabetic activity of semisynthetic moronic acid derivatives.

    PubMed

    Cerón-Romero, Litzia; Paoli, Paolo; Camici, Guido; Flores-Morales, Virginia; Rios, María Yolanda; Ramírez-Espinosa, Juan J; Hidalgo-Figueroa, Sergio; Navarrete-Vázquez, Gabriel; Estrada-Soto, Samuel

    2016-04-15

    Six derivatives (1-6) of moronic acid were semi-synthesized and their in vitro protein tyrosine phosphatase 1B (PTP-1B) inhibition activity assessed. Derivatives 2 (IC50=10.8 ± 0.5 μM) and 6 (IC50=7.5 ± 0.1 μM) displayed the most potent inhibitory activity. Therefore, they (50mg/Kg) were tested for their antidiabetic effect in vivo using a non-insulin dependent diabetes mellitus rat model. The results indicated that they decrease plasma glucose levels during all the experiment (p <0.05). Docking analysis of 2 and 6 with PTP-1B orthosteric site A and allosteric site B, showed that 2 had polar and Van der Waals interactions in both sites with Val49, Gln262, Met258, Phe182, Ala217, Ile219 and Gly259, displaying more affinity for site A. Compound 6 showed polar interaction with Gln262 and Van der Waals with Val49, Ile219, Gly259, Arg254, Ala27, Phe52, Met258, Asp48 and Phe182, suggesting that the potential binding site is localized in site B, close to the catalytic site A. Therefore, derivatives 2 and 6 have potential for the development of antidiabetic agents.

  18. The t(8;21) fusion protein interferes with AML-1B-dependent transcriptional activation.

    PubMed Central

    Meyers, S; Lenny, N; Hiebert, S W

    1995-01-01

    The AML-1/CBF beta transcription factor complex is targeted by both the t(8;21) and the inv(16) chromosomal alterations, which are frequently observed in acute myelogenous leukemia. AML-1 is a site-specific DNA-binding protein that recognizes the enhancer core motif TGTGGT. The t(8;21) translocation fuses the first 177 amino acids of AML-1 to MTG8 (also known as ETO), generating a chimeric protein that retains the DNA-binding domain of AML-1. Analysis of endogenous AML-1 DNA-binding complexes suggested the presence of at least two AML-1 isoforms. Accordingly, we screened a human B-cell cDNA library and isolated a larger, potentially alternatively spliced, form of AML1, termed AML1B. AML-1B is a protein of 53 kDa that binds to a consensus AML-1-binding site and complexes with CBF beta. Subcellular fractionation experiments demonstrated that both AML-1 and AML-1/ETO are efficiently extracted from the nucleus under ionic conditions but that AML-1B is localized to a salt-resistant nuclear compartment. Analysis of the transcriptional activities of AML-1, AML-1B, and AML-1/ETO demonstrated that only AML-1B activates transcription from the T-cell receptor beta enhancer. Mixing experiments indicated that AML-1/ETO can efficiently block AML-1B-dependent transcriptional activation, suggesting that the t(8;21) translocation creates a dominant interfering protein. PMID:7891692

  19. Aspirin Hydrolysis in Plasma Is a Variable Function of Butyrylcholinesterase and Platelet-activating Factor Acetylhydrolase 1b2 (PAFAH1b2)*

    PubMed Central

    Zhou, Gang; Marathe, Gopal K.; Hartiala, Jaana; Hazen, Stanley L.; Allayee, Hooman; Tang, W. H. Wilson; McIntyre, Thomas M.

    2013-01-01

    Aspirin is rapidly hydrolyzed within erythrocytes by a heterodimer of PAFAH1b2/PAFAH1b3 but also in plasma by an unidentified activity. Hydrolysis in both compartments was variable, with a 12-fold variation in plasma among 2226 Cleveland Clinic GeneBank patients. Platelet inhibition by aspirin was suppressed in plasma that rapidly hydrolyzed aspirin. Plasma aspirin hydrolysis was significantly higher in patients with coronary artery disease compared with control subjects (16.5 ± 4.4 versus 15.1 ± 3.7 nmol/ml/min; p = 3.4 × 10−8). A genome-wide association study of 2054 GeneBank subjects identified a single locus immediately adjacent to the BCHE (butyrylcholinesterase) gene associated with plasma aspirin hydrolytic activity (lead SNP, rs6445035; p = 9.1 × 10−17). However, its penetrance was low, and plasma from an individual with an inactivating mutation in BCHE still effectively hydrolyzed aspirin. A second aspirin hydrolase was identified in plasma, the purification of which showed it to be homomeric PAFAH1b2. This is distinct from the erythrocyte PAFAH1b2/PAFAH1b3 heterodimer. Inhibitors showed that both butyrylcholinesterase (BChE) and PAFAH1b2 contribute to aspirin hydrolysis in plasma, with variation primarily reflecting non-genetic variation of BChE activity. Therefore, aspirin is hydrolyzed in plasma by two enzymes, BChE and a new extracellular form of platelet-activating factor acetylhydrolase, PAFAH1b2. Hydrolytic effectiveness varies widely primarily from non-genetic variation of BChE activity that affects aspirin bioavailability in blood and the ability of aspirin to inhibit platelet aggregation. PMID:23508960

  20. Inhibitory Effects of Green Tea and (-)-Epigallocatechin Gallate on Transport by OATP1B1, OATP1B3, OCT1, OCT2, MATE1, MATE2-K and P-Glycoprotein.

    PubMed

    Knop, Jana; Misaka, Shingen; Singer, Katrin; Hoier, Eva; Müller, Fabian; Glaeser, Hartmut; König, Jörg; Fromm, Martin F

    2015-01-01

    Green tea catechins inhibit the function of organic anion transporting polypeptides (OATPs) that mediate the uptake of a diverse group of drugs and endogenous compounds into cells. The present study was aimed at investigating the effect of green tea and its most abundant catechin epigallocatechin gallate (EGCG) on the transport activity of several drug transporters expressed in enterocytes, hepatocytes and renal proximal tubular cells such as OATPs, organic cation transporters (OCTs), multidrug and toxin extrusion proteins (MATEs), and P-glycoprotein (P-gp). Uptake of the typical substrates metformin for OCTs and MATEs and bromosulphophthalein (BSP) and atorvastatin for OATPs was measured in the absence and presence of a commercially available green tea and EGCG. Transcellular transport of digoxin, a typical substrate of P-gp, was measured over 4 hours in the absence and presence of green tea or EGCG in Caco-2 cell monolayers. OCT1-, OCT2-, MATE1- and MATE2-K-mediated metformin uptake was significantly reduced in the presence of green tea and EGCG (P < 0.05). BSP net uptake by OATP1B1 and OATP1B3 was inhibited by green tea [IC50 2.6% (v/v) and 0.39% (v/v), respectively]. Green tea also inhibited OATP1B1- and OATP1B3-mediated atorvastatin net uptake with IC50 values of 1.9% (v/v) and 1.0% (v/v), respectively. Basolateral to apical transport of digoxin was significantly decreased in the presence of green tea and EGCG. These findings indicate that green tea and EGCG inhibit multiple drug transporters in vitro. Further studies are necessary to investigate the effects of green tea on prototoypical substrates of these transporters in humans, in particular on substrates of hepatic uptake transporters (e.g. statins) as well as on P-glycoprotein substrates.

  1. MAP1B Regulates Axonal Development by Modulating Rho-GTPase Rac1 Activity

    PubMed Central

    Montenegro-Venegas, Carolina; Tortosa, Elena; Rosso, Silvana; Peretti, Diego; Bollati, Flavia; Bisbal, Mariano; Jausoro, Ignacio; Avila, Jesus; Cáceres, Alfredo

    2010-01-01

    Cultured neurons obtained from MAP1B-deficient mice have a delay in axon outgrowth and a reduced rate of axonal elongation compared with neurons from wild-type mice. Here we show that MAP1B deficiency results in a significant decrease in Rac1 and cdc42 activity and a significant increase in Rho activity. We found that MAP1B interacted with Tiam1, a guanosine nucleotide exchange factor for Rac1. The decrease in Rac1/cdc42 activity was paralleled by decreases in the phosphorylation of the downstream effectors of these proteins, such as LIMK-1 and cofilin. The expression of a constitutively active form of Rac1, cdc42, or Tiam1 rescued the axon growth defect of MAP1B-deficient neurons. Taken together, these observations define a new and crucial function of MAP1B that we show to be required for efficient cross-talk between microtubules and the actin cytoskeleton during neuronal polarization. PMID:20719958

  2. Detergent-induced activation of the hepatitis C virus genotype 1b RNA polymerase.

    PubMed

    Weng, Leiyun; Kohara, Michinori; Wakita, Takaji; Shimotohno, Kunitada; Toyoda, Tetsuya

    2012-04-01

    Recently, we found that sphingomyelin bound and activated hepatitis C virus (HCV) 1b RNA polymerase (RdRp), thereby recruiting the HCV replication complex into lipid raft structures. Detergents are commonly used for resolving lipids and purifying proteins, including HCV RdRp. Here, we tested the effect of detergents on HCV RdRp activity in vitro and found that non-ionic (Triton X-100, NP-40, Tween 20, Tween 80, and Brij 35) and twitterionic (CHAPS) detergents activated HCV 1b RdRps by 8-16.6 folds, but did not affect 1a or 2a RdRps. The maximum effect of these detergents was observed at around their critical micelle concentrations. On the other hand, ionic detergents (SDS and DOC) completely inactivated polymerase activity at 0.01%. In the presence of Triton X-100, HCV 1b RdRp did not form oligomers, but recruited more template RNA and increased the speed of polymerization. Comparison of polymerase and RNA-binding activity between JFH1 RdRp and Triton X-100-activated 1b RdRp indicated that monomer RdRp showed high activity because JFH1 RdRp was a monomer in physiological conditions of transcription. Besides, 502H plays a key role on oligomerization of 1b RdRp, while 2a RdRps which have the amino acid S at position 502 are monomers. This oligomer formed by 502H was disrupted both by high salt and Triton X-100. On the contrary, HCV 1b RdRp completely lost fidelity in the presence of 0.02% Triton X-100, which suggests that caution should be exercised while using Triton X-100 in anti-HCV RdRp drug screening tests.

  3. Cancer Activation and Polymorphisms of Human Cytochrome P450 1B1

    PubMed Central

    Chun, Young-Jin; Kim, Donghak

    2016-01-01

    Human cytochrome P450 enzymes (P450s, CYPs) are major oxidative catalysts that metabolize various xenobiotic and endogenous compounds. Many carcinogens induce cancer only after metabolic activation and P450 enzymes play an important role in this phenomenon. P450 1B1 mediates bioactivation of many procarcinogenic chemicals and carcinogenic estrogen. It catalyzes the oxidation reaction of polycyclic aromatic carbons, heterocyclic and aromatic amines, and the 4-hydroxylation reaction of 17β-estradiol. Enhanced expression of P450 1B1 promotes cancer cell proliferation and metastasis. There are at least 25 polymorphic variants of P450 1B1 and some of these have been reported to be associated with eye diseases. In addition, P450 1B1 polymorphisms can greatly affect the metabolic activation of many procarcinogenic compounds. It is necessary to understand the relationship between metabolic activation of such substances and P450 1B1 polymorphisms in order to develop rational strategies for the prevention of its toxic effect on human health. PMID:27123158

  4. HTLV-1 bZIP Factor Enhances T-Cell Proliferation by Impeding the Suppressive Signaling of Co-inhibitory Receptors

    PubMed Central

    Shimura, Kazuya; Onishi, Chiho; Iyoda, Tomonori; Inaba, Kayo

    2017-01-01

    Human T-cell leukemia virus type 1 (HTLV-1) causes adult T-cell leukemia-lymphoma (ATL) and inflammatory diseases. To enhance cell-to-cell transmission of HTLV-1, the virus increases the number of infected cells in vivo. HTLV-1 bZIP factor (HBZ) is constitutively expressed in HTLV-1 infected cells and ATL cells and promotes T-cell proliferation. However, the detailed mechanism by which it does so remains unknown. Here, we show that HBZ enhances the proliferation of expressing T cells after stimulation via the T-cell receptor. HBZ promotes this proliferation by influencing the expression and function of multiple co-inhibitory receptors. HBZ suppresses the expression of BTLA and LAIR-1 in HBZ expressing T cells and ATL cells. Expression of T cell immunoglobulin and ITIM domain (TIGIT) and Programmed cell death 1 (PD-1) was enhanced, but their suppressive effect on T-cell proliferation was functionally impaired. HBZ inhibits the co-localization of SHP-2 and PD-1 in T cells, thereby leading to impaired inhibition of T-cell proliferation and suppressed dephosphorylation of ZAP-70 and CD3ζ. HBZ does this by interacting with THEMIS, which associates with Grb2 and SHP-2. Thus, HBZ interacts with the SHP containing complex, impedes the suppressive signal from PD-1 and TIGIT, and enhances the proliferation of T cells. Although HBZ was present in both the nucleus and the cytoplasm of T cells, HBZ was localized largely in the nucleus by suppressed expression of THEMIS by shRNA. This indicates that THEMIS is responsible for cytoplasmic localization of HBZ in T cells. Since THEMIS is expressed only in T-lineage cells, HBZ mediated inhibition of the suppressive effects of co-inhibitory receptors accounts for how HTLV-1 induces proliferation only of T cells in vivo. This study reveals that HBZ targets co-inhibitory receptors to cause the proliferation of infected cells. PMID:28046066

  5. Comparison of the Isw1a, Isw1b, and Isw2 nucleosome disrupting activities.

    PubMed

    Krajewski, Wladyslaw A

    2013-10-08

    The three Saccharomyces cerevisiae ISWI chromatin remodeling complexes, Isw1a, Isw1b, and Isw2, are implicated in the regularization of arrayed nucleosomes and regulation of gene activity. Although Isw1a and Isw1b are based on the same catalytic unit, in general, their functions in vivo do not overlap. To better understand the structural consequences of these complexes, we compared the putative nucleosome disrupting activities of the purified Isw1a, Isw1b, and Isw2. To account for the putative effects of nucleosomal environment, we employed reconstituted dinucleosomes in which the histone octamers were specifically positioned by the 146 base pair high-affinity nucleosome sequence "601". We have compared the MNase and deoxyribonuclease I protection patterns of remodeled nucleosome templates and evaluated the nucleosome destabilizing abilities of the Isw1a/b and Isw2 using restriction endonucleases. Although the Isw2 showed little evidence of nucleosome disassembly, the Isw1b remodeled dinucleosomes exhibited some common features with the ySwi-Snf remodeling products. The nuclease digestion data suggest that Isw1a can also promote ATP-dependent distortion of nucleosome structure, although less efficiently than the Isw1b complex.

  6. Melanoma inhibitory activity in Brazilian patients with cutaneous melanoma*

    PubMed Central

    Odashiro, Macanori; Hans Filho, Gunter; Pereira, Patricia Rusa; Castro, Ana Rita Coimbra Motta; Stief, Alcione Cavalheiro; Pontes, Elenir Rose Jardim Cury; Odashiro, Alexandre Nakao

    2015-01-01

    BACKGROUND: Melanoma inhibitory activity is a protein secreted by melanoma cells and has been used as a tumor marker. Increased Melanoma inhibitory activity serum levels are related to metastatic disease or tumor recurrence. Currently there are no studies on Melanoma inhibitory activity and cutaneous melanoma involving Brazilian patients. OBJECTIVE: To evaluate the performance and feasibility of measuring Melanoma inhibitory activity levels in Brazilian patients with cutaneous melanoma. METHODS: Blood was obtained from ten patients with proved metastatic cutaneous melanoma (Group 1), 15 patients resected for cutaneous melanoma without metastasis (Group 2) and 5 healthy donors (Group 3). Melanoma inhibitory activity was measured using a commercially available ELISA kit. RESULTS: There was a statistically significant difference of Melanoma inhibitory activity levels between patients with and without metastasis (p=0.002), and between patients with metastasis and healthy donors (p=0.002). There was no difference between patients without metastasis and healthy donors (p=0.443). CONCLUSION: Melanoma inhibitory activity is a tumor marker for cutaneous melanoma and the Melanoma inhibitory activity-ELISA test can be easily performed. Patients with metastasis have increased Melanoma inhibitory activity serum levels when compared to patients without metastasis and healthy donors. PMID:26131861

  7. Ion channel TRPV1-dependent activation of PTP1B suppresses EGFR-associated intestinal tumorigenesis

    PubMed Central

    de Jong, Petrus R.; Takahashi, Naoki; Harris, Alexandra R.; Lee, Jihyung; Bertin, Samuel; Jeffries, James; Jung, Michael; Duong, Jen; Triano, Amy I.; Lee, Jongdae; Niv, Yaron; Herdman, David S.; Taniguchi, Koji; Kim, Chang-Whan; Dong, Hui; Eckmann, Lars; Stanford, Stephanie M.; Bottini, Nunzio; Corr, Maripat; Raz, Eyal

    2014-01-01

    The intestinal epithelium has a high rate of turnover, and dysregulation of pathways that regulate regeneration can lead to tumor development; however, the negative regulators of oncogenic events in the intestinal epithelium are not fully understood. Here we identified a feedback loop between the epidermal growth factor receptor (EGFR), a known mediator of proliferation, and the transient receptor potential cation channel, subfamily V, member 1 (TRPV1), in intestinal epithelial cells (IECs). We found that TRPV1 was expressed by IECs and was intrinsically activated upon EGFR stimulation. Subsequently, TRPV1 activation inhibited EGFR-induced epithelial cell proliferation via activation of Ca2+/calpain and resulting activation of protein tyrosine phosphatase 1B (PTP1B). In a murine model of multiple intestinal neoplasia (ApcMin/+ mice), TRPV1 deficiency increased adenoma formation, and treatment of these animals with an EGFR kinase inhibitor reversed protumorigenic phenotypes, supporting a functional association between TRPV1 and EGFR signaling in IECs. Administration of a TRPV1 agonist suppressed intestinal tumorigenesis in ApcMin/+ mice, similar to — as well as in conjunction with — a cyclooxygenase-2 (COX-2) inhibitor, which suggests that targeting both TRPV1 and COX-2 has potential as a therapeutic approach for tumor prevention. Our findings implicate TRPV1 as a regulator of growth factor signaling in the intestinal epithelium through activation of PTP1B and subsequent suppression of intestinal tumorigenesis. PMID:25083990

  8. Sustained High Protein-tyrosine Phosphatase 1B Activity in the Sperm of Obese Males Impairs the Sperm Acrosome Reaction*

    PubMed Central

    Shi, Lei; Zhang, Qipeng; Xu, Binqiang; Jiang, Xiaohong; Dai, Yutian; Zhang, Chen-Yu; Zen, Ke

    2014-01-01

    Evidence of a causal link between male obesity and subfertility or infertility has been demonstrated previously. However, the mechanism underlying this link is incompletely understood. Here, we report that sustained high protein-tyrosine phosphatase 1B (PTP1B) activity in sperm of obese donors plays an essential role in coupling male obesity and subfertility or infertility. First, PTP1B level and activity were significantly higher in sperm from ob/ob mice than in wild-type littermates. High PTP1B level and activity in sperm was also observed in obese patients compared with non-obese donors. The enhanced sperm PTP1B level and activity in ob/ob mice and obese patients correlated with a defect of the sperm acrosome reaction (AR). Second, treating sperm from male ob/ob mice or obese men with a specific PTP1B inhibitor largely restored the sperm AR. Finally, blockade of sperm AR by enhanced PTP1B activity in male ob/ob mice or obese men was due to prolonged dephosphorylation of N-ethylmaleimide-sensitive factor by PTP1B, leading to the inability to reassemble the trans-SNARE complexes, which is a critical step in sperm acrosomal exocytosis. In summary, our study demonstrates for the first time that a sustained high PTP1B level or activity in the sperm of obese donors causes a defect of sperm AR and that PTP1B is a novel potential therapeutic target for male infertility treatment. PMID:24519936

  9. Superoxide anion radicals induce IGF-1 resistance through concomitant activation of PTP1B and PTEN.

    PubMed

    Singh, Karmveer; Maity, Pallab; Krug, Linda; Meyer, Patrick; Treiber, Nicolai; Lucas, Tanja; Basu, Abhijit; Kochanek, Stefan; Wlaschek, Meinhard; Geiger, Hartmut; Scharffetter-Kochanek, Karin

    2015-01-01

    The evolutionarily conserved IGF-1 signalling pathway is associated with longevity, metabolism, tissue homeostasis, and cancer progression. Its regulation relies on the delicate balance between activating kinases and suppressing phosphatases and is still not very well understood. We report here that IGF-1 signalling in vitro and in a murine ageing model in vivo is suppressed in response to accumulation of superoxide anions (O2∙-) in mitochondria, either by chemical inhibition of complex I or by genetic silencing of O2∙--dismutating mitochondrial Sod2. The O2∙--dependent suppression of IGF-1 signalling resulted in decreased proliferation of murine dermal fibroblasts, affected translation initiation factors and suppressed the expression of α1(I), α1(III), and α2(I) collagen, the hallmarks of skin ageing. Enhanced O2∙- led to activation of the phosphatases PTP1B and PTEN, which via dephosphorylation of the IGF-1 receptor and phosphatidylinositol 3,4,5-triphosphate dampened IGF-1 signalling. Genetic and pharmacologic inhibition of PTP1B and PTEN abrogated O2∙--induced IGF-1 resistance and rescued the ageing skin phenotype. We thus identify previously unreported signature events with O2∙-, PTP1B, and PTEN as promising targets for drug development to prevent IGF-1 resistance-related pathologies.

  10. Activity-dependent inhibitory synapse remodeling through gephyrin phosphorylation.

    PubMed

    Flores, Carmen E; Nikonenko, Irina; Mendez, Pablo; Fritschy, Jean-Marc; Tyagarajan, Shiva K; Muller, Dominique

    2015-01-06

    Maintaining a proper balance between excitation and inhibition is essential for the functioning of neuronal networks. However, little is known about the mechanisms through which excitatory activity can affect inhibitory synapse plasticity. Here we used tagged gephyrin, one of the main scaffolding proteins of the postsynaptic density at GABAergic synapses, to monitor the activity-dependent adaptation of perisomatic inhibitory synapses over prolonged periods of time in hippocampal slice cultures. We find that learning-related activity patterns known to induce N-methyl-D-aspartate (NMDA) receptor-dependent long-term potentiation and transient optogenetic activation of single neurons induce within hours a robust increase in the formation and size of gephyrin-tagged clusters at inhibitory synapses identified by correlated confocal electron microscopy. This inhibitory morphological plasticity was associated with an increase in spontaneous inhibitory activity but did not require activation of GABAA receptors. Importantly, this activity-dependent inhibitory plasticity was prevented by pharmacological blockade of Ca(2+)/calmodulin-dependent protein kinase II (CaMKII), it was associated with an increased phosphorylation of gephyrin on a site targeted by CaMKII, and could be prevented or mimicked by gephyrin phospho-mutants for this site. These results reveal a homeostatic mechanism through which activity regulates the dynamics and function of perisomatic inhibitory synapses, and they identify a CaMKII-dependent phosphorylation site on gephyrin as critically important for this process.

  11. HbS Binding to GP1bα Activates Platelets in Sickle Cell Disease

    PubMed Central

    Gupta, Avinash; Chawla, Sheetal; Batra, Harish; Seth, Tulika

    2016-01-01

    Intravascular hemolysis increases the risk of thrombosis in hemolytic disorders. Our previous study showed that the binding of adult hemoglobin (HbA) to glycoprotein (GP) 1bα induced the activation of platelets. The elevated plasma Hb or platelet surface bound Hb positively correlated with platelet activation in patients with paroxysmal nocturnal hemoglobinuria (PNH). Furthermore, this study shows that the sickle Hb [HbS, occurs due to single nucleotide polymorphism at A>T of β-globin gene of Hb and causes sickle cell disease (SCD)] also bound to GP1bα and activated platelets in a concentration-dependent manner. The HbS bound to glycocalicin (extramembranous part of GP1bα) with KD ~ 10.46 ± 3 μM. HbS induced phosphorylation of signaling adapter proteins, such as Lyn, PI3K, Akt and ERK in platelets, and also increased the surface expression of platelet activation markers such as P-selectin (10.7 fold) and PAC1 binding (10.4 fold) in platelet surface in a concentration-dependent manner. HbS also increased the platelet microparticle-generation (4.7 fold) and thrombus-formation (4.3 fold) in a concentration-dependent manner. An elevated level of extracellular Hb in plasma correlated directly with platelet activation markers such as P-selectin (r = 0.7947), PAC1 binding (r = 0.5914) on platelet surface and plasma levels of platelet-derived microparticles (r = 0.7834) in patients with SCD. Our study therefore suggests that the HbS-induced platelet activation may play a crucial role in intravascular clot formation observed in SCD patients characterized by high propensity to vascular occlusion and hypercoagulable states. PMID:27936141

  12. 77 FR 53912 - Agency Information Collection Activities; Submission for OMB Review; Comment Request; H-1B...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-04

    ...; H-1B Technical Skills Training Grants and H-1B Jobs and Innovation Accelerator Challenge Grants... Administration (ETA) sponsored information collection request (ICR) proposal titled, ``H-1B Technical Skills Training Grants and H-1B Jobs and Innovation Accelerator Challenge Grants,'' to the Office of...

  13. The CLK family kinases, CLK1 and CLK2, phosphorylate and activate the tyrosine phosphatase, PTP-1B.

    PubMed

    Moeslein, F M; Myers, M P; Landreth, G E

    1999-09-17

    The protein-tyrosine phosphatase PTP-1B is an important regulator of intracellular protein tyrosine phosphorylation, and is itself regulated by phosphorylation. We report that PTP-1B and its yeast analog, YPTP, are phosphorylated and activated by members of the CLK family of dual specificity kinases. CLK1 and CLK2 phosphorylation of PTP-1B in vitro activated the phosphatase activity approximately 3-5-fold using either p-nitrophenol phosphate, or tyrosine-phosphorylated myelin basic protein as substrates. Co-expression of CLK1 or CLK2 with PTP-1B in HEK 293 cells led to a 2-fold stimulation of phosphatase activity in vivo. Phosphorylation of PTP-1B at Ser(50) by CLK1 or CLK2 is responsible for its enzymatic activation. These findings suggest that phosphorylation at Ser(50) by serine threonine kinases may regulate the activation of PTP-1B in vivo. We also show that CLK1 and CLK2 phosphorylate and activate the S. cerevisiae PTP-1B family member, YPTP1. CLK1 phosphorylation of YPTP1 led to a 3-fold stimulation of phosphatase activity in vitro. We demonstrate that CLK phosphorylation of Ser(83) on YPTP1 is responsible for the activation of this enzyme. These findings demonstrate that the CLK kinases activate PTP-1B family members, and this phosphatase may be an important cellular target for CLK action.

  14. Imidazo[2,1-b]thiazole system: a scaffold endowing dihydropyridines with selective cardiodepressant activity.

    PubMed

    Budriesi, Roberta; Ioan, Pierfranco; Locatelli, Alessandra; Cosconati, Sandro; Leoni, Alberto; Ugenti, Maria P; Andreani, Aldo; Di Toro, Rosanna; Bedini, Andrea; Spampinato, Santi; Marinelli, Luciana; Novellino, Ettore; Chiarini, Alberto

    2008-03-27

    The synthesis, characterization, and functional in vitro assays in cardiac tissues and smooth muscle (vascular and nonvascular) of a number of 4-imidazo[2,1- b]thiazole-1,4-dihydropyridines are reported. The binding properties for the novel compounds have been investigated and the interaction with the binding site common to other aryl-dihydropyridines has been demonstrated. Interestingly, the novel 4-aryl-dihydropyridines are L-type calcium channel blockers with a peculiar pharmacological behavior. Indeed, the imidazo[2,1- b]thiazole system is found to confer to the dihydropyridine scaffold an inotropic and/or chronotropic cardiovascular activity with a high selectivity toward the nonvascular tissue. Finally, molecular modeling studies were undertaken for the most representative compounds with the aim of describing the binding properties of the new ligands at molecular level and to rationalize the found structure-activity relationship data. Due to the observed pharmacological behavior of our compounds, they might be promising agents for the treatment of specific cardiovascular pathologies such as cardiac hypertrophy and ischemia.

  15. Serotonin suppresses β-casein expression via PTP1B activation in human mammary epithelial cells.

    PubMed

    Chiba, Takeshi; Maeda, Tomoji; Sanbe, Atsushi; Kudo, Kenzo

    2016-04-22

    Serotonin (5-hydroxytriptamine, 5-HT) has an important role in milk volume homeostasis within the mammary gland during lactation. We have previously shown that the expression of β-casein, a differentiation marker in mammary epithelial cells, is suppressed via 5-HT-mediated inhibition of signal transduction and activator of transcription 5 (STAT5) phosphorylation in the human mammary epithelial MCF-12A cell line. In addition, the reduction of β-casein in turn was associated with 5-HT7 receptor expression in the cells. The objective of this study was to determine the mechanisms underlying the 5-HT-mediated suppression of β-casein and STAT5 phosphorylation. The β-casein level and phosphorylated STAT5 (pSTAT5)/STAT5 ratio in the cells co-treated with 5-HT and a protein kinase A (PKA) inhibitor (KT5720) were significantly higher than those of cells treated with 5-HT alone. Exposure to 100 μM db-cAMP for 6 h significantly decreased the protein levels of β-casein and pSTAT5 and the pSTAT5/STAT5 ratio, and significantly increased PTP1B protein levels. In the cells co-treated with 5-HT and an extracellular signal-regulated kinase1/2 (ERK) inhibitor (FR180294) or Akt inhibitor (124005), the β-casein level and pSTAT5/STAT5 ratio were equal to those of cells treated with 5-HT alone. Treatment with 5-HT significantly induced PTP1B protein levels, whereas its increase was inhibited by KT5720. In addition, the PTP1B inhibitor sc-222227 increased the expression levels of β-casein and the pSTAT5/STAT5 ratio. Our observations indicate that PTP1B directly regulates STAT5 phosphorylation and that its activation via the cAMP/PKA pathway downstream of the 5-HT7 receptor is involved in the suppression of β-casein expression in MCF-12A cells.

  16. Global optogenetic activation of inhibitory interneurons during epileptiform activity.

    PubMed

    Ledri, Marco; Madsen, Marita Grønning; Nikitidou, Litsa; Kirik, Deniz; Kokaia, Merab

    2014-02-26

    Optogenetic techniques provide powerful tools for bidirectional control of neuronal activity and investigating alterations occurring in excitability disorders, such as epilepsy. In particular, the possibility to specifically activate by light-determined interneuron populations expressing channelrhodopsin-2 provides an unprecedented opportunity of exploring their contribution to physiological and pathological network activity. There are several subclasses of interneurons in cortical areas with different functional connectivity to the principal neurons (e.g., targeting their perisomatic or dendritic compartments). Therefore, one could optogenetically activate specific or a mixed population of interneurons and dissect their selective or concerted inhibitory action on principal cells. We chose to explore a conceptually novel strategy involving simultaneous activation of mixed populations of interneurons by optogenetics and study their impact on ongoing epileptiform activity in mouse acute hippocampal slices. Here we demonstrate that such approach results in a brief initial action potential discharge in CA3 pyramidal neurons, followed by prolonged suppression of ongoing epileptiform activity during light exposure. Such sequence of events was caused by massive light-induced release of GABA from ChR2-expressing interneurons. The inhibition of epileptiform activity was less pronounced if only parvalbumin- or somatostatin-expressing interneurons were activated by light. Our data suggest that global optogenetic activation of mixed interneuron populations is a more effective approach for development of novel therapeutic strategies for epilepsy, but the initial action potential generation in principal neurons needs to be taken in consideration.

  17. Carnosol, a Constituent of Zyflamend, Inhibits Aryl Hydrocarbon Receptor-Mediated Activation of CYP1A1 and CYP1B1 Transcription and Mutagenesis

    PubMed Central

    Mohebati, Arash; Guttenplan, Joseph B.; Kochhar, Amit; Zhao, Zhong-Lin; Kosinska, Wieslawa; Subbaramaiah, Kotha; Dannenberg, Andrew J.

    2012-01-01

    The aryl hydrocarbon receptor (AhR), a ligand-activated member of the basic-helix-loop-helix family of transcription factors, plays a significant role in polycyclic aromatic hydrocarbon (PAH) induced carcinogenesis. In the upper aerodigestive tract of humans, tobacco smoke, a source of PAHs, activates the AhR leading to increased expression of CYP1A1 and CYP1B1, which encode proteins that convert PAHs to genotoxic metabolites. Inhibitors of Hsp90 ATPase cause a rapid decrease in levels of AhR, an Hsp90 client protein, and thereby block PAH-mediated induction of CYP1A1 and CYP1B1. The main objective of this study was to determine whether Zyflamend, a polyherbal preparation, suppressed PAH-mediated induction of CYP1A1 and CYP1B1 and inhibited DNA adduct formation and mutagenesis. We also investigated whether carnosol, one of multiple phenolic antioxidants in Zyflamend, had similar inhibitory effects. Treatment of cell lines derived from oral leukoplakia (MSK-Leuk1) and skin (HaCaT) with benzo[a]pyrene (B[a]P), a prototypic PAH, induced CYP1A1 and CYP1B1 transcription, resulting in enhanced levels of message and protein. Both Zyflamend and carnosol suppressed these effects of B[a]P. Notably, both Zyflamend and carnosol inhibited Hsp90 ATPase activity and caused a rapid reduction in AhR levels. The formation of B[a]P induced DNA adducts and mutagenesis were also inhibited by Zyflamend and carnosol. Collectively, these results show that Zyflamend and carnosol inhibit Hsp90 ATPase leading to reduced levels of AhR, suppression of B[a]P-mediated induction of CYP1A1 and CYP1B1 and inhibition of mutagenesis. Carnosol-mediated inhibition of Hsp90 ATPase activity can help explain the chemopreventive activity of herbs such as Rosemary, which contain this phenolic antioxidant. PMID:22374940

  18. Leptin induces CYP1B1 expression in MCF-7 cells through ligand-independent activation of the ERα pathway

    SciTech Connect

    Khanal, Tilak; Kim, Hyung Gyun; Do, Minh Truong; Choi, Jae Ho; Won, Seong Su; Kang, Wonku; Chung, Young Chul; Jeong, Tae Cheon; Jeong, Hye Gwang

    2014-05-15

    Leptin, a hormone with multiple biological actions, is produced predominantly by adipose tissue. Among its functions, leptin can stimulate tumour cell growth. Oestrogen receptor α (ERα), which plays an essential role in breast cancer development, can be transcriptionally activated in a ligand-independent manner. In this study, we investigated the effect of leptin on CYP1B1 expression and its mechanism in breast cancer cells. Leptin induced CYP1B1 protein, messenger RNA expression and promoter activity in ERα-positive MCF-7 cells but not in ERα-negative MDA-MB-231 cells. Additionally, leptin increased 4-hydroxyoestradiol in MCF-7 cells. Also, ERα knockdown by siRNA significantly blocked the induction of CYP1B1 expression by leptin, indicating that leptin induced CYP1B1 expression via an ERα-dependent mechanism. Transient transfection with CYP1B1 deletion promoter constructs revealed that the oestrogen response element (ERE) plays important role in the up-regulation of CYP1B1 by leptin. Furthermore, leptin stimulated phosphorylation of ERα at serine residues 118 and 167 and increased ERE-luciferase activity, indicating that leptin induced CYP1B1 expression by ERα activation. Finally, we found that leptin activated ERK and Akt signalling pathways, which are upstream kinases related to ERα phosphorylation induced by leptin. Taken together, our results indicate that leptin-induced CYP1B1 expression is mediated by ligand-independent activation of the ERα pathway as a result of the activation of ERK and Akt in MCF-7 cells. - Highlights: • Leptin increased 4-hydroxyoestradiol in MCF-7 breast cancer cells. • Leptin activated ERK and Akt kinases related to ERα phosphorylation. • Leptin induces phosphorylation of ERα at serine residues 118 and 167. • Leptin induces ERE-luciferase activity.

  19. Parallel language activation and inhibitory control in bimodal bilinguals

    PubMed Central

    Giezen, Marcel R.; Blumenfeld, Henrike K.; Shook, Anthony; Marian, Viorica; Emmorey, Karen

    2015-01-01

    Findings from recent studies suggest that spoken-language bilinguals engage nonlinguistic inhibitory control mechanisms to resolve cross-linguistic competition during auditory word recognition. Bilingual advantages in inhibitory control might stem from the need to resolve perceptual competition between similar-sounding words both within and between their two languages. If so, these advantages should be lessened or eliminated when there is no perceptual competition between two languages. The present study investigated the extent of inhibitory control recruitment during bilingual language comprehension by examining associations between language co-activation and nonlinguistic inhibitory control abilities in bimodal bilinguals, whose two languages do not perceptually compete. Cross-linguistic distractor activation was identified in the visual world paradigm, and correlated significantly with performance on a nonlinguistic spatial Stroop task within a group of 27 hearing ASL-English bilinguals. Smaller Stroop effects (indexing more efficient inhibition) were associated with reduced co-activation of ASL signs during the early stages of auditory word recognition. These results suggest that the role of inhibitory control in auditory word recognition is not limited to resolving perceptual linguistic competition in phonological input, but is also used to moderate competition that originates at the lexico-semantic level. PMID:25912892

  20. Flavones Inhibit the Activity of AKR1B10, a Promising Therapeutic Target for Cancer Treatment.

    PubMed

    Zemanova, Lucie; Hofman, Jakub; Novotna, Eva; Musilek, Kamil; Lundova, Tereza; Havrankova, Jana; Hostalkova, Anna; Chlebek, Jakub; Cahlikova, Lucie; Wsol, Vladimír

    2015-11-25

    AKR1B10 is an NADPH-dependent reductase that plays an important function in several physiological reactions such as the conversion of retinal to retinol, reduction of isoprenyl aldehydes, and biotransformation of procarcinogens and drugs. A growing body of evidence points to the important role of the enzyme in the development of several types of cancer (e.g., breast, hepatocellular), in which it is highly overexpressed. AKR1B10 is regarded as a therapeutic target for the treatment of these diseases, and potent and specific inhibitors may be promising therapeutic agents. Several inhibitors of AKR1B10 have been described, but the area of natural plant products has been investigated sparingly. In the present study almost 40 diverse phenolic compounds and alkaloids were examined for their ability to inhibit the recombinant AKR1B10 enzyme. The most potent inhibitors-apigenin, luteolin, and 7-hydroxyflavone-were further characterized in terms of IC50, selectivity, and mode of action. Molecular docking studies were also conducted, which identified putative binding residues important for the interaction. In addition, cellular studies demonstrated a significant inhibition of the AKR1B10-mediated reduction of daunorubicin in intact cells by these inhibitors without a considerable cytotoxic effect. Although these compounds are moderately potent and selective inhibitors of AKR1B10, they constitute a new structural type of AKR1B10 inhibitor and may serve as a template for the development of better inhibitors.

  1. Competitive inhibition of carcinogen-activating CYP1A1 and CYP1B1 enzymes by a standardized complex mixture of PAH extracted from coal tar

    SciTech Connect

    Mahadevan, B.; Marston, C.P.; Luch, A.; Dashwood, W.M.; Brooks, E.; Pereira, C.; Doehmer, J.; Baird, W.M.

    2007-03-15

    A complex mixture of polycyclic aromatic hydrocarbons (PAH) extracted from coal tar, the Standard Reference Material (SRM) 1597, was recently shown to decrease the levels of DNA binding of the 2 strong carcinogens benzo(a)pyrene (BP) and dibenzo(a,l)pyrene (DBP) in the human mammary carcinoma-derived cell line MCF-7. The present study was designed to further elucidate the biochemical mechanisms involved in this inhibition process. We examined the effects of SRM 1597 on the metabolic activation of BP and DBP toward DNA-binding derivatives in Chinese hamster cells expressing either human cytochrome P450 (CYP) 1A1 or CYP1B1. The data obtained from biochemical experiments revealed that SRM 1597 competitively inhibited the activity of both human enzymes as analyzed by 7-ethoxyresorufin O-deethylation assays. While the Michaelis-Menten constant (K-M) was {lt} 0.4 {mu}M in the absence of SRM 1597, this value increased up to 1.12 (CYP1A1) or 4.45 {mu}M (CYP1B1) in the presence of 0.1 {mu} g/ml SRM 1597. Hence the inhibitory effects of the complex mixture on human CYP1B1 were much stronger when compared to human CYP1A1 Taken together, the decreases in PAH-DNA adduct formation on co-treatment with SRM 1597 revealed inhibitory effects on the CYP enzymes that convert carcinogenic PAH into DNA-binding metabolites. The implications for the tumorigenicity of complex environmental PAR mixtures are discussed.

  2. High agonist-independent activity is a distinguishing feature of the dopamine D1B receptor subtype.

    PubMed

    Tiberi, M; Caron, M G

    1994-11-11

    Dopamine D1A and D1B receptor subtypes belong to the superfamily of G protein-coupled receptors. Both receptors are coupled to the activation of adenylyl cyclase and exhibit distinct brain distribution. To identify functional differences, binding and stimulation of adenylyl cyclase were assessed in 293 cells expressing transiently either dopamine D1A or D1B receptors. Membranes expressing D1B receptors displayed higher affinities for agonists than those expressing D1A receptors, whereas antagonist affinities were lower at the D1B than at the D1A receptor. Basal activity of adenylyl cyclase in whole 293 cells expressing various levels of D1B receptors was significantly higher than the basal activity measured in cells expressing D1A receptors. Maximal activation of adenylyl cyclase resulting from stimulation of the D1B receptor was less than that obtained following agonist activation of the D1A receptor. In cells expressing D1B receptors, agonists displayed an increased potency for stimulating adenylyl cyclase in comparison with the potencies determined for the D1A receptor. On the other hand, certain antagonists displayed "negative efficacy" at both receptor subtypes but had a more profound inhibition on the agonist-independent signaling activity of the D1B receptor. The properties described here are reminiscent of those of constitutively active G protein-coupled receptors obtained by site-directed mutations. Thus, the D1B receptor may represent a naturally occurring receptor subtype with properties akin to those of constitutively active G protein-coupled receptors. The different anatomical distribution and biochemical properties of these D1 receptors strengthen the functional distinctions between the two subtypes and could account for the basis of heterogeneity within a given class of neurotransmitter or hormone receptors. In addition, if these properties are recapitulated in cells expressing the D1B receptors, they may underlie important role in the regulation of

  3. alpha-Glucosidase inhibitory activity of Mangifera indica bark.

    PubMed

    Prashanth, D; Amit, A; Samiulla, D S; Asha, M K; Padmaja, R

    2001-08-01

    The ethanolic extracts of Lawsonia inermis leaves, Holarrhena antidysenterica bark, Swertia chirata whole plant and Mangifera indica bark were tested (in-vitro) for alpha-glucosidase inhibitory activity. M. indica extract was found to be the most potent, with an IC(50) value of 314 microg/ml.

  4. Synthesis and inhibitory activity of glycosidase inhibitors, glycosylamino-oxazolines.

    PubMed

    Uchida, C; Ogawa, S

    1996-02-01

    In connection with structural modification of the trehalase inhibitor trehazolin (1), as a new-type of glycohydrolase inhibitor, some glycosylamino-oxazolines were designed and synthesized. Among three oxazolines beta-galacto (3), beta-gluco (5) and alpha-manno-types (6) obtained in stable form, the latter 6 has been shown to possess a moderate inhibitory activity against alpha-mannosidase.

  5. Adsorption between TC-stabilized AuNPs and the phosphate group: application of the PTP1B activity assay.

    PubMed

    Lv, Jun; Wang, Xiaonan; Zhang, Yuanyuan; Li, Defeng; Zhang, Juan; Sun, Lizhou

    2015-12-07

    Based on the adsorption between tetracycline (TC) and phosphate groups, a general colorimetric method is explored in this work by using TC-stabilized gold nanoparticles (TC/AuNPs) and 4-aminophenyl phosphate-functionalized Fe3O4 magnetic nanoparticles (APP/MNPs). Taking protein tyrosine phosphatase 1B (PTP1B) as an example, 4-aminophenyl phosphate (APP) can be hydrolyzed into 4-aminophenol (AP) by PTP1B, resulting in the disappearance of the phosphate group on the outer layer of MNPs and the loss of corresponding adsorptive ability. Upon addition of TC/AuNP solution, TC/AuNPs will remain in the supernatant solution after magnetic separation and a high absorbance value can be observed. So PTP1B activity is related to the concentrations of TC/AuNPs in the supernatant solution. In this work, the enzyme activity can be determined at levels as low as 0.0885 U mL(-1) and over a linear detection range as wide as 0.1 U mL(-1) to 0.9 U mL(-1). Moreover, using the proposed method, the inhibition effect of betulinic acid (BA) and sodium orthovanadate (Na3VO4) on PTP1B activity can be tested with IC50 values of 30 μM and 4 μM, respectively. Therefore, a universal platform for the accurate colorimetric analysis of kinase and phosphatase activities can be established through the adsorption between TC and phosphate groups.

  6. One-pot synthesis of new triazole--Imidazo[2,1-b][1,3,4]thiadiazole hybrids via click chemistry and evaluation of their antitubercular activity.

    PubMed

    Ramprasad, Jurupula; Nayak, Nagabhushana; Dalimba, Udayakumar; Yogeeswari, Perumal; Sriram, Dharmarajan

    2015-10-01

    A new series of triazole-imidazo[2,1-b][1,3,4]thiadiazole hybrids (6a-s, 7a) were designed by a molecular hybridisation approach and the target molecules were synthesized via one pot click chemistry protocol. All the intermediates and final molecules were characterised using spectral methods and one of the target compounds (6c) was analysed by the single crystal XRD study. The derivatives were screened for their antimycobacterial activity against Mycobacterium tuberculosis H37Rv strain. Two compounds, 6f and 6n, demonstrated significant growth inhibitory activity against the bacterial strain with a MIC of 3.125 μg/mL. The presence of chloro substituent on the imidazo[2,1-b][1,3,4]thiadiazole ring and ethyl, benzyl or cyanomethylene groups on the 1,2,3-triazole ring enhance the inhibition activity of the molecules. The active compounds are not toxic to a normal cell line which signifies the lack of general cellular toxicity of these compounds.

  7. Phenolic compounds with IL-6 inhibitory activity from Aster yomena.

    PubMed

    Kim, A Ryun; Jin, Qinglong; Jin, Hong-Guang; Ko, Hae Ju; Woo, Eun-Rhan

    2014-07-01

    A new biflavonoid, named asteryomenin (1), as well as six known phenolic compounds, esculetin (2), 4-O-β-D-glucopyranoside-3-hydroxy methyl benzoate (3), caffeic acid (4), isoquercitrin (5), isorhamnetin-3-O-glucoside (6), and apigenin (7) were isolated from the aerial parts of Aster yomena. The structures of compounds (1-7) were identified based on 1D and 2D NMR, including (1)H-(1)H COSY, HSQC, HMBC and NOESY spectroscopic analyses. Compounds 2-7 were isolated from this plant for the first time. For these isolates, the inhibitory activity of IL-6 production in the TNF-α stimulated MG-63 cell was examined. Among these isolates, compounds 4 and 7 appeared to have potent inhibitory activity of IL-6 production in the TNF-α stimulated MG-63 cell, while compounds 1-3 and 5-6 showed moderate activity.

  8. Cry1B and Cry3A are active against Hypothenemus hampei Ferrari (Coleoptera: Scolytidae).

    PubMed

    López-Pazos, Silvio Alejandro; Cortázar Gómez, Jorge Eduardo; Cerón Salamanca, Jairo Alonso

    2009-07-01

    Cry1B and Cry3 proteins from Bacillus thuringiensis are toxic to beetles such as the colorado potato beetle and the cottonwood leaf beetle. We report the development of a suitable rearing, bioassay method and the toxicity of these Cry proteins to coffee berry borer first instar larvae.

  9. Urease inhibitory activities of β-boswellic acid derivatives

    PubMed Central

    2013-01-01

    Background and the purpose of the study Boswellia carterii have been used in traditional medicine for many years for management different gastrointestinal disorders. In this study, we wish to report urease inhibitory activity of four isolated compound of boswellic acid derivative. Methods 4 pentacyclic triterpenoid acids were isolated from Boswellia carterii and identified by NMR and Mass spectroscopic analysis (compounds 1, 3-O-acetyl-9,11-dehydro-β-boswellic acid; 2, 3-O-acetyl-11-hydroxy-β-boswellic acid; 3. 3-O- acetyl-11-keto-β-boswellic acid and 4, 11-keto-β-boswellic acid. Their inhibitory activity on Jack bean urease were evaluated. Docking and pharmacophore analysis using AutoDock 4.2 and Ligandscout 3.03 programs were also performed to explain possible mechanism of interaction between isolated compounds and urease enzyme. Results It was found that compound 1 has the strongest inhibitory activity against Jack bean urease (IC50 = 6.27 ± 0.03 μM), compared with thiourea as a standard inhibitor (IC50 = 21.1 ± 0.3 μM). Conclusion The inhibition potency is probably due to the formation of appropriate hydrogen bonds and hydrophobic interactions between the investigated compounds and urease enzyme active site and confirms its traditional usage. PMID:23351363

  10. Plants from Brazilian Cerrado with Potent Tyrosinase Inhibitory Activity

    PubMed Central

    Souza, Paula Monteiro; Elias, Silvia Taveira; Simeoni, Luiz Alberto; de Paula, José Elias; Gomes, Sueli Maria; Guerra, Eliete Neves Silva; Fonseca, Yris Maria; Silva, Elton Clementino; Silveira, Dâmaris; Magalhães, Pérola Oliveira

    2012-01-01

    The increased amount of melanin leads to skin disorders such as age spots, freckles, melasma and malignant melanoma. Tyrosinase is known to be the key enzyme in melanin production. Plants and their extracts are inexpensive and rich resources of active compounds that can be utilized to inhibit tyrosinase as well as can be used for the treatment of dermatological disorders associated with melanin hyperpigmentation. Using in vitro tyrosinase inhibitory activity assay, extracts from 13 plant species from Brazilian Cerrado were evaluated. The results showed that Pouteria torta and Eugenia dysenterica extracts presented potent in vitro tyrosinase inhibition compared to positive control kojic acid. Ethanol extract of Eugenia dysenterica leaves showed significant (p<0.05) tyrosinase inhibitory activity exhibiting the IC50 value of 11.88 µg/mL, compared to kojic acid (IC50 value of 13.14 µg/mL). Pouteria torta aqueous extract leaves also showed significant inhibitory activity with IC50 value of 30.01 µg/mL. These results indicate that Pouteria torta and Eugenia dysenterica extracts and their isolated constituents are promising agents for skin-whitening or antimelanogenesis formulations. PMID:23173036

  11. Tyrosinase inhibitory components from Aloe vera and their antiviral activity.

    PubMed

    Kim, Jang Hoon; Yoon, Ju-Yeon; Yang, Seo Young; Choi, Seung-Kook; Kwon, Sun Jung; Cho, In Sook; Jeong, Min Hee; Ho Kim, Young; Choi, Gug Seoun

    2017-12-01

    A new compound, 9-dihydroxyl-2'-O-(Z)-cinnamoyl-7-methoxy-aloesin (1), and eight known compounds (2-9) were isolated from Aloe vera. Their structures were elucidated using 1D/2D nuclear magnetic resonance and mass spectra. Compound 9 exhibited reversible competitive inhibitory activity against the enzyme tyrosinase, with an IC50 value of 9.8 ± 0.9 µM. A molecular simulation revealed that compound 9 interacts via hydrogen bonding with residues His244, Thr261, and Val283 of tyrosinase. Additionally, compounds 3 and 7 were shown by half-leaf assays to exhibit inhibitory activity towards Pepper mild mottle virus.

  12. Expression and Biological Activity of the Cystine Knot Bioinsecticide PA1b (Pea Albumin 1 Subunit b)

    PubMed Central

    Eyraud, Vanessa; Karaki, Lamis; Rahioui, Isabelle; Sivignon, Catherine; Da Silva, Pedro; Rahbé, Yvan; Royer, Corinne; Gressent, Frédéric

    2013-01-01

    The PA1b (Pea Albumin 1, subunit b) peptide is an entomotoxin extract from Legume seeds with lethal activity on several insect pests, such as mosquitoes, some aphids and cereal weevils. This 37 amino-acid cysteine-rich peptide has been, until now, obtained by biochemical purification or chemical synthesis. In this paper, we present our results for the transient production of the peptide in Nicotiana benthamiana by agro-infiltration, with a yield of about 35 µg/g of fresh leaves and maximum production 8 days after infiltration. PA1b is part of the PA1 gene which, after post-translational modifications, encodes two peptides (PA1b and PA1a). We show that transforming tobacco with the PA1b cDNA alone does not result in production of the toxin and, in fact, the entire cDNA is necessary, raising the question of the role of PA1a. We constructed a PA1-cassette, allowing for the quick “cut/paste” of different PA1b mutants within a conserved PA1 cDNA. This cassette enabled us to produce the six isoforms of PA1b which exist in pea seeds. Biological tests revealed that all the isoforms display similar activity, with the exception of one which is inactive. The lack of activity in this isoform led us to conclude that the amphiphilic nature of the peptide is necessary for activity. The possible applications of this expression system for other cysteine-rich biomolecules are discussed. PMID:24349099

  13. Expression and biological activity of the cystine knot bioinsecticide PA1b (Pea Albumin 1 Subunit b).

    PubMed

    Eyraud, Vanessa; Karaki, Lamis; Rahioui, Isabelle; Sivignon, Catherine; Da Silva, Pedro; Rahbé, Yvan; Royer, Corinne; Gressent, Frédéric

    2013-01-01

    The PA1b (Pea Albumin 1, subunit b) peptide is an entomotoxin extract from Legume seeds with lethal activity on several insect pests, such as mosquitoes, some aphids and cereal weevils. This 37 amino-acid cysteine-rich peptide has been, until now, obtained by biochemical purification or chemical synthesis. In this paper, we present our results for the transient production of the peptide in Nicotiana benthamiana by agro-infiltration, with a yield of about 35 µg/g of fresh leaves and maximum production 8 days after infiltration. PA1b is part of the PA1 gene which, after post-translational modifications, encodes two peptides (PA1b and PA1a). We show that transforming tobacco with the PA1b cDNA alone does not result in production of the toxin and, in fact, the entire cDNA is necessary, raising the question of the role of PA1a. We constructed a PA1-cassette, allowing for the quick "cut/paste" of different PA1b mutants within a conserved PA1 cDNA. This cassette enabled us to produce the six isoforms of PA1b which exist in pea seeds. Biological tests revealed that all the isoforms display similar activity, with the exception of one which is inactive. The lack of activity in this isoform led us to conclude that the amphiphilic nature of the peptide is necessary for activity. The possible applications of this expression system for other cysteine-rich biomolecules are discussed.

  14. Receptor specificity and trigemino-vascular inhibitory actions of a novel 5-HT1B/1D receptor partial agonist, 311C90 (zolmitriptan)

    PubMed Central

    Martin, G R; Robertson, A D; MacLennan, S J; Prentice, D J; Barrett, V J; Buckingham, J; Honey, A C; Giles, H; Moncada, S

    1997-01-01

    311C90 (zolmitriptan zomig: (S)-4[[3-[2-(dimethylamino)ethyl]-1H-indol-5-yl]methyl]-2-oxazolidinone) is a novel 5-HT1B/1D receptor agonist with proven efficacy in the acute treatment of migraine. Here, we describe the receptor specificity of the drug and its actions on trigeminal-evoked plasma protein extravasation into the dura mater of the anaesthetized guinea-pig. At the ‘5-HT1B-like' receptor mediating vascular contraction (rabbit saphenous vein), the compound was a potent (p[A50]=6.79±0.06) partial agonist achieving 77±4% of the maximum effect to 5-hydroxytryptamine (5-HT). In the same experiments, sumatriptan (p[A50]=6.48±0.04) was half as potent as 311C90 and produced 97±2% of the 5-HT maximum effect. Studies in which receptor inactivation methods were used to estimate the affinity (pKA) and efficacy relative to 5-HT (τrel.) for each agonist confirmed that 311C90 exhibits higher affinity than sumatriptan (pKA=6.63±0.04 and 6.16±0.03, respectively) and that both drugs are partial agonists relative to 5-HT (τrel=0.61±0.03 and 0.63±0.10, respectively, compared to 5-HT=1.0). Consistent with its effects in rabbit saphenous vein, 311C90 also produced concentration-dependent contractions of primate basilar artery and human epicardial coronary artery rings. In basilar artery, agonist potency (p[A50]=6.92±0.07) was similar to that demonstrated in rabbit saphenous vein, again being 2–3 fold higher than for sumatriptan (p[A50]=6.46±0.03). Both agonists produced about 50% of the maximum response obtained with 5-HT in the same preparations. In rings of human coronary artery, the absolute potency of 311C90 and sumatriptan was higher than in primate basilar artery (p[A50]=7.3±0.1 and 6.7±0.1, respectively), but maximum effects relative to 5-HT were lower (37±8% and 35±7%, respectively). In both types of vessel, the inability of 5-HT1B/1D agonists to achieve the same maximum as the endogenous agonist 5-HT is explained by the additional presence of 5-HT2A

  15. HNF1B variants associate with promoter methylation and regulate gene networks activated in prostate and ovarian cancer

    PubMed Central

    Ross-Adams, Helen; Ball, Stephen; Lawrenson, Kate; Halim, Silvia; Russell, Roslin; Wells, Claire; Strand, Siri H.; Ørntoft, Torben F.; Larson, Melissa; Armasu, Sebastian; Massie, Charles E.; Asim, Mohammad; Mortensen, Martin M.; Borre, Michael; Woodfine, Kathryn; Warren, Anne Y.; Lamb, Alastair D.; Kay, Jonathan; Whitaker, Hayley; Ramos-Montoya, Antonio; Murrell, Adele; Sørensen, Karina D.; Fridley, Brooke L.; Goode, Ellen L.; Gayther, Simon A.; Masters, John

    2016-01-01

    Two independent regions within HNF1B are consistently identified in prostate and ovarian cancer genome-wide association studies (GWAS); their functional roles are unclear. We link prostate cancer (PC) risk SNPs rs11649743 and rs3760511 with elevated HNF1B gene expression and allele-specific epigenetic silencing, and outline a mechanism by which common risk variants could effect functional changes that increase disease risk: functional assays suggest that HNF1B is a pro-differentiation factor that suppresses epithelial-to-mesenchymal transition (EMT) in unmethylated, healthy tissues. This tumor-suppressor activity is lost when HNF1B is silenced by promoter methylation in the progression to PC. Epigenetic inactivation of HNF1B in ovarian cancer also associates with known risk SNPs, with a similar impact on EMT. This represents one of the first comprehensive studies into the pleiotropic role of a GWAS-associated transcription factor across distinct cancer types, and is the first to describe a conserved role for a multi-cancer genetic risk factor. PMID:27732966

  16. Histamine release inhibitory activity of Piper nigrum leaf.

    PubMed

    Hirata, Noriko; Naruto, Shunsuke; Inaba, Kazunori; Itoh, Kimihisa; Tokunaga, Masashi; Iinuma, Munekazu; Matsuda, Hideaki

    2008-10-01

    Oral administration of a methanolic extract of Piper nigrum leaf (PN-ext, 50, 200 and 500 mg/kg) showed a potent dose-dependent inhibition of dinitrofluorobenzene (DNFB)-induced cutaneous reaction at 1 h [immediate phase response (IPR)] after and 24 h [late phase response (LPR)] after DNFB challenge in mice which were passively sensitized with anti-dinitrophenyl (DNP) IgE antibody. Ear swelling inhibitory effect of PN-ext (50, 200 and 500 mg/kg, per os (p.o.)) on very late phase response (vLPR) in the model mice was significant but weaker than that on IPR. Oral administration of PN-ext (50, 200 and 500 mg/kg for 7 d) inhibited picryl chloride (PC)-induced ear swelling in PC sensitized mice. PN-ext exhibited in vitro inhibitory effect on compound 48/80-induced histamine release from rat peritoneal mast cells. Two lignans of PN-ext, (-)-cubebin (1) and (-)-3,4-dimethoxy-3,4-desmethylenedioxycubebin (2), were identified as major active principles having histamine release inhibitory activity.

  17. Synthesis and protein tyrosine phosphatase 1B inhibition activities of two new synthetic bromophenols and their methoxy derivatives

    NASA Astrophysics Data System (ADS)

    Cui, Yongchao; Shi, Dayong; Hu, Zhiqiang

    2011-11-01

    3-bromo-4,5-bis(2,3-dibromo-4,5-dihydroxybenzyl)-1,2-benzenediol ( 1) is a natural bromophenol isolated from the red algae Rhodomela confervoides that exhibits significant inhibition against protein tyrosine phosphatase 1B (PTP1B). Based on its activity, we synthesized two new synthetic bromophenols and their methoxy derivatives from vanillin using the structure of natural bromophenol 1 as a scaffold. The structures of these bromophenols were elucidated from 1H NMR, 13C NMR, and high resolution electron ionization mass spectrometry as 2,3-dibromo-1-(2'-bromo-6'-(3″,4″-dimethoxybenzyl)-3',4'-dimethoxybenzyl)-4,5-dimethoxybenzene ( 2), 2,3-dibromo-1-(2'-bromo-6'-(2″-bromo-4″,5″-dimethoxybenzyl)-3',4'-dimethoxybenzyl)-4,5-dimethoxybenzene ( 3), 3,4-dibromo-5-(2'-bromo-6'-(2″-bromo-4″,5″-dihydroxybenzyl)-3',4'-dihydroxybenzyl)pyrocatechol ( 4) and 3,4-dibromo-5-(2'-bromo-6'-(3″,4″-dihydroxybenzyl)-3',4'-dihydroxybenzyl)pyrocatechol ( 5). PTP1B inhibition activities of these compounds were evaluated using a colorimetric assay, and compounds 3 and 4 demonstrated interesting activity against PTP1B.

  18. Polycyclic aromatic hydrocarbon-induced CYP1B1 activity is suppressed by perillyl alcohol in MCF-7 cells

    SciTech Connect

    Chan, Nelson L.S.; Wang Huan; Wang Yun; Leung, H.Y.; Leung, Lai K. . E-mail: laikleung@yahoo.com

    2006-06-01

    Perillyl alcohol (POH) is a dietary monoterpene with potential applications in chemoprevention and chemotherapy. Although clinical trials are under way, POH's physiological and pharmacological properties are still unclear. In the present study, the effect of POH on polycyclic aromatic hydrocarbon (PAH)-induced genotoxicity, and the related expression were examined in MCF-7 cells. Exposure to environmental toxicant increases the risk of cancer. Many of these compounds are pro-carcinogens and are biotransformed into their ultimate genotoxic structures by xenobiotic metabolizing enzymes. CYP1A1 and 1B1 are enzymes that catalyze the biotransformation of dimethylbenz[a]anthracene (DMBA). Our data revealed that 0.5 {mu}M of POH was effective in blocking DMBA-DNA binding. Ethoxyresorufin-O-deethylase (EROD) assay indicated that the administration of POH inhibited the DMBA-induced enzyme activity in MCF-7 cells. Enzyme kinetic analysis revealed that POH inhibited CYP1B1 but not CYP1A1 activity. Quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) assay also demonstrated that the monoterpene reduced CYP1B1 mRNA abundance induced by DMBA. The present study illustrated that POH might inhibit and downregulate CYP1B1, which could protect against PAH-induced carcinogenesis.

  19. Synthesis and 5-lipoxygenase inhibitory activity of new cinnamoyl and caffeoyl clusters.

    PubMed

    Doiron, Jérémie; Boudreau, Luc H; Picot, Nadia; Villebonet, Benoît; Surette, Marc E; Touaibia, Mohamed

    2009-02-15

    Novel cinnamoyl and caffeoyl clusters were synthesized by multiple Cu(I)-catalyzed [1,3]-dipolar cycloadditions and their anti-5-lipoxygenase inhibitory activity was tested. Caffeoyl cluster showed an improved 5-lipoxygenase inhibitory activity compared to caffeic acid, with caffeoyl trimer 16 and tetramer 19 showing the best 5-lipoxygenase inhibitory activity.

  20. Phosphodiesterase 1B differentially modulates the effects of methamphetamine on locomotor activity and spatial learning through DARPP32-dependent pathways: evidence from PDE1B-DARPP32 double-knockout mice.

    PubMed

    Ehrman, L A; Williams, M T; Schaefer, T L; Gudelsky, G A; Reed, T M; Fienberg, A A; Greengard, P; Vorhees, C V

    2006-10-01

    Mice lacking phosphodiesterase 1B (PDE1B) exhibit an exaggerated locomotor response to D-methamphetamine and increased in vitro phosphorylation of DARPP32 (dopamine- and cAMP-regulated phosphoprotein, M r 32 kDa) at Thr34 in striatal brain slices treated with the D1 receptor agonist, SKF81297. These results indicated a possible regulatory role for PDE1B in pathways involving DARPP32. Here, we generated PDE1B x DARPP32 double-knockout (double-KO) mice to test the role of PDE1B in DARPP32-dependent pathways in vivo. Analysis of the response to d-methamphetamine on locomotor activity showed that the hyperactivity experienced by PDE1B mutant mice was blocked in PDE1B-/- x DARPP32-/- double-KO mice, consistent with participation of PDE1B and DARPP32 in the same pathway. Further behavioral testing in the elevated zero-maze revealed that DARPP32-/- mice showed a less anxious phenotype that was nullified in double-mutant mice. In contrast, in the Morris water maze, double-KO mice showed deficits in spatial reversal learning not observed in either single mutant compared with wild-type mice. The data suggest a role for PDE1B in locomotor responses to psychostimulants through modulation of DARPP32-dependent pathways; however, this modulation does not necessarily impact other behaviors, such as anxiety or learning. Instead, the phenotype of double-KOs observed in these latter tasks may be mediated through independent pathways.

  1. CYP1B1 Enhances Cell Proliferation and Metastasis through Induction of EMT and Activation of Wnt/β-Catenin Signaling via Sp1 Upregulation

    PubMed Central

    Kwon, Yeo-Jung; Baek, Hyoung-Seok; Ye, Dong-Jin; Shin, Sangyun; Kim, Donghak; Chun, Young-Jin

    2016-01-01

    Cytochrome P450 1B1 (CYP1B1) is a major E2 hydroxylase involved in the metabolism of potential carcinogens. CYP1B1 expression has been reported to be higher in tumors compared to normal tissues, especially in hormone-related cancers including breast, ovary, and prostate tumors. To explore the role of CYP1B1 in cancer progression, we investigated the action of CYP1B1 in cells with increased CYP1B1 via the inducer 7,12-dimethylbenz[α]anthracene (DMBA) or an overexpression vector, in addition to decreased CYP1B1 via the inhibitor tetramethoxystilbene (TMS) or siRNA knockdown. We observed that CYP1B1 promoted cell proliferation, migration, and invasion in MCF-7 and MCF-10A cells. To understand its molecular mechanism, we measured key oncogenic proteins including β-catenin, c-Myc, ZEB2, and matrix metalloproteinases following CYP1B1 modulation. CYP1B1 induced epithelial-mesenchymal transition (EMT) and activated Wnt/β-catenin signaling via upregulation of CTNNB1, ZEB2, SNAI1, and TWIST1. Sp1, a transcription factor involved in cell growth and metastasis, was positively regulated by CYP1B1, and suppression of Sp1 expression by siRNA or DNA binding activity using mithramycin A blocked oncogenic transformation by CYP1B1. Therefore, we suggest that Sp1 acts as a key mediator for CYP1B1 action. Treatment with 4-hydroxyestradiol (4-OHE2), a major metabolite generated by CYP1B1, showed similar effects as CYP1B1 overexpression, indicating that CYP1B1 activity mediated various oncogenic events in cells. In conclusion, our data suggests that CYP1B1 promotes cell proliferation and metastasis by inducing EMT and Wnt/β-catenin signaling via Sp1 induction. PMID:26981862

  2. CYP1B1 Enhances Cell Proliferation and Metastasis through Induction of EMT and Activation of Wnt/β-Catenin Signaling via Sp1 Upregulation.

    PubMed

    Kwon, Yeo-Jung; Baek, Hyoung-Seok; Ye, Dong-Jin; Shin, Sangyun; Kim, Donghak; Chun, Young-Jin

    2016-01-01

    Cytochrome P450 1B1 (CYP1B1) is a major E2 hydroxylase involved in the metabolism of potential carcinogens. CYP1B1 expression has been reported to be higher in tumors compared to normal tissues, especially in hormone-related cancers including breast, ovary, and prostate tumors. To explore the role of CYP1B1 in cancer progression, we investigated the action of CYP1B1 in cells with increased CYP1B1 via the inducer 7,12-dimethylbenz[α]anthracene (DMBA) or an overexpression vector, in addition to decreased CYP1B1 via the inhibitor tetramethoxystilbene (TMS) or siRNA knockdown. We observed that CYP1B1 promoted cell proliferation, migration, and invasion in MCF-7 and MCF-10A cells. To understand its molecular mechanism, we measured key oncogenic proteins including β-catenin, c-Myc, ZEB2, and matrix metalloproteinases following CYP1B1 modulation. CYP1B1 induced epithelial-mesenchymal transition (EMT) and activated Wnt/β-catenin signaling via upregulation of CTNNB1, ZEB2, SNAI1, and TWIST1. Sp1, a transcription factor involved in cell growth and metastasis, was positively regulated by CYP1B1, and suppression of Sp1 expression by siRNA or DNA binding activity using mithramycin A blocked oncogenic transformation by CYP1B1. Therefore, we suggest that Sp1 acts as a key mediator for CYP1B1 action. Treatment with 4-hydroxyestradiol (4-OHE2), a major metabolite generated by CYP1B1, showed similar effects as CYP1B1 overexpression, indicating that CYP1B1 activity mediated various oncogenic events in cells. In conclusion, our data suggests that CYP1B1 promotes cell proliferation and metastasis by inducing EMT and Wnt/β-catenin signaling via Sp1 induction.

  3. Purification and sequencing of the active site tryptic peptide from penicillin-binding protein 1b of Escherichia coli

    SciTech Connect

    Nicholas, R.A.; Suzuki, H.; Hirota, Y.; Strominger, J.L.

    1985-07-02

    This paper reports the sequence of the active site peptide of penicillin-binding protein 1b from Escherichia coli. Purified penicillin-binding protein 1b was labeled with (/sup 14/C)penicillin G, digested with trypsin, and partially purified by gel filtration. Upon further purification by high-pressure liquid chromatography, two radioactive peaks were observed, and the major peak, representing over 75% of the applied radioactivity, was submitted to amino acid analysis and sequencing. The sequence Ser-Ile-Gly-Ser-Leu-Ala-Lys was obtained. The active site nucleophile was identified by digesting the purified peptide with aminopeptidase M and separating the radioactive products on high-pressure liquid chromatography. Amino acid analysis confirmed that the serine residue in the middle of the sequence was covalently bonded to the (/sup 14/C)penicilloyl moiety. A comparison of this sequence to active site sequences of other penicillin-binding proteins and beta-lactamases is presented.

  4. Angiotensin-converting enzyme inhibitory activity in Mexican Fresco cheese.

    PubMed

    Torres-Llanez, M J; González-Córdova, A F; Hernandez-Mendoza, A; Garcia, H S; Vallejo-Cordoba, B

    2011-08-01

    The objective of this study was to evaluate if Mexican Fresco cheese manufactured with specific lactic acid bacteria (LAB) presented angiotensin I-converting enzyme inhibitory (ACEI) activity. Water-soluble extracts (3 kDa) obtained from Mexican Fresco cheese prepared with specific LAB (Lactococcus, Lactobacillus, Enterococcus, and mixtures: Lactococcus-Lactobacillus and Lactococcus-Enterococcus) were evaluated for ACEI activity. Specific peptide fractions with high ACEI were analyzed using reverse phase-HPLC coupled to mass spectrometry for determination of amino acid sequence. Cheese containing Enterococcus faecium or a Lactococcus lactis ssp. lactis-Enterococcus faecium mixture showed the largest number of fractions with ACEI activity and the lowest half-maximal inhibitory concentration (IC(50); <10 μg/mL). Various ACEI peptides derived from β-casein [(f(193-205), f(193-207), and f(193-209)] and α(S1)-casein [f(1-15), f(1-22), f(14-23), and f(24-34)] were found. The Mexican Fresco cheese manufactured with specific LAB strains produced peptides with potential antihypertensive activity.

  5. Fucosterol activates the insulin signaling pathway in insulin resistant HepG2 cells via inhibiting PTP1B.

    PubMed

    Jung, Hyun Ah; Bhakta, Himanshu Kumar; Min, Byung-Sun; Choi, Jae Sue

    2016-10-01

    Insulin resistance is a characteristic feature of type 2 diabetes mellitus (T2DM) and is characterized by defects in insulin signaling. This study investigated the modulatory effects of fucosterol on the insulin signaling pathway in insulin-resistant HepG2 cells by inhibiting protein tyrosine phosphatase 1B (PTP1B). In addition, molecular docking simulation studies were performed to predict binding energies, the specific binding site of fucosterol to PTP1B, and to identify interacting residues using Autodock 4.2 software. Glucose uptake was determined using a fluorescent D-glucose analogue and the glucose tracer 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino]-2-deoxyglucose, and the signaling pathway was detected by Western blot analysis. We found that fucosterol enhanced insulin-provoked glucose uptake and conjointly decreased PTP1B expression level in insulin-resistant HepG2 cells. Moreover, fucosterol significantly reduced insulin-stimulated serine (Ser307) phosphorylation of insulin receptor substrate 1 (IRS1) and increased phosphorylation of Akt, phosphatidylinositol-3-kinase, and extracellular signal- regulated kinase 1 at concentrations of 12.5, 25, and 50 µM in insulin-resistant HepG2 cells. Fucosterol inhibited caspase-3 activation and nuclear factor kappa B in insulin-resistant hepatocytes. These results suggest that fucosterol stimulates glucose uptake and improves insulin resistance by downregulating expression of PTP1B and activating the insulin signaling pathway. Thus, fucosterol has potential for development as an anti-diabetic agent.

  6. Oleanane triterpenes as protein tyrosine phosphatase 1B (PTP1B) inhibitors from Camellia japonica.

    PubMed

    Uddin, Mohammad Nasir; Sharma, Govinda; Yang, Jun-Li; Choi, Hong Seok; Lim, Seong-Il; Kang, Keon Wook; Oh, Won Keun

    2014-07-01

    Protein tyrosine phosphatase 1B (PTP1B) plays a key role in metabolic signaling, thereby making it an exciting drug target for type 2 diabetes and obesity. Besides, there is substantial evidence that shows its overexpression is involved in breast cancer, which suggests that selective PTP1B inhibition might be effective in breast cancer treatment. As part of our continuous research on PTP1B inhibitors from medicinal plants, four oleanane-type triterpenes were isolated from an EtOAc-soluble extract of fruit peels of Camellia japonica (Theaceae), together with 6 previously known compounds of this class. Their structures were determined on the basis of spectroscopic data analysis (UV, IR, (1)H and (13)CNMR, HMBC, HSQC, NOESY, and MS). All isolates were evaluated for their inhibitory effects on PTP1B, as well as their cytotoxic effects against human breast cancer cell lines MCF7, MCF7/ADR, and MDA-MB-231. Several compounds with OH-3 or/and COOH-28 functionalities showed strong PTP1B inhibitory activity (IC50 values ranging from 3.77±0.11 to 6.40±0.81 μM) as well as significant cytotoxicity (IC50 values ranging from 0.51±0.05 to 13.55±1.44 μM).

  7. Absolute stereochemistry of fungal beauveriolide III and ACAT inhibitory activity of four stereoisomers.

    PubMed

    Ohshiro, Taichi; Namatame, Ichiji; Nagai, Kenichiro; Sekiguchi, Takafumi; Doi, Takayuki; Takahashi, Takashi; Akasaka, Kazuaki; Rudel, Lawrence L; Tomoda, Hiroshi; Omura, Satoshi

    2006-09-29

    Fungal beauveriolide III (BeauIII, 1b), a cyclodepsipeptide inhibiting acyl-CoA:cholesterol acyltransferase (ACAT) and showing antiatherogenic activity in mouse models, consists of L-Phe, L-Ala, D-allo-Ile, and 3-hydroxy-4-methyloctanoic acid (HMA) moieties, but the stereochemistry of the HMA part has not until now been fully defined. To determine it, four HMA stereoisomers were synthesized and labeled with (S)-(+)-2-(anthracene-2,3-dicarboximido)-1-propyl trifluoromethane sulfonate (AP-OTf), a chiral fluorescent reagent. The derivatives were separated by HPLC and compared with the natural HMA derivative, which was thereby identified as (3S,4S)HMA in BeauIII. Furthermore, the four beauveriolide III isomers ((3S,4S)BeauIII (23a), (3R,4R)BeauIII (23b), (3R,4S)BeauIII (23c), and (3S,4R)BeauIII (23d)) were synthesized, and it was shown that all the spectral data for 23a were identical with those for natural 1b. Isomers 23a and 23d showed potent inhibitory activity of lipid droplet accumulation in macrophages, while the other two isomers caused weak inhibition. Thus, the 3S configuration of BeauIII is important for this activity. Furthermore, 23a and 23d showed rather specific inhibition against the ACAT1 isozyme.

  8. ACAT inhibitory activity of exudates from Calocedrus macrolepis var. formosana.

    PubMed

    Hsieh, Yu-Hsin; Chen, Kuan-Jung; Chien, Shih-Chang; Cheng, Wen-Ling; Xiao, Jun-Hong; Wang, Sheng-Yang

    2012-12-01

    Cholesterol acyltransferase (ACAT) is an enzyme controlling cholesterol esterification in cells. Large amounts of cholesterol esters accumulate in macrophages and smooth muscle cells of blood vessel walls resulting in the initial stages of atherosclerosis. Thus, atherosclerosis might be inhibited through inhibition of the activity of ACAT. In the present study, we identified by spectral analysis and chromatographic quantification that ferruginol was the most abundant component of exudates secreted from the wounding site of Calocedrus macrolepis Kurz var. formosana. Results obtained from the cholesterol absorption assay revealed that ferruginol exhibited a significant inhibitory activity on cholesterol absorption in mice macrophages (RAW 264.7 cell). Based on the results from analyzing the ratio of cholesterol esterification, ferruginol dose-dependently suppressed cholesterol esterification and the IC50 value was 2.0 microg/mL. In conclusion, ferruginol revealed strong inhibitory activities that retarded the absorption and esterification of cholesterol in cells. Our finding indicates that ferruginol might possess a potential for development as a pharmaceutical product for preventing arteriosclerosis.

  9. Design, Synthesis and Inhibitory Activity of Photoswitchable RET Kinase Inhibitors

    PubMed Central

    Ferreira, Rubén; Nilsson, Jesper R.; Solano, Carlos; Andréasson, Joakim; Grøtli, Morten

    2015-01-01

    REarranged during Transfection (RET) is a transmembrane receptor tyrosine kinase required for normal development and maintenance of neurons of the central and peripheral nervous systems. Deregulation of RET and hyperactivity of the RET kinase is intimately connected to several types of human cancers, most notably thyroid cancers, making it an attractive therapeutic target for small-molecule kinase inhibitors. Novel approaches, allowing external control of the activity of RET, would be key additions to the signal transduction toolbox. In this work, photoswitchable RET kinase inhibitors based on azo-functionalized pyrazolopyrimidines were developed, enabling photonic control of RET activity. The most promising compound displays excellent switching properties and stability with good inhibitory effect towards RET in cell-free as well as live-cell assays and a significant difference in inhibitory activity between its two photoisomeric forms. As the first reported photoswitchable small-molecule kinase inhibitor, we consider the herein presented effector to be a significant step forward in the development of tools for kinase signal transduction studies with spatiotemporal control over inhibitor concentration in situ. PMID:25944708

  10. Design, Synthesis and Inhibitory Activity of Photoswitchable RET Kinase Inhibitors

    NASA Astrophysics Data System (ADS)

    Ferreira, Rubén; Nilsson, Jesper R.; Solano, Carlos; Andréasson, Joakim; Grøtli, Morten

    2015-05-01

    REarranged during Transfection (RET) is a transmembrane receptor tyrosine kinase required for normal development and maintenance of neurons of the central and peripheral nervous systems. Deregulation of RET and hyperactivity of the RET kinase is intimately connected to several types of human cancers, most notably thyroid cancers, making it an attractive therapeutic target for small-molecule kinase inhibitors. Novel approaches, allowing external control of the activity of RET, would be key additions to the signal transduction toolbox. In this work, photoswitchable RET kinase inhibitors based on azo-functionalized pyrazolopyrimidines were developed, enabling photonic control of RET activity. The most promising compound displays excellent switching properties and stability with good inhibitory effect towards RET in cell-free as well as live-cell assays and a significant difference in inhibitory activity between its two photoisomeric forms. As the first reported photoswitchable small-molecule kinase inhibitor, we consider the herein presented effector to be a significant step forward in the development of tools for kinase signal transduction studies with spatiotemporal control over inhibitor concentration in situ.

  11. Silencing of the constitutive activity of the dopamine D1B receptor. Reciprocal mutations between D1 receptor subtypes delineate residues underlying activation properties.

    PubMed

    Charpentier, S; Jarvie, K R; Severynse, D M; Caron, M G; Tiberi, M

    1996-11-08

    Recently, we have shown that the dopamine D1B/D5 receptor displays binding and coupling properties that are reminiscent of those of the constitutively activated G protein-coupled receptors when compared with the related D1A/D1 receptor subtype (Tiberi, M., and Caron, M. G. (1994) J. Biol. Chem. 269, 27925-27931). The carboxyl-terminal region of the third cytoplasmic loop of several G protein-coupled receptors has been demonstrated to be important for the regulation of the equilibrium between inactive and active receptor conformations. In this cytoplasmic region, the primary structure of dopamine D1A and D1B receptors differs by only two residues: Phe264/Arg266 are present in D1A receptor compared with Ile288/Lys290 in the D1B receptor. To investigate whether these structural differences could account for the distinct binding and coupling properties of these dopamine receptor subtypes, we swapped the variant residues located in the carboxyl-terminal region by site-directed mutagenesis. The exchange of the D1A receptor residue Phe264 by the D1B receptor counterpart isoleucine led to a D1A receptor mutant exhibiting D1B-like constitutive properties. In contrast, substitution of D1B receptor Ile288 by the D1A receptor counterpart phenylalanine resulted in a loss of constitutive activation of the D1B receptor with binding and coupling properties similar to the D1A receptor. The Arg/Lys substitution had no effect on the function of either receptor. These results demonstrate that the carboxyl-terminal region, and in particular residue Ile288, is a major determinant of the constitutive activity of the dopamine D1B receptor. Moreover, these results establish that not only can agonist-independent activity of a receptor be induced, but when given the appropriate mutation, it can be reversed or silenced.

  12. Soluble epoxide hydrolase inhibitory activity of anthraquinone components from Aloe.

    PubMed

    Sun, Ya Nan; Kim, Jang Hoon; Li, Wei; Jo, A Reum; Yan, Xi Tao; Yang, Seo Young; Kim, Young Ho

    2015-10-15

    Aloe is a short-stemmed succulent herb widely used in traditional medicine to treat various diseases and as raw material in cosmetics and heath foods. In this study, we isolated and identified two new anthraquinone derivatives, aloinoside C (6) and aloinoside D (7), together with six known compounds from an aqueous dissolved Aloe exudate. Their structures were identified by spectroscopic analysis. The inhibitory effects of the isolated compounds on soluble epoxide hydrolase (sEH) were evaluated. Compounds 1-8 inhibited sEH activity potently, with IC50 values ranging from 4.1±0.6 to 41.1±4.2 μM. A kinetic analysis of compounds 1-8 revealed that the inhibitory actions of compounds 1, 6 and 8 were non-competitive, whereas those of compounds 2-5 and 7 were the mixed-type. Molecular docking increases our understanding of receptor-ligand binding of all compounds. These results demonstrate that compounds 1-8 from Aloe are potential sEH inhibitors.

  13. EGFR tyrosine kinase targeted compounds: in vitro antitumor activity and molecular modeling studies of new benzothiazole and pyrimido[2,1-b]benzothiazole derivatives.

    PubMed

    Gabr, Moustafa T; El-Gohary, Nadia S; El-Bendary, Eman R; El-Kerdawy, Mohamed M

    2014-01-01

    In this study, we illustrate computer aided drug design of new benzothiazole and pyrimido[2,1-b]benzothiazole derivatives as epidermal growth factor receptor tyrosine kinase (EGFR-TK) inhibitors. Compounds 1-5 were screened at NCI, USA, for antitumor activity against non-small cell lung cancer (NCI-H522), colon cancer (HCT-116, HCT-15 and HT29) and breast cancer (MDA-MB-468 and MDA-MB-231/ATCC) cell lines in which EGFR is overexpressed in varying levels. Results indicated that these compounds are more potent antitumor agents compared to erlotinib against HT29 and MDA-MB-231/ATCC cell lines. Compound 3 showed GI50 value of 22.3 nM against NCI-H522 cell line, while erlotinib exhibited GI50 value of 1 µM against the same cell line. In addition, these compounds were studied for their EGFR tyrosine kinase inhibitory activity. Virtual screening utilizing molecular modeling and QSAR techniques enabled the understanding of the pharmacophoric requirements for antitumor activity. Docking the designed compounds into the ATP binding site of EGFR-TK domain was done to predict the analogous binding mode of these compounds to the EGFR-TK inhibitors.

  14. EGFR tyrosine kinase targeted compounds: in vitro antitumor activity and molecular modeling studies of new benzothiazole and pyrimido[2,1-b]benzothiazole derivatives

    PubMed Central

    Gabr, Moustafa T.; El-Gohary, Nadia S; El-Bendary, Eman R.; El-Kerdawy, Mohamed M.

    2014-01-01

    In this study, we illustrate computer aided drug design of new benzothiazole and pyrimido[2,1-b]benzothiazole derivatives as epidermal growth factor receptor tyrosine kinase (EGFR-TK) inhibitors. Compounds 1-5 were screened at NCI, USA, for antitumor activity against non-small cell lung cancer (NCI-H522), colon cancer (HCT-116, HCT-15 and HT29) and breast cancer (MDA-MB-468 and MDA-MB-231/ATCC) cell lines in which EGFR is overexpressed in varying levels. Results indicated that these compounds are more potent antitumor agents compared to erlotinib against HT29 and MDA-MB-231/ATCC cell lines. Compound 3 showed GI50 value of 22.3 nM against NCI-H522 cell line, while erlotinib exhibited GI50 value of 1 µM against the same cell line. In addition, these compounds were studied for their EGFR tyrosine kinase inhibitory activity. Virtual screening utilizing molecular modeling and QSAR techniques enabled the understanding of the pharmacophoric requirements for antitumor activity. Docking the designed compounds into the ATP binding site of EGFR-TK domain was done to predict the analogous binding mode of these compounds to the EGFR-TK inhibitors. PMID:26417284

  15. In Vitro and In Vivo Metabolism and Inhibitory Activities of Vasicine, a Potent Acetylcholinesterase and Butyrylcholinesterase Inhibitor

    PubMed Central

    Liu, Wei; Shi, Xiaoyuan; Yang, Yadi; Cheng, Xuemei; Liu, Qing; Han, Han; Yang, Baohua; He, Chunyong; Wang, Yongli; Jiang, Bo; Wang, Zhengtao; Wang, Changhong

    2015-01-01

    Vasicine (VAS), a potential natural cholinesterase inhibitor, exhibited promising anticholinesterase activity in preclinical models and has been in development for treatment of Alzheimer’s disease. This study systematically investigated the in vitro and in vivo metabolism of VAS in rat using ultra performance liquid chromatography combined with electrospray ionization quadrupole time-of-flight mass spectrometry. A total of 72 metabolites were found based on a detailed analysis of their 1H- NMR and 13C NMR data. Six key metabolites were isolated from rat urine and elucidated as vasicinone, vasicinol, vasicinolone, 1,2,3,9-tetrahydropyrrolo [2,1-b] quinazolin-3-yl hydrogen sulfate, 9-oxo-1,2,3,9-tetrahydropyrrolo [2,1-b] quinazolin-3-yl hydrogen sulfate, and 1,2,3,9-tetrahydropyrrolo [2,1-b] quinazolin-3-β-D-glucuronide. The metabolic pathway of VAS in vivo and in vitro mainly involved monohydroxylation, dihydroxylation, trihydroxylation, oxidation, desaturation, sulfation, and glucuronidation. The main metabolic soft spots in the chemical structure of VAS were the 3-hydroxyl group and the C-9 site. All 72 metabolites were found in the urine sample, and 15, 25, 45, 18, and 11 metabolites were identified from rat feces, plasma, bile, rat liver microsomes, and rat primary hepatocyte incubations, respectively. Results indicated that renal clearance was the major excretion pathway of VAS. The acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities of VAS and its main metabolites were also evaluated. The results indicated that although most metabolites maintained potential inhibitory activity against AChE and BChE, but weaker than that of VAS. VAS undergoes metabolic inactivation process in vivo in respect to cholinesterase inhibitory activity. PMID:25849329

  16. Predicting Monoamine Oxidase Inhibitory Activity through Ligand-Based Models

    PubMed Central

    Vilar, Santiago; Ferino, Giulio; Quezada, Elias; Santana, Lourdes; Friedman, Carol

    2013-01-01

    The evolution of bio- and cheminformatics associated with the development of specialized software and increasing computer power has produced a great interest in theoretical in silico methods applied in drug rational design. These techniques apply the concept that “similar molecules have similar biological properties” that has been exploited in Medicinal Chemistry for years to design new molecules with desirable pharmacological profiles. Ligand-based methods are not dependent on receptor structural data and take into account two and three-dimensional molecular properties to assess similarity of new compounds in regards to the set of molecules with the biological property under study. Depending on the complexity of the calculation, there are different types of ligand-based methods, such as QSAR (Quantitative Structure-Activity Relationship) with 2D and 3D descriptors, CoMFA (Comparative Molecular Field Analysis) or pharmacophoric approaches. This work provides a description of a series of ligand-based models applied in the prediction of the inhibitory activity of monoamine oxidase (MAO) enzymes. The controlled regulation of the enzymes’ function through the use of MAO inhibitors is used as a treatment in many psychiatric and neurological disorders, such as depression, anxiety, Alzheimer’s and Parkinson’s disease. For this reason, multiple scaffolds, such as substituted coumarins, indolylmethylamine or pyridazine derivatives were synthesized and assayed toward MAO-A and MAO-B inhibition. Our intention is to focus on the description of ligand-based models to provide new insights in the relationship between the MAO inhibitory activity and the molecular structure of the different inhibitors, and further study enzyme selectivity and possible mechanisms of action. PMID:23231398

  17. Native New Zealand plants with inhibitory activity towards Mycobacterium tuberculosis

    PubMed Central

    2010-01-01

    Background Plants have long been investigated as a source of antibiotics and other bioactives for the treatment of human disease. New Zealand contains a diverse and unique flora, however, few of its endemic plants have been used to treat tuberculosis. One plant, Laurelia novae-zelandiae, was reportedly used by indigenous Maori for the treatment of tubercular lesions. Methods Laurelia novae-zelandiae and 44 other native plants were tested for direct anti-bacterial activity. Plants were extracted with different solvents and extracts screened for inhibition of the surrogate species, Mycobacterium smegmatis. Active plant samples were then tested for bacteriostatic activity towards M. tuberculosis and other clinically-important species. Results Extracts of six native plants were active against M. smegmatis. Many of these were also inhibitory towards M. tuberculosis including Laurelia novae-zelandiae (Pukatea). M. excelsa (Pohutukawa) was the only plant extract tested that was active against Staphylococcus aureus. Conclusions Our data provide support for the traditional use of Pukatea in treating tuberculosis. In addition, our analyses indicate that other native plant species possess antibiotic activity. PMID:20537175

  18. Triclosan activates aryl hydrocarbon receptor (AhR)-dependent apoptosis and affects Cyp1a1 and Cyp1b1 expression in mouse neocortical neurons.

    PubMed

    Szychowski, Konrad A; Wnuk, Agnieszka; Kajta, Małgorzata; Wójtowicz, Anna K

    2016-11-01

    Triclosan (TCS) is an antimicrobial agent that is used extensively in personal care and in sanitizing products, such as soaps, toothpastes, and hair products. A number of studies have revealed the presence of TCS in human tissues, such as fat, liver and brain, in addition to blood and breast milk. The aim of the present study was to investigate the impact of TCS on AhR and Cyp1a1/Cyp1b1 signaling in mouse neocortical neurons in primary cultures. In addition to the use of selective ligands and siRNAs, expression levels of mRNA and proteins as well as caspase-3 activity, reactive oxygen species (ROS) formation, and lactate dehydrogenase (LDH) release have been measured. We also studied the involvement of the AhR in TCS-induced LDH release and caspase-3 activation as well as the effect of TCS on ROS generation. Cultures of neocortical neurons were prepared from Swiss mouse embryos on day 15/16 of gestation. The cells were cultured in phenol red-free Neurobasal medium with B27 and glutamine, and the neurons were exposed to 1 and 10µM TCS. Our experiments showed that the expression of AhR and Cyp1a1 mRNA decreased in cells exposed to 10µM TCS for 3 or 6h. In the case of Cyp1b1, mRNA expression remained unchanged compared with the control group following 3h of exposure to TCS, but after 6h, the mRNA expression of Cyp1b1 was decreased. Our results confirmed that the AhR is involved in the TCS mechanism of action, and our data demonstrated that after the cells were transfected with AhR siRNA, the cytotoxic and pro-apoptotic properties of TCS were decreased. The decrease in Cyp1a1 mRNA and protein expression levels accompanied by a decrease in its activity. The stimulation of Cyp1a1 activity produced by the application of an AhR agonist (βNF) was attenuated by TCS, whereas the addition of AhR antagonist (αNF) reversed the inhibitory effects of TCS. In our experiments, TCS diminished Cyp1b1 mRNA and enhanced its protein expression. In case of Cyp1a1 we observed

  19. Acetylcholinesterase inhibitory activity of uleine from Himatanthus lancifolius.

    PubMed

    Seidl, Cláudia; Correia, Beatriz L; Stinghen, Andréa E M; Santos, Cid A M

    2010-01-01

    Application of acetylcholinesterase (AChE) inhibitors is the primary treatment for Alzheimer's disease. Alkaloids, such as physostigmine, galanthamine, and huperzine A, play an important role as AChE inhibitors. The aim of this work was to evaluate Himatanthus lancifolius (Muell. Arg.) Woodson, a Brazilian species of Apocynaceae, and its main indole alkaloid uleine, in order to identify new AChE inhibitors. The plant fluid extract, fractions, and uleine were tested for AChE inhibitory activity using Ellman's colorimetric method for thin-layer chromatography (TLC), 96-well microplates, and also Marston's TLC colorimetric method. Both TLC assays showed similar results. At 5 mg/mL, the fluid extract inhibited the AChE enzyme by (50.71 +/- 8.2)%. The ethyl acetate fraction exhibited the highest level of AChE inhibition, followed by the dichloromethane fraction. The isolated alkaloid uleine displayed an IC50 value of 0.45 microM.

  20. Inhibitory neurotransmission regulates vagal efferent activity and gastric motility

    PubMed Central

    McMenamin, Caitlin A; Travagli, R Alberto

    2016-01-01

    The gastrointestinal tract receives extrinsic innervation from both the sympathetic and parasympathetic nervous systems, which regulate and modulate the function of the intrinsic (enteric) nervous system. The stomach and upper gastrointestinal tract in particular are heavily influenced by the parasympathetic nervous system, supplied by the vagus nerve, and disruption of vagal sensory or motor functions results in disorganized motility patterns, disrupted receptive relaxation and accommodation, and delayed gastric emptying, amongst others. Studies from several laboratories have shown that the activity of vagal efferent motoneurons innervating the upper GI tract is inhibited tonically by GABAergic synaptic inputs from the adjacent nucleus tractus solitarius. Disruption of this influential central GABA input impacts vagal efferent output, hence gastric functions, significantly. The purpose of this review is to describe the development, physiology, and pathophysiology of this functionally dominant inhibitory synapse and its role in regulating vagally determined gastric functions. PMID:27302177

  1. Macrophage migration inhibitory factor (MIF) enzymatic activity and lung cancer.

    PubMed

    Mawhinney, Leona; Armstrong, Michelle E; O' Reilly, Ciaran; Bucala, Richard; Leng, Lin; Fingerle-Rowson, Gunter; Fayne, Darren; Keane, Michael P; Tynan, Aisling; Maher, Lewena; Cooke, Gordon; Lloyd, David; Conroy, Helen; Donnelly, Seamas C

    2015-04-16

    The cytokine macrophage migration inhibitory factor (MIF) possesses unique tautomerase enzymatic activity, which contributes to the biological functional activity of MIF. In this study, we investigated the effects of blocking the hydrophobic active site of the tautomerase activity of MIF in the pathogenesis of lung cancer. To address this, we initially established a Lewis lung carcinoma (LLC) murine model in Mif-KO and wild-type (WT) mice and compared tumor growth in a knock-in mouse model expressing a mutant MIF lacking enzymatic activity (Mif (P1G)). Primary tumor growth was significantly attenuated in both Mif-KO and Mif (P1G) mice compared with WT mice. We subsequently undertook a structure-based, virtual screen to identify putative small molecular weight inhibitors specific for the tautomerase enzymatic active site of MIF. From primary and secondary screens, the inhibitor SCD-19 was identified, which significantly attenuated the tautomerase enzymatic activity of MIF in vitro and in biological functional screens. In the LLC murine model, SCD-19, given intraperitoneally at the time of tumor inoculation, was found to significantly reduce primary tumor volume by 90% (p < 0.001) compared with the control treatment. To better replicate the human disease scenario, SCD-19 was given when the tumor was palpable (at d 7 after tumor inoculation) and, again, treatment was found to significantly reduce tumor volume by 81% (p < 0.001) compared with the control treatment. In this report, we identify a novel inhibitor that blocks the hydrophobic pocket of MIF, which houses its specific tautomerase enzymatic activity, and demonstrate that targeting this unique active site significantly attenuates lung cancer growth in in vitro and in vivo systems.

  2. Spontaneous Activity Defines Effective Convergence Ratios in an Inhibitory Circuit

    PubMed Central

    Lu, Hsin-Wei

    2016-01-01

    Many neurons fire spontaneously, and the rate of this firing is subject to neuromodulation. How this firing affects functional connectivity within a neural network remains largely unexplored. Here we show that changes in spontaneous firing of cartwheel interneurons in the mouse dorsal cochlear nucleus (DCN) alter the effective convergence ratio of interneurons onto their postsynaptic targets through short-term synaptic plasticity. Spontaneous firing of cartwheel cells led to activity-dependent synaptic depression of individual cartwheel synapses. Depression was rapid and profound at stimulation frequencies between 10 and 200 Hz, suggesting the presence of high release probability (Pr) vesicles at these inhibitory synapses. Weak, transient synaptic facilitation could be induced after synapses were predepressed, indicating that low-Pr vesicles are also recruited, and may thus support steady-state transmission. A two-pool vesicle depletion model with 10-fold differences in Pr could account for the synaptic depression over a wide range of stimulus conditions. As a result of depression during high spontaneous activity, more cartwheel interneurons were required for effective inhibition. Convergence of four interneurons was sufficient to compensate for the effects of depression during physiologically expected rates of activity. By simulating synaptic release during spontaneous firing, we found that recruitment of low-Pr vesicles at the synapse plays a critical role in maintaining effective inhibition within a small population of interneurons. The interplay between spontaneous spiking, short-term synaptic plasticity, and vesicle recruitment thus determines the effective size of a convergent neural network. SIGNIFICANCE STATEMENT We examined the relationship between the structure of a small neural circuit and the properties of its individual synapses. Successful synaptic inhibition of a target cell firing requires a critical inhibitory synaptic strength. Synapses often

  3. Soil Moisture Active Passive (SMAP) Project Algorithm Theoretical Basis Document SMAP L1B Radiometer Data Product: L1B_TB

    NASA Technical Reports Server (NTRS)

    Piepmeier, Jeffrey; Mohammed, Priscilla; De Amici, Giovanni; Kim, Edward; Peng, Jinzheng; Ruf, Christopher; Hanna, Maher; Yueh, Simon; Entekhabi, Dara

    2016-01-01

    The purpose of the Soil Moisture Active Passive (SMAP) radiometer calibration algorithm is to convert Level 0 (L0) radiometer digital counts data into calibrated estimates of brightness temperatures referenced to the Earth's surface within the main beam. The algorithm theory in most respects is similar to what has been developed and implemented for decades for other satellite radiometers; however, SMAP includes two key features heretofore absent from most satellite borne radiometers: radio frequency interference (RFI) detection and mitigation, and measurement of the third and fourth Stokes parameters using digital correlation. The purpose of this document is to describe the SMAP radiometer and forward model, explain the SMAP calibration algorithm, including approximations, errors, and biases, provide all necessary equations for implementing the calibration algorithm and detail the RFI detection and mitigation process. Section 2 provides a summary of algorithm objectives and driving requirements. Section 3 is a description of the instrument and Section 4 covers the forward models, upon which the algorithm is based. Section 5 gives the retrieval algorithm and theory. Section 6 describes the orbit simulator, which implements the forward model and is the key for deriving antenna pattern correction coefficients and testing the overall algorithm.

  4. Human FGF1 promoter is active in ependymal cells and dopaminergic neurons in the brains of F1B-GFP transgenic mice.

    PubMed

    Chen, Mei-Shu; Lin, Hua-Kuo; Chiu, Hsun; Lee, Don-Ching; Chung, Yu-Fen; Chiu, Ing-Ming

    2015-03-01

    FGF1 is involved in multiple biological functions and exhibits the importance in neuroprotective effects. Our previous studies indicated that, in human brain and retina, the FGF1B promoter controlled the expression of FGF1. However, the exact function and regulation of FGF1 in brain is still unclear. Here, we generated F1B-GFP transgenic mice that expressed the GFP reporter gene under the control of human FGF1B promoter (-540 to +31). Using the fresh brain sections of F1B-GFP transgenic mice, we found that the F1B-GFP cells expressed strong fluorescent signals in the ventricular system throughout the brain. The results of immunohistochemistry further showed that two distinct populations of F1B-GFP(+) cells existed in the brains of F1B-GFP transgenic mice. We demonstrated that one population of F1B-GFP(+) cells was ependymal cells, which distributed along the entire ventricles, and the second population of F1B-GFP(+) cells was neuronal cells that projected their long processes into multiple directions in specific areas of the brain. The double labeling of F1B-GFP(+) cells and tyrosine hydroxylase indicated that a subpopulation of F1B-GFP(+) -neuronal cells was dopaminergic neurons. Importantly, these F1B-GFP(+) /TH(+) cells were distributed in the main dopaminergic neuronal groups including hypothalamus, ventral tegmental area, and raphe nuclei. These results suggested that human FGF1B promoter was active in ependymal cells, neurons, and a portion of dopaminergic neurons. Thus, the F1B-GFP transgenic mice provide an animal model not only for studying FGF1 gene expression in vivo but also for understanding the role of FGF1 contribution in neurodegenerative disorders such as Parkinson's disease and Alzheimer's disease.

  5. Bacterial maximum non-inhibitory and minimum inhibitory concentrations of different water activity depressing solutes.

    PubMed

    Cebrián, G; Arroyo, C; Mañas, P; Condón, S

    2014-10-01

    The NaCl MNICs (maximum non-inhibitory concentrations) and MICs (minimum inhibitory concentrations) for growth of various strains of six bacterial species were determined and then compared with those obtained for seven other solutes. The influence of prior growth conditions on the MNICs and MICs was also evaluated. No significant changes on the MNICs and MICs were found among the strains studied within each species. Among all factors investigated, only growth phase -for Gram-negatives- and growth at high NaCl concentrations led to a change in the NaCl MNICs. Species could be classified depending on its NaCl MNICs and MICs (in decreasing order) as follows: Staphylococcus aureus, Listeria monocytogenes, Cronobacter sakazakii, Enterococcus faecium, Escherichia coli and Salmonella Typhimurium. Similar results were obtained for KCl, LiCl, and sodium acetate, but not for the remaining solutes investigated (sucrose, glycerol, MgCl2 and CaCl2). Results obtained indicate that, in general, Gram-negatives showed lower MNICs and MICs than Gram-positives for all the solutes, S. aureus being the most solute tolerant microorganism. When compared on a molar basis, glycerol showed the highest MNICs and MICs for all the microorganisms -except for S. aureus- and LiCl the lowest ones. NaCl MNICs and MICs were not significantly different from those of KCl when compared on a molar basis. Therefore, the inhibitory action of NaCl could not be linked to the specific action of Na(+). Results also showed that the Na(+) tolerance of some species was Cl(-) dependent whereas for others it was not, and that factors others than aw-decrease contribute to the inhibitory action of LiCl, CaCl2 and MgCl2.

  6. Imperanene, a novel phenolic compound with platelet aggregation inhibitory activity from Imperata cylindrica.

    PubMed

    Matsunaga, K; Shibuya, M; Ohizumi, Y

    1995-01-01

    Imperanene, a novel phenolic compound [1] has been isolated from Imperata cylindrica. Its structure was elucidated by spectroscopic evidence. Imperanene showed platelet aggregation inhibitory activity.

  7. A protein tyrosine phosphatase 1B activity inhibitor from the fruiting bodies of Ganoderma lucidum (Fr.) Karst and its hypoglycemic potency on streptozotocin-induced type 2 diabetic mice.

    PubMed

    Teng, Bao-Song; Wang, Chen-Dong; Yang, Hong-Jie; Wu, Jia-Sheng; Zhang, Dan; Zheng, Min; Fan, Zhao-Hua; Pan, Deng; Zhou, Ping

    2011-06-22

    Inhibition of protein tyrosine phosphatase 1B (PTP1B) activity has been considered to be a promising therapy approach to treat type 2 diabetes. In this work, a novel PTP1B activity inhibitor, named FYGL (Fudan-Yueyang-G. lucidum), was screened from the fruiting bodies of Ganoderma lucidum and showed an efficient PTP1B inhibitory potency with IC₅₀ = 5.12 ± 0.05 μg/mL. FYGL is a water-soluble macromolecular proteoglycan with a protein to polysaccharide ratio of 17:77 and a viscosity-average molecular weight (M(η)) of 2.6 × 10⁵. The type 2 diabetic mice treated orally by FYGL showed an obvious decrease in plasma glucose level compared with the diabetic controls without drug treatment, comparable with that of diabetic mice treated with metformin, a clinical drug. The toxicity of FYGL is very low. The results indicate that FYGL may serve as a drug candidate or a health-care food for diabetic therapy or protection.

  8. Probing the origins of aromatase inhibitory activity of disubstituted coumarins via QSAR and molecular docking.

    PubMed

    Worachartcheewan, Apilak; Suvannang, Naravut; Prachayasittikul, Supaluk; Prachayasittikul, Virapong; Nantasenamat, Chanin

    2014-01-01

    This study investigated the quantitative structure-activity relationship (QSAR) of imidazole derivatives of 4,7-disubstituted coumarins as inhibitors of aromatase, a potential therapeutic protein target for the treatment of breast cancer. Herein, a series of 3,7- and 4,7-disubstituted coumarin derivatives (1-34) with R1 and R2 substituents bearing aromatase inhibitory activity were modeled as a function of molecular and quantum chemical descriptors derived from low-energy conformer geometrically optimized at B3LYP/6-31G(d) level of theory. Insights on origins of aromatase inhibitory activity was afforded by the computed set of 7 descriptors comprising of F10[N-O], Inflammat-50, Psychotic-80, H-047, BELe1, B10[C-O] and MAXDP. Such significant descriptors were used for QSAR model construction and results indicated that model 4 afforded the best statistical performance. Good predictive performance were achieved as verified from the internal (comprising the training and the leave-one-out cross-validation (LOO-CV) sets) and external sets affording the following statistical parameters: R (2) Tr = 0.9576 and RMSETr = 0.0958 for the training set; Q (2) CV = 0.9239 and RMSECV = 0.1304 for the LOO-CV set as well as Q (2) Ext = 0.7268 and RMSEExt = 0.2927 for the external set. Significant descriptors showed correlation with functional substituents, particularly, R1 in governing high potency as aromatase inhibitor. Molecular docking calculations suggest that key residues interacting with the coumarins were predominantly lipophilic or non-polar while a few were polar and positively-charged. Findings illuminated herein serve as the impetus that can be used to rationally guide the design of new aromatase inhibitors.

  9. Rac1b enhances cell survival through activation of the JNK2/c-JUN/Cyclin-D1 and AKT2/MCL1 pathways

    PubMed Central

    Wang, Hong; Wei, Si-Si; Chen, Jie; Chen, Yi-He; Xu, Wei-Ping; Jie, Qi-Qiang; Zhou, Qing; Li, Yi-Gang; Wei, Yi-Dong; Wang, Yue-Peng

    2016-01-01

    Rac1b is a constitutively activated, alternatively spliced form of the small GTPase Rac1. Previous studies showed that Rac1b promotes cell proliferation and inhibits apoptosis. In the present study, we used microarray analysis to detect genes differentially expressed in HEK293T cells and SW480 human colon cancer cells stably overexpressing Rac1b. We found that the pro-proliferation genes JNK2, c-JUN and cyclin-D1 as well as anti-apoptotic AKT2 and MCL1 were all upregulated in both lines. Rac1b promoted cell proliferation and inhibited apoptosis by activating the JNK2/c-JUN/cyclin-D1 and AKT2/MCL1 pathways, respectively. Very low Rac1b levels were detected in the colonic epithelium of wild-type Sprague-Dawley rats. Knockout of the rat Rac1 gene exon-3b or knockdown of endogenous Rac1b in HT29 human colon cancer cells downregulated only the AKT2/MCL1 pathway. Our study revealed that very low levels of endogenous Rac1b inhibit apoptosis, while Rac1b upregulation both promotes cell proliferation and inhibits apoptosis. It is likely the AKT2/MCL1 pathway is more sensitive to Rac1b regulation. PMID:26918455

  10. miR-27b synergizes with anticancer drugs via p53 activation and CYP1B1 suppression

    PubMed Central

    Mu, Wenjing; Hu, Chaobo; Zhang, Haibin; Qu, Zengqiang; Cen, Jin; Qiu, Zhixin; Li, Chao; Ren, Haozhen; Li, Yixue; He, Xianghuo; Shi, Xiaolei; Hui, Lijian

    2015-01-01

    Liver and kidney cancers are notorious for drug resistance. Due to the complexity, redundancy and interpatient heterogeneity of resistance mechanisms, most efforts targeting a single pathway were unsuccessful. Novel personalized therapies targeting multiple essential drug resistance pathways in parallel hold a promise for future cancer treatment. Exploiting the multitarget characteristic of microRNAs (miRNAs), we developed a new therapeutic strategy by the combinational use of miRNA and anticancer drugs to increase drug response. By a systems approach, we identified that miR-27b, a miRNA deleted in liver and kidney cancers, sensitizes cancer cells to a broad spectrum of anticancer drugs in vitro and in vivo. Functionally, miR-27b enhances drug response by activating p53-dependent apoptosis and reducing CYP1B1-mediated drug detoxification. Notably, miR-27b promotes drug response specifically in patients carrying p53-wild-type or CYP1B1-high signature. Together, we propose that miR-27b synergizes with anticancer drugs in a defined subgroup of liver and kidney cancer patients. PMID:25698578

  11. Activation of platelet-activating factor (PAF) receptor stimulates nitric oxide (NO) release via protein kinase C-alpha in HEC-1B human endometrial epithelial cell line.

    PubMed Central

    Dearn, S.; Rahman, M.; Lewis, A.; Ahmed, Z.; Eggo, M. C.; Ahmed, A.

    2000-01-01

    BACKGROUND: Impairment of the fertility in the platelet-activating factor (PAF) receptor transgenic female mice suggests changes in PAF functions can influence uterine receptivity. We hypothesized that vasodilatory actions of PAF in the uterus was exerted by PAF-mediated nitric oxide (NO) release via activation of isoenzyme-specific protein kinase C (PKC). MATERIALS AND METHODS: Inducible and endothelial NOS was shown by Reverse transcription polymerase chain reaction RT-PCR in cDNA synthesized from RNA extract of proliferative and secretory endometrium as well endometrial epithelial cell lines HEC-1B. The effect of WEB2170, N(G)-monomethyl-L-arginine (L-NMMA) and Ro31-8220 on PAF mediated NO release by HEC-1B cell was determined. PAF induced translocation of PKCalpha in HEC-1B cell and its antagonist effect by Ro 31-8220 was studied by Western immunoblot analysis. PKC isoenzyme regulated by PAF was determined in HEC-1B cell lysate by immunoprecipitation. RESULTS: PAF-evoked a rapid and concentration-dependent biphasic increase in total NO in human HEC-1B endometrial epithelial cell line [as measured by a Sievers NOA 280A NO Chemiluminescent Analyser.] This increase in NO release was attenuated by the PAF receptor antagonist, WEB2170. Inhibition of NO synthesis by N(G)-monomethyl-L-arginine produced marked dose-dependent attenuation of PAF-mediated NO release, indicating nitric oxide synthase (NOS) activation. PAF-mediated NO release was also inhibited by the PKC inhibitor Ro 31-8220 and by the removal of extracellular calcium, suggesting a dependency on PKC and calcium, respectively. RT-PCR analysis showed expression of inducible NOS and endothelial NOS in human endometrium, myometrium and HEC-1B cells. Western immunoblot analysis showed PKCalpha, betaII and iota were the principal isozymes present in the HEC-1B cell line and normal endometrium, suggesting that both HEC-1B cells and normal endometrium have similar PKC isozymes. PAF induced the translocation of

  12. Protein tyrosine phosphatase 1B inhibitors isolated from Artemisia roxburghiana.

    PubMed

    Shah, Muhammad Raza; Ishtiaq; Hizbullah, Syed Muhammad; Habtemariam, Solomon; Zarrelli, Armando; Muhammad, Akhtar; Collina, Simona; Khan, Inamulllah

    2016-08-01

    Artemisia roxburghiana is used in traditional medicine for treating various diseases including diabetes. The present study was designed to evaluate the antidiabetic potential of active constituents by using protein tyrosine phosphatase 1B (PTP1B) as a validated target for management of diabetes. Various compounds were isolated as active principles from the crude methanolic extract of aerial parts of A. roxburghiana. All compounds were screened for PTP1B inhibitory activity. Molecular docking simulations were performed to investigate the mechanism behind PTP1B inhibition of the isolated compound and positive control, ursolic acid. Betulinic acid, betulin and taraxeryl acetate were the active PTP1B principles with IC50 values 3.49 ± 0.02, 4.17 ± 0.03 and 87.52 ± 0.03 µM, respectively. Molecular docking studies showed significant molecular interactions of the triterpene inhibitors with Gly220, Cys215, Gly218 and Asp48 inside the active site of PTP1B. The antidiabetic activity of A. roxburghiana could be attributed due to PTP1B inhibition by its triterpene constituents, betulin, betulinic acid and taraxeryl acetate. Computational insights of this study revealed that the C-3 and C-17 positions of the compounds needs extensive optimization for the development of new lead compounds.

  13. Molecular determinants of the platelet aggregation inhibitory activity of carbamoylpiperidines.

    PubMed

    Feng, Z; Gollamudi, R; Dillingham, E O; Bond, S E; Lyman, B A; Purcell, W P; Hill, R J; Korfmacher, W A

    1992-08-07

    A series of alpha,alpha'-bis[3-(N,N-dialkylcarbamoyl)piperidino]-p- xylenes were synthesized and tested for their inhibitory activity on ADP-induced aggregation of human platelets. A parabolic curve was obtained when log 1/C (activity) was plotted against log P (octanol/water partition coefficient). Using this as a model, a new analogue, alpha,alpha'-bis-[3-(N-methyl-N-butylcarbamoyl)piperidino]-p-xylen e (3g), was synthesized with a predicted IC50 of 25 microM. When this compound was subsequently evaluated, the IC50 was 22.1 +/- 5.5 microM, demonstrating the applicability of this model. The amide oxygen of the carbamoyl substituent appeared necessary for activity. Thus, for example, when the amide carbonyl group of 3a (IC50 = 44.5 microM) was reduced to CH2, the resulting compound 4 had a dramatically reduced activity, IC50 = 1565 microM. Compound 3a was resolved into (+) and (-) enantiomers and a meso (0) diastereomer using fractional crystallization, diastereomeric tartrate formation, and chiral HPLC. Compared to (-)-3a, the (+) isomer was 15 times more potent when ADP was the agonist and 19 times more active when collagen was used as the agonist. Molecular modeling of R,R- and S,S-3a using the SYBYL program was used to examine their interactions with phosphatidylinositol (PI). There was a better fit between PI and the R,R-3a with the energy of interaction being 17.6 kcal/mol less than that of the S,S-3a/PI complex. Although the absolute stereochemistry of individual enantiomers is not known, this study shows that R,R-3a interacts more favorably with PI than does S,S-3a and that (+)-3a is a more potent inhibitor of human platelet aggregation than (-)-3a. It is postulated that because of their lipophilicity, these compounds penetrate the platelet membrane and are then protonated at the pH of the cytosol. The protonated N then neutralizes the anionic charge on the membrane phosphoinositides, thereby rendering them less susceptible to hydrolysis by phospholipase C

  14. Identification of selective covalent inhibitors of platelet activating factor acetylhydrolase 1B2 from the screening of an oxadiazolone-capped peptoid-azapeptoid hybrid library.

    PubMed

    Sarma, Bani Kanta; Liu, Xiaodan; Kodadek, Thomas

    2016-09-01

    A potent and selective inhibitor of platelet-activating factor acetylhydrolase 1B2 (PAFAH1B2) is described. The compound was derived by improvement of a modest affinity primary hit isolated from the screening of a bead-displayed peptoid-azapeptoid hybrid library tethered to an oxadiazolone 'warhead'. The oxadiazolone moiety of the inhibitors was found to react covalently with the active site serine residue of PAFAH1B2. This screening strategy may be useful for the identification of many selective, covalent inhibitors of serine hydrolases.

  15. Chordin and dickkopf-1b are essential for the formation of head structures through activation of the FGF signaling pathway in zebrafish.

    PubMed

    Tanaka, Shingo; Hosokawa, Hiroshi; Weinberg, Eric S; Maegawa, Shingo

    2017-04-15

    The ability of the Spemann organizer to induce dorsal axis formation is dependent on downstream factors of the maternal Wnt/β-catenin signaling pathway. The fibroblast growth factor (FGF) signaling pathway has been identified as one of the downstream components of the maternal Wnt/β-catenin signaling pathway. The ability of the FGF signaling pathway to induce the formation of a dorsal axis with a complete head structure requires chordin (chd) expression; however, the molecular mechanisms involved in this developmental process, due to activation of FGF signaling, remain unclear. In this study, we showed that activation of the FGF signaling pathway induced the formation of complete head structures through the expression of chd and dickkopf-1b (dkk1b). Using the organizer-deficient maternal mutant, ichabod, we identified dkk1b as a novel downstream factor in the FGF signaling pathway. We also demonstrate that dkk1b expression is necessary, after activation of the FGF signaling pathway, to induce neuroectoderm patterning along the anteroposterior (AP) axis and for formation of complete head structures. Co-injection of chd and dkk1b mRNA resulted in the formation of a dorsal axis with a complete head structure in ichabod embryos, confirming the role of these factors in this developmental process. Unexpectedly, we found that chd induced dkk1b expression in ichabod embryos at the shield stage. However, chd failed to maintain dkk1b expression levels in cells of the shield and, subsequently, in the cells of the prechordal plate after mid-gastrula stage. In contrast, activation of the FGF signaling pathway maintained the dkk1b expression from the beginning of gastrulation to early somitogenesis. In conclusion, activation of the FGF signaling pathway induces the formation of a dorsal axis with a complete head structure through the expression of chd and subsequent maintenance of dkk1b expression levels.

  16. Antioxidant Activity and α-Glucosidase Inhibitory Activities of the Polycondensate of Catechin with Glyoxylic Acid

    PubMed Central

    Ma, Hanjun; Liu, Benguo

    2016-01-01

    In order to investigate polymeric flavonoids, the polycondensate of catechin with glyoxylic acid (PCG) was prepared and its chemically antioxidant, cellular antioxidant (CAA) and α-glucosidase inhibitory activities were evaluated. The DPPH and ABTS radical scavenging activities and antiproliferative effect of PCG were lower than those of catechin, while PCG had higher CAA activity than catechin. In addition, PCG had very high α-glucosidase inhibitory activities (IC50 value, 2.59 μg/mL) in comparison to catechin (IC50 value, 239.27 μg/mL). Inhibition kinetics suggested that both PCG and catechin demonstrated a mixture of noncompetitive and anticompetitive inhibition. The enhanced CAA and α-glucosidase inhibitor activities of PCG could be due to catechin polymerization enhancing the binding capacity to the cellular membrane and enzymes. PMID:26960205

  17. Antioxidant Activity and α-Glucosidase Inhibitory Activities of the Polycondensate of Catechin with Glyoxylic Acid.

    PubMed

    Geng, Sheng; Shan, Sharui; Ma, Hanjun; Liu, Benguo

    2016-01-01

    In order to investigate polymeric flavonoids, the polycondensate of catechin with glyoxylic acid (PCG) was prepared and its chemically antioxidant, cellular antioxidant (CAA) and α-glucosidase inhibitory activities were evaluated. The DPPH and ABTS radical scavenging activities and antiproliferative effect of PCG were lower than those of catechin, while PCG had higher CAA activity than catechin. In addition, PCG had very high α-glucosidase inhibitory activities (IC50 value, 2.59 μg/mL) in comparison to catechin (IC50 value, 239.27 μg/mL). Inhibition kinetics suggested that both PCG and catechin demonstrated a mixture of noncompetitive and anticompetitive inhibition. The enhanced CAA and α-glucosidase inhibitor activities of PCG could be due to catechin polymerization enhancing the binding capacity to the cellular membrane and enzymes.

  18. Pyranoflavones: A Group of Small-molecule Probes for Exploring the Active Site Cavities of Cytochrome P450 Enzymes 1A1, 1A2, and 1B1

    PubMed Central

    Liu, Jiawang; Taylor, Shannon F.; Dupart, Patrick S.; Arnold, Corey L.; Sridhar, Jayalakshmi; Jiang, Quan; Wang, Yuji; Skripnikova, Elena V.; Zhao, Ming; Foroozesh, Maryam

    2013-01-01

    Selective inhibition of P450 enzymes is the key to block the conversion of environmental procarcinogens to their carcinogenic metabolites in both animals and humans. To discover highly potent and selective inhibitors of P450s 1A1, 1A2, and 1B1, as well as to investigate active site cavities of these enzymes, 14 novel flavone derivatives were prepared as chemical probes. Fluorimetric enzyme inhibition assays were used to determine the inhibitory activities of these probes towards P450s 1A1, 1A2, 1B1, 2A6, and 2B1. A highly selective P450 1B1 inhibitor, 5-hydroxy-4′-propargyloxyflavone (5H4′FPE) was discovered. Some tested compounds also showed selectivity between P450s 1A1 and 1A2. Alpha-naphthoflavone-like and 5-hydroxyflavone derivatives preferentially inhibited P450 1A2, while beta-naphthoflavone-like flavone derivatives showed selective inhibition of P450 1A1. On the basis of structural analysis, the active site cavity models of P450 enzymes 1A1 and 1A2 were generated, demonstrating a planar long strip cavity and a planar triangular cavity, respectively. PMID:23600958

  19. Synthesis and in vitro antitumor activity of new series of benzothiazole and pyrimido[2,1-b]benzothiazole derivatives.

    PubMed

    Gabr, Moustafa T; El-Gohary, Nadia S; El-Bendary, Eman R; El-Kerdawy, Mohamed M

    2014-10-06

    New series of benzothiazole and pyrimido[2,1-b]benzothiazole derivatives were synthesized and characterized by analytical and spectrometrical methods (IR, HRMS, (1)H and (13)C NMR). Nineteen of the synthesized compounds were selected by the National Cancer Institute (NCI), USA, to be screened for their antitumor activity at a single dose (10 μM) against a panel of 60 cancer cell lines. The most active compounds, 4, 6, 10, 14, 17 and 20 were selected for further evaluation at five dose level screening. Compounds 17 (GI50 = 0.44 μM, TGI = 1.2 μM and LC50 MG-MID = 6.6 μM) and 4 (GI50 = 0.77 μM, TGI = 2.08 μM and LC50 MG-MID = 11.74 μM) were proved to be the most active members in this study. 3D and 2D pharmacophoric maps for the structural features of both compounds were studied.

  20. Status Report for Remediation Decision Support Project, Task 1, Activity 1.B – Physical and Hydraulic Properties Database and Interpretation

    SciTech Connect

    Rockhold, Mark L.

    2008-09-26

    The objective of Activity 1.B of the Remediation Decision Support (RDS) Project is to compile all available physical and hydraulic property data for sediments from the Hanford Site, to port these data into the Hanford Environmental Information System (HEIS), and to make the data web-accessible to anyone on the Hanford Local Area Network via the so-called Virtual Library. In past years efforts were made by RDS project staff to compile all available physical and hydraulic property data for Hanford sediments and to transfer these data into SoilVision{reg_sign}, a commercial geotechnical software package designed for storing, analyzing, and manipulating soils data. Although SoilVision{reg_sign} has proven to be useful, its access and use restrictions have been recognized as a limitation to the effective use of the physical and hydraulic property databases by the broader group of potential users involved in Hanford waste site issues. In order to make these data more widely available and useable, a decision was made to port them to HEIS and to make them web-accessible via a Virtual Library module. In FY08 the objectives of Activity 1.B of the RDS Project were to: (1) ensure traceability and defensibility of all physical and hydraulic property data currently residing in the SoilVision{reg_sign} database maintained by PNNL, (2) transfer the physical and hydraulic property data from the Microsoft Access database files used by SoilVision{reg_sign} into HEIS, which has most recently been maintained by Fluor-Hanford, Inc., (3) develop a Virtual Library module for accessing these data from HEIS, and (4) write a User's Manual for the Virtual Library module. The development of the Virtual Library module was to be performed by a third party under subcontract to Fluor. The intent of these activities is to make the available physical and hydraulic property data more readily accessible and useable by technical staff and operable unit managers involved in waste site assessments and

  1. PTP1B inhibitors from stems of Angelica keiskei (Ashitaba).

    PubMed

    Li, Jin-Long; Gao, Li-Xin; Meng, Fan-Wang; Tang, Chun-Lan; Zhang, Ru-Jun; Li, Jing-Ya; Luo, Cheng; Li, Jia; Zhao, Wei-Min

    2015-01-01

    Three new chalcones, xanthoangelols K-M (1-3), together with 19 known compounds were isolated from the stems of Angelica keiskei Koidzumi, a well-known rejuvenated and anti-diabetic plant originated from Japan. The structures of compounds 1-3 were elucidated on the basis of spectroscopic data and Mosher's method. All compounds were evaluated for their inhibitory activity against protein tyrosine phosphatase 1B (PTP1B). Among them, six chalcones, xanthoangelol K (1), xanthoangelol (4), xanthoangelol F (5), 4-hydroxyderricin (6), xanthoangelol D (7), xanthoangelol E (8), and a coumarin, methoxsalen (17), showed strong PTP1B inhibitory effect with IC50 values of 0.82, 1.97, 1.67, 2.47, 3.97, 1.43, and 2.53μg/mL, respectively. A kinetic study revealed that compound 1 inhibited PTP1B with characteristics typical of a competitive inhibitor. Molecular docking simulations elucidated that ring B of 1 may anchor in a pocket of PTP1B and the molecule is stabilized by hydrogen bonds with Arg47, Asp48, and π-π interaction with Phe182 of PTP1B.

  2. Cytochrome P450 1B1 gene polymorphisms as predictors of anticancer drug activity: studies with in vitro models.

    PubMed

    Laroche-Clary, Audrey; Le Morvan, Valérie; Yamori, Takao; Robert, Jacques

    2010-12-01

    Cytochrome P450 1B1 (CYP1B1) is found in tumor tissue and is suspected to play a role in oncogenesis and drug resistance. CYP1B1 gene polymorphisms have been associated with the risk of developing lung and other cancers. They may be associated with tumor response to anticancer drugs. We have determined 4 frequent nonsynonymous gene polymorphisms of CYP1B1 in the human tumor cell lines panels of the National Cancer Institute (NCI) and the Japanese Foundation for Cancer Research (JFCR): rs10012 (R48G), rs1056827 (A119S), rs1056836 (L432V), and rs1800440 (N453S). Numerous anticancer drugs have been tested against these panels that offer the opportunity to detect associations between gene polymorphisms and drug sensitivity. CYP1B1 single nucleotide polymorphisms were in marked linkage disequilibrium. The L432V allelic variants were significantly associated with reduced sensitivity to DNA-interacting anticancer agents, alkylators, camptothecins, topoisomerase II inhibitors, and some antimetabolites. For instance, in the NCI panel, cell lines homozygous for the V432 allele were globally 2-fold resistant to alkylating agents (P = 5 × 10(-10)) and 4.5-fold to camptothecins (P = 6.6 × 10(-9)) than cell lines homozygous for the L432 allele. Similar features were exhibited by the JFCR panel. Cell lines homozygous for the V432 allele were globally less sensitive to DNA-interfering drugs than cell lines having at least 1 common allele. There was no significant association between mRNA expression of CYP1B1 and CYP1B1 genotype, and no significant association between CYP1B1 mRNA expression and drug cytotoxicity. These observations open the way to clinical studies exploring the role of CYP1B1 gene polymorphisms for predicting tumor sensitivity to chemotherapy.

  3. Convergence of inhibitory neural inputs regulate motor activity in the murine and monkey stomach.

    PubMed

    Shaylor, Lara A; Hwang, Sung Jin; Sanders, Kenton M; Ward, Sean M

    2016-11-01

    Inhibitory motor neurons regulate several gastric motility patterns including receptive relaxation, gastric peristaltic motor patterns, and pyloric sphincter opening. Nitric oxide (NO) and purines have been identified as likely candidates that mediate inhibitory neural responses. However, the contribution from each neurotransmitter has received little attention in the distal stomach. The aims of this study were to identify the roles played by NO and purines in inhibitory motor responses in the antrums of mice and monkeys. By using wild-type mice and mutants with genetically deleted neural nitric oxide synthase (Nos1(-/-)) and P2Y1 receptors (P2ry1(-/-)) we examined the roles of NO and purines in postjunctional inhibitory responses in the distal stomach and compared these responses to those in primate stomach. Activation of inhibitory motor nerves using electrical field stimulation (EFS) produced frequency-dependent inhibitory junction potentials (IJPs) that produced muscle relaxations in both species. Stimulation of inhibitory nerves during slow waves terminated pacemaker events and associated contractions. In Nos1(-/-) mice IJPs and relaxations persisted whereas in P2ry1(-/-) mice IJPs were absent but relaxations persisted. In the gastric antrum of the non-human primate model Macaca fascicularis, similar NO and purine neural components contributed to inhibition of gastric motor activity. These data support a role of convergent inhibitory neural responses in the regulation of gastric motor activity across diverse species.

  4. GABA and neuroligin signaling: linking synaptic activity and adhesion in inhibitory synapse development

    PubMed Central

    Huang, Z. Josh; Scheiffele, Peter

    2013-01-01

    GABA-mediated synaptic inhibition is crucial in neural circuit operations. In mammalian brains, the development of inhibitory synapses and innervation patterns is often a prolonged postnatal process, regulated by neural activity. Emerging evidence indicates that GABA acts beyond inhibitory transmission and regulates inhibitory synapse development. Indeed, GABAA receptors not only function as chloride channels that regulate membrane voltage and conductance but also play structural roles in synapse maturation and stabilization. The link from GABAA receptors to post- and pre- synaptic adhesion is likely mediated, in part, by neuroligin-reurexin interactions, which are potent in promoting GABAergic synapse formation. Therefore, similar to glutamate signaling at excitatory synapse, GABA signaling may coordinate maturation of pre- and post- synaptic sites at inhibitory synapses. Defining the many steps from GABA signaling to receptor trafficking/stability and neuroligin function will provide further mechanistic insights into activity-dependent development and possibly plasticity of inhibitory synapses. PMID:18513949

  5. Testosterone 5alpha-reductase inhibitory active constituents of Piper nigrum leaf.

    PubMed

    Hirata, Noriko; Tokunaga, Masashi; Naruto, Shunsuke; Iinuma, Munekazu; Matsuda, Hideaki

    2007-12-01

    Previously we reported that Piper nigrum leaf extract showed a potent stimulation effect on melanogenesis and that (-)-cubebin (1) and (-)-3,4-dimethoxy-3,4-desmethylenedioxycubebin (2) were isolated as active constituents. As a part of our continuous studies on Piper species for the development of cosmetic hair-care agents, testosterone 5alpha-reductase inhibitory activity of aqueous ethanolic extracts obtained from several different parts of six Piper species, namely Piper nigrum, P. methysticum, P. betle, P. kadsura, P. longum, and P. cubeba, were examined. Among them, the extracts of P. nigrum leaf, P. nigrum fruit and P. cubeba fruit showed potent inhibitory activity. Activity-guided fractionation of P. nigrum leaf extract led to the isolation of 1 and 2. Fruits of P. cubeba contain 1 as a major lignan, thus inhibitory activity of the fruit may be attributable to 1. As a result of further assay on other known constituents of the cited Piper species, it was found that piperine, a major alkaloid amide of P. nigrum fruit, showed potent inhibitory activity, thus a part of the inhibitory activity of P. nigrum fruit may depend on piperine. The 5alpha-reductase inhibitory activities of 1 and piperine were found for the first time. In addition, the P. nigrum leaf extract showed in vivo anti-androgenic activity using the hair regrowth assay in testosterone sensitive male C57Black/6CrSlc strain mice.

  6. Angiotensin-converting enzyme inhibitory activity of peptides derived from caprine kefir.

    PubMed

    Quirós, A; Hernández-Ledesma, B; Ramos, M; Amigo, L; Recio, I

    2005-10-01

    In this study, a potent angiotensin-converting enzyme (ACE)-inhibitory activity was found in a commercial kefir made from caprine milk. The low molecular mass peptides released from caseins during fermentation were mainly responsible for this activity. Sixteen peptides were identified by HPLC-tandem mass spectrometry. Two of these peptides, with sequences PYVRYL and LVYPFTGPIPN, showed potent ACE-inhibitory properties. The impact of gastrointestinal digestion on ACE-inhibitory activity of kefir peptides was also evaluated. Some of these peptides were resistant to the incubation with pepsin followed by hydrolysis with Corolase PP. The ACE-inhibitory activity after simulated digestion was similar to or slightly lower than unhydrolyzed peptides, except for peptide beta-casein f(47-52) (DKIHPF), which exhibited an activity 8 times greater after hydrolysis.

  7. Inhibition of RhoA GTPase and the subsequent activation of PTP1B protects cultured hippocampal neurons against amyloid β toxicity

    PubMed Central

    2011-01-01

    Background Amyloid beta (Aβ) is the main agent responsible for the advent and progression of Alzheimer's disease. This peptide can at least partially antagonize nerve growth factor (NGF) signalling in neurons, which may be responsible for some of the effects produced by Aβ. Accordingly, better understanding the NGF signalling pathway may provide clues as to how to protect neurons from the toxic effects of Aβ. Results We show here that Aβ activates the RhoA GTPase by binding to p75NTR, thereby preventing the NGF-induced activation of protein tyrosine phosphatase 1B (PTP1B) that is required for neuron survival. We also show that the inactivation of RhoA GTPase and the activation of PTP1B protect cultured hippocampal neurons against the noxious effects of Aβ. Indeed, either pharmacological inhibition of RhoA with C3 ADP ribosyl transferase or the transfection of cultured neurons with a dominant negative form of RhoA protects cultured hippocampal neurons from the effects of Aβ. In addition, over-expression of PTP1B also prevents the deleterious effects of Aβ on cultured hippocampal neurons. Conclusion Our findings indicate that potentiating the activity of NGF at the level of RhoA inactivation and PTP1B activation may represent a new means to combat the noxious effects of Aβ in Alzheimer's disease. PMID:21294893

  8. Polysaccharide with antioxidant, α-amylase inhibitory and ACE inhibitory activities from Momordica charantia.

    PubMed

    Tan, Hwee-Feng; Gan, Chee-Yuen

    2016-04-01

    Functional polysaccharide was isolated from Momordica charantia, with a yield of 36% (w/w). M. charantia bioactive polysaccharide (MCBP) was an acidic and branched heteropolysaccharide with a molecular weight of 92 kDa. Fourier transform infrared spectroscopic analysis indicated that MCBP was a pectin-like polysaccharide with an esterification degree of 53% and it contains numerous monosaccharides, predominantly glucose, galactose, and galaturonic acid. The results also showed that MCBP exhibited free radical scavenging activity (31.9%), ferric reducing antioxidant power (0.95 mM), α-amylase inhibition (89.1%), and angiotensin-converting enzyme inhibition (94.1%). In the terms of functionality, MCBP showed a lower water-holding capacity but higher in oil-holding capacity, emulsifying activity and foaming capacity compared to citrus pectin. Scanning electron microscopy images demonstrated that MCBP formed gels with a porous structure, and flow analysis showed that the gel solution exhibited pseudoplastic shear-thinning behavior. These findings indicated that MCBP is a promising functional macromolecular carbohydrate for the food and nutraceutical industries.

  9. Design, synthesis and aromatase inhibitory activities of novel indole-imidazole derivatives.

    PubMed

    Wang, Rui; Shi, Hong-Fan; Zhao, Jing-Feng; He, Yan-Ping; Zhang, Hong-Bin; Liu, Jian-Ping

    2013-03-15

    A series of novel indole-imidazole derivatives have been prepared and evaluated in vitro on the aromatase inhibitory activities. The results suggested that proton or a small electron-withdrawing group at para-position of the phenyl ring would enhance the inhibitory activities and any bulky group should be avoided in order to keep a relative small volume for this kind of molecules.

  10. Remodeling and Tenacity of Inhibitory Synapses: Relationships with Network Activity and Neighboring Excitatory Synapses.

    PubMed

    Rubinski, Anna; Ziv, Noam E

    2015-11-01

    Glutamatergic synapse size remodeling is governed not only by specific activity forms but also by apparently stochastic processes with well-defined statistics. These spontaneous remodeling processes can give rise to skewed and stable synaptic size distributions, underlie scaling of these distributions and drive changes in glutamatergic synapse size "configurations". Where inhibitory synapses are concerned, however, little is known on spontaneous remodeling dynamics, their statistics, their activity dependence or their long-term consequences. Here we followed individual inhibitory synapses for days, and analyzed their size remodeling dynamics within the statistical framework previously developed for glutamatergic synapses. Similar to glutamatergic synapses, size distributions of inhibitory synapses were skewed and stable; at the same time, however, sizes of individual synapses changed considerably, leading to gradual changes in synaptic size configurations. The suppression of network activity only transiently affected spontaneous remodeling dynamics, did not affect synaptic size configuration change rates and was not followed by the scaling of inhibitory synapse size distributions. Comparisons with glutamatergic synapses within the same dendrites revealed a degree of coupling between nearby inhibitory and excitatory synapse remodeling, but also revealed that inhibitory synapse size configurations changed at considerably slower rates than those of their glutamatergic neighbors. These findings point to quantitative differences in spontaneous remodeling dynamics of inhibitory and excitatory synapses but also reveal deep qualitative similarities in the processes that control their sizes and govern their remodeling dynamics.

  11. Remodeling and Tenacity of Inhibitory Synapses: Relationships with Network Activity and Neighboring Excitatory Synapses

    PubMed Central

    Rubinski, Anna; Ziv, Noam E.

    2015-01-01

    Glutamatergic synapse size remodeling is governed not only by specific activity forms but also by apparently stochastic processes with well-defined statistics. These spontaneous remodeling processes can give rise to skewed and stable synaptic size distributions, underlie scaling of these distributions and drive changes in glutamatergic synapse size “configurations”. Where inhibitory synapses are concerned, however, little is known on spontaneous remodeling dynamics, their statistics, their activity dependence or their long-term consequences. Here we followed individual inhibitory synapses for days, and analyzed their size remodeling dynamics within the statistical framework previously developed for glutamatergic synapses. Similar to glutamatergic synapses, size distributions of inhibitory synapses were skewed and stable; at the same time, however, sizes of individual synapses changed considerably, leading to gradual changes in synaptic size configurations. The suppression of network activity only transiently affected spontaneous remodeling dynamics, did not affect synaptic size configuration change rates and was not followed by the scaling of inhibitory synapse size distributions. Comparisons with glutamatergic synapses within the same dendrites revealed a degree of coupling between nearby inhibitory and excitatory synapse remodeling, but also revealed that inhibitory synapse size configurations changed at considerably slower rates than those of their glutamatergic neighbors. These findings point to quantitative differences in spontaneous remodeling dynamics of inhibitory and excitatory synapses but also reveal deep qualitative similarities in the processes that control their sizes and govern their remodeling dynamics. PMID:26599330

  12. Acetylcholinesterase-inhibitory activities of the extracts from sponges collected in mauritius waters.

    PubMed

    Beedessee, Girish; Ramanjooloo, Avin; Surnam-Boodhun, Rashmee; van Soest, Rob W M; Marie, Daniel E P

    2013-03-01

    Patients diagnosed with Alzheimer's disease (AD) show a characteristic neurochemical deficit of acetylcholine, especially in the basal forebrains. The use of acetylcholinesterase (AChE) inhibitors to retard the hydrolysis of acetylcholine has been suggested as a promising strategy for AD treatment. In this study, we evaluated the acetylcholinesterase inhibitory (AChEI) activities of 134 extracts obtained from 45 species of marine sponges. Thin-layer chromatography (TLC) and microplate assays reveal potent acetylcholinsterase inhibitory activities of two AcOEt extracts from the sponges Pericharax heteroraphis and Amphimedon navalis PULITZER-FINALI. We further investigated the inhibitory kinetics of the extracts and found them to display mixed competitive/noncompetitive inhibition and associated their inhibitory activity partly to terpenoids. Acetylcholinesterase inhibitors from marine organisms have been rarely studied, and this study demonstrated the potential of marine sponges as a source of pharmaceutical leads against neurodegenerative diseases.

  13. DYRK1B blocks canonical and promotes non-canonical Hedgehog signaling through activation of the mTOR/AKT pathway

    PubMed Central

    Singh, Rajeev; Dhanyamraju, Pavan Kumar; Lauth, Matthias

    2017-01-01

    Hedgehog (Hh) signaling plays important roles in embryonic development and in tumor formation. Apart from the well-established stimulation of the GLI family of transcription factors, Hh ligands promote the phosphorylation and activation of mTOR and AKT kinases, yet the molecular mechanism underlying these processes are unknown. Here, we identify the DYRK1B kinase as a mediator between Hh signaling and mTOR/AKT activation. In fibroblasts, Hh signaling induces DYRK1B protein expression, resulting in activation of the mTOR/AKT kinase signaling arm. Furthermore, DYRK1B exerts positive and negative feedback regulation on the Hh pathway itself: It negatively interferes with SMO-elicited canonical Hh signaling, while at the same time it provides positive feed-forward functions by promoting AKT-mediated GLI stability. Due to the fact that the mTOR/AKT pathway is itself subject to strong negative feedback regulation, pharmacological inhibition of DYRK1B results in initial upregulation followed by downregulation of AKT phosphorylation and GLI stabilization. Addressing this issue therapeutically, we show that a pharmacological approach combining a DYRK1B antagonist with an mTOR/AKT inhibitor results in strong GLI1 targeting and in pronounced cytotoxicity in human pancreatic and ovarian cancer cells. PMID:27903983

  14. Down-regulated expression of the protein-tyrosine phosphatase 1B (PTP1B) is associated with aggressive clinicopathologic features and poor prognosis in hepatocellular carcinoma

    SciTech Connect

    Zheng, Long-Yi; Zhou, Dong-Xun; Lu, Jin; Zhang, Wen-Jun; Zou, Da-Jin

    2012-04-13

    Highlights: Black-Right-Pointing-Pointer PTP1B protein showed decreased expression in 67.79% of the HCC patients. Black-Right-Pointing-Pointer Low PTP1B expression predicts poor prognosis of HCC. Black-Right-Pointing-Pointer Low PTP1B expression is correlated with expansion of OV6{sup +} tumor-initiating cells. Black-Right-Pointing-Pointer Down-regulation of PTP1B is associated with activation of Wnt/{beta}-Catenin signaling. -- Abstract: The protein-tyrosine phosphatase 1B (PTP1B) is a classical non-transmembrane protein tyrosine phosphatase that plays a key role in metabolic signaling and can exert both tumor suppressing and tumor promoting effects in different cancers depending on the substrate involved and the cellular context. However, the expression level and function of PTP1B in hepatocellular carcinoma (HCC) remain unclear. In this study, PTP1B expression was detected by immunohistochemistry in normal liver tissue (n = 16) and hepatocellular carcinoma (n = 169). The correlations between PTP1B expression level and clinicopathologic features and patient survival were also analyzed. One hundred and eleven of 169 HCC patients (65.7%) had negative or low PTP1B expression in tumorous tissues, whereas normal tissues always expressed strong PTP1B. Decreased PTP1B expression was significantly associated with aggressive clinicopathologic features and poor prognosis. Immunohistochemistry also showed that low PTP1B expression level was correlated with high percentage of OV6{sup +} tumor-initiating cells (T-ICs) and high frequency of nuclear {beta}-Catenin expression in HCC specimens. Our findings demonstrate for the first time that the loss of inhibitory effect of PTP1B may contribute to progression and invasion of HCC through activation of Wnt/{beta}-Catenin signaling and expansion of liver T-ICs. PTP1B may serve as a valuable prognostic biomarker and potential therapeutic target in HCC.

  15. Characterization of angiotensin-converting enzyme inhibitory activity of fermented milk produced by Lactobacillus helveticus.

    PubMed

    Chen, Yongfu; Li, Changkun; Xue, Jiangang; Kwok, Lai-yu; Yang, Jie; Zhang, Heping; Menghe, Bilige

    2015-08-01

    Hypertension affects up to 30% of the adult population in most countries. It is a known risk factor for cardiovascular diseases, including coronary heart disease, peripheral artery disease, and stroke. Owing to the increased health awareness of consumers, the application of angiotensin-converting enzyme (ACE)-inhibitory peptides produced by Lactobacillushelveticus to prevent or control high blood pressure has drawn wide attention. A total of 59 L. helveticus strains were isolated from traditional fermented dairy products and the ACE-inhibitory activity of the fermented milks produced with the isolated microorganisms was assayed. The ACE-inhibitory activity of 38 L. helveticus strains was more than 50%, and 3 strains (IMAU80872, IMAU80852, and IMAU80851) expressing the highest ACE-inhibitory activity were selected for further studies. Particularly, the gastrointestinal protease tolerance and thermostability of the ACE-inhibitory activity in the fermented milks were assessed. Based on these 2 criteria, IMAU80872 was found to be superior over the other 2 strains. Furthermore, IMAU80872 exhibited a high in vitro ACE-inhibitory activity at the following fermentation conditions: fermentation temperature at 40°C, inoculation concentration of 1×10(6) cfu/mL, and fermentation for 18h. Finally, by using ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry analysis, we observed changes of the metabolome along the milk fermentation process of IMAU80872. Furthermore, 6 peptides were identified, which might have ACE-inhibitory activity. In conclusion, we identified a novel ACE-inhibitory L. helveticus strain suitable for the production of fermented milk or other functional dairy products.

  16. Hyaluronidase-inhibitory activities of glycosaminoglycans from Liparis tessellatus eggs.

    PubMed

    Ticar, Bernadeth F; Rohmah, Zuliyati; Mussatto, Solange I; Lim, Jae-Min; Park, Seongha; Choi, Byeong-Dae

    2017-04-01

    Polysaccharide fractions isolated from L. tessellatus eggs were purified and eluted using the DEAE-sepharose fast flow column. These were collected, tested and pooled based on their sugars content: F1, F2, and F3 which contain 26.8, 23.3, and 20.2% sulfated glycans; 34.5, 38.2, and 45.0% uronic acids; and 23.5, 19.0, and 7.5% acetylhexosamines and hexosamines, respectively. Hyaluronidase inhibitory effects of the fractions are in the order F3>F2>F1>Ascorbic acid, with F3 having the highest inhibition among the fractions and that of the standard, ascorbic acid. The electrospray ionization tandem mass spectrometry (ESI-MS/MS) confirmed the presence of uronic acids on F3, which could be a (0,2)A2 fragment plus loss of methyl group which is very common among non-methylated, sulfated disaccharides.

  17. Neuronal activity and TrkB ligands influence Kv3.1b and Kv3.2 expression in developing cortical interneurons.

    PubMed

    Grabert, J; Wahle, P

    2008-10-15

    Among the GABAergic neocortical interneurons, fast-spiking (FS) basket and chandelier cells are essential mediators for feed-forward inhibition, network synchrony and oscillations. The FS properties are in part mediated by the voltage-gated potassium channels Kv3.1b/3.2 which allow the fast repolarization of the membrane necessary for firing non-adapting action potentials at high frequencies. It has been recently reported that the FS phenotype fails to mature in BDNF knockout mice suggesting a role for neurotrophins. We now describe the role of neuronal activity and neurotrophins for Kv3.1b/3.2 expression using organotypic cultures of rat visual cortex as model system. Chronic activity deprivation from 2 days in vitro (DIV) prevented the postnatal developmental increase of Kv3.2, but not Kv3.1b mRNA expression. However, chronic activity deprivation failed to alter Kv3.1b and marginally delayed Kv3.2 protein expression. Activity deprivation by glutamate receptor blockade from 10 to 20 DIV reduced both mRNAs, whereas deprivation with tetrodotoxin (TTX) reduced both mRNAs and the Kv3.2 protein. Thalamic and cortical afferents in cocultures failed to alter the expression. BDNF and NT4 supplemented from 2 DIV onwards increased the expression of Kv3.1b, but not Kv3.2 mRNA in young cultures. Only NT4 increased the expression of both mRNAs later in development. Kv3 protein levels were not changed by exogenous tropomyosin-related kinase B (TrkB) ligands, but the levels decreased upon inhibiting the MAPK signaling suggesting a role for endogenous factors and in particular MEK2 signaling for translation. The results show that Kv3.1b/3.2 expression is differentially controlled by neuronal activity and neurotrophic factors.

  18. A rationally-designed chimeric KDM1A/KDM1B histone demethylase tower domain deletion mutant retaining enzymatic activity.

    PubMed

    Burg, Jonathan M; Makhoul, Alan T; Pemble, Charles W; Link, Jennifer E; Heller, Frederick J; McCafferty, Dewey G

    2015-08-19

    A target with therapeutic potential, lysine-specific demethylase 1A (KDM1A) is a regulator of gene expression whose tower domain is a protein-protein interaction motif. This domain facilitates the interaction of KDM1A with coregulators and multiprotein complexes that direct its activity to nucleosomes. We describe the design and characterization of a chimeric 'towerless' KDM1A, termed nΔ150 KDM1AΔTower KDM1B chimera (chKDM1AΔTower), which incorporates a region from the paralog lysine-specific demethylase 1B (KDM1B). This chimera copurifies with FAD and displays demethylase activity, but fails to bind the partner protein corepressor of the RE1-silencing transcription factor (CoREST). We conclude that KDM1A catalysis can be decoupled from tower-dependent interactions, lending chKDM1AΔTower useful for dissecting molecular contributions to KDM1A function.

  19. REM theta activity enhances inhibitory control in typically developing children but not children with ADHD symptoms.

    PubMed

    Cremone, Amanda; Lugo-Candelas, Claudia I; Harvey, Elizabeth A; McDermott, Jennifer M; Spencer, Rebecca M C

    2017-02-28

    Sleep disturbances impair cognitive functioning in typically developing populations. Children with attention-deficit/hyperactivity disorder (ADHD), a disorder characterized by impaired inhibitory control and attention, commonly experience sleep disturbances. Whether inhibitory impairments are related to sleep deficits in children with ADHD is unknown. Children with ADHD (n = 18; M age = 6.70 years) and typically developing controls (n = 15; M age = 6.73 years) completed a Go/No-Go task to measure inhibitory control and sustained attention before and after polysomnography-monitored overnight sleep. Inhibitory control and sustained attention were improved following overnight sleep in typically developing children. Moreover, morning inhibitory control was positively correlated with rapid eye movement (REM) theta activity in this group. Although REM theta activity was greater in children with ADHD compared to typically developing children, it was functionally insignificant. Neither inhibitory control nor sustained attention was improved following overnight sleep in children with ADHD symptoms, and neither of these behaviors was associated with REM theta activity in this group. Taken together, these results indicate that elevated REM theta activity may be functionally related to ADHD symptomology, possibly reflecting delayed cortical maturation.

  20. Interaction of digitalis-like compounds with liver uptake transporters NTCP, OATP1B1, and OATP1B3.

    PubMed

    Gozalpour, Elnaz; Greupink, Rick; Wortelboer, Heleen M; Bilos, Albert; Schreurs, Marieke; Russel, Frans G M; Koenderink, Jan B

    2014-06-02

    Digitalis-like compounds (DLCs) such as digoxin, digitoxin, and ouabain, also known as cardiac glycosides, are among the oldest pharmacological treatments for heart failure. The compounds have a narrow therapeutic window, while at the same time, DLC pharmacokinetics is prone to drug-drug interactions at the transport level. Hepatic transporters organic anion transporting polypeptide (OATP) 1B1, OATP1B3, and Na(+)-dependent taurocholate co-transporting polypeptide (NTCP) influence the disposition of a variety of drugs by mediating their uptake from blood into hepatocytes. The interaction of digoxin, digitoxin, and ouabain with hepatic uptake transporters has been studied before. However, here, we systematically investigated a much wider range of structurally related DLCs for their capability to inhibit or to be transported by these transporters in order to better understand the relation between the activity and chemical structure of this compound type. We studied the uptake and inhibitory potency of a series of 14 structurally related DLCs in Chinese hamster ovary cells expressing NTCP (CHO-NTCP) and human embryonic kidney cells expressing OATP1B1 and OATP1B3 (HEK-OATP1B1 and HEK-OATP1B3). The inhibitory effect of the DLCs was measured against taurocholic acid (TCA) uptake in CHO-NTCP cells and against uptake of β-estradiol 17-β-d-glucuronide (E217βG) in HEK-OATP1B1 and HEK-OATP1B3 cells. Proscillaridin A was the most effective inhibitor of NTCP-mediated TCA transport (IC50 = 22 μM), whereas digitoxin and digitoxigenin were the most potent inhibitors of OATP1B1 and OAPTP1B3, with IC50 values of 14.2 and 36 μM, respectively. Additionally, we found that the sugar moiety and hydroxyl groups of the DLCs play different roles in their interaction with NTCP, OATP1B1, and OATP1B3. The sugar moiety decreases the inhibition of NTCP and OATP1B3 transport activity, whereas it enhances the inhibitory potency against OATP1B1. Moreover, the hydroxyl group at position 12

  1. Synthesis and acetylcholinesterase inhibitory activity of polyhydroxylated sulfated steroids: structure/activity studies.

    PubMed

    Richmond, Victoria; Murray, Ana P; Maier, Marta S

    2013-11-01

    Disulfated and trisulfated steroids have been synthesized from cholesterol and their acetylcholinesterase inhibitory activity has been evaluated. In our studies we have found that the activity was not only dependent on the location of the sulfate groups but on their configurations. 2β,3α,6α-trihydroxy-5α-cholestan-6-one trisulfate (18) was the most active steroid with an IC50 value of 15.48 μM comparable to that of 2β,3α-dihydroxy-5α-cholestan-6-one disulfate (1). Both compounds were found to be less active than the reference compound eserine. The butyrylcholinesterase activity of 1 and 18 was one magnitude lower than that against acetylcholinesterase revealing a selective inhibitor profile.

  2. Protein Kinase C Activation Promotes α1B-Adrenoceptor Internalization and Late Endosome Trafficking through Rab9 Interaction. Role in Heterologous Desensitization.

    PubMed

    Alfonzo-Méndez, Marco A; Hernández-Espinosa, David A; Carmona-Rosas, Gabriel; Romero-Ávila, M Teresa; Reyes-Cruz, Guadalupe; García-Sáinz, J Adolfo

    2017-04-01

    Upon agonist stimulation, α1B-adrenergic receptors couple to Gq proteins, calcium signaling and protein kinase C activation; subsequently, the receptors are phosphorylated, desensitized, and internalized. Internalization seems to involve scaffolding proteins, such as β-arrestin and clathrin. However, the fine mechanisms that participate remain unsolved. The roles of protein kinase C and the small GTPase, Rab9, in α1B-AR vesicular traffic were investigated by studying α1B-adrenergic receptor-Rab protein interactions, using Förster resonance energy transfer (FRET), confocal microscopy, and intracellular calcium quantitation. In human embryonic kidney 293 cells overexpressing Discosoma spp. red fluorescent protein (DsRed)-tagged α1B-ARs and enhanced green fluorescent protein--tagged Rab proteins, pharmacological protein kinase C activation mimicked α1B-AR traffic elicited by nonrelated agents, such as sphingosine 1-phosphate (i.e., transient α1B-AR-Rab5 FRET signal followed by a sustained α1B-AR-Rab9 interaction), suggesting brief receptor localization in early endosomes and transfer to late endosomes. This latter interaction was abrogated by blocking protein kinase C activity, resulting in receptor retention at the plasma membrane. Similar effects were observed when a dominant-negative Rab9 mutant (Rab9-GDP) was employed. When α1B-adrenergic receptors that had been mutated at protein kinase C phosphorylation sites (S396A, S402A) were used, phorbol ester-induced desensitization of the calcium response was markedly decreased; however, interaction with Rab9 was only partially decreased and internalization was observed in response to phorbol esters and sphingosine 1-phosphate. Finally, Rab9-GDP expression did not affect adrenergic-mediated calcium response but abolished receptor traffic and altered desensitization. Data suggest that protein kinase C modulates α1B-adrenergic receptor transfer to late endosomes and that Rab9 regulates this process and

  3. 7,12-Dimethylbenzanthracene induces apoptosis in RL95-2 human endometrial cancer cells: Ligand-selective activation of cytochrome P450 1B1

    SciTech Connect

    Kim, Ji Young; Lee, Seung Gee; Chung, Jin-Yong; Kim, Yoon-Jae; Park, Ji-Eun; Oh, Seunghoon; Lee, Se Yong; Choi, Hong Jo; Yoo, Young Hyun; and others

    2012-04-15

    7,12-Dimethylbenzanthracene (DMBA), a polycyclic aromatic hydrocarbon, exhibits mutagenic, carcinogenic, immunosuppressive, and apoptogenic properties in various cell types. To achieve these functions effectively, DMBA is modified to its active form by cytochrome P450 1 (CYP1). Exposure to DMBA causes cytotoxicity-mediated apoptosis in bone marrow B cells and ovarian cells. Although uterine endometrium constitutively expresses CYP1A1 and CYP1B1, their apoptotic role after exposure to DMBA remains to be elucidated. Therefore, we chose RL95-2 endometrial cancer cells as a model system for studying DMBA-induced cytotoxicity and cell death and hypothesized that exposure to DMBA causes apoptosis in this cell type following CYP1A1 and/or CYP1B1 activation. We showed that DMBA-induced apoptosis in RL95-2 cells is associated with activation of caspases. In addition, mitochondrial changes, including decrease in mitochondrial potential and release of mitochondrial cytochrome c into the cytosol, support the hypothesis that a mitochondrial pathway is involved in DMBA-induced apoptosis. Exposure to DMBA upregulated the expression of AhR, Arnt, CYP1A1, and CYP1B1 significantly; this may be necessary for the conversion of DMBA to DMBA-3,4-diol-1,2-epoxide (DMBA-DE). Although both CYP1A1 and CYP1B1 were significantly upregulated by DMBA, only CYP1B1 exhibited activity. Moreover, knockdown of CYP1B1 abolished DMBA-induced apoptosis in RL95-2 cells. Our data show that RL95-2 cells are susceptible to apoptosis by exposure to DMBA and that CYP1B1 plays a pivotal role in DMBA-induced apoptosis in this system. -- Highlights: ► Cytotoxicity-mediated apoptogenic action of DMBA in human endometrial cancer cells. ► Mitochondrial pathway in DMBA-induced apoptosis of RL95-2 endometrial cancer cells. ► Requirement of ligand-selective activation of CYP1B1 in DMBA-induced apoptosis.

  4. In vitro evidence that KLK14 regulates the components of the HGF/Met axis, pro-HGF and HGF-activator inhibitor 1A and 1B.

    PubMed

    Reid, Janet C; Bennett, Nigel C; Stephens, Carson R; Carroll, Melanie L; Magdolen, Viktor; Clements, Judith A; Hooper, John D

    2016-12-01

    Kallikrein-related peptidase (KLK) 14 is a serine protease linked to several pathologies including prostate cancer. We show that KLK14 has biphasic effects in vitro on activating and inhibiting components of the prostate cancer associated hepatocyte growth factor (HGF)/Met system. At 5-10 nm, KLK14 converts pro-HGF to the two-chain heterodimer required for Met activation, while higher concentrations degrade the HGF α-chain. HGF activator-inhibitor (HAI)-1A and HAI-1B, which inhibit pro-HGF activators, are degraded by KLK14 when protease:inhibitor stoichiometry is 1:1 or the protease is in excess. When inhibitors are in excess, KLK14 generates HAI-1A and HAI-1B fragments known to inhibit pro-HGF activating serine proteases. These in vitro data suggest that increased KLK14 activity could contribute at multiple levels to HGF/Met-mediated processes in prostate and other cancers.

  5. Discrimination and Nitric Oxide Inhibitory Activity Correlation of Ajwa Dates from Different Grades and Origin.

    PubMed

    Abdul-Hamid, Nur Ashikin; Mediani, Ahmed; Maulidiani, M; Abas, Faridah; Ismail, Intan Safinar; Shaari, Khozirah; Lajis, Nordin H

    2016-10-28

    This study was aimed at examining the variations in the metabolite constituents of the different Ajwa grades and farm origins. It is also targeted at establishing the correlations between the metabolite contents and the grades and further to the nitric oxide (NO) inhibitory activity. Identification of the metabolites was generated using ¹H-NMR spectroscopy metabolomics analyses utilizing multivariate methods. The NO inhibitory activity was determined using a Griess assay. Multivariate data analysis, for both supervised and unsupervised approaches, showed clusters among different grades of Ajwa dates obtained from different farms. The compounds that contribute towards the observed separation between Ajwa samples were suggested to be phenolic compounds, ascorbic acid and phenylalanine. Ajwa dates were shown to have different metabolite compositions and exhibited a wide range of NO inhibitory activity. It is also revealed that Ajwa Grade 1 from the al-Aliah farm exhibited more than 90% NO inhibitory activity compared to the other grades and origins. Phenolic compounds were among the compounds that played a role towards the greater capacity of NO inhibitory activity shown by Ajwa Grade 1 from the al-Aliah farm.

  6. Glucosidase inhibitory activity and antioxidant activity of flavonoid compound and triterpenoid compound from Agrimonia Pilosa Ledeb

    PubMed Central

    2014-01-01

    Background In Chinese traditional medicine, Agrimonia pilosa Ledeb (APL) exhibits great effect on treatment of type 2 diabetes mellitus (T2DM), however its mechanism is still unknown. Considering that T2DM are correlated with postprandial hyperglycemia and oxidative stress, we investigated the α-glucosidase inhibitory activity and the antioxidant activity of flavonoid compound (FC) and triterpenoid compound (TC) from APL. Methods Entire plants of APL were extracted using 95% ethanol and 50% ethanol successively. The resulting extracts were partitioned and isolated by applying liquid chromatography using silica gel column and Sephadex LH 20 column to give FC and TC. The content of total flavonoids in FC and the content of total triterpenoids in TC were determined by using UV spectrophotometry. HPLC analysis was used to identify and quantify the monomeric compound in FC and TC. The α-glucosidase inhibitory activities were determined using the chromogenic method with p-nitrophenyl-α-D-glucopyranoside as substrate. Antioxidant activities were assessed through three kinds of radical scavenging assays (DPPH radical, ABTS radical and hydroxyl radical) & β-carotene-linoleic acid assay. Results The results indicate FC is abundant of quercitrin, and hyperoside, and TC is abundant of 1β, 2β, 3β, 19α-tetrahydroxy-12-en-28-oic acid (265.2 mg/g) and corosolic acid (100.9 mg/g). The FC & the TC have strong α-glucosidase inhibitory activities with IC50 of 8.72 μg/mL and 3.67 μg/mL, respectively. We find that FC show competitive inhibition against α-glucosidase, while the TC exhibits noncompetitive inhibition. Furthermore, The FC exhibits significant radical scavenging activity with the EC50 values of 7.73 μg/mL, 3.64 μg/mL and 5.90 μg/mL on DPPH radical, hydroxyl radical and ABTS radical, respectively. The FC also shows moderate anti-lipid peroxidation activity with the IC50 values of 41.77 μg/mL on inhibiting β-carotene bleaching. Conclusion These results

  7. Inhibitory Activity of (+)-Usnic Acid against Non-Small Cell Lung Cancer Cell Motility.

    PubMed

    Yang, Yi; Nguyen, Thanh Thi; Jeong, Min-Hye; Crişan, Florin; Yu, Young Hyun; Ha, Hyung-Ho; Choi, Kyung Hee; Jeong, Hye Gwang; Jeong, Tae Cheon; Lee, Kwang Youl; Kim, Kyung Keun; Hur, Jae-Seoun; Kim, Hangun

    2016-01-01

    Lichens are symbiotic organisms that produce various unique chemicals that can be used for pharmaceutical purposes. With the aim of screening new anti-cancer agents that inhibit cancer cell motility, we tested the inhibitory activity of seven lichen species collected from the Romanian Carpathian Mountains against migration and invasion of human lung cancer cells and further investigated the molecular mechanisms underlying their anti-metastatic activity. Among them, Alectoria samentosa, Flavocetraria nivalis, Alectoria ochroleuca, and Usnea florida showed significant inhibitory activity against motility of human lung cancer cells. HPLC results showed that usnic acid is the main compound in these lichens, and (+)-usnic acid showed similar inhibitory activity that crude extract have. Mechanistically, β-catenin-mediated TOPFLASH activity and KITENIN-mediated AP-1 activity were decreased by (+)-usnic acid treatment in a dose-dependent manner. The quantitative real-time PCR data showed that (+)-usnic acid decreased the mRNA level of CD44, Cyclin D1 and c-myc, which are the downstream target genes of both β-catenin/LEF and c-jun/AP-1. Also, Rac1 and RhoA activities were decreased by treatment with (+)-usnic acid. Interestingly, higher inhibitory activity for cell invasion was observed when cells were treated with (+)-usnic acid and cetuximab. These results implied that (+)-usnic acid might have potential activity in inhibition of cancer cell metastasis, and (+)-usnic acid could be used for anti-cancer therapy with a distinct mechanisms of action.

  8. Inhibitory Activity of (+)-Usnic Acid against Non-Small Cell Lung Cancer Cell Motility

    PubMed Central

    Yang, Yi; Nguyen, Thanh Thi; Jeong, Min-Hye; Crişan, Florin; Yu, Young Hyun; Ha, Hyung-Ho; Choi, Kyung Hee; Jeong, Hye Gwang; Jeong, Tae Cheon; Lee, Kwang Youl; Kim, Kyung Keun; Hur, Jae-Seoun; Kim, Hangun

    2016-01-01

    Lichens are symbiotic organisms that produce various unique chemicals that can be used for pharmaceutical purposes. With the aim of screening new anti-cancer agents that inhibit cancer cell motility, we tested the inhibitory activity of seven lichen species collected from the Romanian Carpathian Mountains against migration and invasion of human lung cancer cells and further investigated the molecular mechanisms underlying their anti-metastatic activity. Among them, Alectoria samentosa, Flavocetraria nivalis, Alectoria ochroleuca, and Usnea florida showed significant inhibitory activity against motility of human lung cancer cells. HPLC results showed that usnic acid is the main compound in these lichens, and (+)-usnic acid showed similar inhibitory activity that crude extract have. Mechanistically, β-catenin-mediated TOPFLASH activity and KITENIN-mediated AP-1 activity were decreased by (+)-usnic acid treatment in a dose-dependent manner. The quantitative real-time PCR data showed that (+)-usnic acid decreased the mRNA level of CD44, Cyclin D1 and c-myc, which are the downstream target genes of both β-catenin/LEF and c-jun/AP-1. Also, Rac1 and RhoA activities were decreased by treatment with (+)-usnic acid. Interestingly, higher inhibitory activity for cell invasion was observed when cells were treated with (+)-usnic acid and cetuximab. These results implied that (+)-usnic acid might have potential activity in inhibition of cancer cell metastasis, and (+)-usnic acid could be used for anti-cancer therapy with a distinct mechanisms of action. PMID:26751081

  9. Understanding the molecular mechanism for the differential inhibitory activities of compounds against MTH1.

    PubMed

    Wang, Mian; Zhou, Shuilian; Chen, Qing; Wang, Lisheng; Liang, Zhiqun; Wang, Jianyi

    2017-01-11

    MTH1 can hydrolyze oxidized nucleotides and is required for cancer survival. The IC50 values were 0.8 nM for TH287 with a methyl substitution, 5.0 nM for TH588 with a cyclopropyl substitution, and 2.1 μM for TH650 with an oxetanyl substitution. Thus, it is very significant to understand inhibitory mechanisms of these structurally similar compounds against MTH1 and influences of the substituent on the bioactivities. Our MD researches indicate that TH287 maintains significant hydrogen bonds with Asn33 and Asp119, stabilizes the binding site, and induces MTH1 adopt a closed motion, leading to a high inhibitory activity. When bound with TH588, the binding site can be partially stabilized and take a semi-closed state, which is because the cyclopropyl group in TH588 has larger steric hindrance than a methyl group in TH287. So TH588 has a slightly reduced inhibitory activity compared to TH287. TH650 induces greater conformation fluctuations than TH588 and the binding site adopts an opening state, which is caused by the large bulk of oxetanyl group and the interference of solvent on the oxetanyl substituent, leading to the lowest inhibitory activity. Thus, the inhibitory activity follows a TH287 > TH588 > TH650 trend, which well matches with the experimental finding.

  10. Understanding the molecular mechanism for the differential inhibitory activities of compounds against MTH1

    NASA Astrophysics Data System (ADS)

    Wang, Mian; Zhou, Shuilian; Chen, Qing; Wang, Lisheng; Liang, Zhiqun; Wang, Jianyi

    2017-01-01

    MTH1 can hydrolyze oxidized nucleotides and is required for cancer survival. The IC50 values were 0.8 nM for TH287 with a methyl substitution, 5.0 nM for TH588 with a cyclopropyl substitution, and 2.1 μM for TH650 with an oxetanyl substitution. Thus, it is very significant to understand inhibitory mechanisms of these structurally similar compounds against MTH1 and influences of the substituent on the bioactivities. Our MD researches indicate that TH287 maintains significant hydrogen bonds with Asn33 and Asp119, stabilizes the binding site, and induces MTH1 adopt a closed motion, leading to a high inhibitory activity. When bound with TH588, the binding site can be partially stabilized and take a semi-closed state, which is because the cyclopropyl group in TH588 has larger steric hindrance than a methyl group in TH287. So TH588 has a slightly reduced inhibitory activity compared to TH287. TH650 induces greater conformation fluctuations than TH588 and the binding site adopts an opening state, which is caused by the large bulk of oxetanyl group and the interference of solvent on the oxetanyl substituent, leading to the lowest inhibitory activity. Thus, the inhibitory activity follows a TH287 > TH588 > TH650 trend, which well matches with the experimental finding.

  11. Absolute Side-chain Structure at Position 13 Is Required for the Inhibitory Activity of Bromein*

    PubMed Central

    Sawano, Yoriko; Hatano, Ken-ichi; Miyakawa, Takuya; Tanokura, Masaru

    2008-01-01

    Bromelain isoinhibitor (bromein), a cysteine proteinase inhibitor from pineapple stem, has a unique double-chain structure. The bromein precursor protein includes three homologous inhibitor domains, each containing an interchain peptide between the light and heavy chains. The interchain peptide in the single-chain precursor is immediately processed by bromelain, a target proteinase. In the present study, to clarify the essential inhibitory site of bromein, we constructed 44 kinds of site-directed and deletion mutants and investigated the inhibitory activity of each toward bromelain. As a result, the complete chemical structure of Leu13 in the light chain was revealed to be essential for inhibition. Pro12 prior to the leucine residue was also involved in the inhibitory activity and would control the location of the leucine side chain by the fixed φ dihedral angle of proline. Furthermore, the five-residue length of the interchain peptide was strictly required for the inhibitory activity. On the other hand, no inhibitory activity against bromelain was observed by the substitution of proline for the N terminus residue Thr15 of the interchain peptide. In summary, these mutational analyses of bromein demonstrated that the appropriate position and conformation of Leu13 are absolutely crucial for bromelain inhibition. PMID:18948264

  12. Understanding the molecular mechanism for the differential inhibitory activities of compounds against MTH1

    PubMed Central

    Wang, Mian; Zhou, Shuilian; Chen, Qing; Wang, Lisheng; Liang, Zhiqun; Wang, Jianyi

    2017-01-01

    MTH1 can hydrolyze oxidized nucleotides and is required for cancer survival. The IC50 values were 0.8 nM for TH287 with a methyl substitution, 5.0 nM for TH588 with a cyclopropyl substitution, and 2.1 μM for TH650 with an oxetanyl substitution. Thus, it is very significant to understand inhibitory mechanisms of these structurally similar compounds against MTH1 and influences of the substituent on the bioactivities. Our MD researches indicate that TH287 maintains significant hydrogen bonds with Asn33 and Asp119, stabilizes the binding site, and induces MTH1 adopt a closed motion, leading to a high inhibitory activity. When bound with TH588, the binding site can be partially stabilized and take a semi-closed state, which is because the cyclopropyl group in TH588 has larger steric hindrance than a methyl group in TH287. So TH588 has a slightly reduced inhibitory activity compared to TH287. TH650 induces greater conformation fluctuations than TH588 and the binding site adopts an opening state, which is caused by the large bulk of oxetanyl group and the interference of solvent on the oxetanyl substituent, leading to the lowest inhibitory activity. Thus, the inhibitory activity follows a TH287 > TH588 > TH650 trend, which well matches with the experimental finding. PMID:28074893

  13. Screening Estrogenic Activities of Chemicals or Mixtures In Vivo Using Transgenic (cyp19a1b-GFP) Zebrafish Embryos

    PubMed Central

    Brion, François; Le Page, Yann; Piccini, Benjamin; Cardoso, Olivier; Tong, Sok-Keng; Chung, Bon-chu; Kah, Olivier

    2012-01-01

    The tg(cyp19a1b-GFP) transgenic zebrafish expresses GFP (green fluorescent protein) under the control of the cyp19a1b gene, encoding brain aromatase. This gene has two major characteristics: (i) it is only expressed in radial glial progenitors in the brain of fish and (ii) it is exquisitely sensitive to estrogens. Based on these properties, we demonstrate that natural or synthetic hormones (alone or in binary mixture), including androgens or progestagens, and industrial chemicals induce a concentration-dependent GFP expression in radial glial progenitors. As GFP expression can be quantified by in vivo imaging, this model presents a very powerful tool to screen and characterize compounds potentially acting as estrogen mimics either directly or after metabolization by the zebrafish embryo. This study also shows that radial glial cells that act as stem cells are direct targets for a large panel of endocrine disruptors, calling for more attention regarding the impact of environmental estrogens and/or certain pharmaceuticals on brain development. Altogether these data identify this in vivo bioassay as an interesting alternative to detect estrogen mimics in hazard and risk assessment perspective. PMID:22586461

  14. Screening estrogenic activities of chemicals or mixtures in vivo using transgenic (cyp19a1b-GFP) zebrafish embryos.

    PubMed

    Brion, François; Le Page, Yann; Piccini, Benjamin; Cardoso, Olivier; Tong, Sok-Keng; Chung, Bon-chu; Kah, Olivier

    2012-01-01

    The tg(cyp19a1b-GFP) transgenic zebrafish expresses GFP (green fluorescent protein) under the control of the cyp19a1b gene, encoding brain aromatase. This gene has two major characteristics: (i) it is only expressed in radial glial progenitors in the brain of fish and (ii) it is exquisitely sensitive to estrogens. Based on these properties, we demonstrate that natural or synthetic hormones (alone or in binary mixture), including androgens or progestagens, and industrial chemicals induce a concentration-dependent GFP expression in radial glial progenitors. As GFP expression can be quantified by in vivo imaging, this model presents a very powerful tool to screen and characterize compounds potentially acting as estrogen mimics either directly or after metabolization by the zebrafish embryo. This study also shows that radial glial cells that act as stem cells are direct targets for a large panel of endocrine disruptors, calling for more attention regarding the impact of environmental estrogens and/or certain pharmaceuticals on brain development. Altogether these data identify this in vivo bioassay as an interesting alternative to detect estrogen mimics in hazard and risk assessment perspective.

  15. Signalling pathways activated by 5-HT(1B)/5-HT(1D) receptors in native smooth muscle and primary cultures of rabbit renal artery smooth muscle cells.

    PubMed

    Hinton, J M; Hill, P; Jeremy, J; Garland, C

    2000-01-01

    The potential of primary cultures of rabbit renal artery vascular smooth muscle cells (VSMCs) was assessed as a means to investigate the signalling pathways linked to 5-hydroxytryptamine (5-HT) 5-HT(1B)/5-HT(1D) receptors in native arteries. In renal artery segments denuded of endothelium, incubated with ketanserin and prazosin (each 1 microM), and prestimulated with 20 mM K(+) Krebs buffer, 5-HT and CP 93,129, a 5-HT(1B) receptor agonist, evoked concentration-dependent contractions. GR 127935, a 5-HT(1B)/5-HT(1D) receptor antagonist, significantly antagonised 5-HT-evoked contractions at nanomolar concentrations. Reverse transcription polymerase chain reaction (RT-PCR) of mRNA from smooth muscle cells from the isolated renal artery and from primary cultures of VSMCs from the same artery expressed mRNA transcripts for the 5-HT(1B) receptor and the 5-HT(1D) receptor in both preparations. The sequence of the PCR fragments corresponded to the known sequence for these receptors. Application of 5-HT evoked a concentration-dependent, pertussis toxin (PTx)-sensitive reduction in cyclic AMP in both cultured cells and intact artery (cyclic AMP concentration reduced by 65.53 +/- 3.33 and 52.65 +/- 5.34% from basal with 10 microM 5-HT, respectively). The effect of 10 microM 5-HT on cAMP was increased in the presence of 20 mM K(+) (reduced by 82.50 +/- 2.50 and 87.54 +/- 3.97%, respectively). In intact arteries, contraction through 5-HT(1B)/5-HT(1D) receptors was significantly attenuated by inhibitors of phosphatidylinositol 3-kinase (wortmannin) and activated mitogen-activated protein kinase (MAPK), MEK (U0126). In the cultured VSMCs, activated MAPK was identified by immunocytochemistry and immunoblotting after stimulation with 5-HT, but only if 20 mM K(+) was present at the onset of stimulation. These data provide the first direct evidence that 5-HT(1B)/5-HT(1B) receptors are linked to the activation of MAPK and indicate that primary cultures of renal VSMCs could provide a

  16. Optimization of the aromatase inhibitory activities of pyridylthiazole analogues of resveratrol.

    PubMed

    Mayhoub, Abdelrahman S; Marler, Laura; Kondratyuk, Tamara P; Park, Eun-Jung; Pezzuto, John M; Cushman, Mark

    2012-04-01

    Aromatase is an established target not only for breast cancer chemotherapy, but also for breast cancer chemoprevention. The moderate and non-selective aromatase inhibitory activity of resveratrol (1) was improved about 100-fold by replacement of the ethylenic bridge with a thiadiazole and the phenyl rings with pyridines (e.g., compound 3). The aromatase inhibitory activity was enhanced over 6000-fold by using a 1,3-thiazole as the central ring and modifying the substituents on the 'A' ring to target the Met374 residue of aromatase. On the other hand, targeting the hydroxyl group of Thr310 by a hydrogen-bond acceptor on the 'B' ring did not improve the aromatase inhibitory activity.

  17. Protection against phalloidin-induced liver injury by oleanolic acid involves Nrf2 activation and suppression of Oatp1b2

    PubMed Central

    Lu, Yuan-Fu; Liu, Jie; Wu, Kai Connie; Klaassen, Curtis D.

    2014-01-01

    This study utilized pharmacological activation of Nrf2 with oleanolic acid (OA, 22.5 mg/kg, sc for 4d) and the genetic Nrf2 activation (Nrf2-null, wild-type, and Keap1-HKO mice) to examine the role of Nrf2 in protection against phalloidin hepatotoxicity. Mice were given phalloidin (1.5 mg/kg, ip for 8 h) to examine liver injury and the expression of toxicity-related genes. Phalloidin increased serum enzyme activities and caused extensive hepatic hemorrhage and necrosis in Nrf2-null and wild-type mice, but less injury was seen in Keap1-HKO mice and OA-pretreated mice. Phalloidin increased the expression of neutrophil-specific chemokine mKC and MIP-2 in Nrf2-null and WT mice, but such increases were attenuated in Keap1-HKO and OA-pretreated mice. Phalloidin increased, while Nrf2 activation attenuated, the expression of genes involved in acute-phase response (Ho-1) and DNA-damage response genes (Gadd45 and Chop10). Phalloidin is taken up by hepatocytes through Oatp1b2, but there was no difference in basal and phalloidin-induced Oatp1b2 expression among Nrf2-null, wild-type, and Keap1-HKO mice. In contrast, OA decreased phalloidin-induced Oatp1b2. Phalloidin activated MAPK signaling (p-JNK), which was attenuated by activation of Nrf2. In conclusion, this study demonstrates that protection against phalloidin hepatotoxicity by OA involves activation of Nrf2 and suppression of Oatp1b2. PMID:25280775

  18. TES Level 1B

    Atmospheric Science Data Center

    2014-12-08

    TES Level 1B data files contain radiometric calibrated spectral radiances and their ... and some engineering data are also provided. A Level 1B data file contains data from a single TES orbit for one focal ... as the Aura orbit number at the time of the South Pole apex crossing. version id represents the version identification number, ...

  19. Inhibitory Activities of Alkyl Syringates and Related Compounds on Aflatoxin Production

    PubMed Central

    Furukawa, Tomohiro; Iimura, Kurin; Kimura, Taichi; Yamamoto, Toshiyoshi; Sakuda, Shohei

    2016-01-01

    Inhibitors of aflatoxin production of aflatoxigenic fungi are useful for preventing aflatoxin contamination in crops. As methyl syringate weakly inhibits aflatoxin production, aflatoxin production inhibitory activities of additional alkyl syringates with alkyl chains from ethyl to octyl were examined. Inhibitory activity toward aflatoxin production of Aspergillus flavus became stronger as the length of the alkyl chains on the esters became longer. Pentyl, hexyl, heptyl, and octyl syringates showed strong activity at 0.05 mM. Heptyl and octyl parabens, and octyl gallate also inhibited aflatoxin production as strongly as octyl syringate. Alkyl parabens and alkyl gallates inhibit the complex II activity of the mitochondrial respiration chain; thus, whether alkyl syringates inhibit complex II activity was examined. Inhibitory activities of alkyl syringates toward complex II also became stronger as the length of the alkyl chains increased. The complex II inhibitory activity of octyl syringate was comparable to that of octyl paraben and octyl gallate. These results suggest that alkyl syringates, alkyl parabens, and alkyl gallates, including commonly used food additives, are useful for aflatoxin control. PMID:27338472

  20. Costus afer Possesses Carbohydrate Hydrolyzing Enzymes Inhibitory Activity and Antioxidant Capacity In Vitro

    PubMed Central

    Tchamgoue, Armelle D.; Tchokouaha, Lauve R. Y.; Tarkang, Protus A.; Kuiate, Jules-Roger; Agbor, Gabriel A.

    2015-01-01

    Diabetes mellitus is a metabolic disorder of glucose metabolism which correlates with postprandial hyperglycemia and oxidative stress. Control of blood glucose level is imperative in the management of diabetes. The present study tested the hypothesis that Costus afer, an antihyperglycemic medicinal plant, possesses inhibitory activity against carbohydrate hydrolyzing enzymes. Hexane, ethyl acetate, methanol, and water extracts were prepared from the leaf, stem, and rhizome of C. afer and subjected to phytochemical screening, assayed for α-amylase and α-glucosidase inhibitory activities and antioxidant capacity (determined by total phenolic and total flavonoids contents, ferric reducing antioxidant power (FRAP), and DPPH radical scavenging activity). All extracts inhibited α-amylase and α-glucosidase activities. Ethyl acetate rhizome and methanol leaf extracts exhibited the best inhibitory activity against α-amylase and α-glucosidase (IC50: 0.10 and 5.99 mg/mL), respectively. Kinetic analysis revealed two modes of enzyme inhibition (competitive and mixed). All extracts showed antioxidant capacity, with hexane extracts exhibiting the best activity. DPPH assay revealed that methanol leaf, rhizome, and ethyl acetate stem extracts (IC50 < 5 mg/mL) were the best antioxidants. The presence of bioactive compounds such as flavonoids, alkaloids, phenols, and tannins may account for the antioxidant capacity and carbohydrate hydrolyzing enzyme inhibitory activity of C. afer. PMID:26246844

  1. Ascorbyl palmitate-loaded chitosan nanoparticles: characteristic and polyphenol oxidase inhibitory activity.

    PubMed

    Kim, Mi Kyung; Lee, Ji-Soo; Kim, Kwang Yup; Lee, Hyeon Gyu

    2013-03-01

    The aim of this study was to produce ascorbyl palmitate (AP)-loaded nanoparticles in order to inhibit polyphenol oxidase (PPO) in bananas. AP-loaded chitosan nanoparticles were prepared using acetic acid and citric acid (denoted as CS/AA and CS/CA nanoparticles, respectively). As the initial AP concentration increases, the particle size significantly decreases, and the zeta potential, entrapment and loading efficiency significantly increases. The PPO inhibitory activity of AP was effectively improved when AP was nano-encapsulated by chitosan compared to no encapsulation. These results suggest that chitosan nano-encapsulation can be used to enhance the PPO inhibitory activity of AP.

  2. Three new resin glycosides compounds from Argyreia acuta and their α-glucosidase inhibitory activity.

    PubMed

    Wang, Li; Yan, You-Shao; Cui, Hong-Hua; Yin, Yong-Qin; Pan, Jie-Tao; Yu, Bang-Wei

    2017-03-01

    Three new phenolic compounds, acutacoside C (1), acutacoside D (2) and acutacoside E (3) were isolated from the aerial part of Argyreia acuta. The oligosaccharide chain was composed of two glucoses and three rhamnoses, and the aglycone was (11S)-hydroxyhexadecanoic acid (jalapinolic acid). The core of the three compounds was operculinic acid B, which was rare in resin glycosides. Their structures were established by a combination of spectroscopic and chemical methods. Compounds 1-3 have been evaluated for inhibitory activity against α-glucosidase, which all showed weak inhibitory activities.

  3. Novel Antiproliferative Chimeric Compounds with Marked Histone Deacetylase Inhibitory Activity

    PubMed Central

    2014-01-01

    Given our interest in finding potential antitumor agents and in view of the multifactorial mechanistic nature of cancer, in the present work, taking advantage of the multifunctional ligands approach, new chimeric molecules were designed and synthesized by combining in single chemical entities structural features of SAHA, targeting histone deacetylases (HDACs), with substituted stilbene or terphenyl derivatives previously obtained by us and endowed with antiproliferative and pro-apoptotic activity. The new chimeric derivatives were characterized with respect to their cytotoxic activity and their effects on cell cycle progression on different tumor cell lines, as well as their HDACs inhibition. Among the other, trans-6 showed the most interesting biological profile, as it exhibited a strong pro-apoptotic activity in tumor cell lines in comparison with both of its parent compounds and a marked HDAC inhibition. PMID:25221651

  4. Selective, State-Dependent Activation of Somatostatin-Expressing Inhibitory Interneurons in Mouse Neocortex

    PubMed Central

    Fanselow, Erika E.; Richardson, Kristen A.; Connors, Barry W.

    2008-01-01

    The specific functions of subtypes of cortical inhibitory neurons are not well understood. This is due in part to a dearth of information about the behaviors of interneurons under conditions when the surrounding circuit is in an active state. We investigated the firing behavior of a subset of inhibitory interneurons, identified using mice that express green fluorescent protein (GFP) in a subset of somatostatin-expressing inhibitory cells (“GFP-expressing inhibitory neuron” [GIN] cells). The somata of the GIN cells were in layer 2/3 of somatosensory cortex and had dense, layer 1–projecting axons that are characteristic of Martinotti neurons. Interestingly, GIN cells fired similarly during a variety of diverse activating conditions: when bathed in fluids with low-divalent cation concentrations, when stimulated with brief trains of local synaptic inputs, when exposed to group I metabotropic glutamate receptor agonists, or when exposed to muscarinic cholinergic receptor agonists. During these manipulations, GIN cells fired rhythmically and persistently in the theta-frequency range (3–10 Hz). Synchronous firing was often observed and its strength was directly proportional to the magnitude of electrical coupling between GIN cells. These effects were cell type specific: the four manipulations that persistently activated GIN cells rarely caused spiking of regular-spiking (RS) pyramidal cells or fast-spiking (FS) inhibitory interneurons. Our results suggest that supragranular GIN interneurons form an electrically coupled network that exerts a coherent 3- to 10-Hz inhibitory influence on its targets. Because GIN cells are more readily activated than RS and FS cells, it is possible that they act as “first responders” when cortical excitatory activity increases. PMID:18799598

  5. Antioxidant and hyaluronidase inhibitory activities of diverse phenolics in Phyllanthus emblica.

    PubMed

    Xu, Min; Zhu, Hong-Tao; Cheng, Rong-Rong; Wang, Dong; Yang, Chong-Ren; Tanaka, Takashi; Kouno, Isao; Zhang, Ying-Jun

    2016-02-12

    Fifty-eight phenolic compounds isolated from Phyllanthus emblica were screened and compared for their in vitro and in vivo antioxidant properties, as well as hyaluronidase (HAase) inhibitory activities. Among them, 20 compounds showed to be promising antioxidants due to the stronger scavenging activity in both DPPH radical and Danio rerio reactive oxygen species assays, while nine compounds were potential HAase inhibitors with 100-fold stronger activities than that of the positive control, DSCG. The structure activity relationship was discussed.

  6. Phytochemical Analysis of Agrimonia pilosa Ledeb, Its Antioxidant Activity and Aldose Reductase Inhibitory Potential

    PubMed Central

    Kim, Set Byeol; Hwang, Seung Hwan; Suh, Hong-Won; Lim, Soon Sung

    2017-01-01

    The aim of this study was to determine aldose reductase (AR) inhibitory activity and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity of compounds from Agrimonia pilosa Ledeb (AP). We isolated agrimoniin (AM), four flavonoid glucosides and two flavonoid glucuronides from the n-butanol fraction of AP 50% methanol extract. In addition to isolated compounds, the AR-inhibitory activity and the DPPH free radical scavenging activity of catechin, 5-flavonoids, and 4-flavonoid glucosides (known components of AP) against rat lens AR (RLAR) and DPPH assay were measured. AM showed IC50 values of 1.6 and 13.0 μM against RLAR and DPPH scavenging activity, respectively. Additionally, AM, luteolin-7-O-glucuronide (LGN), quercitrin (QU), luteolin (LT) and afzelin (AZ) showed high inhibitory activity against AR and were first observed to decrease sorbitol accumulation in the rat lens under high-sorbitol conditions ex vivo with inhibitory values of 47.6%, 91.8%, 76.9%, 91.8% and 93.2%, respectively. Inhibition of recombinant human AR by AM, LGN and AZ exhibited a noncompetitive inhibition pattern. Based on our results, AP and its constituents may play partial roles in RLAR and oxidative radical inhibition. Our results suggest that AM, LGN, QU, LT and AZ may potentially be used as natural drugs for treating diabetic complications. PMID:28208627

  7. Ultrasonic extraction of polysaccharides from Laminaria japonica and their antioxidative and glycosidase inhibitory activities

    NASA Astrophysics Data System (ADS)

    Wan, Peng; Yang, Xiaoman; Cai, Bingna; Chen, Hua; Sun, Huili; Chen, Deke; Pan, Jianyu

    2015-08-01

    In the present study, ultrasonic extraction technique (UET) is used to improve the yield of polysaccharides from Laminaria japonica (LJPs). And their antioxidative as well as glycosidase inhibitory activities are investigated. Box-Behnken design (BBD) combined with response surface methodology (RSM) is applied to optimize ultrasonic extraction for polysaccharides. The optimized conditions are obtained as extraction time at 54 min, ultrasonic power at 1050 W, extraction temperature at 80°C and ratio of material to solvent at 1:50 (g mL-1). Under these optimal ultrasonic extraction conditions, an actual experimental yield (5.75% ± 0.3%) is close to the predicted result (5.67%) with no significant difference ( P > 0.05). Vitro antioxidative and glycosidase inhibitory activities tests indicate that the crude polysaccharides (LJP) and two major ethanol precipitated fractions (LJP1 and LJP2) are in a concentration-dependent manner. LJP2 (30%-60% ethanol precipitated polysaccharides) possesses the strongest α-glucosidase inhibitory activity and moderate scavenging activity against hydroxyl radicals (66.09% ± 2.19%, 3.0 mg mL-1). Also, the inhibitory activity against α-glucosidase (59.08% ± 3.79%, 5.0 mg mL-1) is close to that of acarbose (63.99% ± 3.27%, 5.0 mg mL-1). LJP1 (30% ethanol precipitated polysaccharides) exhibits the strongest scavenging activity against hydroxyl radicals (99.80% ± 0.00%, 3.0 mg mL-1) and moderate α-glucosidase inhibitory activity (47.76% ± 1.92%, 5.0 mg mL-1). LJP shows the most remarkable DPPH scavenging activity (66.20% ± 0.11%, 5.0 mg mL-1) but weakest α-glucosidase inhibitory activity (37.77% ± 1.30%, 5.0 mg mL-1). However, all these LJPs exert weak inhibitory effects against α-amylase. These results show that UET is an effective method for extracting bioactive polysaccharides from seaweed materials. LJP1 and LJP2 can be developed as a potential ingredient in hypoglycemic agents or functional food for the management of

  8. Design and Synthesis of Norendoxifen Analogues with Dual Aromatase Inhibitory and Estrogen Receptor Modulatory Activities

    PubMed Central

    Lv, Wei; Liu, Jinzhong; Skaar, Todd C.; Flockhart, David A.; Cushman, Mark

    2015-01-01

    Both selective estrogen receptor modulators and aromatase inhibitors are widely used for the treatment of breast cancer. Compounds with both aromatase inhibitory and estrogen receptor modulatory activities could have special advantages for treatment of breast cancer. Our previous efforts led to the discovery of norendoxifen as the first compound with dual aromatase inhibitory and estrogen receptor binding activities. To optimize its efficacy and aromatase selectivity versus other cytochrome P450 enzymes, a series of structurally related norendoxifen analogues were designed and synthesized. The most potent compound, 4'-hydroxynorendoxifen (10), displayed elevated inhibitory potency against aromatase and enhanced affinity for estrogen receptors when compared to norendoxifen. The selectivity of 10 for aromatase versus other cytochrome P450 enzymes was also superior to norendoxifen. 4'-Hydroxynorendoxifen is therefore an interesting lead for further development to obtain new anticancer agents of potential value for the treatment of breast cancer. PMID:25751283

  9. Antiproliferative and GH-inhibitory activity of chimeric peptides consisting of GHRP-6 and somatostatin.

    PubMed

    Dasgupta, P; Singh, A T; Mukherjee, R

    1999-06-07

    Chimeric peptides consisting of growth hormone releasing peptide (GHRP-6) linked to somatostatin (6-11) via an amide bond to provide the effector parts of both the peptides were synthesized. The anti-proliferative, cytotoxic, and GH-inhibitory activities of these chimeric peptides were determined in vitro in the rat pituitary adenoma cell line GH3. One of the chimeric peptides, GSD, exhibited significantly greater (p < 0.001) anti-neoplastic and GH-inhibitory activity, as compared to RC-160. The hybrid peptides displayed high affinity binding to somatostatin receptors on GH3 cells. The bioactivity of GSD was found to be mediated by the stimulation of tyrosine phosphatase, involving a cGMP-dependent pathway, through pertussis toxin-sensitive G-proteins. Such potent GH-inhibitory chimeric peptides may be of potential importance in the therapy of acromegaly, as well as provide novel tools to study the regulation of GH secretion by GHRP and somatostatin.

  10. Inhibitory activity of benzophenones from Anemarrhena asphodeloides on pancreatic lipase.

    PubMed

    Jo, Yang Hee; Kim, Seon Beom; Ahn, Jong Hoon; Liu, Qing; Hwang, Bang Yeon; Lee, Mi Kyeong

    2013-04-01

    Pancreatic lipase is a key enzyme for lipid absorption by hydrolysis of total dietary fats. Therefore, inhibition of pancreatic lipase is suggested to be an effective therapy in the regulation of obesity. The EtOAc-soluble fraction of Anemarrhena asphodeloides rhizomes significantly inhibited pancreatic lipase activity as assessed using porcine pancreatic lipase as an in vitro assay system. Further fractionation of the EtOAc-soluble fraction of A. asphodeloides led to the isolation of a new benzophenone glycoside, zimoside A (1), together with the eleven known compounds iriflophenone (2), 2,4',6-trihydroxy-4-methoxybenzophenone (3), foliamangiferoside A (4), (2,3-dihydroxy-4-methoxyphenyl)(4-hydroxyphenyl)-methanone (5), 1,4,5,6,-tetrahydroxyxanthone (6), isosakuranetin (7), 4-hydroxybenzoic acid (8), 4-hydroxyacetophenone (9), vanillic acid (10), tyrosol (11) and 5-hydroxymethyl-2-furaldehyde (12). Among the isolated compounds, 3, 5 and 10 showed significant inhibition of pancreatic lipase activity.

  11. Inhibitory effect of disulfiram (Antabuse) on alcohol dehydrogenase activity.

    PubMed

    Carper, W R; Dorey, R C; Beber, J H

    1987-10-01

    We investigated the effect of disulfiram (Antabuse) on the activity of alcohol dehydrogenase (EC 1.1.1.1) in vitro. We observed a time-dependent inhibition of this dehydrogenase by disulfiram and diethyldithiocarbamate similar to that obtained for aldehyde dehydrogenase (EC 1.2.1.3). These results suggest a possible explanation for various side effects observed in the clinical use of Antabuse.

  12. Acetylcholinesterase inhibitory activity of pyrrolizidine alkaloids from Echium confusum Coincy.

    PubMed

    Benamar, Houari; Tomassini, Lamberto; Venditti, Alessandro; Marouf, Abderrazak; Bennaceur, Malika; Serafini, Mauro; Nicoletti, Marcello

    2017-06-01

    Four pyrrolizidine alkaloids, namely 7-O-angeloyllycopsamine N-oxide 1, echimidine N-oxide 2, echimidine 3 and 7-O-angeloylretronecine 4, were isolated for the first time from the whole plant ethanolic extract of Echium confusum Coincy, through bioassay-guided approach. Their structures were determined by spectroscopic means. All the isolates compounds showed moderate activities in inhibiting AChE, with IC50 0.276-0.769.

  13. Extracts of marine algae show inhibitory activity against osteoclast differentiation.

    PubMed

    Koyama, Tomoyuki

    2011-01-01

    Osteoclasts are multinucleated cells that play a crucial role in bone resorption. The imbalance between bone resorption and bone formation results in osteoporosis. Therefore, substances that can suppress osteoclast formation are potential candidate materials for drug development or functional foods. There have been reports that extracts or purified compounds from marine micro- and macroalgae can suppress osteoclast differentiation. Symbioimine, isolated from the cultured dinoflagellate Symbiodinium sp., had suppressive effects against osteoclast differentiation in osteoclast-like cells. Norzoanthamine, isolated from the colonial zoanthid Zoanthas sp., has been shown to have antiosteoporosis activity in ovariectomized mice. With regard to marine extracts, the fucoxanthin-rich component from brown algae has been shown to have suppressive effects against osteoclast differentiation. An extract of Sargassum fusiforme has recently been shown to have antiosteoporosis activity. This extract suppressed both osteoclast differentiation and accelerated osteoblast formation in separate in vitro experiments. It also showed antiosteoporosis activity in ovariectomized mice by regulating the balance between bone resorption and bone formation. These marine algae and their extracts may be sources of marine medicinal foods for the prevention of osteoporosis.

  14. The Human Adenovirus Type 5 E4orf6/E1B55K E3 Ubiquitin Ligase Complex Enhances E1A Functional Activity

    PubMed Central

    Dallaire, Frédéric; Schreiner, Sabrina; Blair, G. Eric; Dobner, Thomas; Branton, Philip E.

    2015-01-01

    ABSTRACT Human adenovirus (Ad) E1A proteins have long been known as the central regulators of virus infection as well as the major source of adenovirus oncogenic potential. Not only do they activate expression of other early viral genes, they make viral replication possible in terminally differentiated cells, at least in part, by binding to the retinoblastoma (Rb) tumor suppressor family of proteins to activate E2F transcription factors and thus viral and cellular DNA synthesis. We demonstrate in an accompanying article (F. Dallaire et al., mSphere 1:00014-15, 2016) that the human adenovirus E3 ubiquitin ligase complex formed by the E4orf6 and E1B55K proteins is able to mimic E1A activation of E2F transactivation factors. Acting alone in the absence of E1A, the Ad5 E4orf6 protein in complex with E1B55K was shown to bind E2F, disrupt E2F/Rb complexes, and induce hyperphosphorylation of Rb, leading to induction of viral and cellular DNA synthesis, as well as stimulation of early and late viral gene expression and production of viral progeny. While these activities were significantly lower than those exhibited by E1A, we report here that this ligase complex appeared to enhance E1A activity in two ways. First, the E4orf6/E1B55K complex was shown to stabilize E1A proteins, leading to higher levels in infected cells. Second, the complex was demonstrated to enhance the activation of E2F by E1A products. These findings indicated a new role of the E4orf6/E1B55K ligase complex in promoting adenovirus replication. IMPORTANCE Following our demonstration that adenovirus E3 ubiquitin ligase formed by the viral E4orf6 and E1B55K proteins is able to mimic the activation of E2F by E1A, we conducted a series of studies to determine if this complex might also promote the ability of E1A to do so. We found that the complex both significantly stabilizes E1A proteins and also enhances their ability to activate E2F. This finding is of significance because it represents an entirely new

  15. Natural compounds with aromatase inhibitory activity: an update.

    PubMed

    Balunas, Marcy J; Kinghorn, A Douglas

    2010-08-01

    Several synthetic aromatase inhibitors are currently in clinical use for the treatment of postmenopausal women with hormone-receptor positive breast cancer. However, these treatments may lead to untoward side effects and so the search for new aromatase inhibitors continues, especially those for which the activity is promoter-specific, targeting the breast-specific promoters I.3 and II. Recently, numerous natural compounds have been found to inhibit aromatase in noncellular, cellular, and IN VIVO studies. These investigations, covering the last two years, as well as additional studies that have focused on the evaluation of natural compounds as promoter-specific aromatase inhibitors or as aromatase inducers, are described in this review.

  16. ATP1B3 Protein Modulates the Restriction of HIV-1 Production and Nuclear Factor κ Light Chain Enhancer of Activated B Cells (NF-κB) Activation by BST-2*

    PubMed Central

    Nishitsuji, Hironori; Sugiyama, Ryuichi; Abe, Makoto; Takaku, Hiroshi

    2016-01-01

    Here, we identify ATP1B3 and fibrillin-1 as novel BST-2-binding proteins. ATP1B3 depletion in HeLa cells (BST-2-positive cells), but not 293T cells (BST-2-negative cells), induced the restriction of HIV-1 production in a BST-2-dependent manner. In contrast, fibrillin-1 knockdown reduced HIV-1 production in 293T and HeLa cells in a BST-2-independent manner. Moreover, NF-κB activation was enhanced by siATP1B3 treatment in HIV-1- and HIV-1ΔVpu-infected HeLa cells. In addition, ATP1B3 silencing induced high level BST-2 expression on the surface of HeLa cells. These results indicate that ATP1B3 is a co-factor that accelerates BST-2 degradation and reduces BST-2-mediated restriction of HIV-1 production and NF-κB activation. PMID:26694617

  17. Adenovirus type 5 early region 1B 55-kDa oncoprotein can promote cell transformation by a mechanism independent from blocking p53-activated transcription.

    PubMed

    Härtl, B; Zeller, T; Blanchette, P; Kremmer, E; Dobner, T

    2008-06-12

    Inhibition of p53-activated transcription is an integral part of the mechanism by which early region 1B 55K oncoprotein (E1B-55K) from adenovirus type 5 (Ad5) contributes to complete cell transformation in combination with Ad E1A. In addition, more recent data suggest that the mode of action of the Ad protein during transformation may involve additional functions and other protein interactions. In the present study, we performed a comprehensive mutational analysis to assign further transforming functions of Ad5 E1B-55K to distinct domains within the viral polypeptide. Results from these studies show that the functions required for transformation are encoded within several patches of the 55K primary sequence, including several clustered cysteine and histidine residues, some of which match the consensus for zinc fingers. In addition, two amino-acid substitutions (C454S/C456S) created a 55K mutant protein, which had substantially reduced transforming activity. Interestingly, the same mutations neither affected binding to p53 nor inhibition of p53-mediated transactivation. Therefore, an activity necessary for efficient transformation of primary rat cells can be separated from functions required for inhibition of p53-stimulated transcription. Our data indicate that this activity is linked to the ability of the Ad5 protein to bind to components of the Mre11/Rad50/NBS1 DNA double-strand break repair complex, and/or its ability to assemble multiprotein aggregates in the cytoplasm and nucleus of transformed rat cells. These results introduce a new function for Ad5 E1B-55K and suggest that the viral protein contributes to cell transformation through p53 transcription-dependent and -independent pathways.

  18. Pancreatic lipase inhibitory activity of taraxacum officinale in vitro and in vivo.

    PubMed

    Zhang, Jian; Kang, Min-Jung; Kim, Myung-Jin; Kim, Mi-Eun; Song, Ji-Hyun; Lee, Young-Min; Kim, Jung-In

    2008-01-01

    Obesity has become a worldwide health problem. Orlistat, an inhibitor of pancreatic lipase, is currently approved as an anti-obesity drug. However, gastrointestinal side effects caused by Orlistat may limit its use. In this study the inhibitory activities of dandelion (Taraxacum officinale) against pancreatic lipase in vitro and in vivo were measured to determine its possible use as a natural anti-obesity agent. The inhibitory activities of the 95% ethanol extract of T. officinale and Orlistat were measured using 4-methylumbelliferyl oleate (4-MU oleate) as a substrate at concentrations of 250, 125, 100, 25, 12.5 and 4 microg/ml. To determine pancreatic lipase inhibitory activity in vivo, mice (n=16) were orally administered with corn oil emulsion (5 ml/kg) alone or with the 95% ethanol extract of T. officinale (400 mg/kg) following an overnight fast. Plasma triglyceride levels were measured at 0, 90, 180, and 240 min after treatment and incremental areas under the response curves (AUC) were calculated. The 95% ethanol extract of T. officinale and Orlistat, inhibited, porcine pancreatic lipase activity by 86.3% and 95.7% at a concentration of 250 microg/ml, respectively. T. officinale extract showed dose-dependent inhibition with the IC(50) of 78.2 microg/ml. A single oral dose of the extract significantly inhibited increases in plasma triglyceride levels at 90 and 180 min and reduced AUC of plasma triglyceride response curve (p<0.05). The results indicate that T. officinale exhibits inhibitory activities against pancreatic lipase in vitro and in vivo. Further studies to elucidate anti-obesity effects of chronic consumption of T. officinale and to identify the active components responsible for inhibitory activity against pancreatic lipase are necessary.

  19. Protein glycation inhibitory activity and antioxidant capacity of clove extract.

    PubMed

    Suantawee, Tanyawan; Wesarachanon, Krittaporn; Anantsuphasak, Kanokphat; Daenphetploy, Tanuch; Thien-Ngern, Sroshin; Thilavech, Thavaree; Pasukamonset, Porntip; Ngamukote, Sathaporn; Adisakwattana, Sirichai

    2015-06-01

    Syzygium aromaticum (L.) (clove) is one of the most widely cultivated spices in many tropical countries. The aim of this study was to determine the phytochemical content, the antioxidant properties and the antiglycation properties of aqueous extract of clove against fructose-mediated protein glycation and oxidation. The result showed that the content of total phenolics and flavonoids in clove extract was 239.58 ± 0.70 mg gallic acid equivalents/g dried extract and 65.67 ± 0.01 mg catechin equivalents/g dried extract, respectively. In addition, clove exhibited antioxidant properties including DPPH radical scavenging activity (IC50 = 0.29 ± 0.01 mg/ml), Trolox equivalent antioxidant capacity (4.69 ± 0.03 μmol Trolox equivalents/mg dried extract), ferric reducing antioxidant power (20.55 ± 0.11 μmol ascorbic acid equivalents/mg dried extract), Oxygen radical absorbance capacity (31.12 ± 0.21 μmol Trolox equivalents/mg dried extract), hydroxyl radical scavenging activity (0.15 ± 0.04 mg Trolox equivalents/mg dried extract), and superoxide radical scavenging activity (18.82 ± 0.50 mg Trolox equivalents/mg dried extract). The aqueous extract of clove (0.25-1.00 mg/ml) significantly inhibited the formation of fluorescent advanced glycation end products (AGEs) and non-fluorescent AGEs (N(ɛ)-(carboxymethyl) lysine (CML)) in glycated BSA during 4 weeks of incubation. The extract also markedly prevented oxidation-induced protein damage by decreasing protein carbonyl formation and protecting against the loss of protein thiol group. These results clearly demonstrated that a polyphenol enriched clove extract, owing to its antioxidant, was capable to inhibit the formation of AGEs and protein glycation. The findings might lead to the possibility of using the clove extract for targeting diabetic complications.

  20. The inhibitory effect of combination treatment with leptin and cannabinoid CB1 receptor agonist on food intake and body weight gain is mediated by serotonin 1B and 2C receptors.

    PubMed

    Wierucka-Rybak, M; Wolak, M; Juszczak, M; Drobnik, J; Bojanowska, E

    2016-06-01

    Previous studies reported that the co-injection of leptin and cannabinoid CB1 receptor antagonists reduces food intake and body weight in rats, and this effect is more profound than that induced by these compounds individually. Additionally, serotonin mediates the effects of numerous anorectic drugs. To investigate whether serotonin interacts with leptin and endocannabinoids to affect food intake and body weight, we administered 5-hydroxytryptamine(HT)1B and 5-hydroxytryptamine(HT)2C serotonin receptor antagonists (3 mg/kg GR 127935 and 0.5 mg/kg SB 242084, respectively) to male Wistar rats treated simultaneously with leptin (100 μg/kg) and the CB1 receptor inverse agonist AM 251 (1 mg/kg) for 3 days. In accordance with previous findings, the co-injection of leptin and AM 251, but not the individual injection of each drug, resulted in a significant decrease in food intake and body weight gain. Blockade of the 5-HT1B and 5-HT2C receptors completely abolished the leptin- and AM 251-induced anorectic and body-weight-reducing effects. These results suggest that serotonin mediates the leptin- and AM 251-dependent regulation of feeding behavior in rats via the 5-HT1B and 5-HT2C receptors.

  1. Natural Product Compounds with Aromatase Inhibitory Activity: An Update

    PubMed Central

    Balunas, Marcy J.; Kinghorn, A. Douglas

    2010-01-01

    Several synthetic aromatase inhibitors are currently in clinical use for the treatment of postmenopausal women with hormone-receptor positive breast cancer. However, these treatments may lead to untoward side effects and so a search for new aromatase inhibitors continues, especially those for which the activity is promoter-specific, targeting the breast-specific promoters I.3 and II. Recently, numerous natural product compounds have been found to inhibit aromatase in non-cellular, cellular, and in vivo studies. These investigations, covering the last two years, as well as additional studies that have focused on the evaluation of natural product compounds as promoter-specific aromatase inhibitors or as aromatase inducers, are described in this review. PMID:20635310

  2. Urease Inhibitory Activities of some Commonly Consumed Herbal Medicines

    PubMed Central

    Mahernia, Shabnam; Bagherzadeh, Kowsar; Mojab, Faraz; Amanlou, Massoud

    2015-01-01

    Urease enzyme has a crucial role in the persistent habitation of Helicobacter pylori (H. pylori) that induces gastrointestinal diseases, in particular gastritis, duodenal, peptic ulcer, and gastric cancer. Plants have long been utilized as the biggest source of substances with medicinal properties from natural origin and therefore result in less toxicity and adverse side effects upon usage. 15 medicinal plant extracts were examined against Jack bean urease activity by Berthelot reaction. Each herb was extracted using 80% aqueous methanol. The more effective extracts were further tested and their IC50 values were determined. Three plant extracts including Ginkgo biloba, Rhus coriaria, and Matricaria inodora were found to be the most effective ones with IC50 values of 36.17, 80.29, and 100.6 μg/mL, respectively. PMID:26330884

  3. Urease Inhibitory Activities of some Commonly Consumed Herbal Medicines.

    PubMed

    Mahernia, Shabnam; Bagherzadeh, Kowsar; Mojab, Faraz; Amanlou, Massoud

    2015-01-01

    Urease enzyme has a crucial role in the persistent habitation of Helicobacter pylori (H. pylori) that induces gastrointestinal diseases, in particular gastritis, duodenal, peptic ulcer, and gastric cancer. Plants have long been utilized as the biggest source of substances with medicinal properties from natural origin and therefore result in less toxicity and adverse side effects upon usage. 15 medicinal plant extracts were examined against Jack bean urease activity by Berthelot reaction. Each herb was extracted using 80% aqueous methanol. The more effective extracts were further tested and their IC50 values were determined. Three plant extracts including Ginkgo biloba, Rhus coriaria, and Matricaria inodora were found to be the most effective ones with IC50 values of 36.17, 80.29, and 100.6 μg/mL, respectively.

  4. Assessment of intake and nutritional status of vitamin b1, b2, and b6 in men and women with different physical activity levels.

    PubMed

    Malara, M; Hübner-Wozniak, E; Lewandowska, I

    2013-06-01

    The purpose of the present study was to examine the nutritional status of vitamin B1, B2, and B6 in respect to dietary intake of these vitamins and activity coefficients of the erythrocyte enzymes transketolase, glutathione reductase, and aspartic aminotransferase in young men and women with different physical activity levels. The participants of this study were 20 women and 20 men with high physical activity (groups HAW and HAM, respectively), and 20 women and 20 men with low physical activity (groups LAW and LAM, respectively). The intake of vitamins B1, B2, B6, proteins, and calorie content of the diet was based on the average of the 4-day dietary recalls. To assess nutritional status of vitamin B1, B2, and B6, the activity coefficients (α) of erythrocyte transketolase (ETK), erythrocyte glutathione reductase (EGR), and erythrocyte aspartic aminotransferase (EAST) were estimated in blood hemolysates. The intake of the studied vitamins in the diet was statistically significantly lower in the female groups compared with the respective male groups. Deficiency of vitamin B6 in the diet was present more often in women than in men (in terms of the recommended dietary allowances [RDA]). Values of the activity coefficient αETK indicated that none of the groups in this study suffered the risk of vitamin B1 deficiency. The value of the activity coefficient αEGR indicated that the groups of women and men with low physical activity were more prone to vitamin B2 deficiency compared with the high physical activity groups. The risk of vitamin B6 deficiency (αEAST) in both male groups was higher than in both female groups. The obtained results do not allow for unequivocal determination of the impact of sex and the level of physical activity on intake and nutritional status of vitamin B1, B2, and B6. Independently of sex and the level of physical activity, the women and men consumed insufficient quantities of vitamins B1 and B6, although this was not always related to

  5. Molecular docking studies and in vitro cholinesterase enzyme inhibitory activities of chemical constituents of Garcinia hombroniana.

    PubMed

    Jamila, Nargis; Yeong, Khaw Kooi; Murugaiyah, Vikneswaran; Atlas, Amir; Khan, Imran; Khan, Naeem; Khan, Sadiq Noor; Khairuddean, Melati; Osman, Hasnah

    2015-01-01

    Garcinia species are reported to possess antimicrobial, anti-inflammatory, anticancer, anti-HIV and anti-Alzheimer's activities. This study aimed to investigate the in vitro cholinesterase enzyme inhibitory activities of garcihombronane C (1), garcihombronane F (2), garcihombronane I (3), garcihombronane N (4), friedelin (5), clerosterol (6), spinasterol glucoside (7) and 3β-hydroxy lup-12,20(29)-diene (8) isolated from Garcinia hombroniana, and to perform molecular docking simulation to get insight into the binding interactions of the ligands and enzymes. The cholinesterase inhibitory activities were evaluated using acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. In this study, compound 4 displayed the highest concentration-dependent inhibition of both AChE and BChE. Docking studies exhibited that compound 4 binds through hydrogen bonds to amino acid residues of AChE and BChE. The calculated docking and binding energies also supported the in vitro inhibitory profiles of IC50. In conclusion, garcihombronanes C, F, I and N (1-4) exhibited dual and moderate inhibitory activities against AChE and BChE.

  6. Phenolic constituents of Carex vulpinoidea seeds and their tyrosinase inhibitory activities.

    PubMed

    Niesen, Daniel B; Ma, Hang; Yuan, Tao; Bach, Alvin C; Henry, Geneive E; Seeram, Navindra P

    2015-03-01

    Two new phenolics, a stilbenoid, vulpinoideol A (1), and a chalcone, vulpinoideol B (2), along with ten known compounds (3-12) were isolated from Carex vulpinoidea Michx. seeds. The structures of compounds 1-12 were elucidated based on spectrometric and spectroscopic analyses including HRESIMS, 1D and 2D NMR data. All compounds were evaluated for their tyrosinase enzyme inhibitory activities.

  7. Evaluation of the Antioxidant Activities and Tyrosinase Inhibitory Property from Mycelium Culture Extracts.

    PubMed

    Park, Ki Moon; Kwon, Kyung Min; Lee, Seung Ho

    2015-01-01

    Since mushrooms have many bioactive components, they have been used as components in folk medicine. Because mycelium has an advantage when it comes to large-scale production, this study aimed to evaluate the antioxidant properties and anti-tyrosinase activity from 55 mycelia in culture media. Relatively high 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging capacity was detected from the ethanol extract of culture media including mycelium (EECiM) of Morchella esculenta var. esculenta (MEVE), Auricularia polytricha (APO), Tremella aurantia (TAU), Volvariella bombycina (VBO), and Oudemansiella sp. (Osp), which also showed strong reducing power and inhibitory activity in relation to the thiobarbituric acid (TBA) value. On the other hand, relatively high tyrosinase inhibitory activity was detected in Inonotus mikadoi (IMI), Coriolus versicolor (CVE), Volvariella volvacea (VVO), Panellus serotinus (PSE), Auricularia auricula (AAU), and Fomitopsis sp. (Fsp). Interestingly, the APO EECiM exhibited the highest DPPH radical scavenging rate (77.5 ± 4.3%) and reducing power (1.18 ± 0.041), while the highest inhibitory power of the TBA value and antityrosinase activity were detected in that of TAU (64.5 ± 4.1%) and IMI (46.0 ± 7.5%), respectively. Overall, our study suggested potential candidates for EECiMs that exhibited powerful antioxidant and tyrosinase inhibitory properties and might be used as natural antioxidant tyrosinase inhibitor.

  8. Evaluation of the Antioxidant Activities and Tyrosinase Inhibitory Property from Mycelium Culture Extracts

    PubMed Central

    Park, Ki Moon; Kwon, Kyung Min; Lee, Seung Ho

    2015-01-01

    Since mushrooms have many bioactive components, they have been used as components in folk medicine. Because mycelium has an advantage when it comes to large-scale production, this study aimed to evaluate the antioxidant properties and anti-tyrosinase activity from 55 mycelia in culture media. Relatively high 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging capacity was detected from the ethanol extract of culture media including mycelium (EECiM) of Morchella esculenta var. esculenta (MEVE), Auricularia polytricha (APO), Tremella aurantia (TAU), Volvariella bombycina (VBO), and Oudemansiella sp. (Osp), which also showed strong reducing power and inhibitory activity in relation to the thiobarbituric acid (TBA) value. On the other hand, relatively high tyrosinase inhibitory activity was detected in Inonotus mikadoi (IMI), Coriolus versicolor (CVE), Volvariella volvacea (VVO), Panellus serotinus (PSE), Auricularia auricula (AAU), and Fomitopsis sp. (Fsp). Interestingly, the APO EECiM exhibited the highest DPPH radical scavenging rate (77.5 ± 4.3%) and reducing power (1.18 ± 0.041), while the highest inhibitory power of the TBA value and antityrosinase activity were detected in that of TAU (64.5 ± 4.1%) and IMI (46.0 ± 7.5%), respectively. Overall, our study suggested potential candidates for EECiMs that exhibited powerful antioxidant and tyrosinase inhibitory properties and might be used as natural antioxidant tyrosinase inhibitor. PMID:26345142

  9. An automated sequential injection spectrophotometric method for evaluation of tyramine oxidase inhibitory activity of some flavonoids.

    PubMed

    Moonrungsee, Nuntaporn; Shimamura, Tomoko; Kashiwagi, Takehiro; Jakmunee, Jaroon; Higuchi, Keiro; Ukeda, Hiroyuki

    2014-05-01

    An automated sequential injection (SI) spectrophotometric system has been developed for evaluation of tyramine oxidase (TOD) inhibitory activity. The method is based on the inhibition of TOD that catalyzes the oxidation of tyramine substrate to produce aldehyde and hydrogen peroxide (H₂O₂). The produced H₂O₂ reacts with vanillic acid and 4-aminoantipyrine (4-AA) in the presence of peroxidase (POD) to form a quinoneimine dye, the absorbance of which is measured of absorbance at wavelength of 490 nm. The decrease of the quinoneimine dye is related to an increase of TOD inhibitory activity. Under the optimum conditions: 1.0 mM tyramine, 8 U mL(-1) TOD, 1.0 mM vanillic acid, 1.0 mM 4-AA and delay time of 10 s, some flavonoid compounds were examined for the TOD inhibitory activity expressed as IC₅₀ value. It was found that flavonols (quercetin and myricetin) and flavans (epicatechin gallate (ECG) and epigallocatechin (EGC)) showed higher TOD inhibitory activity than flavones and flavanones. The results of IC₅₀ values obtained from the proposed method and a batch-wise method were not significantly different from each other. Moreover, the SI system enabled automation of the analysis, leading to more convenient, more sensitive and faster analysis than the batch-wise method. A precise timing of the system also improves precision and accuracy of the assay, especially when the measurement of absorbance at non-steady state condition is involved.

  10. ACE Inhibitory and Antioxidant Activities of Collagen Hydrolysates from the Ribbon Jellyfish (Chrysaora sp.)

    PubMed Central

    Latiff, Aishah Abd; Gan, Chee-Yuen; Abedin, Md. Zainul; Alias, Abd Karim

    2014-01-01

    Summary Collagen isolated from the ribbon jellyfish (Chrysaora sp.) was hydrolysed using three different proteases (i.e. trypsin, alcalase and Protamex) to obtain bioactive peptides. Angiotensin-I-converting enzyme (ACE) inhibitory activity and antioxidant activities (i.e. ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity) of the peptides were measured and compared, and the effect of the duration of hydrolysis on the bioactivity (ACE inhibitory and antioxidant activities) of peptides was also evaluated. FRAP activity was the highest in Protamex-induced (25–27 mM) and trypsin-induced hydrolysates (24–26 mM) at 7 and 9 h, respectively. Conversely, hydrolysates produced by trypsin for 1 and 3 h showed the highest DPPH radical scavenging activities (94 and 92%, respectively). Trypsin-induced hydrolysates (at 3 h) also showed the highest ACE inhibitory activity (89%). The peptide sequences with the highest activities were identified using tandem mass spectrometry, and the results show that the hydrolysates had a high content of hydrophobic amino acids as well as unique amino acid sequences, which likely contribute to their biological activities. PMID:27904323

  11. A novel inhibitory nucleo-cortical circuit controls cerebellar Golgi cell activity

    PubMed Central

    Ankri, Lea; Husson, Zoé; Pietrajtis, Katarzyna; Proville, Rémi; Léna, Clément; Yarom, Yosef; Dieudonné, Stéphane; Uusisaari, Marylka Yoe

    2015-01-01

    The cerebellum, a crucial center for motor coordination, is composed of a cortex and several nuclei. The main mode of interaction between these two parts is considered to be formed by the inhibitory control of the nuclei by cortical Purkinje neurons. We now amend this view by showing that inhibitory GABA-glycinergic neurons of the cerebellar nuclei (CN) project profusely into the cerebellar cortex, where they make synaptic contacts on a GABAergic subpopulation of cerebellar Golgi cells. These spontaneously firing Golgi cells are inhibited by optogenetic activation of the inhibitory nucleo-cortical fibers both in vitro and in vivo. Our data suggest that the CN may contribute to the functional recruitment of the cerebellar cortex by decreasing Golgi cell inhibition onto granule cells. DOI: http://dx.doi.org/10.7554/eLife.06262.001 PMID:25965178

  12. Lipoxygenase Inhibitory Activity of Korean Indigenous Mushroom Extracts and Isolation of an Active Compound from Phellinus baumii

    PubMed Central

    Lee, Seung Woong; Song, Ja-Gyeong; Hwang, Byung Soon; Kim, Dae-Won; Lee, Yoon-Ju; Woo, E-Eum; Kim, Ji-Yul; Lee, In-Kyoung

    2014-01-01

    We investigated a total of 335 samples of Korean native mushroom extracts as part of our lipoxygenase (LOX) inhibitor screening program. Among the mushroom-methanolic extracts we investigated, 35 exhibited an inhibitory activity greater than 30% against LOX at a concentration of 100 µg/mL. Especially, Collybia maculata, Tylopilus neofelleus, Strobilomyces confusus, Phellinus gilvus, P. linteus, P. baumii, and Inonotus mikadoi exhibited relatively potent LOX inhibitory activities of 73.3%, 51.6%, 52.4%, 66.7%, 59.5%, 100.0%, and 85.2%, respectively. Bioassay-guided fractionation led to the isolation of inoscavin A from the methanolic extract of P. baumii, which showed the most potent activity and was identified by spectroscopic methods. Specifically, inoscavin A exhibited potent LOX inhibitory activity with an IC50 value of 6.8 µM. PMID:25071389

  13. Angiotensin I-converting enzyme (ACE) inhibitory activity and ACE inhibitory peptides of salmon (Salmo salar) protein hydrolysates obtained by human and porcine gastrointestinal enzymes.

    PubMed

    Darewicz, Małgorzata; Borawska, Justyna; Vegarud, Gerd E; Minkiewicz, Piotr; Iwaniak, Anna

    2014-08-13

    The objectives of the present study were two-fold: first, to detect whether salmon protein fractions possess angiotensin I-converting enzyme (ACE) inhibitory properties and whether salmon proteins can release ACE inhibitory peptides during a sequential in vitro hydrolysis (with commercial porcine enzymes) and ex vivo digestion (with human gastrointestinal enzymes). Secondly, to evaluate the ACE inhibitory activity of generated hydrolysates. A two-step ex vivo and in vitro model digestion was performed to simulate the human digestion process. Salmon proteins were degraded more efficiently by porcine enzymes than by human gastrointestinal juices and sarcoplasmic proteins were digested/hydrolyzed more easily than myofibrillar proteins. The ex vivo digested myofibrillar and sarcoplasmic duodenal samples showed IC50 values (concentration required to decrease the ACE activity by 50%) of 1.06 and 2.16 mg/mL, respectively. The in vitro hydrolyzed myofibrillar and sarcoplasmic samples showed IC50 values of 0.91 and 1.04 mg/mL, respectively. Based on the results of in silico studies, it was possible to identify 9 peptides of the ex vivo hydrolysates and 7 peptides of the in vitro hydrolysates of salmon proteins of 11 selected peptides. In both types of salmon hydrolysates, ACE-inhibitory peptides IW, IY, TVY and VW were identified. In the in vitro salmon protein hydrolysates an ACE-inhibitory peptides VPW and VY were also detected, while ACE-inhibitory peptides ALPHA, IVY and IWHHT were identified in the hydrolysates generated with ex vivo digestion. In our studies, we documented ACE inhibitory in vitro effects of salmon protein hydrolysates obtained by human and as well as porcine gastrointestinal enzymes.

  14. Growth-inhibitory activity of lymphoid cell plasma membranes. II. Partial characterization of the inhibitor

    PubMed Central

    1984-01-01

    We have shown that plasma membranes from lymphoid cells have inhibitory activity for the growth of normal lymphocytes and lymphoid tumor cells (Stallcup, K. C., A. Dawson, and M. F. Mescher, J. Cell Biol. 99:1221- 1226). This growth-inhibitory activity has been found to co-purify with major histocompatibility complex class I antigens (H-2K and D) when these cell surface glycoproteins are isolated from detergent lysates of cells by affinity chromatography on monoclonal antibody columns. When incorporated into liposomes, the affinity-purified H-2 antigens inhibited the growth of both normal lymphocytes and tumor cells at concentrations of 1-3 micrograms/ml. Inhibition was readily reversed upon removal of the liposomes from the cell cultures, even after several days of exposure of cells to the inhibitor. Inhibitory activity was insensitive to protease digestion or heat treatment, indicating that it was not due to the H-2 glycoproteins. This was confirmed by the demonstration that inhibitory activity could be separated from the H-2 protein by gel filtration in the presence of deoxycholate and could be extracted from membranes or H-2 antigen preparations with organic solvents. The results demonstrate that the growth-inhibitory component(s) of the plasma membrane is a minor lipid or lipid-like molecule which retains activity in the absence of other membrane components. The findings reported here and in the preceding article suggest that this novel membrane component may have a role in control of lymphoid cell growth, possibly mediated by cell contacts. PMID:6332814

  15. In vitro growth-inhibitory activity and malaria risk in a cohort study in mali.

    PubMed

    Crompton, Peter D; Miura, Kazutoyo; Traore, Boubacar; Kayentao, Kassoum; Ongoiba, Aissata; Weiss, Greta; Doumbo, Safiatou; Doumtabe, Didier; Kone, Younoussou; Huang, Chiung-Yu; Doumbo, Ogobara K; Miller, Louis H; Long, Carole A; Pierce, Susan K

    2010-02-01

    Immunity to the asexual blood stage of Plasmodium falciparum is complex and likely involves several effector mechanisms. Antibodies are thought to play a critical role in malaria immunity, and a corresponding in vitro correlate of antibody-mediated immunity has long been sought to facilitate malaria vaccine development. The growth inhibition assay (GIA) measures the capacity of antibodies to limit red blood cell (RBC) invasion and/or growth of P. falciparum in vitro. In humans, naturally acquired and vaccine-induced P. falciparum-specific antibodies have growth-inhibitory activity, but it is unclear if growth-inhibitory activity correlates with protection from clinical disease. In a longitudinal study in Mali, purified IgGs, obtained from plasmas collected before the malaria season from 220 individuals aged 2 to 10 and 18 to 25 years, were assayed for growth-inhibitory activity. Malaria episodes were recorded by passive surveillance over the subsequent 6-month malaria season. Logistic regression showed that greater age (odds ratio [OR], 0.78; 95% confidence interval [95% CI], 0.63 to 0.95; P = 0.02) and growth-inhibitory activity (OR, 0.50; 95% CI, 0.30 to 0.85; P = 0.01) were significantly associated with decreased malaria risk in children. A growth-inhibitory activity level of 40% was determined to be the optimal cutoff for discriminating malaria-immune and susceptible individuals in this cohort, with a sensitivity of 97.0%, but a low specificity of 24.3%, which limited the assay's ability to accurately predict protective immunity and to serve as an in vitro correlate of antibody-mediated immunity. These data suggest that antibodies which block merozoite invasion of RBC and/or inhibit the intra-RBC growth of the parasite contribute to but are not sufficient for the acquisition of malaria immunity.

  16. Ligand based approach to L-type calcium channel by imidazo[2,1-b]thiazole-1,4-dihydropyridines: from heart activity to brain affinity.

    PubMed

    Locatelli, Alessandra; Cosconati, Sandro; Micucci, Matteo; Leoni, Alberto; Marinelli, Luciana; Bedini, Andrea; Ioan, Pierfranco; Spampinato, Santi Mario; Novellino, Ettore; Chiarini, Alberto; Budriesi, Roberta

    2013-05-23

    The synthesis, characterization, and functional in vitro assay in cardiac and smooth muscle (vascular and nonvascular) of a series of 4-imidazo[2,1-b]thiazole-1,4-dihydropyridines are reported. To define the calcium blocker nature of the imidazo[2,1-b]thiazole-1,4-DHPs and their selectivity on Cav1.2 and Cav1.3 isoforms, we performed binding studies on guinea pig atrial and ventricular membranes on intact cells expressing the cloned Cav1.2a subunit and on rat brain cortex. To get major insights into the reasons for the affinity for Cav1.2 and/or Cav1.3, molecular modeling studies were also undertaken. Some physicochemical and pharmacokinetic properties of selected compounds were calculated and compared. All the biological data collected and reported herein allowed us to rationalize the structure-activity relationship of the 4-imidazo[2,1-b]thiazole-1,4-DHPs and to identify which of these enhanced the activity at the central level.

  17. Parvalbumin-Positive Inhibitory Interneurons Oppose Propagation But Favor Generation of Focal Epileptiform Activity.

    PubMed

    Sessolo, Michele; Marcon, Iacopo; Bovetti, Serena; Losi, Gabriele; Cammarota, Mario; Ratto, Gian Michele; Fellin, Tommaso; Carmignoto, Giorgio

    2015-07-01

    Parvalbumin (Pv)-positive inhibitory interneurons effectively control network excitability, and their optogenetic activation has been reported to block epileptic seizures. An intense activity in GABAergic interneurons, including Pv interneurons, before seizures has been described in different experimental models of epilepsy, raising the hypothesis that an increased GABAergic inhibitory signal may, under certain conditions, initiate seizures. It is therefore unclear whether the activity of Pv interneurons enhances or opposes epileptiform activities. Here we use a mouse cortical slice model of focal epilepsy in which the epileptogenic focus can be identified and the role of Pv interneurons in the generation and propagation of seizure-like ictal events is accurately analyzed by a combination of optogenetic, electrophysiological, and imaging techniques. We found that a selective activation of Pv interneurons at the focus failed to block ictal generation and induced postinhibitory rebound spiking in pyramidal neurons, enhancing neuronal synchrony and promoting ictal generation. In contrast, a selective activation of Pv interneurons distant from the focus blocked ictal propagation and shortened ictal duration at the focus. We revealed that the reduced ictal duration was a direct consequence of the ictal propagation block, probably by preventing newly generated afterdischarges to travel backwards to the original focus of ictal initiation. Similar results were obtained upon individual Pv interneuron activation by intracellular depolarizing current pulses. The functional dichotomy of Pv interneurons here described opens new perspectives to our understanding of how local inhibitory circuits govern generation and spread of focal epileptiform activities.

  18. In vitro anti-inflammatory and xanthine oxidase inhibitory activity of Tephrosia purpurea shoot extract.

    PubMed

    Nile, Shivraj H; Khobragade, Chandrahasy N

    2011-10-01

    The methanolic extract of Tephrosia purpurea (Leguminosae) shoots was evaluated in-vitro for its anti-inflammatory and xanthine oxidase inhibitory activity. Anti-inflammatory activity was measured by the Diene-conjugate, HET-CAM and beta-glucuronidase methods. The enzyme inhibitory activity was tested against isolated cow milk xanthine oxidase. The average anti-inflammatory activity of T. purpurea shoot extract in the concentration range of 1-2 microg/mL in the reacting system revealed significant anti-inflammatory activities, which, as recorded by the Diene-conjugate, HET-CAM and beta-glucuronidase assay methods, were 45.4, 10.5, and 70.5%, respectively. Screening of the xanthine oxidase inhibitory activity of the extract in terms of kinetic parameters revealed a mixed type of inhibition, wherein the Km and Vmax values in the presence of 25 to 100 microg/mL shoot extract was 0.20 mM/mL and 0.035, 0.026, 0.023 and 0.020 microg/min, while, for the positive control, the Km and Vmax values were 0.21 mM/mL and 0.043 microg/min, respectively. These findings suggest that T. purpurea shoot extract may possess constituents with good medicinal properties that could be exploited to treat the diseases associated with oxidative stress, xanthine oxidase enzyme activity and inflammation.

  19. Effect of Jatropha curcas Peptide Fractions on the Angiotensin I-Converting Enzyme Inhibitory Activity

    PubMed Central

    Segura-Campos, Maira R.; Peralta-González, Fanny; Castellanos-Ruelas, Arturo; Chel-Guerrero, Luis A.; Betancur-Ancona, David A.

    2013-01-01

    Hypertension is one of the most common worldwide diseases in humans. Angiotensin I-converting enzyme (ACE) plays an important role in regulating blood pressure and hypertension. An evaluation was done on the effect of Alcalase hydrolysis of defatted Jatropha curcas kernel meal on ACE inhibitory activity in the resulting hydrolysate and its purified fractions. Alcalase exhibited broad specificity and produced a protein hydrolysate with a 21.35% degree of hydrolysis and 34.87% ACE inhibition. Ultrafiltration of the hydrolysate produced peptide fractions with increased biological activity (24.46–61.41%). Hydrophobic residues contributed substantially to the peptides' inhibitory potency. The 5–10 and <1 kDa fractions were selected for further fractionation by gel filtration chromatography. ACE inhibitory activity (%) ranged from 22.66 to 45.96% with the 5–10 kDa ultrafiltered fraction and from 36.91 to 55.83% with the <1 kDa ultrafiltered fraction. The highest ACE inhibitory activity was observed in F2 (IC50 = 6.7 μg/mL) from the 5–10 kDa fraction and F1 (IC50 = 4.78 μg/mL) from the <1 kDa fraction. ACE inhibitory fractions from Jatropha kernel have potential applications in alternative hypertension therapies, adding a new application for the Jatropha plant protein fraction and improving the financial viability and sustainability of a Jatropha-based biodiesel industry. PMID:24224169

  20. Antioxidant, antimicrobial and tyrosinase inhibitory activities of xanthones isolated from Artocarpus obtusus F.M. Jarrett.

    PubMed

    Hashim, Najihah Mohd; Rahmani, Mawardi; Ee, Gwendoline Cheng Lian; Sukari, Mohd Aspollah; Yahayu, Maizatulakmal; Amin, Muhamad Aizat Mohd; Ali, Abd Manaf; Go, Rusea

    2012-05-21

    One of the most promising plants in biological screening test results of thirteen Artocarpus species was Artocarpus obtusus FM Jarrett and detailed phytochemical investigation of powdered dried bark of the plant has led to the isolation and identification of three xanthones; pyranocycloartobiloxanthone A (1), dihydroartoindonesianin C (2) and pyranocycloartobiloxanthone B (3). These compounds were screened for antioxidant, antimicrobial and tyrosinase inhibitory activities. Pyranocycloartobiloxanthone A (1) exhibited a strong free radical scavenger towards DPPH free radicals with IC50 value of 2 µg/mL with prominent discoloration observed in comparison with standard ascorbic acid, α-tocopherol and quercetin, The compound also exhibited antibacterial activity against methicillin resistant Staphylococcus aureus (ATCC3359) and Bacillus subtilis (clinically isolated) with inhibition zone of 20 and 12 mm, respectively. However the other two xanthones were found to be inactive. For the tyrosinase inhibitory activity, again compound (1) displayed strong activity comparable with the standard kojic acid.

  1. 2′-Epi-uscharin from the Latex of Calotropis gigantea with HIF-1 Inhibitory Activity

    PubMed Central

    Parhira, Supawadee; Zhu, Guo-Yuan; Jiang, Ren-Wang; Liu, Liang; Bai, Li-Ping; Jiang, Zhi-Hong

    2014-01-01

    Two stereoisomeric cardenolides, uscharin (1) and a new compound, 2′-epi-uscharin (2), were isolated from the latex of Calotropis gigantea (Asclepiadaceae). Their structures were fully elucidated based on their spectroscopic data, X-ray crystallographic data and chemical evidences. Both epimers (1 and 2) exhibited strong inhibitory effects on HIF-1 activity with different magnitudes. Compound 1 showed much more potent activity than 2 and digoxin, a well-known HIF-1 inhibitor. Discrepancy in potencies between 1 and 2 revealed the contribution of a β-configuration of 2′ hydroxyl moiety for HIF-1 inhibitory activity. This is a first report of the activity of HIF-1 inhibition of thiazoline ring-containing cardenolides. PMID:24756103

  2. Inhibition of protein tyrosine phosphatase 1B by lignans from Myristica fragrans.

    PubMed

    Yang, Senugmi; Na, Min Kyun; Jang, Jun Pil; Kim, Kyung Ah; Kim, Bo Yeon; Sung, Nak Ju; Oh, Won Keun; Ahn, Jong Seog

    2006-08-01

    Inhibition of protein tyrosine phosphatase 1B (PTP1B) has been proposed as one of the drug targets for treating type 2 diabetes and obesity. Bioassay-guided fractionation of a MeOH extract of the semen of Myristica fragrans Houtt. (Myristicaceae) afforded PTP1B inhibitory compounds, meso-dihydroguaiaretic acid (1) and otobaphenol (2). Compounds 1 and 2 inhibited PTP1B with IC(50) values of 19.6 +/- 0.3 and 48.9 +/- 0.5 microM, respectively, in the manner of non-competitive inhibitors. Treatment with compound 1 on 32D cells overexpressing the insulin receptor (IR) resulted in a dose-dependent increase in the tyrosine phosphorylation of IR. These results indicate that compound 1 can act as an enhancing agent in intracellular insulin signaling, possibly through the inhibition of PTP1B activity.

  3. A new phenolic fatty acid ester with lipoxygenase inhibitory activity from Jacaranda filicifolia.

    PubMed

    Ali, R M; Houghton, P J

    1999-06-01

    The dichloromethane extract of the stem of jacaranda filicifolia Don. showed inhibitory activity in vitro against soybean 5-lipoxygenase. Systematic fractionation to isolate the compounds responsible resulted in the isolation of three active compounds, 2 alpha, 3 alpha-dihydroxyurs-12-en-28-oic acid, beta-sitosterol, and one of which was new which was characterised as 2-(4-hydroxyphenyl)ethyl 1-dodecyloctadecanoate. This type of compound has not previously been reported to inhibit lipoxygenase.

  4. Inhibitory activity of phosphates on molds isolated from foods and food processing plants.

    PubMed

    Suárez, V B; Frisón, L; de Basílico, M Z; Rivera, M; Reinheimer, J A

    2005-11-01

    Six commercial phosphates were evaluated for inhibition of the growth of 17 molds isolated from food sources. The assays were performed at neutral and natural (without pH adjustment) pH values, and the molds were streaked on plate count agar with added phosphates. Phosphate concentrations of 0.1, 0.3, 0.5, 1.0, and 1.5% (wt/vol) were used, and the MIC was determined. The resistance of molds to phosphates depended on the species. At a neutral pH, Aspergillus ochraceus and Fusarium proliferatum were resistant to all phosphates at all concentrations assayed, and Byssochlamys nivea, Aureobasidium pullulans, and Penicillium glabrum were most sensitive. The most inhibitory phosphates were those with chain lengths greater than 15 phosphate units and the highest sequestering power. At natural pH values (resulting from dissolving the phosphate in the medium), inhibitory activity changed dramatically for phosphates that produced alkaline or acidic pH in the medium. Phosphates with alkaline pH values (sodium tripolyphosphate of high solubility, sodium tripolyphosphate, and sodium neutral pyrophosphate) were much more inhibitory than phosphates at a neutral pH, but sodium acid pyrophosphate (acidic pH) had decreased inhibitory activity. The results indicate that some phosphates could be used in the food industry to inhibit molds linked to food spoilage.

  5. Inhibitory effects of polyphenols from grape pomace extract on collagenase and elastase activity.

    PubMed

    Wittenauer, Judith; Mäckle, Sonja; Sußmann, Daniela; Schweiggert-Weisz, Ute; Carle, Reinhold

    2015-03-01

    Breakdown and disorganization of extracellular matrix proteins like collagen, fibronectin and elastin are main characteristics of skin aging due to the enhanced activation of proteolytic enzymes such as collagenases and elastases. Inhibition of their enzymatic activities by natural plant compounds might be a promising approach to prevent extrinsic skin aging. Especially polyphenols are supposed to interact with those enzymes due to their molecular nature. In our investigation, extracts of pomace from Riesling grapes were analyzed for their inhibitory properties on collagenase as well as elastase. Crude grape pomace extract showed a dose-dependent inhibitory activity against both enzymes with IC50-values of 20.3μg/ml and 14.7μg/ml for collagenase and elastase activity, respectively. The extracts were fractionated into four fractions containing phenolic compounds differing in chemical structure and polarity. Except for the stilbene containing fraction, all other fractions showed inhibitory effects on both enzyme activities. The most pronounced impact was found for the hydrophilic low molecular weight polyphenols containing the free phenolic acids. In particular, gallic acid showed considerable inhibition values. EGCG was used as a positive control and showed a dose-dependent inhibition of collagenase activity (IC50=0.9mM).

  6. Cytochrome P450-inhibitory activity of parabens and phthalates used in consumer products.

    PubMed

    Ozaki, Hitomi; Sugihara, Kazumi; Watanabe, Yoko; Ohta, Shigeru; Kitamura, Shigeyuki

    2016-01-01

    The in vitro cytochrome P450 (CYP)-inhibitory effects of 11 parabens and 7 phthalates used in consumer products, as well as their hydrolytic metabolites, were investigated, using rat liver microsomes as an enzyme source. The effects on individual CYP isozymes were evaluated by assaying inhibition of activities towards specific substrates, i.e., ethoxyresorufin O-dealkylase (EROD), methoxyresorufin O-dealkylase (MROD), pentoxyresorufin O-dealkylase (PROD), 7-benzyloxy-4-trifluoromethylcoumarin dealkylase (BFCD), 7-methoxy-4-trifluoromethylcoumarin dealkylase (MFCD) and 7-ethoxy-4-trifluoromethylcoumarin dealkylase (EFCD) activities. These activities were dose-dependently inhibited, most potently by medium-side-chain parabens (C6-9) and phthalates (C4-6), and less potently by shorter- and longer-side-chain esters. The hydrolytic product of parabens, 4-hydroxybenzoic acid, was not inhibitory, while those of phthalates, phthalic acid monoesters, showed lower inhibitory activity than the parent phthalates. Parabens showed relatively potent inhibition of MFCD activity, considered to be mainly due to CYP2C, and phthalates showed relatively potent inhibition of PROD activity, considered to be mainly due to CYP2B.

  7. NGF-activated protein tyrosine phosphatase 1B mediates the phosphorylation and degradation of I-kappa-Balpha coupled to NF-kappa-B activation, thereby controlling dendrite morphology.

    PubMed

    Chacón, Pedro J; Arévalo, María Angeles; Tébar, Alfredo Rodríguez

    2010-04-01

    NGF diminishes dendrite complexity in cultured hippocampal neurons by decreasing the number of primary and secondary dendrites, while increasing the length of those that remain. The transduction pathway used by NGF to provoke dendrite elongation involves the activation of NF-kappa-B and the expression of the homologues of Enhancer-of-split 1 gene. Here, we define important steps that link NGF with NF-kappa-B activation, through the activity of protein tyrosine phosphatase 1B (PTP1B). Binding of NGF to p75(NTR) stimulates PTP1B activity, which can be blocked by either pharmacological inhibition of the phosphatase or by transfecting neurons with a dn PTP1B isoform, whereby NGF is no longer able to stimulate dendrite growth. Indeed, overexpressing PTP1B alone provoked dendrite growth and further studies revealed a role for the src kinase downstream of PTP1B. Again, loss of src activity largely cancelled out the capacity of NGF to promote dendrite growth, whereas overexpression of v-src in neurons was sufficient to promote dendrite growth. Finally, the NGF/p75(NTR)/PTP1B/src kinase pathway led to the tyrosine phosphorylation of I-kappa-Balpha prior to its degradation, an event that is necessary for NF-kappa-B activation. Indeed, the dendrite growth response to NGF was lost when neurons were transfected with a mutant form of I-kappa-Balpha that lacks tyr42. Thus, our data suggest that PTP1B fulfils a central role in the NGF signalling that controls dendrite patterning in hippocampal neurons.

  8. Inhibitory effect of vanillin on cellulase activity in hydrolysis of cellulosic biomass.

    PubMed

    Li, Yun; Qi, Benkun; Wan, Yinhua

    2014-09-01

    Pretreatment of lignocellulosic material produces a wide variety of inhibitory compounds, which strongly inhibit the following enzymatic hydrolysis of cellulosic biomass. Vanillin is a kind of phenolics derived from degradation of lignin. The effect of vanillin on cellulase activity for the hydrolysis of cellulose was investigated in detail. The results clearly showed that vanillin can reversibly and non-competitively inhibit the cellulase activity at appropriate concentrations and the value of IC50 was estimated to be 30 g/L. The inhibition kinetics of cellulase by vanillin was studied using HCH-1 model and inhibition constants were determined. Moreover, investigation of three compounds with similar structure of vanillin on cellulase activity demonstrated that aldehyde group and phenolic hydroxyl groups of vanillin had inhibitory effect on cellulase. These results provide valuable and detailed information for understanding the inhibition of lignin derived phenolics on cellulase.

  9. A cortico-hippocampal learning rule shapes inhibitory microcircuit activity to enhance hippocampal information flow.

    PubMed

    Basu, Jayeeta; Srinivas, Kalyan V; Cheung, Stephanie K; Taniguchi, Hiroki; Huang, Z Josh; Siegelbaum, Steven A

    2013-09-18

    How does coordinated activity between distinct brain regions implement a set of learning rules to sculpt information processing in a given neural circuit? Using interneuron cell-type-specific optical activation and pharmacogenetic silencing in vitro, we show that temporally precise pairing of direct entorhinal perforant path (PP) and hippocampal Schaffer collateral (SC) inputs to CA1 pyramidal cells selectively suppresses SC-associated perisomatic inhibition from cholecystokinin (CCK)-expressing interneurons. The CCK interneurons provide a surprisingly strong feedforward inhibitory drive to effectively control the coincident excitation of CA1 pyramidal neurons by convergent inputs. Thus, in-phase cortico-hippocampal activity provides a powerful heterosynaptic learning rule for long-term gating of information flow through the hippocampal excitatory macrocircuit by the silencing of the CCK inhibitory microcircuit.

  10. [Expression of Chinese sturgeon cystatin in yeast Pichia pastoris and its proteinase inhibitory activity analysis].

    PubMed

    Ma, Dong-Mei; Bai, Jun-Jie; Jian, Qing; Lao, Hai-Hua; Ye, Xing; Luo, Jian-Ren

    2003-09-01

    Cystatin, which widely distributed in both tissues and body fluids of animal and plant, was a superfamily of cysteine proteinase inhibitors. It could form activity-inhibitor complexes with cysteine proteinases to inhibit the hydrolytic activity of proteinases. Cystatin played important roles not only in the inhibition of the proteolytic degradation of fish muscle, but also in biological defense systems against invaders. To explore the functions of fish cystatin and the potential values in fish disease prevention and cure, as well as seafood processing, the recombinant yeast strains which could express Chinese sturgeon cystatin were constructed. First, the cystatin cDNA of Chinese sturgeon, which had been PCR modified, was subcloned into yeast integrated vector pPICZaA. After extracted and purified, the recombinant plasmids were linearized by Sac I. The yeast Pichia pastoris GS115 strain was transformed by use of the Lithium Chloride transformation method, and the recombinant cystatin yeast strains got. After 0.5% methanol induction, SDS-PAGE analysis of the culture supernatant indicated that the yield of recombinant cystatin was about 215mg x L(-1) with the percentage about 73.6%. The recombinant cystatin was purified through Q-Sepharose anion-exchange chromatography, and the purity reached about 94.2%. The inhibitory activity of recombinant cystatin was measured by inhibiting the proteinase activity of papain. The results showed that about 1 microg recombinant cystatin could inhibit the activity of 15 microg papain. Heat stability assay results showed that there was a decrease in inhibitory activity of cystatin with the increasing of temperature. When solution of recombinant cystatin was kept at 70 degrees C for 5min, the inhibitory activity reduced fast. While the recombinant cystatin was heated to 90 degrees C for 5min, the inhibitory activity of recombinant cystatin was undetected. The inhibitory activity for recombinant Chinese sturgeon cystatin was higher

  11. Acetylcholinesterase inhibitory activity of lycopodane-type alkaloids from the Icelandic Lycopodium annotinum ssp. alpestre.

    PubMed

    Halldorsdottir, Elsa Steinunn; Jaroszewski, Jerzy W; Olafsdottir, Elin Soffia

    2010-02-01

    The aim of this study was to investigate structures and acetylcholinesterase inhibitory activities of lycopodane-type alkaloids isolated from an Icelandic collection of Lycopodium annotinum ssp. alpestre. Ten alkaloids were isolated, including annotinine, annotine, lycodoline, lycoposerramine M, anhydrolycodoline, gnidioidine, lycofoline, lannotinidine D, and acrifoline, as well as a previously unknown N-oxide of annotine. 1H and 13C NMR data of several of the alkaloids were provided for the first time. Solvent-dependent equilibrium constants between ketone and hemiketal form of acrifoline were determined. Conformation of acrifoline was characterized using NOESY spectroscopy and molecular modelling. The isolated alkaloids were evaluated for their in vitro inhibitory activity against acetylcholinesterase and butyrylcholinesterase. Ligand docking studies based on mutated 3D structure of Torpedo californica acetylcholinesterase provided rationale for low inhibitory activity of the isolated alkaloids as compared to huperzine A or B, which are potent acetylcholinesterase inhibitors belonging to the lycodine class. Based on the modelling studies the lycopodane-type alkaloids seem to fit well into the active site gorge of the enzyme but the position of their functional groups is not compatible with establishing strong hydrogen bonding interactions with the amino acid residues that line the binding site. The docking studies indicate possibilities of additional functionalization of the lycopodane skeleton to render potentially more active analogues.

  12. A Novel Heptapeptide with Tyrosinase Inhibitory Activity Identified from a Phage Display Library.

    PubMed

    Nie, Huali; Liu, Lin; Yang, Huiqin; Guo, Hongzhen; Liu, Xiang; Tan, Yuanhao; Wang, Wen; Quan, Jing; Zhu, Limin

    2017-01-01

    Peptidic inhibition of the enzyme tyrosinase, responsible for skin pigmentation and food browning, would be extremely useful for the food, cosmetics, and pharmaceutical industries. In order to identify novel inhibitory peptides, a library of short sequence oligopeptides was screened to reveal direct interaction with the tyrosinase. A phage displaying heptapeptide (IQSPHFF) was found to bind most strongly to tyrosinase. The inhibitory activity of the heptapeptide was evaluated using mushroom tyrosinase. The results showed that the peptide inhibited both the monophenolase and diphenolase activities of mushroom tyrosinase with IC50 values of 1.7 and 4.0 mM, respectively. The heptapeptide is thought to be a reversible competitive inhibitor of diphenolase with the inhibition constants (Ki) of 0.765 mM. To further investigate how the heptapeptide exerts its inhibitory effect, a docking study between tyrosinase and heptapeptide was performed. The simulation showed that the heptapeptide binds in the active site of the enzyme near the catalytically active Cu ions and forms hydrogen bonds with five histidine residues on the active site. Phage display technology is thus a useful approach for the screening of potential tyrosinase inhibitors and could be widely applicable to a much wider range of enzymes.

  13. Metabolism and growth inhibitory activity of cranberry derived flavonoids in bladder cancer cells.

    PubMed

    Prasain, Jeevan K; Rajbhandari, Rajani; Keeton, Adam B; Piazza, Gary A; Barnes, Stephen

    2016-09-14

    In the present study, anti-proliferative activities of cranberry derived flavonoids and some of their in vivo metabolites were evaluated using a panel of human bladder tumor cell lines (RT4, SCABER, and SW-780) and non-tumorigenic immortalized human uroepithelial cells (SV-HUC). Among the compounds tested, quercetin 3-O-glucoside, isorhamnetin (3'-O-methylquercetin), myricetin and quercetin showed strong concentration-dependent cell growth inhibitory activities in bladder cancer cells with IC50 values in a range of 8-92 μM. Furthermore, isorhamnetin and myricetin had very low inhibitory activity against SV-HUC even at very high concentrations (>200 μM) compared to bladder cancer cells, indicating that their cytotoxicity is selective for cancer cells. To determine whether the differential cell growth inhibitory effects of isomeric flavonoids quercetin 3-O-glucoside (active) and hyperoside (quercetin 3-O-galactoside) (inactive) are related to their metabolism by the cancer cells, SW-780 cells were incubated with these compounds and their metabolism was examined by LC-MS/MS. Compared to quercetin 3-O-glucoside, hyperoside undergoes relatively less metabolic biotransformation (methylation, glucuronidation and quinone formation). These data suggest that isorhamnetin and quercetin 3-O-glucoside may be the active forms of quercetin in prevention of bladder cancer in vivo and emphasize the importance of metabolism for the prevention of bladder cancer by diets rich in cranberries.

  14. Fos-activation of FoxP2 and Lmx1b neurons in the parabrachial nucleus evoked by hypotension and hypertension in conscious rats

    PubMed Central

    Miller, Rebecca L.; Knuepfer, Mark M.; Wang, Michelle H.; Denny, George O.; Gray, Paul A.; Loewy, Arthur D.

    2012-01-01

    The parabrachial nucleus (PB) is a brainstem cell group that receives a strong input from the nucleus tractus solitarius regarding the physiological status of the internal organs and sends efferent projections throughout the forebrain. Since the neuroanatomical organization of the PB remains unclear, our first step was to use specific antibodies against two neural lineage transcription factors: Forkhead box protein2 (FoxP2) and LIM homeodomain transcription factor 1 beta (Lmx1b) to define the PB in adult rats. This allowed us to construct a cytoarchitectonic PB map based on the distribution of neurons that constitutively express these two transcription factors. Second, the in situ hybridization method combined with immunohistochemistry demonstrated that mRNA for glutamate vesicular transporter Vglut2 (Slc17a6) was present in most of the Lmx1b+ and FoxP2+ parabrachial neurons, indicating these neurons use glutamate as a transmitter. Third, conscious rats were maintained in a hypotensive or hypertensive state for two hours, and then, their brainstems were prepared by the standard c-Fos method which is a measure of neuronal activity. Both hypotension and hypertension resulted in c-Fos activation of Lmx1b+ neurons in the external lateral-outer subdivision of the PB (PBel-outer). Hypotension, but not hypertension, caused c-Fos activity in the FoxP2+ neurons of the central lateral PB (PBcl) subnucleus. The Kölliker-Fuse nucleus as well as the lateral crescent PB and rostralmost part of the PBcl contain neurons that co-express FoxP2+ and Lmx1b+, but none of these were activated after blood pressure changes. Salt-sensitive FoxP2 neurons in the pre-locus coeruleus and PBel-inner were not c-Fos activated following blood pressure changes. In summary, the present study shows that the PBel-outer and PBcl subnuclei originate from two different neural progenitors, contain glutamatergic neurons, and are affected by blood pressure changes, with the PBel-outer reacting to both hypo

  15. Effects of incentives, age, and behavior on brain activation during inhibitory control: a longitudinal fMRI study.

    PubMed

    Paulsen, David J; Hallquist, Michael N; Geier, Charles F; Luna, Beatriz

    2015-02-01

    We investigated changes in brain function supporting inhibitory control under age-controlled incentivized conditions, separating age- and performance-related activation in an accelerated longitudinal design including 10- to 22-year-olds. Better inhibitory control correlated with striatal activation during neutral trials, while Age X Behavior interactions in the striatum indicated that in the absence of extrinsic incentives, younger subjects with greater reward circuitry activation successfully engage in greater inhibitory control. Age was negatively correlated with ventral amygdala activation during Loss trials, suggesting that amygdala function more strongly mediates bottom-up processing earlier in development when controlling the negative aspects of incentives to support inhibitory control. Together, these results indicate that with development, reward-modulated cognitive control may be supported by incentive processing transitions in the amygdala, and from facilitative to obstructive striatal function during inhibitory control.

  16. Antioxidant and enzyme inhibitory activities of Plebeian herba (Salvia plebeia R. Br.) under different cultivation conditions.

    PubMed

    Chen, Lei; Kang, Young-Hwa

    2014-03-12

    An adaptation of cultural management to the specific cultural system, as well as crop demand, can further result in the improvement of the quality of horticultural products. Therefore, this study focused on the antioxidant and enzyme inhibitory activities of Plebeian herba (Salvia plebeia R. Br.) grown in hydroponics in comparison with those of the plant grown in soil. The antioxidant activities of Plebeian herba extract were measured as 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging abilities as well as the reducing power by decreasing nitric oxide (NO) and superoxide dismutase activity (SOD) in vitro. Interestingly, by comparison with hydroponics and traditional cultivation, Plebeian herba cultivated in nutrition-based soil improved inhibitory effect on free radicals of DPPH, ABTS, and NO and increased the contents of phenolics such as caffeic acid (1), luteolin-7-glucoside (2), homoplantaginin (3), hispidulin (4), and eupatorin. Free radical scavenging and SOD activity, as well as α-glucosidase inhibitory effect, were higher in Plebeian herba grown in nutrition-based soil than in plants grown in hydroponics and traditional condition.

  17. Patterns of Brain Activation in Foster Children and Nonmaltreated Children During an Inhibitory Control Task

    PubMed Central

    Bruce, Jacqueline; Fisher, Philip A.; Graham, Alice M.; Moore, William E.; Peake, Shannon J.; Mannering, Anne M.

    2012-01-01

    Children in foster care have often encountered a range of adverse experiences, including neglectful and/or abusive care and multiple caregiver transitions. Prior research findings suggest that such experiences negatively affect inhibitory control and the underlying neural circuitry. In the current study, event-related functional magnetic resonance imaging (fMRI) was employed during a go/no go task that assesses inhibitory control to compare the behavioral performance and brain activation of foster children and nonmaltreated children. The sample included two groups of 9- to 12-year-old children: 11 maltreated foster children and 11 nonmaltreated children living with their biological parents. There were no significant group differences on behavioral performance on the task. In contrast, patterns of brain activation differed by group. The nonmaltreated children demonstrated stronger activation than the foster children across several regions including the right anterior cingulate cortex, middle frontal gyrus, and right lingual gyrus during correct no go trials, whereas the foster children displayed stronger activation than the nonmaltreated children in the left inferior parietal lobule and right superior occipital cortex including the lingual gyrus and cuneus during incorrect no go trials. These results provide preliminary evidence that the early adversity experienced by foster children impacts the neural substrates of inhibitory control. PMID:24229540

  18. Linking trait-based phenotypes to prefrontal cortex activation during inhibitory control.

    PubMed

    Rodrigo, Achala H; Di Domenico, Stefano I; Graves, Bryanna; Lam, Jaeger; Ayaz, Hasan; Bagby, R Michael; Ruocco, Anthony C

    2016-01-01

    Inhibitory control is subserved in part by discrete regions of the prefrontal cortex whose functionality may be altered according to specific trait-based phenotypes. Using a unified model of normal range personality traits, we examined activation within lateral and medial aspects of the prefrontal cortex during a manual go/no-go task. Evoked hemodynamic oxygenation within the prefrontal cortex was measured in 106 adults using a 16-channel continuous-wave functional near-infrared spectroscopy system. Within lateral regions of the prefrontal cortex, greater activation was associated with higher trait levels of extraversion, agreeableness and conscientiousness, and lower neuroticism. Higher agreeableness was also related to more activation in the medial prefrontal cortex during inhibitory control. These results suggest that personality traits reflecting greater emotional stability, extraversion, agreeableness and conscientiousness may be associated with more efficient recruitment of control processes subserved by lateral regions of the prefrontal cortex. These findings highlight key links between trait-based phenotypes and neural activation patterns in the prefrontal cortex underlying inhibitory control.

  19. Linking trait-based phenotypes to prefrontal cortex activation during inhibitory control

    PubMed Central

    Rodrigo, Achala H.; Di Domenico, Stefano I.; Graves, Bryanna; Lam, Jaeger; Ayaz, Hasan; Bagby, R. Michael

    2016-01-01

    Inhibitory control is subserved in part by discrete regions of the prefrontal cortex whose functionality may be altered according to specific trait-based phenotypes. Using a unified model of normal range personality traits, we examined activation within lateral and medial aspects of the prefrontal cortex during a manual go/no-go task. Evoked hemodynamic oxygenation within the prefrontal cortex was measured in 106 adults using a 16-channel continuous-wave functional near-infrared spectroscopy system. Within lateral regions of the prefrontal cortex, greater activation was associated with higher trait levels of extraversion, agreeableness and conscientiousness, and lower neuroticism. Higher agreeableness was also related to more activation in the medial prefrontal cortex during inhibitory control. These results suggest that personality traits reflecting greater emotional stability, extraversion, agreeableness and conscientiousness may be associated with more efficient recruitment of control processes subserved by lateral regions of the prefrontal cortex. These findings highlight key links between trait-based phenotypes and neural activation patterns in the prefrontal cortex underlying inhibitory control. PMID:26163672

  20. Effect of phlorotannins isolated from Ecklonia cava on angiotensin I-converting enzyme (ACE) inhibitory activity

    PubMed Central

    Wijesinghe, W.A.J.P.; Ko, Seok-Chun

    2011-01-01

    Inhibition of angiotensin I-converting enzyme (ACE) activity is the most common mechanism underlying the lowering of blood pressure. In the present study, five organic extracts of a marine brown seaweed Ecklonia cava were prepared by using ethanol, ethyl acetate, chloroform, hexane, and diethyl ether as solvents, which were then tested for their potential ACE inhibitory activities. Ethanol extract showed the strongest ACE inhibitory activity with an IC50 value of 0.96 mg/ml. Five kinds of phlorotannins, phloroglucinol, triphlorethol-A, eckol, dieckol, and eckstolonol, were isolated from ethanol extract of E. cava, which exhibited potential ACE inhibition. Dieckol was the most potent ACE inhibitor and was found to be a non-competitive inhibitor against ACE according to Lineweaver-Burk plots. Dieckol had an inducible effect on the production of NO in EAhy926 cells without having cytotoxic effect. The results of this study indicate that E. cava could be a potential source of phlorotannins with ACE inhibitory activity for utilization in production of functional foods. PMID:21556221

  1. Kappa opioid receptor activation decreases inhibitory transmission and antagonizes alcohol effects in rat central amygdala.

    PubMed

    Gilpin, Nicholas W; Roberto, Marisa; Koob, George F; Schweitzer, Paul

    2014-02-01

    Activation of the kappa opioid receptor (KOR) system mediates negative emotional states and considerable evidence suggests that KOR and their natural ligand, dynorphin, are involved in ethanol dependence and reward. The central amygdala (CeA) plays a major role in alcohol dependence and reinforcement. Dynorphin peptide and gene expression are activated in the amygdala during acute and chronic administration of alcohol, but the effects of activation or blockade of KOR on inhibitory transmission and ethanol effects have not been studied. We used the slice preparation to investigate the physiological role of KOR and interaction with ethanol on GABA(A) receptor-mediated synaptic transmission. Superfusion of dynorphin or U69593 onto CeA neurons decreased evoked inhibitory postsynaptic potentials (IPSPs) in a concentration-dependent manner, an effect prevented by the KOR antagonist norbinaltorphimine (norBNI). Applied alone, norBNI increased GABAergic transmission, revealing a tonic endogenous activity at KOR. Paired-pulse analysis suggested a presynaptic KOR mechanism. Superfusion of ethanol increased IPSPs and pretreatment with KOR agonists diminished the ethanol effect. Surprisingly, the ethanol-induced augmentation of IPSPs was completely obliterated by KOR blockade. Our results reveal an important role of the dynorphin/KOR system in the regulation of inhibitory transmission and mediation of ethanol effects in the CeA.

  2. Effect of phlorotannins isolated from Ecklonia cava on angiotensin I-converting enzyme (ACE) inhibitory activity.

    PubMed

    Wijesinghe, W A J P; Ko, Seok-Chun; Jeon, You-Jin

    2011-04-01

    Inhibition of angiotensin I-converting enzyme (ACE) activity is the most common mechanism underlying the lowering of blood pressure. In the present study, five organic extracts of a marine brown seaweed Ecklonia cava were prepared by using ethanol, ethyl acetate, chloroform, hexane, and diethyl ether as solvents, which were then tested for their potential ACE inhibitory activities. Ethanol extract showed the strongest ACE inhibitory activity with an IC(50) value of 0.96 mg/ml. Five kinds of phlorotannins, phloroglucinol, triphlorethol-A, eckol, dieckol, and eckstolonol, were isolated from ethanol extract of E. cava, which exhibited potential ACE inhibition. Dieckol was the most potent ACE inhibitor and was found to be a non-competitive inhibitor against ACE according to Lineweaver-Burk plots. Dieckol had an inducible effect on the production of NO in EAhy926 cells without having cytotoxic effect. The results of this study indicate that E. cava could be a potential source of phlorotannins with ACE inhibitory activity for utilization in production of functional foods.

  3. Serotonin 1A, 1B, and 7 receptors of the rat medial nucleus accumbens differentially regulate feeding, water intake, and locomotor activity.

    PubMed

    Clissold, Kara A; Choi, Eugene; Pratt, Wayne E

    2013-11-01

    Serotonin (5-HT) signaling has been widely implicated in the regulation of feeding behaviors in both humans and animal models. Recently, we reported that co-stimulation of 5-HT1&7 receptors of the anterior medial nucleus accumbens with the drug 5-CT caused a dose-dependent decrease in food intake, water intake, and locomotion in rats (Pratt et al., 2009). The current experiments sought to determine which of three serotonin receptor subtypes (5-HT1A, 5-HT1B, or 5-HT7) might be responsible for these consummatory and locomotor effects. Food-deprived rats were given 2-h access to rat chow after stimulation of nucleus accumbens 5-HT1A, 5-HT1B, or 5-HT7 receptors, or blockade of the 5-HT1A or 5-HT1B receptors. Stimulation of 5-HT1A receptors with 8-OH-DPAT (at 0.0, 2.0, 4.0, and 8.0 μg/0.5 μl/side) caused a dose-dependent decrease in food and water intake, and reduced rearing behavior but not ambulation. In contrast, rats that received the 5-HT1B agonist CP 93129 (at 0.0, 1.0, 2.0 and 4.0 μg/0.5 μl/side) showed a significant dose-dependent decrease in water intake only; stimulation of 5-HT7 receptors (AS 19; at 0.0, 1.0, and 5.0 μg/0.5 μl/side) decreased ambulatory activity but did not affect food or water consumption. Blockade of 5-HT1A or 5-HT1B receptors had no lasting effects on measures of food consumption. These data suggest that the food intake, water intake, and locomotor effects seen after medial nucleus accumbens injections of 5-CT are due to actions on separate serotonin receptor subtypes, and contribute to growing evidence for selective roles of individual serotonin receptors within the nucleus accumbens on motivated behavior.

  4. Discovery, structure-activity relationship study, and oral analgesic efficacy of cyproheptadine derivatives possessing N-type calcium channel inhibitory activity.

    PubMed

    Yamamoto, Takashi; Niwa, Seiji; Iwayama, Satoshi; Koganei, Hajime; Fujita, Shin-ichi; Takeda, Tomoko; Kito, Morikazu; Ono, Yukitsugu; Saitou, Yuki; Takahara, Akira; Iwata, Seinosuke; Yamamoto, Hiroshi; Shoji, Masataka

    2006-08-01

    Antiallergic drug cyproheptadine (Cyp) is known to have inhibitory activities for L-type calcium channels in addition to histamine and serotonin receptors. Since we found that Cyp had an inhibitory activity against N-type calcium channel, Cyp was optimized to obtain more selective N-type calcium channel blocker with analgesic action. As a consequence of the optimization, we found 13 with potent N-type calcium channel inhibitory activity which had lower inhibitory activities against L-type calcium channel, histamine (H1), and serotonin (5-HT2A) receptors than those of Cyp. 13 showed an oral analgesic activity in rat formalin-induced pain model.

  5. Synthesis, characterization and carbonic anhydrase inhibitory activity of novel benzothiazole derivatives.

    PubMed

    Küçükbay, F Zehra; Buğday, Nesrin; Küçükbay, Hasan; Tanc, Muhammet; Supuran, Claudiu T

    2016-12-01

    N-protected amino acids were reacted with substituted benzothiazoles to give the corresponding N-protected amino acid-benzothiazole conjugates (60-89%). Their structures were confirmed by proton nuclear magnetic resonance ((1)H NMR), carbon-13 nuclear magnetic resonance ((13)C NMR), IR and elemental analysis. Their carbonic anhydrase (CA, EC 4.2.1.1) inhibitory activities were determined against two cytosolic human isoforms (hCA I and hCA II), one membrane-associated (hCA IV) and one transmembrane (hCA XII) enzyme by a stopped-flow CO2 hydrase assay method. The new compounds showed rather weak, micromolar inhibitory activity against most of these enzymes.

  6. Bergamotane Sesquiterpenes with Alpha-Glucosidase Inhibitory Activity from the Plant Pathogenic Fungus Penicillium expansum.

    PubMed

    Ying, You-Min; Fang, Cheng-An; Yao, Feng-Qi; Yu, Yuan; Shen, Ying; Hou, Zhuo-Ni; Wang, Zhen; Zhang, Wei; Shan, Wei-Guang; Zhan, Zha-Jun

    2017-01-01

    Two new bergamotane sesquiterpene lactones, named expansolides C and D (1 and 2), together with two known compounds expansolides A and B (3 and 4), were isolated from the plant pathogenic fungus Penicillium expansum ACCC37275. The structures of the new compounds were established by detailed analyses of the spectroscopic data, especially 1D-, 2D-NMR, and HR-ESI-MS. In an in vitro bioassay, the epimeric mixture of expansolides C and D (1 and 2) (in a ratio of 2:1 at the temprature of the bioassay) exhibited more potent α-glucosidase inhibitory activity (IC50 =0.50 ± 0.02 mm) as compared with the positive control acarbose (IC50 = 1.90 ± 0.05 mm). To the best of our knowledge, it was the first report on the α-glucosidase inhibitory activity of bergamotane sesquiterpenes.

  7. Screening of Korean Medicinal Plant Extracts for α-Glucosidase Inhibitory Activities.

    PubMed

    Sancheti, Shruti; Sancheti, Sandesh; Lee, Seung-Hun; Lee, Jae-Eun; Seo, Sung-Yum

    2011-01-01

    Glycosidases are the enzymes involved in various biochemical processes related to metabolic disorders and diseases. Therefore, much effort has been focused on searching novel pharmacotherapy for the treatment of these ailments from medicinal plants due to higher safety margins. To pursue these efforts, the present study was performed to evaluate the α-glucosidase inhibitory activities of thirty Korean medicinal plant extracts. Among the plants studied, Euonymus sachalinensis, Rhododendron schlippenbachii, Astilbe chinensis and Juglans regia showed the strongest α-glucosidase inhibitory activity with IC50 values of 10, 20, 30 and 80 µg/mL, respectively. In addition, Meliosma oldhamii and Symplocos chinensis showed moderate α-glucosidase inhibition with IC50 values of 150 and 220 µg/mL, respectively. Therefore, they might prove to be a potential natural source for the treatment of metabolic ailments such as, diabetes, and need further investigations.

  8. Melanogenesis Inhibitory Activity of Two Generic Drugs: Cinnarizine and Trazodone in Mouse B16 Melanoma Cells

    PubMed Central

    Chang, Te-Sheng; Lin, Victor Chia-Hsiang

    2011-01-01

    More than 200 generic drugs were screened to identify the inhibitory activity on melanogenesis in mouse B16 melanoma cells. Cinnarizine and trazodone were identified as melanogenesis inhibitors. The inhibitory effects of the two drugs on cell survival, melanogenesis, and tyrosinase activity were investigated. The results showed that both cinnarizine and trazodone inhibited melanogenesis in B16 cells by a dose-dependent manner at the non-cytotoxic concentrations. Based on the results of the present study, seeking new melanogenesis inhibitors from generic drugs is an alternative approach to developing new depigmenting agents in cosmeceuticals. Moreover, cinnarizine and trazodone were proven to be good candidates as skin-whitening agents for treatment of skin hyperpigmentation. PMID:22272104

  9. Melanogenesis inhibitory activity of two generic drugs: cinnarizine and trazodone in mouse B16 melanoma cells.

    PubMed

    Chang, Te-Sheng; Lin, Victor Chia-Hsiang

    2011-01-01

    More than 200 generic drugs were screened to identify the inhibitory activity on melanogenesis in mouse B16 melanoma cells. Cinnarizine and trazodone were identified as melanogenesis inhibitors. The inhibitory effects of the two drugs on cell survival, melanogenesis, and tyrosinase activity were investigated. The results showed that both cinnarizine and trazodone inhibited melanogenesis in B16 cells by a dose-dependent manner at the non-cytotoxic concentrations. Based on the results of the present study, seeking new melanogenesis inhibitors from generic drugs is an alternative approach to developing new depigmenting agents in cosmeceuticals. Moreover, cinnarizine and trazodone were proven to be good candidates as skin-whitening agents for treatment of skin hyperpigmentation.

  10. Predicting the DPP-IV inhibitory activity pIC₅₀ based on their physicochemical properties.

    PubMed

    Gu, Tianhong; Yang, Xiaoyan; Li, Minjie; Wu, Milin; Su, Qiang; Lu, Wencong; Zhang, Yuhui

    2013-01-01

    The second development program developed in this work was introduced to obtain physicochemical properties of DPP-IV inhibitors. Based on the computation of molecular descriptors, a two-stage feature selection method called mRMR-BFS (minimum redundancy maximum relevance-backward feature selection) was adopted. Then, the support vector regression (SVR) was used in the establishment of the model to map DPP-IV inhibitors to their corresponding inhibitory activity possible. The squared correlation coefficient for the training set of LOOCV and the test set are 0.815 and 0.884, respectively. An online server for predicting inhibitory activity pIC50 of the DPP-IV inhibitors as described in this paper has been given in the introduction.

  11. Screening of Korean Medicinal Plant Extracts for α-Glucosidase Inhibitory Activities

    PubMed Central

    Sancheti, Shruti; Sancheti, Sandesh; Lee, Seung-Hun; Lee, Jae-Eun; Seo, Sung-Yum

    2011-01-01

    Glycosidases are the enzymes involved in various biochemical processes related to metabolic disorders and diseases. Therefore, much effort has been focused on searching novel pharmacotherapy for the treatment of these ailments from medicinal plants due to higher safety margins. To pursue these efforts, the present study was performed to evaluate the α-glucosidase inhibitory activities of thirty Korean medicinal plant extracts. Among the plants studied, Euonymus sachalinensis, Rhododendron schlippenbachii, Astilbe chinensis and Juglans regia showed the strongest α-glucosidase inhibitory activity with IC50 values of 10, 20, 30 and 80 µg/mL, respectively. In addition, Meliosma oldhamii and Symplocos chinensis showed moderate α-glucosidase inhibition with IC50 values of 150 and 220 µg/mL, respectively. Therefore, they might prove to be a potential natural source for the treatment of metabolic ailments such as, diabetes, and need further investigations. PMID:24250352

  12. Structure activity relationship modelling of milk protein-derived peptides with dipeptidyl peptidase IV (DPP-IV) inhibitory activity.

    PubMed

    Nongonierma, Alice B; FitzGerald, Richard J

    2016-05-01

    Quantitative structure activity type models were developed in an attempt to predict the key features of peptide sequences having dipeptidyl peptidase IV (DPP-IV) inhibitory activity. The models were then employed to help predict the potential of peptides, which are currently reported in the literature to be present in the intestinal tract of humans following milk/dairy product ingestion, to act as inhibitors of DPP-IV. Two models (z- and v-scale) for short (2-5 amino acid residues) bovine milk peptides, behaving as competitive inhibitors of DPP-IV, were developed. The z- and the v-scale models (p<0.05, R(2) of 0.829 and 0.815, respectively) were then applied to 56 milk protein-derived peptides previously reported in the literature to be found in the intestinal tract of humans which possessed a structural feature of DPP-IV inhibitory peptides (P at the N2 position). Ten of these peptides were synthetized and tested for their in vitro DPP-IV inhibitory properties. There was no agreement between the predicted and experimentally determined DPP-IV half maximal inhibitory concentrations (IC50) for the competitive peptide inhibitors. However, the ranking for DPP-IV inhibitory potency of the competitive peptide inhibitors was conserved. Furthermore, potent in vitro DPP-IV inhibitory activity was observed with two peptides, LPVPQ (IC50=43.8±8.8μM) and IPM (IC50=69.5±8.7μM). Peptides present within the gastrointestinal tract of human may have promise for the development of natural DPP-IV inhibitors for the management of serum glucose.

  13. Screening of some rare endemic Italian plants for inhibitory activity on 5-lipoxygenase.

    PubMed

    Prieto, José-María; Bader, Ammar; Martini, Francesca; Ríos, José-Luis; Morelli, Ivano

    2005-12-01

    The extracts of four rare plants found on the islands of Sicily, Vulcano and Marettimo, Southern Italy, were screened for their inhibitory effect on the production of leukotriene B4 by 5-lipoxygenase in intact cells. The methanol extracts of pods of Cytisus aeolicus and aerial parts of Thymus richardii were the most active extracts, inhibiting almost completely the leukotriene B4 production at 200 and 50 microg/ml, respectively.

  14. Overexpression of protein-tyrosine phosphatase-1B in adipocytes inhibits insulin-stimulated phosphoinositide 3-kinase activity without altering glucose transport or Akt/Protein kinase B activation.

    PubMed

    Venable, C L; Frevert, E U; Kim, Y B; Fischer, B M; Kamatkar, S; Neel, B G; Kahn, B B

    2000-06-16

    Previous studies suggested that protein-tyrosine phosphatase 1B (PTP1B) antagonizes insulin action by catalyzing dephosphorylation of the insulin receptor (IR) and/or other key proteins in the insulin signaling pathway. In adipose tissue and muscle of obese humans and rodents, PTP1B expression is increased, which led to the hypothesis that PTP1B plays a role in the pathogenesis of insulin resistance. Consistent with this, mice in which the PTP1B gene was disrupted exhibit increased insulin sensitivity. To test whether increased expression of PTP1B in an insulin-sensitive cell type could contribute to insulin resistance, we overexpressed wild-type PTP1B in 3T3L1 adipocytes using adenovirus-mediated gene delivery. PTP1B expression was increased approximately 3-5-fold above endogenous levels at 16 h, approximately 14-fold at 40 h, and approximately 20-fold at 72 h post-transduction. Total protein-tyrosine phosphatase activity was increased by 50% at 16 h, 3-4-fold at 40 h, and 5-6-fold at 72 h post-transduction. Compared with control cells, cells expressing high levels of PTP1B showed a 50-60% decrease in maximally insulin-stimulated tyrosyl phosphorylation of IR and insulin receptor substrate-1 (IRS-1) and phosphoinositide 3-kinase (PI3K) activity associated with IRS-1 or with phosphotyrosine. Akt phosphorylation and activity were unchanged. Phosphorylation of p42 and p44 MAP kinase (MAPK) was reduced approximately 32%. Overexpression of PTP1B had no effect on basal, submaximally or maximally (100 nm) insulin-stimulated glucose transport or on the EC(50) for transport. Our results suggest that: 1) insulin stimulation of glucose transport in adipocytes requires activation of PI3K, 2) a novel PI3K-independent pathway may play a role in insulin-induced glucose transport in adipocytes, and 3) overexpression of PTP1B alone in adipocytes does not impair glucose transport.

  15. Design, Synthesis and Biological Evaluation of Stilbene Derivatives as Novel Inhibitors of Protein Tyrosine Phosphatase 1B.

    PubMed

    He, Haibing; Ge, Yinghua; Dai, Hong; Cui, Song; Ye, Fei; Jin, Jia; Shi, Yujun

    2016-12-16

    By imitating the scaffold of lithocholic acid (LCA), a natural steroidal compound displaying Protein Tyrosine Phosphatase 1B (PTP1B) inhibitory activity, a series of stilbene derivatives containing phenyl-substituted isoxazoles were designed and synthesized. The structures of the title compounds were confirmed by ¹H-NMR, (13)C-NMR and HRMS. Activities of the title compounds were evaluated on PTP1B and the homologous enzyme TCPTP by using a colorimetric assay. Most of the target compounds had good activities against PTP1B. Among them, compound 29 (IC50 = 0.91 ± 0.33 μM), characterized by a 5-(2,3-dichlorophenyl) isoxazole moiety, exhibited an activity about 14-fold higher than the lead compound LCA and a 4.2-fold selectivity over TCPTP. Compound 29 was identified as a competitive inhibitor of PTP1B with a Ki value of 0.78 μM in enzyme kinetic studies.

  16. Bioactive compounds, antioxidant, xanthine oxidase inhibitory, tyrosinase inhibitory and anti-inflammatory activities of selected agro-industrial by-products.

    PubMed

    Oskoueian, Ehsan; Abdullah, Norhani; Hendra, Rudi; Karimi, Ehsan

    2011-01-01

    Evaluation of abundantly available agro-industrial by-products for their bioactive compounds and biological activities is beneficial in particular for the food and pharmaceutical industries. In this study, rapeseed meal, cottonseed meal and soybean meal were investigated for the presence of bioactive compounds and antioxidant, anti-inflammatory, xanthine oxidase and tyrosinase inhibitory activities. Methanolic extracts of rapeseed meal showed significantly (P < 0.01) higher phenolics and flavonoids contents; and significantly (P < 0.01) higher DPPH and nitric oxide free radical scavenging activities when compared to that of cottonseed meal and soybean meal extracts. Ferric thiocyanate and thiobarbituric acid tests results showed rapeseed meal with the highest antioxidant activity (P < 0.01) followed by BHT, cotton seed meal and soybean meal. Rapeseed meal extract in xanthine oxidase and tyrosinase inhibitory assays showed the lowest IC(50) values followed by cottonseed and soybean meals. Anti-inflammatory assay using IFN-γ/LPS stimulated RAW 264.7 cells indicated rapeseed meal is a potent source of anti-inflammatory agent. Correlation analysis showed that phenolics and flavonoids were highly correlated to both antioxidant and anti-inflammatory activities. Rapeseed meal was found to be promising as a natural source of bioactive compounds with high antioxidant, anti-inflammatory, xanthine oxidase and tyrosinase inhibitory activities in contrast to cotton and soybean meals.

  17. Inhibitory Effects of Garcinia cambogia Extract on CYP2B6 Enzyme Activity.

    PubMed

    Yu, Jun Sang; Choi, Min Sun; Park, Jong Suk; Rehman, Shaheed Ur; Nakamura, Katsunori; Yoo, Hye Hyun

    2017-03-13

    This study assessed the inhibitory effects of Garcinia cambogia extract on the cytochrome P450 enzymes in vitro. G. cambogia extract was incubated with cytochrome P450 isozyme-specific substrates in human liver microsomes and recombinant CYP2B6 isozyme, and the formation of the marker metabolites was measured to investigate the inhibitory potential on cytochrome P450 enzyme activities. The results showed that G. cambogia extract has significant inhibitory effects on CYP2B6 activity in a concentration-dependent manner. Furthermore, the inhibition was potentiated following preincubation with NADPH, indicating that G. cambogia extract is a time-dependent inhibitor of CYP2B6. Meanwhile, hydroxycitric acid, the major bioactive ingredient of G. cambogia extract, did not exhibit significant inhibition effects on cytochrome P450 enzyme activities. G. cambogia extract could modulate the pharmacokinetics of CYP2B6 substrate drugs and lead to interactions with those drugs. Therefore, caution may be required with respect to concomitant intake of dietary supplements containing G. cambogia extract with CYP2B6 substrates.

  18. Synthesis and in vitro α-chymotrypsin inhibitory activity of 6-chlorobenzimidazole derivatives.

    PubMed

    Siddiqui, Hina; Farooq, Rabia; Marasini, Bishnu P; Malik, Rizwana; Syed, Naima; Moin, Syed Tarique; Atta-Ur-Rahman; Choudhary, M Iqbal

    2016-08-15

    A library of benzimidazole derivatives 1-20 were synthesized, and studied for their α-chymotrypsin (α-CT) inhibitory activity in vitro. Kinetics and molecular docking studies were performed to identify the type of inhibition. Compound 1 was found to be a good inhibitor of α-chymotrypsin enzyme (IC50=14.8±0.1μM, Ki=16.4μM), when compared with standard chymostatin (IC50=5.7±0.13μM). Compounds 2-8, 15, 17, and 18 showed significant inhibitory activities. All the inhibitors were found to be competitive inhibitors, except compound 17, which was a mixed type inhibitor. The substituents (R) in para and ortho positions of phenyl ring B, apparently played a key role in the inhibitory potential of the series. Compounds 1-20 were also studied for their cytotoxicity profile by using 3T3 mouse fibroblast cells and compounds 3, 5, 6, 8, 12-14, 16, 17, 19, and 20 were found to be cytotoxic. Molecular docking was performed on the most active members of the series in comparison to the standard compound, chymostatin, to identify the most likely binding modes. The compounds reported here can serve as templates for further studies for new inhibitors of α-chymotrypsin and other chymotrypsin-like serine proteases enzymes.

  19. Medicinal Plants and Their Inhibitory Activities against Pancreatic Lipase: A Review

    PubMed Central

    Seyedan, Atefehalsadat; Alshawsh, Mohammed Abdullah; Alshagga, Mustafa Ahmed; Koosha, Sanaz; Mohamed, Zahurin

    2015-01-01

    Obesity is recognized as a major life style disorder especially in developing countries and it is prevailing at an alarming speed in new world countries due to fast food intake, industrialization, and reduction of physical activity. Furthermore, it is associated with a vast number of chronic diseases and disabilities. To date, relatively effective drugs, from either natural or synthetic sources, are generally associated with serious side effects, often leading to cessation of clinical trials or even withdrawal from the market. In order to find new compounds which are more effective or with less adverse effects compared to orlistat, the drug that has been approved for obesity, new compounds isolated from natural products are being identified and screened for antiobesity effects, in particular, for their pancreatic lipase inhibitory effect. Pancreatic lipase inhibitory activity has been extensively used for the determination of potential efficacy of natural products as antiobesity agents. In attempts to identify natural products for overcoming obesity, more researches have been focused on the identification of newer pancreatic lipase inhibitors with less unpleasant adverse effects. In this review, we consider the potential role of plants that have been investigated for their pancreatic lipase inhibitory activity. PMID:26640503

  20. Hypotensive and Angiotensin-Converting Enzyme Inhibitory Activities of Eisenia fetida Extract in Spontaneously Hypertensive Rats

    PubMed Central

    Mao, Shumei; Li, Chengde

    2015-01-01

    Objectives. This study aimed to investigate the antihypertensive effects of an Eisenia fetida extract (EFE) and its possible mechanisms in spontaneously hypertensive rats (SHR rats). Methods. Sixteen-week-old SHR rats and Wistar-Kyoto rats (WKY rats) were used in this study. Rats were, respectively, given EFE (EFE group), captopril (captopril group), or phosphate-buffered saline (PBS) (normal control group and SHR group) for 4 weeks. ACE inhibitory activity of EFE in vitro was determined. The systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured using a Rat Tail-Cuff Blood Pressure System. Levels of angiotensin II (Ang II), aldosterone (Ald), and 6-keto-prostaglandin F1 alpha (6-keto-PGF1α) in plasma were determined by radioimmunoassay, and serum nitric oxide (NO) concentration was measured by Griess reagent systems. Results. EFE had marked ACE inhibitory activity in vitro (IC50 = 2.5 mg/mL). After the 4-week drug management, SHR rats in EFE group and in captopril group had lower SBP and DBP, lower levels of Ang II and Ald, and higher levels of 6-keto-PGF1α and NO than the SHR rats in SHR group. Conclusion. These results indicate that EFE has hypotensive effects in SHR rats and its effects might be associated with its ACE inhibitory activity. PMID:26798397

  1. Protein tyrosine phosphatase 1B (PTP1B)-inhibiting constituents from the leaves of Syzygium polyanthum.

    PubMed

    Saifudin, Azis; Tanaka, Ken; Kadota, Shigetoshi; Tezuka, Yasuhiro

    2012-08-01

    A methanol extract of the leaves of Syzygium polyanthum (Wight) Walp. afforded four new acylbenzene derivatives (1-4) together with seven known compounds (5-11). The structures of 1-11 were elucidated by extensive spectroscopic methods and comparison with the literature data. The new compounds 1-3 and a known compound, campest-4-en-3-one (10), exhibited a significant protein tyrosine phosphatase 1B inhibitory activity with IC₅₀ values of 13.1 ± 0.1, 5.77 ± 0.15, 4.01 ± 0.26, and 10.4 ± 0.5 µM, respectively. The inhibitory potency of the new compounds 2 and 3 was comparable to that of a positive control RK-682 (IC₅₀, 5.51 ± 0.04 µM).

  2. Growth inhibitory activity of extracts and compounds from Cimicifuga species on human breast cancer cells.

    PubMed

    Einbond, Linda Saxe; Wen-Cai, Ye; He, Kan; Wu, Hsan-au; Cruz, Erica; Roller, Marc; Kronenberg, Fredi

    2008-06-01

    The purpose of this report is to explore the growth inhibitory effect of extracts and compounds from black cohosh and related Cimicifuga species on human breast cancer cells and to determine the nature of the active components. Black cohosh fractions enriched for triterpene glycosides and purified components from black cohosh and related Asian species were tested for growth inhibition of the ER(-) Her2 overexpressing human breast cancer cell line MDA-MB-453. Growth inhibitory activity was assayed using the Coulter Counter, MTT and colony formation assays. Results suggested that the growth inhibitory activity of black cohosh extracts appears to be related to their triterpene glycoside composition. The most potent Cimicifuga component tested was 25-acetyl-7,8-didehydrocimigenol 3-O-beta-d-xylopyranoside, which has an acetyl group at position C-25. It had an IC(50) of 3.2microg/ml (5microM) compared to 7.2microg/ml (12.1microM) for the parent compound 7,8-didehydrocimigenol 3-O-beta-d-xylopyranoside. Thus, the acetyl group at position C-25 enhances growth inhibitory activity. The purified triterpene glycoside actein (beta-d-xylopyranoside), with an IC(50) equal to 5.7microg/ml (8.4microM), exhibited activity comparable to cimigenol 3-O-beta-d-xyloside. MCF7 (ER(+)Her2 low) cells transfected for Her2 are more sensitive than the parental MCF7 cells to the growth inhibitory effects of actein from black cohosh, indicating that Her2 plays a role in the action of actein. The effect of actein on Her2 overexpressing MDA-MB-453 and MCF7 (ER(+)Her2 low) human breast cancer cells was examined by fluorescent microscopy. Treatment with actein altered the distribution of actin filaments and induced apoptosis in these cells. These findings, coupled with our previous evidence that treatment with the triterpene glycoside actein induced a stress response and apoptosis in human breast cancer cells, suggest that compounds from Cimicifuga species may be useful in the prevention and

  3. Discovery of Diverse Small Molecule Chemotypes with Cell-Based PKD1 Inhibitory Activity

    PubMed Central

    Sharlow, Elizabeth R.; Mustata Wilson, Gabriela; Close, David; Leimgruber, Stephanie; Tandon, Manuj; Reed, Robyn B.; Shun, Tong Ying; Wang, Q. Jane; Wipf, Peter; Lazo, John S.

    2011-01-01

    Protein kinase D (PKD) is a novel family of serine/threonine kinases regulated by diacylglycerol, which is involved in multiple cellular processes and various pathological conditions. The limited number of cell-active, selective inhibitors has historically restricted biochemical and pharmacological studies of PKD. We now markedly expand the PKD1 inhibitory chemotype inventory with eleven additional novel small molecule PKD1 inhibitors derived from our high throughput screening campaigns. The in vitro IC50s for these eleven compounds ranged in potency from 0.4 to 6.1 µM with all of the evaluated compounds being competitive with ATP. Three of the inhibitors (CID 1893668, (1Z)-1-(3-ethyl-5-methoxy-1,3-benzothiazol-2-ylidene)propan-2-one; CID 2011756, 5-(3-chlorophenyl)-N-[4-(morpholin-4-ylmethyl)phenyl]furan-2-carboxamide; CID 5389142, (6Z)-6-[4-(3-aminopropylamino)-6-methyl-1H-pyrimidin-2-ylidene]cyclohexa-2,4-dien-1-one) inhibited phorbol ester-induced endogenous PKD1 activation in LNCaP prostate cancer cells in a concentration-dependent manner. The specificity of these compounds for PKD1 inhibitory activity was supported by kinase assay counter screens as well as by bioinformatics searches. Moreover, computational analyses of these novel cell-active PKD1 inhibitors indicated that they were structurally distinct from the previously described cell-active PKD1 inhibitors while computational docking of the new cell-active compounds in a highly conserved ATP-binding cleft suggests opportunities for structural modification. In summary, we have discovered novel PKD1 inhibitors with in vitro and cell-based inhibitory activity, thus successfully expanding the structural diversity of small molecule inhibitors available for this important pharmacological target. PMID:21998636

  4. Evaluation of Selected Culinary-Medicinal Mushrooms for Antioxidant and ACE Inhibitory Activities

    PubMed Central

    Abdullah, Noorlidah; Ismail, Siti Marjiana; Aminudin, Norhaniza; Shuib, Adawiyah Suriza; Lau, Beng Fye

    2012-01-01

    Considering the importance of diet in prevention of oxidative stress-related diseases including hypertension, this study was undertaken to evaluate the in vitro antioxidant and ACE inhibitory activities of selected culinary-medicinal mushrooms extracted by boiling in water for 30 min. Antioxidant capacity was measured using the following assays: DPPH free radical scavenging activity, β-carotene bleaching, inhibition of lipid peroxidation, reducing power ability, and cupric ion reducing antioxidant capacity (CUPRAC). Antioxidant potential of each mushroom species was calculated based on the average percentages relative to quercetin and summarized as Antioxidant Index (AI). Ganoderma lucidum (30.1%), Schizophyllum commune (27.6%), and Hericium erinaceus (17.7%) showed relatively high AI. Total phenolics in these mushrooms varied between 6.19 to 63.51 mg GAE/g extract. In the ACE inhibitory assay, G. lucidum was shown to be the most potent species (IC50 = 50 μg/mL). Based on our findings, culinary-medicinal mushrooms can be considered as potential source of dietary antioxidant and ACE inhibitory agents. PMID:21716693

  5. Local field potentials primarily reflect inhibitory neuron activity in human and monkey cortex

    PubMed Central

    Teleńczuk, Bartosz; Dehghani, Nima; Le Van Quyen, Michel; Cash, Sydney S.; Halgren, Eric; Hatsopoulos, Nicholas G.; Destexhe, Alain

    2017-01-01

    The local field potential (LFP) is generated by large populations of neurons, but unitary contribution of spiking neurons to LFP is not well characterised. We investigated this contribution in multi-electrode array recordings from human and monkey neocortex by examining the spike-triggered LFP average (st-LFP). The resulting st-LFPs were dominated by broad spatio-temporal components due to ongoing activity, synaptic inputs and recurrent connectivity. To reduce the spatial reach of the st-LFP and observe the local field related to a single spike we applied a spatial filter, whose weights were adapted to the covariance of ongoing LFP. The filtered st-LFPs were limited to the perimeter of 800 μm around the neuron, and propagated at axonal speed, which is consistent with their unitary nature. In addition, we discriminated between putative inhibitory and excitatory neurons and found that the inhibitory st-LFP peaked at shorter latencies, consistently with previous findings in hippocampal slices. Thus, in human and monkey neocortex, the LFP reflects primarily inhibitory neuron activity. PMID:28074856

  6. Absolute Configurations and NO Inhibitory Activities of Terpenoids from Curcuma longa.

    PubMed

    Xu, Jing; Ji, Feifei; Kang, Jing; Wang, Hao; Li, Shen; Jin, Da-Qing; Zhang, Qiang; Sun, Hongwei; Guo, Yuanqiang

    2015-06-24

    Curcuma longa L., belonging to the Zingiberaceae family, is a perennial herb and has been used as a spice and a pigment in the food industry. In the ongoing search for inhibitory reagents of NO production and survey of the chemical composition of natural vegetable foods, the chemical constituents of C. longa used as spice were investigated. This investigation resulted in the isolation of 2 new terpenoids and 14 known analogues. Their structures were established on the basis of the extensive analyses of 1D and 2D NMR spectroscopic data, and the absolute configurations of 1-4 were elucidated by comparison of the calculated and experimental ECD spectra. Among them, compound 1 is a rare norditerpene with an ent-labdane skeleton, and 2 is a skeletally novel sesquiterpene having an eight-membered ring. All of the compounds were found to possess NO inhibitory activities in murine microglial BV-2 cells. The discovery of two new compounds in this chemical investigation further disclosed the chemical composition of C. longa used a food spice, and the bioassay implied that the natural food spice C. longa, containing terpenoids with NO inhibitory activities, may be potentially promotive to human health.

  7. Evaluation of Selected Culinary-Medicinal Mushrooms for Antioxidant and ACE Inhibitory Activities.

    PubMed

    Abdullah, Noorlidah; Ismail, Siti Marjiana; Aminudin, Norhaniza; Shuib, Adawiyah Suriza; Lau, Beng Fye

    2012-01-01

    Considering the importance of diet in prevention of oxidative stress-related diseases including hypertension, this study was undertaken to evaluate the in vitro antioxidant and ACE inhibitory activities of selected culinary-medicinal mushrooms extracted by boiling in water for 30 min. Antioxidant capacity was measured using the following assays: DPPH free radical scavenging activity, β-carotene bleaching, inhibition of lipid peroxidation, reducing power ability, and cupric ion reducing antioxidant capacity (CUPRAC). Antioxidant potential of each mushroom species was calculated based on the average percentages relative to quercetin and summarized as Antioxidant Index (AI). Ganoderma lucidum (30.1%), Schizophyllum commune (27.6%), and Hericium erinaceus (17.7%) showed relatively high AI. Total phenolics in these mushrooms varied between 6.19 to 63.51 mg GAE/g extract. In the ACE inhibitory assay, G. lucidum was shown to be the most potent species (IC(50) = 50 μg/mL). Based on our findings, culinary-medicinal mushrooms can be considered as potential source of dietary antioxidant and ACE inhibitory agents.

  8. Poly(amidoamine) Dendrimers with Carbonic Anhydrase Inhibitory Activity and Antiglaucoma Action.

    PubMed

    Carta, Fabrizio; Osman, Sameh M; Vullo, Daniela; Gullotto, Antonella; Winum, Jean-Yves; AlOthman, Zeid; Masini, Emanuela; Supuran, Claudiu T

    2015-05-14

    Four generations of poly(amidoamine) (PAMAM) dendrimers decorated with benzenesulfonamide moieties were prepared by derivatizing the amino groups of the dendrimer with 4-carboxy-benzenesulfonamide functionalities. Compounds incorporating 4, 8, 16, and 32 sulfonamide moieties were thus obtained, which showed an increasing carbonic anhydrase (CA, EC 4.2.1.1) inhibitory action with the increase of the number of sulfamoyl groups in the dendrimer. Best inhibitory activity (in the low nanomolar-subnanomolar range) was observed for isoforms CA II and XII, involved among others in glaucoma. In an animal model of this disease, the chronic administration of such dendrimers for 5 days led to a much more efficient drop of intraocular pressure compared to the standard drug dorzolamide.

  9. New compound with DNA Topo I inhibitory activity purified from Penicillium oxalicum HSY05.

    PubMed

    Liu, Bing; Wang, Hai-Feng; Zhang, Li-Hua; Liu, Fang; He, Feng-Jun; Bai, Jiao; Hua, Hui-Ming; Chen, Gang; Pei, Yue-Hu

    2015-01-01

    Strain HSY05 was isolated from sea sediment collected from the South China Sea and was later identified as Penicillium oxalicum by 16S rDNA sequence analysis. Various chromatographic processes led to the isolation and purification of two metabolites from the fermentation culture of HSY05, including one new compound, 2,2',4,4'-tetrahyoxy-8'-methyl-6-methoxy-acyl-ethyl-diphenylmethanone (1), and a known compound secalonic acid D (SAD, 2), as characterised by UV, IR, 1D, 2D-NMR and MS data. The inhibitory activities against topoisomerase I of these two compounds were evaluated. The result showed that in addition to the known topo I inhibitor SAD (2), compound 1 also exhibited a moderate inhibitory effect.

  10. Increased alpha band activity indexes inhibitory competition across a border during figure assignment.

    PubMed

    Sanguinetti, Joseph L; Trujillo, Logan T; Schnyer, David M; Allen, John J B; Peterson, Mary A

    2016-09-01

    Figure-ground assignment is thought to entail inhibitory competition between potential objects on opposite sides of a shared border; the winner is perceived as the figure, and the loser as the shapeless ground. Computational models and response time measures support this understanding but to date no online measure of inhibitory competition during figure-ground assignment has been reported. The current study assays electroencephalogram (EEG) alpha power as a measure of inhibitory competition during figure-ground assignment. Activity in the EEG alpha band has been linked to functional inhibition in the brain, and it has been proposed that increased alpha power reflects increased inhibition. In 2 experiments participants viewed silhouettes designed so that the insides would be perceived as figures. Real-world silhouettes depicted namable objects. Novel silhouettes depicted novel objects on the insides of their borders, but varied in the amount of hypothesized cross-border competition for figural status: In "Low-Competition" silhouettes, the borders suggested novel objects on the outside as well as on the inside. In "High-Competition" silhouettes the borders suggested portions of real-world objects on the outside; these compete with the figural properties favoring the inside as figure. Participants accurately categorized both types of novel silhouettes as "novel" objects and were unaware of the real world objects suggested on the outside of the High-Competition silhouettes. In both experiments, we observed more alpha power while participants viewed High- rather than Low-Competition novel silhouettes. These are the first results to show via an online index of neural activity that figure assignment entails inhibitory competition.

  11. Chemical constituents of Swertia longifolia Boiss. with α-amylase inhibitory activity

    PubMed Central

    Saeidnia, Soodabeh; Ara, Leila; Hajimehdipoor, Homa; Read, Roger W.; Arshadi, Sattar; Nikan, Marjan

    2016-01-01

    α-Amylase inhibitors play a critical role in the control of diabetes and many of medicinal plants have been found to act as α-amylase inhibitors. Swertia genus, belonging to the family Gentianaceae, comprises different species most of which have been used in traditional medicine of several cultures as antidiabetic, anti-pyretic, analgesic, liver and gastrointestinal tonic. Swertia longifolia Boiss. is the only species of Swertia growing in Iran. In the present investigation, phytochemical study of S. longifolia was performed and α-amylase inhibitory effects of the plant fractions and purified compounds were determined. Aerial parts of the plant were extracted with hexane, chloroform, methanol and water, respectively. The components of the hexane and chloroform fractions were isolated by different chromatographic methods and their structures were determined by 1H NMR and 13C NMR data. α-Amylase inhibitory activity was determined by a colorimetric assay using 3,5-dinitro salysilic acid. During phytochemical examination, α-amyrin, β-amyrin and β-sitosterol were purified from the hexane fraction, while ursolic acid, daucosterol and swertiamarin were isolated from chloroform fraction. The results of the biochemical assay revealed α-amylase inhibitory activity of hexane, chloroform, methanol and water fractions, of which the chloroform and methanol fractions were more potent (IC50 16.8 and 18.1 mg/ml, respectively). Among examined compounds, daucosterol was found to be the most potent α-amylase inhibitor (57.5% in concentration 10 mg/ml). With regard to α-amylase inhibitory effects of the plant extracts, purified constituents, and antidiabetic application of the species of Swertia genus in traditional medicine of different countries, S. longifolia seems more appropriate species for further mechanistic antidiabetic evaluations. PMID:27051429

  12. Salvia leriifolia Benth (Lamiaceae) extract demonstrates in vitro antioxidant properties and cholinesterase inhibitory activity.

    PubMed

    Loizzo, Monica R; Tundis, Rosa; Conforti, Filomena; Menichini, Federica; Bonesi, Marco; Nadjafi, Farsad; Frega, Natale Giuseppe; Menichini, Francesco

    2010-12-01

    The object of the present study was to investigate the in vitro antioxidant properties and cholinesterase inhibitory activity of Salvia leriifolia Benth extracts and fractions. The functional role of herbs and spices and their constituents is a hot topic in food-related plant research. Salvia species have been used since ancient times in folk medicine for cognitive brain function and have been subjected to extensive research. Thus, we hypothesize that S leriifolia, because of its functional properties, would be a good candidate to use as a nutraceutical product for improving memory in the elderly or patients affected by Alzheimer disease (ad). To test this hypothesis, we examined the cholinesterase inhibitory activity using the modified colorimetric Ellman's method against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). The n-hexane exhibited the highest activity, with inhibitory concentration 50% (IC(50)) values of 0.59 and 0.21 mg/mL, for AChE and BChE, respectively. This extract was fractionated, and 9 of these fractions (A-I) were obtained and tested. Fraction G, characterized by the presence of sesquiterpenes as major components, was the most active against AChE (IC(50) = 0.05 mg/mL). Because oxidative stress is a critical event in the pathogenesis of AD, we decided to screen the antioxidant activity (AA) using 2,2-diphenyl-1-picrylhydrazyl test, β-carotene bleaching test, and bovine brain peroxidation (thiobarbituric acid) assay. The ethyl acetate extract showed the highest activity, with IC(50) values of 2 and 33 μg/mL on β-carotene bleaching test and thiobarbituric acid test, respectively. These results suggest potential health benefits of S leriifolia extracts. However, this finding requires additional investigation in vivo.

  13. Xanthine oxidase inhibitory activity of the methanolic extracts of selected Jordanian medicinal plants

    PubMed Central

    Hudaib, Mohammad M.; Tawaha, Khaled A.; Mohammad, Mohammad K.; Assaf, Areej M.; Issa, Ala Y.; Alali, Feras Q.; Aburjai, Talal A.; Bustanji, Yasser K.

    2011-01-01

    Background: The search for novel xanthine oxidase (XO) inhibitors with a higher therapeutic activity and fewer side effects are desired not only to treat gout but also to combat various other diseases associated with the XO activity. At present, the potential of developing successful natural products for the management of XO-related diseases is still largely unexplored. In the present study, we have screened the methanolic extracts of various Jordanian medicinal plants for their XO inhibitory activities using an optimized protocol. Materials and Methods: The methanolic extracts of 23 medicinal plants, belonging to 12 families, were tested in vitro, at 200 μg/ml concentrations, for their XO inhibitory potential. The dose-dependent inhibition profiles of the most active plants were further evaluated by estimating the IC50 values of their corresponding extracts. Results: Six plants were found most active (% inhibition more than 39%). These plants are Salvia spinosa L. (IC50 = 53.7 μg/ml), Anthemis palestina Boiss. (168.0 μg/ml), Chrysanthemum coronarium L. (199.5 μg/ml), Achillea biebersteinii Afansiev (360.0 μg/ml), Rosmarinus officinalis L. (650.0 μg/ml), and Ginkgo biloba L. (595.8 μg/ml). Moreover, four more plants, namely Lavandula angustifolia Mill. (28.7% inhibition), Helianthemum ledifolium (L.) Mill. (28.4%), Majorana syriaca (L.) Kostel. (25.1%), and Mentha spicata L. (22.5%) showed a XO inhibitory activity in the range of 22–30%. Conclusion: The study showed that many of the tested plant species are potential sources of natural XO inhibitors that can be developed, upon further investigation, into successful herbal drugs for treatment of gout and other XO-related disorders. PMID:22262935

  14. Oleanane-type triterpene oligoglycosides with pancreatic lipase inhibitory activity from the pericarps of Sapindus rarak.

    PubMed

    Morikawa, Toshio; Xie, Yuanyuan; Asao, Yasunobu; Okamoto, Masaki; Yamashita, Chihiro; Muraoka, Osamu; Matsuda, Hisashi; Pongpiriyadacha, Yutana; Yuan, Dan; Yoshikawa, Masayuki

    2009-06-01

    The methanolic extract from the pericarps of Sapindus rarak DC. was found to show pancreatic lipase inhibitory activity (IC50=ca. 614 microg/mL). From the extract, oleanane-type triterpene oligoglycosides, rarasaponins I-III (1-3), and raraoside A (4), were isolated together with 13 known saponins and four known sesquiterpene glycosides. Among them, several saponin constituents including rarasaponins I (1, IC50=131microM) and II (2, 172microM), and raraoside A (4, 151microM) inhibited pancreatic lipase activity, which were stronger than that of theasaponin E(1) (270microM).

  15. Contributions of diverse excitatory and inhibitory neurons to recurrent network activity in cerebral cortex.

    PubMed

    Neske, Garrett T; Patrick, Saundra L; Connors, Barry W

    2015-01-21

    The recurrent synaptic architecture of neocortex allows for self-generated network activity. One form of such activity is the Up state, in which neurons transiently receive barrages of excitatory and inhibitory synaptic inputs that depolarize many neurons to spike threshold before returning to a relatively quiescent Down state. The extent to which different cell types participate in Up states is still unclear. Inhibitory interneurons have particularly diverse intrinsic properties and synaptic connections with the local network, suggesting that different interneurons might play different roles in activated network states. We have studied the firing, subthreshold behavior, and synaptic conductances of identified cell types during Up and Down states in layers 5 and 2/3 in mouse barrel cortex in vitro. We recorded from pyramidal cells and interneurons expressing parvalbumin (PV), somatostatin (SOM), vasoactive intestinal peptide (VIP), or neuropeptide Y. PV cells were the most active interneuron subtype during the Up state, yet the other subtypes also received substantial synaptic conductances and often generated spikes. In all cell types except PV cells, the beginning of the Up state was dominated by synaptic inhibition, which decreased thereafter; excitation was more persistent, suggesting that inhibition is not the dominant force in terminating Up states. Compared with barrel cortex, SOM and VIP cells were much less active in entorhinal cortex during Up states. Our results provide a measure of functional connectivity of various neuron types in barrel cortex and suggest differential roles for interneuron types in the generation and control of persistent network activity.

  16. Triton 2 (1B)

    NASA Technical Reports Server (NTRS)

    Clark, Michelle L.; Meiss, A. G.; Neher, Jason R.; Rudolph, Richard H.

    1994-01-01

    The goal of this project was to perform a detailed design analysis on a conceptually designed preliminary flight trainer. The Triton 2 (1B) must meet the current regulations in FAR Part 23. The detailed design process included the tasks of sizing load carrying members, pulleys, bolts, rivets, and fuselage skin for the safety cage, empennage, and control systems. In addition to the regulations in FAR Part 23, the detail design had to meet established minimums for environmental operating conditions and material corrosion resistance.

  17. The Potent Inhibitors of Protein Tyrosine Phosphatase 1B from the Fruits of Melaleuca leucadendron

    PubMed Central

    Saifudin, Azis; Lallo, Subehan Ab; Tezuka, Yasuhiro

    2016-01-01

    Background: Melaleuca leucadendron (Myrtaceae) is a kind of fruit used as Indonesian medicinal component and recorded in Jamu (tonic made of medical herbs) prescription records for the diabetes treatment. Its methanol extract exhibited a strong inhibitory activity with the half maximal inhibitory concentration (IC50) value of 2.05 μg/mL, while it is the same value with positive control RK-682. Objective: To isolate the chemical constituents of M. leucadendron and to evaluate their activity against protein tyrosine phosphatase 1B (PTP1B). Further, determine their toxicity potential against T-cell protein tyrosine phosphatase (TCPTP). Materials and Methods: Methanol extract was fractionated using silica column chromatography, and the obtained fraction was purified using Sephadex 20-LH. The structure of isolated compounds was identified based on 1H and 13Nuclear Magnetic Resonance Spectrometry. Furthermore, the compounds were examined against PTP1B and TCPTP. Results: Methanol extract of M. leucadendron (Myrtaceae) afforded two triterpenes: Betulinic acid and ursolic acid in high quantities. Both compounds exhibited a strong inhibitory activity against PTP1B inhibition with IC50 value of 1.5 and 2.3 μg/mL, respectively (positive control RK-682, IC50 = 2.05 μg/mL). Their activity toward TCPTP, on the other hand, were at 2.4 and 3.1 μg/mL, respectively. Based on this purification work, betulinic acid and ursolic acid presented 7.6% and 2.4%, respectively, as markedly M. leucadendron most potential for betulinic acid source among Indonesian plants. The result should have demonstrated that the antidiabetes of M. dendron could be through the inhibition of PTP1B. SUMMARY Melaleuca leucadendron is a good source for ursolic acid.Confirming traditional use for type II diabetes via PTP1B inhibition. PMID:27114690

  18. Inhibitory activity and mechanism of two scorpion venom peptides against herpes simplex virus type 1.

    PubMed

    Hong, Wei; Li, Tian; Song, Yu; Zhang, Runhong; Zeng, Zhengyang; Han, Shisong; Zhang, Xianzheng; Wu, Yingliang; Li, Wenxin; Cao, Zhijian

    2014-02-01

    Herpes simplex virus type 1 (HSV-1) is a widespread human pathogen that causes severe diseases, but there are not effective and safe drugs in clinical therapy besides acyclovir (ACV) and related nucleoside analogs. In this study, two new venom peptides from the scorpion Heterometrus petersii were identified with effective inhibitory effect on HSV-1 infection in vitro. Both Hp1036 and Hp1239 peptides exhibited potent virucidal activities against HSV-1 (EC50=0.43±0.09 and 0.41±0.06μM, respectively) and effective inhibitory effects when added at the viral attachment (EC50=2.87±0.16 and 5.73±0.61μM, respectively), entry (EC50=4.29±0.35 and 4.32±0.47μM, respectively) and postentry (EC50=7.86±0.80 and 8.41±0.73μM, respectively) steps. Both Hp1036 and Hp1239 peptides adopted α-helix structure in approximate membrane environment and resulted in the destruction of the viral morphology. Moreover, Hp1036 and Hp1239 peptides entered Vero cells and reduced the intracellular viral infectivity. Taken together, Hp1036 and Hp1239 peptides are two anti-viral peptides with effective inhibitory effect on multiple steps of HSV-1 life cycle and therefore are good candidate for development as virucides.

  19. ACE-inhibitory activity of enzymatic protein hydrolysates from lupin and other legumes.

    PubMed

    Boschin, Giovanna; Scigliuolo, Graziana Maria; Resta, Donatella; Arnoldi, Anna

    2014-02-15

    The objective of this investigation was to compare the angiotensin converting enzyme (ACE)-inhibitory activity of the hydrolysates obtained by pepsin digestion of proteins of some legumes, such as chickpea, common bean, lentil, lupin, pea, and soybean, by using the same experimental procedure. The ACE-inhibitory activity was measured by using the tripeptide hippuryl-histidyl-leucine (HHL), as model peptide, and HPLC-DAD, as analytical method. The peptide mixtures of all legumes were active, with soybean and lupin the most efficient, with IC50 values of 224 and 226 μg/ml, respectively. Considering the promising results obtained with lupin, and aiming to identify the protein(s) that release(s) the peptides responsible for the activity, the peptides obtained from the pepsin digestion of some industrial lupin protein isolates and purified protein fractions were tested. The most active mixture, showing an IC50 value of 138 μg/ml, was obtained hydrolysing a mixture of lupin α+β conglutin.

  20. Antibacterial and EGFR-tyrosine kinase inhibitory activities of polyhydroxylated xanthones from Garcinia succifolia.

    PubMed

    Duangsrisai, Susawat; Choowongkomon, Kiattawee; Bessa, Lucinda J; Costa, Paulo M; Amat, Nurmuhammat; Kijjoa, Anake

    2014-11-28

    Chemical investigation of the methanol extract of the wood of Garcinia succifolia Kurz (Clusiaceae) led to the isolation of 1,5-dihydroxyxanthone (1), 1,7-dihydroxyxanthone (2), 1,3,7-trihydroxyxanthone (3), 1,5,6-trihydroxyxanthone (4), 1,6,7-trihydroxyxanthone (5), and 1,3,6,7-tetrahydroxyxanthone (6). All of the isolated xanthones were evaluated for their antibacterial activity against bacterial reference strains, two Gram-positive (Staphylococcus aureus ATTC 25923, Bacillus subtillis ATCC 6633) and two Gram-negative (Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853), and environmental drug-resistant isolates (S. aureus B1, Enteroccoccus faecalis W1, and E. coli G1), as well as for their epidermal growth factor receptor (EGFR) of tyrosine kinase inhibitory activity. Only 1,5,6-trihydroxy-(4), 1,6,7-trihydroxy-(5), and 1,3,6,7-tetrahydroxyxanthones (6) exhibited antibacterial activity against Gram-positive bacteria, however none was active against vancomycin-resistant E. faecalis. Additionally, 1,7-dihydroxyxanthone (2) showed synergism with oxacillin, but not with ampicillin. On the other hand, only 1,5-dihydroxyxanthone (1) and 1,7-dihydroxyxanthone (2) were found to exhibit the EGFR-tyrosine kinase inhibitory activity, with IC50 values of 90.34 and 223 nM, respectively.

  1. Ongoing network state controls the length of sleep spindles via inhibitory activity.

    PubMed

    Barthó, Péter; Slézia, Andrea; Mátyás, Ferenc; Faradzs-Zade, Lejla; Ulbert, István; Harris, Kenneth D; Acsády, László

    2014-06-18

    Sleep spindles are major transient oscillations of the mammalian brain. Spindles are generated in the thalamus; however, what determines their duration is presently unclear. Here, we measured somatic activity of excitatory thalamocortical (TC) cells together with axonal activity of reciprocally coupled inhibitory reticular thalamic cells (nRTs) and quantified cycle-by-cycle alterations in their firing in vivo. We found that spindles with different durations were paralleled by distinct nRT activity, and nRT firing sharply dropped before the termination of all spindles. Both initial nRT and TC activity was correlated with spindle length, but nRT correlation was more robust. Analysis of spindles evoked by optogenetic activation of nRT showed that spindle probability, but not spindle length, was determined by the strength of the light stimulus. Our data indicate that during natural sleep a dynamically fluctuating thalamocortical network controls the duration of sleep spindles via the major inhibitory element of the circuits, the nRT.

  2. Synthesis of Triazole Schiff's Base Derivatives and Their Inhibitory Kinetics on Tyrosinase Activity.

    PubMed

    Yu, Feng; Jia, Yu-Long; Wang, Hui-Fang; Zheng, Jing; Cui, Yi; Fang, Xin-Yu; Zhang, Lin-Min; Chen, Qing-Xi

    2015-01-01

    In the present study, new Schiff's base derivatives: (Z)-4-amino-5-(2-(3- fluorobenzylidene)hydrazinyl)-4H-1,2,4-triazole-3-thiol (Y1), (Z)-3-((2-(4-amino-5- mercapto-4H-1,2,4-triazol-3-yl)hydrazono)methyl)phenol (Y2), (Z)-2-((2-(4-amino-5- mercapto-4H-1,2,4-triazol-3-yl)hydrazono)methyl)phenol (Y3) and 3-((Z)-(2-(4- (((E)-3-hydroxybenzylidene)amino)-5-mercapto-4H-1,2,4-triazol-3-yl)hydrazono)methyl)phenol (Y4) were synthesized and their structures were characterized by LC-MS, IR and 1H NMR. The inhibitory effects of these compounds on tyrosinase activites were evaluated. Compounds Y1, Y2 and Y3 showed potent inhibitory effects with respective IC50 value of 12.5, 7.0 and 1.5 μM on the diphenolase activities. Moreover, the inhibition mechanisms were determined to be reversible and mixed types. Interactions of the compounds with tyrosinase were further analyzed by fluorescence quenching, copper interaction, and molecular simulation assays. The results together with the anti-tyrosinase activities data indicated that substitution on the second position of benzene ring showed superior ant-ityrosinase activities than that on third position, and that hydroxyl substitutes were better than fluorine substitutes. In addition, two benzene rings connecting to the triazole ring would produce larger steric hindrance, and affect the bonding between tyrosinase and inhibitors to decrease the inhibitory effects. The anti-tyrosinase effects of these compounds were in contrast to their antioxidant activities. In summary, this research will contribute to the development and design of antityrosinase agents.

  3. Synthesis of Triazole Schiff’s Base Derivatives and Their Inhibitory Kinetics on Tyrosinase Activity

    PubMed Central

    Wang, Hui-Fang; Zheng, Jing; Cui, Yi; Fang, Xin-Yu; Zhang, Lin-Min; Chen, Qing-Xi

    2015-01-01

    In the present study, new Schiff’s base derivatives: (Z)-4-amino-5-(2-(3- fluorobenzylidene)hydrazinyl)-4H-1,2,4-triazole-3-thiol (Y1), (Z)-3-((2-(4-amino-5- mercapto-4H-1,2,4-triazol-3-yl)hydrazono)methyl)phenol (Y2), (Z)-2-((2-(4-amino-5- mercapto-4H-1,2,4-triazol-3-yl)hydrazono)methyl)phenol (Y3) and 3-((Z)-(2-(4- (((E)-3-hydroxybenzylidene)amino)-5-mercapto-4H-1,2,4-triazol-3-yl)hydrazono)methyl)phenol (Y4) were synthesized and their structures were characterized by LC-MS, IR and 1H NMR. The inhibitory effects of these compounds on tyrosinase activites were evaluated. Compounds Y1, Y2 and Y3 showed potent inhibitory effects with respective IC50 value of 12.5, 7.0 and 1.5 μM on the diphenolase activities. Moreover, the inhibition mechanisms were determined to be reversible and mixed types. Interactions of the compounds with tyrosinase were further analyzed by fluorescence quenching, copper interaction, and molecular simulation assays. The results together with the anti-tyrosinase activities data indicated that substitution on the second position of benzene ring showed superior ant-ityrosinase activities than that on third position, and that hydroxyl substitutes were better than fluorine substitutes. In addition, two benzene rings connecting to the triazole ring would produce larger steric hindrance, and affect the bonding between tyrosinase and inhibitors to decrease the inhibitory effects. The anti-tyrosinase effects of these compounds were in contrast to their antioxidant activities. In summary, this research will contribute to the development and design of antityrosinase agents. PMID:26422245

  4. Fumonisin concentration and ceramide synthase inhibitory activity of corn, masa, and tortilla chips.

    PubMed

    Voss, Kenneth A; Norred, William P; Meredith, Filmore I; Riley, Ronald T; Stephen Saunders, D

    2006-07-01

    Nixtamalization removes fumonisins from corn and reduces their amounts in masa and tortilla products. Fumonisin concentrations and potential toxicity could be underestimated, however, if unknown but biologically active fumonisins are present. Therefore, the relative amounts of fumonisins in extracts of fumonisin-contaminated corn and its masa and tortilla chip nixtamalization products were determined with an in vitro ceramide synthase inhibition bioassay using increased sphinganine (Sa) and sphinganine to sphingosine ratio (Sa/So) as endpoints. African green monkey kidney cells (Vero cells ATCC CCL-81) were grown in 1-ml wells and exposed to 4 microl of the concentrated extracts for 48 h. The corn extract inhibited ceramide synthase as Sa (mean = 132 pmol/well) and Sa/So (mean = 2.24) were high compared to vehicle controls (Sa = 9 pmol/well; Sa/So = 0.10). Inhibitory activity (mean Sa = 14-24 pmol/well; mean Sa/So = 0.17-0.28) of the masa and tortilla chip extracts were reduced > or = 80% compared to the corn extract. Results were corroborated in a second experiment in which Sa and Sa/So of the wells treated with masa or tortilla chip extracts were reduced > or = 89% compared to those treated with the corn extract. Masa and tortilla chip FB1 concentrations (4-7 ppm) were reduced about 80-90% compared to the corn (30 ppm) when the materials were analyzed by high-performance liquid chromatography (HPLC). Therefore, nixtamalization reduced both the measured amount of FB1 and the ceramide synthase inhibitory activity of masa and tortilla chips extracts. The results further suggest that the masa and tortilla chip extracts did not contain significant amounts of unknown fumonisins having ceramide synthase inhibitory activity.

  5. Identification of new potent phthalazine derivatives with VEGFR-2 and EGFR kinase inhibitory activity.

    PubMed

    Amin, Kamilia M; Barsoum, Flora F; Awadallah, Fadi M; Mohamed, Nehal E

    2016-11-10

    Efforts to develop new antitumor agents are now directed towards multitarget therapies that are believed to have high potency and low tendency to resistance compared to conventional drugs. Herein, we highlighted the synthesis and antitumor activity of five series of phthalazine-based compounds featuring a variety of bioactive chemical fragments at position 1 of the phthalazine nucleus. The antitumor activity of the target compounds was performed against fourteen cancer cell lines where all compounds were active in the nanomolar level. In addition, the mechanism of action of the target compounds was investigated through an enzymatic inhibitory assay against VEGFR-2 and EGFR kinases, revealing potent and preferential activity toward VEGFR-2. Binding mode of the most active compounds was studied using docking experiment.

  6. FOLH1B — EDRN Public Portal

    Cancer.gov

    FOLH1B, or PSMAL, is a cytoplasmic protein. It has been found in the kidney and liver, and has not been detected in the prostate. GO annotations related to this gene include metallopeptidase activity and dipeptidase activity.

  7. Activation of NPY type 5 receptors induces a long-lasting increase in spontaneous GABA release from cerebellar inhibitory interneurons

    PubMed Central

    Dubois, C. J.; Ramamoorthy, P.; Whim, M. D.

    2012-01-01

    Neuropeptide Y (NPY), a widely distributed neuropeptide in the central nervous system, can transiently suppress inhibitory synaptic transmission and alter membrane excitability via Y2 and Y1 receptors (Y2rs and Y1rs), respectively. Although many GABAergic neurons express Y5rs, the functional role of these receptors in inhibitory neurons is not known. Here, we investigated whether activation of Y5rs can modulate inhibitory transmission in cerebellar slices. Unexpectedly, application of NPY triggered a long-lasting increase in the frequency of miniature inhibitory postsynaptic currents in stellate cells. NPY also induced a sustained increase in spontaneous GABA release in cultured cerebellar neurons. When cerebellar cultures were examined for Y5r immunoreactivity, the staining colocalized with that of VGAT, a presynaptic marker for GABAergic cells, suggesting that Y5rs are located in the presynaptic terminals of inhibitory neurons. RT-PCR experiments confirmed the presence of Y5r mRNA in the cerebellum. The NPY-induced potentiation of GABA release was blocked by Y5r antagonists and mimicked by application of a selective peptide agonist for Y5r. Thus Y5r activation is necessary and sufficient to trigger an increase in GABA release. Finally, the potentiation of inhibitory transmission could not be reversed by a Y5r antagonist once it was initiated, consistent with the development of a long-term potentiation. These results indicate that activation of presynaptic Y5rs induces a sustained increase in spontaneous GABA release from inhibitory neurons in contrast to the transient suppression of inhibitory transmission that is characteristic of Y1r and Y2r activation. Our findings thus reveal a novel role of presynaptic Y5rs in inhibitory interneurons in regulating GABA release and suggest that these receptors could play a role in shaping neuronal network activity in the cerebellum. PMID:22190627

  8. Membrane nanoclusters of FcγRI segregate from inhibitory SIRPα upon activation of human macrophages

    PubMed Central

    Valvo, Salvatore; Felce, James H.

    2017-01-01

    Signal integration between activating Fc receptors and inhibitory signal regulatory protein α (SIRPα) controls macrophage phagocytosis. Here, using dual-color direct stochastic optical reconstruction microscopy, we report that Fcγ receptor I (FcγRI), FcγRII, and SIRPα are not homogeneously distributed at macrophage surfaces but are organized in discrete nanoclusters, with a mean radius of 71 ± 11 nm, 60 ± 6 nm, and 48 ± 3 nm, respectively. Nanoclusters of FcγRI, but not FcγRII, are constitutively associated with nanoclusters of SIRPα, within 62 ± 5 nm, mediated by the actin cytoskeleton. Upon Fc receptor activation, Src-family kinase signaling leads to segregation of FcγRI and SIRPα nanoclusters to be 197 ± 3 nm apart. Co-ligation of SIRPα with CD47 abrogates nanocluster segregation. If the balance of signals favors activation, FcγRI nanoclusters reorganize into periodically spaced concentric rings. Thus, a nanometer- and micron-scale reorganization of activating and inhibitory receptors occurs at the surface of human macrophages concurrent with signal integration. PMID:28289091

  9. Human single-chain variable fragment antibody inhibits macrophage migration inhibitory factor tautomerase activity.

    PubMed

    Tarasuk, Mayuri; Poungpair, Ornnuthchar; Ungsupravate, Duangporn; Bangphoomi, Kunan; Chaicumpa, Wanpen; Yenchitsomanus, Pa-Thai

    2014-03-01

    Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine, secreted from a variety of immune cells, that regulates innate and adaptive immune responses. Elevation of MIF levels in plasma correlates with the severity of inflammatory diseases in humans. Inhibition of MIF or its tautomerase activity ameliorates disease severity by reducing inflammatory responses. In this study, the human single-chain variable fragment (HuScFv) antibody specific to MIF was selected from the human antibody phage display library by using purified recombinant full-length human MIF (rMIF) as the target antigen. Monoclonal HuScFv was produced from phage-transformed bacteria and tested for their binding activities to rMIF by indirect enzyme-linked immunosorbent assay as well as to native MIF by western blot analysis and immunofluorescence assay. The HuScFv with highest binding signal to rMIF also inhibited the tautomerase activities of both rMIF and native MIF in human monoblastic leukemia (U937) cells in a dose-dependent manner. Mimotope searching and molecular docking concordantly demonstrated that the HuScFv interacted with Lys32 and Ile64 in the MIF tautomerase active site. To the best of our knowledge, this is the first study to focus on MIF-specific fully-human antibody fragment with a tautomerase-inhibitory effect that has potential to be developed as anti-inflammatory biomolecules for human use.

  10. Interstitial cells of Cajal integrate excitatory and inhibitory neurotransmission with intestinal slow-wave activity.

    PubMed

    Klein, Sabine; Seidler, Barbara; Kettenberger, Anna; Sibaev, Andrei; Rohn, Michael; Feil, Robert; Allescher, Hans-Dieter; Vanderwinden, Jean-Marie; Hofmann, Franz; Schemann, Michael; Rad, Roland; Storr, Martin A; Schmid, Roland M; Schneider, Günter; Saur, Dieter

    2013-01-01

    The enteric nervous system contains excitatory and inhibitory neurons, which control contraction and relaxation of smooth muscle cells as well as gastrointestinal motor activity. Little is known about the exact cellular mechanisms of neuronal signal transduction to smooth muscle cells in the gut. Here we generate a c-Kit(CreERT2) knock-in allele to target a distinct population of pacemaker cells called interstitial cells of Cajal. By genetic loss-of-function studies, we show that interstitial cells of Cajal, which generate spontaneous electrical slow waves and thus rhythmic contractions of the smooth musculature, are essential for transmission of signals from enteric neurons to gastrointestinal smooth muscle cells. Interstitial cells of Cajal, therefore, integrate excitatory and inhibitory neurotransmission with slow-wave activity to orchestrate peristaltic motor activity of the gut. Impairment of the function of interstitial cells of Cajal causes severe gastrointestinal motor disorders. The results of our study show at the genetic level that these disorders are not only due to loss of slow-wave activity but also due to disturbed neurotransmission.

  11. Structures and antioxidant and intestinal disaccharidase inhibitory activities of A-type proanthocyanidins from peanut skin.

    PubMed

    Zhang, Huiwen; Yerigui; Yang, Yumei; Ma, Chaomei

    2013-09-18

    Nine compounds including a new A-type proanthocyanidin trimer, epicatechin-(2β→O→7,4β→8)-[catechin-(6→4β)]-epicatechin (8), and a known trimer, epicatechin-(4β→8)-epicatechin-(2β→O→7,4β→8)-catechin (9), being reported for peanut skin for the first time, were isolated and purified. Their structures were determined by spectroscopic methods and by degradation reactions with L-cysteine in acidic conditions. The DPPH radical scavenging activity and the inhibitory activity on maltase and sucrase of the isolated compounds were investigated. All compounds showed strong DPPH scavenging activities (EC₅₀ < 20 μg/mL). Compound 8 showed the strongest inhibitory activity on maltase with an IC₅₀ value of 0.088 mg/mL, while compound 9 exhibited the strongest inhibition on sucrase with an IC₅₀ value of 0.091 mg/mL.

  12. AMP-activated protein kinase counteracted the inhibitory effect of glucose on the phosphoenolpyruvate carboxykinase gene expression in rat hepatocytes.

    PubMed

    Hubert, A; Husson, A; Chédeville, A; Lavoinne, A

    2000-09-22

    The effect of AMP-activated protein kinase (AMPK) in the regulation of the phosphoenolpyruvate carboxykinase (PEPCK) gene expression was studied in isolated rat hepatocytes. Activation of AMPK by AICAR counteracted the inhibitory effect of glucose on the PEPCK gene expression, both at the mRNA and the transcriptional levels. It is proposed that a target for AMPK is involved in the inhibitory effect of glucose on PEPCK gene transcription.

  13. Self-reported Physical Activity Predicts Pain Inhibitory and Facilitatory Function

    PubMed Central

    Naugle, Kelly M.; Riley, Joseph L.

    2013-01-01

    Considerable evidence suggests regular physical activity can reduce chronic pain symptoms. Dysfunction of endogenous facilitatory and inhibitory systems has been implicated in multiple chronic pain conditions. However, few studies have investigated the relationship between levels of physical activity and descending pain modulatory function. Purpose This study’s purpose was to determine whether self-reported levels of physical activity in healthy adults predicted 1) pain sensitivity to heat and cold stimuli, 2) pain facilitatory function as tested by temporal summation of pain (TS), and 3) pain inhibitory function as tested by conditioned pain modulation (CPM) and offset analgesia. Methods Forty-eight healthy adults (age range 18–76) completed the International Physical Activity Questionnaire (IPAQ) and the following pain tests: heat pain thresholds (HPT), heat pain suprathresholds, cold pressor pain (CPP), temporal summation of heat pain, conditioned pain modulation, and offset analgesia. The IPAQ measured levels of walking, moderate, vigorous and total physical activity over the past seven days. Hierarchical linear regressions were conducted to determine the relationship between each pain test and self-reported levels of physical activity, while controlling for age, sex and psychological variables. Results Self-reported total and vigorous physical activity predicted TS and CPM (p’s <.05). Individuals who self-reported more vigorous and total physical activity exhibited reduced temporal summation of pain and greater CPM. The IPAQ measures did not predict any of the other pain measures. Conclusion Thus, these results suggest that healthy older and younger adults who self-report greater levels of vigorous and total physical activity exhibit enhanced descending pain modulatory function. Improved descending pain modulation may be a mechanism through which exercise reduces or prevents chronic pain symptoms. PMID:23899890

  14. DC-159a Shows Inhibitory Activity against DNA Gyrases of Mycobacterium leprae

    PubMed Central

    Yamaguchi, Tomoyuki; Yokoyama, Kazumasa; Nakajima, Chie

    2016-01-01

    Background Fluoroquinolones are a class of antibacterial agents used for leprosy treatment. Some new fluoroquinolones have been attracting interest due to their remarkable potency that is reportedly better than that of ofloxacin, the fluoroquinolone currently recommended for treatment of leprosy. For example, DC-159a, a recently developed 8-methoxy fluoroquinolone, has been found to be highly potent against various bacterial species. Nonetheless, the efficacy of DC-159a against Mycobacterium leprae is yet to be examined. Methodology/Principal Findings To gather data that can support highly effective fluoroquinolones as candidates for new remedies for leprosy treatment, we conducted in vitro assays to assess and compare the inhibitory activities of DC-159a and two fluoroquinolones that are already known to be more effective against M. leprae than ofloxacin. The fluoroquinolone-inhibited DNA supercoiling assay using recombinant DNA gyrases of wild type and ofloxacin-resistant M. leprae revealed that inhibitory activities of DC-159a and sitafloxacin were at most 9.8- and 11.9-fold higher than moxifloxacin. Also the fluoroquinolone–mediated cleavage assay showed that potencies of those drugs were at most 13.5- and 9.8-fold higher than moxifloxacin. In addition, these two drugs retained their inhibitory activities even against DNA gyrases of ofloxacin-resistant M. leprae. Conclusions/Significance The results indicated that DC-159a and sitafloxacin are more effective against wild type and mutant M. leprae DNA gyrases than moxifloxacin, suggesting that these antibacterial drugs can be good candidates that may supersede current fluoroquinolone remedies. DC-159a in particular is very promising because it is classified in a subgroup of fluoroquinolones that is known to be less likely to cause adverse effects. Our results implied that DC-159a is well worth further investigation to ascertain its in vivo effectiveness and clinical safety for humans. PMID:27681932

  15. Activity-dependent transmission and integration control the timescales of auditory processing at an inhibitory synapse.

    PubMed

    Ammer, Julian J; Siveke, Ida; Felmy, Felix

    2015-06-15

    To capture the context of sensory information, neural networks must process input signals across multiple timescales. In the auditory system, a prominent change in temporal processing takes place at an inhibitory GABAergic synapse in the dorsal nucleus of the lateral lemniscus (DNLL). At this synapse, inhibition outlasts the stimulus by tens of milliseconds, such that it suppresses responses to lagging sounds, and is therefore implicated in echo suppression. Here, we untangle the cellular basis of this inhibition. We demonstrate with in vivo whole-cell patch-clamp recordings in Mongolian gerbils that the duration of inhibition increases with sound intensity. Activity-dependent spillover and asynchronous release translate the high presynaptic firing rates found in vivo into a prolonged synaptic output in acute slice recordings. A key mechanism controlling the inhibitory time course is the passive integration of the hyperpolarizing inhibitory conductance. This prolongation depends on the synaptic conductance amplitude. Computational modeling shows that this prolongation is a general mechanism and relies on a non-linear effect caused by synaptic conductance saturation when approaching the GABA reversal potential. The resulting hyperpolarization generates an efficient activity-dependent suppression of action potentials without affecting the threshold or gain of the input-output function. Taken together, the GABAergic inhibition in the DNLL is adjusted to the physiologically relevant duration by passive integration of inhibition with activity-dependent synaptic kinetics. This change in processing timescale combined with the reciprocal connectivity between the DNLLs implements a mechanism to suppress the distracting localization cues of echoes and helps to localize the initial sound source reliably.

  16. Enzymolysis kinetics and activities of ACE inhibitory peptides from wheat germ protein prepared with SFP ultrasound-assisted processing.

    PubMed

    Qu, Wenjuan; Ma, Haile; Jia, Junqiang; He, Ronghai; Luo, Lin; Pan, Zhongli

    2012-09-01

    There is a great demand for developing efficient enzymolysis methods in order to increase the enzymolysis efficiencies and activities of angiotensin converting enzyme (ACE) inhibitory peptides from wheat germ protein. The enzymolysis kinetics, ACE inhibitory activity of peptide and conversion rate of protein were studied using sweep frequency and pulsed (SFP) ultrasound-assisted enzymolysis and the results were compared with traditional enzymolysis. The studied factors were enzymolysis time and substrate concentration. By considering the activity of ACE inhibitory peptide and operation cost, the recommended conditions of SFP ultrasound-assisted enzymolysis were enzymolysis time of 120 min and substrate concentration of 24.0 g/L, which gave high conversion rates of protein (60.7%) and ACE inhibitory activity of peptide (65.9%). Compared to traditional enzymolysis, SFP ultrasound-assisted enzymolysis significantly increased the initial reaction rate (V) by 60.0% at substrate concentration of 24.0 g/L, increased the apparent breakdown rate constant (k(A)) by 66.7%, decreased the apparent constant (K(M)) by 6.9%, and raised the conversion rate of protein by 35.5% and ACE inhibitory activity of peptides by 35.6% under the recommended conditions. It has been concluded that SFP ultrasound can remarkably raise the enzymolysis efficiency and activity of ACE inhibitory peptides from wheat germ protein.

  17. Aromatic glycosyl disulfide derivatives: evaluation of their inhibitory activities against Trypanosoma cruzi.

    PubMed

    Gutiérrez, Bessy; Muñoz, Christian; Osorio, Luis; Fehér, Krisztina; Illyés, Tünde-Zita; Papp, Zsuzsa; Kumar, Ambati Ashok; Kövér, Katalin E; Sagua, Hernán; Araya, Jorge E; Morales, Patricio; Szilágyi, László; González, Jorge

    2013-06-15

    Aromatic oligovalent glycosyl disulfides and some diglycosyl disulfides were tested against three different Trypanosoma cruzi strains. Di-(β-D-galactopyranosyl-dithiomethylene) benzenes 2b and 4b proved to be the most active derivatives against all three strains of cell culture-derived trypomastigotes with IC50 values ranging from 4 to 11 μM at 37 °C. The inhibitory activities were maintained, although somewhat lowered, at a temperature of 4 °C as well. Three further derivatives displayed similar activities against at least one of the three strains. Low cytotoxicities of the active compounds, tested on confluent HeLa, Vero and peritoneal macrophage cell cultures, resulted in significantly higher selectivity indices (SI) than that of the reference drug benznidazole. Remarkably, several molecules of the tested panel strongly inhibited the parasite release from T. cruzi infected HeLa cell cultures suggesting an effect against the intracellular development of T. cruzi amastigotes as well.

  18. The inhibitory effect of metals and other ions on acid phosphatase activity from Vigna aconitifolia seeds.

    PubMed

    Srivastava, Pramod Kumar; Anand, Asha

    2015-01-01

    Sensitivity of acid phosphatase from Vigna aconitifolia seeds to metal ions, fluoride, and phosphate was examined. All the effectors had different degree of inhibitory effect on the enzyme. Among metal ions, molybdate and ferric ion were observed to be most potent inhibitors and both exhibited mixed type of inhibition. Acid phosphatase activity was inhibited by Cu2+ in a noncompetitive manner. Zn and Mn showed mild inhibition on the enzyme activity. Inhibition kinetics analysis explored molybdate as a potent inhibitor for acid phosphatase in comparison with other effectors used in this study. Fluoride was the next most strong inhibitor for the enzyme activity, and caused a mixed type of inhibition. Phosphate inhibited the enzyme competitively, which demonstrates that inhibition due to phosphate is one of the regulatory factors for enzyme activity.

  19. New cassane-type diterpenoids of Caesalpinia echinata (Leguminosae) exhibiting NF-κB inhibitory activities.

    PubMed

    Mitsui, Taichi; Ishihara, Risa; Hayashi, Ken-ichiro; Sunadome, Mitsuhisa; Matsuura, Nobuyasu; Nozaki, Hiroshi

    2014-01-01

    Seven new cassane-type diterpenoids, echinalides A-G (1-7), were isolated from the stem of Caesalpinia echinata LAM. (Leguminosae). The structures were established on the basis of their chemical properties and spectroscopic evidence, including two dimensional (2D)-NMR analysis. These compounds were assessed for inhibitory activity against nuclear factor κB (NF-κB). Echinalides C and D, in particular, significantly inhibited NF-κB-responsive reporter gene expression at 5.0 µM, an effect almost equivalent to that of parthenolide, a known potent inhibitor of NF-κB.

  20. Synthesis, oxygen radical absorbance capacity, and tyrosinase inhibitory activity of glycosides of resveratrol, pterostilbene, and pinostilbene.

    PubMed

    Uesugi, Daisuke; Hamada, Hiroki; Shimoda, Kei; Kubota, Naoji; Ozaki, Shin-Ichi; Nagatani, Naoki

    2017-02-01

    The stilbene compound resveratrol was glycosylated to give its 4'-O-β-D-glucoside as the major product in addition to its 3-O-β-D-glucoside by a plant glucosyltransferase from Phytolacca americana expressed in recombinant Escherichia coli. This enzyme transformed pterostilbene to its 4'-O-β-D-glucoside, and converted pinostilbene to its 4'-O-β-D-glucoside as a major product and its 3-O-β-D-glucoside as a minor product. An analysis of antioxidant capacity showed that the above stilbene glycosides had lower oxygen radical absorbance capacity (ORAC) values than those of the corresponding stilbene aglycones. The 3-O-β-D-glucoside of resveratrol showed the highest ORAC value among the stilbene glycosides tested, and pinostilbene had the highest value among the stilbene compounds. The tyrosinase inhibitory activities of the stilbene aglycones were improved by glycosylation; the stilbene glycosides had higher activities than the stilbene aglycones. Resveratrol 3-O-β-D-glucoside had the highest tyrosinase inhibitory activity among the stilbene compounds tested.

  1. Hypocholesterolemic Effect and In Vitro Pancreatic Lipase Inhibitory Activity of an Opuntia ficus-indica Extract

    PubMed Central

    Flores-Fernandez, Jose Miguel; Fernandez-Flores, Ofelia; Gutierrez-Mercado, Yanet; Carmona-de la Luz, Joel; Sandoval-Salas, Fabiola; Mendez-Carreto, Carlos

    2015-01-01

    Cholesterol control is fundamental for prevention of cardiovascular disorders. In this work, the hypocholesterolemic activity of an aqueous Opuntia ficus-indica extract (AOE) was tested in triton-induced mice. The inhibitory activity on pancreatic lipase enzyme was evaluated in vitro by the same extract. Furthermore, polyphenol content of the extract was evaluated. Hypercholesterolemia was induced in three groups of mice by intraperitoneal administration of Triton WR-1339. After induction of hypercholesterolemia, the groups were treated with an AOE (500 mg/kg) and saline solution and the positive control group with orlistat, respectively. Cholesterol levels were measured 24 h later in peripheral blood. The levels of blood cholesterol after administration of AOE significantly decreased compared to negative control. The inhibitory activity of AOE on pancreatic lipase enzyme was evaluated at concentrations from 60 to 1000 μg/mL. The AOE inhibited the pancreatic lipase with an IC50 = 588.5 μg/mL. The AOE had a high content of polyphenolic compounds. These results show that AOE is able to prevent hypercholesterolemia by pancreatic lipase inhibition, in part due to its polyphenolic compounds. PMID:26078966

  2. Xanthine oxidase inhibitory activity and hypouricemic effect of aspalathin from unfermented rooibos.

    PubMed

    Kondo, Makoto; Hirano, Yoshiaki; Nishio, Masahiro; Furuya, Yutaka; Nakamura, Hiromichi; Watanabe, Tsuyoshi

    2013-12-01

    Rooibos is rich in flavonoids such as aspalathin, which is a unique C-glycosyl dihydrochalcone, that is used as a traditional herbal tea. This study was designed to evaluate the in vitro xanthine oxidase (XOD) inhibitory activity of the aspalathin-rich fraction (ARF) and purified aspalathin from rooibos. The hypouricemic effects of the ARF and aspalathin on hyperuricemic mice were also assessed. The ARF was prepared from aqueous extract of unfermented rooibos leaves and stems, and it was collected by column chromatography; the aspalathin content in this fraction was 21.4%. The ARF and aspalathin inhibited XOD in a dose-dependent manner. The concentrations of the ARF and aspalathin required to inhibit XOD at 50% (IC50 ) were 20.4 μg/mL (4.4 μg/mL aspalathin equivalents) and 4.5 μg/mL, respectively. Lineweaver-Burk plot analysis indicated that aspalathin was a competitive inhibitor of XOD, and the inhibition constant (Ki) was 3.1 μM. In hyperuricemic mice induced by inosine-5'-monophosphate, treatment with the ARF and aspalathin significantly suppressed the increased plasma uric acid level in a dose-dependent manner. The suppressed plasma uric acid level in mice could be attributed to the XOD inhibitory activity of the ARF and aspalathin. Further study is required to determine the effect of aspalathin or its metabolites on XOD activity in vivo.

  3. Hypocholesterolemic Effect and In Vitro Pancreatic Lipase Inhibitory Activity of an Opuntia ficus-indica Extract.

    PubMed

    Padilla-Camberos, Eduardo; Flores-Fernandez, Jose Miguel; Fernandez-Flores, Ofelia; Gutierrez-Mercado, Yanet; Carmona-de la Luz, Joel; Sandoval-Salas, Fabiola; Mendez-Carreto, Carlos; Allen, Kirk

    2015-01-01

    Cholesterol control is fundamental for prevention of cardiovascular disorders. In this work, the hypocholesterolemic activity of an aqueous Opuntia ficus-indica extract (AOE) was tested in triton-induced mice. The inhibitory activity on pancreatic lipase enzyme was evaluated in vitro by the same extract. Furthermore, polyphenol content of the extract was evaluated. Hypercholesterolemia was induced in three groups of mice by intraperitoneal administration of Triton WR-1339. After induction of hypercholesterolemia, the groups were treated with an AOE (500 mg/kg) and saline solution and the positive control group with orlistat, respectively. Cholesterol levels were measured 24 h later in peripheral blood. The levels of blood cholesterol after administration of AOE significantly decreased compared to negative control. The inhibitory activity of AOE on pancreatic lipase enzyme was evaluated at concentrations from 60 to 1000 μg/mL. The AOE inhibited the pancreatic lipase with an IC50 = 588.5 μg/mL. The AOE had a high content of polyphenolic compounds. These results show that AOE is able to prevent hypercholesterolemia by pancreatic lipase inhibition, in part due to its polyphenolic compounds.

  4. Neuraminidase inhibitory activities of quaternary isoquinoline alkaloids from Corydalis turtschaninovii rhizome.

    PubMed

    Kim, Jang Hoon; Ryu, Young Bae; Lee, Woo Song; Kim, Young Ho

    2014-11-01

    Clostridium perfringens is a Gram-positive spore-forming bacterium that causes food poisoning. The neuraminidase (NA) protein of C. perfringens plays a pivotal role in bacterial proliferation and is considered a novel antibacterial drug target. Based on screens for novel NA inhibitors, a 95% EtOH extract of Corydalis turtschaninovii rhizome showed NA inhibitory activity (68% at 30 μg/ml), which resulted in the isolation of 10 isoquinoline alkaloids; namely, palmatine (1), berberine (2), coptisine (3), pseudodehydrocorydaline (4), jatrorrhizine (5), dehydrocorybulbine (6), pseudocoptisine (7), glaucine (8), corydaline (9) and tetrahydrocoptisine (10). Interestingly, seven quaternary isoquinoline alkaloids 1-7 (IC50 = 12.8 ± 1.5 to 65.2 ± 4.5 μM) showed stronger NA inhibitory activity than the tertiary alkaloids 8-10. In addition, highly active compounds 1 and 2 showed reversible non-competitive behavior based on a kinetic study. Molecular docking simulations using the Autodock 4.2 software increased our understanding of receptor-ligand binding of these compounds. In addition, we demonstrated that compounds 1 and 2 suppressed bacterial growth.

  5. Acetylcholinesterase inhibitory activity of Thai traditional nootropic remedy and its herbal ingredients.

    PubMed

    Tappayuthpijarn, Pimolvan; Itharat, Arunporn; Makchuchit, Sunita

    2011-12-01

    The incidence of Alzheimer disease (AD) is increasing every year in accordance with the increasing of elderly population and could pose significant health problems in the future. The use of medicinal plants as an alternative prevention or even for a possible treatment of the AD is, therefore, becoming an interesting research issue. Acetylcholinesterase (AChE) inhibitors are well-known drugs commonly used in the treatment of AD. The aim of the present study was to screen for AChE inhibitory activity of the Thai traditional nootropic recipe and its herbal ingredients. The results showed that ethanolic extracts of four out of twenty-five herbs i.e. Stephania pierrei Diels. Kaempfera parviflora Wall. ex Baker, Stephania venosa (Blume) Spreng, Piper nigrum L at 0.1 mg/mL showed % AChE inhibition of 89, 64, 59, 50; the IC50 were 6, 21, 29, 30 microg/mL respectively. The other herbs as well as combination of the whole recipe had no synergistic inhibitory effect on AChE activity. However some plants revealed antioxidant activity. More research should have be performed on this local wisdom remedy to verify the uses in scientific term.

  6. Novel polyacetylene derivatives and their inhibitory activities on acetylcholinesterase obtained from Panax ginseng roots.

    PubMed

    Murata, Kazuya; Iida, Daiki; Ueno, Yoshihiro; Samukawa, Keiichi; Ishizaka, Toshihiko; Kotake, Takeshi; Matsuda, Hideaki

    2017-01-01

    In our research program to identify cholinesterase and β-secretase inhibitors, we investigated Ginseng (root of Panax ginseng), a crude drug described as a multifunctional drug in the ancient Chinese herbal book Shennong Ben Cao Jing. Results from hexane and methanol extracts showed moderate inhibitory activities. This suggests that ginseng roots may be effective for the prevention of and therapy for dementia. We then focused on hexane extracts of raw ginseng root and dried ginseng root since the determination of hexane extract constituents has not been studied extensively. Activity-guided fractionation and purification led to the isolation of 4 polyacetylene compounds; homopanaxynol, homopanaxydol, (9Z)-heptadeca-1, 9-diene-4,6-diyn-3-one, and (8E)-octadeca-1,8-diene-4,6-diyn-3,10-diol. The chemical structures of these compounds, including stereochemistry, were determined. This is the first study to identify the structure of homopanaxynol and homopanaxydol. Moreover, the modes of action of some compounds were characterized as competitive inhibitors. This study showed, for the first time, that polyacetylene compounds possess acetylcholinesterase inhibitory activities.

  7. Spectroscopic studies on the inhibitory effects of ionic liquids on lipase activity.

    PubMed

    Fan, Yunchang; Dong, Xing; Li, Xiaojing; Zhong, Yingying; Kong, Jichuan; Hua, Shaofeng; Miao, Juan; Li, Yan

    2016-04-15

    The effects of ionic liquids (ILs) on the lipase activity were studied by UV-Vis spectroscopy and the IL-lipase interaction mechanism at the molecular level was investigated by fluorescence technique. Experimental results indicated that the lipase activity was inhibited by ILs and the degree of inhibition highly depended on the chemical structures of ILs. The inhibitory ability of the Cl(-)- and Br(-)-based ILs increased with increasing the alkyl chain length in the IL cation. Thermodynamic parameters, enthalpy change (ΔH) and entropy change (ΔS) were obtained by analyzing the fluorescence behavior of lipase with the addition of ILs. Both ΔH and ΔS were positive suggesting hydrophobicity was the major driven force for the Cl(-)- and Br(-)-based ILs. For the BF4(-)-, CF3SO3(-)-, ClO4(-)- and N(CN)2(-)-based ILs, hydrogen bonding was the main driven force. For a more comprehensive understanding of the effects of ILs on lipase activity, the roles of hydrophobicity and hydrogen bonding must be considered simultaneously. A regression-based equation was developed to describe the relationship of the inhibitory ability of ILs and their hydrophobicity and hydrogen bonding ability.

  8. Mold-inhibitory activity of different yeast species during airtight storage of wheat grain.

    PubMed

    Adel Druvefors, Ulrika; Schnürer, Johan

    2005-02-01

    The yeast Pichia anomala J121 inhibits spoilage by Penicillium roqueforti in laboratory and pilot studies with high-moisture wheat in malfunctioning airtight storage. We tested the biocontrol ability of an additional 57 yeast species in a grain mini silo system. Most yeast species grew to CFU levels comparable to that of P. anomala J121 after 14 days of incubation (>10(6) CFU g(-1)). Of the 58 species, 38 (63 strains) had no mold-inhibitory effects (Pen. roqueforti levels >10(5) CFU g(-1)). Among these were 11 species (18 strains) that did not grow on the wheat grain. Several of the non-inhibiting yeast species have previously been reported as biocontrol agents in other postharvest environments. Weak inhibitory activity, reducing Pen. roqueforti levels to between 10(4) and 10(5) CFU g(-1), was observed with 11 species (12 strains). Candida silvicola and Pichia guillermondii reduced Pen. roqueforti to <10(4) CFU g(-1). Candida fennica, Candida pelliculosa, Candida silvicultrix, P. anomala (29 strains), Pichia burtonii, Pichia farinosa and Pichia membranifaciens strongly inhibited Pen. roqueforti (<10(3) CFU g(-1)) in the mini silos, but none had higher biocontrol activity than P. anomala strain J121. This report is the first of biocontrol activity of C. fennica and C. silvicultrix. The ability of 27 yeast species to grow to high CFU values without inhibiting mold growth suggests that nutrient competition may not be the main mode of action of P. anomala J121.

  9. 5 Alpha-reductase inhibitory and antiandrogenic activities of novel steroids in hamster seminal vesicles.

    PubMed

    Cabeza, Marisa; Bratoeff, Eugene; Flores, Eugenio; Ramírez, Elena; Calleros, Jorge; Montes, Diana; Quiroz, Alexandra; Heuze, Ivonne

    2002-11-01

    The pharmacological activity of several 16-bromosubstituted trienediones 4 and 5, 16-methyl substituted dienediones 6 and 7 and the 16-methyl substituted trienedione 8 was determined on gonadectomized hamster seminal vesicles by measuring the in vitro conversion of testosterone (T) to dihydrotestosterone (DHT) as 5alpha-reductase inhibitors and also the ability of these steroids to bind to the androgen receptor. Steroids 6 and 7 when injected together with T decreased the weight of the seminal vesicles thus showing an antiandrogenic effect. Compounds 5 and 6 reduced substantially the conversion of T to DHT and therefore can be considered good inhibitors for the enzyme 5alpha-reductase; however both steroids failed to form a complex with the androgen receptor. On the other hand compound 7 which showed a very small inhibitory activity for the enzyme 5alpha-reductase, exhibited a very high affinity for the androgen receptor and thus can be considered an effective antiandrogen. This compound also reduced substantially the weight of the seminal vesicles. Steroids 4 and 8 did not reduce the weight of the seminal vesicles and exhibited a low affinity for the androgen receptor; 8 showed a weak 5alpha-reductase inhibitory activity, whereas 4 exhibited a weak androgenic effect.

  10. Mutation at Glu23 eliminates the neuron growth inhibitory activity of human metallothionein-3

    SciTech Connect

    Ding Zhichun; Teng Xinchen; Cai Bin; Wang Hui; Zheng Qi; Wang Yang; Zhou Guoming; Zhang Mingjie; Wu Houming; Sun Hongzhe . E-mail: hsun@hku.hk; Huang Zhongxian . E-mail: zxhuang@fudan.edu.cn

    2006-10-20

    Human metallothionein-3 (hMT3), first isolated and identified as a neuronal growth inhibitory factor (GIF), is a metalloprotein expressed predominantly in brain. However, untill now, the exact mechanism of the bioactivity of hMT3 is still unknown. In order to study the influence of acid-base catalysis on S-nitrosylation of hMT3, we constructed the E23K mutant of hMT3. During the course of bioassay, we found out unexpectedly that mutation at E23 of hMT3 eliminates the neuronal growth inhibitory activity completely. To the best of our knowledge, it is First report that other residues, besides the TCPCP motif, in the {beta}-domain can alter the bioactivity of hMT3. In order to figure out the causes for the loss of bioactivity of the E23K mutant, the biochemical properties were characterized by UV-vis spectroscopy, CD spectroscopy, pH titration, DTNB reaction, EDTA reaction, and SNOC reaction. All data demonstrated that stability of the metal-thiolate cluster and overall structure of the E23K mutant were not altered too much. However, the reaction of the E23K mutant with SNOC exhibited biphasic kinetics and the mutant protein released zinc ions much faster than hMT3 in the initial step, while hMT3 exhibited single kinetic process. The 2D [{sup 1}H-{sup 15}N] HSQC was also employed to characterize structural changes during the reaction of hMT3 with varying mounts of nitric oxide. It was shown that the resonance of Glu23 disappeared at a molar ratio of NO to protein of 4. Based on these results, we suggest that mutation at Glu23 may alter the NO metabolism and/or affect zinc homeostasis in brain, thus altering the neuronal growth inhibitory activity.

  11. Enzyme Inhibitory Properties, Antioxidant Activities, and Phytochemical Profile of Three Medicinal Plants from Turkey

    PubMed Central

    Zengin, Gokhan; Guler, Gokalp Ozmen; Aktumsek, Abdurrahman; Ceylan, Ramazan; Picot, Carene Marie Nancy; Mahomoodally, M. Fawzi

    2015-01-01

    We aimed to investigate the inhibitory potential of three medicinal plants (Hedysarum varium, Onobrychis hypargyrea, and Vicia truncatula) from Turkey against key enzymes involved in human pathologies, namely, diabetes (α-amylase and α-glucosidase), neurodegenerative disorders (tyrosinase, acetylcholinesterase, and butyrylcholinesterase), and hyperpigmentation (tyrosinase). The antioxidant potential, phenolic and flavonoid content of ethyl acetate, and methanolic and aqueous extracts were investigated using in vitro assays. The total antioxidant capacity (TAC), β-carotene/linoleic acid bleaching activity, 1,1-diphenyl-2-picrylhydrazyl free radical (DPPH•), 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+), cupric ion reducing antioxidant capacity (CUPRAC), ferric reducing antioxidant power (FRAP), and metal chelating activity on ferrous ions were used to evaluate the antioxidant capabilities of the extracts. The half-maximal inhibitory concentrations (IC50) of the extracts on cholinesterase, tyrosinase, and α-amylase were significantly higher than the references, galantamine, kojic acid, and acarbose, respectively. The half-maximal effective concentrations (EC50) of the extracts on TAC, CUPRAC, and FRAP were significantly higher than trolox. The phenol and flavonoid contents of the plant extracts were in the range 20.90 ± 0.190–83.25 ± 0.914 mg gallic acid equivalent/g extract and 1.45 ± 0.200–39.71 ± 0.092 mg rutin equivalent/g extract, respectively. The plants were found to possess moderate antioxidant capacities and interesting inhibitory action against key enzymes. PMID:26798334

  12. Inhibitory effect of aqueous dandelion extract on HIV-1 replication and reverse transcriptase activity

    PubMed Central

    2011-01-01

    Background Acquired immunodeficiency syndrome (AIDS), which is caused by the human immunodeficiency virus (HIV), is an immunosuppressive disease that results in life-threatening opportunistic infections. The general problems in current therapy include the constant emergence of drug-resistant HIV strains, adverse side effects and the unavailability of treatments in developing countries. Natural products from herbs with the abilities to inhibit HIV-1 life cycle at different stages, have served as excellent sources of new anti-HIV-1 drugs. In this study, we aimed to investigate the anti-HIV-1 activity of aqueous dandelion extract. Methods The pseudotyped HIV-1 virus has been utilized to explore the anti-HIV-1 activity of dandelion, the level of HIV-1 replication was assessed by the percentage of GFP-positive cells. The inhibitory effect of the dandelion extract on reverse transcriptase activity was assessed by the reverse transcriptase assay kit. Results Compared to control values obtained from cells infected without treatment, the level of HIV-1 replication and reverse transcriptase activity were decreased in a dose-dependent manner. The data suggest that dandelion extract has a potent inhibitory activity against HIV-1 replication and reverse transcriptase activity. The identification of HIV-1 antiviral compounds from Taraxacum officinale should be pursued. Conclusions The dandelion extract showed strong activity against HIV-1 RT and inhibited both the HIV-1 vector and the hybrid-MoMuLV/MoMuSV retrovirus replication. These findings provide additional support for the potential therapeutic efficacy of Taraxacum officinale. Extracts from this plant may be regarded as another starting point for the development of an antiretroviral therapy with fewer side effects. PMID:22078030

  13. Activity-dependent PSA expression regulates inhibitory maturation and onset of critical period plasticity.

    PubMed

    Di Cristo, Graziella; Chattopadhyaya, Bidisha; Kuhlman, Sandra J; Fu, Yu; Bélanger, Marie-Claude; Wu, Cai Zhi; Rutishauser, Urs; Maffei, Lamberto; Huang, Z Josh

    2007-12-01

    Functional maturation of GABAergic innervation in the developing visual cortex is regulated by neural activity and sensory inputs and in turn influences the critical period of ocular dominance plasticity. Here we show that polysialic acid (PSA), presented by the neural cell adhesion molecule, has a role in the maturation of GABAergic innervation and ocular dominance plasticity. Concentrations of PSA significantly decline shortly after eye opening in the adolescent mouse visual cortex; this decline is hindered by visual deprivation. The developmental and activity-dependent regulation of PSA expression is inversely correlated with the maturation of GABAergic innervation. Premature removal of PSA in visual cortex results in precocious maturation of perisomatic innervation by basket interneurons, enhanced inhibitory synaptic transmission, and earlier onset of ocular dominance plasticity. The developmental and activity-dependent decline of PSA expression therefore regulates the timing of the maturation of GABAergic inhibition and the onset of ocular dominance plasticity.

  14. Inhibitory effect of plant Manilkara subsericea against biological activities of Lachesis muta snake venom.

    PubMed

    De Oliveira, Eduardo Coriolano; Fernandes, Caio Pinho; Sanchez, Eladio Flores; Rocha, Leandro; Fuly, André Lopes

    2014-01-01

    Snake venom is composed of a mixture of substances that caused in victims a variety of pathophysiological effects. Besides antivenom, literature has described plants able to inhibit injuries and lethal activities induced by snake venoms. This work describes the inhibitory potential of ethanol, hexane, ethyl acetate, or dichloromethane extracts and fractions from stem and leaves of Manilkara subsericea against in vivo (hemorrhagic and edema) and in vitro (clotting, hemolysis, and proteolysis) activities caused by Lachesis muta venom. All the tested activities were totally or at least partially reduced by M. subsericea. However, when L. muta venom was injected into mice 15 min first or after the materials, hemorrhage and edema were not inhibited. Thus, M. subsericea could be used as antivenom in snakebites of L. muta. And, this work also highlights Brazilian flora as a rich source of molecules with antivenom properties.

  15. Excitatory synaptic activity is associated with a rapid structural plasticity of inhibitory synapses on hippocampal CA1 pyramidal cells.

    PubMed

    Lushnikova, Irina; Skibo, Galina; Muller, Dominique; Nikonenko, Irina

    2011-04-01

    Synaptic activity, such as long-term potentiation (LTP), has been shown to induce morphological plasticity of excitatory synapses on dendritic spines through the spine head and postsynaptic density (PSD) enlargement and reorganization. Much less, however, is known about activity-induced morphological modifications of inhibitory synapses. Using an in vitro model of rat organotypic hippocampal slice cultures and electron microscopy, we studied activity-related morphological changes of somatic inhibitory inputs triggered by a brief oxygen-glucose deprivation (OGD) episode, a condition associated with a synaptic enhancement referred to as anoxic LTP and a structural remodeling of excitatory synapses. Three-dimensional reconstruction of inhibitory axo-somatic synapses at different times before and after brief OGD revealed important morphological changes. The PSD area significantly and markedly increased at synapses with large and complex PSDs, but not at synapses with simple, macular PSDs. Activity-related changes of PSD size and presynaptic bouton volume developed in a strongly correlated manner. Analyses of single and serial sections further showed that the density of inhibitory synaptic contacts on the cell soma did not change within 1 h after OGD. In contrast, the proportion of the cell surface covered with inhibitory PSDs, as well as the complexity of these PSDs significantly increased, with less macular PSDs and more complex, segmented shapes. Together, these data reveal a rapid activity-related restructuring of somatic inhibitory synapses characterized by an enlargement and increased complexity of inhibitory PSDs, providing a new mechanism for a quick adjustment of the excitatory-inhibitory balance. This article is part of a Special Issue entitled 'Synaptic Plasticity & Interneurons'.

  16. Predicting the activity phase of a follower neuron with A-current in an inhibitory network.

    PubMed

    Zhang, Yu; Bose, Amitabha; Nadim, Farzan

    2008-09-01

    The transient potassium A-current is present in most neurons and plays an important role in determining the timing of action potentials. We examine the role of the A-current in the activity phase of a follower neuron in a rhythmic feed-forward inhibitory network with a reduced three-variable model and conduct experiments to verify the usefulness of our model. Using geometric analysis of dynamical systems, we explore the factors that determine the onset of activity in a follower neuron following release from inhibition. We first analyze the behavior of the follower neuron in a single cycle and find that the phase plane structure of the model can be used to predict the potential behaviors of the follower neuron following release from inhibition. We show that, depending on the relative scales of the inactivation time constant of the A-current and the time constant of the recovery variable, the follower neuron may or may not reach its active state following inhibition. Our simple model is used to derive a recursive set of equations to predict the contribution of the A-current parameters in determining the activity phase of a follower neuron as a function of the duration and frequency of the inhibitory input it receives. These equations can be used to demonstrate the dependence of activity phase on the period and duty cycle of the periodic inhibition, as seen by comparing the predictions of the model with the activity of the pyloric constrictor (PY) neurons in the crustacean pyloric network.

  17. Production of feline leukemia inhibitory factor with biological activity in Escherichia coli.

    PubMed

    Kanegi, R; Hatoya, S; Tsujimoto, Y; Takenaka, S; Nishimura, T; Wijewardana, V; Sugiura, K; Takahashi, M; Kawate, N; Tamada, H; Inaba, T

    2016-07-15

    Leukemia inhibitory factor (LIF) is a cytokine which is essential for oocyte and embryo development, embryonic stem cell, and induced pluripotent stem cell maintenance. Leukemia inhibitory factor improves the maturation of oocytes in the human and the mouse. However, feline LIF (fLIF) cloning and effects on oocytes during IVM have not been reported. Thus, we cloned complete cDNA of fLIF and examined its biological activity and effects on oocytes during IVM in the domestic cat. The aminoacid sequence of fLIF revealed a homology of 81% or 92% with that of mouse or human. The fLIF produced by pCold TF DNA in Escherichia coli was readily soluble and after purification showed bioactivity in maintaining the undifferentiated state of mouse embryonic stem cells and enhancing the proliferation of human erythrocyte leukemia cells. Furthermore, 10- and 100-ng/mL fLIF induced cumulus expansion with or without FSH and EGF (P < 0.05). The rate of metaphase II oocytes was also improved with 100-ng/mL fLIF (P < 0.05). We therefore confirmed the successful production for the first time of biologically active fLIF and revealed its effects on oocytes during IVM in the domestic cat. Feline LIF will further improve reproduction and stem cell research in the feline family.

  18. Inhibitory effect of trichothecene mycotoxins on bovine platelets stimulated by platelet activating factor.

    PubMed Central

    Gentry, P A; Ross, M L; Bondy, G S

    1987-01-01

    Several species of fungi, which infect cereals and grains, can produce a class of compounds, known as trichothecene mycotoxins, which is characterized by a substituted epoxy-trichothecene ring structure. Cattle are susceptible to intoxication from feeds contaminated with T-2 toxin, one of the more potent trichothecene mycotoxins, while swine refuse to ingest feed contaminated with T-2 toxin. The bovine platelet has been used as a model cell system to evaluate the effects of T-2 toxin and its natural metabolites, HT-2 toxin and T-2 tetraol, on cell function in vitro. Due to the lipophilic nature of these mycotoxins, a biologically active phospholipid was used to stimulate the platelets in the presence and absence of the toxins. The mycotoxin T-2 toxin and its major metabolite HT-2 toxin inhibited platelet activating factor-stimulated bovine platelets, suspended in homologous plasma, in a concentration but not time dependent manner. Significant inhibition of platelet function (p less than 0.01) occurred with 135 ng T-2 toxin per 10(6) platelets and with 77 ng HT-2 toxin per 10(6) platelets. These mycotoxins exerted an additive inhibitory effect on the platelet aggregation response. In contrast, the minor metabolite T-2 tetraol had no inhibitory effect on platelet function and had no influence on the responses of T-2 toxin or HT-2 toxin when the mycotoxins were present together in the platelet suspensions.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3453270

  19. acetylcholinesterase inhibitory potential and insecticidal activity of an endophytic Alternaria sp. from Ricinus communis.

    PubMed

    Singh, Bahaderjeet; Thakur, Abhinay; Kaur, Sanehdeep; Chadha, B S; Kaur, Amarjeet

    2012-11-01

    Keeping in view the vast potential of endophytic fungi to produce bioactive molecules, this study aimed at isolating and screening endophytes for the production of acetylcholinesterase inhibitors. Fifty-four endophytic fungi were isolated from Ricinus communis and screened for their AChE inhibitory activity using Ellman's colorimetric assay method. Six isolates were found to possess AChE inhibitory activity with maximum inhibition of 78 % being evinced by culture Cas1 which was identified to be Alternaria sp. on the basis of molecular as well as microscopic methods. Optimization of inhibitor production was carried out using one factor at a time approach. Maximum production of inhibitor was obtained on potato dextrose broth after 10 days incubation. The IC(50) of the chloroform extract was observed to be 40 μg/ml. The extract was purified on silica gel and eluted stepwise with a gradient of chloroform/methanol. The insecticidal potential of the extract was evaluated by feeding the larvae of Spodoptera litura on diet containing varying concentrations of the extract. It was observed that with increase in the concentration of the extract, mortality of the larvae increased. The culture has the potential of being exploited in medicine as well as a biocontrol agent.

  20. Optogenetic activation of serotonergic terminals facilitates GABAergic inhibitory input to orexin/hypocretin neurons

    PubMed Central

    Chowdhury, Srikanta; Yamanaka, Akihiro

    2016-01-01

    Orexin/hypocretin neurons play a crucial role in the regulation of sleep/wakefulness, primarily in the maintenance of wakefulness. These neurons innervate wide areas of the brain and receive diverse synaptic inputs including those from serotonergic (5-HT) neurons in the raphe nucleus. Previously we showed that pharmacological application of 5-HT directly inhibited orexin neurons via 5-HT1A receptors. However, it was still unclear how 5-HT neurons regulated orexin neurons since 5-HT neurons contain not only 5-HT but also other neurotransmitters. To reveal this, we generated new triple transgenic mice in which orexin neurons express enhanced green fluorescent protein (EGFP) and 5-HT neurons express channelrhodopsin2 (ChR2). Immunohistochemical studies show that nerve endings of ChR2-expressing 5-HT neurons are in close apposition to EGFP-expressing orexin neurons in the lateral hypothalamic area. Using these mice, we could optogenetically activate 5-HT nerve terminals and record postsynaptic effects from orexin neurons. Activation of nerve terminals of 5-HT neurons directly inhibited orexin neurons via the 5HT1A receptor, and also indirectly inhibited orexin neurons by facilitating GABAergic inhibitory inputs without affecting glutamatergic inputs. Increased GABAergic inhibitory inputs in orexin neurons were confirmed by the pharmacological application of 5-HT. These results suggest that orexin neurons are inhibited by 5-HT neurons, primarily via 5-HT, in both direct and indirect manners. PMID:27824065

  1. Novel derivatives of monascus pigment having a high CETP inhibitory activity.

    PubMed

    Jang, Heeyoung; Choe, Deokyeong; Shin, Chul Soo

    2014-01-01

    The cholesteryl ester transfer protein (CETP), inhibition of which assists in maintaining a high level of high-density lipoprotein cholesterol in the blood, is a target for anti-atherosclerosis treatments. Orange monascus pigment was produced by a Monascus species in a 5 L jar fermenter and various derivative compounds were synthesised by incorporating 19 different L-amino acids into the orange pigment. Among them, the L-Thr and L-Tyr derivatives exhibited high inhibitory activities against the CETP reaction. The inhibitory activities of the L-Thr and L-Tyr derivatives increased in a dose-dependent manner, resulting in IC50 values of 1.0 and 2.3 μM, respectively. When CETP reactions in the presence of the derivatives were performed, the inhibition modes of the L-Thr and L-Tyr derivatives were non-competitive with inhibition constant (Ki) values of 2.7 and 4.3 μM, respectively.

  2. The effects of inhibitory control training for preschoolers on reasoning ability and neural activity.

    PubMed

    Liu, Qian; Zhu, Xinyi; Ziegler, Albert; Shi, Jiannong

    2015-09-23

    Inhibitory control (including response inhibition and interference control) develops rapidly during the preschool period and is important for early cognitive development. This study aimed to determine the training and transfer effects on response inhibition in young children. Children in the training group (N = 20; 12 boys, mean age 4.87 ± 0.26 years) played "Fruit Ninja" on a tablet computer for 15 min/day, 4 days/week, for 3 weeks. Children in the active control group (N = 20; 10 boys, mean age 4.88 ± 0.20 years) played a coloring game on a tablet computer for 10 min/day, 1-2 days/week, for 3 weeks. Several cognitive tasks (involving inhibitory control, working memory, and fluid intelligence) were used to evaluate the transfer effects, and electroencephalography (EEG) was performed during a go/no-go task. Progress on the trained game was significant, while performance on a reasoning task (Raven's Progressive Matrices) revealed a trend-level improvement from pre- to post-test. EEG indicated that the N2 effect of the go/no-go task was enhanced after training for girls. This study is the first to show that pure response inhibition training can potentially improve reasoning ability. Furthermore, gender differences in the training-induced changes in neural activity were found in preschoolers.

  3. ACE-I Inhibitory Activity from Phaseolus lunatus and Phaseolus vulgaris Peptide Fractions Obtained by Ultrafiltration.

    PubMed

    Betancur-Ancona, David; Dávila-Ortiz, Gloria; Chel-Guerrero, Luis Antonio; Torruco-Uco, Juan Gabriel

    2015-11-01

    The involvement of angiotensin-I-converting enzyme (ACE-I) as one of the mechanisms controlling blood pressure is being studied to find alternative means of control of hypertension on human beings. On the market there are synthetic drugs that can control it, but these can cause undesirable health side effects. In this work was assessed the fractionation by ultrafiltration of the Lima bean (Phaseolus lunatus) and Jamapa bean (Phaseolus vulgaris), protein hydrolysates obtained with Alcalase(®) and Flavourzyme(®) on ACE-I inhibitory activity. Four membranes of different molecular cutoffs (10, 5, 3, and 1 kDa) were used. Fractions that had a higher inhibitory activity in both legumes were denominated as E (<1 kDa) with IC50 of 30.3 and 51.8 μg/mL values for the P. lunatus with Alcalase and Flavourzyme, respectively, and for the Phaseolus vulgaris with Alcalase and Flavourzyme with about 63.8 and 65.8 μg/mL values, respectively. The amino acid composition of these fractions showed residues in essential amino acids, which make a good source of energy and amino acids. On the other hand, the presence of hydrophobic amino acids such as V and P is a determining factor in the ACE-I inhibitor effect. The results suggest the possibility of obtaining and utilizing these peptide fractions in the development and innovation of a functional product that helps with treatment and/or prevention of hypertension.

  4. The effects of inhibitory control training for preschoolers on reasoning ability and neural activity

    PubMed Central

    Liu, Qian; Zhu, Xinyi; Ziegler, Albert; Shi, Jiannong

    2015-01-01

    Inhibitory control (including response inhibition and interference control) develops rapidly during the preschool period and is important for early cognitive development. This study aimed to determine the training and transfer effects on response inhibition in young children. Children in the training group (N = 20; 12 boys, mean age 4.87 ± 0.26 years) played “Fruit Ninja” on a tablet computer for 15 min/day, 4 days/week, for 3 weeks. Children in the active control group (N = 20; 10 boys, mean age 4.88 ± 0.20 years) played a coloring game on a tablet computer for 10 min/day, 1–2 days/week, for 3 weeks. Several cognitive tasks (involving inhibitory control, working memory, and fluid intelligence) were used to evaluate the transfer effects, and electroencephalography (EEG) was performed during a go/no-go task. Progress on the trained game was significant, while performance on a reasoning task (Raven’s Progressive Matrices) revealed a trend-level improvement from pre- to post-test. EEG indicated that the N2 effect of the go/no-go task was enhanced after training for girls. This study is the first to show that pure response inhibition training can potentially improve reasoning ability. Furthermore, gender differences in the training-induced changes in neural activity were found in preschoolers. PMID:26395158

  5. In vitro xanthine oxidase inhibitory and in vivo hypouricemic activity of herbal coded formulation (Gouticin).

    PubMed

    Akram, Muhammad; Usmanghani, Khan; Ahmed, Iqbal; Azhar, Iqbal; Hamid, Abdul

    2014-05-01

    Currently, natural products have been used in treating gouty arthritis and are recognized as xanthine oxidase inhibitors. Current study was designed to evaluate in vitro xanthine oxidase inhibitory potential of Gouticin and its ingredients extracts and in vivo hypouricemic activity of gouticin tablet 500 mg twice daily. Ethanol extracts of Gouticin and its ingredients were evaluated in vitro, at 200, 100, 50, 25 μ g/ml concentrations for xanthine oxidase inhibitory activity. IC(50) values of Gouticin and its ingredients were estimated. Further, in vivo therapeutic effect of Gouticin was investigated in comparison with allopathic medicine (Allopurinol) to treat gout. Total patients were 200 that were divided into test and control group. Herbal coded medicine (Gouticin) was given to test group and allopathic medicine allopurinol was administered to control group. In vitro, Gouticin has the highest percent inhibition at 96% followed by Allopurinol with 93% inhibition. In vivo study, mean serum uric acid level of patients was 4.62 mg/dl and 5.21mg/dl by use of Gouticin and Allopurinol at end of therapy. The study showed that herbal coded formulation gouticin and its ingredients are potential sources of natural xanthine oxidase inhibitors. Gouticin 500 mg twice daily is more effective than the allopurinol 300mg once daily in the management of gout.

  6. Screening of α-Glucosidase Inhibitory Activity from Some Plants of Apocynaceae, Clusiaceae, Euphorbiaceae, and Rubiaceae

    PubMed Central

    Elya, Berna; Basah, Katrin; Mun'im, Abdul; Yuliastuti, Wulan; Bangun, Anastasia; Septiana, Eva Kurnia

    2012-01-01

    Diabetes mellitus (DM) is recognized as a serious global health problem that is characterized by high blood sugar levels. Type 2 DM is more common in diabetic populations. In this type of DM, inhibition of α-glucosidase is a useful treatment to delay the absorption of glucose after meals. As a megabiodiversity country, Indonesia still has a lot of potential unexploited forests to be developed as a medicine source, including as the α-glucosidase inhibitor. In this study, we determine the α-glucosidase inhibitory activity of 80% ethanol extracts of leaves and twigs of some plants from the Apocynaceae, Clusiaceae, Euphorbiaceae, and Rubiaceae. Inhibitory activity test of the α-glucosidase was performed in vitro using spectrophotometric methods. Compared with the control acarbose (IC50 117.20 μg/mL), thirty-seven samples of forty-five were shown to be more potent α-glucosidase inhibitors with IC50 values in the range 2.33–112.02 μg/mL. PMID:22187534

  7. Inhibitory activity of Thai condiments on pandemic strain of Vibrio parahaemolyticus.

    PubMed

    Vuddhakul, Varaporn; Bhoopong, Phuangthip; Hayeebilan, Fadeeya; Subhadhirasakul, Sanan

    2007-06-01

    Antibacterial activity of 13 condiments used in Thai cooking was investigated with a pandemic strain of Vibrio parahaemolyticus. Using a disk diffusion technique, freshly squeezed extracts from galangal, garlic and lemon, at a concentration of 10 microl/disk produced a clear zone of 13.6+/-0.5, 11.6+/-0.5 and 8.6+/-1.2mm, respectively. The inhibitory activity of these 3 condiments on pandemic strains was not significantly different from that on non-pandemic strains of V. parahaemolyticus. Because of its popularity in seafood cooking, galangal was subjected to further investigation. Only a chloroform extract of galangal inhibited growth of V. parahaemolyticus producing a clear zone of 9.5+/-0.5, 12.0+/-0 and 13.5+/-0.5mm diameter at concentrations of 25, 50 and 100 microg/disk, respectively. One active component is identified as 1'-acetoxychavicol acetate. The activity of galangal was not reduced at pH 3 or in the presence of 0.15% bile salt but was reduced by freeze and spray drying. Heating a fresh preparation of galangal to 100 degrees C but not 50 degrees C for 30 min also reduced growth inhibition. Therefore, using fresh galangal in cooking was recommended. The MIC and MBC of a freshly squeezed preparation of galangal were 1:16 and 1:16, respectively. This is the first report of an inhibitory activity of a Thai medicinal plant, galangal that is used in Thai cooking, on the pandemic strain of V. parahaemolyticus.

  8. Antioxidant Activities and Tyrosinase Inhibitory Effects of Different Extracts from Pleurotus ostreatus Fruiting Bodies

    PubMed Central

    Alam, Nuhu; Yoon, Ki Nam; Lee, Kyung Rim; Shin, Pyung Gyun; Cheong, Jong Chun; Yoo, Young Bok; Shim, Ja Mi; Lee, Min Woong; Lee, U Youn

    2010-01-01

    We evaluated the antioxidant activity and tyrosinase inhibitory effects of Pleurotus ostreatus fruiting bodies extracted with acetone, methanol, and hot water. The antioxidant activities were tested against β-carotene-linoleic acid, reducing power, 1,1-diphenyl-2-picrylhydrazyl free radical scavenging activity, and ferrous chelating ability. Furthermore, phenolic acid and flavonoid contents were also analyzed. The methanol extract showed the strongest β-carotene-linoleic acid inhibition as compared to the other exracts. The acetone extract (8 mg/mL) showed a significantly high reducing power of 1.54 than the other extracts. The acetone extract was more effective than other extracts for scavenging on 1,1-diphenyl-2-picrylhydrazyl radicals. The strongest chelating effect (85.66%) was obtained from the acetone extract at 1.0 mg/mL. The antioxidant activities of the extracts from the P. ostreatus fruiting bodies increased with increasing concentration. A high performance liquid chromatography analysis detected seven phenolic compounds, including gallic acid, protocatechuic acid, chlorogenic acid, naringenin, hesperetin, formononetin, and biochanin-A in an acetonitrile and 0.1 N hydrochloric acid (5 : 1) solvent extract. The total phenolic compound concentration was 188 µg/g. Tyrosinase inhibition of the acetone, methanol, and hot water P. ostreatus extracts increased with increasing concentration. The results revealed that the methanol extract had good tyrosinase inhibitory ability, whereas the acetone and hot water extracts showed moderate activity at the concentrations tested. The results suggested that P. ostreatus may have potential as a natural antioxidant. PMID:23956669

  9. Inhibitory Effect of mTOR Activator MHY1485 on Autophagy: Suppression of Lysosomal Fusion

    PubMed Central

    Choi, Yeon Ja; Park, Yun Jung; Park, Ji Young; Jeong, Hyoung Oh; Kim, Dae Hyun; Ha, Young Mi; Kim, Ji Min; Song, Yu Min; Heo, Hyoung-Sam; Yu, Byung Pal; Chun, Pusoon; Moon, Hyung Ryong; Chung, Hae Young

    2012-01-01

    Autophagy is a major degradative process responsible for the disposal of cytoplasmic proteins and dysfunctional organelles via the lysosomal pathway. During the autophagic process, cells form double-membraned vesicles called autophagosomes that sequester disposable materials in the cytoplasm and finally fuse with lysosomes. In the present study, we investigated the inhibition of autophagy by a synthesized compound, MHY1485, in a culture system by using Ac2F rat hepatocytes. Autophagic flux was measured to evaluate the autophagic activity. Autophagosomes were visualized in Ac2F cells transfected with AdGFP-LC3 by live-cell confocal microscopy. In addition, activity of mTOR, a major regulatory protein of autophagy, was assessed by western blot and docking simulation using AutoDock 4.2. In the result, treatment with MHY1485 suppressed the basal autophagic flux, and this inhibitory effect was clearly confirmed in cells under starvation, a strong physiological inducer of autophagy. The levels of p62 and beclin-1 did not show significant change after treatment with MHY1485. Decreased co-localization of autophagosomes and lysosomes in confocal microscopic images revealed the inhibitory effect of MHY1485 on lysosomal fusion during starvation-induced autophagy. These effects of MHY1485 led to the accumulation of LC3II and enlargement of the autophagosomes in a dose- and time- dependent manner. Furthermore, MHY1485 induced mTOR activation and correspondingly showed a higher docking score than PP242, a well-known ATP-competitive mTOR inhibitor, in docking simulation. In conclusion, MHY1485 has an inhibitory effect on the autophagic process by inhibition of fusion between autophagosomes and lysosomes leading to the accumulation of LC3II protein and enlarged autophagosomes. MHY1485 also induces mTOR activity, providing a possibility for another regulatory mechanism of autophagy by the MHY compound. The significance of this study is the finding of a novel inhibitor of autophagy

  10. Inhibitory effect of mTOR activator MHY1485 on autophagy: suppression of lysosomal fusion.

    PubMed

    Choi, Yeon Ja; Park, Yun Jung; Park, Ji Young; Jeong, Hyoung Oh; Kim, Dae Hyun; Ha, Young Mi; Kim, Ji Min; Song, Yu Min; Heo, Hyoung-Sam; Yu, Byung Pal; Chun, Pusoon; Moon, Hyung Ryong; Chung, Hae Young

    2012-01-01

    Autophagy is a major degradative process responsible for the disposal of cytoplasmic proteins and dysfunctional organelles via the lysosomal pathway. During the autophagic process, cells form double-membraned vesicles called autophagosomes that sequester disposable materials in the cytoplasm and finally fuse with lysosomes. In the present study, we investigated the inhibition of autophagy by a synthesized compound, MHY1485, in a culture system by using Ac2F rat hepatocytes. Autophagic flux was measured to evaluate the autophagic activity. Autophagosomes were visualized in Ac2F cells transfected with AdGFP-LC3 by live-cell confocal microscopy. In addition, activity of mTOR, a major regulatory protein of autophagy, was assessed by western blot and docking simulation using AutoDock 4.2. In the result, treatment with MHY1485 suppressed the basal autophagic flux, and this inhibitory effect was clearly confirmed in cells under starvation, a strong physiological inducer of autophagy. The levels of p62 and beclin-1 did not show significant change after treatment with MHY1485. Decreased co-localization of autophagosomes and lysosomes in confocal microscopic images revealed the inhibitory effect of MHY1485 on lysosomal fusion during starvation-induced autophagy. These effects of MHY1485 led to the accumulation of LC3II and enlargement of the autophagosomes in a dose- and time-dependent manner. Furthermore, MHY1485 induced mTOR activation and correspondingly showed a higher docking score than PP242, a well-known ATP-competitive mTOR inhibitor, in docking simulation. In conclusion, MHY1485 has an inhibitory effect on the autophagic process by inhibition of fusion between autophagosomes and lysosomes leading to the accumulation of LC3II protein and enlarged autophagosomes. MHY1485 also induces mTOR activity, providing a possibility for another regulatory mechanism of autophagy by the MHY compound. The significance of this study is the finding of a novel inhibitor of autophagy

  11. The impact of photo-induced molecular changes of dairy proteins on their ACE-inhibitory peptides and activity.

    PubMed

    Kerkaert, Barbara; Mestdagh, Frédéric; Cucu, Tatiana; Shrestha, Kshitij; Van Camp, John; De Meulenaer, Bruno

    2012-08-01

    Among all dietary proteins, dairy proteins are the most important source of bio-active peptides which can, however, be affected by modifications upon processing and storage. Since it is still unknown to which extent the biological activity of dairy proteins is altered by chemical reactions, this study focuses on the effect of photo-induced molecular changes on the angiotensin I converting enzyme (ACE) inhibitory activity. Milk proteins were dissolved in phosphate buffer containing riboflavin and stored under light at 4 °C for one month during which the molecular changes and the ACE-inhibitory activity were analysed. An increase in the total protein carbonyls and the N-formylkynurenine content was observed, besides a decrease in the free thiol, tryptophan, tyrosine and histidine content. These changes were more severe in caseins compared with whey proteins and resulted moreover in the aggregation of caseins. Due to these photo-induced molecular changes, a significant loss of the ACE-inhibitory activity was observed for casein peptides. A peptide analysis moreover illustrated that the decreased activity was not attributed to a reduced digestibility but to losses of specific ACE-inhibitory peptides. The observed molecular changes, more specifically the degradation of specific amino acids and the casein aggregation, could be assigned as the cause of the altered peptide pattern and as such of the loss in ACE-inhibitory activity.

  12. Dibenzocyclooctadiene lignans from Schisandra chinensis and their inhibitory activity on NO production in lipopolysaccharide-activated microglia cells.

    PubMed

    Hu, Di; Yang, Zhiyou; Yao, Xuechun; Wang, Hua; Han, Na; Liu, Zhihui; Wang, Yu; Yang, Jingyu; Yin, Jun

    2014-08-01

    Four dibenzocyclooctadiene lignans, schisanchinins A-D, and 10 known compounds were isolated from the EtOAc extract of fruits of Schisandra chinensis (Turcz.) Baill. Structures of compounds 1-4 were elucidated using a combination of spectroscopic techniques, including MS, UV and IR, NMR ((1)H NMR, (13)C NMR, HMQC, HMBC). The stereochemistry of the chiral centers and the biphenyl configuration were determined using NOESY, as well as analysis of CD spectra. In vitro activity assays showed that 11 of the 14 compounds exhibited inhibitory activity on lipopolysaccharide (LPS)-induced NO release in primary murine BV2 microglia cells.

  13. α-Glucosidase inhibitory activity of marine sponges collected in Mauritius waters.

    PubMed

    Ramanjooloo, Avin; Cresteil, Thierry; Lebrasse, Cindy; Beedessee, Girish; Oogarah, Preeti; van Soest, Rob W M; Marie, Daniel E P

    2015-01-01

    This report describes the use of α-glucosidase to evaluate the anti-diabetic potential of extracts from marine sponges collected in the Mauritius waters. Initial screening at 1.0 mg/mL of 141 extracts obtained from 47 sponge species revealed 10 extracts with inhibitory activity greater than 85%. Seven of the 10 extracts were further tested at 0.1 and 0.01 mg/mL and only the methanol extract of two sponges namely Acanthostylotella sp. (ASSM) and Echinodictyum pykei (EPM) showed inhibition activity greater than 60% at 0.1 mg/mL with an IC50 value of 0.16 ± 0.02 and 0.04 ± 0.01 mg/mL, respectively, while being inactive at 0.01 mg/mL.

  14. Alkaloid profiles and acetylcholinesterase inhibitory activities of Fumaria species from Bulgaria.

    PubMed

    Vrancheva, Radka Z; Ivanov, Ivan G; Aneva, Ina Y; Dincheva, Ivayla N; Badjakov, Ilian K; Pavlov, Atanas I

    2016-01-01

    GC-MS analysis of alkaloid profiles of five Fumaria species, naturally grown in Bulgaria (F. officinalis, F. thuretii, F. kralikii, F. rostellata and F. schrammii) and analysis of acetylcholinesterase inhibitory activity of alkaloid extracts were performed. Fourteen isoquinoline alkaloids were identified, with the principle ones being protopine, cryptopine, sinactine, parfumine, fumariline, fumarophycine, and fumaritine. Protopine contents, defined by HPLC analysis varied between 210.6 ± 8.8 μg/g DW (F. schrammii) and 334.5 ± 7.1 μg/g DW. (F. rostellata). While all of the investigated alkaloid extracts significantly inhibited acetylcholinesterase activity, the F. kralikii demonstrated the highest level of inhibition (IC(50) 0.13 ± 0.01 mg extract/mL).

  15. Potent α-amylase inhibitory activity of Indian Ayurvedic medicinal plants

    PubMed Central

    2011-01-01

    Background Indian medicinal plants used in the Ayurvedic traditional system to treat diabetes are a valuable source of novel anti-diabetic agents. Pancreatic α-amylase inhibitors offer an effective strategy to lower the levels of post-prandial hyperglycemia via control of starch breakdown. In this study, seventeen Indian medicinal plants with known hypoglycemic properties were subjected to sequential solvent extraction and tested for α-amylase inhibition, in order to assess and evaluate their inhibitory potential on PPA (porcine pancreatic α-amylase). Preliminary phytochemical analysis of the lead extracts was performed in order to determine the probable constituents. Methods Analysis of the 126 extracts, obtained from 17 plants (Aloe vera (L.) Burm.f., Adansonia digitata L., Allium sativum L., Casia fistula L., Catharanthus roseus (L.) G. Don., Cinnamomum verum Persl., Coccinia grandis (L.) Voigt., Linum usitatisumum L., Mangifera indica L., Morus alba L., Nerium oleander L., Ocimum tenuiflorum L., Piper nigrum L., Terminalia chebula Retz., Tinospora cordifolia (Willd.) Miers., Trigonella foenum-graceum L., Zingiber officinale Rosc.) for PPA inhibition was initially performed qualitatively by starch-iodine colour assay. The lead extracts were further quantified with respect to PPA inhibition using the chromogenic DNSA (3, 5-dinitrosalicylic acid) method. Phytochemical constituents of the extracts exhibiting≥ 50% inhibition were analysed qualitatively as well as by GC-MS (Gas chromatography-Mass spectrometry). Results Of the 126 extracts obtained from 17 plants, 17 extracts exhibited PPA inhibitory potential to varying degrees (10%-60.5%) while 4 extracts showed low inhibition (< 10%). However, strong porcine pancreatic amylase inhibitory activity (> 50%) was obtained with 3 isopropanol extracts. All these 3 extracts exhibited concentration dependent inhibition with IC50 values, viz., seeds of Linum usitatisumum (540 μgml-1), leaves of Morus alba (1440

  16. Solution phase parallel synthesis and evaluation of MAPK inhibitory activities of close structural analogues of a Ras pathway modulator.

    PubMed

    Lu, Yingchun; Sakamuri, Sukumar; Chen, Quin-Zene; Keng, Yen-Fang; Khazak, Vladimir; Illgen, Katrin; Schabbert, Silke; Weber, Lutz; Menon, Sanjay R

    2004-08-02

    A solution phase parallel synthesis approach was undertaken to rapidly explore the structure-activity relationship of an inhibitor of the Ras/Raf protein interaction identified from a small molecule compound library. Evaluation of the MAPK pathway signaling inhibitory activity of the synthesized analogues as well as their antiproliferative activity and ability to inhibit soft agar growth were performed.

  17. Conformation-dependent QSAR approach for the prediction of inhibitory activity of bromodomain modulators.

    PubMed

    García-Jacas, C R; Martinez-Mayorga, K; Marrero-Ponce, Y; Medina-Franco, J L

    2017-01-01

    Epigenetic drug discovery is a promising research field with growing interest in the scientific community, as evidenced by the number of publications and the large amount of structure-epigenetic activity information currently available in the public domain. Computational methods are valuable tools to analyse and understand the activity of large compound collections from their structural information. In this manuscript, QSAR models to predict the inhibitory activity of a diverse and heterogeneous set of 88 organic molecules against the bromodomains BRD2, BRD3 and BRD4 are presented. A conformation-dependent representation of the chemical structures was established using the RDKit software and a training and test set division was performed. Several two-linear and three-linear QuBiLS-MIDAS molecular descriptors ( www.tomocomd.com ) were computed to extract the geometric structural features of the compounds studied. QuBiLS-MIDAS-based features sets, to be used in the modelling, were selected using dimensionality reduction strategies. The multiple linear regression procedure coupled with a genetic algorithm were employed to build the predictive models. Regression models containing between 6 to 9 variables were developed and assessed according to several internal and external validation methods. Analyses of outlier compounds and the applicability domain for each model were performed. As a result, the models against BRD2 and BRD3 with 8 variables and the model with 9 variables against BRD4 were those with the best overall performance according to the criteria accounted for. The results obtained suggest that the models proposed will be a good tool for studying the inhibitory activities of drug candidates against the bromodomains considered during epigenetic drug discovery.

  18. The NRTIs Lamivudine, Stavudine and Zidovudine Have Reduced HIV-1 Inhibitory Activity in Astrocytes

    PubMed Central

    Gray, Lachlan R.; Tachedjian, Gilda; Ellett, Anne M.; Roche, Michael J.; Cheng, Wan-Jung; Guillemin, Gilles J.; Brew, Bruce J.; Turville, Stuart G.; Wesselingh, Steve L.; Gorry, Paul R.; Churchill, Melissa J.

    2013-01-01

    HIV-1 establishes infection in astrocytes and macroage-lineage cells of the central nervous system (CNS). Certain antiretroviral drugs (ARVs) can penetrate the CNS, and are therefore often used in neurologically active combined antiretroviral therapy (Neuro-cART) regimens, but their relative activity in the different susceptible CNS cell populations is unknown. Here, we determined the HIV-1 inhibitory activity of CNS-penetrating ARVs in astrocytes and macrophage-lineage cells. Primary human fetal astrocytes (PFA) and the SVG human astrocyte cell line were used as in vitro models for astrocyte infection, and monocyte-derived macrophages (MDM) were used as an in vitro model for infection of macrophage-lineage cells. The CNS-penetrating ARVs tested were the nucleoside reverse transcriptase inhibitors (NRTIs) abacavir (ABC), lamivudine (3TC), stavudine (d4T) and zidovudine (ZDV), the non-NRTIs efavirenz (EFV), etravirine (ETR) and nevirapine (NVP), and the integrase inhibitor raltegravir (RAL). Drug inhibition assays were performed using single-round HIV-1 entry assays with luciferase viruses pseudotyped with HIV-1 YU-2 envelope or vesicular stomatitis virus G protein (VSV-G). All the ARVs tested could effectively inhibit HIV-1 infection in macrophages, with EC90s below concentrations known to be achievable in the cerebral spinal fluid (CSF). Most of the ARVs had similar potency in astrocytes, however the NRTIs 3TC, d4T and ZDV had insufficient HIV-1 inhibitory activity in astrocytes, with EC90s 12-, 187- and 110-fold greater than achievable CSF concentrations, respectively. Our data suggest that 3TC, d4T and ZDV may not adequately target astrocyte infection in vivo, which has potential implications for their inclusion in Neuro-cART regimens. PMID:23614033

  19. Cytotoxic and melanogenesis-inhibitory activities of limonoids from the leaves of Azadirachta indica (Neem).

    PubMed

    Takagi, Mio; Tachi, Yosuke; Zhang, Jie; Shinozaki, Takuro; Ishii, Kenta; Kikuchi, Takashi; Ukiya, Motohiko; Banno, Norihiro; Tokuda, Harukuni; Akihisa, Toshihiro

    2014-03-01

    Seventeen limonoids (tetranortriterpenoids), 1-17, including three new compounds, i.e., 17-defurano-17-(2,5-dihydro-2-oxofuran-3-yl)-28-deoxonimbolide (14), 17-defurano-17-(2ξ-2,5-dihydro-2-hydroxy-5-oxofuran-3-yl)-28-deoxonimbolide (15), and 17-defurano-17-(5ξ-2,5-dihydro-5-hydroxy-2-oxofuran-3-yl)-2',3'-dehydrosalannol (17), were isolated from an EtOH extract of the leaf of neem (Azadirachta indica). The structures of the new compounds were elucidated on the basis of extensive spectroscopic analyses and comparison with literature. Upon evaluation of the cytotoxic activities of these compounds against leukemia (HL60), lung (A549), stomach (AZ521), and breast (SK-BR-3) cancer cell lines, seven compounds, i.e., 1-3, 12, 13, 15, and 16, exhibited potent cytotoxicities with IC50 values in the range of 0.1-9.9 μM against one or more cell lines. Among these compounds, cytotoxicity of nimonol (1; IC50 2.8 μM) against HL60 cells was demonstrated to be mainly due to the induction of apoptosis by flow cytometry. Western blot analysis suggested that compound 1 induced apoptosis via both the mitochondrial and death receptor-mediated pathways in HL60 cells. In addition, when compounds 1-17 were evaluated for their inhibitory activities against melanogenesis in B16 melanoma cells, induced with α-melanocyte-stimulating hormone (α-MSH), seven compounds, 1, 2, 4-6, 15, and 16, exhibited inhibitory activities with 31-94% reduction of melanin content at 10 μM concentration with no or low toxicity to the cells (82-112% of cell viability at 10 μM). All 17 compounds were further evaluated for their inhibitory effects against the EpsteinBarr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells.

  20. Inhibitory responses in Aplysia pleural sensory neurons act to block excitability, transmitter release, and PKC Apl II activation.

    PubMed

    Dunn, Tyler W; Farah, Carole A; Sossin, Wayne S

    2012-01-01

    Expression of the 5-HT(1Apl(a)) receptor in Aplysia pleural sensory neurons inhibited 5-HT-mediated translocation of the novel PKC Apl II in sensory neurons and prevented PKC-dependent synaptic facilitation at sensory to motoneuron synapses (Nagakura et al. 2010). We now demonstrate that the ability of inhibitory receptors to block PKC activation is a general feature of inhibitory receptors and is found after expression of the 5-HT(1Apl(b)) receptor and with activation of endogenous dopamine and FMRFamide receptors in sensory neurons. Pleural sensory neurons are heterogeneous for their inhibitory response to endogenous transmitters, with dopamine being the most prevalent, followed by FMRFamide, and only a small number of neurons with inhibitory responses to 5-HT. The inhibitory response is dominant, reduces membrane excitability and synaptic efficacy, and can reverse 5-HT facilitation at both naive and depressed synapses. Indeed, dopamine can reverse PKC translocation during the continued application of 5-HT. Reversal of translocation can also be seen after translocation mediated by an analog of diacylglycerol, suggesting inhibition is not through blockade of diacylglycerol production. The effects of inhibition on PKC translocation can be rescued by phosphatidic acid, consistent with the inhibitory response involving a reduction or block of production of this lipid. However, phosphatidic acid could not recover PKC-dependent synaptic facilitation due to an additional inhibitory effect on the non-L-type calcium flux linked to synaptic transmission. In summary, we find a novel mechanism downstream of inhibitory receptors linked to inhibition of PKC activation in Aplysia sensory neurons.

  1. Feeding deterrent and growth inhibitory activities of PONNEEM, a newly developed phytopesticidal formulation against Helicoverpa armigera (Hubner)

    PubMed Central

    Packiam, Soosaimanickam Maria; Baskar, Kathirvelu; Ignacimuthu, Savarimuthu

    2014-01-01

    Objective To assess the feeding deterrent, growth inhibitory and egg hatchability effects of PONNEEM on Helicoverpa armigera (H. armigera). Methods Five oil formulations were prepared at different ratios to assess the feeding deterrent, growth inhibitory and egg hatchability effects on H. armigera. Results Invariably all the newly formulated phytopesticidal oil formulations showed the feeding deterrent and growth inhibitory activities against H. armigera. The maximum feeding deterrent activity of 88.44% was observed at 15 µL/L concentration of PONNEEM followed by formulation A (74.54%). PONNEEM was found to be effective in growth inhibitory activities and egg hatchability at 10 µL/L concentration. It exhibited statistically significant feeding deterrent activity and growth inhibitory activity compared with all the other treatments. Conclusions PONNEEM was found to be effective phytopesticidal formulation to control the larval stage of H. armigera. This is the first report for the feeding deterrent activity of PONNEEM against H. armigera. This newly formulated phytopesticide was patented in India. PMID:25183105

  2. Comparison of inhibitory activities and mechanisms of five mulberry plant bioactive components against α-glucosidase.

    PubMed

    He, Hao; Lu, Yan-Hua

    2013-08-28

    The α-glucosidase inhibitory effects of five bioactive components, namely 1-deoxynojirimycin, cyanidin-3-glucoside, cyanidin-3-rutinoside, resveratrol and oxyresveratrol contained in mulberry (Morus, Moraceae) plants have been compared. Spectroscopy methods were employed to compare their α-glucosidase inhibitory mechanisms. The results revealed that 1-deoxynojirimycin (competitive), resveratrol and oxyresveratrol (noncompetitive) were stronger inhibitors than acarbose, while cyanidin-3-glucoside and cyanidin-3-rutinoside (mix competitive and noncompetitive) showed modest activities. 1-Deoxynojirimycin, resveratrol and oxyresveratrol could quench the fluorescence spectra statically by forming stable complexes, while the quenching of cyanidin-3-rutinoside and cyanidin-3-glucoside belonged to dynamic quenching by the collision of molecules. The interactions between ligands and α-glucosidase were mainly driven by hydrophobic force, or hydrogen bonding consequently induced conformational changes and reduced surface hydrophobicity. Docking results suggested that they could bind to α-glucosidase at different sites. This work provides useful information for the understanding of the ligands-α-glucosidase interactions and identifies oxyresveratrol as a potent α-glucosidase inhibitor.

  3. Macrophage Migration Inhibitory Factor Activates Hypoxia-Inducible Factor in a p53-Dependent Manner

    PubMed Central

    Oda, Seiko; Oda, Tomoyuki; Nishi, Kenichiro; Takabuchi, Satoshi; Wakamatsu, Takuhiko; Tanaka, Tomoharu; Adachi, Takehiko; Fukuda, Kazuhiko; Semenza, Gregg L.; Hirota, Kiichi

    2008-01-01

    Background Macrophage migration inhibitory factor (MIF) is not only a cytokine which has a critical role in several inflammatory conditions but also has endocrine and enzymatic functions. MIF is identified as an intracellular signaling molecule and is implicated in the process of tumor progression, and also strongly enhances neovascularization. Overexpression of MIF has been observed in tumors from various organs. MIF is one of the genes induced by hypoxia in an hypoxia-inducible factor 1 (HIF-1)-dependent manner. Methods/Principal Findings The effect of MIF on HIF-1 activity was investigated in human breast cancer MCF-7 and MDA-MB-231 cells, and osteosarcoma Saos-2 cells. We demonstrate that intracellular overexpression or extracellular administration of MIF enhances activation of HIF-1 under hypoxic conditions in MCF-7 cells. Mutagenesis analysis of MIF and knockdown of 53 demonstrates that the activation is not dependent on redox activity of MIF but on wild-type p53. We also indicate that the MIF receptor CD74 is involved in HIF-1 activation by MIF at least when MIF is administrated extracellularly. Conclusion/Significance MIF regulates HIF-1 activity in a p53-dependent manner. In addition to MIF's potent effects on the immune system, MIF is linked to fundamental processes conferring cell proliferation, cell survival, angiogenesis, and tumor invasiveness. This functional interdependence between MIF and HIF-1α protein stabilization and transactivation activity provide a molecular mechanism for promotion of tumorigenesis by MIF. PMID:18493321

  4. Synthesis and Activity Evaluation of 2-(1-naphtho[2,1-b]furan-2-yl-carbonyl)-3,5-disubstituted-2,3-dihydro-1H-pyrazoles

    PubMed Central

    Kumaraswamy, M. N.; Chandrashekhar, C.; Shivakumar, H.; Prathima Mathias, D. A.; Mahadevan, K. M.; Vaidya, V. P.

    2008-01-01

    Ethyl naphtho[2,1-b]furan-2-carboxylate (2) on reaction with hydrazine hydrate in presence of acid catalyst in ethanol medium affords naphtho[2,1-b]furan-2-carbohydrazide (3). The reaction of substituted acetophenones (4a-c) with aromatic aldehydes (5a-e) produces chalcones (6a-o) via the Claisen condensation. The reaction of naphtho[2,1-b]furan-2-carbohydrazide (3) with chalcones (6a-6o) in presence of acetic acid as catalyst in dioxane produces 1-(naphtho[2,1-b]furan-2-yl-carbonyl)-3,5-disubstituted-2,3-dihydro-1H-pyrazoles (7a-o). The structures of newly synthesized compounds have been established by elemental analysis and spectral studies. The compounds 7a-o have been evaluated for their antimicrobial activity and some selected compounds evaluated for antiinflammatory, analgesic, anthelmintic, diuretic and antipyretic activities. PMID:21369430

  5. Isolation of lactic acid bacteria with inhibitory activity against pathogens and spoilage organisms associated with fresh meat.

    PubMed

    Jones, Rhys J; Hussein, Hassan M; Zagorec, Monique; Brightwell, Gale; Tagg, John R

    2008-04-01

    The use of lactic acid bacteria (LAB) as protective cultures in vacuum-packed chill-stored meat has potential application for assuring and improving food quality, safety and market access. In a study to identify candidate strains suitable for evaluation in a meat model, agar-based methods were employed to screen 181 chilled meat and meat process-related LAB for strains inhibitory to pathogens and spoilage organisms of importance to the meat industry. Six meat-derived strains, including Lactobacillus sakei and Lactococcus lactis, were found to be inhibitory to one or more of the target strains Listeria monocytogenes, Brochothrix thermosphacta, Campylobacter jejuni and Clostridium estertheticum. The inhibitory agents appeared to be either cell-associated or molecules released extracellularly with bacteriocin-like properties. Variations detected in the antimicrobial activity of LAB associated with changes to test parameters such as substrate composition underlined the importance of further in situ evaluation of the inhibitory strains in stored meat trials.

  6. Fumosorinone, a novel PTP1B inhibitor, activates insulin signaling in insulin-resistance HepG2 cells and shows anti-diabetic effect in diabetic KKAy mice

    SciTech Connect

    Liu, Zhi-Qin; Liu, Ting; Chen, Chuan; Li, Ming-Yan; Wang, Zi-Yu; Chen, Ruo-song; Wei, Gui-xiang; Wang, Xiao-yi; Luo, Du-Qiang

    2015-05-15

    Insulin resistance is a characteristic feature of type 2 diabetes mellitus (T2DM) and is characterized by defects in insulin signaling. Protein tyrosine phosphatase 1B (PTP1B) is a key negative regulator of the insulin signaling pathways, and its increased activity and expression are implicated in the pathogenesis of insulin resistance. Therefore, the inhibition of PTP1B is anticipated to become a potential therapeutic strategy to treat T2DM. Fumosorinone (FU), a new natural product isolated from insect fungi Isaria fumosorosea, was found to inhibit PTP1B activity in our previous study. Herein, the effects of FU on insulin resistance and mechanism in vitro and in vivo were investigated. FU increased the insulin-provoked glucose uptake in insulin-resistant HepG2 cells, and also reduced blood glucose and lipid levels of type 2 diabetic KKAy mice. FU decreased the expression of PTP1B both in insulin-resistant HepG2 cells and in liver tissues of diabetic KKAy mice. Furthermore, FU increased the phosphorylation of IRβ, IRS-2, Akt, GSK3β and Erk1/2 in insulin-resistant HepG2 cells, as well as the phosphorylation of IRβ, IRS-2, Akt in liver tissues of diabetic KKAy mice. These results showed that FU increased glucose uptake and improved insulin resistance by down-regulating the expression of PTP1B and activating the insulin signaling pathway, suggesting that it may possess antidiabetic properties. - Highlights: • Fumosorinone is a new PTP1B inhibitor isolated from insect pathogenic fungi. • Fumosorinone attenuated the insulin resistance both in vitro and in vivo. • Fumosorinone decreased the expression of PTP1B both in vitro and in vivo. • Fumosorinone activated the insulin signaling pathway both in vitro and in vivo.

  7. Screening the methanol extracts of some Iranian plants for acetylcholinesterase inhibitory activity

    PubMed Central

    Gholamhoseinian, A.; Moradi, M.N.; Sharifi-far, F.

    2009-01-01

    Acetylcholinesterase (AChE) is the main enzyme for the breakdown of acetylcholine. Nowadays, usage of the inhibitors of this enzyme is one of the most important types of treatment of mild to moderate neurodegenerative diseases such as Alzheimer’s disease. Herbal medicines can be a new source of inhibitors of this enzyme. In this study we examined around 100 different plants to evaluate their inhibitory properties for AChE enzyme. Plants were scientifically identified and their extracts were prepared by methanol percolation. Acetylcholinesterase activity was measured using a colorimetric method in the presence or absence of the extracts. Eserine was used as a positive control. Methanol extracts of the Levisticum officinale, Bergeris integrima and Rheum ribes showed more than 50% AChE inhibitory activity. The inhibition kinetics were studied in the presence of the most effective extracts. L. officinale and B. integrima inhibited AChE activity in a non-competitive manner, while R. ribes competitively inhibitied the enzyme as revealed by double-reciprocal Linweaver-Burk plot analysis. Under controlled condition, Km and Vmax values of the enzyme were found to be 9.4 mM and 0.238 mM/min, respectively. However, in the presence of L. officinale, B. integrima, and R. ribes extracts, Vmax values were 0.192, 0.074 and 0.238 mM/min, respectively. Due to the competitive inhibition of the enzyme by R. ribes extract, the Km value of 21.2 mM was obtained. The concentration required for 50% enzyme inhibition (IC50 value) was 0.5, 0.9, and 0.95 mg/ml for the L. officinale, B. integrima and R. ribes extracts, respectively. The IC50 of the eserine was determined to be 0.8 mg/ml. PMID:21589805

  8. Activity-dependent modulation of inhibitory synaptic kinetics in the cochlear nucleus

    PubMed Central

    Nerlich, Jana; Keine, Christian; Rübsamen, Rudolf; Burger, R. Michael; Milenkovic, Ivan

    2014-01-01

    Spherical bushy cells (SBCs) in the anteroventral cochlear nucleus respond to acoustic stimulation with discharges that precisely encode the phase of low-frequency sound. The accuracy of spiking is crucial for sound localization and speech perception. Compared to the auditory nerve input, temporal precision of SBC spiking is improved through the engagement of acoustically evoked inhibition. Recently, the inhibition was shown to be less precise than previously understood. It shifts from predominantly glycinergic to synergistic GABA/glycine transmission in an activity-dependent manner. Concurrently, the inhibition attains a tonic character through temporal summation. The present study provides a comprehensive understanding of the mechanisms underlying this slow inhibitory input. We performed whole-cell voltage clamp recordings on SBCs from juvenile Mongolian gerbils and recorded evoked inhibitory postsynaptic currents (IPSCs) at physiological rates. The data reveal activity-dependent IPSC kinetics, i.e., the decay is slowed with increased input rates or recruitment. Lowering the release probability yielded faster decay kinetics of the single- and short train-IPSCs at 100 Hz, suggesting that transmitter quantity plays an important role in controlling the decay. Slow transmitter clearance from the synaptic cleft caused prolonged receptor binding and, in the case of glycine, spillover to nearby synapses. The GABAergic component prolonged the decay by contributing to the asynchronous vesicle release depending on the input rate. Hence, the different factors controlling the amount of transmitters in the synapse jointly slow the inhibition during physiologically relevant activity. Taken together, the slow time course is predominantly determined by the receptor kinetics and transmitter clearance during short stimuli, whereas long duration or high frequency stimulation additionally engage asynchronous release to prolong IPSCs. PMID:25565972

  9. Phosphodiesterase-1 Inhibitory Activity of Two Flavonoids Isolated from Pistacia integerrima J. L. Stewart Galls

    PubMed Central

    Saleem, Muhammad; Uddin, Ghias; Siddiqui, Bina S.; Khan, Haroon; Raza, Muslim; Hamid, Syeda Zehra; Khan, Ajmal; Maione, Francesco; Mascolo, Nicola

    2015-01-01

    Pistacia integerrima is one of twenty species among the genus Pistacia. Long horn-shaped galls that develop on this plant are harvested and used in Ayurveda and Indian traditional medicine to make “karkatshringi”, a herbal medicine used for the treatment of asthma and different disorders of respiratory tract. However, until now, the molecular mechanisms of action of “karkatshringi” and its chemical characterization are partially known. This study deals with the isolation and characterization of the active constituents from the methanolic extract of P. integerrima galls and it was also oriented to evaluate in vitro and in silico their potential enzymatic inhibitory activity against phosphodiesterase-1 (PDE1), a well-known enzyme involved in airway smooth muscle activity and airway inflammation. Our results showed that the methanolic extract of P. integerrima galls and some of its active constituents [naringenin (1) and 3,5,7,4′-tetrahydroxy-flavanone (2)] are able in vitro to inhibit PDE1 activity (59.20 ± 4.95%, 75.90 ± 5.90%, and 65.25 ± 5.25%, resp.) and demonstrate in silico an interesting interaction with this enzymatic site. Taken together, our results add new knowledge of chemical constituents responsible for the biological activity of P. integerrima and contextually legitimate the use of this plant in folk medicine. PMID:25945110

  10. Protease and protease inhibitory activity in pregnant and postpartum involuting uterus

    SciTech Connect

    Milwidsky, A.; Beller, U.; Palti, Z.; Mayer, M.

    1982-08-15

    The presence of two distinct proteolytic activities in the rat uterus was confirmed with /sup 14/C-labeled globin used as a sensitive protein substrate and following release of label into the trichloroacetic acid-soluble supernatant fraction. Protease I is a cytoplasmic acid protease while protease II is associated with the pellet fraction, can be extracted by 0.6 M sodium chloride, and is active at pH 7.0. Protease I activity is low during pregnancy and markedly increases at term achieving maximal activity at day 3 post partum with a subsequent decline to preterm activity values. Lactation did not affect the uterine protease I activity. Protease II activity is not significantly different during pregnancy, at term, and post partum. The presence of an inhibitor of protease I was suggested by a decrease in enzyme activity with an increased cytosolic protein concentration. The inhibitor also lessened bovine trypsin activity but had no effect on protease II. Although its inhibitory potency on trypsin fluctuated during the various uterine physiologic stages, these changes appeared to be statistically insignificant. Human uterine samples were also found to contain the two protease activities with similar changes in protease I post partum. It is suggested that, both in the rat and in man, uterine involution post partum is associated with a marked increase in activity of acid cytosolic protease, while a particulate neutral protease and a soluble inhibitor of trypsin, which are also present in uterine cells, do not appear to play a significant role in the dissolution of uterine tissues after parturition.

  11. Inhibitory effect of deferoxamine or macrophage activation on transformation of Paracoccidioides brasiliensis conidia ingested by macrophages: reversal by holotransferrin.

    PubMed

    Cano, L E; Gomez, B; Brummer, E; Restrepo, A; Stevens, D A

    1994-04-01

    Conidia of P. brasiliensis ingested by murine macrophages at 37 degrees C showed enhanced transformation to yeast cells and further intracellular growth compared with conidia in culture medium alone. Treatment of macrophages with the iron chelator deferoxamine inhibited the intracellular conidium-to-yeast transformation. Cytokine-activated macrophages could also exert this inhibitory effect. Holotransferrin reversed the inhibitory effect of either deferoxamine or activated macrophages on intracellular conidium-to-yeast transformation. These results indicate that iron restriction is one of the mechanisms by which activated macrophages control the intracellular transformation of ingested conidia and growth of yeast cells.

  12. Inhibitory effect of deferoxamine or macrophage activation on transformation of Paracoccidioides brasiliensis conidia ingested by macrophages: reversal by holotransferrin.

    PubMed Central

    Cano, L E; Gomez, B; Brummer, E; Restrepo, A; Stevens, D A

    1994-01-01

    Conidia of P. brasiliensis ingested by murine macrophages at 37 degrees C showed enhanced transformation to yeast cells and further intracellular growth compared with conidia in culture medium alone. Treatment of macrophages with the iron chelator deferoxamine inhibited the intracellular conidium-to-yeast transformation. Cytokine-activated macrophages could also exert this inhibitory effect. Holotransferrin reversed the inhibitory effect of either deferoxamine or activated macrophages on intracellular conidium-to-yeast transformation. These results indicate that iron restriction is one of the mechanisms by which activated macrophages control the intracellular transformation of ingested conidia and growth of yeast cells. PMID:8132359

  13. Fumosorinone, a novel PTP1B inhibitor, activates insulin signaling in insulin-resistance HepG2 cells and shows anti-diabetic effect in diabetic KKAy mice.

    PubMed

    Liu, Zhi-Qin; Liu, Ting; Chen, Chuan; Li, Ming-Yan; Wang, Zi-Yu; Chen, Ruo-Song; Wei, Gui-Xiang; Wang, Xiao-Yi; Luo, Du-Qiang

    2015-05-15

    Insulin resistance is a characteristic feature of type 2 diabetes mellitus (T2DM) and is characterized by defects in insulin signaling. Protein tyrosine phosphatase 1B (PTP1B) is a key negative regulator of the insulin signaling pathways, and its increased activity and expression are implicated in the pathogenesis of insulin resistance. Therefore, the inhibition of PTP1B is anticipated to become a potential therapeutic strategy to treat T2DM. Fumosorinone (FU), a new natural product isolated from insect fungi Isaria fumosorosea, was found to inhibit PTP1B activity in our previous study. Herein, the effects of FU on insulin resistance and mechanism in vitro and in vivo were investigated. FU increased the insulin-provoked glucose uptake in insulin-resistant HepG2 cells, and also reduced blood glucose and lipid levels of type 2 diabetic KKAy mice. FU decreased the expression of PTP1B both in insulin-resistant HepG2 cells and in liver tissues of diabetic KKAy mice. Furthermore, FU increased the phosphorylation of IRβ, IRS-2, Akt, GSK3β and Erk1/2 in insulin-resistant HepG2 cells, as well as the phosphorylation of IRβ, IRS-2, Akt in liver tissues of diabetic KKAy mice. These results showed that FU increased glucose uptake and improved insulin resistance by down-regulating the expression of PTP1B and activating the insulin signaling pathway, suggesting that it may possess antidiabetic properties.

  14. Comparison of human immunodeficiency virus type 1-specific inhibitory activities in saliva and other human mucosal fluids.

    PubMed

    Kazmi, Shamim H; Naglik, Julian R; Sweet, Simon P; Evans, Robert W; O'Shea, Siobhan; Banatvala, Jangu E; Challacombe, Stephen J

    2006-10-01

    Several human mucosal fluids are known to possess an innate ability to inhibit human immunodeficiency virus type 1 (HIV-1) infection and replication in vitro. This study compared the HIV-1 inhibitory activities of several mucosal fluids, whole, submandibular/sublingual (sm/sl), and parotid saliva, breast milk, colostrum, seminal plasma, and cervicovaginal secretions, from HIV-1-seronegative donors by using a 3-day microtiter infection assay. A wide range of HIV-1 inhibitory activity was exhibited in all mucosal fluids tested, with some donors exhibiting high levels of activity while others showed significantly lower levels. Colostrum, whole milk, and whole saliva possessed the highest levels of anti-HIV-1 activity, seminal fluid, cervicovaginal secretions, and sm/sl exhibited moderate levels, and parotid saliva consistently demonstrated the lowest levels of HIV-1 inhibition. Fast protein liquid chromatography gel filtration studies revealed the presence of at least three distinct peaks of inhibitory activity against HIV-1 in saliva and breast milk. Incubation of unfractionated and fractionated whole saliva with antibodies raised against human lactoferrin (hLf), secretory leukocyte protease inhibitor (SLPI), and, to a lesser extent, MG2 (high-molecular-weight mucinous glycoprotein) reduced the HIV-1 inhibitory activity significantly. The results suggest that hLf and SLPI are two key components responsible for HIV-1 inhibitory activity in different mucosal secretions. The variation in HIV inhibitory activity between the fluids and between individuals suggests that there may be major differences in susceptibility to HIV infection depending both on the individual and on the mucosal fluid involved.

  15. Reverse type I binding spectra of human cytochrome P450 1B1 induced by flavonoid, stilbene, pyrene, naphthalene, phenanthrene, and biphenyl derivatives that inhibit catalytic activity: a structure-function relationship study.

    PubMed

    Shimada, Tsutomu; Tanaka, Katsuhiro; Takenaka, Shigeo; Foroozesh, Maryam K; Murayama, Norie; Yamazaki, Hiroshi; Guengerich, F Peter; Komori, Masayuki

    2009-07-01

    Fifty-one chemicals including derivatives of 16 flavonoids, three stilbenes, six pyrenes, seven naphthalenes, seven phenanthrenes, 10 biphenyls, 17beta-estradiol, and estrone were examined for their abilities to induce reverse type I binding spectra with human cytochrome P450 (P450) 1B1 and to inhibit 7-ethoxyresorufin O-deethylation (EROD) activities catalyzed by P450 1B1. Forty-nine chemicals showed reverse type I spectra with P450 1B1, and we found that 3,5,7-trihydroxyflavone, 3',4'-dimethoxy-5,7-dihydroxyflavone, 4'-methoxy-5,7-dihydroxyflavone, alpha- and beta-naphthoflavones, 2,4,3',5'-tetramethoxystilbene, pyrene, and several acetylenic pyrenes and phenanthrenes were strong inducers of the spectra and also potent inhibitors of EROD activities catalyzed by P450 1B1. The spectral dissociation constant (K(s)) and the magnitude of the binding (DeltaA(max)/K(s)) of 49 chemicals were correlated with the inhibition potencies of EROD activities by these chemicals [correlation coefficients (r) of 0.72 and 0.74, respectively]. The K(s) and DeltaA(max)/K(s) values were more correlated with IC(50) values when compared in a group of derivatives of flavonoids, stilbenes, and estrogens (r = 0.81 and 0.88, respectively) or a group of derivatives of pyrenes, naphthalenes, phenanthrenes, and biphenyls (r = 0.88 and 0.91, respectively). Among 14 flavonoids examined, 3,5,7-trihydroxyflavone and 4'-methoxy- and 3',4'-dimethoxy-5,7-dihydroxyflavone were more active than flavone in interacting with P450 1B1, but the respective 7,8-dihydroxyflavones were less active. Pyrene itself was highly active in interacting with P450 1B1, but its binding was slightly decreased when substituted with acetylenic groups. In contrast, substitution of naphthalene with methyl and ethyl propargyl ethers led to more interaction with P450 1B1 than with naphthalene itself. Similarly, substitution on phenanthrene or biphenyl with acetylenic groups and propargyl ethers increased affinities to P450 1B1

  16. Activation of kinetically distinct synaptic conductances on inhibitory interneurons by electrotonically overlapping afferents.

    PubMed

    Walker, Harrison C; Lawrence, J Josh; McBain, Chris J

    2002-07-03

    Mossy fiber (MF) and CA3 collateral (CL) axons activate common interneurons via synapses comprised of different AMPA receptors to provide feedforward and feedback inhibitory control of the CA3 hippocampal network. Because synapses potentially occur over variable electrotonic distances that distort somatically recorded synaptic currents, it is not known whether the underlying afferent-specific synaptic conductances are associated with different time courses. Using a somatic voltage jump technique to alter the driving force at the site of the synapse, we demonstrate that MF and CL synapses overlap in electrotonic location yet differ in conductance time course. Thus, afferent-specific conductance time courses allow single interneurons to differentially integrate feedforward and feedback information without the need to segregate distinct AMPA receptor subunits to different electrotonic domains.

  17. In vitro cholinesterase inhibitory activity of some plants used in Iranian traditional medicine.

    PubMed

    Saeedi, Mina; Babaie, Khatereh; Karimpour-Razkenari, Elahe; Vazirian, Mahdi; Akbarzadeh, Tahmineh; Khanavi, Mahnaz; Hajimahmoodi, Mannan; Shams Ardekani, Mohammad Reza

    2017-03-06

    In this study, in vitro evaluation of cholinesterase inhibitory (ChEI) activity of various plants including betel nuts (Areca catechu L.), clove buds (Syzygium aromaticum L.), aerial parts of dodder (Cuscuta chinensis Lam.), common polypody rhizomes (Polypodium vulgare L.) and turpeth roots (Ipomoea turpethum R. Br.) which were recommended for the treatment of AD symptoms in Iranian Traditional Medicine (ITM) is reported. Among them, aqueous extract of A. catechu L. was found as the most potent anti-AChE (IC50 = 32.00 μg/mL) and anti-BChE (IC50 = 48.81 ± 0.1200 μg/mL) agent.

  18. Compounds from Polyphaga plancyi and their inhibitory activities against JAK3 and DDR1 kinases.

    PubMed

    Zhu, Hong-Jie; Yan, Yong-Ming; Tu, Zheng-Chao; Luo, Jin-Feng; Liang, Rui; Yang, Tong-Hua; Cheng, Yong-Xian; Wang, Shu-Mei

    2016-10-01

    Plancyamides A (1) and B (3), plancypyrazine A (2), and plancyols A (4) and B (5), five new compounds (1-5), and three known ones (6-8), were isolated from the whole bodies of Polyphaga plancyi Bolivar. Their structures were elucidated by a combination of spectroscopic analyses including 1D and 2D NMR, and HRESIMS. Among them, compound 3 is racemic, chiral HPLC separation afforded its respective enantiomers. The absolute configuration of 1 was assigned by computational methods. Biological evaluation of all the compounds with exception of 7 and 8 discloses that compounds 2 and 4 could inhibit JAK3 kinase with IC50 values of 12.6 and 5.0μM, respectively. In addition, compound 4 exhibit inhibitory activity towards DDR1 kinase with IC50 value of 4.87μM.

  19. Structural requirement of phenylthiourea analogs for their inhibitory activity of melanogenesis and tyrosinase.

    PubMed

    Thanigaimalai, Pillaiyar; Lee, Ki-Cheul; Sharma, Vinay K; Joo, Cheonik; Cho, Won-Jea; Roh, Eunmiri; Kim, Youngsoo; Jung, Sang-Hun

    2011-11-15

    Effect of a series of 1-phenylthioureas 1a-k and 1,3-disubstituted thioureas 2a-k were evaluated against melanin formation in melanoma B16 cell line and mushroom tyrosinase. Inhibitory activity of tyrosinase of 1-phenylthioureas 1a-k is parallel to their melanogenic inhibition. Thus, the melanogenic inhibition in melanoma B16 cells of 1-phenylthioureas could be the result of inhibition of tyrosinase. However, 1,3-diaryl or 1-phenyl-3-alkylthioureas, 2a-k, appears as melanogenic inhibitor without inhibition of tyrosinase. The molecular docking study of 1e and 2b to binding pocket of tyrosinase provided convincing explanation regarding the necessity of direct connection of planar phenyl to thiourea unit without N'-substitution of phenylthioureas 1 as tyrosinase inhibitor and 2 as non-tyrosinase inhibitor.

  20. Terpenoids with alpha-glucosidase inhibitory activity from the submerged culture of Inonotus obliquus.

    PubMed

    Ying, You-Min; Zhang, Lin-Yan; Zhang, Xia; Bai, Hai-Bo; Liang, Dong-E; Ma, Lie-Feng; Shan, Wei-Guang; Zhan, Zha-Jun

    2014-12-01

    Lanostane-type triterpenoids, inotolactones A and B, a drimane-type sesquiterpenoid, inotolactone C, and five known terpenoids 6β-hydroxy-trans-dihydroconfertifolin, inotodiol, 3β,22-dihydroxyanosta-7,9(11),24-triene, 3β-hydroxycinnamolide, and 17-hydroxy-ent-atisan-19-oic acid, were isolated from the submerged culture of chaga mushroom, Inonotus obliquus. Their structures were characterized by spectroscopic methods, including MS and NMR (1D and 2D) spectroscopic techniques. Inotolactones A and B, examples of lanostane-type triterpenoids bearing α,β-dimethyl, α,β-unsaturated δ-lactone side chains, exhibited more potent alpha-glucosidase inhibitory activities than the positive control acarbose. This finding might be related to the anti-hyperglycemic properties of the fungus and to its popular role as a diabetes treatment. In addition, a drimane-type sesquiterpenoid and an atisane-type diterpenoid were isolated from I. obliquus.

  1. Synthesis and GGCT Inhibitory Activity of N-Glutaryl-L-alanine Analogues.

    PubMed

    Ii, Hiromi; Yoshiki, Tatsuhiro; Hoshiya, Naoyuki; Uenishi, Jun'ichi

    2016-01-01

    γ-Glutamylcyclotransferase (GGCT) is an important enzyme that cleaves γ-glutamyl-amino acid in the γ-glutamyl cycle to release 5-oxoproline and amino acid. Eighteen N-acyl-L-alanine analogues including eleven new compounds have been synthesized and examined for their inhibitory activity against recombinant human GGCT protein. Simple N-glutaryl-L-alanine was found to be the most potent inhibitor for GGCT. Other N-glutaryl-L-alanine analogues having methyl and dimethyl substituents at the 2-position were moderately effective, while N-(3R-aminoglutary)-L-alanine, the substrate having an (R)-amino group at the 3-position or N-(N-methyl-3-azaglutaryl)-L-alanine, the substrate having an N-methyl substituent on the 3-azaglutaryl carbon, in constract, exhibited excellent inhibition properties.

  2. Glucose level determines excitatory or inhibitory effects of adiponectin on arcuate POMC neuron activity and feeding

    PubMed Central

    Suyama, Shigetomo; Maekawa, Fumihiko; Maejima, Yuko; Kubota, Naoto; Kadowaki, Takashi; Yada, Toshihiko

    2016-01-01

    Adiponectin regulates glucose and lipid metabolism, acting against metabolic syndrome and atherosclerosis. Accumulating evidence suggest that adiponectin acts on the brain including hypothalamic arcuate nucleus (ARC), where proopiomelanocortin (POMC) neurons play key roles in feeding regulation. Several studies have examined intracerebroventricular (ICV) injection of adiponectin and reported opposite effects, increase or decrease of food intake. These reports used different nutritional states. The present study aimed to clarify whether adiponectin exerts distinct effects on food intake and ARC POMC neurons depending on the glucose concentration. Adiponectin was ICV injected with or without glucose for feeding experiments and administered to ARC slices with high or low glucose for patch clamp experiments. We found that adiponectin at high glucose inhibited POMC neurons and increased food intake while at low glucose it exerted opposite effects. The results demonstrate that glucose level determines excitatory or inhibitory effects of adiponectin on arcuate POMC neuron activity and feeding. PMID:27503800

  3. Cholinesterase inhibitors: SAR and enzyme inhibitory activity of 3-[omega-(benzylmethylamino)alkoxy]xanthen-9-ones.

    PubMed

    Piazzi, Lorna; Belluti, Federica; Bisi, Alessandra; Gobbi, Silvia; Rizzo, Stefano; Bartolini, Manuela; Andrisano, Vincenza; Recanatini, Maurizio; Rampa, Angela

    2007-01-01

    In this work, we further investigated a previously introduced class of cholinesterase inhibitors. The removal of the carbamic function from the lead compound xanthostigmine led to a reversible cholinesterase inhibitors 3. Some new 3-[omega-(benzylmethylamino)alkoxy]xanthen-9-one analogs were designed, synthesized, and evaluated for their inhibitory activity against both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). The length of the alkoxy chain of compound 3 was increased and different substituents were introduced. From the IC(50) values, it clearly appears that the carbamic residue is crucial to obtain highly potent AChE inhibitors. On the other hand, peculiarity of these compounds is the high selectivity toward BuChE with respect to AChE, being compound 12 the most selective one (6000-fold). The development of selective BuChE inhibitors may be of great interest to clarify the physiological role of this enzyme and to provide novel therapeutics for various diseases.

  4. [Liver monoamine oxidase activity of the lamprey Lampetra fluviatilis. the substrate-inhibitory specificity].

    PubMed

    Iagodina, O V; Basova, I N

    2013-01-01

    Based on data of substrate-inhibitory analysis with use of specific inhibitors--deprenyl, chlorgi-lin--and specific substrates--serotonin, noradrenalin, benzylamine, beta-phenylethylamine, and N-methylhistamine--a suggestion is put forward about the possible existence of one molecular form of monoamine oxidase (MAO) in liver of mature individuals of the European lamprey Lampetra fluviatilis. There are determined kinetic parameters of monoamine oxidase deamination of eight substrates, which indicates the large spectrum of substrate specificity of the lamprey liver MAO. The studied enzyme does not deaminate histamine and putrescine and is not sensitive to 10(-2) M semicarbaside. Results of study of the substrate-inhibitor specificity allow us to suggest some resemblance of catalytic properties of the lamprey liver MAO and the mammalian form A MAO. The revealed low activity of the enzyme at deamination of all used substrates seems to be connected with low detoxational functional of the lamprey liver.

  5. Cholinesterase inhibitory activity of chlorophenoxy derivatives-Histamine H3 receptor ligands.

    PubMed

    Łażewska, Dorota; Jończyk, Jakub; Bajda, Marek; Szałaj, Natalia; Więckowska, Anna; Panek, Dawid; Moore, Caitlin; Kuder, Kamil; Malawska, Barbara; Kieć-Kononowicz, Katarzyna

    2016-08-15

    In recent years, multitarget-directed ligands have become an interesting strategy in a search for a new treatment of Alzheimer's disease. Combination of both: a histamine H3 receptor antagonist/inverse agonist and a cholinesterases inhibitor in one molecule could provide a new therapeutic opportunity. Here, we present biological evaluation of histamine H3 receptor ligands-chlorophenoxyalkylamine derivatives against cholinesterases: acetyl- and butyrylcholinesterase. The target compounds showed cholinesterase inhibitory activity in a low micromolar range. The most potent in this group was 1-(7-(4-chlorophenoxy)heptyl)homopiperidine (18) inhibiting the both enzymes (EeAChE IC50=1.93μM and EqBuChE IC50=1.64μM). Molecular modeling studies were performed to explain the binding mode of 18 with histamine H3 receptor as well as with cholinesterases.

  6. Four new sesquiterpenes from the rhizomes of Curcuma phaeocaulis and their iNOS inhibitory activities.

    PubMed

    Ma, Jiang-Hao; Wang, Ying; Liu, Yue; Gao, Su-Yu; Ding, Li-Qin; Zhao, Feng; Chen, Li-Xia; Qiu, Feng

    2015-05-01

    Three new guaiane-type sesquiterpenes named phaeocaulisins K-M (1-3), and one germacrane-type sesquiterpenoid with new ring system of 1,5- and 1,8-ether groups named phagermadiol (4), were isolated from rhizomes of Curcuma phaeocaulis. Their structures were established based on extensive spectroscopic analysis. Compound 1, the first example of norsesquiterpene with tropone backbone, and compound 3 with a novel 1,2-dioxolane sesquiterpene alcohol were isolated from the genus Curcuma. All of the isolated compounds were tested for inhibitory activity against lipopolysaccharide-induced nitric oxide (NO) production in RAW 264.7 macrophages. Compound 3 inhibited NO production with IC50 value of 6.05 ± 0.43 μM. The plausible biosynthetic pathway for compounds 3 and 4 in C. phaeocaulis was also discussed.

  7. Inhibitory activity of Aloe vera gel on some clinically isolated cariogenic and periodontopathic bacteria.

    PubMed

    Fani, Mohammadmehdi; Kohanteb, Jamshid

    2012-03-01

    Aloe vera is a medicinal plant with anti-inflammatory, antimicrobial, antidiabetic and immune-boosting properties. In the present study we investigated the inhibitory activities of Aloe vera gel on some cariogenic (Streptococcus mutans), periodontopathic (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis) and an opportunistic periodontopathogen (Bacteroides fragilis) isolated from patients with dental caries and periodontal diseases. Twenty isolates of each of these bacteria were investigated for their sensitivity to Aloe vera gel using the disk diffusion and microdilution methods. S. mutans was the species most sensitive to Aloe vera gel with a MIC of 12.5 µg/ml, while A. actinomycetemcomitans, P. gingivalis, and B. fragilis were less sensitive, with a MIC of 25-50 µg/ml (P < 0.01). Based on our present findings it is concluded that Aloe vera gel at optimum concentration could be used as an antiseptic for prevention of dental caries and periodontal diseases.

  8. Design, synthesis, and AChE inhibitory activity of new benzothiazole-piperazines.

    PubMed

    Demir Özkay, Ümide; Can, Özgür Devrim; Sağlık, Begüm Nurpelin; Acar Çevik, Ulviye; Levent, Serkan; Özkay, Yusuf; Ilgın, Sinem; Atlı, Özlem

    2016-11-15

    In the current study, 14 new benzothiazole-piperazine compounds were designed to meet the structural requirements of acetylcholine esterase (AChE) inhibitors. The target compounds were synthesised in three steps. Structures of the newly synthesised compounds (7-20) were confirmed using IR, (1)H NMR, (13)C NMR, and HRMS methods. The inhibitory potential of the compounds on AChE (E.C.3.1.1.7, from electric eel) was then investigated. Among the compounds, 19 and 20 showed very good activity on AChE enzyme. Kinetics studies were performed to observe the effects of the most active compounds on the substrate-enzyme relationship. Cytotoxicity studies, genotoxicity studies, and theoretical calculation of pharmacokinetics properties were also carried out. The compounds 19 and 20 were found to be nontoxic in both of the toxicity assays. A good pharmacokinetics profile was predicted for the synthesised compounds. Molecular docking studies were performed for the most active compounds, 19 and 20, and interaction modes with enzyme active sites were determined. Docking studies indicated a strong interaction between the active sites of AChE enzyme and the analysed compounds.

  9. Structural and Kinetic Analyses of Macrophage Migration Inhibitory Factor Active Site Interactions

    SciTech Connect

    Crichlow, G.; Lubetsky, J; Leng, L; Bucala, R; Lolis, E

    2009-01-01

    Macrophage migration inhibitory factor (MIF) is a secreted protein expressed in numerous cell types that counters the antiinflammatory effects of glucocorticoids and has been implicated in sepsis, cancer, and certain autoimmune diseases. Interestingly, the structure of MIF contains a catalytic site resembling the tautomerase/isomerase sites of microbial enzymes. While bona fide physiological substrates remain unknown, model substrates have been identified. Selected compounds that bind in the tautomerase active site also inhibit biological functions of MIF. It had previously been shown that the acetaminophen metabolite, N-acetyl-p-benzoquinone imine (NAPQI), covalently binds to the active site of MIF. In this study, kinetic data indicate that NAPQI inhibits MIF both covalently and noncovalently. The structure of MIF cocrystallized with NAPQI reveals that the NAPQI has undergone a chemical alteration forming an acetaminophen dimer (bi-APAP) and binds noncovalently to MIF at the mouth of the active site. We also find that the commonly used protease inhibitor, phenylmethylsulfonyl fluoride (PMSF), forms a covalent complex with MIF and inhibits the tautomerase activity. Crystallographic analysis reveals the formation of a stable, novel covalent bond for PMSF between the catalytic nitrogen of the N-terminal proline and the sulfur of PMSF with complete, well-defined electron density in all three active sites of the MIF homotrimer. Conclusions are drawn from the structures of these two MIF-inhibitor complexes regarding the design of novel compounds that may provide more potent reversible and irreversible inhibition of MIF.

  10. Determination of a-glucosidase inhibitory activity from selected Fabaceae plants.

    PubMed

    Dej-Adisai, Sukanya; Pitakbut, Thanet

    2015-09-01

    Nineteen plants from Fabaceae family, which were used in Thai traditional medicine for treatment of diabetes, were determined of α-glucosidase inhibitory activity via enzymatic reaction. In this reaction, α-glucosidase was used as enzyme, which, reacted with the substrate, p-nitrophenol-D-glucopyranoside (pNPG). After that the product, p-nitro phenol (pNP) will be occurred and observed the yellow colour at 405 nm. In this study, acarbose was used as positive standard which, inhibited this enzyme with IC₅₀ as 331 ± 4.73 μg/ml. Caesalpinia pulcherrima leaves showed the highest activity with IC₅₀ as 436.97 ± 9.44 μg/ml. Furthermore, Bauhinia malabarica leaves presented moderately activity with IC₅₀ as 745.08 ± 11.15 μg/ml. However, the other plants showed mild to none activity of α-glucosidase inhibition. Accordingly, this study can support anti-diabetes of these plants in traditional medicine and it will be the database of the biological activity of Fabaceae plant.

  11. Screening of some medicinal plants from cameroon for beta-lactamase inhibitory activity.

    PubMed

    Gangoué-Piéboji, Joseph; Baurin, Stéphane; Frère, Jean-Marie; Ngassam, Pierre; Ngameni, Bathelemy; Azebaze, Anatole; Pegnyemb, Dieudonné Emmanuel; Watchueng, Jean; Goffin, Colette; Galleni, Moreno

    2007-03-01

    In efforts to find new bioactive beta-lactamase inhibitors, this study investigated 16 Cameroonian plants belonging to 10 families which were evaluated for anti-beta-lactamase activity. The investigation showed that extracts 2, 6, 3 and 5 of the 16 plants investigated presented interesting in vitro beta-lactamase inhibition (over 90%), respectively, of the beta-lactamases TEM-1, OXA-10, IMP-1 and P99. These extracts were from Mammea africana (all beta-lactamases), Garcinia lucida, G. kola (OXA-10, IMP-1 and P99), Bridelia micrantha (OXA-10, P99), Ochna afzelii (OXA-10, P99), Prunus africana (IMP-1) and Adenia lobata (TEM-1). After elimination of tannins (according to the European Pharmacopoeia) the extracts from B. micrantha, G. lucida and M. africana were tested further for their anti-beta-lactamase activity. The extracts from B. micrantha and G. lucida exhibited potent inhibitory activity, respectively, of beta-lactamase OXA-10 (IC(50) = 0.02 mg/mL) and P99 (IC(50) = 0.01 mg/mL). The anti-beta-lactamase activity of M. africana extract was weak. The isolation and the structural elucidation of the active constituents of G. lucida and B. micrantha will provide useful leads in the development of beta-lactamase inhibitors.

  12. Cytotoxic and HIV-1 enzyme inhibitory activities of Red Sea marine organisms

    PubMed Central

    2014-01-01

    Background Cancer and HIV/AIDS are two of the greatest public health and humanitarian challenges facing the world today. Infection with HIV not only weakens the immune system leading to AIDS and increasing the risk of opportunistic infections, but also increases the risk of several types of cancer. The enormous biodiversity of marine habitats is mirrored by the molecular diversity of secondary metabolites found in marine animals, plants and microbes which is why this work was designed to assess the anti-HIV and cytotoxic activities of some marine organisms of the Red Sea. Methods The lipophilic fractions of methanolic extracts of thirteen marine organisms collected from the Red Sea (Egypt) were screened for cytotoxicity against two human cancer cell lines; leukaemia (U937) and cervical cancer (HeLa) cells. African green monkey kidney cells (Vero) were used as normal non-malignant control cells. The extracts were also tested for their inhibitory activity against HIV-1 enzymes, reverse transcriptase (RT) and protease (PR). Results Cytotoxicity results showed strong activity of the Cnidarian Litophyton arboreum against U-937 (IC50; 6.5 μg/ml ±2.3) with a selectivity index (SI) of 6.45, while the Cnidarian Sarcophyton trochliophorum showed strong activity against HeLa cells (IC50; 5.2 μg/ml ±1.2) with an SI of 2.09. Other species showed moderate to weak cytotoxicity against both cell lines. Two extracts showed potent inhibitory activity against HIV-1 protease; these were the Cnidarian jelly fish Cassiopia andromeda (IC50; 0.84 μg/ml ±0.05) and the red algae Galaxura filamentosa (2.6 μg/ml ±1.29). It is interesting to note that the most active extracts against HIV-1 PR, C. andromeda and G. filamentosa showed no cytotoxicity in the three cell lines at the highest concentration tested (100 μg/ml). Conclusion The strong cytotoxicity of the soft corals L. arboreum and S. trochliophorum as well as the anti-PR activity of the jelly fish C. andromeda and the red

  13. A five-domain Kazal-type serine proteinase inhibitor from black tiger shrimp Penaeus monodon and its inhibitory activities.

    PubMed

    Somprasong, Nawarat; Rimphanitchayakit, Vichien; Tassanakajon, Anchalee

    2006-01-01

    A novel five-domain Kazal-type serine proteinase inhibitor, SPIPm2, identified from the hemocyte cDNA library of black tiger shrimp Penaeus monodon was successfully expressed in the Escherichia coli expression system. The expressed recombinant SPIPm2 (rSPIPm2) as inclusion bodies was solubilized with a sodium carbonate buffer, pH10, and purified by gel filtration chromatography. The molecular mass of rSPIPm2 was determined using MALDI-TOF mass spectrometry to be 29.065 kDa. The inhibitory activities of rSPIPm2 were tested against trypsin, alpha-chymotrypsin, subtilisin and elastase. The inhibitor exhibited potent inhibitory activities against subtilisin and elastase, weak inhibitory activity against trypsin, and did not inhibit chymotrypsin. Tight-binding inhibition assay suggested that the molar ratios of SPIPm2 to subtilisin and elastase were 1:2 and 1:1, respectively. The inhibition against subtilisin and elastase was a competitive type with inhibition constants (Ki) of 0.52 and 3.27 nM, respectively. The inhibitory activity of SPIPm2 against subtilisin implies that, in shrimp, it may function as a defense component against proteinases from pathogenic bacteria but the elastase inhibitory function is not known.

  14. Intrinsic conductances actively shape excitatory and inhibitory postsynaptic responses in olfactory bulb external tufted cells.

    PubMed

    Liu, Shaolin; Shipley, Michael T

    2008-10-08

    The initial synapse in the olfactory system is from olfactory nerve (ON) terminals to postsynaptic targets in olfactory bulb glomeruli. Recent studies have disclosed multiple presynaptic factors that regulate this important linkage, but less is known about the contribution of postsynaptic intrinsic conductances to integration at these synapses. The present study demonstrates voltage-dependent amplification of EPSPs in external tufted (ET) cells in response to monosynaptic (ON) inputs. This amplification is mainly exerted by persistent Na(+) conductance. Larger EPSPs, which bring the membrane potential to a relatively depolarized level, are further boosted by the low-voltage-activated Ca(2+) conductance. In contrast, the hyperpolarization-activated nonselective cation conductance (I(h)) attenuates EPSPs mainly by reducing EPSP duration; this also reduces temporal summation of multiple EPSPs. Regulation of EPSPs by these subthreshold, voltage-dependent conductances can enhance both the signal-to-noise ratio and the temporal summation of multiple synaptic inputs and thus help ET cells differentiate high- and low-frequency synaptic inputs. I(h) can also transform inhibitory inputs to postsynaptic excitation. When the ET cell membrane potential is relatively depolarized, as during a burst of action potentials, IPSPs produce classic inhibition. However, near resting membrane potentials where I(h) is engaged, IPSPs produce rebound bursts of action potentials. ET cells excite GABAergic PG cells. Thus, the transformation of inhibitory inputs to postsynaptic excitation in ET cells may enhance intraglomerular inhibition of mitral/tufted cells, the main output neurons in the olfactory bulb, and hence shape signaling to olfactory cortex.

  15. Inhibitory activity of carbonyl compounds on alcoholic fermentation by Saccharomyces cerevisiae.

    PubMed

    Cao, Dongxu; Tu, Maobing; Xie, Rui; Li, Jing; Wu, Yonnie; Adhikari, Sushil

    2014-01-29

    Aldehydes and acids play important roles in the fermentation inhibition of biomass hydrolysates. A series of carbonyl compounds (vanillin, syringaldehyde, 4-hydroxybenzaldehyde, pyrogallol aldehyde, and o-phthalaldehyde) were used to examine the quantitative structure-inhibitory activity relationship of carbonyl compounds on alcoholic fermentation, based on the glucose consumption rate and the final ethanol yield. It was observed that pyrogallol aldehyde and o-phthalaldehyde (5.0 mM) reduced the initial glucose consumption rate by 60 and 89%, respectively, and also decreased the final ethanol yield by 60 and 99%, respectively. Correlating the molecular descriptors to inhibition efficiency in yeast fermentation revealed a strong relationship between the energy of the lowest unoccupied molecular orbital (ELUMO) of aldehydes and their inhibitory efficiency in fermentation. On the other hand, vanillin, syringaldehyde, and 4-hydroxybenzaldehyde (5.0 mM) increased the final ethanol yields by 11, 4, and 1%, respectively. Addition of vanillin appeared to favor ethanol formation over glycerol formation and decreased the glycerol yield in yeast fermentation. Furthermore, alcohol dehydrogenase (ADH) activity dropped significantly from 3.85 to 2.72, 1.83, 0.46, and 0.11 U/mg at 6 h of fermentation at vanillin concentrations of 0, 2.5, 5.0, 10.0, and 25.0 mM correspondingly. In addition, fermentation inhibition by acetic acid and benzoic acid was pH-dependent. Addition of acetate, benzoate, and potassium chloride increased the glucose consumption rate, likely because the salts enhanced membrane permeability, thus increasing glucose consumption.

  16. Shifting FcγRIIA-ITAM from activation to inhibitory configuration ameliorates arthritis.

    PubMed

    Ben Mkaddem, Sanae; Hayem, Gilles; Jönsson, Friederike; Rossato, Elisabetta; Boedec, Erwan; Boussetta, Tarek; El Benna, Jamel; Launay, Pierre; Goujon, Jean-Michel; Benhamou, Marc; Bruhns, Pierre; Monteiro, Renato C

    2014-09-01

    Rheumatoid arthritis-associated (RA-associated) inflammation is mediated through the interaction between RA IgG immune complexes and IgG Fc receptors on immune cells. Polymorphisms within the gene encoding the human IgG Fc receptor IIA (hFcγRIIA) are associated with an increased risk of developing RA. Within the hFcγRIIA intracytoplasmic domain, there are 2 conserved tyrosine residues arranged in a noncanonical immunoreceptor tyrosine-based activation motif (ITAM). Here, we reveal that inhibitory engagement of the hFcγRIIA ITAM either with anti-hFcγRII F(ab')2 fragments or intravenous hIgG (IVIg) ameliorates RA-associated inflammation, and this effect was characteristic of previously described inhibitory ITAM (ITAMi) signaling for hFcαRI and hFcγRIIIA, but only involves a single tyrosine. In hFcγRIIA-expressing mice, arthritis induction was inhibited following hFcγRIIA engagement. Moreover, hFcγRIIA ITAMi-signaling reduced ROS and inflammatory cytokine production through inhibition of guanine nucleotide exchange factor VAV-1 and IL-1 receptor-associated kinase 1 (IRAK-1), respectively. ITAMi signaling was mediated by tyrosine 304 (Y304) within the hFcγRIIA ITAM, which was required for recruitment of tyrosine kinase SYK and tyrosine phosphatase SHP-1. Anti-hFcγRII F(ab')2 treatment of inflammatory synovial cells from RA patients inhibited ROS production through induction of ITAMi signaling. These data suggest that shifting constitutive hFcγRIIA-mediated activation to ITAMi signaling could ameliorate RA-associated inflammation.

  17. A novel synthetic quinolinone inhibitor presents proteolytic and hemorrhagic inhibitory activities against snake venom metalloproteases.

    PubMed

    Baraldi, Patrícia T; Magro, Angelo J; Matioli, Fábio F; Marcussi, Silvana; Lemke, Ney; Calderon, Leonardo A; Stábeli, Rodrigo G; Soares, Andreimar M; Correa, Arlene G; Fontes, Marcos R M

    2016-02-01

    Metalloproteases play a fundamental role in snake venom envenomation inducing hemorrhagic, fibrigen(ogen)olytic and myotoxic effects in their victims. Several snake venoms, such as those from the Bothrops genus, present important local effects which are not efficiently neutralized by conventional serum therapy. Consequently, these accidents may result in permanent sequelae and disability, creating economic and social problems, especially in developing countries, leading the attention of the World Health Organization that considered ophidic envenomations a neglected tropical disease. Aiming to produce an efficient inhibitor against bothropic venoms, we synthesized different molecules classified as quinolinones - a group of low-toxic chemical compounds widely used as antibacterial and antimycobacterial drugs - and tested their inhibitory properties against hemorrhage caused by bothropic venoms. The results from this initial screening indicated the molecule 2-hydroxymethyl-6-methoxy-1,4-dihydro-4-quinolinone (Q8) was the most effective antihemorrhagic compound among all of the assayed synthetic quinolinones. Other in vitro and in vivo experiments showed this novel compound was able to inhibit significantly the hemorrhagic and/or proteolytic activities of bothropic crude venoms and isolated snake venom metalloproteases (SVMPs) even at lower concentrations. Docking and molecular dynamic simulations were also performed to get insights into the structural basis of Q8 inhibitory mechanism against proteolytic and hemorrhagic SVMPs. These structural studies demonstrated that Q8 may form a stable complex with SVMPs, impairing the access of substrates to the active sites of these toxins. Therefore, both experimental and structural data indicate that Q8 compound is an interesting candidate for antiophidic therapy, particularly for the treatment of the hemorrhagic and necrotic effects induced by bothropic venoms.

  18. Aldo-keto reductase 1B10 promotes development of cisplatin resistance in gastrointestinal cancer cells through down-regulating peroxisome proliferator-activated receptor-γ-dependent mechanism.

    PubMed

    Matsunaga, Toshiyuki; Suzuki, Ayaka; Kezuka, Chihiro; Okumura, Naoko; Iguchi, Kazuhiro; Inoue, Ikuo; Soda, Midori; Endo, Satoshi; El-Kabbani, Ossama; Hara, Akira; Ikari, Akira

    2016-08-25

    Cisplatin (cis-diamminedichloroplatinum, CDDP) is one of the most effective chemotherapeutic drugs that are used for treatment of patients with gastrointestinal cancer cells, but its continuous administration often evokes the development of chemoresistance. In this study, we investigated alterations in antioxidant molecules and functions using a newly established CDDP-resistant variant of gastric cancer MKN45 cells, and found that aldo-keto reductase 1B10 (AKR1B10) is significantly up-regulated with acquisition of the CDDP resistance. In the nonresistant MKN45 cells, the sensitivity to cytotoxic effect of CDDP was decreased and increased by overexpression and silencing of AKR1B10, respectively. In addition, the AKR1B10 overexpression markedly suppressed accumulation and cytotoxicity of 4-hydroxy-2-nonenal that is produced during lipid peroxidation by CDDP treatment, suggesting that the enzyme acts as a crucial factor for facilitation of the CDDP resistance through inhibiting induction of oxidative stress by the drug. Transient exposure to CDDP and induction of the CDDP resistance decreased expression of peroxisome proliferator-activated receptor-γ (PPARγ) in MKN45 and colon cancer LoVo cells. Additionally, overexpression of PPARγ in the cells elevated the sensitivity to the CDDP toxicity, which was further augmented by concomitant treatment with a PPARγ ligand rosiglitazone. Intriguingly, overexpression of AKR1B10 in the cells resulted in a decrease in PPARγ expression, which was recovered by addition of an AKR1B10 inhibitor oleanolic acid, inferring that PPARγ is a downstream target of AKR1B10-dependent mechanism underlying the CDDP resistance. Combined treatment with the AKR1B10 inhibitor and PPARγ ligand elevated the CDDP sensitivity, which was almost the same level as that in the parental cells. These results suggest that combined treatment with the AKR1B10 inhibitor and PPARγ ligand is an effective adjuvant therapy for overcoming CDDP resistance of

  19. a-glucosidase inhibitory activity and antioxidant capacities in peel and pulp of mixed species blueberry (Vaccinium spp.) genotypes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Variation in inhibition of a-glucosidase inhibitory activity, phenolic levels, anthocyanin levels, and antioxidant activity of peel and pulp was investigated in 19 blueberry genotypes [16 rabbiteye hybrid derivatives (Vaccinium ashei × Vaccinium spp.), 1 rabbiteye cultivar (V. ashei Reade) and 2 hig...

  20. Cell Assembly Dynamics of Sparsely-Connected Inhibitory Networks: A Simple Model for the Collective Activity of Striatal Projection Neurons

    PubMed Central

    Angulo-Garcia, David; Berke, Joshua D.; Torcini, Alessandro

    2016-01-01

    Striatal projection neurons form a sparsely-connected inhibitory network, and this arrangement may be essential for the appropriate temporal organization of behavior. Here we show that a simplified, sparse inhibitory network of Leaky-Integrate-and-Fire neurons can reproduce some key features of striatal population activity, as observed in brain slices. In particular we develop a new metric to determine the conditions under which sparse inhibitory networks form anti-correlated cell assemblies with time-varying activity of individual cells. We find that under these conditions the network displays an input-specific sequence of cell assembly switching, that effectively discriminates similar inputs. Our results support the proposal that GABAergic connections between striatal projection neurons allow stimulus-selective, temporally-extended sequential activation of cell assemblies. Furthermore, we help to show how altered intrastriatal GABAergic signaling may produce aberrant network-level information processing in disorders such as Parkinson’s and Huntington’s diseases. PMID:26915024

  1. Synthesis, crystal structures, fluorescence and xanthine oxidase inhibitory activity of pyrazole-based 1,3,4-oxadiazole derivatives

    NASA Astrophysics Data System (ADS)

    Qi, De-Qiang; Yu, Chuan-Ming; You, Jin-Zong; Yang, Guang-Hui; Wang, Xue-Jie; Zhang, Yi-Ping

    2015-11-01

    A series of pyrazole-based 1,3,4-oxadiazole derivatives were rationally designed and synthesized in good yields by following a convenient route. All the newly synthesized molecules were fully characterized by IR, 1H NMR and elemental analysis. Eight compounds were structurally determined by single crystal X-ray diffraction analysis. The fluorescence properties of all the compounds were investigated in dimethyl sulfoxide media. In addition, these newly synthesized compounds were evaluated for in vitro inhibitory activity against commercial enzyme xanthine oxidase (XO) by measuring the formation of uric acid from xanthine. Among the compounds synthesized and tested, 3d and 3e were found to be moderate inhibitory activity against commercial XO with IC50 = 72.4 μM and 75.6 μM. The studies gave a new insight in further optimization of pyrazole-based 1,3,4-oxadiazole derivatives with excellent fluorescence properties and XO inhibitory activity.

  2. Activation of constitutive 5-hydroxytryptamine(1B) receptor by a series of mutations in the BBXXB motif: positioning of the third intracellular loop distal junction and its G(o)alpha protein interactions.

    PubMed Central

    Pauwels, P J; Gouble, A; Wurch, T

    1999-01-01

    Constitutive activity of the recombinant human 5-hydroxytryptamine(1B) (5-HT(1B)) receptor (RC code 2.1.5HT.01.B) was investigated by mutagenesis of the BBXXB motif (in which B represents a basic residue and X a non-basic residue) located in the C-terminal portion of the third intracellular loop. In contrast with wild-type 5-HT(1B) receptors, three receptor mutants (Thr(313)-->Lys, Thr(313)-->Arg and Thr(313)-->Gln) increased their agonist-independent guanosine 5'-[gamma-[(35)S]thio]triphosphate binding response by 26-41%. This activity represented approx. 30% of the maximal response induced by 5-HT and could be reversed by the inverse agonists methiothepin and 3-(3-dimethylaminopropyl)-4-hydroxy-N-(4-pyridin-4-yl phenyl)-benzenamide (GR 55562). Enhanced agonist-independent and agonist-dependent 5-HT(1B) receptor activation was provided by co-expression of a pertussis toxin-resistant rat G(o)alpha Cys(351)-->Ile protein. The wild-type 5-HT(1B) receptor displayed a doubling in basal activity, whereas a spectrum of enhanced basal activities (313-571%) was observed with a series of diverse amino acid substitutions (isoleucine, glycine, asparagine, alanine, lysine, phenylalanine, glutamine and arginine) at the 5-HT(1B) receptor position 313 in the presence of pertussis toxin (100 ng/ml). Consequently, the constitutive 5-HT(1B) receptor activity can be modulated by the mutation of Thr(313), and displays a graded range between 11% and 59% of maximal 5-HT(1B) receptor activation by 5-HT. No clear pattern is apparent in the framework of traditionally cited amino acid characteristics (i.e. residue size, charge or hydrophobicity) to explain the observed constitutive activities. The various amino acid substitutions that yielded enhanced activity are unlikely to make similar intramolecular interactions within the 5-HT(1B) receptor. It is hypothesized that the positioning of the junction between the third intracellular loop and transmembrane domain VI is altered by mutation of

  3. Antioxidant and cholinesterases inhibitory activities of Verbascum xanthophoeniceum Griseb. and its phenylethanoid glycosides.

    PubMed

    Georgiev, Milen; Alipieva, Kalina; Orhan, Ilkay; Abrashev, Radoslav; Denev, Petko; Angelova, Maria

    2011-09-01

    The members of Verbascum L. (Scrophulariaceae) are known to be rich in phenylethnoid glycosides, and among them Verbascum xanthophoeniceum is an endemic plant species for the Balkan region, Northwestern, and Southern Turkey. A scheme was developed for the isolation of the main active constituents that accumulate in plant aerial parts. The antioxidant activities of total methanol extracts, collected phenylethanoid glycosides fractions and specific active constituents (forsythoside B, verbascoside and leucosceptoside B) were then evaluated in 2,2'-diphenyl-1-picrylhydrazyl (DPPH·), oxygen radical absorbance capacity (ORACFL), hydroxyl radical averting capacity (HORACFL), ferric-reducing antioxidant power (FRAP), and superoxide anion (O2(-)) radical scavenging assays. In vitro acetylcholinesterase (AChE) and butyrylcholinesterase (BChe) inhibitory activities of abovementioned extracts, fractions and isolated pure compounds were also examined. Depending on the method used, forsythoside B, verbascoside and leucosceptoside B proved to be effective radical scavengers and cholinesterases inhibitors. On the basis of these findings it can be proposed that in addition to providing a potent source of antimicrobial and anti-inflammatory compounds, Verbascum plants could serve as attractive mines of powerful antioxidants for various purposes.

  4. Insights into cholinesterase inhibitory and antioxidant activities of five Juniperus species.

    PubMed

    Orhan, Nilufer; Orhan, Ilkay Erdogan; Ergun, Fatma

    2011-09-01

    In vitro acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory and antioxidant activities of the aqueous and ethanol extracts of the leaves, ripe fruits, and unripe fruits of Juniperus communis ssp. nana, Juniperus oxycedrus ssp. oxycedrus, Juniperus sabina, Juniperus foetidissima, and Juniperus excelsa were investigated in the present study. Cholinesterase inhibition of the extracts was screened using ELISA microplate reader. Antioxidant activity of the extracts was tested by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radical scavenging, ferrous ion-chelating, and ferric-reducing antioxidant power (FRAP) assays. Total phenol and flavonoid contents of the extracts were determined spectrophotometrically. The extracts had low or no inhibition towards AChE, whereas the leaf aqueous extract of J. foetidissima showed the highest BChE inhibition (93.94 ± 0.01%). The leaf extracts usually exerted higher antioxidant activity. We herein describe the first study on anticholinesterase and antioxidant activity by the methods of ferrous ion-chelating, superoxide radical scavenging, and ferric-reducing antioxidant power (FRAP) assays of the mentioned Juniperus species.

  5. α-Glucosidase and aldose reductase inhibitory activities from the fruiting body of Phellinus merrillii.

    PubMed

    Huang, Guan-Jhong; Hsieh, Wen-Tsong; Chang, Heng-Yuan; Huang, Shyh-Shyun; Lin, Ying-Chih; Kuo, Yueh-Hsiung

    2011-05-25

    The inhibitory activity from the isolated component of the fruiting body Phellinus merrillii (PM) was evaluated against α-glucosidase and lens aldose reductase from Sprague-Dawley male rats and compared to the quercetin as an aldose reductase inhibitor and acarbose as an α-glucosidase inhibitor. The ethanol extracts of PM (EPM) showed the strong α-glucosidase and aldose reductase activities. α-Glucosidase and aldose reductase inhibitors were identified as hispidin (A), hispolon (B), and inotilone (C), which were isolated from EtOAc-soluble fractions of EPM. The above structures were elucidated by their spectra and comparison with the literatures. Among them, hispidin, hispolon, and inotilone exhibited potent against α-glucosidase inhibitor activity with IC(50) values of 297.06 ± 2.06, 12.38 ± 0.13, and 18.62 ± 0.23 μg/mL, respectively, and aldose reductase inhibitor activity with IC(50) values of 48.26 ± 2.48, 9.47 ± 0.52, and 15.37 ± 0.32 μg/mL, respectively. These findings demonstrated that PM may be a good source for lead compounds as alternatives for antidiabetic agents currently used. The importance of finding effective antidiabetic therapeutics led us to further investigate natural compounds.

  6. Optimization of pancreatic lipase inhibitory and antioxidant activities of Ilex paraguariensis by using response surface methodology.

    PubMed

    Oh, Kyung-Eon; Shin, Hyeji; Jeon, Young Ho; Jo, Yang Hee; Lee, Mi Kyeong; Lee, Ken S; Park, Byoungduck; Lee, Ki Yong

    2016-07-01

    Response surface methodology (RSM) using a Box-Behnken design was used to optimize the extraction conditions for obtaining pancreatic lipase inhibitory and antioxidant principles from Ilex paraguariensis leaves. Three influencing factors: extraction time (min), the liquid-solid ratio, and ethanol concentration (%, v/v) were investigated in the ultrasonic extraction process. Optimization of the extraction conditions to obtain a product with minimum PL activity, maximum antioxidant activity, and maximum yield was performed using RSM by focusing on the three target influencing factors. The optimum conditions were established as the ethanol concentration (54.8 %), liquid-solid ratio (35.4), and extraction time (70.0 min). Under these conditions, the 2,2-diphenyl-1-picrylhydrazyl scavenging activity, PL activity, extraction yield were 59.3 ± 3.5, 35.3 ± 3.0, and 34.4 ± 0.4 %, respectively, similar to the theoretical predicted values of 59.7, 35.2, and 34.3 %, respectively.

  7. Green Synthesis and Urease Inhibitory Activity of Spiro-Pyrimidinethiones/Spiro-Pyrimidinones-Barbituric Acid Derivatives

    PubMed Central

    Mohammadi Ziarani, Ghodsi; Asadi, Shima; Faramarzi, Sakineh; Amanlou, Massoud

    2015-01-01

    Sulfonic acid functionalized SBA-15 (SBA-Pr-SO3H) with pore size 6 nm as an efficient heterogeneous nanoporous solid acid catalyst exhibited good catalytic activity in the Biginelli-like reaction in the synthesis of spiroheterobicyclic rings with good yield and good recyclability. Spiro-pyrimidinethiones/spiro-pyrimidinones-barbituric acid derivatives were synthesized in a simple and efficient method using the one-pot three-component reaction of a cyclic 1,3- dicarbonyl compounds (barbituric acid), an aromatic aldehyde and urea or thiourea in the presence of nanoporous silica SBA-Pr-SO3H under solvent free conditions. Urease inhibitory activity of spiro compounds were tested against Jack bean urease using Berthelot alkaline phenol–hypochlorite method. Five of 13 compounds were inhibitor and two of them were enzyme activators. Analysis of the docking results showed that, in most of the spiro molecules, one of the carbonyl groups is coordinated with both nickel atoms, while the other one is involved in the formation of hydrogen bonds with important active-site residues. The effect of inserting two methyl groups on N atoms of barbiturate ring, S substituted, ortho, meta and para substituted compounds were investigated too. PMID:26664377

  8. Inhibitory activity for the interferon-induced protein kinase is associated with the reovirus serotype 1 sigma 3 protein.

    PubMed Central

    Imani, F; Jacobs, B L

    1988-01-01

    In this report we demonstrate that reovirus serotype 1-infected cells contain an inhibitor of the interferon-induced, double-stranded RNA (dsRNA)-dependent protein kinase. We provide evidence that suggests that the virus-encoded sigma 3 protein is likely responsible for this kinase inhibitory activity. We could not detect activation of the dsRNA-dependent protein kinase in extracts prepared from either interferon-treated or untreated reovirus serotype 1-infected mouse L cells under conditions that led to activation of the kinase in extracts prepared from either interferon-treated or untreated, uninfected cells. Extracts from reovirus-infected cells blocked activation of kinase in extracts from interferon-treated cells when the two were mixed prior to assay. The kinase inhibitory activity in extracts of reovirus-infected cells could be overcome by adding approximately 100-fold excess of dsRNA over the amount required to activate kinase in extracts of uninfected cells. Kinase inhibitory activity in extracts of interferon-treated, virus-infected cells could be overcome with somewhat less dsRNA (approximately 10-fold excess). Most of the inhibitory activity in the extracts could be removed by adsorption with immobilized anti-reovirus sigma 3 serum or immobilized dsRNA, suggesting that the dsRNA-binding sigma 3 protein is necessary for kinase inhibitory activity. Purified sigma 3 protein, when added to reaction mixtures containing partially purified kinase, inhibited enzyme activation. Control of activation of this kinase, which can modify eukaryotic protein synthesis initiation factor 2, may be relevant to the sensitivity of reovirus replication to treatment of cells with interferon and to the shutoff of host protein synthesis in reovirus-infected cells. Images PMID:2460857

  9. Characterization of inhibitory mechanism and antifungal activity between group-1 and group-2 phytocystatins from taro (Colocasia esculenta).

    PubMed

    Wang, Ke-Ming; Kumar, Senthil; Cheng, Yi-Sheng; Venkatagiri, Shripathi; Yang, Ai-Hwa; Yeh, Kai-Wun

    2008-10-01

    Tarocystatin from Colocasia esculenta, a group-2 phytocystatin, is a defense protein against phytopathogenic nematodes and fungi. It is composed of a highly conserved N-terminal region, which is homological to group-1 cystatin, and a repetitive peptide at the C-terminus. The purified recombinant proteins of tarocystatin, such as full-length (FL), N-terminus (Nt) and C-terminus (Ct) peptides, were produced and their inhibitory activities against papain as well as their antifungal effects were investigated. Kinetic analysis revealed that FL peptide exhibited mixed type inhibition (K(ia) = 0.098 microM and K(ib) = 0.252 microM) and Nt peptide showed competitive inhibition (K(i) = 0.057 microM), whereas Ct peptide possessed weak papain activation properties. A shift in the inhibitory pattern from competitive inhibition of Nt peptide alone to mixed type inhibition of FL peptide implied that the Ct peptide has an regulatory effect on the function of FL peptide. Based on the inhibitory kinetics of FL (group-2) and Nt (group-1) peptides on papain activity, an inhibitory mechanism of group-2 phytocystatins and a regulatory mechanism of extended Ct peptide have each been proposed. By contrast, the antifungal activity of Nt peptide appeared to be greater than that of FL peptide, and the Ct peptide showed no effect on antifungal activity, indicating that the antifungal effect is not related to proteinase inhibitory activity. The results are valid for most phytocystatins with respect to the inhibitory mechanism against cysteine proteinase.

  10. Angiotensin-I Converting Enzyme (ACE) Inhibitory and Anti-Oxidant Activities of Sea Cucumber (Actinopyga lecanora) Hydrolysates

    PubMed Central

    Ghanbari, Raheleh; Zarei, Mohammad; Ebrahimpour, Afshin; Abdul-Hamid, Azizah; Ismail, Amin; Saari, Nazamid

    2015-01-01

    In recent years, food protein-derived hydrolysates have received considerable attention because of their numerous health benefits. Amongst the hydrolysates, those with anti-hypertensive and anti-oxidative activities are receiving special attention as both activities can play significant roles in preventing cardiovascular diseases. The present study investigated the angiotensin-I converting enzyme (ACE) inhibitory and anti-oxidative activities of Actinopyga lecanora (A. lecanora) hydrolysates, which had been prepared by alcalase, papain, bromelain, flavourzyme, pepsin, and trypsin under their optimum conditions. The alcalase hydrolysate showed the highest ACE inhibitory activity (69.8%) after 8 h of hydrolysis while the highest anti-oxidative activities measured by 2,2-diphenyl 1-1-picrylhydrazyl radical scavenging (DPPH) (56.00%) and ferrous ion-chelating (FIC) (59.00%) methods were exhibited after 24 h and 8 h of hydrolysis, respectively. The ACE-inhibitory and anti-oxidative activities displayed dose-dependent trends, and increased with increasing protein hydrolysate concentrations. Moreover, strong positive correlations between angiotensin-I converting enzyme (ACE) inhibitory and anti-oxidative activities were also observed. This study indicates that A. lecanora hydrolysate can be exploited as a source of functional food owing to its anti-oxidant as well as anti-hypertension functions. PMID:26690117

  11. Triterpenes from Cynomorium songaricium--analysis of HCV protease inhibitory activity, quantification, and content change under the influence of heating.

    PubMed

    Ma, Chao-Mei; Wei, Ying; Wang, Zhi-Gang; Hattori, Masao

    2009-01-01

    Inhibitory activity of the three major triterpenes from the stems of Cynomorium songaricum--ursolic acid, acetyl ursolic acid, and malonyl ursolic acid hemiester--and their related compounds were tested for their inhibitory activity on HCV protease; malonyl ursolic acid hemiester was the most potent. A HPLC-PAD (photo diode array detector)-MS method was established to quantify the contents of each triterpene in C. songaricum. Using this method, the effect heating had on the contents was also investigated. It was found that among the three triterpenes, the content of malonyl ursolic acid hemiester decreased most quickly during the heating process.

  12. A facile chemo-, regio- and stereoselective synthesis and cholinesterase inhibitory activity of spirooxindole-pyrrolizine-piperidine hybrids.

    PubMed

    Kia, Yalda; Osman, Hasnah; Kumar, Raju Suresh; Murugaiyah, Vikneswaran; Basiri, Alireza; Perumal, Subbu; Razak, Ibrahim Abdul

    2013-05-15

    A series of novel hybrid spiro heterocycles comprising pyrrolizine, spiroxindole and piperidine moieties was synthesized chemo-, regio- and stereoselectively in good yields from 1,3-dipolar cycloaddition reaction of a series of 1-acryloyl-3,5-bisarylmethylidenepiperidin-4-ones with azomethine ylides generated in situ from 5-choloroisatin and l-proline in methanol. These cycloadducts displayed significant cholinesterase inhibitory activity. Among the compounds screened, 8g and 8e, showed maximum inhibitory activity against acetylcholinesterase (AChE) and butyrylcholinestrase (BChE) with IC50 values of 3.33 and 3.13μM, respectively.

  13. Inhibitory potency of 4-carbon alkanes and alkenes toward CYP2E1 activity.

    PubMed

    Hartman, Jessica H; Miller, Grover P; Boysen, Gunnar

    2014-04-06

    CYP2E1 has been implicated in the bioactivation of many small molecules into reactive metabolites which form adducts with proteins and DNA, and thus a better understanding of the molecular determinants of its selectivity are critical for accurate toxicological predictions. In this study, we determined the potency of inhibition of human CYP2E1 for various 4-carbon alkanes, alkenes and alcohols. In addition, known CYP2E1 substrates and inhibitors including 4-methylpyrazole, aniline, and dimethylnitrosamine were included to determine their relative potencies. Of the 1,3-butadiene-derived metabolites studied, 3,4-epoxy-1-butene was the strongest inhibitor with an IC50 of 110 μM compared to 1700 μM and 6600 μM for 1,2-butenediol and 1,2:3,4-diepoxybutane, respectively. Compared to known inhibitors, inhibitory potency of 3,4-epoxy-1-butene is between 4-methylpyrazole (IC50 = 1.8 μM) and dimethylnitrosamine (IC50 = 230 μM). All three butadiene metabolites inhibit CYP2E1 activity through a simple competitive mechanism. Among the 4-carbon compounds studied, the presence and location of polar groups seems to influence inhibitory potency. To further examine this notion, the investigation was extended to include structurally and chemically similar analogues, including propylene oxide and various butane alcohols. Those results demonstrated preferential recognition of CYP2E1 toward the type and location of polar and hydrophobic structural elements. Taken together, CYP2E1 metabolism may be modified in vivo by exposure to 4-carbon compounds, such as drugs, and nutritional constituents, a finding that highlights the complexity of exposure to mixtures.

  14. Antagonism of serotonin receptor 1B decreases viability and promotes apoptosis in the COS canine osteosarcoma cell line.

    PubMed

    Viall, A K; Goodall, C P; Stang, B; Marley, K; Chappell, P E; Bracha, S

    2016-06-01

    Serotonin receptor 1B (5HTR1B) traditionally exhibits anti-proliferative activity in osteoblasts. We examined the expression and function of 5HTR1B in the COS canine osteosarcoma cell line and normal canine osteoblasts. Equal levels of 5HTR1B gene and protein expression were found between normal and malignant osteoblasts. Treatment with serotonin enhanced viability of osteosarcoma cells but not normal osteoblasts. Challenge with the 5HTR1B agonist anpirtoline caused no change in cell viability. Rather incubation with the specific receptor antagonist SB224289 caused reduction in osteoblast viability, with this effect more substantial in osteosarcoma cells. Investigation of this inhibitory activity showed 5HTR1B antagonism induces apoptosis in malignant cells. Evaluation of phosphorylated levels of CREB and ERK, transcriptional regulators associated with serotonin receptor signalling in osteoblasts, revealed aberrant 5HTR1B signalling in COS. Our results confirm the presence of 5HTR1B in a canine osteosarcoma cell line and highlight this receptor as a possible novel therapeutic target.

  15. Antifungal and Zearalenone Inhibitory Activity of Pediococcus pentosaceus Isolated from Dairy Products on Fusarium graminearum.

    PubMed

    Sellamani, Muthulakshmi; Kalagatur, Naveen K; Siddaiah, Chandranayaka; Mudili, Venkataramana; Krishna, Kadirvelu; Natarajan, Gopalan; Rao Putcha, Venkata L

    2016-01-01

    The present study was aimed to evaluate the bio-control efficacy of Pediococcus pentosaceus isolated from traditional fermented dairy products originated from India, against the growth and zearalenone (ZEA) production of Fusarium graminearum. The cell-free supernatants of P. pentosaceus (PPCS) were prepared and chemical profiling was carried out by GC-MS and MALDI-TOF analysis. Chemical profiling of PPCS evidenced that, the presence of phenolic antioxidants, which are responsible for the antifungal activity. Another hand, MALDI-TOF analysis also indicated the presence of antimicrobial peptides. To know the antioxidant potential of PPCS, DPPH free radical scavenging assay was carried out and IC50 value was determined as 32 ± 1.89 μL/mL. The antifungal activity of P. pentosaceus was determined by dual culture overlay technique and zone of inhibition was recorded as 47 ± 2.81%, and antifungal activity of PPCS on F. graminearum was determined by micro-well dilution and scanning electron microscopic techniques. The minimum inhibitory concentration (MIC) of PPCS was determined as 66 ± 2.18 μL/mL in the present study. Also a clear variation in the micromorphology of mycelia treated with MIC value of PPCS compared to untreated control was documented. Further, the mechanism of growth inhibition was revealed by ergosterol analysis and determination of reactive oxygen species (ROS) in PPCS treated samples. The effects of PPCS on mycelial biomass and ZEA production were observed in a dose-dependent manner. The mechanism behind the suppression of ZEA production was studied by reverse transcriptase qPCR analysis of ZEA metabolic pathway genes (PKS4 and PKS13), and results showed that there is a dose dependent down-regulation of target gene expression in PPCS treated samples. The results of the present study were collectively proved that, the antifungal and ZEA inhibitory activity of PPCS against F. graminearum and it may find a potential application in agriculture and food

  16. Antifungal and Zearalenone Inhibitory Activity of Pediococcus pentosaceus Isolated from Dairy Products on Fusarium graminearum

    PubMed Central

    Sellamani, Muthulakshmi; Kalagatur, Naveen K.; Siddaiah, Chandranayaka; Mudili, Venkataramana; Krishna, Kadirvelu; Natarajan, Gopalan; Rao Putcha, Venkata L.

    2016-01-01

    The present study was aimed to evaluate the bio-control efficacy of Pediococcus pentosaceus isolated from traditional fermented dairy products originated from India, against the growth and zearalenone (ZEA) production of Fusarium graminearum. The cell-free supernatants of P. pentosaceus (PPCS) were prepared and chemical profiling was carried out by GC-MS and MALDI-TOF analysis. Chemical profiling of PPCS evidenced that, the presence of phenolic antioxidants, which are responsible for the antifungal activity. Another hand, MALDI-TOF analysis also indicated the presence of antimicrobial peptides. To know the antioxidant potential of PPCS, DPPH free radical scavenging assay was carried out and IC50 value was determined as 32 ± 1.89 μL/mL. The antifungal activity of P. pentosaceus was determined by dual culture overlay technique and zone of inhibition was recorded as 47 ± 2.81%, and antifungal activity of PPCS on F. graminearum was determined by micro-well dilution and scanning electron microscopic techniques. The minimum inhibitory concentration (MIC) of PPCS was determined as 66 ± 2.18 μL/mL in the present study. Also a clear variation in the micromorphology of mycelia treated with MIC value of PPCS compared to untreated control was documented. Further, the mechanism of growth inhibition was revealed by ergosterol analysis and determination of reactive oxygen species (ROS) in PPCS treated samples. The effects of PPCS on mycelial biomass and ZEA production were observed in a dose-dependent manner. The mechanism behind the suppression of ZEA production was studied by reverse transcriptase qPCR analysis of ZEA metabolic pathway genes (PKS4 and PKS13), and results showed that there is a dose dependent down-regulation of target gene expression in PPCS treated samples. The results of the present study were collectively proved that, the antifungal and ZEA inhibitory activity of PPCS against F. graminearum and it may find a potential application in agriculture and food

  17. Inhibitory activities of soluble and bound millet seed phenolics on free radicals and reactive oxygen species.

    PubMed

    Chandrasekara, Anoma; Shahidi, Fereidoon

    2011-01-12

    Oxidative stress, caused by reactive oxygen species (ROS), is responsible for modulating several pathological conditions and aging. Soluble and bound phenolic extracts of commonly consumed millets, namely, kodo, finger (Ravi), finger (local), foxtail, proso, little, and pearl, were investigated for their phenolic content and inhibition of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and ROS, namely, hydroxyl radical, peroxyl radical, hydrogen peroxide (H(2)O(2)), hypochlorous acid (HOCl), and singlet oxygen ((1)O(2)). Inhibition of DPPH and hydroxyl radicals was detrmined using electron paramagnetic resonance (EPR) spectroscopy. The peroxyl radical inhibitory activity was measured using the oxygen radical absorbance capacity (ORAC) assay. The scavenging of H(2)O(2), HOCl, and (1)O(2) was evaluated using colorimetric methods. The results were expressed as micromoles of ferulic acid equivalents (FAE) per gram of grain on a dry weight basis. In addition, major hydroxycinnamic acids were identified and quantified using high-performance liquid chromatography (HPLC) and HPLC-mass spectrometry (MS). All millet varieties displayed effective radical and ROS inhibition activities, which generally positively correlated with phenolic contents, except for hydroxyl radical. HPLC analysis revealed the presence of ferulic and p-coumaric acids as major hydroxycinnamic acids in phenolic extract and responsible for the observed effects. Bound extracts of millet contributed 38-99% to ROS scavenging, depending on the variety and the test system employed. Hence, bound phenolics must be included in the evaluation of the antioxidant activity of millets and other cereals.

  18. Bioactive fraction of Saraca indica prevents diabetes induced cataractogenesis: An aldose reductase inhibitory activity

    PubMed Central

    Somani, Gauresh; Sathaye, Sadhana

    2015-01-01

    Background: The present study was designed to investigate the effect of Saraca indica (SI) flowers extract and different bioactive fraction on in vitro aldose reductase (AR) inhibitory activity, high glucose-induced cataract in goat lens and in vivo streptozotocin (STZ; 45 mg/kg, i.p) induced cataract in rats. Methods: Extract of flowers of SI tested for inhibition against rat lens AR. Furthermore, bioactive fraction was investigated against high glucose-induced opacification of the lens in vitro lens culture and STZ induced diabetic cataract in rats. Identification of the bioactive component was attempted through high-performance thin-layer chromatography, high-performance liquid chromatography and liquid chromatography-mass spectrometry analysis. Results: Ethyl acetate fraction of S. indica (EASI) produced maximum inhibition that may be due to high phenolic content. Goat lenses in media containing glucose developed a distinctly opaque ring in 72 h and treatment with EASI fraction lowered lens opacity in 72 h. Prolonged treatment with EASI to STZ-induced diabetic rats inhibited the AR activity and delayed cataract progression in a dose dependent manner. Conclusion: Ethyl acetate fraction of S. indica fraction has potential to inhibit rat lens AR enzyme and prevent cataractogenesis not only in goat lens model (in vitro), but also in STZ induced diabetic rats (in vivo). This study is suggestive of the anticataract activity of EASI fraction that could be attributed to the phytoconstituents present in the same. PMID:25709218

  19. Troglitazone enhances tamoxifen-induced growth inhibitory activity of MCF-7 cells

    SciTech Connect

    Yu, Hong-Nu; Noh, Eun-Mi; Lee, Young-Rae; Roh, Si-Gyun; Song, Eun-Kyung; Han, Myung-Kwan; Lee, Yong-Chul; Shim, In Kyong; Lee, Seung Jin; Jung, Sung Hoo; Kim, Jong-Suk Youn, Hyun Jo

    2008-12-05

    Peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}) ligands have been identified as a potential source of therapy for human cancers. However, PPAR{gamma} ligands have a limitation for breast cancer therapy, since estrogen receptor {alpha} (ER{sub {alpha}}) negatively interferes with PPAR{gamma} signaling in breast cancer cells. Here we show that ER{sub {alpha}} inhihits PPAR{gamma} transactivity and ER{sub {alpha}}-mediated inhibition of PPAR{gamma} transactivity is blocked by tamoxifen, an estrogen receptor blocker. The activation of ER{sub {alpha}} with 17-{beta}-estradiol blocked PPRE transactivity induced by troglitazone, a PPAR{gamma} ligand, indicating the resistance of ER{sub {alpha}}-positive breast cancer cells to troglitazone. Indeed, troglitazone inhibited the growth of ER{sub {alpha}}-negative MDA-MB-231 cells more than that of ER{sub {alpha}}-positive MCF-7 cells. Combination of troglitazone with tamoxifen led to a marked increase in growth inhibition of ER{sub {alpha}}-positive MCF-7 cells compared to either agent alone. Our data indicates that troglitazone enhances the growth inhibitory activity of tamoxifen in ER{sub {alpha}}-positive MCF-7 cells.

  20. Inhibitory effects of pesticides on proteasome activity: implication in Parkinson's disease.

    PubMed

    Wang, Xue-Feng; Li, Sharon; Chou, Arthur P; Bronstein, Jeff M

    2006-07-01

    Epidemiological studies have suggested a correlation of pesticides and Parkinson's disease (PD) while genetic and biochemical studies have implicated the ubiquitin-proteasome system (UPS) in the pathogenesis of PD. In the present studies, we tested the hypothesis that pesticide exposure increases the risk of developing PD by inhibiting the UPS. The effects of pesticides on proteasome activity were examined in SK-N-MC neuroblastoma cells overexpressing a GFP-conjugated proteasome degradation signal, GFP(u). Six out of 25 representative pesticides, including rotenone, ziram, diethyldithiocarbamate, endosulfan, benomyl, and dieldrin, showed inhibitory effects on proteasome activities at low concentrations (10 nM to 10 microM). Unlike proteasome inhibitors, they did not inhibit 20 S proteasome activities in cell lysates. Except for rotenone, the other five pesticides did not induce significantly cellular oxidative stress. The cytotoxic effects of these pesticides were closely correlated with proteasome inhibition. Our results suggest proteasome inhibition as a potential mechanism for the epidemiological association of pesticides and PD.

  1. Fluorination Effects on NOS Inhibitory Activity of Pyrazoles Related to Curcumin.

    PubMed

    Nieto, Carla I; Cabildo, María Pilar; Cornago, María Pilar; Sanz, Dionisia; Claramunt, Rosa M; Torralba, María Carmen; Torres, María Rosario; Elguero, José; García, José A; López, Ana; Acuña-Castroviejo, Darío

    2015-08-28

    A series of new (E)-3(5)-[β-(aryl)-ethenyl]-5(3)-phenyl-1H-pyrazoles bearing fluorine atoms at different positions of the aryl group have been synthesized starting from the corresponding β-diketones. All compounds have been characterized by elemental analysis, DSC as well as NMR (¹H, (13)C, (19)F and (15)N) spectroscopy in solution and in solid state. Three structures have been solved by X-ray diffraction analysis, confirming the tautomeric forms detected by solid state NMR. The in vitro study of their inhibitory potency and selectivity on the activity of nNOS and eNOS (calcium-calmodulin dependent) as well as iNOS (calcium-calmodulin independent) isoenzymes is presented. A qualitative structure-activity analysis allowed the establishment of a correlation between the presence/ absence of different substituents with the inhibition data proving that fluorine groups enhance the biological activity. (E)-3(5)-[β-(3-Fluoro-4-hydroxyphenyl)-ethenyl]-5(3)-phenyl-1H-pyrazole (13), is the best inhibitor of iNOS, being also more selective towards the other two isoforms.

  2. PvD1 defensin, a plant antimicrobial peptide with inhibitory activity against Leishmania amazonensis.

    PubMed

    do Nascimento, Viviane V; Mello, Érica de O; Carvalho, Laís P; de Melo, Edésio J T; Carvalho, André de O; Fernandes, Katia V S; Gomes, Valdirene M

    2015-08-18

    Plant defensins are small cysteine-rich peptides and exhibit antimicrobial activity against a variety of both plant and human pathogens. Despite the broad inhibitory activity that plant defensins exhibit against different micro-organisms, little is known about their activity against protozoa. In a previous study, we isolated a plant defensin named PvD1 from Phaseolus vulgaris (cv. Pérola) seeds, which was seen to be deleterious against different yeast cells and filamentous fungi. It exerted its effects by causing an increase in the endogenous production of ROS (reactive oxygen species) and NO (nitric oxide), plasma membrane permeabilization and the inhibition of medium acidification. In the present study, we investigated whether PvD1 could act against the protozoan Leishmania amazonensis. Our results show that, besides inhibiting the proliferation of L. amazonensis promastigotes, the PvD1 defensin was able to cause cytoplasmic fragmentation, formation of multiple cytoplasmic vacuoles and membrane permeabilization in the cells of this organism. Furthermore, we show, for the first time, that PvD1 defensin was located within the L. amazonensis cells, suggesting the existence of a possible intracellular target.

  3. PvD1 defensin, a plant antimicrobial peptide with inhibitory activity against Leishmania amazonensis

    PubMed Central

    do Nascimento, Viviane V.; Mello, Érica de O.; Carvalho, Laís P.; de Melo, Edésio J.T.; Carvalho, André de O.; Fernandes, Katia V.S.; Gomes, Valdirene M.

    2015-01-01

    Plant defensins are small cysteine-rich peptides and exhibit antimicrobial activity against a variety of both plant and human pathogens. Despite the broad inhibitory activity that plant defensins exhibit against different micro-organisms, little is known about their activity against protozoa. In a previous study, we isolated a plant defensin named PvD1 from Phaseolus vulgaris (cv. Pérola) seeds, which was seen to be deleterious against different yeast cells and filamentous fungi. It exerted its effects by causing an increase in the endogenous production of ROS (reactive oxygen species) and NO (nitric oxide), plasma membrane permeabilization and the inhibition of medium acidification. In the present study, we investigated whether PvD1 could act against the protozoan Leishmania amazonensis. Our results show that, besides inhibiting the proliferation of L. amazonensis promastigotes, the PvD1 defensin was able to cause cytoplasmic fragmentation, formation of multiple cytoplasmic vacuoles and membrane permeabilization in the cells of this organism. Furthermore, we show, for the first time, that PvD1 defensin was located within the L. amazonensis cells, suggesting the existence of a possible intracellular target. PMID:26285803

  4. Synthesis, structures and urease inhibitory activity of cobalt(III) complexes with Schiff bases.

    PubMed

    Jing, Changling; Wang, Cunfang; Yan, Kai; Zhao, Kedong; Sheng, Guihua; Qu, Dan; Niu, Fang; Zhu, Hailiang; You, Zhonglu

    2016-01-15

    A series of new cobalt(III) complexes were prepared. They are [CoL(1)(py)3]·NO3 (1), [CoL(2)(bipy)(N3)]·CH3OH (2), [CoL(3)(HL(3))(N3)]·NO3 (3), and [CoL(4)(MeOH)(N3)] (4), where L(1), L(2), L(3) and L(4) are the deprotonated form of N'-(2-hydroxy-5-methoxybenzylidene)-3-methylbenzohydrazide, N'-(2-hydroxybenzylidene)-3-hydroxylbenzohydrazide, 2-[(2-dimethylaminoethylimino)methyl]-4-methylphenol, and N,N'-bis(5-methylsalicylidene)-o-phenylenediamine, respectively, py is pyridine, and bipy is 2,2'-bipyridine. The complexes were characterized by infrared and UV-Vis spectra, and single crystal X-ray diffraction. The Co atoms in the complexes are in octahedral coordination. Complexes 1 and 4 show effective urease inhibitory activities, with IC50 values of 4.27 and 0.35 μmol L(-1), respectively. Complex 2 has medium activity against urease, with IC50 value of 68.7 μmol L(-1). While complex 3 has no activity against urease. Molecular docking study of the complexes with Helicobacter pylori urease was performed.

  5. Aldo-keto Reductase 1B15 (AKR1B15)

    PubMed Central

    Weber, Susanne; Salabei, Joshua K.; Möller, Gabriele; Kremmer, Elisabeth; Bhatnagar, Aruni; Adamski, Jerzy; Barski, Oleg A.

    2015-01-01

    Aldo-keto reductases (AKRs) comprise a superfamily of proteins involved in the reduction and oxidation of biogenic and xenobiotic carbonyls. In humans, at least 15 AKR superfamily members have been identified so far. One of these is a newly identified gene locus, AKR1B15, which clusters on chromosome 7 with the other human AKR1B subfamily members (i.e. AKR1B1 and AKR1B10). We show that alternative splicing of the AKR1B15 gene transcript gives rise to two protein isoforms with different N termini: AKR1B15.1 is a 316-amino acid protein with 91% amino acid identity to AKR1B10; AKR1B15.2 has a prolonged N terminus and consists of 344 amino acid residues. The two gene products differ in their expression level, subcellular localization, and activity. In contrast with other AKR enzymes, which are mostly cytosolic, AKR1B15.1 co-localizes with the mitochondria. Kinetic studies show that AKR1B15.1 is predominantly a reductive enzyme that catalyzes the reduction of androgens and estrogens with high positional selectivity (17β-hydroxysteroid dehydrogenase activity) as well as 3-keto-acyl-CoA conjugates and exhibits strong cofactor selectivity toward NADP(H). In accordance with its substrate spectrum, the enzyme is expressed at the highest levels in steroid-sensitive tissues, namely placenta, testis, and adipose tissue. Placental and adipose expression could be reproduced in the BeWo and SGBS cell lines, respectively. In contrast, AKR1B15.2 localizes to the cytosol and displays no enzymatic activity with the substrates tested. Collectively, these results demonstrate the existence of a novel catalytically active AKR, which is associated with mitochondria and expressed mainly in steroid-sensitive tissues. PMID:25577493

  6. A structural model of the anaphase promoting complex co-activator (Cdh1) and in silico design of inhibitory compounds

    PubMed Central

    Rahimi, H.; Negahdari, B.; Shokrgozar, M.A.; Madadkar-Sobhani, A.; Mahdian, R.; Foroumadi, A.; Amin, M. Kafshdouzi; Karimipoor, M.

    2015-01-01

    Anaphase promoting complex (APC) controls cell cycle and chromosome segregation. The APC activation occurs after binding of co-activators, cdh1 and cdc20. Cdh1 plays a role in cancer pathogenesis and is known as a potential drug target. The main aim of this study was prediction of 3D structure of cdh1 and designing the inhibitory compounds based on the structural model. First, 3D structure of cdh1 was predicted by means of homology modelling and molecular dynamics tools, MODELLER and Gromacs package, respectively. Then, inhibitory compounds were designed using virtual screening and molecular docking by means AutoDock package. The overall structure of cdh1 is propeller like and each DW40 repeat contains four anti-parallel beta-sheets. Moreover, binding pocket of the inhibitory compounds was determined. The results might be helpful in finding a suitable cdh1 inhibitor for the treatment of cancer. PMID:26430458

  7. Alkaloids from Hippeastrum argentinum and Their Cholinesterase-Inhibitory Activities: An in Vitro and in Silico Study.

    PubMed

    Ortiz, Javier E; Pigni, Natalia B; Andujar, Sebastián A; Roitman, German; Suvire, Fernando D; Enriz, Ricardo D; Tapia, Alejandro; Bastida, Jaume; Feresin, Gabriela E

    2016-05-27

    Two new alkaloids, 4-O-methylnangustine (1) and 7-hydroxyclivonine (2) (montanine and homolycorine types, respectively), and four known alkaloids were isolated from the bulbs of Hippeastrum argentinum, and their cholinesterase-inhibitory activities were evaluated. These compounds were identified using GC-MS, and their structures were defined by physical data analysis. Compound 2 showed weak butyrylcholinesterase (BuChE)-inhibitory activity, with a half-maximal inhibitory concentration (IC50) value of 67.3 ± 0.09 μM. To better understand the experimental results, a molecular modeling study was also performed. The combination of a docking study, molecular dynamics simulations, and quantum theory of atoms in molecules calculations provides new insight into the molecular interactions of compound 2 with BuChE, which were compared to those of galantamine.

  8. A structural model of the anaphase promoting complex co-activator (Cdh1) and in silico design of inhibitory compounds.

    PubMed

    Rahimi, H; Negahdari, B; Shokrgozar, M A; Madadkar-Sobhani, A; Mahdian, R; Foroumadi, A; Amin, M Kafshdouzi; Karimipoor, M

    2015-01-01

    Anaphase promoting complex (APC) controls cell cycle and chromosome segregation. The APC activation occurs after binding of co-activators, cdh1 and cdc20. Cdh1 plays a role in cancer pathogenesis and is known as a potential drug target. The main aim of this study was prediction of 3D structure of cdh1 and designing the inhibitory compounds based on the structural model. First, 3D structure of cdh1 was predicted by means of homology modelling and molecular dynamics tools, MODELLER and Gromacs package, respectively. Then, inhibitory compounds were designed using virtual screening and molecular docking by means AutoDock package. The overall structure of cdh1 is propeller like and each DW40 repeat contains four anti-parallel beta-sheets. Moreover, binding pocket of the inhibitory compounds was determined. The results might be helpful in finding a suitable cdh1 inhibitor for the treatment of cancer.

  9. GABAA receptor activity shapes the formation of inhibitory synapses between developing medium spiny neurons

    PubMed Central

    Arama, Jessica; Abitbol, Karine; Goffin, Darren; Fuchs, Celine; Sihra, Talvinder S.; Thomson, Alex M.; Jovanovic, Jasmina N.

    2015-01-01

    Basal ganglia play an essential role in motor coordination and cognitive functions. The GABAergic medium spiny neurons (MSNs) account for ~95% of all the neurons in this brain region. Central to the normal functioning of MSNs is integration of synaptic activity arriving from the glutamatergic corticostriatal and thalamostriatal afferents, with synaptic inhibition mediated by local interneurons and MSN axon collaterals. In this study we have investigated how the specific types of GABAergic synapses between the MSNs develop over time, and how the activity of GABAA receptors (GABAARs) influences this development. Isolated embryonic (E17) MSNs form a homogenous population in vitro and display spontaneous synaptic activity and functional properties similar to their in vivo counterparts. In dual whole-cell recordings of synaptically connected pairs of MSNs, action potential (AP)-activated synaptic events were detected between 7 and 14 days in vitro (DIV), which coincided with the shift in GABAAR operation from depolarization to hyperpolarization, as detected indirectly by intracellular calcium imaging. In parallel, the predominant subtypes of inhibitory synapses, which innervate dendrites of MSNs and contain GABAAR α1 or α2 subunits, underwent distinct changes in the size of postsynaptic clusters, with α1 becoming smaller and α2 larger over time, while both the percentage and the size of mixed α1/α2-postsynaptic clusters were increased. When activity of GABAARs was under chronic blockade between 4–7 DIV, the structural properties of these synapses remained unchanged. In contrast, chronic inhibition of GABAARs between 7–14 DIV led to reduction in size of α1- and α1/α2-postsynaptic clusters and a concomitant increase in number and size of α2-postsynaptic clusters. Thus, the main subtypes of GABAergic synapses formed by MSNs are regulated by GABAAR activity, but in opposite directions, and thus appear to be driven by different molecular mechanisms. PMID

  10. Fatty acids from the cyanobacterium Microcystis aeruginosa with potent inhibitory effects on fish gill Na+/K+-ATPase activity.

    PubMed

    Bury, N R; Codd, G A; Wendelaaar Bonga, S E; Flik, G

    1998-01-01

    Fatty acids from two strains of the cyanobacterium Microcystis aeruginosa, PCC 7820 (a strain that produces the hepatotoxin microcystin-LR, MC-LR) and CYA 43 (a strain that produces only small quantities of MC-LR), were extracted, partially characterised and tested for their inhibitory effect on the K+-dependent p-nitrophenol phosphatase (pNPPase) activity of tilapia (Oreochromis mossambicus) gill basolateral membrane. Thin-layer chromatography of the lipids from dichloromethane:methanol extracts of M. aeruginosa PCC 7820 and CYA 43, using diethylether:isopropanol:formic acid (100:4.5:2.5) as solvent, yielded five inhibitory products from M. aeruginosa 7820 and six from M. aeruginosa CYA 43. None of these products could be related to MC-LR. The inhibitory behaviour of the products mimics that of a slow, tight-binding inhibitor. The inhibitory activity is removed by incubation of extracts with fatty-acid-free bovine serum albumin (FAF-BSA). However, FAF-BSA only partially reversed the inhibition of K+-dependent pNPPase on fish gills pre-exposed to the extracted products. We conclude that M. aeruginosa strains PCC 7820 and CYA 43 produce fatty acids with potent inhibitory effects on K+-dependent pNPPase. The release of these products following lysis of cyanobacterial blooms may help to explain fish kills through a disturbance of gill functioning.

  11. Inhibitory activity of monoacylglycerols on biofilm formation in Aeromonas hydrophila, Streptococcus mutans, Xanthomonas oryzae, and Yersinia enterocolitica.

    PubMed

    Ham, Youngseok; Kim, Tae-Jong

    2016-01-01

    Biofilm provides a bacterial hiding place by forming a physical barrier and causing physiological changes in cells. The elimination of biofilm is the main goal of hygiene. Chemicals that are inhibitory to biofilm formation have been developed for use in food, personal hygiene products, and medical instruments. Monoacylglycerols are recognized as safe and are used in food as emulsifiers. In this study, the inhibitory activity of monoacylglycerols on bacterial biofilm formation was evaluated systematically with four bacterial strains, Aeromonas hydrophila, Streptococcus mutans, Xanthomonas oryzae, and Yersinia enterocolitica. Monoacylglycerols with two specific lengths of fatty acid moiety, monolaurin and monobehenin, were found to have strong inhibitory activity toward bacterial biofilm formation of S. mutans, X. oryzae, and Y. enterocolitica in a strain specific manner. First, this result suggested that biofilm formation was not inhibited by the detergent characteristics of monoacylglycerols. This suggestion was supported by the inhibitory action of monolaurin on biofilm development but not on the initial cell attachment of Y. enterocolitica in flow cytometric observation. Second, it was also suggested that two distinct response mechanisms to monoacylglycerols existed in bacteria. The existence of these two inhibitory response mechanisms was bacterial strain specific.

  12. Inhibitory activity of 2-deoxy-D-glucose and Candida saitoana against Penicillium digitatum.

    PubMed

    Arras, G; Molinu, M G; Dore, A; Venditti, T; Fois, M; Petretto, A; D'Hallewin, G

    2006-01-01

    The toxic activity of 2-deoxy-D-glucose (2-DG) alone or combined with the biocontrol yeast Candida saitoana strain 8C was evaluated in vitro and in vivo against the postharvest fungal pathogen Penicillium digitatum. In order to assess the effect of the 2-DG on both the biocontrol yeast and fungal pathogen, in vitro tests were performed in Petri dishes containing potato dextrose agar amended with different concentrations (1.5, 3.0, 6.0, 15.0, 30.0, 60.0 mM) of the sugar. The plates were then seeded with 25 microl of a P. digitatum conidial suspension at 10(5) conidia/mL. Result of the assays showed an enhanced inhibitory activity as concentration increased from 15.0 to 60.0 mM. Corroborated by SEM observations showing a reduced growth and the appearance of damaged hyphae were found. At 60 mM of 2-DG, a total inhibition occurred while concentrations from 1.5 to 6.0 mM resulted ineffective. The same tests evidenced no adverse effects on the yeast 8C at all tested concentrations. In vivo assays were carried out on orange fruit cv 'Biondo comune', wounded in 5 sites around the calyx. Each wound (2.5 wide and 3.4 mm depth) was first filled with 25 microl of a 0, 3.0, 6.0, 15.0, 30.0 or 60.0 mM 2-DG-water solution alone or combined with the yeast 8C at 10(8) cells/mL and then a 25 microl of the P. digitatum conidial suspension was added. Each treatment consisted of 3 replicates of 8 fruit (5 wounds/fruit) for a total 120 wounds per treatment. Oranges were maintained at 20 degrees C and high RH (95-98%) for up to 5 days, during which infection was monitored and the inhibitory activity calculated. The tests in vitro evedenced a significant slowing of the pathogen growth with the highest concentrations of 2-DG (15.0, 30.0 and 60.0 mM) with respect to the control; while at lower concentrations (1.5, 3.0, 6.0 mM) the development of the fungi was not significantly reduced. C. saitoana was resistant to all the doses employed to the abovementioned compound. In vivo the yeast

  13. New insights into mechanisms of opioid inhibitory effects on capsaicin-induced TRPV1 activity during painful diabetic neuropathy.

    PubMed

    Shaqura, Mohammed; Khalefa, Baled I; Shakibaei, Mehdi; Zöllner, Christian; Al-Khrasani, Mahmoud; Fürst, Susanna; Schäfer, Michael; Mousa, Shaaban A

    2014-10-01

    Painful diabetic neuropathy is a disease of the peripheral sensory neuron with impaired opioid responsiveness. Since μ-opioid receptor (MOR) activation can inhibit the transient receptor potential vanilloid 1 (TRPV1) activity in peripherally sensory neurons, this study investigated the mechanisms of impaired opioid inhibitory effects on capsaicin-induced TRPV1 activity in painful diabetic neuropathy. Intravenous injection of streptozotocin (STZ, 45 mg/kg) in Wistar rats led to a degeneration of insulin producing pancreatic β-cells, elevated blood glucose, and mechanical hypersensitivity (allodynia). In these animals, local morphine's inhibitory effects on capsaicin-induced nocifensive behavior as well as on capsaicin-induced TRPV1 current in dorsal root ganglion cells were significantly impaired. These changes were associated with a loss in MOR but not TRPV1 in peripheral sensory neurons. Intrathecal delivery of nerve growth factor in diabetic animals normalized sensory neuron MOR and subsequently rescued morphine's inhibitory effects on capsaicin-induced TRPV1 activity in vivo and in vitro. These findings identify a loss in functional MOR on sensory neurons as a contributing factor for the impaired opioid inhibitory effects on capsaicin-induced TRPV1 activity during advanced STZ-induced diabetes. Moreover, they support growing evidence of a distinct regulation of opioid responsiveness during various painful states of disease (e.g. arthritis, cancer, neuropathy) and may give novel therapeutic incentives.

  14. New Alkaloids from Green Vegetable Soybeans and Their Inhibitory Activities on the Proliferation of Concanavalin A-Activated Lymphocytes.

    PubMed

    Wang, Taoyun; Zhao, Jianping; Li, Xiaoran; Xu, Qiongming; Liu, Yanli; Khan, Ikhlas A; Yang, Shilin

    2016-03-02

    A comprehensive phytochemical study of the chemical constituents of green vegetable soybeans resulted in the isolation of two new alkaloids, soyalkaloid A, 1, and isoginsenine, 2, together with four known ones, ginsenine, 3, (1S,3S)-1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid, 4, (1R,3S)-1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid, 5, and indole-3-carboxylic acid, 6. The structures of compounds 1-6 were elucidated on the basis of spectroscopic and chemical analyses. All of the alkaloids were isolated from soybeans for the first time, and compound 1 was a new indole-type alkaloid with a novel carbocyclic skeleton. Their inhibitory activities on the proliferation of concanalin A-activated lymphocytes were assessed by CCK8 assay.

  15. Polychlorinated biphenyls-153 induces metabolic dysfunction through activation of ROS/NF-κB signaling via downregulation of HNF1b.

    PubMed

    Wu, Hao; Yu, Weihua; Meng, Fansen; Mi, Jie; Peng, Jie; Liu, Jiangzheng; Zhang, Xiaodi; Hai, Chunxu; Wang, Xin

    2017-03-07

    Polychlorinated biphenyls (PCB) is a major type of persistent organic pollutants (POPs) that act as endocrine-disrupting chemicals. In the current study, we examined the mechanism underlying the effect of PCB-153 on glucose and lipid metabolism in vivo and in vitro. We found that PCB-153 induced per se and worsened high fat diet (HFD)-resulted increase of blood glucose level and glucose and insulin intolerance. In addition, PCB-153 induced per se and worsened HFD-resulted increase of triglyceride content and adipose mass. Moreover, PCB-153 concentration-dependently inhibited insulin-dependent glucose uptake and lipid accumulation in cultured hepatocytes and adipocytes. PCB-153 induced the expression and nuclear translocation of p65 NF-κB and the expression of its downstream inflammatory markers, and worsened HFD-resulted increase of those inflammatory markers. Inhibition of NF-κB significantly suppressed PCB-153-induced inflammation, lipid accumulation and decrease of glucose uptake. PCB-153 induced oxidative stress and decreased hepatocyte nuclear factor 1b (HNF1b) and glutathione peroxidase 1 (GPx1) expression in vivo and in vitro. Overexpression of HNF1b increased GPx1 expression, decreased ROS level, decreased Srebp1, ACC and FAS expression, and inhibited PCB-153-resulted oxidative stress, NF-κB-mediated inflammation, and final glucose/lipid metabolic disorder. Our results suggest that dysregulation of HNF1b/ROS/NF-κB plays an important role in PCB-153-induced glucose/lipid metabolic disorder.

  16. A 5-HT(1B) receptor agonist inhibits light-induced suppression of pineal melatonin production.

    PubMed

    Rea, M A; Pickard, G E

    2000-03-10

    Serotonin (5-HT) modulates the phase adjusting effects of light on the mammalian circadian clock through the activation of presynaptic 5-HT(1B) receptors located on retinal terminals in the suprachiasmatic nucleus (SCN). The current study was conducted to determine whether activation of 5-HT(1B) receptors also alters photic regulation of nocturnal pineal melatonin production. Systemic administration of the 5-HT(1B) receptor agonist TFMPP attenuated the inhibitory effect of light on pineal melatonin synthesis in a dose-related manner with an apparent ED(50) value of 0.9 mg/kg. The effect of TFMPP on light-induced melatonin suppression was blocked by the 5-HT(1) receptor antagonist, methiothepin, but not by the 5-HT(1A) antagonist, WAY 100,635, consistent with the involvement of 5-HT(1B) receptors. The results are consistent with the interpretation that activation of presynaptic 5-HT(1B) receptors on retinal terminals in the SCN attenuates the effect of light on pineal melatonin production, as well as on circadian phase.

  17. Characterization of DicB by partially masking its potent inhibitory activity of cell division

    PubMed Central

    Yang, Shaoyuan; Pei, Hairun; Zhang, Xiaoying; Wei, Qiang; Zhu, Jia; Zheng, Jimin; Jia, Zongchao

    2016-01-01

    DicB, a protein encoded by the Kim (Qin) prophage in Escherichia coli, inhibits cell division through interaction with MinC. Thus far, characterization of DicB has been severely hampered owing to its potent activity which ceases cell division and leads to cell death. In this work, through fusing maltose-binding protein to the N-terminus of DicB (MBP–DicB), we successfully expressed and purified recombinant DicB that enabled in vitro analysis for the first time. More importantly, taking advantage of the reduced inhibitory activity of MBP–DicB, we were able to study its effects on cell growth and morphology. Inhibition of cell growth by MBP–DicB was systematically evaluated using various DicB constructs, and their corresponding effects on cell morphology were also investigated. Our results revealed that the N-terminal segment of DicB plays an essential functional role, in contrast to its C-terminal tail. The N-terminus of DicB is of critical importance as even the first amino acid (following the initial Met) could not be removed, although it could be mutated. This study provides the first glimpse of the molecular determinants underlying DicB's function. PMID:27466443

  18. Natural Compounds with Proteasome Inhibitory Activity for Cancer Prevention and Treatment

    PubMed Central

    Yang, H; Landis-Piwowar, KR.; Chen, D; Milacic, V; Dou, QP

    2012-01-01

    The proteasome is a multicatalytic protease complex that degrades most endogenous proteins including misfolded or damaged proteins to ensure normal cellular function. The ubiquitin-proteasome degradation pathway plays an essential role in multiuple cellular processes, including cell cycle progression, proliferation, apoptosis and angiogenesis. It has been shown that human cancer cells are more sensitive to proteasome inhibition than normal cells, indicating that a proteasome inhibitor could be used as a novel anticancer drug. Indeed, this idea has been supported by the encouraging results of the clinical trials using the proteasome inhibitor Bortezomib (Velcade, PS-341), a drug approved by the US Food and Drug Administration (FDA). Several natural compounds, including the microbial metabolite lactacystin, green tea polyphenols, and traditional medicinal triterpenes, have been shown to be potent proteasome inhibitors. These findings suggest the potential use of natural proteasome inhibitors as not only chemopreventive and chemotherapeutic agents, but also tumor sensitizers to conventional radiotherapy and chemotherapy. In this review, we will summarize the structure and biological activities of the proteasome and several natural compounds with proteasome inhibitory activity, and will discuss the potential use of these compounds for the prevention and treatment of human cancers. PMID:18537678

  19. In vitro metabolism of pyripyropene A and ACAT inhibitory activity of its metabolites.

    PubMed

    Matsuda, Daisuke; Ohshiro, Taichi; Ohtawa, Masaki; Yamazaki, Hiroyuki; Nagamitsu, Tohru; Tomoda, Hiroshi

    2015-01-01

    Pyripyropene A (PPPA, 1) of fungal origin, a selective inhibitor of acyl-CoA:cholesterol acyltransferase 2 (ACAT2), proved orally active in atherogenic mouse models. The in vitro metabolites of 1 in liver microsomes and plasma of human, rabbit, rat and mouse were analyzed by ultra fast liquid chromatography and liquid chromatography/tandem mass spectrometry. In the liver microsomes from all species, successive hydrolysis occurred at the 1-O-acetyl residue, then at the 11-O-acetyl residue of 1, while the 7-O-acetyl residue was resistant to hydrolysis. Furthermore, dehydrogenation of the newly generated 11-alcoholic hydroxyl residue occurred in human and mouse-liver microsomes, while oxidation of the pyridine ring occurred in human and rabbit liver microsomes. On the other hand, hydrolysis of the 7-O-acetyl residue proceeded only in the mouse plasma. These data indicated that the in vitro metabolic profiles of 1 have subtle differences among animal species. All of the PPPA metabolites observed in liver microsomes and plasma markedly decreased ACAT2 inhibitory activity. These findings will help us to synthesize new PPPA derivatives more effective in in vivo study than 1.

  20. Expression, purification and characterization of active untagged recombinant human leukemia inhibitory factor from E coli.

    PubMed

    Xi, Xueyan; Li, Xiaolu; Wu, Fan; Guan, Xin; Jin, Lan; Guo, Yang; Song, Wei; Du, Boyu

    2017-03-24

    Leukemia inhibitory factor (LIF), a member of IL-6 cytokine family, is considered to be a pleiotropic cytokine and function both in cellular proliferation and differentiation. It had been widely used in biomedical research. The large requirement for this cytokine led to the continuing development of its efficient production methods. Due to its low expression and purification yields when it was produced in eukaryotic cells, recombinant human LIF had always been expressed either as inclusion body or as fusion protein in E coli. But these methods had already been proved to be tedious and low-efficiency. Here we introduced a simple method to express LIF in soluble form in E coli and a subsequent purification method. LIF was induced at low temperature and most of the expressed LIF was observed to be shifted from insoluble to soluble form. Then by using three steps of chromatography, which could be easily scaled-up for industrial purpose, active untagged LIF was purified with similar activity as compared to the commercialized product. The endotoxin level of purified LIF protein in our method was determined to be as low as < 1EU/μg, which was also comparable to those commercial products. Furthermore, as LIF was expressed in a soluble form, there was no need to develop the denaturation and renaturation methods. The yield for LIF protein was evaluated to be approximately 1 mg LIF from 1 g wet weight of E coli in our method.

  1. Calcineurin-NFAT activation and DSCR-1 auto-inhibitory loop: how is homoeostasis regulated?

    PubMed

    Minami, Takashi

    2014-04-01

    Calcineurin-nuclear factor of activated T cells (NFAT) signalling plays a critical role not only in the immune and nervous systems, but also in cardiovascular development and pathological endothelial cell activation during angiogenesis or inflammation. Studies in NFAT-null mice demonstrated that there is high redundancy between functions of the different NFAT family members. Deletion of only one NFAT causes mild phenotypes, but compound deletions of multiple NFAT family members leads to severe abnormalities in multiple organ systems. Genome-wide transcription analysis revealed that many NFAT target genes are related to cell growth and inflammation, whereas the gene most strongly induced by NFAT in endothelial cells is an auto-inhibitory molecule, Down syndrome critical region (DSCR)-1. The NFAT-DSCR-1 signalling axis may vary depending on the cell-type or signal dosage level under the microenvironment. In the endothelium, stable expression of the DSCR-1 short isoform attenuates septic inflammatory shock, tumour growth and tumour metastasis to lung. Moreover, dysfunction of DSCR-1 and the NFAT priming kinase, DYRK1A, prevents NFAT nuclear occupancy. This change in NFAT nuclear localization is responsible for many of the features of Down syndrome. Thus, fine-tuning of the NFAT-DSCR-1 negative feedback loop may enable therapeutic manipulation in vasculopathic diseases.

  2. Inhibitory effect of oestradiol on activation of rat hepatic stellate cells in vivo and in vitro

    PubMed Central

    Shimizu, I; Mizobuchi, Y; Yasuda, M; Shiba, M; Ma, Y; Horie, T; Liu, F; Ito, S

    1999-01-01

    Background—Hepatic stellate cells play a key role in the pathogenesis of hepatic fibrosis. 
Aims—To examine the inhibitory effect of oestradiol on stellate cell activation. 
Methods—In vivo, hepatic fibrosis was induced in rats by dimethylnitrosamine or pig serum. In vitro, rat stellate cells were activated by contact with plastic dishes resulting in their transformation into myofibroblast-like cells. 
Results—In the dimethylnitrosamine and pig serum models, treatment with oestradiol at gestation related doses resulted in a dose dependent suppression of hepatic fibrosis with restored content of hepatic retinyl palmitate, reduced collagen content, lower areas of stellate cells which express α smooth muscle actin (α-SMA) and desmin, and lower procollagen type I and III mRNA levels in the liver. In cultured stellate cells, oestradiol inhibited type I collagen production, α-SMA expression, and cell proliferation. These findings suggest that oestradiol is a potent inhibitor of stellate cell transformation. 
Conclusion—The antifibrogenic role of oestradiol in the liver may contribute to the sex associated differences in the progression from hepatic fibrosis to cirrhosis. 

 Keywords: hepatic stellate cells; hepatic fibrosis; oestradiol; α smooth muscle actin; retinyl palmitate PMID:9862839

  3. Prediction of aromatase inhibitory activity using the efficient linear method (ELM)

    PubMed Central

    Shoombuatong, Watshara; Prachayasittikul, Veda; Prachayasittikul, Virapong; Nantasenamat, Chanin

    2015-01-01

    Aromatase inhibition is an effective treatment strategy for breast cancer. Currently, several in silico methods have been developed for the prediction of aromatase inhibitors (AIs) using artificial neural network (ANN) or support vector machine (SVM). In spite of this, there are ample opportunities for further improvements by developing a simple and interpretable quantitative structure-activity relationship (QSAR) method. Herein, an efficient linear method (ELM) is proposed for constructing a highly predictive QSAR model containing a spontaneous feature importance estimator. Briefly, ELM is a linear-based model with optimal parameters derived from genetic algorithm. Results showed that the simple ELM method displayed robust performance with 10-fold cross-validation MCC values of 0.64 and 0.56 for steroidal and non-steroidal AIs, respectively. Comparative analyses with other machine learning methods (i.e. ANN, SVM and decision tree) were also performed. A thorough analysis of informative molecular descriptors for both steroidal and non-steroidal AIs provided insights into the mechanism of action of compounds. Our findings suggest that the shape and polarizability of compounds may govern the inhibitory activity of both steroidal and non-steroidal types whereas the terminal primary C(sp3) functional group and electronegativity may be required for non-steroidal AIs. The R code of the ELM method is available at http://dx.doi.org/10.6084/m9.figshare.1274030. PMID:26535037

  4. Macrophage Migration Inhibitory Factor (MIF): Biological Activities and Relation with Cancer.

    PubMed

    Nobre, Camila Cristina Guimarães; de Araújo, Josélio Maria Galvão; Fernandes, Thales Allyrio Araújo de Medeiros; Cobucci, Ricardo Ney Oliveira; Lanza, Daniel Carlos Ferreira; Andrade, Vânia Sousa; Fernandes, José Veríssimo

    2016-10-23

    Macrophage migration inhibitory factor (MIF) emerged in recent years as an important inflammation mediator, playing a prominent role in the pathogenesis of various types of malignant neoplasm. MIF is a glycoprotein that presents a wide spectrum of biological activities and exerts a complex interaction with various cellular signaling pathways, causing imbalance of homeostasis. Experimental and clinical studies show that high levels of MIF are found in almost all types of human cancers and are implicated in seemingly all stages of development of the tumors. The production of MIF is triggered through an autocrine signal emitted by tumor cells, and stimulates the production of cytokines, chemokines, and growth as well as angiogenic factors that lead to growth of the tumor, increasing its aggressiveness and metastatic potential. MIF is produced by virtually all types of human body cells, in response to stress caused by different factors, leading to pathological conditions such as chronic inflammation and immunomodulation with suppression of immune surveillance and of immune response against tumors, angiogenesis, and carcinogenesis. In this review, we present recent advances on the biological activity of MIF, the signaling pathways with which it is involved and their role in tumorigenesis.

  5. Cholinesterase inhibitory activity of isoquinoline alkaloids from three Cryptocarya species (Lauraceae).

    PubMed

    Wan Othman, Wan Nurul Nazneem; Liew, Sook Yee; Khaw, Kooi Yeong; Murugaiyah, Vikneswaran; Litaudon, Marc; Awang, Khalijah

    2016-09-15

    Alzheimer's disease is the most common form of dementia among older adults. Acetylcholinesterase and butyrylcholinesterase are two enzymes involved in the breaking down of the neurotransmitter acetylcholine. Inhibitors for these enzymes have potential to prolong the availability of acetylcholine. Hence, the search for such inhibitors especially from natural products is needed in developing potential drugs for Alzheimer's disease. The present study investigates the cholinesterase inhibitory activity of compounds isolated from three Cryptocarya species towards acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Nine alkaloids were isolated; (+)-nornantenine 1, (-)-desmethylsecoantofine 2, (+)-oridine 3, (+)-laurotetanine 4 from the leaves of Cryptocarya densiflora BI., atherosperminine 5, (+)-N-methylisococlaurine 6, (+)-N-methyllaurotetanine 7 from the bark of Cryptocarya infectoria Miq., 2-methoxyatherosperminine 8 and (+)-reticuline 9 from the bark of Cryptocarya griffithiana Wight. In general, most of the alkaloids showed higher inhibition towards BChE as compared to AChE. The phenanthrene type alkaloid; 2-methoxyatherosperminine 8, exhibited the most potent inhibition against BChE with IC50 value of 3.95μM. Analysis of the Lineweaver-Burk (LB) plot of BChE activity over a range of substrate concentration suggested that 2-methoxyatherosperminine 8 exhibited mixed-mode inhibition with an inhibition constant (Ki) of 6.72μM. Molecular docking studies revealed that 2-methoxyatherosperminine 8 docked well at the choline binding site and catalytic triad of hBChE (butyrylcholinesterase from Homo sapiens); hydrogen bonding with Tyr 128 and His 438 residues respectively.

  6. [Constituents relating to anti-oxidative and alpha-glucosidase inhibitory activities in Yacon aerial part extract].

    PubMed

    Terada, Sumio; Ito, Kikuo; Yoshimura, Akira; Noguchi, Naoto; Ishida, Takashi

    2006-08-01

    Hot water extract of the aerial part of Yacon (Smallanthus sonchifolia, Compositae) showed potent free radical-scavenging activity and inhibitory effects on lipid peroxidation in rat brain homogenate. The most potent antioxidative activity focused on the 50% MeOH-eluted fraction on DIAION HP-20 column chromatography. The structure of the major component in the fraction was identified as 2,3,5-tricaffeoylaltraric acid (TCAA) based on spectroscopic evidence. The antioxidative activity of TCAA is superior to that of natural antioxidants such as (+/-)-catechin, alpha-tocopherol, and ellagic acid, and TCAA also showed selective maltase-inhibitory activity (IC(50) 49 microg/ml). As the hypoglycemic activity of Yacon extract was described in a previous report, the present results showing that the aerial part of Yacon has strong antioxidative activity may encourage its potential use as a food supplement to prevent type II diabetes.

  7. Spontaneous pre-stimulus fluctuations in the activity of right fronto-parietal areas influence inhibitory control performance

    PubMed Central

    Chavan, Camille F.; Manuel, Aurelie L.; Mouthon, Michael; Spierer, Lucas

    2013-01-01

    Inhibitory control refers to the ability to suppress planned or ongoing cognitive or motor processes. Electrophysiological indices of inhibitory control failure have been found to manifest even before the presentation of the stimuli triggering the inhibition, suggesting that pre-stimulus brain-states modulate inhibition performance. However, previous electrophysiological investigations on the state-dependency of inhibitory control were based on averaged event-related potentials (ERPs), a method eliminating the variability in the ongoing brain activity not time-locked to the event of interest. These studies thus left unresolved whether spontaneous variations in the brain-state immediately preceding unpredictable inhibition-triggering stimuli also influence inhibitory control performance. To address this question, we applied single-trial EEG topographic analyses on the time interval immediately preceding NoGo stimuli in conditions where the responses to NoGo trials were correctly inhibited [correct rejection (CR)] vs. committed [false alarms (FAs)] during an auditory spatial Go/NoGo task. We found a specific configuration of the EEG voltage field manifesting more frequently before correctly inhibited responses to NoGo stimuli than before FAs. There was no evidence for an EEG topography occurring more frequently before FAs than before CR. The visualization of distributed electrical source estimations of the EEG topography preceding successful response inhibition suggested that it resulted from the activity of a right fronto-parietal brain network. Our results suggest that the fluctuations in the ongoing brain activity immediately preceding stimulus presentation contribute to the behavioral outcomes during an inhibitory control task. Our results further suggest that the state-dependency of sensory-cognitive processing might not only concern perceptual processes, but also high-order, top-down inhibitory control mechanisms. PMID:23761747

  8. Cylindol A, a novel biphenyl ether with 5-lipoxygenase inhibitory activity, and a related compound from Imperata Cylindrica.

    PubMed

    Matsunaga, K; Ikeda, M; Shibuya, M; Ohizumi, Y

    1994-09-01

    Cylindol A [1] and B [2], two novel substances, have been isolated from Imperata cylindrica, and their structures have been elucidated on the basis of their spectral data coupled with chemical evidence and total synthesis. Cylindol A [1] showed 5-lipoxygenase inhibitory activity.

  9. Effects of temperature and medium composition on inhibitory activities of gossypol-related compounds against aflatoxigenic fungi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Effects of temperature and medium composition on growth/aflatoxin inhibitory activities of gossypol, gossypolone and apogossypolone against Aspergillus flavus and A. parasiticus were investigated. The compounds were tested in a Czapek agar medium at 25 C, 31 C and 37 C at a concentration of 100 µg ...

  10. Phytochemical screening and evaluation of in vitro angiotensin-converting enzyme inhibitory activity of Artocarpus altilis leaf.

    PubMed

    Siddesha, Jalahalli M; Angaswamy, Nataraju; Vishwanath, Bannikuppe S

    2011-12-01

    This study investigates the effect of Artocarpus altilis leaf extracts on angiotensin-converting enzyme (ACE) activity. Among the extracts tested, hot ethanol extract exhibited a potent ACE-inhibitory activity with an IC₅₀ value of 54.08 ± 0.29 µg mL⁻¹ followed by cold ethyl acetate extract (IC₅₀ of 85.44 ± 0.85 µg mL⁻¹). In contrast, the hot aqueous extracts showed minimum inhibition with the IC₅₀ value of 765.52 ± 11.97 µg mL⁻¹ at the maximum concentration tested. Further, the phytochemical analysis indicated the varied distribution of tannins, phenolics, glycosides, saponins, steroids, terpenoids and anthraquinones in cold and hot leaf extracts. The correlation between the phytochemical analysis and ACE-inhibitory activity suggests that the high content of glycosidic and phenolic compounds could be involved in exerting ACE-inhibitory activity. In conclusion, this study supports the utilisation of A. altilis leaf in the folk medicine for the better treatment of hypertension. Further studies on isolation and characterisation of specific ACE-inhibitory molecule(s) from ethyl acetate, ethanol and methanol extracts of A. altilis leaf would be highly interesting.

  11. Identification of flavonoids and flavonoid rhamnosides from Rhododendron mucronulatum for. albiflorum and their inhibitory activities against aldose reductase.

    PubMed

    Mok, So-Youn; Lee, Sanghyun

    2013-01-15

    To investigate the therapeutic potential of compounds from natural sources, Rhododendron mucronulatum for. albiflorum flowers (RMAF) and R. mucronulatum flowers (RMF) were tested for inhibition of aldose reductase (AR). The methanol extracts of RMAF and RMF exhibited AR inhibitory activities (IC(50) values 1.07 and 1.29 μg/mL, respectively). The stepwise polarity fractions of RMAF were tested for in vitro inhibition of AR from rat lenses. Of these, the ethyl acetate (EtOAc) fraction exhibited AR inhibitory activity (IC(50) 0.15 μg/mL). A chromatography of the active EtOAc fraction of RMAF led to the isolation of six flavonoids, which were identified by spectroscopic analysis as kaempferol (1), afzelin (2), quercetin (3), quercitrin (4), myricetin (5) and myricitrin (6). Compounds 1-6 exhibited high AR inhibitory activity, with IC(50) values of 0.79, 0.31, 0.48, 0.13, 11.92 and 2.67 μg/mL, respectively. HPLC/UV analysis revealed that the major flavonoids of RMAF and RMF are quercitrin (4) and myricitrin (6). Our results suggest that RMAF containing these six flavonoids could be a useful natural source in the development of a novel AR inhibitory agent against diabetic complications.

  12. Determination of antioxidant capacity and a-amylase inhibitory activity of the essential oils from citronella grass and lemongrass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of the present study was to determine the antioxidant capacity of and in vitro a-amylase inhibitory activity of the essential oils extracted from citronella grass and lemongrass. The chemical composition of the extracted essential oils was determined by GC-MS. The antioxidant capacity ...

  13. Inhibitory effect of putranjivain A on allergic inflammation through suppression of mast cell activation

    SciTech Connect

    Kim, Hui-Hun; Park, Seung-Bin; Lee, Soyoung; Kwon, Taeg Kyu; Shin, Tae-Yong; Park, Pil-Hoon; Lee, Seung-Ho; Kim, Sang-Hyun

    2014-02-01

    A great number of people are suffering from allergic inflammatory disease such as asthma, atopic dermatitis, and sinusitis. Therefore discovery of drugs for the treatment of these diseases is an important subject in human health. Putranjivain A (PJA), member of ellagitannin, is known to possess beneficial effects including anti-cancer and anti-viral activities. The aim of the present study was to elucidate whether PJA modulates the allergic inflammatory reaction and to study its possible mechanisms of action using mast cell-based in vitro and in vivo models. The study was performed in anaphylaxis mouse model and cultured mast cells. PJA inhibited the expression of pro-inflammatory cytokines in immunoglobulin E-stimulated mast cells. PJA reduced this expression by inhibiting nuclear factor (NF)-κB and nuclear factor of activated T cell. The oral administration of PJA reduced systemic and cutaneous anaphylaxis, the release of serum histamine, and the expression of the histamine H{sub 1} receptor. In addition, PJA attenuated the activation of mast cells. PJA inhibited the release of histamine from various types of mast cells by the suppression of intracellular calcium. The inhibitory activity of PJA on the allergic reaction was similar to that of disodium cromoglycate, a known anti-allergic drug. These results suggest that PJA can facilitate the prevention or treatment of allergic inflammatory diseases mediated by mast cells. - Highlights: • PJA reduced the degranulation of mast cells. • PJA inhibited the production of inflammatory cytokines. • The effect of PJA on allergic reaction was comparable to the DSCG. • PJA might be a candidate for the treatment of allergic inflammatory diseases.

  14. The critical role of macrophage migration inhibitory factor in insulin activity.

    PubMed

    Vujicic, Milica; Senerovic, Lidija; Nikolic, Ivana; Saksida, Tamara; Stosic-Grujicic, Stanislava; Stojanovic, Ivana

    2014-09-01

    Macrophage migration inhibitory factor (MIF) is a molecule with plethora of functions such as regulation of immune response, hormone-like, enzymatic and chaperone-like activity. Further, MIF is a major participant in glucose homeostasis since it is an autocrine stimulator of insulin secretion. MIF absence in male knockout mice (MIF-KO) results in development of glucose intolerance, while sensitivity to insulin is fully preserved. Since our results confirm that beta cells from MIF-KO mice express, produce and secrete insulin similarly to beta cells of their wild type (WT) counterparts C57BL/6 mice, we hypothesize that MIF-KO-derived insulin is less active. Indeed, insulin from MIF-KO islets is unable to significantly induce glucose uptake into hepatocytes and to efficiently promote insulin-triggered Akt phosphorylation determined by immunoblot. However, MIF's tautomerase function is not crucial for insulin biosynthesis since MIF inhibitors had no impact on WT insulin activity. Importantly, MIF recognition by anti-MIF antibody (ELISA) after in vitro co-incubation with purified insulin was significantly lower suggesting that insulin covers MIF immunodominant epitope. In addition, MIF binds insulin within beta cell as confirmed by co-immunoprecipitation. WT and MIF-KO-derived insulin exhibited different cleavage patterns suggesting different protein conformations. Finally, pre-incubation of recombinant MIF with insulin promotes formation of insulin hexamers. These results imply that MIF probably enables proper insulin folding what results in insulin full activity. This newly discovered feature of the cytokine MIF could be potentially important for commercially produced insulin, for increasing its stability and/or bioavailability.

  15. Inhibitory and Cytotoxic Activities of Chrysin on Human Breast Adenocarcinoma Cells by Induction of Apoptosis

    PubMed Central

    Samarghandian, Saeed; Azimi-Nezhad, Mohsen; Borji, Abasalt; Hasanzadeh, Malihe; Jabbari, Farahzad; Farkhondeh, Tahereh; Samini, Mohammad

    2016-01-01

    Objectives: Chrysin, an active natural bioflavonoid found in honey and many plant extracts, was first known for its antioxidant and anti-inflammatory effects. The fact that antioxidants have several inhibitory effects against different diseases, such as cancer, led to search for food rich in antioxidants. In this study, we investigated the antiproliferative and apoptotic effects of chrysin on the cultured human breast cancer cells (MCF-7). Materials and Methods: Cells were cultured in Roswell Park Memorial Institute medium and treated with different chrysin concentrations for three consecutive days. Cell viability was quantitated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The percentage of apoptotic cells was determined by flow cytometry using Annexin V-fluorescein isothiocyanate. Results: The MTT assay showed that chrysin had an antiproliferative effect on MCF-7 cells in a dose- and time-dependent manner. The 50% cell growth inhibition values for chrysin against MCF-7 cells were 19.5 and 9.2 μM after 48 and 72 h, respectively. Chrysin induced apoptosis in MCF-7 cells as determined by flow cytometry. Chrysin inhibits the growth of the breast cancer cells by inducing cancer cell apoptosis which may, in part, explain its anticancer activity. Conclusion: This study shows that chrysin could also be considered as a promising chemotherapeutic agent and anticancer activity in treatment of the breast cancer cells in future. SUMMARY Chrysin had an antiproliferative effect on human breast cancer cells (MCF-7) cells in a dose- and time-dependent mannerChrysin induced apoptosis in MCF-7 cells, as determined by flow cytometryChrysin inhibits the growth of the breast cancer cells by inducing cancer cell apoptosisChrysin may have anticancer activity. Abbreviations used: Human breast cancer cells (MCF-7), 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), phosphate-buffered saline (PBS), normal fibroblast mouse (L929). PMID

  16. Zinc ferrite nanoparticles activate IL-1b, NFKB1, CCL21 and NOS2 signaling to induce mitochondrial dependent intrinsic apoptotic pathway in WISH cells.

    PubMed

    Saquib, Quaiser; Al-Khedhairy, Abdulaziz A; Ahmad, Javed; Siddiqui, Maqsood A; Dwivedi, Sourabh; Khan, Shams T; Musarrat, Javed

    2013-12-01

    The present study has demonstrated the translocation of zinc ferrite nanoparticles (ZnFe2O4-NPs) into the cytoplasm of human amnion epithelial (WISH) cells, and the ensuing cytotoxicity and genetic damage. The results suggested that in situ NPs induced oxidative stress, alterations in cellular membrane and DNA strand breaks. The [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) and neutral red uptake (NRU) cytotoxicity assays indicated 64.48 ± 1.6% and 50.73 ± 2.1% reduction in cell viability with 100 μg/ml of ZnFe2O4-NPs exposure. The treated WISH cells exhibited 1.2-fold higher ROS level with 0.9-fold decline in membrane potential (ΔΨm) and 7.4-fold higher DNA damage after 48h of ZnFe2O4-NPs treatment. Real-time PCR (qPCR) analysis of p53, CASP 3 (caspase-3), and bax genes revealed 5.3, 1.6, and 14.9-fold upregulation, and 0.18-fold down regulation of bcl 2 gene vis-à-vis untreated control. RT(2) Profiler™ PCR array data elucidated differential up-regulation of mRNA transcripts of IL-1b, NFKB1, NOS2 and CCL21 genes in the range of 1.5 to 3.7-folds. The flow cytometry based cell cycle analysis suggested the transfer of 15.2 ± 2.1% (p<0.01) population of ZnFe2O4-NPs (100 μg/ml) treated cells into apoptotic phase through intrinsic pathway. Over all, the data revealed the potential of ZnFe2O4-NPs to induce cellular and genetic toxicity in cells of placental origin. Thus, the significant ROS production, reduction in ΔΨm, DNA damage, and activation of genes linked to inflammation, oxidative stress, proliferation, DNA damage and repair could serve as the predictive toxicity and stress markers for ecotoxicological assessment of ZnFe2O4-NPs induced cellular and genetic damage.

  17. FOXM1b, which is present at elevated levels in cancer cells, has a greater transforming potential than FOXM1c

    PubMed Central

    Lam, Andy K. Y.; Ngan, Adaline W. L.; Leung, Man-Hong; Kwok, Davis C. T.; Liu, Vincent W. S.; Chan, David W.; Leung, Wai Y.; Yao, Kwok-Ming

    2013-01-01

    The forkhead box (FOX) M1 transcription factor is required to maintain the proliferation of cancer cells. Two transcriptionally active isoforms of FOXM1, FOXM1b and FOXM1c, have been identified, but their functional differences remain unclear. FOXM1c is distinguished from FOXM1b by an extra exon (exon Va) that contains an ERK1/2 target sequence. Based on a literature search and quantitative PCR analysis, we concluded that FOXM1b is the predominant isoform that is overexpressed in cancers. The further characterization of FOXM1b and FOXM1c revealed two interesting differences. First, FOXM1b exhibited a higher transforming ability than FOXM1c in a soft agar assay. Second, the transactivating activity of FOXM1c, but not that of FOXM1b, was sensitive to activation by RAF/MEK/MAPK signaling. Importantly, the MEK1 activation of FOXM1c was associated with proteolytic processing to generate short forms that might represent constitutively active forms missing the N-terminal inhibitory domain; in contrast, the proteolytic processing of FOXM1b did not require MEK1 activation. Our findings suggest that FOXM1b is functionally more active. These results provide novel insights into the regulation of FOXM1 activity and its role in tumorigenesis. PMID:23386997

  18. Antioxidant, Liver Protective and Angiotensin I-converting Enzyme Inhibitory Activities of Old Laying Hen Hydrolysate in Crab Meat Analogue.

    PubMed

    Jin, Sang Keun; Choi, Jung Seok; Choi, Yeung Joon; Lee, Seung-Jae; Lee, Seung Yun; Hur, Sun Jin

    2016-12-01

    The purpose of this study was to evaluate the antioxidative activities of Crab meat analogue prepared with protein hydrolysates obtained from mechanically deboned chicken meat (MDCM) from spent laying hens. 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) radical-scavenging activity was increased by adding MDCM hydrolysates during storage, and activity correlated with the concentration of DPPH added up to 6 weeks of storage. Hydroxyl radical-scavenging activity was increased in all analogues containing MDCM hydrolysates. At 0 days of storage, angiotensin I-converting enzyme (ACE)-inhibitory activity was increased by the addition of MDCM hydrolysates. Activity did not correlate after 6 weeks of storage, in which ACE-inhibitory activity was increased with low concentrations of MDCM hydrolysates, but no ACE-inhibitory activity was observed at higher concentrations. The liver-protecting activity of crab meat analogue was shown to be around 60% of the positive control; however, it was not significantly different among the samples during storage. These results support the use of MDCM as a source of health-promoting constituents in crab meat analogue.

  19. Antioxidant, Liver Protective and Angiotensin I-converting Enzyme Inhibitory Activities of Old Laying Hen Hydrolysate in Crab Meat Analogue

    PubMed Central

    Jin, Sang Keun; Choi, Jung Seok; Choi, Yeung Joon; Lee, Seung-Jae; Lee, Seung Yun; Hur, Sun Jin

    2016-01-01

    The purpose of this study was to evaluate the antioxidative activities of Crab meat analogue prepared with protein hydrolysates obtained from mechanically deboned chicken meat (MDCM) from spent laying hens. 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) radical-scavenging activity was increased by adding MDCM hydrolysates during storage, and activity correlated with the concentration of DPPH added up to 6 weeks of storage. Hydroxyl radical-scavenging activity was increased in all analogues containing MDCM hydrolysates. At 0 days of storage, angiotensin I-converting enzyme (ACE)-inhibitory activity was increased by the addition of MDCM hydrolysates. Activity did not correlate after 6 weeks of storage, in which ACE-inhibitory activity was increased with low concentrations of MDCM hydrolysates, but no ACE-inhibitory activity was observed at higher concentrations. The liver-protecting activity of crab meat analogue was shown to be around 60% of the positive control; however, it was not significantly different among the samples during storage. These results support the use of MDCM as a source of health-promoting constituents in crab meat analogue. PMID:26954200

  20. Complete unconscious control: using (in)action primes to demonstrate completely unconscious activation of inhibitory control mechanisms.

    PubMed

    Hepler, Justin; Albarracin, Dolores

    2013-09-01

    Although robust evidence indicates that action initiation can occur unconsciously and unintentionally, the literature on action inhibition suggests that inhibition requires both conscious thought and intentionality. In prior research demonstrating automatic inhibition in response to unconsciously processed stimuli, the unconscious stimuli had previously been consciously associated with an inhibitory response within the context of the experiment, and participants had consciously formed a goal to activate inhibition processes when presented with the stimuli (because task instructions required participants to engage in inhibition when the stimuli occurred). Therefore, prior work suggests that some amount of conscious thought and intentionality are required for inhibitory control. In the present research, we recorded event-related potentials during two go/no-go experiments in which participants were subliminally primed with general action/inaction concepts that had never been consciously associated with task-specific responses. We provide the first demonstration that inhibitory control processes can be modulated completely unconsciously and unintentionally.

  1. Rice phytochrome-interacting factor protein OsPIF14 represses OsDREB1B gene expression through an extended N-box and interacts preferentially with the active form of Phytochrome B

    PubMed Central

    Cordeiro, André M.; Figueiredo, Duarte D.; Tepperman, James; Borba, Ana Rita; Lourenço, Tiago; Abreu, Isabel A.; Ouwerkerk, Pieter B.F.; Quail, Peter H.; Oliveira, M. Margarida; Saibo, Nelson J. M.

    2016-01-01

    DREB1/CBF genes, known as major regulators of plant stress responses, are rapidly and transiently induced by low temperatures. Using a Yeast one Hybrid screening, we identified a putative Phytochrome-Interacting bHLH Factor (OsPIF14), as binding to the OsDREB1B promoter. bHLH proteins are able to bind to hexameric E-box (CANNTG) or N-box (CACG(A/C)G) motifs, depending on transcriptional activity. We have shown that OsPIF14 binds to the OsDREB1B promoter through two N-boxes and that the flanking regions of the hexameric core are essential for protein-DNA interaction and stability. We also showed that OsPIF14 down-regulates OsDREB1B gene expression in rice protoplasts, corroborating the OsPIF14 repressor activity observed in the transactivation assays using Arabidopsis protoplasts. In addition, we showed that OsPIF14 is indeed a Phytochrome Interacting Factor, which preferentially binds to the active form (Pfr) of rice phytochrome B. This raises the possibility that OsPIF14 activity might be modulated by light. However, we did not observe any regulation of the OsDREB1B gene expression by light under control conditions. Moreover, OsPIF14 gene expression was shown to be modulated by different treatments, such as drought, salt, cold and ABA. Interestingly, OsPIF14 showed also a specific cold-induced alternative splicing. All together, these results suggest the possibility that OsPIF14 is involved in cross-talk between light and stress signaling through interaction with the OsDREB1B promoter. Although in the absence of stress, OsDREB1B gene expression was not regulated by light, given previous reports, it remains possible that OsPIF14 has a role in light modulation of stress responses. PMID:26732823

  2. Rice phytochrome-interacting factor protein OsPIF14 represses OsDREB1B gene expression through an extended N-box and interacts preferentially with the active form of phytochrome B

    DOE PAGES

    Cordeiro, André M.; Figueiredo, Duarte D.; Tepperman, James; ...

    2015-12-28

    DREB1/CBF genes, known as major regulators of plant stress responses, are rapidly and transiently induced by low temperatures. Using a yeast one-hybrid screening, we identified a putative Phytochrome-Interacting bHLH Factor (OsPIF14), as binding to the OsDREB1B promoter. bHLH proteins are able to bind to hexameric E-box (CANNTG) or N-box (CACG(A/C)G) motifs, depending on transcriptional activity. We have shown that OsPIF14 binds to the OsDREB1B promoter through two N-boxes and that the flanking regions of the hexameric core are essential for protein–DNA interaction and stability. We also showed that OsPIF14 down-regulates OsDREB1B gene expression in rice protoplasts, corroborating the OsPIF14 repressormore » activity observed in the transactivation assays using Arabidopsis protoplasts. Additionally, we showed that OsPIF14 is indeed a phytochrome interacting factor, which preferentially binds to the active form (Pfr) of rice phytochrome B. This raises the possibility that OsPIF14 activity might be modulated by light. However, we did not observe any regulation of the OsDREB1B gene expression by light under control conditions. Moreover, OsPIF14 gene expression was shown to be modulated by different treatments, such as drought, salt, cold and ABA. Interestingly, OsPIF14 showed also a specific cold-induced alternative splicing. Our results suggest the possibility that OsPIF14 is involved in cross-talk between light and stress signaling through interaction with the OsDREB1B promoter. Finally, although in the absence of stress, OsDREB1B gene expression was not regulated by light, given previous reports, it remains possible that OsPIF14 has a role in light modulation of stress responses.« less

  3. Rice phytochrome-interacting factor protein OsPIF14 represses OsDREB1B gene expression through an extended N-box and interacts preferentially with the active form of phytochrome B.

    PubMed

    Cordeiro, André M; Figueiredo, Duarte D; Tepperman, James; Borba, Ana Rita; Lourenço, Tiago; Abreu, Isabel A; Ouwerkerk, Pieter B F; Quail, Peter H; Margarida Oliveira, M; Saibo, Nelson J M

    2016-02-01

    DREB1/CBF genes, known as major regulators of plant stress responses, are rapidly and transiently induced by low temperatures. Using a yeast one-hybrid screening, we identified a putative Phytochrome-Interacting bHLH Factor (OsPIF14), as binding to the OsDREB1B promoter. bHLH proteins are able to bind to hexameric E-box (CANNTG) or N-box (CACG(A/C)G) motifs, depending on transcriptional activity. We have shown that OsPIF14 binds to the OsDREB1B promoter through two N-boxes and that the flanking regions of the hexameric core are essential for protein-DNA interaction and stability. We also showed that OsPIF14 down-regulates OsDREB1B gene expression in rice protoplasts, corroborating the OsPIF14 repressor activity observed in the transactivation assays using Arabidopsis protoplasts. In addition, we showed that OsPIF14 is indeed a phytochrome interacting factor, which preferentially binds to the active form (Pfr) of rice phytochrome B. This raises the possibility that OsPIF14 activity might be modulated by light. However, we did not observe any regulation of the OsDREB1B gene expression by light under control conditions. Moreover, OsPIF14 gene expression was shown to be modulated by different treatments, such as drought, salt, cold and ABA. Interestingly, OsPIF14 showed also a specific cold-induced alternative splicing. All together, these results suggest the possibility that OsPIF14 is involved in cross-talk between light and stress signaling through interaction with the OsDREB1B promoter. Although in the absence of stress, OsDREB1B gene expression was not regulated by light, given previous reports, it remains possible that OsPIF14 has a role in light modulation of stress responses.

  4. Rice phytochrome-interacting factor protein OsPIF14 represses OsDREB1B gene expression through an extended N-box and interacts preferentially with the active form of phytochrome B

    SciTech Connect

    Cordeiro, André M.; Figueiredo, Duarte D.; Tepperman, James; Borba, Ana Rita; Lourenço, Tiago; Abreu, Isabel A.; Ouwerkerk, Pieter B. F.; Quail, Peter H.; Margarida Oliveira, M.; Saibo, Nelson J. M.

    2015-12-28

    DREB1/CBF genes, known as major regulators of plant stress responses, are rapidly and transiently induced by low temperatures. Using a yeast one-hybrid screening, we identified a putative Phytochrome-Interacting bHLH Factor (OsPIF14), as binding to the OsDREB1B promoter. bHLH proteins are able to bind to hexameric E-box (CANNTG) or N-box (CACG(A/C)G) motifs, depending on transcriptional activity. We have shown that OsPIF14 binds to the OsDREB1B promoter through two N-boxes and that the flanking regions of the hexameric core are essential for protein–DNA interaction and stability. We also showed that OsPIF14 down-regulates OsDREB1B gene expression in rice protoplasts, corroborating the OsPIF14 repressor activity observed in the transactivation assays using Arabidopsis protoplasts. Additionally, we showed that OsPIF14 is indeed a phytochrome interacting factor, which preferentially binds to the active form (Pfr) of rice phytochrome B. This raises the possibility that OsPIF14 activity might be modulated by light. However, we did not observe any regulation of the OsDREB1B gene expression by light under control conditions. Moreover, OsPIF14 gene expression was shown to be modulated by different treatments, such as drought, salt, cold and ABA. Interestingly, OsPIF14 showed also a specific cold-induced alternative splicing. Our results suggest the possibility that OsPIF14 is involved in cross-talk between light and stress signaling through interaction with the OsDREB1B promoter. Finally, although in the absence of stress, OsDREB1B gene expression was not regulated by light, given previous reports, it remains possible that OsPIF14 has a role in light modulation of stress responses.

  5. Promotion and computation of inhibitory effect on tyrosinase activity of herbal cream by incorporating indigenous medicinal plants.

    PubMed

    Sahu, Ram Kumar; Roy, Amit; Dwivedi, Jaya; Jha, Arvind Kumar

    2014-01-01

    Herbal cream imparts a chief role in regulating melanin production of skin. The phytoconstituents present in herbal cream impact biological functions of skin and contribute nutrients required for the healthy skin. In the present study, it was envisaged to prepare three batches of herbal cream (HC1, HC2 and HC3) containing ethanol extracts of Emblica officinalis (fruits), Daucus carota (root), Mangifera indica (leaves), Mentha arvensis (leaves), Terminalia arjuna (bark) and Cucumis sativus (fruits) and investigated the prepared cream for inhibitory effect on tyrosinase activity. The herbal cream was formulated by incorporating different ratio of extracts, by using cream base. Each formulation HC1, HC2 and HC3 were segregated into three different formulations (HC1.1, HC1.2, HC1.3, HC2.1, HC2.2, HC2.3, HC3.1, HC3.2 and HC3.3) by incorporating increasing ratio of extract in formulation. The HC3.2 cream produces highest tyrosinase inhibitory effect 65.23 +/- 0.07%, while the HC2.1 exhibited minimum tyrosinase inhibitory effect 26.19 +/- 0.08% compared to other prepared cream. Comparison of the inhibitory activity of the formulations demonstrated that the rank order was HC3.2 > HC3.3 > HC1.2 > HC1.3 > HC3.1 > HC1.1 > HC2.3 > HC2.2 > HC2.1. It has been observed from the result that the formulations of antityrosinase activity were not concentrate dependent. This finding suggests that decrease in antityrosinase activity of HC1 and HC3 might be considering that the incompatibility of the higher extract content with the base of cream. The HC3 produce the maximum inhibitory effects on tyrosinase activity might be due to higher level of polyphenol and flavonoids present in extracts.

  6. The relationship between activating affects, inhibitory affects, and self-compassion in patients with Cluster C personality disorders.

    PubMed

    Schanche, Elisabeth; Stiles, Tore C; McCullough, Leigh; Svartberg, Martin; Nielsen, Geir Høstmark

    2011-09-01

    In the short-term dynamic psychotherapy model termed "Affect Phobia Treatment," it is assumed that increase in patients' defense recognition, decrease in inhibitory affects (e.g., anxiety, shame, guilt), and increase in the experience of activating affects (e.g., sadness, anger, closeness) are related to enhanced self-compassion across therapeutic approaches. The present study aimed to test this assumption on the basis of data from a randomized controlled trial, which compared a 40-session short-term dynamic psychotherapy (N = 25) with 40-session cognitive treatment (N = 25) for outpatients with Cluster C personality disorders. Patients' defense recognition, inhibitory affects, activating affects, and self-compassion were rated with the Achievement of Therapeutic Objectives Scale (McCullough et al., 2003b) in Sessions 6 and 36. Results showed that increase in self-compassion from early to late in therapy significantly predicted pre- to post-decrease in psychiatric symptoms, interpersonal problems, and personality pathology. Decrease in levels of inhibitory affects and increase in levels of activating affects during therapy were significantly associated with higher self-compassion toward the end of treatment. Increased levels of defense recognition did not predict higher self-compassion when changes in inhibitory and activating affects were statistically controlled for. There were no significant interaction effects with type of treatment. These findings support self-compassion as an important goal of psychotherapy and indicate that increase in the experience of activating affects and decrease in inhibitory affects seem to be worthwhile therapeutic targets when working to enhance self-compassion in patients with Cluster C personality disorders.

  7. Prepotent motor activity and inhibitory control demands in different variants of the go/no-go paradigm.

    PubMed

    Wessel, Jan R

    2017-04-08

    Inhibitory control enables humans to stop prepotent motor activity, and is commonly studied using go/no-go or stop-signal tasks. In stop-signal tasks, prepotent motor activity is elicited by delaying stop signals relative to go signals. In go/no-go tasks, however, trials include only one signal-go or no-go. Hence, prepotent motor activity has to be ensured differently-for example, by using rare no-go trials and short trial durations. However, a literature survey shows that ∼40% of studies use equiprobable go/no-go trials and ∼20% use long stimulus-stimulus intervals (> 4 s). It is unclear whether such slow-paced, equiprobable go/no-go tasks elicit prepotent motor activity and probe inhibitory control. We recorded EEG during four go/no-go tasks, varying in no-go probability and trial duration. We quantified prepotent motor activity on successfully inhibited no-go trials using the lateralized readiness potential. Only fast-paced go/no-go tasks with rare no-go trials reliably evoked such activity. We then used a stop-signal task and independent component analysis to isolate an established neural signature of inhibitory control, and investigated this signature's activity across the go/no-go tasks. Across tasks, increased prepotent motor activity on individual no-go trials was accompanied by greater frontocentral P3 amplitudes, confirming it as an index of inhibition. Crucially, this inhibition-related activity showed a 75% reduction in slow-paced, equiprobable go/no-go tasks compared to fast-paced, rare no-go versions. Therefore, since many common go/no-go task configurations do not reliably evoke prepotent motor activity, their inhibitory requirements are greatly reduced. This has major implications for the usage of go/no-go tasks in psychological experiments.

  8. Thyroxine is a potential endogenous antagonist of macrophage migration inhibitory factor (MIF) activity

    PubMed Central

    Al-Abed, Yousef; Metz, Christine N.; Cheng, Kai Fan; Aljabari, Bayan; VanPatten, Sonya; Blau, Steven; Lee, Hans; Ochani, Mahendar; Pavlov, Valentin A.; Coleman, Thomas; Meurice, Nathalie; Tracey, Kevin J.; Miller, Edmund J.

    2011-01-01

    Abnormally low plasma concentrations of thyroid hormones during sepsis often occur in the absence of thyroidal illness; however, the mechanisms involved in the “euthyroid sick syndrome” remain poorly understood. Here, we describe a previously unrecognized interaction between the thyroid hormone thyroxine (T4) and the proinflammatory cytokine macrophage migration inhibitory factor (MIF), together with its clinical relevance in sepsis. We found that in both patients with severe sepsis, and our rodent model, low plasma T4 concentrations were inversely correlated with plasma MIF concentrations. The MIF molecule contains a hydrophobic pocket that is important for many of its proinflammatory activities. Binding of L-T4 (or its hormonally inert isomer D-T4) significantly, and dose-dependently, inhibited the catalytic activity of this pocket. Moreover, administration of exogenous D-T4 significantly improved survival in mice with severe sepsis. To examine the specificity of the MIF∶T4 interaction, wild-type and MIF knockout mice were subjected to the carrageenan-air pouch model of inflammation and then treated with D-T4 or vehicle. D-T4 significantly inhibited leukocyte infiltration in wild-type mice but not in MIF knockout mice, providing evidence that in vivo T4 may influence MIF-mediated inflammatory responses via inhibition of its hydrophobic proinflammatory pocket. These findings demonstrate a new physiological role for T4 as a natural inhibitor of MIF proinflammatory activity. The data may also, in part, explain the low plasma T4 concentrations in critically ill, euthyroid patients and suggest that targeting the imbalance between MIF and T4 may be beneficial in improving outcome from sepsis. PMID:21536912

  9. Broad spectrum antiviral activity for paramyxoviruses is modulated by biophysical properties of fusion inhibitory peptides

    PubMed Central

    Mathieu, Cyrille; Augusto, Marcelo T.; Niewiesk, Stefan; Horvat, Branka; Palermo, Laura M.; Sanna, Giuseppina; Madeddu, Silvia; Huey, Devra; Castanho, Miguel A. R. B.; Porotto, Matteo; Santos, Nuno C.; Moscona, Anne

    2017-01-01

    Human paramyxoviruses include global causes of lower respiratory disease like the parainfluenza viruses, as well as agents of lethal encephalitis like Nipah virus. Infection is initiated by viral glycoprotein-mediated fusion between viral and host cell membranes. Paramyxovirus viral fusion proteins (F) insert into the target cell membrane, and form a transient intermediate that pulls the viral and cell membranes together as two heptad-repeat regions refold to form a six-helix bundle structure that can be specifically targeted by fusion-inhibitory peptides. Antiviral potency can be improved by sequence modification and lipid conjugation, and by adding linkers between the protein and lipid components. We exploit the uniquely broad spectrum antiviral activity of a parainfluenza F-derived peptide sequence that inhibits both parainfluenza and Nipah viruses, to investigate the influence of peptide orientation and intervening linker length on the peptides’ interaction with transitional states of F, solubility, membrane insertion kinetics, and protease sensitivity. We assessed the impact of these features on biodistribution and antiviral efficacy in vitro and in vivo. The engineering approach based on biophysical parameters resulted in a peptide that is a highly effective inhibitor of both paramyxoviruses and a set of criteria to be used for engineering broad spectrum antivirals for emerging paramyxoviruses. PMID:28344321

  10. Harnessing the natural inhibitory domain to control TNFα Converting Enzyme (TACE) activity in vivo

    PubMed Central

    Wong, Eitan; Cohen, Tal; Romi, Erez; Levin, Maxim; Peleg, Yoav; Arad, Uri; Yaron, Avraham; Milla, Marcos E.; Sagi, Irit

    2016-01-01

    Dysregulated activity of A Disintegrin And Metalloproteinase 17 (ADAM17)/TNFα Converting Enzyme (TACE) is associated with inflammatory disorders and cancer progression by releasing regulatory membrane-tethered proteins like TNFα, IL6R and EGFR ligands. Although specific inhibition of TACE is thought to be a viable strategy for inflammatory disorders and for malignancies treatment, the generation of effective inhibitors in vivo has been proven to be challenging. Here we report on the development of a protein inhibitor that leverages the endogenous modulator of TACE. We have generated a stable form of the auto-inhibitory TACE prodomain (TPD), which specifically inhibits in vitro and cell-surface TACE, but not the related ADAM10, and effectively modulated TNFα secretion in cells. TPD significantly attenuated TACE-mediated disease models of sepsis, rheumatoid arthritis (RA) and inflammatory bowel disease (IBD), and reduced TNFα in synovial fluids from RA patients. Our results demonstrate that intervening with endogenous ADAM sheddase modulatory mechanisms holds potential as a general strategy for the design of ADAM inhibitors. PMID:27982031

  11. Anoctamin Calcium-Activated Chloride Channels May Modulate Inhibitory Transmission in the Cerebellar Cortex.

    PubMed

    Zhang, Weiping; Schmelzeisen, Steffen; Parthier, Daniel; Frings, Stephan; Möhrlen, Frank

    2015-01-01

    Calcium-activated chloride channels of the anoctamin (alias TMEM16) protein family fulfill critical functions in epithelial fluid transport, smooth muscle contraction and sensory signal processing. Little is known, however, about their contribution to information processing in the central nervous system. Here we examined the recent finding that a calcium-dependent chloride conductance impacts on GABAergic synaptic inhibition in Purkinje cells of the cerebellum. We asked whether anoctamin channels may underlie this chloride conductance. We identified two anoctamin channel proteins, ANO1 and ANO2, in the cerebellar cortex. ANO1 was expressed in inhibitory interneurons of the molecular layer and the granule cell layer. Both channels were expressed in Purkinje cells but, while ANO1 appeared to be retained in the cell body, ANO2 was targeted to the dendritic tree. Functional studies confirmed that ANO2 was involved in a calcium-dependent mode of ionic plasticity that reduces the efficacy of GABAergic synapses. ANO2 channels attenuated GABAergic transmission by increasing the postsynaptic chloride concentration, hence reducing the driving force for chloride influx. Our data suggest that ANO2 channels are involved in a Ca2+-dependent regulation of synaptic weight in GABAergic inhibition. Thus, in balance with the chloride extrusion mechanism via the co-transporter KCC2, ANO2 appears to regulate ionic plasticity in the cerebellum.

  12. Inhibitory Effects of Glycyrrhetinic Acid on DNA Polymerase and Inflammatory Activities

    PubMed Central

    Ishida, Tsukasa; Mizushina, Yoshiyuki; Yagi, Saori; Irino, Yasuhiro; Nishiumi, Shin; Miki, Ikuya; Kondo, Yasuyuki; Mizuno, Shigeto; Yoshida, Hiromi; Azuma, Takeshi; Yoshida, Masaru

    2012-01-01

    We investigated the inhibitory effect of three glycyrrhizin derivatives, such as Glycyrrhizin (compound 1), dipotassium glycyrrhizate (compound 2) and glycyrrhetinic acid (compound 3), on the activity of mammalian pols. Among these derivatives, compound 3 was the strongest inhibitor of mammalian pols α, β, κ, and λ, which belong to the B, A, Y, and X families of pols, respectively, whereas compounds 1 and 2 showed moderate inhibition. Among the these derivatives tested, compound 3 displayed strongest suppression of the production of tumor necrosis factor-α (TNF-α) induced by lipopolysaccharide (LPS) in a cell-culture system using mouse macrophages RAW264.7 and peritoneal macrophages derived from mice. Moreover, compound 3 was found to inhibit the action of nuclear factor-κB (NF-κB) in engineered human embryonic kidney (HEK) 293 cells. In addition, compound 3 caused greater reduction of 12-O-tetradecanoylphorbol-13-acetate-(TPA-) induced acute inflammation in mouse ear than compounds 1 and 2. In conclusion, this study has identified compound 3, which is the aglycone of compounds 1 and 2, as a promising anti-inflammatory candidate based on mammalian pol inhibition. PMID:21785649

  13. Anoctamin Calcium-Activated Chloride Channels May Modulate Inhibitory Transmission in the Cerebellar Cortex

    PubMed Central

    Parthier, Daniel; Frings, Stephan; Möhrlen, Frank

    2015-01-01

    Calcium-activated chloride channels of the anoctamin (alias TMEM16) protein family fulfill critical functions in epithelial fluid transport, smooth muscle contraction and sensory signal processing. Little is known, however, about their contribution to information processing in the central nervous system. Here we examined the recent finding that a calcium-dependent chloride conductance impacts on GABAergic synaptic inhibition in Purkinje cells of the cerebellum. We asked whether anoctamin channels may underlie this chloride conductance. We identified two anoctamin channel proteins, ANO1 and ANO2, in the cerebellar cortex. ANO1 was expressed in inhibitory interneurons of the molecular layer and the granule cell layer. Both channels were expressed in Purkinje cells but, while ANO1 appeared to be retained in the cell body, ANO2 was targeted to the dendritic tree. Functional studies confirmed that ANO2 was involved in a calcium-dependent mode of ionic plasticity that reduces the efficacy of GABAergic synapses. ANO2 channels attenuated GABAergic transmission by increasing the postsynaptic chloride concentration, hence reducing the driving force for chloride influx. Our data suggest that ANO2 channels are involved in a Ca2+-dependent regulation of synaptic weight in GABAergic inhibition. Thus, in balance with the chloride extrusion mechanism via the co-transporter KCC2, ANO2 appears to regulate ionic plasticity in the cerebellum. PMID:26558388

  14. New constituents with iNOS inhibitory activity from mycelium of Antrodia camphorata.

    PubMed

    Yang, Sien-Sing; Wang, Guei-Jane; Wang, Shiang-Yi; Lin, Yu-Ying; Kuo, Yueh-Hsiung; Lee, Tzong-Huei

    2009-04-01

    In continuing our investigation on the bioactive constituents of mycelium of Antrodia camphorata, antroquinonol B (1), 4-acetyl-antroquinonol B (2), 2,3-(methylenedioxy)-6-methylbenzene-1,4-diol (3) and 2,4-dimethoxy-6-methylbenzene-1,3-diol (4) along with antrodin D (5) were isolated by the guidance of an inducible nitric oxide synthase (iNOS) inhibitory assay and identified on the basis of their spectroscopic analysis. The effect of these compounds on the inhibition of NO production in lipopolysaccharide (LPS)-activated murine macrophages was further evaluated. Compounds 4 and 5 significantly inhibited NO production without any cytotoxicity, the IC(50) values being 32.2 +/- 0.1 and 26.3 +/- 1.6 microg/mL, respectively. Compounds 1 and 2 possessed greater effects on NO inhibition, with IC(50) values of 16.2 +/- 0.8 and 14.7 +/- 2.8 microg/mL, respectively, but displayed cytotoxicity at considerably higher concentrations. Compound 3 showed the lowest percent cell viability of 45.5 +/- 1.8 % as observed in treated cells at a concentration of 16.8 microg/mL.

  15. Inhibitory effect of NAP-22 on the phosphatase activity of synaptojanin-1.

    PubMed

    Takaichi, Rika; Odagaki, Sin-Ichi; Kumanogoh, Haruko; Nakamura, Shun; Morita, Mitsuhiro; Maekawa, Shohei

    2012-01-01

    Endocytosis of the synaptic vesicle is a complicated process, in which many proteins and lipids participate. Phosphatidylinositol 4,5-bisphosphate (PIP(2) ) plays important roles in the process, and the dynamic regulation of this lipid is one of the key events. Synaptojanin is a PIP(2) phosphatase, and dephosphorylation of PIP(2) of the clathrin coated-vesicle results in the uncoating of the vesicle. NAP-22 is one of the major proteins of the neuronal detergent-resistant membrane microdomain and localizes in both the presynaptic plasma membrane and the synaptic vesicle. To elucidate the role of NAP-22 in synaptic function, a screening of the NAP-22 binding proteins through pull-down assay was performed. In addition to CapZ protein, synaptojanin-1 was detected by LC-MS/MS, and Western blotting using antisynaptojanin-1 confirmed this result. The interaction seems to be important in the course of synaptic vesicle endocytosis, because NAP-22 inhibited the phosphatase activity of synaptojanin in a dose-dependent manner. The inhibitory region for 5-phosphatase and the binding region for PIP(2) overlapped in the amino acid sequence of NAP-22, so elucidation of the regulatory mechanism of the PIP(2) binding ability of NAP-22 could be important in understanding the membrane dynamics at the presynaptic region.

  16. Constituents of Asparagus officinalis evaluated for inhibitory activity against cyclooxygenase-2.

    PubMed

    Jang, Dae Sik; Cuendet, Muriel; Fong, Harry H S; Pezzuto, John M; Kinghorn, A Douglas

    2004-04-21

    As part of a project directed toward the discovery of new cancer chemopreventive agents from plants, two new natural products, asparagusic acid anti-S-oxide methyl ester (1) and asparagusic acid syn-S-oxide methyl ester (2), a new acetylenic compound, 2-hydroxyasparenyn [3',4'-trans-2-hydroxy-1-methoxy-4-[5-(4-methoxyphenoxy)-3-penten-1-ynyl]-benzene] (3), as well as eleven known compounds, asparenyn (4), asparenyol (5), (+/-)-1-monopalmitin (6), ferulic acid (7), 1,3-O-di-p-coumaroylglycerol (8), 1-O-feruloyl-3-O-p-coumaroylglycerol (9), blumenol C, (+/-)-epipinoresinol, linoleic acid, 1,3-O-diferuloylglycerol, and 1,2-O-diferuloylglycerol, were isolated from an ethyl acetate-soluble fraction of the methanol extract of the aerial parts of Asparagus officinalis (Asparagus), using a bioassay based on the inhibition of cyclooxygenase-2 to monitor chromatographic fractionation. The structures of compounds 1-3 were elucidated by 1D- and 2D-NMR experiments ((1)H NMR, (13)C NMR, DEPT, COSY, HMQC, HMBC and NOESY). All the isolates were evaluated for their inhibitory effects against both cyclooxygenase-1 and -2, with the most active compound being linoleic acid.

  17. Comparison of HCV NS3 protease and NS5B polymerase inhibitor activity in 1a, 1b and 2a replicons and 2a infectious virus.

    PubMed

    Paulson, Matthew S; Yang, Huiling; Shih, I-hung; Feng, Joy Y; Mabery, Eric M; Robinson, Margaret F; Zhong, Weidong; Delaney, William E

    2009-08-01

    The hepatitis C virus infection system represents an important new tool for drug discovery. In this study, we compared the in vitro antiviral efficacy of several NS3 and NS5B inhibitors in genotype 1a, 1b, and 2a replicons and in the 2a infectious virus system. The nucleoside inhibitor 2'-C-methyl adenosine showed similar efficacy in each system tested. Three non-nucleoside inhibitors had small differences in potency between genotype 1a and 1b. In contrast, there was a dramatic loss of potency for these non-nucleoside inhibitors in the genotype 2a replicon, 2a infectious virus, and 2a NS5B biochemical assays. The protease inhibitor BILN-2061 had similar efficacy against 1a and 1b replicons but was 61-109-fold less potent against the 2a replicon and virus, respectively. VX-950, a covalent protease inhibitor, had similar efficacy (<3-fold changes in EC(50)) regardless of genotype or subtype. Importantly, we observed a significant correlation (p<0.0001) in antiviral potency between the 2a replicon and 2a infectious virus for all classes of compounds tested.

  18. Zinc ferrite nanoparticles activate IL-1b, NFKB1, CCL21 and NOS2 signaling to induce mitochondrial dependent intrinsic apoptotic pathway in WISH cells

    SciTech Connect

    Saquib, Quaiser; Al-Khedhairy, Abdulaziz A.; Ahmad, Javed; Siddiqui, Maqsood A.; Dwivedi, Sourabh; Khan, Shams T.; Musarrat, Javed

    2013-12-01

    The present study has demonstrated the translocation of zinc ferrite nanoparticles (ZnFe{sub 2}O{sub 4}-NPs) into the cytoplasm of human amnion epithelial (WISH) cells, and the ensuing cytotoxicity and genetic damage. The results suggested that in situ NPs induced oxidative stress, alterations in cellular membrane and DNA strand breaks. The [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) and neutral red uptake (NRU) cytotoxicity assays indicated 64.48 ± 1.6% and 50.73 ± 2.1% reduction in cell viability with 100 μg/ml of ZnFe{sub 2}O{sub 4}-NPs exposure. The treated WISH cells exhibited 1.2-fold higher ROS level with 0.9-fold decline in membrane potential (ΔΨm) and 7.4-fold higher DNA damage after 48 h of ZnFe{sub 2}O{sub 4}-NPs treatment. Real-time PCR (qPCR) analysis of p53, CASP 3 (caspase-3), and bax genes revealed 5.3, 1.6, and 14.9-fold upregulation, and 0.18-fold down regulation of bcl 2 gene vis-à-vis untreated control. RT{sup 2} Profiler™ PCR array data elucidated differential up-regulation of mRNA transcripts of IL-1b, NFKB1, NOS2 and CCL21 genes in the range of 1.5 to 3.7-folds. The flow cytometry based cell cycle analysis suggested the transfer of 15.2 ± 2.1% (p < 0.01) population of ZnFe{sub 2}O{sub 4}-NPs (100 μg/ml) treated cells into apoptotic phase through intrinsic pathway. Over all, the data revealed the potential of ZnFe{sub 2}O{sub 4}-NPs to induce cellular and genetic toxicity in cells of placental origin. Thus, the significant ROS production, reduction in ΔΨm, DNA damage, and activation of genes linked to inflammation, oxidative stress, proliferation, DNA damage and repair could serve as the predictive toxicity and stress markers for ecotoxicological assessment of ZnFe{sub 2}O{sub 4}-NPs induced cellular and genetic damage. - Highlights: • First report on the molecular toxicity of ZnFe{sub 2}O{sub 4}-NPs in cells of placental origin • WISH cells treated with ZnFe{sub 2}O{sub 4}-NPs exhibited cytoplasmic

  19. Prediction of Inhibitory Activity of Epidermal Growth Factor Receptor Inhibitors Using Grid Search-Projection Pursuit Regression Method

    PubMed Central

    Du, Hongying; Hu, Zhide; Bazzoli, Andrea; Zhang, Yang

    2011-01-01

    The epidermal growth factor receptor (EGFR) protein tyrosine kinase (PTK) is an important protein target for anti-tumor drug discovery. To identify potential EGFR inhibitors, we conducted a quantitative structure–activity relationship (QSAR) study on the inhibitory activity of a series of quinazoline derivatives against EGFR tyrosine kinase. Two 2D-QSAR models were developed based on the best multi-linear regression (BMLR) and grid-search assisted projection pursuit regression (GS-PPR) methods. The results demonstrate that the inhibitory activity of quinazoline derivatives is strongly correlated with their polarizability, activation energy, mass distribution, connectivity, and branching information. Although the present investigation focused on EGFR, the approach provides a general avenue in the structure-based drug development of different protein receptor inhibitors. PMID:21811593

  20. Memory retrieval of inhibitory avoidance requires histamine H1 receptor activation in the hippocampus

    PubMed Central

    Fabbri, Roberta; Furini, Cristiane Regina Guerino; Passani, Maria Beatrice; Provensi, Gustavo; Baldi, Elisabetta; Bucherelli, Corrado; Izquierdo, Ivan; de Carvalho Myskiw, Jociane; Blandina, Patrizio

    2016-01-01

    Retrieval represents a dynamic process that may require neuromodulatory signaling. Here, we report that the integrity of the brain histaminergic system is necessary for retrieval of inhibitory avoidance (IA) memory, because rats depleted of histamine through lateral ventricle injections of α-fluoromethylhistidine (a-FMHis), a suicide inhibitor of histidine decarboxylase, displayed impaired IA memory when tested 2 d after training. a-FMHis was administered 24 h after training, when IA memory trace was already formed. Infusion of histamine in hippocampal CA1 of brain histamine-depleted rats (hence, amnesic) 10 min before the retention test restored IA memory but was ineffective when given in the basolateral amygdala (BLA) or the ventral medial prefrontal cortex (vmPFC). Intra-CA1 injections of selective H1 and H2 receptor agonists showed that histamine exerted its effect by activating the H1 receptor. Noteworthy, the H1 receptor antagonist pyrilamine disrupted IA memory retrieval in rats, thus strongly supporting an active involvement of endogenous histamine; 90 min after the retention test, c-Fos–positive neurons were significantly fewer in the CA1s of a-FMHis–treated rats that displayed amnesia compared with in the control group. We also found reduced levels of phosphorylated cAMP-responsive element binding protein (pCREB) in the CA1s of a-FMHis–treated animals compared with in controls. Increases in pCREB levels are associated with retrieval of associated memories. Targeting the histaminergic system may modify the retrieval of emotional memory; hence, histaminergic ligands might reduce dysfunctional aversive memories and improve the efficacy of exposure psychotherapies. PMID:27118833

  1. Memory retrieval of inhibitory avoidance requires histamine H1 receptor activation in the hippocampus.

    PubMed

    Fabbri, Roberta; Furini, Cristiane Regina Guerino; Passani, Maria Beatrice; Provensi, Gustavo; Baldi, Elisabetta; Bucherelli, Corrado; Izquierdo, Ivan; de Carvalho Myskiw, Jociane; Blandina, Patrizio

    2016-05-10

    Retrieval represents a dynamic process that may require neuromodulatory signaling. Here, we report that the integrity of the brain histaminergic system is necessary for retrieval of inhibitory avoidance (IA) memory, because rats depleted of histamine through lateral ventricle injections of α-fluoromethylhistidine (a-FMHis), a suicide inhibitor of histidine decarboxylase, displayed impaired IA memory when tested 2 d after training. a-FMHis was administered 24 h after training, when IA memory trace was already formed. Infusion of histamine in hippocampal CA1 of brain histamine-depleted rats (hence, amnesic) 10 min before the retention test restored IA memory but was ineffective when given in the basolateral amygdala (BLA) or the ventral medial prefrontal cortex (vmPFC). Intra-CA1 injections of selective H1 and H2 receptor agonists showed that histamine exerted its effect by activating the H1 receptor. Noteworthy, the H1 receptor antagonist pyrilamine disrupted IA memory retrieval in rats, thus strongly supporting an active involvement of endogenous histamine; 90 min after the retention test, c-Fos-positive neurons were significantly fewer in the CA1s of a-FMHis-treated rats that displayed amnesia compared with in the control group. We also found reduced levels of phosphorylated cAMP-responsive element binding protein (pCREB) in the CA1s of a-FMHis-treated animals compared with in controls. Increases in pCREB levels are associated with retrieval of associated memories. Targeting the histaminergic system may modify the retrieval of emotional memory; hence, histaminergic ligands might reduce dysfunctional aversive memories and improve the efficacy of exposure psychotherapies.

  2. Inhibitory effect of CuSO₄ on α-glucosidase activity in ddY mice.

    PubMed

    Yoshikawa, Yutaka; Hirata, Ryoko; Yasui, Hiroyuki; Hattori, Masakazu; Sakurai, Hiromu

    2010-01-01

    We investigated the effects of divalent alkaline earth and first-row transition metal and zinc ions on α-glucosidase activity in vitro and in vivo. CuSO₄ and ZnSO₄ exhibited a high α-glucosidase inhibitory effect in vitro. The IC(50) values of CuSO₄ were 0.77 ± 0.01 (substrate; maltose) and 0.78 ± 0.01 (substrate; sucrose), and those of ZnSO₄ were 5.49 ± 0.14 (substrate; maltose) and 4.70 ± 0.06 (substrate; sucrose) for yeast α-glucosidase. On the basis of Lineweaver-Burk plots, both CuSO₄ and ZnSO₄ exhibited different modes of inhibition against α-glucosidase. Subsequently, oral glucose and sucrose tolerance tests (OGTT and OSTT) were performed on non-diabetic ddY mice to examine the effect of the metal ions on their blood glucose levels. As a result of single oral administration of CuSO₄ in non-diabetic ddY mice, a significant and potent lowering of the blood glycemic response toward disaccharide, sucrose, ingestion was observed at 45 min after doses of 0.08 and 0.24 mmol kg(-1) body weight. In contrast, the CuSO₄ administration showed no suppression of the elevation of blood glucose levels in mice after a monosaccharide, glucose, administration. These results indicate that CuSO₄ suppresses disaccharide digestion by inhibiting α-glucosidase