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Sample records for butylated hydroxytoluene chemoprevention

  1. Mechanisms of butylated hydroxytoluene chemoprevention of aflatoxicosis-inhibition of aflatoxin B1 metabolism

    International Nuclear Information System (INIS)

    Chemoprevention of toxicoses and/or cancer through the use of nutrients or pharmacologic compounds is the subject of intense study. Among the many compounds examined, food additives such as antioxidants are being considered due to their ability to reduce disease formation by either induction or inhibition of key enzyme systems. One such compound, butylated hydroxytoluene (BHT), has been found to protect against cancer formation caused by exposure to aflatoxin B1 (AFB1) in rodents. We have shown that dietary BHT protects against clinical signs of aflatoxicosis in turkeys, a species that is very susceptible to this mycotoxin. In this study, the effect of BHT on AFB1 metabolism and other cytochrome P450 (CYP)-related enzyme activities in turkey liver microsomes was examined to discern possible mechanisms of BHT-mediated protection against aflatoxicosis. Ethoxyresorufin O-deethylase (EROD), methoxyresorufin O-demethylase (MROD), prototype activities for CYP1A1 and 1A2, respectively, were decreased in the BHT fed (4000 ppm) animals, while oxidation of nifedipine, a prototype activity for CYP3A4, was increased. However, BHT added to microsomal incubations inhibited these CYP activities in a concentration-related manner. Importantly, BHT inhibited conversion of AFB1 to the reactive intermediate AFB1-8,-9-epoxide (AFBO), exhibiting Michaelis-Menton competitive inhibition kinetics (Ki = 0.81 μM). Likewise, microsomes prepared from turkeys fed BHT were significantly less active in AFBO formation compared to those from control birds. When turkeys were fed BHT for up to 40 days, residual BHT was present in liver, breast meat, thigh meat and abdominal fat in concentrations substantially below U.S. FDA guidelines for this antioxidant, but in concentrations greater than the Ki, likely sufficient to inhibit bioactivation of AFB1in vivo. BHT-induced hydropic degeneration in the livers of BHT fed animals was significantly greater in birds that remained on BHT treatment for up to 30

  2. 21 CFR 582.3173 - Butylated hydroxytoluene.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Butylated hydroxytoluene. 582.3173 Section 582.3173 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... § 582.3173 Butylated hydroxytoluene. (a) Product. Butylated hydroxytol- uene. (b) Tolerance....

  3. 21 CFR 182.3173 - Butylated hydroxytoluene.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Butylated hydroxytoluene. 182.3173 Section 182.3173 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives §...

  4. Physicochemical and Spectroscopic Characterization of Biofield Treated Butylated Hydroxytoluene

    OpenAIRE

    Trivedi, Mahendra Kumar

    2015-01-01

    The antioxidants play an important role in the preservation of foods and the management of oxidative stress related diseases by acting on reactive oxygen species and free radicals. However, their use in high temperature processed food and pharmaceuticals are limited due to its low thermal stability. The objective of the study was to use the bioeld energy treatment on butylated hydroxytoluene (BHT) i.e. antioxidant and analyse its impact on the physical, thermal, and spectral properties of BH...

  5. Intake of butylated hydroxyanisole and butylated hydroxytoluene and stomach cancer risk : results from analyses in the Netherlands : cohort study

    NARCIS (Netherlands)

    Botterweck, A.A.M.; Verhagen, H.; Goldbohm, R.A.; Kleinjans, J.; Brandt, P.A. van den

    2000-01-01

    Both carcinogenic and anticarcinogenic properties have been reported for the synthetic antioxidants butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). The association between dietary intake of BHA and BHT and stomach cancer risk was investigated in the Netherlands Cohort Study (NLCS)

  6. Biological fate of butylated hydroxytoluene (BHT) in rats, (3)

    International Nuclear Information System (INIS)

    Butylated hydroxytoluene (BHT) is the chemical widely used not only as the antioxidant for food additives but also as that for containers. 14C-BHT was administered orally to rats, and the subcellular distribution and the change of existence mode in course of time in kidneys were investigated, also the separation and identification of the metabolites in urine were tested. Radioactivity was determined with a liquid scintillation counter. Subcellular fractions were separated by the gel-filtration with Sephadex, and thin layer autoradiography was performed, and radioactive parts were confirmed. The radioactivity in each fraction of the reference group showed the highest 6 hours after the administration, and then it decreased rapidly, but the radioactivity in microsome fraction was the highest at 12 hours after the administration. Only BHT acids was identified out of the metabolites in urine by the thin layer autoradiography, and further investigation will be made about other metabolites. (Kobatake, H.)

  7. Radiostability of butylated hydroxytoluene (BHT): An ESR study

    Science.gov (United States)

    Tuner, H.; Korkmaz, M.

    2007-05-01

    In the present work, the effects of gamma radiation on solid butylated hydroxytoluene (BHT), which is used as an antioxidant, were investigated by ESR spectroscopy. While unirradiated BHT presented no ESR signal, irradiated BHT exhibited an ESR spectrum with many resonance maxima and minima spread over a magnetic field range of 12 mT and centered at about g = 2.0026. Weak satellite and central intense resonance lines, likely, originated from radical species of different stabilities and ratios were observed to be responsible from experimental ESR spectrum of gamma irradiated BHT. Studies based on the variations of the observed line intensities and spectrum area under different experimental conditions were carried out and characteristic features of the radical species responsible from experimental ESR spectrum were determined. Mesomeric radical species of different stabilities providing to BHT a G value of 0.25 were believed to be induced in gamma irradiated BHT. While species responsible from weak satellite lines were unstable, the species causing central intense lines were found to be relatively stable. BHT belongs to a class of compounds with low radiosensitivity ( G = 0.25). This feature of BHT enables the feasibility of radiosterilizations of the products containing BHT as antioxidant without very much loss from its antioxidant benefit. BHT has been shown to provide an opportunity in the estimation of applied radiation dose with a reasonable accuracy if an appropriate mathematical function is used to describe experimental dose-response data.

  8. Radiostability of butylated hydroxytoluene (BHT): An ESR study

    Energy Technology Data Exchange (ETDEWEB)

    Tuner, H. [Department of Physics Engineering, Faculty of Engineering, Hacettepe University, Beytepe, Ankara 06800 (Turkey)]. E-mail: htuner@hacettepe.edu.tr; Korkmaz, M. [Department of Physics Engineering, Faculty of Engineering, Hacettepe University, Beytepe, Ankara 06800 (Turkey)

    2007-05-15

    In the present work, the effects of gamma radiation on solid butylated hydroxytoluene (BHT), which is used as an antioxidant, were investigated by ESR spectroscopy. While unirradiated BHT presented no ESR signal, irradiated BHT exhibited an ESR spectrum with many resonance maxima and minima spread over a magnetic field range of 12 mT and centered at about g = 2.0026. Weak satellite and central intense resonance lines, likely, originated from radical species of different stabilities and ratios were observed to be responsible from experimental ESR spectrum of gamma irradiated BHT. Studies based on the variations of the observed line intensities and spectrum area under different experimental conditions were carried out and characteristic features of the radical species responsible from experimental ESR spectrum were determined. Mesomeric radical species of different stabilities providing to BHT a G value of 0.25 were believed to be induced in gamma irradiated BHT. While species responsible from weak satellite lines were unstable, the species causing central intense lines were found to be relatively stable. BHT belongs to a class of compounds with low radiosensitivity (G = 0.25). This feature of BHT enables the feasibility of radiosterilizations of the products containing BHT as antioxidant without very much loss from its antioxidant benefit. BHT has been shown to provide an opportunity in the estimation of applied radiation dose with a reasonable accuracy if an appropriate mathematical function is used to describe experimental dose-response data.

  9. Effect of Butylated Hydroxytoluene and Butylated Hydroxyanisole on Some Properties of Kidney Fat and Tail Fat During Frozen Storage

    OpenAIRE

    ATAY, Ömür

    1998-01-01

    Some physical and chemical properties of kidney fat (obtained from cattle) and tail fat (obtained from sheep) were determined in this study. Effects of butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA) and BHT+BHA on free fatty acids (FFA) contents, thiobarbituric acid (TBA) values and peroxide number were also examined during frozen storage at -18°C for 9 months. The following values were determined for kidney fat; melting point 47°C, saponification number 193, iodine number...

  10. Instrumental laboratories based on the analysis of butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA)

    Science.gov (United States)

    Wiginton, John Franklin

    A semester-long series of instrumental analysis laboratory activities appropriate for advanced undergraduate and graduate students is described. The activities incorporate five analytical instruments commonly found in post-secondary educational, industrial, and governmental laboratories: a gas chromatograph with a flame ionization detector (GC), a gas chromatograph with a mass specific detector (GC/MS), a high-pressure liquid chromatograph with a UV-Visible detector (HPLC), a high-performance liquid chromatograph with a mass specific detector (LC/MS), and a nuclear magnetic resonance spectrometer (NMR). The series of activities utilizes two analytes, butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA), which are qualitatively and quantitatively analyzed, then structurally characterized. The protocol for each laboratory activity directs students to accomplish a specific analysis in the most efficient manner, but leaves the actual procedure vague enough to give the student a chance to experiment with the instrument. Student success is assessed by two means, having the student submit a detailed journal-style lab report and a class-wide discussion regarding the development of experimental protocols and individual instrument capabilities and limitations.

  11. Voltammetric Determination of Dinonyl Diphenylamine and Butylated Hydroxytoluene in Mineral and Synthetic Oil

    OpenAIRE

    Xiang, Yaling; Qian, Xuzheng; Hua, Meng; Cheng, Bingxue; Chen, Wu; Li, Jian

    2016-01-01

    ABSTRACT A method is reported for the determination of diphenylamine and butylated hydroxytoluene in mineral and synthetic oil. The procedure used differential pulse voltammetry with a glassy carbon electrode. This method was then used for determining these antioxidants in supporting electrolyte consisting of dilute sulfuric acid and sodium dodecyl sulfonate in ethanol. Anodic peaks were obtained for both analytes. Oxidation peaks at 250 mV were observed from a mixture of butylated hydroxytol...

  12. The antioxidant butylated hydroxytoluene prevents early cholesterol-induced microcirculatory changes in rabbits.

    OpenAIRE

    Xiu, R J; Freyschuss, A; X Ying; Berglund, L.; Henriksson, P; Björkhem, I

    1994-01-01

    Microcirculation was studied during 10 wk in untreated rabbits (n = 13) and in rabbits treated with dietary addition of 1% cholesterol (n = 13), 1% cholesterol + 1% of the antioxidant BHT (butylated hydroxytoluene) (n = 11), or 1% BHT (n = 5). The studies were performed by direct intravital microscopic imaging of the left and right conjunctivae with the use of a stereo microscope and a high resolution television camera. Microvessel diameter, erythrocyte flow velocity, and microhemorheologic c...

  13. Neutrophils Are Required for 3-Methylcholanthrene-Initiated, Butylated Hydroxytoluene-Promoted Lung Carcinogenesis

    OpenAIRE

    Vikis, Haris G.; Gelman, Andrew E.; Franklin, Andrew; Stein, Lauren; Rymaszewski, Amy; Zhu, Jihong; Liu, Pengyuan; Tichelaar, Jay W.; Krupnick, Alexander S.; You, Ming

    2011-01-01

    Multiple studies have shown a link between chronic inflammation and lung tumorigenesis. Inbred mouse strains vary in their susceptibility to methylcholanthrene (MCA)-initiated butylated hydroxytoluene (BHT)-promoted lung carcinogenesis. In the present study we investigated whether neutrophils play a role in strain dependent differences in susceptibility to lung tumor promotion. We observed a significant elevation in homeostatic levels of neutrophils in the lungs of tumor-susceptible BALB/cByJ...

  14. The reorientation of t-butyl groups in butylated hydroxytoluene: A deuterium nuclear magnetic resonance spectral and relaxation time study

    Science.gov (United States)

    Polson, James M.; Fyfe, J. D. Dean; Jeffrey, Kenneth R.

    1991-03-01

    Deuterium nuclear magnetic resonance (NMR) spectra and spin-lattice relaxation times were determined in order to study the dynamics of t-butyl groups in butylated hydroxytoluene. The results are consistent with a model first proposed by Beckmann et al. [J. Magn. Reson. 36, 199 (1979)], where there is an inequivalence between the methyl groups within each t-butyl group. While two methyl groups reorient rapidly relative to the whole t-butyl rotation, the remaining methyl group is more restricted in its motion, reorienting at a rate comparable to that of the t-butyl group itself. The spin-lattice relaxation data show two T1 minima, the high temperature minimum (40 °C) corresponding to the combined t-butyl and ``slow'' methyl rotations, and the low temperature minimum corresponding to ``fast'' methyl group rotation. Using an explicitly defined T1 fitting function, the T1 data yield activation energies of 2.2 and 6.0 kcal/mol for the fast methyl and t-butyl rotations, respectively, both in agreement with Beckmann's values obtained from proton T1 experiments. It was also possible to simulate the low temperature deuterium NMR spectra from T=-160 °C to T=-80 °C using the aforementioned dynamical inequivalence between the t-butyl methyl groups. While the fast methyl group rotation was in the motional narrowing region for T>-160 °C, it was possible, from the simulations, to determine the t-butyl exchange rates to within 10%. The jump rates are remarkably close to the values predicted from the T1 results. Above -80 °C, the spectra could not be simulated, implying that a third motion must be present to further alter the high temperature line shapes. The effective axial asymmetry of the T>-20° spectra indicates that the additional motion involves a two site exchange.

  15. Comparative cytotoxicity between butylated hydroxytoluene and its methylcarbamate derivative, terbucarb, on isolated rat hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, Y.; Yaguchi, K.; Suzuki, T. (Tokyo Metropolitan Research Lab. of Public Health (Japan))

    1994-08-01

    Butylated hydroxytoluene (3,5-di-tert-butyl-4-hydroxytoluene; BHT) is widely used as phenolic antioxidant in processed foods, cosmetics and petroleum products. It is well known that high doses of BHT cause acute hepatic damage accompanied by centrilobular necrosis in rats. The hepatic damage is associated with prolonged depletion of glutathione (GSH). Terbucarb (2,6-di-tert-butyl-para-tolyl-methylcarbamate), which has a methylcarbamate group substituted for the phenol group on BHT, was developed as an insecticide and is also presently used as a herbicide on turfgrass. Despite the metabolic and toxicological details known about BHT in vivo and in vitro, no extensive studies have been reported on the metabolism and toxicity of Terbucarb. The isolated hepatocyte system provides a very useful system for the study of the temporal sequences leading to cell damage caused by chemicals and drugs. Here, using freshly isolated rat hepatocytes, we report on the comparative toxic effects of BHT and its methylcarbamate derivative, Terbucarb. 17 refs., 2 figs., 2 tabs.

  16. Enhanced tumor development by butylated hydroxytoluene (BHT) in liver, lung and gastrointestinal tract

    Energy Technology Data Exchange (ETDEWEB)

    Witschi, H.P.

    1986-04-03

    Continuous feeding of 0.5% or 0.05% of butylated hydroxytoluene (BHT) enhances the development of spontaneously occurring liver tumors in C3H mice, but not in BALB/c mice. In mouse lung, the tumor-enhancing effects of BHT vary with the carcinogen used and in the gastrointestinal tract of mice and rats BHT enhances development of dimethylhydrazine-induced tumors but is without effect on tumors produced by methylnitrosourea. Strain differences, effect upon various carcinogens, paradoxical dose-responses and mechanisms of action remain major questions in the toxicology of BHT. 14 refs., 2 tabs.

  17. Pengaruh Penambahan Antioksidan BHT (Butylated Hydroxytoluene) Terhadap Bilangan Peroksida RBDPO (Refined Bleached Deodorized Palm Oil)

    OpenAIRE

    Milana, Muharinnisa

    2014-01-01

    The quality standard is the most important thing to determine a good quality cooking oil. One of the factors that determine the quality standard of cooking oil is peroxide value. Peroxide value is the index of the amount of fat or oil that has undergone oxidation. The amount of peroxide in the cooking oil can cause rancidity. The addition of antioxidants Butylated hydroxytoluene(BHT) with iodometric titrimetric method can reduce the number of peroxide so as to improve the quality of the cooki...

  18. Antioxidant effect of mango seed extract and butylated hydroxytoluene in bologna-type mortadella during storage

    OpenAIRE

    Ana Lúcia Fernandes Pereira; Tatiana Fontoura Vidal; Marcílio Costa Teixeira; Patrícia Freitas de Oliveira; Roberto Cláudio Fernandes Franco Pompeu; Marieta Maria Martins Vieira; Jorge Fernando Fuentes Zapata

    2011-01-01

    The effects of mango seed extract (MSE) and butylated hydroxytoluene (BHT) on pH, lipid oxidation, and color of Bologna-type mortadella during refrigerated storage for 21 days were studied. Bologna-type mortadella samples were formulated to contain 0.1% MSE, 0.2% MSE, or 0.01% BHT. After 14 days of storage, the products containing MSE 0.1 or 0.2% had higher pH values than those containing BHT 0.01%. Lipid oxidation values increased with storage time but were not affected by the type of antiox...

  19. Effect of butylated hydroxytoluene, curcumin, propyl gallate and thiabendazole on cytochrome P450 forms in cultured human hepatocytes

    NARCIS (Netherlands)

    Price, R.J.; Scott, M.P.; Giddings, A.M.; Walters, D.G.; Stierum, R.H.; Meredith, C.; Lake, B.G.

    2008-01-01

    1. The objective of this study was to investigate the effects of four food chemicals, namely butylated hydroxytoluene (BHT), curcumin (CC), propyl gallate (PG) and thiabendazole (TB), on cytochrome P450 (CYP) forms in cultured human hepatocytes. 2. Treatment of human hepatocytes for 72 h with 2-200

  20. Modification of radiation-induced genetic damage in Drosophila melanogaster male germ cells by butylated hydroxytoluene

    International Nuclear Information System (INIS)

    The effects of butylated hydroxytoluene (BHT) on genetic damage induced by ionizing radiation were studied in post-meiotic male cells of Drosophila melanogaster. Prior to submitting Samarkand males to 2 krad of X-rays, BHT was administered (a) with the food (0.2 per cent final concentration) from emergence of the imago for 7 days or (b) by intra-abdominal injection (0.05 per cent) to 7-day-old adults. Dominant lethality (embryonic and total), II-III translocations and sex-linked recessive lethals were recorded. The only effect of BHT observed was a decrease in the frequency of recessive lethals induced, detected in early spermatids. Since oxygen plays an important role in the high radiosensitivity of these cells, it is suggested that the sparing action of BHT was due to its antioxidative and radical scavenging properties. (U.K.)

  1. Tests for mutagenic effects of ammoniated glycyrrhizin, butylated hydroxytoluene, and gum arabic in roden germ cells

    Energy Technology Data Exchange (ETDEWEB)

    Sheu, C.W.; Cain, K.T.; Rushbrook, C.J.; Jorgenson, T.A.; Generoso, W.M.

    1986-01-01

    Ammoniated glycyrrhizin, butylated hydroxytoluene, and gum Arabic are generally recognized as safe (GRAS) substances that are used primarily as additives in foods. These substances were incorporated into rodent diets and fed to male rats and mice for 10 and 8 wk, respectively. The treated male mice and rats were then tested for dominant lethal effects. The mice were also tested for induced heritable translocation. Results of the rat studies indicated a statistically significant dominant lethal effect of each of the compounds tested; however, the biological significance of this response is not known. Results of the mouse dominant lethal and heritable translocation studies, on the other hand, indicated no adverse effects of the compounds tested.

  2. Levels of synthetic antioxidants (ethoxyquin, butylated hydroxytoluene and butylated hydroxyanisole) in fish feed and commercially farmed fish.

    Science.gov (United States)

    Lundebye, A-K; Hove, H; Måge, A; Bohne, V J B; Hamre, K

    2010-12-01

    Several synthetic antioxidants are authorized for use as feed additives in the European Union. Ethoxyquin (EQ) and butylated hydroxytoluene (BHT) are generally added to fish meal and fish oil, respectively, to limit lipid oxidation. The study was conducted to examine the concentrations of EQ, BHT and butylated hydroxyanisole (BHA) in several commercially important species of farmed fish, namely Atlantic salmon, halibut and cod and rainbow trout, as well as concentrations in fish feed. The highest levels of BHT, EQ and BHA were found in farmed Atlantic salmon fillets, and were 7.60, 0.17 and 0.07 mg kg(-1), respectively. The lowest concentrations of the synthetic antioxidants found were in cod. The concentration of the oxidation product ethoxyquin dimer (EQDM) was more than ten-fold higher than the concentration of parent EQ in Atlantic salmon halibut and rainbow trout, whereas this dimer was not detected in cod fillets. The theoretical consumer exposure to the synthetic antioxidants EQ, BHA and BHT from the consumption of farmed fish was calculated. The contribution of EQ from a single portion (300 g) of skinned fillets of the different species of farmed fish would contribute at most 15% of the acceptable daily intake (ADI) for a 60 kg adult. The consumption of farmed fish would not contribute measurably to the intake of BHA; however, a 300 g portion of farmed Atlantic salmon would contribute up to 75% of the ADI for BHT. PMID:20931417

  3. Effect of various concentrations of butylated hydroxyanisole and butylated hydroxytoluene on freezing capacity of Turkman stallion sperm.

    Science.gov (United States)

    Seifi-Jamadi, Afshin; Kohram, Hamid; Zareh-Shahne, Ahmad; Dehghanizadeh, Parvaneh; Ahmad, Ejaz

    2016-07-01

    The present study aimed to determine the effect of different concentrations of butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) on post-thaw stallion sperm quality. The ejaculates collected from four healthy mature Turkmen stallions were pooled and divided into eight aliquots. The samples were diluted with extenders containing different concentrations (0.5, 1 or 2mM/mL) of BHA or BHT. The positive control (PC) samples were diluted with extender containing 0.5% ethanol (v/v) whereas; the negative control (NC) samples were diluted with basic extender only. Semen samples were frozen according to a standard protocol. After thawing of samples, sperm motility, viability, membrane integrity, total abnormality and lipid peroxidation were assessed. The greatest (P<0.05) values for total sperm motility, viability and plasma membrane functionality and least values for malonedialdehyde (MDA) concentration were observed in samples supplemented either with 1mM BHT or 2mM BHA. However, the progressive motility was greater (P<0.05) only in samples treated with 2mM BHA. In conclusion, the use of 1mM BHT or 2mM BHA in extender improves the freezing capacity of stallion sperm by reducing oxidative stress during freeze-thaw process. PMID:27112036

  4. Hydrolysis of the quinone methide of butylated hydroxytoluene in aqueous solutions.

    Science.gov (United States)

    Willcockson, Maren Gulsrud; Toteva, Maria M; Stella, Valentino J

    2013-10-01

    Butylated hydroxytoluene or BHT is an antioxidant commonly used in pharmaceutical formulations. BHT upon oxidation forms a quinone methide (QM). QM is a highly reactive electrophilic species that can undergo nucleophilic addition. Here, the kinetic reactivity of QM with water at various apparent pH values in a 50% (v/v) water-acetonitrile solution at constant ionic strength of I = 0.5 (NaCl)4 , was studied. The hydrolysis of QM in the presence of added acid, base, sodium chloride, and phosphate buffer resulted in the formation of only one product--the corresponding 3,5-di-tert-butyl-4-hydroxybenzyl alcohol (BA). The rate of BA formation was catalyzed by the addition of acid and base, but not chloride and phosphate species. Nucleophilic excipients, used in the pharmaceutical formulation, or nucleophilic groups on active pharmaceutical ingredient molecule may form adducts with QM, the immediate oxidative product of BHT degradation, thus having implications for drug product impurity profiles. Because of these considerations, BHT should be used with caution in formulations containing drugs or excipients capable of acting as nucleophiles.

  5. Hydrolysis of the quinone methide of butylated hydroxytoluene in aqueous solutions.

    Science.gov (United States)

    Willcockson, Maren Gulsrud; Toteva, Maria M; Stella, Valentino J

    2013-10-01

    Butylated hydroxytoluene or BHT is an antioxidant commonly used in pharmaceutical formulations. BHT upon oxidation forms a quinone methide (QM). QM is a highly reactive electrophilic species that can undergo nucleophilic addition. Here, the kinetic reactivity of QM with water at various apparent pH values in a 50% (v/v) water-acetonitrile solution at constant ionic strength of I = 0.5 (NaCl)4 , was studied. The hydrolysis of QM in the presence of added acid, base, sodium chloride, and phosphate buffer resulted in the formation of only one product--the corresponding 3,5-di-tert-butyl-4-hydroxybenzyl alcohol (BA). The rate of BA formation was catalyzed by the addition of acid and base, but not chloride and phosphate species. Nucleophilic excipients, used in the pharmaceutical formulation, or nucleophilic groups on active pharmaceutical ingredient molecule may form adducts with QM, the immediate oxidative product of BHT degradation, thus having implications for drug product impurity profiles. Because of these considerations, BHT should be used with caution in formulations containing drugs or excipients capable of acting as nucleophiles. PMID:23873381

  6. Hepatotoxicity induced by the anti-oxidant food additive, butylated hydroxytoluene BHT, in rats. An electron microscopical study

    OpenAIRE

    Safer, A.M.; Al-Nughamish, A.J.

    1999-01-01

    The anti-oxidant food additive, butylated hydroxytoluene (BHT), was fed to Sprague-Dawley rats at three concentrations: 0.2%, 0.4% and 0.8% for periods of 6, 12, 18 and 24 weeks, and the results were compared with corresponging groups treated with a potent carcinogen, 7,12-dimethylbenz[a]anthracene (DMBA) groups, with olive oil, and with untreated control groups. BHT resulted in a significant increase in liver weight. The liver cells presented gradual vacuo...

  7. The effect of 3-methylcholanthrene and butylated hydroxytoluene on glycogen levels of liver, muscle, testis, and tumor tissues of rats

    OpenAIRE

    POLAT, Fikriye; DERE, Egemen; GÜL, Eylem; YELKUVAN, İzzet; ÖZDEMİR, Öztürk; BİNGÖL, Günsel

    2013-01-01

    This study examined the effects of separate and combined applications of 3-methylcholanthrene, a polycyclic aromatic hydrocarbon and potent carcinogenic agent, and butylated hydroxytoluene, the antioxidant food additive, on the glycogen levels of liver, muscle, testis, and tumor tissues in rats. Adult male Wistar albino rats weighing 100-110 g at 8 weeks of age were used in this study. This study consisted of a control group (n = 9) and 3 different experiment groups in which rats were chronic...

  8. Analysis of Ki-ras Exon 2 Gene Mutations in 3-Methylcholanthrene and Butylated Hydroxytoluene-Induced Rat Lung Tissues

    OpenAIRE

    POLAT, Fikriye; ÖZDEMİR, Öztürk; ELAGÖZ, Şahende

    2008-01-01

    3-Methylcholanthrene (MCA) is a polycyclic aromatic hydrocarbon and potent carcinogenic agent that is often used in experimental cancer studies. Butylated hydroxytoluene (BHT) has been widely used for many years as an antioxidant to preserve and stabilize the freshness, nutritional value, flavor, and color of foods. The aim of the present study was to investigate the role of the application of MCA and BHT in the development of lung cancer, and to detect any mutation in the Ki-ras gene exon 2....

  9. Radioprotection by butylated hydroxytoluene against radiation induced genetic and lethal effects in yeast

    International Nuclear Information System (INIS)

    Butylated hydroxytoluene (BHT) is a phenolic antioxidant which is used widely in food industry as a food preservative for fats and oils; in plastics and also in cosmetics and fragrances. Generally it is considered harmless, however BHT has also shown potentiation of radiation effects in some studies. The objective of this study was to test the modifying properties of BHT in a eukaryotic model system comprising of Saccharomyces cerevisiae D7, a diploid yeast strain, against the genotoxic effects induced by 60Co gamma radiation. Log phase cells were exposed to 100 Gy of radiation in the absence or presence of 0.025-0.25 mM BHT. In another set of experiments, log phase cells were exposed to 400 Gy of radiation in the absence or presence of 0.025 mM BHT. Cells were washed and plated. The results indicated that presence of BHT reduced the frequencies of gene conversion and back mutation as well as cell killing induced by radiation. The results obtained in the present study can be explained on the basis of potent radical scavenging ability of BHT, which is a well known standard antioxidant and whose free radical scavenging ability has been very well established and documented using stable free radical DPPH. (author)

  10. Carcinogenicity study on butylated hydroxytoluene (BHT) in Wistar rats exposed in utero

    DEFF Research Database (Denmark)

    Olsen, P.; Meyer, Otto A.; Bille, N.;

    1986-01-01

    Groups of 60, 40, 40 and 60 F0 Wistar rats of each sex were fed a semi-synthetic diet containing butylated hydroxytoluene (BHT) in concentrations to provide intakes of 0, 25, 100 or 500 mg/kg body weight/day, respectively. The F0 rats were mated and groups of 100, 80, 80 or 100 F1 rats of each sex...... were formed from 40, 29, 30 and 44 litters, respectively. After weaning, the highest dose (500 mg BHT/kg/day) was lowered to 250 mg/kg/day for the F1 rats. The numbers of litters of ten or more pups at birth decreased with increasing BHT dose. At weaning, treated F1 rats had lower body weights than the...... controls, the extent of the reduction being dose related; the effect, which persisted throughout the study, was most pronounced in the males. The survival of BHT-treated F1 rats of both sexes was significantly better than that of the controls. No significant changes attributable to BHT treatment were found...

  11. Antioxidant effect of mango seed extract and butylated hydroxytoluene in bologna-type mortadella during storage

    Directory of Open Access Journals (Sweden)

    Ana Lúcia Fernandes Pereira

    2011-03-01

    Full Text Available The effects of mango seed extract (MSE and butylated hydroxytoluene (BHT on pH, lipid oxidation, and color of Bologna-type mortadella during refrigerated storage for 21 days were studied. Bologna-type mortadella samples were formulated to contain 0.1% MSE, 0.2% MSE, or 0.01% BHT. After 14 days of storage, the products containing MSE 0.1 or 0.2% had higher pH values than those containing BHT 0.01%. Lipid oxidation values increased with storage time but were not affected by the type of antioxidant. The highest values for color parameter L* were observed for mortadella containing BHT 0.01% after 7, 14, and 21 days of storage. Values for the color parameters a* and b* tended to decrease during mortadella storage. Products containing 0.1 or 0.2% MSE showed higher values for color parameter a* and lower values for color parameter b* compared to those containing 0.01% BHT. It can be concluded that MSE can be used in 0.1 or 0.2% levels in Bologna-type mortadella with similar or better antioxidant effects than those of BHT 0.01%.

  12. Understanding the chemistry behind the antioxidant activities of butylated hydroxytoluene (BHT): a review.

    Science.gov (United States)

    Yehye, Wageeh A; Rahman, Noorsaadah Abdul; Ariffin, Azhar; Abd Hamid, Sharifah Bee; Alhadi, Abeer A; Kadir, Farkaad A; Yaeghoobi, Marzieh

    2015-08-28

    Hindered phenols find a wide variety of applications across many different industry sectors. Butylated hydroxytoluene (BHT) is a most commonly used antioxidant recognized as safe for use in foods containing fats, pharmaceuticals, petroleum products, rubber and oil industries. In the past two decades, there has been growing interest in finding novel antioxidants to meet the requirements of these industries. To accelerate the antioxidant discovery process, researchers have designed and synthesized a series of BHT derivatives targeting to improve its antioxidant properties to be having a wide range of antioxidant activities markedly enhanced radical scavenging ability and other physical properties. Accordingly, some structure-activity relationships and rational design strategies for antioxidants based on BHT structure have been suggested and applied in practice. We have identified 14 very sensitive parameters, which may play a major role on the antioxidant performance of BHT. In this review, we attempt to summarize the current knowledge on this topic, which is of significance in selecting and designing novel antioxidants using a well-known antioxidant BHT as a building-block molecule. Our strategy involved investigation on understanding the chemistry behind the antioxidant activities of BHT, whether through hydrogen or electron transfer mechanism to enable promising anti-oxidant candidates to be synthesized. PMID:26150290

  13. Butylated Hydroxytoluene Analogs: Synthesis and Evaluation of Their Multipotent Antioxidant Activities

    Directory of Open Access Journals (Sweden)

    Wageeh A. Yehye

    2012-06-01

    Full Text Available A computer-aided predictions of antioxidant activities were performed with the Prediction Activity Spectra of Substances (PASS program. Antioxidant activity of compounds 1, 3, 4 and 5 were studied using 1,1-diphenyl-2-picrylhydrazyl (DPPH and lipid peroxidation assays to verify the predictions obtained by the PASS program. Compounds 3 and 5 showed more inhibition of DPPH stable free radical at 10−4 M than the well-known standard antioxidant, butylated hydroxytoluene (BHT. Compound 5 exhibited promising in vitro inhibition of Fe2+-induced lipid peroxidation of the essential egg yolk as a lipid-rich medium (83.99%, IC50 16.07 ± 3.51 µM/mL compared to a-tocopherol (a-TOH, 84.6%, IC50 5.6 ± 1.09 µM/mL. The parameters for drug-likeness of these BHT analogues were also evaluated according to the Lipinski’s “rule-of-five” (RO5. All the BHT analogues were found to violate one of the Lipinski’s parameters (LogP > 5, even though they have been found to be soluble in protic solvents. The predictive polar surface area (PSA and absorption percent (% ABS data allow us to conclude that they could have a good capacity for penetrating cell membranes. Therefore, one can propose these new multipotent antioxidants (MPAOs as potential antioxidants for tackling oxidative stress and lipid peroxidation processes.

  14. Lung damage induced by butylated hydroxytoluene in mice. Biochemical, cellular, and morphologic characterization.

    Science.gov (United States)

    Smith, L J

    1984-11-01

    This study was designed to characterize the biochemical, cellular, and morphologic events produced in mice by butylated hydroxytoluene (BHT) and to relate these events to changes in extracellular angiotensin-converting enzyme (ACE) activity. On Day 1 after the administration of BHT, bronchoalveolar lavage (BAL) ACE activity increased 4-fold (p less than 0.001), its specific activity relative to BAL protein increased 3-fold (p less than 0.001), and both type 1 cell damage and endothelial cell damage were detected by electron microscopy. The early increase in BAL ACE activity preceded changes in plasma ACE levels, BAL cell number, protein, lactate, and lactate dehydrogenase (LDH) activity in both plasma and BAL, and the ACE content of alveolar macrophages. On Day 2, BAL ACE activity increased 9-fold, BAL protein increased 4-fold (p less than 0.001), BAL LDH activity increased 34% (p less than 0.05), and the BAL cell count doubled (p less than 0.01). Changes in each animal's appearance, body weight, wet and dry lung weights, and plasma ACE levels occurred between Days 3 and 5. The BAL differential cell count, which consisted of greater than 95% macrophages in uninjured mice, did not change until Day 5 when there was a small increase in polymorphonuclear leukocytes (PMN). On Day 7, the number of PMN peaked, and some of the other measures of lung injury began returning toward normal. These results indicate that BAL ACE activity is a sensitive, early marker of BHT-induced lung injury, which appears to reflect damage to the cells of the alveolar-capillary barrier. In addition, PMN do not appear to play a major role in this model of lung injury. Because of its effects on angiotensin, bradykinin, and prostaglandins, the early release of ACE from damaged cells may modulate the subsequent injury. PMID:6093659

  15. Protective effect of butylated hydroxytoluene (BHT) against the clastogenic acitivity of cadmium chloride and potassium dichromate in hamster ovary cells

    OpenAIRE

    Grillo Claudia A.; Seoane Analía I.; Dulout Fernando N.

    1999-01-01

    The effect of butylated hydroxytoluene (BHT), a widely used food additive, on chromosomal alterations induced by cadmium chloride (CC) and potassium dichromate (PD) in Chinese hamster ovary (CHO) cells was studied both at metaphase and anaphase-telophase. CHO cells were cultured for 15-16 h in the presence of PD (6.0, 9.0 or 12.0 mM), BHT (1.0 mg/ml), or PD plus BHT as well as CC (0.5, 1.0 and 2.0 mM), BHT or CC plus BHT for the analysis of chromosomal aberrations. To perform the anaphase-tel...

  16. Effect of supplementation of butylated hydroxytoluene on post-thaw sperm viability, motility and membrane integrity of Hariana bulls

    OpenAIRE

    Akhil Patel; Atul Saxena; Dilip Kumar Swain; Dushyant Yadav; Sanjay Singh Yadav; Abhishek Kumar; Anuj Kumar

    2015-01-01

    Aim: This study was aimed to see the beneficial effect of butylated hydroxytoluene (BHT) as a semen additive of Hariana bull semen. Materials and Methods: The study was carried out in Hariana bulls. Twenty-four ejaculates from two bulls were used for this study. Each ejaculate was extended with standard glycerolated egg yolk tris extender and supplemented with BHT at two concentrations as 0.5 mM (T1) and 1.0 mM (T2). After dilution, equilibration and 24 h of cryopreservation, the samples w...

  17. Free radical-derived quinone methide mediates skin tumor promotion by butylated hydroxytoluene hydroperoxide: expanded role for electrophiles in multistage carcinogenesis.

    OpenAIRE

    Guyton, K Z; Bhan, P; Kuppusamy, P.; Zweier, J L; Trush, M A; Kensler, T W

    1991-01-01

    Free radical derivatives of peroxides, hydroperoxides, and anthrones are thought to mediate tumor promotion by these compounds. Further, the promoting activity of phorbol esters is attributed, in part, to their ability to stimulate the cellular generation of oxygen radicals. A hydroperoxide metabolite of butylated hydroxytoluene, 2,6-di-tert-butyl-4-hydroperoxyl-4-methyl-2,5-cyclohexadienone (BHTOOH), has previously been shown to be a tumor promoter in mouse skin. BHTOOH is extensively metabo...

  18. Transcriptome analysis provides new insights into liver changes induced in the rat upon dietary administration of the food additives butylated hydroxytoluene, curcumin, propyl gallate and thiabendazole

    NARCIS (Netherlands)

    Stierum, R.; Conesa, A.; Heijne, W.; Ommen, B.v.; Junker, K.; Scott, M.P.; Price, R.J.; Meredith, C.; Lake, B.G.; Groten, J.

    2008-01-01

    Transcriptomics was performed to gain insight into mechanisms of food additives butylated hydroxytoluene (BHT), curcumin (CC), propyl gallate (PG), and thiabendazole (TB), additives for which interactions in the liver can not be excluded. Additives were administered in diets for 28 days to Sprague-D

  19. Non-Specific Inhibition of Ischemia- and Acidosis-Induced Intracellular Calcium Elevations and Membrane Currents by α-Phenyl-N-tert-butylnitrone, Butylated Hydroxytoluene and Trolox

    OpenAIRE

    Christopher Katnik; Javier Cuevas

    2014-01-01

    Ischemia, and subsequent acidosis, induces neuronal death following brain injury. Oxidative stress is believed to be a key component of this neuronal degeneration. Acute chemical ischemia (azide in the absence of external glucose) and acidosis (external media buffered to pH 6.0) produce increases in intracellular calcium concentration ([Ca2+] i ) and inward membrane currents in cultured rat cortical neurons. Two α-tocopherol analogues, trolox and butylated hydroxytoluene (BHT), and the spin t...

  20. Rational Design and Synthesis of New, High Efficiency, Multipotent Schiff Base-1,2,4-triazole Antioxidants Bearing Butylated Hydroxytoluene Moieties

    OpenAIRE

    Wageeh A. Yehye; Noorsaadah Abdul Rahman; Omar Saad; Azhar Ariffin; Sharifah Bee Abd Hamid; Alhadi, Abeer A.; Kadir, Farkaad A; Marzieh Yaeghoobi; Abdulsalam A. Matlob

    2016-01-01

    A new series of multipotent antioxidants (MPAOs), namely Schiff base-1,2,4-triazoles attached to the oxygen-derived free radical scavenging moiety butylated hydroxytoluene (BHT) were designed and subsequently synthesized. The structure-activity relationship (SAR) of the designed antioxidants was established alongside the prediction of activity spectra for substances (PASS). The antioxidant activities of the synthesized compounds 4–10 were tested by the DPPH bioassay. The synthesized compounds...

  1. Effect of supplementation of butylated hydroxytoluene on post-thaw sperm viability, motility and membrane integrity of Hariana bulls

    Directory of Open Access Journals (Sweden)

    Akhil Patel

    2015-06-01

    Full Text Available Aim: This study was aimed to see the beneficial effect of butylated hydroxytoluene (BHT as a semen additive of Hariana bull semen. Materials and Methods: The study was carried out in Hariana bulls. Twenty-four ejaculates from two bulls were used for this study. Each ejaculate was extended with standard glycerolated egg yolk tris extender and supplemented with BHT at two concentrations as 0.5 mM (T1 and 1.0 mM (T2. After dilution, equilibration and 24 h of cryopreservation, the samples were analyzed for progressive motility, sperm viability and membrane integrity. Results: Progressive motility, sperm viability and sperm membrane integrity were significantly (p<0.05 increased in the samples fortified with BHT as compared to the control during the process of cryopreservation and thawing. The BHT concentration of 1 mM revealed better results as compared to 0.5 mM. Conclusion: Addition of 1.0 mM BHT was found better in cryopreservation of Hariana bull semen compared to 0.5 mM BHT and control samples. The addition of BHT has improved the sperm quality by acting as an antioxidant thereby reducing the lipid peroxidation of the sperms.

  2. Protective effect of butylated hydroxytoluene (BHT against the clastogenic acitivity of cadmium chloride and potassium dichromate in hamster ovary cells

    Directory of Open Access Journals (Sweden)

    Grillo Claudia A.

    1999-01-01

    Full Text Available The effect of butylated hydroxytoluene (BHT, a widely used food additive, on chromosomal alterations induced by cadmium chloride (CC and potassium dichromate (PD in Chinese hamster ovary (CHO cells was studied both at metaphase and anaphase-telophase. CHO cells were cultured for 15-16 h in the presence of PD (6.0, 9.0 or 12.0 mM, BHT (1.0 mg/ml, or PD plus BHT as well as CC (0.5, 1.0 and 2.0 mM, BHT or CC plus BHT for the analysis of chromosomal aberrations. To perform the anaphase-telophase test, cells were cultured in cover glasses and treated 8 h before fixation with the same chemicals. An extra dose of CC (4 mM was used in this test. Both metal salts significantly increased chromosomal aberration frequencies in relation to untreated controls, and to DMSO- and BHT-treated cells. Post-treatment with BHT decreased the yield of chromosomal damage in relation to treatments performed with CC and PD. However, chromosomal aberration frequencies were significantly higher than those of the controls. In the anaphase-telophase test, CC significantly increased the yield of lagging chromosomes with the four doses employed and the frequency of lagging fragments with the highest dose. In combined treatments of CC and BHT, frequencies of the two types of alterations decreased significantly in relation to the cells treated with CC alone. No significant variation was found in the frequencies of chromatin bridges. Significant increases of numbers of chromatin bridges, lagging chromosomes and lagging fragments were found in cells treated with PD. The protective effect of BHT in combined treatments was evidenced by the significant decrease of chromatid bridges and lagging chromosomes in relation to PD-treated cells. Whereas BHT is able to induce chromosomal damage, it can also protect against oxidative damage induced by other genotoxicants.

  3. Butylated hydroxytoluene can protect polyunsaturated fatty acids in dried blood spots from degradation for up to 8 weeks at room temperature

    OpenAIRE

    Metherel, Adam H; Hogg, Ryan C; Buzikievich, Lindy M; Stark, Ken D.

    2013-01-01

    Background Dried blood spots (DBS) from fingertip prick blood can enable high throughput fatty acid profiling but may be prone to lipid peroxidation during storage. The use of butylated hydroxytoluene (BHT) on chromatography paper can prevent polyunsaturated fatty acid (PUFA) loss but examinations on the length of storage times possible are not comprehensive. Method In the first study, venous whole blood was saturated on paper strips pre-soaked with 0, 2.5 or 5.0 mg/mL BHT and exposed to air ...

  4. Adsorption of 2,6-di-t-butyl-p-hydroxytoluene (BHT) on gold nanoparticles: Assignment and interpretation of surface-enhanced Raman scattering

    Science.gov (United States)

    Sun, Ying-Ying; Xie, Yun-Fei; Wang, He-Ya; Qian, He; Yao, Wei-Rong

    2012-11-01

    2,6-Di-t-butyl-p-hydroxytoluene (BHT), a common antioxidant, has been implicated in oil foods and food packaging materials as a substance that could migrate into the food supply chain and cause suppression of human respiratory enzymes. In this study, BHT solutions in different solvents were measured by surface enhanced Raman spectroscopy (SERS) in combination with SERS-active substrates: gold colloidal nanoparticles. The limit of detection of BHT can reach the level of 10 μg/mL with SERS in methanol. The Raman peak at 766 cm-1 was used as the index of quantitative analysis and the correlation coefficient was 0.9761. These results demonstrated the applicability of utilizing SERS to detect low concentrations of BHT. By comparing the features of SERS peaks with the density functional theory (DFT)-calculated Raman spectrum, the adsorption behavior of BHT on the surface of gold nanoparticles was analyzed in detail and it was determined that the dominant contribution to the SERS signal in this case should be the electromagnetic enhancement mechanism. A charge-transfer mechanism also contributed to the SERS signal for BHT adsorbed on gold nanoparticles by the Phsbnd O(H) (Ph = phenyl) coalescent format.

  5. Phenothiazines inhibit copper and endothelial cell-induced peroxidation of low density lipoprotein. A comparative study with probucol, butylated hydroxytoluene and vitamin E.

    Science.gov (United States)

    Breugnot, C; Mazière, C; Salmon, S; Auclair, M; Santus, R; Morlière, P; Lenaers, A; Mazière, J C

    1990-11-01

    The effect of two phenothiazines, chlorpromazine (CPZ) and trifluoperazine (TFP) on the copper and endothelial cell-induced peroxidation of low density lipoprotein (LDL) has been studied and compared to that of drugs previously shown to protect LDL against peroxidation: probucol (PBC) and butylated hydroxytoluene (BHT). Incubation with CPZ or TFP inhibited in a dose-dependent manner LDL peroxidation induced either by copper ions or by cultured endothelial cells. Both the electrophoretic mobility and the thiobarbituric reactive substance content of LDL returned to almost normal values in the presence of 50 microM CPZ or TFP. The two studied phenothiazines also strongly inhibited the hydrolysis of LDL phosphatidylcholine which accompanies copper or endothelial cell-induced peroxidation of the particle. CPZ and TFP were as effective as PBC and BHT in inhibiting the LDL peroxidation. Whereas copper or endothelial cell-oxidized LDL were recognized and rapidly catabolized by mouse peritoneal macrophages, CPZ- or TFP-, as well as PBC- or BHT-treated LDL were not. Moreover, it was found that, in contrast to vitamin E, neither CPZ nor PBC reacted with model peroxy radicals formed by gamma irradiation of aerated ethanol. The possible mechanisms underlying this protective effect of phenothiazines against LDL oxidative modification are discussed. PMID:2242028

  6. Rational Design and Synthesis of New, High Efficiency, Multipotent Schiff Base-1,2,4-triazole Antioxidants Bearing Butylated Hydroxytoluene Moieties

    Directory of Open Access Journals (Sweden)

    Wageeh A Yehye

    2016-06-01

    Full Text Available A new series of multipotent antioxidants (MPAOs, namely Schiff base-1,2,4-triazoles attached to the oxygen-derived free radical scavenging moiety butylated hydroxytoluene (BHT were designed and subsequently synthesized. The structure-activity relationship (SAR of the designed antioxidants was established alongside the prediction of activity spectra for substances (PASS. The antioxidant activities of the synthesized compounds 4–10 were tested by the DPPH bioassay. The synthesized compounds 4–10 inhibited stable DPPH free radicals at a level that is 10−4 M more than the well-known standard antioxidant BHT. Compounds 8–10 with para-substituents were less active than compounds 4 and 5 with trimethoxy substituents compared to those with a second BHT moiety (compounds 6 and 7. With an IC50 of 46.13 ± 0.31 µM, compound 6 exhibited the most promising in vitro inhibition at 89%. Therefore, novel MPAOs containing active triazole rings, thioethers, Schiff bases, and BHT moieties are suggested as potential antioxidants for inhibiting oxidative stress processes and scavenging free radicals, hence, this combination of functions is anticipated to play a vital role in repairing cellular damage, preventing various human diseases and in medical therapeutic applications.

  7. Rational Design and Synthesis of New, High Efficiency, Multipotent Schiff Base-1,2,4-triazole Antioxidants Bearing Butylated Hydroxytoluene Moieties.

    Science.gov (United States)

    Yehye, Wageeh A; Abdul Rahman, Noorsaadah; Saad, Omar; Ariffin, Azhar; Abd Hamid, Sharifah Bee; Alhadi, Abeer A; Kadir, Farkaad A; Yaeghoobi, Marzieh; Matlob, Abdulsalam A

    2016-06-28

    A new series of multipotent antioxidants (MPAOs), namely Schiff base-1,2,4-triazoles attached to the oxygen-derived free radical scavenging moiety butylated hydroxytoluene (BHT) were designed and subsequently synthesized. The structure-activity relationship (SAR) of the designed antioxidants was established alongside the prediction of activity spectra for substances (PASS). The antioxidant activities of the synthesized compounds 4-10 were tested by the DPPH bioassay. The synthesized compounds 4-10 inhibited stable DPPH free radicals at a level that is 10(-4) M more than the well-known standard antioxidant BHT. Compounds 8-10 with para-substituents were less active than compounds 4 and 5 with trimethoxy substituents compared to those with a second BHT moiety (compounds 6 and 7). With an IC50 of 46.13 ± 0.31 µM, compound 6 exhibited the most promising in vitro inhibition at 89%. Therefore, novel MPAOs containing active triazole rings, thioethers, Schiff bases, and BHT moieties are suggested as potential antioxidants for inhibiting oxidative stress processes and scavenging free radicals, hence, this combination of functions is anticipated to play a vital role in repairing cellular damage, preventing various human diseases and in medical therapeutic applications.

  8. Rational Design and Synthesis of New, High Efficiency, Multipotent Schiff Base-1,2,4-triazole Antioxidants Bearing Butylated Hydroxytoluene Moieties.

    Science.gov (United States)

    Yehye, Wageeh A; Abdul Rahman, Noorsaadah; Saad, Omar; Ariffin, Azhar; Abd Hamid, Sharifah Bee; Alhadi, Abeer A; Kadir, Farkaad A; Yaeghoobi, Marzieh; Matlob, Abdulsalam A

    2016-01-01

    A new series of multipotent antioxidants (MPAOs), namely Schiff base-1,2,4-triazoles attached to the oxygen-derived free radical scavenging moiety butylated hydroxytoluene (BHT) were designed and subsequently synthesized. The structure-activity relationship (SAR) of the designed antioxidants was established alongside the prediction of activity spectra for substances (PASS). The antioxidant activities of the synthesized compounds 4-10 were tested by the DPPH bioassay. The synthesized compounds 4-10 inhibited stable DPPH free radicals at a level that is 10(-4) M more than the well-known standard antioxidant BHT. Compounds 8-10 with para-substituents were less active than compounds 4 and 5 with trimethoxy substituents compared to those with a second BHT moiety (compounds 6 and 7). With an IC50 of 46.13 ± 0.31 µM, compound 6 exhibited the most promising in vitro inhibition at 89%. Therefore, novel MPAOs containing active triazole rings, thioethers, Schiff bases, and BHT moieties are suggested as potential antioxidants for inhibiting oxidative stress processes and scavenging free radicals, hence, this combination of functions is anticipated to play a vital role in repairing cellular damage, preventing various human diseases and in medical therapeutic applications. PMID:27367658

  9. Non-Specific Inhibition of Ischemia- and Acidosis-Induced Intracellular Calcium Elevations and Membrane Currents by α-Phenyl-N-tert-butylnitrone, Butylated Hydroxytoluene and Trolox

    Directory of Open Access Journals (Sweden)

    Christopher Katnik

    2014-02-01

    Full Text Available Ischemia, and subsequent acidosis, induces neuronal death following brain injury. Oxidative stress is believed to be a key component of this neuronal degeneration. Acute chemical ischemia (azide in the absence of external glucose and acidosis (external media buffered to pH 6.0 produce increases in intracellular calcium concentration ([Ca2+]i and inward membrane currents in cultured rat cortical neurons. Two α-tocopherol analogues, trolox and butylated hydroxytoluene (BHT, and the spin trapping molecule α-Phenyl-N-tert-butylnitrone (PBN were used to determine the role of free radicals in these responses. PBN and BHT inhibited the initial transient increases in [Ca2+]i, produced by ischemia, acidosis and acidic ischemia and increased steady state levels in response to acidosis and the acidic ischemia. BHT and PBN also potentiated the rate at which [Ca2+]i increased after the initial transients during acidic ischemia. Trolox inhibited peak and sustained increases in [Ca2+]i during ischemia. BHT inhibited ischemia induced initial inward currents and trolox inhibited initial inward currents activated by acidosis and acidic ischemia. Given the inconsistent results obtained using these antioxidants, it is unlikely their effects were due to elimination of free radicals. Instead, it appears these compounds have non-specific effects on the ion channels and exchangers responsible for these responses.

  10. Evaluation of Keishi-bukuryo-gan in a diabetic nephropathy model by comparison with aminoguanidine, butylated hydroxytoluene and captopril

    OpenAIRE

    Nakagawa, Takako; Oya, Takeshi; Sasahara, Masakiyo; Terasawa, Katsutoshi; Yokozawa, Takako

    2002-01-01

    桂枝茯苓丸の糖尿病性腎症に対する作用を,モデルラットを用い検討した。腎機能パラメーター,病理組織学的検討に加え,advanced glycation end products(AGEs)の蓄積,酸化ストレスに及ぼす影響を,アミノグアニジン(AGEs阻害薬),カプトプリル(アンジオテンシン変換酵素阻害薬),buthylated hydroxytoluene(BHT)(抗酸化剤)とで比較検討した。桂枝茯苓丸では腎機能(血清Cr,尿蛋白排泄量)と病理所見の有意な改善作用が認められ,糖尿病性腎症の進展を抑制することが実験的に明らかとなったが,このような腎保護作用はカプトプリルよりは弱く,アミノグアニジンと同程度であった。BHTには腎保護作用は認められなかった。腎組織中のAGEsの蓄積に対しては,桂枝茯苓丸,カプトプリル,BHTがいずれも有意に低下していたが,アミノグアニジンの作用よりは弱かった。腎組織中の脂質過酸化量はBHTで最も低下し,桂枝茯苓丸,カプトプリルでも有意に低下していた。一方,血中脂質過酸化に対しては,すべてにおいて有意な低下作用が認められたが,カプトプリルで最も強かった。...

  11. Carbonyl reductase inactivation may contribute to mouse lung tumor promotion by electrophilic metabolites of butylated hydroxytoluene: protein alkylation in vivo and in vitro.

    Science.gov (United States)

    Shearn, Colin T; Fritz, Kristofer S; Meier, Brent W; Kirichenko, Oleg V; Thompson, John A

    2008-08-01

    Promotion of lung tumors in mice by the food additive butylated hydroxytoluene (BHT) is mediated by electrophilic metabolites produced in the target organ. Identifying the proteins alkylated by these quinone methides (QMs) is a necessary step in understanding the underlying mechanisms. Covalent adducts of the antioxidant enzymes peroxiredoxin 6 and Cu,Zn superoxide dismutase were detected previously in lung cytosols from BALB/c mice injected with BHT, and complimentary in vitro studies demonstrated that QM alkylation causes inactivation and enhances oxidative stress. In the present work, adducts of another protective enzyme, carbonyl reductase (CBR), were detected by Western blotting and mass spectrometry in mitochondria from lungs of mice one day after a single injection of BHT and throughout a 28-day period of weekly injections required to achieve tumor promotion. BHT treatment was accompanied by the accumulation of protein carbonyls in lung cytosol from sustained oxidative stress. Studies in vitro demonstrated that CBR activity in lung homogenates was susceptible to concentration- and time-dependent inhibition by QMs. Recombinant CBR underwent irreversible inhibition during QM exposure, and mass spectrometry was utilized to identify alkylation sites at Cys 51, Lys 17, Lys 189, Lys 201, His 28, and His 204. Except for Lys 17, all of these adducts were eliminated as a cause of enzyme inhibition either by chemical modification (cysteine) or site-directed mutagenesis (lysines and histidines). The data demonstrated that Lys 17 is the critical alkylation target, consistent with the role of this basic residue in NADPH binding. These data support the possibility that CBR inhibition occurs in BHT-treated mice, thereby compromising one pathway for inactivating lipid peroxidation products, particularly 4-oxo-2-nonenal. These data, in concert with previous evidence for the inactivation of antioxidant enzymes, provide a molecular basis to explain lung inflammation leading to

  12. Activation of liver X receptor inhibits the development of pulmonary carcinomas induced by 3-methylcholanthrene and butylated hydroxytoluene in BALB/c mice.

    Science.gov (United States)

    Wang, Qixue; Sun, Lei; Yang, Xiaoxiao; Ma, Xingzhe; Li, Qi; Chen, Yuanli; Liu, Ying; Zhang, Di; Li, Xiaoju; Xiang, Rong; Wei, Yuquan; Han, Jihong; Duan, Yajun

    2016-01-01

    We previously reported that LXR ligand, T0901317, inhibited the growth of inoculated Lewis lung carcinoma in C57BL/6 mice by activating IFN-γ production. However, the effects of T0901317 on carcinogen-induced pulmonary carcinomas remain unknown. In this study, we initially conducted a statistical analysis on the data of human lung cancer samples extracted from the TCGA database, and determined that survival rate/time of lung cancer patients and grade of lung adenocarcinoma were positively and negatively related to lung IFN-γ levels, respectively. We then determined the inhibitory effects of T0901317 on mouse pulmonary carcinomas induced by 3-methylcholanthrene (MCA) and butylated hydroxytoluene (BHT) or urethane. We found that T0901317 reduced morbidity and mortality in MCA/BHT-injected BALB/c mice by inhibiting lung adenocarcinoma. T0901317 also protected C57BL/6 mice, but not IFN-γ deficient (IFN-γ(-/-), C57BL/6 background) mice, against MCA/BHT-induced lung hyperplasia/inflammation. In addition, we determined that T0901317 inhibited urethane-induced lung tumors in BABL/c mice. Furthermore, we determined that T0901317 prevented metastasis of 4T1 breast cancer cells in BALB/c mice. Administration of T0901317 substantially increased serum IFN-γ levels and lung IFN-γ expression in BABL/c and C57BL/6 mice. Taken together, our study demonstrates that LXR inhibits MCA/BHT-induced pulmonary carcinomas in BABL/c mice and the inhibition is associated with induction of IFN-γ production. PMID:27250582

  13. Butylated hydroxytoluene can reduce oxidative stress and improve quality of frozen-thawed bull semen processed in lecithin and egg yolk based extenders.

    Science.gov (United States)

    Khumran, A M; Yimer, N; Rosnina, Y; Ariff, M O; Wahid, H; Kaka, Asmatullah; Ebrahimi, M; Sarsaifi, K

    2015-12-01

    The aims of this study were to evaluate the effects of anti-oxidant butylated hydroxytoluene (BHT), when added at different concentrations into lecithin-based Bioxcell(®) (BX) and two egg-yolk-based; Tris (TY) and citrate (CE) semen extenders, on post-thaw bull sperm quality and oxidative stress. A total of 30 ejaculates from three bulls were collected using an electro ejaculator. Ejaculates were extended with one of the BX, TY and CE extenders, which contained different concentrations (0.0 - control, 0.5, 1.0, 1.5, 2.0 and 3.0mM/ml) of BHT. The extended semen samples were chilled to 4 °C, and then frozen slowly to -196 °C in 0.25 ml straws before being stored in liquid nitrogen for 2 weeks. Results showed that supplementation of BHT improved (P<0.05) general motility, progressive motility, morphology, acrosome integrity, DNA integrity and malondialdehyde of sperm at 0.5mM/ml for BX and at 1-1.5mM/ml of BHT for TY and CE when compared with the control. However, greater concentrations of 2.0 and 3.0mM/ml of BHT had a detrimental (P<0.05) effect compared with the control with all extenders evaluated. In conclusion, BHT supplementation at lesser concentrations (0.5-1.5mM/ml) could improve frozen-thawed bull sperm quality by reducing oxidative stress produced during the freezing-thawing procedures in either lecithin or egg-yolk based extenders. PMID:26515370

  14. Effects of the antioxidant butylated hydroxytoluene (BHT) on retinal degeneration induced transplacentally by a single low dosage of N-methyl-N-nitrosourea (MNU).

    Science.gov (United States)

    Smith, S B; Cooke, C B; Yielding, K L

    1988-01-01

    A 1 mg/kg dose of the DNA alkylating agent, N-methyl-N-nitrosourea (MNU), when administered on day 16 of gestation provokes a progressive retinal degeneration in CD-1 albino mice reared under standard fluorescent lighting conditions (12 hr light: 12 hr dark); this degeneration begins at about 4 weeks post-natally and worsens with age. It is accelerated by constant fluorescent light exposure but is retarded greatly by constant darkness, suggesting the importance of secondary insults in the post-natal period for development of the degenerative disease. To determine whether the secondary photochemical damage might be specifically blocked, MNU-exposed and control animals in the present study were fed an antioxidant-enriched diet of Purina mouse chow supplemented with 0.75% butylated hydroxytoluene (BHT). A second group of MNU-exposed and control animals were fed a non-BHT supplemented standard Purina mouse chow diet. Systematic measurements of the number of rows of photoreceptor cell nuclei, the thickness of the inner/outer segment layer, and the thickness of the whole retina were made, to quantify and degenerative changes in animals 2, 4, 6, and 8 weeks of age. By 8 weeks, retinas of BHT-fed, MNU-exposed animals were significantly thicker and had more rows of photoreceptor cell nuclei than regular-diet, MNU-exposed animals. Moreover, the retinas of BHT-fed animals, both for MNU-exposed and controls, demonstrated sporadic morphologic changes in the form of circular configurations composed of ganglion cells, arcades of nuclear and plexiform layers, and, in one control animal, a hyperplastic nodule. These experiments suggested that MNU-induced retinal degeneration may be retarded by a BHT-enriched diet; however, continuous high doses of this compound pre- and postnatally may induce other retinal abnormalities. PMID:2906176

  15. Effect of previous chilling storage on quality loss in frozen (–20 °C) sierra (Scomberomorus sierra) muscle packed with a low-density polyethylene film containing butylated hydroxytoluene

    OpenAIRE

    Herlinda Soto-Valdez; Josafat Marina Ezquerra-Brauer; Enrique Márquez-Ríos; Wilfrido Torres-Arreola

    2015-01-01

    Rancidity development during frozen storage (–20 °C) of sierra fish (Scomberomorus sierra) was studied. Fillets were packed in low-density polyethylene films with and without butylated hydroxytoluene added (BHT-LDPE and LDPE respectively). Fillets stored with no package were used as control. Special attention was given to the effect of previous ice storage (0, 3, 6, 9 and 15 days) on the quality of the frozen fish. Physical (pH and texture) and chemical (peroxide value, PV and thiobarbituric ...

  16. Effect of Naphthalene, Butylated Hydroxytoluene, Dioctyl Phthalate, and Adipic Dioctyl Ester, Chemicals Found in the Nests of the Formosan Subterranean Termite (Isoptera: Rhinotermitidae) on a Saprophytic Mucor sp.

    Science.gov (United States)

    Fungi are commonly found associated with termites and their nests. Four chemicals that have been isolated from the nests of the Formosan subterranean termite, Coptotermes formosanus Shiraki, were evaluated to determine their effect on a common nest fungus, a saprophytic Mucor sp. Butylated hydroxyto...

  17. Effect of previous chilling storage on quality loss in frozen (–20 °C sierra (Scomberomorus sierra muscle packed with a low-density polyethylene film containing butylated hydroxytoluene

    Directory of Open Access Journals (Sweden)

    Herlinda Soto-Valdez

    2015-03-01

    Full Text Available Rancidity development during frozen storage (–20 °C of sierra fish (Scomberomorus sierra was studied. Fillets were packed in low-density polyethylene films with and without butylated hydroxytoluene added (BHT-LDPE and LDPE respectively. Fillets stored with no package were used as control. Special attention was given to the effect of previous ice storage (0, 3, 6, 9 and 15 days on the quality of the frozen fish. Physical (pH and texture and chemical (peroxide value, PV and thiobarbituric acid index, TBA-i analyses were carried out. Lipid oxidation increased with ice storage time in fish muscle without film packing, being greater than the film packed muscle (with and without antioxidant. An effect of previous ice storage time was observed on the frozen product (in all treatments. However, fish muscle with film packing containing antioxidant showed less lipid deterioration. Under the conditions applied in this study, the plastic films with antioxidant prevented the lipids oxidation during the cold handling of the sierra muscle.

  18. Development and validation of a reverse phase-liquid chromatographic method for the estimation of butylated hydroxytoluene as antioxidant in paricalcitol hard gelatin capsule formulation dosage form

    OpenAIRE

    Vaghela, Bhupendrasinh; Rao, Surendra Singh; Sharma, Nitish; Balakrishna, P.; Reddy, A. Malleshwar

    2011-01-01

    Introduction: A novel and simple isocratic reverse phase liquid chromatographic (RP-LC) method was developed for the quantitative determination of antioxidant-butylated hydroxy toluene (BHT) in paricalcitol hard gelatin capsule. In the paricalcitol capsule BHT concentration is very low. This method is precisely able to estimate BHT at low concentration at about 0.0039 μg/mL and to separate BHT from paricalcitol main compound and other oil-based excipients. Materials and Methods: The method wa...

  19. Effect of. cap alpha. -tocopherol, butylated-hydroxytoluene and hydroxy-anisole on the activation and binding of aflatoxin B/sub 1/ to macromolecules

    Energy Technology Data Exchange (ETDEWEB)

    Ch' ih, J.J.; Biedrzycka, D.; Devlin, T.M.

    1987-05-01

    The anti-oxidants, ..cap alpha..-tocopherol(TPA), butylated-hydroxy-toluene(BHT) and hydroxyanisole(BHA) inhibit the carcinogenic and toxic effects of a variety of chemical compounds, their effect on aflatoxin B/sub 1/ (AFB/sub 1/) activation and binding was examined utilizing rat liver microsomes and cells. With a NADPH generating system, oxygen, microsomes, (/sup 3/H)-AFB/sub 1/, 2.2 pmoles/h/mg protein was activated and bound to macromolecules. In hepatocytes, 3.4 and 1.4 pmoles of AFB/sub 1/ per 10/sup 6/ cells were taken up and bound to macromolecules, whereas the nucleic acid fraction contained 0.19 pmoles of bound AFB/sub 1/. Moderate decreases of AFB/sub 1/ activation and binding were observed when TPA was present in both cell-free and hepatocytes systems. Only in hepatocytes, BHT inhibited the AFB/sub 1/ uptake and binding to nucleic acids. BHA, however, inhibited microsomal activation of AFB/sub 1/ by 73%; maximum inhibition was reached at 1 mM. AFB/sub 1/ uptake, and binding to nucleic acids were inhibited by 65% and 79% by BHA. GSH-transferase activity of cells treated with these agents was not altered. The effect of BHA at various concentrations on AFB activation was compared with cytochrome P-450 inhibitors; the ED/sub 50/ of SKF 525A, BHA and metyrapone was 9 uM, 80 uM and 380 uM respectively. The data suggest that TPA, BHA and BHT exert their effect by different mechanisms.

  20. BIBRA toxicity profile of butylated hydroxytoluene

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1989-12-31

    The BIBRA Toxicity Profile is a comprehensive yet concise review of the toxicological data on the profiled chemical. All studies identified have been carefully evaluated (using primary data sources wherever possible), but only the data most pertinent to hazard assessment are included. Information is summarized, where available, on the effects in man, as well as other species, and studies relating to the principal exposure routes are given precedence. The Profile is divided into the following main sections: Summary, Identification, Local Effects (including skin, eye and respiratory tract irritation), Sensitization and Intolerance, General Systemic Effects (including single and repeated administration), Reproductive Toxicity, Carcinogenicity and Other Genotoxicity.

  1. Effects of Aging Corn Diet Supplemented with Tea Polyphenol, Vitamin E and Butylated Hydroxytoluene on Growth Performance and Antioxidant Function of Meat Ducks%陈玉米饲粮中添加茶多酚、维生素 E和二丁基羟基甲苯对肉鸭生长性能和抗氧化功能的影响

    Institute of Scientific and Technical Information of China (English)

    张亚茹; 王忠; 蔡少敏; 张璐爽; 刘洋; 袁建敏; 夏兆飞

    2015-01-01

    The present study was conducted to investigate the effects of aging corn diet supplemented with tea polyphenol ( TP) , vitamin E and butylated hydroxytoluene ( BHT ) on growth performance and antioxidant function of meat ducks. A total of 192 one⁃day⁃old male ducks were randomly divided into 4 groups with 6 rep⁃licates per group and 8 ducks per replicate. Corn stored for 3 years was utilized to formulate appropriate basal diets. Ducks in the group Ⅰ ( control group) were fed the basal diet without antioxidant, and the others in groups Ⅱ, Ⅲ and Ⅳ were fed the basal diet supplemented with 120 mg/kg TP, vitamin E and BHT, respec⁃tively. This experiment lasted for 42 days. The results showed as follows:1) compared with the control group, TP significantly increased average daily gain ( ADG) at 22 to 42 days of age ( P0.05) . 2) Compared with the control group, TP significantly increased total antioxi⁃dant capacity ( T⁃AOC) at 21 and 42 days of age and catalase ( CAT) activity at 42 days of age in serum ( P<0.05), vitamin E significantly increased CAT activity at 42 days of age in serum (P<0.05), BHT significant⁃ly increased T⁃AOC at 21 days of age and CAT activity at 21 and 42 days of age in serum ( P<0.05) . In con⁃clusion, aging corn diet supplemented with TP and vitamin E can improve growth performance and antioxidant function of meat ducks, aging corn diet supplemented with BHT only can improve antioxidant function of meat ducks. Aging corn diet supplemented with TP has the best effect.%本试验旨在研究陈玉米饲粮中添加茶多酚( TP)、维生素E和二丁基羟基甲苯( BHT)对肉鸭生长性能和抗氧化功能的影响。选取1日龄雄性北京鸭192只,随机分为4组,每组6个重复,每个重复8只。以储存3年玉米作为能量原料,Ⅰ组(对照组)饲喂基础饲粮(不添加饲料抗氧化剂),Ⅱ、Ⅲ、Ⅳ组分别饲喂在基础饲粮中添加120 mg/kg TP、维生素E

  2. Cancer chemoprevention by natural compounds

    OpenAIRE

    スズキ, マスミ; Masumi, SUZUI

    2007-01-01

    There is growing interest in the use of natural compounds for the treatment and prevention of a wide variety of diseases, including cancer. Several herb-derived components are currently evaluated in preclinical studies as potential cancer chemopreventive agents. We have recently found that several herbal plants in the Ryukyu Islands, or any other natural compound, have a potential chemopreventive effect on biomarkers of colon carcinogenesis and a growth inhibitory effect on human cancer cells...

  3. Carcinogenicity study on butylated hydroxytoluene (BHT) in Wistar rats exposed in utero

    DEFF Research Database (Denmark)

    Olsen, P.; Meyer, Otto A.; Bille, N.;

    1986-01-01

    the controls, the extent of the reduction being dose related; the effect, which persisted throughout the study, was most pronounced in the males. The survival of BHT-treated F1 rats of both sexes was significantly better than that of the controls. No significant changes attributable to BHT treatment were found...... detected when the F1 rats were more than 2 yr old. Tumours were found in many other organs of some of the treated rats, but their incidence was not significantly different from that in controls. The role of BHT in the development of hepatocellular tumours requires further elucidation....

  4. Protective effect of butylated hydroxytoluene on sperm function in human spermatozoa cryopreserved by vitrification technique.

    Science.gov (United States)

    Merino, O; Aguagüiña, W E; Esponda, P; Risopatrón, J; Isachenko, E; Isachenko, V; Sánchez, R

    2015-03-01

    Butylhydroxytoluene (BHT), a synthetic analogue of vitamin E, shows antioxidant and antiviral properties and has been successfully used for mammalian sperm cryopreservation. In this study, BHT was included in a vitrification solution to determine its cryoprotective effect on human spermatozoa. Spermatozoa were selected by swim-up and vitrified in close sealed straw using either a combination of human tubal fluid (HTF), sucrose and BHT 1 mm (VMBHT), or only HTF and sucrose (VM). The optimal concentration of BHT was determined by the observation of preserved progressive sperm motility (PSM) after warming and detection of plasma membrane (PMI), membrane mitochondrial potential (ΔΨm) and DNA integrity. The presence of reactive oxygen species (ROS) was also detected. The PSM was significantly higher in the VMBHT group (80.86 ± 5.41%) compared with the VM group (68.9 ± 3.67%) (P < 0.05). Butylhydroxytoluene significantly preserved DNA integrity (4.0 ± 0.1% versus 6.1 ± 1.6%; P < 0.05) and reduced ROS production (5.5 ± 2.2 versus 8.6 ± 1.8%; P < 0.05). Plasma membrane and ΔΨm showed no statistical differences. One millimolar BHT effectively maintained cell function and due to its antioxidant and antiviral properties could be used in semen cryopreservation of patients with viral infections transmitted by seminal plasma. PMID:24612426

  5. Butylated Hydroxytoluene Analogs: Synthesis and Evaluation of Their Multipotent Antioxidant Activities

    OpenAIRE

    Wageeh A. Yehye; Noorsaadah Abdul Rahman; Alhadi, Abeer A.; Hamid Khaledi; Ng Seik Weng; Azhar Ariffin

    2012-01-01

    A computer-aided predictions of antioxidant activities were performed with the Prediction Activity Spectra of Substances (PASS) program. Antioxidant activity of compounds 1, 3, 4 and 5 were studied using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and lipid peroxidation assays to verify the predictions obtained by the PASS program. Compounds 3 and

  6. Antioxidant activity and cytotoxicity of solubilized C60 and its conjugates with butylated hydroxytoluene

    OpenAIRE

    Nunes, A. S.; A Matias; Caetano, Liliana Aranha; Graça, Anabela; Simplício, Ana Luísa

    2011-01-01

    It has been described that fullerenes (C60) present interesting properties with potential application in clinical conditions related to oxidative stress. One of the most prominent features of fullerenes is the ability to quench free radicals. However, because of its poor solubility, this has been studied mostly in organic solutions, while the antioxidant activity and cytotoxicity of fullerenes and their derivates in aqueous medium is not well characterized. The antioxidant capacity of s...

  7. The Quantitative Determination of Butylated Hydroxytoluene in Chewing Gum Using GC--MS

    Science.gov (United States)

    Witter, A. E.

    2005-01-01

    The experiment to measure concentration of Photophysical Characterization(BHT) and determine percent recovery in chewing gum is described. The results demonstrated that over time, the concentration of BHT in the extract decreased owing to aerial oxidation.

  8. Current status of oral cancer chemoprevention

    Institute of Scientific and Technical Information of China (English)

    Moni Abraham Kuriakose

    2008-01-01

    @@ Chemoprevention is the administration of agents to block or reverse carcinogenesis. Chemoprevention in oral cancer has been directed towards reversal of premalignant lesion and prevention of second primary tumor.

  9. Moringa oleifera Lam: Targeting Chemoprevention.

    Science.gov (United States)

    Karim, Nurul Ashikin Abd; Ibrahim, Muhammad Din; Kntayya, Saie Brindha; Rukayadi, Yaya; Hamid, Hazrulizawati Abd; Razis, Ahmad Faizal Abdull

    2016-01-01

    Moringa oleifera Lam, family Moringaceae, is a perennial plant which is called various names, but is locally known in Malaysia as "murungai" or "kelor". Glucomoringin, a glucosinolate with from M. oleifera is a major secondary metabolite compound. The seeds and leaves of the plant are reported to have the highest amount of glucosinolates. M. oleifera is well known for its many uses health and benefits. It is claimed to have nutritional, medicinal and chemopreventive potentials. Chemopreventive effects of M. oleifera are expected due to the existence of glucosinolate which it is reported to have the ability to induce apoptosis in anticancer studies. Furthermore, chemopreventive value of M. oleifera has been demonstrated in studies utilizing its leaf extract to inhibit the growth of human cancer cell lines. This review highlights the advantages of M. oleifera targeting chemoprevention where glucosinolates could help to slow the process of carcinogenesis through several molecular targets. It is also includes inhibition of carcinogen activation and induction of carcinogen detoxification, anti-inflammatory, anti-tumor cell proliferation, induction of apoptosis and inhibition of tumor angiogenesis. Finally, for synergistic effects of M. oleifera with other drugs and safety, essential for chemoprevention, it is important that it safe to be consumed by human body and works well. Although there is promising evidence about M. oleifera in chemoprevention, extensive research needs to be done due to the expected rise of cancer in coming years and to gain more information about the mechanisms involved in M. oleifera influence, which could be a good source to inhibit several major mechanisms involved in cancer development. PMID:27644601

  10. Chemoprevention with green propolis green propolis extracted in L-lysine versus carcinogenesis promotion with L-lysine in N-Butyl-N-[4-hydroxybutyl] nitrosamine (BBN induced rat bladder cancer Quimioprevenção com própolis verde extraído em L-Lisina versus promoção da carcinogênese como L-Lisina em ratos induzidos ao câncer de bexiga pelo N-Butyl-N-[4-hydroxybutyl] nitrosamine (BBN

    Directory of Open Access Journals (Sweden)

    Conceição Aparecida Dornelas

    2012-02-01

    Full Text Available PURPOSE: To determine the effects of green propolis extracted in L-lysine (WSDP and of L- lysine for 40 weeks on induced rat bladder carcinogenesis. METHODS: The animals (groups I, II, III, IV, V and VI received BBN during 14 weeks. Group I was treated with propolis 30 days prior received BBN, and then these animals were treated daily with propolis; Groups II and III was treated with subcutaneous and oral propolis (respectively concurrently with BBN. The animals of Group IV were treated L-lysine; Group V received water subcutaneous; and Group VI received only to BBN. Among the animals not submitted to carcinogenesis induction, Group VII received propolis, Group VIII received L-lysine and Group IX received water. RESULTS: The carcinoma incidence in Group I was lower than that of control (Group VI. The carcinoma multiplicity in Group IV was greater than in Group VI. All animals treated with L-lysine developed carcinomas, and they were also more invasive in Group IV than in controls. On the other hand, Group VIII showed no bladder lesions. CONCLUSION: The WSDP is chemopreventive against rat bladder carcinogenesis, if administered 30 days prior to BBN , and that L-lysine causes promotion of bladder carcinogenesis.OBJETIVO: Determinar os efeitos da própolis verde extraída em L - Lisina (WSDP e da L-Lisina por 40 semanas em ratos induzidos a carcinogênese de bexiga. MÉTODOS: Os animais (grupos I, II, III, IV, V e VI receberam BBN por 14 semanas. O grupo I foi tratado com própolis 30 dias antes de receber BBN e em seguida estes animais foram tratados diariamente com própolis; Os grupos II e III foram tratados com própolis subcutânea e oral (respectivamente e concorretemente com BBN. Os animais do grupo IV foram tratados com L- Lisina; o grupo V recebeu água subcutânea; o grupo VI recebeu apenas BBN. Entre os animais não submetidos a indução de carcinogênese, Grupo VII, receberam própolis, Grupo VIII, receberam L-Lisina e Grupo IX

  11. Chemoprevention of familial adenomatous polyposis.

    Science.gov (United States)

    Lynch, Patrick M

    2016-07-01

    Familial adenomatous polyposis (FAP) has always been first and foremost a surgical disease, whose treatment with colectomy has long been known to reduce risk of premature cancer death. The notion of reducing polyp burden and potentially delaying surgical intervention has spawned a host of "chemoprevention" trials. In this paper I selectively review the findings from these studies, highlighting trial design issues and in particular some of the limitations of historical and existing trial endpoint measures. Nonsteroidal anti-inflammatory agents have been the most commonly employed chemopreventive agents. Sulindac, largely by historical accident, has been the most extensively studied, and is widely considered the standard of care when a clinical decision to intervene medically is made. Newer trials are evaluating combinations of agents in order to take advantage of differing mechanisms of action, in the hope of achieving synergy, as no single agent predictably or completely suppresses adenoma growth. Some of these studies and other single-agent interventions are discussed, though an exploration of the various mechanisms of action is beyond the scope of this paper. It is essential that future trials focus on the issue of "clinical benefit", not simply because the US Food and Drug Administration has insisted on it, but because only real evidence-based advances can improve the standard of medical care for FAP patients. Hence my focus on issues of trial design and clinically relevant endpoints. PMID:27083160

  12. Comet Assay in Cancer Chemoprevention.

    Science.gov (United States)

    Santoro, Raffaela; Ferraiuolo, Maria; Morgano, Gian Paolo; Muti, Paola; Strano, Sabrina

    2016-01-01

    The comet assay can be useful in monitoring DNA damage in single cells caused by exposure to genotoxic agents, such as those causing air, water, and soil pollution (e.g., pesticides, dioxins, electromagnetic fields) and chemo- and radiotherapy in cancer patients, or in the assessment of genoprotective effects of chemopreventive molecules. Therefore, it has particular importance in the fields of pharmacology and toxicology, and in both environmental and human biomonitoring. It allows the detection of single strand breaks as well as double-strand breaks and can be used in both normal and cancer cells. Here we describe the alkali method for comet assay, which allows to detect both single- and double-strand DNA breaks. PMID:26608293

  13. [Chemoprevention of prostate cancer - a plea].

    Science.gov (United States)

    Schmitz-Dräger, B J; Bismarck, E; Schöffski, O; Fischer, C

    2012-05-01

    The high disease prevalence, the presentation in older age, a frequently slowly progressing course of disease, and high costs make the diagnosis of and therapy for prostate cancer a special challenge for urologists. Effective prevention of the disease may help to improve some of the problems mentioned above. Two randomised, controlled studies have proved that effective chemoprevention of prostate cancer is viable using 5α-reductase inhibitors (finasteride, dutasteride). Furthermore, there is increasing evidence that other compounds, e. g., selective oestrogen receptor modulators (SERMs), NSAIDs and statins might also be effective. This review investigates potential risks and benefits of chemoprevention including a consideration of health economical aspects. The authors conclude that the options of chemoprevention should be investigated in an open and unbiased way. PMID:22639024

  14. Ellagitannins in Cancer Chemoprevention and Therapy.

    Science.gov (United States)

    Ismail, Tariq; Calcabrini, Cinzia; Diaz, Anna Rita; Fimognari, Carmela; Turrini, Eleonora; Catanzaro, Elena; Akhtar, Saeed; Sestili, Piero

    2016-01-01

    It is universally accepted that diets rich in fruit and vegetables lead to reduction in the risk of common forms of cancer and are useful in cancer prevention. Indeed edible vegetables and fruits contain a wide variety of phytochemicals with proven antioxidant, anti-carcinogenic, and chemopreventive activity; moreover, some of these phytochemicals also display direct antiproliferative activity towards tumor cells, with the additional advantage of high tolerability and low toxicity. The most important dietary phytochemicals are isothiocyanates, ellagitannins (ET), polyphenols, indoles, flavonoids, retinoids, tocopherols. Among this very wide panel of compounds, ET represent an important class of phytochemicals which are being increasingly investigated for their chemopreventive and anticancer activities. This article reviews the chemistry, the dietary sources, the pharmacokinetics, the evidence on chemopreventive efficacy and the anticancer activity of ET with regard to the most sensitive tumors, as well as the mechanisms underlying their clinically-valuable properties. PMID:27187472

  15. Ellagitannins in Cancer Chemoprevention and Therapy

    Directory of Open Access Journals (Sweden)

    Tariq Ismail

    2016-05-01

    Full Text Available It is universally accepted that diets rich in fruit and vegetables lead to reduction in the risk of common forms of cancer and are useful in cancer prevention. Indeed edible vegetables and fruits contain a wide variety of phytochemicals with proven antioxidant, anti-carcinogenic, and chemopreventive activity; moreover, some of these phytochemicals also display direct antiproliferative activity towards tumor cells, with the additional advantage of high tolerability and low toxicity. The most important dietary phytochemicals are isothiocyanates, ellagitannins (ET, polyphenols, indoles, flavonoids, retinoids, tocopherols. Among this very wide panel of compounds, ET represent an important class of phytochemicals which are being increasingly investigated for their chemopreventive and anticancer activities. This article reviews the chemistry, the dietary sources, the pharmacokinetics, the evidence on chemopreventive efficacy and the anticancer activity of ET with regard to the most sensitive tumors, as well as the mechanisms underlying their clinically-valuable properties.

  16. Chemoprevention of photocarcinogenesis by selected dietary botanicals.

    OpenAIRE

    Baliga, Manjeshwar S; Santosh K. Katiyar

    2006-01-01

    KEYWORDS - CLASSIFIACATION: adverse effects;Animals;Antineoplastic Agents;Antineoplastic Agents,Phytogenic;Antioxidants;chemistry;Chemoprevention;drug therapy;Dermatology;dietary modulation of cancer & cancer biomarkers;Dietary Supplements;Evaluation;Humans;methods;Neoplasms,Radiation-Induced;prevention & control;Phytotherapy;radiation effects;Research;Skin;Skin Neoplasms;therapeutic use;toxicity;Ultraviolet Rays. Epidemiological, clinical and laboratory studies have implicated solar ultra...

  17. Pancreatic Cancer Chemoprevention Translational Workshop: Meeting Report.

    Science.gov (United States)

    Miller, Mark Steven; Allen, Peter; Brentnall, Teresa A; Goggins, Michael; Hruban, Ralph H; Petersen, Gloria M; Rao, Chinthalapally V; Whitcomb, David C; Brand, Randall E; Chari, Suresh T; Klein, Alison P; Lubman, David M; Rhim, Andrew D; Simeone, Diane M; Wolpin, Brian M; Umar, Asad; Srivastava, Sudhir; Steele, Vernon E; Rinaudo, Jo Ann S

    2016-09-01

    Pancreatic cancer is the fourth leading cause of cancer related deaths in the United States with a 5-year survival rate of less than 10%. The Division of Cancer Prevention of the National Cancer Institute sponsored the Pancreatic Cancer Chemoprevention Translational Workshop on September 10 to 11, 2015. The goal of the workshop was to obtain information regarding the current state of the science and future scientific areas that should be prioritized for pancreatic cancer prevention research, including early detection and intervention for high-risk precancerous lesions. The workshop addressed the molecular/genetic landscape of pancreatic cancer and precursor lesions, high-risk populations and criteria to identify a high-risk population for potential chemoprevention trials, identification of chemopreventative/immunopreventative agents, and use of potential biomarkers and imaging for assessing short-term efficacy of a preventative agent. The field of chemoprevention for pancreatic cancer is emerging, and this workshop was organized to begin to address these important issues and promote multi-institutional efforts in this area. The meeting participants recommended the development of an National Cancer Institute working group to coordinate efforts, provide a framework, and identify opportunities for chemoprevention of pancreatic cancer. PMID:27518363

  18. Breast Cancer Chemoprevention: Old and New Approaches

    Directory of Open Access Journals (Sweden)

    Massimiliano Cazzaniga

    2012-01-01

    Full Text Available In 1976, Sporn has defined chemoprevention as “the use of pharmacologic or natural agents that inhibit the development of invasive breast cancer either by blocking the DNA damage that initiates carcinogenesis, or by arresting or reversing the progression of premalignant cells in which such damage has already occurred.” Although the precise mechanism or mechanisms that promote a breast cancer are not completely established, the success of several recent clinical trials in preventive settings in selected high-risk populations suggests that chemoprevention is a rational and an appealing strategy. Breast cancer chemoprevention has focused heavily on endocrine intervention using selective estrogen receptor modulators (SERMs and aromatase inhibitors (AIs. Achieving much success in this particular setting and new approaches as low-dose administration are actually under investigations in several topics. Unfortunately, these drugs are active in prevention of endocrine responsive lesions only and have no effect in reducing the risk of estrogen-negative breast cancer. Thus, recently new pathways, biomarkers, and agents likely are to be effective in this subgroup of cancers and were put under investigation. Moreover, the identification of new potential molecular targets and the development of agents aimed at these targets within cancer have already had a significant impact on advanced cancer therapy and provide a wealth of opportunities for chemoprevention. This paper will highlight current clinical research in both ER-positive and ER-negative breast cancer chemoprevention, explaining the biologic effect of the various agents on carcinogenesis and precancerous lesions, and finally presenting an excursus on the state-of-the-art about new molecular targets under investigations in breast cancer settings.

  19. Breast Cancer Chemoprevention: Old and New Approaches

    OpenAIRE

    Massimiliano Cazzaniga; Bernardo Bonanni

    2012-01-01

    In 1976, Sporn has defined chemoprevention as “the use of pharmacologic or natural agents that inhibit the development of invasive breast cancer either by blocking the DNA damage that initiates carcinogenesis, or by arresting or reversing the progression of premalignant cells in which such damage has already occurred.” Although the precise mechanism or mechanisms that promote a breast cancer are not completely established, the success of several recent clinical trials in preventive settings i...

  20. Preclinical Assays for Identifying Cancer Chemopreventive Phytochemicals

    OpenAIRE

    Oyama, Takeru; Yasui, Yumiko; Sugie, Shigeyuki; Tanaka, Takuji

    2009-01-01

    Dietary factors influence carcinogenesis in a variety of tissues. The consumption of fruits and vegetables is associated with a decreased risk of several types of epithelial malignancies. In addition, there are interrelationships between diet, environmental factors, and genetics that can affect cancer risk. Potential chemopreventive agents against cancer development can be found among nutritive and/or nonnutritive compounds in inedible and edible plants. To identify potential cancer chemoprev...

  1. Beneficial and adverse effects of chemopreventive agents

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung Mu; Park, Kwang-Kyun

    2003-03-01

    The beneficial and adverse effects of some chemopreventive agents, such as Vitamins A, C, E, beta-carotene, indole-3-carbinol, capsaicin, garlic, and aloe are reviewed. Two large randomized trials with a lung cancer endpoint, the Alpha-Tocopherol, Beta-Carotene (ATBC) Prevention Study and the Beta-Carotene and Retinol Efficacy Trial (CARET), suggested that antioxidants might be harmful in smokers. However, the results of the Linxian study and of the ATBC or the CARET studies were significantly different in this respect, and therefore, the relationship between antioxidant and carcinogenesis remains open to debate. Indole-3-carbinol has cancer promoting activities in the colon, thyroid, pancreas, and liver, whereas capsaicin alters the metabolism of chemical carcinogens and may promote carcinogenesis at high doses. Organosulfur compounds and selenium from garlic have no or a little enhancing effect on cancer promotion stage. Information upon chemopreventive mechanisms that inhibit carcinogenesis is imperfect, although the causes and natures of certain human cancers are known. Therefore, definitive preventive guidelines should be carefully offered for various types of tumors, which properly consider ethnic variations, and the efficacies and the safety of chemopreventive agents.

  2. Chemoprevention of prostate cancer by isoflavonoids.

    Science.gov (United States)

    Aufderklamm, Stefan; Miller, Florian; Galasso, Anastasia; Stenzl, Arnulf; Gakis, Georgios

    2014-01-01

    In Europe, prostate cancer (PC) is the most common malignancy in males. There are three known risk factors strongly coherent to the development of PC: heredity, ethnical origin, and age. Migration studies have shown that environmental factors may influence the development of PC. In this context, specific nutritional components may exert an influence on the tumorigenesis of PC. Primary prevention of PC is still an important issue due to its high prevalence, treatment-associated morbidities, and long-term complications. Phytoestrogenes as flavonoids seem to play an essential role in the chemoprevention of PC which is possibly due to their hormonal function and antioxidative capability. Flavonoids and their subgroups are naturally existent in traditional asian and vegetarian nutrients as coverings of plants, fruits, and vegetables. Two of the most frequently investigated flavonoids are genistein and quercetin. These nutritional components may have therapeutic potential and may impact the development of PC. Even though these flavonoids show promising results in the chemoprevention of PC, the literature is almost experimental, epidemiological, and retrospective with a missing long-term follow-up. Therefore, randomized clinical trials are urgently needed to evaluate in depth its oncologic effects in PC. PMID:24531783

  3. Cancer Chemopreventive Ability of Conjugated Linolenic Acids

    Directory of Open Access Journals (Sweden)

    Kazuo Miyashita

    2011-11-01

    Full Text Available Conjugated fatty acids (CFA have received increased interest because of their beneficial effects on human health, including preventing cancer development. Conjugated linoleic acids (CLA are such CFA, and have been reviewed extensively for their multiple biological activities. In contrast to other types of CFAs including CLA that are found at low concentrations (less than 1% in natural products, conjugated linolenic acids (CLN are the only CFAs that occur in higher quantities in natural products. Some plant seeds contain a considerably high concentration of CLN (30 to 70 wt% lipid. Our research group has screened CLN from different plant seed oils to determine their cancer chemopreventive ability. This review describes the physiological functions of CLN isomers that occur in certain plant seeds. CLN are able to induce apoptosis through decrease of Bcl-2 protein in certain human cancer cell lines, increase expression of peroxisome proliferator-activated receptor (PPAR-γ, and up-regulate gene expression of p53. Findings in our preclinical animal studies have indicated that feeding with CLN resulted in inhibition of colorectal tumorigenesis through modulation of apoptosis and expression of PPARγ and p53. In this review, we summarize chemopreventive efficacy of CLN against cancer development, especially colorectal cancer.

  4. Beer constituents as potential cancer chemopreventive agents.

    Science.gov (United States)

    Gerhäuser, Clarissa

    2005-09-01

    Beer is a complex alcoholic beverage made from barley (malt), hop, water and yeast. Phenolic constituents of beer are derived from malt (70-80%) and hop (20-30%). Structural classes include simple phenols, benzoic- and cinnamic acid derivatives, coumarins, catechins, di-, tri- and oligomeric proanthocyanidins, (prenylated) chalcones and flavonoids as well as alpha- and iso-alpha-acids derived from hop. Compounds belonging to different structural classes have distinct profiles of biological activity in in vitro test systems, and in combination might lead to enhanced effects. Scientific evidence has accumulated over the past 10 years pointing to the cancer preventive potential of selected hop-derived beer constituents, i.e., prenylflavonoids including xanthohumol and isoxanthohumol, and hop bitter acids. Chemopreventive activities observed with these compounds relevant to inhibition of carcinogenesis at the initiation, promotion and progression phases, as well as results from in vivo studies on metabolism, bioavailability and efficacy are summarised in this review. PMID:15953717

  5. Chemopreventive Herbal Anti-Oxidants: Current Status and Future Perspectives

    OpenAIRE

    Patel, Rachana; Garg, Rachana; Erande, Suvarna; B. Maru, Girish

    2007-01-01

    Cancer chemoprevention is fast becoming a lucrative approach for controlling cancer. Carcinogenesis being a complex multi-step, multi-factorial process, a number of chemopreventive interventions can be employed. These strategies are generally directed against two broad events of carcinogenesis viz., initiation and promotion/progression. Anti-initiation interventions principally involve inhibition of carcinogen activation, scavenging of free radicals and reactive carcinogen metabolites along w...

  6. The Use of Animal Models for Cancer Chemoprevention Drug Development

    OpenAIRE

    Steele, Vernon E.; Lubet, Ronald A.

    2010-01-01

    Animal models currently are used to assess the efficacy of potential chemopreventive agents, including synthetic chemicals, chemical agents obtained from natural products and natural product mixtures. The observations made in these models as well as other data are then used to prioritize agents to determine which are qualified to progress to clinical chemoprevention trials. Organ specific animal models are employed to determine which agents or classes of agents are likely to be the most effec...

  7. Molecular Targeted Therapies Using Botanicals for Prostate Cancer Chemoprevention

    OpenAIRE

    Kumar, Nagi; Chornokur, Ganna

    2012-01-01

    In spite of the large number of botanicals demonstrating promise as potential cancer chemopreventive agents, most have failed to prove effectiveness in clinical trials. Critical requirements for moving botanical agents to recommendation for clinical use include adopting a systematic, molecular-target based approach and utilizing the same ethical and rigorous methods that are used to evaluate other pharmacological agents. Preliminary data on a mechanistic rationale for chemoprevention activity...

  8. Evaluation of the cancer chemopreventive potency of dithiolethione analogs of oltipraz.

    Science.gov (United States)

    Roebuck, B D; Curphey, Thomas J; Li, Yuan; Baumgartner, Karen J; Bodreddigari, Sridevi; Yan, Jian; Gange, Stephen J; Kensler, Thomas W; Sutter, Thomas R

    2003-12-01

    Oltipraz and related dithiolethiones constitute an important class of chemopreventive agents that enhance the expression of carcinogen detoxication and antioxidant genes. Dose-response studies were undertaken to characterize the cancer chemopreventive activities of several dithiolethiones that are at least as active as oltipraz as inducers. Inhibition of formation of pre-neoplastic lesions and formation of DNA adducts in livers of rats exposed to aflatoxin B1 (AFB1) was monitored. In the tumorigenesis experiment, the dithiolethiones were orally gavaged 3 days/week for 3 successive weeks and at four doses ranging from 0.03 to 0.3 mmol/kg body wt. AFB1 was gavaged beginning 1 week after the start of the dithiolethiones and for two successive weeks. The burden of AFB1-induced putative pre-neoplastic lesions (glutathione S-transferase-placental isoform positive foci) was quantified by light microscopy. Reduction in AFB-DNA adduct burden was assessed 24 h following the first dose of AFB1. Both the parent 1,2-dithiole-3-thione (D3T) and its 5-tert-butyl derivative were more potent inhibitors than oltipraz against these endpoints, while two of the seven tested analogs were slightly less inhibitory. D3T, the most potent dithiolethione of this series, was examined by microarray analysis for induction of hepatic genes at an intermediate chemopreventive dose (0.1 mmol/kg). Transcript levels of eight genes, including two known to detoxify aflatoxin, namely, glutathione S-transferase A5 (GSTA5) and AFB1 aldehyde reductase (AFAR) were elevated. Western analysis indicated that induction of hepatic GSTA5 and AFAR were directly related to the dose of D3T. At the highest dose of D3T (0.3 mmol/kg), protein levels of GSTA5 and AFAR were induced by 7- and 27-fold, respectively. While efficacy in humans has yet to be tested, D3T is clearly more potent than oltipraz and serves as a useful molecular probe for determining the key events associated with protection by this class of agents

  9. Chemoprevention--history and general principles.

    Science.gov (United States)

    Wu, Xiangwei; Patterson, Sherri; Hawk, Ernest

    2011-08-01

    Our current understanding of tumourigenesis suggests that cancer develops as a series of cumulative genetic and epigenetic derangements across time culminating in a clone of cells differing from its population of origin in terms of cellular identity, growth control, and its contextual relationship to its environment. Our increasing knowledge of the timing, sequence, frequency, and specific implications of these changes provides unique opportunities for earlier identification of aberrations and preventive interventions. Here we discuss the fundamentals of cancer prevention including the targets, cohorts, agents, endpoints, mechanistic biomarkers, designs, and strategies employed in preventive drug development. There have been many notable successes in this field such as the identification and development of tamoxifen and raloxifene for breast cancer risk reduction, instillational BCG and valrubicin for treatment of preinvasive bladder cancer, and a variety of topical and systemic agents that effectively treat preinvasive neoplastic lesions of the skin. A variety of null or negative developmental endeavours have occurred as well, including trials of beta-carotene for lung cancer prevention, nutritional modifications for colorectal adenoma prevention, and most recently, selenium and alpha-tocopherol for prostate cancer prevention. A third category of prevention trials can be summarized as investigationally successful, but not achieving regulatory success. The development of finasteride and dutasteride for prostate cancer prevention, and celecoxib for colorectal neoplasia prevention fall into this category. In less than four decades, cancer chemoprevention has transformed from a concept to an achievable reality. PMID:22122762

  10. Endotoxin and cancer chemo-prevention.

    Science.gov (United States)

    Mastrangelo, Giuseppe; Fadda, Emanuela; Cegolon, Luca

    2013-10-01

    Reduced rates of lung cancer have been observed in several occupational groups exposed to high levels of organic dusts contaminated by endotoxin. The underlying anti-neoplastic mechanism of endotoxin may be an increased secretion of endogenous anti-neoplastic mediators and activation of the toll-like receptors (TLR). A detoxified endotoxin derivative, Monophosphoryl Lipid A (MPL(®)) is marketed in Europe since 1999 as part of the adjuvant systems in allergy vaccines for treatment of allergic rhino-conjunctivitis and allergic asthma. Over 200,000 patients have used them to date (nearly 70% in Germany). Since detailed exposure (MPL(®) dose and timing of administration) and individual data are potentially available, an observational follow-up study could be conducted in Germany to investigate the protective effect of MPL(®) against cancer, comparing cancer incidence in two groups of patients with allergic rhinitis: those treated with allergoids plus MPL(®) and those treated with a vaccine including the same allergoids but not MPL(®). The protective effect of MPL(®) could be quantified in ever and never smokers. If this proposed observational study provides evidence of protective effects, MPL(®) could be immediately used as a chemo-preventive agent since it is already in use as adjuvant in human vaccines against cancer.

  11. Advanced drug delivery systems of curcumin for cancer chemoprevention.

    Science.gov (United States)

    Bansal, Shyam S; Goel, Mehak; Aqil, Farrukh; Vadhanam, Manicka V; Gupta, Ramesh C

    2011-08-01

    Since ancient times, chemopreventive agents have been used to treat/prevent several diseases including cancer. They are found to elicit a spectrum of potent responses including anti-inflammatory, antioxidant, antiproliferative, anticarcinogenic, and antiangiogenic activity in various cell cultures and some animal studies. Research over the past 4 decades has shown that chemopreventives affect a number of proteins involved in various molecular pathways that regulate inflammatory and carcinogenic responses in a cell. Various enzymes, transcription factors, receptors, and adhesion proteins are also affected by chemopreventives. Although, these natural compounds have shown significant efficacy in cell culture studies, they elicited limited efficacy in various clinical studies. Their introduction into the clinical setting is hindered largely by their poor solubility, rapid metabolism, or a combination of both, ultimately resulting in poor bioavailability upon oral administration. Therefore, to circumvent these limitations and to ease their transition to clinics, alternate strategies should be explored. Drug delivery systems such as nanoparticles, liposomes, microemulsions, and polymeric implantable devices are emerging as one of the viable alternatives that have been shown to deliver therapeutic concentrations of various potent chemopreventives such as curcumin, ellagic acid, green tea polyphenols, and resveratrol into the systemic circulation. In this review article, we have attempted to provide a comprehensive outlook for these delivery approaches, using curcumin as a model agent, and discussed future strategies to enable the introduction of these highly potent chemopreventives into a physician's armamentarium. PMID:21546540

  12. Chemoprevention of Radiation Induced Rat Mammary Neoplasms

    Science.gov (United States)

    Huso, David L.

    1999-01-01

    Radiations encountered in space include protons and heavy ions such as iron as well as their secondaries. The relative biological effect (RBE) of these ions is not known, particularly at the doses and dose-rates expected for planetary missions. Neutrons, are not particularly relevant to space travel, but have been found experimentally to have an increase in their RBE with decreasing dose. If a similar trend of increasing RBE with decreasing dose is present for heavy ions and protons during irradiation in space, the small doses received during space travel could potentially have substantial carcinogenic risk. Clearly more investigation of the effects of heavy ions and protons is needed before accurate risk assessment for prolonged travel in space can be done. One means to mitigate the increased risk of cancer due to radiation exposure in space is by developing effective countermeasures that can reduce the incidence of tumor development. Tamoxifen has recently been shown to be an effective chemopreventive agent in both animal models and humans for the prevention of mammary tumors. Tamoxifen is a unique drug, with a highly specific mechanism of action affecting a specific radiation-sensitive population of epithelial cells in the mammary gland. In human studies, the annual incidence of a primary tumor in the contralateral breast of women with previous breast cancer is about 8 per 1000, making them an exceedingly high-risk group for the development of breast cancer. In this high risk group, treated with tamoxifen, daily, for 2 years, the incidence of a new primary tumor in the contralateral breast was approximately one third of that noted in the non-tamoxifen treatment group. Tamoxifen antagonizes the action of estrogen by competing for the nuclear receptor complex thereby altering the association of the receptor complex and nuclear binding sites. Its effects in reducing the development of breast cancer could be accomplished by controlling clinically undetectable

  13. Molecular Mechanisms Behind the Chemopreventive Effects of Anthocyanidins

    Directory of Open Access Journals (Sweden)

    De-Xing Hou

    2004-01-01

    Full Text Available Anthocyanins are polyphenolic ring-based flavonoids, and are widespread in fruits and vegetables of red-blue color. Epidemiological investigations and animal experiments have indicated that anthocyanins may contribute to cancer chemoprevention. The studies on the mechanism have been done recently at molecular level. This review summarizes current molecular bases for anthocyanidins on several key steps involved in cancer chemoprevention: (i inhibition of anthocyanidins in cell transformation through targeting mitogen-activated protein kinase (MAPK pathway and activator protein 1 (AP-1 factor; (ii suppression of anthocyanidins in inflammation and carcinogenesis through targeting nuclear factor kappa B (NF-κB pathway and cyclooxygenase 2 (COX-2 gene; (iii apoptotic induction of cancer cells by anthocyanidins through reactive oxygen species (ROS / c-Jun NH2-terminal kinase (JNK-mediated caspase activation. These data provide a first molecular view of anthocyanidins contributing to cancer chemoprevention.

  14. Frugal chemoprevention: targeting Nrf2 with foods rich in sulforaphane.

    Science.gov (United States)

    Yang, Li; Palliyaguru, Dushani L; Kensler, Thomas W

    2016-02-01

    With the properties of efficacy, safety, tolerability, practicability and low cost, foods containing bioactive phytochemicals are gaining significant attention as elements of chemoprevention strategies against cancer. Sulforaphane [1-isothiocyanato-4-(methylsulfinyl)butane], a naturally occurring isothiocyanate produced by cruciferous vegetables such as broccoli, is found to be a highly promising chemoprevention agent against not only a variety of cancers such as breast, prostate, colon, skin, lung, stomach or bladder, but also cardiovascular disease, neurodegenerative diseases, and diabetes. For reasons of experimental exigency, preclinical studies have focused principally on sulforaphane itself, while clinical studies have relied on broccoli sprout preparations rich in either sulforaphane or its biogenic precursor, glucoraphanin. Substantive subsequent evaluation of sulforaphane pharmacokinetics and pharmacodynamics has been undertaken using either pure compound or food matrices. Sulforaphane affects multiple targets in cells. One key molecular mechanism of action for sulforaphane entails activation of the Nrf2-Keap1 signaling pathway although other actions contribute to the broad spectrum of efficacy in different animal models. This review summarizes the current status of pre-clinical chemoprevention studies with sulforaphane and highlights the progress and challenges for the application of foods rich in sulforaphane and/or glucoraphanin in the arena of clinical chemoprevention.

  15. Is There a Future for Chemoprevention of Prostate Cancer?

    Science.gov (United States)

    Bosland, Maarten C

    2016-08-01

    The outcome of the Selenium and Vitamin E Cancer Prevention Trial, demonstrating harm and no preventive activity of selenomethionine and α-tocopherol for prostate cancer, and the lack of approval by the FDA for the use of 5α-reductase inhibitors to prevent prostate cancer have cast doubt about the future of chemoprevention of prostate cancer. This article attempts to critically assess whether the notion that chemoprevention of prostate cancer has no future is warranted. Risk of prostate cancer is modifiable and chemoprevention of prostate cancer, particularly fatal/lethal cancer, is both needed and possible. However, the approach to prostate cancer-chemopreventive agent development has not followed a rational and systematic process. To make progress, the following steps are necessary: (i) identification of intermediate biomarkers predictive of fatal/lethal disease; (ii) development of a rational approach to identification of candidate agents, including high-throughput screening and generation of information on mechanism and biology of candidate agents and potential molecular targets; and (iii) systematic evaluation of the predictive value of preclinical models, phase II trials, and intermediate biomarkers for the outcome of phase III trials. New phase III trials should be based on adequate preclinical and phase II studies. Cancer Prev Res; 9(8); 642-7. ©2016 AACR. PMID:27099271

  16. Chemoprevention of prostate cancer with nutrients and supplements.

    Science.gov (United States)

    Van Poppel, Hendrik; Tombal, Bertrand

    2011-01-01

    As the adult population is increasing, prostate cancer (PCa) will become a considerable health problem in the next millennium. This has raised public interest in potential chemoprevention of this disease. As PCa is extremely common and generally slow to progress it is regarded as an ideal candidate for chemoprevention. At present, the 5 alpha-reductase inhibitors finasteride and dutasteride have been identified as preventive agents. This review describes whether selenium, alpha-tocopherol, isoflavones, lycopene green tea polyphenols, calcium, and resveratrol may be useful for decreasing the risk of PCa in men. Although encouraging results are present, some studies show negative results. Differences in study design, sample size, dose administered, and/or concentrations achieved in the body may be the reason for these inconsistencies. Today, chemopreventive agents may be appropriate for high-risk patients like those with high-grade prostatic intraepithelial neoplasia and other high-risk groups such as patients with elevated prostate specific antigen (PSA) and negative biopsy, rapid PSA velocity, and with a family history of PCa. Although larger randomized controlled studies are needed and epidemiologic evidence should be placed in a clinical context, physicians must be aware of these preventive opportunities in PCa care. Combinations of chemopreventive agents should be carefully investigated because mechanisms of action may be additive or synergistic. PMID:21629831

  17. Risk adapted chemoprevention for prostate cancer: an option?

    Science.gov (United States)

    Schmitz-Dräger, Bernd J; Schöffski, Oliver; Marberger, Michael; Sahin, Sevim; Schmid, Hans-Peter

    2014-01-01

    A high disease prevalence, the presentation in older age, a frequently slowly progressing course of disease, and high costs make diagnosis and therapy of prostate cancer a special challenge for urologists. Effective prevention of the disease may help to resolve some of the problems mentioned above. Two randomised, controlled studies prove that effective chemoprevention of prostate cancer is possible using 5-α reductase inhibitors (finasteride, dutasteride) (LoE 1) both in individuals at low and those at high risk developing prostate cancer. Furthermore, there is evidence that other compounds, e.g. selective estrogen receptor modulators (SERMs), non-steroidal anti-inflammatory drugs (NSAIDs) and statins might also be effective. This review investigates potential risks and benefits of chemoprevention including a consideration of health economic aspects. The authors conclude that chemoprevention in a high risk cohort using 5-α reductase inhibitors is a viable option and may even be cost effective. In consequence, the options of chemoprevention in prostate cancer should be further explored in an open and unbiased way. PMID:24531781

  18. Frugal chemoprevention: targeting Nrf2 with foods rich in sulforaphane.

    Science.gov (United States)

    Yang, Li; Palliyaguru, Dushani L; Kensler, Thomas W

    2016-02-01

    With the properties of efficacy, safety, tolerability, practicability and low cost, foods containing bioactive phytochemicals are gaining significant attention as elements of chemoprevention strategies against cancer. Sulforaphane [1-isothiocyanato-4-(methylsulfinyl)butane], a naturally occurring isothiocyanate produced by cruciferous vegetables such as broccoli, is found to be a highly promising chemoprevention agent against not only a variety of cancers such as breast, prostate, colon, skin, lung, stomach or bladder, but also cardiovascular disease, neurodegenerative diseases, and diabetes. For reasons of experimental exigency, preclinical studies have focused principally on sulforaphane itself, while clinical studies have relied on broccoli sprout preparations rich in either sulforaphane or its biogenic precursor, glucoraphanin. Substantive subsequent evaluation of sulforaphane pharmacokinetics and pharmacodynamics has been undertaken using either pure compound or food matrices. Sulforaphane affects multiple targets in cells. One key molecular mechanism of action for sulforaphane entails activation of the Nrf2-Keap1 signaling pathway although other actions contribute to the broad spectrum of efficacy in different animal models. This review summarizes the current status of pre-clinical chemoprevention studies with sulforaphane and highlights the progress and challenges for the application of foods rich in sulforaphane and/or glucoraphanin in the arena of clinical chemoprevention. PMID:26970133

  19. Hepatic retention and toxicological responses during feeding and depuration periods in Atlantic salmon ( Salmo salar ) fed graded levels of the synthetic antioxidant, butylated hydroxytoluene.

    Science.gov (United States)

    Holaas, Eivind; Bohne, Victoria B; Hamre, Kristin; Arukwe, Augustine

    2008-12-10

    The human safety aspects of seafood production require the expansion of vital knowledge of both nutrients and possible contaminants along the entire production chain. Thus, production of safer seafood can be achieved by using feed materials that are low in contaminants, while maintaining balanced nutrition, in order to secure optimal fish and consumer health. Our understanding of primary responses of fish health and production related diseases, as well as biological processes that influence carry-over and lowering of contaminants in farmed fish, will contribute to a sustainable production of safer seafood products. Therefore, we have studied the liver deposition and toxicological effects in salmon fed graded levels of BHT during a 12-week feeding followed by a 2-week depuration period using chemical, molecular, and catalytic assays. In general, our data showed that BHT was significantly retained in the liver and selectively modulated toxicological responses in the xenobiotic biotransformation pathways during the feeding period. Specifically, BHT produced consistent dose- and time-specific gene expression patterns for AhR2alpha, AhR2beta, CYP1A1, CYP3A, UGT1, and GSTpi. The effect of BHT on the gene expression of biotransformation enzyme did not parallel enzyme activity levels, suggesting a possible inhibition by parent BHT or its metabolites. As a safety precaution, the production of farmed Atlantic salmon in Norway requires a mandatory 2-week depuration period prior to slaughtering and market delivery to ensure the elimination of veterinary medicaments, additives, and other undesirable components. Comparison of feeding and depuration periods showed that BHT was highly retained in fish liver, as only 8-13% of fed BHT was eliminated during the 2-week depuration period. This is just a part of the total concentration in the whole fish, since BHT may have been distributed and accumulated in other organs. Since BHT or its metabolites putatively inhibited biotransformation enzymes and affected metabolism of the compound, they may have potential for toxicological and adverse health effects for both fish and fish consumers through carry-over processes from the fish products. PMID:19007167

  20. Activation of liver X receptor inhibits the development of pulmonary carcinomas induced by 3-methylcholanthrene and butylated hydroxytoluene in BALB/c mice

    OpenAIRE

    Qixue Wang; Lei Sun; Xiaoxiao Yang; Xingzhe Ma; Qi Li; Yuanli Chen; Ying Liu; Di Zhang; Xiaoju Li; Rong Xiang; Yuquan Wei; Jihong Han; Yajun Duan

    2016-01-01

    We previously reported that LXR ligand, T0901317, inhibited the growth of inoculated Lewis lung carcinoma in C57BL/6 mice by activating IFN-γ production. However, the effects of T0901317 on carcinogen-induced pulmonary carcinomas remain unknown. In this study, we initially conducted a statistical analysis on the data of human lung cancer samples extracted from the TCGA database, and determined that survival rate/time of lung cancer patients and grade of lung adenocarcinoma were positively and...

  1. Keap1 eye on the target: chemoprevention of liver cancer

    Institute of Scientific and Technical Information of China (English)

    Melinda Sue YATES; Thomas Wells KENSLER

    2007-01-01

    Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide,causing nearly 600000 deaths each year. Increased risk of HCC due to chronic infection with hepatitis B virus (HBV) and exposure to dietary aflatoxins is respon-sible for many of these deaths. Prevention strategies targeting HBV infection and aflatoxin exposure could dramatically impact the rates of HCC. Universal HBV vaccination programs have begun in some high-risk areas. Strategies to reduce aflatoxin contamination in food stores have also been implemented. However,complete elimination of aflatoxin contamination might not be possible. For this reason, chemoprevention strategies which alter aflatoxin disposition are a practi-cal strategy to reduce the incidence of HCC in populations with high dietary aflatoxin exposure. The mechanisms of aflatoxin-induced hepatocarcinogenesis are well known. This knowledge provides the basis for evaluation of both expo-sures to aflatoxin, as well as modulation of aflatoxin disposition by chemopreventive agents. Products of aflatoxin DNA damage and toxicity as well as other metabo-lites can be used as biomarkers to evaluate modulation of aflatoxin disposition.Modulation of aflatoxin disposition can be achieved through induction of conju-gating and cytoprotective enzymes. Many of these enzymes are regulated through Kelch ECH-associating protein 1 (Keap 1)-NF-E2-related factor 2(Nrf2)-antioxi-dant response element (ARE) signaling, making this pathway an important mo-lecular target for chemoprevention. Rodent studies have identified several classes of chemopreventive agents which induce cytoprotective genes. These inducers include phenolic antioxidants, dithiolethiones, isothiocyanates, and triterpenoids.Furthermore, clinical interventions have shown that inducers of Keap 1-Nrf2-ARE signaling increase cytoprotective enzyme expression, resulting in modula-tion of aflatoxin disposition. Much work remains to be done in order to take promising chemopreventive

  2. Chemoprevention of prostate cancer with nutrients and supplements

    Directory of Open Access Journals (Sweden)

    Van Poppel H

    2011-04-01

    Full Text Available Hendrik Van Poppel1, Bertrand Tombal21Department of Urology, University Hospital, KU Leuven, Leuven, Belgium; 2Service d’Urologie, Cliniques Universtaires Saint Luc, Brussels, BelgiumAbstract: As the adult population is increasing, prostate cancer (PCa will become a considerable health problem in the next millennium. This has raised public interest in potential chemoprevention of this disease. As PCa is extremely common and generally slow to progress it is regarded as an ideal candidate for chemoprevention. At present, the 5 alpha-reductase inhibitors finasteride and dutasteride have been identified as preventive agents. This review describes whether selenium, alpha-tocopherol, isoflavones, lycopene green tea polyphenols, calcium, and resveratrol may be useful for decreasing the risk of PCa in men. Although encouraging results are present, some studies show negative results. Differences in study design, sample size, dose administered, and/or concentrations achieved in the body may be the reason for these inconsistencies. Today, chemopreventive agents may be appropriate for high-risk patients like those with high-grade prostatic intraepithelial neoplasia and other high-risk groups such as patients with elevated prostate specific antigen (PSA and negative biopsy, rapid PSA velocity, and with a family history of PCa. Although larger randomized controlled studies are needed and epidemiologic evidence should be placed in a clinical context, physicians must be aware of these preventive opportunities in PCa care. Combinations of chemopreventive agents should be carefully investigated because mechanisms of action may be additive or synergistic.Keywords: alpha-tocopherol, chemoprevention, isoflavones, lycopene, polyphenols, prostate cancer, selenium

  3. The role of natural dietary compounds in colorectal cancer chemoprevention

    Directory of Open Access Journals (Sweden)

    Anna Olejnik

    2010-04-01

    Full Text Available This review discusses the preventive and therapeutic potential of natural dietary compounds against colorectal cancer. The chemopreventive properties of many natural food matrices and purified bioactive compounds have been evaluated. Prominent among the dietary constituents that are the focus of interest in colorectal cancer chemoprevention are dietary fiber, probiotics and prebiotics, methionine and folate, vitamins D and E, calcium and selenium, anthocyanins, procyanidins, phytoestrogens, isothiocyanates, epigallocatechin gallate, curcumin, and resveratrol. Laboratory studies provide strong evidence for the antitumor potential of these dietary agents. The mechanisms of their chemopreventive action are associated with, for example, the modulation of gene expression involved in the regulation of cell proliferation, differentiation, and apoptosis and the suppression of metastasis and angiogenesis. The anti-carcinogenic properties of these food compounds are also related to inhibition of many inflammatory agents, including the expression of cyclooxygenase-2. [i]In vitro[/i] and animal studies showed that most of them can protect against various carcinogens mediating colon cancer and suggest that they can also sensitize tumors to chemotherapy and radiation. Although experimental studies have clearly demonstrated their anticancer activity, not many clinical trials have provided satisfying results, not only because of the lack of efficiency of the chemopreventive agents, but also due to the lack of precise biomarkers monitoring their effects on colon cancer. Despite the lack of strong evidence for the anticancer potential of natural food compounds, clinicians have high hopes for using these factors in colon cancer chemoprevention and decreasing the incidence of this common malignancy in the future.

  4. The Mechanism in Gastric Cancer Chemoprevention by Allicin.

    Science.gov (United States)

    Luo, Runlan; Fang, Dengyang; Hang, Hongdong; Tang, Zeyao

    2016-01-01

    Gastric cancer remains high prevalence and fatality rates in China even though its morbidity has been decreased drastically. Allicin, which is from an assistance food-garlic (Allium Sativum L), was found to be effective in gastric cancer treatment. It is a defensive substance with a board biological properties: inhibition of bacteria, fungus, virus, controlled hypertension, diabetes, and chemoprevention of several cancers, etc. Experiments have shown that allicin can be chemopreventive to gastric cancer by inhibiting the growth of cancer cells, arresting cell cycle at G2/M phase, endoplasmic reticulum (ER) stress, and mitochondria-mediated apoptosis, which includes the caspase-dependent/-independent pathways and death receptor pathway. Those mechanisms probably involve in modulating enzymatic activity, restraining DNA formation, scavenging free radicals, and affecting cell proliferation and even tumor growth. Therefore, this review is focus on the mechanism of allicin in gastric cancer. PMID:26555611

  5. Shrimp Lipids: A Source of Cancer Chemopreventive Compounds

    Directory of Open Access Journals (Sweden)

    Armando Burgos-Hernández

    2013-10-01

    Full Text Available Shrimp is one of the most popular seafoods worldwide, and its lipids have been studied for biological activity in both, muscle and exoskeleton. Free fatty acids, triglycerides, carotenoids, and other lipids integrate this fraction, and some of these compounds have been reported with cancer chemopreventive activities. Carotenoids and polyunsaturated fatty acids have been extensively studied for chemopreventive properties, in both in vivo and in vitro studies. Their mechanisms of action depend on the lipid chemical structure and include antioxidant, anti-proliferative, anti-mutagenic, and anti-inflammatory activities, among others. The purpose of this review is to lay groundwork for future research about the properties of the lipid fraction of shrimp.

  6. Evidence supporting the conceptual framework of cancer chemoprevention in canines.

    Science.gov (United States)

    Kondratyuk, Tamara P; Adrian, Julie Ann Luiz; Wright, Brian; Park, Eun-Jung; van Breemen, Richard B; Morris, Kenneth R; Pezzuto, John M

    2016-01-01

    As with human beings, dogs suffer from the consequences of cancer. We investigated the potential of a formulation comprised of resveratrol, ellagic acid, genistein, curcumin and quercetin to modulate biomarkers indicative of disease prevention. Dog biscuits were evaluated for palatability and ability to deliver the chemopreventive agents. The extent of endogenous DNA damage in peripheral blood lymphocytes from dogs given the dietary supplement or placebo showed no change. However, H2O2-inducible DNA damage was significantly decreased after consumption of the supplement. The expression of 11 of 84 genes related to oxidative stress was altered. Hematological parameters remained in the reference range. The concept of chemoprevention for the explicit benefit of the canine is compelling since dogs are an important part of our culture. Our results establish a proof-of-principle and provide a framework for improving the health and well-being of "man's best friend". PMID:27216246

  7. Polyphenols: Key Issues Involved in Chemoprevention of Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Sebastiano Cimino

    2012-01-01

    Full Text Available Prostate cancer is is the most common solid neoplasm and it is now recognized as one of the most important medical problems facing the male population. Due to its long latency and its identifiable preneoplastic lesions, prostate cancer is an ideal target tumor for chemoprevention. Different compounds are available and certainly polyphenols represent those with efficacy against prostate cancer. This review take a look at activity and properties of major polyphenolic substances, such as epigallocatechin-3-gallate, curcumin, resveratrol and the flavonoids quercetin and genistein. Although the current studies are limited, mechanisms of action of polyphenols added with the lack of side effects show a a start for future strategies in prostate chemoprevention.

  8. Discovery and development of sulforaphane as a cancer chemopreventive phytochemical

    Institute of Scientific and Technical Information of China (English)

    Yuesheng ZHANG; Li TANG

    2007-01-01

    Sulforaphane (SF) is a phytochemical that displays both anticarcinogenic and anticancer activity. SF modulates many cancer-related events, including suscep-tibility to carcinogens, cell death, cell cycle, angiogenesis, invasion and metastasis.We review its discovery and development as a cancer chemopreventive agent with the intention of encouraging further research on this important compound and facilitating the identification and development of new phytochemicals for cancer prevention.

  9. Crocus sativus L. (saffron) for cancer chemoprevention: A mini review

    OpenAIRE

    Prasan R Bhandari

    2015-01-01

    Cancer is one of the most feared diseases globally and there has been a sustained rise in its incidence in both developing and developed countries. Despite the growing therapeutic options for patients with cancer, their efficacy is time-limited and non-curative. Hence to overcome these drawbacks, an incessant screening for superior and safer drugs has been ongoing for numerous decades, resulting in the detection of anti-cancer properties of several phytochemicals. Chemoprevention using readil...

  10. Colon cancer chemoprevention with ginseng and other botanicals.

    OpenAIRE

    Wargovich, M J

    2001-01-01

    Colorectal cancer is becoming increasingly common in Asian countries and still remains the second leading cause of cancer deaths in the United States. Efforts to prevent colon cancer have targeted early detection through screening and chemoprevention. For the last ten years our laboratory has utilized an in vivo screening assay for the testing of potential cancer preventives for colon cancer. We have conducted investigations on over 150 compounds including many with botanical or herbal origin...

  11. The strategies to control prostate cancer by chemoprevention approaches

    International Nuclear Information System (INIS)

    Prostate cancer (PCA) is the most commonly diagnosed cancer in men in the United States with growing worldwide incidence. Despite intensive investment in improving early detection, PCA often escapes timely detection and mortality remains high; this malignancy being the second highest cancer-associated mortality in American men. Collectively, health care costs of PCA results in an immense financial burden that is only expected to grow. Additionally, even in cases of successful treatment, PCA is associated with long-term and pervasive effects on patients. A proactive alternative to treat PCA is to prevent its occurrence and progression prior to symptomatic malignancy. This may serve to address the issue of burgeoning healthcare costs and increasing number of sufferers. One potential regimen in service of this alternative is PCA chemoprevention. Here, chemical compounds with cancer preventive efficacy are identified on the basis of their potential in a host of categories: their historical medicinal use, correlation with reduced risk in population studies, non-toxicity, their unique chemical properties, or their role in biological systems. PCA chemopreventive agents are drawn from multiple broad classes of chemicals, themselves further subdivided based on source or potential effect, with most derived from natural products. Many such compounds have shown efficacy, varying from inhibiting deregulated PCA cell signaling, proliferation, epithelial to mesenchymal transition (EMT), invasion, metastasis, tumor growth and angiogenesis and inducing apoptosis. Overall, these chemopreventive agents show great promise in PCA pre-clinical models, though additional work remains to be done in effectively translating these findings into clinical use

  12. Sulforaphane (SFN: An Isothiocyanate in a Cancer Chemoprevention Paradigm

    Directory of Open Access Journals (Sweden)

    Mohammad Fahad Ullah

    2015-07-01

    Full Text Available The International Agency for Research on Cancer (IARC in its latest World Cancer Report (2014 has projected the increase in the global cancer burden from 14 million (2012 to 22 million incidence annually within the next two decades. Such statistics warrant a collaborative engagement of conventional and complementary and alternative therapies to contain and manage cancer. In recent years, there has been a shift in the cancer chemoprevention paradigm with a significant focus turning towards bioactive components of human diets for their anticancer properties. Since diet is an integral part of lifestyle and given that an estimated one third of human cancers are believed to be preventable though appropriate lifestyle modification including dietary habits, the current shift in the conventional paradigm assumes significance. Several epidemiological studies have indicated that consumption of broccoli is associated with a lower risk of cancer incidence including breast, prostate, lung, stomach and colon cancer. The edible plant belonging to the family of cruciferae such as broccoli is a rich source of glucoraphanin, a precursor of isothiocyanate sulforaphane which is considered to be a potent anti-cancer agent. Plant-based dietary agents such as sulforaphane mimic chemotherapeutic drugs such as vorinostat, possessing histone deacetylase inhibition activity. Evidence from epidemiological and experimental studies have emerged, enhancing the clinical plausibility and translational value of sulforaphane in cancer chemoprevention. The present review provides the current understanding of the cancer chemopreventive pharmacology of sulforaphane towards its potential as an anticancer agent.

  13. Estrogen intracrinology: therapy and chemoprevention of breast cancer

    Directory of Open Access Journals (Sweden)

    Barbara Licznerska

    2010-05-01

    Full Text Available Breast cancer affects approximately 1 in 10 women and is the leading cause of death in females between the ages of 40 and 50 years in the Western world. The World Health Organization (WHO classified estrogens as carcinogenic in humans and one of the most important risk factors of breast cancer. One of the main arguments has been that estrogens can not only promote cancers but may also initiate mutations caused by certain estrogen metabolites. Therapeutics and chemopreventive agents (e.g. tamoxifen currently in use for breast cancer generally act through an estrogen receptor (ER mechanism and are thus inappropriate for estrogen-independent disease. In the last decade, numerous studies have searched for new therapeutic and preventive agents acting independently of ER status, hence suitable for cases of estrogen-independent breast cancer. In postmenopausal women, when gonads stop producing estrogens, active hormones are produced locally. These locally produced bioactive estrogens exert their actions in the cells of tissues that have not been considered classical hormone-producing sites (i.e. breast cancer tissue and where synthesis occurs without release into the circulation. This mechanism has been termed “intracrinology”, a phenomenon different from the classical concept of endocrinology. Interference in the local production of estrogens seems to be a good alternative to chemotherapy and chemoprevention of breast carcinoma. In this article, crucial enzymes in estrogen’s biosynthesis in the breast and their potential use in therapy and chemoprevention are discussed.

  14. Chain elongation analog of resveratrol as potent cancer chemoprevention agent.

    Science.gov (United States)

    Kang, Yan-Fei; Qiao, Hai-Xia; Xin, Long-Zuo; Ge, Li-Ping

    2016-09-01

    Resveratrol is identified as a natural cancer chemoprevention agent. There has been a lot of interest in designing and developing resveratrol analogs with cancer chemoprevention activity superior to that of parent molecule and exploring their action mechanism in the past several decades. In this study, we have synthesized resveratrol analogs of compounds A-C via conjugated chain elongation based on isoprene unit retention strategy. Remarkably, cytotoxic activity analysis results indicated that compound B possesses the best proliferation inhibition activity for NCI-H460 cells in all the test compounds. Intriguingly, compound B displayed a higher cytotoxicity against human non-small cell lung cancer cells (NCI-H460) compared to normal human embryonic lung fibroblasts (MRC-5). Afterward, flow cytometry analysis showed that compound B would induce cell apoptosis. We further researched the action mechanism. When NCI-H460 cells were incubated by compound B for 6 or 9 h, respectively, the intracellular reactive oxygen species (ROS) level was enhanced obviously. With elevation of intracellular ROS level, flow cytometry measurement verified mitochondrial transmembrane potential collapse, which was accompanied by the up-regulation of Bax and down-regulation of Bcl-2. More interestingly, compound B increased the expression of caspase-9 and caspase-3, which induced cell apoptosis. Moreover, compound B arrested cell cycle in G0/G1 phase. These are all to provide useful information for designing resveratrol-based chemoprevention agent and understanding the action mechanism. PMID:27160168

  15. Australian clinicians and chemoprevention for women at high familial risk for breast cancer

    Directory of Open Access Journals (Sweden)

    Keogh Louise A

    2009-05-01

    Full Text Available Abstract Objectives Effective chemoprevention strategies exist for women at high risk for breast cancer, yet uptake is low. Physician recommendation is an important determinant of uptake, but little is known about clinicians' attitudes to chemoprevention. Methods Focus groups were conducted with clinicians at five Family Cancer Centers in three Australian states. Discussions were recorded, transcribed and analyzed thematically. Results Twenty three clinicians, including genetic counselors, clinical geneticists, medical oncologists, breast surgeons and gynaecologic oncologists, participated in six focus groups in 2007. The identified barriers to the discussion of the use of tamoxifen and raloxifene for chemoprevention pertained to issues of evidence (evidence for efficacy not strong enough, side-effects outweigh benefits, oophorectomy superior for mutation carriers, practice (drugs not approved for chemoprevention by regulatory authorities and not government subsidized, chemoprevention not endorsed in national guidelines and not many women ask about it, and perception (clinicians not knowledgeable about chemoprevention and women thought to be opposed to hormonal treatments. Conclusion The study demonstrated limited enthusiasm for discussing breast cancer chemoprevention as a management option for women at high familial risk. Several options for increasing the likelihood of clinicians discussing chemoprevention were identified; maintaining up to date national guidelines on management of these women and education of clinicians about the drugs themselves, the legality of "off-label" prescribing, and the actual costs of chemopreventive medications.

  16. Chemoprevention with Acetylsalicylic Acid, Vitamin D and Calcium Reduces Risk of Carcinogen-induced Lung Tumors

    DEFF Research Database (Denmark)

    Pommergaard, Hans-Christian; Burcharth, Jakob; Rosenberg, J;

    2013-01-01

    Background/Aim: Research has shown that chemoprevention may be effective against the development of lung cancer. The purpose of the present study was to evaluate the effect of oral chemoprevention in a mouse model of tobacco carcinogen-induced lung tumor.......Background/Aim: Research has shown that chemoprevention may be effective against the development of lung cancer. The purpose of the present study was to evaluate the effect of oral chemoprevention in a mouse model of tobacco carcinogen-induced lung tumor....

  17. Demand boom boosts ethyl, butyl acetate

    International Nuclear Information System (INIS)

    US ethyl and butyl acetate markets are being described as 'extremely tight.' One major domestic producer is 'in a sold-out position' and has 'gone on sales control' with respect to these two products. Producers say that sales of both ethyl and butyl acetate have increased during the past year, and industry observers say they expect to see an April 1 price initiative of 2 cts to 3 cts/lb, and possibly a second increase in October. While one producer suggests that this market strength could be 'a sign that the coatings industry is turning around,' most agree that reformulation is the principal driver of growth. Ethyl acetate is said to be replacing methyl ethyl ketone in many formulations, while butyl acetate and butyl acetate blends are substituting for methyl isobutyl ketone. In addition, both ethyl and butyl acetate work as substitutes for xylene and toluene in certain applications. In an effort to conform to the requirements of the Clean Air Act of 1990 and to cooperate with the Environmental Protection Agency's 33/50 voluntary emissions reduction program, coatings manufacturers are moving as quickly as possible to eliminate solvents from their products. And although solvents as a whole will eventually see a dramatic decline in consumption, the temporary beneficiaries of reformulation will be certain of the oxygenated solvents, says Jeff Back, business manager at Kline ampersand Co

  18. Compound list: butylated hydroxyanisole [Open TG-GATEs

    Lifescience Database Archive (English)

    Full Text Available butylated hydroxyanisole BHA 00156 ftp://ftp.biosciencedbc.jp/archive/open-tggates/...LATEST/Human/in_vitro/butylated_hydroxyanisole.Human.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/o...pen-tggates/LATEST/Rat/in_vivo/Liver/Single/butylated_hydroxyanisole.Rat.in_vivo.Liver.Single.zip ftp://ftp....biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vivo/Liver/Repeat/butylated_hydroxyanisole.Rat.in_vivo.Liver.Repeat.zip ...

  19. Update on the chemopreventive effects of ginger and its phytochemicals.

    Science.gov (United States)

    Baliga, Manjeshwar Shrinath; Haniadka, Raghavendra; Pereira, Manisha Maria; D'Souza, Jason Jerome; Pallaty, Princy Louis; Bhat, Harshith P; Popuri, Sandhya

    2011-07-01

    The rhizomes of Zingiber officinale Roscoe (Zingiberaceae), commonly known as ginger, is one of the most widely used spice and condiment. It is also an integral part of many traditional medicines and has been extensively used in Chinese, Ayurvedic, Tibb-Unani, Srilankan, Arabic, and African traditional medicines, since antiquity, for many unrelated human ailments including common colds, fever, sore throats, vomiting, motion sickness, gastrointestinal complications, indigestion, constipation, arthritis, rheumatism, sprains, muscular aches, pains, cramps, hypertension, dementia, fever, infectious diseases, and helminthiasis. The putative active compounds are nonvolatile pungent principles, namely gingerols, shogaols, paradols, and zingerone. These compounds are some of the extensively studied phytochemicals and account for the antioxidant, anti-inflammatory, antiemetic, and gastroprotective activities. A number of preclinical investigations with a wide variety of assay systems and carcinogens have shown that ginger and its compounds possess chemopreventive and antineoplastic effects. A number of mechanisms have been observed to be involved in the chemopreventive effects of ginger. The cancer preventive activities of ginger are supposed to be mainly due to free radical scavenging, antioxidant pathways, alteration of gene expressions, and induction of apoptosis, all of which contribute towards decrease in tumor initiation, promotion, and progression. This review provides concise information from preclinical studies with both cell culture models and relevant animal studies by focusing on the mechanisms responsible for the chemopreventive action. The conclusion describes directions for future research to establish its activity and utility as a human cancer preventive and therapeutic drug. The above-mentioned mechanisms of ginger seem to be promising for cancer prevention; however, further clinical studies are warranted to assess the efficacy and safety of ginger. PMID

  20. Implications for chemoprevention of prostate cancer with intake of cruciferous vegetables

    Institute of Scientific and Technical Information of China (English)

    Jeanny B Aragon-Ching

    2011-01-01

    @@ Efforts on chemoprevention have been an attractive target of investigation for prostate cancer.Since prostate cancer is the most common non-cutaneous malignancy among American men, efforts for chemopreventative strategies make sense.However, such undertaking has been wrought with problems and wide-scale efforts to launch drug chemoprevention have been dampened by mixed results.

  1. 21 CFR 182.3169 - Butylated hydroxyanisole.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Butylated hydroxyanisole. 182.3169 Section 182.3169 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives §...

  2. Recovering/recycling of butyl and halogenated butyl rubber via ionizing radiation

    International Nuclear Information System (INIS)

    Polymeric materials (plastics and rubbers) attain a continuous and raising proportion of urban and industrial scraps discarded in landfills; their impact on environment are more and more concerning. The implementation of new technologies in order to reduce impacts of plastic waste on the environment, at an effective cost, proved to be a great problem, due to inherent complexity for polymers re-using. Ionizing radiation is capable to modify structure and properties of polymeric material. Butyl and halobutyl rubbers have been used within a comprehensive scale, applications such as tires spare parts and diverse artifacts. The major high energy photon effect, as gamma-rays in butyl and halo butyl rubbers consists in free-radicals generation along changes in mechanical properties.This work aims to the development of controlled degradation processes (devulcanization) of butyl and halo butyl (chlorine and bromine) rubbers, in order to characterize their availability for transformation and modification of properties. Experimental results obtained showed that butyl and halobutyl rubbers,irradiated at 25 kGy and further sheared, are able to be used as an initial point for mixtures with pristine. (author)

  3. Targeting multiple signal pathways by chemopreventive agents for cancer prevention and therapy

    Institute of Scientific and Technical Information of China (English)

    Fazlul H SARKAR; Yi-wei LI

    2007-01-01

    In recent years, growing interest has been focused on the field of cancer prevention.Cancer prevention by chemopreventive agents offers significant promise for re-ducing the incidence and mortality of cancer. Chemopreventive agents may exert their effects either by blocking or metabolizing carcinogens or by inhibiting tumor cell growth. Another important benefit of chemopreventive agents is their non-toxic nature. Therefore, chemopreventive agents have recently been used for cancer treatment in combination with chemotherapeutics or radiotherapy, uncov-ering a novel strategy for cancer therapy. This strategy opens a new avenue fromcancer prevention to cancer treatment. In vitro and in vivo studies have demon-strated that chemopreventive agents could enhance the antitumor activity of chemotherapeutics, improving the treatment outcome. Growing evidence has shown that chemopreventive agents potentiate the efficacy of chemotherapy and radiotherapy through the regulation of multiple signaling pathways, including Akt, NF-κB, c-Myc, cyclooxygenase-2, apoptosis, and others, suggesting a multitargeted nature of chemopreventive agents. However, further in-depth mecha-nistic studies, in vivo animal experiments, and clinical trials are needed to investi-gate the effects of chemopreventive agents in combination treatment of cancer with conventional cancer therapies. More potent natural and synthetic chemo-preventive agents are also needed to improve the efficacy of mechanism-based and targeted therapeutic strategies against cancer, which are likely to make a significant impact on saving lives. Here, we have briefly reviewed the role of chemopreventive agents in cancer prevention, but most importantly, we have reviewed how they could be useful for cancer therapy in combination with con-ventional therapies.

  4. Antioxidative and Chemopreventive Properties of Vernonia amygdalina and Garcinia biflavonoid

    Directory of Open Access Journals (Sweden)

    Olatunde Owoeye

    2011-06-01

    Full Text Available Recently, considerable attention has been focused on dietary and medicinal phytochemicals that inhibit, reverse or retard diseases caused by oxidative and inflammatory processes. Vernonia amygdalina is a perennial herb belonging to the Asteraceae family. Extracts of the plant have been used in various folk medicines as remedies against helminthic, protozoal and bacterial infections with scientific support for these claims. Phytochemicals such as saponins and alkaloids, terpenes, steroids, coumarins, flavonoids, phenolic acids, lignans, xanthones, anthraquinones, edotides and sesquiterpenes have been extracted and isolated from Vernonia amygdalina. These compounds elicit various biological effects including cancer chemoprevention. Garcinia kola (Guttiferae seed, known as “bitter kola”, plays an important role in African ethnomedicine and traditional hospitality. It is used locally to treat illnesses like colds, bronchitis, bacterial and viral infections and liver diseases. A number of useful phytochemicals have been isolated from the seed and the most prominent of them is the Garcinia bioflavonoids mixture called kolaviron. It has well-defined structure and an array of biological activities including antioxidant, antidiabetic, antigenotoxic and hepatoprotective properties. The chemopreventive properties of Vernonia amygdalina and Garcinia biflavonoids have been attributed to their abilities to scavenge free radicals, induce detoxification, inhibit stress response proteins and interfere with DNA binding activities of some transcription factors.

  5. Phytochemicals as Anticancer and Chemopreventive Topoisomerase II Poisons

    Science.gov (United States)

    Ketron, Adam C.

    2013-01-01

    Phytochemicals are a rich source of anticancer drugs and chemopreventive agents. Several of these chemicals appear to exert at least some of their effects through interactions with topoisomerase II, an essential enzyme that regulates DNA supercoiling and removes knots and tangles from the genome. Topoisomerase II-active phytochemicals function by stabilizing covalent protein-cleaved DNA complexes that are intermediates in the catalytic cycle of the enzyme. As a result, these compounds convert topoisomerase II to a cellular toxin that fragments the genome. Because of their mode of action, they are referred to as topoisomerase II poisons as opposed to catalytic inhibitors. The first sections of this article discuss DNA topology, the catalytic cycle of topoisomerase II, and the two mechanisms (interfacial vs. covalent) by which different classes of topoisomerase II poisons alter enzyme activity. Subsequent sections discuss the effects of several phytochemicals on the type II enzyme, including demethyl-epipodophyllotoxins (semisynthetic anticancer drugs) as well as flavones, flavonols, isoflavones, catechins, isothiocyanates, and curcumin (dietary chemopreventive agents). Finally, the leukemogenic potential of topoisomerase II-targeted phytochemicals is described. PMID:24678287

  6. Tea beverage in chemoprevention and chemotherapy of prostate cancer

    Institute of Scientific and Technical Information of China (English)

    Imtiaz A SIDDIQUI; Mohammad SALEEM; Vaqar M ADHAMI; Mohammad ASIM; Hasan MUKHTAR

    2007-01-01

    Prostate cancer (Pca) is the most frequently diagnosed malignancy and the sec-ond leading cause of cancer-related deaths in American males with similar trends in many western countries. The existing treatment approaches and surgical inter-vention have not been able to effectively cope with this dreaded disease. For these reasons, it is necessary to intensify our efforts for a better understanding of the disease process and for the development of novel approaches for its preven-tion and treatment. Based on considerable evidence from in vivo and in vitro data and epidemiological studies, in recent years the beverage tea has gained consid-erable attention for reducing the risk of several cancers. Much of the cancerpreventive effects of tea, especially green tea appear to be mediated by the polyphe-nols present therein. Geographical evidence suggests that the incidence and occurrence of Pca is lower in populations that consume tea regularly. This evi-dence suggests that tea polyphenols could be extrapolated to optimize their chemopreventive properties against Pca. Pca represents an excellent candidate disease for chemoprevention because it is typically diagnosed in men over 50 years of age and therefore, even a modest delay in neoplastic development achieved through pharmacological or nutritional intervention could result in a substantial reduction in the incidence of clinically detectable disease. In this review we address the issue of possible use of tea, especially green tea, for the prevention aswell as treatment of Pca.

  7. The role of aspirin in colorectal cancer chemoprevention.

    Science.gov (United States)

    Singh Ranger, Gurpreet

    2016-08-01

    Considerable interest has emerged over the last decade regarding the role of aspirin in prevention of colorectal cancer. This disease is one of the commonest cancers in the Western World, therefore, the existence of a simple "everyday" agent, which could have the ability to prevent the disease, represents an invaluable opportunity clinicians may be able to exploit. Evidence from case-control and cohort studies, and recent updates of randomised controlled trials have been very encouraging-indicating benefit from long term use of aspirin at low dose. Possible mechanisms of chemoprevention include inhibition of the cyclooxygenase (COX) pathway, or COX-independent mechanisms, for example, the PIK3CA pathway, or therapy-induced senescence of cancer cells. The most serious side effect of prolonged aspirin treatment is haemorrhage, especially from the GI tract. This is likely to be less of a problem with chemoprevention at lower doses. One also needs to consider the impact if aspirin resistance, an increasingly recognised clinical entity. PMID:27289249

  8. Terpenoids as potential chemopreventive and therapeutic agents in liver cancer.

    Science.gov (United States)

    Thoppil, Roslin J; Bishayee, Anupam

    2011-09-27

    Despite significant advances in medicine, liver cancer, predominantly hepatocellular carcinoma remains a major cause of death in the United States as well as the rest of the world. As limited treatment options are currently available to patients with liver cancer, novel preventive control and effective therapeutic approaches are considered to be reasonable and decisive measures to combat this disease. Several naturally occurring dietary and non-dietary phytochemicals have shown enormous potential in the prevention and treatment of several cancers, especially those of the gastrointestinal tract. Terpenoids, the largest group of phytochemicals, traditionally used for medicinal purposes in India and China, are currently being explored as anticancer agents in clinical trials. Terpenoids (also called "isoprenoids") are secondary metabolites occurring in most organisms, particularly plants. More than 40 000 individual terpenoids are known to exist in nature with new compounds being discovered every year. A large number of terpenoids exhibit cytotoxicity against a variety of tumor cells and cancer preventive as well as anticancer efficacy in preclinical animal models. This review critically examines the potential role of naturally occurring terpenoids, from diverse origins, in the chemoprevention and treatment of liver tumors. Both in vitro and in vivo effects of these agents and related cellular and molecular mechanisms are highlighted. Potential challenges and future directions involved in the advancement of these promising natural compounds in the chemoprevention and therapy of human liver cancer are also discussed. PMID:21969877

  9. Carnosol: A Phenolic Diterpene With Cancer Chemopreventive Potential

    Science.gov (United States)

    Chun, Kyung-Soo; Kundu, Juthika; Chae, In Gyeong; Kundu, Joydeb Kumar

    2014-01-01

    Cancer is an unbeaten health challenge for the humankind. After striving for decades to find a cancer cure, attention has now been shifted to reduce the morbidity and mortality from cancer by halting the course of tumor development. Numerous bioactive phytochemicals, especially those present in edible and non-edible plant species, have been reported to reduce the risk of many cancers. Multiple lines of evidence suggest that carnosol, a phenolic diterpene present in rosemary (Rosmarinus officinalis L.), holds the promise of preventing certain types of cancer. A remarkable progress has been made in delineating the biochemical mechanisms underlying the chemopreventive effects of carnosol. Results from in vitro cell culture studies as well as animal model experiments have revealed that carnosol inhibits experimentally induced carcinogenesis and exhibits potent anti-oxidative, anti-inflammatory, antiproliferative and apoptosis inducing properties. Moreover, carnosol enhances the sensitivity of chemoresistant cancer cells to chemotherapeutic agents. The purpose of this review is to shed light on the detailed mechanistic aspects of cancer chemoprevention with carnosol. PMID:25337578

  10. Intrinsic fluorescence biomarkers in cells treated with chemopreventive drugs

    Science.gov (United States)

    Kirkpatrick, Nathaniel D.; Brands, William R.; Zou, Changping; Brewer, Molly A.; Utzinger, Urs

    2005-03-01

    Non-invasive monitoring of cellular metabolism offers promising insights into areas ranging from biomarkers for drug activity to cancer diagnosis. Fluorescence spectroscopy can be utilized in order to exploit endogenous fluorophores, typically metabolic co-factors nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD), and estimate the redox status of the sample. Fluorescence spectroscopy was applied to follow metabolic changes in epithelial ovarian cells as well as bladder epithelial cancer cells during treatment with a chemopreventive drug that initiates cellular quiescence. Fluorescence signals consistent with NADH, FAD, and tryptophan were measured to monitor cellular activity, redox status, and protein content. Cells were treated with varying concentrations of N-4-(hydroxyphenyl) retinamide (4-HPR) and measured in a stable environment with a sensitive fluorescence spectrometer. A subset of measurements was completed on a low concentration of cells to demonstrate feasibility for medical application such as in bladder or ovary washes. Results suggest that all of the cells responded with similar dose dependence but started at different estimated redox ratio baseline levels correlating with cell cycle, growth inhibition, and apoptosis assays. NADH and tryptophan related fluorescence changed significantly while FAD related fluorescence remained unaltered. Fluorescence data collected from approximately 1000 - 2000 cells, comparable to a bladder or ovary wash, was measurable and useful for future experiments. This study suggests that future intrinsic biomarker measurements may need to be most sensitive to changes in NADH and tryptophan related fluorescence while using FAD related fluorescence to help estimate the baseline redox ratio and predict response to chemopreventive agents.

  11. Ginseng Metabolites on Cancer Chemoprevention: An Angiogenesis Link?

    Directory of Open Access Journals (Sweden)

    Chong-Zhi Wang

    2015-09-01

    Full Text Available Cancer is a leading cause of death in the United States. Angiogenesis inhibitors have been introduced for the treatment of cancer. Based on the fact that many anticancer agents have been developed from botanical sources, there is a significant untapped resource to be found in natural products. American ginseng is a commonly used herbal medicine in the U.S., which possesses antioxidant properties. After oral ingestion, natural ginseng saponins are biotransformed to their metabolites by the enteric microbiome before being absorbed. The major metabolites, ginsenoside Rg3 and compound K, showed significant potent anticancer activity compared to that of their parent ginsenosides Rb1, Rc, and Rd. In this review, the molecular mechanisms of ginseng metabolites on cancer chemoprevention, especially apoptosis and angiogenic inhibition, are discussed. Ginseng gut microbiome metabolites showed significant anti-angiogenic effects on pulmonary, gastric and ovarian cancers. This review suggests that in addition to the chemopreventive effects of ginseng compounds, as angiogenic inhibitors, ginsenoside metabolites could be used in combination with other cancer chemotherapeutic agents in cancer management.

  12. Oral Carcinogenesis and Oral Cancer Chemoprevention: A Review

    Directory of Open Access Journals (Sweden)

    Takuji Tanaka

    2011-01-01

    Full Text Available Oral cancer is one of the major global threats to public health. The development of oral cancer is a tobacco-related multistep and multifocal process involving field cancerization and carcinogenesis. The rationale for molecular-targeted prevention of oral cancer is promising. Biomarkers of genomic instability, including aneuploidy and allelic imbalance, are possible to measure the cancer risk of oral premalignancies. Understanding of the biology of oral carcinogenesis will yield important advances for detecting high-risk patients, monitoring preventive interventions, and assessing cancer risk and pharmacogenomics. In addition, novel chemopreventive agents based on molecular mechanisms and targets against oral cancers will be derived from studies using appropriate animal carcinogenesis models. New approaches, such as molecular-targeted agents and agent combinations in high-risk oral individuals, are undoubtedly needed to reduce the devastating worldwide consequences of oral malignancy.

  13. Repurposing old drugs to chemoprevention: the case of metformin.

    Science.gov (United States)

    Heckman-Stoddard, Brandy M; Gandini, Sara; Puntoni, Matteo; Dunn, Barbara K; DeCensi, Andrea; Szabo, Eva

    2016-02-01

    Multiple epidemiologic studies have documented an association between the anti-diabetic agent metformin and reduced cancer incidence and mortality. However, this effect has not been consistently demonstrated in animal models or more recent epidemiological studies. The purpose of this paper is to examine metformin's chemopreventive potential by reviewing relevant mechanisms of action, preclinical evidence of efficacy, updated epidemiologic evidence after correction for potential biases and confounders, and recently completed and ongoing clinical trials. Although repurposing drugs with well described mechanisms of action and safety profiles is an appealing strategy for cancer prevention, there is no substitute for well executed late phase clinical trials to define efficacy and populations that are most likely to benefit from an intervention. PMID:26970131

  14. Women victims of sexual violence: adherence to chemoprevention of HIV.

    Science.gov (United States)

    Diniz, Normélia Maria Freire; de Almeida, Lílian Conceição Guimarães; dos S Ribeiro, Bárbara Cristina; de Macêdo, Valéria Góes

    2007-01-01

    This study aimed to investigate the adherence of women victims of sexual violence, to AIDS chemoprevention treatment. A quantitative study was carried out at a care service to victims of sexual violence in Salvador (Bahia, Brazil). Study participants were 172 women. Data were collected through interviews with forms and consultation of patient files. The results showed that 45.4% of the abused women were teenagers and 40.7% of the attended women were raped. Only 54% of the women were advised to use antiretrovirals to prevent HIV. Adherence to treatment occurred in 57.4% of cases and discontinuity corresponded to 42.6%. Non-adherence to treatment was attributed to psychological or emotional disorders and non-understanding of the established treatment. Therefore, it is important that professionals pay careful attention in order to perceive the conditions that might increase women's vulnerability to the infection. PMID:17375226

  15. Aspirin as a chemoprevention agent for colorectal cancer.

    LENUS (Irish Health Repository)

    Lee, Chun Seng

    2012-11-01

    Colorectal cancer (CRC) is one of the leading causes of mortality in the western world. It is widely accepted that neoplasms such as colonic polyps are precursors to CRC formation; with the polyp-adenoma-carcinoma sequences well described in medical literature [1, 2]. It has been shown that Aspirin and other non-steroid anti-inflammatory drugs (NSAID) have a negative effect on polyp and cancer formation. This review aims to describe some of the mechanism behind the chemoprotective properties of aspirin; COX 2 inhibition, regulation of proliferation and apoptosis and effects on the immune system and also the current evidence that supports its use as a chemoprevention agent against CRC. We will also aim to explore the side effects with the use of aspirin and the pitfalls of using aspirin routinely for primary prophylaxis against CRC.

  16. Chemoprevention of chemical-induced skin cancer by Panax ginseng root extract

    OpenAIRE

    Sharma, Jyoti; Pradeep K. Goyal

    2015-01-01

    Background Cancer has emerged as a major health problem globally as a consequence to the increased longevity of the population, changing the environment and life style. Chemoprevention is a new and promising strategy for reducing cancer burden. Recently, some natural products have been identified for their chemopreventive activity to reduce the cancer incidence. Ginseng is known for its potential to treat various ailments in human beings. The present study was designed to explore the anticanc...

  17. Chemopreventive drugs: Mechanisms via inhibition of cancer stem cells in colorectal cancer

    OpenAIRE

    Kim, Tae Il

    2014-01-01

    Recent epidemiological studies, basic research and clinical trials on colorectal cancer (CRC) prevention have helped identify candidates for effective chemopreventive drugs. However, because of the conflicting results of clinical trials or side effects, the effective use of chemopreventive drugs has not been generalized, except for patients with a high-risk for developing hereditary CRC. Advances in genetic and molecular technologies have highlighted the greater complexity of carcinogenesis, ...

  18. Biomarker and animal models for assessment of retinoid efficacy in cancer chemoprevention

    Institute of Scientific and Technical Information of China (English)

    Richard M NILES

    2007-01-01

    Vitamin A is essential for normal growth and development. Epidemiology and laboratory studies suggest that decreased vitamin A levels and defective metabo-lisrn/action may contribute to the genesis of certain cancers. Based on this information, natural and synthetic derivatives of vitamin A (retinoids) have been used for chemoprevention of cancer. Retinoids have had some success in the chemoprevention of leukoplakia and in the decreased incidence of second prima-ties in head and neck cancer. There is little information on biomarkers that can be used to assess the efficacy of the chemopreventive activity of retinoids. The ability of retinoids to induce RARb has been consistently shown to correlate with the response of cells and tissues to retinoic acid, but few other biomarkers have been certified as indicators of retinoid activity. In light of the failure of the ATBC and CARET clinical intervention trials for chemoprevention of lung cancer, greater use of animal models for chemoprevention studies is necessary. The potential combination of phytochemicals that inhibit DNA methyltransferase activity with retinoids holds promise for more effective chemoprevention of retinoid-unrespon-sive premalignant lesions.

  19. Combination chemoprevention with diclofenac, calcipotriol and difluoromethylornithine inhibits development of non-melanoma skin cancer in mice

    DEFF Research Database (Denmark)

    Pommergaard, Hans-Christian; Burcharth, Jakob; Rosenberg, Jacob;

    2013-01-01

    Background/Aim: With increasing incidence of non-melanoma skin cancer (NMSC), focus on chemoprevention of this disease is growing. The aim of this study was to evaluate topical combination therapies as chemoprevention of UV radiation-induced tumors in a mouse model.......Background/Aim: With increasing incidence of non-melanoma skin cancer (NMSC), focus on chemoprevention of this disease is growing. The aim of this study was to evaluate topical combination therapies as chemoprevention of UV radiation-induced tumors in a mouse model....

  20. An efficient and highly selective ortho-tert-butylation of p-cresol with methyl tert-butyl ether catalyzed by sulfonated ionic liquids

    Directory of Open Access Journals (Sweden)

    Alamdari Reza Fareghi

    2014-01-01

    Full Text Available A novel series of sulfonic acid-functionalized ionic liquids (SFILs was found to act as efficient catalysts for ortho-tert-butylation of p-cresol with methyl tert-butyl ether (MTBE as the tert-butylating agent without an added solvent. The mono o-tert-butylated product was obtained in up to 80.4% isolated yield and 95.2% selectivity under such green conditions. No O-tert-butylated byproducts were formed.

  1. An efficient and highly selective ortho-tert-butylation of p-cresol with methyl tert-butyl ether catalyzed by sulfonated ionic liquids

    OpenAIRE

    Alamdari Reza Fareghi; Zamani Faezeh Ghorbani; Zekri Negar

    2014-01-01

    A novel series of sulfonic acid-functionalized ionic liquids (SFILs) was found to act as efficient catalysts for ortho-tert-butylation of p-cresol with methyl tert-butyl ether (MTBE) as the tert-butylating agent without an added solvent. The mono o-tert-butylated product was obtained in up to 80.4% isolated yield and 95.2% selectivity under such green conditions. No O-tert-butylated byproducts were formed.

  2. Plant Polyphenols as Chemopreventive Agents for Lung Cancer

    Science.gov (United States)

    Amararathna, Madumani; Johnston, Michael R.; Rupasinghe, H. P. Vasantha

    2016-01-01

    Lung cancer may be prevented by a diet rich in fruits and vegetables as they are enriched with dietary antioxidant polyphenols, such as flavonoids, proanthocyanidins, lignans, stilbenes, and phenolic acids. Dietary polyphenols exert a wide range of beneficial biological functions beyond their antioxidative properties and are involved in regulation of cell survival pathways leading to anticarcinogenic and antimutagenic functions. There are sufficient evidence from in vitro, in vivo, and epidemiological studies to suggest that the dietary intervention of polyphenols in cancer prevention, including the chemopreventive ability of dietary polyphenols, act against lung carcinogens. Cohort and epidemiological studies in selected risk populations have evaluated clinical effects of polyphenols. Polyphenols have demonstrated three major actions: antioxidative activity, regulation of phase I and II enzymes, and regulation of cell survival pathways against lung carcinogenesis. They have also shown an inverse association of lung cancer occurrences among high risk populations who consumed considerable amounts of fruits and vegetables in their daily diet. In in vitro cell culture experimental models, polyphenols bind with electrophilic metabolites from carcinogens, inactivate cellular oxygen radicals, prevent membrane lipid peroxidation and DNA oxidative damage, and adduct formation. Further, polyphenols enhance the detoxifying enzymes such as the phase II enzymes, glutathione transferases and glucuronosyl transferases. PMID:27548149

  3. Chemopreventive effect of apple and berry fruits against colon cancer.

    Science.gov (United States)

    Jaganathan, Saravana Kumar; Vellayappan, Muthu Vignesh; Narasimhan, Gayathri; Supriyanto, Eko; Octorina Dewi, Dyah Ekashanti; Narayanan, Aqilah Leela T; Balaji, Arunpandian; Subramanian, Aruna Priyadarshini; Yusof, Mustafa

    2014-12-01

    Colon cancer arises due to the conversion of precancerous polyps (benign) found in the inner lining of the colon. Prevention is better than cure, and this is very true with respect to colon cancer. Various epidemiologic studies have linked colorectal cancer with food intake. Apple and berry juices are widely consumed among various ethnicities because of their nutritious values. In this review article, chemopreventive effects of these fruit juices against colon cancer are discussed. Studies dealing with bioavailability, in vitro and in vivo effects of apple and berry juices are emphasized in this article. A thorough literature survey indicated that various phenolic phytochemicals present in these fruit juices have the innate potential to inhibit colon cancer cell lines. This review proposes the need for more preclinical evidence for the effects of fruit juices against different colon cancer cells, and also strives to facilitate clinical studies using these juices in humans in large trials. The conclusion of the review is that these apple and berry juices will be possible candidates in the campaign against colon cancer.

  4. Cancer chemopreventive and therapeutic activities of red ginseng.

    Science.gov (United States)

    Xiaoguang, C; Hongyan, L; Xiaohong, L; Zhaodi, F; Yan, L; Lihua, T; Rui, H

    1998-02-01

    Red ginseng extract A and B are the active components of Panax ginseng. Red ginseng is a classical traditional Chinese medicine. Among Chinese herbs, red ginseng has been considered as one of the tonics. Many studies indicated that red ginseng could enhance immune function of the human body. The effects of red ginseng extracts on transplantable tumors, proliferation of lymphocyte, two-stage model and rat liver lipid peroxidation were studied. In a two-stage model, red ginseng extracts had a significant cancer chemoprevention. At 50-400 mg/kg, they could inhibit DMBA/Croton oil-induced skin papilloma in mice, decrease the incidence of papilloma, prolong the latent period of tumor occurrence and reduce tumor number per mouse in a dose-dependent manner. Red ginseng extract B could effectively inhibit the Fe2+/cysteine-induced lipid peroxidation of rat liver microsome, suggesting that red ginseng extract B has a stronger antioxidative effect than that of extract A. The results indicated that red ginseng extracts (50 approximately 400 mg/kg) could significantly inhibit the growth of transplantable mouse sarcoma S180 and melanoma B16. Red ginseng extracts A (0.5 mg/ml) and B (0.1 and 0.25 mg/ml) might effectively promote the transformation of T lymphocyte, but there was no influence on lymphocyte proliferation stimulated by concanavalin A. This suggests that red ginseng extracts have potent tumor therapeutic activity and improve the cell immune system. PMID:9533434

  5. Advances in prostate cancer chemoprevention: a translational perspective.

    Science.gov (United States)

    Nambiar, Dhanya; Singh, Rana P

    2013-01-01

    Chemopreventive interventions are steadily emerging as an important aspect of cancer management and control. Herein, we have discussed the major epidemiological and clinical studies advocating the role of androgen inhibitors, flavonoids and antioxidants in preventing prostate cancer (PCa). Androgen inhibitors have lately been discussed not only in treatment of PCa, but also as preventive agents especially after trials with Finasteride and Dutasteride. Flavonoids such as silibinin, green tea polyphenols, genistein, curcumin have shown great promise, but avenues to improve their bioavailability are requisite. Agents with antioxidant potentials like lycopene, selenium, and vitamin E have also been explored. Antioxidant trials have yielded mixed results or benefitted only a subgroup of population, although further studies are needed to establish them as preventive agent. Although a majority of the trials resulted in positive outcomes supporting their role as preventive agents; one should be cautious of neutral or negative results as well. For clinical applicability of these agents, we need to identify the ideal target population, time of intervention, appropriate dosage, and extent of intervention required. Incoherency of data with these agents urges for a stringent study design and thorough interpretation to accurately judge the necessity and feasibility of the preventive measures. PMID:23682779

  6. Crocus sativus L. (saffron) for cancer chemoprevention: A mini review.

    Science.gov (United States)

    Bhandari, Prasan R

    2015-04-01

    Cancer is one of the most feared diseases globally and there has been a sustained rise in its incidence in both developing and developed countries. Despite the growing therapeutic options for patients with cancer, their efficacy is time-limited and non-curative. Hence to overcome these drawbacks, an incessant screening for superior and safer drugs has been ongoing for numerous decades, resulting in the detection of anti-cancer properties of several phytochemicals. Chemoprevention using readily available natural substances from vegetables, fruits, herbs and spices is one of the significantly important approaches for cancer prevention in the present era. Among the spices, Crocus sativus L. (saffron; fān hóng huā) has generated interest because pharmacological experiments have established numerous beneficial properties including radical scavenging, anti-mutagenic and immuno-modulating effects. The more powerful components of saffron are crocin, crocetin and safranal. Studies in animal models and with cultured human malignant cell lines have demonstrated antitumor and cancer preventive activities of saffron and its main ingredients. This review provides a brief insight into the anticancer properties of saffron and its components.

  7. Molecular targets of cancer chemoprevention by garlic-derived organosulfides

    Institute of Scientific and Technical Information of China (English)

    Anna HERMAN-ANTOSIEWICZ; Anna A POWOLNY; Shivendra V SINGH

    2007-01-01

    The medicinal benefits of Allium vegetables, especially garlic, have been noted throughout recorded history. The known health benefits of Allium vegetables and their constituents include cardiovascular protective effects, stimulation of immune function, reduction of blood glucose level, radioprotection, improvement of memory loss, protection against microbial, viral and fungal infections, as well as anticancer effects. Population-based case control studies have suggested an inverse correlation between dietary intake of Allium vegetables and the risk of different types of cancers. The anticarcinogenic effect of Allium vegetables in-eluding garlic is attributed to organosulfur compounds (OSC), which are highly effective in affording protection against cancer in animal models induced by a variety of chemical carcinogens. More recent studies have shown that certain naturally occurring OSC analogues can suppress proliferation of cancer cells in culture and in vivo. The OSC-induced changes in the proliferation of cancer Cellsare frequently associated with perturbations in cell cycle progression and induc-tion of G2/M phase arrest. The OSC have also been demonstrated to induce apoptosis via the intrinsic pathway by altering the ratio of the Bc1-2 family of proteins both in cell culture and in in vivo models. Anti-angiogenic activity for garlic-derived OSC has also been documented. This article summarizes current knowledge on molecular targets of cancer chemoprevention by OSC.

  8. Hedera nepalensis K. Koch: A Novel Source of Natural Cancer Chemopreventive and Anticancerous Compounds.

    Science.gov (United States)

    Jafri, Laila; Saleem, Samreen; Kondrytuk, Tamara P; Haq, Ihsan-ul; Ullah, Nazif; Pezzuto, John M; Mirza, Bushra

    2016-03-01

    Traditional medicinal plants are often used for both the prevention and the treatment of local diseases. Taking into consideration the medicinal importance of Hedera nepalensis within local Pakistani traditions, the present study was undertaken to analyze the in vitro cancer chemopreventive and cytotoxic properties of the plant. The in vitro cancer chemopreventive testing was performed using nitrite assay, NFκB assay, aromatase assay, and quinone reductase 1 (QR1) assay. The cytotoxic potential was evaluated on three cancer-cell lines: MCF-7, MDA-MB-231, and HeLa using sulforhodamine B (SRB) assay. The results of cancer chemopreventive assays show that n-hexane and ethyl acetate fractions of tested plant have promising cancer chemopreventive potential. Lupeol isolated from n-hexane as well as ethyl acetate fraction showed lowest IC50 (0.20 ± 1.9 μM) in NFκB assay. Crude extract and its fractions inhibited the growth of three cancer cell lines by more than 60%, IC50 value of lupeol varied from 2.32 to 10.2 μM. HPLC-DAD-based quantification of lupeol in different plant tissues demonstrated that leaves of H. nepalensis are a rich source of lupeol (0.196 mg/100 mg dry weight). Our data have shown that H. nepalensis harbors cancer chemopreventive and cytotoxic agents. PMID:26692176

  9. The Role of Nutraceuticals in Chemoprevention and Chemotherapy and Their Clinical Outcomes

    Directory of Open Access Journals (Sweden)

    Sabita N. Saldanha

    2012-01-01

    Full Text Available The genesis of cancer is often a slow process and the risk of developing cancer increases with age. Altering a diet that includes consumption of beneficial phytochemicals can influence the balance and availability of dietary chemopreventive agents. In chemopreventive approaches, foods containing chemicals that have anticancer properties can be supplemented in diets to prevent precancerous lesions from occurring. This necessitates further understanding of how phytochemicals can potently maintain healthy cells. Fortunately there is a plethora of plant-based phytochemicals although few of them are well studied in terms of their application as cancer chemopreventive and therapeutic agents. In this analysis we will examine phytochemicals that have strong chemopreventive and therapeutic properties in vitro as well as the design and modification of these bioactive compounds for preclinical and clinical applications. The increasing potential of combinational approaches using more than one bioactive dietary compound in chemoprevention or cancer therapy will also be evaluated. Many novel approaches to cancer prevention are on the horizon, several of which are showing great promise in saving lives in a cost-effective manner.

  10. Solubilization of meso-carbon microbeads by potassium- or dibutylzinc-promoted butylation and structural analysis of the butylated products; Mesocarbon microbeads no butyl ka ni yoru kayoka to erareta butyl kabutsu no kozo kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Murata, S.; Zhang, Y.; Kidena, K.; Nomura, M. [Osaka University, Osaka (Japan). Faculty of Engineering

    1996-10-28

    Tetrahydrofuran (THF) solubility and structure of the butylated products of meso-carbon microbeads (MCMB) were studied experimentally. In experiment, MCMB-A and MCMB-B obtained from two kinds of coal-tar pitch were used as specimens. MCMBs were butylated by BZ method using dibutylzinc-butyl iodide and KT method using K-butyl iodide-THF, and the butylated products were successfully obtained. The butylated products were investigated through THF solubility test, {sup 13}C-NMR measurement and gel permeation chromatography (GPC) measurement. As the experimental result, a BZ method produced the butylated products at a yield of nearly 170%, while a KT method produced them at a yield of nearly 130%. The THF solubility was estimated to be 89-97%. As the study result of molecular weight distributions by GPC measurement of solvent solubles, the molecular weight of raw material MCMB was estimated to be 590-770 in terms of polystyrene. 6 refs., 2 figs., 1 tab.

  11. Ascorbic acid in cancer chemoprevention: translational perspectives and efficacy.

    Science.gov (United States)

    Ullah, Mohammad F; Bhat, Showket H; Hussain, Eram; Abu-Duhier, Faisel; Ahmad, Aamir; Hadi, S M

    2012-12-01

    Chemoprevention, which is referred to as the use of nontoxic natural or synthetic chemicals to intervene in multistage carcinogenesis has since decades attracted a considerable interest in plant-derived chemical constituents often termed as "phytochemicals" or sometimes as "Nutraceuticals" in case they are derived from dietary sources. A comprehensive search of the literature show that such an interest in natural product pharmacology has surged in the last 25 years and particularly risen at exponential rates since the last one decade. Phytochemicals such as curcumin (from spice turmeric), resveratrol (from red wine) and genistein (from soy) share the major efforts as indicated by overwhelming publications, despite skepticism concerning their bioavailability. Ascorbic acid (AA), the popular anti-oxidant in fruits and vegetables, has even a longer historical perspective than these dietary agents as for more than 35 years; there had been lingering questions about the efficacy of AA in cancer therapy. The footprints of AA from "scurvy" to "cancer" though complex seems to carry potential provided the puzzle could be set right. The use of AA in cancer treatment has been debated extensively as evident from the literature but surprisingly the complementing early phase bench work on the mechanistic studies for anticancer action was rather retarded. Proposed mechanisms of action for AA in the prevention and treatment of cancer includes antioxidant as well as pro-oxidant properties, stimulation of the immune system, altering carcinogen metabolism, enhancement of collagen synthesis necessary for tumor encapsulation and interference with cancer cell signaling. The observation that the intravenous administration of AA enhances its bioavailability to the extent of deriving pharmacological benefits against cancer has in recent years partially supported the clinical plausibility (efficacy) of AA towards realizing its translational advantage. Here, we provide an overview of AA with

  12. Chemopreventive Agents from Physalis minima Function as Michael Reaction Acceptors

    Science.gov (United States)

    Men, Ruizhi; Li, Ning; Ding, Chihong; Tang, Yingzhan; Xing, Yachao; Ding, Wanjing; Ma, Zhongjun

    2016-01-01

    Background: The fruits of some varieties of genus Physalis have been used as delicious fruits and functional food in the Northeast of China. Materials and Methods: To reveal the functional material basis, we performed bioactivity-guided phytochemical research and chemopreventive effect assay of the constituents from Physalis minima. Results: It was demonstrated that the ethyl acetate extract of P. minima L. (EEPM) had potential quinone reductase (QR) inducing activity with induction ratio (IR, QR induction activity) value of 1.47 ± 0.24, and glutathione binding property as potential Michael reaction acceptors (with an α, β-unsaturated ketone moiety). Furthermore, bioactivity-guided phytochemical research led eight compounds (1–8), which were elucidated as 3-isopropyl-5-acetoxycyclohexene-2-one-1 (1), isophysalin B (2), physalin G (3), physalin D (4), physalin I (5), physordinose B (6), stigmasterol-3-O-β-D-glucopyranoside (7) and 5α-6β-dihydroxyphysalin R (8) on the basis of nuclear magnetic resonance spectroscopy analyses and HRESIMS. Then, isophysalin B (2) and physordinose B (6) showed significant QR inducing activity with IR value of 2.80 ± 0.19 and 2.38 ± 0.46, respectively. SUMMARY An ultra-performance liquid chromatographic method with glutathione as the substrate was used to detect the Michael reaction acceptors in extracts of Physalis minima (EPM)We investigated the chemical constituents of EPM guided by biological activity methodIsophysalin B (1) and physordinose B (6) showed strong quinone reductase inducing activity with induction ratio values of 2.80 ± 0.19 and 2.38 ± 0.46This study generated useful information for consumers and many encourage researchers to utilize edible fruits from Physalis as a source of phytochemicals Abbreviations used: EPM: Extracts of Physalis minima, EEPM: Ethyl acetate extract of Physalis minima L., GSH: Glutathione, MRAs: Michael reaction acceptors, QR: Quinone reductase. PMID:27279713

  13. Pomegranate fruit juice for chemoprevention and chemotherapy of prostate cancer

    Science.gov (United States)

    Malik, Arshi; Afaq, Farrukh; Sarfaraz, Sami; Adhami, Vaqar M.; Syed, Deeba N.; Mukhtar, Hasan

    2005-01-01

    Prostate cancer is the most common invasive malignancy and the second leading cause of cancer-related deaths among U.S. males, with a similar trend in many Western countries. One approach to control this malignancy is its prevention through the use of agents present in diet consumed by humans. Pomegranate from the tree Punica granatum possesses strong antioxidant and antiinflammatory properties. We recently showed that pomegranate fruit extract (PFE) possesses remarkable antitumor-promoting effects in mouse skin. In this study, employing human prostate cancer cells, we evaluated the antiproliferative and proapoptotic properties of PFE. PFE (10-100 μg/ml; 48 h) treatment of highly aggressive human prostate cancer PC3 cells resulted in a dose-dependent inhibition of cell growth/cell viability and induction of apoptosis. Immunoblot analysis revealed that PFE treatment of PC3 cells resulted in (i) induction of Bax and Bak (proapoptotic); (ii) down-regulation of Bcl-XL and Bcl-2 (antiapoptotic); (iii) induction of WAF1/p21 and KIP1/p27; (iv) a decrease in cyclins D1, D2, and E; and (v) a decrease in cyclin-dependent kinase (cdk) 2, cdk4, and cdk6 expression. These data establish the involvement of the cyclin kinase inhibitor-cyclin-cdk network during the antiproliferative effects of PFE. Oral administration of PFE (0.1% and 0.2%, wt/vol) to athymic nude mice implanted with androgen-sensitive CWR22Rν1 cells resulted in a significant inhibition in tumor growth concomitant with a significant decrease in serum prostate-specific antigen levels. We suggest that pomegranate juice may have cancer-chemopreventive as well as cancer-chemotherapeutic effects against prostate cancer in humans. PMID:16192356

  14. Cancer Prevention and Interception: A New Era for Chemopreventive Approaches.

    Science.gov (United States)

    Albini, Adriana; DeCensi, Andrea; Cavalli, Franco; Costa, Alberto

    2016-09-01

    At several recent, internationally attended scientific meetings, including the American Association for Cancer Research (AACR)'s "Shaping the Future of Cancer Prevention: A Roadmap for Integrative Cancer Science and Public Health" summit in Leesburg (VA) and the AACR Annual Meeting in New Orleans, the focus on cancer prevention to reduce cancer-related deaths was extensively discussed with renewed attention and emphasis. Cancer prevention should be actively proposed even to healthy individuals, and not just to individuals with high cancer risk. We discuss evaluation of a high cancer risk versus the relatively low risk for side effects of chemopreventive agents. The concept of cancer interception, which is halting transformed cells from becoming malignant cancers, should be adopted for cancer prevention. Potential prevention/interception actions include adopting healthy life style and avoiding carcinogens, repressing inflammation and pathologic angiogenesis, controlling metabolism, correcting insulin resistance and other metabolic alterations. Current drugs with limited toxicity can be repurposed to reduce cancer incidence. Aspirin is now being recommended for the prevention of colorectal cancer and it prevents other neoplasms as well. Metformin and β-blockers could be valuable for reducing pancreatic and breast cancer onset. On the basis of the evaluation of cancer risk, we here call for personalized approaches for cancer prevention and preventive interception and we envisage a list of measures and potential guidelines for preventive and interceptive strategies to reduce cancer burden. Investment into translational research to bring these approaches into public health policies and in the clinic is urgently needed. Clin Cancer Res; 22(17); 4322-7. ©2016 AACR. PMID:27220959

  15. Chemopreventive Effect of Aerosolized Polyphenon E on Lung Tumorigenesis in A/J Mice

    Directory of Open Access Journals (Sweden)

    Ying Yan

    2007-05-01

    Full Text Available Effective chemoprevention of lung cancer in high-risk patients through the administration of pharmacologic or nutritional agents is urgently needed. Aerosol inhalation can deliver chemopreventive agents directly to the respiratory tract to inhibit the tumorigenic process. In this study, polyphenon E (PolyE and (-epigallocatechin-3-gal late (EGCG were administered by aerosol delivery to A/J mice beginning 2 weeks after carcinogen treatment and continuing daily by inhalation throughout the remainder of the study (20 weeks. PolyE decreased tumor load by ∼ 59%. However, EGCG, both at the same dose and at a higher dose, failed to inhibit lung carcinogenesis. These results indicate that aerosol delivery of PolyE, but not EGCG, may be a useful chemopreventive protocol in subjects at high risk for lung cancer.

  16. Chemopreventive effect of Lagenaria siceraria in two stages DMBA plus croton oil induced skin papillomagenesis.

    Science.gov (United States)

    Kumar, Navneet; Kale, Raosaheb K; Tiku, Ashu B

    2013-01-01

    Cancer chemoprevention is a dietary or therapeutic strategy to prevent, suppress, or delay carcinogenesis either at initiation or progression level with nontoxic agents. Use of natural dietary compounds has been a major chemopreventive approach to modulate tumorigenic pathways. In the present study, we have evaluated Lagenaria siceraria (bottle gourd), a common vegetable of Indian household for its chemomodulatory potential. The fruit has been used in traditional medicine for a very long time for health benefits and to cure pain, ulcers, fever, cough, asthma, and other bronchial disorders. However, despite its reported beneficial effect the chemo modulatory potential of this plant has not been reported. Therefore chemopreventive effect of bottle gourd juice (BGJ) was studied against 7,12-dimethylbenz(a)anthracene (DMBA) plus croton oil induced skin papillomagenesis in Swiss albino mice. The effect was studied both at antiinitiation and antiinitiation/promotion level followed by histopathological study. A dose of 2.5% and 5% given in drinking water showed significant decrease in papilloma number, papilloma incidence, papilloma multiplicity, papilloma latency, papilloma volume, and papilloma size in different size range. Histopathological study showed chemopreventive effect by minimizing loss of stratification, a decrease in number of epithelial layers, reducing dermal infiltration and protection for various cytoplasmic changes. Higher dose of BGJ was found to be more effective than lower dose and the chemopreventive effect was maximum for antiinitiation/promotion treatment. Altogether, this study reports the chemopreventive effect of Lagenaria siceraria on skin papillomagenesis for the first time and suggests that its consumption may help in suppression of skin cancer. PMID:23914728

  17. Oral chemoprevention with acetyl salicylic Acid, vitamin d and calcium reduces the risk of tobacco carcinogen-induced bladder tumors in mice

    DEFF Research Database (Denmark)

    Pommergaard, Hans-Christian; Burcharth, J; Rosenberg, J;

    2013-01-01

    , and diet with chemoprevention (acetyl salicylic acid, 1-alpha 25(0H)2-vitamin D3 and calcium). There were significantly fewer tumors (0 (0-0) vs. 0 (0-2), p = .045) and fewer animals with tumors (0/20 vs. 5/20, p = .045) in the chemoprevention group compared with controls. Thus, chemoprevention diet...

  18. The Potential Role of Nitric Oxide in Halting Cancer Progression Through Chemoprevention

    Science.gov (United States)

    Vahora, Huzefa; Khan, Munawwar Ali; Alalami, Usama; Hussain, Arif

    2016-01-01

    Nitric oxide (NO) in general plays a beneficial physiological role as a vasorelaxant and the role of NO is decided by its concentration present in physiological environments. NO either facilitates cancer-promoting characters or act as an anti-cancer agent. The dilemma in this regard still remains unanswered. This review summarizes the recent information on NO and its role in carcinogenesis and tumor progression, as well as dietary chemopreventive agents which have NO-modulating properties with safe cytotoxic profile. Understanding the molecular mechanisms and cross-talk modulating NO effect by these chemopreventive agents can allow us to develop better therapeutic strategies for cancer treatment. PMID:27051643

  19. LC-MS-Based Metabolomic Investigation of Chemopreventive Phytochemical-Elicited Metabolic Events.

    Science.gov (United States)

    Wang, Lei; Yao, Dan; Chen, Chi

    2016-01-01

    Phytochemicals are under intensive investigation for their potential use as chemopreventive agents in blocking or suppressing carcinogenesis. Metabolic interactions between phytochemical and biological system play an important role in determining the efficacy and toxicity of chemopreventive phytochemicals. However, complexities of phytochemical biotransformation and intermediary metabolism pose challenges for studying phytochemical-elicited metabolic events. Metabolomics has become a highly effective technical platform to detect subtle changes in a complex metabolic system. Here, using green tea polyphenols as an example, we describe a workflow of LC-MS-based metabolomics study, covering the procedures and techniques in sample collection, preparation, LC-MS analysis, data analysis, and interpretation. PMID:26608291

  20. Phenol Tert-Butylation Catalyzed by Zeolite H-Mordenite

    Institute of Scientific and Technical Information of China (English)

    HAN Sen; LI Zhenhua; ZHANG Kui

    2005-01-01

    Para-tert-butyl phenol (p-TBP) and 2,4-di-tert-butyl phenol (2,4-DTBP) are widely used for the preparation of antioxidants. Zeolite catalysts showed good performance for the synthesis of p-TBP and 2,4-DTBP. In this work, zeolite H-mordenite (HM) catalyst was prepared and the alkylation of phenol with tert-butyl alcohol over zeolite HM catalyst was investigated at different reaction conditions. It is found that increasing temperature enhances the selectivity to p-TBP and the optimum reaction temperature for phenol conversion is 438 K. Increasing flow rate decreases phenol conversion apparently while the selectivity to p-TBP has a little increase. The suitable tert-butyl alcohol/phenol molar ratio is 2. Lower alcohol/phenol molar ratios are beneficial to p-TBP while higher ones are helpful for producing 2,4-DTBP.

  1. Radiation degradation of spent butyl rubbers

    Science.gov (United States)

    Telnov, A. V.; Zavyalov, N. V.; Khokhlov, Yu. A.; Sitnikov, N. P.; Smetanin, M. L.; Tarantasov, V. P.; Shadrin, D. N.; Shorikov, I. V.; Liakumovich, A. L.; Miryasova, F. K.

    2002-03-01

    Radiation methods of materials modification applied in technological chains can have significant economical and ecological advantages as compared to the established chemical, thermal and mechanical methods. Each year the problems of nature resources economy through the use of production and consumption wastes acquire a more significant value, as it allows to solve also ecological issues along with economical ones. This is mostly acute in relation to polymeric systems based on saturated rubbers, for example butyl rubber (BR) used in the tyre industry, as due to their high resistance to the action of oxygen, ozone, solar radiation and bacteria, they contaminate the environment for rather a long period. At VNIIEF and KSPU experiments were carried out on application of electron beams with energy from 6 to 10 MeV for radiation destruction of spent rubber based on BR. The radiation-degraded material was tested for re-use in the formulation of initial diaphragm mixture, rubber mixture for producing rubberized fabric and roofing.

  2. NQR in tert-butyl chloride

    Science.gov (United States)

    Brunetti, Aldo H.

    2004-03-01

    Tert-butyl chloride has been broadly studied experimentally through various techniques such as X-ray crystallography, DTA, and NMR. It was also studied experimentally through nuclear quadrupole resonance (NQR), but this study was limited and incomplete. In this paper, we present a more detailed study of TBC through the NQR of 35Cl. Our results show that near 120 K, the onset of the CH 3 groups semirotations around symmetry axis C3 takes place with an activation energy U=16.1 kJ mol -1. This intramolecular movement produces a T1 minimum near 148 K and is the dominant mechanism of the nuclear spin-lattice relaxation in phase III of this compound. In phase II of TBC, we show that there are not only methyl groups semirotations, but also semirotations of the whole molecule around a different axis from the symmetry axis C' 3 (C-Cl bond) with an activation energy of E=10.4 kJ mol -1.

  3. COX-independent mechanisms of cancer chemoprevention by anti-inflammatory drugs

    Directory of Open Access Journals (Sweden)

    Evrim eGurpinar

    2013-07-01

    Full Text Available Epidemiological and clinical studies suggest that non-steroidal anti-inflammatory drugs (NSAIDs, including cyclooxygenase (COX-2 selective inhibitors, reduce the risk of developing cancer. Experimental studies in human cancer cell lines and rodent models of carcinogenesis support these observations by providing strong evidence for the antineoplastic properties of NSAIDs. The involvement of COX-2 in tumorigenesis and its overexpression in various cancer tissues suggest that inhibition of COX-2 is responsible for the chemopreventive efficacy of these agents. However, the precise mechanisms by which NSAIDs exert their antiproliferative effects are still a matter of debate. Numerous other studies have shown that NSAIDs can act through COX-independent mechanisms. This review provides a detailed description of the major COX-independent molecular targets of NSAIDs and discusses how these targets may be involved in their anticancer effects. Toxicities resulting from COX inhibition and the suppression of prostaglandin synthesis preclude the long-term use of NSAIDs for cancer chemoprevention. Furthermore, chemopreventive efficacy is incomplete and treatment often leads to the development of resistance. Identification of alternative NSAID targets and elucidation of the biochemical processes by which they inhibit tumor growth could lead to the development of safer and more efficacious drugs for cancer chemoprevention.

  4. Azoxymethane-induced rat aberrant crypt foci: Relevance in studying chemoprevention of colon cancer

    Institute of Scientific and Technical Information of China (English)

    Jayadev Raju

    2008-01-01

    The pathogenesis of colon cancer involves sequential and multistep progression of epithelial cells initiated to a cancerous state with defined precancerous intermediaries.Aberrant crypt foci (ACF) represent the earliest identifiable intermediate precancerous lesions during colon carcinogenesis in both laboratory animals and humans.ACF are easily induced by colon-specific carcinogens in rodents and can be used to learn more about the process of colon carcinogenesis.For over two decades,since its first discovery,azoxymethane(AOM)-induced rodent ACF have served as surrogate biomarkers in the screening of various anticarcinogens and carcinogens.Several dietary constituents and phytochemicals have been tested for their colon cancer chemopreventive efficacy using the ACF system.There has been substantial effort in defining and refining ACF in terms of understanding their molecular make-up,and extensive research in this field is currently in progress.In chemoprevention studies,AOM-induced rat ACF have been very successful as biomarkers,and have provided several standardized analyses of data.There have been several studies that have reported that ACF data do not correlate to actual colon tumor outcome,however,and hence there has been an ambiguity about their role as biomarkers.The scope of this mini-review is to provide valuable insights and limitations of AOM-induced rat ACF as biomarkers in colon cancer chemoprevention studies.The role of the dynamics and biological heterogeneity of ACF is critical in understanding them as biomarkers in chemoprevention studies.

  5. Dietary Pterostilbene is a novel MTA1-targeted chemopreventive and therapeutic agent in prostate cancer

    Science.gov (United States)

    Dietary nutrients with ability to reverse adverse epigenetic events have great potential for cancer chemoprevention. Overexpression of the epigenetic modifier metastasis-associated protein 1 (MTA1) is associated with aggressive human prostate cancer. The purpose of this study was to determine MTA1-d...

  6. Acteoside-mediates chemoprevention of experimental liver carcinogenesis through STAT-3 regulated oxidative stress and apoptosis.

    Science.gov (United States)

    Peerzada, Kaiser J; Faridi, Aamir H; Sharma, Love; Bhardwaj, Subhash C; Satti, Naresh K; Shashi, Bhushan; Tasduq, Sheikh A

    2016-07-01

    In the absence of an effective therapy against Hepatocellular Carcinoma (HCC), chemoprevention remains an important strategy to circumvent morbidity and mortality. Here, we examined chemopreventive potential of Acteoside (ACT), a plant derived phenylethanoid glycoside against an environmental and dietary carcinogen, diethylnitrosamine (DEN)-induced rat hepatocarcinogenesis. ACT treatment (0.1 and 0.3% supplemented with diet) started 2 weeks before DEN challenge and continued for 18 weeks thereafter, showed a remarkable chemopreventive activity. ACT treatment resulted in reduced HCC nodules. Histopathology showed progressive tissue damage, necrosis (5 weeks), hepatocytic injury (10 weeks), anisonucleosis with presence of prominent nucleoli, sinusidal dilations, and lymphomono nuclear inflammation (18 weeks). Biochemical analysis showed hepatocytic injury (raised ALT, p reactive oxygen species (ROS) levels and prevented mitochondrial membrane potential (MMP) loss. Immunoblotting showed ACT treatment reversed DEN-induced NF-κB, Bax, Cytochrome C, Bcl-2, and Stat-3 levels. We conclude that chemoprotective effect of ACT is mediated by STAT-3 dependent regulation of oxidative stress and apoptosis and ACT has potential to be developed as a chemopreventive agent. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 782-798, 2016. PMID:26990576

  7. Chemoprevention of prostate cancer: Natural compounds, antiandrogens, and antioxidants - In vivo evidence

    Directory of Open Access Journals (Sweden)

    Nur Özten-Kandas

    2011-01-01

    Full Text Available Prostate cancer is the leading non-skin malignancy detected in US males and the second cause of death due to male cancer, in the US. Interventions with drugs or diet supplements that slow down the growth and progression of prostate cancer are potentially very effective in reducing the burden of prostate cancer, particularly if these treatments also prevent the de novo development of new prostatic malignancies. Challenges to identify efficacious agents and develop them for chemopreventive application in men at risk for prostate cancer have included uncertainty about which preclinical models have the ability to predict efficacy in men and lack of consensus about which early phase clinical trial designs are the most appropriate and cost-effective to test promising agents. Efficacy studies in animal models have identified several agents with potential chemopreventive activity against prostate cancer, but few of these findings have been translated into clinical trials. This article identifies some of the major issues associated with prostate cancer chemoprevention research and summarizes the most significant current results from animal efficacy studies and human clinical prevention trials. This summary focuses on: (1 Naturally occurring agents and compounds derived from such agents, including green tea and its constituents, silibinin and milk thistle, and genistein and soy, (2 chemoprevention drugs including agents interfering with androgen action, and (3 antioxidants such as selenium, vitamin E, and lycopene. The general lack of activity of antioxidants is discussed, followed by considerations about translation of preclinical chemoprevention efficacy data, focusing on dose, form, bioavailability, and timing of administration of the agent, as well as discussion of study design of clinical trials and the predictive ability of preclinical models.

  8. Regulation of rat glutathione S-transferase A5 by cancer chemopreventive agents: mechanisms of inducible resistance to aflatoxin B1.

    Science.gov (United States)

    Hayes, J D; Pulford, D J; Ellis, E M; McLeod, R; James, R F; Seidegård, J; Mosialou, E; Jernström, B; Neal, G E

    1998-04-24

    The rat can be protected against aflatoxin B1 (AFB1) hepatocarcinogenesis by being fed on a diet containing the synthetic antioxidant ethoxyquin. Evidence suggests that chemoprotection against AFB1 is due to increased detoxification of the mycotoxin by one or more inducible drug-metabolising enzymes. The glutathione S-transferase (GST) isoenzymes in rat liver that contribute to ethoxyquin-induced chemoprotection against AFB1 have been identified by protein purification. This approach resulted in the isolation of several heterodimeric class alpha GST, all of which contained the A5 subunit and possessed at least 50-fold greater activity towards AFB1-8,9-epoxide than previously studied transferases. Molecular cloning and heterologous expression of rat GSTA5-5 has led to the demonstration that it exhibits substantially greater activity for AFB1-8,9-epoxide than other rat transferases. The A5 homodimer can also catalyse the conjugation of glutathione with other epoxides, such as trans-stilbene oxide and 1,2-epoxy-3-(4'-nitrophenoxy)propane, and possesses high catalytic activity for the reactive aldehyde 4-hydroxynonenal. Western blotting has shown that the A5 subunit is not only induced by ethoxyquin but that it is also induced by other cancer chemopreventive agents, such as butylated hydroxyanisole, oltipraz, benzyl isothiocyanate, indole-3-carbinol and coumarin. In addition to GSTA5, we have identified a novel aflatoxin-aldehyde reductase (AFAR) that is similarly induced by ethoxyquin. However, immunoblotting has shown that GSTA5 and AFAR are not always co-ordinately regulated by chemoprotectors. In order to gain a better understanding of the mechanisms responsible for the induction of GSTA5 protein, the GSTA5 gene has been cloned. It was isolated on two overlapping bacteriophage lambda clones and found to be approximately 12 kb in length. The transcriptional start site of GSTA5 has been identified 228 bp upstream from the ATG translational initiation codon. Computer

  9. Conversion of Lignocellulosic Biomass to Ethanol and Butyl Acrylate

    Energy Technology Data Exchange (ETDEWEB)

    Binder, Thomas [Archer Daniels Midland Company, Decatur, IL (United States); Erpelding, Michael [Archer Daniels Midland Company, Decatur, IL (United States); Schmid, Josef [Archer Daniels Midland Company, Decatur, IL (United States); Chin, Andrew [Archer Daniels Midland Company, Decatur, IL (United States); Sammons, Rhea [Archer Daniels Midland Company, Decatur, IL (United States); Rockafellow, Erin [Archer Daniels Midland Company, Decatur, IL (United States)

    2015-04-10

    Conversion of Lignocellulosic Biomass to Ethanol and Butyl Acrylate. The purpose of Archer Daniels Midlands Integrated Biorefinery (IBR) was to demonstrate a modified acetosolv process on corn stover. It would show the fractionation of crop residue to distinct fractions of cellulose, hemicellulose, and lignin. The cellulose and hemicellulose fractions would be further converted to ethanol as the primary product and a fraction of the sugars would be catalytically converted to acrylic acid, with butyl acrylate the final product. These primary steps have been demonstrated.

  10. 75 FR 44184 - Aluminum tris(O-ethylphosphonate), Butylate, Chlorethoxyfos, Clethodim, et al.; Proposed...

    Science.gov (United States)

    2010-07-28

    ...-ethylphosphonate) and fenarimol; the herbicides butylate, clethodim, clomazone, fenoxaprop-ethyl, flumetsulam... fungicides aluminum tris(O-ethylphosphonate) and fenarimol; the herbicides butylate, clethodim, clomazone... stoichiometric equivalent of clofentezine, in or on the commodity. 6. Clomazone. In order to describe...

  11. Chemopreventive Potential of Flavonoids in Oral Squamous Cell Carcinoma in Human Studies

    Directory of Open Access Journals (Sweden)

    Elena Maria Varoni

    2013-07-01

    Full Text Available Evidence available from nutritional epidemiology has indicated an inverse association between regular consumption of fruits and vegetables and the risk of developing certain types of cancer. In turn, preclinical studies have attributed the health-promoting effects of plant foods to some groups of phytochemicals, by virtue of their many biological activities. In this survey, we briefly examine the chemopreventive potential of flavonoids and flavonoid-rich foods in human oral carcinogenesis. Despite the paucity of data from clinical trials and epidemiological studies, in comparison to in vitro/in vivo investigations, a high level of evidence has been reported for epigallocatechin gallate (EGCG and anthocyanins. These flavonoids, abundant in green tea and black raspberries, respectively, represent promising chemopreventive agents in human oral cancer.

  12. Chronic unpredictable stress deteriorates the chemopreventive efficacy of pomegranate through oxidative stress pathway.

    Science.gov (United States)

    Hasan, Shirin; Suhail, Nida; Bilal, Nayeem; Ashraf, Ghulam Md; Zaidi, Syed Kashif; AlNohair, Sultan; Banu, Naheed

    2016-05-01

    Chronic unpredictable stress (CUS) can influence the risk and progression of cancer through increased oxidative stress. Pomegranate is known to protect carcinogenesis through its anti-oxidative properties. This study is carried out to examine whether CUS affects the chemopreventive potential of pomegranate through oxidative stress pathway. Role of CUS on early stages of 7, 12 dimethyl benz(a) anthracene (DMBA) induced carcinogenesis, and its pre-exposure effect on chemopreventive efficacy of pomegranate juice (PJ) was examined in terms of in vivo antioxidant and biochemical parameters in Swiss albino rats. Rats were divided in various groups and were subjected to CUS paradigm, DMBA administration (65 mg/kg body weight, single dose), and PJ treatment. Exposure to stress (alone) and DMBA (alone) led to increased oxidative stress by significantly decreasing the antioxidant enzymes activities and altering the glutathione (GSH), malondialdehyde (MDA), glutamate oxaloacetate transaminase (GOT), and glutamate pyruvate transaminase (GPT) levels. A significant increase in DNA damage demonstrated by comet assay was seen in the liver cells. Stress exposure to DMBA-treated rats further increased the oxidative stress and disturbed the biochemical parameters as compared to DMBA (alone)-treated rats. Chemoprevention with PJ in DMBA (alone)-treated rats restored the altered parameters. However, in the pre-stress DMBA-treated rats, the overall antioxidant potential of PJ was significantly diminished. Our results indicate that chronic stress not only increases the severity of carcinogenesis but also diminishes the anti-oxidative efficacy of PJ. In a broader perspective, special emphasis should be given to stress management and healthy diet during cancer chemoprevention. PMID:26596837

  13. Injectable Sustained Release Microparticles of Curcumin: A New Concept for Cancer Chemoprevention

    OpenAIRE

    Shahani, Komal; Swaminathan, Suresh Kumar; Freeman, Diana; Blum, Angela; Ma, Linan; Panyam, Jayanth

    2010-01-01

    Poor oral bioavailability limits the use of curcumin and other dietary polyphenols in the prevention and treatment of cancer. Minimally invasive strategies that can provide effective and sustained tissue concentrations of these agents will be highly valuable tools in the fight against cancer. The objective of this study was to investigate the use of an injectable sustained release microparticle formulation of curcumin as a novel approach to breast cancer chemoprevention. A biodegradable and b...

  14. STAT3 as a chemoprevention target in carcinogen-induced head and neck squamous cell carcinoma.

    OpenAIRE

    Peyser, ND; Wang, L.; Zeng, Y.; Acquafondata, M.; Freilino, ML; Li, H.; M. Sen; Gooding, WE; Satake, M; Wang, Z.; Johnson; Grandis, JR

    2016-01-01

    Head and neck squamous cell carcinoma (HNSCC) is a frequently fatal disease due in large part to a high rate of second primary tumor (SPT) formation. The 4-nitroquinoline 1-oxide (4-NQO) mouse model of oral carcinogenesis provides a robust system in which to study chemopreventive agents in the context of chemically-induced HNSCC tumors. Signal transducer and activator of transcription 3 (STAT3) is a potent oncogene that is hyperactivated by tyrosine phosphorylation early in HNSCC carcinogenes...

  15. Chemopreventive Effects of RXR-Selective Rexinoid Bexarotene on Intestinal Neoplasia of ApcMin/+ Mice

    OpenAIRE

    Janakiram, Naveena B; Altaf Mohammed; Li Qian; Chang-In Choi; Steele, Vernon E.; Rao, Chinthalapally V.

    2012-01-01

    Retinoid X receptor (RXR) has been implicated in several neoplastic diseases. Previously, we have shown that RXR-α is downregulated in human and rodent colonic tumors, suggesting a potential target for colon cancer prevention (http://www.cancer.org/Cancer/ColonandRectumCancer/DetailedGuide/colorectal-cancer-key-statistics). Experiments were designed to assess the chemopreventive efficacy of the selective RXR agonist bexarotene for the suppression of intestinal tumorigenesis in ApcMin/+ mice. ...

  16. Participation of Asian-American Women in Cancer Chemoprevention Research: Physician Perspectives

    OpenAIRE

    Nguyen, Tung T.; Somkin, Carol P.; Ma, Yifei

    2005-01-01

    To the authors’ knowledge, little is known regarding the participation of Asian Americans in cancer prevention research. In 2002, the authors mailed surveys to primary care physicians in Northern California to assess their knowledge, attitudes, behaviors, and barriers concerning the participation of Asian-American women in breast cancer chemoprevention research. The response rate was 52.3% (n = 306 physicians). For physician barriers, most respondents selected lack of study knowledge (73%) an...

  17. Chemoprevention of prostate cancer: Natural compounds, antiandrogens, and antioxidants - In vivo evidence

    OpenAIRE

    Nur Özten-Kandas; Bosland, Maarten C.

    2011-01-01

    Prostate cancer is the leading non-skin malignancy detected in US males and the second cause of death due to male cancer, in the US. Interventions with drugs or diet supplements that slow down the growth and progression of prostate cancer are potentially very effective in reducing the burden of prostate cancer, particularly if these treatments also prevent the de novo development of new prostatic malignancies. Challenges to identify efficacious agents and develop them for chemopreventive appl...

  18. Notes from the Field: “Green” Chemoprevention as Frugal Medicine

    OpenAIRE

    Fahey, Jed W.; Talalay, Paul; Kensler, Thomas W.

    2012-01-01

    Prevention trials of whole foods or simple extracts offer prospects for reducing an expanding global burden of cancer effectively and, in contrast to promising isolated phytochemicals or pharmaceuticals, frugally. We use the term “green chemoprevention” to differentiate a food-centered approach that is sustainable in underserved populations. It can be applied to personalized medicine just as well as can a pharmaceutical approach, but only green chemoprevention can be applied in both rich and ...

  19. Chemopreventive Effects of Oplopantriol A, a Novel Compound Isolated from Oplopanax horridus, on Colorectal Cancer

    OpenAIRE

    Zhiyu Zhang; Chunhao Yu; Chun-Feng Zhang; Xiao-Hui Wu; Xiao-Dong Wen; Samantha Anderson; Wei Du; Wei-Hua Huang; Shao-Ping Li; Chong-Zhi Wang; Chun-Su Yuan

    2014-01-01

    Oplopanax horridus is a North American botanical that has received limited investigations. We previously isolated over a dozen of the constituents from O. horridus, and among them oplopantriol A (OPT A) is a novel compound. In this study, we firstly evaluated the in vivo chemoprevention activities of OPT A using the xenograft colon cancer mouse model. Our data showed that this compound significantly suppressed tumor growth with dose-related effects (p < 0.01). Next, we characterized the co...

  20. Polyamines as mediators of APC-dependent intestinal carcinogenesis and cancer chemoprevention

    OpenAIRE

    Rial, Nathaniel S; Meyskens, Frank L.; Gerner, Eugene W.

    2009-01-01

    Combination chemoprevention for cancer was proposed a quarter of a century ago, but has not been implemented in standard medical practice owing to limited efficacy and toxicity. Recent trials have targeted inflammation and polyamine biosynthesis, both of which are increased in carcinogenesis. Preclinical studies have demonstrated that DFMO (difluoromethylornithine), an irreversible inhibitor of ODC (ornithine decarboxylase) which is the first enzyme in polyamine biosynthesis, combined with NS...

  1. Multitargeted Low-Dose GLAD Combination Chemoprevention: A Novel and Promising Approach to Combat Colon Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Altaf Mohammed

    2013-05-01

    Full Text Available Preclinical studies have shown that gefitinib, licofelone, atorvastatin, and α-difluoromethylornithine (GLAD are promising colon cancer chemopreventive agents. Because low-dose combination regimens can offer potential additive or synergistic effects without toxicity, GLAD combination was tested for toxicity and chemopreventive efficacy for suppression of intestinal tumorigenesis in adenomatous polyposis coli (APCMin/+ mice. Six-week-old wild-type and APCMin/+ mice were fed modified American Institute of Nutrition 76A diets with or without GLAD (25 + 50 + 50 + 500 ppm for 14 weeks. Dietary GLAD caused no signs of toxicity based on organ pathology and liver enzyme profiles. GLAD feeding strongly inhibited (80–83%, P 95% fewer polyps with sizes of >2 mm compared with control mice and showed 75% and 85% inhibition of colonic tumors in males and females, respectively. Molecular analyses of polyps suggested that GLAD exerts efficacy by inhibiting cell proliferation, inducing apoptosis, decreasing β-catenin and caveolin-1 levels, increasing caspase-3 cleavage and p21, and modulating expression profile of inflammatory cytokines. These observations demonstrate that GLAD, a novel cocktail of chemopreventive agents at very low doses, suppresses intestinal tumorigenesis in APCMin/+ mice with no toxicity. This novel strategy to prevent colorectal cancer is an important step in developing agents with high efficacy without unwanted side effects.

  2. Chemopreventive effect of Curcuma longa Linn on liver pathology in HBx transgenic mice.

    Science.gov (United States)

    Kim, Jungsun; Ha, Hye-Lin; Moon, Hyung-Bae; Lee, Yeon-Weol; Cho, Chong-Kwan; Yoo, Hwa-Seung; Yu, Dae-Yeul

    2011-06-01

    Unlike other forms of hepatocellular carcinoma (HCC), HCC induced by hepatitis B virus (HBV) infection shows a poor prognosis after conventional therapies. HBV induces liver cirrhosis and HCC. Many researchers have made efforts to find new substances that suppress the activity of HBV. Curcuma longa Linn (CLL) has been used for traditional medicine and food in Asia, especially in India, and has shown chemopreventive effects in a HBV-related in vitro model. This in vivo study was designed to seek the chemopreventive effects of CLL and its mechanisms. CLL mixture concentrated with dextrose water by boiling was lyophilized. CLL extracts were administrated to HBV X protein (HBx) transgenic mice aged 4 weeks for 2 to 4 weeks and aged 6 months for 3 months. After administration, histological changes in the liver tissue and expression of HBx-related genes were investigated. CLL-treated mice showed less visceral fat, a smaller liver/body weight ratio and delayed liver pathogenesis. Proliferating cell nuclear antigen (PCNA) expression was also increased in CLL-treated HBx transgenic mice, indicating regeneration of damaged liver tissue. CLL treatment decreased expression of HBx and increased p21 and cyclin D1 in livers of HBx transgenic mice. In addition, p-p53 was increased after CLL treatment. These results suggest that CLL can have beneficial effects on the early and late stages of liver pathogenesis, preventing and delaying liver carcinogenesis. This drug should be considered as a potential chemopreventive agent for HBV-related hepatocarcinogenesis.

  3. Chemopreventive effect of Quercus infectoria against chemically induced renal toxicity and carcinogenesis

    Directory of Open Access Journals (Sweden)

    Muneeb U Rehman

    2012-06-01

    Full Text Available In this study we have shown that Quercus infectoria attenuates Fe- NTA induced renal oxidative stress, hyperproliferative response and renal carcinogenesis in rats. Fe-NTA promoted DEN (N-diethyl nitrosamine initiated renal carcinogenesis by increasing the percentage incidence of tumors and induces early tumor markers viz. ornithine decarboxylase (ODC level and PCNA expression. Fe- NTA (9 mg Fe/kg body weight, intraperitoneally enhances renal Malondialdehyde, xanthine oxidase and hydrogen peroxide generation with reduction in renal glutathione content, antioxidant enzymes, viz., glutathione peroxidase, glutathione reductase, catalase, glucose-6-phosphate dehydrogenase and phase-II metabolizing enzymes such as glutathione-S-transferase and quinone reductase. It also enhances blood urea nitrogen and serum creatinine. Fe-NTA also lead to increase in levels of some inflammatory markers viz NO and MPO and some proinflammatory cytokines viz PGE-2 and TNF-1. The chemopreventive efficacy of Quercus infectoria was studied in terms of xenobiotic metabolizing enzyme activities, LPO, redox status, serum toxicity markers, inflammatory and proinflammatory markers and cell proliferation in the kidney tissue. Oral administration of Quercus infectoria at doses of 75 and 150 mg/kg b wt effectively suppressed renal oxidative stress, inflammation and tumor incidence. Chemopreventive effects of Quercus infectoria were associated with up-regulation of xenobiotic metabolizing enzyme activities and down regulation of serum toxicity markers. Present study supports Quercus infectoria as a potent chemopreventive agent and suppresses Fe-NTA-induced renal carcinogenesis and oxidative and inflammatory response in Wistar rat.

  4. Chemopreventive Properties and Toxicity of Kelulut Honey in Sprague Dawley Rats Induced with Azoxymethane.

    Science.gov (United States)

    Saiful Yazan, Latifah; Muhamad Zali, Muhamad Firdaus Shyfiq; Mohd Ali, Razana; Zainal, Nurul Amira; Esa, Nurulaidah; Sapuan, Sarah; Ong, Yong Sze; Tor, Yin Sim; Gopalsamy, Banulata; Voon, Fui Ling; Syed Alwi, Sharifah Sakinah

    2016-01-01

    Ethnopharmacological Relevance. Colon cancer has been a major problem worldwide. Kelulut honey (KH) is produced by the stingless bees from Trigona species and has strong antioxidant activities that could be one of the potential chemopreventive agents from natural resources. Aim of This Study. This study investigated the chemopreventive properties and toxicity of KH in Sprague Dawley rats induced with azoxymethane (AOM). Material and Method. Twenty-four male Sprague Dawley rats aged 5 weeks were divided into 4 groups: (G1) untreated group not induced with AOM, (G2) untreated group induced with AOM, (G3) treated group induced with AOM, and (G4) treated group not induced with AOM. Injection of AOM (15 mg/kg) was via intraperitoneal route once a week for two subsequent weeks. The treatment groups were given oral administration of KH (1183 mg/kg body weight) twice daily for 8 weeks. Results. Treatment with KH significantly reduced the total number of aberrant crypt foci (ACF) and aberrant crypts (AC) and crypt multiplicity. KH was not toxic to the animals since the level of blood profile parameters, liver enzymes, and kidney functions was in normal range. Conclusions. The current finding shows that KH has chemopreventive properties in rats induced with colorectal cancer and also was found not toxic towards the animals. PMID:27525267

  5. Anthocyans from fruits and vegetables--does bright colour signal cancer chemopreventive activity?

    Science.gov (United States)

    Cooke, Darren; Steward, William P; Gescher, Andreas J; Marczylo, Tim

    2005-09-01

    Consumption of fruits and berries has been associated with decreased risk of developing cancer. The most abundant flavonoid constituents of fruits and berries are anthocyans (i.e. anthocyanins, glycosides, and their aglycons, anthocyanidins) that cause intense colouration. In this review, we describe epidemiological evidence hinting at the cancer preventive activity of anthocyan-containing foods in humans, results of chemoprevention studies in rodent models with anthocyans or anthocyan-containing fruit/vegetable extracts, and pharmacological properties of anthocyans. Anthocyanidins have been shown to inhibit malignant cell survival and confound many oncogenic signalling events in the 10(-6)-10(-4) M concentration range. Studies of the pharmacokinetics of anthocyanins after their consumption as single agents, anthocyanin mixtures or berry extracts suggest that anthocyanins reach levels of 10(-8)-10(-7) M in human blood. It is unclear whether such concentrations are sufficient to explain anticarcinogenic effects, and whether anthocyanins exert chemopreventive efficacy themselves, or if they need to undergo hydrolysis to their aglyconic counterparts. The currently available literature provides tantalising hints of the potential usefulness of anthocyans or anthocyan mixtures as cancer chemopreventive interventions. Nevertheless further studies are necessary to help adjudge the propitiousness of their clinical development. PMID:16084717

  6. Colon Cancer Chemoprevention by Sage Tea Drinking: Decreased DNA Damage and Cell Proliferation.

    Science.gov (United States)

    Pedro, Dalila F N; Ramos, Alice A; Lima, Cristovao F; Baltazar, Fatima; Pereira-Wilson, Cristina

    2016-02-01

    Salvia officinalis and some of its isolated compounds have been found to be preventive of DNA damage and increased proliferation in vitro in colon cells. In the present study, we used the azoxymethane model to test effects of S. officinalis on colon cancer prevention in vivo. The results showed that sage treatment reduced the number of ACF formed only if administered before azoxymethane injection, demonstrating that sage tea drinking has a chemopreventive effect on colorectal cancer. A decrease in the proliferation marker Ki67 and in H2 O2 -induced and azoxymethane-induced DNA damage to colonocytes and lymphocytes were found with sage treatment. This confirms in vivo the chemopreventive effects of S. officinalis. Taken together, our results show that sage treatment prevented initiation phases of colon carcinogenesis, an effect due, at least in part, to DNA protection, and reduced proliferation rates of colon epithelial cell that prevent mutations and their fixation through cell replication. These chemopreventive effects of S. officinalis on colon cancer add to the many health benefits attributed to sage and encourage its consumption.

  7. Novel aspects for the application of Curcumin in chemoprevention of various cancers.

    Science.gov (United States)

    Bachmeier, Beatrice E; Killian, Peter; Pfeffer, Ulrich; Nerlich, Andreas G

    2010-01-01

    Chemoprevention of malignant tumor growth is a novel and potentially powerful approach for tumor therapy. Recent in vitro and in vivo investigations provide increasing evidence that naturally occurring substances may exhibit significant chemopreventive activities. To this regard, the spice Curcumin, widely used in Indian cuisine, has been identified to show considerable anti-tumor effects. Most interestingly, numerous studies have not shown toxic side effects of this substance. Curcumin induces tumor cell apoptosis along with a reduction of tumor cell invasion and metastasis. Recent molecular studies provide evidence that Curcumin acts via a control of the NFkappaB pathway exerting most of the various modulating and moderating effects on malignant cells. Along with these in vitro studies, ex vivo and first clinical investigations confirm the anti-tumor effects of Curcumin, either as an isolated chemoprevention substance or in combination with chemotherapeutic agents as supportive measure reducing pharmaceutical resistance of tumor cells to certain chemotherapeutics. Despite our increasing knowledge on this interesting substance there still remain many unknown effects that deserve intense investigation. PMID:20036978

  8. Capsaicin: A novel chemopreventive molecule and its underlying molecular mechanisms of action

    Directory of Open Access Journals (Sweden)

    A A Oyagbemi

    2010-01-01

    Full Text Available Capsaicin (trans-8-methyl-N-vanillyl-6-nonenamide is the a principal pungent ingredient of hot red and chili peppers that belong to the plant genus Capsicum (Solanaceae. Capsaicin is a cancer-suppressing agent. It blocks the translocation of nuclear factor kappa B (NF-kB, activator protein 1 (AP-1, and signal transducer and activator of transcription (STAT3 signaling pathway that are required for carcinogenesis. The anti-inflammatory potential of capsaicin is attributed to its inhibitory effect on inducible COX-2 mRNA expression. Cytochrome P4502E1 mediates the activation of xenobiotics such as vinyl carbamate and dimethyl nitrosamine to their toxic metabolites. This metabolic activation of xenobiotics by Cytochrome P4502E1 has been shown to be inhibited by capsaicin. Capsaicin also generates reactive oxygen species in cells with resultant induction of apoptosis and cell cycle arrest, which is beneficial for cancer chemoprevention. Therefore, the use of capsaicin as a chemopreventive agent is of immense benefit for cancer chemoprevention. The search strategy included printed journals, pubmed, and medline, using the terms ′capsaicin′ and ′anticancer′ citations, relevant to anticancer properties of capsaicin.

  9. Enhanced Heterogeneous Catalytic Conversion of Furfuryl Alcohol into Butyl Levulinate

    NARCIS (Netherlands)

    P.D.. Carà; R. Ciriminna; N.R. Shiju; G. Rothenberg; M. Pagliaro

    2014-01-01

    We study the catalytic condensation of furfuryl alcohol with 1-butanol to butyl levulinate. A screening of several commercial and as-synthesized solid acid catalysts shows that propylsulfonic acid-functionalized mesoporous silica outperforms the state-of-the-art phosphotungstate acid catalysts. The

  10. 27 CFR 21.118 - Methyl n-butyl ketone.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Methyl n-butyl ketone. 21.118 Section 21.118 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants §...

  11. 27 CFR 21.100 - n-Butyl alcohol.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false n-Butyl alcohol. 21.100 Section 21.100 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants §...

  12. 27 CFR 21.101 - tert-Butyl alcohol.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false tert-Butyl alcohol. 21.101 Section 21.101 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants §...

  13. 76 FR 59906 - Fluazifop-P-butyl; Pesticide Tolerances

    Science.gov (United States)

    2011-09-28

    ... Performance Liquid Chromatography/Ultra-Violet Spectrometry (HPLC/UV)) is available to enforce the tolerance... of fluazifop-P-butyl in or on cotton, gin byproducts; cotton, refined oil; and cotton, undelinted... Tolerance In the Federal Register of December 15, 2010 (75 FR 78240) (FRL- 8853-1), EPA issued a...

  14. A Study of the Teratogenicity of Butylated Hydroxyanisole on Rabbits

    DEFF Research Database (Denmark)

    Hansen, Ernst; Meyer, Otto A.

    1978-01-01

    A teratogenicity study on butylated hydroxyanisole (BHA) was carried out in SPF New Zealand White rabbits. BHA was given by gavage from day 7–18 of the gestation period in doses of 0, 50, 200 and 400 mg/kg body wt./day. The fetuses were removed on day 28. No effect related to the treatment with BHA...

  15. Rethinking Dosing Regimen Selection of Piperaquine for Malaria Chemoprevention: A Simulation Study.

    Directory of Open Access Journals (Sweden)

    Nancy C Sambol

    Full Text Available The combination of short-acting dihydroartemisinin and long-acting piperaquine (DP is among the first-line therapies for the treatment of uncomplicated Plasmodium falciparum malaria. Population pharmacokinetic models of piperaquine (PQ based on data from acute treatment of young children can be used to predict exposure profiles of piperaquine under different DP chemoprevention regimens. The purpose of our study was to make such predictions in young children.Based on a prior population pharmacokinetic model of PQ in young Ugandan children, we simulated capillary plasma concentration-time profiles (including their variability of candidate chemoprevention regimens for a reference population of 1-2 year olds weighing at least 11 kg. Candidate regimens that were tested included monthly administration of standard therapeutic doses, bimonthly dosing, and weekly dosing (with and without a loading dose.Once daily doses of 320 mg for three days (960 mg total at the beginning of each month are predicted to achieve an average steady-state trough capillary piperaquine concentration of 35 ng/mL, with 60% achieving a level of 30 ng/mL or higher. In contrast, weekly dosing of 320 mg (i.e., 33% higher amount per month is predicted to approximately double the average steady-state trough concentration, increase the percent of children predicted to achieve 30 ng/mL or higher (94%, while at the same time lowering peak concentrations. Exposure at steady-state, reached at approximately 3 months of multiple dosing, is expected to be approximately 2-fold higher than exposure following initial dosing, due to accumulation. A loading dose improves early exposure, thereby reducing the risk of breakthrough infections at the initiation of chemoprevention.Once weekly chemoprevention of DP predicts favourable exposures with respect to both trough and peak concentrations. These predictions need to be verified, as well as safety evaluated, in field-based clinical studies of young

  16. (R)-N-{2-tert-Butyl-2-[(R)-tert-butyl­sulfonamido]ethylidene}-tert-butane­sulfonamide

    OpenAIRE

    Cong-Bin Fan; Xiao-Xia Sun; Yu Hu

    2008-01-01

    The title compound, C14H30N2O2S2, is the product of the monoaddition reaction of tert-butyl magnesium chloride with bis-[(R)-N-tert-butanesulfinyl]ethanediimine. There are two almost identical molecules in the asymmetric unit, the molecular conformation of which is stabilized by an intramolecular N—H...N hydrogen bond.

  17. A comparison of the effect of intranasal desmopressin and intramuscular hyoscine N-butyl bromide combination with intramuscular hyoscine N-butyl bromide alone in acute renal colic

    OpenAIRE

    Abdol-Reza Kheirollahi; Mohammad Tehrani; Mohammad Bashashati

    2010-01-01

    Background: Patients with acute renal colic usually require immediate diagnosis and treatment. In this clinical trial analgesic effect of hyoscine N-butyl bromide and desmopressin combination in comparison with hyoscine N-butyl bromide alone in patients with acute renal colic induced by urinary stones was assessed. Methods: The study included 114 patients randomly allocated in two groups (A and B). Patients in group A received 20 mg intramuscular hyoscine N-butyl bromide at admission tim...

  18. 5-aminosalicylic acid is an attractive candidate agent for chemoprevention of colon cancer in patients with inflammatory bowel disease

    Institute of Scientific and Technical Information of China (English)

    Yang Cheng; Pierre Desreumaux

    2005-01-01

    Inflammatory bowel disease (IBD) is classically subdivided into ulcerative colitis (UC) and Crohn's disease (CD). Patients with IBD have increased risk for colorectal cancer. Because the pathogenesis of colorectal carcinoma has not been entirely defined yet and there is no ideal treatment for colon cancer, cancer prevention has become increasingly important in patients with IBD. The two adopted methods to prevent the development of colon cancer in clinical practice include the prophylactic colectomy and colonoscopic surveillance.But patients and physicians seldom accept colectomy as a routine preventive method and most patients do not undergo appropriate colonoscopic surveillance. Chemoprevention refers to the use of natural or synthetic chemical agents to reverse, suppress, or to delay the process of carcinogenesis.Chemoprevention is a particularly useful method in the management of patients at high risk for the development of specific cancers based on inborn genetic susceptibility, the presence of cancer-associated disease, or other known risk factors. Prevention of colorectal cancer by administration of chemopreventive agents is one of the most promising options for IBD patients who are at increased risks of the disease. The chemopreventive efficacy of nonsteroidal antiinflammatory drugs (NSAIDs) against intestinal tumors has been well established. But with reports that NSAIDs aggravated the symptoms of colitis, their sustained use for the purpose of cancer chemoprevention has been relatively contraindicated in IBD patients. Another hopeful candidate chemoprevention drug for IBD patients is 5-aminosalicylic acid (5-ASA), which is well tolerated by most patients and has limited systemic adverse effects, and no gastrointestinal toxicity. 5-ASA lacks the well-known side effects of longterm NSAIDs use. Retrospective correlative studies have suggested that the long-term use of 5-ASA in IBD patients may significantly reduce the risk of development of colorectal cancer

  19. 2-Benzhydryl-6-tert-butyl-4-methylphenol

    Directory of Open Access Journals (Sweden)

    Sungwoo Yoon

    2013-02-01

    Full Text Available The title compound, C24H26O, was prepared by the reaction between 2-tert-butyl-4-methylphenol and diphenylmethanol in the presence of sulfuric acid. Three benzene rings are attached directly to the central C—H group in a twisted propeller conformation with the local pseudo-C3 rotational axis coinciding with the C—H bond. There are three short C—H...O contacts in the molecule.

  20. Study of the butyl acetate synthesis - 1. Catalyst selection

    Directory of Open Access Journals (Sweden)

    Álvaro Orjuela Londoño

    2010-04-01

    Full Text Available In this work, a laboratory scale selection study over eight catalytic agents was made, in the acetic acid and butyl alcohol esterification reaction (seven lon exchange resins and a zeolytic solid. Considering some physicochemical characteristics as the activation pre-treating requirements, acidity, thermal stability, reaction performance, etc., it was found that macroporous ion exchange resins are the most efficient catalysts, especially Lewatit K-2431 resin.

  1. 76 FR 5696 - Fluazifop-P-butyl; Pesticide Tolerances

    Science.gov (United States)

    2011-02-02

    ... fluazifop-P-butyl in or on potato, tuber at 1.1 ppm; potato, peel (wet) at 1.1 ppm; potato, chips at 3.0 ppm... Federal Register of January 6, 2010 (75 FR 864) (FRL-8801- 5), EPA issued a notice pursuant to section 408...) at 3.5 ppm. In the Federal Register of February 4, 2010 (75 FR 5790) (FRL-8807- 5), EPA issued...

  2. Antiproliferative and cancer-chemopreventive properties of sulfated glycosylated extract derived from Leucaena leucocephala

    Directory of Open Access Journals (Sweden)

    Gamal-Eldeen Amira

    2007-01-01

    Full Text Available This work aimed to prove that simple chemical modification could provide new cancer chemopreventive and/or anticancer properties to the inactive extracted polysaccharide derived from Leucaena leucocephala . Polysaccharides were extracted from Leucaena leucocephala seeds and its 2,4-pentanedione-treated derivative (glycosylated form was prepared, which is further sulphated to give sulphated glycosylated form. Estimation of their anti-initiation activity, modulation of carcinogen metabolism, was indicated by the inhibition cytochrome P450 1A (CYP1A and the induction of glutathione-S-transferases (GSTs. Anti-proliferation activity was investigated by MTT assay against human hepatocarcinoma (HepG2, breast carcinoma (MCF-7 and lymphoblastic leukemia (1301. Apoptosis/necrosis and cell cycle were analyzed by flow cytometry. The results revealed that glycosylated form inhibited both CYP1A and GSTs, while sulphated glycosylated form not only inhibited CYP1A, but also induced the GSTs. Unlike GE, sulphated glycosylated form possessed a significant anti-proliferative activity against different cell lines. Analysis of HepG2 cell cycle phases demonstrated that glycosylated form led to a delay of G2/M-phase, while sulphated glycosylated form led to a concomitant arrest in S- and G2/M-phases. Investigation of apoptosis/necrosis ratio demonstrated that both of glycosylated form and sulphated glycosylated form induced HepG2 cell death by necrosis, but not apoptosis. Unmodified crude extract was neither active as cancer chemopreventive nor as anti-proliferative. In conclusion, chemical modification of Leucaena gum induced its cancer chemopreventive and anti-proliferative activities.

  3. Recruitment strategies for a lung cancer chemoprevention trial involving ex-smokers.

    Science.gov (United States)

    Kye, Steve H; Tashkin, Donald P; Roth, Michael D; Adams, Bradley; Nie, Wen-Xian; Mao, Jenny T

    2009-09-01

    The ability to recruit qualified subjects who are willing to adhere to the study protocol in clinical trials is an essential component of translational research. Such tasks can be particularly challenging for chemoprevention studies when the targeted study population is healthy, at risk individuals who do not have signs or symptoms of the disease, and the study participation involves complex scheduling and invasive procedures such as bronchoscopy. In this report, we describe the recruitment process and evaluated the effectiveness of various recruitment strategies utilized in our National Cancer Institute sponsored lung cancer chemoprevention study with celecoxib. Heavy ex-smokers were recruited into the study through various methods such as radio advertisements, print media, mass mailings, flyers, internet postings and others. The number of inquiries, on-site screenees and randomization generated by each method determined the efficacy of that recruitment strategy. We prescreened 4470 individuals, invited 323 people for on-site screening and randomized 137 subjects. Radio advertisements (ads) generated the most inquiries (71.1%), followed by internet posting (11.8%), print media (6.0%), posted and racked flyers (4.4%), mass mailings (2.7%) and other strategies such as referrals from friends or family members or health care providers (2.3%). Radio ads, although costly, yielded the most subjects for on-site screening and randomization. Moreover, among the various types of radio stations, news radio stations were by far the most successful. Our results suggest that advertising on news radio is a highly effective recruitment method for successful accrual of ex-smokers into lung cancer chemoprevention trials. PMID:19508900

  4. Natural products for cancer-targeted therapy: citrus flavonoids as potent chemopreventive agents.

    Science.gov (United States)

    Meiyanto, Edy; Hermawan, Adam; Anindyajati

    2012-01-01

    Targeted therapy has been a very promising strategy of drug development research. Many molecular mechanims of diseases have been known to be regulated by abundance of proteins, such as receptors and hormones. Chemoprevention for treatment and prevention of diseases are continuously developed. Pre-clinical and clinical studies in chemoprevention field yielded many valuable data in preventing the onset of disease and suppressing the progress of their growth, making chemoprevention a challenging and a very rational strategy in future researches. Natural products being rich of flavonoids are those fruits belong to the genus citrus. Ethanolic extract of Citrus reticulata and Citrus aurantiifolia peels showed anticarcinogenic, antiproliferative, co-chemotherapeutic and estrogenic effects. Several examples of citrus flavonoids that are potential as chemotherapeutic agents are tangeretin, nobiletin, hesperetin, hesperidin, naringenin, and naringin. Those flavonoids have been shown to possess inhibition activity on certain cancer cells' growth through various mechanisms. Moreover, citrus flavonoids also perform promising effect in combination with several chemotherapeutic agents against the growth of cancer cells. Some mechanisms involved in those activities are through cell cycle modulation, antiangiogenic effect, and apoptosis induction. Previous studies showed that tangeretin suppressed the growth of T47D breast cancer cells by inhibiting ERK phosphorylation. While in combination with tamoxifen, doxorubicin, and 5-FU, respectively, it was proven to be synergist on several cancer cells. Hesperidin and naringenin increased cytotoxicitity of doxorubicin on MCF-7 cells and HeLa cells. Besides, citrus flavonoids also performed estrogenic effect in vivo. One example is hesperidin having the ability to decrease the concentration of serum and hepatic lipid and reduce osteoporosis of ovariectomized rats. Those studies showed the great potential of citrus fruits as natural product

  5. Butylated hydroxyanisole induces distinct expression patterns of Nrf2 and detoxification enzymes in the liver and small intestine of C57BL/6 mice.

    Science.gov (United States)

    Luo, Lin; Chen, Yeru; Wu, Deqi; Shou, Jiafeng; Wang, Shengcun; Ye, Jie; Tang, Xiuwen; Wang, Xiu Jun

    2015-11-01

    Butylated hydroxyanisole (BHA) is widely used as an antioxidant and preservative in food, food packaging and medicines. Its chemopreventive properties are attributing to its ability to activate the transcription factor NF-E2 p45-related factor 2 (Nrf2), which directs central genetic programs of detoxification and protection against oxidative stress. This study was to investigate the histological changes of Nrf2 and its regulated phase II enzymes Nqo1, AKR1B8, and Ho-1 in wild-type (WT) and Nrf2(-/-) mice induced by BHA. The mice were given a 200mg/kg oral dose of BHA daily for three days. Immunohistochemistry revealed that, in the liver from WT mice, BHA increased Nqo1 staining in hepatocytes, predominately in the pericentral region. In contrast, the induction of AKR1B8 appeared mostly in hepatocytes in the periportal region. The basal and inducible Ho-1 was located almost exclusively in Kupffer cells. In the small intestine from WT mice, the inducible expression patterns of Nqo1 and AKR1B8 were nearly identical to that of Nrf2, with more intense staining in the villus than that the crypt. Conversely, Keap1 was more highly expressed in the crypt, where the proliferative cells reside. Our study demonstrates that BHA elicited differential expression patterns of phase II-detoxifying enzymes in the liver and small intestine from WT but not Nrf2(-/-) mice, demonstrating a cell type specific response to BHA in vivo. PMID:26291391

  6. HIGH LEVELS OF MONOAROMATIC COMPOUNDS LIMIT THE USE OF SOLID-PHASE MICROEXTRACTION OF METHYL TERTIARY BUTYL ETHER AND TERTIARY BUTYL ALCOHOL

    Science.gov (United States)

    Recently, two papers reported the use of solid-phase microextraction (SPME) with polydimethylsiloxane(PDMS)/Carboxen fibers to determine trace levels of methyl tertiary butyl ether (MTBE) and tertiary butyl alcohol (tBA) in water. Attempts were made to apply this technique to th...

  7. Cyclooxygenase as a target for chemoprevention in colorectal cancer: lost cause or a concept coming of age?

    LENUS (Irish Health Repository)

    Doherty, Glen A

    2009-02-01

    COX-2 is upregulated at an early stage in colorectal carcinogenesis and generates prostaglandins, which promote cancer cell proliferation, impair apoptosis and enhance angiogenesis, promoting tumour growth and metastasis. There are ample data from animal models and human studies to demonstrate enhanced tumour progression associated with COX-2 activity in cancer cells. Conversely, NSAIDs including aspirin inhibit COX-2 and, therefore, have anti-neoplastic properties. There has been sustained interest in COX-2 as a chemopreventive target in colorectal cancer (CRC) and although both aspirin and COX-2 selective NSAIDs have demonstrated efficacy, adverse effects have limited their widespread adoption. In particular, evidence of the cardiovascular effects of COX-2 selective inhibitors has led to questioning of the suitability of COX-2 as a target for chemoprevention. This review examines the basis for targeting COX-2 in CRC chemoprevention, evaluates the efficacy and safety of the approach and examines future strategies in this area.

  8. Chemoprevention of Lung Squamous Cell Carcinoma in Mice by a Mixture of Chinese Herbs

    OpenAIRE

    Wang, Yian; Zhang, Zhongqiu; Garbow, Joel R.; Rowland, Doug J.; Ronald A Lubet; Sit, Daniel; Law, Frances; You, Ming

    2009-01-01

    Anti-tumor B (ATB) is a Chinese herbal mixture of six plants. Previous studies have shown significant chemopreventive efficacy of ATB against human esophageal and lung cancers. We have recently developed a new mouse model for lung squamous cell carcinomas (SCC). In this study, lung SCC mouse model was characterized using small-animal imaging techniques (MRI and CT). ATB decreased lung SCC significantly (3.1 fold, p < 0.05) and increased lung hyperplastic lesions by 2.4 fold (p < 0.05). This o...

  9. Tea: age-old beverage as an effective cancer chemopreventive agent

    Directory of Open Access Journals (Sweden)

    Jasmine George

    2011-12-01

    Full Text Available Cancer is the major public health problem, causing approximately 7 million deaths every year worldwide. The existing treatment approaches and surgical techniques have not been able to cope effectively with this dreaded disease. Because of this, the concept of chemoprevention is now considered a valid approach to reduce the incidence of cancer. There is convincing epidemiological and experimental evidence to show that dietary polyphenolic plant-derived compounds have cancer preventive properties. Based on evidence from in vitro, in vivo data and epidemiological studies, tea has received considerable attention over recent years for reducing the risk of several cancers. Much of the cancer preventive effects of tea, and in particular green tea, appear to be mediated by the polyphenols they contain. In addition to inhibiting mutagenesis and proliferation, tea is relatively non-toxic, is low cost, and can be taken orally or as a part of the daily diet. Therefore it is logical that future clinical studies should focus on examining the efficacy of tea and its active constituents, such as epigallocatechin- 3-gallate (EGCG and theaflavins (TFs, in chemoprevention as an alternative to pharmacological agents. In this review, we address the use of tea and its constituents for the prevention and treatment of cancer. Further mechanistic and dose-response studies will help us to understand the effects of tea consumption on human carcinogenesis.

  10. Chemopreventive effects of cardamom (Elettaria cardamomum L.) on chemically induced skin carcinogenesis in Swiss albino mice.

    Science.gov (United States)

    Qiblawi, Samir; Al-Hazimi, Awdah; Al-Mogbel, Mohammed; Hossain, Ashfaque; Bagchi, Debasis

    2012-06-01

    The chemopreventive potential of cardamom was evaluated on 7,12-dimethylbenz[a]anthracene-initiated and croton oil-promoted mouse skin papillomagenesis. A significant reduction in the values of tumor incidence, tumor burden, and tumor yield and the cumulative number of papillomas was observed in mice treated orally with 0.5 mg of cardamom powder in suspension continuously at pre-, peri-, and post-initiational stages of papillomagenesis compared with the control group. The average weight and diameter of tumors recorded were also comparatively lower in the cardamom-treated mouse group. Treatment of cardamom suspension by oral gavage for 15 days resulted in a significant decrease in the lipid peroxidation level of the liver (P < .01). In addition, the reduced glutathione level was significantly elevated in comparison with the control group (P < .05) following cardamom suspension treatment. Taken together, these findings indicate the potential of cardamom as a chemopreventive agent against two-stage skin cancer. PMID:22404574

  11. Chemoprevention of Lung Cancer: Prospects and Disappointments in Human Clinical Trials

    Directory of Open Access Journals (Sweden)

    William N. Rom

    2013-01-01

    Full Text Available Decreasing the risk of lung cancer, or preventing its development in high-risk individuals, would have a huge impact on public health. The most effective means to decrease lung cancer incidence is to eliminate exposure to carcinogens. However, with recent advances in the understanding of pulmonary carcinogenesis and the identification of intermediate biomarkers, the prospects for the field of chemoprevention research have improved dramatically. Here we review the most recent research in lung cancer chemoprevention—focusing on those agents that have been investigated in human clinical trials. These agents fall into three major categories. First, oxidative stress plays an important role in pulmonary carcinogenesis; and therefore, antioxidants (including vitamins, selenium, green tea extracts, and isothiocyanates may be particularly effective in preventing the development of lung cancer. Second, inflammation is increasingly accepted as a crucial factor in carcinogenesis, and many investigators have focused on anti-inflammatory agents, such as glucocorticoids, NSAIDs, statins, and PPARγ agonists. Finally, the PI3K/AKT/mTOR pathway is recognized to play a central role in tobacco-induced carcinogenesis, and inhibitors of this pathway, including myoinositol and metformin, are promising agents for lung cancer prevention. Successful chemoprevention will likely require targeting of multiple pathways to carcinogenesis—both to minimize toxicity and maximize efficacy.

  12. Clinical cancer chemoprevention: From the hepatitis B virus (HBV) vaccine to the human papillomavirus (HPV) vaccine.

    Science.gov (United States)

    Tsai, Horng-Jyh

    2015-04-01

    Approximately 2 million new cancer cases are attributed to infectious agents each year worldwide. Vaccines for the hepatitis B virus (HBV), a risk factor of hepatocellular cancer, and human papillomavirus (HPV), a risk factor of cervical cancer, are considered major successes in clinical chemoprevention of cancer. In Taiwan, the first evidence of cancer prevention through vaccinations was provided by HBV vaccination data in infants. The Taiwanese HBV vaccination program has since become a model immunization schedule for newborns worldwide. Persistent infection with high-risk HPV is generally accepted as prerequisite for cervical cancer diagnosis; however, cervical cancer is a rare complication of HPV infections. This is due to the fact that such infections tend to be transient. The safety and efficacy of both available HPV quadrivalent vaccine and bivalent vaccine are not in doubt at the present time. Until a human cytomegalovirus (CMV) vaccine becomes available, simple hygienic practices, such as hand washing, can prevent CMV infection both before and during pregnancy. Each country should establish her official guidelines regarding which vaccines should be used to treat various conditions, the target population (i.e., universal or limited to a selected population), and the immunization schedules. After a vaccine is recommended, decisions regarding reimbursement by the public health care fund are evaluated. The guidelines become part of the immunization schedule, which is updated annually and published in the official bulletin. In conclusion, both HBV and HPV vaccines are considered major successes in the chemoprevention of cancer.

  13. Curcumin and Other Polyphenolic Compounds in Head and Neck Cancer Chemoprevention

    Directory of Open Access Journals (Sweden)

    Philipp Baumeister

    2012-01-01

    Full Text Available Despite clear results of observational studies linking a diet rich in fruits and vegetables to a decreased cancer risk, large interventional trials evaluating the impact of dietary micronutrient supplementation, mostly vitamins, could not show any beneficial effects. Today it has become clear that a single micronutrient, given in supernutritional doses, cannot match cancer preventive effects of whole fruits and vegetables. In this regard polyphenols came into focus, not only because of their antioxidant potential but also because of their ability to interact with molecular targets within the cells. Because polyphenols occur in many foods and beverages in high concentration and evidence for their anticancer activity is best for tissues they can come into direct contact with, field cancerization predestines upper aerodigestive tract epithelium for cancer chemoprevention by polyphenols. In this paper, we summarize cancer chemopreventive attempts with emphasis on head and neck carcinogenesis and discuss some methodological issues. We present data regarding antimutagenic effects of curcumin and epigallocatechin-3-gallate in human oropharyngeal mucosa cultures exposed to cigarette smoke condensate.

  14. Cancer chemoprevention activity of labdane diterpenes from rhizomes of Hedychium coronarium

    Directory of Open Access Journals (Sweden)

    Denise C. Endringer

    2014-08-01

    Full Text Available Hedychium coronarium J. Koenig, Zingiberaceae, is a medicinal plant popularly used to treat inflammatory conditions in different countries. Three labdane diterpenes [isocoronarin D (1, methoxycoronarin D (2, ethoxycoronarin D (3] and benzoyl eugenol (4 were isolated from rhizomes and their chemopreventive potential was evaluated using in vitro assays, namely the inhibition of NF-κB, COX-1 and -2, the induction of antioxidant response element (ARE, and the inhibition of cell proliferation. Diterpene 1 activated ARE (EC50 57.6 ± 2.4 µM, while 2, 3 and 4 significantly inhibited NF-κB (IC50 of 7.3 ± 0.3, 3.2 ± 0.3 and 32.5 ± 4.9 µM, respectively. In addition, 2 and 3 selectively inhibited COX-1 (IC50 values of 0.9 ± 0.0 and 3.8 ± 0.0 µM, respectively. These data support the potential chemopreventive activity of constituents from H. coronarium rhizomes.

  15. Enantioselective degradation and chiral stability of the herbicide fluazifop-butyl in soil and water.

    Science.gov (United States)

    Qi, Yanli; Liu, Donghui; Luo, Mai; Jing, Xu; Wang, Peng; Zhou, Zhiqiang

    2016-03-01

    The stereoselective degradation and transformation of the enantiomers of the herbicide fluazifop-butyl in soil and water were studied to investigate the environmental behavior and chiral stability of the optical pure product. Its main chiral metabolite fluazifop was also monitored. LC/MS/MS with Chiralpak IC chiral column was used to separate the enantiomers of fluazifop-butyl and fluazifop. Validated enantioselective residue analysis methods were established with recoveries ranging from 77.1 to 115.4% and RSDs from 0.85 to 8.9% for the enantiomers. It was found the dissipation of fluazifop-butyl was rapid in the three studied soils (Beijing, Harbin and Anhui soil), and the degradation half-lives of the enantiomers ranged from 0.136 to 2.7 d. Enantioselective degradations were found in two soils. In Beijing soil, R-fluazifop-butyl was preferentially degraded leading to relative enrichment of S-enantiomer, but in Anhui soil, S-fluazifop-butyl dissipated faster. There was no conversion of the R-fluazifop-butyl into S-fluazifop-butyl or vice versa in the soils. The formation of fluazifop in the soils was rapidly accompanied with the fast degradation of fluazifop-butyl, and the enantioselectivity and the transformation of S-fluazifop to R-fluazifop were found. The degradation of fluazifop-butyl in water was also quick, with half-lives of the enantiomers ranging from 0.34 to 2.52 d, and there was no significant enantioselectivity of the degradation of fluazifop-butyl and the formation of fluazifop. The effects of pH on the degradation showed fluazifop-butyl enantiomers degraded faster in alkaline conditions. This study showed an evidence of enantioselective behavior and enantiomerization of the chiral herbicide fluazifop-butyl.

  16. Molecular recognition study of Carbamazepine, antiseizure drug, by p-t-butyl calix(8)arene

    Science.gov (United States)

    Meenakshi, C.; Jayabal, P.; Ramakrishnan, V.

    2014-03-01

    The formation of inclusion complex of Carbamazepine, a antiseizure drug molecule, with the supra molecule, p-t-butyl calix(8)arene was studied. p-t-Butyl calix(8)arene was the host molecule and Carbamazepine was the guest molecule. Optical absorption spectral studies were carried out to study the molecular recognition properties of p-t-butyl calix(8)arene with Carbamazepine. The stochiometry of the host-guest complex and the binding constant were determined.

  17. tert-Butyl N-(thiophen-2-ylcarbamate

    Directory of Open Access Journals (Sweden)

    Gene C. Hsu

    2013-09-01

    Full Text Available In the title compound, C9H13NO2S, the dihedral angle between the thiophene ring and the carbamate group is 15.79 (14°. In the crystal structure, intramolecular C—H...O interactions in tandem with the tert-butyl groups render the packing of adjacent molecules in the [001] direction nearly perpendicular [the angle between adjacent thiophene rings is 74.83 (7°]. An intermolecular N—H...O hydrogen bond gives rise to a chain extending along [001]. The crystal studied was found to be a racemic twin.

  18. The rotational spectrum of tertiary-butyl alcohol

    Science.gov (United States)

    Cohen, E. A.; Drouin, B. J.; Valenzuela, E. A.; Woods, R. C.; Caminati, W.; Maris, A.; Melandri, S.

    2010-03-01

    The rotational spectrum of tertiary-butyl alcohol has been recorded in selected regions between 8 and 500 GHz. Early data from the University of Wisconsin in the 8-40 GHz region have been combined with recent measurements from the University of Bologna and the Jet Propulsion Laboratory in the millimeter and submillimeter wavelength regions. The spectrum was fit over a wide range of J's and K's using a common set of parameters for both the A and E states. This paper describes the initial assignment at Wisconsin and the final procedure used to assign and fit the higher rotational states. The resulting molecular constants and their interpretation are discussed.

  19. Tris(tert-butyl isocyanide-κC)carbonylnickel(0)

    OpenAIRE

    Wolfgang Imhof; Helmar Görls; Kathi Halbauer

    2008-01-01

    The title compound, [Ni(C5H9N)3(CO)], was prepared from Ni(CO)4 and a tenfold excess of tert-butyl isocyanide. It crystallizes with two symmetry-independent mol­ecules per asymmetric unit. The central Ni atom of each independent mol­ecule has a nearly perfect tetra­hedral coordination environment, comprising one carbon monoxide and three isocyanide ligands. The title compound is the first structurally characterized Ni0 compound with a mixed CO/RNC coordination.

  20. Effect of Parameters on Oxychlorination of Tert-Butyl Ethers

    OpenAIRE

    Gaca, Jerzy; Gackowska, Alicja; Belt, Natalia

    2008-01-01

    The effect of concentration, molar ratios of reagents, pH, and temperature on formation of chloro-organic products in reaction of tert-butyl ethers with chloride ions and hydrogen peroxide has been determined. A significant effect of Cl− ions and H2O2 molar ratios on the rate of chloro-organic product formation has been observed. Studies on oxychlorination of tert-butylethyl ether (ETBE) at pH 7, 3.5, and 2.5 have been carried out. It was found that introduction of hydronium ions into the rea...

  1. Breaking the relay in deregulated cellular signal transduction as a rationale for chemoprevention with anti-inflammatory phytochemicals

    Energy Technology Data Exchange (ETDEWEB)

    Kundu, Joydeb Kumar [National Research Laboratory of Molecular Carcinogenesis and Chemoprevention, College of Pharmacy, Seoul National University, Shinlim-dong, Kwanak-gu, Seoul 151-742 (Korea, Republic of); Surh, Young-Joon [National Research Laboratory of Molecular Carcinogenesis and Chemoprevention, College of Pharmacy, Seoul National University, Shinlim-dong, Kwanak-gu, Seoul 151-742 (Korea, Republic of)]. E-mail: surh@plaza.snu.ac.kr

    2005-12-11

    Center to the cancer biology is disrupted intracellular signaling network, which transmits improper signals resulting in abnormal cellular functioning. Therefore, modulation of inappropriate cell signaling cascades might be a rational approach in achieving chemoprevention. Inflammation has long been suspected to contribute to carcinogenesis. A new horizon in chemoprevention research is the recent discovery of molecular links between inflammation and cancer. Components of the cell signaling network, especially those converge on redox-sensitive transcription factor nuclear factor-{kappa}B involved in mediating inflammatory response, have been implicated in carcinogenesis. Intracellular signaling through another redox-sensitive transcription factor AP-1 and that transmitted via a more recently identified oncoprotein {beta}-catenin are also considered to be crucial for inflammation-associated cancer. Epidemiological and experimental studies have revealed that a wide variety of phytochemicals present in our daily diet are potential chemopreventive agents that can alter or correct undesired cellular functions caused by abnormal pro-inflammatory signal transmission. Modulation of cellular signaling involved in chronic inflammatory response by anti-inflammatory phytochemicals may comprise a rational and pragmatic strategy in molecular target-based chemoprevention.

  2. Pomegranate exerts chemoprevention of experimentally induced mammary tumorigenesis by suppression of cell proliferation and induction of apoptosis.

    Science.gov (United States)

    Bishayee, Anupam; Mandal, Animesh; Bhattacharyya, Piyali; Bhatia, Deepak

    2016-01-01

    Breast cancer is the second leading cause of cancer-related death in women in the United States and discovery and development of safe chemopreventive drugs is urgently needed. The fruit pomegranate (Punica granatum) is gaining importance because of its various health benefits. This study was initiated to investigate chemopreventive potential of a pomegranate emulsion (PE) against 7,12-dimethylbenz(a)anthracene (DMBA) rat mammary carcinogenesis. The animals were orally administered with PE (0.2-5.0 g/kg), starting 2 wk before and 16 wk following DMBA treatment. PE exhibited a striking reduction of DMBA-induced mammary tumor incidence, total tumor burden, and reversed histopathological changes. PE dose-dependently suppressed cell proliferation and induced apoptosis in mammary tumors. Immunohistochemical studies showed that PE increased intratumor Bax, decreased Bcl2 and manifested a proapoptotic shift in Bax/Bcl2 ratio. In addition, our gene expression study showed PE-mediated upregulation of Bad, caspase-3, caspase-7, caspase-9, poly (ADP ribose) polymerase and cytochrome c in mammary tumors. Thus, PE exerts chemoprevention of mammary carcinogenesis by suppressing cell proliferation and inducing apoptosis mediated through upregulation of Bax and downregulation of Bcl2 in concert with caspase cascades. Pomegranate bioactive phytoconstituents could be developed as a chemopreventive drug to reduce the risk of breast cancer. PMID:26699876

  3. Pomegranate exerts chemoprevention of experimentally induced mammary tumorigenesis by suppression of cell proliferation and induction of apoptosis

    Science.gov (United States)

    Bishayee, Anupam; Mandal, Animesh; Bhattacharyya, Piyali; Bhatia, Deepak

    2016-01-01

    abstract Breast cancer is the second leading cause of cancer-related death in women in the United States and discovery and development of safe chemopreventive drugs is urgently needed. The fruit pomegranate (Punica granatum) is gaining importance because of its various health benefits. This study was initiated to investigate chemopreventive potential of a pomegranate emulsion (PE) against 7,12-dimethylbenz(a)anthracene (DMBA) rat mammary carcinogenesis. The animals were orally administered with PE (0.2–5.0 g/kg), starting 2 wk before and 16 wk following DMBA treatment. PE exhibited a striking reduction of DMBA-induced mammary tumor incidence, total tumor burden, and reversed histopathological changes. PE dose-dependently suppressed cell proliferation and induced apoptosis in mammary tumors. Immunohistochemical studies showed that PE increased intratumor Bax, decreased Bcl2 and manifested a proapoptotic shift in Bax/Bcl2 ratio. In addition, our gene expression study showed PE-mediated upregulation of Bad, caspase-3, caspase-7, caspase-9, poly (ADP ribose) polymerase and cytochrome c in mammary tumors. Thus, PE exerts chemoprevention of mammary carcinogenesis by suppressing cell proliferation and inducing apoptosis mediated through upregulation of Bax and downregulation of Bcl2 in concert with caspase cascades. Pomegranate bioactive phytoconstituents could be developed as a chemopreventive drug to reduce the risk of breast cancer. PMID:26699876

  4. Acceptability by community health workers in Senegal of combining community case management of malaria and seasonal malaria chemoprevention

    DEFF Research Database (Denmark)

    Tine, Roger Ck; Ndiaye, Pascal; Ndour, Cheikh T;

    2013-01-01

    Community case management of malaria (CCMm) and seasonal malaria chemoprevention (SMC) are anti-malarial interventions that can lead to substantial reduction in malaria burden acting in synergy. However, little is known about the social acceptability of these interventions. A study was undertaken...... to assess whether combining the interventions would be an acceptable approach to malaria control for community health workers (CHWs)....

  5. New Enlightenment of Skin Cancer Chemoprevention through Phytochemicals: In Vitro and In Vivo Studies and the Underlying Mechanisms

    Directory of Open Access Journals (Sweden)

    Madhulika Singh

    2014-01-01

    Full Text Available Skin cancer is still a major cause of morbidity and mortality worldwide. Skin overexposure to ultraviolet irradiations, chemicals, and several viruses has a capability to cause severe skin-related disorders including immunosuppression and skin cancer. These factors act in sequence at various steps of skin carcinogenesis via initiation, promotion, and/or progression. These days cancer chemoprevention is recognized as the most hopeful and novel approach to prevent, inhibit, or reverse the processes of carcinogenesis by intervention with natural products. Phytochemicals have antioxidant, antimutagenic, anticarcinogenic, and carcinogen detoxification capabilities thereby considered as efficient chemopreventive agents. Considerable efforts have been done to identify the phytochemicals which may possibly act on one or several molecular targets that modulate cellular processes such as inflammation, immunity, cell cycle progression, and apoptosis. Till date several phytochemicals in the light of chemoprevention have been studied by using suitable skin carcinogenic in vitro and in vivo models and proven as beneficial for prevention of skin cancer. This revision presents a comprehensive knowledge and the main molecular mechanisms of actions of various phytochemicals in the chemoprevention of skin cancer.

  6. Densities and isobaric vapor-liquid equilibria for the mixtures formed by four butyl esters and 1-butanol

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, E.; Ortega, J. [Univ. of Las Palmas de Gran Canaria (Spain)

    1996-01-01

    Densities of 298.15 K and the vapor-liquid equilibria for 1-butanol + butyl methanoate, + butyl ethanoate, + butyl propanoate, and + butyl butanoate have been measured at 101.32 kPa in small capacity ebulliometer. All results were found to be thermodynamically consistent with a point-to-point test. The mixtures containing butyl methanoate and butyl ethanoate show azeotropes at T = 379.14 K, x = 0.871 and T = 389.64 K, x = 0.222, respectively. Different group-contribution methods were applied to these mixtures.

  7. Cancer chemoprevention and nutriepigenetics: state of the art and future challenges.

    Science.gov (United States)

    Gerhauser, Clarissa

    2013-01-01

    The term "epigenetics" refers to modifications in gene expression caused by heritable, but potentially reversible, changes in DNA methylation and chromatin structure. Epigenetic alterations have been identified as promising new targets for cancer prevention strategies as they occur early during carcinogenesis and represent potentially initiating events for cancer development. Over the past few years, nutriepigenetics - the influence of dietary components on mechanisms influencing the epigenome - has emerged as an exciting new field in current epigenetic research. During carcinogenesis, major cellular functions and pathways, including drug metabolism, cell cycle regulation, potential to repair DNA damage or to induce apoptosis, response to inflammatory stimuli, cell signalling, and cell growth control and differentiation become deregulated. Recent evidence now indicates that epigenetic alterations contribute to these cellular defects, for example epigenetic silencing of detoxifying enzymes, tumor suppressor genes, cell cycle regulators, apoptosis-inducing and DNA repair genes, nuclear receptors, signal transducers and transcription factors by promoter methylation, and modifications of histones and non-histone proteins such as p53, NF-κB, and the chaperone HSP90 by acetylation or methylation.The present review will summarize the potential of natural chemopreventive agents to counteract these cancer-related epigenetic alterations by influencing the activity or expression of DNA methyltransferases and histone modifying enzymes. Chemopreventive agents that target the epigenome include micronutrients (folate, retinoic acid, and selenium compounds), butyrate, polyphenols from green tea, apples, coffee, black raspberries, and other dietary sources, genistein and soy isoflavones, curcumin, resveratrol, dihydrocoumarin, nordihydroguaiaretic acid (NDGA), lycopene, anacardic acid, garcinol, constituents of Allium species and cruciferous vegetables, including indol-3-carbinol

  8. Statins in the chemoprevention of colorectal cancer in established animal models of sporadic and colitis-associated cancer.

    Science.gov (United States)

    Pikoulis, Emmanouil; Margonis, Georgios A; Angelou, Anastasios; Zografos, George C; Antoniou, Efstathios

    2016-03-01

    Despite the availability of effective surveillance for colorectal cancer with colonoscopy, chemoprevention might be an acceptable alternative. Statins are potent inhibitors of cholesterol biosynthesis. In clinical trials, statins have been found to be beneficial in the primary and secondary prevention of coronary heart disease. However, the overall benefits observed with statins appear to be greater than what might be expected from changes in lipid levels alone, suggesting effects beyond cholesterol lowering. This systematic review aimed to gather information on the possible chemopreventive role of statins in preventing carcinogenesis and tumor promotion by a diverse array of mechanisms in both sporadic and colitis-associated cancer in animal models. The MEDLINE database was thoroughly searched using the following keywords: 'statin, HMG-CoA reductase inhibitor, colon cancer, mice, rats, chemoprevention, colitis-associated cancer'. Additional articles were gathered and evaluated. There are a lot of clinical studies and meta-analyses, as well as a plethora of basic research studies implementing cancer cell lines and animal models, on the chemopreventive role of statins in colorectal cancer (CRC). However, data derived from clinical studies are inconclusive, yet they show a tendency toward a beneficial role of statins against CRC pathogenesis. Thus, more research on the molecular pathways of CRC tumorigenesis as related to statins is warranted to uncover new mechanisms and compare the effect of statins on both sporadic and colitis-associated cancer in animal models. Basic science results could fuel exclusive colitis-associated cancer clinical trials to study the chemopreventive effects of statins and to differentiate between their effects on the two types of CRCs in humans. PMID:25768976

  9. Methyltert-butyl Ether (MTBE Degradation by a Microbial Consortium

    Directory of Open Access Journals (Sweden)

    S. B. Mortazavi

    2005-01-01

    Full Text Available Methyl tert-butyl ether (MTBE is added to reformulated gasoline to meet the 1990 Clean Air Act directives. Widespread use of MTBE in gasoline has resulted in groundwater contamination. Because of its undesirable effects on drinking water and ecologically harmful effects, MTBE removal has become a public health and environmental concern. In this study, we have isolated a mixed bacterial culture which is capable of degrading the MTBE as a sole carbon and energy source. This consortium was developed from mixed urban and petrochemical activated sludge after 4 month's enrichment. Enrichment was conducted in batch reactor, fitted with a screw cap and butyl rubber septum. MTBE concentration was measured in head space by gas chromatography. Degradation was determined by MTBE removal. MTBE biodegradation was depended to Dissolved Oxygen (DO concentration and not affected by the changes in concentration of trace element solution or other stimulator Substances. Degradation rates were nearly 1.478 mg MTBE h-1 g-1 (wet biomass and didn't change with MTBE concentration (up 500 mg L-1.

  10. Antisickling activity of butyl stearate isolated from Ocimum basilicum (Lamiaceae)

    Institute of Scientific and Technical Information of China (English)

    Dorothe Dinangayi Tshilanda; Pius Tshimankinda Mpiana; Damase Nguwo Vele Onyamboko; Blaise Mavinga Mbala; Koto-te-Nyiwa Ngbolua; Damien Sha Tshibey Tshibangu; Matthieu Kokengo Bokolo; Kalulu Muzele Taba; Teddy Kabeya Kasonga

    2014-01-01

    Objective: To perform phytochemical analyses on the leaves of Ocimum basilicum L. (O. basilicum), to elucidate the structure of isolate and then perform the antisickling activity on the crude extract and on the isolate. Methods:The Emmel test performed on the acidified methanolic extract of this plant was used to evaluate the antisickling activity. The structure characterization of the active compound was performed using chromatographic techniques for the separation and the spectroscopic ones for structure elucidation (1H-NMR, 13C-NMR, COSY, HMBC). Results: The chemical screening on the crude extract revealed the presence of polyphenols (flavonoids, anthocyanins, leucoanthocyanins, tannins, quinones) alkaloids, saponins, triterpenoids and steroids. The obtained extract after evaporation yielded 34.50 g (11.5%) out of 300 g of powdered leaves of O. basilicum. The acidified methanolic extract and butyl stearate showed an interesting antisickling activity. Conclusions:The acidified methanolic extract and butyl stearate from O. basilicum displayed a good antisickling activity. To the best of our knowledge, this is the first time to report the antisickling activity of this compound in this plant. The synthesized compound presented the same spectroscopic characteristics than the natural one and the antisickling activities of its derivatives are understudying.

  11. Production of butyl solvents from lignocellulose: An economic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wright, J D; Daling, R; Sandel, R L; Fitzpatrick, S W

    1986-11-01

    A process is described that produces butyl solvents, butanol, isopropanol, and ethanol from wood or other lignocellulosic feedstock. Two new elements of technology introduced are the processing batch reactor developed at SERI that produces high yields of fermentable sugars (hexoses and pentoses) at the appropriate concentration for the butyl solvents fermentation and a novel method of separating products using liquid-liquid extraction, which reduces the separation energy required to about 30% of energy required in the conventional batch method. Economic analysis suggests that the project is attractive at a feedstock capacity of 400,000 dry MTA or larger (178 million lb/yr solvents). There are, however, uncertainties associated with the project because of the relatively early stage of development of the key elements of the process technology and the sensitivity of the DCFIROR to estimated capital cost. A further conclusion is that the process economics would benefit greatly from reduced capital cost of the fermentation section. This could perhaps be accomplished by developing a continuous fermentation process. Such fermentation technology has been demonstrated on laboratory scale, but as far as is known, has not been developed to pilot scale. 21 refs., 4 figs., 3 tabs.

  12. Thermophysical properties of 1-butyl-4-methylpyridinium tetrafluoroborate

    International Nuclear Information System (INIS)

    Highlights: ► (p, ρ, T) data of 1-butyl-4-methylpyridinium tetrafluoroborate are estimated. ► The measurements were carried out with a vibration-tube densimeter. ► The thermomechanical coefficients were calculated. - Abstract: Thermophysical properties, {(p, ρ, T) at T = (283.15 to 393.15) K, pressures up to p = 100 MPa, and viscosity at T = (283.15 to 373.15) K and p = 0.101 MPa}, of 1-butyl-4-methylpyridinium tetrafluoroborate [b4mpy][BF4] are reported. The measurements were carried out with a recently constructed Anton-Paar DMA HPM vibration-tube densimeter and a fully automated SVM 3000 Anton-Paar rotational Stabinger viscometer. The vibration-tube densimeter was calibrated using double-distilled water, methanol, toluene, and aqueous NaCl solutions. An empirical equation of state for fitting of the (p, ρ, T) data of [b4mpy][BF4] has been developed as a function of pressure and temperature to calculate the thermal properties of the ionic liquid (IL), such as isothermal compressibility, isobaric thermal expansibility, differences in isobaric and isochoric heat capacities, thermal pressure coefficient, and internal pressure. Internal pressure and the temperature coefficient of internal pressure data were used to make conclusions on the molecular characteristics of the IL.

  13. Reactive Distillation for Producing n-Butyl Acetate: Experiment and Simulation%Reactive Distillation for Producing n-Butyl Acetate: Experiment and Simulation

    Institute of Scientific and Technical Information of China (English)

    田晖; 黄智贤; 邱挺; 王晓达; 吴燕翔

    2012-01-01

    In this paper, a reactive distillation (RD) column was applied for synthesis n-butyl acetate from n-butanol and acetic acid. The Langmuir-Hinshelwood-Hougen-Watson (LHHW) kinetic model and an equilibrium stage model for separation were employed to study the RD process. The results obtained from the equilibrium stage model agreed well with the experiments. The effects of operating variables on the n-butanol conversion and n-butyl acetate purity were further investigated. The optimal column configuration for the production of n-butyl acetate was designed with 5 rectifying stages, 8 reaction stages and 13 stripping stages by the simulation study. According to the simulation results, n-butanol conversion and n-butyl acetate purity all reached greater than 96%.

  14. Biomedical Properties of a Natural Dietary Plant Metabolite, Zerumbone, in Cancer Therapy and Chemoprevention Trials

    Directory of Open Access Journals (Sweden)

    Heshu Sulaiman Rahman

    2014-01-01

    Full Text Available Zerumbone (ZER is a naturally occurring dietary compound, present in many natural foods consumed today. The compound derived from several plant species of the Zingiberaceae family that has been found to possess multiple biomedical properties, such as antiproliferative, antioxidant, anti-inflammatory, and anticancer activities. However, evidence of efficacy is sparse, pointing to the need for a more systematic review for assessing scientific evidence to support therapeutic claims made for ZER and to identify future research needs. This review provides an updated overview of in vitro and in vivo investigations of ZER, its cancer chemopreventive properties, and mechanisms of action. Therapeutic effects of ZER were found to be scientifically plausible and could be explained partially by in vivo and in vitro pharmacological activities. Much of the research outlined in this paper will serve as a foundation to explain ZER anticancer bioactivity, which will open the door for the development of strategies in the treatment of malignancies using ZER.

  15. Preclinical Cancer Chemoprevention Studies Using Animal Model of Inflammation-Associated Colorectal Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Takuji Tanaka

    2012-07-01

    Full Text Available Inflammation is involved in all stages of carcinogenesis. Inflammatory bowel disease, such as ulcerative colitis and Crohn’s disease is a longstanding inflammatory disease of intestine with increased risk for colorectal cancer (CRC. Several molecular events involved in chronic inflammatory process are reported to contribute to multi-step carcinogenesis of CRC in the inflamed colon. They include over-production of free radicals, reactive oxygen and nitrogen species, up-regulation of inflammatory enzymes in arachidonic acid biosynthesis pathway, up-regulation of certain cytokines, and intestinal immune system dysfunction. In this article, firstly I briefly introduce our experimental animal models where colorectal neoplasms rapidly develop in the inflamed colorectum. Secondary, data on preclinical cancer chemoprevention studies of inflammation-associated colon carcinogenesis by morin, bezafibrate, and valproic acid, using this novel inflammation-related colorectal carcinogenesis model is described.

  16. Breast Cancer Metabolism and Mitochondrial Activity: The Possibility of Chemoprevention with Metformin

    Directory of Open Access Journals (Sweden)

    Massimiliano Cazzaniga

    2015-01-01

    Full Text Available Metabolic reprogramming refers to the ability of cancer cells to alter their metabolism in order to support the increased energy request due to continuous growth, rapid proliferation, and other characteristics typical of neoplastic cells. It has long been believed that the increase of metabolic request was independent of the mitochondrial action but recently we know that mitochondrial activity together with metabolism plays a pivotal role in the regulation of the energy needed for tumor cell growth and proliferation. For these reasons the mitochondria pathways could be a new target for therapeutic and chemopreventive intervention. Metformin in particular is actually considered a promising agent against mitochondrial activity thanks to its ability to inhibit the mitochondrial complex I.

  17. Breast Cancer Metabolism and Mitochondrial Activity: The Possibility of Chemoprevention with Metformin.

    Science.gov (United States)

    Cazzaniga, Massimiliano; Bonanni, Bernardo

    2015-01-01

    Metabolic reprogramming refers to the ability of cancer cells to alter their metabolism in order to support the increased energy request due to continuous growth, rapid proliferation, and other characteristics typical of neoplastic cells. It has long been believed that the increase of metabolic request was independent of the mitochondrial action but recently we know that mitochondrial activity together with metabolism plays a pivotal role in the regulation of the energy needed for tumor cell growth and proliferation. For these reasons the mitochondria pathways could be a new target for therapeutic and chemopreventive intervention. Metformin in particular is actually considered a promising agent against mitochondrial activity thanks to its ability to inhibit the mitochondrial complex I. PMID:26605341

  18. Preclinical Cancer Chemoprevention Studies Using Animal Model of Inflammation-Associated Colorectal Carcinogenesis

    International Nuclear Information System (INIS)

    Inflammation is involved in all stages of carcinogenesis. Inflammatory bowel disease, such as ulcerative colitis and Crohn’s disease is a longstanding inflammatory disease of intestine with increased risk for colorectal cancer (CRC). Several molecular events involved in chronic inflammatory process are reported to contribute to multi-step carcinogenesis of CRC in the inflamed colon. They include over-production of free radicals, reactive oxygen and nitrogen species, up-regulation of inflammatory enzymes in arachidonic acid biosynthesis pathway, up-regulation of certain cytokines, and intestinal immune system dysfunction. In this article, firstly I briefly introduce our experimental animal models where colorectal neoplasms rapidly develop in the inflamed colorectum. Secondary, data on preclinical cancer chemoprevention studies of inflammation-associated colon carcinogenesis by morin, bezafibrate, and valproic acid, using this novel inflammation-related colorectal carcinogenesis model is described

  19. Preclinical Cancer Chemoprevention Studies Using Animal Model of Inflammation-Associated Colorectal Carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Takuji [Cytopatholgy Division, Tohkai Cytopathology Institute, Cancer Research and Prevention (TCI-CaRP), 5-1-2 Minami-uzura, Gifu 500-8285 (Japan); Department of Tumor Pathology, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194 (Japan)

    2012-07-16

    Inflammation is involved in all stages of carcinogenesis. Inflammatory bowel disease, such as ulcerative colitis and Crohn’s disease is a longstanding inflammatory disease of intestine with increased risk for colorectal cancer (CRC). Several molecular events involved in chronic inflammatory process are reported to contribute to multi-step carcinogenesis of CRC in the inflamed colon. They include over-production of free radicals, reactive oxygen and nitrogen species, up-regulation of inflammatory enzymes in arachidonic acid biosynthesis pathway, up-regulation of certain cytokines, and intestinal immune system dysfunction. In this article, firstly I briefly introduce our experimental animal models where colorectal neoplasms rapidly develop in the inflamed colorectum. Secondary, data on preclinical cancer chemoprevention studies of inflammation-associated colon carcinogenesis by morin, bezafibrate, and valproic acid, using this novel inflammation-related colorectal carcinogenesis model is described.

  20. 76 FR 46796 - Butylate; Registration Review Proposed Decision; Notice of Availability

    Science.gov (United States)

    2011-08-03

    ... Register on July 28, 2010 (75 FR 44240; FRL-8835-2). For the remaining butylate product registrations... published in the Federal Register on March 23, 2011 (76 FR 16147, FRL-8867-8). Due to the cancellation...-use registrant, Arysta Lifescience North America, LLC, to voluntarily cancel the last butylate...

  1. REDUCTIVE ACTIVATION OF DIOXYGEN FOR DEGRADATION OF METHYL TERT-BUTYL ETHER BY BIFUNCTION

    Science.gov (United States)

    Bifunctional aluminum is prepared by sulfating aluminum metal with sulfuric acid. The use of bifunctional aluminum to degrade methyl tert-butyl ether (MTBE) in the presence of dioxygen has been examined using batch systems. Primary degradation products were tert-butyl alcohol, ...

  2. Inhibition of akt enhances the chemopreventive effects of topical rapamycin in mouse skin

    Science.gov (United States)

    Dickinson, Sally E; Janda, Jaroslav; Criswell, Jane; Blohm-Mangone, Karen; Olson, Erik R.; Liu, Zhonglin; Barber, Christie; Rusche, Jadrian J.; Petricoin, Emmanuel; Calvert, Valerie; Einspahr, Janine G.; Dickinson, Jesse; Stratton, Steven P.; Curiel-Lewandrowski, Clara; Saboda, Kathylynn; Hu, Chengcheng; Bode, Ann M.; Dong, Zigang; Alberts, David S.; Bowden, G. Timothy

    2016-01-01

    The PI3Kinase/Akt/mTOR pathway has important roles in cancer development for multiple tumor types, including UV-induced non-melanoma skin cancer. Immunosuppressed populations are at increased risk of aggressive cutaneous squamous cell carcinoma (SCC). Individuals who are treated with rapamycin, (sirolimus, a classical mTOR inhibitor) have significantly decreased rates of developing new cutaneous SCCs compared to those that receive traditional immunosuppression. However, systemic rapamycin use can lead to significant adverse events. Here we explored the use of topical rapamycin as a chemopreventive agent in the context of solar simulated light (SSL)-induced skin carcinogenesis. In SKH-1 mice, topical rapamycin treatment decreased tumor yields when applied after completion of 15 weeks of SSL exposure compared to controls. However, applying rapamycin during SSL exposure for 15 weeks, and continuing for 10 weeks after UV treatment, increased tumor yields. We also examined whether a combinatorial approach might result in more significant tumor suppression by rapamycin. We validated that rapamycin causes increased Akt (S473) phosphorylation in the epidermis after SSL, and show for the first time that this dysregulation can be inhibited in vivo by a selective PDK1/Akt inhibitor, PHT-427. Combining rapamycin with PHT-427 on tumor prone skin additively caused a significant reduction of tumor multiplicity compared to vehicle controls. Our findings indicate that patients taking rapamycin should avoid sun exposure, and that combining topical mTOR inhibitors and Akt inhibitors may be a viable chemoprevention option for individuals at high risk for cutaneous SCC.

  3. Chemoprevention gene therapy (CGT): novel combinatorial approach for preventing and treating pancreatic cancer.

    Science.gov (United States)

    Sarkar, S; Azab, B M; Das, S K; Quinn, B A; Shen, X; Dash, R; Emdad, L; Thomas, S; Dasgupta, S; Su, Z-Z; Wang, X-Y; Sarkar, D; Fisher, P B

    2013-08-01

    Pancreatic cancer remains one of the deadliest of all cancers despite aggressive surgical treatment combined with adjuvant radiotherapy and chemotherapy. Chemoresistance and radioresistance are the principal causes of failure of pancreatic cancer patients to respond to therapy. Conditionally replication competent adenovirus (CRCA)-based cancer gene therapy is an innovative strategy for treating cancers displaying inherent resistance to treatment. Limitations of current adenovirus (Ad)-based gene therapies for malignant tumors include lack of cancer-specificity, and effective and targeted delivery. To remedy this situation, CRCAs have been designed that express E1A, necessary for Ad replication, under the control of a cancer-specific progression elevated gene-3 promoter (PEG-Prom) with concomitant expression of an immunomodulatory cytokine, such as mda-7/IL-24 or interferon-γ (IFN-γ), under the control of a ubiquitous and strong cytomegalovirus promoter (CMV-Prom) from the E3 region. These bipartite CRCAs, when armed with a transgene, are called cancer terminator viruses (CTVs), i.e., Ad.PEG-E1A-CMV-mda-7 (CTV-M7) and Ad.PEG-E1A-CMV-IFN-γ (CTV-γ), because of their universal effectiveness in cancer treatment irrespective of p53/pRb/p16 or other genetic alterations in tumor cells. In addition to their selective oncolytic effects in tumor cells, the potent 'bystander antitumor' properties of MDA-7/IL-24 and IFN-γ embody the CTVs with expanded treatment properties for both primary and distant cancers. Pancreatic cancer cells display a "translational block" of mda-7/IL-24 mRNA, limiting production of MDA-7/IL-24 protein and cancer-specific apoptosis. Specific chemopreventive agents abrogate this "translational block" resulting in pancreatic cancer-specific killing. This novel chemoprevention gene therapy (CGT) strategy holds promise for both prevention and treatment of pancreatic cancers where all other strategies have proven ineffective.

  4. Chemopreventive effect of sinapic acid on 1,2-dimethylhydrazine-induced experimental rat colon carcinogenesis.

    Science.gov (United States)

    Balaji, C; Muthukumaran, J; Nalini, N

    2014-12-01

    Sinapic acid (SA) is a naturally occurring phenolic acid found in various herbal plants which is attributed with numerous pharmacological properties. This study was aimed to investigate the chemopreventive effect of SA on 1,2-dimethylhydrazine (DMH)-induced rat colon carcinogenesis. Rats were treated with DMH injections (20 mg kg(-1) bodyweight (b.w.) subcutaneously once a week for the first 4 consecutive weeks and SA (20, 40 and 80 mg kg(-1) b.w.) post orally for 16 weeks. At the end of the 16-week experimental period, all the rats were killed, and the tissues were evaluated biochemically. Our results reveal that DMH alone treatment decreased the levels/activities of lipid peroxidation by-products such as thiobarbituric acid reactive substances, conjugated dienes and antioxidants such as superoxide dismutase, catalase, glutathione reductase, glutathione peroxidase and reduced glutathione in the intestine and colonic tissues which were reversed on supplementation with SA. Moreover, the activities of drug-metabolizing enzymes of phase I (cytochrome P450 and P4502E1) were enhanced and those of phase II (glutathione-S-transferase, DT-diaphorase and uridine diphosphate glucuronosyl transferase) were diminished in the liver and colonic mucosa of DMH alone-treated rats and were reversed on supplementation with SA. All the above changes were supported by the histopathological observations of the rat liver and colon. These findings suggest that SA at the dose of 40 mg kg(-1) b.w. was the most effective dose against DMH-induced colon carcinogenesis, and thus, SA could be used as a potential chemopreventive agent. PMID:24532707

  5. Cancer chemoprevention by phytochemicals: potential molecular targets,biomarkers and animal models

    Institute of Scientific and Technical Information of China (English)

    Ki Han KWON; Avantika BARVE; Siwang YU; Mou-Tuan HUANG; Ah-Ng Tony KONG

    2007-01-01

    Recent studies have strongly indicated that certain daily-consumed dietary phytochemicals could have cancer protective effects against transgenic mice can-cer models and cancers mediated by carcinogens, irradiations and carcinogenic metabolites derived from exogenous or endogenous sources. The cancer-protec-tive effects elicited by these dietary compounds are believed to be due at least in part to the induction of cellular defense systems including the detoxifying and antioxidant enzymes system, as well as the inhibition of anti-inflammatory and anti-cell growth signaling pathways culminating in cell cycle arrest and/or cell-death. In this review, we summarize the potential mechanisms including the modu-lation of nuclear factor kappaB (NF-κB), cyclooxygenases-2 (COX-2), activator protein-1 (AP-1), mitogen-activated protein kinases (MAPKs) and the induction of phase Ⅱ cellular detoxifying and antioxidant enzymes mediated mainly by the antioxidant response elements (ARE) within the promoter regions of these genes through nuclear factor-erythroid 2-related factor 2 (Nrf2), a member of the Cap 'n' collar (CNC) family of the basic region-leucine zipper transcription factor. In addition, we also review several animal models of carcinogenesis and cancer chemopreventive efficacy studies of these animal models using dietary chemopreventive compounds. Finally, we discuss the cellular signaling cascades mediated by Nrf2, NF-κB, AP-1, MAPKs and COX-2, which have been considered to play pivotal roles in tumor initiation, promotion and progression processes,and could be promising molecular targets for the design of drugs targeting cancer prevention and therapy.

  6. The Chemopreventive Effect of Tamoxifen Combined with Celecoxib on DMBA chemically-Induced Breast Cancer

    Institute of Scientific and Technical Information of China (English)

    Xiaoxu Liu; Huafeng Kang; Xijing Wang; Zhijun Dai; Fengjie Xue; Xinghuan Xue

    2007-01-01

    Objective: To investigate the chemopreventive effect of tamoxifen combined with a COX-2 selective inhibitor, celecoxib, on breast cancer in rats chemically induced by 7,12-dimethylben (a)anthracene (DMBA). Methods:DMBA was irrigated into the stomaches of SD female rats to build breast cancer model. A total of 120 rats were divided into four groups: control group, tamoxifen group, celecoxib group and combined group. The incidence rate, latent period, number and volume of breast cancer were detected and analyzed. Results:The tumor incidence rate of tamoxifen group (48.15%, 13/27) and celecoxib group (50.00%,14/28) were lower than that of control group (85.71%, 24/28), but higher than that of combined group (21.43%, 6/28). The tumor's latent period of tamoxifen group (97.54±1.85 d) and celecoxib group (96.79±2.89 d) were longer than that of control group (89.50±5.99 d), but shorter than that of combined group (103.67±3.39 d). The average tumor number of tamoxifen group (1.77±0.73) and celecoxib group (1.71±0.61) were less than that of control group (3.50±1.62), but more than that of combined group ( 1.17±0.42 ). The average tumor volume of tamoxifen group (1.78±0.71 cm3) and celecoxib group (2.05±1.04 cm3) were smaller than that of control group (6.42±3.96 cm3), but bigger than that of combined group (0.71±0.96 cm3) (P < 0.05 respectively).Conclusion:Celecoxib and tamoxifen are effective drugs in preventing the occurrence of rat breast cancer chemically induced by DMBA. Furthermore, combination of them has better chemopreventive effect.

  7. The DNA base excision repair protein Ape1/Ref-1 as a therapeutic and chemopreventive target.

    Science.gov (United States)

    Fishel, Melissa L; Kelley, Mark R

    2007-01-01

    With our growing understanding of the pathways involved in cell proliferation and signaling, targeted therapies, in the treatment of cancer are entering the clinical arena. New and emerging targets are proteins involved in DNA repair pathways. Inhibition of various proteins in the DNA repair pathways sensitizes cancer cells to DNA damaging agents such as chemotherapy and/or radiation. We study the apurinic endonuclease 1/redox factor-1 (Ape1/Ref-1) and believe that its crucial function in DNA repair and reduction-oxidation or redox signaling make it an excellent target for sensitizing tumor cells to chemotherapy. Ape1/Ref-1 is an essential enzyme in the base excision repair (BER) pathway which is responsible for the repair of DNA caused by oxidative and alkylation damage. As importantly, Ape1/Ref-1 also functions as a redox factor maintaining transcription factors in an active reduced state. Ape1/Ref-1 stimulates the DNA binding activity of numerous transcription factors that are involved in cancer promotion and progression such as AP-1 (Fos/Jun), NFkappaB, HIF-1alpha, CREB, p53 and others. We will discuss what is known regarding the pharmacological targeting of the DNA repair activity, as well as the redox activity of Ape1/Ref-1, and explore the budding clinical utility of inhibition of either of these functions in cancer treatment. A brief discussion of the effect of polymorphisms in its DNA sequence is included because of Ape1/Ref-1's importance to maintenance and integrity of the genome. Experimental modification of Ape1/Ref-1 activity changes the response of cells and of organisms to DNA damaging agents, suggesting that Ape1/Ref-1 may also be a productive target of chemoprevention. In this review, we will provide an overview of Ape1/Ref-1's activities and explore the potential of this protein as a target in cancer treatment as well as its role in chemoprevention.

  8. The Chemopreventive Phytochemical Moringin Isolated from Moringa oleifera Seeds Inhibits JAK/STAT Signaling.

    Science.gov (United States)

    Michl, Carina; Vivarelli, Fabio; Weigl, Julia; De Nicola, Gina Rosalinda; Canistro, Donatella; Paolini, Moreno; Iori, Renato; Rascle, Anne

    2016-01-01

    Sulforaphane (SFN) and moringin (GMG-ITC) are edible isothiocyanates present as glucosinolate precursors in cruciferous vegetables and in the plant Moringa oleifera respectively, and recognized for their chemopreventive and medicinal properties. In contrast to the well-studied SFN, little is known about the molecular pathways targeted by GMG-ITC. We investigated the ability of GMG-ITC to inhibit essential signaling pathways that are frequently upregulated in cancer and immune disorders, such as JAK/STAT and NF-κB. We report for the first time that, similarly to SFN, GMG-ITC in the nanomolar range suppresses IL-3-induced expression of STAT5 target genes. GMG-ITC, like SFN, does not inhibit STAT5 phosphorylation, suggesting a downstream inhibitory event. Interestingly, treatment with GMG-ITC or SFN had a limited inhibitory effect on IFNα-induced STAT1 and STAT2 activity, indicating that both isothiocyanates differentially target JAK/STAT signaling pathways. Furthermore, we showed that GMG-ITC in the micromolar range is a more potent inhibitor of TNF-induced NF-κB activity than SFN. Finally, using a cellular system mimicking constitutive active STAT5-induced cell transformation, we demonstrated that SFN can reverse the survival and growth advantage mediated by oncogenic STAT5 and triggers cell death, therefore providing experimental evidence of a cancer chemopreventive activity of SFN. This work thus identified STAT5, and to a lesser extent STAT1/STAT2, as novel targets of moringin. It also contributes to a better understanding of the biological activities of the dietary isothiocyanates GMG-ITC and SFN and further supports their apparent beneficial role in the prevention of chronic illnesses such as cancer, inflammatory diseases and immune disorders. PMID:27304884

  9. The Chemopreventive Phytochemical Moringin Isolated from Moringa oleifera Seeds Inhibits JAK/STAT Signaling

    Science.gov (United States)

    Weigl, Julia; De Nicola, Gina Rosalinda; Canistro, Donatella; Paolini, Moreno; Iori, Renato; Rascle, Anne

    2016-01-01

    Sulforaphane (SFN) and moringin (GMG-ITC) are edible isothiocyanates present as glucosinolate precursors in cruciferous vegetables and in the plant Moringa oleifera respectively, and recognized for their chemopreventive and medicinal properties. In contrast to the well-studied SFN, little is known about the molecular pathways targeted by GMG-ITC. We investigated the ability of GMG-ITC to inhibit essential signaling pathways that are frequently upregulated in cancer and immune disorders, such as JAK/STAT and NF-κB. We report for the first time that, similarly to SFN, GMG-ITC in the nanomolar range suppresses IL-3-induced expression of STAT5 target genes. GMG-ITC, like SFN, does not inhibit STAT5 phosphorylation, suggesting a downstream inhibitory event. Interestingly, treatment with GMG-ITC or SFN had a limited inhibitory effect on IFNα-induced STAT1 and STAT2 activity, indicating that both isothiocyanates differentially target JAK/STAT signaling pathways. Furthermore, we showed that GMG-ITC in the micromolar range is a more potent inhibitor of TNF-induced NF-κB activity than SFN. Finally, using a cellular system mimicking constitutive active STAT5-induced cell transformation, we demonstrated that SFN can reverse the survival and growth advantage mediated by oncogenic STAT5 and triggers cell death, therefore providing experimental evidence of a cancer chemopreventive activity of SFN. This work thus identified STAT5, and to a lesser extent STAT1/STAT2, as novel targets of moringin. It also contributes to a better understanding of the biological activities of the dietary isothiocyanates GMG-ITC and SFN and further supports their apparent beneficial role in the prevention of chronic illnesses such as cancer, inflammatory diseases and immune disorders. PMID:27304884

  10. Chemopreventive potential of Annona muricata L leaves on chemically-induced skin papillomagenesis in mice.

    Science.gov (United States)

    Hamizah, Sulaiman; Roslida, A H; Fezah, O; Tan, K L; Tor, Y S; Tan, C I

    2012-01-01

    Annona muricata L (Annonaceae), commonly known as soursop has a long, rich history in herbal medicine with a lengthy recorded indigenous use. It had also been found to be a promising new anti-tumor agent in numerous in vitro studies. The present investigation concerns chemopreventive effects in a two-stage model of skin papillomagenesis. Chemopreventive effects of an ethanolic extract of A. muricata leaves (AMLE) was evaluated in 6-7 week old ICR mice given a single topical application of 7,12-dimethylbenza(α)anthracene (DMBA 100 μg/100 μl acetone) and promotion by repeated application of croton oil (1% in acetone/ twice a week) for 10 weeks. Morphological tumor incidence, burden and volume were measured, with histological evaluation of skin tissue. Topical application of AMLE at 30, 100 and 300 mg/kg significantly reduced DMBA/croton oil induced mice skin papillomagenesis in (i) peri-initiation protocol (AMLE from 7 days prior to 7 days after DMBA), (ii) promotion protocol (AMLE 30 minutes after croton oil), or (iii) both peri-initiation and promotion protocol (AMLE 7 days prior to 7 day after DMBA and AMLE 30 minutes after croton oil throughout the experimental period), in a dose dependent manner (p<0.05) as compared to carcinogen-treated control. Furthermore, the average latent period was significantly increased in the AMLE-treated group. Interestingly, At 100 and 300 mg/ kg, AMLE completely inhibited the tumor development in all stages. Histopathological study revealed that tumor growth from the AMLE-treated groups showed only slight hyperplasia and absence of keratin pearls and rete ridges. The results, thus suggest that the A.muricata leaves extract was able to suppress tumor initiation as well as tumor promotion even at lower dosage.

  11. Synthesis of Highly Porous Poly(tert-butyl acrylate)-b-polysulfone-b-poly(tert-butyl acrylate) Asymmetric Membranes

    KAUST Repository

    Xie, Yihui

    2016-03-24

    For the first time, self-assembly and non-solvent induced phase separation was applied to polysulfone-based linear block copolymers, reaching mechanical stability much higher than other block copolymers membranes used in this method, which were mainly based on polystyrene blocks. Poly(tert-butyl acrylate)-b-polysulfone-b-poly(tert-butyl acrylate) (PtBA30k-b-PSU14k-b-PtBA30k) with a low polydispersity of 1.4 was synthesized by combining step-growth condensation and RAFT polymerization. Various advanced electron microscopies revealed that PtBA30k-b-PSU14k-b-PtBA30k assembles into worm-like cylindrical micelles in DMAc and adopts a “flower-like” arrangement with the PSU central block forming the shell. Computational modeling described the mechanism of micelle formation and morphological transition. Asymmetric nanostructured membranes were obtained with a highly porous interconnected skin layer and a sublayer with finger-like macrovoids. Ultrafiltration tests confirmed a water permeance of 555 L m-2 h-1 bar-1 with molecular weight cut-off of 28 kg/mol. PtBA segments on the membrane surface were then hydrolyzed and complexed with metals, leading to cross-linking and enhancement of antibacterial capability.

  12. Vapor Pressures of Di-n-Butyl Phthalate and Di-iso-Butyl Hexahydrophthalate at Reduced Pressures

    Institute of Scientific and Technical Information of China (English)

    齐欣; 徐立勇; 高正红; 刘志华

    2004-01-01

    In this paper the measured values of the vapor pressures by ebulliometer method of two important maleic anhydride recovery solvents, di-n-butyl phthalate (DBP) and di-iso-butyl hexahydrophthalate (DIBE), between 0.63-17.79 kPa and 0.49-30.95 kPa,are reported respectively.A comparison of the data of DBP with the published data has been made, which shows good consistency. For the convenient use of these vapor pressures, Cragoe equation, Antoine equation and Kirchhoff equation are selected to correlate them. The correlating results show that Antoine equation is the best one of the three equations to fit for the vapor pressures of the two solvents. According to Clausius-Clapeyron equation, the linear relationship between natural logarithm of pressure and reciprocal of temperature is used to calculate the molar latent heats of evaporation of the two organic solvents. The molar latent heats of evaporation of DBP and DIBE are 75.1 kJ/mol and 67.7 kJ/mol, respectively.

  13. Theoretical calculations of hyperfine coupling constants for muoniated butyl radicals.

    Science.gov (United States)

    Chen, Ya Kun; Fleming, Donald G; Wang, Yan Alexander

    2011-04-01

    The hyperfine coupling constants (HFCCs) of all the butyl radicals that can be produced by muonium (Mu) addition to butene isomers (1- and 2-butene and isobutene) have been calculated, to compare with the experimental results for the muon and proton HFFCs for these radicals reported in paper II (Fleming, D. G.; et al. J. Phys. Chem. A 2011, 10.1021/jp109676b) that follows. The equilibrium geometries and HFCCs of these muoniated butyl radicals as well as their unsubstituted isotopomers were treated at both the spin-unrestricted MP2/EPR-III and B3LYP/EPR-III levels of theory. Comparisons with calculations carried out for the EPR-II basis set have also been made. All calculations were carried out in vacuo at 0 K only. A C-Mu bond elongation scheme that lengthens the equilibrium C-H bond by a factor of 1.076, on the basis of recent quantum calculations of the muon HFCCs of the ethyl radical, has been exploited to determine the vibrationally corrected muon HFCCs. The sensitivity of the results to small variations around this scale factor was also investigated. The computational methodology employed was "benchmarked" in comparisons with the ethyl radical, both with higher level calculations and with experiment. For the β-HFCCs of interest, compared to B3LYP, the MP2 calculations agree better with higher level theories and with experiment in the case of the eclipsed C-Mu bond and are generally deemed to be more reliable in predicting the equilibrium conformations and muon HFCCs near 0 K, in the absence of environmental effects. In some cases though, the experimental results in paper II demonstrate that environmental effects enhance the muon HFCC in the solid phase, where much better agreement with the experimental muon HFCCs near 0 K is found from B3LYP than from MP2. This seemingly better level of agreement is probably fortuitous, due to error cancellations in the DFT calculations, which appear to mimic these environmental effects. For the staggered proton HFCCs of the

  14. Trianthema portulacastrum Linn. exerts chemoprevention of 7,12-dimethylbenz(a)anthracene-induced mammary tumorigenesis in rats

    Energy Technology Data Exchange (ETDEWEB)

    Bishayee, Anupam, E-mail: abishayee@auhs.edu [Department of Pharmaceutical Sciences, School of Pharmacy, American University of Health Sciences, Signal Hill, CA 90755 (United States); Mandal, Animesh [Cancer Therapeutics and Chemoprevention Group, Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown, OH 44272 (United States)

    2014-10-15

    Highlights: • Dietary administration of an ethanolic extract of aerial parts of T. portulacastrum (TPE) exhibits a striking chemopreventive effect in an experimentally induced classical animal model of breast cancer. • The mammary tumor-inhibitory effect of TPE could be achieved, at least in part, though intervention of key hallmark capabilities of tumor cells, such as abnormal cell proliferation and evasion of apoptosis. • TPE is capable of diminishing activated canonical Wnt/β-catenin signaling to exhibit antiproliferative, proapoptotic and oncostatic effects during this early-stage mammary carcinoma. • These results coupled with a safety profile of T. portulacastrum may encourage further studies to understand the full potential of this dietary plant for chemoprevention of breast cancer. - Abstract: Due to limited treatment options for advanced-stage metastatic breast cancer, a high priority should be given to develop non-toxic chemopreventive drugs. The value of various natural and dietary agents to reduce the risk of developing breast cancer is well established. Trianthema portulacastrum Linn. (Aizoaceae), a dietary and medicinal plant, has been found to exert antihepatotoxic and antihepatocarcinogenic properties in rodents. This study was initiated to investigate mechanism-based chemopreventive potential of an ethanolic extract of T. portulacastrum (TPE) against 7,12-dimethylbenz(a)anthracene (DMBA)-initiated rat mammary gland carcinogenesis, an experimental tumor model that closely resembles human breast cancer. Rats had access to a basal diet supplemented with TPE to yield three dietary doses of the extract, i.e., 50, 100 and 200 mg/kg body weight. Following two weeks of TPE treatment, mammary tumorigenesis was initiated by oral administration of DMBA (50 mg/kg body weight). At the end of the study (16 weeks after DMBA exposure), TPE exhibited a striking reduction of DMBA-induced mammary tumor incidence, total tumor burden and average tumor weight

  15. tert-Butyl 2-methyl-2-(4-methylbenzoylpropanoate

    Directory of Open Access Journals (Sweden)

    Graham B. Gould

    2010-02-01

    Full Text Available The title compound, C16H22O3, is bent with a dihedral angle of 75.3 (1° between the mean planes of the benzene ring and a group encompassing the ester functionality (O=C—O—C. In the crystal, the molecules are linked into infinite chains held together by weak C—H...O hydrogen-bonded interactions between an H atom on the benzene ring of one molecule and an O atom on the ketone functionality of an adjacent molecule. The chains are arranged with neighbouring tert-butyl and dimethyl groups on adjacent chains exhibiting hydrophobic stacking, with short C—H...H—C contacts (2.37 Å between adjacent chains

  16. Interactions between water and 1-butyl-1-methylpyrrolidinium ionic liquids.

    Science.gov (United States)

    Fadeeva, Tatiana A; Husson, Pascale; DeVine, Jessalyn A; Costa Gomes, Margarida F; Greenbaum, Steven G; Castner, Edward W

    2015-08-14

    We report experimental results on the diffusivity of water in two ionic liquids obtained using the pulsed-gradient spin-echo NMR method. Both ionic liquids have the same cation, 1-butyl-1-methylpyrrolidinium, but different trifluoromethyl-containing anions. One has a strongly hydrophobic anion, bis(trifluoromethylsulfonyl)amide, while the second has a hydrophilic anion, trifluoromethylsulfonate. Transport of water in these ionic liquids is much faster than would be predicted from hydrodynamic laws, indicating that the neutral water molecules experience a very different friction than the anions and cations at the molecular level. Temperature-dependent viscosities, conductivities, and densities are reported as a function of water concentration to further analyze the properties of the ionic liquid-water mixtures. These results on the properties of water in ionic liquids should be of interest to researchers in diverse areas ranging from separations, solubilizing biomass and energy technologies. PMID:26277141

  17. Modeling Low Density Polyethylene with Precisely Placed Butyl Branches

    Science.gov (United States)

    Rojas, Giovanni; Wagener, Kenneth B.

    Polyethylene (PE) is a commodity produced on a massive scale and also is one of the most studied macromolecules. Crystallinity can be controlled by copolymerizing ethylene with α-olefins, producing a wide range of material responses. Physical properties of PE, obtained via α olefin copolymerization, depend on the branch content that is directly related to the comonomer incorporation into the PE backbone. Materials with unknown primary structures are produced via chaingrowth chemistry, because unwanted side reactions generate defects in the main backbone that alter the morphological behavior and thermal response. Acyclic diene metathesis (ADMET) polymerization/hydrogenation methodology produce perfect sequenced copolymers of ethylene with α-olefins. Synthesis and thermal properties of PE with butyl branches precisely placed along the polymer backbone using ADMET chemistry is described within.

  18. Interactions between water and 1-butyl-1-methylpyrrolidinium ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Fadeeva, Tatiana A.; DeVine, Jessalyn A.; Castner, Edward W., E-mail: ed.castner@rutgers.edu [Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854 (United States); Husson, Pascale [CNRS, UMR 6296, Institut de Chimie de Clermont-Ferrand, BP 80026, F-63171 Aubière (France); Clermont Université, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, BP 10448, F-63000 Clermont-Ferrand (France); Costa Gomes, Margarida F. [CNRS, UMR 6296, Institut de Chimie de Clermont-Ferrand, BP 80026, F-63171 Aubière (France); Greenbaum, Steven G. [Department of Physics and Astronomy, Hunter College, CUNY, New York, New York 10065 (United States)

    2015-08-14

    We report experimental results on the diffusivity of water in two ionic liquids obtained using the pulsed-gradient spin-echo NMR method. Both ionic liquids have the same cation, 1-butyl-1-methylpyrrolidinium, but different trifluoromethyl-containing anions. One has a strongly hydrophobic anion, bis(trifluoromethylsulfonyl)amide, while the second has a hydrophilic anion, trifluoromethylsulfonate. Transport of water in these ionic liquids is much faster than would be predicted from hydrodynamic laws, indicating that the neutral water molecules experience a very different friction than the anions and cations at the molecular level. Temperature-dependent viscosities, conductivities, and densities are reported as a function of water concentration to further analyze the properties of the ionic liquid-water mixtures. These results on the properties of water in ionic liquids should be of interest to researchers in diverse areas ranging from separations, solubilizing biomass and energy technologies.

  19. Picosecond photoexcitation dynamics in poly(3-butyl-thiophene) films

    Science.gov (United States)

    Frolov, S. V.; Wei, X.; Gellermann, W.; Vardeny, Z. V.; Ehrenfreund, E.

    1998-02-01

    We have studied photoexcitation dynamics in thin films of poly(3-butyl-thiophene) [P3BT] using ps transient and cw photomodulation techniques, streak camera imaging, electroabsorption and optically detected magnetic resonance spectroscopies. We have determined that intrachain excitons are the primary photoexcitations with a characteristic transient photomodulation spectrum consisting of two photoinduced absorption bands in the near IR spectral range and a broad stimulated emission band in the visible spectral region. The photogenerated excitons are relatively short-lived (150 ps) and can subsequently decay into polaron pairs and triplets, which are longer-lived excitations with lifetimes of order ms. We do not find stimulated emission in very thin P3BT films and this is attributed to high defect concentration close to the film surface.

  20. Interactions between water and 1-butyl-1-methylpyrrolidinium ionic liquids.

    Science.gov (United States)

    Fadeeva, Tatiana A; Husson, Pascale; DeVine, Jessalyn A; Costa Gomes, Margarida F; Greenbaum, Steven G; Castner, Edward W

    2015-08-14

    We report experimental results on the diffusivity of water in two ionic liquids obtained using the pulsed-gradient spin-echo NMR method. Both ionic liquids have the same cation, 1-butyl-1-methylpyrrolidinium, but different trifluoromethyl-containing anions. One has a strongly hydrophobic anion, bis(trifluoromethylsulfonyl)amide, while the second has a hydrophilic anion, trifluoromethylsulfonate. Transport of water in these ionic liquids is much faster than would be predicted from hydrodynamic laws, indicating that the neutral water molecules experience a very different friction than the anions and cations at the molecular level. Temperature-dependent viscosities, conductivities, and densities are reported as a function of water concentration to further analyze the properties of the ionic liquid-water mixtures. These results on the properties of water in ionic liquids should be of interest to researchers in diverse areas ranging from separations, solubilizing biomass and energy technologies.

  1. Gamma-radiation effect on thermal ageing of butyl rubber compounds

    International Nuclear Information System (INIS)

    Butyl rubber has a comprehensive use in sealing systems, especially in tires inner tubes, due to their low permeability to gases. So, it is required that butyl rubber compounds show a better performance, more and more. Butyl rubber is provided with excellent mechanical properties and oxidation resistance. Besides showing these properties, radiation exposures impart modifications in physical-chemical and morphological properties on butyl rubber materials. When exposed to gamma-radiation, rubbers suffer changes in their mechanical and physical properties, caused by material degradation. The major radiation effect in butyl rubbers is chain scission; besides, ageing promotes too the same effect with further build-up of free radicals. This work aims to the study of gamma-radiation in physical-chemical properties of butyl rubber subjected to thermal ageing. Doses used herein were: 25 kGy, 50 kGy, 100 kGy, 150 kGy and 200 KGy. Samples were evaluated before and after ageing according to traditional essays, such as: hardness, tensile strength and elongation at break. From accomplished assessments it is possible to affirm that at doses higher than 50 kGy it was observed a sharp decreasing in butyl rubber physical-chemical properties, before and after exposure to ageing. (author)

  2. Gamma-radiation effect on thermal ageing of butyl rubber compounds

    Energy Technology Data Exchange (ETDEWEB)

    Scagliusi, Sandra R.; Cardoso, Elizabeth C.L.; Lugao, Ademar B., E-mail: srscagliusi@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Butyl rubber has a comprehensive use in sealing systems, especially in tires inner tubes, due to their low permeability to gases. So, it is required that butyl rubber compounds show a better performance, more and more. Butyl rubber is provided with excellent mechanical properties and oxidation resistance. Besides showing these properties, radiation exposures impart modifications in physical-chemical and morphological properties on butyl rubber materials. When exposed to gamma-radiation, rubbers suffer changes in their mechanical and physical properties, caused by material degradation. The major radiation effect in butyl rubbers is chain scission; besides, ageing promotes too the same effect with further build-up of free radicals. This work aims to the study of gamma-radiation in physical-chemical properties of butyl rubber subjected to thermal ageing. Doses used herein were: 25 kGy, 50 kGy, 100 kGy, 150 kGy and 200 KGy. Samples were evaluated before and after ageing according to traditional essays, such as: hardness, tensile strength and elongation at break. From accomplished assessments it is possible to affirm that at doses higher than 50 kGy it was observed a sharp decreasing in butyl rubber physical-chemical properties, before and after exposure to ageing. (author)

  3. Efficacy of geraniol but not of β-ionone or their combination for the chemoprevention of rat colon carcinogenesis

    Directory of Open Access Journals (Sweden)

    A. Vieira

    2011-06-01

    Full Text Available β-ionone (βI, a cyclic isoprenoid, and geraniol (GO, an acyclic monoterpene, represent a promising class of dietary chemopreventive agents against cancer, whose combination could result in synergistic anticarcinogenic effects. The chemopreventive activities of βI and GO were evaluated individually or in combination during colon carcinogenesis induced by dimethylhydrazine in 48 3-week-old male Wistar rats (12 per group weighing 40-50 g. Animals were treated for 9 consecutive weeks with βI (16 mg/100 g body weight, GO (25 mg/100 g body weight, βI combined with GO or corn oil (control. Number of total aberrant crypt foci (ACF and of ACF ≥4 crypts in the distal colon was significantly lower in the GO group (66 ± 13 and 9 ± 2, respectively compared to control (102 ± 9 and 17 ± 3 and without differences in the βI (91 ± 11 and 14 ± 3 and βI+GO groups (96 ± 5 and 19 ± 2. Apoptosis level, identified by classical apoptosis morphological criteria, in the distal colon was significantly higher in the GO group (1.64 ± 0.06 apoptotic cells/mm² compared to control (0.91 ± 0.07 apoptotic cells/mm². The GO group presented a 0.7-fold reduction in Bcl-2 protein expression (Western blot compared to control. Colonic mucosa concentrations of βI and GO (gas chromatography/mass spectrometry were higher in the βI and GO groups, respectively, compared to the control and βI+GO groups. Therefore, GO, but not βI, represents a potential chemopreventive agent in colon carcinogenesis. Surprisingly, the combination of isoprenoids does not represent an efficient chemopreventive strategy.

  4. Topical polyethylene glycol as a novel chemopreventive agent for oral cancer via targeting of epidermal growth factor response.

    Directory of Open Access Journals (Sweden)

    Ramesh K Wali

    Full Text Available Head and neck squamous cell carcinoma (HNSCC is a major cause of morbidity and mortality underscoring the need for safe and effective chemopreventive strategies. Targeting epidermal growth factor receptor (EGFR is attractive in that it is an early critical event in HNSCC pathogenesis. However, current agents lack efficacy or have unacceptable toxicity. Several groups have demonstrated that the over-the-counter medication, polyethylene glycol (PEG has remarkable chemopreventive efficacy against colon carcinogenesis. Importantly, we reported that this effect is mediated through EGFR internalization/degradation. In the current study, we investigated the chemopreventive efficacy of this agent against HNSCC, using both the well validated animal model 4-NQO (4-nitroquinoline 1-oxide rat model and cell culture with the human HNSCC cell line SCC-25. We demonstrated that daily topical application of 10% PEG-8000 in the oral cavity (tongue and cavity wall post 4NQO initiation resulted in a significant reduction in tumor burden (both, tumor size and tumors/tumor bearing rat without any evidence of toxicity. Immunohistochemical studies depicted decreased proliferation (number of Ki67-positive cells and reduced expression of EGFR and its downstream effectors cyclin D1 in the tongue mucosa of 4NQO-rats treated with PEG. We showed that EGFR was also markedly downregulated in SCC-25 cells by PEG-8000 with a concomitant induction of G1-S phase cell-cycle arrest, which was potentially mediated through upregulated p21(cip1/waf1. In conclusion, we demonstrate, for the first time, that PEG has promising efficacy and safety as a chemopreventive efficacy against oral carcinogenesis.

  5. Mixture of Uncaria and Tabebuia Extracts are Potentially Chemopreventive in CBA/Ca Mice - A Long-term Experiment

    OpenAIRE

    Budán, Ferenc; Szabo, István; Varjas, Timea; Nowrasteh, Ghodratollah; Dávid, Tamás; Gergely, Péter; Varga, Zsuzsa; Molnár, Kornélia; Kádár, Balázs; Orsos, Zsuzsa; Kiss, István; Ember, István

    2010-01-01

    Abstract A long-term experimental animal model was developed by our research group for the evaluation of potential chemopreventive effects. The inhibitory effects of agents on carcinogen (7,12-Dimetilbenz[a]anthracene (DMBA)) induced molecular epidemiological biomarkers, in this case the expression of key onco/suppressor genes were investigated. Expression pattern of c-myc, Ha-ras, Bcl-2, K-ras protoonco and p53 tumoursuppressor genes were studied to elucidate early carcinogenic...

  6. Chemopreventive Effects of RXR-Selective Rexinoid Bexarotene on Intestinal Neoplasia of ApcMin/+ Mice1

    OpenAIRE

    Janakiram, Naveena B; Mohammed, Altaf; Qian, Li; Choi, Chang-In; Steele, Vernon E.; Rao, Chinthalapally V.

    2012-01-01

    Retinoid X receptor (RXR) has been implicated in several neoplastic diseases. Previously, we have shown that RXR-α is downregulated in human and rodent colonic tumors, suggesting a potential target for colon cancer prevention (http://www.cancer.org/Cancer/ColonandRectumCancer/DetailedGuide/colorectal-cancer-key-statistics). Experiments were designed to assess the chemopreventive efficacy of the selective RXR agonist bexarotene for the suppression of intestinal tumorigenesis in ApcMin/+ mice. ...

  7. Disruption of androgen and estrogen receptor activity in prostate cancer by a novel dietary diterpene carnosol: implications for chemoprevention

    OpenAIRE

    Jeremy J Johnson; Syed, Deeba N.; Suh, Yewseok; Heren, Chenelle R.; Saleem, Mohammad; Siddiqui, Imtiaz A.; Mukhtar, Hasan

    2010-01-01

    Emerging data is suggesting that estrogens, in addition to androgens, may also be contributing to the development of prostate cancer (PCa). In view of this notion agents that target estrogens, in addition to androgens, may be a novel approach for PCa chemoprevention and treatment. Thus, the identification and development of non-toxic dietary agents capable of disrupting androgen receptor (AR) in addition to estrogen receptor (ER) could be extremely useful in the management of PCa. Through mol...

  8. Acyclic retinoid in chemoprevention of hepatocellular carcinoma: Targeting phosphorylated retinoid X receptor-α for prevention of liver carcinogenesis

    Directory of Open Access Journals (Sweden)

    Masahito Shimizu

    2012-01-01

    Full Text Available One of the key features of hepatocellular carcinoma (HCC is the high rate of intrahepatic recurrence that correlates with poor prognosis. Therefore, in order to improve the clinical outcome for patients with HCC, development of a chemopreventive agent that can decrease or delay the incidence of recurrence is a critical issue for urgent investigation. Acyclic retinoid (ACR, a synthetic retinoid, successfully improves HCC patient survival by preventing recurrence and the formation of secondary tumors. A malfunction of the retinoid X receptor-α (RXRα due to phosphorylation by the Ras-MAPK signaling pathway plays a critical role in liver carcinogenesis, and ACR exerts chemopreventive effects on HCC development by inhibiting RXRα phosphorylation. Here, we review the relationship between retinoid signaling abnormalities and liver disease, the mechanisms of how RXRα phosphorylation contributes to liver carcinogenesis, and the detailed effects of ACR on preventing HCC development, especially based on the results of our basic and clinical research. We also outline the concept of "clonal deletion and inhibition" therapy, which is defined as the removal and inhibition of latent malignant clones from the liver before they expand into clinically detectable HCC, because ACR prevents the development of HCC by implementing this concept. Looking toward the future, we discuss "combination chemoprevention" using ACR as a key drug since it can generate a synergistic effect, and may thus be an effective new strategy for the prevention of HCC.

  9. Mixtures of Uncaria and Tabebuia extracts are potentially chemopreventive in CBA/Ca mice: a long-term experiment.

    Science.gov (United States)

    Budán, Ferenc; Szabó, István; Varjas, Tímea; Nowrasteh, Ghodratollah; Dávid, Tamás; Gergely, Péter; Varga, Zsuzsa; Molnár, Kornélia; Kádár, Balázs; Orsós, Zsuzsa; Kiss, István; Ember, István

    2011-04-01

    A long-term experimental animal model was developed by our research group for the evaluation of potential chemopreventive effects. The inhibitory effects of agents on carcinogen (7,12-dimethylbenz[a]anthracene (DMBA) induced molecular epidemiological biomarkers, in this case the expression of key onco/suppressor genes were investigated. The expression pattern of c-myc, Ha-ras, Bcl-2, K-ras protooncogene and p53 tumour suppressor gene were studied to elucidate early carcinogenic and potential chemopreventive effects. The consumption of so-called Claw of Dragon tea (CoD™ tea) containing the bark of Uncaria guianensis, Cat's Claw (Uncaria sp. U. tomentosa) and Palmer trumpet-tree (Tabebuia sp. T. avellanedae) was able to decrease the DMBA-induced onco/suppressor gene overexpression in a short-term animal experiment. In a following study CBA/Ca mice were treated with 20 mg/kg bw DMBA intraperitoneally (i.p.) and the expression patterns of onco/suppressor genes were examined at several time intervals. According to the examined gene expression patterns in this long-term experiment the chemopreventive effect of CoD™ tea consumption could be confirmed.

  10. Characterization of chemopreventive agents from the dichloromethane extract of Eurycorymbus cavaleriei by liquid chromatography-ion trap mass spectrometry.

    Science.gov (United States)

    Cheng, Lin; Zhang, Xiaoyu; Zhang, Min; Zhang, Peng; Song, Zhihang; Ma, Zhongjun; Cheng, Yiyu; Qu, Haibin

    2009-06-12

    In the present study, we examined the potential chemopreventive activity of dichloromethane extract of Eurycorymbus cavaleriei by investigating the change of constitutions after incubation with glutathione (GSH). The major constitutions in the dichloromethane extract of E. cavaleriei were cumarin compounds and their cleavage pattern was examined by LC-MS-MS and the characteristic product ions at m/z 206 and 207 were helpful to determine the substitutions of coumarinolignoid compounds. The mechanism of conjugations of 5'-demethylaquillochin and its isomer with GSH was discussed and validated through analysis of the conjugations of reference compound 6-hydroxy-7-methoxycoumarin with GSH by LC-MS-MS and NMR spectrum. The relative ability to induce the detoxification enzyme, NAD(P)H:quinone oxidoreductase 1 (NQO1) of nine coumarin compounds was tested which also showed 5'-demethylaquillochin exhibited the most potential chemopreventive ability. These observations suggest that 5'-demethylaquillochin and its isomer from the dichloromethane extract of E. cavaleriei have potential as chemopreventive agents through induction of detoxification enzymes. PMID:19439309

  11. The current role of neoadjuvant/adjuvant/chemoprevention therapy in partial hepatectomy for hepatocellular carcinoma:a systematic review

    Institute of Scientific and Technical Information of China (English)

    Wan-Yee Lau; Eric C. H. Lai; Stephanie H. Y. Lau

    2009-01-01

    BACKGROUND: Following curative treatment for hepato-cellular carcinoma (HCC), 50%-90% of postoperative death is due to recurrent disease. Intra-hepatic recurrence is frequently the only site of recurrence. Thus, any neoadjuvant or adjuvant therapy, which can decrease or delay the incidence of intra-hepatic recurrence, or any cancer chemoprevention which can prevent a new HCC from developing in the liver remnant, will improve the results of liver resection. This article systematically reviewed the current evidence of neoadjuvant, adjuvant, and chemoprevention in partial hepatectomy of HCC. DATA SOURCES: Studies were identiifed by searching MEDLINE and PubMed databases for articles from January 1990 to November 2008 using the keywords"hepatocellular carcinoma", "hepatectomy", "adjuvant therapy", "neoadjuvant therapy", and "regional therapy". Additional papers and book chapters were identiifed by a manual search of the references from the key articles. RESULTS: Neoadjuvant transarterial chemoembolization or adjuvant regional transarterial chemotherapy± embolization+systemic chemotherapy did not add beneift. Both adjuvant transarterial radioembolization with 131I-lipiodol and adjuvant systemic interferon showed promising results. However, there were only a limited number of such studies.CONCLUSIONS: Further randomized controlled studies need to be carried out. Currently, there is no consensus on a standard neoadjuvant/adjuvant/chemoprevention therapy in partial hepatectomy for HCC.

  12. Chemopreventive and renal protective effects for docosahexaenoic acid (DHA: implications of CRP and lipid peroxides

    Directory of Open Access Journals (Sweden)

    Darweish MM

    2009-04-01

    Full Text Available Abstract Background The fish oil-derived ω-3 fatty acids, like docosahexanoic (DHA, claim a plethora of health benefits. We currently evaluated the antitumor effects of DHA, alone or in combination with cisplatin (CP in the EAC solid tumor mice model, and monitored concomitant changes in serum levels of C-reactive protein (CRP, lipid peroxidation (measured as malondialdehyde; MDA and leukocytic count (LC. Further, we verified the capacity of DHA to ameliorate the lethal, CP-induced nephrotoxicity in rats and the molecular mechanisms involved therein. Results EAC-bearing mice exhibited markedly elevated LC (2-fold, CRP (11-fold and MDA levels (2.7-fold. DHA (125, 250 mg/kg elicited significant, dose-dependent reductions in tumor size (38%, 79%; respectively, as well as in LC, CRP and MDA levels. These effects for CP were appreciably lower than those of DHA (250 mg/kg. Interestingly, DHA (125 mg/kg markedly enhanced the chemopreventive effects of CP and boosted its ability to reduce serum CRP and MDA levels. Correlation studies revealed a high degree of positive association between tumor growth and each of CRP (r = 0.85 and leukocytosis (r = 0.89, thus attesting to a diagnostic/prognostic role for CRP. On the other hand, a single CP dose (10 mg/kg induced nephrotoxicity in rats that was evidenced by proteinuria, deterioration of glomerular filtration rate (GFR, -4-fold, a rise in serum creatinine/urea levels (2–5-fold after 4 days, and globally-induced animal fatalities after 7 days. Kidney-homogenates from CP-treated rats displayed significantly elevated MDA- and TNF-α-, but reduced GSH-, levels. Rats treated with DHA (250 mg/kg, but not 125 mg/kg survived the lethal effects of CP, and showed a significant recovery of GFR; while their homogenates had markedly-reduced MDA- and TNF-α-, but -increased GSH-levels. Significant association was detected between creatinine level and those of MDA (r = 0.81, TNF-α r = 0.92 and GSH (r = -0

  13. 醋酸仲丁酯加氢制备仲丁醇%Researches on hydrogenation of sec-butyl acetate to sec-butyl alcohol

    Institute of Scientific and Technical Information of China (English)

    王若愚; 姚志龙; 刘皓; 闵恩泽

    2013-01-01

    Using alumina as the support,a series of CuO/Al2O3 catalysts was prepared by impregnation method. The influence of reaction conditions of sec-butyl acetate hydrogenation was investigated. The results showed that the conversion of sec-butyl acetate and the selectivity to sec-butyl alcohol, butyl alcohol and alcohol were 98. 16% ,20.48% ,93. 37% and 88. 81% respectively under the optimum reaction condition as follows:reaction temperature 265℃ ,reaction pressure 8.0 MPa,space velocity 0.2 h-1 and n (hydrogen ):n( sec-butyl acetate) = 20.%以氧化铝为载体,采用浸制法制备了一系列负载型CuO/Al2O3催化剂,研究了醋酸仲丁酯加氢反应条件对反应结果的影响.结果表明,在反应温度265℃、反应压力8.0 MPa、空速0.2 h-1和氢酯物质的量比20条件下,醋酸仲丁酯转化率为98.16%,仲丁醇选择性为20.48%,丁醇选择性为93.37%,乙醇选择性为88.81%.

  14. Free radical scavenging abilities of flavonoids as mechanism of protection against mutagenicity induced by tert-butyl hydroperoxide or cumene hydroperoxide in Salmonella typhimurium TA102.

    Science.gov (United States)

    Edenharder, R; Grünhage, D

    2003-09-01

    Mutagenicity induced by tert-butyl hydroperoxide (BHP) or cumene hydroperoxide (CHP) in Salmonella typhimurium TA102 was effectively reduced by flavonols with 3',4'-hydroxyl groups such as fisetin, quercetin, rutin, isoquercitrin, hyperoxide, myricetin, myricitrin, robinetin, and to a lesser extent also by morin and kaempferol (ID50=0.25-1.05 micromol per plate). With the exception of isorhamnetin, rhamnetin, morin, and kaempferol, closely similar results were obtained with both peroxides. Hydrogenation of the double bond between carbons 2 and 3 (dihydroquercetin, dihydrorobinetin) as well as the additional elimination of the carbonyl function at carbon 4 (catechins) resulted in a loss of antimutagenicity with the notable exception of catechin itself. Again, all flavones and flavanones tested were inactive except luteolin, luteolin-7-glucoside, diosmetin, and naringenin. The typical radical scavenger butylated hydroxytoluene also showed strong antimutagenicity against CHP (ID50=5.4 micromol per plate) and BHP (ID50=11.4 micromol per plate). Other lipophilic scavengers such as alpha-tocopherol and N,N'-diphenyl-1,4-phenylenediamine exerted only moderate effects, the hydrophilic scavenger trolox was inactive. The metal chelating agent 1,10-phenanthroline strongly reduced mutagenicities induced by CHP and BHP (ID50=2.75 and 2.5 micromol per plate) at low concentrations but induced mutagenic activities at higher concentrations. The iron chelator deferoxamine mesylate, however, was less effective in both respects. The copper chelator neocuproine effectively inhibited mutagenicity induced by BHP (ID50=39.7 micromol per plate) and CHP (ID50=25.9 micrommol per plate), the iron chelator 2,2'-dipyridyl was less potent (ID50=6.25 mmol per plate against BHP, 0.42 mmol per plate against CHP). In the absence of BHP and CHP, yet not in the presence of these hydroperoxides, quercetin, rutin, catechin, epicatechin, and naringenin induced strong mutagenic activities in S

  15. Salvianolic Acid B, a Potential Chemopreventive Agent, for Head and Neck Squamous Cell Cancer

    Directory of Open Access Journals (Sweden)

    Yuan Zhao

    2011-01-01

    Full Text Available Head and neck squamous cell cancer (HNSCC is one of the top ten cancers in the United States. The survival rate of HNSCC has only marginally improved over the last two decades. In addition, African-American men bear a disproportionate burden of this preventable disease. Therefore, a critical challenge of preventive health approaches is warranted. Salvianolic acid B (Sal-B isolated from Salvia miltiorrhiza Bge, which is a well-know Chinese medicines has been safely used to treat and prevent aging diseases for thousand of years. Recently, the anticancer properties of Sal-B have received more attention. Sal-B significantly inhibits or delays the growth of HNSCC in both cultured HNSCC cells and HNSCC xenograft animal models. The following anticancer mechanisms have been proposed: the inhibition of COX-2/PGE-2 pathway, the promotion of apoptosis, and the modulation of angiogenesis. In conclusion, Sal-B is a potential HNSCC chemopreventive agent working through antioxidation and anti-inflammation mechanisms.

  16. Molecular aspects and chemoprevention of dimethylaminoazobenzene-induced hepatocarcinogenesis: A review.

    Science.gov (United States)

    Thomas, Nisha Susan; George, Kiran; Namasivayam, Nalini

    2016-01-01

    The lipophilic azo dye dimethylaminoazobenzene (DAB) is a potent hepatocarcinogen accounted as a group-2B carcinogen causing risk to humans. DAB is commonly used as a coloring agent in food, pharmaceuticals, beverages, soap and polishes. The exploration of DAB-induced hepatocarcinogenesis in animal models helped to an extent to perceive the histological, biochemical and molecular mechanisms of DAB carcinogenesis and also the severity of DAB exposure to humans. In experimental animal models, it is well-proved that the procarcinogen DAB is predominantly metabolized by cytochrome P450 enzymes giving rise to the formation of toxic electrophiles and reactive oxygen species (ROS), which further forms DNA adducts leading to the development of hepatic tumors. Recently, research evidence suggests that dietary phytochemicals and plant polyphenols are promising agents to control the incidence of DAB-induced hepatocarcinogenesis by preventing the generation of toxic electrophiles and ROS thereby inhibiting the formation of DNA adducts. This review highlights the role of specific dietary factors, biotransformation of DAB, phenotypic and genotypic alterations, and significance of certain chemopreventive agents against DAB-induced hepatocarcinogenesis.

  17. Chemopreventive activity of sesquiterpene lactones (SLs) from yacon against TPA-induced Raji cells deformation.

    Science.gov (United States)

    Siriwan, D; Miyawaki, C; Miyamoto, T; Naruse, T; Okazaki, K; Tamura, H

    2011-05-15

    Yacon is a medicinal plant used as a traditional medicine by the natives in South America. In Japan, it becomes popular as a health food. Sesquiterpene Lactones (SLs) from yacon leaves were investigated and the active SLs such as enhydrin, uvedalin and sonchifolin, bearing alpha-methylene-gamma-lactone and epoxides as the active functional groups, were identified by 1H-6000 MHz-NMR. Chemopreventive and cytotoxic activities were determined using different primary screening methods. In this study, all tested SLs strongly inhibited TPA-induced deformed of Raji cells. The IC50 values of yacon SLs from anti-deforming assay were 0.04-0.4 microM. Interestingly, yacon SLs showed more potential of chemo preventive activity than both curcumin and parthenolide. However, the cytotoxicity on Raji cells was observed at high concentration of yacon SLs. The degree of anti-deformation was ranked in order: enhydrin >uvedalin >sonchifolin >parthenolide >curcumin. As according to structure-activity relationship, the high activities of enhydrin, uvedalin and sonchifolin may be due to the 2-methyl-2-butenoate and its epoxide moiety. PMID:22097098

  18. Sirt1 Is Required for Resveratrol-Mediated Chemopreventive Effects in Colorectal Cancer Cells

    Science.gov (United States)

    Buhrmann, Constanze; Shayan, Parviz; Popper, Bastian; Goel, Ajay; Shakibaei, Mehdi

    2016-01-01

    Sirt1 is a NAD+-dependent protein-modifying enzyme involved in regulating gene expression, DNA damage repair, metabolism and survival, as well as acts as an important subcellular target of resveratrol. The complex mechanisms underlying Sirt1 signaling during carcinogenesis remain controversial, as it can serve both as a tumor promoter and suppressor. Whether resveratrol-mediated chemopreventive effects are mediated via Sirt1 in CRC growth and metastasis remains unclear; which was the subject of this study. We found that resveratrol suppressed proliferation and invasion of two different human CRC cells in a dose-dependent manner, and interestingly, this was accompanied with a significant decrease in Ki-67 expression. By transient transfection of CRC cells with Sirt1-ASO, we demonstrated that the anti-tumor effects of resveratrol on cells was abolished, suggesting the essential role of this enzyme in the resveratrol signaling pathway. Moreover, resveratrol downregulated nuclear localization of NF-κB, NF-κB phosphorylation and its acetylation, causing attenuation of NF-κB-regulated gene products (MMP-9, CXCR4) involved in tumor-invasion and metastasis. Finally, Sirt1 was found to interact directly with NF-κB, and resveratrol did not suppress Sirt1-ASO-induced NF-κB phosphorylation, acetylation and NF-κB-regulated gene products. Overall, our results demonstrate that resveratrol can suppress tumorigenesis, at least in part by targeting Sirt1 and suppression of NF-κB activation. PMID:26959057

  19. Oriental herbs as a source of novel anti-androgen and prostate cancer chemopreventive agents

    Institute of Scientific and Technical Information of China (English)

    Junxuan L(U); Sung-Hoon KIM; Cheng JIANG; HyoJeong LEE; Junming GUO

    2007-01-01

    Androgen and androgen receptor (AR) signaling are crucial for the genesis of prostate cancer (Pca), which can often develop into androgen-ligand-indepen-dent diseases that are lethal to the patients. Recent studies show that even these hormone-refractory Pca require ligand-independent AR signaling for survival. As current chemotherapy is largely ineffective for Pca and has serious toxic side-effects, we have initiated a collaborative effort to identify and develop novel, safe and naturally occurring agents that target AR signaling from Oriental medicinal herbs for the chemoprevention and treatment of Pca. We highlight our discovery of decursin from an Oriental formula containing Korean Angelica gigas Nakal(Dang Gui) root as a novel anti-androgen/AR agent. We have identified the following mechanisms to account for the specific anti-AR actions: rapid block of AR nuclear translocation, inhibition of binding of 5α-dihydrotestesterone to Arand increased proteasomal degradation of AR protein. Furthermore, decursin lacks the agonist activity of the "pure" anti-androgen bicalutamide and is more potent than bicalutamide in inducing Pca apoptosis. Structure-activity analyses reveal a critical requirement of the side-chain on decursin or its structural isomerdecursinol angelate for anti-AR, cell cycle arrest and proapoptotic activities. This work demonstrates the feasibility of using activity-guided fractionation in cell culture assays combined with mechanistic studies to identify novel anti-andro-gen/AR agents from complex herbal mixtures.

  20. A review of the content of the putative chemopreventive phytoalexin resveratrol in red wine

    DEFF Research Database (Denmark)

    Stervbo, Ulrik; Vang, Ole; Bonnesen, Christine

    2007-01-01

    Resveratrol, a naturally occurring compound of various fruits such as grapes, is thought to possess chemopreventive properties. The levels of resveratrol in grapes and grape products including wine, varies from region to region and from one year to another. This paper reviews the resveratrol...... content in red wine based on relevant published data. Red wine contains an average of 1.9 ± 1.7 mg trans-resveratrol/ l (8.2 ± 7.5 lM), ranging from non-detectable levels to 14.3 mg/l (62.7 lM) trans-resveratrol. In general, wines made from grapes of the Pinot Noir and St. Laurent varieties showed...... the highest level of trans-resveratrol. No region can be said to produce wines with significantly higher level of trans-resveratrol than all other regions. Levels of cis-resveratrol follow the same trend as trans-resveratrol. The average level of trans-resveratrol-glucoside (trans-piceid) in a red wine may...

  1. Sirt1 Is Required for Resveratrol-Mediated Chemopreventive Effects in Colorectal Cancer Cells.

    Science.gov (United States)

    Buhrmann, Constanze; Shayan, Parviz; Popper, Bastian; Goel, Ajay; Shakibaei, Mehdi

    2016-03-05

    Sirt1 is a NAD⁺-dependent protein-modifying enzyme involved in regulating gene expression, DNA damage repair, metabolism and survival, as well as acts as an important subcellular target of resveratrol. The complex mechanisms underlying Sirt1 signaling during carcinogenesis remain controversial, as it can serve both as a tumor promoter and suppressor. Whether resveratrol-mediated chemopreventive effects are mediated via Sirt1 in CRC growth and metastasis remains unclear; which was the subject of this study. We found that resveratrol suppressed proliferation and invasion of two different human CRC cells in a dose-dependent manner, and interestingly, this was accompanied with a significant decrease in Ki-67 expression. By transient transfection of CRC cells with Sirt1-ASO, we demonstrated that the anti-tumor effects of resveratrol on cells was abolished, suggesting the essential role of this enzyme in the resveratrol signaling pathway. Moreover, resveratrol downregulated nuclear localization of NF-κB, NF-κB phosphorylation and its acetylation, causing attenuation of NF-κB-regulated gene products (MMP-9, CXCR4) involved in tumor-invasion and metastasis. Finally, Sirt1 was found to interact directly with NF-κB, and resveratrol did not suppress Sirt1-ASO-induced NF-κB phosphorylation, acetylation and NF-κB-regulated gene products. Overall, our results demonstrate that resveratrol can suppress tumorigenesis, at least in part by targeting Sirt1 and suppression of NF-κB activation.

  2. Chemopreventive action of Syzygium cumini on DMBA-induced skin papillomagenesis in mice.

    Science.gov (United States)

    Parmar, Jyoti; Sharma, Priyanka; Verma, Preeti; Goyal, P K

    2010-01-01

    Syzygium cumini L. is widely used for the treatment of diabetes in various parts of India. The protective efficacy of S. cumini seed extract (SCE) against peroxidative damage contributing to skin carcinogenesis in Swiss albino mice was tested in the present study. A single topical application of 7,12-dimethyl benz(a)anthracene (100 microg/100 microl acetone), followed 2 weeks later by repeated application of croton oil (1% in acetone three times a week) and continued till the end of the experiment (i.e., 16 weeks) caused a 100% tumor incidence. In contrast, mice treated with the SCE (125 mg/ kg/ b.wt./ animal /day) in either the peri (i.e. 7 days before and 7 days after the application of DMBA) or post-initiation (i.e. from the day of start of croton oil treatment and continued till the end of the experiment) phases demonstrated significant reduction in cumulative numbers of papillomas and tumor incidence (75%). The average latency period in the SCE treated group was also significantly increased (Pre Group - 11.1 weeks; Post Group - 10.9 weeks) as compared with the carcinogen control group (7.9). Results from the present study indicate that the anticarcinogenic activity of SCE during DMBA-induced skin papillomagenesis is mediated through alteration of antioxidant status. Thus, SCE can be considered as a readily accessible, promising novel cancer chemopreventive agent. PMID:20593968

  3. Sirt1 Is Required for Resveratrol-Mediated Chemopreventive Effects in Colorectal Cancer Cells

    Directory of Open Access Journals (Sweden)

    Constanze Buhrmann

    2016-03-01

    Full Text Available Sirt1 is a NAD+-dependent protein-modifying enzyme involved in regulating gene expression, DNA damage repair, metabolism and survival, as well as acts as an important subcellular target of resveratrol. The complex mechanisms underlying Sirt1 signaling during carcinogenesis remain controversial, as it can serve both as a tumor promoter and suppressor. Whether resveratrol-mediated chemopreventive effects are mediated via Sirt1 in CRC growth and metastasis remains unclear; which was the subject of this study. We found that resveratrol suppressed proliferation and invasion of two different human CRC cells in a dose-dependent manner, and interestingly, this was accompanied with a significant decrease in Ki-67 expression. By transient transfection of CRC cells with Sirt1-ASO, we demonstrated that the anti-tumor effects of resveratrol on cells was abolished, suggesting the essential role of this enzyme in the resveratrol signaling pathway. Moreover, resveratrol downregulated nuclear localization of NF-κB, NF-κB phosphorylation and its acetylation, causing attenuation of NF-κB-regulated gene products (MMP-9, CXCR4 involved in tumor-invasion and metastasis. Finally, Sirt1 was found to interact directly with NF-κB, and resveratrol did not suppress Sirt1-ASO-induced NF-κB phosphorylation, acetylation and NF-κB-regulated gene products. Overall, our results demonstrate that resveratrol can suppress tumorigenesis, at least in part by targeting Sirt1 and suppression of NF-κB activation.

  4. Arsenic immunotoxicity and immunomodulation by phytochemicals: potential relations to develop chemopreventive approaches.

    Science.gov (United States)

    Ramos Elizagaray, Sabina I; Soria, Elio A

    2014-01-01

    Arsenic (As) contaminates drinking water worldwide, and As exposure, hypersensitivity and deficiency are involved in the immunopathogenesis of various health problems. Its chemoprevention thus has a high health impact. Given its oxidative potential, antioxidant compounds are good candidates to counteract arsenic's deleterious effects on humans. Phytochemicals (e.g., phenolics, carotenoids, etc.) act through free radical chelation activity and regulation of cellular targets. Consequently, they are appropriate for developing anti-As strategies derived from plants, and Argentinean flora is rich in useful species. Several molecular pathways involved in immune regulation are at the same time targets of exogenous agents, and oxidative stress itself is a modulating phenomenon of immunity. Since xenohormesis has been described as the organic enhancement of resistance to stress conditions (e.g., oxidation, pollution, etc.) by consuming xenobiotics, immunoxenohormesis implies also defense improvement. This review focuses on recent patents on the development of vegetable redox-related immunomodulating agents, which might be applied in As-induced dysfunctions, with their scientific basis being reviewed.

  5. Chemopreventive Effects of Oplopantriol A, a Novel Compound Isolated from Oplopanax horridus, on Colorectal Cancer

    Directory of Open Access Journals (Sweden)

    Zhiyu Zhang

    2014-07-01

    Full Text Available Oplopanax horridus is a North American botanical that has received limited investigations. We previously isolated over a dozen of the constituents from O. horridus, and among them oplopantriol A (OPT A is a novel compound. In this study, we firstly evaluated the in vivo chemoprevention activities of OPT A using the xenograft colon cancer mouse model. Our data showed that this compound significantly suppressed tumor growth with dose-related effects (p < 0.01. Next, we characterized the compound’s growth inhibitory effects in human colorectal cancer cell lines HCT-116 and SW-480. With OPT A treatment, these malignant cells were significantly inhibited in both a concentration- and time-dependent manner (both p < 0.01. The IC50 was approximately 5 µM for HCT-116 and 7 µM for SW-480 cells. OPT A significantly induced apoptosis and arrested the cell cycle at the G2/M phase. From further mechanism explorations, our data showed that OPT A significantly upregulated the expression of a cluster of genes, especially the tumor necrosis factor receptor family and caspase family, suggesting that the tumor necrosis factor-related apoptotic pathway plays a key role in OPT A induced apoptosis.

  6. 77 FR 1682 - Butylate, Fenoxycarb, Sodium Tetrathiocarbonate, and Temephos Registration Review Final Decisions...

    Science.gov (United States)

    2012-01-11

    ... field corn, pop corn, and sweet corn. The last butylate pesticide product registered for use in the... a soil fumigant used for the management of nematodes and phytophthora root rot, oak root fungus,...

  7. Synthesis of n-Butyl Ether%正丁醚的合成

    Institute of Scientific and Technical Information of China (English)

    李公春; 鞠志宇; 李再永; 唐红; 吴长增

    2015-01-01

    ABSTRACT:n-Butyl ether was synthesized by refluxing under the conditions of stirring, with n-butyl alcohol as raw material, concentrated sulfuric acid as catalyst. The effects of the amount of concentrated sul-furic acid, reaction time and water-carrying agents on yield of n-butyl ether were studied, The highest yield of n-butyl ether was 41.1%.%以正丁醇为原料,浓硫酸为催化剂,在搅拌条件下加热回流,制备正丁醚。研究改变浓硫酸的用量、反应时间和加入带水剂等反应条件对反应产率的影响,正丁醚产率最高可达41.1%。

  8. A comparison of the effect of intranasal desmopressin and intramuscular hyoscine N-butyl bromide combination with intramuscular hyoscine N-butyl bromide alone in acute renal colic

    Directory of Open Access Journals (Sweden)

    Abdol-Reza Kheirollahi

    2010-01-01

    Full Text Available Background: Patients with acute renal colic usually require immediate diagnosis and treatment. In this clinical trial analgesic effect of hyoscine N-butyl bromide and desmopressin combination in comparison with hyoscine N-butyl bromide alone in patients with acute renal colic induced by urinary stones was assessed. Methods: The study included 114 patients randomly allocated in two groups (A and B. Patients in group A received 20 mg intramuscular hyoscine N-butyl bromide at admission time and patients in group B received 20 μg of intranasal desmopressin in combination with 20 mg intramuscular hyoscine N-butyl bromide. A visual analogue scale (VAS; a 10-cm horizontal scale ranging from "zero or no pain" to "10 or unbearable pain" was hired to assess the patients′ pain severity at baseline, 30 and 60 minutes after the treatments. Results: On admission, the pain level was similar in both groups (group A: 8.95 ± 0.11 and group B: 8.95 ± 0.12. In group A, the mean of pain level showed a decrease after 30 minutes (group A: 7.26 ± 0.25 and group B: 5.95 ± 0.28 but further decreasing did not occur; however in group B, the pain consistently decreased and the mean after 60 minutes was significantly decreased (group A: 6.80 ± 0.31 and group B: 3.71 ± 0.31. No side effects were detected in this study. Conclusions: The combination of hyoscine N-butyl bromide and desmopressin is more effective than hyoscine N-butyl bromide alone in patients with renal colic. Further studies are recommended to validate these findings and compare the different doses of desmopressin.

  9. APPLICATION OF PHOTOCATALYTIC PROCESS FOR REMOVAL OF METHYL TERT-BUTYL ETHER FROM HIGHLYCONTAMINATED WATER

    Directory of Open Access Journals (Sweden)

    A. Mesdaghinia

    2007-09-01

    Full Text Available The oxygenate methyl tert-butyl ether is added to gasoline to increase the octane level and to reduce carbon monoxide and hydrocarbon emissions by vehicles. The high mobility, water solubility, and resistance to natural attenuation associated with methyl tert-butyl ether may result in contamination of ground and surface waters. In this research the degradation of aqueous methyl tert-butyl ether at relatively high concentrations was investigated by UV-vis/TiO2/H2O2 photocatalytic process. The effect of important operational parameters such as pH, amount of H2O2, catalyst loading, and irradiation time were also studied. Concentrations of methyl tert-butyl ether and intermediates such as tert-butyl formate and tert-butyl alcohol were measured over a 180 min period using a gas chromatograph equipped with flame ionization detector and combined with headspace sampler. Results showed that the time required for complete degradation increased from 30 to 180min, when the initial concentration was increased from 10 to 500mg/L. The first order rate constant for degradation of methyl tert-butyl ether from the hydroxyl radical was estimated to be 0.177 to 0.022 1/min as the concentration increased from 10 to 500mg/L. Study on the overall mineralization monitored by total organic carbon (TOC analysis showed that in the initial concentration of 100mg/L methyl tert-butyl ether, complete mineralization was obtained after 110min under UV-vis/TiO2/H2O2 photocatalytic process.

  10. Occupational exposures to new dry cleaning solvents: High-flashpoint hydrocarbons and butylal.

    Science.gov (United States)

    Ceballos, Diana M; Whittaker, Stephen G; Lee, Eun Gyung; Roberts, Jennifer; Streicher, Robert; Nourian, Fariba; Gong, Wei; Broadwater, Kendra

    2016-10-01

    The dry cleaning industry is moving away from using perchloroethylene. Occupational exposures to two alternative dry cleaning solvents, butylal and high-flashpoint hydrocarbons, have not been well characterized. We evaluated four dry cleaning shops that used these alternative solvents. The shops were staffed by Korean- and Cantonese-speaking owners, and Korean-, Cantonese-, and Spanish-speaking employees. Because most workers had limited English proficiency we used language services in our evaluations. In two shops we collected personal and area air samples for butylal. We also collected air samples for formaldehyde and butanol, potential hydrolysis products of butylal. Because there are no occupational exposure limits for butylal, we assessed employee health risks using control banding tools. In the remaining two shops we collected personal and area air samples for high-flashpoint hydrocarbon solvents. In all shops the highest personal airborne exposures occurred when workers loaded and unloaded the dry cleaning machines and pressed dry cleaned fabrics. The air concentrations of formaldehyde and butanol in the butylal shops were well below occupational exposure limits. Likewise, the air concentrations of high-flashpoint hydrocarbons were also well below occupational exposure limits. However, we saw potential skin exposures to these chemicals. We provided recommendations on appropriate work practices and the selection and use of personal protective equipment. These recommendations were consistent with those derived using control banding tools for butylal. However, there is insufficient toxicological and health information to determine the safety of butylal in occupational settings. Independent evaluation of the toxicological properties of these alternative dry cleaning solvents, especially butylal, is urgently needed. PMID:27105306

  11. Permeability of Noble Gases through Kapton, Butyl, Nylon, and "Silver Shield"

    CERN Document Server

    Schowalter, Steven J; Doyle, John M

    2009-01-01

    Noble gas permeabilities and diffusivities of Kapton, butyl, nylon, and "Silver Shield" are measured at temperatures between 22C and 115C. The breakthrough times and solubilities at 22C are also determined. The relationship of the room temperature permeabilities to the noble gas atomic radii is used to estimate radon permeability for each material studied. For the noble gases tested, Kapton and Silver Shield have the lowest permeabilities and diffusivities, followed by nylon and butyl, respectively.

  12. Embolotherapy using N-butyl cyanoacrylate for abdominal wall bleeding

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Young Ho; Koh, Young Hwan; Han, Dae Hee; Kim, Ji Hoon; Cha, Joo Hee; Lee, Eun Hye; Song, Chi Sung [Seoul National University Boramae Hospital, Seoul (Korea, Republic of)

    2008-05-15

    We describe our experience with the use of N-butyl cyanoacrylate (NBCA) embolization of abdominal wall bleeding and we evaluate the clinical effectiveness of the procedure. Embolization was performed in nine patients with abdominal wall bleeding. The sites of embolization were the left first lumbar (n = 1), left second lumbar (n = 1), right inferior epigastric (n 2), left inferior epigastric (n = 3), right circumflex iliac (n = 1), and left circumflex iliac artery (n = 1). A coil was used with NBCA in one patient due to difficulty in selecting only a bleeding focus and anticipated reflux. NBCA was mixed with Lipiodol at the ratio of 1:1 to 1:4. Blood pressure and heart rate were measured before and after the embolization procedure, and the serial hemoglobin and hematocrit levels and transfusion requirements were reviewed to evaluate hemostasis and rebleeding. Hemostasis was obtained in six out of the nine patients and technical success was achieved in all patients. There were no procedure-related complications. Four out of the nine patients died due to rebleeding of a subarachnoid hemorrhage (n = 1), multiorgan failure (n = 1), and hepatic failure (n =2) that occurred two to nine days after the embolization procedure. One patient had rebleeding. The five surviving patients had no rebleeding, and the patients continue to visit the clinical on an outpatient basis. NBCA embolization is a clinically safe procedure and is effective for abdominal wall bleeding.

  13. Biodegradation of methyl tert-butyl ether by Kocuria sp.

    Directory of Open Access Journals (Sweden)

    Kiković Dragan D.

    2012-01-01

    Full Text Available Methyl tert-butyl ether (MTBE has been used to replace the toxic compounds from gasoline and to reduce emission of air pollutants. Due to its intensive use, MTBE has become one of the most important environment pollutants. The aim of this paper is isolation and identification of the bacteria from wastewater sample of “HIP Petrohemija” Pančevo (Serbia, capable of MTBE biodegradation. The results of the investigation showed that only the bacterial isolate 27/1 was capable of growth on MTBE. The result of sequence analyzes of 16S rDNA showed that this bacterial isolate belongs to the Kocuria sp. After the incubation period of 86 days, the degradation rates of initial MTBE concentration of 25 and 125 μg/ml were 55 and 36%, respectively. These results indicated that bacteria Kocuria sp. is successfully adapted on MTBE and can be potentially used in bioremediation of soils and waters contaminated with MTBE.

  14. Dietary Exposure to Benzyl Butyl Phthalate in China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lei; JIANG Ding Guo; SUI Hai Xia; WU Ping Gu; LIU Ai Dong; YANG Da Jin; LIU Zhao Ping; SONG Yan; LI Ning

    2016-01-01

    ObjectiveBenzyl butyl phthalate (BBP) is a plasticizer used in food contact materials. Dietary exposure to BBP might lead to reproduction and developmental damages to human. The present paper was aimed to assess the health risk of BBP dietary exposure in Chinese population. MethodsThe BBP contents were detected in 7409 food samples from 25 foodcategories by gas chromatography-mass spectrometry operated in selected ion monitoring (SIM) mode. The dietary exposures of BBP in different age and sex groups were estimated by combining the content data with food consumption data derived from 2002 China National Nutrient and Health Survey, and evaluated according to the tolerable daily intake (TDI) of BBP established by European Food safety Agency. ResultsIt was found that BBP was undetectable in most samples and the highest level was 1.69 mg/kg detected in a vegetable oil sample. The average dietary exposure of BBP in people aged≥2 years was 1.03 μg/kgbw perday and the highest average exposure was found in 2-6 years old children (1.98 μg/kg bw perday). The BBP exposure in 7-12 months old children excessed 10% of tolerable daily intake (TDI) in worst scenario. ConclusionThe health risk of BBP dietary exposure in Chinese population is low and, considering BBP alone, there is no safety concern.

  15. Degradation of n-butyl xanthate using fly ash as heterogeneous Fenton-like catalyst

    Institute of Scientific and Technical Information of China (English)

    陈绍华; 杜冬云

    2014-01-01

    Heterogeneous Fenton-like process using fly ash as a catalyst was studied to degrade n-butyl xanthate form aqueous solution. The different reaction parameters on the degradation efficiency of the process were investigated. The fly ash/H2O2 catalyst possesses a high oxidation activity for n-butyl xanthate degradation in aqueous solution. It is found that both the dosage of catalyst and initial solution pH significantly affect the n-butyl xanthate conversion efficient. The results indicate that by using 1.176 mmol/L H2O2 and 1.0 g/L fly ash catalyst with mass fraction of 4.14%Fe(III) oxide at pH 3.0, almost 96.90%n-butyl xanthate conversion and over 96.66%COD removal can be achieved within 120 min with heterogeneous catalysis by fly ash. CS2 as an intermediate of n-butyl xanthate oxidation. Finally, it is demonstrated that the fly ash/H2O2 catalytic oxidation process can be an efficient method for the treatment of n-butyl xanthate containing wastewater.

  16. Cyhalofop-p-butyl mobility and distribution of residues in soil at various depths.

    Science.gov (United States)

    Khare, Rishi Raj; Sondhia, Shobha

    2014-01-01

    This study was conducted to evaluate cyhalofop-p-butyl mobility in a sandy loam soil and subsequent distribution of residues at various depths under field conditions. Soil samples were taken from 0 to 150 cm depths at 3-90 d after rains in lysemeter of 1 and 2 m depths. Cyhalofop-p-butyl application at two rates and subsequent precipitation had a significant impact on soil, physico-chemical properties and herbicide mobility. Precipitation caused substantial mobility of cyhalofop-p-butyl in the soil and 1.1-7.6 μg L(-1) of cyhalofop-p-butyl was found in leachates. Cyhalofop-p-butyl residues in the leachates were probably due to preferential flow through the soil. Cyhalofop-p-butyl residues were detected in significant amounts from the soil up to 10 d, later, residues were found below the detection limit but its three transformation products viz., cyhalofop acid, diacid, and phenol were detected. PMID:24762176

  17. Potential chemoprevention of diethylnitrosamine-induced hepatocarcinogenesis in rats: myrrh (Commiphora molmol) vs. turmeric (Curcuma longa).

    Science.gov (United States)

    El-Shahat, Mohamed; El-Abd, Sabah; Alkafafy, Mohamed; El-Khatib, Gamal

    2012-09-01

    The aim of the present study was to assess the potential chemopreventive effects of myrrh (Commiphora molmol) vs. turmeric (Curcuma longa) in hepatocarcinogenic rats induced by a single intraperitoneal injection of diethylnitrosamine (DENA) (200 mg/kg body weight). Ninety male Wistar rats used in this study were randomly divided into six equal groups (n=15). Group 1 rats served as negative controls; group 2 received a single i.p. injection of DENA and served as positive controls. Rats in both groups were fed on basal diet. Group 3 rats were fed a diet containing 5% turmeric, whereas group 4 rats were fed a diet containing 2% myrrh. Rats in groups 5 and 6 received a single i.p. injection of DENA and were fed diets containing 5% turmeric and 2% myrrh, respectively. The study demonstrated that DENA caused a significant increase in serum indices of liver enzymes and also severe histological and immunohistochemical changes in hepatic tissues. These included disorganized hepatic parenchyma, appearance of pseudoacinar and trabecular arrays of hepatocytes and alterations in CD10-immunoreactivity. Dietary supplementation of turmeric relatively improved the biochemical parameters to values approximating those of the negative controls and delayed the initiation of carcinogenesis. In contrast, myrrh did not improve the biochemical parameters or delay the hepatocarcinogenesis. Both turmeric and myrrh induced significant biochemical and histological changes in non-treated rats. In conclusion, DENA significantly changes the biological enzymatic activities in serum and the integrity of hepatic tissues. Phytochemicals with potential hepatoprotective effects must be applied cautiously owing to their potential hepatotoxicity.

  18. Colon cancer chemopreventive efficacy of silibinin through perturbation of xenobiotic metabolizing enzymes in experimental rats.

    Science.gov (United States)

    Sangeetha, Nagarajan; Viswanathan, Periyaswamy; Balasubramanian, Thangavel; Nalini, Namasivayam

    2012-01-15

    Our findings reported so far demonstrate that silibinin modulates gut microbial enzymes, colonic oxidative stress and Wnt/β-catenin signaling, to exert its antiproliferative effect against 1,2 di-methylhydrazine (DMH) induced colon carcinogenesis. Since xenobiotic metabolizing enzymes play a crucial role in carcinogen activation and metabolism, we aimed to explore the effect of silibinin on xenobiotic metabolizing enzymes during DMH induced colon carcinogenesis. Male albino rats were randomly divided into six groups. Group 1 served as control and group 2 rats received 50mg/kg body weight of silibinin p.o. every day. Groups 3-6 rats were given DMH at a dose of (20mg/kg body weight subcutaneously) once a week for 15 weeks to induce colonic tumors. In addition to DMH, group 4 (initiation), group 5 (post-initiation) and group 6 (entire period) rats received silibinin (50mg/kg body weight, p.o., everyday) at different time points during the experimental period of 32 weeks. Rats exposed to DMH alone showed increased activities of phase I enzymes (cytochrome b5, cytochrome b5 reductase, cytochromeP450, cytochromeP450 reductase, cytochromP4502E1) and decreased activities of phase II enzymes (Uridine diphospho glucuronyl transferase, Glutathione-S-transferase and DT-Diaphorase) in the liver and colonic mucosa as compared to control rats. Silibinin supplementation modulates the xenobiotic metabolizing enzymes favoring carcinogen detoxification. Evaluation of lipid peroxidation and antioxidants status showed that silibinin supplementation counteracts DMH induced hepatic and circulatory oxidative stress. Tumor burden in experimental animals was assessed both macroscopically and microscopically in the colon tissues. Our findings emphasize the potential chemopreventive action of silibinin against DMH induced colon carcinogenesis. PMID:22115893

  19. Hydrogen peroxide is a second messenger in phase 2 enzyme induction by cancer chemopreventive dithiolethiones.

    Science.gov (United States)

    Holland, Ryan; Navamal, Mettachit; Velayutham, Murugesan; Zweier, Jay L; Kensler, Thomas W; Fishbein, James C

    2009-08-01

    The ability of three dithiolethione cancer chemopreventives, oltipraz 1, anetholedithione (ADT) 2, 1,2-dithiole-3-thione (D3T) 3, and the major metabolite, 4, of 1, to induce the cytoprotective enzyme NQO1 in Hepa 1c1c7 cells and the inhibition of this induction by catalase are demonstrated. The ability of 1, 3, and 4 to form O(2)(*) has been reported, and it is here demonstrated that 2 decomposes in the presence of GSH to form, upon addition of the nitrone spin trap DMPO, the DMPO-OH adduct that is detectable by EPR. Decomposition of 2 in the presence of GSH elicits, upon the addition of hydroethidine and excitation at 510 nm, fluorescence at 580 nm that is diminished by the addition of superoxide dismutase. The compound 4, is a product of the reduction of 1, and it is demonstrated that 2 and 3 decompose in the presence of reductants such as thiolates and NaBH(4), followed by addition of CH(3)I, to form the dimethylated products of reductive cleavage of the S(1)-S(2) bond. The same products are isolated subsequent to lysis in buffer containing CH(3)I of Hepa 1c1c7 cells treated with 2 or 3. Reductive cleavage of 2 and 3 in aqueous ethanol by NaBH(4) in an argon atmosphere, followed by acidic destruction of remaining borohydride and neutralization and introduction of O(2) results in the reformation of 2 and 3 to the extent of 80 and 33%, respectively. The data in toto are consistent with a model in which dithiolethiones, generally, undergo reductive cleavage in Hepa 1c1c7 cells, thereby resulting in the generation of O(2)(*) that dismutates to H(2)O(2), that subsequently, by direct or indirect means, effects the nuclear translocation of transcription factor Nrf2, that upregulates phase 2 enzyme expression.

  20. CANCER CHEMOPREVENTIVE ACTIVITIES OF S-3-1,A SYNTHETIC DERIVATIVE OF DANSHINONE

    Institute of Scientific and Technical Information of China (English)

    XIAO-GUANG CHEN; YAN LI; CHUN-HONG YAN; LIAN-NIANG LI; RUI HAN

    2001-01-01

    Salvia miltiorrhiza is a traditional Chinese medicine which has been well documented for its anti-cancer effects. Based on the structure of danshinone, one of the active compounds derived from Salvia miltiorrhiza, we synthesized a simplified phenolic analog, S-3-1, and tried to explore its possible actions in preventing the development of cancer. With the Ames test, S-3-1 was found to efficiently suppress the mutagenicity of benzo[a]pyrene. This result is consistent with the inhibitory effect of S-3-1 on the activation of benzo[α]pyrene by hepatic microsomal enzymes. Besides the anti-initiation effects, S-3-1 could significantly inhibit the croton oil induced increase of mouse skin epithermal ornithine decarboxylase activity. Moreover, S-3-1 quenched both superoxide and hydroxyl free radicals whereas it inhibited lipid peroxidation in the in vitro model. These results suggest that S-3-1 might act as anti-initiation and anti-promo tion agents through reversing the biochemical alterations induced by carcinogen during carcino genesis. Therefore, we further investigated the effects of S-3-1 on carcinogenesis. In vitro, S-3-1inhibited the benzo[a]pyrene-induced transformation of V79 Chinese hamster lung fibroblasts.At 10-40 mg/kg, S-3-1 was found to inhibit the development of DM BA/croton oil-induced skin papilloma in mice through decreasing the incidence of papilloma, prolonging the latent period of tumor occurrence and reducing tumor number per mouse in a dose-dependent manner. We concluded from this study that S-3-1 might be developed as a new chemopreventive drug.

  1. Chemopreventive Effects of RXR-Selective Rexinoid Bexarotene on Intestinal Neoplasia of ApcMin/+ Mice

    Directory of Open Access Journals (Sweden)

    Naveena B. Janakiram

    2012-02-01

    Full Text Available Retinoid X receptor (RXR has been implicated in several neoplastic diseases. Previously, we have shown that RXR-α is downregulated in human and rodent colonic tumors, suggesting a potential target for colon cancer prevention (http://www.cancer.org/Cancer/ColonandRectumCancer/DetailedGuide/colorectal-cancer-key-statistics. Experiments were designed to assess the chemopreventive efficacy of the selective RXR agonist bexarotene for the suppression of intestinal tumorigenesis in ApcMin/+ mice. Before the efficacy studies, we determined that the maximal tolerated dose in C57BL/6J mice was less than 400 ppm. For the efficacy study, 6-week-old male and female C57BL/6J-ApcMin/+ mice (nine mice per group were fed diets containing 0, 30, and 60 ppm of bexarotene or 200 ppm of bexarotene for 80 days before intestinal tumors were evaluated. Dietary administration of 30 and 60 ppm of bexarotene suppressed the intestinal polyp formation by 38% (P < .015 and 60% (P < .0001 in males, respectively, and by 8.5% and 37% (P < .007 in females, respectively. Also, significant inhibition (50%–100% of colonic tumor formation was observed in both male and female mice with bexarotene treatment. Administration of 200 ppm of bexarotene showed significant suppression of tumor formation (66%, P < .0001; however, it had significant toxicity. Intestinal tumors of bexarotene-fed mice showed significantly reduced expression of proliferating cell nuclear antigen (60%, P < .0001, cyclin D1, and cyclooxygenase 2 and increased RXR-α messenger RNA and uptake of oleate (34%, P < .01. Also, bexarotene-fed mice showed dose-dependent suppression of serum triglycerides (25%–72%, P < .0001 and inflammatory cytokines.

  2. Dietary factors and cancer chemoprevention: An overview of obesity-related malignancies

    Directory of Open Access Journals (Sweden)

    Murthy N

    2009-01-01

    Full Text Available Obesity is a growing health problem in developed nations and in countries that are in the process of westernization like India. Obesity is linked with several health disorders such as hypertension and cardiovascular diseases, Type 2 diabetes, dyslipidemia and certain cancers. Currently, obesity-related malignancies, e.g., cancers of the breast, prostate and colon are the leading cancers in the industrialized societies. An increased amount of fat or adipose tissue in an overweight or obese person probably influences the development of cancer by releasing several hormone-like factors or adipokines. The majority of adipokines are pro-inflammatory, which promote pathological conditions like insulin resistance and cancer. On the other hand, many recent studies have shown that adiponectin, an anti-inflammatory adipokine, has anti-cancer and insulin-sensitizing effects. Adiponectin exerts its physiological functions chiefly by activation of AMP kinase via adiponectin receptors. Interestingly, several fruits and vegetables may contain adiponectin-like molecules or may increase the biosynthesis of adiponectin in our body. Studies on adiponectin analogues or adiponectin receptor agonists are a promising area of cancer chemoprevention research. In general, fruits and vegetables contain various dietary substances such as vitamins, minerals (like calcium and selenium, fiber and phytochemicals or phenolic compounds (like flavonoids and vanilloids, which may act as anti-cancer agents. Similarly, several dietary constituents including phytochemicals may have anti-obesity effects. Consumption of such dietary compounds along with caloric restriction and physical activity may be helpful in preventing obesity-related cancers. For this review article, we searched PubMed primarily to get the relevant literature.

  3. Molecular classification of non-invasive breast lesions for personalised therapy and chemoprevention.

    Science.gov (United States)

    Buckley, Niamh; Boyle, David; McArt, Darragh; Irwin, Gareth; Harkin, D Paul; Lioe, Tong; McQuaid, Stephen; James, Jacqueline A; Maxwell, Perry; Hamilton, Peter; Mullan, Paul B; Salto-Tellez, Manuel

    2015-12-22

    Breast cancer screening has led to a dramatic increase in the detection of pre-invasive breast lesions. While mastectomy is almost guaranteed to treat the disease, more conservative approaches could be as effective if patients can be stratified based on risk of co-existing or recurrent invasive disease.Here we use a range of biomarkers to interrogate and classify purely non-invasive lesions (PNL) and those with co-existing invasive breast cancer (CEIN). Apart from Ductal Carcinoma In Situ (DCIS), relative homogeneity is observed. DCIS contained a greater spread of molecular subtypes. Interestingly, high expression of p-mTOR was observed in all PNL with lower expression in DCIS and invasive carcinoma while the opposite expression pattern was observed for TOP2A.Comparing PNL with CEIN, we have identified p53 and Ki67 as predictors of CEIN with a combined PPV and NPV of 90.48% and 43.3% respectively. Furthermore, HER2 expression showed the best concordance between DCIS and its invasive counterpart.We propose that these biomarkers can be used to improve the management of patients with pre-invasive breast lesions following further validation and clinical trials. p53 and Ki67 could be used to stratify patients into low and high-risk groups for co-existing disease. Knowledge of expression of more actionable targets such as HER2 or TOP2A can be used to design chemoprevention or neo-adjuvant strategies. Increased knowledge of the molecular profile of pre-invasive lesions can only serve to enhance our understanding of the disease and, in the era of personalised medicine, bring us closer to improving breast cancer care. PMID:26657114

  4. Chemoprevention of prostate cancer by d,l-sulforaphane is augmented by pharmacological inhibition of autophagy.

    Science.gov (United States)

    Vyas, Avani R; Hahm, Eun-Ryeong; Arlotti, Julie A; Watkins, Simon; Stolz, Donna Beer; Desai, Dhimant; Amin, Shantu; Singh, Shivendra V

    2013-10-01

    There is a preclinical evidence that the oral administration of d,l-sulforaphane (SFN) can decrease the incidence or burden of early-stage prostate cancer [prostatic intraepithelial neoplasia (PIN)] and well-differentiated cancer (WDC) but not late-stage poorly differentiated cancer (PDC). Because SFN treatment induces cytoprotective autophagy in cultured human prostate cancer cells, the present study tested the hypothesis that chemopreventive efficacy of SFN could be augmented by the pharmacologic inhibition of autophagy using chloroquine (CQ). Incidence of PDC characterized by prostate weight of more than 1 g was significantly lower in the SFN + CQ group than in control (P = 0.004), CQ group (P = 0.026), or SFN group (P = 0.002 by Fisher exact test). Average size of the metastatic lymph node was lower by about 42% in the SFN + CQ group than in control (P = 0.043 by Wilcoxon test). On the other hand, the SFN + CQ combination was not superior to SFN alone with respect to inhibition of incidence or burden of microscopic PIN or WDC. SFN treatment caused in vivo autophagy as evidenced by transmission electron microscopy. Mechanistic studies showed that prevention of prostate cancer and metastasis by the SFN + CQ combination was associated with decreased cell proliferation, increased apoptosis, alterations in protein levels of autophagy regulators Atg5 and phospho-mTOR, and suppression of biochemical features of epithelial-mesenchymal transition. Plasma proteomics identified protein expression signature that may serve as biomarker of SFN + CQ exposure/response. This study offers a novel combination regimen for future clinical investigations for prevention of prostate cancer in humans.

  5. Folic acid supplementation inhibits recurrence of colorectal adenomas: A randomized chemoprevention trial

    Institute of Scientific and Technical Information of China (English)

    Richard Jaszewski; Adhip PN Majumdar; Sabeena Misra; Martin Tobi; Nadeem Ullah; Jo Ann Naumoff; Omer Kucuk; Edi Levi; Bradley N Axelrod; Bhaumik B Patel

    2008-01-01

    AIM: To determine whether folic acid supplementation will reduce the recurrence of colorectal adenomas,the precursors of colorectal cancer, we performed a double-blind placebo-controlled trial in patients with adenomatous polyps.METHODS: In the current double-blind, placebo-controlled trial at this VA Medical Center, patients with colorectal adenomas were randomly assigned to receive either a daily 5 mg dose of folic acid or a matched identical placebo for 3 years. All polyps were removed at baseline colonoscopy and each patient had a follow up colonoscopy at 3 years. The primary endpoint was a reduction in the number of recurrent adenomas at 3 years.RESULTS: Of 137 subjects, who were eligible after confirmation of polyp histology and run-in period to conform compliance, 94 completed the study; 49 in folic acid group and 45 in placebo group. Recurrence of adenomas at 3-year was compared between the two groups. The mean number of recurrent polyps at 3-year was 0.36 (SD, 0.69) for folic acid treated patients compared to 0.82 (SD, 1.17) for placebo treated subjects, resulting in a 3-fold increase in polyp recurrence in the placebo group. Patients below 70 years of age and those with left-sided colonic adenomas or advanced adenomas responded better to folic acid supplementation.CONCLUSION: High dose folic acid supplementation is associated with a significant reduction in the recurrence of colonic adenomas suggesting that folic acid may be an effective chemopreventive agent for colorectal neoplasia.

  6. Targeting Receptor Tyrosine Kinases for Chemoprevention by Green Tea Catechin, EGCG

    Directory of Open Access Journals (Sweden)

    Hisataka Moriwaki

    2008-06-01

    Full Text Available Tea is one of the most popular beverages consumed worldwide. Epidemiologic studies show an inverse relationship between consumption of tea, especially green tea, and development of cancers. Numerous in vivo and in vitro studies indicate strong chemopreventive effects for green tea and its constituents against cancers of various organs. (–-Epigallocatechin-3-gallate (EGCG, the major catechin in green tea, appears to be the most biologically active constituent in tea with respect to inhibiting cell proliferation and inducing apoptosis in cancer cells. Recent studies indicate that the receptor tyrosine kinases (RTKs are one of the critical targets of EGCG to inhibit cancer cell growth. EGCG inhibits the activation of EGFR (erbB1, HER2 (neu/erbB2 and also HER3 (neu/erbB3, which belong to subclass I of the RTK superfamily, in various types of human cancer cells. The activation of IGF-1 and VEGF receptors, the other members of RTK family, is also inhibited by EGCG. In addition, EGCG alters membrane lipid organization and thus inhibits the dimerization and activation of EGFR. Therefore, EGCG inhibits the Ras/MAPK and PI3K/Akt signaling pathways, which are RTK-related cell signaling pathways, as well as the activation of AP-1 and NF-κB, thereby modulating the expression of target genes which are associated with induction of apoptosis and cell cycle arrest in cancer cells. These findings are significant because abnormalities in the expression and function of RTKs and their downstream effectors play a critical role in the development of several types of human malignancies. In this paper we review evidence indicating that EGCG exerts anticancer effects, at least in part, through inhibition of activation of the specific RTKs and conclude that targeting RTKs and related signaling pathway by tea catechins might be a promising strategy for the prevention of human cancers.

  7. Transcatheter Embolotherapy with N-Butyl Cyanoacrylate for Ectopic Varices

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jin Woo; Kim, Hyo-Cheol, E-mail: angiointervention@gmail.com; Jae, Hwan Jun, E-mail: jaemdphd@gmail.com; Jung, Hyun-Seok; Hur, Saebeom; Lee, Myungsu; Chung, Jin Wook [Seoul National University Hospital, Department of Radiology, Seoul National University College of Medicine (Korea, Republic of)

    2015-04-15

    PurposeTo address technical feasibility and clinical outcome of transcatheter embolotherapy with N-butyl cyanoacrylate (NBCA) for bleeding ectopic varices.MethodsThe institutional review board approved this retrospective study and waived informed consent. From January 2004 to June 2013, a total of 12 consecutive patients received transcatheter embolotherapy using NBCA for bleeding ectopic varices in our institute. Clinical and radiologic features of the endovascular procedures were comprehensively reviewed.ResultsPreprocedural computed tomography images revealed ectopic varices in the jejunum (n = 7), stoma (n = 2), rectum (n = 2), and duodenum (n = 1). The 12 procedures consisted of solitary embolotherapy (n = 8) and embolotherapy with portal decompression (main portal vein stenting in 3, transjugular intrahepatic portosystemic shunt in 1). With regard to vascular access, percutaneous transhepatic access (n = 7), transsplenic access (n = 4), and transjugular intrahepatic portosystemic shunt tract (n = 1) were used. There was no failure in either the embolotherapy or the vascular accesses (technical success rate, 100 %). Two patients died within 1 month from the procedure from preexisting fatal medical conditions. Only one patient, with a large varix that had been partially embolized by using coils and NBCA, underwent rebleeding 5.5 months after the procedure. The patient was retreated with NBCA and did not undergo any bleeding afterward for a follow-up period of 2.5 months. The remaining nine patients did not experience rebleeding during the follow-up periods (range 1.5–33.2 months).ConclusionTranscatheter embolotherapy using NBCA can be a useful option for bleeding ectopic varices.

  8. Chelation of heavy metals by potassium butyl dithiophosphate

    Institute of Scientific and Technical Information of China (English)

    Ying Xu; Zhigang Xie; Lu Xue

    2011-01-01

    Potassium butyl dithiophosphate (PBD) was developed and introduced as a new chelating agent for heavy metal removal.The synthesized PBD were characterized by IR and NMR.The effects of pH, chelating agent dosage, and other heavy metal ions on the performance of PBD in Cd2+ removal from water are investigated.Experimental results showed that the chelating agent could be used to treat acidic heavy metal wastewater.The Cd2+ removal was not affected by solution pH value within the range of 2 to 6.The Cd2+ removal rate could reach over 99%.Therefore, the deficiency of the precipitation process using hydroxide under alkaline condition can be overcome.Without the need for pH adjustment, the method could save on costs.If Cd2+ co-exists with Pb2+ and Cu2+, the affinity of the chelating agent with these three heavy metal ions was in the order of: Cu2+ > Pb2+ > Cd2+.Through PBD chelating precipitation,all the contents of Pb2+, Cd2+, and Cu2+ in wastewater met the standard levels through a one-step treatment.The one-step treatment process was superior to the process (sectional treatment is required) of precipitation with hydroxide.When the pH was between 3 and 11, the amount of leached chelated Cd2+ was much lower than that obtained by precipitation with hydroxide.Therefore, the risk of environmental pollution could be further reduced.

  9. N-butyl cyanoacrylate embolotherapy for acute gastroduodenal ulcer bleeding

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Young Ho; Kim, Ji Hoon; Koh, Young Hwan; Han, Dae Hee; Cha, Joo Hee; Seong, Chang Kyu; Song, Chi Sung [Seoul National University Boramae Hospital, Seoul (Korea, Republic of)

    2007-01-15

    Various embolic agents have been used for embolization of acute gastrointestinal (GI) arterial bleeding. N-butyl cyanoacrylate (NBCA) is not easy to handle, but it is a useful embolic agent. In this retrospective study, we describe our experience with NBCA embolization of acute gastroduodenal ulcer bleeding. NBCA embolization was performed in seven patients with acute upper GI arterial bleeding; they had five gastric ulcers and two duodenal ulcers. NBCA embolization was done in the left gastric artery (n = 3), right gastric artery (n = 2), gastroduodenal artery (n = 1) and pancreaticoduodenal artery (n = 1). Coil was used along with NBCA in a gastric bleeding patient because of difficulty in selecting a feeding artery. NBCA was mixed with Lipiodol at the ratio of 1:1 to 1:2. The blood pressure and heart rate around the time of embolization, the serial hemoglobin and hematocrit levels and the transfusion requirements were reviewed to evaluate hemostasis and rebleeding. Technical success was achieved in all the cases. Two procedure-related complications happened; embolism of the NBCA mixture to the common hepatic artery occurred in a case with embolization of the left gastric artery, and reflux of the NBCA mixture occurred into the adjacent gastric tissue, but these did not cause any clinical problems. Four of seven patients did not present with rebleeding, but two had rebleeding 10 and 16 days, respectively, after embolization and they died of cardiac arrest at 2 months and 37 days, respectively. One other patient died of sepsis and respiratory failure within 24 hours without rebleeding. NBCA embolization with or without other embolic agents could be safe and effective for treating acute gastroduodenal ulcer bleeding.

  10. N-butyl cyanoacrylate embolotherapy for acute gastroduodenal ulcer bleeding

    International Nuclear Information System (INIS)

    Various embolic agents have been used for embolization of acute gastrointestinal (GI) arterial bleeding. N-butyl cyanoacrylate (NBCA) is not easy to handle, but it is a useful embolic agent. In this retrospective study, we describe our experience with NBCA embolization of acute gastroduodenal ulcer bleeding. NBCA embolization was performed in seven patients with acute upper GI arterial bleeding; they had five gastric ulcers and two duodenal ulcers. NBCA embolization was done in the left gastric artery (n = 3), right gastric artery (n = 2), gastroduodenal artery (n = 1) and pancreaticoduodenal artery (n = 1). Coil was used along with NBCA in a gastric bleeding patient because of difficulty in selecting a feeding artery. NBCA was mixed with Lipiodol at the ratio of 1:1 to 1:2. The blood pressure and heart rate around the time of embolization, the serial hemoglobin and hematocrit levels and the transfusion requirements were reviewed to evaluate hemostasis and rebleeding. Technical success was achieved in all the cases. Two procedure-related complications happened; embolism of the NBCA mixture to the common hepatic artery occurred in a case with embolization of the left gastric artery, and reflux of the NBCA mixture occurred into the adjacent gastric tissue, but these did not cause any clinical problems. Four of seven patients did not present with rebleeding, but two had rebleeding 10 and 16 days, respectively, after embolization and they died of cardiac arrest at 2 months and 37 days, respectively. One other patient died of sepsis and respiratory failure within 24 hours without rebleeding. NBCA embolization with or without other embolic agents could be safe and effective for treating acute gastroduodenal ulcer bleeding

  11. Butyl acetate synthesis using immobilized lipase in calcium alginate beads

    International Nuclear Information System (INIS)

    The esterification reaction of acetic acid and n-butanol using immobilized lipase encapsulated in calcium alginate beads (Lipase - CAB) and in chitosan coated calcium alginate beads (Lipase-CCAB) in n-hexane under mild reaction conditions were studied. Effects of temperature and substrate concentration (acetic acid and n-butanol) using Lipase - CAB, Lipase - CCAB and free lipase on the esterification reaction and their thermal stability towards esterification reaction were investigated. Results of temperature studies showed that the butyl acetate conversion increased with increase of temperature and reached the highest yield of about 70% around 50 degree Celsius for both immobilized systems but the yield of product catalyzed by free enzyme decreased as temperature was increased. Thermal stabilities studies showed that the Lipase-CCAB and Lipase-CAB were stable throughout the temperature range of 30-60 degree Celsius. However, free lipase became less stable at temperatures higher than 50 degree Celsius. The substrates, n-butanol and acetic acid exerted different effects on the esterification reaction and the reaction was favoured by higher acetic acid concentration than butanol. Kinetics parameters, Km and Vmax values for both substrates and the specific activities of the three enzyme system were also determined. The beads morphology was examined using SEM. Batch-wise operational stability studies for both immobilized systems demonstrated that the immobilized lipase performed better in the batch wise reactor system than the continuous bioreactor system and that the immobilized lipase remained active for at least 5 cycles of batch wise esterification reactions. (author)

  12. Transcatheter Embolotherapy with N-Butyl Cyanoacrylate for Ectopic Varices

    International Nuclear Information System (INIS)

    PurposeTo address technical feasibility and clinical outcome of transcatheter embolotherapy with N-butyl cyanoacrylate (NBCA) for bleeding ectopic varices.MethodsThe institutional review board approved this retrospective study and waived informed consent. From January 2004 to June 2013, a total of 12 consecutive patients received transcatheter embolotherapy using NBCA for bleeding ectopic varices in our institute. Clinical and radiologic features of the endovascular procedures were comprehensively reviewed.ResultsPreprocedural computed tomography images revealed ectopic varices in the jejunum (n = 7), stoma (n = 2), rectum (n = 2), and duodenum (n = 1). The 12 procedures consisted of solitary embolotherapy (n = 8) and embolotherapy with portal decompression (main portal vein stenting in 3, transjugular intrahepatic portosystemic shunt in 1). With regard to vascular access, percutaneous transhepatic access (n = 7), transsplenic access (n = 4), and transjugular intrahepatic portosystemic shunt tract (n = 1) were used. There was no failure in either the embolotherapy or the vascular accesses (technical success rate, 100 %). Two patients died within 1 month from the procedure from preexisting fatal medical conditions. Only one patient, with a large varix that had been partially embolized by using coils and NBCA, underwent rebleeding 5.5 months after the procedure. The patient was retreated with NBCA and did not undergo any bleeding afterward for a follow-up period of 2.5 months. The remaining nine patients did not experience rebleeding during the follow-up periods (range 1.5–33.2 months).ConclusionTranscatheter embolotherapy using NBCA can be a useful option for bleeding ectopic varices

  13. Safety and chemopreventive effect of Polyphenon E in preventing early and metastatic progression of prostate cancer in TRAMP mice.

    Science.gov (United States)

    Kim, Seung Joon; Amankwah, Ernest; Connors, Shahnjayla; Park, Hyun Y; Rincon, Maria; Cornnell, Heather; Chornokur, Ganna; Hashim, Arig Ibrahim; Choi, Junsung; Tsai, Ya-Yu; Engelman, Robert W; Kumar, Nagi; Park, Jong Y

    2014-04-01

    Prostate cancer treatment is often accompanied by untoward side effects. Therefore, chemoprevention to reduce the risk and inhibit the progression of prostate cancer may be an effective approach to reducing disease burden. We investigated the safety and efficacy of Polyphenon E, a green tea extract, in reducing the progression of prostate cancer in transgenic adenocarcinoma of the mouse prostate (TRAMP) mice. A total of 119 male TRAMP and 119 C57BL/6J mice were treated orally with one of 3 doses of Polyphenon E (200, 500, and 1,000 mg/kg/day) in drinking water ad libitum replicating human achievable doses. Baseline assessments were performed before treatments. Safety and efficacy assessments during treatments were performed when mice were 12, 22, and 32 weeks old. The number and size of tumors in treated TRAMP mice were significantly decreased compared with untreated animals. In untreated 32 weeks old TRAMP mice, prostate carcinoma metastasis to distant sites was observed in 100% of mice (8/8), compared with 13% of mice (2/16) treated with high-dose Polyphenon E during the same period. Furthermore, Polyphenon E treatment significantly inhibited metastasis in TRAMP mice in a dose-dependent manner (P = 0.0003). Long-term (32 weeks) treatment with Polyphenon E was safe and well tolerated with no evidence of toxicity in C57BL/6J mice. Polyphenon E is an effective chemopreventive agent in preventing the progression of prostate cancer to metastasis in TRAMP mice. Polyphenon E showed no toxicity in these mouse models. Our findings provide additional evidence for the safety and chemopreventive effect of Polyphenon E in preventing metastatic progression of prostate cancer.

  14. Chemoprevention of HBV-related hepatocellular carcinoma by the combined product of resveratrol and silymarin in transgenic mice

    Directory of Open Access Journals (Sweden)

    Wen-Chuan Hsieh

    2013-09-01

    Full Text Available ABSTRACTBackground: Patients with chronic hepatitis B virus (HBV infection are at a high risk to develop hepatocellular carcinoma (HCC. Recently, metabolic syndrome has been found to carry a risk for HCC development. Considering the limitation of chemotherapeutic drugs for HCCs, the development of chemopreventive agents for high risk chronic HBV carriers is urgently demanded. In this study, we used combined silymarin and resveratrol extract which have been shown to exhibit biologic effects on activating peroxisome proliferator activated receptors (PPAR and inhibiting mTOR signaling in a transgenic mice model harboring HBV viral oncoproteins.Methods: The transgenic mice model harboring HBx and pre-S2 mutant constructs which develop HCC was adopted. First, we in vitro tested the ideal combination dosages of the silymarin and resveratrol product, and then we fed the natural product to the transgenic mice.The chemopreventive effects on preventing the development of HCC were evaluated.Results: MTT assay showed an enhanced effect of the combined silymarin and resveratrol product on the reduction of cell proliferation in two hepatoma cell lines, Huh-7 and Hep G2. In vitro reporter assay and Western blot analyses revealed that the combined product couldactivate PPAR/PGC-1 signaling and inhibit mTOR expression. In vivo, the combined products could significantly ameliorate fatty liver and reduce HCCs in transgenic miceharboring HBV oncoproteins.Conclusions: The combined silymarin and resveratrol product exhibits a synergistic effect on the reduction of HCC development in transgenic mice model and may represent a potential agent for the prevention of HCC in high risk chronic HBV carriers.Key words: HBV, HCC, Transgenic mice, Chemoprevention

  15. Anti-cancer and potential chemopreventive actions of ginseng by activating Nrf2 (NFE2L2 anti-oxidative stress/anti-inflammatory pathways

    Directory of Open Access Journals (Sweden)

    Wu Qing

    2010-10-01

    Full Text Available Abstract This article reviews recent basic and clinical studies of ginseng, particularly the anti-cancer effects and the potential chemopreventive actions by activating the transcriptional factor, nuclear factor (erythroid-derived 2-like 2 (Nrf2 or NFE2L2-mediated anti-oxidative stress or anti-inflammatory pathways. Nrf2 is a novel target for cancer prevention as it regulates the antioxidant responsive element (ARE, a critical regulatory element in the promoter region of genes encoding cellular phase II detoxifying and anti-oxidative stress enzymes. The studies on the chemopreventive effects of ginseng or its components/products showed that Nrf2 could also be a target for ginseng's actions. A number of papers also demonstrated the anti-inflammatory effects of ginseng. Targeting Nrf2 pathway is a novel approach to the investigation of ginseng's cancer chemopreventive actions, including some oxidative stress and inflammatory conditions responsible for the initiation, promotion and progression of carcinogenesis.

  16. Human gallbladder morphology after gallstone dissolution with methyl tert-butyl ether.

    Science.gov (United States)

    vanSonnenberg, E; Zakko, S; Hofmann, A F; D'Agostino, H B; Jinich, H; Hoyt, D B; Miyai, K; Ramsby, G; Moossa, A R

    1991-06-01

    The effects of methyl tert-butyl ether exposure on the human gallbladder in five patients who were treated for gallstones by contact dissolution is described. Two patients underwent cholecystectomy within 1 week of methyl tert-butyl ether treatment, one patient 2 weeks after, another 10 weeks after, and one 12 weeks after. Indications for cholecystectomy were bilirubinate stones (resistant to methyl tert-butyl ether), catheter dislodgement, bile leakage, and gallstone recurrence (2 patients). Gallstones were dissolved completely in three patients, there was approximately 50% stone reduction in one patient, and no dissolution occurred in the fifth patient. Each gallbladder was examined grossly and histologically. Electron microscopic evaluation was performed in one cases. Typical inflammatory findings of chronic cholecystitis were observed in each gallbladder and were most conspicuous in the submucosa; the mucosal and serosal surfaces were intact. Mild acute inflammatory changes were noted in the submucosa in the two patients with the shortest interval between methyl tert-butyl ether administration and cholecystectomy. There were no ulcerations in the mucosa and no unusual wall thickening or fibrosis in any patient. These observations support the safety of methyl tert-butyl ether perfusion in the human gallbladder; the mild acute changes may be a transient and reversible phenomenon.

  17. Hydrogen bonded rings, chains and lassos: the case of t-butyl alcohol clusters

    Science.gov (United States)

    Zimmermann, D.; Häber, Th.; Schaal, H.; Suhm, M. A.

    Infrared OH stretching spectra of hydrogen bonded 2-methyl-propan-2-ol (t-butyl alcohol) clusters are investigated by ragout-jet FTIR spectroscopy. A spectral difference technique is used to discriminate approximately between neighbouring cluster sizes. Dimers, trimers and cyclic tetramers can be detected along with larger clusters, which exhibit a surprisingly structured vibrational fingerprint. Comparison is made to the spectra of related alcohols and to energetic and harmonic vibrational predictions from electronic structure calculations. The experimentally observed 32% increase in OH stretching wavenumber shift from methanol dimer to t-butyl alcohol dimer is reproduced at the HF/3-21G level (+ 33%). It is also qualitatively correct at the MP2/6-31+ G* level (+ 15%), whereas it has the wrong sign at the B3LYP/6-31+ G* level (-5%) and is negligible at the HF/6-31+ G* level, disregarding anharmonic effects. The cyclic tetramer of t-butyl alcohol is found to be particularly stable due to a favourable up-down alternation of the bulky t-butyl groups. Beyond the t-butyl alcohol tetramer, lasso structures are found to be energetically competitive with simple ring structures. A many-body decomposition shows that this is due to a reduced cooperativity in the sterically hindered pentamer ring. The resulting thermodynamic and kinetic relevance of cyclic tetramers is discussed.

  18. Alkylation of Catechol with tert-Butyl Alcohol Catalyzed by Mesoporous Acidic Montmorillonite Heterostructure Catalysts

    Institute of Scientific and Technical Information of China (English)

    周春晖; 葛忠华; 李小年; 童东绅; 李庆伟; 郭红强

    2004-01-01

    The liquid phase alkylation of catechol with tert-butyl alcohol to produce 4-tert-butyl catechol (4-TBC) was carried out over MCM-41, HZSM-5, H-exchanged montmorillonite and novel acidic porous montmorillonite heterostructures (PMHs). Upon all catalysts tested, 4-TBC is the main product and 3-tert-butyl catechol (3-TBC) and 3,5-di-tert-butyl catechol are the side products. The synthetic PMHs showed higher conversion of catechol and better selectivity to 4-TBC compared to other solid acid catalysts tested. Over the PMHs derived from H-exchanged montmorillonite through template extraction processes, the suitable reaction temperature is ca 410 K, the ratio of catechol to tert-butyl alcohol is 1:2. Increasing the amount of catalyst (lower weight hourly space velocity) can improve the conversion of catechol and influence the selectivity slightly. The reasonable reaction time is ca 8 h.The type and strength of acidity of H-montmorillonite and PMH were determined by pyridine adsorption FT-IR and ammonia temperature-programmed desorption techniques. The medium and strong acid sites are conducive to producing 4-TBC and the weak acid sites to facilitating the 3-TBC formation. The differences between the PMHs from calcination and those fi'om extraction are attributed to proton migration and acidity change in the gallery surface.

  19. The electrospinning of the copolymer of styrene and butyl acrylate for its application as oil absorbent.

    Science.gov (United States)

    Xu, Naiku; Cao, Jipeng; Lu, Yuyao

    2016-01-01

    Electrospun polystyrene materials have been employed as oil absorbents, but they have visible drawbacks such as poor strength at low temperature and unreliable integrity because of brittleness and insufficient cohesive force among fibers. Butyl acrylate can polymerize into flexible chains, and its polymer can be used as elastomer and adhesive material. Thereby it is possible to obtain the material that has better performance in comparison with electrospun polystyrene material through the electrospinning of the copolymer of styrene and butyl acrylate. In this work, a polymer was synthesized through suspension polymerization by using styrene and butyl acrylate as comonomers. The synthesis of the copolymer of styrene and butyl acrylate was verified through dissolution and hydrolysis experimental data; as well through nuclear magnetic resonance spectrometry. The viscous flow activation energy of the solution consisting of copolymer and N, N-dimethylformamide was determined via viscosity method and then adopted to establish the entanglement characteristics of butyl acrylate's chain segments. Finally, in order to electrospin the copolymer solution into fibrous membrane, the effects of monomer feed ratio and spinning parameters were investigated. The prepared fibrous membrane was found to have a potential use as oil absorbent. PMID:27610302

  20. Cancer chemoprevention: Evidence of a nonlinear dose response for the protective effects of resveratrol in humans and mice.

    Science.gov (United States)

    Cai, Hong; Scott, Edwina; Kholghi, Abeer; Andreadi, Catherine; Rufini, Alessandro; Karmokar, Ankur; Britton, Robert G; Horner-Glister, Emma; Greaves, Peter; Jawad, Dhafer; James, Mark; Howells, Lynne; Ognibene, Ted; Malfatti, Michael; Goldring, Christopher; Kitteringham, Neil; Walsh, Joanne; Viskaduraki, Maria; West, Kevin; Miller, Andrew; Hemingway, David; Steward, William P; Gescher, Andreas J; Brown, Karen

    2015-07-29

    Resveratrol is widely promoted as a potential cancer chemopreventive agent, but a lack of information on the optimal dose prohibits rationally designed trials to assess efficacy. To challenge the assumption that "more is better," we compared the pharmacokinetics and activity of a dietary dose with an intake 200 times higher. The dose-response relationship for concentrations generated and the metabolite profile of [(14)C]-resveratrol in colorectal tissue of cancer patients helped us to define clinically achievable levels. In Apc(Min) mice (a model of colorectal carcinogenesis) that received a high-fat diet, the low resveratrol dose suppressed intestinal adenoma development more potently than did the higher dose. Efficacy correlated with activation of adenosine monophosphate-activated protein kinase (AMPK) and increased expression of the senescence marker p21. Nonlinear dose responses were observed for AMPK and mechanistic target of rapamycin (mTOR) signaling in mouse adenoma cells, culminating in autophagy and senescence. In human colorectal tissues exposed to low dietary concentrations of resveratrol ex vivo, we measured enhanced AMPK phosphorylation and autophagy. The expression of the cytoprotective NAD(P)H dehydrogenase, quinone 1 (NQO1) enzyme was also increased in tissues from cancer patients participating in our [(14)C]-resveratrol trial. These findings warrant a revision of developmental strategies for diet-derived agents designed to achieve cancer chemoprevention. PMID:26223300

  1. Synergistic chemopreventive effects of curcumin and berberine on human breast cancer cells through induction of apoptosis and autophagic cell death.

    Science.gov (United States)

    Wang, Kai; Zhang, Chao; Bao, Jiaolin; Jia, Xuejing; Liang, Yeer; Wang, Xiaotong; Chen, Meiwan; Su, Huanxing; Li, Peng; Wan, Jian-Bo; He, Chengwei

    2016-01-01

    Curcumin (CUR) and berberine (BBR) are renowned natural compounds that exhibit potent anticancer activities through distinct molecular mechanisms. However, the anticancer capacity of either CUR or BBR is limited. This prompted us to investigate the chemopreventive potential of co-treatment of CUR and BBR against breast cancers. The results showed that CUR and BBR in combination synergistically inhibited the growth of both MCF-7 and MDA-MB-231 breast cancer cells than the compounds used alone. Further study confirmed that synergistic anti-breast cancer activities of co-treatment of these two compounds was through inducing more apoptosis and autophagic cell death (ACD). The co-treatment-induced apoptosis was caspase-dependent and through activating ERK pathways. Our data also demonstrated that co-treatment of CUR and BBR strongly up-regulated phosphorylation of JNK and Beclin1, and decreased phosphorylated Bcl-2. Inhibition of JNK by SP600125 markedly decreased LC3-II and Beclin1, restored phosphorylated Bcl-2, and reduced the cytotoxicity induced by the two compounds in combination. These results strongly suggested that JNK/Bcl-2/Beclin1 pathway played a key role in the induction of ACD in breast cancer cells by co-treatment of CUR and BBR. This study provides an insight into the potential application of curcumin and berberine in combination for the chemoprevention and treatment of breast cancers. PMID:27263652

  2. A theoretical study on predicted protein targets of apple polyphenols and possible mechanisms of chemoprevention in colorectal cancer.

    Science.gov (United States)

    Scafuri, Bernardina; Marabotti, Anna; Carbone, Virginia; Minasi, Paola; Dotolo, Serena; Facchiano, Angelo

    2016-01-01

    We investigated the potential role of apple phenolic compounds in human pathologies by integrating chemical characterization of phenolic compounds in three apple varieties, computational approaches to identify potential protein targets of the compounds, bioinformatics analyses on data from public archive of gene expression data, and functional analyses to hypothesize the effects of the selected compounds in molecular pathways. Starting by the analytic characterization of phenolic compounds in three apple varieties, i.e. Annurca, Red Delicious, and Golden Delicious, we used computational approaches to verify by reverse docking the potential protein targets of the identified compounds. Direct docking validation of the potential protein-ligand interactions has generated a short list of human proteins potentially bound by the apple phenolic compounds. By considering the known chemo-preventive role of apple antioxidants' extracts against some human pathologies, we performed a functional analysis by comparison with experimental gene expression data and interaction networks, obtained from public repositories. The results suggest the hypothesis that chemo-preventive effects of apple extracts in human pathologies, in particular for colorectal cancer, may be the interference with the activity of nucleotide metabolism and methylation enzymes, similarly to some classes of anticancer drugs. PMID:27587238

  3. A theoretical study on predicted protein targets of apple polyphenols and possible mechanisms of chemoprevention in colorectal cancer

    Science.gov (United States)

    Scafuri, Bernardina; Marabotti, Anna; Carbone, Virginia; Minasi, Paola; Dotolo, Serena; Facchiano, Angelo

    2016-01-01

    We investigated the potential role of apple phenolic compounds in human pathologies by integrating chemical characterization of phenolic compounds in three apple varieties, computational approaches to identify potential protein targets of the compounds, bioinformatics analyses on data from public archive of gene expression data, and functional analyses to hypothesize the effects of the selected compounds in molecular pathways. Starting by the analytic characterization of phenolic compounds in three apple varieties, i.e. Annurca, Red Delicious, and Golden Delicious, we used computational approaches to verify by reverse docking the potential protein targets of the identified compounds. Direct docking validation of the potential protein-ligand interactions has generated a short list of human proteins potentially bound by the apple phenolic compounds. By considering the known chemo-preventive role of apple antioxidants’ extracts against some human pathologies, we performed a functional analysis by comparison with experimental gene expression data and interaction networks, obtained from public repositories. The results suggest the hypothesis that chemo-preventive effects of apple extracts in human pathologies, in particular for colorectal cancer, may be the interference with the activity of nucleotide metabolism and methylation enzymes, similarly to some classes of anticancer drugs. PMID:27587238

  4. Impact of Short-term 1,25-Dihydroxyvitamin D3 on the Chemopreventive Efficacy of Erlotinib against Oral Cancer.

    Science.gov (United States)

    Bothwell, Katelyn D; Shaurova, Tatiana; Merzianu, Mihai; Suresh, Amritha; Kuriakose, Moni A; Johnson, Candace S; Hershberger, Pamela A; Seshadri, Mukund

    2015-09-01

    Activation of the epidermal growth factor receptor (EGFR) pathway is an early event in head and neck carcinogenesis. As a result, targeting EGFR for chemoprevention of head and neck squamous cell carcinomas (HNSCC) has received considerable attention. In the present study, we examined the impact of 1,25(OH)2D3, the active metabolite of the nutritional supplement vitamin D on the chemopreventive efficacy of the EGFR inhibitor, erlotinib, against HNSCC. Experimental studies were conducted in patient-derived xenografts (PDX) and the 4-nitroquinoline-1-oxide (4NQO) carcinogen-induced model of HNSCC. Short-term treatment (4 weeks) of PDX-bearing mice with 1,25(OH)2D3 and erlotinib resulted in significant inhibition of tumor growth. Noninvasive MRI enabled longitudinal monitoring of disease progression in the 4NQO model with 100% of control animals showing evidence of neoplastic lesions by 24 weeks. Among the experimental groups, animals treated with the combination regimen showed the greatest reduction in tumor incidence and volume (P phospho-EGFR and phospho-Akt with the combination regimen. These results highlight the potential of 1,25(OH)2D3 to augment the efficacy of erlotinib against HNSCC. Further optimization of schedule and sequence of this combination regimen along with investigation into the activity of less calcemic analogues or dietary vitamin D is essential to fully realize the potential of this approach.

  5. Resveratrol mobilizes endogenous copper in human peripheral lymphocytes leading to oxidative DNA breakage: a putative mechanism for chemoprevention of cancer.

    Science.gov (United States)

    Hadi, S M; Ullah, M F; Azmi, A S; Ahmad, A; Shamim, U; Zubair, H; Khan, H Y

    2010-06-01

    Plant polyphenols are important components of human diet, and a number of them are considered to possess chemopreventive and therapeutic properties against cancer. They are recognized as naturally occurring anti-oxidants but also act as pro-oxidants catalyzing DNA degradation in the presence of metal ions such as copper. The plant polyphenol resveratrol confers resistance to plants against fungal agents and has been implicated as a cancer chemopreventive agent. Of particular interest is the observation that resveratrol has been found to induce apoptosis in cancer cell lines but not in normal cells. Over the last few years, we have shown that resveratrol is capable of causing DNA breakage in cells such as human lymphocytes. Such cellular DNA breakage is inhibited by copper specific chelators but not by iron and zinc chelating agents. Similar results are obtained by using permeabilized cells or with isolated nuclei, indicating that chromatin-bound copper is mobilized in this reaction. It is well established that tissue, cellular and serum copper levels are considerably elevated in various malignancies. Therefore, cancer cells may be more subject to electron transfer between copper ions and resveratrol to generate reactive oxygen species responsible for DNA cleavage. The results are in support of our hypothesis that anti-cancer mechanism of plant polyphenols involves mobilization of endogenous copper and the consequent pro-oxidant action. Such a mechanism better explains the anti-cancer effects of resveratrol, as it accounts for the preferential cytotoxicity towards cancer cells.

  6. In Vivo Immunomodulation and Lipid Peroxidation Activities Contributed to Chemoprevention Effects of Fermented Mung Bean against Breast Cancer

    Directory of Open Access Journals (Sweden)

    Swee Keong Yeap

    2013-01-01

    Full Text Available Mung bean has been reported to have antioxidant, cytotoxic, and immunomodulatory effects in vitro. Fermented products are reported to have enhanced immunomodulation and cancer chemopreventive effects. In this study, fermented mung bean treatments in vivo were studied by monitoring tumor development, spleen immunity, serum cytokine (interleukin 2 and interferon gamma levels, and spleen/tumor antioxidant levels after injection with low and high risk 4T1 breast cancer cells. Pretreatment with fermented mung bean was associated with delayed tumor formation in low risk mice. Furthermore, this treatment was connected with higher serum anticancer cytokine levels, spleen T cell populations, splenocyte cytotoxicity, and spleen/tumor antioxidant levels. Histopathological evaluation of fermented mung bean treated tumor revealed lower event of mitotic division. On the other hand, antioxidant and nitric oxide levels that were significantly increased in the untreated mice were inhibited in the fermented mung bean treated groups. These results suggested that fermented mung bean has potential cancer chemoprevention effects through the stimulation of immunity, lipid peroxidation, and anti-inflammation.

  7. In vivo phase II-enzymes inducers, as potential chemopreventive agents, based on the chalcone and furoxan skeletons.

    Science.gov (United States)

    Cabrera, Mauricio; Mastandrea, Ignacio; Otero, Gabriel; Cerecetto, Hugo; González, Mercedes

    2016-04-15

    Cancer chemoprevention involves prevention/delay/reverse of the carcinogenic process through administration of cancer chemopreventive agents (CCA). Compounds which are able to induce detoxification-enzymes, especially monofunctional phase II enzymes, have become in excellent approaches for new CCA. Herein, we report the synthesis of new furoxanyl chalcone-like hybrid compounds as CCA. In vitro studies showed that phenylfuroxanyl derivatives 6 and 9 displayed the best activities being 9 the greatest monofunctional-inducer. Additionally, compounds were non-mutagenic against TA98 Salmonella typhimurium strain (Ames test) and could be used in the prevention of the progression of pre-malignant lesions for their cytotoxic activity against tumoral cells. In vivo proof of concept showed increment on phase II-enzymes activities in liver, colon and mammary gland having derivative 9 the best induction profiles. We probed Nrf2 nuclear translocation is operative for both compounds allowing to exert protective effects via expression of downstream phase-II enzymes. PMID:26970663

  8. Chemopreventive Action of Bacopa monnieri (Brahmi Hydromethanolic Extract on DMBA- Induced Skin Carcinogenesis in Swiss Albino Mice

    Directory of Open Access Journals (Sweden)

    Shiki Vishnoi

    2013-07-01

    Full Text Available Bacopa monnieri (L. Wettst. (Brahmi (Family: Scrophulariaceae, has been used in the Ayurvedic system of medicine for centuries. In the present study, Cancer Chemopreventive property of B. monnieri was evaluated on 7,12-dimethyl benz(aanthracene (DMBA induced skin papillomagenesis in male Swiss albino mice (6-7 weeks old. A single topical application of 7,12-dimethyl benz(aanthracene (104 µg/100 µl of acetone, followed 2 weeks later by repeated application of croton oil (1% in 100 µl acetone two times in a week and continued till the end of the experiment (After 16 weeks exhibited 100% tumor incidence. In contrast, mice topically treated on the shaven dorsal side with the Bacopa monnieri Hydromethanolic extract (BMH (dose 120 mg/kg body wt. & (dose 240mg/kg body wt. at one hour before each application of 1% Croton oil two times in a week., a significant reduction in the values of tumor incidence, average number of tumors per tumor bearing mouse and papillomas per papilloma bearing mouse were observed. Thus results showed that BMH possesses a Chemopreventive activity and provide evidences for its traditional usage in clinical studies.

  9. Molecular recognition study of ethosuximide by the supramolecular probe, p-t-butyl calix(8)arene

    Energy Technology Data Exchange (ETDEWEB)

    Meenakshi, C., E-mail: geethu.laxi@gmail.com [Department of Chemistry, Shri Meenakshi Government College for Women (Autonomous), Madurai 625002 (India); Sangeetha, P.; Ramakrishnan, V. [Department of Laser Studies, School of Physics, Madurai Kamaraj University, Madurai 625021 (India)

    2013-06-15

    The supramolecule, p-t-Butyl calix(8)arene, forms inclusion complex with the antiseizure drug molecule, ethosuximide. This feature is explained on the basis of optical absorption spectroscopy. Here p-t-Butyl calix(8)arene is the host molecule and ethosuximide is the guest molecule. The stoichiometry of the host–guest complex and the binding constant has been determined using Benesi–Hildebrand plot. Based on the result obtained the structure of the inclusion complex has been proposed. -- Highlights: ► Third generation supramolecule, t-butyl calix (8) arene, is used as a host molecule. ► Anti seizure drug molecule is used as a guest molecule. ► Inclusion complex is formed between the host and guest molecule.

  10. Molecular recognition study of ethosuximide by the supramolecular probe, p-t-butyl calix(8)arene

    International Nuclear Information System (INIS)

    The supramolecule, p-t-Butyl calix(8)arene, forms inclusion complex with the antiseizure drug molecule, ethosuximide. This feature is explained on the basis of optical absorption spectroscopy. Here p-t-Butyl calix(8)arene is the host molecule and ethosuximide is the guest molecule. The stoichiometry of the host–guest complex and the binding constant has been determined using Benesi–Hildebrand plot. Based on the result obtained the structure of the inclusion complex has been proposed. -- Highlights: ► Third generation supramolecule, t-butyl calix (8) arene, is used as a host molecule. ► Anti seizure drug molecule is used as a guest molecule. ► Inclusion complex is formed between the host and guest molecule

  11. Percutaneous N-Butyl cyanoacrylate embolization of a pancreatic pseudoaneurysm after failed attempts of transcatheter embolization

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ri Hyeon; Yoo, Roh Eul; Kim, Hyo Cheol [Seoul National University Medical Research Center, and Clinical Research Institute, Seoul National University Hospital, Seoul (Korea, Republic of)

    2014-10-15

    One common complication after major pancreatic surgery is bleeding. Herein we describe a case of pancreatic pseudoaneurysm which developed after pylorous preserving pancreaticoduodenectomy for common bile duct cancer. Three attempts of transcatheter embolization failed since feeders to the pseudoaneurysm had unfavorable anatomy. Direct percutaneous N-butyl cyanoacrylate injection was performed under fluoroscopy-guidance and the pseudoaneurysm was successfully treated. Percutaneous fluoroscopy-guided direct N-butyl cyanoacrylate injection may be a useful alternative when selective transcatheter embolization fails or is technically challenging.

  12. Estimation of the fraction of biologically active methyl tert-butyl ether degraders in a heterogeneous biomass sample

    DEFF Research Database (Denmark)

    Waul, Christopher Kevin; Arvin, Erik; Schmidt, Jens Ejbye

    2008-01-01

    The fraction of biologically active methyl tert-butyl ether degraders in reactors is just as important for prediction of removal rates as knowledge of the kinetic parameters. The fraction of biologically active methyl tert-butyl ether degraders in a heterogeneous biomass sample, taken from a packed...

  13. An alternative approach to synthesis of 2--butyl-5-nitrobenzofuran derivative: A key starting material for dronedarone hydrochloride

    Indian Academy of Sciences (India)

    P Raja Gopal; E R R Chandrashekar; M Saravanan; B Vijaya Bhaskar; P Veera Somaiah

    2012-09-01

    A practical synthesis of (2-butyl-5-nitrobenzofuran-3-yl)(4-hydroxyphenyl)methanone, a key intermediate in the preparation of anti arrhythmic drug, is described. The commercially available 4-nitrophenol (3) is converted in five steps to 2-butyl-5-nitrobenzofuran (9) which upon Friedel-Crafts acylation with 4-methoxybenzoyl chloride followed by deprotection of methyl group gives (2).

  14. From chemoprevention and organ preservation programmes to postoperative management : major achievements and strategies of the EORTC Head and Neck Cancer Group

    NARCIS (Netherlands)

    Bernier, J; Vermorken, JB; Debruyne, C; Andry, G; Licitra, L; Grandi, C; Langendijk, H; De Mulder, PHM; Lefebvre, JL

    2002-01-01

    The purpose of this article is to review the most significant results of the clinical studies conducted in the past two decades by the EORTC Head and Neck Cancer Group (HNCG). As for phase III trials. the HNCG investigated. besides the efficacy of chemopreventive drugs, the impact of cytostatic agen

  15. Potential Impact of Seasonal Malaria Chemoprevention on the Acquisition of Antibodies Against Glutamate-Rich Protein and Apical Membrane Antigen 1 in Children Living in Southern Senegal

    DEFF Research Database (Denmark)

    Ndiaye, Magatte; Sylla, Khadime; Sow, Doudou;

    2015-01-01

    Seasonal malaria chemoprevention (SMC) is defined as the intermittent administration of full treatment courses of an antimalarial drug to children during the peak of malaria transmission season with the aim of preventing malaria-associated mortality and morbidity. SMC using sulfadoxine-pyrimetham...

  16. 40 CFR 721.10193 - 1-Butanaminium, N-(3-aminopropyl)-N-butyl-N-(2-carboxyethyl)-, N-coco acyl derivs., inner salts.

    Science.gov (United States)

    2010-07-01

    ...-butyl-N-(2-carboxyethyl)-, N-coco acyl derivs., inner salts. 721.10193 Section 721.10193 Protection of...-aminopropyl)-N-butyl-N-(2-carboxyethyl)-, N-coco acyl derivs., inner salts. (a) Chemical substance and...-aminopropyl)-N-butyl-N-(2-carboxyethyl)-, N-coco acyl derivs., inner salts (PMN P-06-263, Chemical B; CAS...

  17. Identification of mercury methylation product by tert-butyl compounds in aqueous solution under light irradiation

    International Nuclear Information System (INIS)

    Highlights: • Tert-butyl alcohol and hydroperoxide are methyl donors of Hg photo-methylation. • The hydroxyl radical can initially promote the photo-methylation of inorganic Hg. • Excessive ·OH can lead to the degradation of MeHg. • MeHg can be produced via intramolecular methyl transfer. - Abstract: The methylation of mercury (Hg) is of great concern as methylmercury (MeHg), the most toxic species, is produced. This study examined the possibilities of tert-butyl compounds (tert-butyl alcohol (TBA) and tert-butyl hydroperoxide (TBH)) and other alcohols serving as methyl donors for Hg photo-methylation under light irradiation. The yield of MeHg varied among the methyl donors, and it was also significantly influenced by salinity and pH. MeHg could be generated in the presence of TBH under visible light irradiation. The hydroxyl radical (·OH) was found to promote MeHg production at low levels, but degrade MeHg in excess. The photo-production of MeHg was tentatively proposed via the complexation of Hg and methyl donors, the formation of an intermediate (·O(Hg)C(CH3)3), and the intramolecular methyl transfer from methyl donors to Hg. This study implicates photoreactions between Hg and organic pollutants in understanding the fate and transformation of Hg in the aquatic environment

  18. 2-Butyl-4-chloroimidazole based substituted piperazine-thiosemicarbazone hybrids as potent inhibitors of Mycobacterium tuberculosis.

    Science.gov (United States)

    Jallapally, Anvesh; Addla, Dinesh; Yogeeswari, Perumal; Sriram, Dharmarajan; Kantevari, Srinivas

    2014-12-01

    Here a series of 2-butyl-4-chloroimidazole based substituted piperazine-thiosemicarbazone hybrids were designed by combining three different pharmacophoric fragments in single molecular architecture. 2-Butyl-4-chloro-1-(3-(4-substituted)piperazin-1-yl)propyl)-1H-imidazole-5-carbaldehydes (4a-p) prepared by reacting carboxaldehyde 2 with N-alkyl piperazines 3a-p which were condensed with thiosemicarbazine to give desired compounds 5a-p in very good yields. Among all sixteen compounds screened for in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Rv (MTB), two compounds (E)-2-((2-butyl-4-chloro-1-(3-(4-(o-tolyl) piperazin-1-yl)propyl)-1H-imidazol-5-yl)methylene)hydrazinecarbothioamide 5e and (E)-2-((2-butyl-4-chloro-1-(3-(4-(2-methoxyphenyl)piperazin-1-yl)propyl)-1H-imidazol-5-yl)methylene) hydrazine carbothioamide 5f were found to be the most potent antitubercular agents (MIC: 3.13 μg/mL) with low toxicity profile. PMID:25451998

  19. A direct and sustainable synthesis of tertiary butyl esters enabled by flow microreactors.

    Science.gov (United States)

    Degennaro, Leonardo; Maggiulli, Daniela; Carlucci, Claudia; Fanelli, Flavio; Romanazzi, Giuseppe; Luisi, Renzo

    2016-08-01

    Tertiary butyl esters find large applications in synthetic organic chemistry. A straightforward method for the direct introduction of the tert-butoxycarbonyl group into a variety of organic compounds has been developed using flow microreactor systems. The resultant flow process was more efficient, versatile and sustainable compared to the batch. PMID:27383138

  20. Blootstelling aan xenobiotica in voeding. Voorbeeldstoffen: Butyl benzyl phtalate (BBP), Benzo(a)pyreen en Fluorantheen

    NARCIS (Netherlands)

    Heisterkamp SH; Veen MP van; LBO

    1997-01-01

    Een tweetal 'ad-hoc' blootstellingsbeoordelingen van chemische stoffen in voedsel werden uitgevoerd om de algemene richtlijnen uit een eerder rapport te testen. De eerste beoordeling omvatte butyl benzyl phtalate (BBP), de tweede twee PAK's te weten benzo(a)pyreen en fluorantheen.

  1. Optimization of coproduction of ethyl acetate and n-butyl acetate by reactive distillation☆

    Institute of Scientific and Technical Information of China (English)

    Hui Tian; Suying Zhao; Huidong Zheng; Zhixian Huang

    2015-01-01

    Based on a previous investigation, a simulation model was used for optimization of coproduction of ethyl acetate and n-butyl acetate by reactive distil ation. An experimental setup was established to verify the simulated results. The effects of various operating variables, such as ethanol feed location, acetic acid feed location, feed stage of reaction mixture of acetic acid and n-butanol, reflux ratio of ethyl acetate reactive distillation column, and distil-late to feed ratio of n-butyl acetate column, on the ethanol/n-butanol conversions, ethyl acetate/n-butyl acetate purity, and energy consumption were investigated. The optimal results in the simulation study are as follows:ethanol feed location, 15th stage;acetic acid feed location, eighth stage;feed location of reaction mixture of acetic acid and n-butanol, eighth stage;reflux ratio of ethyl acetate reactive distillation column, 2.0;and distillate to feed ratio of n-butyl acetate, 0.6.

  2. Iodine catalyzed and tertiary butyl ammonium bromide promoted p reparation of b enzoxazaphosphininyl phenylboronates

    Directory of Open Access Journals (Sweden)

    K. R. Kishore K. Reddy,

    2009-05-01

    Full Text Available Benzoxazaphosphininyl Phenylboronates were prepared by O-Phosphorylation of potassium salt ofphenylboronic acid with cyclic phosphoromonochloridates in the presence of stoichiometric amount of Iodineand catalytic amount of tertiary butyl ammonium bromide at 50-60 °C in dry toluene.

  3. Selective enzymatic hydrolysis of C-terminal tert-butyl esters of peptides

    OpenAIRE

    Eggen, I.F.; Boeriu, C.G.

    2007-01-01

    The present invention relates to a process for the selective enzymatic hydrolysis of C-terminal esters of peptide substrates in the synthesis of peptides, comprising hydrolysing C-terminal tert-butyl esters using the protease subtilisin. This process is useful in the production of protected or unprotected peptides.

  4. Selective enzymatic hydrolysis of C-terminal tert-butyl esters of peptides

    NARCIS (Netherlands)

    Eggen, I.F.; Boeriu, C.G.

    2007-01-01

    The present invention relates to a process for the selective enzymatic hydrolysis of C-terminal esters of peptide substrates in the synthesis of peptides, comprising hydrolysing C-terminal tert-butyl esters using the protease subtilisin. This process is useful in the production of protected or unpro

  5. Automatic mechanism generation for pyrolysis of di-tert-butyl sulfide.

    Science.gov (United States)

    Class, Caleb A; Liu, Mengjie; Vandeputte, Aäron G; Green, William H

    2016-08-01

    The automated Reaction Mechanism Generator (RMG), using rate parameters derived from ab initio CCSD(T) calculations, is used to build reaction networks for the thermal decomposition of di-tert-butyl sulfide. Simulation results were compared with data from pyrolysis experiments with and without the addition of a cyclohexene inhibitor. Purely free-radical chemistry did not properly explain the reactivity of di-tert-butyl sulfide, as the previous experimental work showed that the sulfide decomposed via first-order kinetics in the presence and absence of the radical inhibitor. The concerted unimolecular decomposition of di-tert-butyl sulfide to form isobutene and tert-butyl thiol was found to be a key reaction in both cases, as it explained the first-order sulfide decomposition. The computer-generated kinetic model predictions quantitatively match most of the experimental data, but the model is apparently missing pathways for radical-induced decomposition of thiols to form elemental sulfur. Cyclohexene has a significant effect on the composition of the radical pool, and this led to dramatic changes in the resulting product distribution. PMID:27431650

  6. A new efficient synthesis of isothiocyanates from amines using di-tert-butyl dicarbonate

    DEFF Research Database (Denmark)

    Munch, Henrik; Hansen, Jon S.; Pittelkow, Michael;

    2008-01-01

    Alkyl and aryl amines are converted smoothly to the corresponding isothiocyanates via the dithiocarbamates in good to excellent yields using di-tert-butyl dicarbonate (Boc(2)O) and 1-3 mol% of DMAP or DABCO as catalyst. As most of the byproducts are volatile, the work-up involves simple evaporation...

  7. (R-N-{2-tert-Butyl-2-[(R-tert-butylsulfonamido]ethylidene}-tert-butanesulfonamide

    Directory of Open Access Journals (Sweden)

    Cong-Bin Fan

    2008-10-01

    Full Text Available The title compound, C14H30N2O2S2, is the product of the monoaddition reaction of tert-butyl magnesium chloride with bis-[(R-N-tert-butanesulfinyl]ethanediimine. There are two almost identical molecules in the asymmetric unit, the molecular conformation of which is stabilized by an intramolecular N—H...N hydrogen bond.

  8. Energetic Materials Center Report--Small-Scale Safety and Thermal Testing Evaluation of Butyl Nitrate

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Peter C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Energetic Materials Center; Reynolds, John G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Energetic Materials Center

    2013-04-26

    Butyl Nitrate (BN) was examined by Small-Scale Safety and Thermal (SSST) Testing techniques to determine its sensitivity to impact, friction, spark and thermal exposure simulating handling and storage conditions. Under the conditions tested, the BN exhibits thermal sensitivity above 150 °C, and does not exhibit sensitive to impact, friction or spark.

  9. IRIS Toxicological Review of Tert-Butyl Alcohol (Tert-Butanol) (Interagency Science Consultation Draft)

    Science.gov (United States)

    On April 29, 2016, the Toxicological Review of tert-Butyl Alcohol (tert-Butanol) (Public Comment Draft) was released for public comment. The draft Toxicological Review and charge were reviewed internally by EPA and by other federal agencies and the Executive Office ...

  10. IRIS Toxicological Review of Tert-Butyl Alcohol (Tert-Butanol) (Public Comment Draft)

    Science.gov (United States)

    EPA is developing an Integrated Risk Information System (IRIS) assessment of tert-butyl Alcohol (tert-butanol) and has released the public comment draft assessment for public comment and external peer review. When final, the assessment will appear on the IRIS databa...

  11. Aerobic mineralization of MTBE and tert-butyl alcohol by stream-bed sediment microorganisms

    Science.gov (United States)

    Bradley, P.M.; Landmeyer, J.E.; Chapelle, F.H.

    1999-01-01

    Microorganisms indigenous to the stream-bed sediments at two gasoline- contaminated groundwater sites demonstrated significant mineralization of the fuel oxygenates, methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA). Up to 73% of [U-14C]-MTBE and 84% of [U-14C]-TBA were degraded to 14CO2 under mixed aerobic/anaerobic conditions. No significant mineralization was observed under strictly anaerobic conditions. The results indicate that, under the mixed aerobic/anaerobic conditions characteristic of stream-bed sediments, microbial processes may provide a significant environmental sink for MTBE and TBA delivered to surface water bodies by contaminated groundwater or by other sources.Microorganisms indigenous to the stream-bed sediments at two gasoline-contaminated groundwater sites demonstrated significant mineralization of the fuel oxygenates, methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA). Up to 73% of [U-14C]-MTBE and 84% of [U-14C]-TBA were degraded to 14CO2 under mixed aerobic/anaerobic conditions. No significant mineralization was observed under strictly anaerobic conditions. The results indicate that, under the mixed aerobic/anaerobic conditions characteristic of stream-bed sediments, microbial processes may provide a significant environmental sink for MTBE and TBA delivered to surface water bodies by contaminated groundwater or by other sources.

  12. MONITORED NATURAL ATTENUATION OF TERTIARY BUTYL ALCOHOL (TBA) IN GROUND WATER AT GASOLINE SPILL SITES

    Science.gov (United States)

    The state agencies that implement the Underground Storage Tank program rely heavily on Monitored Natural Attenuation (MNA) to clean up contaminants such as benzene and methyl tertiary butyl ether (MTBE) at gasoline spill sites. This is possible because the contaminants are biolo...

  13. A direct and sustainable synthesis of tertiary butyl esters enabled by flow microreactors.

    Science.gov (United States)

    Degennaro, Leonardo; Maggiulli, Daniela; Carlucci, Claudia; Fanelli, Flavio; Romanazzi, Giuseppe; Luisi, Renzo

    2016-08-01

    Tertiary butyl esters find large applications in synthetic organic chemistry. A straightforward method for the direct introduction of the tert-butoxycarbonyl group into a variety of organic compounds has been developed using flow microreactor systems. The resultant flow process was more efficient, versatile and sustainable compared to the batch.

  14. Kinetic Study of the Reaction between Tert-butyl Hydrazine and Nitrous Acid

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The kinetic study of the reaction between tert-butyl hydrazine(TBH)and nitrous acid in nitric acid system is performed by spectrophotometry. The effect of some factors such as the concentration of TBH, the concentration of nitric acid, ionic strength, temperature and the

  15. A new steroidal compound (β-sitosterol-3-O-butyl isolated from Caesalpinia gilliesii flowers

    Directory of Open Access Journals (Sweden)

    Samir Mohamed Osman

    2015-01-01

    Full Text Available Summary. The study aimed to evaluate the cytotoxic activity of total extracts from leaves, flowers and pods of Caesalpinia gilliesii (Fabaceae, Caesalpinoideae. In addition, a detailed phytochemical investigation of flower extracts was carried out to isolate and elucidate the structures of the bioactive compounds. Flower extract was the most cytotoxic against MCF7 and HepG2 cancer cells with IC50 values of 10 and 15.6 µg/mL, respectively. A new β-sitosterol-3-O-butyl was isolated from dichloromethane fraction of flowers together with another known sterol (daucosterol, and two flavonoids (isorhamnetin and isorhamnetin 3-O-rhamnoside. β-sitosterol-3-O-butyl was the most active compound against both HepG2 and MCF7 cells with IC50 values of 13.1 and 14.4 µg/mL, respectively. Isorhamnetin possesses a moderate antioxidant activity with an IC50 value 370 µg/mL as determined by DPPH radical scavenging assay.Industrial relevance. β-sitosterol-3-O-butyl and the other phytosterols are responsible for the cytotoxicity of the extracts which would correlate with the known abortifacient, antimalarial and anthelmintic properties, which can provide a cheap alternative drug.Keywords. Cytotoxicity, antioxidant; Caesalpinia gilliesii; β-sitosterol-3-O-butyl; daucosterol; isorhamnetin-3-O-rhamnoside

  16. A Chiral Macroscopic Force between Liquid of Butyl Alcohol and Copper Block

    Institute of Scientific and Technical Information of China (English)

    HU Yong-Hong; LIU Zhong-Zhu

    2008-01-01

    A non-zero macroscopic chirality-dependent force between a copper block and a vessel of homochiral molecules(butyl alcohol) is calculated quantitatively with the central field approximation. The magnitude of the force is estimated with the published limits of the scalar and pseudo-scalar coupling constants.

  17. PHOTOCATALYTIC OXIDATION OF METHYL-TERT-BUTYL ETHER FOR DRINKING WATER TREATMENT

    Science.gov (United States)

    The photo-oxidation of methyl tert-butyl ether (MTBE) in water was investigated to determine the feasibility of using photocatalysis for the treatment of MTBE-contaminated drinking water. The feasibility assessment was conducted using slurries of titanium dioxide in both a photo-...

  18. TREATMENT OF METHYL TERT-BUTYL ETHER CONTAMINATED WATER USING PHOTOCATALYSIS

    Science.gov (United States)

    The feasibility of photo-oxidation treatment of methyl tert-butyl ether (MTBE) in water was investigated in three ways, 1) using a slurry falling film photo-reactor, 2) a batch solar reactor system, and 3) a combination of air-stripping and gas phase photooxidation system. MTBE-c...

  19. Polypyrrole-coated styrene-butyl acrylate copolymer composite particles with tunable conductivity

    Institute of Scientific and Technical Information of China (English)

    HUANG Liyan; HOU Wenbo; LIU Zhengping; ZHANG Qingyue

    2005-01-01

    A series of near or monodisperse styrene-butyl acrylate (SBA) copolymer latex particles with different butyl acrylate contents were coated with polypyrrole. The structure of the SBA/PPy composites was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), diffuse reflectance infrared Fourier transform spectroscopy (DRIFT), X-ray photoelectron spectroscopy (XPS), differential scanning calorimetry (DSC) and standard four-probe method. The core-shell morphology of the SBA/PPy composite particles was confirmed. The result of DSC showed that Tg of the composite is mainly determined by the core component. The effects of the concentration of polypyrrole, the butyl acrylate content in SBA copolymer and the nature of the counter-anion on the electrical conductivity of compression-moulded samples were studied. It was first found that the electrical conductivity of the samples can be tuned by varying the butyl acrylate content in SBA copolymer and the highest conductivity of the core-shell composite was 0.17 S·cm-1.

  20. Simultaneous clostridial fermentation, lipase-catalyzed esterification, and ester extraction to enrich diesel with butyl butyrate

    NARCIS (Netherlands)

    Berg, C. van den; Heeres, A.S.; Wielen, L.A.M. van der; Straathof, A.J.J.

    2013-01-01

    The recovery of 1-butanol from fermentation broth is energy-intensive since typical concentrations in fermentation broth are below 20gL -1. To prevent butanol inhibition and high downstream processing costs, we aimed at producing butyl esters instead of 1-butanol. It is shown that it is possible to

  1. A Case of Successful Ablation of a Gastrophrenic Fistula with n-Butyl-2-Cyanoacrylate

    Directory of Open Access Journals (Sweden)

    Ashish Mahajan

    2008-01-01

    Full Text Available A 79-year-old woman with a fistula between a subphrenic abscess and the fundus of the stomach was successfully treated with n-Butyl-2-Cyanoacrylate. Conservative management had failed. Clinical presentation, treatment progress and imaging findings by computed tomography scan, ultrasound, gastroscopy and fluoroscopy are presented, along with a brief review of the relevant literature.

  2. Morphology and film formation of poly(butyl methacrylate)-polypyrrole core-shell latex particles

    NARCIS (Netherlands)

    Huijs, F; Lang, J

    2000-01-01

    Core-shell latex particles made of a poly(butyl methacrylate) (PBMA) core and a thin polypyrrole (PPy) shell were synthesized by two-stage polymerization. In the first stage, PBMA latex particles were synthesized in a semicontinuous process by free-radical polymerization. PBMA latex particles were l

  3. Chemopreventive potential of Tribulus terrestris against 7,12- dimethylbenz (a) anthracene induced skin papillomagenesis in mice.

    Science.gov (United States)

    Kumar, Manish; Soni, Anil Kumar; Shukla, Shalini; Kumar, Ashok

    2006-01-01

    In the present investigation, the chemopreventive potential of aqueous extracts of the root and fruit of Tribulus terrestris (an Ayurvedic medicinal plant) on 7, 12 - dimethylbenz (a) anthracene (DMBA) induced papillomagenesis in male Swiss albino mice was studied. A significant reduction in tumor incidence, tumor burden and cumulative number of papillomas was observed, along with a significant increase in average latent period in mice treated orally with Tribulus terrestris suspension continuously at pre, peri and post-initiation stages of papillomagenesis as compared to the control group treated with DMBA and croton oil alone. Treatment with Tribulus terrestris suspension by oral gavage for 7 days resulted in a significant increase in the reduced glutathione content in the liver (P< 0.001 for both root and fruit extracts). Conversely, lipid peroxidation levels were significantly decreased (P< 0.001). PMID:16839225

  4. Evaluation of the chemopreventive response of naringenin-loaded nanoparticles in experimental oral carcinogenesis using laser-induced autofluorescence spectroscopy

    International Nuclear Information System (INIS)

    The aim of the present study is to investigate the chemopreventive effects of prepared naringenin-loaded nanoparticles (NARNPs) relative to the efficacy of free naringenin (NAR) in modifying the carcinogenic process and to study the changes in the endogenous fluorophores during DMBA-induced hamster buccal pouch (HBP) carcinogenesis by laser-induced autofluorescence (LIAF) spectroscopy. LIAF emission spectra from the hamster buccal mucosa of the control and experimental groups of animals were recorded in the 350–700 nm spectral range on a miniature fiber optic spectrometer from different anatomical sites of each group, with excitation at 404 nm from a diode laser. Oral squamous cell carcinoma (OSCC) was developed in the buccal pouch of golden Syrian hamsters by painting with 0.5% DMBA in liquid paraffin three times a week for 14 weeks. DMBA-painted animals revealed morphological changes, hyperplasia, dysplasia and well-differentiated squamous cell carcinoma. LIAF emission spectra showed significant difference between the control and tumor tissues. The tumor tissues are characterized by an increase in the emission of porphyrins and a decrease in the emission of nicotinamide adenine dinucleotide hydrogenase (NADH) and flavin adenine nucleotide (FAD) when compared to the control tissues. Furthermore, oral administration of NAR and its nanoparticulates restored the status of endogenous fluorophores in the buccal mucosa of DMBA-painted animals. On a comparative basis, the treatment of nanoparticulate naringenin was found to be more effective than free naringenin in completely preventing the formation of squamous cell carcinoma and in improving the status of endogenous porphyrins to a normal range in DMBA-induced hamster buccal pouch carcinogenesis. The result of the present study further suggests that LIAF spectroscopy may be a very valuable tool for rapid and sensitive detection of endogenous fluorophore changes in response to chemopreventive agents. (paper)

  5. Evaluation of the chemopreventive response of naringenin-loaded nanoparticles in experimental oral carcinogenesis using laser-induced autofluorescence spectroscopy

    Science.gov (United States)

    Sulfikkarali, N. K.; Krishnakumar, N.

    2013-04-01

    The aim of the present study is to investigate the chemopreventive effects of prepared naringenin-loaded nanoparticles (NARNPs) relative to the efficacy of free naringenin (NAR) in modifying the carcinogenic process and to study the changes in the endogenous fluorophores during DMBA-induced hamster buccal pouch (HBP) carcinogenesis by laser-induced autofluorescence (LIAF) spectroscopy. LIAF emission spectra from the hamster buccal mucosa of the control and experimental groups of animals were recorded in the 350-700 nm spectral range on a miniature fiber optic spectrometer from different anatomical sites of each group, with excitation at 404 nm from a diode laser. Oral squamous cell carcinoma (OSCC) was developed in the buccal pouch of golden Syrian hamsters by painting with 0.5% DMBA in liquid paraffin three times a week for 14 weeks. DMBA-painted animals revealed morphological changes, hyperplasia, dysplasia and well-differentiated squamous cell carcinoma. LIAF emission spectra showed significant difference between the control and tumor tissues. The tumor tissues are characterized by an increase in the emission of porphyrins and a decrease in the emission of nicotinamide adenine dinucleotide hydrogenase (NADH) and flavin adenine nucleotide (FAD) when compared to the control tissues. Furthermore, oral administration of NAR and its nanoparticulates restored the status of endogenous fluorophores in the buccal mucosa of DMBA-painted animals. On a comparative basis, the treatment of nanoparticulate naringenin was found to be more effective than free naringenin in completely preventing the formation of squamous cell carcinoma and in improving the status of endogenous porphyrins to a normal range in DMBA-induced hamster buccal pouch carcinogenesis. The result of the present study further suggests that LIAF spectroscopy may be a very valuable tool for rapid and sensitive detection of endogenous fluorophore changes in response to chemopreventive agents.

  6. Increased chemopreventive effect by combining arctigenin, green tea polyphenol and curcumin in prostate and breast cancer cells.

    Science.gov (United States)

    Wang, Piwen; Wang, Bin; Chung, Seyung; Wu, Yanyuan; Henning, Susanne M; Vadgama, Jaydutt V

    2014-08-01

    The low bioavailability of most flavonoids limits their application as anti-carcinogenic agents in humans. A novel approach of treatment with a mixture of bioactive compounds that share molecular anti-carcinogenic targets may enhance the effect on these targets at low concentrations of individual compound, thereby overcoming the limitations of reduced bioavailability. We therefore investigated whether a combination of three natural products arctigenin (Arc), a novel anti-inflammatory lignan from the seeds of Arctium lappa, green tea polyphenol (-)-epigallocatechin gallate (EGCG) and curcumin (Cur) increases the chemopreventive potency of individual compounds. LNCaP prostate cancer and MCF-7 breast cancer cells were treated with 2-4 mg/L (about 5-10μM) Cur, 1μM Arc and 40μM EGCG alone or in combination for 48h. In both cell lines treatment with the mixture of Cur, Arc and EGCG synergistically increased the antiproliferative effect. In LNCaP cells both Arc and EGCG increased the pro-apoptotic effect of Cur. Whereas in MCF-7 cells Arc increased the cell apoptosis of Cur while EGCG enhanced cell cycle arrest of Cur at G0/G1 phase. The strongest effects on cell cycle arrest and apoptosis were achieved by combining all three compounds in both cell lines. The combination treatment significantly increased the ratio of Bax to Bcl-2 proteins, decreased the activation of NFκB, PI3K/Akt and Stat3 pathways and cell migration compared to individual treatment. These results warrant in vivo studies to confirm the efficacy of this novel regimen by combining Arc and EGCG with Cur to enhance chemoprevention in both prostate and breast cancer. PMID:25243063

  7. α-Santalol, a skin cancer chemopreventive agent with potential to target various pathways involved in photocarcinogenesis.

    Science.gov (United States)

    Santha, Sreevidya; Dwivedi, Chandradhar

    2013-01-01

    This study is designed to investigate the chemopreventive effect and molecular mechanisms of α-santalol on UVB-induced skin tumor development in SKH-1 hairless mouse, a widely used model for human photocarcinogenesis. A dose of UVB radiation (30 mJ cm(-2) day(-1)) that is in the range of human sunlight exposure was used for the initiation and promotion of tumor. Topical treatment of mice with α-santalol (10%, wt/vol in acetone) caused reduction in tumor incidence, multiplicity and volume. In our study, the anticarcinogenic action of α-santalol against UVB-induced photocarcinogenesis was found to be associated with inhibition of inflammation and epidermal cell proliferation, cell cycle arrest and induction of apoptosis. α-Santalol pretreatment strongly inhibited UVB-induced epidermal hyperplasia and thickness of the epidermis, expression of proliferation and inflammation markers proliferating cell nuclear antigen (PCNA), Ki-67 and cyclooxygenase 2 (Cox-2). Significant decrease in the expression of cyclins A, B1, D1 and D2 and cyclin-dependent kinases (Cdk)s Cdk1 (Cdc2), Cdk2, Cdk4 and Cdk6 and an upregulated expression of cyclin-dependent kinase (CDK) inhibitor Cip1/p21 were found in α-santalol pretreated group. Furthermore, an elevated level of cleaved caspase 3 and cleaved poly (ADP-ribose) polymerase (PARP) were observed in α-santalol-treated group. Our data suggested that α-santalol is a safer and promising skin cancer chemopreventive agent with potential to target various pathways involved in photocarcinogenesis. PMID:23480292

  8. Urinary PGE-M levels are associated with risk of colorectal adenomas and chemopreventive response to anti-inflammatory drugs.

    Science.gov (United States)

    Bezawada, Navya; Song, Mingyang; Wu, Kana; Mehta, Raaj S; Milne, Ginger L; Ogino, Shuji; Fuchs, Charles S; Giovannucci, Edward L; Chan, Andrew T

    2014-07-01

    Prostaglandin E2 (PGE2) promotes colorectal carcinogenesis. Overall, systemic PGE2 production can be assessed by measuring its major metabolite, PGE-M, in urine. We examined the potential role of PGE-M as a biomarker for colorectal adenoma risk and chemopreventive response to anti-inflammatory drugs. We conducted a prospective case-control study nested within the Nurses' Health Study. Among women who previously provided a urine sample, we identified 420 cases diagnosed with colorectal adenoma during follow-up and matched them to 420 endoscopy-negative controls. We measured urinary PGE-M using an LC/MS assay. Compared with women in the lowest quartile of urinary PGE-M, women in the highest quartile had a multivariate OR of 1.40 (95% confidence interval (CI), 0.92-2.14) for any adenoma; 0.91 (95% CI, 0.48-1.72) for low-risk adenoma (solitary adenoma aspirin/NSAIDs per week) was associated with a significant reduction in adenoma risk (multivariate OR, 0.61; 95% CI, 0.43-0.87) in women with high baseline PGE-M (quartiles 2-4), but not low PGE-M (quartile 1).Urinary PGE-M is associated with an increased risk of high-risk adenoma. Anti-inflammatory drugs seem to reduce adenoma risk among women with high, but not low PGE-M. Urinary PGE-M may serve as a biomarker to define subsets of the population who may obtain differential chemopreventive benefit from anti-inflammatory drugs. PMID:24824037

  9. Targeting angiogenic pathway for chemoprevention of experimental colon cancer using C-phycocyanin as cyclooxygenase-2 inhibitor.

    Science.gov (United States)

    Saini, Manpreet Kaur; Sanyal, Sankar Nath

    2014-06-01

    An angiogenic pathway was studied that involved stromal tissue degradation with matrix metalloproteinases (MMPs), vesicular endothelial growth factor-A (VEGF-A), and hypoxia inducible factor-1α (HIF-1α) mediated growth regulation in a complex interaction with chemokines, such as monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-1β (MIP-1β). Gene and protein expression was studied with real-time PCR, Western immunoblot, and immunofluorescence. Morphological and histopathological analysis of tumor was done, as also the activity of MMPs and HIF-1α by gelatin zymography and ELISA. Binding interactions of proteins were studied by molecular docking. Piroxicam, a traditional NSAID and C-phycocyanin, a biliprotein from Spirulina platensis, were utilized in the chemoprevention of DMH-induced rat colon cancer. A significant number of tumors was evident in DMH treated animals, while with piroxicam and C-phycocyanin, the number and size of tumors/lesions were reduced. Colonic tissues showed severe dysplasia, tubular adenoma, and adenocarcinoma from DMH, with invasive features along with signet ring cell carcinoma. No occurrence of carcinoma was detected in either of the drug treatments or in a combination regimen. An elevated VEGF-A, MMP-2, and MMP-9 level was observed, which is required for metastasis and invasion into surrounding tissues. Drugs induced chemoprevention by down-regulating these proteins. Piroxicam docked in VEGF-A binding site of VEGF-A receptors i.e., VEGFR1 and VEGFR2, while phycocyanobilin (a chromophore of C-phycocyanin) docked with VEGFR1 alone. HIF-1α is up-regulated which is associated with increased oxygen demand and angiogenesis. MCP-1 and MIP-1β expression was also found altered in DMH and regulated by the drugs. Anti-angiogenic role of piroxicam and C-phycocyanin is well demonstrated. PMID:24861078

  10. α-Santalol, a skin cancer chemopreventive agent with potential to target various pathways involved in photocarcinogenesis.

    Science.gov (United States)

    Santha, Sreevidya; Dwivedi, Chandradhar

    2013-01-01

    This study is designed to investigate the chemopreventive effect and molecular mechanisms of α-santalol on UVB-induced skin tumor development in SKH-1 hairless mouse, a widely used model for human photocarcinogenesis. A dose of UVB radiation (30 mJ cm(-2) day(-1)) that is in the range of human sunlight exposure was used for the initiation and promotion of tumor. Topical treatment of mice with α-santalol (10%, wt/vol in acetone) caused reduction in tumor incidence, multiplicity and volume. In our study, the anticarcinogenic action of α-santalol against UVB-induced photocarcinogenesis was found to be associated with inhibition of inflammation and epidermal cell proliferation, cell cycle arrest and induction of apoptosis. α-Santalol pretreatment strongly inhibited UVB-induced epidermal hyperplasia and thickness of the epidermis, expression of proliferation and inflammation markers proliferating cell nuclear antigen (PCNA), Ki-67 and cyclooxygenase 2 (Cox-2). Significant decrease in the expression of cyclins A, B1, D1 and D2 and cyclin-dependent kinases (Cdk)s Cdk1 (Cdc2), Cdk2, Cdk4 and Cdk6 and an upregulated expression of cyclin-dependent kinase (CDK) inhibitor Cip1/p21 were found in α-santalol pretreated group. Furthermore, an elevated level of cleaved caspase 3 and cleaved poly (ADP-ribose) polymerase (PARP) were observed in α-santalol-treated group. Our data suggested that α-santalol is a safer and promising skin cancer chemopreventive agent with potential to target various pathways involved in photocarcinogenesis.

  11. Dextran sulfate sodium-induced colitis-associated neoplasia: a promising model for the development of chemopreventive interventions

    Institute of Scientific and Technical Information of China (English)

    Margie Lee CLAPPER; Harry Stanley COOPER; Wen-Chi Lee CHANG

    2007-01-01

    Individuals diagnosed with ulcerative colitis face a significantly increased risk of developing colorectal dysplasia and cancer during their lifetime. To date, little attention has been given to the development of a chemopreventive intervention for this high-risk population. The mouse model of dextran sulfate sodium (DSS) -induced colitis represents an excellent preclinical system in which to both charac-terize the molecular events required for tumor formation in the presence of inflam-marion and assess the ability of select agents to inhibit this process. Cyclic admin-istration of DSS in drinking water results in the establishment of chronic colitis and the development of colorectal dysplasias and cancers with pathological fea-tures that resemble those of human colitis-associated neoplasia. The incidence and multiplicity of lesions observed varies depending on the mouse strain used (ie, Swiss Webster, C57BL/6J, CBA, ICR) and the dose (0.7%-5.0%) and schedule (1-15 cycles with or without a subsequent recovery period) of DSS. The incidence of neoplasia can be increased and its progression to invasive cancer accelerated significantly by administering DSS in combination with a known colon carcinogen(azoxymethane (AOM), 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)) or iron. More recent induction of colitis-associated neoplasia in genetically defined mouse strains has provided new insight into the role of specific genes (ie, adenomatous polyposis coli (Apc),p53, inducible nitric oxide synthase (iNOS), Msh2) in the development of colitis-associated neoplasias. Emerging data from chemopreventive intervention studies document the efficacy of several agents in inhibiting DSS-induced neoplasia and provide great promise that colitis-associated colorectal neoplasia is a pre-ventable disease.

  12. Synthesis, Resolution, and Enantiomeric Purity Assay of 2-n-Butylbutanedioic Acid 4-t-Butyl Esters

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Racemic 2-n-butylbutanedioic acid 4-t-butyl esters were synthesized from methyl hexanoate and t-butyl α-iodoacetate via alkylation and subsequently selective hydrolyzation. The (R)-and (S)-2-n-butylbutanedioic acid 4-t-butyl esters were obtained by the resolution of the above-mentioned racemic compounds with(S)-( - ) or(R)-( + )-α-methylbenzylamine, respectively. The e.e. values of the two optical active products were determined to be above 99% by HPLC after the formation of two pairs of diastereoisomers with ( R)-( + )-α-methylbenzylamine and (S)-phenylalanine methyl ester.

  13. Cyhalofop-butyl has the potential to induce developmental toxicity, oxidative stress and apoptosis in early life stage of zebrafish (Danio rerio)

    International Nuclear Information System (INIS)

    Cyhalofop-butyl is a selective herbicide widely employed in paddy field, which can transfer into aquatic environments. However, details of the environmental risk and aquatic toxicity of cyhalofop-butyl have not been fully investigated. In this study, zebrafish (Danio rerio) embryos were exposed to a range of cyhalofop-butyl until 120 hour post-fertilization (hpf) to assess embryonic toxicity of the chemical. Our results demonstrated that cyhalofop-butyl was highly toxic to zebrafish embryos, with concentration-dependent negative effects in embryonic development. In addition, exposure to cyhalofop-butyl resulted in significant increases in reactive oxygen species (ROS) production and cell apoptosis in heart area. The mRNA levels of the genes related to oxidative stress and apoptosis were also altered significantly after cyhalofop-butyl exposure. Moreover, the activity of capspase-9 and caspase-3 were significantly increased. Therefore, we speculated that oxidative stress-induced apoptosis should be responsible for abnormal development during embryogenesis after cyhalofop-butyl exposure. - Highlights: • Cyhalofop-butyl can induce developmental toxicity in zebrafish embryos. • Cyhalofop-butyl can induce oxidative stress and apoptosis in zebrafish embryos. • Oxidative stress-induced apoptosis might be responsible for abnormal development. - Cyhalofop-butyl could induce negative effects in embryonic development. The cyhalofop-butyl – induced developmental toxicity could be explained by oxidative stress-induced apoptosis

  14. 2,4-Di-tert-butyl-6-[1-(3,5-di-tert-butyl-2-hydroxyphenylethyl]phenyl 4-methylbenzenesulfonate

    Directory of Open Access Journals (Sweden)

    Jincai Wu

    2009-01-01

    Full Text Available The title compound, C37H52O4S, was obtained by the reaction of 6,6′-(ethane-1,1-diylbis(2,4-di-tert-butylphenol and 4-methylbenzene-1-sulfonyl chloride. The molecular conformation is stabilized by an intramolecular O—H...O hydrogen bond. Two of the tert-butyl groups are disordered over two sets of sites with occupancies 0.530 (15/0.470 (15 and 0.615 (11/0.385 (11.

  15. Isothermal (vapor + liquid) equilibria and excess enthalpy data of {1-hexene + methyl butyl ether (MBE)} and {1-hexene + methyl tert-butyl ether (MTBE)} binary systems at several temperatures

    International Nuclear Information System (INIS)

    Highlights: ► Vapor pressures of (1-hexene + methyl butyl ether) or (1-hexene + methyl tert-butyl ether) are reported between (263 and 363) K. ► The two mixtures exhibit positive GE. ► Additionally, molar excess enthalpies, HE, for the two binary systems have been measured at 303.15. - Abstract: The vapor pressures of {1-hexene + methyl butyl ether (MBE)} and {1-hexene + methyl tert-butyl ether (MTBE)} binary mixtures and of the three pure components were measured by means of a static device at temperatures between (263 and 333) K. The data were correlated with the Antoine equation. From these data, excess Gibbs functions were calculated for several constant temperatures and fitted to a third-order Redlich–Kister equation using the Barker’s method. Additionally, molar excess enthalpies, HE, for the two binary systems have been measured at 303.15 K using an isothermal flow calorimeter.

  16. Simultaneous liquid chromatographic determination of carotenoids, retinoids, and tocopherols in human buccal mucosal cells.

    Science.gov (United States)

    Peng, Y S; Peng, Y M

    1992-01-01

    Epidemiological and experimental data have suggested that some micronutrients, including various carotenoids, retinoids, and alpha-tocopherol, may have chemopreventive activity against certain types of human cancer. In order to define the role of these micronutrients in cancer prevention, it is necessary to measure their concentrations in the target tissues, since these are critical to the chemopreventive effect. We have developed a sensitive and reproducible high-performance liquid chromatography procedure for the simultaneous determination of lutein, zeaxanthin, beta-cryptoxanthin, lycopene, alpha-carotene, beta-carotene, cis-beta-carotene, retinol, retinyl palmitate, alpha-tocopherol, and gamma-tocopherol in an easily accessible human target tissue, the buccal mucosal cells. This procedure used a gradient of two mobile phases which consisted of acetonitrile, tetrahydrofuran, methanol, 1% ammonium acetate, and butylated hydroxytoluene (in v/v/v/v/w): mobile phase A, 85:5:5:5:0.05; mobile phase B, 55:35:5:5:0.05. The run time, including reequilibration, was 47 min: from 100% A to 100% B in 27 min, remaining at that mobile phase for 10 min, then back to 100% A at 43 min at a constant flow rate of 1.3 ml/min. The high-performance liquid chromatography effluent was monitored at 300, 325, and 452 nm for tocopherols, retinoids, and carotenoids, respectively, with a photodiode array detector. The average recovery was 83% for lycopene and > 92% for others. The precision of the assay for all the compounds was less than 10% in a 1-month period. The micronutrients were extracted by incubating the cells with protease, followed by vortex mixing with 1% sodium dodecyl sulfate in ethanol containing 0.1% butylated hydroxytoluene, and, finally, hexane extraction.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1305470

  17. Drugs with potential chemopreventive properties in relation to epithelial ovarian cancer--a nationwide case-control study.

    Science.gov (United States)

    Baandrup, Louise

    2015-07-01

    Ovarian cancer has a poor prognosis because the disease in the majority of patients is diagnosed at an advanced stage as a result of nonspecific symptoms and lack of efficient screening methods. Because of the poor prognosis of ovarian cancer and the challenge of early detection of the disease, identification of protective factors is important. It has been suggested that some commonly used drugs may have a protective effect against cancer, including ovarian cancer; however, the literature on chemopreventive measures for ovarian cancer is sparse and the results are inconclusive. Most previous studies have substantial methodological constraints, including limited study size and self-reporting of drug use, which introduces potential recall bias and misclassification. This PhD thesis includes a nationwide case-control study to evaluate associations between use of drugs with potential chemopreventive properties and risk of epithelial ovarian cancer. The study is nested in the entire Danish female population using data from the following nationwide registries: the Danish Cancer Registry, the Danish Civil Registration System, the Danish Prescription Registry, the Danish National Patient Register, and registries in Statistics Denmark on fertility, education, and income. Information from the included registries is linked by use of the unique personal identification number assigned to all Danish citizens. The cases were all women in Denmark with epithelial ovarian cancer diagnosed during 2000-2009 (Paper 1) and 2000-2011 (Papers 2 and 3), identified in the Cancer Registry. Age-matched female population controls were randomly selected from the Civil Registration System by risk-set sampling. We required that cases and controls have no history of cancer (except non-melanoma skin cancer) and that controls not previously have undergone bilateral oophorectomy or salpingo-oophorectomy. The total study population comprised 3741 epithelial ovarian cancer cases and 50,576 controls in

  18. No Promoting Effect of Ethyl Tertiary-butyl Ether (ETBE) on Rat Urinary Bladder Carcinogenesis Initiated with N-Butyl-N-(4-hydroxybutyl)nitrosamine.

    Science.gov (United States)

    Hagiwara, Akihiro; Imai, Norio; Doi, Yuko; Suguro, Mayuko; Kawabe, Mayumi; Furukawa, Fumio; Nagano, Kasuke; Fukushima, Shoji

    2013-12-01

    The effects of ethyl tertiary-butyl ether (ETBE) on two-stage urinary bladder carcinogenesis in male F344 rats initiated with N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) were investigated at various dose levels with regard to possible promoting activity. Groups of 30 rats were given drinking water containing 500 ppm BBN, as an initiator, for 4 weeks and starting one week thereafter received ETBE by gavage (daily, 7 days/week) at dose levels of 0 (control), 100, 300, 500 or 1000 mg/kg/day until experimental week 36. No statistically significant differences in incidences of preneoplastic lesions, papillomas, and carcinomas of the urinary bladder were evident in rats treated with 100-1000 mg/kg/day ETBE as compared with control values. Furthermore, the average numbers of preneoplastic or neoplastic lesions per unit length of basement membrane in rats given 100-1000 mg/kg/day ETBE were also comparable to control values. However, papillomatosis of the urinary bladder was found in 4 out of 30 rats (13%) in the group given 1000 mg/kg/day ETBE, and soft stones in the urinary bladder were found in 3 out of these 4 rats. The results thus demonstrated that ETBE did not exert promotional activity on urinary bladder carcinogenesis. However, papillomatosis of the urinary bladder developed in small numbers of the rats given ETBE at 1000 mg/kg/day but not in rats given 500 mg/kg/day or lower doses.

  19. Combined toxicities of methyl tert-butyl ether and its metabolite tert-butyl alcohol on earthworms via different exposure routes.

    Science.gov (United States)

    Lee, Woo-Mi; Yoon, Youngdae; An, Youn-Joo

    2015-06-01

    Methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) are among the major soil contaminants that threaten the health of soil ecosystems. Many MTBE-contaminated sites accumulate TBA, because TBA is the intermediate of MTBE biodegradation. To access the risk of MTBE and TBA in soil, we investigated the combined toxicities of MTBE and TBA using two earthworm species, Perionyx excavatus and Eisenia andrei, as well as the toxic effects via different exposure routes. The combined toxicity showed weak antagonistic effects (LC50mix values were slightly greater than 1.0), and sensitivity toward same pollutants differed in the two earthworm species. Moreover, the toxicity of MTBE and TBA was also affected by the exposure route; both filter paper and artificial soil tests showed that dermal-only exposure to MTBE had an even greater toxic effect than combined dermal and oral exposure. Thus, we suggest that diverse environmental factors including organic materials, the physicochemical properties of the contact media, and the exposure routes of the organism, should be taken into consideration when assessing the effects of pollutants on organisms in diverse environmental systems. PMID:25706436

  20. Bio-Source of di-n-butyl phthalate production by filamentous fungi

    Science.gov (United States)

    Tian, Congkui; Ni, Jinren; Chang, Fang; Liu, Sitong; Xu, Nan; Sun, Weiling; Xie, Yuan; Guo, Yongzhao; Ma, Yanrong; Yang, Zhenxing; Dang, Chenyuan; Huang, Yuefei; Tian, Zhexian; Wang, Yiping

    2016-02-01

    Although DBP (di-n-butyl phthalate) is commonly encountered as an artificially-synthesized plasticizer with potential to impair fertility, we confirm that it can also be biosynthesized as microbial secondary metabolites from naturally occurring filamentous fungi strains cultured either in an artificial medium or natural water. Using the excreted crude enzyme from the fungi for catalyzing a variety of substrates, we found that the fungal generation of DBP was largely through shikimic acid pathway, which was assembled by phthalic acid with butyl alcohol through esterification. The DBP production ability of the fungi was primarily influenced by fungal spore density and incubation temperature. This study indicates an important alternative natural waterborne source of DBP in addition to artificial synthesis, which implied fungal contribution must be highlighted for future source control and risk management of DBP.

  1. Thin PDMS films using long spin times or tert-butyl alcohol as a solvent.

    Directory of Open Access Journals (Sweden)

    John H Koschwanez

    Full Text Available Thin polydimethylsiloxane (PDMS films are frequently used in "lab on a chip" devices as flexible membranes. The common solvent used to dilute the PDMS for thin films is hexane, but hexane can swell the underlying PDMS substrate. A better solvent would be one that dissolves uncured PDMS but doesn't swell the underlying substrate. Here, we present protocols and spin curves for two alternatives to hexane dilution: longer spin times and dilution in tert-butyl alcohol. The thickness of the PDMS membranes under different spin speeds, spin times, and PDMS concentrations was measured using an optical profilometer. The use of tert-butyl alcohol to spin thin PDMS films does not swell the underlying PDMS substrate, and we have used these films to construct multilayer PDMS devices.

  2. Dissolution of wood flour and lignin in 1-butyl-3-methyl-1-imidazolium chloride

    Directory of Open Access Journals (Sweden)

    Yasmin Nasiri Khonsari

    2013-10-01

    Full Text Available The ionic solvent, 1-butyl-3-methyl imidazolium chloride was used to dissolve the samples. Two lignocellulosic material including bagasse soda lignin and Populus deltoides wood flour were used. One gram of samples were dissolved in 10 ml ionic solvent, 1-butyl-3-methyl- imidazolium chloride at 70 ºC for 72 h while stirring with a magnetic stirrer. The wood flour and lignin samples were acetylated with addition of acetic anhydride to each container with a ratio of 0.25 ml/ 0.25 ml. The samples were heated for 3 days at 110 ° C. Two control samples (without acetylation and two treatments (acetylation were used. The functional groups were determined using FT-IR Spectrometer. The number and type of carbon and their structure were examined using 13CNMR Spectrometer. The guaiacyl, syringyl, coniferyl alcohol and biphenyls structures were identified.

  3. Aging of Weapon Seals – An Update on Butyl O-ring Issues

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Mark H.

    2011-07-13

    During testing under the Enhanced Surveillance Campaign in 2001, preliminary data detected a previously unknown and potentially serious concern with recently procured butyl o-rings on several programs. All butyl o-rings molded from a proprietary formulation throughout the period circa 1999 through 2001 had less than a full cure. Engineering judgment was that under curing is detrimental and could possibly lead to sub-optimum performance or, in the worst case, premature seal failure. An aging study was undertaken to ensure that suspect o-rings installed in the stockpile will retain sufficient sealing force for a minimum ten-year service life. A new prediction model developed for this study indicates suspect o-rings do not need to be replaced before the ten-year service life. Long-term testing results are reported on a yearly basis to validate the prediction model. This report documents the aging results for the period September 2002 to January 2011.

  4. Crystal structure of 1-butyl-2,3-dimethylimidazolium dicarba-7,8-nido-undecaborate

    Directory of Open Access Journals (Sweden)

    M. J. Klemes

    2015-03-01

    Full Text Available In the title molecular salt, C9H17N2+·C2H12B9−, the carborane cage has a bridging B—H—B bond on the open B3C2 face. The butyl side chain of the cation adopts an extended conformation [C—C—C—C = 179.6 (1°]. In the crystal, the imidazolium ring is almost coplanar with the open face of the carborane anion. The cations stack in the [010] direction and the dihedral angle between the imidazolium rings of adjacent cations is 68.45 (6°. The butyl chains extend into the space between carborane anions.

  5. Thermodynamic Properties of Hydrogen + Tetra-n-Butyl Ammonium Bromide Semi-Clathrate Hydrate

    Directory of Open Access Journals (Sweden)

    Shunsuke Hashimoto

    2010-01-01

    Full Text Available Thermodynamic stability and hydrogen occupancy on the hydrogen + tetra-n-butyl ammonium bromide semi-clathrate hydrate were investigated by means of Raman spectroscopic and phase equilibrium measurements under the three-phase equilibrium condition. The structure of mixed gas hydrates changes from tetragonal to another structure around 95 MPa and 292 K depending on surrounding hydrogen fugacity. The occupied amount of hydrogen in the semi-clathrate hydrate increases significantly associated with the structural transition. Tetra-n-butyl ammonium bromide semi-clathrate hydrates can absorb hydrogen molecules by a pressure-swing without destroying the hydrogen bonds of hydrate cages at 15 MPa or over.

  6. New blends of ethylene-butyl acrylate copolymers with thermoplastic starch. Characterization and bacterial biodegradation.

    Science.gov (United States)

    Morro, A; Catalina, F; Corrales, T; Pablos, J L; Marin, I; Abrusci, C

    2016-09-20

    Ethylene-butyl acrylate copolymer (EBA) with 13% of butyl acrylate content was used to produce blends with 10, 30 and 60% of thermoplastic starch (TPS) plasticized with glycerol. Ethylene-acrylic acid copolymer (EAA) was used as compatibilizer at 20% content with respect to EBA. The blends were characterized by X-ray diffraction, ATR-Fourier Transform Infrared Spectroscopy (ATR-FTIR), Scanning Electron Microscopy (SEM), water-Contact Angle measurements (CA), Differential Scanning Calorimetry (DSC) and Stress-strain mechanical tests. Initiated autoxidation of the polymer blends was studied by chemiluminescence (CL) confirming that the presence of the polyolefin-TPS interphase did not substantially affect the oxidative thermostability of the materials. Three bacterial species have been isolated from the blend films buried in soil and identified as Bacillus subtilis, Bacillus borstelensis and Bacillus licheniformis. Biodegradation of the blends (28days at 45°C) was evaluated by carbon dioxide measurement using the indirect impedance technique. PMID:27261731

  7. The oxidation of 2,6-di-tert-butyl-4-methylphenol

    Science.gov (United States)

    Yohe, G.R.; Dunbar, J.E.; Pedrotti, R.L.; Scheidt, F.M.; Lee, F.G.H.; Smith, E.C.

    1956-01-01

    The products formed in the oxidation of 2,6-di-tert-butyl-4-methylphenol with oxygen and sodium hydroxide at about 100?? are 3,5-di-tert-butyl-4-hydroxybenzaldehyde, trimethylacetic acid, an acidic compound C14H22O3, and probably 2,6-di-tert-butylbenzoquinone (which was actually isolated in the similar oxidation of the above-named benzaldehyde), in addition to compounds previously reported. Some of the properties of C14H22O3 are given, and the oxidation of it to 2,3-di-tert-butylsuccinic anhydride is described, but assignment of structure is reserved pending the completion of more experimental work.

  8. Small-angle neutron scattering studies of sodium butyl benzene sulfonate aggregates in aqueous solution

    Indian Academy of Sciences (India)

    O R Pal; V G Gaikar; J V Joshi; P S Goyal; V K Aswal

    2004-08-01

    The aggregation behaviour of a hydrotrope, sodium -butyl benzene sulfonate (Na-NBBS), in aqueous solutions is investigated by small-angle neutron scattering (SANS). Nearly ellipsoidal aggregates of Na-NBBS at concentrations well above its minimum hydrotrope concentration were detected by SANS. The hydrotrope seems to form self-assemblies with aggregation number of 36–40 with a substantial charge on the aggregate. This aggregation number is weakly affected by the hydrotrope concentration.

  9. Preparation and Properties of Triethoxyvinylsilane-Modified Styrene - Butyl Acrylate Emulsion Copolymers

    OpenAIRE

    NAGHASH, Hamid Javaherian; KARIMZADEH, Akram; MOMENI, Ahmad Reza

    2007-01-01

    The copolymers of triethoxyvinylsilane (TEVS) with styrene (St), butyl acrylate (BA), and methacrylic acid (MAA) were prepared by emulsion polymerization. The copolymerization was carried out by using auxiliary agents at 90 °C in the presence of potassium peroxodisulfate (KPS) as the initiator. Nonylphenol ethylene oxide -- 40 units (NP-40) and sodium lauryl sulfoacetate (SLSA) were used as nonionic and anionic emulsifiers, respectively. The resulting copolymers were characterized b...

  10. Effect of Impeller Agitation on Preparation of Tetra-n-Butyl Ammonium Bromide Semiclathrate Hydrate Slurries

    OpenAIRE

    Yoshiro Inoue; Kazunari Ohgaki; Shunsuke Hashimoto; Hiroyuki Ito

    2012-01-01

    The slurries-containing tetra-n-butyl ammonium bromide (TBAB) solution and its semiclathrate hydrate have attracted a lot of interest as latent heat transport media. These hydrate slurries contain some microparticles of crystal, and the size and shape of these hydrate particles could affect the mobility of slurries. Hence, it is essential to investigate the efficient hydrate-slurry preparation methods and the effect of hydrate particles on the fluid property of slurries for the application to...

  11. Butyl 3-oxo-2,3-dihydrobenzo[d][1,2]thiazole-2-carboxylate

    Directory of Open Access Journals (Sweden)

    Jian-Xin Yang

    2011-12-01

    Full Text Available The title compound, C12H13NO3S, was synthesised by the reaction of benzo[d]isothiazol-3(2H-one with butyl alcohol in toluene. The benzoisothiazolone ring system is almost planar with a mean deviation of 0.041 (1 Å. In the crystal, molecules are linked by weak intermolecular C—H...O hydrogen bonds.

  12. Temperature effect on tert-butyl alcohol (TBA biodegradation kinetics in hyporheic zone soils

    Directory of Open Access Journals (Sweden)

    Sims Ronald C

    2007-09-01

    Full Text Available Abstract Background Remediation of tert-butyl alcohol (TBA in subsurface waters should be taken into consideration at reformulated gasoline contaminated sites since it is a biodegradation intermediate of methyl tert-butyl ether (MTBE, ethyl tert-butyl ether (ETBE, and tert-butyl formate (TBF. The effect of temperature on TBA biodegradation has not been not been published in the literature. Methods Biodegradation of [U 14C] TBA was determined using hyporheic zone soil microcosms. Results First order mineralization rate constants of TBA at 5°C, 15°C and 25°C were 7.84 ± 0.14 × 10-3, 9.07 ± 0.09 × 10-3, and 15.3 ± 0.3 × 10-3 days-1, respectively (or 2.86 ± 0.05, 3.31 ± 0.03, 5.60 ± 0.14 years-1, respectively. Temperature had a statistically significant effect on the mineralization rates and was modelled using the Arrhenius equation with frequency factor (A and activation energy (Ea of 154 day-1 and 23,006 mol/J, respectively. Conclusion Results of this study are the first to determine mineralization rates of TBA for different temperatures. The kinetic rates determined in this study can be used in groundwater fate and transport modelling of TBA at the Ronan, MT site and provide an estimate for TBA removal at other similar shallow aquifer sites and hyporheic zones as a function of seasonal change in temperature.

  13. Synthesis, Characterization and Evaluation of the Transformations in Hibiscus sabdariffa-graft-poly(butyl acrylate)

    OpenAIRE

    Kaith, B. S.; Chauhan, Aashish

    2008-01-01

    Different reaction parameters for the graft copolymerization of butyl acrylate onto Hibiscus sabdariffa fiber were optimized. Graft copolymers thus obtained were subjected to characterization using XRD, TGA, DTA, SEM and FTIR techniques and were evaluated for physio-chemical changes in the behavior. The percentage crystallinity and crystallinity index were found to decrease with increase in grafting while there was reduction in moisture absorption and increase in chemical, thermal resistance ...

  14. Adsorption of Methyl Tertiary Butyl Ether on Granular Zeolites: Batch and Column Studies

    OpenAIRE

    Abu-Lail, Laila; Bergendahl, John A.; Thompson, Robert W

    2010-01-01

    Methyl tertiary butyl ether (MTBE) has been shown to be readily removed from water with powdered zeolites, but the passage of water through fixed beds of very small powdered zeolites produces high friction losses not encountered in flow through larger sized granular materials. In this study, equilibrium and kinetic adsorption of MTBE onto granular zeolites, a coconut shell granular activated carbon (CS-1240), and a commercial carbon adsorbent (CCA) sample was evaluated. In addition, the effec...

  15. 1-[(E-2-(5-tert-Butyl-2-hydroxyphenyldiazen-1-yl]naphthalen-2-ol

    Directory of Open Access Journals (Sweden)

    Hassiba Bougueria

    2014-02-01

    Full Text Available The non-H atoms of the title compound, C20H20N2O2, is located on a mirror plane except two methyl groups of the tert-butyl group. Intramolecular N—H...O hydrogen bonds exist between the hydroxy and diazenyl groups. In the crystal, molecules are linked by weak C—H...O hydrogen bonds into supramolecular chains running along the a-axis direction.

  16. Vinyl Acetate/butyl acrylate/acrylate Research of Ternary Soap-free Emulsion Polymerization

    Directory of Open Access Journals (Sweden)

    Xiao Li-guang

    2016-01-01

    Full Text Available Through the vinyl acetate/butyl acrylate/acrylic acrylic emulsion preparation without soap vinegar, with solid content, gel, emulsion stability and film forming properties and tensile strength as the main index to study the effect of raw materials on the properties of emulsion. Through the infrared spectrometer soap-free emulsion for microscopic analysis research. Study of the ternary soap-free vinegar acrylic emulsion with good performance.

  17. (2-tert-Butyl-5-hydroxymethyl-1,3-dioxan-5-ylmethanol

    Directory of Open Access Journals (Sweden)

    Berenice Vargas

    2012-07-01

    Full Text Available In the title compound, C10H20O4, the dioxane ring adopts a chair conformation. The tert-butyl group occupies an equatorial position, and is staggered with respect to the O atoms of the dioxane ring. In the crystal, molecules are connected by O—H...O hydrogen-bonds into zigzag chains of R44(8 and R22(12 ring motifs that run parallel to the a axis.

  18. Crystal structures of three complexes of zinc chloride with tri-tert-butyl­phosphane

    Science.gov (United States)

    Finke, Aaron D.; Gray, Danielle L.; Moore, Jeffrey S.

    2016-01-01

    Under anhydrous conditions and in the absence of a Lewis-base solvent, a zinc chloride complex with tri-tert-butyl­phosphane as the μ-bridged dimer is formed, viz. di-μ-chlorido-bis­[chlorido­bis­(tri-tert-butyl­phosphane)zinc], [ZnCl4(C12H27P)2], (1), which features a nearly square-shaped (ZnCl)2 cyclic core and whose Cl atoms inter­act weakly with C—H groups on the phosphane ligand. In the presence of THF, monomeric di­chlorido­(tetra­hydro­furan-κO)(tri-tert-butyl­phosphane-κP)zinc, [ZnCl2(C4H8O)(C12H27P)] or [P(tBu3)(THF)ZnCl2], (2), is formed. This slightly distorted tetra­hedral Zn complex has weak C—H⋯Cl inter­actions between the Cl atoms and phosphane and THF C—H groups. Under ambient conditions, the hydrolysed complex tri-tert-butyl­phospho­nium aqua­tri­chlorido­zincate 1,2-di­chloro­ethane monosolvate, (C12H28P)[ZnCl3(H2O)]·C2H4Cl2 or [HPtBu3]+ [(H2O)ZnCl3]−·C2H4Cl2, (3), is formed. This complex forms chains of [(H2O)ZnCl3]− anions from hydrogen-bonding inter­actions between the water H atoms and Cl atoms that propagate along the b axis. PMID:26870580

  19. Stark effect in the J = 3 4 microwave line of tert-butyl chloride molecule

    Science.gov (United States)

    Gierszal, S.; Mis-Kuzminska, E.; Stankowski, J.; Galica, J.

    1984-03-01

    Stark effect in the J = 3 - 4 transition spectrum of the tert-butyl chloride has been investigated. The perturbation of the rotational levels by combined effect of the quadrupole and an intermediate electric fields was calculated and used for identify the Stark components. The rotational spectrum of tert-butyl chloride /CH 3/ 3CCl is characterised by the rotational constants A = 4518.70 MHz[1] and B = 3017.85 MHz, dipole moment U= 2.12 D, and quadrupole interaction constant eqQ = -67.58 MHz [2,3]. The energy of rotational states of the tert-butyl chloride molecule is described by the Hamiltonian ? where H 0 is the unperturbed rotational energy, H Q that of interaction of the angular momentum and quadrupole moment of the chlorine nucleus, and H E the Stark energy. Since H Q ˜ H E for the electric field strengths applied during the present investigation, we are dealing with the case of intermediate fields. To solve the problem theoretically we had recourse to the representation in F-space and calculated the energy for the perturbation H Q + H E as done by Low and Townes [4]. The theoretical distances of the Stark components from the absorption line of tert-butyl chloride for various electric field strengths at J = 3 - 4 and ΔM F = 0 is shown in Fig. 1a and 1b. We applied the theoretically calculated distances of the Stark components from the absorption line of /CH 3/ 3CCl as function of the electric field strength as well as the relative intensities of the components in order to interpret our experimental results concerning the Stark effect.

  20. Bis(1-tert-butyl-1H-imidazole-κN3)dichloridocobalt(II).

    Science.gov (United States)

    Herdtweck, Eberhardt; Zeller, Alexander; Strassner, Thomas

    2012-06-01

    In the crystal structure of the title compound, [CoCl(2)(C(7)H(12)N(2))(2)], molecular units are formed by coordination of the unsubstituted N atoms of two tert-butyl-substituted imidazole molecules and two chloride ligands, which distinguishes the complex from structures of imidazolium-based dications with tetrachloridocobaltate dianions. There are two crystallographically independent molecules in the asymmetric unit, related by a noncrystallographic inversion centre. PMID:22669189

  1. Crystal structures of three complexes of zinc chloride with tri-tert-butyl-phosphane.

    Science.gov (United States)

    Finke, Aaron D; Gray, Danielle L; Moore, Jeffrey S

    2016-01-01

    Under anhydrous conditions and in the absence of a Lewis-base solvent, a zinc chloride complex with tri-tert-butyl-phosphane as the μ-bridged dimer is formed, viz. di-μ-chlorido-bis-[chlorido-bis-(tri-tert-butyl-phosphane)zinc], [ZnCl4(C12H27P)2], (1), which features a nearly square-shaped (ZnCl)2 cyclic core and whose Cl atoms inter-act weakly with C-H groups on the phosphane ligand. In the presence of THF, monomeric di-chlorido-(tetra-hydro-furan-κO)(tri-tert-butyl-phosphane-κP)zinc, [ZnCl2(C4H8O)(C12H27P)] or [P(tBu3)(THF)ZnCl2], (2), is formed. This slightly distorted tetra-hedral Zn complex has weak C-H⋯Cl inter-actions between the Cl atoms and phosphane and THF C-H groups. Under ambient conditions, the hydrolysed complex tri-tert-butyl-phospho-nium aqua-tri-chlorido-zincate 1,2-di-chloro-ethane monosolvate, (C12H28P)[ZnCl3(H2O)]·C2H4Cl2 or [HPtBu3](+) [(H2O)ZnCl3](-)·C2H4Cl2, (3), is formed. This complex forms chains of [(H2O)ZnCl3](-) anions from hydrogen-bonding inter-actions between the water H atoms and Cl atoms that propagate along the b axis. PMID:26870580

  2. Reactivity Ratios for Microemulsion Copolymerization of N-butyl Maleimide and Styrene

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The oil-in-water microemulsion containing N-butyl maleimide(NBMI, M1) and styrene(St, M2) was prepared. The complexation properties of NBMI and St in microemulsion were investigated by means of 1H-NMR. With the participation of charge-transfer complex(CTC), four reactivity ratios and the relative reactivity of free monomers and CTC were obtained. The result was compared with that measured by Mayo-Lewis method.

  3. Two Cases of Adrenal Abscesses Following Histoacryl® (N-butyl-2-cyanocrylate) Injection

    OpenAIRE

    Lee, Bo Young; Jang, Jae Young; Jeong, Soung Won; Bok, Gene Hyun; Ham, Jeong Ho; Cho, Joo Young; Lee, Joon Seong; Shim, Chan Sup

    2011-01-01

    We report two cases of adrenal abscesses that occurred following a Histoacryl® (N-butyl-2-cyanocrylate) injection for variceal bleeding. Patients had been diagnosed with alcoholic liver cirrhosis and gastric varices bleeding and received a Histoacryl® injection for the variceal bleeding. Patients had fever and abdominal tenderness and were diagnosed with an adrenal abscess at 2 months following the Histoacryl® injection. One patient received open drainage and the other underwent percutaneous ...

  4. The REDUCE metagram: a comprehensive prediction tool for determining the utility of dutasteride chemoprevention in men at risk for prostate cancer

    OpenAIRE

    Carvell eNguyen; Brandon eIsariyawongse; Changhong eYu; Michael eKattan

    2012-01-01

    Introduction: 5-alpha reductase inhibitors can reduce the risk of prostate cancer but can be associated with significant side effects. A library of nomograms which predict the risk of clinical endpoints relevant to dutasteride treatment may help determine if chemoprevention is suited to the individual patient. Methods: Data from the REDUCE trial was used to identify predictive factors for nine endpoints relevant to dutasteride treatment. Using the treatment and placebo groups from the bio...

  5. The REDUCE metagram: a comprehensive prediction tool for determining the utility of dutasteride chemoprevention in men at risk for prostate cancer

    OpenAIRE

    Nguyen, Carvell T.; Isariyawongse, Brandon; Yu, Changhong; Michael W Kattan

    2012-01-01

    Introduction: 5-alpha reductase inhibitors can reduce the risk of prostate cancer (PCa) but can be associated with significant side effects. A library of nomograms which predict the risk of clinical endpoints relevant to dutasteride treatment may help determine if chemoprevention is suited to the individual patient. Methods: Data from the REDUCE trial was used to identify predictive factors for 9 endpoints relevant to dutasteride treatment. Using the treatment and placebo groups from the biop...

  6. Feasibility, safety and effectiveness of combining home based malaria management and seasonal malaria chemoprevention in children less than 10 years in Senegal

    DEFF Research Database (Denmark)

    Tine, Roger C K; Ndour, Cheikh T; Faye, Babacar;

    2014-01-01

    Home-based management of malaria (HMM) may improve access to diagnostic testing and treatment with artemisinin combination therapy (ACT). In the Sahel region, seasonal malaria chemoprevention (SMC) is now recommended for the prevention of malaria in children. It is likely that combinations of ant...... of antimalarial interventions can reduce the malaria burden. This study assessed the feasibility, effectiveness and safety of combining SMC and HMM delivered by community health workers (CHWs)....

  7. Alkylation of C60. Reaction between C60 anions and tert-butyl chloride and mass spectrometry analysis

    Science.gov (United States)

    Bourcier, S.; Chaurand, P.; Ciot, C.; Della-Negra, S.; Fabre, C.; Greugny, V.; Marx, L.; Rassat, A.; Rousseau, A.

    1996-11-01

    Alkylation of C60 in tetrahydrofuran with tert-butyl chloride and lithium gives a variety of products. Adducts of general formula C60Hn(t-Bu)qOx(thf)y (where t-Bu is the tert-butyl group and thf the tetrahydrofuryl group (C4H7O)) have been detected by mass spectrometry, with n <= 8, q + y <= 18 and x = 0, 1, 2 depending on experimental conditions. IR and NMR spectra of products confirm these assignments.

  8. Synthesis and Structure of an Octopus-like Octapropargyl Tetra-iso-butyl-resorcin[4]arene

    Institute of Scientific and Technical Information of China (English)

    LIU Xiang; LIU Yu-Jie; ZHANG Qian-Feng

    2005-01-01

    Treatment of tetra-iso-butyl-resorcin[4]arene 1 with propargyl bromide in the presence of K2CO3 as base gave an octopus-like octapropargyl tetra-iso-butyl-resorcin[4]arene 2 (C68H72O8, Mr = 1017.26) in a quantitative yield.Single-crystal structure of 2 was determined by X-ray crystallography.2 crystallizes in the monoclinic system, space group P21/n with a =13.3247(6), b = 24.7929(11), c = 19.1810(9)(。A), β= 109.272(1)°, V= 5981.5(5)(。A)3, Dc.= 1.130 g/cm3, μ = 0.073 mm-1, F(000) = 2176 and Z = 4.Overall structure of 2 reveals an octopus-like resorcinarene with eight propargyl groups in different directions.The resorcinarene adopts the boat conformation where the iso-butyl residues act as four-legged piano stool.The two opposite aryl rings of the macrocyclic framework are almost coplanar, and the two others facing each other are perpendicular to this plane.

  9. Vapour phase alkylation of ethylbenzene with -butyl alcohol over mesoporous Al-MCM-41 molecular sieves

    Indian Academy of Sciences (India)

    V Umamaheswari; M Palanichamy; Banumathi Arabindoo; V Murugesan

    2002-06-01

    The alkylation of ethylbenzene with -butyl alcohol was studied over Al-MCM-41 (Si/Al = 50 and 90) and Al, Mg-MCM-41 (Si/(Al + Mg) =50) in the vapour phase from 200 to 400°C. The products were --butylethylbenzene (--BEB), --butylvinylbenzene (--BVB) and --butylethylbenzene ( --BEB). Ethylbenzene conversion decreased with increase in temperature and increase in the ethylbenzene content of the feed. The reaction between the freely diffusing ethylbenzene in the channel and the -butyl cations remaining as charge compensating ions yielded --BEB. --BVB, an unexpected product in this investigation, was produced by dehydrogenation of --BEB over alumina particles present in the channels of the molecular sieves. Adsorption of ethylbenzene on Brønsted acid sites and its subsequent reaction with very closely adsorbed -butyl cations proved to be necessary to obtain --BEB. Though --BEB was obtained, the corresponding --butylvinylbenzene was not observed in this study. Study of time durations indicated rapid and slow catalyst deactivation at lower and higher streams respectively.

  10. Comprehensive testing to measure the response of butyl rubber to Hanford tank waste simulant

    Energy Technology Data Exchange (ETDEWEB)

    NIGREY,PAUL J.

    2000-05-01

    This report presents the findings of the Chemical Compatibility Program developed to evaluate plastic packaging components that may be incorporated in packaging mixed-waste forms for transportation. Consistent with the methodology outlined in this report, the authors performed the second phase of this experimental program to determine the effects of simulant Hanford tank mixed wastes on packaging seal materials. That effort involved the comprehensive testing of five plastic liner materials in an aqueous mixed-waste simulant. The testing protocol involved exposing the materials to {approximately}143, 286, 571, and 3,670 krad of gamma radiation and was followed by 7-, 14-, 28-, 180-day exposures to the waste simulant at 18, 50, and 60 C. Butyl rubber samples subjected to the same protocol were then evaluated by measuring seven material properties: specific gravity, dimensional changes, mass changes, hardness, compression set, vapor transport rates, and tensile properties. From the analyses, they determined that butyl rubber has relatively good resistance to radiation, this simulant, and a combination of these factors. These results suggest that butyl rubber is a relatively good seal material to withstand aqueous mixed wastes having similar composition to the one used in this study.

  11. Catalytic Upgrading of Biomass-Derived Furfuryl Alcohol to Butyl Levulinate Biofuel over Common Metal Salts

    Directory of Open Access Journals (Sweden)

    Lincai Peng

    2016-09-01

    Full Text Available Levulinate ester has been identified as a promising renewable fuel additive and platform chemical. Here, the use of a wide range of common metal salts as acid catalysts for catalytic upgrading of biomass-derived furfuryl alcohol to butyl levulinate was explored by conventional heating. Both alkali and alkaline earth metal chlorides did not lead effectively to the conversion of furfuryl alcohol, while several transition metal chlorides (CrCl3, FeCl3, and CuCl2 and AlCl3 exhibited catalytic activity for the synthesis of butyl levulinate. For their sulfates (Cr(III, Fe(III, Cu(II, and Al(III, the catalytic activity was low. The reaction performance was correlated with the Brønsted acidity of the reaction system derived from the hydrolysis/alcoholysis of cations, but was more dependent on the Lewis acidity from the metal salts. Among these investigated metal salts, CuCl2 was found to be uniquely effective, leading to the conversion of furfuryl alcohol to butyl levulinate with an optimized yield of 95%. Moreover, CuCl2 could be recovered efficiently from the resulting reaction mixture and remained with almost unchanged catalytic activity in multiple recycling runs.

  12. Synthesis of n-butyl acetate%乙酸正丁酯的合成

    Institute of Scientific and Technical Information of China (English)

    补朝阳

    2013-01-01

    以乙酸和正丁醇为原料,在硫酸氢钾催化下合成了乙酸正丁酯;考察了反应时间、醇酸比、催化剂用量、带水剂用量及催化剂的重复使用对酯化率的影响.结果表明:当正丁醇用量为0.1 mol ,乙酸用量为0.135 mol ,催化剂硫酸氢钾用量为0.8g,带水剂环己烷用量为8mL时,反应的酯化率达95.2%.%Butyl acetate was synthesized with acetic acid and butyl alcohol as the raw materials and potassium bisulfate as the catalyst .The effects of reaction time ,the ratio of alcohol to acid ,dosage of catalyst ,dosage of water-carrying agent ,and the reuse of the catalyst on the esterification rate were investigated .Results show that an esterification rate of 95 .2% is ob-tained when the dosage of butyl alcohol ,acetic acid ,potassium bisulfate catalyst ,and water-carrying agent cyclohexane is set as 0 .1 mol ,0 .135 mol ,0 .8 g ,and 8 mL .

  13. Gamma radiolysis of methyl t-butyl ether: a study of hydroxyl radical mediated reaction pathways

    Energy Technology Data Exchange (ETDEWEB)

    Wu Taixing; Cruz, Vivian; Mezyk, Stephen; Cooper, William J.; O' Shea, Kevin E. E-mail: osheak@fiu.edu

    2002-11-01

    The reactions of hydroxyl radicals with methyl t-butyl ether (MTBE) were studied using gamma radiolysis. Aqueous solutions of 100 ppm MTBE were saturated with 4:1 N{sub 2}O/O{sub 2} gas mixture prior to irradiation. Under these conditions hydroxyl radical is the predominant reactive species generated during gamma radiolysis. Complete degradation of MTBE is achieved within {approx}30 min of irradiation at a dose rate of 0.21 kGy/min. The major volatile organic compounds (VOCs) produced are t-butyl formate (TBF), t-butyl alcohol (TBA), acetone, and methyl acetate. Under the reaction conditions, TBF does not yield TBA, but rather acetone as the primary reaction product. The formation of TBA by hydrolysis of TBF and a hemiacetal formed during the initial oxidative processes of MTBE appear to be minor reaction pathways. Although 2-methyl-2-methoxyl-propionaldehyde (MMP) has been proposed as a reaction product, we were unable to confirm its existence and we therefore, propose a reaction pathway, which does not involve MMP, as the predominant path leading to the formation of methyl acetate. The overall yields of VOCs are low with maximum individual yields between 4% and 13%. Upon extended treatment with gamma radiolysis the VOCs can be completely degraded. These studies contribute to a better fundamental understanding of the reactions of hydroxyl radicals with MTBE, and the resulting oxidation products, TBF and TBA.

  14. Reaction kinetics for synthesis of sec-butyl alcohol catalyzed by acid-functionalized ionic liquid

    Institute of Scientific and Technical Information of China (English)

    Ting Qiu; Wenli Tang; Chenggang Li; Chengming Wu; Ling Li

    2015-01-01

    The acid-functionalized ionic liquid ([HSO3Pmim]HSO4) was synthesized by a two-step method. Nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FT-IR) show that the synthesis method is feasible and high purity of ionic liquid can be obtained. Using [HSO3Pmim]HSO4 as the catalyst, we studied the reaction kinetics of synthesizing sec-butyl alcohol from sec-butyl acetate and methanol by transesterification in a high-pressure batch reactor. The effects of temperature, initial molar ratio of methanol to ester, and catalyst concentration on the conversion of sec-butyl acetate were studied. Based on its possible reaction mechanism, a ho-mogeneous kinetic model was established. The results show that the reaction heatΔH is 10.94 × 103 J·mol−1, so the reaction is an endothermic reaction. The activation energies Ea+and Ea−are 60.38 × 103 and 49.44 × 103 J·mol−1, respectively.

  15. N-acetil-l-cysteine and 2-amino-2-thiiazoline N-acetyl-l-cysteinate as a possible cancer chemopreventive agents in murine models.

    Science.gov (United States)

    Simkeviciene, Vitalija; Straukas, J; Uleckiene, Saule

    2002-01-01

    The aim of this study was to investigate N-acetyl-cysteine (NAC) and its 2-amino-2-thiazoline salt (NACAT) as potential chemopreventive agents on experimentally induced lung tumours by urethane (U) in mice. Female BALB/c mice were used. U was given by intraperitoneal injections during 2 weeks (single dose - 10 mg/mouse, total - 50 mg/mouse). Mice were treated daily per os with NAC 1/10 LD50, NACAT 1/10 or 1/100 LD50 starting 2 weeks prior U administration, then during U treatment and thereafter for 2 months. The duration of experiment was 4 months. The results showed that NAC (1000 mg/kg) reduced the lung tumour incidence to 30% that of controls, P < or = 0.05. Most effective of NACAT was 100 mg/kg dose; it reduced an average of lung adenomas per mouse by 26%, P < or = 0.05, but lower dose (10 mg/kg) was less effective. In order to achieve similar chemopreventive effect (approximately 30%) on mice, it is necessary to use 0.38 mM/kg of NACAT or 6.13 mM/kg of NAC. It means that 16 times less of NACAT is required, if calculated by molar concentration. In general, NAC and NACAT have a moderate chemopreventive effect on lung tumorigenesis induced by urethane in mice. PMID:12371608

  16. Soil adsorption studies of a rice herbicide, cyhalofop-butyl, in two texturally different soils of India.

    Science.gov (United States)

    Sondhia, Shobha; Khare, Rishi Raj

    2014-10-01

    The ability of herbicides to be adsorbed by the soil and sediment and their tendency to be desorbed are some of the most important factors affecting soil and water contamination. Therefore, a sorption study was conducted to evaluate the adsorption of cyhalofop-butyl, butyl (2R)-2-[4-(4-cyano-2-fluorophenoxy) phenoxy] propanoate, in the sandy clay loam and clayey soils using a batch equilibrium method. The adsorption of cyhalofop-butyl was found positively related with the clay and organic carbon content. Freundlich constants (Kf) of cyhalofop-butyl in the clayey and sandy clay loam were found to be 13.39 and 2.21, respectively. Sorption coefficients (Koc) and distribution coefficients (Kd) were found to be 265.38 and 2,092.79, and 1.38 and 11.48, for sandy clay loam and clayey soils, respectively. The adsorption isotherm suggested a relatively higher affinity of cyhalofop-butyl to the adsorption sites at low equilibrium concentrations. The low value of the soil organic carbon partition coefficient (Koc) of cyhalofop-butyl in the sandy loam soil suggested its weaker adsorption in soil and thus increased its risk of mobility into water sources; hence, it should be used judiciously to prevent groundwater contamination. PMID:24875347

  17. Discovery and application of new bacterial strains for asymmetric synthesis of L-tert-butyl leucine in high enantioselectivity.

    Science.gov (United States)

    Jin, Jian-Zhong; Chang, Dong-Liang; Zhang, Jie

    2011-06-01

    Discovery of new bacterial strains with fast identification in a miniaturized system was performed for the synthesis of optically active L-tert-butyl leucine. With tert-butyl leucine amide as nitrogen source, one bacterial strain with high conversion and high enantioselectivity was discovered among 120 isolated microorganisms from local soils and identified as Mycobacterium sp. JX009. Glucose and ammonium chloride were examined as the good carbon source and nitrogen source for the cells' growth separately. The cells grew better at 30 °C and at pH 7.5 with higher activity of 2,650 U/l in comparison with other conditions. Cells' stability was improved by immobilization on synthetic resin 0730 without pretreatment. Tert-butyl leucine amide (30 mM) was successfully hydrolyzed by immobilized cells and examined as the highest chemical concentration that cells could endure. After six reaction cycles, the immobilized cells retained 90% activity with production of L-tert-butyl leucine in 98% ee. The results firstly reported the application of new bacterial strain in the hydrolysis of tert-butyl leucine amide to produce optically active L-tert-butyl leucine in an efficient way with investigation in detail. PMID:21153891

  18. A novel role of the aryl hydrocarbon receptor (AhR in centrosome amplification - implications for chemoprevention

    Directory of Open Access Journals (Sweden)

    Chatterjee Payel

    2010-06-01

    Full Text Available Abstract Background Centrosome aberrations can cause genomic instability and correlate with malignant progression in common human malignancies such as breast and prostate cancer. Deregulation of cyclin/cyclin-dependent kinase 2 (CDK2 activity has previously been shown to be critically involved in centrosome overduplication. We therefore test here whether small molecule CDK inhibitors derived from the bis-indole indirubin can be used to suppress centrosome aberrations as a novel approach to chemoprevention of malignant progression. Results As expected, we found that the CDK inhibitor indirubin-3'-oxime (IO suppresses centrosome amplification in breast cancer cells. However, we made the unexpected discovery that indirubin-derived compounds that have been chemically modified to be inactive as kinase inhibitors such as 1-methyl-indirubin-3'-oxime (MeIO still significantly reduced centrosome amplification. All indirubins used in the present study are potent agonists of the aryl hydrocarbon receptor (AhR, which is known for its important role in the cellular metabolism of xenobiotics. To corroborate our results, we first show that the coincidence of nuclear AhR overexpression, reflecting a constitutive activation, and numerical centrosome aberrations correlates significantly with malignancy in mammary tissue specimens. Remarkably, a considerable proportion (72.7% of benign mammary tissue samples scored also positive for nuclear AhR overexpression. We furthermore provide evidence that continued expression of endogenous AhR is critical to promote centriole overduplication induced by cyclin E and that AhR and cyclin E may function in the same pathway. Overexpression of the AhR in the absence of exogenous ligands was found to rapidly disrupt centriole duplication control. Nonetheless, the AhR agonists IO and MeIO were still found to significantly reduce centriole overduplication stimulated by ectopic AhR expression. Conclusions Our results indicate that

  19. Lipid-based oral delivery systems for skin deposition of a potential chemopreventive DIM derivative: characterization and evaluation.

    Science.gov (United States)

    Boakye, Cedar H A; Patel, Ketan; Patel, Apurva R; Faria, Henrique A M; Zucolotto, Valtencir; Safe, Stephen; Singh, Mandip

    2016-10-01

    The objective of this study was to explore the oral route as a viable potential for the skin deposition of a novel diindolylmethane derivative (DIM-D) for chemoprevention activity. Various lipid-based oral delivery systems were optimized and compared for enhancing DIM-D's oral bioavailability and skin deposition. Preformulation studies were performed to evaluate the log P and solubility of DIM-D. Microsomal metabolism, P-glycoprotein efflux, and caco-2 monolayer permeability of DIM-D were determined. Comparative evaluation of the oral absorption and skin deposition of DIM-D-loaded various lipid-based formulations was performed in rats. DIM-D showed pH-dependent solubility and a high log P value. It was not a strong substrate of microsomal degradation and P-glycoprotein. SMEDDs comprised of medium chain triglycerides, monoglycerides, and kolliphor-HS15 (36.70 ± 0.42 nm). SNEDDs comprised of long chain triglycerides, cremophor RH40, labrasol, and TPGS (84.00 ± 14.14 nm). Nanostructured lipid carriers (NLC) consisted of compritol, miglyol, and surfactants (116.50 ± 2.12 nm). The blank formulations all showed >70 % cell viability in caco-2 cells. Differential Scanning Calorimetry confirmed the amorphization of DIM-D within the lipid matrices while Atomic Force Microscopy showed particle size distribution similar to the dynamic light scattering data. DIM-D also showed reduced permeation across caco-2 monolayer that was enhanced (p < 0.05) by SNEDDs in comparison to SMEDDs and NLC. Fabsolute for DIM-D SNEDDs, SMEDDs, and NLC was 0.14, 0.04, and 0.007, respectively. SNEDDs caused 53.90, 11.32, and 15.08-fold more skin deposition of DIM-D than the free drug, SMEDDs, and NLC, respectively, at 2 h following oral administration and shows a viable potential for use in skin cancer chemoprevention. Graphical Abstract ᅟ. PMID:27405772

  20. Sulforaphane, a cancer chemopreventive agent, induces pathways associated with membrane biosynthesis in response to tissue damage by aflatoxin B1.

    Science.gov (United States)

    Techapiesancharoenkij, Nirachara; Fiala, Jeannette L A; Navasumrit, Panida; Croy, Robert G; Wogan, Gerald N; Groopman, John D; Ruchirawat, Mathuros; Essigmann, John M

    2015-01-01

    Aflatoxin B1 (AFB1) is one of the major risk factors for liver cancer globally. A recent study showed that sulforaphane (SF), a potent inducer of phase II enzymes that occurs naturally in widely consumed vegetables, effectively induces hepatic glutathione S-transferases (GSTs) and reduces levels of hepatic AFB1-DNA adducts in AFB1-exposed Sprague Dawley rats. The present study characterized the effects of SF pre-treatment on global gene expression in the livers of similarly treated male rats. Combined treatment with AFB1 and SF caused reprogramming of a network of genes involved in signal transduction and transcription. Changes in gene regulation were observable 4h after AFB1 administration in SF-pretreated animals and may reflect regeneration of cells in the wake of AFB1-induced hepatotoxicity. At 24h after AFB1 administration, significant induction of genes that play roles in cellular lipid metabolism and acetyl-CoA biosynthesis was detected in SF-pretreated AFB1-dosed rats. Induction of this group of genes may indicate a metabolic shift toward glycolysis and fatty acid synthesis to generate and maintain pools of intermediate molecules required for tissue repair, cell growth and compensatory hepatic cell proliferation. Collectively, gene expression data from this study provide insights into molecular mechanisms underlying the protective effects of SF against AFB1 hepatotoxicity and hepatocarcinogenicity, in addition to the chemopreventive activity of this compound as a GST inducer. PMID:25450479

  1. Chemopreventive potential of fungal taxol against 7, 12-dimethylbenz[a]anthracene induced mammary gland carcinogenesis in Sprague Dawley rats.

    Science.gov (United States)

    Gokul Raj, Kathamuthu; Chidambaram, Ranganathan; Varunkumar, Krishnamoorthy; Ravikumar, Vilwanathan; Pandi, Mohan

    2015-11-15

    Breast cancer is the second most prevalent cancer and foremost global public health problem. The present study was designed to appraise the chemopreventive potential of fungal taxol against 7,12-dimethylbenz[a]anthracene (DMBA) induced mammary gland carcinogenesis in Sprague Dawley rats. After 90 days of tumor induction, fungal and authentic taxol were given intraperitoneally once in a week for four weeks. Infrared thermal imaging analysis, serum biochemical parameters such as lipid peroxidase (LPO), creatinine, enzymic and non enzymic antioxidants, liver markers tests such as alanine transaminase (ALT), aspartate aminotransferase (AST), total cholesterol (TC), triglycerides (TG) and lipoproteins was analysed. In addition, histopathological observation (breast, kidney and liver), immunohistochemical analysis (p53 and Her2/neu) and western blotting experiments (bcl-2, bax and caspase-9) were performed both in control and experimental animals. In thermal imaging, decreased temperature was observed in rat treated with fungal and authentic taxol when compared to tumor induced rats. The significant decrease in LPO, creatinine, ALT, AST, TC, TG, lipoproteins and increase in enzymic, non-enzymic antioxidants were exemplified in serum of treated groups. Further histopathology, immunohistochemical and western blot analysis (bax, cas-9 and bcl-2) of apoptotic markers in breast tissues clearly showed the anti-carcinogenic property of fungal taxol. Our findings implement that fungal taxol is a potential chemo preventive agent against DMBA induced mammary gland carcinogenesis.

  2. Familial adenomatous polyposis in pediatrics: natural history, emerging surveillance and management protocols, chemopreventive strategies, and areas of ongoing debate.

    Science.gov (United States)

    Septer, Seth; Lawson, Caitlin E; Anant, Shrikant; Attard, Thomas

    2016-07-01

    Familial adenomatous polyposis (FAP) is a hereditary condition with a near 100 % lifetime risk of colorectal cancer without prophylactic colectomy. Most patients with FAP have a mutation in the adenomatous polyposis coli gene on chromosome 5q22. This condition frequently presents in children with polyps developing most frequently in the second decade of life and surveillance colonoscopy is required starting at age ten. Polyps are found not only in the colon, but in the stomach and duodenum. Knowledge of the natural history of FAP is important as there are several extra-colonic sequelae which also require surveillance. In infants and toddlers, there is an increased risk of hepatoblastoma, while in teenagers and adults duodenal carcinomas, desmoid tumors, thyroid cancer and medulloblastoma are more common in FAP than in the general population. Current chemopreventive strategies include several medications and natural products, although to this point there is no consensus on the most efficacious and safe agent. Genetic counseling is an important part of the diagnostic process for FAP. Appropriate use and interpretation of genetic testing is best accomplished with genetic counselor involvement as many families also have concerns regarding future insurability or discrimination when faced with genetic testing. PMID:27056662

  3. Use of the disulfiram/copper complex for breast cancer chemoprevention in MMTV-erbB2 transgenic mice.

    Science.gov (United States)

    Yang, Yanhui; Deng, Qian; Feng, Xiaoshan; Sun, Junjun

    2015-07-01

    The disulfiram/copper complex (DS/Cu) has been demonstrated to exert potent anti-tumor effects in various types of cancer. At present, whether DS/Cu has chemopreventive effects on breast cancer development remains to be fully elucidated. In the present study, using MMTV-erbB2 transgenic mice, it was identified for the first time that DS/Cu treatment was able to inhibit cell growth in breast cancer cells while sparing normal cells in vitro, in addition to delaying the development of mammary tumor development in MMTV-erbB2 transgenic mice in vivo. Morphological examination demonstrated that DS/Cu treatment resulted in cell proliferation inhibition and apoptosis activation in vitro and in vivo. Furthermore, the present study observed that DS/Cu may inhibit proliferation via inhibition of AKT and cyclin D1 signaling and promote apoptosis via c-Jun N-terminal kinase activation and suppression of nuclear factor κB signaling. These results suggested that DS/Cu treatment may be a promising therapy for the prevention of erbB2-positive breast cancer.

  4. 5-tert-Butyl-2-[5-(5-tert-butyl-1,3-benzoxazol-2-yl-2-thienyl]-1,3-benzoxazole

    Directory of Open Access Journals (Sweden)

    Fang-Fang Jian

    2008-12-01

    Full Text Available The title compound, C26H26N2O2S, was prepared by the reaction of thiophene-2,5-dicarboxylic acid and 2-amino-4-tert-butylphenol. One of the tert-butyl groups is disordered over two conformations, with occupancies of 0.539 (1 and 0.461 (2. The two 1,3-benzoxazole rings are almost planar, with dihedral angles of 0.83 (18 and 1.64 (17° between the five- and six-membered rings. The thiophene ring makes dihedral angles of 21.54 (19 and 4.49 (18° with the planes of the five-membered oxazole rings. The crystal packing is controlled by π–π stacking interactions involving the thiophene and benzene rings, with a centroid–centroid distance of 3.748 (2 Å.

  5. Forensic analysis of tertiary-butyl alcohol (TBA) detections in a hydrocarbon-rich groundwater basin.

    Science.gov (United States)

    Quast, Konrad W; Levine, Audrey D; Kester, Janet E; Fordham, Carolyn L

    2016-04-01

    Tertiary-butyl alcohol (TBA), a high-production volume (HPV) chemical, was sporadically detected in groundwater and coalbed methane (CBM) wells in southeastern Colorado's hydrocarbon-rich Raton Basin. TBA concentrations in shallow water wells averaged 75.1 μg/L, while detections in deeper CBM wells averaged 14.4 μg/L. The detection of TBA prompted a forensic investigation to try to identify potential sources. Historic and recent data were reviewed to determine if there was a discernable pattern of TBA occurrence. Supplemental samples from domestic water wells, monitor wells, CBM wells, surface waters, and hydraulic fracturing (HF) fluids were analyzed for TBA in conjunction with methyl tertiary-butyl ether (MTBE) and ethyl tertiary-butyl ether (ETBE), proxies for evidence of contamination from reformulated gasoline or associated oxygenates. Exploratory microbiological sampling was conducted to determine if methanotrophic organisms co-occurred with TBA in individual wells. Meaningful comparisons of historic TBA data were limited due to widely varying reporting limits. Mapping of TBA occurrence did not reveal any spatial patterns or physical associations with CBM operations or contamination plumes. Additionally, TBA was not detected in HF fluids or surface water samples. Given the widespread use of TBA in industrial and consumer products, including water well completion materials, it is likely that multiple diffuse sources exist. Exploratory data on stable isotopes, dissolved gases, and microbial profiling provide preliminary evidence that methanotrophic activity may be producing TBA from naturally occurring isobutane. Reported TBA concentrations were significantly below a conservative risk-based drinking water screening level of 8000 μg/L derived from animal toxicity data. PMID:26946495

  6. Removal of Methyl Tert-Butyl Ether (MTBE from Contaminated Water by Photocatalytic Process

    Directory of Open Access Journals (Sweden)

    A Eslami

    2009-06-01

    Full Text Available "nBackground: Methyl tert-butyl ether (MTBE has been commercially used as an octane enhancer to replace tetraethyl lead in gasoline since 1979. The high mobility, water solubility, and resistance to natural attenuation associated with MTBE may re­sult in contamination of ground and surface waters. In this investigation the degradation of aqueous MTBE at relatively high concentrations was studied by UV-vis/TiO2/O2 photocatalytic process. The effect of important operational parameters such as pH, oxygen flow, catalyst loading, and irradiation time were also studied."nMethods:Concentration of MTBE and intermediates such as tert-butyl formate (TBF and tert-butyl alcohol (TBA were meas­ured using a gas chromatograph equipped with flam ionization detector and combined with headspace sampler."nResults: The time required for complete degradation increased from 15 to 150 min, when the initial concentration was in­creased from 10 to 500 mg/L. The first order rate constant for degradation of MTBE from the hydroxyl radical was esti­mated to be 0.266 to 0.033 min-1 as the concentration increased from 10 to 500 mg/L. Study on the overall mineralization moni­tored by total organic carbon (TOC analysis showed that in the initial concentration of 100 mg/L MTBE, complete min­eralization was obtained after 110 min under UV-vis/TiO2/O2 photocatalytic process."nConclusion: The data presented in this paper clearly indicate that UV/TiO2/O2 advanced oxidation process provides an effi­cient treatment alternative for the remediation of MTBE contaminated water.  

  7. Effect of layered silicate on the barrier properties of cured butyl rubber

    Energy Technology Data Exchange (ETDEWEB)

    Krzeminska, S [Central Institute for Labour Protection - National Research Institute, Department of Personal Equipment, Wierzbowa 48, 90-133 Lodz (Poland); Rzymski, W M [Technical University of Lodz, Institute of Polymer and Dye Technology, Stefanowskiego 12/16, 90-924 Lodz (Poland)], E-mail: sykrz@ciop.lodz.pl

    2009-01-01

    The aim of the study was to investigate the effect of layered silicate nanofiller (bentonite: Nanofil 15, Poro Additive) on the barrier properties of non-polar butyl rubber (the IIR, BK 1675 N brand) conventionally cured with sulphur in respect of selected organic solvents. The barrier properties were assessed on the basis of determination of standarized breakthrough time for cured IIR exposed to the selected solvents with different thermodynamic affinities to IIR, i.e. polar butyl acetate and non-polar cyclohexane. In the case of the non-polar solvent - cyclohexane - no effect of the content of the layered silicate (5 - 20 phr) on improvement of barrier properties of the tested IIR vulcanizates was observed. In contrast, a favorable effect of the silicate nanofiller was observed in the case of the polar solvent - butyl acetate, for which the breakthrough time tested for filler-containing vulcanizate (10 - 20 phr) reached 160 -200 min, whereas the breakthrough time obtained for unfilled vulcanizate was 129 min only. The testing of barrier properties of IIR vulcanizates containing various fillers (layered silicate Nanofil 15 and active silica Ultrasil VN3) added in the amount of 20 phr, indicate the favorable effect of layered silicate only in tests with the polar solvent used (an increase in breaktrhough time from 129 to 164 min). Contrary, the presence of conventional silica leads to decrease of breakthrough time (to 118 min). In the case of the non-polar solvent, no effect of the filler type on barrier properties of the tested vulcanizates was observed.

  8. Molecular Dynamics of Tert-butyl Chloride Confined to CPG (7.4, 15.6 nm)

    Science.gov (United States)

    Szutkowska, L.; Peplińska, B.; Jurga, S.

    2006-08-01

    The paper complements our earlier NMR investigation of molecular dynamics of tert-butyl chloride restricted by geometries of the type MCM-41 and CPG by the new sizes of CPG and by differential scanning calorimetry method. We report proton and deuteron NMR lineshapes and the spin-lattice relaxation results of tert-butyl chloride in CPG of the 15.6 nm and 7.4 nm pore diameter in the temperature range 70 K ≤ T ≤ 292 K. The bulk-like component of the confined tert-butyl chloride, in temperatures corresponding to phase III, is interpreted as a composition of two dynamically different subphases. The parameters of motions of both subphases are derived. The tert-butyl group motion in both subphases is more restricted than in the bulk tert-butyl chloride, although the activation energies are lower. Differential scanning calorimetry was used to determine temperatures of the phase transitions (140 K ≤T ≤292 K). The results show that the depression of the phase transition temperature is pore size dependent and that the confinement has less influence on transition to the plastic phase than on the freezing and on the solid II - solid III transition.

  9. Structure and Supersaturation of Highly Concentrated Solutions of Buckyball in 1-Butyl-3-Methylimidazolium Tetrafluoroborate

    DEFF Research Database (Denmark)

    Fileti, E. E.; Chaban, V. V.

    2014-01-01

    Solubilization of fullerenes is of high interest because of their wide usage in both fundamental research and numerous applications. This paper reports molecular dynamics (MD) simulations of saturated and supersaturated solutions of C-60 in 1-butyl-3-methylimidazolium tetrafluoroborate, [C4C1IM......][BF4], room-temperature ionic liquid (RTIL). The simulations cover a wide range of temperatures between 280 and 500 K at ambient pressure. Unlike in simpler solvents, C-60 in [C4C1IM][BF4] forms highly supersaturated solutions, whose internal arrangement remains unaltered during nearly a microsecond...

  10. Kinetic Study of Np(Ⅵ) Reduction With Tert-butyl Hydrazine

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Tert-butyl hydrazine(TBH) is a new salt free reductant, it can effectively reduce Np(Ⅵ) to Np(Ⅴ) but reduce Pu(Ⅳ)very slowly. Further more, it has the highest ratio of rate constant for Np(Ⅵ) reduction to the rate constant for Pu(Ⅳ) reduction in hydrazine derivatives, so it’s a promising reductant to separate Np, Pu effectively,Reduction kinetic study of the reaction in nitric acid is performed by spectrophotometry. The effect of some factors such as concentration of TBH, HNO3, Np(Ⅵ) and temperature on the redox

  11. 2-sec-Butyl-1-(2-hydroxyethyl-1H-benzimidazole-5-carboxylic acid

    Directory of Open Access Journals (Sweden)

    Nurasyikin Hamzah

    2012-07-01

    Full Text Available In the title compound, C14H18N2O3, the carboxylic group is tilted by 12.00 (4° with respect to the mean plane throught the benzimidazole ring system. The alcohol and carboxyl hydroxy groups are involved in intermolecular O—H...O and O—H...N hydrogen bonds, forming a two-dimensional network extending parallel the ab plane. The network is further stabilized by weak C—H...O interactions. The sec-butyl group is disordered over two sets of sites with refined occupancies of 0.484 (4 and 0.516 (4.

  12. Synthesis and characterization of birch wood xylan succinoylated in 1-n-butyl-3-methylimidazolium chloride

    DEFF Research Database (Denmark)

    Hansen, Natanya Majbritt Louie; Plackett, David

    2011-01-01

    The chemical modification of birch wood xylan was undertaken in the ionic liquid 1-n-butyl-3-methylimidazolium chloride (C4mimCl) using three different long-chain succinic anhydrides: n-octenyl succinic anhydride (n-OSA), n-dodecenyl succinic anhydride (n-DDSA) and n-octadecenyl succinic anhydride...... analysis of the modified and native xylans showed a slight lowering of thermal stability with functionalization. Contact angle measurements on spin-coated surfaces of modified xylan films showed a significant increase in hydrophobicity with the introduction of the alkenyl-functionalized succinic anhydride...

  13. THERMOPHYSICAL PROPERTIES OF 1-BUTYL-3-METHYLIMIDAZOLIUM BIS(TRIFLUOROMETHYLSULFONYL)IMIDE AT HIGH TEMPERATURES AND PRESSURES

    OpenAIRE

    R. Hamidova; I. Kul; Safarov, J.; A. Shahverdiyev; Van Hassel, E.

    2015-01-01

    Abstract Pressure-density-temperature (p, ρ ,T) data of the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [BMIM][NTF2] at T = (273.15 to 413.15) K and pressures up to p =140 MPa are reported with an estimated experimental relative combined standard uncertainty of Δ ρ / ρ = ±(0.01 to 0.08)% in density. The measurements were carried out with a newly constructed Anton-Paar DMA HPM vibration-tube densimeter. The system was calibrated using double-distilled water, aque...

  14. Oxidative DNA damage in male wistar rats exposed to di-n-butyl phthalate

    DEFF Research Database (Denmark)

    Wellejus, A.; Dalgaard, Majken; Loft, S.

    2002-01-01

    Dialkyl phthalate esters are used in the plastic industry and widely distributed in the environment, Previously, it has been shown that di-n-butyl phthalate (DBP) produces testicular atrophy and liver enlargement in rodents, and the mechanisms behind this could involve reactive oxygen species (ROS...... in the formation of testicular atrophy in phthalate-exposed rats, no apparent sign of oxidative DNA damage was found after phthalate exposure perinatally or during the preadult stage, With respect to phthalate-induced oxidative DNA damage in the liver, it appears that the developmental stage during exposure...

  15. Crystal structure of 4-azidomethyl-6-tert-butyl-2H-chromen-2-one

    Directory of Open Access Journals (Sweden)

    Nasseem El-Khatatneh

    2015-04-01

    Full Text Available In the title compound, C14H15N3O2, one of the methyl C atoms of the tert-butyl group lies almost in the plane of the chromene ring system [deviation = −0.097 (2 Å], one lies above and one lies below [deviations = 1.460 (3 and 1.006 (3 Å, respectively]. The C—C—N—N torsion angle is 142.33 (17°. In the crystal, moelcules are linked by weak C—H...O hydrogen bonds to generate C(6 chains propagating in the [010] direction.

  16. tert-Butyl N-[2-(N-isobutyl-4-methoxybenzenesulfonamidoethyl]carbamate

    Directory of Open Access Journals (Sweden)

    Xiao-Guang Bai

    2014-06-01

    Full Text Available The title compound, C18H30N2O5S, was synthesized by the reaction of tert-butyl 2-(isobutylaminoethylcarbamate with p-methoxyphenylsulfonyl chloride. In the molecule, two intramolecular C—H...O hydrogen bonds are observed. In the crystal, molecules are linked by N—H...O hydrogen bonds involving the imino group N atom and the ester group O atom into chains running parallel to the b axis. The chains are further connected by C—H...O hydrogen bonds, forming layers parallel to the bc plane.

  17. Degradation of a recalcitrant xenobiotic compound: methyl tert-butyl ether (MTBE) metabolism by mycobacterium austroafricanum; Degradation d'un compose xenobiotique recalcitrant: metabolisme du methyl tert-butyl ether (MTBE) par mycobacterium austroafricanum IFP 2012

    Energy Technology Data Exchange (ETDEWEB)

    Francois, A.

    2002-11-01

    Methyl tert-butyl ether (MTBE) is introduced up to 15% (vol/vol) in gasoline in order to obtain a good octane number and to prevent carbon monoxide emissions. However, as a consequence of storage tanks leakage, MTBE became one of the major pollutants of aquifers because of its very low biodegradability. The present study aimed at investigating the biodegradation of MTBE by Mycobacterium austroafricanum IFP 2012. The MTBE metabolic pathway was partially elucidated owing to the identification of some intermediates (tert-butyl formate (TBF), tert-butyl alcohol (TBA), a-hydroxy-isobutyric acid and acetone) and some enzymatic activities (MTBE/TBA monooxygenase (non hemic and inducible), TBF esterase, 2-propanol: NDMA oxidoreductase and another monooxygenase involved in acetone degradation). The involvement of TBF and the requirement of cobalt could be explanations for the low natural attenuation of MTBE; whereas the methoxy group does not seem to be implicated. (author)

  18. Study to evaluate molecular mechanics behind synergistic chemo-preventive effects of curcumin and resveratrol during lung carcinogenesis.

    Directory of Open Access Journals (Sweden)

    Anshoo Malhotra

    Full Text Available BACKGROUND: The combination approach is the future of the war against cancer and the present study evaluated molecular mechanics behind the synergistic effects of curcumin and resveratrol during lung carcinogenesis. METHODS: The mice were segregated into five groups which included normal control, Benzo[a]pyrene[BP] treated, BP+curcumin treated, BP+resveratrol treated and BP+curcumin+resveratrol treated. RESULTS: The morphological analyses of tumor nodules confirmed lung carcinogenesis in mice after 22 weeks of single intra-peritoneal[i.p] injection of BP at a dose of 100 mg/Kg body weight. The BP treatment resulted in a significant increase in the protein expressions of p53 in the BP treated mice. Also, a significant increase in the protein expression of phosphorylated p53[ser15] confirmed p53 hyper-phosphorylation in BP treated mice. On the other hand, enzyme activities of caspase 3 and caspase 9 were noticed to be significantly decreased following BP treatment. Further, radiorespirometric studies showed a significant increase in the 14C-glucose turnover as well as 14C-glucose uptake in the lung slices of BP treated mice. Moreover, a significant rise in the cell proliferation was confirmed indirectly by enhanced uptake of 3H-thymidine in the lung slices of BP treated mice. Interestingly, combined treatment of curcumin and resveratrol to BP treated animals resulted in a significant decrease in p53 hyper-phosphorylation, 14C glucose uptakes/turnover and 3H-thymidine uptake in the BP treated mice. However, the enzyme activities of caspase 3 and caspase 9 showed a significant increase upon treatment with curcumin and resveratrol. CONCLUSION: The study, therefore, concludes that molecular mechanics behind chemo-preventive synergism involved modulation of p53 hyper-phosphorylation, regulation of caspases and cellular metabolism enzymes.

  19. The chemopreventive potential of Curcuma purpurascens rhizome in reducing azoxymethane-induced aberrant crypt foci in rats.

    Science.gov (United States)

    Rouhollahi, Elham; Moghadamtousi, Soheil Zorofchian; Al-Henhena, Nawal; Kunasegaran, Thubasni; Hasanpourghadi, Mohadeseh; Looi, Chung Yeng; Abd Malek, Sri Nurestri; Awang, Khalijah; Abdulla, Mahmood Ameen; Mohamed, Zahurin

    2015-01-01

    Curcuma purpurascens BI. rhizome, a member of the Zingiberaceae family, is a popular spice in Indonesia that is traditionally used in assorted remedies. Dichloromethane extract of C. purpurascens BI. rhizome (DECPR) has previously been shown to have an apoptosis-inducing effect on colon cancer cells. In the present study, we examined the potential of DECPR to prevent colon cancer development in rats treated with azoxymethane (AOM) (15 mg/kg) by determining the percentage inhibition in incidence of aberrant crypt foci (ACF). Starting from the day immediately after AOM treatment, three groups of rats were orally administered once a day for 2 months either 10% Tween 20 (5 mL/kg, cancer control), DECPR (250 mg/kg, low dose), or DECPR (500 mg/kg, high dose). Meanwhile, the control group was intraperitoneally injected with 5-fluorouracil (35 mg/kg) for 5 consecutive days. After euthanizing the rats, the number of ACF was enumerated in colon tissues. Bax, Bcl-2, and proliferating cell nuclear antigen (PCNA) protein expressions were examined using immunohistochemical and Western blot analyses. Antioxidant enzymatic activity was measured in colon tissue homogenates and associated with malondialdehyde level. The percentage inhibition of ACF was 56.04% and 68.68% in the low- and high-dose DECPR-treated groups, respectively. The ACF inhibition in the treatment control group was 74.17%. Results revealed that DECPR exposure at both doses significantly decreased AOM-induced ACF formation, which was accompanied by reduced expression of PCNA. Upregulation of Bax and downregulation of Bcl-2 suggested the involvement of apoptosis in the chemopreventive effect of DECPR. In addition, the oxidative stress resulting from AOM treatment was significantly attenuated after administration of DECPR, which was shown by the elevated antioxidant enzymatic activity and reduced malondialdehyde level. Taken together, the present data clearly indicate that DECPR significantly inhibits ACF formation

  20. 植物多酚对胃癌的化学预防%Chemoprevention of plant polyphenols in gastric cancer

    Institute of Scientific and Technical Information of China (English)

    刘入铭; 姜晶; 马麟; 曹雪源

    2012-01-01

    胃癌的发病是多因素相互作用的过程,与宿主因素、幽门螺杆菌(Hp)感染、饮食等因素相关.植物多酚是广泛存在于植物中的一大类多酚化合物的总称,具有较强的抗氧化性,许多动物实验和临床研究表明,多酚类物质能够通过抑制Hp感染、抑制核转录因子-κB(NF-κB)表达、促进肿瘤细胞凋亡等多种途径实现对胃癌的抑制.植物多酚的应用拓宽了胃癌化学预防的途径.%Gastric cancer carcinogenesis is a multifactorial process which is related to an interaction of host factors,Helieobacter pylori (Hp) infection,dietary factors and so on.The plant polyphenols which are widely present in many plants are the general term for a large group polyphenolic compounds.They have strong antioxidant activity.Furthermore,many animal experiments and clinical studies have proved that the polyphenols could inhibit gastric cancer via inhibiting Hp infection,suppressing the expression of nuclear factor-κB (NF-κB),promoting apoptosis in cancer cells and so on.The application of plant polyphenols could broaden the approaches for chemoprevention of gastric cancer.

  1. Anti-proliferative and proapoptotic effects of (-)-epigallocatechin-3-gallate on human melanoma: possible implications for the chemoprevention of melanoma.

    Science.gov (United States)

    Nihal, Minakshi; Ahmad, Nihal; Mukhtar, Hasan; Wood, Gary S

    2005-04-20

    Melanoma accounts for only about 4% of all skin cancer cases but most of skin cancer-related deaths. Standard systemic therapies such as interferon (IFN) have not been adequately effective in the management of melanoma. Therefore, novel approaches are needed for prevention and treatment of this disease. Chemoprevention by naturally occurring agents present in food and beverages has shown benefits in certain cancers including nonmelanoma skin cancers. Here, employing 2 human melanoma cell lines (A-375 amelanotic malignant melanoma and Hs-294T metastatic melanoma) and normal human epidermal melanocytes (NHEM), we studied the antiproliferative effects of epigallocatechin-3-gallate (EGCG), the major polyphenolic antioxidant present in green tea. EGCG treatment was found to result in a dose-dependent decrease in the viability and growth of both melanoma cell lines. Interestingly, at similar EGCG concentrations, the normal melanocytes were not affected. EGCG treatment of the melanoma cell lines resulted in decreased cell proliferation (as assessed by Ki-67 and PCNA protein levels) and induction of apoptosis (as assessed cleavage of PARP, TUNEL assay and JC-1 assay). EGCG also significantly inhibited the colony formation ability of the melanoma cells studied. EGCG treatment of melanoma cells resulted in a downmodulation of anti-apoptotic protein Bcl2, upregulation of proapoptotic Bax and activation of caspases -3, -7 and -9. Furthermore, our data demonstrated that EGCG treatment resulted in a significant, dose-dependent decrease in cyclin D1 and cdk2 protein levels and induction of cyclin kinase inhibitors (ckis) p16INK4a, p21WAF1/CIP1 and p27KIP1. Our data suggest that EGCG causes significant induction of cell cycle arrest and apoptosis of melanoma cells that is mediated via modulations in the cki-cyclin-cdk network and Bcl2 family proteins. Thus, EGCG, alone or in conjunction with current therapies, could be useful for the management of melanoma.

  2. Disruption of androgen and estrogen receptor activity in prostate cancer by a novel dietary diterpene carnosol: implications for chemoprevention

    Science.gov (United States)

    Johnson, Jeremy J.; Syed, Deeba N.; Suh, Yewseok; Heren, Chenelle R.; Saleem, Mohammad; Siddiqui, Imtiaz A.; Mukhtar, Hasan

    2010-01-01

    Emerging data is suggesting that estrogens, in addition to androgens, may also be contributing to the development of prostate cancer (PCa). In view of this notion agents that target estrogens, in addition to androgens, may be a novel approach for PCa chemoprevention and treatment. Thus, the identification and development of non-toxic dietary agents capable of disrupting androgen receptor (AR) in addition to estrogen receptor (ER) could be extremely useful in the management of PCa. Through molecular modeling we found carnosol, a dietary diterpene fits within the ligand binding domain of both AR and ER-α. Using a TR-FRET assay we found that carnosol interacts with both AR and ER-α and additional experiments confirmed that it functions as a receptor antagonist with no agonist effects. LNCaP, 22Rv1, and MCF7 cells treated with carnosol (20–40 µM) showed decreased protein expression of AR and ER-α. Oral administration of carnosol at 30 mg/kg five days weekly for 28 days to 22Rv1 PCa xenografted mice suppressed tumor growth by 36% (p = 0.028) and was associated with a decrease in serum PSA by 26% (p=0.0042). These properties make carnosol unique to any known anti-androgen or anti-estrogen investigated so far for the simultaneous disruption of AR and ER-α. We suggest that carnosol may be developed or chemically modified through more rigorous structure activity relationship studies for a new class of investigational agents - a dual AR/ER modulator. PMID:20736335

  3. Chemopreventive effect of Korean Angelica root extract on TRAMP carcinogenesis and integrative "omic" profiling of affected neuroendocrine carcinomas.

    Science.gov (United States)

    Zhang, Jinhui; Wang, Lei; Zhang, Yong; Li, Li; Tang, Suni; Xing, Chengguo; Kim, Sung-Hoon; Jiang, Cheng; Lü, Junxuan

    2015-12-01

    Angelica gigas Nakai (AGN) root ethanol extract exerts anti-cancer activity in several allograft and xenograft models. Here we examined its chemopreventive efficacy through gavage administration against primary carcinogenesis in the transgenic adenocarcinoma of mouse prostate (TRAMP) model. Male C57BL/6 TRAMP mice and wild type littermates were given a daily gavage (5 mg/mouse, Monday-Friday) of AGN or vehicle, beginning at 8 wk of age (WOA). All mice were terminated at 24 WOA, unless earlier euthanasia was necessitated by large tumors. Whereas AGN-treated TRAMP mice decreased dorsolateral prostate lesion growth by 30% (P = 0.009), they developed fewer and smaller neuroendocrine-carcinomas (NE-Ca) (0.12 g/mouse) than vehicle-treated counterparts (0.81 g/mouse, P = 0.037). We analyzed the proteome and transcriptome of banked NE-Ca to gain molecular insights. Angiogenesis-antibody array detected a substantial reduction in AGN-treated NE-Ca of basic fibroblast growth factor (FGF2), an angiogenesis stimulator. iTRAQ proteomics plus data mining suggested changes of genes upstream and downstream of FGF2 functionally consistent with AGN inhibiting FGF2/FGFR1 signaling at different levels of the transduction cascade. Moreover, AGN upregulated mRNA of genes related to immune responses, restored expression of many tumor suppressor genes, and prostate function and muscle differentiation genes. On the other hand, AGN down-regulated mRNA of genes related to neuron signaling, oncofetal antigens, inflammation, and mast cells, Wnt signaling, embryonic morphogenesis, biosynthesis, cell adhesion, motility, invasion, and angiogenesis. These changes suggest not only multiple cancer cell targeting actions of AGN but also impact on the tumor microenvironments such as angiogenesis, inflammation, and immune surveillance.

  4. Effects of chemopreventive natural products on non-homologous end-joining DNA double-strand break repair.

    Science.gov (United States)

    Charles, Catherine; Nachtergael, Amandine; Ouedraogo, Moustapha; Belayew, Alexandra; Duez, Pierre

    2014-07-01

    Double-strand breaks (DSBs) may result from endogenous (e.g., reactive oxygen species, variable (diversity) joining, meiotic exchanges, collapsed replication forks, nucleases) or exogenous (e.g., ionizing radiation, chemotherapeutic agents, radiomimetic compounds) events. DSBs disrupt the integrity of DNA and failed or improper DSBs repair may lead to genomic instability and, eventually, mutations, cancer, or cell death. Non-homologous end-joining (NHEJ) is the major pathway used by higher eukaryotic cells to repair these lesions. Given the complexity of NHEJ and the number of proteins and cofactors involved, secondary metabolites from medicinal or food plants might interfere with the process, activating or inhibiting repair. Twelve natural products, arbutin, curcumin, indole-3-carbinol, and nine flavonoids (apigenin, baicalein, chalcone, epicatechin, genistein, myricetin, naringenin, quercetin, sakuranetin) were chosen for their postulated roles in cancer chemoprevention and/or treatment. The effects of these compounds on NHEJ were investigated with an in vitro protocol based on plasmid substrates. Plasmids were linearized by a restriction enzyme, generating cohesive ends, or by a combination of enzymes, generating incompatible ends; plasmids were then incubated with a nuclear extract prepared from normal human small-intestinal cells (FHS 74 Int), either treated with these natural products or untreated (controls). The NHEJ repair complex from nuclear extracts ligates linearized plasmids, resulting in plasmid oligomers that can be separated and quantified by on-chip microelectrophoresis. Some compounds (chalcone, epicatechin, myricetin, sakuranetin and arbutin) clearly activated NHEJ, whereas others (apigenin, baicalein and curcumin) significantly reduced the repair rate of both types of plasmid substrates. Although this in vitro protocol is only partly representative of the in vivo situation, the natural products appear to interfere with NHEJ repair and warrant

  5. Seasonal Malaria Chemoprevention with Sulphadoxine-Pyrimethamine and Amodiaquine Selects Pfdhfr-dhps Quintuple Mutant Genotype in Mali

    Science.gov (United States)

    Maiga, Hamma; Lasry, Estrella; Diarra, Modibo; Sagara, Issaka; Bamadio, Amadou; Traore, Aliou; Coumare, Samba; Bahonan, Soma; Sangare, Boubou; Dicko, Yeyia; Diallo, Nouhoum; Tembely, Aly; Traore, Djibril; Niangaly, Hamidou; Dao, François; Haidara, Aboubecrine; Dicko, Alassane; Doumbo, Ogobara K.; Djimde, Abdoulaye A.

    2016-01-01

    Background Seasonal malaria chemoprevention (SMC) with sulphadoxine-pyrimethamine (SP) plus amodiaquine (AQ) is being scaled up in Sahelian countries of West Africa. However, the potential development of Plasmodium falciparum resistance to the respective component drugs is a major concern. Methods Two cross-sectional surveys were conducted before (August 2012) and after (June 2014) a pilot implementation of SMC in Koutiala, Mali. Children aged 3–59 months received 7 rounds of curative doses of SP plus AQ over two malaria seasons. Genotypes of P. falciparum Pfdhfr codons 51, 59 and 108; Pfdhps codons 437 and 540, Pfcrt codon 76 and Pfmdr1codon 86 were analyzed by PCR on DNA from samples collected before and after SMC, and in non-SMC patient population as controls (November 2014). Results In the SMC population 191/662 (28.9%) and 85/670 (12.7%) of children were P. falciparum positive by microscopy and were included in the molecular analysis before (2012) and after SMC implementation (2014), respectively. In the non-SMC patient population 220/310 (71%) were successfully PCR analyzed. In the SMC children, the prevalence of all molecular markers of SP resistance increased significantly after SMC including the Pfdhfr-dhps quintuple mutant genotype, which was 1.6% before but 7.1% after SMC (p = 0.02). The prevalence of Pfmdr1-86Y significantly decreased from 26.7% to 15.3% (p = 0.04) while no significant change was seen for Pfcrt 76T. In 2014, prevalence of all molecular markers of SP resistance were significantly higher among SMC children compared to the non-SMC population patient (p falciparum resistance to SP in the treated children. However, there was no significant increase of these markers of resistance in the general parasite population after 2 years and 7 rounds of SMC. PMID:27662368

  6. Selection of drug resistance-mediating Plasmodium falciparum genetic polymorphisms by seasonal malaria chemoprevention in Burkina Faso.

    Science.gov (United States)

    Somé, Anyirékun Fabrice; Zongo, Issaka; Compaoré, Yves-Daniel; Sakandé, Souleymane; Nosten, François; Ouédraogo, Jean-Bosco; Rosenthal, Philip J

    2014-07-01

    Seasonal malaria chemoprevention (SMC), with regular use of amodiaquine plus sulfadoxine-pyrimethamine (AQ/SP) during the transmission season, is now a standard malaria control measure in the Sahel subregion of Africa. Another strategy under study is SMC with dihydroartemisinin plus piperaquine (DP). Plasmodium falciparum single nucleotide polymorphisms (SNPs) in P. falciparum crt (pfcrt), pfmdr1, pfdhfr, and pfdhps are associated with decreased response to aminoquinoline and antifolate antimalarials and are selected by use of these drugs. To characterize selection by SMC of key polymorphisms, we assessed 13 SNPs in P. falciparum isolated from children aged 3 to 59 months living in southwestern Burkina Faso and randomized to receive monthly DP or AQ/SP for 3 months in 2009. We compared SNP prevalence before the onset of SMC and 1 month after the third treatment in P. falciparum PCR-positive samples from 120 randomly selected children from each treatment arm and an additional 120 randomly selected children from a control group that did not receive SMC. The prevalence of relevant mutations was increased after SMC with AQ/SP. Significant selection was seen for pfcrt 76T (68.5% to 83.0%, P = 0.04), pfdhfr 59R (54.8% to 83.3%, P = 0.0002), and pfdhfr 108N (55.0% to 87.2%, P = 0.0001), with trends toward selection of pfmdr1 86Y, pfdhfr 51I, and pfdhps 437G. After SMC with DP, only borderline selection of wild-type pfmdr1 D1246 (mutant; 7.7% to 0%, P = 0.05) was seen. In contrast to AQ/SP, SMC with DP did not clearly select for known resistance-mediating polymorphisms. SMC with AQ/SP, but not DP, may hasten the development of resistance to components of this regimen. (This study has been registered at ClinicalTrials.gov under registration no. NCT00941785.).

  7. Quimioprevenção do câncer de mama Current status of breast cancer chemoprevention

    Directory of Open Access Journals (Sweden)

    Vilmar Marques de Oliveira

    2006-12-01

    Full Text Available Quimioprevenção é definida como o uso de agentes químicos naturais ou sintéticos para reverter, suprimir ou prevenir a progressão carcinogênica para carcinoma invasor. Os fármacos que agem como agentes quimiopreventivos contra o câncer de mama são divididos em dois grupos principais: os que previnem cânceres de mama receptor de estrogênio (RE positivos, como os moduladores seletivos do receptor de estrogênio (SERM, inibidores de aromatase, agonistas de GnRH e fitoestrogênios; e os fármacos que previnem os cânceres RE-negativos, como os inibidores da ciclooxigenase-2 (COX-2, retinóides, as estatinas, os inibidores do receptor tirosina quinase, o anticorpo monoclonal contra HER-2 e os inbidores da telomerase. Resultados do estudo conduzido pelo NSABP que comparou o tamoxifeno com o raloxifeno (STAR, avaliando a eficácia na redução de risco, assim como a toxicidade desses dois SERMs em uma população similar e de alto risco para câncer de mama, demonstrou que o raloxifeno é tão efetivo quanto o tamoxifeno na redução de risco de câncer de mama invasor (p=0,83 e apresentou menor risco de eventos tromboembólicos e catarata; todavia, exibiu maior risco de carcinoma não invasor, porém sem significância estatística. Baseado nos dados promissores que revelaram diminuição de risco de câncer de mama contralateral em estudos de adjuvância, alguns inibidores de aromatase, incluindo o letrozol, anastrazol e exemestane, estão sendo incorporados em investigações para avaliar sua eficácia como agentes preventivos de alto risco em mulheres. Os inibidores de COX-2 demonstraram sua eficácia na prevenção do câncer de mama em estudos caso-controle e coorte, sendo necessários estudos aleatórios para atestar sua eficácia. O resultado positivo de alguns ensaios clínicos na prevenção do câncer de mama em populações de alto risco sugere que a quimioprevenção é uma estratégia racional e atraente.Chemoprevention is

  8. Crystal structure of catena-poly[[(3-tert-butyl­pyridine-κN)(4-tert-butyl­pyridine-κN)cadmium]-di-μ-thio­cyanato-κ2 N:S;κ2 S:N

    OpenAIRE

    Werner, Julia; Reinert, Thorben; Jess, Inke; Näther, Christian

    2014-01-01

    In the crystal structure of the title compound, [Cd(NCS)2(C9H13N)2] n , the CdII cations are coordinated in a slightly distorted octa­hedral geometry by one 3-tert-butyl­pyridine ligand, one 4-tert-butyl­pyridine ligand and two pairs of translationally-equivalent μ-1,3-bridging thio­cyanate ligands, all of which are in general positions. These μ-1,3-bridging thio­cyante anions bridge the CdII cations, forming chains that propagate parallel to the b axis.

  9. Chemopreventive potential of Triphala (a composite Indian drug) on Benzo(a)pyrene induced forestomach tumorigenesis in murine tumor model system

    Energy Technology Data Exchange (ETDEWEB)

    Deep, G.; Dhirman, M.; Rao, A.R.; Kale, R.K. [Jawaharlan Nehru Univ., New Delhi (India). Radiation and Cancer Biology Laboratory

    2005-12-15

    The present work is probably the first report on cancer chemopreventive potential of Triphala, a combination of fruit powder of three different plants namely Terminalia chebula, Terminalia belerica and Emblica officinalis. Triphala is a popular formulation of the Ayurvedic system of medicine. Our findings have shown that Triphala in diet has significantly reduced the benzo(a)pyrene [B(a)P] induced forestomach papillomagenesis in mice. In the short term treatment groups, the tumor incidences were lowered to 77.77% by both doses of Triphala mixed diet. In the case of long-term treatment the tumor incidences were reduced to 66.66% and 62.50% respectively by 2.5% and 5% triphala containing diet. Tumor burden was 7.27{+-}1.16 in the B(a)P treated control group, whereas it reduced to 3.00{+-}0.82 (p<0.005) by 2.5% dose and 2.33 +/- 1.03 (p<0.001) by 5% dose of Triphala. In long-term studies the tumor burden was reduced to 2.17{+-}0.75 (p<0.001) and 2.00{+-}0.71 (p<0.001) by 2.5% and 5% diet of Triphala, respectively. It was important to observe that Triphala was more effective in reducing tumor incidences compared to its individual constituents. Triphala also significantly increased the antioxidant status of animals which might have contributed to the chemoprevention. It was inferred that the concomitant use of multiple agents seemed to have a high degree of chemoprevention potential.

  10. DNA damage and aberrant crypt foci as putative biomarkers to evaluate the chemopreventive effect of annatto (Bixa orellana L.) in rat colon carcinogenesis.

    Science.gov (United States)

    Agner, Aniele R; Bazo, Ana P; Ribeiro, Lúcia R; Salvadori, Daisy M F

    2005-04-01

    Chemoprevention opens new perspectives in the prevention of cancer and other degenerative diseases. Use of target-organ biological models at the histological and genetic levels can markedly facilitate the identification of such potential chemopreventive agents. Colon cancer is one of the highest incidence rates throughout the world and some evidences have indicated carotenoids as possible agents that decrease the risk of colorectal cancer. In the present study, we evaluate the activity of annatto (Bixa orellana L.), a natural food colorant rich in carotenoid, on the formation of aberrant crypt foci (ACF) induced by dimethylhydrazine (DMH) in rat colon. Further, we investigate, the effect of annatto on DMH-induced DNA damage, by the comet assay. Male Wistar rats were given s.c. injections of DMH (40 mg/kg body wt.) twice a week for 2 weeks to induce ACF. They also received experimental diets containing annatto at 20, 200 or 1000 ppm for five 5 weeks before (pre-treatment), or 10 weeks after (post-treatment) DMH treatment. In both protocols the rats were sacrificed on week 15th. For the comet assay, the animals were fed with the same experimental diets for 2 weeks. Four hours before the sacrifice, the animals received an s.c. injection of DMH (40 mg/kg body wt.). Under such conditions, dietary administration of 1000 ppm annatto neither induce DNA damage in blood and colon cells nor aberrant crypt foci in rat distal colon. Conversely, annatto was successful in inhibiting the number of crypts/colon (animal), but not in the incidence of DMH-induced ACF, mainly when administered after DMH. However, no antigenotoxic effect was observed in colon cells. These findings suggest possible chemopreventive effects of annatto through their modulation of the cryptal cell proliferation but not at the initiation stage of colon carcinogenesis. PMID:15781219

  11. Paricalcitol Enhances the Chemopreventive Efficacy of 5-Fluorouracil on an Intermediate-Term Model of Azoxymethane-Induced Colorectal Tumors in Rats.

    Science.gov (United States)

    El-Shemi, Adel Galal; Refaat, Bassem; Kensara, Osama Adnan; Mohamed, Amr Mohamed; Idris, Shakir; Ahmad, Jawwad

    2016-06-01

    Colorectal cancer is a common cancer with high mortality rate. Despite being the standard anti-colorectal cancer drug, 5-fluorouracil (5-FU) exhibits only limited therapeutic benefits. Herein, we investigated whether paricalcitol, a synthetic vitamin D analogue with potential antitumor properties, would enhance the chemopreventive efficacy of 5-FU on an intermediate-term (15 weeks) model of colorectal tumors induced by azoxymethane (AOM) in rats. After AOM injection, 5-FU was administered during the 9th and 10th weeks (12 mg/kg/day for 4 days, then 6 mg/kg every other day for another 4 doses), whereas paricalcitol (2.5 μg/kg/day; 3 days/week) was given from the 7th to the 15th week. At week 15, the animals were euthanized and their resected colons were examined macroscopically and microscopically. Quantitative RT-PCR was used to measure the transcription activities of Wnt, β-catenin, DKK-1, CDNK-1A, NF-κB, and COX-2 genes, and ELISA was used to quantify the protein levels of β-catenin, COX-2, HSP90, and VEGF. IHC was additionally used to measure β-catenin, HSP90, and inducible nitric oxide synthase (iNOS). Compared with their individual therapy, combination of 5-FU and paricalcitol showed more significant reducing effect on numbers of grown tumors and large aberrant crypts foci. Mechanistically, paricalcitol and 5-FU had cooperated together to repress the expression of procancerous Wnt, β-catenin, NF-κB, COX-2, iNOS, VEGF, and HSP-90 more, and to upregulate the expression of antitumorigenesis DKK-1 and CDNK-1A, compared with their monotherapies. Our findings suggest that combined use of paricalcitol with 5-FU exhibits an augmenting chemopreventive effect against colorectal tumors, and might potentially be useful for chemoprevention in colorectal cancer patients. Cancer Prev Res; 9(6); 491-501. ©2016 AACR. PMID:27020656

  12. Acid-Assisted Ball Milling of Cellulose as an Efficient Pretreatment Process for the Production of Butyl Glycosides.

    Science.gov (United States)

    Boissou, Florent; Sayoud, Nassim; De Oliveira Vigier, Karine; Barakat, Abdellatif; Marinkovic, Sinisa; Estrine, Boris; Jérôme, François

    2015-10-12

    Ball milling of cellulose in the presence of a catalytic amount of H2SO4 was found to be a promising pre-treatment process to produce butyl glycosides in high yields. Conversely to the case of water, n-butanol has only a slight effect on the recrystallization of ball-milled cellulose. As a result, thorough depolymerization of cellulose prior the glycosylation step is no longer required, which is a pivotal aspect with respect to energy consumption. This process was successfully transposed to wheat straw from which butyl glycosides and xylosides were produced in good yields. Butyl glycosides and xylosides are important chemicals as they can be used as hydrotropes but also as intermediates in the production of valuable amphiphilic alkyl glycosides. PMID:26346950

  13. Higher levels of ethyl paraben and butyl paraben in rat amniotic fluid than in maternal plasma after subcutaneous administration

    DEFF Research Database (Denmark)

    Frederiksen, Hanne; Taxvig, Camilla; Hass, Ulla;

    2008-01-01

    to obtain more knowledge about the distribution of ethyl paraben and butyl paraben in pregnant rats and pups after perinatal exposure, the presented study was designed. The data show response and distribution of ethyl paraben and butyl paraben in maternal rat plasma, pools of amniotic fluids, placenta...... with >or= 100 mg/kg bw/day, while both compounds were excreted into amniotic fluid in a dose-dependent manner. Significant difference was found between the level of ethyl paraben in maternal plasma and amniotic fluid after dosing with 200 mg/kg bw/day as well as between the levels of butyl paraben...... in maternal plasma and amniotic fluid after dosing with 100, 200, and 400 mg/kg bw/day....

  14. Alkylation of Hydroquinone with tert-Butyl Alcohol over Bis[(perfluoroalkyl)sulfonyl]imides Supported on MCM-41

    Institute of Scientific and Technical Information of China (English)

    YUAN, Yu-Bin; NIE, Jin; ZHANG, Zheng-Bo; ZHOU, San-Yi

    2006-01-01

    Bis[(perfluoroalkyl)sulfonyl]imides [HN(SO2Rf)2, and Rf represents the perfluorinated alkyl group] supported on MCM-41 were synthesized and characterized by XRD, FTIR, SEM, TGA and N2-adsorption techniques. The supported catalysts, HN(SO2Rf)2/MCM-41, were used as the catalysts for the tert-butylation of hydroquinone (HQ)with tert-butyl alcohol (TBA) in the liquid phase. A high yield (52.0%) of 2-tert-butyl hydroquinone (TBHQ) could be obtained in the presence of 5 mol% HN(SO2C4F9)2/MCM-41 under the optimized reaction conditions and the heterogeneous catalyst could be recycled at least 6 times without substantial loss of activity.

  15. Catalytic Synthesis of Glycerol tert-Butyl Ethers as Fuel Additives from the Biodiesel By-Product Glycerol

    Directory of Open Access Journals (Sweden)

    Rui Huang

    2015-01-01

    Full Text Available Glycerol is a major by-product in the biodiesel production process. Every 100 kg of biodiesel produced generates approximately 10 kg of crude glycerol. As the biodiesel industry has expanded rapidly in recent years, finding new uses of the excess crude glycerol is important. Many studies have examined alternative uses of crude glycerol. One of them is the use of glycerol derivatives, such as glycerol tert-butyl ethers as fuel additives. In this paper, the etherification kinetics of glycerol with tert-butyl alcohol to glycerol tert-butyl ethers was studied using an Amberlyst catalyst. The influences of the catalyst type and loading, reaction time, molar ratio, and temperature were investigated in detail.

  16. BINDING OF THERMO-SENSITIVE AND pH-SENSITIVE BUTYLATED POLY(ALLYLAMINE)S WITH LYSOZYME

    Institute of Scientific and Technical Information of China (English)

    Jing-jing Liu; Yun-feng Yan; Ping Yao

    2011-01-01

    Butyl modified poly(allylamine)s with butyl substitution degrees of 15% to 70% were prepared. The polymers show pH sensitive property and lower critical solution temperature (LCST) behavior. The LCST appears at lower temperature, lower pH and lower polymer concentration for the polymer with higher butylated degree. The binding of native lysozyme with the polymers depends on the hydrophobicity of the polymers at the pH range that the protein and the polymer carry the same positive charges. The increase of polymer hydrophobicity can increase the binding with lysozyme, but the self-aggregation of the polymer decreases the binding. The bound lysozyme molecules can recover their native activity completely after the dissociation of the complexes. Compared with native lysozyme, the denatured one which exposes the hydrophobic residues can increase the binding with the polymer and form stable complex nanoparticles.

  17. Molecular recognition of curcumin (Indian Ayurvedic medicine) by the supramolecular probe, p-t-butyl calix(8)arene

    Science.gov (United States)

    Meenakshi, C.; Jayabal, P.; Ramakrishnan, V.

    2014-06-01

    The thermodynamic property of the host-guest complexes formed between the curcumin, component of Indian Ayurvedic medicine turmeric, a drug molecule, with the supra molecule, p-t-butyl calix(8)arene was studied. p-t-Butyl calix(8)arene has been used as a host molecule and curcumin as a guest molecule. Optical absorption spectral studies were carried out to investigate the molecular recognition properties of p-t-butyl calix(8)arene with curcumin. The stochiometry of the host-guest complexes formed and the binding constant were determined. An interesting 1:1 and 4:1 stochiometric host-guest complexes were formed. Job's continuous method of variation and Benesi-Hildebrand expression were used for the determination of binding constant and the stochiometry of the host-guest complex formed.

  18. The chemopreventive activity of the histone deacetylase inhibitor tributyrin in colon carcinogenesis involves the induction of apoptosis and reduction of DNA damage

    Energy Technology Data Exchange (ETDEWEB)

    Heidor, Renato [Laboratory of Diet, Nutrition and Cancer, Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Advanced Research Center in Food Science and Nutrition (NAPAN) and Food Research Center (FoRC), Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Furtado, Kelly Silva; Ortega, Juliana Festa [Laboratory of Diet, Nutrition and Cancer, Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Oliveira, Tiago Franco de [Department of Clinical and Toxicological Analyses, Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Tavares, Paulo Eduardo Latorre Martins; Vieira, Alessandra; Miranda, Mayara Lilian Paulino [Laboratory of Diet, Nutrition and Cancer, Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Purgatto, Eduardo [Laboratory of Food Chemistry and Biochemistry, Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Advanced Research Center in Food Science and Nutrition (NAPAN) and Food Research Center (FoRC), Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Moreno, Fernando Salvador, E-mail: rmoreno@usp.br [Laboratory of Diet, Nutrition and Cancer, Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Advanced Research Center in Food Science and Nutrition (NAPAN) and Food Research Center (FoRC), Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil)

    2014-04-15

    The chemopreventive activity of the histone deacetylase inhibitor (HDACi) tributyrin (TB), a prodrug of butyric acid (BA), was evaluated in a rat model of colon carcinogenesis. The animals were treated with TB (TB group: 200 mg/100 g of body weight, b.w.) or maltodextrin (MD isocaloric control group: 300 mg/100 g b.w.) daily for 9 consecutive weeks. In the 3rd and 4th weeks of treatment, the rats in the TB and MD groups were given DMH (40 mg/kg b.w.) twice a week. After 9 weeks, the animals were euthanized, and the distal colon was examined. Compared with the control group (MD group), TB treatment reduced the total number of aberrant crypt foci (ACF; p < 0.05) as well as the ACF with ≥ 4 crypts (p < 0.05), which are considered more aggressive, but not inhibited the formation of DMH-induced O6-methyldeoxyguanosine DNA adducts. The TB group also showed a higher apoptotic index (p < 0.05) and reduced DNA damage (p < 0.05) compared with MD group. TB acted as a HDACi, as rats treated with the prodrug of BA had higher levels of histone H3K9 acetylation compared with the MD group (p < 0.05). TB administration resulted in increased colonic tissue concentrations of BA (p < 0.05) compared with the control animals. These results suggest that TB can be considered a promising chemopreventive agent for colon carcinogenesis because it reduced the number of ACF, including those that were more aggressive. Induction of apoptosis and reduction of DNA damage are cellular mechanisms that appear to be involved in the chemopreventive activity of TB. - Highlights: • Tributyrin is a chemopreventive agent for rat colon aberrant crypt foci. • Tributyrin increased apoptosis in an experimental rat colon carcinogenesis model. • Tributyrin treatment in a rat colon carcinogenesis model decreased DNA damage. • Tributyrin treatment induced H3K9 acetylation in a rat colon carcinogenesis model.

  19. The chemopreventive activity of the histone deacetylase inhibitor tributyrin in colon carcinogenesis involves the induction of apoptosis and reduction of DNA damage

    International Nuclear Information System (INIS)

    The chemopreventive activity of the histone deacetylase inhibitor (HDACi) tributyrin (TB), a prodrug of butyric acid (BA), was evaluated in a rat model of colon carcinogenesis. The animals were treated with TB (TB group: 200 mg/100 g of body weight, b.w.) or maltodextrin (MD isocaloric control group: 300 mg/100 g b.w.) daily for 9 consecutive weeks. In the 3rd and 4th weeks of treatment, the rats in the TB and MD groups were given DMH (40 mg/kg b.w.) twice a week. After 9 weeks, the animals were euthanized, and the distal colon was examined. Compared with the control group (MD group), TB treatment reduced the total number of aberrant crypt foci (ACF; p < 0.05) as well as the ACF with ≥ 4 crypts (p < 0.05), which are considered more aggressive, but not inhibited the formation of DMH-induced O6-methyldeoxyguanosine DNA adducts. The TB group also showed a higher apoptotic index (p < 0.05) and reduced DNA damage (p < 0.05) compared with MD group. TB acted as a HDACi, as rats treated with the prodrug of BA had higher levels of histone H3K9 acetylation compared with the MD group (p < 0.05). TB administration resulted in increased colonic tissue concentrations of BA (p < 0.05) compared with the control animals. These results suggest that TB can be considered a promising chemopreventive agent for colon carcinogenesis because it reduced the number of ACF, including those that were more aggressive. Induction of apoptosis and reduction of DNA damage are cellular mechanisms that appear to be involved in the chemopreventive activity of TB. - Highlights: • Tributyrin is a chemopreventive agent for rat colon aberrant crypt foci. • Tributyrin increased apoptosis in an experimental rat colon carcinogenesis model. • Tributyrin treatment in a rat colon carcinogenesis model decreased DNA damage. • Tributyrin treatment induced H3K9 acetylation in a rat colon carcinogenesis model

  20. Sarcophine-Diol, a Skin Cancer Chemopreventive Agent, Inhibits Proliferation and Stimulates Apoptosis in Mouse Melanoma B16F10 Cell Line

    OpenAIRE

    Hesham Fahmy; Ahmed, Safwat A.; Szymanski, Pawel T.; Bhimanna Kuppast; Sherief Khalifa

    2011-01-01

    Sarcodiol (SD) is a semi-synthetic derivative of sarcophine, a marine natural product. In our previous work, we reported the significant chemopreventive effects of SD against non-melanoma skin cancer both in vitro and in vivo mouse models. In this investigation, we extended this work to study the effect of sarcodiol on melanoma development, the more deadly form of skin cancer, using the mouse melanoma B16F10 cell line. In this study we report that SD inhibits the de novo DNA synthesis and enh...

  1. Dose-Response on the Chemopreventive Effects of Sarcophine-Diol on UVB-Induced Skin Tumor Development in SKH-1 Hairless Mice

    Directory of Open Access Journals (Sweden)

    Chandradhar Dwivedi

    2012-09-01

    Full Text Available Sarcophine-diol (SD is a lactone ring-opened analogue of sarcophine. It has shown chemopreventive effects on chemically-induced skin tumor development in female CD-1 mice, as well as in a UVB-induced skin tumor development model in hairless SKH-1 mice at a dose of 30 μg SD applied topically and 180 mJ/cm2 UVB. The objective of this study was to determine the dose-response on the chemopreventive effects of SD on SKH-1 hairless mice when exposed to a UVB radiation dose of 30 mJ/cm2. This UVB dose better represents chronic human skin exposure to sunlight leading to skin cancer than previous studies applying much higher UVB doses. Carcinogenesis was initiated and promoted by UVB radiation. Female hairless SKH-1 mice were divided into five groups. The control group was topically treated with 200 μL of acetone (vehicle, and the SD treatment groups were topically treated with SD (30 μg, 45 μg, and 60 μg dissolved in 200 μL of acetone 1 h before UVB radiation (30 mJ/cm2. The last group of animals received 60 μg SD/200 μL acetone without UVB exposure. These treatments were continued for 27 weeks. Tumor multiplicity and tumor volumes were recorded on a weekly basis for 27 weeks. Weight gain and any signs of toxicity were also closely monitored. Histological characteristics and the proliferating cell nuclear antigen (PCNA were evaluated in the mice skin collected at the end of the experiment. The dose-response study proved a modest increase in chemopreventive effects with the increase in SD dose. SD reduced the number of cells positively stained with PCNA proliferation marker in mice skin. The study also showed that SD application without UVB exposure has no effect on the structure of skin. The results from this study suggest that broader range doses of SD are necessary to improve the chemopreventive effects.

  2. Chemopreventive effect of resveratrol, sesamol, sesame oil and sunflower oil in the Epstein-Barr virus early antigen activation assay and the mouse skin two-stage carcinogenesis.

    Science.gov (United States)

    Kapadia, Govind J; Azuine, Magnus A; Tokuda, Harukuni; Takasaki, Midori; Mukainaka, Teruo; Konoshima, Takao; Nishino, Hoyoku

    2002-06-01

    Resveratrol, sesamol, sesame oil and sunflower oil are known natural dietary components with intrinsic cancer chemopreventive potentials. As a part of our study of dietary constituents as potential cancer chemopreventive agents, we have assessed the anti-cancer potentials of these products in the promotion stage of cancer development employing the in vitro Epstein-Barr virus early antigen activation assay induced by the tumor promoter 12-O-tetradecanoylphorbol 13-acetate (TPA). Further, we studied the activities of these compounds in the brine shrimp cytotoxicity assay as well as on the stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging bioassay with a view to comparing some of the mechanisms of their anti-cancer activity. Finally, we compared the observed chemoprotective capabilities of the four products in the in vivo 7,12 dimethylbenz(a)anthracene initiated and TPA-promoted mouse skin two-stage carcinogenesis protocols. All the products tested showed a profound inhibitory effect on the Epstein-Barr virus early antigen induction using Raji cells. Comparatively, sesame oil was the most potent followed by sesamol and then resveratrol. Only sesamol and resveratrol showed a remarkable cytotoxic activity in the brine shrimp lethality assays as well as profound free radical scavenging activity in the DPPH bioassay. In both test systems, sesamol exhibited a more remarkable activity than resveratrol while sesame oil and sunflower oil did not exhibit any appreciable activity even at the highest concentrations tested (4000 microg ml(-1) ). In our in vivo assay at a 50-fold molar ratio to TPA, sesamol offered 50% reduction in mouse skin papillomas at 20 weeks after promotion with TPA. Under an identical molar ratio to TPA, resveratrol offered a 60% reduction in the papillomas in mouse at 20 weeks. Thus sesamol seems to be an almost equally potent chemopreventive agent. Sesame oil and sunflower oil offered 20 and 40% protection, respectively, in the mouse

  3. Gadoxetic Acid-Enhanced MRI and Sonoelastography: Non-Invasive Assessments of Chemoprevention of Liver Fibrosis in Thioacetamide-Induced Rats with Sho-Saiko-To

    OpenAIRE

    Chen, Ya-Wen; Tsai, Meng-Yuan; Pan, Huay-Ben; Tseng, Hui-Hwa; Hung, Yu-Ting; Chou, Chen-Pin

    2014-01-01

    Background This study aimed to compare the performance of gadoxetic acid -enhanced magnetic resonance imaging (MRI) and sonoelastography in evaluating chemopreventive effects of Sho-Saiko-To (SST) in thioacetamide (TAA)-induced early liver fibrosis in rats. Materials and Methods Ten of Sprague-Dawley rats receiving TAA (200 mg/kg of body weight) intraperitoneal injection were divided into three groups: Group 1 (TAA only, n = 3), Group 2 (TAA +0.25 g/kg SST, n = 4) and Group 3 (TAA+1 g/kg SST,...

  4. Electric Heating Property from Butyl Rubber-Loaded Boron Carbide Composites

    Institute of Scientific and Technical Information of China (English)

    MENG Dechuan; WANG Ninghui; LI Guofeng

    2014-01-01

    We researched the electric heating property from butyl rubber-loaded boron carbide composite. The effects of boron carbide content on bulk resistivity, voltage-current characteristic, thermal conductivity and thermal stability of boron carbide/butyl rubber (IIR) polymer composite were introduced. The analysis results indicated that the bulk resistivity decreased greatly with increasing boron carbide content, and when boron carbide content reached to 60%, the bulk resistivity achieved the minimum. Accordingly, electric heating behavior of the composite is strongly dependent on boron carbide content as well as applied voltage. The content of boron carbide was found to be effective in achieving high thermal conductivity in composite systems. The thermal conductivity of the composite material with added boron carbide was improved nearly 20 times than that of the pure IIR. The thermal stability test showed that, compared with pure IIR, the thermal stable time of composites was markedly extended, which indicated that the boron carbide can significantly improve the thermal stability of boron carbide/IIR composite.

  5. Biodegradation of Methyl tert-Butyl Ether by Co-Metabolism with a Pseudomonas sp. Strain

    Directory of Open Access Journals (Sweden)

    Shanshan Li

    2016-09-01

    Full Text Available Co-metabolic bioremediation is supposed to be an impressive and promising approach in the elimination technology of methyl tert-butyl ether (MTBE, which was found to be a common pollutant worldwide in the ground or underground water in recent years. In this paper, bacterial strain DZ13 (which can co-metabolically degrade MTBE was isolated and named as Pseudomonas sp. DZ13 based on the result of 16S rRNA gene sequencing analysis. Strain DZ13 could grow on n-alkanes (C5-C8, accompanied with the co-metabolic degradation of MTBE. Diverse n-alkanes with different carbon number showed a significant influence on the degradation rate of MTBE and accumulation of tert-butyl alcohol (TBA. When Pseudomonas sp. DZ13 co-metabolically degraded MTBE with n-pentane as the growth substrate, a higher MTBE-degrading rate (Vmax = 38.1 nmol/min/mgprotein, Ks = 6.8 mmol/L and lower TBA-accumulation was observed. In the continuous degradation experiment, the removal efficiency of MTBE by Pseudomonas sp. Strain DZ13 did not show an obvious decrease after five times of continuous addition.

  6. Butyl 2-(5-iodo-3-methylsulfinyl-1-benzofuran-2-ylacetate

    Directory of Open Access Journals (Sweden)

    Uk Lee

    2009-02-01

    Full Text Available In the title compound, C15H17IO4S, the O atom and the methyl group of the methylsulfinyl substituent lie on opposite sides of the plane of the benzofuran fragment. The crystal structure is stabilized by weak intermolecular C—H...π interactions between a methyl H atom of the methylsulfinyl group and the benzene ring of the benzofuran system, and by an I...O halogen bond of 3.173 (3 Å and a nearly linear C—I...O angle of 171.7 (1°. In addition, the crystal structure exhibits weak intermolecular C—H...O hydrogen bonds. The O atom of the carbonyl group and the butyl chain are both disordered over two positions with site-occupancy factors from refinement of 0.55 (4 and 0.45 (4 (for the O atom, and 0.76 (2 and 0.24 (2 (for the butyl group.

  7. Biodegradation of Methyl tert-Butyl Ether by Co-Metabolism with a Pseudomonas sp. Strain.

    Science.gov (United States)

    Li, Shanshan; Wang, Shan; Yan, Wei

    2016-01-01

    Co-metabolic bioremediation is supposed to be an impressive and promising approach in the elimination technology of methyl tert-butyl ether (MTBE), which was found to be a common pollutant worldwide in the ground or underground water in recent years. In this paper, bacterial strain DZ13 (which can co-metabolically degrade MTBE) was isolated and named as Pseudomonas sp. DZ13 based on the result of 16S rRNA gene sequencing analysis. Strain DZ13 could grow on n-alkanes (C₅-C₈), accompanied with the co-metabolic degradation of MTBE. Diverse n-alkanes with different carbon number showed a significant influence on the degradation rate of MTBE and accumulation of tert-butyl alcohol (TBA). When Pseudomonas sp. DZ13 co-metabolically degraded MTBE with n-pentane as the growth substrate, a higher MTBE-degrading rate (Vmax = 38.1 nmol/min/mgprotein, Ks = 6.8 mmol/L) and lower TBA-accumulation was observed. In the continuous degradation experiment, the removal efficiency of MTBE by Pseudomonas sp. Strain DZ13 did not show an obvious decrease after five times of continuous addition. PMID:27608032

  8. Vapor Pressure, Vaporization Enthalpy, Standard Enthalpy of Formation and Standard Entropy of n-Butyl Carbamate

    Institute of Scientific and Technical Information of China (English)

    Zuoxiang Zeng⁎; Zhihong Yang; Weilan Xue⁎; Xiaonan Li

    2014-01-01

    The vapor pressures of n-butyl carbamate were measured in the temperature range from 372.37 K to 479.27 K and fitted with Antoine equation. The compressibility factor of the vapor was calculated with the Virial equation and the second virial coefficient was determined by the Vetere model. Then the standard enthalpy of vaporization for n-butyl carbamate was estimated. The heat capacity was measured for the solid state (299.39–324.2 K) and liquid state (336.65–453.21 K) by means of adiabatic calorimeter. The standard en-thalpy of formationΔfHϴ[crystal (cr),298.15 K] and standard entropy Sϴ(crystal,298.15 K) of the sub-stance were calculated on the basis of the gas-phase standard enthalpy of formationΔfHϴ(g,298.15 K) and gas-phase standard entropy Sϴ(g,298.15 K), which were estimated by the Benson method. The results are acceptable, validated by a thermochemical cycle.

  9. Enhancement of methyl tert-butyl ether degradation by the addition of readily metabolizable organic substrates

    International Nuclear Information System (INIS)

    Supplements with readily metabolizable organic substrates were investigated to increase the biomass and enhance degradation of methyl tert-butyl ether (MTBE) due to the low biomass yield of MTBE which has been one of the factors for low-rate MTBE degradation. The influence of various organic substrates on the rate of aerobic degradation of methyl tert-butyl ether (MTBE) by Methylibium petroleiphilum PM1 was investigated, and only yeast extract (YE), beef extract and tryptone exhibited stimulatory effect. With the concentration of each substrate being 100 mg/L, the average MTBE removal rate could increase to 1.29, 1.20 and 1.04 mg/(L h), respectively, in comparison with 0.71 mg/(L h) when carried out in medium without addition. The stimulatory effects of YE addition, as well as induction period required by MTBE degradation, varied dramatically with the storage conditions, pre-culture medium and concentrations of the inoculums. The extent of stimulatory effects of YE might be closely related to the proportion of induction period in the total time of MTBE-degradation. The removal efficiency increased from about 50% to 90.5% with the addition of YE in a packed-bed reactor loaded with calcium alginate immobilized cells.

  10. Structural elucidation of 4-(cystein-S-yl)butyl glucosinolate from the leaves of Eruca sativa.

    Science.gov (United States)

    Kim, Sun-Ju; Kawaharada, Chiami; Jin, Shigeki; Hashimoto, Makoto; Ishii, Gensho; Yamauchi, Hiroaki

    2007-01-01

    The structurally unique glucosinolate (GSL), 4-(cystein-S-yl)butyl GSL, was identified in the leaves of hydroponically-grown rocket salad (Eruca sativa Mill.). Its electrospray ionization mass spectrometry (ESI-MS)/MS spectrum indicated that this unusual GSL had a molecular weight of 414 as a desulfo (DS)-GSL, and a molecular formula of C(14)H(25)N(2)O(8)S(2) based on its negative ion matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) spectrum. For further confirmation, the 4-(cystein-S-yl)butyl DS-GSL was prepared with authentic L-Ser and purified dimeric 4-mercaptobutyl DS-GSL, and its chemical structure then confirmed by ESI-MS/MS data. It is named "glucorucolamine" as a trivial name from its ammonia sensitivity. This unique GSL was found to the greatest extent when rocket salad was grown in a 100% NH4+-N nutrient solution. Despite it clearly seems to reduce the detoxification of excess NH4+ in the leaves of rocket salad, present knowledge about the unique GSL is still far from being sufficient.

  11. Production of fatty acid butyl esters using the low cost naturally immobilized Carica papaya lipase.

    Science.gov (United States)

    Su, Erzheng; Wei, Dongzhi

    2014-07-01

    In this work, the low cost naturally immobilized Carica papaya lipase (CPL) was investigated for production of fatty acid butyl esters (FABE) to fulfill the aim of reducing the lipase cost in the enzymatic butyl-biodiesel process. The CPL showed specificities to different alcohol acyl acceptors. Alcohols with more than three carbon atoms did not have negative effects on the CPL activity. The CPL catalyzed butanolysis for FABE production was systematically investigated. The reaction solvent, alcohol/oil molar ratio, enzyme amount, reaction temperature, and water activity all affected the butanolysis process. Under the optimized conditions, the highest conversion of 96% could be attained in 24 h. These optimal conditions were further applied to CPL catalyzed butanolysis of other vegetable oils. All of them showed very high conversion. The CPL packed-bed reactor was further developed, and could be operated continuously for more than 150 h. All of these results showed that the low cost Carica papaya lipase can be used as a promising lipase for biodiesel production.

  12. Phases and phase changes in clusters of tert-butyl thiol

    Science.gov (United States)

    Hovick, James W.; Bartell, Lawrence S.

    1997-09-01

    Clusters of tert-butyl thiol (TBT) were generated by condensation of vapor in supersonic flow under various expansion conditions, and their structures were examined during their free flight by electron diffraction. The system had been selected because of its similarity to tert-butyl chloride (TBC), a much more thoroughly studied material with an interesting solid-state chemistry. The warmest crystalline phase of TBT observed for the clusters (diameter, ≈ 130 Å) was the known high-temperature cubic phase I with a lattice constant of 8.609(5) Å at ≈ 160 K. A second phase into which phase I nucleated at a rate of ≈ 10 28 m -3 s -1 at about 157 K was also observed, as well as a third phase generated under conditions of very cold flow. All of the phases gave the rapidly damped, diffuse diffraction patterns characteristic of submicroscopic, poorly ordered, plastically crystalline materials. Patterns were far less distinct than those of TBC, and the structures of the colder two phases could not be determined. From the rapid nucleation rate of phase I into the second phase, it could be inferred that a major translational rearrangement of the molecules could not have been involved.

  13. Isotope effects and the temperature dependences of the hyperfine coupling constants of muoniated sec-butyl radicals in condensed phases.

    Science.gov (United States)

    Fleming, Donald G; Bridges, Michael D; Arseneau, Donald J; Chen, Ya Kun; Wang, Yan Alexander

    2011-04-01

    Reported here is the first μSR study of the muon (A(μ)) and proton (A(p)) β-hyperfine coupling constants (Hfcc) of muoniated sec-butyl radicals, formed by muonium (Mu) addition to 1-butene and to cis- and trans-2-butene. The data are compared with in vacuo spin-unrestricted MP2 and hybrid DFT/B3YLP calculations reported in the previous paper (I), which played an important part in the interpretation of the data. The T-dependences of both the (reduced) muon, A(μ)′(T), and proton, A(p)(T), Hfcc are surprisingly well explained by a simple model, in which the calculated Hfcc from paper I at energy minima of 0 and near ±120° are thermally averaged, assuming an energy dependence given by a basic 2-fold torsional potential. Fitted torsional barriers to A(μ)′(T) from this model are similar (~3 kJ/mol) for all muoniated butyl radicals, suggesting that these are dominated by ZPE effects arising from the C−Mu bond, but for A(p)(T) exhibit wide variations depending on environment. For the cis- and trans-2-butyl radicals formed from 2-butene, A(μ)′(T) exhibits clear discontinuities at bulk butene melting points, evidence for molecular interactions enhancing these muon Hfcc in the environment of the solid state, similar to that found in earlier reports for muoniated tert-butyl. In contrast, for Mu−sec-butyl formed from 1-butene, there is no such discontinuity. The muon hfcc for the trans-2-butyl radical are seemingly very well predicted by B3LYP calculations in the solid phase, but for sec-butyl from 1-butene, showing the absence of further interactions, much better agreement is found with the MP2 calculations across the whole temperature range. Examples of large proton Hfcc near 0 K are also reported, due to eclipsed C−H bonds, in like manner to C−Mu, which then also exhibit clear discontinuities in A(p)(T) at bulk melting points. The data suggest that the good agreement found between theory and experiment from the B3LYP calculations for eclipsed bonds in

  14. Densities and Kinematic Viscosities for the Systems Benzene + Methyl Formate, Benzene + Ethyl Formate, Benzene + Propyl Formate, and Benzene + Butyl Formate

    DEFF Research Database (Denmark)

    Emmerling, Uwe; Rasmussen, Peter

    1998-01-01

    Densities and kinematic viscosities have been measured for the system benzene + methyl formate at 20°C and for the systems benzene + ethyl formate, benzene + propyl formate, and benzene + butyl formate from 20°C to 50°C. The results for the system benzene + methyl formate have been correlated using...... a Redlich-Kister type of expression with temperature-independent parameters and the data for the systems benzene + ethyl formate, benzene + propyl formate, and benzene + butyl formate with temperature-dependent parameters. The viscosities have furthermore been compared to values predicted by means of the GC...

  15. Diisobutyl phthalate has comparable anti-androgenic effects to di-n-butyl phthalate in fetal rat testis

    DEFF Research Database (Denmark)

    Boberg, Julie; Petersen, Marta Axelstad; Vinggaard, Anne;

    2006-01-01

    Phthalates are widely used as plasticizers in various consumer products and building materials. Some of the phthalates are known to interfere with male reproductive development in rats, and di-n-butyl phthalate (DBP), diethylhexyl phthalate (DEHP) and butyl benzyl phthalate (BBP) were recently...... banned for use in toys in the EU mainly due to their reproductive toxicity. Diisobutyl phthalate (DiBP) has similar structural and application properties as DBP. and is being used as a substitute for DBR However, knowledge on male reproductive effects of DiBP in experimental animals is lacking, Methods...

  16. tert-Butyl N-[2-(N-isobutyl-4-meth-oxy-benzene-sulfonamido)-eth-yl]carbamate.

    Science.gov (United States)

    Bai, Xiao-Guang; Wang, Ju-Xian

    2014-06-01

    The title compound, C18H30N2O5S, was synthesized by the reaction of tert-butyl 2-(iso-butyl-amino)-ethyl-carbamate with p-meth-oxy-phenyl-sulfonyl chloride. In the mol-ecule, two intra-molecular C-H⋯O hydrogen bonds are observed. In the crystal, mol-ecules are linked by N-H⋯O hydrogen bonds involving the imino group N atom and the ester group O atom into chains running parallel to the b axis. The chains are further connected by C-H⋯O hydrogen bonds, forming layers parallel to the bc plane. PMID:24940254

  17. A PHYSIOLOGICALLY-BASED PHARMACOKINETIC MODEL FOR INTRAVENOUS AND INHALATION-ROUTE PHARMACOKINETICS OF BUTYL ACETATE AND METABOLITES N-BUTANOL AND N-BUTYRIC ACID

    Science.gov (United States)

    Risk assessment for n-butyl acetate and metabolites n-butanol and n-butyric acid (the butyl series) can be accomplished with limited toxicity data and pharmacokinetic data for each compound through application of the "family approach" (Barton et al., 2000). The necessary quantita...

  18. MEASUREMENT OF EXHALED BREATH AND VENOUS BLOOD TO DEVELOP A PHYSIOLOGICALLY BASED PHARMACOKINETIC MODEL FOR HUMAN EXPOSURE TO METHYL TERTIARY-BUTYL ETHER AND THE PRODUCTION OF THE BIOMARKER TERTIARY-BUTYL ALCOHOL

    Science.gov (United States)

    Methyl tertiary-butyl ether (MTBE) is a common fuel additive used to increase the availability of oxygen in gasoline to reduce winter-time carbon monoxide emissions from automobiles. Also, MTBE boosts gasoline "octane" rating and, as such, allows reduction of benzene...

  19. 水-仲丁醇-乙酸仲丁酯三元体系的液液相平衡研究%Liquid-Liquid Equilibrium of the Water+sec-Butyl Alcohol+sec-Butyl Acetate Ternary System

    Institute of Scientific and Technical Information of China (English)

    李玲; 郭川; 吴燕翔

    2013-01-01

      测定了水-仲丁醇-乙酸仲丁酯三元体系在303.15,323.15,343.15,353.15 K下的液液相平衡数据,并用NRTL模型和 UNIQUAC模型对相平衡数据进行关联,应用单纯形法求得相应的模型参数.计算值与实验值比较结果表明:NRTL模型与UNIQUAC模型的计算值与实验数据吻合良好.%Liquid-liquid equilibrium (LLE) data of the water +sec-butyl alcohol + sec-butyl acetate ternary system were measured at 303.15 K, 323.15 K, 343.15 K and 353.15 K under atmospheric pressure. The active coefficients in the LLE equations were calculated by the NRTL and UNIQUAC models, and the calculated LLE data of water+sec-butyl alcohol+sec-butyl acetate ternary system were compared with the experimental data. Based on the NRTL and UNIQUAC models, the calculated equilibrium compositions of the studied ternary system are in good agreement with the experimental data.

  20. The paradigm-shifting idea and its practice: from traditional abortion Chinese medicine Murraya paniculata to safe and effective cancer metastatic chemopreventives.

    Science.gov (United States)

    Jiang, Zhou; Pang, Yaqiong; Yu, Xiaobo; Zhou, Suxia; Qian, Jun; Zheng, Ning; Dong, Haiyan; Shi, Qing; Kuo, Minliang; Jia, Lee

    2016-04-19

    Recent large epidemiological studies demonstrated benefit of oral contraceptives in reducing cancer risk, and our analysis also showed molecular and cellular similarities between embryo implantation and CTCs adhesion-invasion to endothelium. We here hypothesize that abortion traditional Chinese medicine (TCM) may serve well for pre-metastatic chemoprevention. To test the hypothesis, we selected the safe and well-known abortifacient TCM Murraya paniculata and identified a most-promising extracted fraction G (containing flavonoids and coumarins) from its many raw ethanol/dichloromethane extracts by using the bioactivity-guided fast screen assay. G showed free radical scavenging effect, and specifically inhibited both embryo implantation to human endometrial bed and cancer HT29 cells to human endothelium in a concentration-dependent manner (1-30 μg/mL) without significant cytotoxicity demonstrated by its high adhesion inhibition ratio. The inhibition may result from its down-regulation on expression of integrin β1 and α6, and CD44 on HT29 cells, as well as E-selectin on endothelial cells. Furthermore, G inhibited invasion and migration of HT29 cells. Pretreatment followed by one-month oral administration of G to the immunocompetent mice inoculated with mouse melanoma cells produced significant inhibition on lung metastasis without marked side effects. Collectively, this paradigm-shifting study provides, for the first time, a new strategy to discover safe and effective pre-metastatic chemopreventives from abortion TCM.

  1. 绿茶对前列腺癌的化学预防作用%Green tea in chemoprevention of prostate cancer

    Institute of Scientific and Technical Information of China (English)

    贾晓龙; 秦杰

    2008-01-01

    绿茶是许多国家和地区的重要饮料之一,近年来不断有体外和动物体内实验表明绿茶可以诱导前列腺癌细胞凋亡、抑制前列腺癌浸润及转移,流行病学调查及临床试验也发现绿茶对前列腺癌具有预防作用,可减少高分级前列腺上皮内瘤发展成为前列腺癌的概率,将有可能成为良好的前列腺癌化学预防物质.%Green tea as a main beverage is consumed worldwide. In the last few years, .green tea has been shown to induce apoptosis and to inhibit the infiltration and metastasis of prostate cancer by in vitro and in vivo experiments. Epidemiologic investigations and clinical trials also have demonstrated the chemopreventive role of green tea in prostate cancer, such as reducing the possibility of carcinogenesis of high-grade prostatic in-traepithelial neoplasia, and is hopeful to be applied as chemopreventive agent of prostate cancer in the future.

  2. Sarcophine-diol, a skin cancer chemopreventive agent, inhibits proliferation and stimulates apoptosis in mouse melanoma B₁₆F₁₀ cell line.

    Science.gov (United States)

    Szymanski, Pawel T; Kuppast, Bhimanna; Ahmed, Safwat A; Khalifa, Sherief; Fahmy, Hesham

    2012-01-01

    Sarcodiol (SD) is a semi-synthetic derivative of sarcophine, a marine natural product. In our previous work, we reported the significant chemopreventive effects of SD against non-melanoma skin cancer both in vitro and in vivo mouse models. In this investigation, we extended this work to study the effect of sarcodiol on melanoma development, the more deadly form of skin cancer, using the mouse melanoma B₁₆F₁₀ cell line. In this study we report that SD inhibits the de novo DNA synthesis and enhances fragmentation of DNA. We also evaluated the antitumor effect of SD on melanoma cell viability using several biomarkers for cell proliferation and apoptosis. SD inhibits the expression levels of signal transducers and activators of transcription protein (STAT-3) and cyclin D1, an activator of cyclin-dependent kinase 4 (Cdk4). SD treatment also enhances cellular level of tumor suppressor protein 53 (p53) and stimulates cleavage of the nuclear poly (ADP-ribose) polymerase (cleaved-PARP). SD also enhances cellular levels of cleaved Caspase-3, -8, -9 and stimulates enzymatic activities of Caspase-3, -8 and -9. These results, in addition to inhibition of cell viability, suggest that SD inhibits melanoma cell proliferation by arresting the cell-division cycle in a Go quiescent phase and activates programmed cell death (apoptosis) via extrinsic and intrinsic pathways. Finally, these studies demonstrate that SD shows a very promising chemopreventive effect in melanoma B₁₆F₁₀ tumor cells. PMID:22363217

  3. Effect of gallic acid on xenobiotic metabolizing enzymes in 1,2-dimethyl hydrazine induced colon carcinogenesis in Wistar rats--a chemopreventive approach.

    Science.gov (United States)

    Giftson Senapathy, J; Jayanthi, S; Viswanathan, P; Umadevi, P; Nalini, N

    2011-04-01

    Colon cancer risk may be influenced by phase I and II xenobiotic-metabolizing enzyme systems. The chemopreventive agent gallic acid (GA), a plant polyphenol, is found in various natural products. Our aim was to evaluate the potential role of GA on drug-metabolizing enzymes in 1,2-dimethyl hydrazine (DMH) induced rat colon carcinogenesis. The total experimental duration was 30 weeks. The effect of GA (50 mg/kg b.w.) on the activities of phase I enzymes (cytochrome P450 and cytochrome b5) and phase II enzymes (glutathione S-transferase, DT-diaphorase and gamma glutamyl transpeptidase) were assessed in the liver and colonic mucosa and the colons were also examined visually. In DMH induced rats, there was a decrease in the activities of phase II enzymes and an increase in the activities of phase I enzymes. On GA supplementation, there was a significant increase in the activities of phase II enzymes and a significant decrease in the activities of phase I enzymes, in addition to the decreased tumor incidence. Histopathological changes also confirm this. Thus, the marked potential of GA in modulating the phase I and II xenobiotic-metabolizing enzymes suggests that GA may have a major impact on colon cancer chemoprevention. PMID:21172399

  4. The REDUCE metagram: a comprehensive prediction tool for determining the utility of dutasteride chemoprevention in men at risk for prostate cancer

    Directory of Open Access Journals (Sweden)

    Carvell eNguyen

    2012-10-01

    Full Text Available Introduction: 5-alpha reductase inhibitors can reduce the risk of prostate cancer but can be associated with significant side effects. A library of nomograms which predict the risk of clinical endpoints relevant to dutasteride treatment may help determine if chemoprevention is suited to the individual patient. Methods: Data from the REDUCE trial was used to identify predictive factors for nine endpoints relevant to dutasteride treatment. Using the treatment and placebo groups from the biopsy cohort, Cox proportional hazards and competing risks regression models were used to build 18 nomograms, whose predictive ability was measured by concordance index and calibration plots. Results: A total of 18 nomograms assessing the risks of cancer, high-grade cancer, high grade prostatic intraepithelial neoplasia (HGPIN, atypical small acinar proliferation (ASAP, erectile dysfunction (ED, acute urinary retention (AUR, gynecomastia, urinary tract infection (UTI and BPH-related surgery either on or off dutasteride were created. The nomograms for cancer, high grade cancer, ED, AUR, and BPH-related surgery demonstrated good discrimination and calibration while those for gynecomastia, UTI, HGPIN, and ASAP predicted no better than random chance. Conclusions: To aid patients in determining whether the benefits of dutasteride use outweigh the risks, we have developed a comprehensive metagram that can generate individualized risks of 9 outcomes relevant to men considering chemoprevention. Better models based on more predictive markers are needed for some of the endpoints but the current metagram demonstrates potential as a tool for patient counseling and decision making that is accessible, intuitive, and clinically relevant.

  5. Sarcophine-Diol, a Skin Cancer Chemopreventive Agent, Inhibits Proliferation and Stimulates Apoptosis in Mouse Melanoma B16F10 Cell Line

    Directory of Open Access Journals (Sweden)

    Hesham Fahmy

    2011-12-01

    Full Text Available Sarcodiol (SD is a semi-synthetic derivative of sarcophine, a marine natural product. In our previous work, we reported the significant chemopreventive effects of SD against non-melanoma skin cancer both in vitro and in vivo mouse models. In this investigation, we extended this work to study the effect of sarcodiol on melanoma development, the more deadly form of skin cancer, using the mouse melanoma B16F10 cell line. In this study we report that SD inhibits the de novo DNA synthesis and enhances fragmentation of DNA. We also evaluated the antitumor effect of SD on melanoma cell viability using several biomarkers for cell proliferation and apoptosis. SD inhibits the expression levels of signal transducers and activators of transcription protein (STAT-3 and cyclin D1, an activator of cyclin-dependent kinase 4 (Cdk4. SD treatment also enhances cellular level of tumor suppressor protein 53 (p53 and stimulates cleavage of the nuclear poly (ADP-ribose polymerase (cleaved-PARP. SD also enhances cellular levels of cleaved Caspase-3, -8, -9 and stimulates enzymatic activities of Caspase-3, -8 and -9. These results, in addition to inhibition of cell viability, suggest that SD inhibits melanoma cell proliferation by arresting the cell-division cycle in a Go quiescent phase and activates programmed cell death (apoptosis via extrinsic and intrinsic pathways. Finally, these studies demonstrate that SD shows a very promising chemopreventive effect in melanoma B16F10 tumor cells.

  6. Sarcophine-diol, a skin cancer chemopreventive agent, inhibits proliferation and stimulates apoptosis in mouse melanoma B₁₆F₁₀ cell line.

    Science.gov (United States)

    Szymanski, Pawel T; Kuppast, Bhimanna; Ahmed, Safwat A; Khalifa, Sherief; Fahmy, Hesham

    2012-01-01

    Sarcodiol (SD) is a semi-synthetic derivative of sarcophine, a marine natural product. In our previous work, we reported the significant chemopreventive effects of SD against non-melanoma skin cancer both in vitro and in vivo mouse models. In this investigation, we extended this work to study the effect of sarcodiol on melanoma development, the more deadly form of skin cancer, using the mouse melanoma B₁₆F₁₀ cell line. In this study we report that SD inhibits the de novo DNA synthesis and enhances fragmentation of DNA. We also evaluated the antitumor effect of SD on melanoma cell viability using several biomarkers for cell proliferation and apoptosis. SD inhibits the expression levels of signal transducers and activators of transcription protein (STAT-3) and cyclin D1, an activator of cyclin-dependent kinase 4 (Cdk4). SD treatment also enhances cellular level of tumor suppressor protein 53 (p53) and stimulates cleavage of the nuclear poly (ADP-ribose) polymerase (cleaved-PARP). SD also enhances cellular levels of cleaved Caspase-3, -8, -9 and stimulates enzymatic activities of Caspase-3, -8 and -9. These results, in addition to inhibition of cell viability, suggest that SD inhibits melanoma cell proliferation by arresting the cell-division cycle in a Go quiescent phase and activates programmed cell death (apoptosis) via extrinsic and intrinsic pathways. Finally, these studies demonstrate that SD shows a very promising chemopreventive effect in melanoma B₁₆F₁₀ tumor cells.

  7. The paradigm-shifting idea and its practice: from traditional abortion Chinese medicine Murraya paniculata to safe and effective cancer metastatic chemopreventives

    Science.gov (United States)

    Zhou, Suxia; Qian, Jun; Zheng, Ning; Dong, Haiyan; Shi, Qing; Kuo, Minliang; Jia, Lee

    2016-01-01

    Recent large epidemiological studies demonstrated benefit of oral contraceptives in reducing cancer risk, and our analysis also showed molecular and cellular similarities between embryo implantation and CTCs adhesion-invasion to endothelium. We here hypothesize that abortion traditional Chinese medicine (TCM) may serve well for pre-metastatic chemoprevention. To test the hypothesis, we selected the safe and well-known abortifacient TCM Murraya paniculata and identified a most-promising extracted fraction G (containing flavonoids and coumarins) from its many raw ethanol/dichloromethane extracts by using the bioactivity-guided fast screen assay. G showed free radical scavenging effect, and specifically inhibited both embryo implantation to human endometrial bed and cancer HT29 cells to human endothelium in a concentration-dependent manner (1–30 μg/mL) without significant cytotoxicity demonstrated by its high adhesion inhibition ratio. The inhibition may result from its down-regulation on expression of integrin β1 and α6, and CD44 on HT29 cells, as well as E-selectin on endothelial cells. Furthermore, G inhibited invasion and migration of HT29 cells. Pretreatment followed by one-month oral administration of G to the immunocompetent mice inoculated with mouse melanoma cells produced significant inhibition on lung metastasis without marked side effects. Collectively, this paradigm-shifting study provides, for the first time, a new strategy to discover safe and effective pre-metastatic chemopreventives from abortion TCM. PMID:26959747

  8. Nitric oxide-releasing sulindac is a novel skin cancer chemopreventive agent for UVB-induced photocarcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhary, Sandeep C.; Singh, Tripti; Kapur, Puneet; Weng, Zhiping; Arumugam, Aadithya; Elmets, Craig A. [Department of Dermatology, University of Alabama at Birmingham, 1530 3rd Avenue South, VH509, Birmingham, AL 35294-0019 (United States); Kopelovich, Levy [Division of Cancer Prevention, National Cancer Institute, 6130 Executive Blvd, Suite 2114, Bethesda, MD 20892 (United States); Athar, Mohammad, E-mail: mathar@uab.edu [Department of Dermatology, University of Alabama at Birmingham, 1530 3rd Avenue South, VH509, Birmingham, AL 35294-0019 (United States)

    2013-05-01

    Nitric oxide (NO)-releasing non-steroidal anti-inflammatory drugs (NO-NSAIDs) which have been synthesized to reduce gastro-intestinal and cardiovascular toxicities of NSAIDs, possess anti-proliferative, pro-apoptotic and anti-cancer activities. Here, we show that NO-sulindac inhibited UVB-induced skin tumorigenesis in SKH-1 hairless mice. Topical application of NO-sulindac reduced tumor incidence, number (p < 0.05) and volume (p < 0.005) as compared to UVB (alone)-irradiated vehicle-treated mice. An increase in TUNEL-positive cells in skin lesions was accompanied by the enhanced Bax:Bcl-2 ratio. The expression of pro-apoptotic Bax was increased whereas anti-apoptotic Bcl-2 reduced. However, proliferation was identified as the major target of NO-sulindac in this study. A reduced expression of PCNA and cyclin D1 associated with the dampening of cell cycle progression was observed. The mechanism of this inhibition was related to the reduction in UVB-induced Notch signaling pathway. UVB-induced inflammatory responses were diminished by NO-sulindac as observed by a remarkable reduction in the levels of phosphorylated MAP Kinases Erk1/2, p38 and JNK1/2. In this regard, NO-sulindac also inhibited NFκB by enhancing IκBα as evidenced by the reduced expression of iNOS and COX-2, the direct NFκB transcription target proteins. NO-sulindac significantly diminished the progression of benign lesions to invasive carcinomas by suppressing the tumor aggressiveness and retarding epithelial–mesenchymal transition. A marked decrease in the expression of mesenchymal markers such as Fibronectin, N-cadherin, SNAI, Slug and Twist and an increase in epithelial cell polarity marker E-cadherin were noted in NO-sulindac-treated tumors. Our data suggest that NO-sulindac is a potent inhibitor of UVB-induced skin carcinogenesis and acts by targeting proliferation-regulatory pathways. - Highlights: ► NO-sulindac is a potent chemopreventive agent for UVB-induced skin cancer. ► NO

  9. The chemopreventive potential of Curcuma purpurascens rhizome in reducing azoxymethane-induced aberrant crypt foci in rats

    Directory of Open Access Journals (Sweden)

    Rouhollahi E

    2015-07-01

    DECPR exposure at both doses significantly decreased AOM-induced ACF formation, which was accompanied by reduced expression of PCNA. Upregulation of Bax and downregulation of Bcl-2 suggested the involvement of apoptosis in the chemopreventive effect of DECPR. In addition, the oxidative stress resulting from AOM treatment was significantly attenuated after administration of DECPR, which was shown by the elevated antioxidant enzymatic activity and reduced malondialdehyde level. Taken together, the present data clearly indicate that DECPR significantly inhibits ACF formation in AOM-treated rats and may offer protection against colon cancer development. Keywords: colon cancer, PCNA, Zingiberaceae

  10. Impact and Lessons Learned from Mass Drug Administrations of Malaria Chemoprevention during the Ebola Outbreak in Monrovia, Liberia, 2014

    Science.gov (United States)

    Kuehne, Anna; Tiffany, Amanda; Lasry, Estrella; Janssens, Michel; Besse, Clement; Okonta, Chibuzo; Larbi, Kwabena; Pah, Alfred C.; Danis, Kostas; Porten, Klaudia

    2016-01-01

    Background In October 2014, during the Ebola outbreak in Liberia healthcare services were limited while malaria transmission continued. Médecins Sans Frontières (MSF) implemented a mass drug administration (MDA) of malaria chemoprevention (CP) in Monrovia to reduce malaria-associated morbidity. In order to inform future interventions, we described the scale of the MDA, evaluated its acceptance and estimated the effectiveness. Methods MSF carried out two rounds of MDA with artesunate/amodiaquine (ASAQ) targeting four neighbourhoods of Monrovia (October to December 2014). We systematically selected households in the distribution area and administered standardized questionnaires. We calculated incidence ratios (IR) of side effects using poisson regression and compared self-reported fever risk differences (RD) pre- and post-MDA using a z-test. Findings In total, 1,259,699 courses of ASAQ-CP were distributed. All households surveyed (n = 222; 1233 household members) attended the MDA in round 1 (r1) and 96% in round 2 (r2) (212/222 households; 1,154 household members). 52% (643/1233) initiated ASAQ-CP in r1 and 22% (256/1154) in r2. Of those not initiating ASAQ-CP, 29% (172/590) saved it for later in r1, 47% (423/898) in r2. Experiencing side effects in r1 was not associated with ASAQ-CP initiation in r2 (IR 1.0, 95%CI 0.49–2.1). The incidence of self-reported fever decreased from 4.2% (52/1229) in the month prior to r1 to 1.5% (18/1229) after r1 (p<0.001) and decrease was larger among household members completing ASAQ-CP (RD = 4.9%) compared to those not initiating ASAQ-CP (RD = 0.6%) in r1 (p<0.001). Conclusions The reduction in self-reported fever cases following the intervention suggests that MDAs may be effective in reducing cases of fever during Ebola outbreaks. Despite high coverage, initiation of ASAQ-CP was low. Combining MDAs with longer term interventions to prevent malaria and to improve access to healthcare may reduce both the incidence of malaria and

  11. Chemoprevention of mammary carcinogenesis by 1α-hydroxyvitamin D5, a synthetic analog of Vitamin D

    International Nuclear Information System (INIS)

    Numerous analogs of Vitamin D have been synthesized in recent years with the hope of generating a compound that retains the anticarcinogenic activity of Vitamin D without causing any toxicity. We synthesized such an analog, 1α-hydroxy-24-ethylcholecalciferol [1α-hydroxyvitamin D5 or 1α(OH)D5], and showed that it was tolerated by rats and mice at a much higher dose than 1α,25 dihydroxy cholecalciferol [1α,25(OH)2D3]. This property makes it a prime candidate for chemoprevention studies. In the mouse mammary gland organ culture (MMOC), 1α(OH)D5 inhibited carcinogen-induced development of both mammary alveolar and ductal lesions. In vivo carcinogenesis study showed statistically significant reduction of tumor incidence and multiplicity in N-methyl-N-nitrosourea (MNU)-treated rats that were fed 25-50 μg 1α(OH)D5/kg diet. There were no adverse effects on plasma calcium concentrations. In order to determine if the effect of 1α(OH)D5 would be selective in suppressing proliferation of transformed cells, its effects on cell growth and proliferation were compared between BT474 (cancer) and MCF12F (non-tumorigenic) human breast epithelial cells. Results showed that 1α(OH)D5 induced apoptosis and cell cycle G1 phase arrest in BT474 breast cancer cells without having any effects on proliferation of the MCF12F cells. In addition, in MMOC it had no growth inhibitory effects on normal epithelial cell proliferation in the absence of carcinogen. Similarly, non-tumorigenic human breast epithelial cells in explant culture did not respond to 1α(OH)D5, whereas treatment with 1α(OH)D5 induced cell death in the explants of cancer tissue. These results collectively indicate that 1α(OH)D5 selectively induced apoptosis only in transformed cells but not in normal breast epithelial cells. Interestingly, the growth inhibitory effects of 1α(OH)D5 were observed in Vitamin D receptor positive (VDR+) breast cancer cells, but not in highly metastatic VDR- breast cancer cells, such as

  12. Complexation of uranium with 1, 3, 5-trimethoxy 2, 4, 6-tricarboxymethoxy-P-tert-butyl calix(6) arene

    International Nuclear Information System (INIS)

    Complexation behaviour of UO22+ with 1,3,5-trimethoxy 2,4,6-tricarboxymethoxy-p-tert-butyl calix[6]arene under varying conditions of pH and acetate ion concentration has been studied. These studies indicate that extraction mechanism of uranium is influenced by the presence of Na+ ion. (author)

  13. EVALUATION OF METHYL TERT-BUTYL ETHER (MTBE) AS AN INTERFERENCE ON COMMERCIAL BREATH-ALCOHOL ANALYZERS

    Science.gov (United States)

    Anecdotal reports suggest that high environmental or occupational exposures to the fuel oxygenate methyl tert-butyl ether (MTBE) may result in breath concentrations that are sufficiently elevated to cause a false positive on commercial breath-alcohol analyzers. We evaluated th...

  14. UV absorption spectra, kinetics and mechanism for alkyl and alkyl peroxy radicals originating from t-butyl alcohol

    DEFF Research Database (Denmark)

    Langer, S.; Ljungström, E.; Sehested, J.;

    1994-01-01

    Alkyl and alkyl peroxy radicals from 1-butyl alcohol (TBA), HOC (CH3)2CH2. and HOC(CH3)2CH2O2. have been studied in the ps phase at 298 K. Two techniques were used: pulse radiolysis UV absorption to measure the spectra and kinetics, and long path-length Fourier transform infrared spectroscopy (FTIR...

  15. THE PHYSICS OF ELEMENTARY PARTICLES AND FIELDS: A Chiral Macroscopic Force between Liquid of Butyl Alcohol and Copper Block

    Science.gov (United States)

    Hu, Yong-Hong; Liu, Zhong-Zhu

    2008-11-01

    A non-zero macroscopic chirality-dependent force between a copper block and a vessel of homochiral molecules (butyl alcohol) is calculated quantitatively with the central field approximation. The magnitude of the force is estimated with the published limits of the scalar and pseudo-scalar coupling constants.

  16. Synthesis and characterization of di- and triorganotin(IV) complexes of 2-tert-butyl-4-methyl phenol

    Indian Academy of Sciences (India)

    Neeraj Sharma; Archana; Maridula Thakur; S S Bhatt; S C Chaudhry

    2007-07-01

    The di- and trialkyltin(IV) complexes of composition R2SnCl2-(OAr), and -Bu3Sn(OAr) (R = -Bu and Me; = 1 and 2; OAr = OC6H3Bu-2-Me-4) have been synthesized by the reactions of di-n-butyl and dimethyltin dichlorides and tri-n-butyltin(IV) chloride with 2-tert-butyl-4-methylphenol and triethylamine in tetrahydrofuran. The reaction of triphenyltin chloride with trimethylsilyl-2-t-butyl-4-methylphenoxide in the same solvent however, gives a complex of composition Ph3Sn(OAr). The complexes have been characterized by microanalyses, molar conductance measurements, molecular weight determinations and IR and 1H, 13C and 119Sn NMR and mass spectral studies. Thermal behaviour of the complexes has been studied by TGA and DTA techniques. From the non-isothermal TG data, the kinetic and thermodynamic parameters have been calculated employing Coats-Redfern equation and the mechanism of decomposition has been computed using non-isothermal kinetic method. Thermal investigations on the blends of poly(methylmethacrylate). PMMA, with organotin(IV)-2-tert-butyl-4-methylphenoxides have shown increased thermal stability compared to pure PMMA suggesting thereby their potential as additives towards PMMA.

  17. Crystal structure of 2-tert-butyl-1,3-thiazolo[4,5-b]pyridine

    Directory of Open Access Journals (Sweden)

    Gamal A. El-Hiti

    2014-09-01

    Full Text Available The title compound, C10H12N2S, does not contain any strong hydrogen-bond donors but two long C—H...N contacts are observed in the crystal structure, with the most linear interaction linking molecules along [010]. The ellipsoids of the tert-butyl group indicate large librational motion.

  18. Carbamoylcholine analogs as nicotinic acetylcholine receptor agonists--structural modifications of 3-(dimethylamino)butyl dimethylcarbamate (DMABC)

    DEFF Research Database (Denmark)

    Hansen, Camilla Petrycer; Jensen, Anders Asbjørn; Balle, Thomas;

    2009-01-01

    Compounds based on the 3-(dimethylamino)butyl dimethylcarbamate (DMABC) scaffold were synthesized and pharmacologically characterized at the alpha(4)beta(2), alpha(3)beta(4,) alpha(4)beta(4) and alpha(7) neuronal nicotinic acetylcholine receptors (nAChRs). The carbamate functionality and a small...

  19. SYNTHESIS OF METHYL TERT-BUTYL ETHER CATALYZED BY ACIDIC ION-EXCHANGE RESINS - INFLUENCE OF THE PROTON ACTIVITY

    NARCIS (Netherlands)

    PANNEMAN, HJ; BEENACKERS, AACM

    1995-01-01

    The catalytic activity of various strong acid ion-exchange resins on the synthesis of methyl tert-butyl ether (MtBE) from methanol and isobutene has been investigated. Relative to Amberlyst 15, Kastel CS 381 and Amberlyst CSP have similar rate constants, whereas Duolite ES 276 and Amberlyst XE 307 h

  20. Nonlinear viscoelastic response of carbon black-filled butyl rubber and implications for o-ring aging

    Energy Technology Data Exchange (ETDEWEB)

    Adolf, D.

    1997-11-01

    Butyl rubber, unfortunately, has pronounced nonlinear viscoelastic behavior, which may be modelled by a separable KBKZ formalism. While these effects seem to have minimal impact on accelerated sealing force measurements, they do severely impact compression set tests. Therefore, a new test is suggested for evaluating field-return o-rings which is free from such confounding effects.