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Sample records for butylated hydroxytoluene chemoprevention

  1. 21 CFR 582.3173 - Butylated hydroxytoluene.

    Science.gov (United States)

    2010-04-01

    ... 0.02 percent of fat or oil content, including essential (volatile) oil content of food provided the... 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...

  2. 21 CFR 182.3173 - Butylated hydroxytoluene.

    Science.gov (United States)

    2010-04-01

    ... of fat or oil content, including essential (volatile) oil content of food, provided the substance is... 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...

  3. 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)

  4. 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 se...

  5. 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

  6. Synthetic phenolic antioxidants, including butylated hydroxytoluene (BHT), in resin-based dental sealants.

    Science.gov (United States)

    Wang, Wei; Kannan, Pranav; Xue, Jingchuan; Kannan, Kurunthachalam

    2016-11-01

    Resin-based dental sealants (also referred to as pit-and-fissure sealants) have been studied for their contribution to bisphenol A (BPA) exposure in children. Nevertheless, little attention has been paid to the occurrence of other potentially toxic chemicals in dental sealants. In this study, the occurrence of six synthetic phenolic antioxidants (SPAs), including 2,6-di-tert-butyl-4-hydroxytoluene (BHT), 2,6-di-tert-butyl-4-(hydroxyethyl)phenol (BHT-OH), 3,5-di-tert-butyl-4-hydroxy-benzaldehyde (BHT-CHO), 2,6-di-tert-butylcyclohexa-2,5-diene-1,4-dione (BHT-Q), 3,5-di-tert-butyl-4-hydroxybenzoic acid (BHT-COOH) and 2-tert-butyl-4-methoxyphenol (BHA), was examined in 63 dental sealant products purchased from the U.S. market. BHT was found in all dental sealants at median and maximum concentrations of 56.8 and 1020µg/g, respectively. The metabolites of BHT and BHA were detected in 39-67% of samples, at concentration ranges of shelf-life of the products. The estimated daily intake (EDI) of BHT, following sealant placement, based on a worst-case scenario (application on eight teeth at 8mg each tooth), was 930 and 6510ng/kg bw/d for adults and children, respectively. The EDI of BHT from dental sealants was several orders of magnitude lower than the current acceptable daily intake (ADI) proposed by the European Food Safety Authority (EFSA). Copyright © 2016 Elsevier Inc. All rights reserved.

  7. 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%.

  8. Effect of butylated hydroxytoluene on dog sperm longevity in chilling storage and cryopreservation.

    Science.gov (United States)

    Sahashi, Yu; Otsuki, Tsubasa; Higaki, Shogo; Nagano, Masashi; Yamashita, Yasuhisa; Hishinuma, Mitsugu

    2011-07-01

    This study evaluated the effect of butylated hydroxytoluene (BHT), a lipid-soluble antioxidant, on dog sperm in chilling storage and cryopreservation. In Experiment 1, 0.2, 0.4, 0.8 and 1.6 mM BHT were added to egg yolk Tris extender (EYT), and sperm were stored at 4°C for 96 hr. Sperm motility, viability, acrosomal integrity and morphological abnormality in the BHT treatment groups were not different from those of the control (0 mM BHT). In Experiment 2, the effect of BHT in EYT containing 0.75% Equex STM paste and 5% glycerol on survivability of cryopreserved sperm was examined after culture at 39°C for 3 hr. Sperm motility, viability and acrosomal integrity in the 0.2 to 0.8 mM BHT treatment groups were not different from those of the control. However, sperm motility, viability and acrosomal integrity decreased when 1.6 mM BHT was added to the extender (Pchilling storage and cryopreservation. Supplementation of 1.6 mM BHT did not affect characteristics of chilled sperm but impaired longevity of cryopreserved sperm in the dog.

  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.

    Science.gov (United States)

    Katnik, Christopher; Cuevas, Javier

    2014-02-27

    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. Simultaneous analysis of tert-butylhydroquinone, tert-butylquinone, butylated hydroxytoluene, 2-tert-butyl-4-hydroxyanisole, 3-tert-butyl-4-hydroxyanisole, α-tocopherol, γ-tocopherol, and δ-tocopherol in edible oils by normal-phase high performance liquid chromatography.

    Science.gov (United States)

    Li, Jun; Bi, Yanlan; Sun, Shangde; Peng, Dan

    2017-11-01

    A normal-phase high performance liquid chromatography method for the simultaneous determination of tert-butylhydroquinone, tert-butylquinone, butylated hydroxytoluene, 2-tert-butyl-4-hydroxyanisole, 3-tert-butyl-4-hydroxyanisole, α-tocopherol, γ-tocopherol, and δ-tocopherol in edible oils was investigated. A silica column was used to separate the analytes with the gradient elution. An ultraviolet-visible detector was set at dual wavelengths mode (280 and 310nm). The column temperature was 30°C. The analytes were directly extracted with methanol. Results showed that the normal-phase high performance liquid chromatography method performed well with wide liner ranges (0.10∼500.00μg/mL, R2>0.9998), low limits of detection and quantitation (below 0.40 and 1.21μg/mL, respectively), and good recoveries (81.38∼102.34% in soybean oils and 83.03∼100.79% in lard, respectively). The reduction of tert-butylquinone caused by the reverse-phase high performance liquid chromatography during the injection was avoided with the current normal-phase method. The two isomers of butylated hydroxyanisole can also be separated with good resolution. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. 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.

  12. Use of spin labels and electron spin resonance spectroscopy to characterize membranes of bovine sperm: effect of butylated hydroxytoluene and cold shock

    Energy Technology Data Exchange (ETDEWEB)

    Hammerstedt, R.H.; Amann, R.P.; Rucinsky, T.; Morse, P.D. II; Lepock, J.; Snipes, W.; Keith, A.D.

    1976-05-01

    Spin label probes were used in conjunction with measurements of metabolic rate and electron microscopy to characterize bovine sperm membranes. Aqueous compartments, membrane hydrocarbon zones and lipid : water interfaces were studied separately using appropriate spin labels. For sperm suspended in aqueous medium, the cold shock associated with rapid cooling from room temperature to 0/sup 0/ increased membrane permeability. This membrane damage was readily detected using spin labels but was not detected using thin section electron microscopy. This change was prevented by the addition of butylated hydroxy toluene (BHT). BHT provided partial protection against further damage caused by freezing sperm on solid CO/sub 2/. ESR techniques provide a rapid means to quantify the changes in sperm membranes occurring during the epididymal maturation of sperm and subsequent events within the female tract leading to fertilization. The technique also could be used to assess damage to sperm, ova or embryos during preparation for storage in cryoprotective diluents.

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

    OpenAIRE

    Nunes, A. S.; Matias, A.; 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...

  14. 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.

  15. Chemoprevention of Melanoma

    Science.gov (United States)

    Madhunapantula, SubbaRao V.; Robertson, Gavin P.

    2013-01-01

    Despite advances in drug discovery programs and molecular approaches for identifying the drug targets, incidence and mortality rates due to melanoma continues to rise at an alarming rate. Existing preventive strategies generally involve mole screening followed by surgical removal of the benign nevi and abnormal moles. However, due to lack of effective programs for screening and disease recurrence after surgical resection there is a need for better chemopreventive agents. Although sunscreens have been used extensively for protecting from UV-induced skin cancer, results of correlative population based studies are controversial, requiring further authentication to conclusively confirm the chemoprotective efficacy of sunscreens. Certain studies suggest increased skin-cancer rates in sunscreen users. Therefore, effective chemopreventive agents for preventing melanoma are urgently required. This book-chapter, reviews the current understanding regarding melanoma chemoprevention and the various strategies used to accomplish this objective. PMID:22959032

  16. [Coffee in Cancer Chemoprevention].

    Science.gov (United States)

    Neuwirthová, J; Gál, B; Smilek, P; Urbánková, P

    Coffee consumption is associated with a reduced risk of several diseases including cancer. Its chemopreventive effect has been studied in vitro, in animal models, and more recently in humans. Several modes of action have been proposed, namely, inhibition of oxidative stress and damage, activation of metabolizing liver enzymes involved in carcinogen detoxification processes, and anti-inflammatory effects. The antioxidant activity of coffee relies partly on its chlorogenic acid content and is increased during the roasting process. Maximum antioxidant activity is observed for medium-roasted coffee. The roasting process leads to the formation of several components, e.g., melanoidins, which have antioxidant and anti-inflammatory properties. Coffee also contains two specific diterpenes, cafestol and kahweol, which have anticarcinogenic properties. Roasted coffee is a complex mixture of various chemicals. Previous studies have reported that the chemopreventive components present in coffee induce apoptosis, inhibit growth and metastasis of tumor cells, and elicit antiangiogenic effects. A meta-analysis of epidemiological studies showed that coffee consumption is associated with a lower risk of developing various malignant tumors. This review summarizes the molecular mechanisms and the experimental and epidemiological evidence supporting the chemopreventive effect of coffee.Key words: coffee - chemoprevention - antioxidative enzyme - detoxification enzyme - anti-inflammatory effect The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.Submitted: 11. 9. 2016Accepted: 24. 11. 2016.

  17. Chemoprevention of Lung Cancer

    Science.gov (United States)

    Szabo, Eva; Mao, Jenny T.; Lam, Stephen; Reid, Mary E.

    2013-01-01

    Background: Lung cancer is the most common cause of cancer death in men and women in the United States. Cigarette smoking is the main risk factor. Former smokers are at a substantially increased risk of developing lung cancer compared with lifetime never smokers. Chemoprevention refers to the use of specific agents to reverse, suppress, or prevent the process of carcinogenesis. This article reviews the major agents that have been studied for chemoprevention. Methods: Articles of primary, secondary, and tertiary prevention trials were reviewed and summarized to obtain recommendations. Results: None of the phase 3 trials with the agents β-carotene, retinol, 13-cis-retinoic acid, α-tocopherol, N-acetylcysteine, acetylsalicylic acid, or selenium has demonstrated beneficial and reproducible results. To facilitate the evaluation of promising agents and to lessen the need for a large sample size, extensive time commitment, and expense, surrogate end point biomarker trials are being conducted to assist in identifying the most promising agents for later-stage chemoprevention trials. With the understanding of important cellular signaling pathways and the expansion of potentially important targets, agents (many of which target inflammation and the arachidonic acid pathway) are being developed and tested which may prevent or reverse lung carcinogenesis. Conclusions: By integrating biologic knowledge, additional early-phase trials can be performed in a reasonable time frame. The future of lung cancer chemoprevention should entail the evaluation of single agents or combinations that target various pathways while working toward identification and validation of intermediate end points. PMID:23649449

  18. Evaluation of dose uncertainty in radiation processing using EPR spectroscopy and butylated hydroxytoluene rods as dosimetry system

    Science.gov (United States)

    Alkhorayef, M.; Mansour, A.; Sulieman, A.; Alnaaimi, M.; Alduaij, M.; Babikir, E.; Bradley, D. A.

    2017-12-01

    Butylatedhydroxytoluene (BHT) rods represent a potential dosimeter in radiation processing, with readout via electron paramagnetic resonance (EPR) spectroscopy. Among the possible sources of uncertainty are those associated with the performance of the dosimetric medium and the conditions under which measurements are made, including sampling and environmental conditions. Present study makes estimate of the uncertainties, investigating physical response in different resonance regions. BHT, a white crystalline solid with a melting point of between 70-73 °C, was investigated using 60Co gamma irradiation over the dose range 0.1-100 kGy. The intensity of the EPR signal increases linearly in the range 0.1-35 kGy, the uncertainty budget for high doses being 3.3% at the 2σ confidence level. The rod form represents an excellent alternative dosimeter for high level dosimetry, of small uncertainty compared to powder form.

  19. Preservability of bull spermatozoa in Tris-egg yolk extender enriched with different concentrations of butylated hydroxytoluene

    Directory of Open Access Journals (Sweden)

    El-Sheshtawy RI

    2017-02-01

    Full Text Available Objective: To explore the effect of BHT on cattle spermatozoa during cooling and cryopreservation. Methods: Pooled bull semen were diluted by Tris-Citrate-Fructose egg yolk (TCFY diluent considered as control (0 BHT and different concentrations of BHT (1.0, 2.0, 3.0, 4.0, 5.0 and 6.0 mM were prepared in ethanol in prewarmed (37 ℃ test tubes. The ethanol was allowed to evaporate so that, a thin crystallized layer of BHT was deposited on the inner surface of the tubes. Then extended semen was added into the tubes and incubated at 37 ℃ for 5 min to allow uptake of BHT by spermatozoa. The tubes were cooled slowly (approximately for 2 h up to 5 ℃ and equilibrated for 4 h. After equilibration, semen freezing process was carried out. Extended semen was subjected to evaluation (motility, alive sperm, intact sperm membrane (HOST % and acrosome integrity in both cooled and cryopreserved semen. Results: The result revealed that sperm motility of post-cooled spermatozoa improved (P<0.05 by the use of BHT concentrations (1, 2 and 3 mM in Tris semen extender if compared to the control (85.00±1.09, (83.33± 0.63, (81.67± 0.63 and (78.33± 0.63, respectively. Alive sperm percent was significantly higher in all concentrations of BHT. Sperm abnormalities percent were significantly lower in concentrations of BHT 1 and 2 (11.2±0.2, (11.8±0.2and (13.4±0.4, respectively. Sperm membrane integrity were significantly higher in BHT concentrations (1, 2, 3, 4 and 5 mM. It is exhibited that improved sperm motility in post-thawed frozen semen in the concentrations of BHT (1, 2, 3 and 4 mM if compared to the control. The sperm membrane integrity were significantly improved at all concentrations of BHT. Acrosome integrity was significantly higher at BHT concentration 1 mM (81.80±0.57 and (76.00±2.05, respectively. Conclusions: It could be concluded that some concentrations of BHT improved bull semen quality post-cooling and post-freezing.

  20. Chemoprevention by WR-2721

    Energy Technology Data Exchange (ETDEWEB)

    Grdina, D.J. [Argonne National Lab., IL (United States)]|[Chicago Univ., IL (United States). Dept. of Radiation and Cellular Oncology; Carnes, B.A. [Argonne National Lab., IL (United States)

    1993-05-01

    WR-2721 [S-2-(3-aminopropylamino)ethylphosphorothioic acid] is an effective chemopreventive agent. C57BL {times} BALB/c F{sub 1} female mice, were exposed to a single whole-body dose of 206 cGy from a {sup 60}Co photon source. Those groups treated with VATR-2721 (400 mg/kg) were administered the agent i.p. 30 min prior to irradiation. Over 90% of deaths were determined to be due to tumor involvement. WR-2721 afforded significant protection against life shortening due to radiation-induced tumors of connective tissue and epithelial tissue origins. Subsequent survival time in WR-2721-treated and irradiated animals as compared to matched irradiated-only controls was extended up to 59 days. A single exposure of animals to VVR-2721 did not affect the cumulative survival curves for unirradiated mice. WR-2721 possesses chemopreventive properties which can be clinically exploited to reduce the risk to therapy-induced secondary cancers in patients who otherwise would have an excellent prognosis for cure and long-term survival.

  1. Chemoprevention by WR-2721

    Energy Technology Data Exchange (ETDEWEB)

    Grdina, D.J. (Argonne National Lab., IL (United States) Chicago Univ., IL (United States). Dept. of Radiation and Cellular Oncology); Carnes, B.A. (Argonne National Lab., IL (United States))

    1993-01-01

    WR-2721 [S-2-(3-aminopropylamino)ethylphosphorothioic acid] is an effective chemopreventive agent. C57BL [times] BALB/c F[sub 1] female mice, were exposed to a single whole-body dose of 206 cGy from a [sup 60]Co photon source. Those groups treated with VATR-2721 (400 mg/kg) were administered the agent i.p. 30 min prior to irradiation. Over 90% of deaths were determined to be due to tumor involvement. WR-2721 afforded significant protection against life shortening due to radiation-induced tumors of connective tissue and epithelial tissue origins. Subsequent survival time in WR-2721-treated and irradiated animals as compared to matched irradiated-only controls was extended up to 59 days. A single exposure of animals to VVR-2721 did not affect the cumulative survival curves for unirradiated mice. WR-2721 possesses chemopreventive properties which can be clinically exploited to reduce the risk to therapy-induced secondary cancers in patients who otherwise would have an excellent prognosis for cure and long-term survival.

  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. Chemoprevention of bladder cancer.

    Science.gov (United States)

    Kamat, Ashish M; Lamm, Donald L

    2002-02-01

    The data presented herein, although highly supportive for a protective role of various nutrients against bladder cancer, are far from definitive. Many authorities question the validity of current recommendations for nutritional chemoprevention against bladder cancer. The reason for the wide variations reported in epidemiologic studies lies in the nature of observational studies. Dietary studies are limited in their conclusions because the protection afforded by the consumption of a particular nutrient may be multifactorial, with different components of the food exerting potential chemopreventive effects. Furthermore, measuring levels of nutrients in the food intake of populations is confounded by factors that might affect these levels and also the incidence of cancer. For example, vitamin A can come from animal or vegetarian sources. Because animal fat has been identified as a potential carcinogen in man, depending on the source of the vitamin, varying levels of protection might be deduced. In addition, chemoprevention studies using dietary supplements are expected to have mild effects, and large studies would be required to confirm statistical significance. Even with agents such as intravesical chemotherapy, only half the studies achieve statistical significance [29]. Prospective randomized trials with a large sample size, longer follow-up, and an extended duration of treatment are needed to clarify the association between micronutrients and cancer protection. With these caveats in mind, several recommendations can be made. Simple measures, such as drinking more fluids (especially water), can have a profound impact on the incidence of bladder cancer. Vitamins are being extensively studied in chemopreventive trials for different cancers. There is strong evidence for a chemoprotective effect of vitamin A in bladder cancer. The authors recommend 32,000 IU/day of vitamin A initially, with lower doses (24,000 IU) for persons less than 50 kg. Because liver toxicity is a

  4. 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.

  5. 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

  6. Chemopreventive properties of curcumin analogues ...

    African Journals Online (AJOL)

    Purpose: To examine the chemopreventive activity of curcumin analogues, hexagamavunone-0 (HGV-. 0) and gamavutone-0 (GVT-0), compared to curcumin in a colorectal cancer model in Wistar rats. Methods: Rats (n = 25) were assigned to one of five groups (n = 5 in each group). Colorectal cancer was induced in the ...

  7. Chemopreventive activity of methanol extract of Melastoma ...

    African Journals Online (AJOL)

    Chemopreventive activity of methanol extract of Melastoma malabathricum leaves in DMBA-induced mouse skin carcinogenesis. ... Conclusion: MEMM demonstrated chemoprevention possibly via its antioxidant and anti-inflammatory activities, and the action of flavonoids like quercitrin. Key words: Melastomaceae; skin ...

  8. Nicotinamide for skin cancer chemoprevention.

    Science.gov (United States)

    Damian, Diona L

    2017-08-01

    Nicotinamide (vitamin B 3 ) has a range of photoprotective effects in vitro and in vivo; it enhances DNA repair, reduces UV radiation-induced suppression of skin immune responses, modulates inflammatory cytokine production and skin barrier function and restores cellular energy levels after UV exposure. Pharmacological doses of nicotinamide have been shown to reduce actinic keratoses and nonmelanoma skin cancer incidence in high-risk individuals, making this a nontoxic and accessible option for skin cancer chemoprevention in this population. © 2017 The Australasian College of Dermatologists.

  9. Chemotherapy and Chemoprevention by Thiazolidinediones

    Directory of Open Access Journals (Sweden)

    Eleonore Fröhlich

    2015-01-01

    Full Text Available Thiazolidinediones (TZDs are synthetic ligands of Peroxisome-Proliferator-Activated Receptor gamma (PPARγ. Troglitazone, rosiglitazone, and pioglitazone have been approved for treatment of diabetes mellitus type II. All three compounds, together with the first TZD ciglitazone, also showed an antitumor effect in preclinical studies and a beneficial effect in some clinical trials. This review summarizes hypotheses on the role of PPARγ in tumors, on cellular targets of TZDs, antitumor effects of monotherapy and of TZDs in combination with other compounds, with a focus on their role in the treatment of differentiated thyroid carcinoma. The results of chemopreventive effects of TZDs are also considered. Existing data suggest that the action of TZDs is highly complex and that actions do not correlate with cellular PPARγ expression status. Effects are cell-, species-, and compound-specific and concentration-dependent. Data from human trials suggest the efficacy of TZDs as monotherapy in prostate cancer and glioma and as chemopreventive agent in colon, lung, and breast cancer. TZDs in combination with other therapies might increase antitumor effects in thyroid cancer, soft tissue sarcoma, and melanoma.

  10. 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.

  11. Chemical carcinogenesis and chemoprevention: Scientific priority ...

    African Journals Online (AJOL)

    Occupational cancers are now a serious concern in industrializing developing countries where exposure levels to hazardous chemicals considerably exceed regulatory limits established in industrialized countries. The association between increasing use of chemicals and associated disorders and chemoprevention or ...

  12. Cancer chemoprevention – selected molecular mechanisms

    Directory of Open Access Journals (Sweden)

    Katarzyna Walczak

    2017-03-01

    Full Text Available The effect of diet on cancer formation and prevention of carcinogenesis has attracted considerable attention for years and is the subject of several studies. Some components of the daily diet, such as resveratrol, curcumin, genistein, gingerol, can significantly reduce the risk of cancer or affect the rate of tumor progression. Cancer chemoprevention assumes the use of natural or synthetic biologically active substances in order to prevent, inhibit or reverse the progression of cancer. There are many biologically active compounds in several natural products, i.e. garlic, ginger, soy, curcuma, tomatoes, cruciferous plants or green tea. Their chemopreventive activity is based on the inhibition of processes underlying carcinogenesis (inflammation, transformation and proliferation, but also affects the final phase of carcinogenesis - angiogenesis and metastasis. Despite the relatively low toxicity of chemopreventive agents, their molecular targets often coincide with the objectives of the currently used cancer therapies. The widespread use of chemopreventive agents may contribute to reduction of the rate of cancer incidence, and increase the effectiveness of conventional cancer therapies. In the present study, selected molecular mechanisms of the chemopreventive activity have been discussed, especially their involvement in the regulation of signal transduction, cell cycle regulation, apoptosis, metastasis and angiogenesis. The role of chemopreventive agents in the inflammatory process, the metabolism of xenobiotics and multidrug resistance has been also characterized.

  13. DIETARY TERPENOIDS AND PROSTATE CANCER CHEMOPREVENTION

    Science.gov (United States)

    Rabi, Thangaiyan; Gupta, Sanjay

    2014-01-01

    Cancer chemoprevention by phytochemicals may be one of the most feasible approaches for cancer control. Phytochemicals obtained from vegetables, fruits, spices, teas, herbs and medicinal plants, such as terpenoids and other phenolic compounds, have been proven to suppress experimental carcinogenesis in various organs in pre-clinical models. Recent studies have indicated that mechanisms underlying chemopreventive potential may be a combination of antioxidant, anti-inflammatory, immune-enhancing, and hormone modulation effects, with modification of drug metabolizing enzymes, influence on cell cycle and cell differentiation, induction of apoptosis, suppression of proliferation and angiogenesis playing roles in the initiation and secondary modification stages of neoplastic development. Specific features of prostate cancer, such as high prevalence and long latency period provides ample opportunities for chemopreventive agents to work at various stages of disease progression. Finally, suitable populations with appropriate risk factors, including the presence of pre-malignant lesions and genetic predispositions, need to be well characterized for future chemopreventive interventions. Here we review naturally occurring dietary terpenoids as useful agents for prostate cancer chemoprevention with reference to their classes and sources. PMID:18508447

  14. 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.

  15. Nigerian foodstuffs with prostate cancer chemopreventive polyphenols

    OpenAIRE

    Atawodi, Sunday Eneojo

    2011-01-01

    Dietary polyphenols are antioxidants that can scavenge biological free radicals, and chemoprevent diseases with biological oxidation as their main etiological factor. In this paper, we review our laboratory data vis-?-vis available literature on prostate cancer chemopreventive substances in Nigerian foodstuffs. Dacryodes edulis fruit, Moringa oleifera and Syzygium aromaticum contained prostate active polyphenols like ellagic acid, gallate, methylgallate, catechol, kaempferol quercetin and the...

  16. Meeting Report: Pancreatic Cancer Chemoprevention Translational Workshop

    Science.gov (United States)

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

    2016-01-01

    Pancreatic cancer is the 4th leading cause of cancer related deaths in the US with a 5 year survival rate of Cancer Prevention of the NCI sponsored the Pancreatic Cancer Chemoprevention Translational Workshop on September 10–11th 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/immuopreventative 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 NCI working group to coordinate efforts, provide a framework, and identify opportunities for chemoprevention of pancreatic cancer. PMID:27518363

  17. Cancer chemopreventive property of Bidens pilosa methanolic

    African Journals Online (AJOL)

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    tumor growth. Chemopreventive agents can be broadly classified as blocking and suppressing agents. The blocking agents prevent carcinogenic ... stimulating differentiation in myeloid leukemia cells at a very low concentration, the effects of TPA in mouse with papilloma were investigated in the present study. In the present ...

  18. Cancer chemoprevention by targeting the epigenome.

    Science.gov (United States)

    Huang, Joseph; Plass, Christoph; Gerhauser, Clarissa

    2011-12-01

    The term "epigenetics" refers to modifications in gene expression caused by heritable, but potentially reversible, changes in DNA methylation and chromatin structure. Given the fact that epigenetic modifications occur early in carcinogenesis and represent potentially initiating events in cancer development, they have been identified as promising new targets for prevention strategies. The present review will give a comprehensive overview of the current literature on chemopreventive agents and their influence on major epigenetic mechanisms, that is DNA methylation, histone acetylation and methylation, and microRNAs, both in vitro and in rodent and human studies, taking into consideration specific mechanisms of action, target sites, concentrations, methods used for analysis, and outcome. Chemopreventive agents with reported mechanisms targeting the epigenome include micronutrients (folate, selenium, retinoic acid, Vit. E), butyrate, polyphenols (from green tea, apples, coffee, and other dietary sources), genistein and soy isoflavones, parthenolide, curcumin, ellagitannin, indol-3-carbinol (I3C) and diindolylmethane (DIM), mahanine, nordihydroguaiaretic acid (NDGA), lycopene, sulfur-containing compounds from Allium and cruciferous vegetables (sulforaphane, phenylethyl isothiocyanate (PEITC), phenylhexyl isothiocyanate (PHI), diallyldisulfide (DADS), allyl mercaptan (AM)), antibiotics (mithramycin A, apicidin), pharmacological agents (celecoxib, DFMO, 5-aza-2'-deoxycytidine and zebularine), compounds affecting sirtuin activity (resveratrol, dihydrocoumarin, cambinol), inhibitors of histone acetyl transferases (anacardic acid, garcinol, ursodeoxycholic acid), and relatively unexplored modulators of histone lysine methylation (chaetocin, polyamine analogues, n-3 polyunsaturated fatty acids). Their effects on global DNA methylation, tumor suppressor genes silenced by promoter methylation, histone modifications, and miRNAs deregulated during carcinogenesis have potential

  19. Antimutagenic constituents of adlay (Coix lachryma-jobi L. var. ma-yuen Stapf) with potential cancer chemopreventive activity.

    Science.gov (United States)

    Chen, Huang-Hui; Chiang, Wenchang; Chang, Jang-Yang; Chien, Ya-Lin; Lee, Ching-Kuo; Liu, Ko-Jiunn; Cheng, Yen-Ting; Chen, Ting-Fang; Kuo, Yueh-Hsiung; Kuo, Ching-Chuan

    2011-06-22

    Adlay has long been used in traditional Chinese medicine and as a nourishing food. The acetone extract of adlay hull had previously been demonstrated to possess potent antimutagenic activity. The aims of this study were to identify the antimutagenic constituents from adlay hull by using Ames antimutagenic activity-guide isolation procedures and to investigate their chemopreventive efficacies in cultured cells. The results demonstrated that six compounds showing great antimutagenic activity were identified by spectroscopic methods and by comparison with authentic samples to be p-hydroxybenzaldehyde, vanillin, syringaldehyde, trans-coniferylaldehyde, sinapaldehyde, and coixol. Two of them, trans-coniferylaldehyde and sinapaldehyde, exhibit relatively potent scavenging of DPPH radicals, inhibit TPA stimulated superoxide anion generation in neutrophil-like leukocytes, and induce Nrf2/ARE-driven luciferase activity in HSC-3 cells. Moreover, trans-coniferylaldehyde possesses cytoprotective efficacy against tert-butyl hydroperoxide-induced DNA double-strand breaks in cultured cells, and the chemopreventive potency induced by trans-coniferylaldehyde may be through the activation of kinase signals, including p38, ERK1/2, JNK, MEK1/2, and MSK1/2. In summary, we first identified six antimutagenic constituents from adlay hull. Among them, trans-coniferylaldehyde would be a highly promising agent for cancer chemoprevention and merits further investigation.

  20. 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.

  1. Chemopreventive effect of tadalafil in cisplatin-induced ...

    African Journals Online (AJOL)

    Summary: Nephrotoxicity remains a common untoward effect of cisplatin therapy with limited effective chemopreventive options available till date. This study aims to evaluate the possible chemopreventive effect and mechanism(s) of action of 2 mgkg-1 and 5 mgkg-1 of Tadalafil in cisplatin-induced nephrotoxic rats. In this ...

  2. Optical fibers by butyl methacrylate reactive extrusion

    OpenAIRE

    Berthet, Romuald; Chalamet, Yvan; Taha, Mohamed; Zerroukhi, Amar

    2006-01-01

    51 p.; A process for a poly(butyl methacrylate) optical fibers production by reactive extrusion was developed. The reactive system was adapted to the reduced reaction time in the extruder combining concepts based on the free volume theory and a kinetic model for mass polymerization a butyl methacrylate. A kinetic model was proposed and the reaction evolution was simulated at different temperature and initiator concentration. This allowed the choice of reaction conditions in adequation with re...

  3. Nigerian foodstuffs with prostate cancer chemopreventive polyphenols.

    Science.gov (United States)

    Atawodi, Sunday Eneojo

    2011-09-23

    Dietary polyphenols are antioxidants that can scavenge biological free radicals, and chemoprevent diseases with biological oxidation as their main etiological factor. In this paper, we review our laboratory data vis-ὰ-vis available literature on prostate cancer chemopreventive substances in Nigerian foodstuffs. Dacryodes edulis fruit, Moringa oleifera and Syzygium aromaticum contained prostate active polyphenols like ellagic acid, gallate, methylgallate, catechol, kaempferol quercetin and their derivatives. Also Canarium schweinfurthii Engl oil contained ten phenolic compounds and lignans, namely; catechol, p-hydroxybenzaldehyde, dihydroxyphenylacetic acid, tyrosol, p-hydroxybenzoic acid, dihydroxybenzoic acid, vanillic acid, phloretic acid, pinoresinol, secoisolariciresinol. In addition, tomatoes (Lycopersicon esculentum Mill) which contains the powerful antioxidant and anti-prostate cancer agent, lycopene; cabbage (Brassica oleracea) containing indole-3-carbinol; citrus fruits containing pectin; Soursop (Annona muricata) containing annonaceous acetogenins; soya beans (Glycine max) containing isoflavones; chilli pepper (Capsicum annuum) containing capsaicin, and green tea (Camellia sinensis) containing (-) epigallocatechin gallate (EGCG), (-) epicatechin, (-) epicatechin-3-gallate and (-) epigallocatechin -3-gallate which are widely reported to posses prostate cancer chemopreventive compounds are also grown in Nigeria and other African countries. Thus, the high incidence of prostate cancer among males of African extraction can be dramatically reduced, and the age of onset drastically increased, if the population at risk consumes the right kinds of foods in the right proportion, beginning early in life, especially as prostate cancer has a latency period of about 50 years.

  4. Optimizing Thiadiazole Analogues of Resveratrol vs. Three Chemopreventive Targets

    Science.gov (United States)

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

    2011-01-01

    Chemoprevention is an approach to decrease cancer morbidity and mortality through inhibition of carcinogenesis and prevention of disease progression. Although the trans stilbene derivative resveratrol has chemopreventive properties, its action is compromised by weak non-specific effects on many biological targets. Replacement of the stilbene ethylenic bridge of resveratrol with a 1,2,4-thiadiazole heterocycle and modification of the substituents on the two aromatic rings afforded potential chemopreventive agents with enhanced potencies and selectivities when evaluated as inhibitors of aromatase and NF-κB and inducers of quinone reductase 1 (QR1). PMID:22115839

  5. Optimizing thiadiazole analogues of resveratrol versus three chemopreventive targets.

    Science.gov (United States)

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

    2012-01-01

    Chemoprevention is an approach to decrease cancer morbidity and mortality through inhibition of carcinogenesis and prevention of disease progression. Although the trans stilbene derivative resveratrol has chemopreventive properties, its action is compromised by weak non-specific effects on many biological targets. Replacement of the stilbene ethylenic bridge of resveratrol with a 1,2,4-thiadiazole heterocycle and modification of the substituents on the two aromatic rings afforded potential chemopreventive agents with enhanced potencies and selectivities when evaluated as inhibitors of aromatase and NF-κB and inducers of quinone reductase 1 (QR1). Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Chemopreventive effects of natural dietary compounds on cancer development.

    Science.gov (United States)

    Pan, Min-Hsiung; Ho, Chi-Tang

    2008-11-01

    Chemoprevention, a relatively new and promising strategy to prevent cancer, is defined as the use of natural dietary compounds and/or synthetic substances to block, inhibit, reverse, or retard the process of carcinogenesis. The chemopreventive effects elicited by these natural dietary compounds are believed to include antioxidative, anti-inflammatory activity, induction of phase II enzymes, apoptosis, and cell cycle arrest. Many mechanisms have been shown to account for the anticarcinogenic actions of natural dietary compounds; attention has recently been focused on intracellular-signaling cascades as common molecular targets for various chemopreventive natural dietary compounds. In this critical review, we will summarize current knowledge on natural dietary compounds that act through the signaling pathways and modulate gene expression to induce detoxifying enzymes, programmed cell death, anti-inflammatory, and anti-proliferative effects, thus providing evidence for these substances in cancer chemopreventive action (128 references).

  7. Butylated caffeic acid: An efficient novel antioxidant

    Directory of Open Access Journals (Sweden)

    G. Shi

    2017-09-01

    Full Text Available A novel antioxidant, butylated caffeic acid (BCA was rationally designed by adding a tert-butyl group to caffeic acid, which was synthesized at a high yield (36.2% from 2-methoxy-4-methylphenol by a four-step reaction including Friedel-Crafts alkylation, bromine oxidation, ether bond hydrolysis and Knoevenagel condensation. Its antioxidant capacity was much stronger than common commercial antioxidant tert-butyl hydroquinone (TBHQ and its mother compound, caffeic acid, in both rancimat and deep frying tests. When investigated via the DPPH method, the antioxidant capacity of BCA was almost equal to TBHQ, but lower than caffeic acid. BCA could be a potentially strong antioxidant, especially for food processing at high temperatures such as deep frying and baking.

  8. 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 ...

  9. Thermal Polymerization of N-Butyl Acrylate

    Science.gov (United States)

    Ingham, J. D.

    1982-01-01

    Simple new polymerization method enables production of n-butyl acrylate polymer of desired high molecular weight, without disadvantages that usually attend more conventional methods. Process, which is hybrid of thermal, solution, and emulsion polymerization methods, involves controlled thermal polymerization of monomer at moderate temperatures without use of catalysts or additives.

  10. 21 CFR 582.3169 - Butylated hydroxyanisole.

    Science.gov (United States)

    2010-04-01

    ... 0.02 percent of fat or oil content, including essential (volatile) oil content of food provided the... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Butylated hydroxyanisole. 582.3169 Section 582.3169 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...

  11. 21 CFR 182.3169 - Butylated hydroxyanisole.

    Science.gov (United States)

    2010-04-01

    ... of fat or oil content, including essential (volatile) oil content of food, provided the substance is... 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...

  12. (pt-BUTYL(BENZYL/BENZYLIDEN)AMINO)

    African Journals Online (AJOL)

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    -t-butyl(benzyl/benzyliden)amino)-4,5-dihydro-1H-1,2,4- triazole-5-one: (1) ... All potentiometric measurements were performed in an 80 mL jacketed titration cell ... potentiometric titration curves were formed for all the cases (Figure 2-5).

  13. 40 CFR 721.3438 - Chlorohydroxyalkyl butyl ether (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Chlorohydroxyalkyl butyl ether... Specific Chemical Substances § 721.3438 Chlorohydroxyalkyl butyl ether (generic). (a) Chemical substance... chlorohydroxyalkyl butyl ether (PMN P-99-1295) is subject to reporting under this section for the significant new use...

  14. [The role of natural dietary compounds in colorectal cancer chemoprevention].

    Science.gov (United States)

    Olejnik, Anna; Tomczyk, Joanna; Kowalska, Katarzyna; Grajek, Włodzimierz

    2010-04-07

    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. In vitro 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.

  15. 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

  16. Cancer chemoprevention by dietary phytochemicals: Epidemiological evidence.

    Science.gov (United States)

    Baena Ruiz, Raúl; Salinas Hernández, Pedro

    2016-12-01

    In recent years, natural compounds called "phytochemicals", which are present in fruits, vegetables, and plants, have received special attention due to their potential to interfere with tumour formation and development. Many of these phytochemicals are being used in chemoprevention strategies. However, the scientific evidence regarding the modification of cancer risk continues to be debated. The aim of this paper is to review the current scientific evidence and the most relevant epidemiological studies regarding the consumption or use of phytochemicals and their effects on the incidence of cancer. A search for relevant articles was conducted in EMBASE and PubMed-NCBI through to May 2016 to identify potential interactions between the consumption or use of phytochemicals and cancer risk. The use or consumption of carotenoids, such as lycopene, alpha-carotene, and betacarotene, leads to a reduction in the risk of cancer, such as breast and prostate tumours. For breast cancer, beta-carotene even reduces the risk of recurrence. The use or consumption of soybean isoflavones has led to a reduction in the risk of lung, prostate, colon (in women only), and breast cancers, although this has depended on menopausal and oestrogen receptor status. The use or consumption of isothiocyanates and indole-3-carbinol also seems to reduce the risk of cancer, such as breast, stomach, colorectal, or prostate tumours. The adoption of a diet rich in phytochemicals is associated with a modification of cancer risk. However, the scientific data supporting its use come mainly from in vitro and in vivo studies (especially in animal models). The epidemiological evidence is inconclusive for many of these phytochemicals, so further studies are needed. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  17. 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.

  18. Diet phytochemicals and cutaneous carcinoma chemoprevention: A review.

    Science.gov (United States)

    Wang, Siliang; Shen, Peiliang; Zhou, Jinrong; Lu, Yin

    2017-05-01

    Cutaneous carcinoma, which has occupied a peculiar place among worldwide populations, is commonly responsible for the considerably increasing morbidity and mortality rates. Currently available medical procedures fail to completely avoid cutaneous carcinoma development or to prevent mortality. Cancer chemoprevention, as an alternative strategy, is being considered to reduce the incidence and burden of cancers through chemical agents. Derived from dietary foods, phytochemicals have become safe and reliable compounds for the chemoprevention of cutaneous carcinoma by relieving multiple pathological processes, including oxidative damage, epigenetic alteration, chronic inflammation, angiogenesis, etc. In this review, we presented comprehensive knowledges, main molecular mechanisms for the initiation and development of cutaneous carcinoma as well as effects of various diet phytochemicals on chemoprevention. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Aspirin and colorectal cancer: the promise of precision chemoprevention.

    Science.gov (United States)

    Drew, David A; Cao, Yin; Chan, Andrew T

    2016-03-01

    Aspirin (acetylsalicylic acid) has become one of the most commonly used drugs, given its role as an analgesic, antipyretic and agent for cardiovascular prophylaxis. Several decades of research have provided considerable evidence demonstrating its potential for the prevention of cancer, particularly colorectal cancer. Broader clinical recommendations for aspirin-based chemoprevention strategies have recently been established; however, given the known hazards of long-term aspirin use, larger-scale adoption of an aspirin chemoprevention strategy is likely to require improved identification of individuals for whom the protective benefits outweigh the harms. Such a precision medicine approach may emerge through further clarification of aspirin's mechanism of action.

  20. [Antitumor and chemopreventive activity of lactoferrin].

    Science.gov (United States)

    Artym, Jolanta

    2006-01-01

    Lactoferrin, an evolutionarily old protein of the transferrin family, is among the proteins constituting the system of innate immunity; its action, however, also extends to the regulation of acquired immunity and other immunological phenomena. The actions of LF, confirmed in numerous in vitro and in vivo models, include participation in iron homeostasis, immunoregulatory properties, anti-inflammatory, anti-tumor, and analgesic actions, regulation of bone metabolism, participation in embryonic development, reproductive functions, and others. LF plays an important role in the normal development of a newborn. The anti-tumor properties of LF were discovered about a decade ago and have been confirmed in many laboratory, preclinical, and clinical studies. The immunomodulatory properties of LF play a major role in its anti-tumor actions. Such actions of LF appeared particularly effective in cancer patients with impaired immunity. The growth of tumors is facilitated by low expressions of MHC and co-stimulatory antigens on tumor cells and the induction of suppressor cells and other inhibitory products by tumors. Enhancement of an anti-tumor immunological response may, therefore, restrict tumor growth. Studies showed that LF elevates the number and increases the activity of T and B lymphocytes and NK cells, stimulates the release of a number of cytokines (IL-1, -6, -8, -18, IFN-gamma, TNF alpha), increases phagocytic activity and cytotoxicity of monocytes/macrophages, accelerates the maturation of T and B cells, and elevates the expression of several types of cellular receptors, such as CD4, zeta chain of the CD3 complex, LFA-1, CD11, ICAM-1, and selectin P. Apart from its immunomodulatory properties, LF exhibits direct anti-tumor actions, such as lytic, pro-apoptotic, anti-proliferative, anti-angiogenic, anti-oxidant activity and the chelation of iron ions. LF also possesses chemo-preventive properties, regulates the activity of phase I and II enzymes participating in the

  1. 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. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Role of 4-hydroxynonenal in chemopreventive activities of sulforaphane

    Science.gov (United States)

    Sharma, Rajendra; Sharma, Abha; Chaudhary, Pankaj; Sahu, Mukesh; Jaiswal, Shailesh; Awasthi, Sanjay; Awasthi, Yogesh C.

    2012-01-01

    Chemoprevention of cancer via herbal and dietary supplements is a logical approach to combat cancer and presently it is an attractive area of research investigations. Over the years, the use of isothiocyanates, such as sulforaphane (SFN) found in cruciferous vegetables, has been advocated as chemopreventive agents and their efficacy has been demonstrated in cell lines and animal models. In-vivo studies with SFN suggest that besides protecting normal healthy cells from environmental carcinogens it also exhibits cytotoxicity and apoptotic effects against various cancer cell types. Among several mechanisms for the chemopreventive activity of SFN against chemical carcinogenesis, its effect on drug metabolizing enzymes that causes activation/ neutralization of carcinogenic metabolites is well established. Recent studies suggest that SFN exerts its selective cytotoxicity to cancer cells via reactive oxygen species (ROS)-mediated generation of lipid peroxidation (LPO) products particularly 4-hydroxynonenal (HNE). Against the background of the known biochemical effects of SFN on normal and cancer cells, in this article we have reviewed the underlying molecular mechanisms responsible for the overall chemopreventive effects of SFN focusing on the role of HNE in these mechanisms that may also contribute to its selective cytotoxicity to cancer cells. PMID:22579574

  3. Systematic review: molecular chemoprevention of colorectal malignancy by mesalazine.

    Science.gov (United States)

    Lyakhovich, A; Gasche, C

    2010-01-15

    Mesalazine (mesalamine) (5-ASA) is considered an anti-inflammatory drug for the treatment of inflammatory bowel disease. It is well tolerated by most patients and induces mucosal healing specifically in ulcerative colitis. Besides its anti-inflammatory properties, 5-ASA has been studied for cancer inhibitory activities as it seems to reduce colorectal cancer incidence in patients using this drug for long periods of time. However, detailed molecular mechanisms of drug action are vague. To evaluate known molecular mechanisms of 5-ASA on chemoprevention of colorectal malignancy. Systematic review with search terms '5 aminosalicylic acid, mesalazine, 5-ASA, mesalazine, molecular mechanisms, chemoprevention' between 2006 and August 2009. A total of 48 studies were retrieved that link 5-ASA chemopreventive properties to five distinct pathways. These include interference with cell cycle progression (12 references), scavenging of reactive oxygen- or nitrogen-derived metabolites (16 references), TNF-alpha/TGF-ss signalling (11 references), WNT/beta-catenin signalling (5 references) and anti-bacterial properties (4 references). In the recent years, a large amount of molecular data has accumulated supporting the notion that 5-ASA biological effects interfere with colorectal cancer development. These molecular pathways are of special interest in the search for 5-ASA's molecular target(s) and development of novel chemopreventive compounds.

  4. Colon Cancer Chemoprevention by Flavonoid Silibinin | Division of Cancer Prevention

    Science.gov (United States)

    DESCRIPTION (provided by applicant): Cancer stem cells (CSC) are now recognized as the main cause for initiation, promotion and progression of most of the cancers, including colorectal cancer (CRC). Despite this fact, efficacy of chemopreventive agents towards CSC generation leading to cancer initiation and tumorigenesis has not yet been well- defined. |

  5. New rodent models for studies of chemopreventive agents.

    Science.gov (United States)

    Lipkin, M

    1997-01-01

    Some recent studies of the effects of chemopreventive agents have begun to use new rodent models to improve the analysis of stages of colonic preneoplasia, and how chemopreventive agents modify progressive abnormal cell development. In one of the models of inherited predisposition to colon cancer, mice carrying a truncated Apc allele with a nonsense mutation in exon 15 have been generated by gene targeting and embryonic stem cell technology (Apc1638 mice). These mice develop multiple gastrointestinal lesions, including adenomas and carcinomas, focal areas of high-grade dysplasia (FAD), and polypoid hyperplasias with FADS. The incidence of inherited colonic neoplasms has now been modulated by a chemopreventive regimen. Colonic lesions significantly increased in Apc1638 mice on a Western-style diet, which has higher fat content and lower calcium and vitamin D compared to the same mice on AIN-76A diet. In another rodent model, Min mice were treated with sulindac, which markedly reduced the incidence of intestinal tumors. A third new rodent model containing a targeted mutation in the gene Mcc (mutated in colorectal cancer) recently became available for chemoprevention studies. These mice develop multiple types of neoplasms including adenocarcinomas, focal areas of gastrointestinal dysplasia, papillomas of the forestomach, and tumors in other organs including lung, liver, and lymphoid tissue. Feeding a Western-style diet to the Mcc mutant mice also resulted in significantly increased gastrointestinal lesions. These nutrient modifications also have been given to normal mice, demonstrating without any chemical carcinogen that a Western-style diet induced colonic tumorigenesis. Western-style diets also have now induced modulation of cell proliferation in other organs including mammary gland, pancreas, and prostate. These findings help develop new preclinical rodent models to aid the analysis of genetic and environmental factors leading to neoplasia, as well as new methods

  6. 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

  7. Cancer Chemoprevention and Piperine: Molecular Mechanisms and Therapeutic Opportunities

    Directory of Open Access Journals (Sweden)

    Rafiq A. Rather

    2018-02-01

    Full Text Available Cancer is a genetic disease characterized by unregulated growth and dissemination of malignantly transformed neoplastic cells. The process of cancer development goes through several stages of biochemical and genetic alterations in a target cell. Several dietary alkaloids have been found to inhibit the molecular events and signaling pathways associated with various stages of cancer development and therefore are useful in cancer chemoprevention. Cancer chemoprevention has long been recognized as an important prophylactic strategy to reduce the burden of cancer on health care system. Cancer chemoprevention assumes the use of one or more pharmacologically active agents to block, suppress, prevent, or reverse the development of invasive cancer. Piperine is an active alkaloid with an excellent spectrum of therapeutic activities such as anti-oxidant, anti-inflammatory, immunomodulatory, anti-asthmatic, anti-convulsant, anti-mutagenic, antimycobacterial, anti-amoebic, and anti-cancer activities. In this article, we made an attempt to sum up the current knowledge on piperine that supports the chemopreventive potential of this dietary phytochemical. Many mechanisms have been purported to understand the chemopreventive action of piperine. Piperine has been reported to inhibit the proliferation and survival of many types of cancer cells through its influence on activation of apoptotic signaling and inhibition of cell cycle progression. Piperine is known to affect cancer cells in variety of other ways such as influencing the redox homeostasis, inhibiting cancer stem cell (CSC self-renewal and modulation of ER stress and autophagy. Piperine can modify activity of many enzymes and transcription factors to inhibit invasion, metastasis, and angiogenesis. Piperine is a potent inhibitor of p-glycoprotein (P-gp and has a significant effect on the drug metabolizing enzyme (DME system. Because of its inhibitory influence on P-gp activity, piperine can reverse

  8. Cohorts with familial disposition for colon cancers in chemoprevention trials.

    Science.gov (United States)

    Burt, R W

    1996-01-01

    Colon cancer provides an attractive setting for chemoprevention trials because of the frequency and variation of familial predisposition that is observed in this malignancy. Additionally, the adenomatous polyp, the precursor of colon cancer, is a valuable intermediate marker for judging the effectiveness of candidate chemopreventive agents. Inherited colon cancer susceptibility varies from mild to severe. Conditions with extreme susceptibility include the autosomal dominantly inherited syndromes of familial adenomatous polyposis (FAP) and hereditary nonpolyposis colorectal cancer (HNPCC). These are highly penetrant syndromes with extreme cancer risk. FAP arises from mutations of the APC gene and HNPCC from mutations of the mismatch repair genes. Specific and individual genetic diagnosis is now possible in both syndromes, thus allowing identification of genetically affected individuals for chemoprevention trials. FAP accounts for less than 1% of colon cancers, while HNPCC may be present in up to 5% of cases. Familial clustering is common in the remainder of cases, which are often referred to as sporadic, but probably arise in part from inherited susceptibility. Epidemiologic studies have shown that first-degree relatives have a two- to four-fold increased risk of acquiring colon cancer compared to the general population. Ten percent of individuals in the U.S. have a first-degree with colon cancer. This clinically identifiable higher risk group thus constitutes a large potential cohort for chemoprevention trials. The common familial cases of colon cancer can be further stratified by severity. A relative diagnosed under the age of 50 or two first-degree relatives affected with colon cancer confers an even greater risk for this malignancy, estimated to be four to six times that of the general population. Adenomatous polyps also precede the development of colon cancer in these categories, thereby providing a readily identifiable clinical endpoint to judge the

  9. Small-angle neutron scattering studies of sodium butyl benzene ...

    Indian Academy of Sciences (India)

    shape and size of the aggregates of sodium n-butyl benzene sulfonate in aqueous solutions. To the best of our knowledge this is the first SANS report on the aggre- gation behaviour of a hydrotrope in aqueous solutions. 2. Materials and methods n-Butyl benzene, procured from Herdilia Chemicals, Mumbai, was sulfonated ...

  10. Solvent effects on the magnetic shielding of tertiary butyl alcohol ...

    African Journals Online (AJOL)

    The magnetic shielding and its polarizabilities, have been calculated for tertiary butyl alcohol and tertiary butyl amine. These have been used to rationalise the solvent shifts of the proton spectra of the interesting cosolvent systems with water recently measured by Kipkemboi, et al. Continuum solvation calculations and ...

  11. 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.

  12. 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.

  13. Chemopreventive functional food through selenium biofortification of cauliflower plants

    Directory of Open Access Journals (Sweden)

    Anca Oancea

    2016-03-01

    Full Text Available The aim of this work was to develop a biotechnological approach for production of cauliflower as safe functional food, with an optimal content of chemopreventive compounds, by a protective biofortification, through selenium application together with betaine and spraying adjuvants. In the control and treated cauliflower plants we determined the amount of total selenium, glucosinolates (sulforaphane and SAH (S-Adenosyl-homocysteine. We also assayed the chemopreventive effects of compounds formed in the treated cruciferous plants through in vitro tests, using human colorectal tumor cell line (CaCo2. Extracts of plants treated with selenium applied together with betaine and spraying adjuvant were significantly more active on reduction of tumoral cell viability than the extract of control plants. Cauliflower plants, obtained after our treatments for protective biofortification, were used to feed rabbits, for 10 days. The ingestion of biofortified cauliflower did not modify the hematological and biochemical parameters on the laboratory animals.

  14. Role of saffron and its constituents on cancer chemoprevention

    Science.gov (United States)

    Zhang, Zhiyu; Wang, Chong-Zhi; Wen, Xiao-Dong; Shoyama, Yukihiro; Yuan, Chun-Su

    2014-01-01

    Context Cancer dramatically impacts human life expectancy and quality of life. Natural substances from vegetables, herbs and spices could be beneficial in the prevention or treatment of a variety of cancers. Crocus sativus, which has been used as a folk medicine for treating diseases for ages, showed obvious cancer chemoprevention potential. Objective This article focuses on the effects of Crocus sativus and its main ingredients, such as crocin, on cancer therapeutics. Methods We reviewed research data from saffron, a spice derived from the flower of Crocus sativus, and its constituents using the major databases, viz., Web of Science, SciFinder, and PubMed. Results and conclusion Saffron possesses free radical-scavenging properties and antitumor activities. Significant cancer chemopreventive effects have been shown in both in vitro and in vivo models. Based on current data, saffron and its ingredients could be considered as a promising candidate for clinical anticancer trials. PMID:23570520

  15. Role of saffron and its constituents on cancer chemoprevention.

    Science.gov (United States)

    Zhang, Zhiyu; Wang, Chong-Zhi; Wen, Xiao-Dong; Shoyama, Yukihiro; Yuan, Chun-Su

    2013-07-01

    Cancer dramatically impacts human life expectancy and quality of life. Natural substances from vegetables, herbs and spices could be beneficial in the prevention or treatment of a variety of cancers. Crocus sativus (Iridaceae), which has been used as a folk medicine for treating diseases for ages, showed obvious cancer chemoprevention potential. This article focuses on the effects of Crocus sativus and its main ingredients, such as crocin, on cancer therapeutics. We reviewed research data from saffron, a spice derived from the flower of Crocus sativus, and its constituents using the major databases, namely, Web of Science, SciFinder and PubMed. Saffron possesses free radical-scavenging properties and antitumor activities. Significant cancer chemopreventive effects have been shown in both in vitro and in vivo models. Based on current data, saffron and its ingredients could be considered as a promising candidate for clinical anticancer trials.

  16. 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.

  17. Chemoprevention of cancer: current evidence and future prospects [version 1; referees: 3 approved

    Directory of Open Access Journals (Sweden)

    Vassiliki Benetou

    2015-09-01

    Full Text Available Cancer chemoprevention refers to the use of agents for the inhibition, delay, or reversal of carcinogenesis before invasion. In the present review, agents examined in the context of cancer chemoprevention are classified in four major categories—hormonal, medications, diet-related agents, and vaccines—and the main representatives of each category are presented. Although there are serious constraints in the documentation of effectiveness of chemopreventive agents, mainly stemming from the long latency of the condition they are addressing and the frequent lack of intermediate biomarkers, there is little disagreement about the role of aspirin, whereas a diet rich in vegetables and fruits appears to convey more protection than individual micronutrients. Among categories of cancer chemopreventive agents, hormonal ones and vaccines might hold more promise for the future. Also, the identification of individuals who would benefit most from chemopreventive interventions on the basis of their genetic profiles could open new prospects for cancer chemoprevention.

  18. Chemoprevention of Breast Cancer: The Paradox of Evidence versus Advocacy Inaction

    Directory of Open Access Journals (Sweden)

    Rakhshanda Layeequr Rahman

    2012-10-01

    Full Text Available Women who are at high risk of breast cancer can be offered chemoprevention. Chemoprevention strategies have expanded over the past decade and include selective receptor modulator inhibitors and aromatase inhibitors. Physicians are expected to provide individualized risk assessments to identify high risk women who may be eligible for chemoprevention. It is prudent that physicians utilize a shared decision approach when counseling high risk women about their preventive options. Barriers and misperceptions however exist with patient and physician acceptance of chemoprevention and continue to impede uptake of chemoprevention as a strategy to reduce breast cancer risk. Programs to increase awareness and elucidate the barriers are critical for women to engage in cancer prevention and promote chemoprevention adherence.

  19. Synergistic chemopreventive effects of nobiletin and atorvastatin on colon carcinogenesis.

    Science.gov (United States)

    Wu, Xian; Song, Mingyue; Qiu, Peiju; Rakariyatham, Kanyasiri; Li, Fang; Gao, Zili; Cai, Xiaokun; Wang, Minqi; Xu, Fei; Zheng, Jinkai; Xiao, Hang

    2017-04-01

    Different cancer chemopreventive agents may act synergistically and their combination may produce enhanced protective effects against carcinogenesis than each individual agent alone. Herein, we investigated the chemopreventive effects of nobiletin (NBT, a citrus polymethoxyflavone) and atorvastatin (ATST, a lipid-lowering drug) in colon cancer cells/macrophages and an azoxymethane (AOM)-induced colon carcinogenesis rat model. The results demonstrated that co-treatments of NBT/ATST produced enhanced growth inhibitory and anti-inflammatory effects on the colon cancer cells and macrophages, respectively. Isobologram analysis confirmed that these interactions between NBT and ATST were synergistic. NBT/ATST co-treatment also synergistically induced extensive cell cycle arrest and apoptosis in colon cancer cells. Oral administration of NBT (0.1%, w/w in diet) or ATST (0.04%, w/w in diet) significantly decreased colonic tumor incidence and multiplicity in AOM-treated rats. Most importantly, co-treatment of NBT/ATST at their half doses (0.05% NBT + 0.02% ATST, w/w in diet) resulted in even stronger inhibitory effects on colonic tumor incidence and multiplicity than did NBT or ATST alone at higher doses. Statistical analysis confirmed that the enhanced chemopreventive activities against colon carcinogenesis in rats by the NBT/ATST combination were highly synergistic. Our results further demonstrated that NBT/ATST co-treatment profoundly modulated key cellular signaling regulators associated with inflammation, cell proliferation, cell cycle progression, apoptosis, angiogenesis and metastasis in the colon of AOM-treated rats. In conclusion, for the first time, our results demonstrated a strong synergy in inhibiting colon carcinogenesis produced by the co-treatment of NBT and ATST, which provided a scientific basis for using NBT in combination with ATST for colon cancer chemoprevention in humans. © The Author 2017. Published by Oxford University Press. All rights reserved

  20. Aspirin Metabolomics in Colorectal Cancer Chemoprevention | Division of Cancer Prevention

    Science.gov (United States)

    DESCRIPTION (provided by applicant): Substantial evidence supports the effectiveness of aspirin for cancer chemoprevention in addition to its well-established role in cardiovascular protection. In recent meta-analyses of randomized controlled trials in humans, daily aspirin use reduced incidence, metastasis and mortality from several common types of cancer, especially colorectal cancer. The mechanism(s) by which aspirin exerts an anticancer benefit is uncertain; numerous effects have been described involving both cyclooxygenase-dependent and -independent pathways. |

  1. Chemopreventive potential of natural compounds in head and neck cancer

    OpenAIRE

    Rahman, Mohammad Aminur; Amin, A.R.M. Ruhul; Shin, Dong M.

    2010-01-01

    Head and neck squamous cell carcinoma (HNSCC) is one of the most fatal cancers world-wide. Despite advances in the management of HNSCC, the overall survival for patients has not improved significantly due to advanced stages at diagnosis, high recurrence rate after surgical removal, and second primary tumor development, which together underscore the importance of novel strategies for cancer prevention. Cancer chemoprevention, the use of natural or synthetic compounds to prevent, arrest, or rev...

  2. Arsenic and skin cancer – Case report with chemoprevention

    OpenAIRE

    Uwe Wollina

    2016-01-01

    ABSTRACT Introduction: Arsenic is a potentially hazardous metalloid that can cause skin cancer. We want to demonstrate a case of chronic arsenicosis and the potential of chemoprevention with retinoids. Case Report: This is a case report of a 72-year-old male patient who was exposed to arsenics by dust and direct skin contact over 3 years in a chemical plant in the late fourties. He developed multiple arsenic keratosis clincialll resembling actinic keratoses, Bowen’s disease and palmar...

  3. Cancer chemopreventive activity of compounds isolated from Waltheria indica.

    Science.gov (United States)

    Monteillier, Aymeric; Cretton, Sylvian; Ciclet, Olivier; Marcourt, Laurence; Ebrahimi, Samad Nejad; Christen, Philippe; Cuendet, Muriel

    2017-05-05

    Waltheria indica L. is traditionally used in several countries against inflammatory related diseases and cancer, mainly as a decoction of the aerial parts. The transcription factor NF-κB is known to induce tumor promotion and progression and is considered a major player in inflammation-driven cancers. Therefore, inhibitors of this pathway possess cancer chemopreventive and chemotherapeutic activities. This study aimed first to confirm the use of Waltheria indica as a traditional anti-inflammatory remedy by assessing the NF-κB inhibitory activity and then to identify the major bioactive compounds. The isolated compounds were also tested for their QR inducing property, a complementary strategy in cancer chemoprevention able to target tumor initiation. Finally, the relevance of in vitro results was examined by investigating the occurrence of the active compounds in traditional preparations. Compounds were isolated from the dichloromethane extract of the aerial parts using flash chromatography and semi-preparative HPLC. NF-κB inhibitory activity of pure compounds from Waltheria indica was assessed using a luciferase reporter assay in HEK293 cells. Their QR inducing activity was also assessed in Hepa1c1c7 cells. Twenty-nine compounds, of which 5 are new, were obtained from the dichloromethane extract and tested for their cancer chemoprevention activity. Eleven compounds inhibited NF-κB and/or induced QR in the low to mid µM range. Chrysosplenol E (20) was active in both tests. Two of the most potent NF-κB inhibitors, waltherione A (4) and waltherione C (5), as well as 20 were found in the traditional decoction, in which 4 and 5 were major compounds. The presence of potent NF-κB inhibitors and QR inducing compounds in the decoction of the aerial parts of Waltheria indica supports its traditional use in inflammatory-related diseases and cancer chemoprevention. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  4. 4-tert-Butyl-pyridinium triiodide-4-tert-butyl-pyridine (1/1).

    Science.gov (United States)

    He, Hongshan; Sykes, Andrew G

    2011-01-22

    The title compound, C(9)H(14)N(+)·I(3) (-)·C(9)H(13)N, consists of monoprotonated 4-tert-butyl-pyridinium cations and triiodide anions. The triiodide ion has near-symmetric linear geometry, with bond lengths of 2.9105 (4) Å (I-I) and a bond angle of 177.55 (3)° (I-I-I). For this room-temperature structure, the butyl group on the pyridine ring is disordered and has been treated as a rigid rotator, modeled in three separate positions with 1/3, 1/3, 1/3 occupancies. The cations assemble into dimeric forms by way of N-H⋯N hydrogen bonds.

  5. 4-tert-Butyl­pyridinium triiodide–4-tert-butyl­pyridine (1/1)

    Science.gov (United States)

    He, Hongshan; Sykes, Andrew G.

    2011-01-01

    The title compound, C9H14N+·I3 −·C9H13N, consists of monoprotonated 4-tert-butyl­pyridinium cations and triiodide anions. The triiodide ion has near-symmetric linear geometry, with bond lengths of 2.9105 (4) Å (I—I) and a bond angle of 177.55 (3)° (I—I—I). For this room-temperature structure, the butyl group on the pyridine ring is disordered and has been treated as a rigid rotator, modeled in three separate positions with 1/3, 1/3, 1/3 occupancies. The cations assemble into dimeric forms by way of N—H⋯N hydrogen bonds. PMID:21523100

  6. 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.

  7. Use of nonsteroidal antiinflamatory drugs for chemoprevention of colon cancer

    Directory of Open Access Journals (Sweden)

    Milić Aleksandra

    2013-01-01

    Full Text Available Colorectal cancer is in the third most frequent cancer among malignant tumors of both sexes in developed countries. It is predominantly a disease of older persons and occurs mostly after the age of 60. Although the etiology of colon cancer is unknown, it is assumed to arise as a result of unclear and complex interactions between genetic and environmental factors. The main element in the etiology of colorectal cancer is the process of genetic changes in epithelial cells of colon mucosa. It is believed that specific epidemiological factors such as stress, hypoxia, reduced intake of glucose and other nutrients, a hereditary predisposition to mutagenic effects, the meat in the diet, bile acids, reduced intake of minerals and vitamins as well as changes in pH of feces lead to initiation of the process of carcinogenesis in mucosa of the colon. Cancer chemoprevention is defined as the use of chemical agents in order to block, prevent or delay the reversal development or progress of cancer. It is believed that chemoprevention is a key component of cancer control, and numerous studies indicate potential role of NSAIDs in chemoprevention of colon cancer.

  8. Chemopreventive opportunities to control basal cell carcinoma: Current perspectives.

    Science.gov (United States)

    Tilley, Cynthia; Deep, Gagan; Agarwal, Rajesh

    2015-09-01

    Basal cell carcinoma (BCC) is a major health problem with approximately 2.8 million new cases diagnosed each year in the United States. BCC incidences have continued to rise due to lack of effective chemopreventive options. One of the key molecular characteristics of BCC is the sustained activation of hedgehog signaling through inactivating mutations in the tumor suppressor gene patch (Ptch) or activating mutations in Smoothened. In the past, several studies have addressed targeting the activated hedgehog pathway for the treatment and prevention of BCC, although with toxic effects. Other studies have attempted BCC chemoprevention through targeting the promotional phase of the disease especially the inflammatory component. The compounds that have been utilized in pre-clinical and/or clinical studies include green and black tea, difluoromethylornithine, thymidine dinucleotide, retinoids, non-steroidal anti-inflammatory drugs, vitamin D3, and silibinin. In this review, we have discussed genetic and epigenetic modifications that occur during BCC development as well as the current state of BCC pre-clinical and clinical chemoprevention studies. © 2015 Wiley Periodicals, Inc.

  9. Biomarkers and their use in cervical cancer chemoprevention.

    Science.gov (United States)

    Vlastos, Anne Thérèse; Schottenfeld, David; Follen, Michele

    2003-06-01

    Cervical cancer chemoprevention agents under study include diet and micronutrients (particularly beta-carotene, folate, and vitamins A, C, and E); medications such as retinoids (retinyl acetate gel, all-trans-retinoic acid, and 4-hydroxyphenylretinamide) that are chemically related to micronutrients; and other chemopreventives meant to affect the carcinogenic process at the cellular level, including such polyamine synthesis inhibitors as alpha-difluoromethylornithine. Agents become reasonable candidates for study when they have a biologic rationale, they are of low toxicity, and they can be taken for a long period of time. Since the human papillomavirus (HPV) is the major etiologic agent, the medication should show activity against HPV-positive preinvasive and invasive cell lines. The medication needs to be of low toxicity because it may be taken for long periods of time and less toxicity is tolerated in the precancerous setting. Until 1995, none of the studies used surrogate end point biomarkers (SEBs), relying instead on histologic and colposcopic regression as end points. All studies typically included subjects with cervical intraepithelial neoplasia. Conclusions to be drawn from these studies include the following: Though micronutrients are logical candidates for chemoprevention, they haven't worked consistently, and the reasons remain unclear. Furthermore, SEBs need to be validated in phase I trials. Finally, a better understanding of the role of HPV needs elucidation, including an understanding of the relationship of the medication to HPV status and of the immunobiology of HPV throughout the trial.

  10. Risk factors and chemoprevention in Barrett's esophagus--an update.

    Science.gov (United States)

    Winberg, Hanna; Lindblad, Mats; Lagergren, Jesper; Dahlstrand, Hanna

    2012-04-01

    Barrett's esophagus (BO) is a precursor of esophageal adenocarcinoma (OAC), a cancer with a poor prognosis and an increasing incidence. Hence there is an interest in mapping causal factors underlying BO and finding strategies to reduce the risk of dysplasia progression in patients with BO. Here we review current knowledge on established as well as less risk factors for the development of BO. Additionally, we summarize today's status on the use of chemoprevention aiming to reduce the risk of cancer progression in BO patients. We searched Medline and the Cochrane Library using the MeSH terms "Barrett's esophagus" and "Barrett esophagus," both alone and combined with the terms "risk factor," "aetiology," "diet," or "prevention." Focus was on original contributions, systematic reviews, and meta-analyses. Established risk factors for the development of BO include gastro-esophageal reflux, obesity, male gender, Caucasian ethnicity, and increasing age. Smoking might increase the risk of BO, while aspirin/NSAIDs, Helicobacter pylori infection, and specific "healthy" dietary factors may lower the risk. The potential value of using chemoprevention with proton pump inhibitors, aspirin/NSAIDs, or statins is still uncertain. There is today a substantial knowledge of risk factors of BO. Certain diet may be protective of BO, albeit yet to be proven. The efficiency of chemoprevention in BO is currently addressed further in randomized clinical trials.

  11. Green tea polyphenols for prostate cancer chemoprevention: A translational perspective

    Science.gov (United States)

    Johnson, J.J.; Bailey, H.H.; Mukhtar, H.

    2009-01-01

    Every year nearly 200,000 men in the United States are diagnosed with prostate cancer (PCa), and another 29,000 men succumb to the disease. Within certain regions of the world population based studies have identified a possible role for green tea in the prevention of certain cancers, especially PCa. One constituent in particular, epigallocatechin-3-gallate also known as EGCG has been shown in cell culture models to decrease cell viability and promote apoptosis in multiple cancer cell lines including PCa with no effect on non-cancerous cell lines. In addition, animal models have consistently shown that standardized green tea polyphenols when administered in drinking water delay the development and progression of PCa. Altogether, three clinical trials have been performed in PCa patients and suggest that green tea may have a distinct role as a chemopreventive agent. This review will present the available data for standardized green tea polyphenols in regard to PCa chemoprevention that will include epidemiological, mechanism based studies, safety, pharmacokinetics, and applicable clinical trials. The data that has been collected so far suggests that green tea may be a promising agent for PCa chemoprevention and further clinical trials of participants at risk of PCa or early stage PCa are warranted. PMID:19959000

  12. Arsenic and skin cancer – Case report with chemoprevention

    Directory of Open Access Journals (Sweden)

    Uwe Wollina

    2016-04-01

    Full Text Available ABSTRACT Introduction: Arsenic is a potentially hazardous metalloid that can cause skin cancer. We want to demonstrate a case of chronic arsenicosis and the potential of chemoprevention with retinoids. Case Report: This is a case report of a 72-year-old male patient who was exposed to arsenics by dust and direct skin contact over 3 years in a chemical plant in the late fourties. He developed multiple arsenic keratosis clincialll resembling actinic keratoses, Bowen’s disease and palmar minute keratoses. To prevent a transformation into invasive cancer and to lower the burden of precancerous and in situ cancer lesions, he was treated orally with acitretin 20 mg/day. During 9 months of chemopreventive retinoid therapy a partial response of pre-existent skin lesions was noted. Treatment was well tolerated. During follow-up of 5 years no invasive malignancy developed. Conclusions: Intense exposure to arsenics during a relatively short period of 3 years bears a life-long health hazard with the delayed development of multiple in situ carcinomas and precancerous lesions. Chemoprevention with retinoids can induce a partial response.

  13. Jacalin Has Chemopreventive Effects on Colon Cancer Development

    Directory of Open Access Journals (Sweden)

    Thais Herrero Geraldino

    2017-01-01

    Full Text Available Colorectal cancer, which is one of the most common causes of cancer-related deaths worldwide, has a slow natural history that provides a great opportunity for prevention strategies. Plant-derived natural products have received considerable attention because of their inherent colorectal cancer chemopreventive effects. The plant lectin jacalin specifically recognizes the tumor-associated Thomsen-Friedenreich antigen and has antiproliferative effects on human colon cancer cells, highlighting its potential antitumor activity. To evaluate jacalin’s potential application in colorectal cancer chemoprevention, we studied its effects on the early stages of carcinogenesis. Balb/c mice were given 4 intrarectal deposits of 0.1 ml solution of Methyl-N′-Nitro-N-Nitroso-Guanidine (5 mg/ml twice a week (with a 3-day interval for 2 weeks. Starting 2 weeks before carcinogen administration, animals were treated orally with jacalin (0.5 and 25 μg three times a week (on alternate weekdays for 10 weeks. We show that jacalin treatment reduced the number of preneoplastic lesions in carcinogen-exposed mice. This anticarcinogenic activity was associated with decreased colonic epithelial cell proliferation and stromal COX-2 expression and with increased intestinal production of TNF-α. Our results demonstrate that jacalin is able to modulate the early stages of colon carcinogenesis and emphasize its promising chemopreventive activity in colorectal cancer.

  14. Jacalin Has Chemopreventive Effects on Colon Cancer Development.

    Science.gov (United States)

    Geraldino, Thais Herrero; Modiano, Patricia; Veronez, Luciana Chain; Flória-Santos, Milena; Garcia, Sergio Britto; Pereira-da-Silva, Gabriela

    2017-01-01

    Colorectal cancer, which is one of the most common causes of cancer-related deaths worldwide, has a slow natural history that provides a great opportunity for prevention strategies. Plant-derived natural products have received considerable attention because of their inherent colorectal cancer chemopreventive effects. The plant lectin jacalin specifically recognizes the tumor-associated Thomsen-Friedenreich antigen and has antiproliferative effects on human colon cancer cells, highlighting its potential antitumor activity. To evaluate jacalin's potential application in colorectal cancer chemoprevention, we studied its effects on the early stages of carcinogenesis. Balb/c mice were given 4 intrarectal deposits of 0.1 ml solution of Methyl-N'-Nitro-N-Nitroso-Guanidine (5 mg/ml) twice a week (with a 3-day interval) for 2 weeks. Starting 2 weeks before carcinogen administration, animals were treated orally with jacalin (0.5 and 25 μg) three times a week (on alternate weekdays) for 10 weeks. We show that jacalin treatment reduced the number of preneoplastic lesions in carcinogen-exposed mice. This anticarcinogenic activity was associated with decreased colonic epithelial cell proliferation and stromal COX-2 expression and with increased intestinal production of TNF-α. Our results demonstrate that jacalin is able to modulate the early stages of colon carcinogenesis and emphasize its promising chemopreventive activity in colorectal cancer.

  15. Quantification of hypoglycin A as butyl ester.

    Science.gov (United States)

    Sander, Johannes; Terhardt, Michael; Sander, Stefanie; Janzen, Nils

    2016-09-01

    L-α-amino-methylenecyclopropyl propionic acid (Hypoglycin A, HGA) has been found to be the toxic compound in fruits of the Sapindaceae family causing acute intoxication when ingested as food or feed. Clinical symptoms are consistent with acquired multiple acyl-CoA dehydrogenase deficiency (MADD). Ultra performance liquid chromatography-tandem mass spectrometry was used to measure HGA after butylation. Sample volumes were 10μL for serum and 20μL for urine. Internal standard for HGA was d3-leucine, samples were plotted on a 7-point linear calibration curve. Coefficients of variation were Ackee fruit poisoning or atypical myopathy in horses and for forensic purposes in cases of suspected HGA poisoning. Copyright © 2016 Elsevier B.V. All rights reserved.

  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. 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.

  18. Cactus pear: a natural product in cancer chemoprevention

    Directory of Open Access Journals (Sweden)

    Wang Jian

    2005-09-01

    Full Text Available Abstract Background Cancer chemoprevention is a new approach in cancer prevention, in which chemical agents are used to prevent cancer in normal and/or high-risk populations. Although chemoprevention has shown promise in some epithelial cancers, currently available preventive agents are limited and the agents are costly, generally with side effects. Natural products, such as grape seed, green tea, and certain herbs have demonstrated anti-cancer effects. To find a natural product that can be used in chemoprevention of cancer, we tested Arizona cactus fruit solution, the aqueous extracts of cactus pear, for its anti-cancer effects in cultured cells and in an animal model. Method Aqueous extracts of cactus pear were used to treat immortalized ovarian and cervical epithelial cells, as well as ovarian, cervical, and bladder cancer cells. Aqueous extracts of cactus pear were used at six concentrations (0, 0.5, 1, 5, 10 or 25% to treat cells for 1, 3, or 5 days. Growth inhibition, apoptosis induction, and cell cycle changes were analyzed in the cultured cells; the suppression of tumor growth in nude mice was evaluated and compared with the effect of a synthetic retinoid N-(4-hydroxyphernyl retinamide (4-HPR, which is currently used as a chemoprevention agent. Immunohistochemistry staining of tissue samples from animal tumors was performed to examine the gene expression. Results Cells exposed to cactus pear extracts had a significant increase in apoptosis and growth inhibition in both immortalized epithelial cells and cancer cells in a dose- and time-dependent manner. It also affected cell cycle of cancer cells by increasing G1 and decreasing G2 and S phases. Both 4-HPR and cactus pear extracts significantly suppressed tumor growth in nude mice, increased annexin IV expression, and decreased VEGF expression. Conclusion Arizona cactus pear extracts effectively inhibited cell growth in several different immortalized and cancer cell cultures, suppressed

  19. Emulsion Polymerization of Butyl Acrylate: Spin Trapping and EPR Study

    Science.gov (United States)

    Kim, S.; Westmoreland, D.

    1994-01-01

    The propagating radical in the emulsion polymerization reaction of butyl acrylate was detected by Electron Paramagnetic Resonance spectroscopy using two spin trapping agents, 2-methyl-2nitrosopropane and alpha -N-tert-butylnitrone.

  20. Aquatic Life Criteria - Methyl Tertiary-Butyl Ether (MTBE)

    Science.gov (United States)

    Information pertaining to the 1999 Acute and Chronic Ambient Aquatic Life Water Quality Criteria for Methyl Tertiary-Butyl Ether (MTBE) for freshwater and salt water. Information includes the safe levels of MTBE that should protect the majority of species.

  1. Improvement of the butyl methacrylate-paraffin embedment.

    Science.gov (United States)

    McMillan, P J; Engen, P C; Dalgleish, A; McMillan, J

    1983-05-01

    The excellent butyl methacrylate-paraffin method as an embedment for light microscopy has been technically improved. More uniform and reproducible polymerization has been obtained by using a vacuum oven to degas the polymerizing mixture and to replace the air with nitrogen at 650 Torr. The amount of benzoyl peroxide required must be determined for each batch of butyl methacrylate. A teflon lined, reusable metal mold and a method of one-step blocking of tissues in preparation for sectioning are also described.

  2. Telomerase as an Androgen Receptor-Regulated Target in Selenium Chemoprevention of Prostate Cancer

    Science.gov (United States)

    2011-04-01

    and Vita- min E Chemoprevention Trial (SELECT) indicated that supplementation of healthy individuals with nutritional dose of selenium did not reduce...were conducted by using pharmacologic doses of selenium , not the nutritional dose that was used in the SELECT. Therefore, the negative SELECT finding...Regulated Target in Selenium Chemoprevention of Prostate Cancer PRINCIPAL INVESTIGATOR: Shuang Liu, Ph.D

  3. Identification of dithiolethiones with better chemopreventive properties than oltipraz.

    Science.gov (United States)

    Maxuitenko, Y Y; Libby, A H; Joyner, H H; Curphey, T J; MacMillan, D L; Kensler, T W; Roebuck, B D

    1998-09-01

    Oltipraz and related dithiolethiones are an important class of chemopreventive agents. Studies were undertaken to identify cancer chemopreventive dithiolethiones more active than oltipraz. Largely based upon enzyme induction activities in vitro, 17 dithiolethiones, including oltipraz, were analyzed for their ability to induce hepatic phase II enzyme activities in vivo. Of these compounds, 15 produced greater induction of NAD(P)H:quinone reductase and 11 yielded greater induction of glutathione S-transferase than oltipraz. All 17 dithiolethiones were then tested for their ability to inhibit acute hepatotoxicity by aflatoxin B1 (AFB1), which previously has been shown to be an intermediate predictor of chemopreventive activity. Rats were pretreated with dithiolethiones (0.3 mmol/kg body wt, three times a week per os) and challenged with two acutely toxic doses of AFB1 (0.5 mg/kg body wt, once daily for two successive days per os). Inhibition of hepatotoxicity was measured by changes in body weight gain during AFB1 challenge, reduction in levels of hepatic enzymes in serum and diminution of bile duct cell proliferation. Nine dithiolethiones spanning a range of responses in this toxicity screen were further tested for their ability to prevent AFB1-induced tumorigenicity, as assessed by a reduction in hepatic burden of putative preneoplastic foci. Six dithiolethiones were found to be considerably more effective than oltipraz in preventing AFB1-induced tumorigenesis. In general, dithiolethiones that were very effective in inhibition of acute hepatotoxicity were also found to be effective in prevention of hepatic tumorigenesis.

  4. Nicotinamide and skin cancer chemoprevention: The jury is still out.

    Science.gov (United States)

    Gilmore, Stephen J

    2018-02-01

    Following the publication of the results of a Phase III trial, the administration of oral nicotinamide has been widely advocated as effective in non-melanoma skin cancer chemoprevention in high-risk individuals. However, I performed a Bayesian analysis of the reported findings and show there is insufficient evidence to demonstrate its efficacy, highlighting the significant probability that the positive conclusions drawn will not be reproducible. Given the potential widespread use of oral nicotinamide, future position statements regarding its efficacy are likely to require higher standards of evidence. © 2017 The Australasian College of Dermatologists.

  5. Chemoprevention targets for tobacco-related head and neck cancer: past lessons and future directions.

    Science.gov (United States)

    Sheth, Siddharth H; Johnson, Daniel E; Kensler, Thomas W; Bauman, Julie E

    2015-06-01

    Progress toward identifying an effective chemopreventive agent to reduce the incidence of head and neck squamous cell carcinoma (HNSCC) has been limited by poor efficacy and intolerable toxicity profiles. In this review, we summarize the biological basis of HNSCC chemoprevention, and outline challenges associated with identifying appropriate high-risk HNSCC populations for chemoprevention studies. We discuss findings and lessons learned from clinical trials that have investigated micronutrient and molecular targeting interventions. Finally, we introduce the concept of green chemoprevention, interventions based upon whole plant foods or simple extracts that may represent a safe and cost-conscious option for the next generation of studies. As our scientific understanding of HNSCC reaches new levels, the field is poised to develop chemoprevention studies based on rigorous biological validation with accessibility to all affected individuals regardless of socioeconomic barriers. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Resveratrol in human cancer chemoprevention--choosing the 'right' dose.

    Science.gov (United States)

    Scott, Edwina; Steward, William P; Gescher, Andreas J; Brown, Karen

    2012-01-01

    There is now robust preclinical evidence to suggest that resveratrol possesses cancer chemopreventive properties. A series of clinical pilot studies has provided insights into its pharmacokinetics, and data on its human antineoplastic pharmacodynamics start to emerge. It is likely that resveratrol will be developed further in the clinic as a putative cancer chemopreventive agent. The question that remains unresolved is: What is the most suitable dose of resveratrol for effective cancer preventive intervention? Mechanistic studies in cells in vitro have almost invariably used concentrations of resveratrol in the 10(-5) to 10(-4)  M range, which is much higher than those which can be achieved in the human biophase after consumption of doses up to 1 g. Many of the preclinical efficacy studies in rodent models of carcinogenesis have employed doses which are dramatically above those which can be ingested with the diet. New experimental paradigms need to be used to obtain information on pharmacological changes elicited by resveratrol when present at very low concentrations or when administered at dietary-relevant doses. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. 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.

  8. Grapefruit and its biomedical, antigenotoxic and chemopreventive properties.

    Science.gov (United States)

    Cristóbal-Luna, José Melesio; Álvarez-González, Isela; Madrigal-Bujaidar, Eduardo; Chamorro-Cevallos, Germán

    2018-02-01

    Grapefruit (Citrus paradisi Mcfad) is a perenifolium tree 5-6 m high with a fruit of about 15 cm in diameter, protected by the peel we can find about 11-14 segments (carpels), each of which is surrounded by a membrane and each containing the juice sacs, as well as the seeds. The fruit is made up of numerous compounds, and is known to have nutritive value because of the presence of various vitamins and minerals, among other chemicals. The fruit is also used in the field of gastronomy. Information has been accumulated regarding the participation of the fruit structures in a variety of biomedical, antigenotoxic and chemopreventive effects, surely related with the presence of the numerous chemicals that have been determined to constitute the fruit. Such studies have been carried out in different in vitro and in vivo experimental models, and in a few human assays. The information published so far has shown interesting results, therefore, the aims of the present review are to initially examine the main characteristics of the fruit, followed by systematization of the acquired knowledge concerning the biomedical, antigenotoxic and chemopreventive effects produced by the three main structures of the fruit: peel, seed, and pulp. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. 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.

  10. The Chemopreventive and Chemotherapeutic Potentials of Tea Polyphenols

    Science.gov (United States)

    Thakur, Vijay S; Gupta, Karishma; Gupta, Sanjay

    2011-01-01

    Tea is the second most consumed beverage in the world reported to have multiple health benefits. Preventive and therapeutic benefits of tea polyphenols include enhanced general well being and anti-neoplastic effects. The pharmacologic action of tea is often attributed to various catechins present therein. Experiments conducted in cancer cell lines and animal models demonstrate that tea polyphenols protect against cellular damage caused by oxidative stress and altered immunity. Tea polyphenols modify various metabolic and signaling pathways in the regulation of proliferation, apoptosis, angiogenesis, and metastasis and therefore restrict clonal expansion of cancer cells. Tea polyphenols have been shown to reactivate tumor suppressors, block the unlimited replicative potential of cancer cells, and physically bind to nucleic acids involved in epigenetic alterations of gene regulation. Remarkable interest in green tea as a potential chemopreventive agent has been generated since recent epigenetic data showed that tea polyphenols have the potential to reverse epigenetic modifications which might otherwise be carcinogenic. Like green tea, black tea may also possess chemopreventive and chemotherapeutic potential; however, there is still not enough evidence available to make any conclusive statements. Here we present a brief description of tea polyphenols and discuss the findings of various in vitro and in vivo studies of the anticancer effects of tea polyphenols. Detailed discussion of various studies related to epigenetic changes caused by tea polyphenols leading to prevention of oncogenesis or cancer progression is included. Finally, we discuss on the scope and development of tea polyphenols in cancer prevention and therapy. PMID:21466438

  11. Neoflavonoids and tetrahydroquinolones as possible cancer chemopreventive agents

    Science.gov (United States)

    Luqman, Suaib; Meena, Abha; Singh, Pragya; Kondratyuk, Tamara P.; Marler, Laura E.; Pezzuto, John M.; Negi, Arvind Singh

    2012-01-01

    Several lactone and lactam based neoflavonoids and tetrahydroquinolones were synthesized and evaluated for cancer chemopreventive studies using cell and molecular target based in vitro bioassays, namely NFκB, aromatase, and quinone reductase 1 (QR1). These analogues blocked TNF-α-induced NFκB activation in a dose-dependent manner with IC50 values in the range of 0.11–3.2 μM. In addition, compound 8 inhibited aromatase activity with an IC50 value of 12.12 μM and compound 10 affected QR1 induction (IR: 3.6, CD: 19.57 μM). Neoflavonoids 8 and 10 exhibiting good results, can further be optimized for improved therapeutic profiles. However, investigations into the actions of neoflavonoids and tetrahydroquinolones, especially those related to the NFκB signaling pathway, aromatase inhibition, induction of QR1 expression and in vivo studies could provide new insights into the cancer chemopreventive ability of these molecules. PMID:22726671

  12. Mode of action of aspirin as a chemopreventive agent.

    Science.gov (United States)

    Dovizio, Melania; Bruno, Annalisa; Tacconelli, Stefania; Patrignani, Paola

    2013-01-01

    Aspirin taken for several years at doses of at least 75 mg daily reduced long-term incidence and mortality due to colorectal cancer. The finding of aspirin benefit at low-doses given once daily, used for cardioprevention, locates the antiplatelet effect of aspirin at the center of its antitumor efficacy. In fact, at low-doses, aspirin acts mainly by an irreversible inactivation of platelet cyclooxygenase (COX)-1 in the presystemic circulation, which translates into a long-lasting inhibition of platelet function. Given the short half-life of aspirin in the human circulation(approximately 20 min) and the capacity of nucleated cells to resynthesize the acetylated COX-isozyme(s), it seems unlikely that a nucleated cell could be the target of aspirin chemoprevention. These findings convincingly suggest that colorectal cancer and atherothrombosis may share a common mechanism of disease, i.e. platelet activation in response to epithelial(in tumorigenesis) and endothelial(in tumorigenesis and atherothrombosis) injury. Activated platelets may also enhance the metastatic potential of cancer cells (through a direct interaction and/or the release of soluble mediators or exosomes) at least in part by inducing the overexpression of COX-2. COX-independent mechanisms of aspirin, such as the inhibition of NF-kB signaling and Wnt/β-catenin signaling and the acetylation of extra-COX proteins, have been suggested to play a role in its chemopreventive effects. However, their relevance remains to be demonstrated in vivo at clinical doses.

  13. Chemopreventive potential of natural compounds in head and neck cancer.

    Science.gov (United States)

    Rahman, Mohammad Aminur; Amin, A R M Ruhul; Shin, Dong M

    2010-01-01

    Head and neck squamous cell carcinoma (HNSCC) is one of the most fatal cancers worldwide. Despite advances in the management of HNSCC, the overall survival for patients has not improved significantly due to advanced stages at diagnosis, high recurrence rate after surgical removal, and second primary tumor development, which underscore the importance of novel strategies for cancer prevention. Cancer chemoprevention, the use of natural or synthetic compounds to prevent, arrest, or reverse the process of carcinogenesis at its earliest stages, aims to reverse premalignancies and prevent second primary tumors. Genomics and proteomics information including initial mutation, cancer promotion, progression, and susceptibility has brought molecularly targeted therapies for drug development. The development of preventive approaches using specific natural or synthetic compounds, or both, requires a depth of understanding of the cross-talk between cancer signaling pathways and networks to retain or enhance chemopreventive activity while reducing known toxic effects. Many natural dietary compounds have been identified with multiple molecular targets, effective in the prevention and treatment of cancer. This review describes recent advances in the understanding of the complex signaling networks driving cancer progression and of molecularly targeted natural compounds under preclinical and clinical investigation.

  14. The potential of statins for individualized colorectal cancer chemoprevention.

    Science.gov (United States)

    Jacobs, Rutger J; Kodach, Liudmila L; Hardwick, James C H

    2011-12-01

    Colorectal cancer is a leading cause of death by cancer in the western world. Despite major progress, even new chemotherapeutic regimens have had relatively little impact on long term survival in the approximately 50% of patients with advanced disease at presentation meaning that prevention is the only realistic way to reduce the burden of this disease. Many countries have implemented population-based screening methods to prevent colorectal cancer by the physical removal of its precursor lesion the adenoma, or to detect cancer at an earlier stage when it is amenable to surgical cure. However these programs have only been shown to reduce colorectal cancer deaths by 30% in those screened and therefore new or complimentary approaches are needed. One such approach is chemoprevention. A number of compounds have shown potential in reducing the incidence of colorectal cancer. Most widely known are NSAIDs but recently inhibitors of the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, also known as statins, commonly prescribed medications that lower serum cholesterol, have been shown to reduce colorectal cancer incidence. A critical issue in chemoprevention is the weighing of benefits against risks. In chemoprevention this balance is likely to be unfavourable when used in a wide unselected population even for the safest of compounds. Therapy should therefore be tailored to the individual patient. The balance will be more favourable in high risk groups such as individuals especially susceptible to neoplasia because of environmental risk factors, patients with inflammatory bowel disease, those with a hereditary predisposition and patients with a previous history of colorectal cancer or polyps. Furthermore colorectal cancer is not one disease but a heterogeneous group of diseases with different underlying molecular mechanisms. It is likely that both prevention and therapy will need to be tailored to the molecular subtype of the cancer in question. This may explain

  15. Anaerobic biodegradation of methyl tert-butyl ether and tert-butyl alcohol in petrochemical wastewater.

    Science.gov (United States)

    Ghasemian, Mohammad; Amin, Mohammad Mehdi; Morgenroth, Eberhard; Jaafarzadeh, Neemat

    2012-09-01

    A laboratory-scale anaerobic sequencing batch reactor was used to evaluate treatment of a synthetic substrate mixture representing petrochemical wastewater containing methyl tert-butyl ether (MTBE), ethanol and acetic acid. Influent MTBE concentrations were 5, 10 and 50 mg/l (corresponding to MTBE loading rates of 0.2, 0.4 and 2 mg/l.d) with overall organic loading rates (OLRs) of 1.51, 3.23 and 3.25 g COD/1.d, respectively. These OLRs resulted in removal efficiencies for MTBE of 78%, 98% and 88%. Removal efficiencies for chemical oxygen demand were 85% and 90% with influent MTBE concentrations of 5 and 10mg/l, but were significantly reduced to 72% with influent MTBE concentrations of 50mg/l. During all reactor runs, effluent concentrations oftert-butyl alcohol (TBA) were below the detection limit. Batch degradation of the organic substrate mixture demonstrated initial inhibitory effects when exposed to MTBE concentrations of 50 mg/l and complete inhibition with MTBE concentrations above 2000 mg/l. It is interesting to note that in batch tests using MTBE as the sole organic substrate (initial MTBE concentrations of 50, 100 and 200 mg/l), the specific methanogenic activity decreased to below detection within the first 96 hours, but following a 72-hour lag phase the methane production increased again. Based on low volatile fatty acid (VFA) concentration, disappearance of TBA peaks and no findings of any other intermediate via gas chromatography/mass spectrometry, while the MTBE concentration is still high, it can be suggested that during the batch tests the breakdown of gas production and the following lag phase were the direct effect of higher MTBE concentrations (more than 50 mg/l) and not because of the TBA or VFA accumulations.

  16. 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.

  17. Cancer chemopreventive agents, 4-phenylcoumarins from Calophyllum inophyllum.

    Science.gov (United States)

    Itoigawa, M; Ito, C; Tan, H T; Kuchide, M; Tokuda, H; Nishino, H; Furukawa, H

    2001-08-10

    In a search for anti-tumor-promoting agents, we carried out a primary screening of ten 4-phenylcoumarins isolated from Calophyllum inophyllum L. (Guttiferae), by examining their possible inhibitory effects on Epstein--Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate in Raji cells. All of the compounds tested in this study showed inhibitory activity against EBV, without showing any cytotoxicity. Calocoumarin-A (5) showed more potent activity than any of the other compounds tested. Furthermore, calocoumarin-A (5) exhibited a marked inhibitory effect on mouse skin tumor promotion in an in vivo two-stage carcinogenesis test. The results of the present investigation indicate that some of these 4-phenylcoumarins might be valuable as potential cancer chemopreventive agents (anti-tumor-promoters).

  18. Aspirin as a Chemopreventive Agent for Cancer: a New Hope?

    Directory of Open Access Journals (Sweden)

    Isnatin Miladiyah

    2016-01-01

    Full Text Available Introduction: inflammation has been shown to play a major role in the pathogenesis of cancer. Inflammatory process activates the immune system through pro-inflammatory mediators and subsequent triggers transformation into malignant cells. Some tumors or cancers has been associated with chronic infections, such as hepatitis B and C viruses (hepatocellular carcinoma, human papilloma virus (cervical cancer, Helicobacter pylori (gastric cancer and lymphoma, and prostatitis (prostate cancer. A considerable study have investigated the benefits of aspirin for the prevention and treatment of cancer or tumors. Objectives: This paper aims to describe the relationship between inflammation and cancer incidence, so that use of aspirin as an anti-inflammatory agent is a rational choice in the treatment and prevention of cancer. Conclusion: Aspirin potential for chemoprevention of various types of cancer. Considering the high risk of side effects of aspirin, aspirin is not intended as a routine therapy to prevent the occurrence of cancer.

  19. Flavonoids, Breast Cancer Chemopreventive and/or Chemotherapeutic Agents.

    Science.gov (United States)

    Magne Nde, Chantal Beatrice; Zingue, Stephane; Winter, Evelyn; Creczynski-Pasa, Tânia Beatriz; Michel, Thomas; Fernandez, Xavier; Njamen, Dieudonne; Clyne, Colin

    2015-01-01

    Flavonoids are secondary metabolites abundantly present in commonly consumed fruits and vegetables. They possess diverse properties such as anti-inflammatory, anti-oxidant and anti-cancer. Epidemiologic studies suggest that an enrich flavonoids diet is linked to a decreased risk of breast cancer. These protective properties are due to the alteration of numerous signalling pathways involved in cancer-related phenomena such as inflammation and proliferation. Human clinical trials examining the effect of supplementation of some flavonoids on disease prevention have been conducted. There is no natural flavonoid that has been approved for the treatment of breast cancer. However, natural flavonoids served as lead compounds in the synthesis of cancer chemopreventive and/or therapeutic agents.

  20. 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.

  1. ent-Rosane and abietane diterpenoids as cancer chemopreventive agents.

    Science.gov (United States)

    Núñez, Marvin J; Reyes, Carolina P; Jiménez, Ignacio A; Hayashi, Hirotaka; Tokuda, Harukuni; Bazzocchi, Isabel L

    2011-04-01

    Two ent-rosane- (cuzcol, 1 and 6-dehydroxycuzcol, 2) and a abietatriene- (salvadoriol, 3) type diterpenoids have been isolated from Maytenus cuzcoina and Crossopetalum uragoga, respectively, along with five known diterpene compounds (4-8). Their stereostructures have been elucidated on the basis of spectroscopic analysis, including 1D and 2D NMR techniques, and computational data. The absolute configuration of cuzcol was determined by application of Riguera ester procedure. This is the first instance of isolation of ent-rosane diterpenoids from species of the Celastraceae. The isolated diterpenes were found to be potent anti-tumour-promoter agents, and carnosol (7) also showed a remarkable chemopreventive effect in an in vivo two-stage carcinogenesis model. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. The natural chemopreventive agent sulforaphane inhibits STAT5 activity.

    Directory of Open Access Journals (Sweden)

    Sophia Pinz

    Full Text Available Signal transducer and activator of transcription STAT5 is an essential mediator of cytokine, growth factor and hormone signaling. While its activity is tightly regulated in normal cells, its constitutive activation directly contributes to oncogenesis and is associated to a number of hematological and solid tumor cancers. We previously showed that deacetylase inhibitors can inhibit STAT5 transcriptional activity. We now investigated whether the dietary chemopreventive agent sulforaphane, known for its activity as deacetylase inhibitor, might also inhibit STAT5 activity and thus could act as a chemopreventive agent in STAT5-associated cancers. We describe here sulforaphane (SFN as a novel STAT5 inhibitor. We showed that SFN, like the deacetylase inhibitor trichostatin A (TSA, can inhibit expression of STAT5 target genes in the B cell line Ba/F3, as well as in its transformed counterpart Ba/F3-1*6 and in the human leukemic cell line K562 both of which express a constitutively active form of STAT5. Similarly to TSA, SFN does not alter STAT5 initial activation by phosphorylation or binding to the promoter of specific target genes, in favor of a downstream transcriptional inhibitory effect. Chromatin immunoprecipitation assays revealed that, in contrast to TSA however, SFN only partially impaired the recruitment of RNA polymerase II at STAT5 target genes and did not alter histone H3 and H4 acetylation, suggesting an inhibitory mechanism distinct from that of TSA. Altogether, our data revealed that the natural compound sulforaphane can inhibit STAT5 downstream activity, and as such represents an attractive cancer chemoprotective agent targeting the STAT5 signaling pathway.

  3. Nanoencapsulation of pomegranate bioactive compounds for breast cancer chemoprevention

    Science.gov (United States)

    Shirode, Amit B; Bharali, Dhruba J; Nallanthighal, Sameera; Coon, Justin K; Mousa, Shaker A; Reliene, Ramune

    2015-01-01

    Pomegranate polyphenols are potent antioxidants and chemopreventive agents but have low bioavailability and a short half-life. For example, punicalagin (PU), the major polyphenol in pomegranates, is not absorbed in its intact form but is hydrolyzed to ellagic acid (EA) moieties and rapidly metabolized into short-lived metabolites of EA. We hypothesized that encapsulation of pomegranate polyphenols into biodegradable sustained release nanoparticles (NPs) may circumvent these limitations. We describe here the development, characterization, and bioactivity assessment of novel formulations of poly(D,L-lactic-co-glycolic acid)–poly(ethylene glycol) (PLGA–PEG) NPs loaded with pomegranate extract (PE) or individual polyphenols such as PU or EA. Monodispersed, spherical 150–200 nm average diameter NPs were prepared by the double emulsion–solvent evaporation method. Uptake of Alexa Fluor-488-labeled NPs was evaluated in MCF-7 breast cancer cells over a 24-hour time course. Confocal fluorescent microscopy revealed that PLGA–PEG NPs were efficiently taken up, and the uptake reached the maximum at 24 hours. In addition, we examined the antiproliferative effects of PE-, PU-, and/or EA-loaded NPs in MCF-7 and Hs578T breast cancer cells. We found that PE, PU, and EA nanoprototypes had a 2- to 12-fold enhanced effect on cell growth inhibition compared to their free counterparts, while void NPs did not affect cell growth. PU-NPs were the most potent nanoprototype of pomegranates. Thus, PU may be the polyphenol of choice for further chemoprevention studies with pomegranate nanoprototypes. These data demonstrate that nanotechnology-enabled delivery of pomegranate polyphenols enhances their anticancer effects in breast cancer cells. Thus, pomegranate polyphenols are promising agents for nanochemoprevention of breast cancer. PMID:25624761

  4. Nanoencapsulation of pomegranate bioactive compounds for breast cancer chemoprevention.

    Science.gov (United States)

    Shirode, Amit B; Bharali, Dhruba J; Nallanthighal, Sameera; Coon, Justin K; Mousa, Shaker A; Reliene, Ramune

    2015-01-01

    Pomegranate polyphenols are potent antioxidants and chemopreventive agents but have low bioavailability and a short half-life. For example, punicalagin (PU), the major polyphenol in pomegranates, is not absorbed in its intact form but is hydrolyzed to ellagic acid (EA) moieties and rapidly metabolized into short-lived metabolites of EA. We hypothesized that encapsulation of pomegranate polyphenols into biodegradable sustained release nanoparticles (NPs) may circumvent these limitations. We describe here the development, characterization, and bioactivity assessment of novel formulations of poly(D,L-lactic-co-glycolic acid)-poly(ethylene glycol) (PLGA-PEG) NPs loaded with pomegranate extract (PE) or individual polyphenols such as PU or EA. Monodispersed, spherical 150-200 nm average diameter NPs were prepared by the double emulsion-solvent evaporation method. Uptake of Alexa Fluor-488-labeled NPs was evaluated in MCF-7 breast cancer cells over a 24-hour time course. Confocal fluorescent microscopy revealed that PLGA-PEG NPs were efficiently taken up, and the uptake reached the maximum at 24 hours. In addition, we examined the antiproliferative effects of PE-, PU-, and/or EA-loaded NPs in MCF-7 and Hs578T breast cancer cells. We found that PE, PU, and EA nanoprototypes had a 2- to 12-fold enhanced effect on cell growth inhibition compared to their free counterparts, while void NPs did not affect cell growth. PU-NPs were the most potent nanoprototype of pomegranates. Thus, PU may be the polyphenol of choice for further chemoprevention studies with pomegranate nanoprototypes. These data demonstrate that nanotechnology-enabled delivery of pomegranate polyphenols enhances their anticancer effects in breast cancer cells. Thus, pomegranate polyphenols are promising agents for nanochemoprevention of breast cancer.

  5. 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.

  6. Can transcriptomics provide insight into the underlying chemopreventive mechanisms of complex mixtures of phytochemicals in humans?

    NARCIS (Netherlands)

    Breda, van S.G.; Wilms, L.C.; Gaj, S.; Briedé, J.J.; Helsper, J.P.F.G.; Kleinjans, J.C.; Kok, de T.M.

    2014-01-01

    Blueberries contain relatively large amounts of different phytochemicals which are suggested to have chemopreventive properties, but little information is available on the underlying molecular modes of action. This study investigates whole genome gene expression changes in lymphocytes of 143 humans

  7. In Vitro Formation of 8-hydroxy-2-deoxyguanosine (8-OHdG in Calf Thymus DNA upon Treatment of 2-deoxyguanosine with Propyl Gallate and 2,6-di-tert-butyl-p-benzoquinone

    Directory of Open Access Journals (Sweden)

    Budiawan Budiawan

    2015-12-01

    Full Text Available Oxidative DNA damage caused by propyl gallate (PG and 2,6-di-tert-butyl-p-benzoquinone (BHT-quinone, a metabolite of butylated hydroxytoluene (BHT was analyzed from the 8-hydroxy-2¢-deoxyguanosine (8-OHdG formation in calf thymus DNA and DNA base, 2¢-deoxyguanosine (dG. PG in the presence of CuCl2 increased the 8-OHdG formation in calf thymus DNA by around 9.17 times as compared to the control (untreated DNA. In the presence of CuCl2 at 1.28×10-5 M, the 8-OHdG per dG ratio resulting from the reaction of dG with PG at various concentrations (20–150 ppm ranged from 75.50 to 312.06 8-OHdG per 105 dG. The 8-OHdG formation increased when the PG concentration was increased from 20 ppm to 80 ppm, and then, it began to plateau around 80 ppm. On the other hand, BHT-quinone increased the formation of 8-OHdG in the presence of CuCl2 by 0.05 times as compared to the control (untreated DNA. LC-MS/MS analysis was used to identify the molecular structure of 8-OHdG, which had a base peak (M+. + 1 at m/z = 284 and two main fragments at m/z = 167.9 and m/z = 139.9.

  8. Chemoprevention of Breast Cancer by Mimicking the Protective Effect of Early First Birth. Addendum

    Science.gov (United States)

    2013-03-01

    densities and breast cancer risk. Cancer Epidemiol Biomarkers Prev 1998;7:1133-44. 4. Bartow SA, Pathak DR, Mettler FA. Radiographic microcalcification ...AD_________________ Award Number: W81XWH-05-1-0390 TITLE: Chemoprevention of breast cancer by...REPORT TYPE Final addendum 3. DATES COVERED 2 May 2012 – 2 February 2013 4. TITLE AND SUBTITLE Chemoprevention of breast cancer by mimicking the

  9. Topical tretinoin, another failure in the pursuit of practical chemoprevention for non-melanoma skin cancer.

    Science.gov (United States)

    Wu, Peggy A; Stern, Robert S

    2012-06-01

    Given the high incidence of non-melanoma skin cancer (NMSC), a preventative intervention would be desirable. Except for regular sunscreen use, the quest for chemoprevention of NMSC in the general population has been unsuccessful. Weinstock et al. assessed the effects of 0.1% topical tretinoin on NMSC. Like earlier efforts at chemoprevention, this study failed to show therapeutic benefit. Future successful preventative strategies will likely rely on short-term, intermittent therapy or treatments used for other common indications.

  10. Breast cancer chemopreventive and chemotherapeutic effects of Camellia Sinensis (green tea): an updated review

    OpenAIRE

    Rafieian-Kopaei, Mahmoud; Movahedi, Mino

    2017-01-01

    Introduction Camellia sinensis belongs to the plant family of Theaceae, native to East Asia, the Indian Subcontinent and Southeast Asia, but naturalized in many parts of the world. The aim of this study was to overview its anti-breast cancer chemopreventive and chemotherapeutic effects. This review article is aimed to overview breast cancer chemopreventive and chemotherapeutic effects of Camellia sinensis (green tea). Methods This review article was carried out by searching studies in PubMed,...

  11. Effectiveness of hyoscine butyl bromide in shortening the first stage ...

    African Journals Online (AJOL)

    Background: Prolonged labour from cervical dystocia or stasis is one of the common indications for caesarean delivery. Hyoscine N-butyl bromide (HBB), an anticholinergic and antispasmodic drug, has been found effective in shortening the first stage of labour with no adverse effects on feto-maternal outcomes.

  12. Solvent free lipase catalyzed synthesis of butyl caprylate

    Indian Academy of Sciences (India)

    MEERA T SOSE

    2017-11-10

    Nov 10, 2017 ... Special Issue on Recent Trends in the Design and Development of Catalysts and their Applications. Solvent free lipase ... The ester, butyl caprylate has wide applications in commercial market and it also possesses characteristic fruity ... lyst can offer better advantage rather the use of acid or harmful catalyst ...

  13. 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 § 21...

  14. 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 § 21...

  15. 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...

  16. 76 FR 59906 - Fluazifop-P-butyl; Pesticide Tolerances

    Science.gov (United States)

    2011-09-28

    ... of fluazifop-P-butyl in or on cotton, gin byproducts; cotton, refined oil; and cotton, undelinted...]propanoic acid, expressed as fluazifop, in or on cotton, undelinted seed at 0.9 ppm; and cotton, gin... made changes to the requested tolerances. First, EPA is raising the proposed cotton, gin byproducts...

  17. An alternative approach to synthesis of 2--butyl-5-nitrobenzofuran ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 124; Issue 5. An alternative approach to synthesis of 2--butyl-5-nitrobenzofuran derivative: A key starting material for dronedarone hydrochloride. P Raja Gopal E R R Chandrashekar M Saravanan B Vijaya Bhaskar P Veera Somaiah. Volume 124 Issue 5 September ...

  18. Polymerization behavior of butyl bis(hydroxymethyl)phosphine oxide ...

    Indian Academy of Sciences (India)

    lenovo

    Polymerization behavior of butyl bis(hydroxymethyl)phosphine oxide: Phosphorus containing polyethers for. Li‒ion conductivities. Heeralal Vignesh Babu, Billakanti Srinivas and Krishnamurthi Muralidharan*. School of Chemistry, University of Hyderabad, Hyderabad - 500046, India. Table of Contents. TGA plots of SPE2.

  19. 76 FR 77709 - Butyl acrylate-methacrylic acid-styrene polymer; Tolerance Exemption

    Science.gov (United States)

    2011-12-14

    ... AGENCY 40 CFR Part 180 Butyl acrylate-methacrylic acid-styrene polymer; Tolerance Exemption AGENCY...-propenoate and ethenylbenzene (CAS Reg. No. 25036-16-2); also known as butyl acrylate-methacrylic acid...-risk polymers are described in 40 CFR 723.250(d). Butyl acrylate-methacrylic acid-styrene polymer...

  20. Proton nuclear magnetic resonance study of water + t-butyl alcohol ...

    African Journals Online (AJOL)

    Hydroxyl-proton chemical shifts for water and t-butyl alcohol in water + t-butyl alcohol mixtures with 8 mol% t-butyl alcohol, and the average hydroxyl and amino proton chemical shift for water + t-butylamine mixtures, have been determined at 200 MHz for four temperatures (263, 278, 298 and 313 K) as a function of ...

  1. 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....

  2. 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.

  3. Plant Polyphenols as Chemopreventive Agents for Lung Cancer

    Directory of Open Access Journals (Sweden)

    Madumani Amararathna

    2016-08-01

    Full Text Available 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.

  4. Black tea: Phytochemicals, cancer chemoprevention, and clinical studies.

    Science.gov (United States)

    Singh, Brahma N; Rawat, A K S; Bhagat, R M; Singh, B R

    2017-05-03

    Tea (Camellia sinensis L.) is the most popular, flavored, functional, and therapeutic non-alcoholic drink consumed by two-thirds of the world's population. Black tea leaves are reported to contain thousands of bioactive constituents such as polyphenols, amino acids, volatile compounds, and alkaloids that exhibit a range of promising pharmacological properties. Due to strong antioxidant property, black tea inhibits the development of various cancers by regulating oxidative damage of biomolecules, endogenous antioxidants, and pathways of mutagen and transcription of antioxidant gene pool. Regular drinking of phytochemicals-rich black tea is linked to regulate several molecular targets, including COX-2, 5-LOX, AP-1, JNK, STAT, EGFR, AKT, Bcl2, NF-κB, Bcl-xL, caspases, p53, FOXO1, TNFα, PARP, and MAPK, which may be the basis of how dose of black tea prevents and cures cancer. In vitro and preclinical studies support the anti-cancer activity of black tea; however, its effect in human trails is uncertain, although more clinical experiments are needed at molecular levels to understand its anti-cancer property. This review discusses the current knowledge on phytochemistry, chemopreventive activity, and clinical applications of black tea to reveal its anti-cancer effect.

  5. Plant Polyphenols as Chemopreventive Agents for Lung Cancer.

    Science.gov (United States)

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

    2016-08-19

    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.

  6. Molecular mechanisms of chemopreventive phytochemicals against gastroenterological cancer development

    Science.gov (United States)

    Chung, Min-Yu; Lim, Tae Gyu; Lee, Ki Won

    2013-01-01

    Cancer is one of the leading causes of death worldwide. Commonly used cancer treatments, including chemotherapy and radiation therapy, often have side effects and a complete cure is sometimes impossible. Therefore, prevention, suppression, and/or delaying the onset of the disease are important. The onset of gastroenterological cancers is closely associated with an individual’s lifestyle. Thus, changing lifestyle, specifically the consumption of fruits and vegetables, can help to protect against the development of gastroenterological cancers. In particular, naturally occurring bioactive compounds, including curcumin, resveratrol, isothiocyanates, (-)-epigallocatechin gallate and sulforaphane, are regarded as promising chemopreventive agents. Hence, regular consumption of these natural bioactive compounds found in foods can contribute to prevention, suppression, and/or delay of gastroenterological cancer development. In this review, we will summarize natural phytochemicals possessing potential antioxidant and/or anti-inflammatory and anti-carcinogenic activities, which are exerted by regulating or targeting specific molecules against gastroenterological cancers, including esophageal, gastric and colon cancers. PMID:23467658

  7. Chemoprevention with chlorophyllin in individuals exposed to dietary aflatoxin.

    Science.gov (United States)

    Egner, Patricia A; Muñoz, Alvaro; Kensler, Thomas W

    2003-01-01

    Because of the multiplicative interaction between dietary aflatoxins and hepatitis B virus infection in the etiology of liver cancer, efforts to reduce the consequences of either chemical or viral component are likely to have substantial public health benefit. Chlorophyllin (CHL), a water-soluble form of chlorophyll, was recently evaluated as a chemopreventive agent in a population at high risk for exposure to aflatoxin and subsequent development of hepatocellular carcinoma. CHL, which is used extensively as a food colorant and has numerous medicinal applications, is an effective anticarcinogen in experimental models including aflatoxin-induced hepatocarcinogenesis. CHL is thought to form molecular complexes with carcinogens, thereby blocking their bioavailability. In the clinical trial, administration of CHL three times a day led to a 50% reduction in the median level of urinary excretion of aflatoxin-N(7)-guanine compared to placebo. This excreted DNA adduct biomarker is derived from the ultimate carcinogenic metabolite of aflatoxin B(1), aflatoxin-8,9-epoxide, and is associated with increased risk of developing liver cancer in prospective epidemiologic studies. Compliance in the intervention was outstanding and no toxicities were observed. Thus, CHL has been found to be a safe and effective agent suitable for use in individuals unavoidably exposed to aflatoxins. Copyright 2003 Elsevier Science B.V.

  8. Functional detection of chemopreventive glucosinolates in Arabidopsis thaliana.

    Science.gov (United States)

    Gross; Dalebout; Grubb; Abel

    2000-11-06

    Natural isothiocyanates, derived from glucosinolates by myrosinase-catalyzed hydrolysis, are potent chemopreventive agents that favorably modify carcinogen metabolism in mammals by inhibiting metabolic activation of carcinogens and/or by inducing carcinogen-detoxifying enzymes. Methylsulfinylalkyl isothiocyanates are potent selective inducers of mammalian Phase 2 detoxification enzymes such as quinone reductase [NADP(H):quinone-acceptor oxidoreductase, EC 1.6.99.2]. Members of the Cruciferae family, including the model plant species Arabidopsis thaliana (L.) Heyhn, synthesize methylsulfinylalkyl glucosinolates. We have adapted a colorimetric bioassay for quinone reductase activity in Hepa 1c1c7 murine hepatoma cells as a versatile tool to rapidly monitor methylsulfinylalkyl glucosinolate content in A. thaliana leaf extracts. Using wild type plants and mutant plants defective in the synthesis of 4-methylsulfinylbutyl glucosinolate (glucoraphanin), we have demonstrated that A. thaliana (ecotype Columbia) is a rich source of Phase 2 enzyme inducers and that methylsulfinylalkyl glucosinolates, predominantly glucoraphanin, account for about 80% of the quinone reductase inducer potency of Columbia leaf extracts. We have optimized leaf extraction conditions and the quinone reductase bioassay to allow for screening of large numbers of plant extracts in a molecular genetic approach to dissecting glucosinolate biosynthesis in A. thaliana.

  9. Removal of methyl tert-butyl ether (MTBE) with Nafion.

    Science.gov (United States)

    Lien, Hsing-Lung; Zhang, Wei-Xian

    2007-06-01

    A solid organic polymer, Nafion, is tested for the removal of methyl tert-butyl ether (MTBE) in water. Nafion with perfluorosulfonic acid backbone and terminal sulfonic acid groups has a surface acidity similar to 100% sulfuric acid, and has been commonly used as a strong-acid catalyst in many organic reactions. Sorption and subsequent transformation of MTBE were observed in batch experiments. The transformation of MTBE by porous nanocomposite Nafion SAC-13 to tert-butyl alcohol (TBA), acetone, isobutene and probably methanol was found. Subsequent transformation of TBA to acetone was also observed. Results suggest that transformational pathways may include hydrolysis, dehydrogenation and oxidation. Dissolved oxygen is needed for the oxidation of isobutene to acetone. As Nafion is insoluble in water, chemically stable, and regenerable, its use in packed-bed reactors for MTBE removal looks promising.

  10. A novel organogelator incorporating tert-butyl esters of asparagines.

    Science.gov (United States)

    Lozano, Virginia; Hernández, Rebeca; Mijangos, Carmen; Pérez-Pérez, María-Jesús

    2009-01-21

    A novel organogelator based on tert-butyl esters of asparagines has been synthesized and its organogelation abilities have been investigated. The rheological characterization has confirmed the gelation behavior, and its thixotropic properties. Furthermore, the morphological studies performed reveal a spherical structure. Thus, this organogelator can be considered as a new example of the emerging, but still reduced, list of gels with a non-fibrillar assembly.

  11. 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.

  12. Solution of a gallstone with methyl-tertiary butyl ether

    Energy Technology Data Exchange (ETDEWEB)

    Brambs, H.J.; Roeren, T.; Holstege, A.; Raedecke, J.

    1987-08-01

    Methyl-t-butyl ether is a new agent to dissolve gallstones. The substance proves to be very successful and acts very rapidly. A percutaneous transhepatic drainage supplies an adequate access route to dissolve calculi within the bile ducts. We report the case of a patient where before insertion of an internal stent a stone in the common bile duct was dissolved within 3 1/2 hours.

  13. Di-iso-Butyl Phthalate MATERNAL AND FETAL DATA FROM ...

    Science.gov (United States)

    this file contains the raw data on the effects of in utero administration of di-iso-butyl phthalate on maternal weight gain during dosing and the numbers of fetuses and fetal resorptions. The data have all been previously published, as described on the file metadata sheet. Raw data file from our published studies on DIBP specifically requested (6/14/2016) by NCEA scientists for analysis and inclusion in their assessment of this chemical.

  14. 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.

  15. 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. Copyright © 2015 John Wiley & Sons, Ltd.

  16. Retinoids in the chemoprevention of non-melanoma skin cancers: why, when and how.

    Science.gov (United States)

    Bettoli, Vincenzo; Zauli, Stefania; Virgili, Anna

    2013-06-01

    The chemoprevention refers to the use of various types of chemical agents for preventing carcinogenic progression. Systemic retinoids are the most studied chemopreventive agents due to their capacity to regulate cell proliferation and their demonstrated efficacy in several clinical studies. The aim of the authors was to give precise indications regarding the use of the systemic retinoid in the chemoprevention of non-melanoma skin cancer (NMSC). The authors reviewed the literature found through a search to MEDLINE (from 2001 to December 2011). Both acitretin and isotretinoin are effective for the prevention of NMSC. Isotretinoin is preferred in xeroderma pigmentosum and nevoid basal cell carcinoma syndrome, whereas acitretin is more used in transplant recipients, psoriasis and severe sun damage. Despite numerous studies of the literature concerning retinoids in chemoprevention of NMSC, precise details of the type of retinoid to use, dosage and the duration of this preventive treatment and how to manage side effects in the case of long-lasting treatment are still not uniform and comparable. Moreover, neither guidelines nor approval by Food and Drug Administration exist to regulate the use of retinoids in chemoprevention.

  17. 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...

  18. Aspirin in the Chemoprevention of Colorectal Neoplasia: An Overview

    Science.gov (United States)

    Chan, Andrew T.; Arber, Nadir; Burn, John; Chia, John Whay-Kuang; Elwood, Peter; Hull, Mark A.; Logan, Richard F.; Rothwell, Peter M.; Schrör, Karsten; Baron, John A.

    2011-01-01

    Considerable evidence supports the effectiveness of aspirin for chemoprevention of colorectal cancer (CRC) in addition to its well-established benefits in the prevention of vascular disease. Epidemiologic studies have consistently observed an inverse association between aspirin use and risk of CRC. A recent pooled analysis of a long-term post-trial follow-up of nearly 14,000 patients from 4 randomized, cardiovascular disease prevention trials showed that daily aspirin treatment for about 5 years was associated with a 34% reduction in 20-year CRC mortality. A separate meta-analysis of nearly 3,000 patients with a history of colorectal adenoma or cancer in 4 randomized adenoma prevention trials demonstrated that aspirin reduced the occurrence of advanced adenomas by 28% and any adenoma by 17%. Aspirin has also been shown to be beneficial in a clinical trial of patients with Lynch syndrome, a hereditary CRC syndrome; in those treated with aspirin for at least 2 years, there was a ≥ 50% reduction in the risk of CRC commencing 5 years after randomization and after aspirin had been discontinued. A few observational studies have shown an increase in survival among patients with CRC who use aspirin. Taken together, these findings strengthen the case for consideration of long-term aspirin use in CRC prevention. Despite these compelling data, there is a lack of consensus about the balance of risks and benefits associated with long-term aspirin use, particularly in low-risk populations. The optimal dose to use for cancer prevention and the precise mechanism underlying aspirin’s anticancer effect require further investigation. PMID:22084361

  19. Models for predicting effective HIV chemoprevention in women.

    Science.gov (United States)

    Nicol, Melanie R; Emerson, Cindi W; Prince, Heather M A; Nelson, Julie A E; Fedoriw, Yuri; Sykes, Craig; Geller, Elizabeth J; Patterson, Kristine B; Cohen, Myron S; Kashuba, Angela D M

    2015-04-01

    Model systems that rapidly identify tissue drug concentrations protective of HIV infection could streamline the development of chemoprevention strategies. Tissue models are promising, but limited concentration targets exist, and no systematic comparison to cell models or clinical studies has been performed. We explored the efficacy of maraviroc (MVC) and tenofovir (TFV) for HIV prevention by comparing Emax models from TZM-bl cells to vaginal tissue explants and evaluated their predictive capabilities with a dose-challenge clinical study. HIV-1JR-CSF was used for viral challenge. Drug efficacy was assessed using a luciferase reporter assay in TZM-bl cells and real-time PCR to quantify spliced RNA in a tissue explant model. Cell and tissue concentrations of MVC, TFV, and the active metabolite tenofovir diphosphate were measured by liquid chromatography with tandem mass spectrometry and used to create Emax models of efficacy. Efficacy after a single oral dose of 600 mg MVC and 600 mg tenofovir disoproxil fumarate was predicted from cell and tissue models and confirmed in a clinical study with viral biopsy challenge postdose. TFV was >10-fold and MVC >1000-fold, more potent in TZM-bl cells compared with vaginal explant tissue. In the dose-challenge study, tissues from 3 of 6 women were protected from HIV infection, which was 49% lower than predicted by TZM-bl data and 36% higher than predicted by tissue explant data. Comparative effective concentration data were generated for TFV and MVC in 3 HIV chemoprophylaxis models. These results provide a framework for future early investigations of antiretroviral efficacy in HIV prevention to optimize dosing strategies in clinical investigations.

  20. Vitamin Analogues in Chemoprevention of Hepatocellular Carcinoma After Resection or Ablation—A Systematic Review and Meta-analysis

    Directory of Open Access Journals (Sweden)

    Kai-Jian Chu

    2010-07-01

    Conclusion: There is evidence to suggest that chemopreventive therapy after partial hepatectomy or local ablative therapy is beneficial in prolonging disease-free survival, but the evidence is less for an effect on the overall survival. To confirm the beneficial role of vitamin A or K analogues in the chemoprevention of HCC further and larger randomised trials are now required.

  1. Molecular mechanisms for chemoprevention of colorectal cancer by natural dietary compounds.

    Science.gov (United States)

    Pan, Min-Hsiung; Lai, Ching-Shu; Wu, Jia-Ching; Ho, Chi-Tang

    2011-01-01

    Colorectal cancer is one of the major causes of cancer-related mortality in both men and women worldwide. This review focuses on preventing the initiation and promotion of neoplastic growth in colorectal cancer, particularly with natural dietary compounds. Chemoprevention is defined as the use of natural dietary compounds and/or synthetic substances that can delay, prevent, or even reverse the development of adenomas, as well as the progression from adenoma to carcinoma. The molecular mechanisms of their chemopreventive action are associated with the modulation of signaling cascades, gene expressions involved in the regulation of cell proliferation, differentiation, and apoptosis and the suppression of chronic inflammation, metastasis, and angiogenesis. Here, we summarize the currently known targets and signaling pathways whereby natural dietary compounds interfere with the development of colorectal cancer, and thus providing evidence for these substances in colonic cancer chemopreventive action. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. 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...

  3. 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.

  4. Antibody Array as a Tool for Screening of Natural Agents in Cancer Chemoprevention.

    Science.gov (United States)

    Pulito, Claudio; Sacconi, Andrea; Korita, Etleva; Maidecchi, Anna; Strano, Sabrina

    2016-01-01

    The efficacy of a given drug resides mainly on its ability to specifically target disease mechanisms. Natural products represent the leading source of bioactive molecules with a broad range of activities. It is becoming increasingly clear that natural compounds exert their chemopreventive or antitumoral activities targeting simultaneously diverse cellular pathways. Here we describe the use of antibody array to assess the effects of natural compounds on the expression of multiple proteins and of their posttranslational modifications in cellular systems. This might turn to be a very flexible application for cancer chemoprevention studies.

  5. N-Butyl acrylate polymer composition for solar cell encapsulation and method

    Science.gov (United States)

    Gupta, Amitava (Inventor); Ingham, John D. (Inventor); Yavrouian, Andre H. (Inventor)

    1983-01-01

    A polymer syrup for encapsulating solar cell assemblies. The syrup includes uncrosslinked poly(n-butyl)acrylate dissolved in n-butyl acrylate monomer. Preparation of the poly(n-butyl)acrylate and preparation of the polymer syrup is disclosed. Methods for applying the polymer syrup to solar cell assemblies as an encapsulating pottant are described. Also included is a method for solar cell construction utilizing the polymer syrup as a dual purpose adhesive and encapsulating material.

  6. 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. Copyright © 2015. Published by Elsevier Ltd.

  7. Chemoprevention of Rat Mammary Carcinogenesis by Apiaceae Spices

    Directory of Open Access Journals (Sweden)

    Farrukh Aqil

    2017-02-01

    Full Text Available Scientific evidence suggests that many herbs and spices have medicinal properties that alleviate symptoms or prevent disease. In this study, we examined the chemopreventive effects of the Apiaceae spices, anise, caraway, and celery seeds against 17β-estrogen (E2-mediated mammary tumorigenesis in an ACI (August-Copenhagen Irish rat model. Female ACI rats were given either control diet (AIN 93M or diet supplemented with 7.5% (w/w of anise, caraway, or celery seed powder. Two weeks later, one half of the animals in each group received subcutaneous silastic implants of E2. Diet intake and body weight were recorded weekly, and animals were euthanized after 3 and 12 weeks. E2-treatment showed significantly (2.1- and 3.4-fold enhanced growth of pituitary gland at 3 and 12 weeks, respectively. All test spices significantly offset the pituitary growth by 12 weeks, except celery which was effective as early as three weeks. Immunohistochemical analysis for proliferative cell nuclear antigen (PCNA in mammary tissues showed significant reduction in E2-mediated mammary cell proliferation. Test spices reduced the circulating levels of both E2 and prolactin at three weeks. This protection was more pronounced at 12 weeks, with celery eliciting the highest effect. RT-PCR and western blot analysis were performed to determine the potential molecular targets of the spices. Anise and caraway diets significantly offset estrogen-mediated overexpression of both cyclin D1 and estrogen receptor α (ERα. The effect of anise was modest. Likewise, expression of CYP1B1 and CYP1A1 was inhibited by all test spices. Based on short-term molecular markers, caraway was selected over other spices based on its enhanced effect on estrogen-associated pathway. Therefore, a tumor-end point study in ACI rats was conducted with dietary caraway. Tumor palpation from 12 weeks onwards revealed tumor latency of 29 days in caraway-treated animals compared with first tumor appearance at 92

  8. 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.

  9. 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.

  10. Effect of a vegan diet on biomarkers of chemoprevention in females

    NARCIS (Netherlands)

    Verhagen, H.; Rauma, A.L.; Törrönen, R.; Vogel, N. de; Bruijntjes-Rozier, G.C.D.M.; Dreve, M.A.; Bogaards, J.J.P.; Mykkänen, H.

    1996-01-01

    1. In order to study the potential beneficial effects of a vegan diet, a cross-sectional study was performed and several biomarkers of chemoprevention were measured in a population of female 'living food' eaters ('vegans'; n = 20) vs matched omnivorous controls (n = 20). 2. White blood cells

  11. Chemopreventive agents attenuate rapid inhibition of gap junctional intercellular communication induced by environmental toxicants

    Czech Academy of Sciences Publication Activity Database

    Babica, Pavel; Čtveráčková, Lucie; Lenčešová, Zuzana; Trosko, J. E.; Upham, B. L.

    2016-01-01

    Roč. 68, č. 5 (2016), s. 827-837 ISSN 0163-5581 R&D Projects: GA MŠk LH12034 Institutional support: RVO:67985939 Keywords : gap junctional intercellular communication * chemopreventive agents * environmental toxicants Subject RIV: FR - Pharmacology ; Medidal Chemistry Impact factor: 2.447, year: 2016

  12. Anticancer and cancer chemopreventive potential of grape seed extract and other grape-based products.

    Science.gov (United States)

    Kaur, Manjinder; Agarwal, Chapla; Agarwal, Rajesh

    2009-09-01

    With emerging trends in the incidence of cancer of various organ sites, additional approaches are needed to control human malignancies. Intervention or prevention of cancer by dietary constituents, a strategy defined as chemoprevention, holds great promise in our conquest to control cancer, because it can be implemented on a broader population base with less economic burden. Consistent with this, several epidemiological studies have shown that populations that consume diets rich in fruits and vegetables have an overall lower cancer incidence. Based on these encouraging observations, research efforts from across the globe have focused on identifying, characterizing, and providing scientific basis to the efficacy of various phytonutrients in an effort to develop effective strategy to control various human malignancies. Cancer induction, growth, and progression are multi-step events and numerous studies have demonstrated that various dietary agents interfere with these stages of cancer, thus blocking malignancy. Fruits and vegetables represent untapped reservoir of various nutritive and nonnutritive phytochemicals with potential cancer chemopreventive activity. Grapes and grape-based products are one such class of dietary products that have shown cancer chemopreventive potential and are also known to improve overall human health. This review focuses on recent advancements in cancer chemopreventive and anticancer efficacy of grape seed extract and other grape-based products. Overall, completed studies from various scientific groups conclude that both grapes and grape-based products are excellent sources of various anticancer agents and their regular consumption should thus be beneficial to the general population.

  13. Design, synthesis and experimental validation of novel potential chemopreventive agents using random forest and support vector machine binary classifiers.

    Science.gov (United States)

    Sprague, Brienne; Shi, Qian; Kim, Marlene T; Zhang, Liying; Sedykh, Alexander; Ichiishi, Eiichiro; Tokuda, Harukuni; Lee, Kuo-Hsiung; Zhu, Hao

    2014-06-01

    Compared to the current knowledge on cancer chemotherapeutic agents, only limited information is available on the ability of organic compounds, such as drugs and/or natural products, to prevent or delay the onset of cancer. In order to evaluate chemical chemopreventive potentials and design novel chemopreventive agents with low to no toxicity, we developed predictive computational models for chemopreventive agents in this study. First, we curated a database containing over 400 organic compounds with known chemoprevention activities. Based on this database, various random forest and support vector machine binary classifiers were developed. All of the resulting models were validated by cross validation procedures. Then, the validated models were applied to virtually screen a chemical library containing around 23,000 natural products and derivatives. We selected a list of 148 novel chemopreventive compounds based on the consensus prediction of all validated models. We further analyzed the predicted active compounds by their ease of organic synthesis. Finally, 18 compounds were synthesized and experimentally validated for their chemopreventive activity. The experimental validation results paralleled the cross validation results, demonstrating the utility of the developed models. The predictive models developed in this study can be applied to virtually screen other chemical libraries to identify novel lead compounds for the chemoprevention of cancers.

  14. Design, synthesis and experimental validation of novel potential chemopreventive agents using random forest and support vector machine binary classifiers

    Science.gov (United States)

    Sprague, Brienne; Shi, Qian; Kim, Marlene T.; Zhang, Liying; Sedykh, Alexander; Ichiishi, Eiichiro; Tokuda, Harukuni; Lee, Kuo-Hsiung; Zhu, Hao

    2014-06-01

    Compared to the current knowledge on cancer chemotherapeutic agents, only limited information is available on the ability of organic compounds, such as drugs and/or natural products, to prevent or delay the onset of cancer. In order to evaluate chemical chemopreventive potentials and design novel chemopreventive agents with low to no toxicity, we developed predictive computational models for chemopreventive agents in this study. First, we curated a database containing over 400 organic compounds with known chemoprevention activities. Based on this database, various random forest and support vector machine binary classifiers were developed. All of the resulting models were validated by cross validation procedures. Then, the validated models were applied to virtually screen a chemical library containing around 23,000 natural products and derivatives. We selected a list of 148 novel chemopreventive compounds based on the consensus prediction of all validated models. We further analyzed the predicted active compounds by their ease of organic synthesis. Finally, 18 compounds were synthesized and experimentally validated for their chemopreventive activity. The experimental validation results paralleled the cross validation results, demonstrating the utility of the developed models. The predictive models developed in this study can be applied to virtually screen other chemical libraries to identify novel lead compounds for the chemoprevention of cancers.

  15. 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.

  16. Thermodynamic properties of 1-butyl-3-methylpyridinium tetrafluoroborate

    Energy Technology Data Exchange (ETDEWEB)

    Safarov, Javid, E-mail: javid.safarov@uni-rostock.de [Institute of Technical Thermodynamics, University of Rostock, Albert-Einstein-Str. 2, D-18059 Rostock (Germany); Department of Heat and Refrigeration Techniques, Azerbaijan Technical University, H. Javid Avn. 25, AZ1073 Baku (Azerbaijan); Kul, Ismail [Department of Chemistry, Department of Biochemistry, Widener University, One University Place, Chester, PA 19013 (United States); El-Awady, Waleed A. [Department of Heat and Refrigeration Techniques, Azerbaijan Technical University, H. Javid Avn. 25, AZ1073 Baku (Azerbaijan); Mechanical Power Engineering Department, Mansoura Univeristy, Mansoura (Egypt); Shahverdiyev, Astan [Department of Heat and Refrigeration Techniques, Azerbaijan Technical University, H. Javid Avn. 25, AZ1073 Baku (Azerbaijan); Hassel, Egon [Institute of Technical Thermodynamics, University of Rostock, Albert-Einstein-Str. 2, D-18059 Rostock (Germany)

    2011-09-15

    Highlights: > (p, {rho}, T) data of 1-butyl-3-methylpyridinium tetrafluoroborate are estimated. > The measurements were carried out with a vibration-tube densimeter. > The thermomechanical coefficients were calculated. - Abstract: Pressure, density, temperature (p, {rho}, T) data of 1-butyl-3-methylpyridinium tetrafluoroborate [C4mpyr][BF{sub 4}] at T = (283.15 to 393.15) K and pressures up to p = 100 MPa are reported with an estimated experimental relative combined standard uncertainty of {Delta}{rho}/{rho} = {+-}(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, methanol, toluene and aqueous NaCl solutions. An empirical equation of state for fitting of the (p, {rho}, T) data of [C4mpyr][BF{sub 4}] 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.

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

    Science.gov (United States)

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

    2014-05-01

    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. 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). 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. 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.

  18. The chemopreventive action of equol enantiomers in a chemically induced animal model of breast cancer

    Science.gov (United States)

    Brown, Nadine M.; Belles, Carrie A.; Lindley, Stephanie L.; Zimmer-Nechemias, Linda D.; Zhao, Xueheng; Witte, David P.; Kim, Mi-Ok; Setchell, Kenneth D.R.

    2010-01-01

    We describe for the first time the chemopreventive effects of S-(−)equol and R-(+)equol, diastereoisomers with contrasting affinities for estrogen receptors (ERs). S-(−)equol, a ligand for ERβ, is an intestinally derived metabolite formed by many humans and by rodents consuming diets containing soy isoflavones. Whether the well-documented chemopreventive effect of a soy diet could be explained by equol's action was unclear because neither diastereoisomers had been tested in animal models of chemoprevention. Sprague–Dawley rats (n = 40–41 per group) were fed a soy-free AIN-93G diet or an AIN-93G diet supplemented with 250 mg/kg of S-(−)equol or R-(+)equol beginning day 35. On day 50, mammary tumors were induced by dimethylbenz[a]anthracene and thereafter, animals were palpated for number and location of tumors. On day 190, animals were killed and mammary tumors were removed and verified by histology, and the degree of invasiveness and differentiation was determined. S-(−)equol and R-(+)equol plasma concentrations measured on days 35, 100 and 190 by tandem mass spectrometry confirmed diet compliance and no biotransformation of either diastereoisomer. In this model, S-(−)equol had no chemopreventive action, nor was it stimulatory. In contrast, R-(+)equol compared with Controls reduced palpable tumors (P = 0.002), resulted in 43% fewer tumors (P = 0.004), increased tumor latency (88.5 versus 66 days, P = 0.003), and tumors were less invasive but showed no difference in pattern grade or mitosis. Both enantiomers had no effect on absolute uterine weight but caused a significant reduction in body weight gain. In conclusion, the novel finding that the unnatural enantiomer, R-(+)equol, was potently chemopreventive warrants investigation of its potential for breast cancer prevention and treatment. PMID:20110282

  19. 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.

  20. Breast cancer chemopreventive and chemotherapeutic effects of Camellia Sinensis (green tea): an updated review.

    Science.gov (United States)

    Rafieian-Kopaei, Mahmoud; Movahedi, Mino

    2017-02-01

    Camellia sinensis belongs to the plant family of Theaceae, native to East Asia, the Indian Subcontinent and Southeast Asia, but naturalized in many parts of the world. The aim of this study was to overview its anti-breast cancer chemopreventive and chemotherapeutic effects. This review article is aimed to overview breast cancer chemopreventive and chemotherapeutic effects of Camellia sinensis (green tea). This review article was carried out by searching studies in PubMed, Medline, Web of Science, and IranMedex databases. The initial search strategy identified around 108 references. In this study, 68 studies were accepted for further screening, and met all our inclusion criteria [in English, full text, chemopreventive and chemotherapeutic effects of Camellia sinensis and dated mainly from the year 1999 to 2016. The search terms were Camellia sinensis, chemopreventive, chemotherapeutic properties, pharmacological effects. The result of this study suggested that the catechin available in Camellia sinensis has properties which can prevent and treat breast cancer. It has also been shown to inhibit proliferation of breast cancer cells and to block carcinogenesis. It was found that increased Camellia sinensis consumption may lower the risk of breast cancer. Camellia sinensis intake was shown to reduce the risk of breast cancer incidence. In addition, potential breast cancer chemopreventive effect of Camellia sinensis both in vivo and in vitro was highly confirmed. However, the evidence of low effect and no effect was observed. More clinical trial studies are needed to prove its anti-breast cancer activity decisively. Camellia sinensis is broadly utilized as a part of customary medication since antiquated time because of its cost adequacy, and fewer reaction properties. The studies demonstrated anti-breast cancer activity of Camellia sinensis and its component by adjusting cell signaling pathways such as angiogenesis, apoptosis, and transcription factor. Furthermore

  1. 40 CFR 721.6920 - Butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Butyl acrylate, polymer with... acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane. (a... butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane...

  2. and triorganotin(IV) complexes of 2-tert-butyl-4-methyl phenol

    Indian Academy of Sciences (India)

    TECS

    of organotin(IV) complexes of phenols are found in literature. 13–17 .... method suggested them to exist as monomers. 3.1 IR spectra. In the IR .... Tert-butyl. Phenolic butyl substituent. Phenolic ring carbon. Phenolic ring substituent Methyl. 119. Sn. Compound group protons protons protons R–Sn –CH3. –C o, m and p Cipso.

  3. 75 FR 44184 - Aluminum tris(O-ethylphosphonate), Butylate, Chlorethoxyfos, Clethodim, et al.; Proposed...

    Science.gov (United States)

    2010-07-28

    ... AGENCY 40 CFR Part 180 Aluminum tris(O-ethylphosphonate), Butylate, Chlorethoxyfos, Clethodim, et al...-ethylphosphonate) and fenarimol; the herbicides butylate, clethodim, clomazone, fenoxaprop-ethyl, flumetsulam...(O- ethylphosphonate), clethodim, flumetsulam, and fluridone. In addition, EPA will be removing...

  4. 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.

  5. Impact of di-n-butyl phthalate on reproductive system development in European pikeperch (Sander lucioperca

    Directory of Open Access Journals (Sweden)

    Sylwia Jarmołowicz

    2013-01-01

    Full Text Available Phthalic acid, di-n-butyl ester known as di-n-butyl phthalate, is an organic chemical compound that belongs to the group of endocrine disruptor compounds that have a documented negative impact on mammalian endocrine systems. Di-n-butyl phthalate is used widely as a plasticizer in the manufacture of artificial materials, which is why it is found in all types of environmental samples including those from water basins. The aim of the study was to describe the impact of di-n-butyl phthalate on the development of the reproductive system of European pikeperch (Sander lucioperca during the sex differentiation period (age 61–96 days post hatch. A total of 240 fish were divided into 6 groups (40 fish per tank. Treatments consisted of a control group (0 g di-n-butyl phthalate·kg-1 feed and five trial groups with 0.125, 0.25, 0.5, 1, and 2 g di-n-butyl phthalate·kg-1 feed, respectively. Histological changes of the fish gonads, sex ratio, survival and growth of fish were evaluated. Di-n-butyl phthalate seriously disturbed sex differentiation process of pikeperch. Histopathological analyses revealed that the administration of 2 g di-n-butyl phthalate·kg-1 significantly affected the sex ratio. The feminization process (intersex gonads at concentrations of 1 g and 2 g di-n-butyl phthalate·kg-1 were observed. All analyzed concentrations delayed testicular development. Phthalate did not have a significant impact on the survival or growth rates of the pikeperch. This is the first report of disruption sex differentiation processes in fish by di-n-butyl phthalate.

  6. A Chemopreventive Trial to Study the Effects of High Tea Consumption on Smoking-Related Oxidative Stress

    National Research Council Canada - National Science Library

    Hakim, Iman A

    2006-01-01

    .... We are conducting a 6-month randomized, controlled, double-blinded chemopreventive trial in a group of COPD subjects who are being randomized to green or black tea preparations or a control intervention (matching placebo...

  7. A Chemoprevention Trial to Study the Effects of High Tea Consumption on Smoking-Related Oxidative Stress

    National Research Council Canada - National Science Library

    Hakim, Iman A

    2005-01-01

    .... We are conducting a 6-month randomized, controlled, double-blinded chemopreventive trial in a group of COPD subjects who are being randomized to green or black tea preparations or a control intervention (matching placebo...

  8. A Chemoprevention Trial to Study the Effects of High Tea Consumption on Smoking-Related Oxidative Stress

    National Research Council Canada - National Science Library

    Hakim, Iman A

    2008-01-01

    .... We are conducting a 6-month randomized controlled double-blinded chemopreventive trial in a group of COPD subjects who are being randomized to green or black tea preparations or a control intervention (matching placebo...

  9. A Chemopreventive Trial to Study the Effects of High Tea Consumption on Smoking-Related Oxidative Stress

    National Research Council Canada - National Science Library

    Hakim, Iman

    2004-01-01

    .... We are conducting a 6-month randomized, controlled, double-blinded chemopreventive trial in a group of COPD subjects who are being randomized to green or black tea preparations or a control intervention (matching placebo...

  10. Lung-cancer chemoprevention by induction of synthetic lethality in mutant KRAS premalignant cells in vitro and in vivo

    National Research Council Canada - National Science Library

    Huang, Shaoyi; Ren, Xiaoyang; Wang, Lai; Zhang, Ling; Wu, Xiangwei

    2011-01-01

    .... These data underscore the great need for effective chemoprevention of this cancer. Mutations and activation of KRAS occur frequently in, and are thought to be a primary driver of the development of, non-small cell lung cancers (NSCLC...

  11. A study of butyl acetate synthesis. 4-reaction kinetics

    Directory of Open Access Journals (Sweden)

    Álvaro Orjuela Londoño

    2006-05-01

    Full Text Available This work was aimed at studying liquid-phase acetic acid and butyl alcohol esterification reaction (P atm =0.76 Bar,using an ion exchange resin (Lewatit K-2431 as catalyst. The effect of the absence of internal and external mass transport on catalyst particles was established in the research conditions used here. A set of assays to determine the effect of catalyst load (0.5%, 1%, 2% w/w temperature (73°C, 80°C, 87°C and molar ratio (1:2, 1:1, 2:1 acid/alcohol on reaction rate was carried out and both LHHW and pseudo-homogeneous kinetic expressions were obtained, these being in good agreement with the experimental data.

  12. 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.

  13. Hydrolysis of tert-butyl formate: Kinetics, products, and implications for the environmental impact of methyl tert-butyl ether

    Science.gov (United States)

    Church, Clinton D.; Pankow, James F.; Tratnyek, Paul G.

    1999-01-01

    Asessing the environmental fate of methyl tert-butyl ether (MTBE) has become a subject of renewed interest because of the large quantities of this compound that are being used as an oxygenated additive in gasoline. Various studies on the fate of MTBE have shown that it can be degraded to tert-butyl formate (TBF), particularly in the atmosphere. Although it is generally recognized that TBF is subject to hydrolysis, the kinetics and products of this reaction under environmentally relevant conditions have not been described previously. In this study, we determined the kinetics of TBF hydrolysis as a function of pH and temperature. Over the pH range of 5 to 7, the neutral hydrolysis pathway predominates, with kN = (1.0 ± 0.2) × 10−6/s. Outside this range, strong pH effects were observed because of acidic and basic hydrolyses, from which we determined that kA = (2.7 ± 0.5) × 10−3/(M·s) and kB = 1.7 ± 0.3/(M·s). Buffered and unbuffered systems gave the same hydrolysis rates for a given pH, indicating that buffer catalysis was not significant under the conditions tested. The activation energies corresponding to kN, kA, and kBwere determined to be 78 ± 5, 59 ± 4, and 88 ±11 kJ/mol, respectively. In all experiments, tert-butyl alcohol was found at concentrations corresponding to stoichiometric formation from TBF. Based on our kinetics data, the expected half-life for hydrolysis of TBF at pH = 2 and 4°C (as per some standard preservation protocols for water sampling) is 6 h. At neutral pH and 22°C, the estimated half-life is 5 d, and at pH = 11 and 22°C, the value is only 8 min.

  14. Prostate cancer chemoprevention in men of African descent: current state of the art and opportunities for future research.

    Science.gov (United States)

    Chornokur, Ganna; Kumar, Nagi B

    2013-08-01

    Prostate cancer is the most frequently diagnosed malignancy in men. However, African American/Black men are 60 % more likely to be diagnosed with and 2.4 times more likely to die from prostate cancer, compared to Non-Hispanic White men. Despite the increased burden of this malignancy, no evidence-based recommendation regarding prostate cancer screening exists for the high-risk population. Moreover, in addition to screening and detection, African American men may constitute a prime population for chemoprevention. Early detection and chemoprevention may thus represent an integral part of prostate cancer control in this population. Importantly, recent research has elucidated biological differences in the prostate tumors of African American compared to European American men. The latter may enable a more favorable response in African American men to specific chemopreventive agents that target relevant signal transduction pathways. Based on this evolving evidence, the aims of this review are threefold. First, we aim to summarize the biological differences that were reported in the prostate tumors of African American and European American men. Second, we will review the single- and multi-target chemopreventive agents placing specific emphasis on the pathways implicated in prostate carcinogenesis. And lastly, we will discuss the most promising nutraceutical chemopreventive compounds. Our review underscores the promise of chemoprevention in prostate cancer control, as well as provides justification for further investment in this filed to ultimately reduce prostate cancer morbidity and mortality in this high-risk population of African American men.

  15. Beyond COX-1: the effects of aspirin on platelet biology and potential mechanisms of chemoprevention.

    Science.gov (United States)

    Ornelas, Argentina; Zacharias-Millward, Niki; Menter, David G; Davis, Jennifer S; Lichtenberger, Lenard; Hawke, David; Hawk, Ernest; Vilar, Eduardo; Bhattacharya, Pratip; Millward, Steven

    2017-07-31

    After more than a century, aspirin remains one of the most commonly used drugs in western medicine. Although mainly used for its anti-thrombotic, anti-pyretic, and analgesic properties, a multitude of clinical studies have provided convincing evidence that regular, low-dose aspirin use dramatically lowers the risk of cancer. These observations coincide with recent studies showing a functional relationship between platelets and tumors, suggesting that aspirin's chemopreventive properties may result, in part, from direct modulation of platelet biology and biochemistry. Here, we present a review of the biochemistry and pharmacology of aspirin with particular emphasis on its cyclooxygenase-dependent and cyclooxygenase-independent effects in platelets. We also correlate the results of proteomic-based studies of aspirin acetylation in eukaryotic cells with recent developments in platelet proteomics to identify non-cyclooxygenase targets of aspirin-mediated acetylation in platelets that may play a role in its chemopreventive mechanism.

  16. 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.

  17. Estrogen- and stress-induced DNA damage in breast cancer and chemoprevention with dietary flavonoid.

    Science.gov (United States)

    Yasuda, Michiko T; Sakakibara, Hiroyuki; Shimoi, Kayoko

    2017-01-01

    Breast cancer is one of the most commonly diagnosed female cancers and a leading cause of cancer-related death in women. Multiple factors are responsible for breast cancer and heritable factors have received much attention. DNA damage in breast cancer is induced by prolonged exposure to estrogens, such as 17β-estradiol, daily social/psychological stressors, and environmental chemicals such as polycyclic aromatic hydrocarbons (PAHs) and heterocyclic amines (HCAs). DNA damage induced by estrogen and stress is an important factor in the pathogenesis and development of breast cancer and is now recognized as a critical provision for chemoprevention of breast cancer. In this review, we summarize the relationships between estrogen- and stress-induced DNA damage with regard to the pathogenesis and development of breast cancer. We also discuss recent investigations into chemoprevention using dietary flavonoids such as quercetin and isoflavones.

  18. Characterization of vitamin-cisplatin-loaded chitosan nano-particles for chemoprevention and cancer fatigue.

    Science.gov (United States)

    Othayoth, Rajath; Mathi, Pardhasaradhi; Bheemanapally, Khaggeswar; Kakarla, Lavanya; Botlagunta, Mahendran

    2015-01-01

    Vitamins have been shown to reduce chemotherapy-related fatigue (CRF) by conserving energy loss both during and after cancer treatment. However, it remains unknown whether this reduction of fatigue interferes with the cancer drugs or alters the effectiveness of these agents. The objective was to synthesize vitamin-cisplatin-loaded chitosan nano-particles for chemoprevention and cancer fatigue. Multi-vitamin (C, D3, and B12)-cisplatin composite nano-formulation called NanoCisVital (NCV) to overcome CRF. The interactions between vitamins and NCV were characterized using scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, and a particle size analyser. The chemo-preventive activity was performed by in vitro bio assays. SEM analysis showed spherical shape and the size is cancer properties of cisplatin.

  19. Dietary phytochemicals and cancer chemoprevention: a review of the clinical evidence.

    Science.gov (United States)

    Kotecha, Ritesh; Takami, Akiyoshi; Espinoza, J Luis

    2016-08-09

    Cancer chemoprevention involves the use of different natural or biologic agents to inhibit or reverse tumor growth. Epidemiological and pre-clinical data suggest that various natural phytochemicals and dietary compounds possess chemopreventive properties, and in-vitro and animal studies support that these compounds may modulate signaling pathways involved in cell proliferation and apoptosis in transformed cells, enhance the host immune system and sensitize malignant cells to cytotoxic agents. Despite promising results from experimental studies, only a limited number of these compounds have been tested in clinical trials and have shown variable results. In this review, we summarize the data regarding select phytochemicals including curcumin, resveratrol, lycopene, folates and tea polyphenols with emphasis on the clinical evidence supporting the efficacy of these compounds in high-risk populations.

  20. Copaifera multijuga oleoresin and its constituent diterpene (-)-copalic acid: Genotoxicity and chemoprevention study.

    Science.gov (United States)

    Alves, Jacqueline M; Senedese, Juliana M; Leandro, Luís F; Castro, Pâmela T; Pereira, Daiane E; Carneiro, Luiza J; Ambrósio, Sérgio R; Bastos, Jairo K; Tavares, Denise C

    2017-07-01

    Copaiba oleoresins are used in alternative medicine as anti-inflammatory, antitumoral, and antimicrobial treatments. (-)-Copalic acid (CA) is the major diterpene found in exudates from Copaifera species. We have examined the genotoxicity and the chemopreventive potential of Copaifera multijuga oleoresin (CM) and CA. Genotoxicity assessment was examined with the peripheral blood micronucleus test and the comet assay (male Swiss mouse hepatocytes). In the chemoprevention study, we evaluated the effects of CM and CA on the formation of 1,2-dimethylhydrazine (DMH)-induced aberrant crypt foci (ACF) in male Wistar rat colon. Neither agent caused a significant increase in micronucleus frequency relative to controls, but the highest CM dose tested (400mg/kg b.w.) caused DNA damage in the comet assay. Both agents significantly reduced the frequency of DMH-induced ACF. Both CM and CA suppressed ACF formation and may have a protective effect against colon carcinogenesis. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. 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)

  2. Thyroid disruption by Di-n-butyl phthalate (DBP and mono-n-butyl phthalate (MBP in Xenopus laevis.

    Directory of Open Access Journals (Sweden)

    Ouxi Shen

    Full Text Available BACKGROUND: Di-n-butyl phthalate (DBP, a chemical widely used in many consumer products, is estrogenic and capable of producing seriously reproductive and developmental effects in laboratory animals. However, recent in vitro studies have shown that DBP and mono-n-butyl phthalate (MBP, the major metabolite of DBP, possessed thyroid hormone receptor (TR antagonist activity. It is therefore important to consider DBP and MBP that may interfere with thyroid hormone system. METHODOLOGY/PRINCIPAL FINDINGS: Nieuwkoop and Faber stage 51 Xenopus laevis were exposed to DBP and MBP (2, 10 or 15 mg/L separately for 21 days. The two test chemicals decelerated spontaneous metamorphosis in X. laevis at concentrations of 10 and 15 mg/L. Moreover, MBP seemed to possess stronger activity. The effects of DBP and MBP on inducing changes of expression of selected thyroid hormone response genes: thyroid hormone receptor-beta (TRβ, retinoid X receptor gamma (RXRγ, alpha and beta subunits of thyroid-stimulating hormone (TSHα and TSHβ were detected by qPCR at all concentrations of the compounds. Using mammalian two-hybrid assay in vitro, we found that DBP and MBP enhanced the interactions between co-repressor SMRT (silencing mediator for retinoid and thyroid hormone receptors and TR in a dose-dependent manner, and MBP displayed more markedly. In addition, MBP at low concentrations (2 and 10 mg/L caused aberrant methylation of TRβ in head tissue. CONCLUSIONS: The current findings highlight potential disruption of thyroid signalling by DBP and MBP and provide data for human risk assessment.

  3. Dietary pterostilbene is a novel MTA1-targeted chemopreventive and therapeutic agent in prostate cancer

    OpenAIRE

    Dhar, Swati; Kumar, Avinash; Zhang, Liangfen; Rimando, Agnes M.; Lage, Janice M.; Lewin, Jack R.; Atfi, Azeddine; Zhang, Xu; Levenson, Anait S.

    2016-01-01

    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- targeted chemopreventive and therapeutic efficacy of pterostilbene, a natural potent analog of resveratrol, in pre-clinical models of prostate cancer. Here, we show that high levels of MTA1 expression in Pten-loss prostate cooperate with key oncogenes, including c-Myc and Akt among others, to promote prostate can...

  4. Pomegranate-mediated chemoprevention of experimental hepatocarcinogenesis involves Nrf2-regulated antioxidant mechanisms

    Science.gov (United States)

    Bishayee, Anupam; Bhatia, Deepak; Thoppil, Roslin J.; Darvesh, Altaf S.; Nevo, Eviatar; Lansky, Ephraim P.

    2011-01-01

    Hepatocellular carcinoma (HCC), one of the most prevalent and lethal cancers, has shown an alarming rise in the USA. Without effective therapy for HCC, novel chemopreventive strategies may effectively circumvent the current morbidity and mortality. Oxidative stress predisposes to hepatocarcinogenesis and is the major driving force of HCC. Pomegranate, an ancient fruit, is gaining tremendous attention due to its powerful antioxidant properties. Here, we examined mechanism-based chemopreventive potential of a pomegranate emulsion (PE) against dietary carcinogen diethylnitrosamine (DENA)-induced rat hepatocarcinogenesis that mimics human HCC. PE treatment (1 or 10 g/kg), started 4 weeks prior to the DENA challenge and continued for 18 weeks thereafter, showed striking chemopreventive activity demonstrated by reduced incidence, number, multiplicity, size and volume of hepatic nodules, precursors of HCC. Both doses of PE significantly attenuated the number and area of γ-glutamyl transpeptidase-positive hepatic foci compared with the DENA control. PE also attenuated DENA-induced hepatic lipid peroxidation and protein oxidation. Mechanistic studies revealed that PE elevated gene expression of an array of hepatic antioxidant and carcinogen detoxifying enzymes in DENA-exposed animals. PE elevated protein and messenger RNA expression of the hepatic nuclear factor E2-related factor 2 (Nrf2). Our results provide substantial evidence, for the first time, that pomegranate constituents afford chemoprevention of hepatocarcinogenesis possibly through potent antioxidant activity achieved by upregulation of several housekeeping genes under the control of Nrf2 without toxicity. The outcome of this study strongly supports the development of pomegranate-derived products in the prevention and treatment of human HCC, which remains a devastating disease. PMID:21389260

  5. Biochemical and molecular mechanisms underlying the chemopreventive efficacy of rosmarinic acid in a rat colon cancer.

    Science.gov (United States)

    Venkatachalam, Karthikkumar; Gunasekaran, Sivagami; Namasivayam, Nalini

    2016-11-15

    To shed light on colon cancer chemoprevention, natural phytochemicals attract researchers by virtue of their beneficial biological effects. The chemopreventive potential of rosmarinic acid (RA) was tested by using the colon carcinogen, 1,2-dimethylhydrazine (DMH) by evaluating the Aberrant crypt foci (ACF), tumour incidence, lipid peroxidative byproducts, phase I & II drug metabolizing enzymes, cell proliferative and apoptotic proteins. Rats were divided into six groups and received modified pellet diet. Group 1 served as control rats, group 2 rats received RA (5mg/kg b.w. p.o.), rats in groups 3-6 received DMH (20mg/kg b.w., s.c.) for the first fifteen weeks. In addition to DMH, groups 4-6 received RA at the dose of 5mg/kg b.w. during initiation, post initiation stages and also for the entire study period. DMH treated rats showed an increase in the development of ACF, tumour formation and multiplicity and decrease in lipid peroxidative byproducts. Moreover, it modulates xenobiotic enzymes and reduces the expressions of proapoptotic proteins; increases expressions of anti apoptotic proteins at the end of the study. Supplementation with RA to carcinogen treated rats protected them from the above deleterious effects caused by DMH and thus RA may be used as a potent chemopreventive agent. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Chemoprevention of Colorectal Cancer by Artocarpin, a Dietary Phytochemical from Artocarpus heterophyllus.

    Science.gov (United States)

    Sun, Guochuan; Zheng, Zongping; Lee, Mee-Hyun; Xu, Yijuan; Kang, Soouk; Dong, Zigang; Wang, Mingfu; Gu, Zhennan; Li, Haitao; Chen, Wei

    2017-05-03

    Artocarpus heterophyllus is an evergreen tree distributed in tropical regions, and its fruit (jackfruit) is well-known as the world's largest tree-borne fruit. Although A. heterophyllus has been widely used in folk medicines against inflammation, its potential in cancer chemoprevention remains unclear. Herein we identified artocarpin from A. heterophyllus as a promising colorectal cancer chemopreventive agent by targeting Akt kinase. Phenotypically, artocarpin exhibited selective cytotoxicity against human colon cancer cells. Artocarpin impaired the anchorage-independent growth capability, suppressed colon cancer cell growth, and induced a G1 phase cell cycle arrest which was followed by apoptotic as well as autophagic cell death. Mechanistic studies revealed that artocarpin directly targeted Akt 1 and 2 kinase activity evidenced by in vitro kinase assay, ex vivo binding assay as well as Akt downstream cellular signal transduction. Importantly, oral administration of artocarpin attenuated colitis-associated colorectal tumorigenesis in mice. Taken together, artocarpin, a bioactive component of A. heterophyllus, might merit investigation as a potential colorectal cancer chemopreventive agent.

  7. Breast cancer chemopreventive properties of pomegranate (Punica granatum) fruit extracts in a mouse mammary organ culture.

    Science.gov (United States)

    Mehta, R; Lansky, E P

    2004-08-01

    We previously reported anticancer effects of pomegranate extracts in human breast cancer cells in vitro and also chemopreventive activity of pomegranate fermented juice polyphenols (W) in a mouse mammary organ culture (MMOC). In the present study we decided to expand the MMOC investigations to also include an evaluation of the potential chemopreventive efficacy of a purified chromatographic peak of W (Peak B), and also of whole pomegranate seed oil. In brief, an MMOC was established according to a known method. For the first 10 days of culture, the glands were treated with pomegranate fermented juice polyphenols (W), a high-performance liquid chromatographic (HPLC) peak separated from W (peak B), or pomegranate seed oil (Oil, and on day 3, exposed to the carcinogen 7,12-dimethylbenz[a]anthracene (DMBA), and for 10 days treated with the putative pomegranate chemopreventive. The glands were subsequently harvested and tumours counted by visual inspection. While W effected a 42% reduction in the number of lesions compared with control, peak B and pomegranate seed oil each effected an 87% reduction. The results highlight enhanced breast cancer preventive potential both for the purified compound peak B and for pomegranate seed oil, both greater than that previously reported for pomegranate fermented juice polyphenols.

  8. The chemopreventive activity of apple against carcinogenesis: antioxidant activity and cell cycle control.

    Science.gov (United States)

    Ribeiro, Flávia A P; Gomes de Moura, Carolina F; Aguiar, Odair; de Oliveira, Flavia; Spadari, Regina C; Oliveira, Nara R C; Oshima, Celina T F; Ribeiro, Daniel A

    2014-09-01

    Apples and their derivatives are rich in phytochemicals, including flavonoids (catechins, flavonols, quercetin) and phenolic acids (quercetin glycosides, catechin, epicatechin, procyanidins), vitamins, and fibers, that confer an important antioxidant property. Chemoprevention is defined by the use of natural or synthetic agents to interfere with the progression, reverse, or inhibit carcinogenesis, thereby reducing the risk of developing clinically invasive disease. The aim of this article is to present data generated from the use of apples as a chemopreventive agent in carcinogenesis using in-vivo and in-vitro test systems. Apple and its bioactive compounds can exert chemopreventive properties as a result of antioxidant activity and cell cycle control. However, future focus of research on apple such as identifying the specific phytochemical responsible for the anticarcinogenic effect, timing of consumption, and adequate amount of apples to achieve the best preventive effect using human large randomized-controlled trials is needed. Furthermore, animal studies are also relevant for better understanding the role of this fruit in human health as well as modulation of degenerative diseases such as cancer. Therefore, this area warrants further investigation as a new way of thinking, which would apply not only to apples but also to other fruit used as promising therapeutic agents against human diseases.

  9. Xanthones from Mangosteen Extracts as Natural Chemopreventive Agents: Potential Anticancer Drugs

    Science.gov (United States)

    Shan, T.; Ma, Q.; Guo, K.; Liu, J.; Li, W.; Wang, F.; Wu, E.

    2011-01-01

    Despite decades of research, the treatment and management of malignant tumors still remain a formidable challenge for public health. New strategies for cancer treatment are being developed, and one of the most promising treatment strategies involves the application of chemopreventive agents. The search for novel and effective cancer chemopreventive agents has led to the identification of various naturally occurring compounds. Xanthones, from the pericarp, whole fruit, heartwood, and leaf of mangosteen (Garcinia mangostana Linn., GML), are known to possess a wide spectrum of pharmacologic properties, including anti-oxidant, anti-tumor, anti-allergic, anti-inflammatory, anti-bacterial, anti-fungal, and anti-viral activities. The potential chemopreventive and chemotherapeutic activities of xanthones have been demonstrated in different stages of carcinogenesis (initiation, promotion, and progression) and are known to control cell division and growth, apoptosis, inflammation, and metastasis. Multiple lines of evidence from numerous in vitro and in vivo studies have confirmed that xanthones inhibit proliferation of a wide range of human tumor cell types by modulating various targets and signaling transduction pathways. Here we provide a concise and comprehensive review of preclinical data and assess the observed anticancer effects of xanthones, supporting its remarkable potential as an anticancer agent. PMID:21902651

  10. Clove (Syzygium aromaticum L.), a potential chemopreventive agent for lung cancer.

    Science.gov (United States)

    Banerjee, Sarmistha; Panda, Chinmay Kr; Das, Sukta

    2006-08-01

    Spices and flavoring plants part rich in supposedly health-promoting phytochemicals are currently receiving much attention as a possible source of cancer chemopreventive compounds. Clove, the sun-dried unopened flower bud from the plant Syzygium aromaticum L. is a commonly used spice and food flavor. In the present work we assess the chemopreventive potential of aqueous infusion of clove during benzo[a]pyrene (BP)-induced lung carcinogenesis in strain A mice. Incidence of hyperplasia, dysplasia and carcinoma in situ evident in the carcinogen control group on the 8th, 17th and 26th weeks, respectively, were effectively reduced after treatment with clove infusion. Significant reduction in the number of proliferating cells and an increased number of apoptotic cells was also noted in these BP-induced lung lesions following clove treatment. Western blotting analysis revealed that clove infusion upregulates the expression of pro-apoptotic proteins p53 and Bax, and downregulates the expression of anti-apoptotic protein Bcl-2 in the precancerous stages. Expression of caspase 3 and its activation by clove infusion were evident from a very early stage of carcinogenesis (eighth week). Clove infusion was also found to downregulate the expression of some growth-promoting proteins, viz, COX-2, cMyc, Hras. The observations signify the chemopreventive potential of clove in view of its apoptogenic and anti-proliferative properties.

  11. Endoscopic Injection of a Ruptured Duodenal Varix with N-butyl-2-cyanoacrylate

    Directory of Open Access Journals (Sweden)

    Paulo Salgueiro

    2014-04-01

    Conclusions: The presented case supports endoscopic injection sclerotherapy with N-butyl-2-cyanoacrylate as a treatment option for ruptured duodenal varices that, despite being a rare event, when it occurs, is often fatal.

  12. 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.

  13. The reclaiming of butyl rubber and in-situ compatibilization of thermoplastic elastomer by power ultrasound

    Science.gov (United States)

    Feng, Wenlai

    This is a study of the continuous ultrasound aided extrusion process for the in-situ compatibilization of isotactic polypropylene (iPP)/ethylene-propylene diene rubber (EPDM) thermoplastic elastomer (TPE) using a newly developed ultrasonic treatment reactor. The rheological, mechanical properties and morphology of the TPE with and without ultrasonic treatment were studied. In-situ compatibilization in the ultrasonically treated blends was observed as evident by their more stable morphology after annealing, improved mechanical properties and IR spectra. The obtained results indicated that ultrasonic treatment induced the thermo-mechanical degradations and led to the possibility of enhanced molecular transport and chemical reactions at the interfaces. Processing conditions were established for enhanced in situ compatibilization of the PP/EPDM TPE. The ultrasonic treatments of butyl rubber gum and ultrasonic devulcanization of butyl rubber, tire-curing bladder during extrusion using a grooved barrel ultrasonic reactor were carried out. The ultrasonic treatment of gum caused degradation of the polymer main chain leading to lower molecular weight, broader molecular weight distribution, less unsaturation and changes in physical properties. The devulcanization of butyl rubber was successfully accomplished only at severe conditions of ultrasonic treatment. The mechanical properties of vulcanizates prepared from devulcanized butyl rubber are comparable to that of the virgin vulcanizate. The molecular characterization of sol fraction of devulcanized butyl rubber showed the devulcanization and degradation of butyl rubber occurred simultaneously. 1H NMR transverse relaxation was also used to study butyl rubber gum before and after ultrasonic treatment, and ultrasonically devulcanized unfilled butyl rubber. The T2 relaxation decays were successfully described using a two-component model. The recyclability of tire-curing bladder was also investigated. Gel fraction, crosslink

  14. Control Measures of Sprangletop (Leptochloa chinensis) Resistant Biotype using Propanil Quinclorac and Cyhalofop-butyl

    National Research Council Canada - National Science Library

    M. Motior Rahman; M. Aminul Islam; M. Sofian-Azirun; N.B. Amru; S. Ismail

    2014-01-01

    ...) sprangletop biotype (Kedah-SB8) but finally regain and exhilarate by use of propanil quinclorac and cyhalofop-butyl at eight-folds the recommended field use rates. The effective dose of propanil cyhalofop-butyl and quinclorac to inhibit plant growth by 50% (ED50) was 0.58 g m-2 0.05 g m-2 and 0.09 g m-2 for the R biotype while forthat of the susceptible (S) b...

  15. 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.

  16. 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.

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

    Science.gov (United States)

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

    2013-08-01

    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. A total of 160 SKH-1 mice were randomized to one placebo group and four chemoprevention groups (diclofenac plus difluoromethylornithine; diclofenac plus calcipotriol; difluoromethylornithine plus calcitriol; and diclofenac plus difluoromethylornithine plus calcipotriol). The mice received UVB radiation for 20 weeks followed by 17 weeks with topical application of chemoprevention. The number of mice with tumors, number of tumors per group and tumor area size were compared using a linear regression model. Chemoprevention with diclonefac plus calcipotriol and diclonefac plus difluoromethylornithine had a significant inhibiting effect on the number of tumors per group and the area of tumors. Moreover, diclonefac plus difluoromethylornithine had a significant inhibiting effect on the number of mice with tumors. Potentially, non-melanoma skin cancer in humans may be prevented with these agents with few adverse effects. Therefore, clinical studies are needed to determine their therapeutic/preventive effect and possible adverse effects.

  18. Pharmacogenetics, pharmacogenomics and epigenetics of Nrf2-regulated xenobiotic-metabolizing enzymes and transporters by dietary phytochemical and cancer chemoprevention.

    Science.gov (United States)

    Wu, Tien-Yuan; Khor, Tin Oo; Lee, Jong Hun; Cheung, Ka Lung; Shu, Limin; Chen, Chi; Kong, Ah-Ng

    2013-07-01

    Cancer chemopreventive activities of various phytochemicals have been attributed to the modulation of xenobiotic disposition, which includes absorption, distribution, metabolism, and excretion. The interaction between xenobiotics and xenobiotic-metabolizing enzymes (XMEs) is bidirectional. XMEs are responsible for the biotransformation of xenobiotics such as bioactivation and detoxification. Conversely, xenobiotics affect XMEs through transcriptional regulation (induction or suppression) and post-translational interactions (inhibition or activation). Similar relationships also exist between xenobiotics and their transporters. Studies conducted over the past decade have demonstrated that the transcription factor, nuclear factor erythroid 2-related factor 2 (Nrf2), plays a critical role in the regulation of detoxifying enzymes and transporters through a signaling system that senses and responds to redox imbalance. The role of Nrf2 in the interaction between chemopreventive phytochemicals and detoxifying enzymes/transporters has become an important topic in cancer chemoprevention. In this review, the genetic and epigenetic factors that contribute to Nrf2-mediated regulation of detoxifying XMEs and transporters are discussed in the context of cancer chemoprevention. Phytochemicals may modulate the genome as well as epigenome, altering the regulation of XMEs and transporters, which may be critical for both cancer chemoprevention and the prevention of other oxidative stress- and inflammatory-related diseases, including cardiovascular, metabolic and neurological pathologies. The pharmacogenomic expression of XMEs and transporters, with an emphasis on both genomics and epigenetics, will also be discussed.

  19. Bioactivation of chemopreventive selenocysteine Se-conjugates and related amino acids by amino acid oxidases novel route of metabolism of selenoamino acids

    NARCIS (Netherlands)

    Rooseboom, M.; Vermeulen, N.P.E.; van Hemert, N.; Commandeur, J.N.M.

    2001-01-01

    Several selenocysteine Se-conjugates have been shown to possess potent chemopreventive activity in animal models for chemical carcinogenesis. As a mechanism of action, β-elimination reactions to form chemopreventive selenols, ammonia, and pyruvate has been proposed. The enzymes involved in these

  20. Bioactivation of chemopreventive selenocysteine Se-conjugates and related amino acids by amino acid oxidases novel route of metabolism of selenoamino acids

    NARCIS (Netherlands)

    Rooseboom, M; Vermeulen, N P; van Hemert, N.; Commandeur, J N

    Several selenocysteine Se-conjugates have been shown to possess potent chemopreventive activity in animal models for chemical carcinogenesis. As a mechanism of action, beta-elimination reactions to form chemopreventive selenols, ammonia, and pyruvate has been proposed. The enzymes involved in these

  1. 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.

  2. Benzene and cyclohexane separation using 1-butyl-3-methylimidazolium thiocyanate

    Science.gov (United States)

    Gonfa, Girma; Ismail, Marhaina; Bustam, Mohamad Azmi

    2017-09-01

    Cyclohexane is mainly produced by catalytic hydrogenation of benzene. Removal of unreacted benzene from the product stream is very important in this process. However, due to their close boiling points and azeotrope formation, it is very difficult to separate cyclohexane and benzene by conventional distillation. Currently, special separation processes such as processes extractive distillation is commercially used for this separation. However, this extractive distillation suffers from process complexity and higher energy consumption due to their low extractive selectivity of molecular entrainers used. The aim of the present work is to investigate the applicability of ionic liquids as entrainer in extractive distillation of benzene and cyclohexane mixture. In this study, we investigated 1-butyl-3-methylimidazolium thiocyanate ([BMIM][SCN]) ionic liquid for separation of benzene and cyclohexane by measuring the Vapor Liquid Equilibrium data of the two components in the presence of the ionic liquid. As green and potential environmentally friendly solvents, ionic liquids have attracted increasing attention as alternative conventional entrainers in extractive distillation. Isothermal Vapor Liquid Equilibrium for the benzene + cyclohexane + [BMIM][SCN] ternary system was obtained at 353.15 K using a Head Space Gas Chromatography. The addition of [BMIM][SCN] breaks the benzene-cyclohexane azeotrope and increased the relative volatility cyclohexane to benzene in the mixture. The effect of [BMIM][SCN] on the relative volatility cyclohexane to benzene was studied at various benzene and cyclohexane compositions and solvent to feed ratios. The performance of [BMIM][SCN] was compared with typical conventional solvents, dimethylformamide (DMF) and dimethylsulfoxide (DMSO). The results show that the relative volatility of cyclohexane to benzene in the presence of [BMIM][SCN] is higher compared that of DMSO and DMF.

  3. 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.

  4. Dietary Sulforaphane in Cancer Chemoprevention: The Role of Epigenetic Regulation and HDAC Inhibition.

    Science.gov (United States)

    Tortorella, Stephanie M; Royce, Simon G; Licciardi, Paul V; Karagiannis, Tom C

    2015-06-01

    Sulforaphane, produced by the hydrolytic conversion of glucoraphanin after ingestion of cruciferous vegetables, particularly broccoli and broccoli sprouts, has been extensively studied due to its apparent health-promoting properties in disease and limited toxicity in normal tissue. Recent Studies: Recent identification of a sub-population of tumor cells with stem cell-like self-renewal capacity that may be responsible for relapse, metastasis, and resistance, as a potential target of the dietary compound, may be an important aspect of sulforaphane chemoprevention. Evidence also suggests that sulforaphane may target the epigenetic alterations observed in specific cancers, reversing aberrant changes in gene transcription through mechanisms of histone deacetylase inhibition, global demethylation, and microRNA modulation. In this review, we discuss the biochemical and biological properties of sulforaphane with a particular emphasis on the anticancer properties of the dietary compound. Sulforaphane possesses the capacity to intervene in multistage carcinogenesis through the modulation and/or regulation of important cellular mechanisms. The inhibition of phase I enzymes that are responsible for the activation of pro-carcinogens, and the induction of phase II enzymes that are critical in mutagen elimination are well-characterized chemopreventive properties. Furthermore, sulforaphane mediates a number of anticancer pathways, including the activation of apoptosis, induction of cell cycle arrest, and inhibition of NFκB. Further characterization of the chemopreventive properties of sulforaphane and its capacity to be selectively toxic to malignant cells are warranted to potentially establish the clinical utility of the dietary compound as an anti-cancer compound alone, and in combination with clinically relevant therapeutic and management strategies.

  5. Chemopreventive Effect of Tadalafil in Cisplatin-Induced Nephrotoxicity in Rats.

    Science.gov (United States)

    Adeneye, A A; Benebo, A S

    2016-08-30

    Nephrotoxicity remains a common untoward effect of cisplatin therapy with limited effective chemopreventive options available till date. This study aims to evaluate the possible chemopreventive effect and mechanism(s) of action of 2 mgkg-1 and 5 mgkg-1 of Tadalafil in cisplatin-induced nephrotoxic rats. In this study, twenty-five male Wistar rats were randomly divided into five groups (n = 5 rats per group) and daily pretreated with oral doses of distilled water (10 mLkg-1), ascorbic acid (100 mgkg-1), Tadalafil (2 mgkg-1 and 5 mgkg-1) for 7 days before cisplatin (5 mgkg-1, intraperitoneal) was administered. 72 hours post-cisplatin injections, rats were sacrificed humanely and blood samples for serum electrolytes, urea and creatinine and renal tissues for reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and malonialdehyde dehydrogenase (MAD) assays and histopathology were collected. Results showed that cisplatin injection caused significant decreases in the serum sodium (Na+), potassium (K+), bicarbonate (HCO3-), calcium (Ca2+), phosphate (PO42-) and concomitant significant increases in the serum urea and creatinine levels. In addition, there were significant decreases in the renal tissue GSH, SOD, CAT and increased MAD and GSH-Px levels which were corroborated by histopathological features of tubulonephritis. However, these histo-biochemical alterations were significantly attenuated by ascorbic acid and Tadalafil pretreatments. Overall, results of this study showed the chemopreventive potential of Tadalafil against cisplatin-induced nephrotoxicity which was possibly mediated via antioxidant and anti-lipoperoxidation mechanisms.

  6. 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.

  7. 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

  8. Implications of Cancer Stem Cell Theory for Cancer Chemoprevention by Natural Dietary Compounds

    Science.gov (United States)

    Li, Yanyan; Wicha, Max S.; Schwartz, Steven J.; Sun, Duxin

    2011-01-01

    The emergence of cancer stem cell theory has profound implications for cancer chemoprevention and therapy. Cancer stem cells give rise to the tumor bulk through continuous self-renewal and differentiation. Understanding the mechanisms that regulate self-renewal is of greatest importance for discovery of anti-cancer drugs targeting cancer stem cells. Naturally-occurring dietary compounds have received increasing attention in cancer chemoprevention. The anti-cancer effects of many dietary components have been reported for both in vitro and in vivo studies. Recently, a number of studies have found that several dietary compounds can directly or indirectly affect cancer stem cell self-renewal pathways. Herein we review the current knowledge of most common natural dietary compounds for their impact on self-renewal pathways and potential effect against cancer stem cells. Three pathways (Wnt/β-catenin, Hedgehog, and Notch) are summarized for their functions in self-renewal of cancer stem cells. The dietary compounds, including curcumin, sulforaphane, soy isoflavone, epigallocatechin-3-gallate, resveratrol, lycopene, piperine, and vitamin D3, are discussed for their direct or indirect effect on these self-renewal pathways. Curcumin and piperine have been demonstrated to target breast cancer stem cells. Sulforaphane has been reported to inhibit pancreatic tumor initiating cells and breast cancer stem cells. These studies provide a basis for preclinical and clinical evaluation of dietary compounds for chemoprevention of cancer stem cells. This may enable us to discover more preventive strategies for cancer management by reducing cancer resistance and recurrence and improving patient survival. PMID:21295962

  9. Implications of cancer stem cell theory for cancer chemoprevention by natural dietary compounds.

    Science.gov (United States)

    Li, Yanyan; Wicha, Max S; Schwartz, Steven J; Sun, Duxin

    2011-09-01

    The emergence of cancer stem cell theory has profound implications for cancer chemoprevention and therapy. Cancer stem cells give rise to the tumor bulk through continuous self-renewal and differentiation. Understanding the mechanisms that regulate self-renewal is of greatest importance for discovery of anticancer drugs targeting cancer stem cells. Naturally occurring dietary compounds have received increasing attention in cancer chemoprevention. The anticancer effects of many dietary components have been reported for both in vitro and in vivo studies. Recently, a number of studies have found that several dietary compounds can directly or indirectly affect cancer stem cell self-renewal pathways. Herein we review the current knowledge of most common natural dietary compounds for their impact on self-renewal pathways and potential effect against cancer stem cells. Three pathways (Wnt/β-catenin, Hedgehog and Notch) are summarized for their functions in self-renewal of cancer stem cells. The dietary compounds, including curcumin, sulforaphane, soy isoflavone, epigallocatechin-3-gallate, resveratrol, lycopene, piperine and vitamin D(3), are discussed for their direct or indirect effect on these self-renewal pathways. Curcumin and piperine have been demonstrated to target breast cancer stem cells. Sulforaphane has been reported to inhibit pancreatic tumor-initiating cells and breast cancer stem cells. These studies provide a basis for preclinical and clinical evaluation of dietary compounds for chemoprevention of cancer stem cells. This may enable us to discover more preventive strategies for cancer management by reducing cancer resistance and recurrence and improving patient survival. Copyright © 2011 Elsevier Inc. All rights reserved.

  10. 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.

  11. Does Variation in Either Age at Start of Therapy or Duration of Therapy Make Chemoprevention with Finasteride Cost-Effective?

    Science.gov (United States)

    Stewart, Suzanne Biehn; Scales, Charles D.; Moul, Judd W.; Reed, Shelby D.

    2013-01-01

    Background Incremental cost-effectiveness ratios (ICER) of finasteride for prostate cancer prevention are consistent with estimates beyond $100,000 per quality-adjusted life-year (QALY). The majority of these analyses are based on chemoprevention starting in men aged 50–55yrs. We sought to evaluate the impact of varying both age at commencement of therapy and length of therapy on the cost-effectiveness of finasteride. Methods A probabilistic Markov model was designed to estimate lifetime prostate health related costs and quality-adjusted survival for men receiving or not receiving chemoprevention with finasteride. ICERs across scenarios varying age at start of therapy and duration of chemoprevention were compared. Results The ICER for men starting chemoprevention at age 50 and continuing to age 75 was $88,800 per QALY when assuming finasteride causes a constant risk reduction across all tumor grades (base case 1) and $142,300 per when assuming a differential treatment effect according to Gleason score (base case 2). When starting age is increased, the ICERs trend downward and nadir at 65 years to $64,700 per QALY (base case 1) and $118,600 per QALY (base case 2). Altering duration of therapy had minimal impact. Patient-level experiences with finasteride and BPH significantly influenced the cost-effectiveness of chemoprevention. Conclusion Initiating chemoprevention at ages when prostate cancer incidence is higher improves its cost-effectiveness profile. Only when assuming a constant risk reduction for all tumor grades, did finasteride fall below $100,000 per QALY, but this finding was not upheld when accounting for side effects associated with the drug. PMID:22777393

  12. Chemoprevention by grape seed extract and genistein in carcinogen-induced mammary cancer in rats is diet dependent.

    Science.gov (United States)

    Kim, Helen; Hall, Patti; Smith, Michelle; Kirk, Marion; Prasain, Jeevan K; Barnes, Stephen; Grubbs, Clinton

    2004-12-01

    Many popular dietary supplements are enriched in polyphenols such as the soy isoflavones, tea catechins, and resveratrol (from grape skins), each of which has been shown to have chemopreventive activity in cellular models of cancer. The proanthocyanidins, which are oligomers of the catechins, are enriched in grape seeds and form the basis of the dietary supplement grape seed extract (GSE). Evidence suggests that the proanthocyanidins may be metabolized to the monomeric catechins. This study was carried out to determine whether GSE added to rodent diets protected against carcinogen-induced mammary tumorigenesis in rats and whether this was affected by the composition of the whole diet. Female rats were begun on 5%, 1.25%, or 0% (control) GSE-supplemented diets at age 35 d. At age 50 d they were administered 7,12-dimethylbenz[a]anthracene (DMBA) in sesame oil at 80 mg/kg body weight. They were weighed and monitored weekly for tumor development until 120 d after DMBA administration. Administration of GSE in AIN-76A diet did not show any protective activity of GSE against DMBA-induced breast cancer. However, administration of GSE in a laboratory dry food diet (Teklad 4% rodent diet) resulted in a 50% reduction in tumor multiplicity. In similar experiments, genistein administered in AIN-76A diet also failed to show chemopreventive activity against the carcinogen N-methyl-N-nitrosourea; however, when administered at the same dose in the Teklad 4% rodent diet, genistein exhibited significant chemopreventive activity (44-61%). These results demonstrate that GSE is chemopreventive in an animal model of breast cancer; moreover, the diet dependency of the chemopreventive activity for both GSE and genistein suggests that whether or not a compound is chemopreventive may depend on the diet in which the agent is administered.

  13. Experimental Validation of the Butyl-Rubber Finite Element (FE) Material Model for the Blast-Mitigating Floor Mat

    Science.gov (United States)

    2015-08-01

    Experimental Validation of the Butyl- Rubber Finite Element (FE) Material Model for the Blast-Mitigating Floor Mat by Masayuki Sakamoto...MD 20783-1138 ARL-SR-0329 August 2015 Experimental Validation of the Butyl- Rubber Finite Element (FE) Material Model for the Blast...SUBTITLE Experimental Validation of the Butyl- Rubber Finite Element (FE) Material Model for the Blast-Mitigating Floor Mat 5a. CONTRACT NUMBER 5b

  14. antioxidant activity of the inflorescents of vernonia calvoana growing ...

    African Journals Online (AJOL)

    diseases including cancer, and heart disease. Primary sources of natural occurring antioxidants are whole grains, fruits and vegetables. Plant sourced food ..... includes butylated hydroxytoluene (BHT), butylated hydroxyanisol (BHA) and propylgallate. The use of these common synthetic alternatives has increasingly raised.

  15. 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.

  16. Radiation-induced degradation of butyl rubber vulcanized by three different crosslinking systems

    Science.gov (United States)

    Scagliusi, Sandra R.; Cardoso, Elisabeth C. L.; Lugao, Ademar B.

    2012-08-01

    Butyl rubber (IIR) is an isobutylene/isoprene copolymer and is provided with good properties including low permeability to gases, good thermal stability and high resistance to oxygen and ozone action, among others. It is well known that the major effect of ionizing radiations on butyl rubber is chain scission accompanied with a significant reduction in molar mass. This work aimed to study the effects of gamma radiation on the properties of butyl rubbers vulcanized by three different curing systems, such as, the ones based on sulfur, sulfur donor and phenolic resin to identify which curing system is the most stable under irradiation. The butyl rubber vulcanized by three different systems was gamma irradiated with doses of 25 kGy, 50 kGy, 100 kGy, 150 kGy and 200 kGy. Irradiated and non-irradiated samples were characterized by the following techniques: tensile, elongation and hardness. It was observed that doses higher than 150 kGy practically destroy the assessed properties for all butyl compounds, irrespective of the vulcanization system used; however compounds cured with phenolic resin showed a decrease in properties proportional to the dose.

  17. Chemopreventive effects of nobiletin and its colonic metabolites on colon carcinogenesis.

    Science.gov (United States)

    Wu, Xian; Song, Mingyue; Wang, Minqi; Zheng, Jinkai; Gao, Zili; Xu, Fei; Zhang, Guodong; Xiao, Hang

    2015-12-01

    Nobiletin (NBT) is a major citrus flavonoid with various health benefits. Herein, we investigated the colon cancer chemopreventive effects of NBT and its colonic metabolites in a colitis-associated colon carcinogenesis mouse model as well as in human colon cancer cell models. In azoxymethane/dextran sulfate sodium treated mice, oral administration of NBT effectively decreased both incidence and multiplicity of colonic tumors. NBT showed significant antiproliferative, proapoptotic, and anti-inflammatory effects in the mouse colon. HPLC analysis revealed that oral administration of NBT resulted in high levels of metabolites, i.e. 3'-demethylnobiletin (M1), 4'-demethylnobiletin (M2), and 3',4'-didemethylnobiletin (M3) in the colonic mucosa. In contrast, the colonic level of NBT was about 20-fold lower than the total colonic level of three metabolites. Cell culture studies demonstrated that the colonic metabolites of NBT significantly inhibited the growth of human colon cancer cells, caused cell-cycle arrest, induced apoptosis, and profoundly modulated signaling proteins related with cell proliferation and cell death. All of these effects were much stronger than those produced by NBT alone. Our results demonstrated that oral administration of NBT significantly inhibited colitis-associated colon carcinogenesis in mice, and this chemopreventive effect was strongly associated with its colonic metabolites. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Evaluation of cytotoxic, apoptotic, mutagenic, and chemopreventive activities of semi-synthetic esters of gallic acid.

    Science.gov (United States)

    Silva, I C; Polaquini, C R; Regasini, L O; Ferreira, H; Pavan, F R

    2017-07-01

    Gallic acid and its derivatives are phenolic compounds widely used as food supplements in the form of capsules, liquid extracts, and ointments owing to their good antioxidant properties. Besides, these compounds are potent inhibitors of fungi, bacteria, and some viruses and possess strong antiproliferative and chemopreventive activities. However, gallic acid derivatives are also known to exert harmful effects like mutagenicity and cytotoxicity. The present study aimed to understand and explore the toxicological risks of these compounds. For this, a series of alkyl gallates with side chains varying from five to eight carbons (pentyl, hexyl, heptyl, and octyl gallates) were evaluated for their cytotoxic and pro-apoptotic potential. In addition, the genotoxic effects of alkyl gallates were measured in HepG2 cells using the single cell gel electrophoresis (SCGE)/comet assay and the cytokinesis-blocked micronucleus (CBMN) test. In both the tests, the substances did not induce any significant differences when compared to the control group. In addition, alkyl gallates exhibited a chemopreventive effect, thereby considerably reducing the mutagenicity caused by H2O2. In conclusion, our results suggest that alkyl gallates are non-genotoxic, non-mutagenic, and pro-apoptotic agents, which may serve as suitable and promising candidates for preventing chemically-induced chromosomal damage. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Non-pungent capsaicinoids from sweet pepper synthesis and evaluation of the chemopreventive and anticancer potential.

    Science.gov (United States)

    Macho, Antonio; Lucena, Concepción; Sancho, Rocio; Daddario, Nives; Minassi, Alberto; Muñoz, Eduardo; Appendino, Giovanni

    2003-01-01

    Capsiate, the non-pungent ester isoster of capsaicin, and its dihydroderivative are the major capsaicinoids of sweet peppers. The remarkable difference between the sensory properties of capsaicin vs capsiate is solely due to the way the vanillyl and the acyl moieties of this basic structural motif are linked, via an amide bond in capsaicin-type compounds and via an ester bond in capsiate-type compounds. Since capsaicin induces apoptosis in tumoral cells by a vanilloid receptor type 1(VR1)-independent pathway, we examined the effects of capsiates derived from sweet peppers in the ROS generation and induction of apoptosis in tumoral cells and if these are mediated independently from VR1. We have developed an expeditious synthesis of capsiates based on the esterification of vanillol with the Mitsunobu protocol. Capsiate-induction of apoptosis, generation of reactive oxygen species and disruption of the mitochondria transmembrane potential in tumoral cell lines were measured by flow cytometry. Chemopreventive activity was studied in a two-stage mouse skin carcinogenesis assay. Capsiates induce apoptosis that was preceded by an increase in the production of reactive oxygen species and by a subsequent loss of mitochondria transmembrane potential (DeltaPsi(m)). These properties were retained in simplified synthetic analogues of natural capsiates, one of which (nor-dihydrocapsiate) showed powerful chemopreventive activity. These results suggest that capsiates and related synthetic analogues target a variety of pathways involved in cancer development and inflammation, and have considerable potential for dietary health benefits as well as for pharmaceutical development.

  20. Cellular diamine levels in cancer chemoprevention: modulation by ibuprofen and membrane plasmalogens

    Directory of Open Access Journals (Sweden)

    Wood Paul L

    2011-11-01

    Full Text Available Abstract Background To develop effective strategies in cancer chemoprevention, an increased understanding of endogenous biochemical mediators that block metastatic processes is critically needed. Dietary lipids and non-steroidal anti-inflammatory drugs (NSAIDs have a published track record of providing protection against gastrointestinal malignancies. In this regard, we examined the effects of membrane plasmalogens and ibuprofen on regulation of cellular levels of diamines, polyamine mediators that are augmented in cancer cells. For these studies we utilized Chinese hamster ovary (CHO cells and NRel-4 cells, a CHO cell line with defective plasmalogen synthesis. Results NRel-4 cells, which possess cellular plasmalogen levels that are 10% of control CHO cells, demonstrated 2- to 3-fold increases in cellular diamine levels. These diamine levels were normalized by plasmalogen replacement and significantly reduced by ibuprofen. In both cases the mechanism of action appears to mainly involve increased diamine efflux via the diamine exporter. The actions of ibuprofen were not stereospecific, supporting previous studies that cyclooxygenase (COX inhibition is unlikely to be involved in the ability of NSAIDs to reduce intracellular diamine levels. Conclusions Our data demonstrate that ibuprofen, a drug known to reduce the risk of colorectal cancer, reduces cellular diamine levels via augmentation of diamine efflux. Similarly, augmentation of membrane plasmalogens can increase diamine export from control and plasmalogen-deficient cells. These data support the concept that membrane transporter function may be a therapeutic point of intervention for dietary and pharmacological approaches to cancer chemoprevention.

  1. 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. Copyright © 2015. Published by Elsevier B.V.

  2. Drug delivery strategies for chemoprevention of UVB-induced skin cancer: A review.

    Science.gov (United States)

    Bagde, Arvind; Mondal, Arindam; Singh, Mandip

    2018-01-01

    Annually, more skin cancer cases are diagnosed than the collective incidence of the colon, lung, breast, and prostate cancer. Persistent contact with sunlight is a primary cause for all the skin malignancies. UVB radiation induces reactive oxygen species (ROS) production in the skin which eventually leads to DNA damage and mutation. Various delivery approaches for the skin cancer treatment/prevention have been evolving and are directed toward improvements in terms of delivery modes, therapeutic agents, and site-specificity of therapeutics delivery. The effective chemoprevention activity achieved is based on the efficiency of the delivery system used and the amount of the therapeutic molecule deposited in the skin. In this article, we have discussed different studies performed specifically for the chemoprevention of UVB-induced skin cancer. Ultra-flexible nanocarriers, transethosomes nanocarriers, silica nanoparticles, silver nanoparticles, nanocapsule suspensions, microemulsion, nanoemulsion, and polymeric nanoparticles which have been used so far to deliver the desired drug molecule for preventing the UVB-induced skin cancer. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. 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 (pmuricata leaves extract was able to suppress tumor initiation as well as tumor promotion even at lower dosage.

  4. Dietary pterostilbene is a novel MTA1-targeted chemopreventive and therapeutic agent in prostate cancer

    Science.gov (United States)

    Zhang, Liangfen; Rimando, Agnes M.; Lage, Janice M.; Lewin, Jack R.; Atfi, Azeddine; Zhang, Xu; Levenson, Anait S.

    2016-01-01

    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- targeted chemopreventive and therapeutic efficacy of pterostilbene, a natural potent analog of resveratrol, in pre-clinical models of prostate cancer. Here, we show that high levels of MTA1 expression in Pten-loss prostate cooperate with key oncogenes, including c-Myc and Akt among others, to promote prostate cancer progression. Loss-of-function studies using human prostate cancer cells indicated direct involvement of MTA1 in inducing inflammation and epithelial-to-mesenchymal transition. Importantly, pharmacological inhibition of MTA1 by pterostilbene resulted in decreased proliferation and angiogenesis and increased apoptosis. This restrained prostatic intraepithelial neoplasia (PIN) formation in prostate-specific Pten heterozygous mice and reduced tumor development and progression in prostate-specific Pten-null mice. Our findings highlight MTA1 as a key upstream regulator of prostate tumorigenesis and cancer progression. More significantly, it offers pre-clinical proof for pterostilbene as a promising lead natural agent for MTA1-targeted chemopreventive and therapeutic strategy to curb prostate cancer. PMID:26943043

  5. Chemoprevention of skin cancer using low HLB surfactant nanoemulsion of 5-fluorouracil: a preliminary study.

    Science.gov (United States)

    Shakeel, Faiyaz; Haq, Nazrul; Al-Dhfyan, Abdullah; Alanazi, Fars K; Alsarra, Ibrahim A

    2015-01-01

    Oral delivery of 5-fluorouracil (5-FU) is difficult due to its serious adverse effects and extremely low bioavailability. Therefore, the aim of present investigation was to develop and evaluate low HLB surfactant nanoemulsion of 5-FU for topical chemoprevention of skin cancer. Low HLB surfactant nanoemulsions were prepared by oil phase titration method. Thermodynamically stable nanoemulsions were characterized in terms of droplet size distribution, zeta potential, viscosity and refractive index. Selected formulations and control were subjected to in vitro skin permeation studies through rat skin using Franz diffusion cells. Optimized formulation F9 was subjected to stability and in vitro cytotoxic studies on melanoma cell lines. Enhancement ratio was found to be 22.33 in formulation F9 compared with control and other formulations. The values of steady state flux and permeability coefficient for formulation F9 were found to be 206.40 ± 14.56 µg cm(-2) h(-1) and 2.064 × 10(-2) ± 0.050 × 10(-2 )cm h(-1), respectively. Optimized formulation F9 was found to be physical stable. In vitro cytotoxicity studies on SK-MEL-5 cancer cells indicated that 5-FU in optimized nanoemulsion is much more efficacious than free 5-FU. From these results, it can be concluded that the developed nanoemulsion might be a promising vehicle for chemoprevention of skin cancer.

  6. 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.

  7. In Vitro Chemopreventive Properties of Green Tea, Rooibos and Honeybush Extracts in Skin Cells

    Directory of Open Access Journals (Sweden)

    Tandeka U. Magcwebeba

    2016-11-01

    Full Text Available The chemopreventive properties of the herbal teas rooibos (Aspalathus linearis and honeybush (Cyclopia spp. have been demonstrated on mouse skin in vivo but the underlying mechanisms are not clear. The aim of the current study was to determine the anti-proliferative and pro-apoptotic activity of methanol and aqueous extracts of rooibos and two Cyclopia species in different skin cells, using green tea (Camellia sinensis as a benchmark. Extracts were also characterised for their major individual polyphenols by high performance liquid chromatography and spectroscopically for the total polyphenol (TP groups. The methanol extract of rooibos, containing higher levels of polyphenols than its aqueous extract, displayed similar activity to green tea as it selectively targeted premalignant cells by inhibiting cell proliferation at lower concentrations whilst inducing apoptosis via membrane depolarisation at higher concentrations. Specific roles of the major rooibos dihydrochalcones and flavanol/proanthocyanidin-type (FLAVA compounds are likely to be involved. The aqueous extracts of the Cyclopia species were more active against cell proliferation and at inducing apoptosis which was associated with a higher FLAVA content and a reduced TP/FLAVA ratio. In contrast, their methanol extracts exhibited a cytoprotective effect against apoptosis which was related to their monomeric xanthone and flavanone content. The underlying chemopreventive properties of green tea and the herbal teas appear to be associated with diverse and complex monomeric/polymeric polyphenolic cell interactions.

  8. Cancer chemopreventive effects of the flavonoid-rich fraction isolated from papaya seeds.

    Science.gov (United States)

    Pathak, Neelam; Khan, Saba; Bhargava, Arpit; Raghuram, Gorantla V; Jain, Deepika; Panwar, Hariom; Samarth, Ravindra M; Jain, Subodh K; Maudar, Kewal K; Mishra, Dinesh K; Mishra, Pradyumna K

    2014-01-01

    Intervention to decelerate, arrest, or reverse the process of carcinogenesis by the use of either natural or synthetic agents individually or in combination has emerged as a promising and pragmatic medical approach to reduce cancer risk. In the present study, we examined the cancer chemopreventive potential of a flavonoid-rich fraction isolated from the seeds of Carica papaya, a plant traditionally referred to as papaw. The flavonoid-enriched benzene fraction of the aqueous extract exerted its anticancer properties in vitro through cytoprotection, antioxidative and antiinflammatory mechanisms and genoprotection in response to isocyanate-induced carcinogenicity. Medium-term anticarcinogenicity and 2-stage skin papillomagenesis studies conducted in benzopyrene-induced lung carcinogenesis and 7,12-dimethyl benz(a)anthracene-mediated skin papillomagenesis mouse models further validated our in vitro observations. This is the first demonstration of chemopreventive activities of papaya seed products, however, further studies to understand the subtle targets of intracellular signaling pathways, pharmacological profile and toxicological safety of this bioactive fraction are essential to pave the way for successful clinical translation. Our study supports the inverse association between dietary flavonoid intake and cancer risk.

  9. Oxidative stress and dietary phytochemicals: Role in cancer chemoprevention and treatment.

    Science.gov (United States)

    Chikara, Shireen; Nagaprashantha, Lokesh Dalasanur; Singhal, Jyotsana; Horne, David; Awasthi, Sanjay; Singhal, Sharad S

    2018-01-28

    Several epidemiological observations have shown an inverse relation between consumption of plant-based foods, rich in phytochemicals, and incidence of cancer. Phytochemicals, secondary plant metabolites, via their antioxidant property play a key role in cancer chemoprevention by suppressing oxidative stress-induced DNA damage. In addition, they modulate several oxidative stress-mediated signaling pathways through their anti-oxidant effects, and ultimately protect cells from undergoing molecular changes that trigger carcinogenesis. In several instances, however, the pro-oxidant property of these phytochemicals has been observed with respect to cancer treatment. Further, in vitro and in vivo studies show that several phytochemicals potentiate the efficacy of chemotherapeutic agents by exacerbating oxidative stress in cancer cells. Therefore, we reviewed multiple studies investigating the role of dietary phytochemicals such as, curcumin (turmeric), epigallocatechin gallate (EGCG; green tea), resveratrol (grapes), phenethyl isothiocyanate (PEITC), sulforaphane (cruciferous vegetables), hesperidin, quercetin and 2'-hydroxyflavanone (2HF; citrus fruits) in regulating oxidative stress and associated signaling pathways in the context of cancer chemoprevention and treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. 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.

  11. Castanea sativa Mill. bark extract exhibits chemopreventive properties triggering extrinsic apoptotic pathway in Jurkat cells.

    Science.gov (United States)

    Lenzi, Monia; Malaguti, Marco; Cocchi, Veronica; Hrelia, Silvana; Hrelia, Patrizia

    2017-05-05

    Chemoprevention represents the possibility to prevent, stop or reverse the cancerogenetic process. In this context the interest towards natural extracts and botanical drugs has constantly grown due to their phytochemical content. Castanea sativa Mill. (CSM) extracts showed to exert positive effect in the prevention/counteraction of chronic/degenerative diseases, therefore, we evaluated the potential chemopreventive effect of CSM bark extract. Flow cytometry (FCM) analyses of Jurkat cells treated with CSM bark extract (0-500 μg·mL -1 ) for 24-72 h allowed evaluating its cytotoxicity and ability to induce apoptosis through the intrinsic or extrinsic pathways. Moreover, to evaluate CSM bark extract selectivity towards cancer cells, its cytotoxic and pro-apoptotic effect was also evaluated in human peripheral blood lymphocytes (PBL). CSM bark extract induced apoptosis in Jurkat cells in a dose- and time- dependent manner activating the extrinsic pathways as evidenced by the increase of activated caspase-8 positive cells. Moreover, IC 50 calculated after 24 h treatment resulted 304 and 128 μg·mL -1 in PBL and Jurkat cells respectively. Our data suggest that CSM bark extract might be considered an interesting potential anti-cancer agent, since it induces apoptosis in cancer cells without appreciable cytotoxic effects on non-transformed cells.

  12. Epigenetic impact of dietary polyphenols in cancer chemoprevention: lifelong remodeling of our epigenomes.

    Science.gov (United States)

    Vanden Berghe, Wim

    2012-06-01

    Cancer, as one of the non-communicable diseases, remains one of the leading causes of death around the world. Recently, epigenetic changes in DNA methylation patterns at CpG sites (epimutations) or deregulated chromatin states of tumor promoting genes and noncoding RNAs emerged as major governing factors in tumor progression and cancer drug sensitivity. Furthermore, various environmental factors such as nutrition, behavior, stress, and toxins remodel our epigenomes lifelong in a beneficial or detrimental way. Since epigenetic marks (epimutations) are reversible in contrast to genetic defects, chemopreventive nutritional polyphenols (soy, genistein, resveratrol, catechin, curcumin) are currently evaluated for their ability to reverse adverse epigenetic marks in cancer (stem) cells to attenuate tumorigenesis-progression, prevent metastasis or sensitize for drug sensitivity. Although polyphenols in fruit and vegetables may help to reduce the risk of cancer, few protective effects have been firmly established, presumably because of inappropriate timing or dosing of diet exposure or due to confounding factors such as smoking and alcohol. In this review will discuss the possible epigenetic contributions of dietary polyphenols in cancer chemoprevention. Copyright © 2012 Elsevier Ltd. All rights reserved.

  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. Can transcriptomics provide insight into the chemopreventive mechanisms of complex mixtures of phytochemicals in humans?

    Science.gov (United States)

    van Breda, Simone G J; Wilms, Lonneke C; Gaj, Stan; Jennen, Danyel G J; Briedé, Jacob J; Helsper, Johannes P; Kleinjans, Jos C S; de Kok, Theo M C M

    2014-05-10

    Blueberries contain relatively large amounts of different phytochemicals, which are suggested to have chemopreventive properties, but little information is available on the underlying molecular modes of action. This study investigates whole genome gene expression changes in lymphocytes of 143 humans after a 4-week blueberry-apple juice dietary intervention. Differentially expressed genes and genes correlating with the extent of antioxidant protection were identified in four subgroups. The magnitude of the preventive effect after the intervention differed between these four subgroups. Furthermore, subjects in two groups carried genetic polymorphisms that were previously found to influence the chemopreventive response. Pathway analysis of the identified genes showed strong but complex gene expression changes in pathways signaling for apoptosis, immune response, cell adhesion, and lipid metabolism. These pathways indicate increased apoptosis, upgraded growth control, induced immunity, reduced platelet aggregation and activation, blood glucose homeostasis, and regulation of fatty acid metabolism. Based on these observations, we hypothesize that combining transcriptomic data with phenotypic markers of oxidative stress may provide insight into the relevant cellular processes and genetic pathways, which contribute to the antioxidant response of complex mixtures of phytochemicals, such as found in blueberry-apple juice.

  15. Nutrient and nonnutrient components of legumes, and its chemopreventive activity: a review.

    Science.gov (United States)

    Sánchez-Chino, Xariss; Jiménez-Martínez, Cristian; Dávila-Ortiz, Gloria; Álvarez-González, Isela; Madrigal-Bujaidar, Eduardo

    2015-01-01

    Legumes in combination with other products are the staple food for a large part of the world population, especially the low-income fragment, because their seeds provide valuable amounts of carbohydrates, fiber, and proteins, and have an important composition of essential amino acids, the sulphured amino acids being the limiting ones. Furthermore, legumes also have nonnutritional compounds that may decrease the absorption of nutrients or produce toxic effects; however, it has been reported that depending on the dose, these nonnutritional compounds also have different bioactivities as antioxidant, hypolipidemic, hypoglycemic, and anticarcinogenic agents, which have been proven in scientific studies. It has been observed that in countries with a high consumption of legumes, the incidence of colorectal cancer is lower. Some studies have shown that legume seeds are an alternative chemopreventive therapy against various cancers especially colon; this was verified in various animal models of induced by azoxymethane, a colon specific carcinogenic compound, in which a diet was supplemented with different concentrations of beans, lentils, chickpeas, or soybeans, mostly. These studies have proven the anticancer activity of legumes in early stages of carcinogenesis. Therefore, it is important to review the information available to elucidate the chemopreventive mechanisms of action of legume compounds.

  16. Breast cancer chemoprevention by dietary natural phenolic compounds: specific epigenetic related molecular targets.

    Science.gov (United States)

    Pan, Min-Hsiung; Chiou, Yi-Siou; Chen, Li-Hua; Ho, Chi-Tang

    2015-01-01

    Breast cancer is a systemic malignant disease that is a major cause of cancer-related death among women worldwide. Recently, multiple lines of evidence from epidemiologic studies have suggested that epigenetic and genetic changes are involved in breast cancer development. In breast cancer patients, hormone receptor status, breast cancer stem-like cell population, and tumor microenvironment are reflective of breast cancer progression, drug resistance, and tumor recurrence. Strong relationships between a phytochemical-rich diet and a reversal of epigenetic alterations and/or modulated signaling pathways of carcinogenesis (initiation, promotion, and progression) suggest a potential approach for preventing breast cancer. Additionally, dietary consumption of natural phenolic compounds containing phytoestrogen properties exerts beneficial effects in breast cancer chemoprevention. In this review, we summarize the specific chemopreventive targets of representative phenolic compounds with an emphasis on their efficacy at interfering with epigenetic event related hormonal and nonhormonal signaling cascades that are responsible for multistage breast carcinogenesis. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Spectroscopic analysis of 1-butyl-2,3-dimethylimidazolium ionic liquids: Cation-anion interactions

    Science.gov (United States)

    Men, Shuang; Jiang, Jing; Licence, Peter

    2017-04-01

    In this study, four 1-butyl-2,3-dimethylimidazolium ionic liquids are analysed by X-ray photoelectron spectroscopy, together with three 1-butyl-3-methylimidazolium ionic liquids. A reliable fitting model for the carbon 1s region of 1-butyl-2,3-dimethylimidazolium ionic liquids is modified according to established models. The effect of the anion on the electronic environment of the cation is explored based upon the comparison between measured binding energies of nitrogen 1s and the hydrogen bond acceptor ability. The effect of the cation on the cation-anion interaction is also demonstrated by carefully comparing the hydrogen bond donating ability of different cations, with a definite anion.

  18. Crystal structure of (S)-sec-butyl-ammonium l-tartrate monohydrate.

    Science.gov (United States)

    Publicover, Ernlie A; Kolwich, Jennifer; Stack, Darcie L; Doué, Alyssa J; Ylijoki, Kai E O

    2017-05-01

    The title hydrated mol-ecular salt, C4H12N+·C4H5O6-·H2O, was prepared by deprotonation of enanti-opure l-tartaric acid with racemic sec-butyl-amine in water. Only one enanti-omer was observed crystallographically, resulting from the combination of (S)-sec-butyl-amine with l-tartaric acid. The sec-butyl-ammonium moiety is disordered over two conformations related by rotation around the CH-CH2 bond; the refined occupancy ratio is 0.68 (1):0.32 (1). In the crystal, mol-ecules are linked through a network of O-H⋯O and N-H⋯O hydrogen-bonding inter-actions, between the ammonium H atoms, the tartrate hy-droxy H atoms, and the inter-stitial water, forming a three-dimensional supra-molecular structure.

  19. EFFECTS OF STIMULATOR SUBSTANCES ON AEROBIC METHYL TERT-BUTYL ETHER BIODEGRADATION BY MICROBIAL CONSORTIUM

    Directory of Open Access Journals (Sweden)

    M. Farrokhi ، S. Ahmadizad

    2009-04-01

    Full Text Available In this study dissolved humic substances and yeast extract were tested in different concentrations for enhancing methyl tert-butyl ether mineralization by isolated microorganisms from a variety of sources. All experiments were conducted at a constant temperature of 25ºC. Vials of 50 mL and 125 mL volume sealed with Teflon-lined Mini-Nert caps was used for microcosm experiments. In all experiments 1% sodium azide were used as control. Samples of bacterial cultures that metabolize methyl tert-butyl ether have been analysed by direct GC analysis using flame ionization detector. Cultures able to metabolize have been found in activated sludge and soils. These microorganisms weregram-positive bacterium. An aerobic microbial consortium was enriched in laboratory for four months. Methyl tert-butyl ether has been shown to biodegrade under aerobic and co-metabolic conditions. A microbial consortium isolated from activated sludges was identified as Cocobacillus. The concentration of the initial attached biomass was about 0.11 g/L of dry weight. The maximum mineralization rate and beneficial effects of stimulator substances on aerobic biodegradation of methyl tert-butyl ether occurred with the culture by combined concentrations of 500 mg/L of yeast extract and 20 mg/L of peat humic growth support of microbial consortium within 216 h and in presence of high oxygen levels and well mixing conditions. It was shown that adding, peat humic and yeast extract together, had better stimulatory effect on methyl tert-butyl ether biodegradation. Results clearly showed a stimulatory effect on methyl tert-butyl ether consumption higher than 20%. Consortium was capable of degrading concentrations of ≤1000 mg/L, whereas concentrations of >1000 mg/L, were not degraded.

  20. Curcumin and metformin-mediated chemoprevention of oral cancer is associated with inhibition of cancer stem cells.

    Science.gov (United States)

    Siddappa, Gangotri; Kulsum, Safeena; Ravindra, Doddathimmasandra Ramanjanappa; Kumar, Vinay V; Raju, Nalini; Raghavan, Nisheena; Sudheendra, Holalugunda Vittalamurthy; Sharma, Anupam; Sunny, Sumsum P; Jacob, Tina; Kuruvilla, Binu T; Benny, Merina; Antony, Benny; Seshadri, Mukund; Lakshminarayan, Padma; Hicks, Wesley; Suresh, Amritha; Kuriakose, Moni A

    2017-11-01

    Effective chemoprevention is critical for improving outcomes of oral cancer. As single agents, curcumin and metformin are reported to exhibit chemopreventive properties, in vitro as well as in patients with oral cancer. In this study, the chemopreventive efficacy of this drug combination was tested in a 4-nitro quinoline-1-oxide (4NQO) induced mice oral carcinogenesis model. Molecular analysis revealed a cancer stem cell (CSC)-driven oral carcinogenic progression in this model, wherein a progressive increase in the expression of CSC-specific markers (CD44 and CD133) was observed from 8th to 25th week, at transcript (40-100-fold) and protein levels (P ≤ 0.0001). Chemopreventive treatment of the animals at 17th week with curcumin and metformin indicated that the combination regimen decreased tumor volume when compared to the control arm (0.69+0.03 vs 6.66+2.4 mm 3 ; P = 0.04) and improved overall survival of the animals (P = 0.03). Assessment of the molecular status showed an overall downregulation of CSC markers in the treatment arms as compared to the untreated control. Further, in vitro assessment of the treatment on the primary cells generated from progressive stages of 4NQO-induced mice tissue showed a concordant and consistent downregulation of the CSC markers following combination treatment (P oral squamous cell carcinoma through a CSC-associated mechanism. © 2017 Wiley Periodicals, Inc.

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

    Science.gov (United States)

    Singh, Madhulika; Suman, Shankar; Shukla, Yogeshwer

    2014-01-01

    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.

  2. 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.

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

    Science.gov (United States)

    Singh, Madhulika; Suman, Shankar; Shukla, Yogeshwer

    2014-01-01

    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. PMID:24757666

  4. 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.

  5. 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)....

  6. Chemopreventive Activity of Honokiol against 7, 12 - Dimethylbenz[a]anthracene-Induced Mammary Cancer in Female Sprague Dawley Rats

    Directory of Open Access Journals (Sweden)

    Zhenyu Wang

    2017-05-01

    Full Text Available Breast cancer is a predominant cause of death in women across the globe. Chemoprevention by using natural, dietary or synthetic products has been appearing to be a fascinating approach to combat the growing burden of breast cancer. In the current study, we intended to explore the mechanisms of chemopreventive action of honokiol against 7, 12 - dimethylbenz[a]anthracene (DMBA-induced mammary cancer in female Sprague Dawlely (SD rats. We induced mammary cancer in SD rats by administering single dose of DMBA (80 mg/kg through intra gastric route. Chemopreventive effects of honokiol (80 mg/kg, i.p. were confirmed from its ameliorating effect on the DMBA-induced anomalies such as liver marker enzymes, Phases I and II metabolizing enzymes and oxidative stress markers. Further, honokiol reversed the DMBA-induced abnormalities in inflammatory cytokines levels and serum tumor markers. Additionally, histopathological examination of mammary tissue and protein expression analysis of NF-κB revealed that honokiol is effective against DMBA-induced mammary cancer. In summary, the results of our study support the chemopreventive feature of honokiol in mammary cancer.

  7. 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

  8. The screening of microorganisms capable of methyl tert-butyl ether (MTBE) biodegradation.

    Science.gov (United States)

    Wieczorek, Andrzej; Przybulewska, Krystyna; Karpowicz, Katarzyna; Nowak, Maciej J

    2013-01-01

    As a result of examinations carried out, 16 strains of microorganisms able to grow on mineral media with methyl tert-butyl ether as the sole source of carbon and energy were isolated. Bacteria prevailed among the isolated microorganisms. The growth of microorganisms under laboratory conditions was long and accompanied by low biomass increase. Under the conditions of the experiment, the isolated microorganisms did not show any quantitatively measurable biodegradability of methyl tert-butyl ether (MTBE) under aerobic conditions. This requires far-reaching caution with respect to trading in MTBE-modified petrols in order to protect the natural environment in Poland against contamination with that hard-to-biodegrade substance.

  9. Third phase formation in the extraction of Th(NO{sub 3}){sub 4} by Tri-sec-butyl phosphate. A comparison with Tri-n-butyl phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Chandrasekar, Aditi; Suresh, A.; Sivaraman, N. [Indira Gandhi Centre for Atomic Research, Kalpakkam (India). Chemistry Group

    2017-06-01

    Earlier studies carried out in our laboratory indicated that Tri-sec-butyl phosphate (TsBP) is a potential extractant for U/Th separation. Also, the third phase formation tendency of TsBP is lower compared to its isomers, Tri-n-butyl-phosphate (TBP) and Tri-iso-butyl phosphate (TiBP). In this context, the extraction and third phase formation behaviour of 1.1 M solutions of TiBP and TsBP in n-dodecane in the extraction of Th(IV) from 1 M HNO{sub 3} at 303 K over a wide range of Th concentrations were investigated in the present study and the results are compared with the literature data on TBP system. Concentrations of Th(IV) and HNO{sub 3} loaded in the organic phase before third phase formation (biphasic region) as well as in third phase and diluent-rich phase after third phase formation (triphasic region) were measured as a function of equilibrium aqueous phase Th(IV) concentration. The density of loaded organic phase was also measured at various Th(IV) concentrations. The extraction profiles in the biphasic region indicated that extraction of Th(IV) by TBP is higher than that of TiBP which in turn is higher than that of TsBP. Extractant concentration in the diluent-rich phase and third phase was measured for the triphasic region.

  10. Cancer Chemoprevention Effects of Ginger and its Active Constituents: Potential for New Drug Discovery.

    Science.gov (United States)

    Wang, Chong-Zhi; Qi, Lian-Wen; Yuan, Chun-Su

    2015-01-01

    Ginger is a commonly used spice and herbal medicine worldwide. Besides its extensive use as a condiment, ginger has been used in traditional Chinese medicine for the management of various medical conditions. In recent years, ginger has received wide attention due to its observed antiemetic and anticancer activities. This paper reviews the potential role of ginger and its active constituents in cancer chemoprevention. The phytochemistry, bioactivity, and molecular targets of ginger constituents, especially 6-shogaol, are discussed. The content of 6-shogaol is very low in fresh ginger, but significantly higher after steaming. With reported anti-cancer activities, 6-shogaol can be served as a lead compound for new drug discovery. The lead compound derivative synthesis, bioactivity evaluation, and computational docking provide a promising opportunity to identify novel anticancer compounds originating from ginger.

  11. Cancer chemoprevention by citrus pulp and juices containing high amounts of β-cryptoxanthin and hesperidin.

    Science.gov (United States)

    Tanaka, Takuji; Tanaka, Takahiro; Tanaka, Mayu; Kuno, Toshiya

    2012-01-01

    β-Cryptoxanthin, a carotenoid, and hesperidin, a flavonoid, possess inhibitory effects on carcinogenesis in several tissues. We recently have prepared a pulp (CHRP) and citrus juices (MJ2 and MJ5) from a satsuma mandarin (Citrus unshiu Mar.) juice (MJ). They contain high amounts of β-cryptoxanthin and hesperidin. We have demonstrated that CHRP and/or MJs inhibit chemically induced rat colon, rat tongue, and mouse lung tumorigenesis. Gavage with CHRP resulted in an increase of activities of detoxifying enzymes in the liver, colon, and tongue rats'. CHRP and MJs were also able to suppress the expression of proinflammatory cytokines and inflammatory enzymes in the target tissues. This paper describes the findings of our in vivo preclinical experiments to develop a strategy for cancer chemoprevention of colon, tongue, and lung neoplasms by use of CHRP and MJs.

  12. 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.

  13. Biomedical properties of edible seaweed in cancer therapy and chemoprevention trials: a review.

    Science.gov (United States)

    Namvar, Farideh; Tahir, Paridah M d; Mohamad, Rosfarizan; Mahdavi, Mahnaz; Abedi, Parvin; Najafi, Tahereh Fathi; Rahmanand, Heshu Sulaiman; Jawaid, Mohammad

    2013-12-01

    This review article summarizes in vitro and in vivo experiments on seaweed anticancer activity and seaweed chemical components. Seaweed use in cancer therapy, chemopreventive randomized control trials (RCTs) and quasi-experiments are discussed. The literature reviewed in this article was obtained from various scientific sources and encompasses publications from 2000-2012. Seaweed therapeutic effects were deemed scientifically plausible and may be partially explained by the in vivo and in vitro pharmacological studies described. Although the mechanisms of action remain unclear, seaweed's anticancer properties may be attributable to its major biologically active metabolites. Much of the seaweed research outlined in this paper can serve as a foundation for explaining seaweed anticancer bioactivity. This review will open doors for developing strategies to treat malignancies using seaweed natural products.

  14. 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.

  15. Research Progress on Natural Triterpenoid Saponins in the Chemoprevention and Chemotherapy of Cancer.

    Science.gov (United States)

    Du, Jun-Rong; Long, Fang-Yi; Chen, Chu

    2014-01-01

    Triterpenoid saponins are glycosides with remarkable structural and bioactive diversity. They are becoming increasingly significant in the treatment of cancer due to their efficacy and safety. This chapter provides an update on the sources, pharmacological effects, structure-activity relationships, and clinical studies of anticancer triterpenoid saponins with a particular focus on the molecular mechanisms underlying their therapeutic properties. The correlative references and study reports described were collected through PubMed. The anticancer triterpenoid saponins enable the inhibition of cancer formation and progression by modulating multiple signaling targets related to cellular proliferation, apoptosis, autophagy, metastasis, angiogenesis, inflammation, oxidative stress, multidrug resistance, cancer stem cells, and microRNAs. This review provides new insights into the molecular basis of triterpenoid saponins in the chemoprevention and chemotherapy of cancer. © 2014 Elsevier Inc. All rights reserved.

  16. Bladder urotoxicity pathophysiology induced by the oxazaphosphorine alkylating agents and its chemoprevention 

    Directory of Open Access Journals (Sweden)

    Łukasz Dobrek

    2012-09-01

    Full Text Available The use of oxazaphosphorines (cyclophosphamide, ifosfamide in the treatment of numerous neoplastic disorders is associated with their essential adverse effect in the form of hemorrhagic cystitis, which considerably limits the safety and efficacy of their pharmacotherapy. HC is a complex inflammatory response, induced by toxic oxazaphosphorines metabolite – acrolein with subsequent immunocompetetive cells activation and release of many proinflammatory agents. However, there are some chemoprotectant agents which help reduce the HC exacerbation.The article briefly discuses the mechanism of action of oxazaphosphorines, the pathophysiology of the hemorrhagic cystitis development and currently accepted chemopreventive agents, applied to the objective of urotoxicity amelioration. Moreover, the rationale for some phytopharmaceuticals administration as novel bladder protective compounds accompanying cyclophosphamide or ifosfamide therapy was also mentioned. 

  17. Melanoma and nonmelanoma skin cancer chemoprevention: A role for nicotinamide?

    Science.gov (United States)

    Minocha, Rashi; Damian, Diona L; Halliday, Gary M

    2018-01-01

    Ultraviolet radiation (UVR) causes DNA damage in melanocytes by producing photolesions such as cyclobutane pyrimidine dimers and 8-oxo-7-hydrodeoxyguanosine. The production of reactive oxygen species by UVR also induces inflammatory cytokines that, together with the inherent immunosuppressive properties of UVR, propagate carcinogenesis. Nicotinamide (Vitamin B 3 ) enhances DNA repair, modulates the inflammatory environment produced by UVR, and reduces UV-induced immunosuppression. As nicotinamide reduces the incidence of actinic keratoses and nonmelanoma skin cancers in high-risk individuals and enhances repair of DNA damage in melanocytes, it is a promising agent for the chemoprevention of melanoma in high-risk populations. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Chemoprevention studies of the flavonoids quercetin and rutin in normal and azoxymethane-treated mouse colon.

    Science.gov (United States)

    Yang, K; Lamprecht, S A; Liu, Y; Shinozaki, H; Fan, K; Leung, D; Newmark, H; Steele, V E; Kelloff, G J; Lipkin, M

    2000-09-01

    In this study we investigated the chemopreventive effects of quercetin and rutin when added to standard AIN-76A diet and fed to normal and azoxymethane (AOM)-treated mice. Early changes in colonic mucosa were analyzed, including colonic cell proliferation, apoptotic cell death, cyclin D(1) expression and focal areas of dysplasia (FAD). The findings show that the number of colonic epithelial cells per crypt column increased (P: diet. The number of apoptotic cells/column and apoptotic indices markedly increased (P: diets supplemented either with quercetin (P: FAD. Both the number of mice exhibiting FAD and the total numer of FAD observed were significantly reduced (P: diet. Surprisingly, however, quercetin alone was able to induce FAD in 22% of normal mice fed the standard AIN-76A diet.

  19. Potential chemopreventive activity of a new macrolide antibiotic from a marine-derived Micromonospora sp.

    Science.gov (United States)

    Carlson, Skylar; Marler, Laura; Nam, Sang-Jip; Santarsiero, Bernard D; Pezzuto, John M; Murphy, Brian T

    2013-04-03

    Agents capable of inducing phase II enzymes such as quinone reductase 1 (QR1) are known to have the potential of mediating cancer chemopreventive activity. As part of a program to discover novel phase II enzyme-inducing molecules, we identified a marine-derived actinomycete strain (CNJ-878) that exhibited activity with cultured Hepa 1c1c7 cells. Based on this activity, a new macrolide, juvenimicin C (1), as well as 5-O-α-L-rhamnosyltylactone (2), were isolated from the culture broth of a Micromonospora sp. Compound 1 enhanced QR1 enzyme activity and glutathione levels by two-fold with CD values of 10.1 and 27.7 μM, respectively. In addition, glutathione reductase and glutathione peroxidase activities were elevated. This is the first reported member of the macrolide class of antibiotics found to mediate these responses.

  20. Chemopreventive and antioxidant activity of 6-substituted imidazo[2,1-b]thiazoles.

    Science.gov (United States)

    Andreani, Aldo; Leoni, Alberto; Locatelli, Alessandra; Morigi, Rita; Rambaldi, Mirella; Cervellati, Rinaldo; Greco, Emanuela; Kondratyuk, Tamara P; Park, Eun-Jung; Huang, Ke; van Breemen, Richard B; Pezzuto, John M

    2013-10-01

    The synthesis of new imidazo[2,1-b]thiazoles bearing phenolic groups is reported. These compounds and some previously described analogs were evaluated as antioxidant agents with three chemical model systems, and cancer chemopreventive potential was examined by inhibition of NO production, TNF-α activated NFκB activity, and aromatase activity, as well as induction of QR1 and RXRE binding. Two of the test compounds, 9 and 12, displayed promising activity by inhibiting iNOS, NFκB and aromatase in dose-dependent manner, with IC50 values in low micromolar range. The same compounds activated QR1 in a bifunctional manner. When incubated with human liver microsomes, the active compounds were further hydroxylated on the parent ring system, suggesting the next logical step in the development of these promising leads will entail synthetic production of metabolites followed by additional assessment of biological activity. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  1. Systemic retinoids for chemoprevention of non-melanoma skin cancer in high-risk patients.

    Science.gov (United States)

    Marquez, Christina; Bair, Sarah M; Smithberger, Erica; Cherpelis, Basil S; Glass, L Frank

    2010-07-01

    Patients at high risk for the development of multiple non-melanoma skin cancers, especially those receiving immunosuppressive medications following solid organ transplantation, are candidates for chemoprophylaxis. In patients where photo-protection and topical medications are insufficient to prevent the growth of new cancers, there is considerable evidence that oral retinoids, including vitamin A, and synthetics such as isotretinoin, etretinate and acitretin are efficacious in this regard. This manuscript is a review of the literature regarding the use of these agents for chemoprophylaxis of non-melanoma skin cancer. Also included is anecdotal evidence that bexarotene, a rexinoid, may be as effective as acitretin in terms of chemoprevention, with a comparable side effects at doses recommended for chemoprophylaxis.

  2. Potential Chemopreventive Activity of a New Macrolide Antibiotic from a Marine-Derived Micromonospora sp.

    Directory of Open Access Journals (Sweden)

    Brian T. Murphy

    2013-04-01

    Full Text Available Agents capable of inducing phase II enzymes such as quinone reductase 1 (QR1 are known to have the potential of mediating cancer chemopreventive activity. As part of a program to discover novel phase II enzyme-inducing molecules, we identified a marine-derived actinomycete strain (CNJ-878 that exhibited activity with cultured Hepa 1c1c7 cells. Based on this activity, a new macrolide, juvenimicin C (1, as well as 5-O-α-l-rhamnosyltylactone (2, were isolated from the culture broth of a Micromonospora sp. Compound 1 enhanced QR1 enzyme activity and glutathione levels by two-fold with CD values of 10.1 and 27.7 μM, respectively. In addition, glutathione reductase and glutathione peroxidase activities were elevated. This is the first reported member of the macrolide class of antibiotics found to mediate these responses.

  3. Fresh garlic extract inhibits Staphylococcus aureus biofilm formation under chemopreventive and chemotherapeutic conditions

    Directory of Open Access Journals (Sweden)

    Panan Ratthawongjirakul

    2016-08-01

    Full Text Available Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA are the leading aetiological pathogens of nosocomial infections worldwide. These bacteria form biofilms on both biotic and abiotic surfaces causing biofilm-associated infections. Within the biofilm, these bacteria might develop persistent and antimicrobial resistant characteristics resulting in chronic infections and treatment failures. Garlic exhibits broad pharmaceutical properties and inhibitory activities against S. aureus. We investigated the effects of aqueous fresh garlic extract on biofilm formation in S. aureus ATCC25923 and MRSA strains under chemopreventive and chemotherapeutic conditions. The viable bacteria and biofilm levels were quantified through colony count and crystal violet staining, respectively. The use of fresh garlic extract under both conditions significantly inhibited biofilm formation in S. aureus strains ATCC25923 and MRSA. Garlic could be developed as either a prophylactic or therapeutic agent to manage S. aureus biofilm-associated infections.

  4. Cancer Chemoprevention by Citrus Pulp and Juices Containing High Amounts of β-Cryptoxanthin and Hesperidin

    Science.gov (United States)

    Tanaka, Takuji; Tanaka, Takahiro; Tanaka, Mayu; Kuno, Toshiya

    2012-01-01

    β-Cryptoxanthin, a carotenoid, and hesperidin, a flavonoid, possess inhibitory effects on carcinogenesis in several tissues. We recently have prepared a pulp (CHRP) and citrus juices (MJ2 and MJ5) from a satsuma mandarin (Citrus unshiu Mar.) juice (MJ). They contain high amounts of β-cryptoxanthin and hesperidin. We have demonstrated that CHRP and/or MJs inhibit chemically induced rat colon, rat tongue, and mouse lung tumorigenesis. Gavage with CHRP resulted in an increase of activities of detoxifying enzymes in the liver, colon, and tongue rats'. CHRP and MJs were also able to suppress the expression of proinflammatory cytokines and inflammatory enzymes in the target tissues. This paper describes the findings of our in vivo preclinical experiments to develop a strategy for cancer chemoprevention of colon, tongue, and lung neoplasms by use of CHRP and MJs. PMID:22174562

  5. Cancer Chemoprevention by Citrus Pulp and Juices Containing High Amounts of β-Cryptoxanthin and Hesperidin

    Directory of Open Access Journals (Sweden)

    Takuji Tanaka

    2012-01-01

    Full Text Available β-Cryptoxanthin, a carotenoid, and hesperidin, a flavonoid, possess inhibitory effects on carcinogenesis in several tissues. We recently have prepared a pulp (CHRP and citrus juices (MJ2 and MJ5 from a satsuma mandarin (Citrus unshiu Mar. juice (MJ. They contain high amounts of β-cryptoxanthin and hesperidin. We have demonstrated that CHRP and/or MJs inhibit chemically induced rat colon, rat tongue, and mouse lung tumorigenesis. Gavage with CHRP resulted in an increase of activities of detoxifying enzymes in the liver, colon, and tongue rats'. CHRP and MJs were also able to suppress the expression of proinflammatory cytokines and inflammatory enzymes in the target tissues. This paper describes the findings of our in vivo preclinical experiments to develop a strategy for cancer chemoprevention of colon, tongue, and lung neoplasms by use of CHRP and MJs.

  6. Chemopreventive Effects of Magnesium Chloride Supplementation on Hormone Independent Prostate Cancer Cells

    Directory of Open Access Journals (Sweden)

    Elsa Quiroz

    2016-01-01

    Full Text Available Background: Lifestyle significantly impacts the risk factors associated with prostate cancer, out of which diet appears to be the most influential. An emerging chemopreventive approach, which involves the adequate intake of dietary constituents, has shown great potential in preventing the occurrence or progression of cancer. Magnesium is known to be an essential cofactor for more than 300 enzymatic processes, and is responsible for the regulation of various cellular reactions in the body. A plethora of studies have shown evidence that changes in the intracellular levels of magnesium could contribute to cell proliferation and apoptosis in some normal and malignant cells. The aim of the study was to investigate the effects of magnesium chloride (MgCl2 in DU-145 prostate cancer cells. Methodology: Cultured DU-145 cells were subjected to graded concentrations or doses (50-500 µM of MgCl2 for 48 hours. The cell viability was assessed using MTT and Resazurin reduction assays. NBT assay was also used to assess the treatment-induced intracellular ROS levels. Acridine Orange/Ethidium Bromide (AcrO/EtBr and Rh123/EtBr fluorescent stains were used to assess the cell death type and mitochondrial membrane potential (Δψm respectively. Results: The results revealed a dose-dependent decrease (P < 0.05 in cell viability in treated DU-145 cells after 48 hours. The NBT assay also revealed a dose dependent biphasic response (P < 0.05 in intracellular levels of ROS. There was a drop (P < 0.05 in ROS levels in all groups except at 100 µM, where ROS level was higher than the control. Apoptosis was the primary mode of cell death as observed in the fluorescence analysis. Conclusion: Our finding suggests that MgCl2 may be potentially chemopreventive for prostate cancer. This justifies further studies into its mechanism of action in DU-145 and other prostate cancer cell types.

  7. Personalizing Aspirin Use for Targeted Breast Cancer Chemoprevention in Postmenopausal Women.

    Science.gov (United States)

    Bardia, Aditya; Keenan, Tanya E; Ebbert, Jon O; Lazovich, DeAnn; Wang, Alice H; Vierkant, Robert A; Olson, Janet E; Vachon, Celine M; Limburg, Paul J; Anderson, Kristin E; Cerhan, James R

    2016-01-01

    To evaluate the association of aspirin and other nonsteroidal anti-inflammatory drugs with the incidence of postmenopausal breast cancer for risk subgroups defined by selected nonmodifiable or difficult to modify breast cancer risk factors in order to better understand the potential risk-benefit ratio for targeted chemoprevention. Postmenopausal women with no history of cancer on July 1, 1992 (N=26,580), were prospectively followed up through December 31, 2005, for breast cancer incidence (N=1581). Risk subgroups were defined on the basis of family history of breast cancer, age at menarche, age at menopause, parity/age at first live birth, personal history of benign breast disease, and body mass index. Hazard ratios (HRs) and 95% CIs adjusted for other breast cancer risk factors were estimated using Cox models. Aspirin use was associated with a lower incidence of breast cancer for women with a family history of breast cancer (HR, 0.62 for 6 or more times per week vs never use; 95% CI, 0.41-0.93) and those with a personal history of benign breast disease (HR, 0.69; 95% CI, 0.50-0.95) but not for women in higher-risk subgroups for age at menarche, age at menopause, parity/age at first live birth, or body mass index. In contrast, inverse associations with aspirin use were observed in all lower-risk subgroups. Nonsteroidal anti-inflammatory drug use had no association with breast cancer incidence. On the basis of their increased risk of breast cancer, postmenopausal women with a family history of breast cancer or a personal history of benign breast disease could potentially be targeted for aspirin chemoprevention studies. Future studies are needed to confirm these findings. Copyright © 2016 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  8. Potential toxicity of flavonoids and other dietary phenolics: significance for their chemopreventive and anticancer properties.

    Science.gov (United States)

    Galati, Giuseppe; O'Brien, Peter J

    2004-08-01

    Flavonoids, including isoflavones, are natural components in our diet and, with the burgeoning interest in alternative medicine, are increasingly being ingested by the general population. Plant phenolics, which form moieties on flavonoid rings, such as gallic acid, are also widely consumed. Several beneficial properties have been attributed to these dietary compounds, including antioxidant, anti-inflammatory, and anticarcinogenic effects. Flavonoid preparations are marketed as herbal medicines or dietary supplements for a variety of alleged nontoxic therapeutic effects. However, they have yet to pass controlled clinical trials for efficacy, and their potential for toxicity is an understudied field of research. This review summarizes the current knowledge regarding potential dietary flavonoid/phenolic-induced toxicity concerns, including their pro-oxidant activity, mitochondrial toxicity (potential apoptosis-inducing properties), and interactions with drug-metabolizing enzymes. Their chemopreventive activity in animal in vivo experiments may result from their ability to inhibit phase I and induce phase II carcinogen metabolizing enzymes that initiate carcinogenesis. They also inhibit the promotion stage of carcinogenesis by inhibiting oxygen radical-forming enzymes or enzymes that contribute to DNA synthesis or act as ATP mimics and inhibit protein kinases that contribute to proliferative signal transduction. Finally, they may prevent tumor development by inducing tumor cell apoptosis by inhibiting DNA topoisomerase II and p53 downregulation or by causing mitochondrial toxicity, which initiates mitochondrial apoptosis. While most flavonoids/phenolics are considered safe, flavonoid/phenolic therapy or chemopreventive use needs to be assessed as there have been reports of toxic flavonoid-drug interactions, liver failure, contact dermatitis, hemolytic anemia, and estrogenic-related concerns such as male reproductive health and breast cancer associated with dietary

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

    Directory of Open Access Journals (Sweden)

    Carina Michl

    Full Text Available 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.

  10. Design, synthesis, and biological evaluation of callophycin A and analogues as potential chemopreventive and anticancer agents.

    Science.gov (United States)

    Shen, Li; Park, Eun-Jung; Kondratyuk, Tamara P; Guendisch, Daniela; Marler, Laura; Pezzuto, John M; Wright, Anthony D; Sun, Dianqing

    2011-11-01

    Callophycin A was originally isolated from the red algae Callophycus oppositifolius and shown to mediate anticancer and cytotoxic effects. In our collaborative effort to identify potential chemopreventive and anticancer agents with enhanced potency and selectivity, we employed a tetrahydro-β-carboline-based template inspired by callophycin A for production of a chemical library. Utilizing a parallel synthetic approach, 50 various functionalized tetrahydro-β-carboline derivatives were prepared and assessed for activities related to cancer chemoprevention and cancer treatment: induction of quinone reductase 1 (QR1) and inhibition of aromatase, nitric oxide (NO) production, tumor necrosis factor (TNF)-α-induced NFκB activity, and MCF7 breast cancer cell proliferation. Biological results showed that the n-pentyl urea S-isomer 6a was the strongest inducer of QR1 with an induction ratio (IR) value of 4.9 at 50 μM [the concentration to double the activity (CD)=3.8 μM] and its corresponding R-isomer 6f had an IR value of 4.3 (CD=0.2 μM). The isobutyl carbamate derivative 3d with R stereochemistry demonstrated the most potent inhibitory activity of NFκB, with the half maximal inhibitory concentration (IC(50)) value of 4.8 μM, and also showed over 60% inhibition at 50 μM of NO production (IC(50)=2.8 μM). The R-isomer urea derivative 6j, having an appended adamantyl group, exhibited the most potent MCF7 cell proliferation inhibitory activity (IC(50)=14.7 μM). The S-isomer 12a of callophycin A showed the most potent activity in aromatase inhibition (IC(50)=10.5 μM). Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. 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.

  12. Risicogrenzen voor MTBE (Methyl tertiair-Butyl Ether) in bodem, sediment, grondwater, oppervlaktewater en voor drinkwaterbereiding

    NARCIS (Netherlands)

    Swartjes FA; Baars AJ; Fleuren RHLJ; Otte PF; LER

    2004-01-01

    Recentelijk is politieke commotie ontstaan ten gevolge van de mogelijke schadelijke gezondheidseffecten van Methyl tertiair-Butyl Ether (MTBE). Dit was reden voor het ministerie van VROM om het RIVM te verzoeken risicogrenzen voor MTBE in bodem, sediment, grondwater, oppervlaktewater, drinkwater en

  13. Risicogrenzen voor MTBE (Methyl tertiair-Butyl Ether) in bodem, sediment, grondwater, oppervlaktewater en voor drinkwaterbereiding

    NARCIS (Netherlands)

    Swartjes FA; Baars AJ; Fleuren RHLJ; Otte PF; LER

    2004-01-01

    Recently, possible unacceptable harmful effects from Methyl tertiary-Butyl Ether (MTBE) to humans raised political consternation. For this reason the Dutch Ministry of Housing, Spatial Planning and the Environment ("VROM") ordered the RIVM to derive solid risk limits for soil, sediment,

  14. 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.

  15. Process Intensification of Enzymatic Fatty Acid Butyl Ester Synthesis Using a Continuous Centrifugal Contactor Separator

    NARCIS (Netherlands)

    Ilmi, Miftahul; Abduh, Muhammad Yusuf; Hommes, Arne; Winkelman, Jozef; Hidayat, C.; Heeres, Hero

    2018-01-01

    Fatty acid butyl esters were synthesized from sunflower oil with 1-butanol using a homogeneous Rhizomucor miehei lipase in a biphasic organic (triglyceride, 1-butanol, hexane)– water (with enzyme) system in a continuous setup consisting of a cascade of a stirred tank reactor and a continuous

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. Enhanced diisobutene production in the presence of methyl tertiary butyl ether

    Science.gov (United States)

    Smith, L.A. Jr.

    1983-03-01

    In the liquid phase reaction of isobutene in the presence of resin cation exchange resins with itself in a C[sub 4] hydrocarbon stream to form dimers, the formation of higher polymers, oligomers, and co-dimer by-products is suppressed by the presence of 0.0001 to 1 mole per mole of isobutene of methyl tertiary butyl ether. 1 fig.

  1. IRIS Toxicological Review of Ethylene Glycol Mono-Butyl Ether (Egbe) (Interagency Science Discussion Draft)

    Science.gov (United States)

    EPA released the draft report, Toxicological Review for Ethylene Glycol Mono-Butyl Ether , that was distributed to Federal agencies and White House Offices for comment during the Science Discussion step of the IRIS Assessment Development Process. Comments received from ot...

  2. Impact of activation methods on persulfate oxidation of methyl tert-butyl ether.

    Science.gov (United States)

    Deng, Dayi; Peng, Libin; Guan, Mengyun; Kang, Yuan

    2014-01-15

    To provide guidance on the selection of proper persulfate processes for the remediation of MTBE contaminated groundwater, MTBE aqueous solutions were treated with three common field persulfate processes including heat activated persulfate, Fe(III)-EDTA activated persulfate and alkaline persulfate, respectively. The results were compared with MTBE oxidation by Fenton's reagent and persulfate alone at 25°C. The impact of the activating conditions on the fate of MTBE and its daughter products was investigated. Heat activation at 40°C offered the most rapid removal of MTBE and its daughter products, while Fe(III)-EDTA activation showed higher efficiency of MTBE removal but low removal efficiency of its daughter products. On the other hand, alkaline persulfate showed slower kinetics for the removal of MTBE and less accumulation of the daughter products. Furthermore, tert-butyl alcohol and acetone were observed as the main purgeable daughter products along with a small amount of tert-butyl formate in persulfate oxidation of MTBE, while tert-butyl formate, tert-butyl alcohol and acetone were the main products in Fenton oxidation. Mechanistic analysis suggests that degradation of MTBE by persulfate most likely happens via non-oxygen demand pathways, different from the dominant oxygen demand degradation pathways observed in Fenton oxidation. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. An Evaluation of the Human Carcinogenic Potential of Ethylene Glycol Butyl Ether (Egbe)

    Science.gov (United States)

    This position paper, An Evaluation of the Human Carcinogenic Potential of Ethylene Glycol Butyl Ether, was developed in support of the EPA's evaluation of a petition from the American Chemistry Council requesting to delist EGBE per the Clean Air Act Amendments (CAAA), Titl...

  4. 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...

  5. (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.

  6. Enzymatic synthesis of butyl hydroxycinnamates and their inhibitory effects on LDL-oxidation.

    Science.gov (United States)

    Vafiadi, Christina; Topakas, Evangelos; Alissandratos, Apostolos; Faulds, Craig B; Christakopoulos, Paul

    2008-02-29

    The potential of the Aspergillus niger type A feruloyl esterase (AnFaeA) for the synthesis of various phenolic acid esters was examined using a ternary-organic reaction system consisting of a mixture of n-hexane, 1- or 2-butanol and water. Reaction parameters including the type of methyl hydroxycinnamate, the composition of the reaction media, the temperature, and the substrate concentration were investigated to evaluate their effect on initial rate and conversion to butyl esters of sinapic acids. Optimisation of the reaction parameters lead to 78% and 9% yield for the synthesis of 1-butyl and 2-butyl sinapate, respectively. For the first time, a feruloyl esterase was introduced in the reaction system as cross-linked enzyme aggregates (CLEAs), after optimisation of the immobilisation procedure, allowing the recycling and reuse of the biocatalyst. The inhibition of copper-induced LDL oxidation by hydroxycinnamic acids and their corresponding butyl esters was investigated in vitro. Kinetic analysis of the antioxidation process demonstrates that sinapate derivatives are effective antioxidants indicating that esterification increases the free acid's antioxidant activity especially on dimethoxylated compounds such as sinapic acid compared to methoxy-hydroxy-compounds such as ferulic acid.

  7. Studies on ethylene-propylene-diene rubber modification by N-chlorothio-N-butyl-benzenesulfonamide

    NARCIS (Netherlands)

    Zhang, Hongmei; Datta, Rabin; Talma, Auke; Noordermeer, Jacobus W.M.

    2009-01-01

    N-Chlorothiosulfonamides have been used to modify ethylene-propylene-diene rubber (EPDM) to enhance the compatibility of EPDM in, e.g., natural rubber (NR)/butadiene rubber (BR)/EPDM blends for ozone resistance. N-Chlorothio-N-butyl-benzenesulfonamide (CTBBS) was selected as a representative for

  8. 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.

  9. Morphology and film formation of poly(butyl methacrylate)-polypyrrole core-shell latex particles

    NARCIS (Netherlands)

    Huijs, F; Lang, J

    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

  10. 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...

  11. Inducing PLA/starch compatibility through butyl-etherification of waxy and high amylose starch

    CSIR Research Space (South Africa)

    Wokadala, OC

    2014-06-01

    Full Text Available Carbohydrate Polymers Vol. 112 Inducing PLA/starch compatibility through butyl-etherification ofwaxy and high amylose starch Obiro Cuthbert Wokadalaa,b, Naushad Mohammad Emmambuxc,Suprakas Sinha Raya,b,c,∗ aDST/CSIR National Centre for Nanostructured...

  12. 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...

  13. 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 anhydrid...

  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. 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...... bed reactor, was determined using a batch kinetic based approach. The procedure involved modeling of methyl tert-butyl ether removal rates from batch experiments followed by parameter estimations. It was estimated to be 5-14% (w/w) of the measured volatile suspended solids concentration in the reactor....

  16. Development of novel cancer chemopreventive agents in Europe--neglected Cinderella or rising phoenix? A critical commentary. ESF Workshop on Cancer Chemoprevention, DKFZ, Heidelberg, September 18-20, 2005.

    Science.gov (United States)

    Gerhauser, Clarissa; Bartsch, Helmut; Crowell, James; De Flora, Silvio; D'Incalci, Maurizio; Dittrich, Christian; Frank, Norbert; Mihich, Enrico; Steffen, Christian; Tortora, Giampaolo; Gescher, Andreas

    2006-07-01

    Agents that prevent cancer, delay its onset, or revert premalignant conditions could have dramatic beneficial impacts on human health. Although there is an urgent need to develop cancer chemopreventive agents, researchers in the field suspect that this area of scientific endeavour in Europe leads a Cinderella existence, both in terms of perception of importance and research funding. In order to review current activities in this prevention field and to seek a consensus position, an exploratory workshop was held in September 2005 at the German Cancer Research Center (DKFZ) in Heidelberg, Germany, sponsored mainly by the European Science Foundation (ESF), and also supported by the European Association for Cancer Research (EACR) and the German Cancer Society (DKG). The 35 experts from European countries and the United States of America assessed state-of-the-art cancer chemoprevention research in Europe. The aims that the workshop organizers had pre-defined were: i) assessment of the usefulness of animal models for agent identification; ii) review of ongoing preclinical and clinical work on novel agents; iii) discussion of potential biomarkers predictive for cancer preventive efficacy; and finally iv) the potential role that European pharmaceutical industries could play in furthering chemopreventive agent development. Overall the workshop aimed at raising awareness among European clinical and laboratory researchers of the importance of the development of novel, efficacious and safe cancer preventive agents.

  17. Selenium Supranutrition: Are the Potential Benefits of Chemoprevention Outweighed by the Promotion of Diabetes and Insulin Resistance?

    Science.gov (United States)

    Rocourt, Caroline R. B.; Cheng, Wen-Hsing

    2013-01-01

    Selenium was considered a toxin until 1957, when this mineral was shown to be essential in the prevention of necrotic liver damage in rats. The hypothesis of selenium chemoprevention is principally formulated by the observations that cancer incidence is inversely associated with selenium status. However, recent clinical and epidemiological studies demonstrate a role for some selenoproteins in exacerbating or promoting other disease states, specifically type 2 diabetes, although other data support a role of selenium in stimulating insulin sensitivity. Therefore, it is clear that our understanding in the role of selenium in glucose metabolism and chemoprevention is inadequate and incomplete. Research exploring the role of selenium in individual healthcare is of upmost importance and possibly will help explain how selenium is a double-edged sword in the pathologies of chronic diseases. PMID:23603996

  18. Chemopreventive effects of aloin against 1,2-dimethylhydrazine-induced preneoplastic lesions in the colon of Wistar rats.

    Science.gov (United States)

    Hamiza, O O; Rehman, M U; Khan, R; Tahir, M; Khan, A Q; Lateef, A; Sultana, S

    2014-02-01

    Chemoprevention opens new window in the prevention of all types of cancers including colon cancer. Aloin, an anthracycline in plant pigment, can be utilized as a protective agent in cancer induction. In the present study, we have evaluated the chemopreventive efficacy of aloin against 1,2-dimethylhydrazine (DMH)-induced preneoplastic lesions in the colon of Wistar rats. DMH-induced aberrant crypt foci (ACF) and mucin-depleted foci (MDF) have been used as biomarkers of colon cancer. Efficacy of aloin against the colon toxicity was evaluated in terms of biochemical estimation of antioxidant enzyme activities, lipid peroxidation, ACF, MDF, histopathological changes, and expression levels of molecular markers of inflammation and tumor promotion. Aloin pretreatment ameliorates the damaging effects induced by DMH through a protective mechanism that involved reduction in increased oxidative stress enzymes (p aloin clearly protects against chemically induced colon toxicity and acts reasonably by inducing antioxidant level, anti-inflammatory and antiproliferative markers.

  19. 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.

  20. A novel combinatorial nanotechnology-based oral chemopreventive regimen demonstrates significant suppression of pancreatic cancer neoplastic lesions.

    Science.gov (United States)

    Grandhi, B Karthik; Thakkar, Arvind; Wang, Jeffrey; Prabhu, Sunil

    2013-10-01

    Pancreatic cancer is a deadly disease killing 37,000 Americans each year. Despite two decades of research on treatment options, the chances of survival are still less than 5% upon diagnosis. Recently, chemopreventive strategies have gained considerable attention as an alternative to treatment. We have previously shown significant in vitro chemopreventive effects with low-dose combinations of aspirin, curcumin, and sulforaphane (ACS) on pancreatic cancer cell lines. Here, we report the results of 24-week chemopreventive study with the oral administration of ACS combinations on the N-nitrosobis (2-oxopropyl) amine (BOP)-treated Syrian golden hamster model to suppress the progression of pancreatic intraepithelial neoplasms (PanIN) using unmodified (free drug) combinations of ACS, and nanoencapsulated (solid lipid nanoparticles; SLN) combinations of aspirin, curcumin, and free sulforaphane. The use of three different doses (low, medium, and high) of unmodified ACS combinations exhibited reduction in tumor incidence by 18%, 50%, and 68.7% respectively; whereas the modified nanoencapsulated ACS regimens reduced tumor incidence by 33%, 67%, and 75%, respectively, at 10 times lower dose compared with the free drug combinations. Similarly, although the unmodified free ACS showed a notable reduction in cell proliferation, the SLN encapsulated ACS regimens showed significant reduction in cell proliferation at 6.3%, 58.6%, and 72.8% as evidenced by proliferating cell nuclear antigen expression. Cell apoptotic indices were also upregulated by 1.5, 2.8, and 3.2 times, respectively, compared with BOP control. These studies provide a proof-of-concept for the use of an oral, low-dose, nanotechnology-based combinatorial regimen for the long-term chemoprevention of pancreatic cancer.

  1. Spectral biomarkers for chemoprevention of colonic neoplasia: a placebo-controlled double-blinded trial with aspirin.

    Science.gov (United States)

    Roy, Hemant K; Turzhitsky, Vladimir; Wali, Ramesh; Radosevich, Andrew J; Jovanovic, Borko; Della'Zanna, Gary; Umar, Asad; Rubin, David T; Goldberg, Michael J; Bianchi, Laura; De La Cruz, Mart; Bogojevic, Andrej; Helenowski, Irene B; Rodriguez, Luz; Chatterton, Robert; Skripkauskas, Silvia; Page, Katherine; Weber, Christopher R; Huang, Xiaoke; Richmond, Ellen; Bergan, Raymond C; Backman, Vadim

    2017-02-01

    A major impediment to translating chemoprevention to clinical practice has been lack of intermediate biomarkers. We previously reported that rectal interrogation with low-coherence enhanced backscattering spectroscopy (LEBS) detected microarchitectural manifestations of field carcinogenesis. We now wanted to ascertain if reversion of two LEBS markers spectral slope (SPEC) and fractal dimension (FRAC) could serve as a marker for chemopreventive efficacy. We conducted a multicentre, prospective, randomised, double-blind placebo-controlled, clinical trial in subjects with a history of colonic neoplasia who manifested altered SPEC/FRAC in histologically normal colonic mucosa. Subjects (n=79) were randomised to 325 mg aspirin or placebo. The primary endpoint changed in FRAC and SPEC spectral markers after 3 months. Mucosal levels of prostaglandin E2 (PGE2) and UDP-glucuronosyltransferase (UGT)1A6 genotypes were planned secondary endpoints. At 3 months, the aspirin group manifested alterations in SPEC (48.9%, p=0.055) and FRAC (55.4%, p=0.200) with the direction towards non-neoplastic status. As a measure of aspirin's pharmacological efficacy, we assessed changes in rectal PGE2 levels and noted that it correlated with SPEC and FRAC alterations (R=-0.55, p=0.01 and R=0.57, p=0.009, respectively) whereas there was no significant correlation in placebo specimens. While UGT1A6 subgroup analysis did not achieve statistical significance, the changes in SPEC and FRAC to a less neoplastic direction occurred only in the variant consonant with epidemiological evidence of chemoprevention. We provide the first proof of concept, albeit somewhat underpowered, that spectral markers reversion mirrors antineoplastic efficacy providing a potential modality for titration of agent type/dose to optimise chemopreventive strategies in clinical practice. NCT00468910. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go

  2. 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.

  3. Cast Nanostructured Films of Poly(methyl methacrylate-b-butyl acrylate)/Carbon Nanotubes: Influence of Poly(butyl acrylate) Content on Film Evaporation Rate, Morphology, and Electrical Resistance

    National Research Council Canada - National Science Library

    Soriano-Corral, F; Ramos-de Valle, L. F; Enríquez-Medrano, F. J; De León-Martínez, P. A; López-Quintanilla, M. L; Cabrera-Álvarez, E. N

    2012-01-01

      Nanocomposites of poly(methyl methacrylate-b-butyl acrylate)/multiwalled carbon nanotubes were prepared from different copolymers synthesized by RITP technique using iodine functionalized poly(methyl methacrylate...

  4. Chemopreventive efficacy of menthol on carcinogen-induced cutaneous carcinoma through inhibition of inflammation and oxidative stress in mice.

    Science.gov (United States)

    Liu, Zhaoguo; Shen, Cunsi; Tao, Yu; Wang, Siliang; Wei, Zhonghong; Cao, Yuzhu; Wu, Hongyan; Fan, Fangtian; Lin, Chao; Shan, Yunlong; Zhu, Pingting; Sun, Lihua; Chen, Chen; Wang, Aiyun; Zheng, Shizhong; Lu, Yin

    2015-08-01

    Inflammation and oxidative stress have been implicated in various pathological processes including skin tumorigenesis. Skin cancer is the most common form of cancer responsible for considerable morbidity and mortality, the treatment progress of which remains slow though. Therefore, chemoprevention and other strategies are being considered. Menthol has shown high anticancer activity against various human cancers, but its effect on skin cancer has never been evaluated. We herein investigated the chemopreventive potential of menthol against 9,10-dimethylbenz[a]anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation, oxidative stress and skin carcinogenesis in female ICR mice. Pretreatment with menthol at various doses significantly suppressed tumor formation and growth, and markedly reduced tumor incidence and volume. Moreover, menthol inhibited TPA-induced skin hyperplasia and inflammation, and significantly suppressed the expression of cyclooxygenase-2 (COX-2). Furthermore, pretreatment with menthol inhibited the formation of reactive oxygen species and affected the activities of a battery of antioxidant enzymes in the skin. The expressions of NF-κB, Erk and p38 were down-regulated by menthol administration. Thus, inflammation and oxidative stress collectively played a crucial role in the chemopreventive efficacy of menthol on the murine skin tumorigenesis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. 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.

  6. 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.

  7. Chemopreventive and immunomodulatory effects of Murraya koenigii aqueous extract on 4T1 breast cancer cell-challenged mice.

    Science.gov (United States)

    Yeap, Swee Keong; Abu, Nadiah; Mohamad, Nurul Elyani; Beh, Boon Kee; Ho, Wan Yong; Ebrahimi, Siamak; Yusof, Hamidah Mohd; Ky, Huynh; Tan, Sheau Wei; Alitheen, Noorjahan Banu

    2015-09-04

    The progression of breast cancer is increasing at an alarming rate, particularly in western countries. Meanwhile, the lower incidence in Asian countries could be attributed to the heavy incorporation of green leaves vegetables or spices in their diets. Murraya koenigii (MK) or often times known as curry leaves are common spice used mostly in tropical countries. Anti-inflammatory and chemopreventive effects of MK aqueous extract on 4T1 breast cancer cell-challenged mice were evaluated. Herein, cytotoxic activity of MK was first tested on 4T1 cells in vitroby MTT assay. Then, in vivo chemopreventive study was conducted where mice were fed with extracts prior to and after inducing the tumor (inoculation). Tumor size was monitored post-4T1 inoculation. At the end of experiment, histopathology of tumor sections, T cell immunophenotyping, tumor nitric oxide level, serum cytokine level and qPCR analysis on expression of iNOS, iCAM, NF-kB and c-MYC were performed. MK reduced the tumors' size and lung metastasis aside from inhibited the viability of 4T1 cells in vitro. Furthermore, it decreased the level of nitric oxide and inflammation-related cytokines and genes, including iNOS, iCAM, NF-kB and c-MYC. The results propose that, MK managed to inhibit the progression of tumor via immunostimulatory effect and inflammatory reaction within the tumor samples. This suggests that MKconsumption could be a savior in the search of new chemopreventive agents.

  8. Chemopreventive and adjuvant therapeutic potential of pomegranate (Punica granatum) for human breast cancer.

    Science.gov (United States)

    Kim, Nam Deuk; Mehta, Rajendra; Yu, Weiping; Neeman, Ishak; Livney, Talia; Amichay, Akiva; Poirier, Donald; Nicholls, Paul; Kirby, Andrew; Jiang, Wenguo; Mansel, Robert; Ramachandran, Cheppail; Rabi, Thangaiyan; Kaplan, Boris; Lansky, Ephraim

    2002-02-01

    Fresh organically grown pomegranates (Punica granatum L.) of the Wonderful cultivar were processed into three components: fermented juice, aqueous pericarp extract and cold-pressed or supercritical CO2-extracted seed oil. Exposure to additional solvents yielded polyphenol-rich fractions ('polyphenols') from each of the three components. Their actions, and of the crude whole oil and crude fermented and unfermented juice concentrate, were assessed in vitro for possible chemopreventive or adjuvant therapeutic potential in human breast cancer. The ability to effect a blockade of endogenous active estrogen biosynthesis was shown by polyphenols from fermented juice, pericarp, and oil, which inhibited aromatase activity by 60-80%. Fermented juice and pericarp polyphenols, and whole seed oil, inhibited 17-beta-hydroxysteroid dehydrogenase Type 1 from 34 to 79%, at concentrations ranging from 100 to 1,000 microg/ml according to seed oil > fermented juice polyphenols > pericarp polyphenols. In a yeast estrogen screen (YES) lyophilized fresh pomegranate juice effected a 55% inhibition of the estrogenic activity of 17-beta-estradiol; whereas the lyophilized juice by itself displayed only minimal estrogenic action. Inhibition of cell lines by fermented juice and pericarp polyphenols was according to estrogen-dependent (MCF-7) > estrogen-independent (MB-MDA-231) > normal human breast epithelial cells (MCF-10A). In both MCF-7 and MB-MDA-231 cells, fermented pomegranate juice polyphenols consistently showed about twice the anti-proliferative effect as fresh pomegranate juice polyphenols. Pomegranate seed oil effected 90% inhibition of proliferation of MCF-7 at 100 microg/ml medium, 75% inhibition of invasion of MCF-7 across a Matrigel membrane at 10 microg/ml, and 54% apoptosis in MDA-MB-435 estrogen receptor negative metastatic human breast cancer cells at 50 microg/ml. In a murine mammary gland organ culture, fermented juice polyphenols effected 47% inhibition of cancerous

  9. 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

  10. Effect of thyme/cumin essential oils and butylated hydroxyl anisole/butylated hydroxyl toluene on physicochemical properties and oxidative/microbial stability of chicken patties.

    Science.gov (United States)

    Sariçoban, Cemalettin; Yilmaz, Mustafa Tahsin

    2014-02-01

    In this study, effects of thyme/cumin essential oils (EO) and butylated hydroxyl anisole (BHA)/butylated hydroxyl toluene (BHT) on physicochemical properties and storage stability of chicken patties were compared in different storage periods (0, 3, 7, 14, 21, and 28 d). It was found that there were significant (P < 0.05) differences between physicochemical properties of patty samples treated with EO and the synthetic antioxidants. The EO showed similar performance to those of BHA and BHT in limiting TBARS values of chicken patty samples. Similarity in performance was also the case for microbial stability (total aerobic mesophilic, psychrotrophic, lactic acid, and coliform bacteria as well as molds and yeasts); namely, their effects were significant (P < 0.05). Effect of thyme EO was significant (P < 0.05) and remarkable, not allowing any coliform bacteria to grow in the samples. Given that EO were obtained from natural sources, the data suggested that the EO might be more useful than their synthetic counterparts, BHA and BHT, as additives for chicken patties to maintain oxidative/microbial stability and increase shelf life.

  11. Process Intensification of Enzymatic Fatty Acid Butyl Ester Synthesis Using a Continuous Centrifugal Contactor Separator.

    Science.gov (United States)

    Ilmi, Miftahul; Abduh, Muhammad Y; Hommes, Arne; Winkelman, Jozef G M; Hidayat, Chusnul; Heeres, Hero J

    2018-01-17

    Fatty acid butyl esters were synthesized from sunflower oil with 1-butanol using a homogeneous Rhizomucor miehei lipase in a biphasic organic (triglyceride, 1-butanol, hexane)- water (with enzyme) system in a continuous setup consisting of a cascade of a stirred tank reactor and a continuous centrifugal contactor separator (CCCS), the latter being used for integrated reaction and liquid-liquid separation. A fatty acid butyl ester yield up to 93% was obtained in the cascade when operated in a once-through mode. The cascade was run for 8 h without operational issues. Enzyme recycling was studied by reintroduction of the water phase from the CCCS outlet to the stirred tank reactor. Product yield decreased over time to an average of 50% of the initial value, likely due to accumulation of 1-butanol in water phase, loss of enzyme due to agglomeration, and the formation of a separate enzyme layer.

  12. Di-n-butylbis(N-n-butyl-N-ethyldithiocarbamato-κStin(IV

    Directory of Open Access Journals (Sweden)

    Seik Weng Ng

    2009-05-01

    Full Text Available The Sn atom in the title compound, [Sn(C4H92(C7H14NS22], exists in a tetrahedral C2S2Sn coordination geometry. The geometry is distorted towards skew-trapezoidal-bipyramidal owing to the proximity of the double-bond S atoms [Sn—S = 2.521 (2 and Sn...S = 2.933 (2 Å]. The Sn atom lies on a special position of mm2 site symmetry and the tin-bound n-butyl chain is disordered about a mirror plane. The ethyl and n-butyl groups of the dithiocarbamate unit are disordered about another mirror plane.

  13. 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.

  14. 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.

  15. 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.

  16. Pulmonary embolism after endoscopic injection with N-butyl-2-cyanoacrylate for gastric varices

    Directory of Open Access Journals (Sweden)

    Gabriela Robaina

    2016-12-01

    Full Text Available Gastric varices occur in one-third of patients with portal hypertension. Bleeding from gastric varices remains a significant cause of death. Currently the first-line of treatment for gastric varices is endoscopic obliteration with N-butyl-2-cyanoacrylate. Though relatively safe, this option has several well-known complications. We report the case of a 61-year-old male patient with cryptogenic cirrhosis, who presented with fever, tachycardia and hypoxemia after endoscopic obliteration with N-butyl-2-cyanoacrylate. Radiographic findings were consistent with pulmonary embolism of the sclerosing substance. The aim of this case report is to emphasize the clinical and radiological findings of this complication in order to distinguish it from other similar medical conditions and prevent a delay in diagnosis

  17. The Effect of Hydrogen Bonding on Radical Semi-Batch Copolymerization of Butyl Acrylate and 2-Hydroxyethyl Acrylate

    National Research Council Canada - National Science Library

    Jan E S Schier; David Cohen-Sacal; Owen R Larsen; Robin A Hutchinson

    2017-01-01

    The radical copolymerization of butyl acrylate (BA) and 2-hydroxyethyl acrylate (HEA) was investigated under batch and semi-batch operations, with a focus on the influence of hydrogen-bonding on acrylate backbiting...

  18. Health Risk Assessment for Inhalation Exposure to Methyl Tertiary Butyl Ether at Petrol Stations in Southern China

    National Research Council Canada - National Science Library

    Hu, Dalin; Yang, Jianping; Liu, Yungang; Zhang, Wenjuan; Peng, Xiaowu; Wei, Qinzhi; Yuan, Jianhui; Zhu, Zhiliang

    2016-01-01

    Methyl tertiary butyl ether (MTBE), a well known gasoline additive, is used in China nationwide to enhance the octane number of gasoline and reduce harmful exhaust emissions, yet little is known regarding the potential health risk...

  19. 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.

  20. The role of n-butyl-2-cyanoacrylate in the repair of traumatic diaphragmatic injuries

    Science.gov (United States)

    Bas, Gurhan; Ozkan, Orhan Veli; Alimoglu, Orhan; Eryilmaz, Ramazan; Sahin, Mustafa; Okan, Ismail; Cevikbas, Ugur

    2015-01-01

    Diaphragmatic injuries either by blunt or penetrating trauma require prompt surgical intervention and are often exigent to repair. N-butyl-2-cyanoacrylate (n-butyl-2-CA) is a tissue adhesive which has gained wide application in many areas of surgery including emergency. To repair the extensive injuries of the diaphragm it may be necessary the use of synthetic mesh by fixing it with sutures or staples. The use of tissue adhesives may circumvent the potential problems associated with mesh fixation. This study aimed to evaluate the efficacy and safety of tissue adhesives usage for mesh fixation in diaphragmatic injury repair. Twenty-four rats were divided into 3 groups each of them containing 8 rats. A 1- cm diaphragmatic defect was created in all rats. The defect was repaired by polypropylene suture in Group I, by mesh fixed with sutures in group II and by mesh fixed with n-butyl-2-CA in group III. The rats were sacrificed after 1 month. The episode of hernia and the adhesions were assessed by adhesion density score. Also, the abscess and inflammation in the repaired tissue were evaluated microscopically. The Kruskal-Wallis test was performed for the histopathological analysis. No diaphragmatic hernia was detected in any group. While Group III had higher adhesion density scores than group I (P: 0.027), there were no differences between group III and II (P: 0.317) and group II and I (P = 0.095) regarding adhesion density scores. The inflammation grade was higher in group III than group I and II (P 0.05). Repair of traumatic diaphragmatic injury in penetrating wound, with polypropylene mesh fixed by n-butyl-2-CA in rats appears to be as efficacious and safe as conventional methods in early period. However, further experimental and clinical study are needed to compare the long-term results of adhesive mesh repair with those of the traditional sutured techniques. PMID:26131179

  1. Artificial Neural Network Approach to Predict Biodiesel Production in Supercritical tert-Butyl Methyl Ether

    OpenAIRE

    Obie Farobie; Nur Hasanah

    2016-01-01

    In this study, for the first time artificial neural network was used to predict biodiesel yield in supercritical tert-butyl methyl ether (MTBE). The experimental data of biodiesel yield conducted by varying four input factors (i.e. temperature, pressure, oil-to-MTBE molar ratio, and reaction time) were used to elucidate artificial neural network model in order to predict biodiesel yield. The main goal of this study was to assess how accurately this artificial neural network model to predict b...

  2. Reverse osmosis performance with solutions containing tri-n-butyl phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Siler, J.L.

    1991-10-22

    Tests were conducted to determine whether the reverse osmosis (RO) units at the F/H Effluent Treatment Facility (ETF) at the Savannah River could be made to process solutions containing tri-n-butyl phosphate (TBP). It was desired to test whether operation at a feed pH other than neutral would improve performance. Test results are discussed in this report and indicate that little improvement in the water flux can be expected at other pH values.

  3. High Solid Contents Copoly (Styrene/Butyl Acrylate)-Cloisite 30B Nanocomposites

    OpenAIRE

    M. Mirzataheri

    2013-01-01

    Higher solid contents (20 % and 40 %) nanocomposites of poly (styrene-co-butyl acrylate) including higher content of Cloisite 30B (7 wt% and 10 wt %) were prepared via miniemulsion polymerization. Stability of the final latexes proved outstanding combination of polymerization procedure and surfactants. Morphological studies revealed by TEM, SAX and XRD showed three structures of core-shell, armored and individual dispersion of clay layers within the polymer particles. The effect of Cloisite 3...

  4. 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.

  5. 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.

  6. Synthesis, Characterization and Evaluation of the Transformations in Hibiscus sabdariffa-graft-poly(butyl acrylate

    Directory of Open Access Journals (Sweden)

    B. S. Kaith

    2008-01-01

    Full Text Available 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 of the graft copolymers.

  7. Solvation of 1-butyl-3-methylimidazolium hexafluorophosphate in aqueous ethanol--a green solution for dissolving 'hydrophobic' ionic liquids.

    Science.gov (United States)

    Swatloski, R P; Visser, A E; Reichert, W M; Broker, G A; Farina, L M; Holbrey, J D; Rogers, R D

    2001-10-21

    The relatively hydrophobic ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate has been found to be totally miscible with aqueous ethanol between 0.5 and 0.9 mol fraction ethanol, whereas the ionic liquid is only partially miscible with either pure water or absolute ethanol; the ability to dissolve 1-butyl-3-methylimidazolium hexafluorophosphate in a 'green' aqueous solvent system has important implications for cleaning, purification, and separations using ionic liquids.

  8. Tert-butyl alcohol used to fabricate nano-cellulose aerogels via freeze-drying technology

    Science.gov (United States)

    Wang, Xiaoyu; Zhang, Yang; Jiang, Hua; Song, Yuxuan; Zhou, Zhaobing; Zhao, Hua

    2017-06-01

    Aerogel, a highly porous material, is attracting increasing attention owing to low thermal conductivity and high specific surface area. Freeze-drying technology has been employed to produce nano-cellulose aerogels; however, the resultant product has low specific surface areas. Here, a modified approach to prepare nano-cellulose aerogels was reported, which involves tert-butyl alcohol as a solvent. Nano-cellulose aerogels were prepared via a spontaneous gelation fashion using calcium chloride solution, followed by tert-butyl alcohol solvent displacement and freeze drying. Addition of calcium chloride (0.25%) accelerated the physical gelation process. The application of tert-butyl alcohol as a solvent contributed to preservation of gel network. The obtained spherical nano-cellulose aerogels had a shrinkage rate of 5.89%. The specific surface area and average pore size was 164. 9666 m2 g-1 and 10.01 nm, respectively. Additionally, nano-cellulose aerogels had a comparable thermal degradation property when compared to microcrystalline cellulose. These biophysical properties make nano-cellulose aerogels as a promising absorption material.

  9. [Degradation of methyl tert-butyl ether (MTBE) by O3/H2O2].

    Science.gov (United States)

    Hu, Qin-Hai; Mao, Ke-Hui; Zhu, Miao-Jun; Zhang, Xing-Qing; Xiong, Yun-Long; Wang, Juan

    2008-05-01

    The degradation of methyl tert-butyl ether (MTBE) in water solution has been studied using the combination of ozone/hydrogen peroxide in a bubble column. Effects of air (containing O3) currents, quantities of H2O2, initial concentrations of MTBE, pH values and temperatures on the oxidation of MTBE have been tested, and it is implicated that under the conditions of initial MTBE concentration of 10 mg x L(-1), air current of 0.5 L x min(-1), pH 6.5, 293 K and 2.4 mg x L(-1) H2O2 addition, MTBE can be reduced by 75.5% and the removal rate of COD reaches 68.0% within 30 min. The main of degradation products identified are tert-butyl formate (TBF), tert-butyl alcohol (TBA), acetone (AC) and methyl acetate (MA). On the basis of that, the probable mechanism and pathway of the oxidation of MTBE by ozone/hydrogen peroxide have been proposed.

  10. Synthesis and Characterization of a Gasoline Oxygenate, Ethyl tert-Butyl Ether

    Science.gov (United States)

    Donahue, Craig J.; D'Amico, Teresa; Exline, Jennifer A.

    2002-06-01

    A laboratory procedure involving the synthesis and characterization of ethyl tert-butyl ether (ETBE) is described. This experiment has been used in a general chemistry sequence that includes a section on organic chemistry, but is also well suited for an introductory organic chemistry laboratory course. ETBE is prepared by the acid-catalyzed reaction of tert-butyl alcohol with ethyl alcohol. The product is recovered as a low-boiling azeotrope and purified by liquid liquid extraction with water. By using gas chromatography and IR spectroscopy to examine both the crude and the purified products, students can see how much the purity of their sample improves. They can also appreciate the value of these methods (especially GC) as tools to establish purity. Student results are presented. The use of ETBE and its more prominent cousin methyl tert-butyl ether (MTBE) as gasoline oxygenates has become very controversial because they have polluted underground water supplies. This lab permits students to prepare a compound that has a real use and regularly makes headlines in the news. This lab experiment is part of an effort to develop a general chemistry sequence for engineering students using the theme of "Chemistry and the Automobile".

  11. n-Butyl Cyanoacrylate Synthesis. A New Quality Step Using Microwaves

    Directory of Open Access Journals (Sweden)

    Yaquelin Ramos Carriles

    2014-05-01

    Full Text Available Alkyl cyanoacrylates are interesting products for use in industry because of their properties enabling them to stick together a wide range of substrates. n-Butyl cyanoacrylate is one of the most successfully used tissue adhesives in the field of medicine because it exhibits bacteriostatic and haemostatic characteristics, in addition to its adhesive properties. At present, its synthesis is performed with good yields via Knoevenagel condensation using conventional sources of heating, but this requires a long processing time. The aim of this work was to look for a new way of synthesising n-butyl cyanoacrylate using microwave irradiation as the source of heating. This non-conventional source of heating most likely reduces the process time of the synthesis. In comparison with a conventional heating source, such as an oil bath, the results showed the advantages of this method whereby the n-butyl cyanoacrylate gave the same yield and quality with a reduction in the reaction time by a factor of 3-5-fold.

  12. Fragrance material review on 2-methyl-4-phenyl-2-butyl acetate.

    Science.gov (United States)

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of 2-methyl-4-phenyl-2-butyl acetate when used as a fragrance ingredient is presented. 2-Methyl-4-phenyl-2-butyl acetate is a member of the fragrance structural group Aryl Alkyl Alcohol Simple Acid Esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 2-methyl-4-phenyl-2-butyl acetate were evaluated then summarized and includes physical properties, acute toxicity, skin irritation, skin sensitization, and elicitation data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Azadirachta indica exhibits chemopreventive action against hepatic cancer: Studies on associated histopathological and ultrastructural changes.

    Science.gov (United States)

    Bharati, Sanjay; Rishi, Praveen; Koul, Ashwani

    2012-05-01

    The present study was designed to evaluate the anticarcinogenic potential of Azadirachta indica against N-nitrosodiethylamine (NDEA)-induced hepatocarcinogenesis. Further, the associated histopathological and ultrastructural changes were also analyzed. Hepatic cancer model was developed by the intraperitoneal administration of NDEA to mice at weekly intervals, in successive increasing doses, for a period of 8 weeks. Aqueous A. indica leaf extract (AAILE) was administered orally at a dosage of 100 μg/g body weight thrice a week till termination of the study. A relationship between histopathological grading and chemopreventive effect of A. indica had been established at various stages of carcinogenesis. Anticancer activity of A. indica was evaluated in terms of tumor incidence, tumor multiplicity, and survival rate. A significant reduction in tumor incidence (33%), tumor multiplicity (42%), and increase in survival (34%) was observed upon administration of AAILE to NDEA-abused mice. Transmission and scanning electron microscopic investigations showed severe alterations in organelle organization, cellular arrangement, degree of differentiation, cellular metabolism, and morphology of the hepatocytes. These changes appeared to be distinctly delayed upon AAILE supplementation. The results suggest A. indica may have anticancer potential against NDEA-induced hepatic cancer. Copyright © 2011 Wiley Periodicals, Inc.

  14. Chemopreventive potential of volatile oil from black cumin (Nigella sativa L.) seeds against rat colon carcinogenesis.

    Science.gov (United States)

    Salim, Elsayed I; Fukushima, Shoji

    2003-01-01

    Chemopreventive effects of orally administered Nigella sativa oil on the induction and development of 1,2-dimethylhydrazine-induced aberrant crypt foci (ACF), putative preneoplastic lesions for colon cancer, were investigated in Fischer 344 rats. Starting at 6 wk of age, 45 male rats (groups 1-3) were subcutaneously injected with DMH once a week for 3 wk. Group 1 (15 rats) served as a carcinogen control group without N. sativa administration. Group 2 or 3 (15 rats each) were given the oil in the postinitiation stage or in the initiation stage, respectively. Animals of group 4 (11 rats) were injected with 0.9% saline and received N. sativa oil from the beginning until the termination. At sacrifice, 14 wk after the start, the total numbers of ACF as well as those with at least four crypts were significantly reduced in group 2 (P colonic crypts revealed the N. sativa oil to have significant antiproliferative activity in both initiation and postinitiation stages and especially in the latter. Histological examination revealed no pathological changes in the liver, kidneys, spleen, or other organs of rats treated with N. sativa. In addition, biochemical parameters of blood and urine as well as body weight gain were not affected. These findings demonstrate that the volatile oil of N. sativa has the ability to inhibit colon carcinogenesis of rats in the postinitiation stage, with no evident adverse side effects, and that the inhibition may be associated, in part, with suppression of cell proliferation in the colonic mucosa.

  15. Use of letrozole as a chemopreventive agent in aromatase overexpressing transgenic mice.

    Science.gov (United States)

    Luthra, Roopa; Kirma, Nameer; Jones, Jeremy; Tekmal, Rajeshwar Rao

    2003-09-01

    Our recent studies have shown that overexpression of aromatase results in increased tissue estrogenic activity and induction of hyperplastic and dysplastic lesions in mammary glands, and gynecomastia and testicular cancer in male aromatase transgenic mice. Our studies also have shown that aromatase overexpression-induced changes in mammary glands can be abrogated with very low concentrations of letrozole, an aromatase inhibitor without any effect on normal physiology. In the present study, we have examined the effect of prior low dose letrozole treatment on pregnancy and lactation. We have also investigated the effect of low dose letrozole treatment on subsequent mammary growth and biochemical changes in these animals. There was no change in the litter size, birth weight and no visible birth defects in letrozole-treated animals. Although, there was an insignificant increase in mammary growth in aged animals after 6 weeks of letrozole treatment, the levels of expression of estrogen receptor, progesterone receptor and genes involved in cell cycle and cell proliferation remained low compared to control untreated animals. These observations indicate that aromatase inhibitors such as letrozole can be used as chemopreventive agents without effecting normal physiology in aromatase transgenic mice.

  16. Role of natural phenolic compounds in cancer chemoprevention via regulation of the cell cycle.

    Science.gov (United States)

    Jafari, Samineh; Saeidnia, Soodabeh; Abdollahi, Mohammad

    2014-01-01

    Natural phenolic compounds have been considered as one of the interesting secondary metabolites for their chemopreventive and chemotherapeutic effects in cancer for a long time. These are a large and diverse family of phytochemicals classified into several subgroups such as simple phenols, lignans, phenylpropanoids, flavonoids, coumarins, etc. The antioxidant potential of phenolic compounds is almost bolded in the treatment and prevention of cancer. Due to the concerns on the diverse effects of antioxidants in cancer, differentiation and clarification of their anti-neoplastic mechanisms are necessary. An important mechanism for phenolic compounds is related to their direct effect on the cell cycle progression, which has not been discussed in detail so far. This study aims to criticize the evidence on regulatory mechanisms of phenolic compounds in the cell cycle. Recent studies indicate that phenolic compounds from several subgroups significantly inhibit the proliferation of different cancer cells. The structural diversity of these compounds influences various components involved in cell cycle regulation. Forming active metabolites and sensitizing cancerous cells to chemotherapeutic medicines are additional values of these compounds. In the recent years, many studies on neoplastic cell cultures have been carried out to investigate the mechanisms of action of these compounds but dissimilarity of in vitro systems in comparison with human body in terms of metabolism and bioavailability is a major concern. Therefore, further studies are still needed.

  17. The use of natural compounds for the targeting and chemoprevention of ovarian cancer.

    Science.gov (United States)

    Pistollato, Francesca; Calderón Iglesias, Ruben; Ruiz, Roberto; Aparicio, Silvia; Crespo, Jorge; Dzul Lopez, Luis; Giampieri, Francesca; Battino, Maurizio

    2017-12-28

    Among gynaecological cancers, ovarian cancer represents the leading cause of death in women. Current treatment for ovarian cancer entails surgery followed by combined chemotherapy with platinum and taxane, which are associated, particularly cisplatin, with severe side effects. While this treatment approach appears to be initially effective in a high number of patients, nearly 70% of them suffer a relapse within a few months after initial treatment. Therefore, more effective and better-tolerated treatment options are clearly needed. In recent years, several natural compounds (such as curcumin, epigallocatechin 3-gallate (EGCG), resveratrol, sulforaphane and Withaferin-A), characterized by long-term safety and negligible and/or inexistent side effects, have been proposed as possible adjuvants of traditional chemotherapy. Indeed, several in vitro and in vivo studies have shown that phytocompounds can effectively inhibit tumor cell proliferation, stimulate autophagy, induce apoptosis, and specifically target ovarian cancer stem cells (CSCs), which are generally considered to be responsible for tumor recurrence in several types of cancer. Here we review current literature on the role of natural products in ovarian cancer chemoprevention, highlighting their effects particularly on the regulation of inflammation, autophagy, proliferation and apoptosis, chemotherapy resistance, and ovarian CSC growth. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Developmental windows of breast cancer risk provide opportunities for targeted chemoprevention

    Science.gov (United States)

    Martinson, Holly A.; Lyons, Traci R.; Giles, Erin D.; Borges, Virginia F.; Schedin, Pepper

    2014-01-01

    The magnitude of the breast cancer problem implores researchers to aggressively investigate prevention strategies. However, several barriers currently reduce the feasibility of breast cancer prevention. These barriers include the inability to accurately predict future breast cancer diagnosis at the individual level, the need for improved understanding of when to implement interventions, uncertainty with respect to optimal duration of treatment, and negative side effects associated with currently approved chemoprevention therapies. None-the-less, the unique biology of the mammary gland, with its postnatal development and conditional terminal differentiation, may permit the resolution of many of these barriers. Specifically, lifecycle-specific windows of breast cancer risk have been identified that may be amenable to risk-reducing strategies. Here, we argue for prevention research focused on two of these lifecycle windows of risk: postpartum mammary gland involution and peri-menopause. We provide evidence that these windows are highly amenable to targeted, limited duration treatments. Such approaches could result in the prevention of postpartum and postmenopausal breast cancers, correspondingly. PMID:23664839

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

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    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.

  20. Polyphenolic Nutrients in Cancer Chemoprevention and Metastasis: Role of the Epithelial-to-Mesenchymal (EMT) Pathway.

    Science.gov (United States)

    Amawi, Haneen; Ashby, Charles R; Samuel, Temesgen; Peraman, Ramalingam; Tiwari, Amit K

    2017-08-21

    The epithelial-to-mesenchymal transition (EMT) has received significant interest as a novel target in cancer prevention, metastasis, and resistance. The conversion of cells from an epithelial, adhesive state to a mesenchymal, motile state is one of the key events in the development of cancer metastasis. Polyphenols have been reported to be efficacious in the prevention of cancer and reversing cancer progression. Recently, the antimetastatic efficacy of polyphenols has been reported, thereby expanding the potential use of these compounds beyond chemoprevention. Polyphenols may affect EMT pathways, which are involved in cancer metastasis; for example, polyphenols increase the levels of epithelial markers, but downregulate the mesenchymal markers. Polyphenols also alter the level of expression and functionality of important proteins in other signaling pathways that control cellular mesenchymal characteristics. However, the specific proteins that are directly affected by polyphenols in these signaling pathways remain to be elucidated. The aim of this review is to analyze current evidence regarding the role of polyphenols in attenuating EMT-mediated cancer progression and metastasis. We also discuss the role of the most important polyphenol subclasses and members of the polyphenols in reversing metastasis and targeting EMT. Finally, limitations and future directions to improve our understanding in this field are discussed.

  1. Development of in vitro models for cellular and molecular studies in toxicology and chemoprevention

    Energy Technology Data Exchange (ETDEWEB)

    Mace, K.; Offord, E.A.; Harris, C.C.; Pfeifer, A.M.A. [Nestle Research Center, Lausanne (Switzerland)

    1998-12-31

    Many natural dietary phytochemicals found compounds found in fruits, vegetables, spices and tea have been shown in recent years to be protective against cancer in various animal models. In the light of the potential impact of these compounds on human health it is important to elucidate the mechanisms involved. We therefore developed and characterized relevant in vitro models using immortalized human epithelial cell lines derived from target tissues in carcinogenesis, such as lung, liver and colon. Assays were established, allowing the evaluation of the cytotoxic and genotoxic effects of various procarcinogens, including nitrosamines, mycotoxins and heterocyclic amines on these metabolically-competent human epithelial cell lines. These cellular models appeared to be a useful tool to study the capacity of certain food components to block the initiation stage of carcinogenesis. The ability of carnosol and carnosic acid from rosemary as well as the synthetic dithiolethione, oltipraz, to block the formation of DNA adducts, and their effects on the expression of phase I and phase II enzymes was investigated. We have observed that both rosemary extracts and oltiprax inhibited benzo(a)pyrene- or aflatoxin B{sub 1}-induced DNA adduct formation by strongly inhibiting CYP{sub 450} activities and inducing the expression of glutathione S-transferase. These results in human cell models give some insight into the different mechanisms involved in the chemopreventive action of both natural and synthetic compounds in relation to phase I and phase II enzymes. (orig.)

  2. Antiproliferative and chemopreventive effects of adlay seed on lung cancer in vitro and in vivo.

    Science.gov (United States)

    Chang, Hui-Chiu; Huang, Yu-Chun; Hung, Wen-Chun

    2003-06-04

    This study examined the effects of different extracts of adlay seed on the growth of human lung cancer cells in vitro and in vivo. The data showed that a methanolic extract, but not a water extract, of adlay seed exerted an antiproliferative effect on A549 lung cancer cells by inducing cell cycle arrest and apoptosis. It was also found that tumor growth in vivo was inhibited by the methanolic extract in a dose-dependent manner. The chemopreventive effect of adlay seed on the tobacco-specific carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced lung tumorigenesis in A/J mice was also investigated. Groups of mice were pre-fed with different diets, followed by feeding with NNK-containing drinking water for 8 months. The results indicated that feeding with diet containing 30% of powdered adlay seed reduced the number of surface lung tumors by approximately 50%. Taken together, these results indicate that the components of adlay seed exert an anticancer effect in vitro and in vivo and may be useful for the prevention of lung tumorigenesis.

  3. Cancer chemopreventive potential of aromathecins and phenazines, novel natural product derivatives.

    Science.gov (United States)

    Marler, Laura; Conda-Sheridan, Martin; Cinelli, Maris A; Morrell, Andrew E; Cushman, Mark; Chen, Lian; Huang, Ke; Van Breemen, Richard; Pezzuto, John M

    2010-12-01

    In the search for agents with cancer chemopreventive potential, 14-chloromethyl-12H-5,11a-diazadibenzo[b,h]fluoren-11-one (compound 1), originally synthesized as a potential topoisomerase I inhibitor, and 2,4-dibromo-1-hydroxyphenazine (compound 2), an analog of a substance found in the marine bacteria Streptomyces CNS284, were found to significantly enhance NADP(H):quinone oxidoreductase 1 (QR1), glutathione S-transferase (GST), and glutathione (GSH) levels in cell culture. However, following a short-term absorption study, analyses of livers from the treatment groups did not reveal a significant increase in QR1 or GST activity, or GSH levels. This was consistent with RT-PCR analyses of tissue samples. The compounds were absorbed, as judged by LC/MS analyses of serum and tissue samples, although levels were well below the concentrations required to mediate in vitro responses. Metabolites of compound 2 formed in vitro by human liver microzones were characterized using high resolution tandem mass spectrometry. In sum, the in vivo activity of these compounds appears to be diminished by low bioavailability, but this experimental approach indicates the importance of systematic biomarker investigation.

  4. Evaluation of selected lichens from iceland for cancer chemopreventive and cytotoxic activity.

    Science.gov (United States)

    Ingólfsdóttir, K; Kook Lee, S; Bhat, K P; Lee, K; Chai, H B; Kristinsson, H; Song, L L; Gills, J; Gudmundsdóttir, J T; Mata-Greenwood, E; Jang, M S; Pezzuto, J M

    2000-01-01

    Cancer chemopreventive effects of organic extracts from 29 species of lichens collected in Iceland were evaluated using a panel of in vitro bioassays whereby extracts were tested for potential to induce quinone reductase (QR) and differentiation of human promyelocytic leukemia (HL-60) cells, inhibit cyclooxygenase-1 (COX-1), phorbol ester-induced ornithine decarboxylase (ODC), aromatase and sulfatase, as well as for antioxidant, estrogenic/anti-estrogenic and antiproliferative activity. In addition, the extracts were tested for cytotoxicity against 12 cancer cell lines. The most significant results were exhibited by extracts from Xanthoria elegans and Alectoria nigricans , which respectively, induced QR activity (concentration to double activity = 4.8 µg/ml) and inhibited phorbol ester-induced ODC activity with mouse 308 cells in culture (IC 50 = 2.6 µg/ml). Moderate inhibition of [ 3 H]thymidine incorporation with HL-60 cells was exhibited by the Peltigera leucophlebia extract. Several extracts prevented estrogen formation from estrogen precursors by inhibiting the enzymatic activities of aromatase ( Sphaerophorus globosus , Cetrariella delisei , Melanelia hepatizon ) and sulfatase ( Cladonia gracilis , Sphaerophorus fragilis , S. globosus ). None of the extracts demonstrated significant cytotoxic effects with selected cell lines.

  5. Chemopreventive effects of the juice of Vitis coignetiae Pulliat on two-stage mouse skin carcinogenesis.

    Science.gov (United States)

    Arimoto-Kobayashi, Sakae; Zhang, Xiaomeng; Yuhara, Yuta; Kamiya, Tomonori; Negishi, Tomoe; Okamoto, Goro

    2013-01-01

    Our study revealed the inhibitory effect of Vitis coignetiae Pulliat, known as Yamabudo in Japan, at the stages of multi-step carcinogenesis. The juice of Vitis coignetiae (Y-grape juice) was antimutagenic toward dimethylbenzo[a]anthracene (DMBA), aflatoxin B1, and benzo[a]pyrene in the Ames test. The Y-grape juice was also antigenotoxic in the micronucleus test using HepG2 cells toward DMBA and aflatoxin B1. Topical and oral administration of the Y-grape juice to mice inhibited the induction of inflammation of 12-O-tetradecanoylphorbol-13-acetate (TPA). Topical and oral administration of the Y-grape juice significantly decreased the incidence and mean number of tumors in mice skin with the 2-stage tumorigenesis protocol. To elucidate the mechanisms underlying the antiinflammatory and antitumor promotion activity of the Y-grape juice, the effect of Y-grape juice on cyclooxygenase-2 (COX-2) activity in mouse ear treated with TPA was studied. Both topical and oral application of the Y-grape juice inhibited the TPA-induced increase in COX-2 activity. Caftaric acid, isolated and identified from the Y-grape juice, was antimutagenic toward DMBA and prevented TPA-induced inflammation in mice, suggesting caftaric acid participates in chemopreventive effect/activities of Y-grape juice.

  6. 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.

  7. Nitroxides as antioxidants – possibilities of their application in chemoprevention and radioprotection

    Directory of Open Access Journals (Sweden)

    Sabina Tabaczar

    2011-01-01

    Full Text Available Nitroxides as stabile organic radicals were used initially as spin labels in spectroscopy of electron paramagnetic resonance (EPR with respect to parameters such as pH of an intercellular environment, oxygenation of cells and tissues, fluidity of biological membranes, conformational state and topography of proteins. Nitroxides have also been used in biology and medicine as contrast agents in magnetic resonance imaging (MRI. When their antioxidant activities were discovered, an era of research on the potential utility of these agents began. Nitroxides can modulate the redox state of the cell by participation in oxidation/reduction reactions. Therefore, they are extensively examined in various models of oxidative stress. The antioxidant effect of nitroxides is a result of their ability to catalyze dismutation of superoxide radical (superoxide dismutase-like activity, inhibit lipid peroxidation, prevent Fenton and Haber-Weiss reactions by oxidation of transition metal ions to a higher oxidative state, and confer catalase-like activity on heme proteins. In the present paper the antioxidative mechanisms of nitroxides are presented. The relation between structure, function and the rate of nitroxide reduction inside cells and tissues is also presented. The application of nitroxides in chemoprevention and radioprotection is discussed.

  8. Fractionation of polyphenol-enriched apple juice extracts to identify constituents with cancer chemopreventive potential.

    Science.gov (United States)

    Zessner, Henriette; Pan, Lydia; Will, Frank; Klimo, Karin; Knauft, Jutta; Niewöhner, Regina; Hümmer, Wolfgang; Owen, Robert; Richling, Elke; Frank, Norbert; Schreier, Peter; Becker, Hans; Gerhauser, Clarissa

    2008-06-01

    Apples and apple juices are widely consumed and rich sources of phytochemicals. The aim of the present study was to determine which apple constituents contribute to potential chemopreventive activities, using a bioactivity-directed approach. A polyphenol-enriched apple juice extract was fractionated by various techniques. Extract and fractions were tested in a series of test systems indicative of cancer preventive potential. These test systems measured antioxidant effects, modulation of carcinogen metabolism, anti-inflammatory and antihormonal activities, and antiproliferative potential. Regression analyses indicated that 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging potential correlated with the sum of low molecular weight (LMW) antioxidants (including chlorogenic acid, flavan-3-ols, and flavonols) and procyanidins, whereas peroxyl radicals were more effectively scavenged by LMW compounds than by procyanidins. Quercetin aglycone was identified as a potent Cyp1A inhibitor, whereas phloretin and (-)-epicatechin were the most potent cyclooxygenase 1 (Cox-1) inhibitors. Aromatase and Cyp1A inhibitory potential and cytotoxicity toward HCT116 colon cancer cells increased with increasing content in procyanidins. Overall, apple juice constituents belonging to different structural classes have distinct profiles of biological activity in these in vitro test systems. Since carcinogenesis is a complex process, combination of compounds with complementary activities may lead to enhanced preventive effects.

  9. Final report of the addendum to the safety assessment of n-butyl alcohol as used in cosmetics.

    Science.gov (United States)

    McLain, Valerie C

    2008-01-01

    n-Butyl Alcohol is a primary aliphatic alcohol historically used as a solvent in nail care cosmetic products, but new concentration of use data indicate that it also is being used at low concentrations in eye makeup, personal hygiene, and shaving cosmetic products. n-Butyl Alcohol has been generally recognized as safe for use as a flavoring substance in food and appears on the 1982 Food and Drug Administration (FDA) list of inactive ingredients for approved prescription drug products. n-Butyl Alcohol can be absorbed through the skin, lungs, and gastrointestinal tract. n-Butyl Alcohol may be formed by hydrolysis of butyl acetate in the blood, but is rapidly oxidized. The single oral dose LD(50) of n-Butyl Alcohol for rats was 0.79 to 4.36 g/kg. The dermal LD(50) for rabbits was 4.2 g/kg. Inhalation toxicity studies in humans demonstrate sensory irritation of the upper respiratory tract, but only at levels above 3000 mg/m(3). Animal studies demonstrate intoxication, restlessness, ataxia, prostration, and narcosis. Exposures of rats to levels up to 4000 ppm failed to produce hearing defects. High concentrations of n-Butyl Alcohol vapors can be fatal. Ocular irritation was observed for n-Butyl alcohol at 0.005 ml of a 40% solution. The behavioral no-effect dose for n-Butyl Alcohol injected subcutaneously (s.c.) was 120 mg/kg. Fetotoxicity has been demonstrated, but only at maternally toxic levels (1000 mg/kg). No significant behavioral or neurochemical effects were seen in offspring following either maternal or paternal exposure to 3000 or 6000 ppm. n-Butyl Alcohol was not mutagenic in Ames tests, did not induce sister-chromatid exchange or chromosome breakage in chick embryos or Chinese hamster ovary cells, did not induce micronuclei formation in V79 Chinese hamster cells, did not have any chromosome-damaging effects in a mouse micronucleus test, and did not impair chromosome distribution in the course of mitosis. Clinical testing of n-Butyl Alcohol for

  10. Chemopreventive effects of the polyunsaturated fatty acids omega-3 on the carcinogenesis process of the upper aerodigestive tract induced by 4-nitroquinoline-1-oxide in Swiss mice

    Science.gov (United States)

    Gama, Ricardo Ribeiro; Giovanini, Allan; de Rosa, Fernanda Scarmato; Ogata, Daniel Cury; de Oliveira, André Luiz Vettore; Cardoso Costa, Ana Flávia; Talini, Carolina; Feniman, Denise; Kamei, Douglas; Júnior, Celso Felipe; Coco, Allan; Carvalho, André Lopes

    2014-01-01

    Objective: To study the potential chemopreventive effects of polyunsaturated fatty acids omega-3 in Swiss mice submitted to oral and oesophageal carcinogenesis induction by 4-nitroquinoline-1-oxide (4-NQO). Study design: The animals underwent carcinogenesis induction with 50 µg/mL 4-NQO for eight weeks. The animals were divided into groups: Group I—4-NQO induction without chemoprevention, Group II—chemoprevention with the addition of 5% fish oil (FO) in their diet after 4-NQO carcinogenesis induction, and Group III—chemoprevention with 5% FO in their diet during and after 4-NQO carcinogenesis induction. Results: The incidence of invasive oral carcinoma was: Group I (72.9%), Group II (84.2%), and Group III (64.7%); p = 0.34. The difference in the incidence of invasive oesophageal carcinoma was statistically significant: Group I (37.8%), Group II (68.4%), and Group III (29.4%); p = 0.02. Conclusions: 4-NQO induction led to cancer in the majority of animals. Chemoprevention with FO brought no benefit in preventing the carcinogenesis process initiated by 4-NQO for oral cancer. The suggestive pro-tumour action of FO when given after tumour post-initiation seems to demonstrate that this fatty acid can potentialise the action of 4-NQO in the oesophagus carcinogenesis of the Swiss mice. PMID:24605132

  11. 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.

  12. Natural Products as a Vital Source for the Discovery of Cancer Chemotherapeutic and Chemopreventive Agents.

    Science.gov (United States)

    Cragg, Gordon M; Pezzuto, John M

    2016-01-01

    Throughout history, natural products have played a dominant role in the treatment of human ailments. For example, the legendary discovery of penicillin transformed global existence. Presently, natural products comprise a large portion of current-day pharmaceutical agents, most notably in the area of cancer therapy. Examples include Taxol, vinblastine, and camptothecin. These structurally unique agents function by novel mechanisms of action; isolation from natural sources is the only plausible method that could have led to their discovery. In addition to terrestrial plants as sources for starting materials, the marine environment (e.g., ecteinascidin 743, halichondrin B, and dolastatins), microbes (e.g., bleomycin, doxorubicin, and staurosporin), and slime molds (e.g., epothilone B) have yielded remarkable cancer chemotherapeutic agents. Irrespective of these advances, cancer remains a leading cause of death worldwide. Undoubtedly, the prevention of human cancer is highly preferable to treatment. Cancer chemoprevention, the use of vaccines or pharmaceutical agents to inhibit, retard, or reverse the process of carcinogenesis, is another important approach for easing this formidable public health burden. Similar to cancer chemotherapeutic agents, natural products play an important role in this field. There are many examples, including dietary phytochemicals such as sulforaphane and phenethyl isothiocyanate (cruciferous vegetables) and resveratrol (grapes and grape products). Overall, natural product research is a powerful approach for discovering biologically active compounds with unique structures and mechanisms of action. Given the unfathomable diversity of nature, it is reasonable to suggest that chemical leads can be generated that are capable of interacting with most or possibly all therapeutic targets. © 2015 S. Karger AG, Basel.

  13. 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. Copyright © 2011 Elsevier GmbH. All rights reserved.

  14. 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.

  15. Preliminary evaluation for cancer chemopreventive and cytotoxic potential of naturally growing ethnobotanically selected plants of Pakistan.

    Science.gov (United States)

    Ihsan-ul-Haq; Mirza, Bushra; Kondratyuk, Tamara P; Park, Eun-Jung; Burns, Brittany E; Marler, Laura E; Pezzuto, John M

    2013-03-01

    Natural products are a very productive source of leads for the development of medicines. Six Pakistani plants were chosen for study based on ethnobotanical data. Exploration of important medicinal plants of Pakistan for cancer treatment. The crude extracts of the six plants and their fractions were tested for inhibition of nuclear factor κB (NFκB), aromatase, and nitric oxide (NO) production in lipopolysaccharide (LPS)-activated murine macrophage RAW 264.7 cells, induction of quinone reductase 1 (QR1), agonism of retinoid X receptor, and growth inhibition with MCF-7, LU-1 and MDA-MB-231 cancer cells. Two samples of Withania coagulans (Stocks) Dunal (Solanaceae) demonstrated inhibition of TNF-α induced activity of NFκB with IC₅₀ values of 2.6 and 4.3 µg/mL, respectively. Two fractions from W. coagulans and Euphorbia wallichii Hook F. (Euphorbiaceae) aerial parts inhibited aromatase with IC₅₀ values of 17.0 and 17.7 µg/mL, respectively. A total of 13 samples (five from E. wallichii, one from Acer oblongifolium Hort. ex Dippel (Aceraceae), one from Aster thomsonii C. B. Clarke (Asteraceae) and six from W. coagulans aerial parts with fruits) inhibited NO production with IC₅₀ values ranging from 1.3 to 15.6 µg/mL. Fourteen samples demonstrated induction of QR1 with CD ranging from 1.0 to 20.6 µg/mL, and a total of eight extracts and fractions inhibited the proliferation of cancer cells in culture with IC₅₀ values ranging from 1.2 to 7.8 µg/mL. Selected plants can be a valuable source of chemopreventive and anticancer products. W. coagulans aerial parts showed the strongest activity.

  16. A conformationally defined 6-s-trans-retinoic acid isomer: synthesis, chemopreventive activity, and toxicity.

    Science.gov (United States)

    Vaezi, M F; Alam, M; Sani, B P; Rogers, T S; Simpson-Herren, L; Wille, J J; Hill, D L; Doran, T I; Brouillette, W J; Muccio, D D

    1994-12-23

    A conformationally defined retinoic acid analog (1) which contains a dimethylene bridge to maintain the 6-s-trans orientation for two terminal double bonds in the polyene chain was synthesized. A Reformatsky reaction was utilized to extend the polyene chain of the starting enone, which provided exclusively the 9Z-configuration for the intermediate aldehyde. A Horners-Emmons condensation with this aldehyde then produced retinoic acid analogs with both 9Z- and 9Z,13Z-configurations. An I2-catalyzed isomerization of the intermediate 9Z-aldehyde yielded the all-E-aldehyde, which was olefinated as above to yield the (all-E)- and (13Z)-retinoic acid analogs of 1. Each configurational isomer of 1 was evaluated for its ability to inhibit the binding of retinoic acid to CRABP (chick skin) and to inhibit the chemical induction of ornithine decarboxylase in mouse skin. In each assay (all-E)-1 was the most active isomer, and this activity was comparable to or better than that for (all-E)-retinoic acid. (all-E)-1 and (13Z)-1 were both shown to be equally effective as (13Z)-retinoic acid in suppressing the proliferation of human sebaceous cells in vitro. (all-E)-1 was further evaluated for its ability to prevent the induction of mouse skin papillomas and to induce signs of vitamin A toxicity in mice. The cancer chemopreventive activity of (all-E)-1 was comparable to that of (all-E)-retinoic acid, and the toxicity was comparable to or slightly better than that of the natural vitamin.

  17. Chemopreventive activity of grape juice concentrate (G8000TM) on rat colon carcinogenesis induced by azoxymethane.

    Science.gov (United States)

    Silva, Roseane Mendes; Campanholo, Vanessa Maria de Lima Pazine; Paiotti, Ana Paula Ribeiro; Artigiani Neto, Ricardo; Oshima, Celina Tizuko Fujiyama; Ribeiro, Daniel Araki; Forones, Nora Manoukian

    2015-11-01

    Colorectal cancer is the third most common cancer worldwide in both sexes, with similar geographic patterns between genders. This neoplasm has good prognosis if the disease is diagnosed at early stages. The aim of this study was to evaluate the effect of red grape juice on the expression of COX-2 and Ki-67 expression following colon carcinogenesis induced by azoxymethane (AOM). Thirty-five rats were randomly distributed into seven groups (n=5 per group): G1: SHAM or negative control received only saline; G2 (positive control): animals received 15 mg/kg AOM; G3: animals received 1% red grape juice 2 weeks before the administration of AOM; G4: animals received 2% red grape juice 2 weeks before the administration of AOM; G5: animals received 1% red grape juice 4 weeks after the last administration of AOM; G6: animals received 2% red grape juice 4 weeks after the last administration of AOM; G7: animals received only 2% red grape juice. COX-2 mRNA expression was reduced in animals treated with 1% red grape juice before AOM induction or 2% red grape juice after AOM induction. COX-2 immunoexpression was also reduced to groups treated with red grape juice at 1% before and after AOM induction or 2% red grape juice after AOM induction. Decreased immunoexpression of Ki-67 positive cells was observed in animals treated with 1% grape juice before AOM-treated animals. Taken together, grape juice concentrate is able to exert some chemopreventive activity on rat colon carcinogenesis. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. 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.

  19. Chemoprevention of DMH-induced rat colon carcinoma initiation by combination administration of piroxicam and C-phycocyanin.

    Science.gov (United States)

    Saini, Manpreet Kaur; Vaiphei, Kim; Sanyal, Sankar Nath

    2012-02-01

    Cancer research illustrated that combinatorial studies can provide significant improvement in safety and effectiveness over the monotherapy regimens. A combination of two drugs may restrain precancerous colon polyps, opening a new possible opportunity for chemoprevention of colon cancer. In this context, chemopreventive efficacy of a combination regimen of C-phycocyanin, a biliprotein present in Spirulina platensis, a cyanobacterium, which is a selective cycloxygenase-2 (COX-2) inhibitor and piroxicam, a traditional non-steroidal anti-inflammatory drug was considered in 1,2 dimethylhyadrazine (DMH)-induced colon carcinogenesis in rats. Western blotting, immunohistochemistry, DNA fragmentation, fluorescent staining, PGE(2) enzyme immunoassay, and carrageenan-induced paw edema test were performed along with morphological and histological analysis. DMH treatment showed a rich presence of preneoplastic lesions such as multiple plaque lesions, aberrant crypt foci, and well-characterized dysplasia. These features were reduced with piroxicam and C-phycocyanin administration. The number of apoptotic cells was featured prominently in all the groups compared with DMH. DMH treatment revealed intact high molecular weight genomic DNA with no signs of laddering/DNA fragmentation while it was noticeable significantly in control and DMH + piroxicam + C-phycocyanin. DMH group showed highest COX-2 expression and PGE(2) level in comparison with other groups. Doses of piroxicam and C-phycocyanin used in the present study were established at an anti-inflammatory range. A combination regimen of piroxicam and C-phycocyanin, rather than individually has the much greater potential for reduction of DMH-induced colon cancer development and COX-2 being the prime possible target in such chemoprevention.

  20. Evaluating the potential cancer chemopreventive efficacy of two different solvent extracts of Seriphidium herba-alba in vitro

    Directory of Open Access Journals (Sweden)

    Mahmoud Mohamed Mokhtar

    2017-06-01

    Full Text Available Cancer is the second leading cause of death world-wide. One of the most important medical practices of the 21st century is the chemoprevention of cancer. For a long history, it has been accepted that plants could prevent and exert suitable anti-carcinogenic effects for multiple types of cancers. Seriphidium herba-alba family Asteraceae has been used in the folk medicine by many cultures for treatment of various ailments since ancient times. In the current research we were aimed to evaluate the cancer chemopreventive activity of two crude extracts of S. herba-alba, methylene chloride extract and methanol extract on two cell lines: Human breast cancer cells (MCF-7 and human hepatocellular carcinoma cells (Hep-G2. Assessment of cytotoxicity using methyl thiazole tetrazolium (MTT assay indicated that both extracts exhibit poor cytotoxicity with half maximal inhibitory concentration (IC50 >20 µg/mL. Assessment of glutathione-S-transferases (GSTs activity (spectrophotometrically showed statistically significant enhancement of enzyme activity after treatment with three different doses of methylene chloride extract and glutathione (GSH concentrations were decreased. Analysis of cell mode of death by Ethidium bromide/Acridine orange (EB/AO staining revealed that the dominant mode of death in MCF-7 cells was apoptosis. Assessment of vascular endothelial growth factor (VEGF and platelets derived growth factor (PDGFBB using ELISA showed that VEGF and PDGFBB levels were statistically significant decreased. In Conclusion: both extracts may be cancer chemopreventive agents since they had tumor anti-initiating, and anti-promoting activity.

  1. Benefit/Risk Assessment for Breast Cancer Chemoprevention With Raloxifene or Tamoxifen for Women Age 50 Years or Older

    Science.gov (United States)

    Freedman, Andrew N.; Yu, Binbing; Gail, Mitchell H.; Costantino, Joseph P.; Graubard, Barry I.; Vogel, Victor G.; Anderson, Garnet L.; McCaskill-Stevens, Worta

    2011-01-01

    Purpose The Study of Tamoxifen and Raloxifene (STAR) demonstrated that raloxifene was as effective as tamoxifen in reducing the risk of invasive breast cancer (IBC) in postmenopausal women and had lower risks of thromboembolic events, endometrial cancer, and cataracts but had a nonstatistically significant higher risk of noninvasive breast cancer. There is a need to summarize the risks and benefits of these agents. Patients and Methods Baseline incidence rates of IBC and other health outcomes, absent raloxifene and tamoxifen, were estimated from breast cancer chemoprevention trials; the Surveillance, Epidemiology and End Results Program; and the Women's Health Initiative. Effects of raloxifene and tamoxifen were estimated from STAR and the Breast Cancer Prevention Trial. We assigned weights to health outcomes to calculate the net benefit from raloxifene compared with placebo and tamoxifen compared with placebo. Results Risks and benefits of treatment with raloxifene or tamoxifen depend on age, race, breast cancer risk, and history of hysterectomy. Over a 5-year period, postmenopausal women with an intact uterus had a better benefit/risk index for raloxifene than for tamoxifen. For postmenopausal women without a uterus, the benefit/risk ratio was similar. The benefits and risks of raloxifene and tamoxifen are described in tables that can help identify groups of women for whom the benefits outweigh the risks. Conclusion We developed a benefit/risk index to quantify benefits from chemoprevention with tamoxifen or raloxifene. This index can complement clinical evaluation in deciding whether to initiate chemoprevention and in comparing the benefits and risks of raloxifene versus tamoxifen. PMID:21537036

  2. 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.

  3. The molecular mechanism of action of aspirin, curcumin and sulforaphane combinations in the chemoprevention of pancreatic cancer.

    Science.gov (United States)

    Thakkar, Arvind; Sutaria, Dhruvitkumar; Grandhi, B Karthik; Wang, Jeffrey; Prabhu, Sunil

    2013-04-01

    Pancreatic cancer ranks as the fourth most deadly form of cancer in the United States with ~37,000 deaths each year. The present study evaluated the chemopreventive potential of a combination of aspirin (ASP), curcumin (CUR) and sulforaphane (SFN) in low doses to human pancreatic cancer cells, MIA PaCa-2 and Panc-1. Results demonstrated that low doses of ASP (1 mM), CUR (10 µM) and SFN (5 µM) (ACS) combination reduced cell viability by ~70% (Pmechanisms.

  4. Synthesis of t-Butyl (2R)-Hydroxyisovalerate, A Precursor of Aureobasidin B

    Science.gov (United States)

    Maharani, R.; Puspitasari, D.; Taufiqqurahman; Huspa, D. H. P.; Hidayat, A. T.; Sumiarsa, D.; Hidayat, I. W.

    2017-02-01

    Aureobasidins are a family of cyclodepsipeptides have antifungal properties. They were isolated from the black yeast Aureobasidium pullulans R106 and over 30 derivatives have been successfully characterized. There are few publications reporting the total synthesis of aureobasidins. The limited reports of the synthesis of the aureobasidin derivatives are due to the difficult access to the preparations of precursors. The aim of this research is to synthesise a precursor of aureobasidin B, t-butyl (2R)-hydroxyisovalerate (t-Bu-Hiv), that is prepared for the total synthesis of aureobasidin B. The synthesis of AbB is planned to be undertaken by using a solid phase method, so the ester formation between t-Bu-Hiv and the Fmoc-β-hydroxymethylvaline will be carried out in solution phase to form depsidipeptide. The t-butyl group was used as protecting agent that is due to the straightforward elimination of the protecting group from the Fmoc-depsidipeptide. The t-Bu-Hiv acid was prepared from D-valine through diazotisation to form (2R)-acetyloxyisovaleric acid in 62.7% yield. Product of the first step was then protected by t-butyl group by using Boc-anhydride in t-butanol to give t-butil (2R)-acetyloxyisovalerate in 44% yield. In the last step, the acetyloxy group was eliminated by using potassium carbonate in methanol/water to give the desired product, t-Bu-Hiv in 33.5% yield. The t-Bu-Hiv is ready to be combined with Fmoc-β-hydroxymethylvaline to result in depsidipeptide that will be attached to the resin in the total synthesis of AbB. Each stage of this synthesis was controlled by thin layer chromatography and all products were purified by open column chromatography. All the synthesized products were characterized by various spectroscopic techniques, including infrared spectrophotometer, mass spectroscopy (ESI-MS), 1H-NMR and 13C-NMR.

  5. Uranium stripping from tri-n-butyl phosphate by hydrogen peroxide solutions

    OpenAIRE

    Smirnov, A. L.; Skripchenko, S. Y.; Rychkov, V. N.; Pastukhov, A. M.; Shtutsa, M. G.

    2013-01-01

    The processes of uranium stripping from 30% tri-n-butyl phosphate (TBP) in "odorless" kerosene by H2O2 solutions both with and without NH4OH added were investigated in the temperature range of 20-50 C and with a volumetric ratio of 1 between the organic and aqueous phases. The uranium was selectively precipitated in the form of uranium peroxide during stripping from the organic phase by hydrogen peroxide. The stripping of uranium increased with increasing H2O2 content, increasing temperature ...

  6. Photo catalytic degradation of methyl tert-Butyl Ether (MTBE) from contaminated water: complete mineralization

    Energy Technology Data Exchange (ETDEWEB)

    Eslami, A.; Nasseri, S.; Maleki, A.; Aghvami, T.

    2009-07-01

    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/TiO{sub 2}/O{sub 2} photo catalytic process. The effect of important operational parameters such as ph, oxygen flow, catalyst loading, and irradiation time were also studied. (Author)

  7. A coarse-grained polarizable force field for the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate

    Science.gov (United States)

    Zeman, Johannes; Uhlig, Frank; Smiatek, Jens; Holm, Christian

    2017-12-01

    We present a coarse-grained polarizable molecular dynamics force field for the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIm][PF6]). For the treatment of electronic polarizability, we employ the Drude model. Our results show that the new explicitly polarizable force field reproduces important static and dynamic properties such as mass density, enthalpy of vaporization, diffusion coefficients, or electrical conductivity in the relevant temperature range. In situations where an explicit treatment of electronic polarizability might be crucial, we expect the force field to be an improvement over non-polarizable models, while still profiting from the reduction of computational cost due to the coarse-grained representation.

  8. TRANS-ARTERIAL EMBOLIZATION WITH N-BUTYL CYANOACRYLATE GLUE FOR RENAL BLEEDING: Case Report

    Directory of Open Access Journals (Sweden)

    Benny Young

    2014-08-01

    Full Text Available Background: The objectivity in management of renal bleeding is to preserve a significant renal parenchyma tissue and prevent associated morbidities like anemic shock or renal impairment from substantial nephron demise or obstructed uropathy. Trans-arterial embolization therapy by interventional radiology offers a high success rate with potential of reserving normal renal tissue. The selection material for renal arterial embolization largely depends on vasculature anatomy and end-point of procedure. N-butyl cyanoacrylate glue in our experience is applied in lesion supplied by small size of end-artery. 

  9. Oxidation of heteroleptic diarylpalladium compounds with tert-butyl hydroperoxide. Substituent effects in aromatic oxidation reactions

    NARCIS (Netherlands)

    Koten, G. van; Valk, J.-M.; Boersma, J.

    1996-01-01

    A series of heteroleptic diarylpalladium compounds, containing both a naphthyl (1-C10H6CH2NMe2-2 or 1-C10H5CH2NMe2-2-Me-3) and a phenyl (1-C6H4CH2NMe2-2 or 1-C6H3CH2NMe2-2-Me-x, x = 3, 5, 6) monoanionic C,N-bidentate ligand, was reacted with tert-butyl hydroperoxide (TBHP) to give selective oxygen

  10. tert-Butyl 2-(3-acetylamino-2-oxo-1,2-dihydro-1-pyridylacetate

    Directory of Open Access Journals (Sweden)

    Peter C. Healy

    2008-12-01

    Full Text Available The title compound, C13H18N2O4, crystallizes as discrete molecules associated as N—H...O hydrogen-bonded dimers disposed about a crystallographic inversion centre. The structure is the first solid-state structure for a 3-acetylpyridone without C-4 to C-6 substituents. The amide subsituent at C-3 is coplanar with the pyridone ring, while the tert-butyl ester group is orthogonal to the pyridine ring. The amide and ester carbonyl O atoms are not involved in strong hydrogen bonding with only a number of intramolecular and intermolecular C—H...O interactions apparent in the structure.

  11. Butylated hydroxyanisole sebagai Bahan Aditif Antioksidan pada Makanan dilihat dari Perspektif Kesehatan

    Directory of Open Access Journals (Sweden)

    Nyoman Fitri

    2015-05-01

    Full Text Available Butylated hydroxyanisole (BHA is widely used since 1947 as antioxidant food additives used to prevent oils, fats and shortenings from oxidative deterioration and rancidity. It has been extensively studied for potential activities and its toxicities. This review summarized experimental studies that had been carried out on animals and humans as well. We also briefly reviewed about its absorptions, metabolisms, excretions and carcinogenicity from health perspective. At present there is sufficient evidence for carcinogenicity of BHA, but there is hardly any indication that BHA is genotoxic.

  12. One-electron redox reaction of di-tert-butyl nitroxide at platinum electrode in acetonitrile

    Energy Technology Data Exchange (ETDEWEB)

    Kishioka, Shin-ya; Yamada, Akifumi [Nagaoka University of Technology, Nagaoka, Niigata (Japan). Department of Chemistry, Faculty of Engineering

    2005-10-20

    The electrochemical oxidation of di-tert-butyl nitroxide (DTBN) at a platinum electrode in acetonitrile was examined. The cyclic voltammogram indicated an irreversible response during a normal time scale measurement, whereas chemically reversible voltammograms were obtained during a shorter time using a micro disk electrode with relatively fast sweep rates. The apparent formal redox potential and heterogeneous electron transfer rate constant were estimated to be 0.218 V (versus Fc{sup +}Fc) and 0.035 {+-} 0.015 cms{sup -1} from the digital simulation analysis. (author)

  13. Antimicrobial activity of Butyl acetate, Ethyl acetate and Isopropyl alcohol on undesirable microorganisms in cosmetic products.

    Science.gov (United States)

    Lens, C; Malet, G; Cupferman, S

    2016-10-01

    The microbiological contamination risk of a cosmetic product has to be assessed by the manufacturer, according to the composition, to determine whether microbiological testing is required. Certain ingredients in cosmetic formulations help to create an environment hostile towards microbial growth. In this study, the influence on microbial survival of some solvents used in nail varnishes was evaluated. The purpose of this study was two-fold. The first was to define the thresholds to be considered for the exemption of products from microbiological testing. The second was to assess the cross-contamination risk linked to the use on successive consumers of solvent-based products in beauty salons. Strains of Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Candida albicans and Trichophyton rubrum were exposed to various concentrations of ethyl acetate, butyl acetate and isopropyl alcohol in culture medium to estimate their MIC (minimum inhibitory concentration). These strains are relevant to cosmetic products as they are associated with skin and nail infections. Mixtures of the three solvents, which are characteristic of nail varnish compositions, were also tested for their cidal activity. Ethyl and butyl acetates had a stronger impact than isopropyl alcohol: the MIC of ethyl and butyl acetate is ≤5% for all of the tested strains, whereas that of isopropyl alcohol is ≤10%. Various combinations of the three solvents tested showed a significant effect on both fungal and bacterial strains (greater than 3 log reduction in 15 min for the bacterial test strains and in 30 min for T. rubrum). Products containing more than 5% ethyl or butyl acetate or more than 10% isopropyl alcohol are hostile towards microbial growth. These products can therefore be considered as microbiologically low risk during both production and use, and so do not require microbiological testing (challenge test and end-product testing). Moreover, the nine tested mixtures of these three

  14. High Solid Contents Copoly (Styrene/Butyl Acrylate-Cloisite 30B Nanocomposites

    Directory of Open Access Journals (Sweden)

    M. Mirzataheri

    2013-03-01

    Full Text Available Higher solid contents (20 % and 40 % nanocomposites of poly (styrene-co-butyl acrylate including higher content of Cloisite 30B (7 wt% and 10 wt % were prepared via miniemulsion polymerization. Stability of the final latexes proved outstanding combination of polymerization procedure and surfactants. Morphological studies revealed by TEM, SAX and XRD showed three structures of core-shell, armored and individual dispersion of clay layers within the polymer particles. The effect of Cloisite 30B content on the barrier properties presents excellent and wide use of these films for packaging and nanocoatings industries.

  15. 2,6-Di-tert-butyl-4-(methoxy-meth-yl)phenol.

    Science.gov (United States)

    Zeng, Tao; Sun, Ju-Feng

    2008-02-13

    The title compound, C(16)H(26)O(2), was easily obtained in high yield when 4-bromo-methyl-2,6-di-tert-butyl-phenol was reacted with methanol. There are two independent mol-ecules in the asymmetric unit. The meth-oxy group in each of the independent mol-ecules was found to be disordered, with site-occupation factors of 0.8728 (18)/0.1272 (18) and 0.8781 (17)/0.1219 (17).

  16. 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)

  17. Methyl tert-butyl ether (MTBE) degradation by ferrous ion-activated persulfate oxidation: feasibility and kinetics studies.

    Science.gov (United States)

    Chen, K F; Kao, C M; Wu, L C; Surampalli, R Y; Liang, S H

    2009-07-01

    The objective of this study was to evaluate the feasibility of using ferrous ion-activated persulfate oxidation to remediate groundwater contaminated with methyl tert-butyl ether (MTBE). In this study, batch experiments were conducted to evaluate the effects of various factors on the efficiency of MTBE degradation including persulfate concentrations, ferrous ion concentrations, and persulfate coupled with hydrogen peroxide. Results show that ferrous ion-activated persulfate oxidation was capable of degrading MTBE efficiently. Persulfate and ferrous ion concentrations correlated with MTBE degradation rates. However, excess addition of ferrous ion resulted in decreased MTBE degrading rates most likely because of competition for sulfate free radicals between ferrous ion and MTBE. Two main byproducts of MTBE degradation, tert-butyl formate and tert-butyl alcohol, were detected in the experiments; both were, however, subsequently degraded. Results of sulfate analysis show that proper addition of ferrous ion could prevent unnecessary persulfate decomposition.

  18. 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

    Parabens are a group of antimicrobial preservatives widely used in cosmetics, pharmaceuticals, and in foods. Previous in vitro and in vivo studies have shown weak estrogenic effects of some parabens. Thus, especially, exposure of fetus and infants via the mother is a matter of concern. In order...... 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......, whole-body fetuses, and in fetal liver after dosing of dams with 100, 200, and 400 mg/kg body weight (bw)/day from gestational day 7 to 21. After cesarean section of dams, the fluids and tissues were collected, deconjugated, and purified by solid-phase extraction, and ethyl paraben and butyl paraben...

  19. Raman spectroscopic investigation of the chemopreventive response of naringenin and its nanoparticles in DMBA-induced oral carcinogenesis

    Science.gov (United States)

    Krishnakumar, N.; Sulfikkarali, N. K.; Manoharan, S.; Venkatachalam, P.

    2013-11-01

    Raman spectroscopy is a vibrational spectroscopic technique that can be used to optically probe the biomolecular changes associated with tumor progression. The aim of the present study is to investigate the biomolecular changes in chemopreventive response of prepared naringenin-loaded nanoparticles (NARNPs) relative to efficacy of free naringenin (NAR) during 7,12-dimethyl benz(a)anthracene (DMBA)-induced oral carcinogenesis by Fourier Transform Raman (FT-Raman) spectroscopy. 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. Raman spectra differed significantly between the control and tumor tissues, with tumors showing higher percentage signals for nucleic acids, phenylalanine and tryptophan and a lower in the percentage of phospholipids. Moreover, oral administration of free NAR and NARNPs significantly increased phospholipids and decreased the levels of tryptophan, phenylalanine and nucleic acid contents. On a comparative basis, NARNPs was found to have a more potent antitumor effect than free NAR in completely preventing the formation of squamous cell carcinoma and in improving the biochemical status to a normal range in DMBA-induced oral carcinogenesis. The present study further suggest that Raman spectroscopy could be a valuable tool for rapid and sensitive detection of specific biomolecular changes in response to chemopreventive agents.

  20. Health Promoting Effects of Brassica-Derived Phytochemicals: From Chemopreventive and Anti-Inflammatory Activities to Epigenetic Regulation

    Science.gov (United States)

    Wagner, Anika Eva; Terschluesen, Anna Maria; Rimbach, Gerald

    2013-01-01

    A high intake of brassica vegetables may be associated with a decreased chronic disease risk. Health promoting effects of Brassicaceae have been partly attributed to glucosinolates and in particular to their hydrolyzation products including isothiocyanates. In vitro and in vivo studies suggest a chemopreventive activity of isothiocyanates through the redox-sensitive transcription factor Nrf2. Furthermore, studies in cultured cells, in laboratory rodents, and also in humans support an anti-inflammatory effect of brassica-derived phytochemicals. However, the underlying mechanisms of how these compounds mediate their health promoting effects are yet not fully understood. Recent findings suggest that brassica-derived compounds are regulators of epigenetic mechanisms. It has been shown that isothiocyanates may inhibit histone deacetylase transferases and DNA-methyltransferases in cultured cells. Only a few papers have dealt with the effect of brassica-derived compounds on epigenetic mechanisms in laboratory animals, whereas data in humans are currently lacking. The present review aims to summarize the current knowledge regarding the biological activities of brassica-derived phytochemicals regarding chemopreventive, anti-inflammatory, and epigenetic pathways. PMID:24454992

  1. Protection against aflatoxin B1-induced hepatic toxicity as short-term screen of cancer chemopreventive dithiolethiones.

    Science.gov (United States)

    Maxuitenko, Y Y; Curphey, T J; Kensler, T W; Roebuck, B D

    1996-08-01

    Dithiolethiones are an important class of cancer chemopreventive agents. More than 50 new dithiolethione analogs were synthesized for structure-activity studies. Using selected dithiolethiones, studies were designed to measure protection against the hepatotoxicity of aflatoxin B1 (AFB1) and relate it to the protection against carcinogenicity. Young male F344 rats were pretreated with 0.1 or 0.3 mmol dithiolethiones/kg body wt and challenged with toxic doses of AFB1 (50 micrograms/100 g rat/day) on 2 successive days. One day later, the protection from hepatotoxicity was assessed by measuring serum hepatic enzymes, hepatic necrosis, and degree of bile duct cell proliferation. The ability of these dithiolethiones to prevent AFB1-induced tumorigenicity was assessed by quantifying the hepatic burden of putative preneoplastic lesions [placental glutathione S-transferase (GST-P)-positive foci]. Significant correlations (p bile duct cell proliferation, r = 0.933). These results imply that inhibition of hepatotoxicity affords protection against hepatocarcinogenicity. The extent of protection from acute hepatotoxicity offers a simple, short-term biological endpoint to screen dithiolethiones and related compounds for their chemopreventive properties.

  2. Chemopreventive efficacy of curcumin and piperine during 7,12-dimethylbenz[a]anthracene-induced hamster buccal pouch carcinogenesis.

    Science.gov (United States)

    Manoharan, S; Balakrishnan, S; Menon, V P; Alias, L M; Reena, A R

    2009-02-01

    Oral carcinoma accounts for 40-50 percent of all cancers in India. Tobacco chewing, smoking and alcohol consumption are the major risk factors associated with the high incidence of oral cancer in India. Our aim was to investigate the chemopreventive potential of curcumin and piperine during 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch carcinogenesis. Oral squamous cell carcinoma was developed in the buccal pouch of Syrian golden hamsters, by painting them with 0.5 percent DMBA in liquid paraffin, three times a week for 14 weeks. The tumour incidence, tumour volume and burden were determined in the buccal pouches. The status of phase II detoxification agents, lipid peroxidation and antioxidants were estimated by specific colorimetric methods. We observed 100 percent tumour formation in DMBA-alone painted hamsters. Disturbances in the status of lipid peroxidation, antioxidants and phase II detoxification agents were noticed in DMBA-alone painted hamsters. Oral administration of curcumin (80 mg/kg body weight) and piperine (50 mg/kg body weight) to DMBA-painted hamsters on alternate days to DMBA painting for 14 weeks completely prevented the formation of oral carcinoma. Also, curcumin and piperine restored the status of lipid peroxidation, antioxidants and detoxifying agents in DMBA-painted hamsters. The chemopreventive efficacy of curcumin and piperine is probably due to their antilipidperoxidative and antioxidant potential as well as their modulating effect on the carcinogen detoxification process.

  3. Chemopreventive effects of free and bound phenolics associated to steep waters (nejayote) obtained after nixtamalization of different maize types.

    Science.gov (United States)

    Rojas-García, Carlos; García-Lara, Silverio; Serna-Saldivar, Sergio O; Gutiérrez-Uribe, Janet A

    2012-03-01

    Free and bound phenolics extracts from nejayote solids were obtained after optimally lime-cooking blue, normal white, red, normal yellow, high-carotenoid and quality protein maize types. The extraction yield ranged from 4.47 to 10.05%. Bound phenolics extracts had higher content of total phenolics, antioxidant activity and ferulic acid compared to the free phenolics extracts. In general, free phenolics extracts were less cytotoxic than the bound phenolics counterparts. Bound phenolics extracts had higher induction of quinone reductase (QR) and particularly the normal yellow nejayote exerted the highest chemopreventive index tested in Hepa1c1c7 cells. When tested for monofunctional phase 2 induction capacity in BPrc1 cells, the bound phenolics extracts of blue, normal white and quality protein nejayotes were better inducers than the normal yellow counterpart. Particularly, the free phenolics extract of the white maize nejayote induced BPrc1 cells QR and exerted a higher chemopreventive index compared to the bound phenolics extract. Therefore, the nejayote of the normal white maize was the best source of monofunctional phase 2 enzyme inducers.

  4. Enzymes and genes involved in the aerobic biodegradation of methyl tert-butyl ether (MTBE).

    Science.gov (United States)

    Lopes Ferreira, Nicolas; Malandain, Cédric; Fayolle-Guichard, Françoise

    2006-09-01

    Fuel oxygenates, mainly methyl tert-butyl ether (MTBE) but also ethyl tert-butyl ether (ETBE), are added to gasoline in replacement of lead tetraethyl to enhance its octane index. Their addition also improves the combustion efficiency and therefore decreases the emission of pollutants (CO and hydrocarbons). On the other hand, MTBE, being highly soluble in water and recalcitrant to biodegradation, is a major pollutant of water in aquifers contaminated by MTBE-supplemented gasoline during accidental release. MTBE was shown to be degraded through cometabolic oxidation or to be used as a carbon and energy source by a few microorganisms. We have summarized the present state of knowledge about the microorganisms involved in MTBE degradation and the MTBE catabolic pathways. The role of the different enzymes is discussed as well as the rare and recent data concerning the genes encoding the enzymes involved in the MTBE pathway. The phylogeny of the microorganisms isolated for their capacity to grow on MTBE is also described.

  5. Biodegradation of methyl tert-butyl ether (MTBE) by Enterobacter sp. NKNU02.

    Science.gov (United States)

    Chen, Ssu Ching; Chen, Colin S; Zhan, Kai-Van; Yang, Kai-Hsing; Chien, Chih-Ching; Shieh, Bao-Sen; Chen, Wen-Ming

    2011-02-28

    We previously isolated and identified Enterobacter sp. NKNU02 as a methyl tert-butyl ether (MTBE)-degrading bacterial strain from gasoline-contaminated water. In this study, tert-butyl alcohol, acetic acid, 2-propanol, and propenoic acid were detected using gas chromatography/mass spectrometry when MTBE was degraded by rest cells of Enterobacter sp. NKNU02 cells. We also found that biodegradation of MTBE was decreased, but not totally inhibited in mixtures of benzene, toluene, ethylbenzene and xylene. The effects of MTBE on the biology of Enterobacter sp. NKNU02 were elucidated using 2D proteomic analysis. The cytoplasmic proteins isolated from these MTBE-treated and -untreated cells were carried out for proteomic analysis. Results showed that there were 6 differential protein spots and 8 differential protein spots, respectively, as compared to their corresponding control (without MTBE addition), at the indicated incubation times when 40% and 60% of 100 mg/L of MTBE had been removed, Among these proteins, nine were successfully identified with matrix-assisted laser desorption ionization-time of flight-mass spectrometry. Proteins identified included extracellular solute-binding protein, periplasmic-binding protein ytfQ, cationic amino acid ABC transporter, isocitrate dehydrogenase, cysteine synthase A, alkyl hydroperoxide reductase (AhpC), transaldolase, and alcohol dehydrogenase. Based on these differential proteins, we discuss the bacterial responses to MTBE at the molecular level. Copyright © 2010 Elsevier B.V. All rights reserved.

  6. Pyrolysis of methyl tert-butyl ether (MTBE). 2. Theoretical study of decomposition pathways.

    Science.gov (United States)

    Zhang, Taichang; Zhang, Lidong; Wang, Jing; Yuan, Tao; Hong, Xin; Qi, Fei

    2008-10-23

    The thermal decomposition pathways of MTBE have been investigated using the G3B3 method. On the basis of the experimental observation and theoretical calculation, the pyrolysis channels are provided, especially for primary pyrolysis reactions. The primary decomposition pathways include formation of methanol and isobutene, CH4 elimination, H2 elimination and C-H, C-C, C-O bond cleavage reactions. Among them, the formation channel of methanol and isobutene is the lowest energy pathway, which is in accordance with experimental observation. Furthermore, the secondary pyrolysis pathways have been calculated as well, including decomposition of tert-butyl radical, isobutene, methanol and acetone. The radicals play an important role in the formation of pyrolysis products, for example, tert-butyl radical and allyl radical are major precursors for the formation of allene and propyne. Although some isomers (isobutene and 1-butene, allene and propyne, acetone and propanal) are identified in our experiment, these isomerization reaction pathways occur merely at the high temperature due to their high activation energies. The theoretical calculation can explain the experimental results reported in part 1 and shed further light on the thermal decomposition pathways.

  7. Community characterization of anaerobic methyl tert-butyl ether (MTBE)-degrading enrichment cultures.

    Science.gov (United States)

    Youngster, Laura K G; Kerkhof, Lee J; Häggblom, Max M

    2010-05-01

    Use of the fuel oxygenate methyl tert-butyl ether (MTBE) has led to widespread environmental contamination. Anaerobic biodegradation of MTBE observed under different redox conditions is a potential means for remediation of contaminated aquifers; however, no responsible microorganisms have been identified as yet. We analyzed the bacterial communities in anaerobic-enriched cultures originating from three different contaminated sediments that have retained MTBE-degrading activity for over a decade. MTBE was transformed to tert-butyl alcohol and the methyl group used as a carbon and energy source. Terminal restriction fragment length polymorphism (T-RFLP) analysis of bacterial 16S rRNA genes showed that the MTBE-utilizing microcosms established from different sediment sources had substantially different community profiles, suggesting that multiple species are capable of MTBE biodegradation. The 16S rRNA genes from one enrichment culture were cloned and sequenced. Phylogenetic analysis showed a diverse community, with phylotypes belonging to the Proteobacteria, Bacteroidetes, Firmicutes, Chloroflexi and Thermotogae. Continued enrichment on MTBE further reduced the community to three predominant phylotypes, as evidenced by T-RFLP analysis, which were most closely related to the Deltaproteobacteria, Firmicutes and Chloroflexi. These three common operational taxonomic units were detectable in the enrichments from Atlantic and Pacific coastal samples. Identification of the microorganisms important in mediating anaerobic MTBE transformation will provide the foundation for developing tools for site assessment and bioremediation monitoring.

  8. Production of fatty acid butyl esters using the low cost naturally immobilized Carica papaya lipase.

    Science.gov (United States)

    Su, Erzheng; Wei, Dongzhi

    2014-07-09

    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.

  9. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Biodegradation of methyl t-butyl ether by pure bacterial cultures

    Energy Technology Data Exchange (ETDEWEB)

    Mo, K. [Notre Dame Univ., IN (United States). Dept. of Biological Sciences; Lora, C.O. [Notre Dame Univ., IN (United States). Dept. of Biological Sciences; Wanken, A.E. [Notre Dame Univ., IN (United States). Dept. of Biological Sciences; Javanmardian, M. [Amoco Research Center, Naperville, IL (United States); Yang, X. [Amoco Research Center, Naperville, IL (United States); Kulpa, C.F. [Notre Dame Univ., IN (United States). Dept. of Biological Sciences

    1997-08-01

    Three pure bacterial cultures degrading methyl t-butyl ether (MTBE) were isolated from activated sludge and fruit of the Gingko tree. They have been classified as belonging to the genuses Methylobacterium, Rhodococcus, and Arthrobacter. These cultures degraded 60 ppm MTBE in 1-2 weeks of incubation at 23-25 C. The growth of the isolates on MTBE as sole carbon source is very slow compared with growth on nutrient-rich medium. Uniformly-labeled [{sup 14}C]MTBE was used to determine {sup 14}CO{sub 2} evolution. Within 7 days of incubation, about 8% of the initial radioactivity was evolved as {sup 14}CO{sub 2}. These strains also grow on t-butanol, butyl formate, isopropanol, acetone and pyruvate as carbon sources. The presence of these compounds in combination with MTBE decreased the degradation of MTBE. The cultures pregrown on pyruvate resulted in a reduction in {sup 14}CO{sub 2} evolution from [{sup 14}C]MTBE. The availability of pure cultures will allow the determination of the pathway intermediates and the rate-limiting steps in the degradation of MTBE. (orig.)

  11. 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.

  12. 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.

  13. Biodegradation of di-n-butyl phthalate by bacterial consortium LV-1 enriched from river sludge.

    Directory of Open Access Journals (Sweden)

    Yangyang Wang

    Full Text Available A stable bacterial consortium (LV-1 capable of degrading di-n-butyl phthalate (DBP was enriched from river sludge. Community analysis revealed that the main families of LV-1 are Brucellaceae (62.78% and Sinobacteraceae (14.83%, and the main genera of LV-1 are Brucella spp. (62.78% and Sinobacter spp. (14.83%. The optimal pH and temperature for LV-1 to degrade DBP were pH 6.0 and 30°C, respectively. Inoculum size influenced the degradation ratio when the incubation time was < 24 h. The initial concentration of DBP also influenced the degradation rates of DBP by LV-1, and the degradation rates ranged from 69.0-775.0 mg/l/d in the first 24 h. Degradation of DBP was best fitted by first-order kinetics when the initial concentration was < 300 mg/l. In addition, Cd2+, Cr6+, and Zn2+ inhibited DBP degradation by LV-1 at all considered concentrations, but low concentrations of Pb2+, Cu2+, and Mn2+ enhanced DBP degradation. The main intermediates (mono-ethyl phthalate [MEP], mono-butyl phthalate [MBP], and phthalic acid [PA] were identified in the DBP degradation process, thus a new biochemical pathway of DBP degradation is proposed. Furthermore, LV-1 also degraded other phthalates with shorter ester chains (DMP, DEP, and PA.

  14. Metabolite profiling of polyphenols in Vaccinium berries and determination of their chemopreventive properties.

    Science.gov (United States)

    Prencipe, Francesco Pio; Bruni, Renato; Guerrini, Alessandra; Rossi, Damiano; Benvenuti, Stefania; Pellati, Federica

    2014-02-01

    A detailed investigation on the chemical composition and chemopreventive activity of Vaccinium floribundum Kunth berries was carried out in comparison with Vaccinium myrtillus L. Berry polyphenols were extracted by using two sequential dynamic maceration steps, which enabled to maximize the yields of secondary metabolites. In particular, phenolic acids and flavonols were extracted from berries using ethyl acetate (EtOAc), whereas anthocyanins were extracted from the residue with 0.6M HCl in methanol (MeOH). The analysis of secondary metabolites in berry extracts was performed by means of two specific HPLC methods. Phenolic acids and flavonols were analyzed on an Ascentis C18 column (250mm×4.6mm I.D., 5μm), with a gradient mobile phase composed of 0.1M HCOOH in H2O and ACN. Anthocyanin analysis was carried out on a Zorbax SB-C18 column (150mm×4.6mm I.D., 5μm), with a gradient mobile phase composed of H2O-HCOOH (9:1, v/v) and MeOH-H2O-HCOOH (5:4:1, v/v/v). Detection was performed by UV/DAD, MS and MS(2). The polyphenol composition of V. floribundum and V. myrtillus was studied in detail. The samples of V. floribundum analyzed in this study had a much higher content of both phenolic acids and flavonols in comparison with V. myrtillus (mean value 41.6±10.2 and 13.7±0.2mg/100g FW, respectively), while V. myrtillus showed a higher amount of anthocyanins if compared with V. floribundum (568.8±8.8 and mean value 376.2±49.9mg/100gFW, respectively). The extracts gave negative results in antimutagenic assays against carcinogens 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ) and 4-nitroquinoline-1-oxide (4-NQO), while they performed similarly in both ABTS(+) and DPPH antioxidant assays. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Effects of two disiloxanes ALIS-409 and ALIS-421 on chemoprevention in model experiments.

    Science.gov (United States)

    Tokuda, Harukuni; Maoka, Takashi; Suzuiki, Nobutaka; Hohmann, Judit; Vasas, Andrea; Engi, Helga; Mucsi, Ilona; Olszewski, Ulrike; Hamilton, Gerhard; Amaral, Leonard; Molnar, Joseph

    2013-05-01

    Morpholino-disiloxane (ALIS-409) and piperazino-disiloxane (ALIS-421) compounds were developed as inhibitors of multidrug resistance of various types of cancer cells. In the present study, the effects of ALIS-409 and ALIS-421 compounds were investigated on cancer promotion and on co-existence of tumor and normal cells. The two compounds were evaluated for their inhibitory effects on Epstein-Barr virus immediate-early antigen (EBV-EA) expression induced by tetradecanoyl-phorbol-acetate (TPA) in Raji cell cultures. The method is known as a primary screening test for antitumor effect, below the (IC50) concentration. ALIS-409 was more effective in inhibiting EBV-EA (100 μg/ml) and tumor promotion, than ALIS-421, in the concentration range up to 1000 μg/ml. However, neither of the compounds were able to reduce tumor promotion significantly, expressed as inhibition of TPA-induced tumor antigen activation. Based on the in vitro results, the two disiloxanes were investigated in vivo for their effects on mouse skin tumors in a two-stage mouse skin carcinogenesis study. The application of dimethyl-benzanthracene (DMBA; 390 nmol) as a tumor initiator was followed by exposure to TPA (1.7 nmol/l) as a tumor promoter. The experiments showed that ALIS-409 at a concentration of 85 nmol/l had a weak EBV-EA inhibitory effect in vitro and a moderate antitumor activity, compared to the positive control of DMBA plus TPA-treated mice. Flow cytometry by differential staining demonstrated interactions in co-cultures of MCF7 breast cancer and MRC5 human lung fibroblasts. The growth rate of tumor cells in mixed populations of MCF7 breast cancer and MRC5 normal fibroblast cells was reduced in the presence of ALIS-409, as compared to the control non-treated cell populations. The two disiloxanes were moderately-effective in chemoprevention in DMBA-induced and TPA-promoted in vivo tumor formation. Authors suggest that the inhibition of tumor cell and fibroblast interaction by ALIS409 might

  16. 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...

  17. Enzymatic Kinetic Resolution of tert-Butyl 2-(1-Hydroxyethylphenylcarbamate, A Key Intermediate to Chiral Organoselenanes and Organotelluranes

    Directory of Open Access Journals (Sweden)

    Leandro Piovan

    2011-09-01

    Full Text Available The enzymatic kinetic resolution of tert-butyl 2-(1-hydroxyethyl phenylcarbamate via lipase-catalyzed transesterification reaction was studied. We investigated several reaction conditions and the carbamate was resolved by Candida antarctica lipase B (CAL-B, leading to the optically pure (R- and (S-enantiomers. The enzymatic process showed excellent enantioselectivity (E > 200. (R- and (S-tert-butyl 2-(1-hydroxyethylphenylcarbamate were easily transformed into the corresponding (R- and (S-1-(2-aminophenylethanols.

  18. Use of a continuous-flow microreactor for thiol-ene functionalization of RAFT-derived poly(butyl acrylate)

    OpenAIRE

    Vandenbergh, Joke; Junkers, Thomas

    2012-01-01

    This study describes the synthesis of functionalized RAFT-derived poly(n-butyl acrylate) polymers via the use of a continuous-flow microreactor, in which aminolysis as well as thiol-ene reactions are executed in reaction times of just 20 minutes. Poly(n-butyl acrylate) (M-n = 3800 g mol(-1), PDI = 1.10) with a trithiocarbonate end group was prepared via a conventional RAFT process. The polymer was then functionalized via aminolysis/thiol-ene reactions in the micro-flow reactor with isobornyl ...

  19. 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...

  20. 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...

  1. Chemopreventive effects of Coltect, a novel dietary supplement, alone and in combination with 5-aminosalicylic acid in 1,2-dimethylhydrazine-induced colon cancer in rats

    OpenAIRE

    Aroch, Ilan; Kraus, Sarah; Naumov, Inna; Ron, Ehud; Shapira, Shiran; Kazanov, Dina; Giladi, Nis; Litvak, Alex; Lev-Ari, Shahar; Hallak, Aharon; Dotan, Iris; Shpitz, Baruch; Arber, Nadir

    2010-01-01

    Objectives: Coltect is a novel dietary supplement containing curcumin, green tea and selenomethionine. Previous reports have suggested that these agents can prevent colorectal cancer (CRC). The present study examined the chemopreventive effect of Coltect alone or combined with 5-aminosalicylic acid (5-ASA) using the 1,2-dimethylhydrazine (DMH) model in rats.

  2. Modeling the temperature dependence of N-methylpyrrolidone permeation through butyl- and natural-rubber gloves.

    Science.gov (United States)

    Zellers, E T; Sulewski, R

    1993-09-01

    This paper describes the temperature dependence of N-methylpyrrolidone (NMP) permeation through gloves used in microelectronics fabrication facilities. One type of butyl-rubber glove (North B161), two types of natural-rubber gloves (Edmont Puretek and Ansell Pacific White), and a natural rubber/nitrile/neoprene-blend glove (Pioneer Trionic) were tested at four temperatures from 25-50 degrees C using the ASTM F739-85 permeation test method. The butyl-rubber glove showed no breakthrough after four hours of exposure at any temperature. The variations with temperature of measured breakthrough times (BT) and steady-state permeation rates (SSPR) for the other gloves were described well by Arrhenius relationships, with BT values decreasing by factors of 7-10 and SSPR values increasing by factors of 4-6 over the temperature range studied. Extrapolation to 70 and 93 degrees C, the temperatures at which degreasing is often performed, yielded BT values of < 2 min and < 0.5 min, respectively, in all cases. With the exception of the butyl-rubber glove, following an initial exposure at 25 degrees C and air drying overnight, low levels of NMP vapor were detected off-gassing from the inner surfaces of the gloves. Experimental results were then compared to those expected from several permeation models. Estimates of the equilibrium solvent solubility, S, were calculated using a model based on three-dimensional solubility parameters. Estimates of the solvent diffusion coefficient, D, were obtained from correlations with either the solvent kinematic viscosity or the product of the Flory interaction parameter, chi, and the solvent molar volume. Combining these values of D and S in Fickian diffusion equations gave modeled BT estimates that were within 23% of experimental values over the temperature range examined. Modeled SSPR values were within 50% (typically within 25%) of experimental values. Another model based on a generalized Arrhenius relationship also provided useful but

  3. Chemopreventive effect of raw and cooked lentils (Lens culinaris L) and soybeans (Glycine max) against azoxymethane-induced aberrant crypt foci.

    Science.gov (United States)

    Faris, Mo'ez Al-Islam E; Takruri, Hamed R; Shomaf, Maha S; Bustanji, Yasser K

    2009-05-01

    Although lentils (Lens culinaris L) contain several bioactive compounds that have been linked to the prevention of cancer, the in vivo chemopreventive ability of lentils against chemically induced colorectal cancer has not been examined. Our present study examined the hypothesis that lentils could suppress the early carcinogenesis in vivo by virtue of their bioactive micro- and macroconstituents and that culinary thermal treatment could affect their chemopreventive potential. To accomplish this goal, we used raw whole lentils (RWL), raw split lentils (RSL), cooked whole lentils (CWL), and cooked split lentils (CSL). Raw soybeans (RSB; Glycine max) were used for the purpose of comparison with a well-studied chemopreventive agent. Sixty weanling Fischer 344 male rats, 4 to 5 weeks of age, were randomly assigned to 6 groups (10 rats/group): the control group (C) received AIN-93G diet, and treatment leguminous groups of RWL, CWL, RSL, CSL, and RSB received the treatment diets containing AIN-93G+5% of the above-mentioned legumes. After acclimatization for 1 week (at 5th to 6th week of age), all animals were put on the control and treatment diets separately for 5 weeks (from 6th to 11th week of age). At the end of the 5th week of feeding (end of 11th week of age), all rats received 2 subcutaneous injections of azoxymethane carcinogen at 15 mg/kg rat body weight per dose once a week for 2 consecutive weeks. After 17 weeks of the last azoxymethane injection (from 12th to 29th week of age), all rats were euthanized. Chemopreventive ability was assessed using colonic aberrant crypt foci and activity of hepatic glutathione-S-transferases. Significant reductions (P lentils might be protective against colon carcinogenesis and that hydrothermal treatment resulted in an improvement in the chemopreventive potential for the whole lentils.

  4. Effect of tert-Butyl Functionalization on the Photoexcited Decay of a Fe(II)-N-Heterocyclic Carbene Complex

    DEFF Research Database (Denmark)

    Pápai, Mátyás Imre; Penfold, Thomas J.; Møller, Klaus Braagaard

    2016-01-01

    . This occurs because the tert-butyl functionalization stabilizes the 1MC states, enabling the 1,3MLCT → 1MC population transfer to occur close to the Franck-Condon geometry, making the conversion very efficient. Subsequently, a spin cascade occurs within the MC manifold, leading to the population of triplet...

  5. Ultrasonic promoted catalyst-free N-formylation of amines in neutral ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate

    Directory of Open Access Journals (Sweden)

    Vinod T. Kamble

    2017-05-01

    Full Text Available A catalyst-free, simple and efficient protocol for N-formylation of alkyl, aryl, and heteroaryl amines with formic acid under ultrasonic irradiation at room temperature using 1-butyl-3-methylimidazolium tetrafluoroborate [Bmim]BF4 as a neutral medium is described.

  6. 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.

  7. Di-iso-Butyl Phthalate MATERNAL AND FETAL DATA FROM THE LE GRAY RESEARCH TEAM FOR NCEA June 15 2016

    Science.gov (United States)

    this file contains the raw data on the effects of in utero administration of di-iso-butyl phthalate on maternal weight gain during dosing and the numbers of fetuses and fetal resorptions. The data have all been previously published, as described on the file metadata sheet.

  8. 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.

  9. Antioxidant activity of aqueous extract of a Tolypocladium sp. fungus ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-09-03

    . Butylated hydroxytoluene (BHT, Shanghai. Biochemical Factory, Shanghai, China) was used as positive controls. The scavenging activity of superoxide radical (%) was thus calculated with the equation described as in the ...

  10. Aromatic Plants: Antioxidant Capacity and Polyphenol Characterisation

    National Research Council Canada - National Science Library

    Charalampos Proestos; Theo Varzakas

    2017-01-01

    ...). Results were compared with standard butylated hydroxytoluene (BHT) and ascorbic acid. Total phenol concentration of the extracts was estimated with Folin-Ciocalteu reagent using gallic acid as standard...

  11. Antioxidant and antimicrobial properties of Litsea elliptica Blume and Litsea resinosa Blume (Lauraceae

    Directory of Open Access Journals (Sweden)

    Mui-Hung Wong

    2014-05-01

    Conclusions: Overall, methanol extracts from root and stem of both species showed antioxidant activity comparable to standard butylated hydroxytoluene. Extracts from L. resinosa demonstrated stronger antimicrobial properties compared to that from L. elliptica.

  12. Biodegradation of di-n-butyl phthalate (DnBP) in bioaugmented bioslurry phase reactor.

    Science.gov (United States)

    Shailaja, S; Ramakrishna, M; Venkata Mohan, S; Sarma, P N

    2007-05-01

    Bioremediation of di-n-butyl phthalate (DnBP) in soil was studied with various concentrations in a bioslurry phase batch reactor operated in sequenting batch mode (bioaugmented with effluent treatment plant (ETP) microflora) for a total cycle period of 96h. Process performance during the reactor operation was assessed by monitoring DnBP concentration and biochemical process parameters viz., pH, dissolved oxygen (DO), colony forming units (CFU) and oxygen uptake rate (OUR), during the sequence phase operation. The degradation rate was observed to be rapid at lower substrate concentrations and found to be slow as the substrate concentration increased. The potent bacterial strain was also isolated from the slurry phase reactor. Metabolites formed during the degradation of DnBP in the slurry phase reactor were identified. Studies on the kinetics and half-life of the reaction revealed that the degradation process followed zero-order kinetic model.

  13. Design and Control of Glycerol-tert-Butyl Alcohol Etherification Process

    Science.gov (United States)

    Vlad, Elena; Bozga, Grigore

    2012-01-01

    Design, economics, and plantwide control of a glycerol-tert-butyl alcohol (TBA) etherification plant are presented. The reaction takes place in liquid phase, in a plug flow reactor, using Amberlyst 15 as a catalyst. The products' separation is achieved by two distillation columns where high-purity ethers are obtained and a section involving extractive distillation with 1,4-butanediol as solvent, which separates TBA from the TBA/water azeotrope. Details of design performed in AspenPlus and an economic evaluation of the process are given. Three plantwide control structures are examined using a mass balance model of the plant. The preferred control structure fixes the fresh glycerol flow rate and the ratio glycerol + monoether : TBA at reactor-inlet. The stability and robustness in the operation are checked by rigorous dynamic simulation in AspenDynamics. PMID:23365512

  14. Degradation of methyl tert-butyl ether (MTBE) in water by glow discharge plasma.

    Science.gov (United States)

    Tong, Shaoping; Ni, Yanyan; Shen, Chensi; Wen, Yuezhong; Jiang, Xuanzhen

    2011-01-01

    This study evaluated the ability of the glow discharge plasma (GDP) technique to degrade methyl tert-butyl ether (MTBE) in an aqueous solution. The results showed that a large amount of hydrogen peroxide and highly active *OH free radicals were produced during the treatment. Various experimental parameters including discharge current, initial MTBE concentration and initial pH played significant roles on MTBE degradation. In addition, Fe2+ had a catalytic effect on the degradation of MTBE, which is potentially attributable to the reaction between Fe3+ and the hydrated electron. It was also confirmed that GDP was comparable to electrocatalytic oxidation and high-density plasma and more efficient than photocatalytic degradation techniques. These results suggest that GDP may become a competitive MTBE wastewater treatment technology.

  15. Epidemiology, toxicokinetics, and health effects of methyl tert-butyl ether (MTBE).

    Science.gov (United States)

    Phillips, Scott; Palmer, Robert B; Brody, Aaron

    2008-06-01

    This paper reviews the published information assessing the kinetics and potential for adverse health effects related to exposure to the fuel oxygenate, methyl tert-butyl ether (MTBE). Data were obtained from previously published reports, using human data where possible. If human data were not available, animal studies were cited. The kinetic profile of MTBE in humans is similar for ingestion and inhalation. The concentrations of MTBE to which the general public is expected to be exposed are orders of magnitude below concentrations that have caused adverse health effects in animals. Controlled human studies have not replicated early epidemiology studies that suggested, but did not confirm, a possible association between MTBE exposure and nonspecific health complaints.

  16. Barrierity of hydrogenated butadiene-acrylonitrile rubber and butyl rubber after exposure to organic solvents.

    Science.gov (United States)

    Krzemińska, Sylwia; Rzymski, Władysław M

    2011-01-01

    Resistance of antichemical clothing primarily depends on the type of material it is made from, in particular on the type of polymer used for coating the fabric carrier. This paper reports on systematic investigations on the influence of the cross-linking density of an elastomer and the composition of a cross-linked elastomer on its resistance to permeation of selected organic solvents. Tests of barrier material samples made from nonpolar butyl rubber (IIR) and polar hydrogenated butadiene-acrylonitrile rubber (HNBR) showed that (a) in rubber-solvent systems with medium thermodynamic affinity, cross-linking density influenced resistance to permeation and (b) the polarity of the system had a significant influence on barrierity.

  17. Crystal structure of (1,3-di-tert-butyl-η5-cyclopentadienyltrimethylhafnium(IV

    Directory of Open Access Journals (Sweden)

    Adrián Pérez-Redondo

    2015-05-01

    Full Text Available The molecule of the title organometallic hafnium(IV compound, [Hf(CH33(C13H21] or [HfMe3(η5-C5H3-1,3-tBu2], adopts the classical three-legged piano-stool geometry for monocyclopentadienylhafnium(IV derivatives with the three methyl groups bonded to the Hf(IV atom at the legs. The C atoms of the two tert-butyl group bonded to the cyclopentadienyl (Cp ring are 0.132 (5 and 0.154 (6 Å above the Cp least-squares plane. There are no significant intermolecular interactions present between the molecules in the crystal structure.

  18. FE-SEM observation of swelled seaweed using hydrophilic ionic liquid; 1-butyl-3-methylimidazolium tetrafluoroborate.

    Science.gov (United States)

    Takahashi, Chisato; Shirai, Takashi; Fuji, Masayoshi

    2013-01-01

    The method to observe the exact morphology of swelled seaweed as an example of biological material by field emission scanning electron microscopy (FE-SEM) with the aid of hydrophilic ionic liquid (IL); 1-butyl-3-methylimidazolium tetrafluoroborate is reported. Seaweed was first swelled in 3.5% NaCl solution and then treated with the IL and water mixture in 1:7 weight ratios and centrifuged to remove the excess IL solution. Thus treated seaweed maintained its morphology even at high magnification and did not show drying in the FE-SEM chamber. This observation technique might be useful for various kinds of biological materials to be observed under FE-SEM. Copyright © 2012 Wiley Periodicals, Inc.

  19. Linear Viscoelasticity of Spherical SiO 2 Nanoparticle-Tethered Poly(butyl acrylate) Hybrids

    KAUST Repository

    Goel, Vivek

    2010-12-01

    The melt state linear viscoelastic properties of spherical silica nanoparticles with grafted poly(n-butyl acrylate) chains of varying molecular weight were probed using linear small amplitude dynamic oscillatory measurements and complementary linear stress relaxation measurements. While the pure silica-tethered-polymer hybrids with no added homopolymer exhibit solid-like response, addition of matched molecular weight free matrix homopolymer chains to this hybrid, at low concentrations of added homopolymer, maintains the solid-like response with a lowered modulus that can be factored into a silica concentration dependence and a molecular weight dependence. While the silica concentration dependence of the modulus is strong, the dependence on molecular weight is weak. On the other hand, increasing the amount of added homopolymer changes the viscoelastic response to that of a liquid with a relaxation time that scales exponentially with hybrid concentration. © 2010 American Chemical Society.

  20. Liquid-Liquid equilibria of the water-acetic acid-butyl acetate system

    Directory of Open Access Journals (Sweden)

    Ince E.

    2002-01-01

    Full Text Available Experimental liquid-liquid equilibria of the water-acetic acid-butyl acetate system were studied at temperatures of 298.15± 0.20, 303.15± 0.20 and 308.15± 0.20 K. Complete phase diagrams were obtained by determining solubility and tie-line data. The reliability of the experimental tie-line data was ascertained by using the Othmer and Tobias correlation. The UNIFAC group contribution method was used to predict the observed ternary liquid-liquid equilibrium (LLE data. It was found that UNIFAC group interaction parameters used for LLE did not provide a good prediction. Distribution coefficients and separation factors were evaluated for the immiscibility region.

  1. Study of n-Butyl Acrylate Self-Initiation Reaction Experimentally and via Macroscopic Mechanistic Modeling

    Directory of Open Access Journals (Sweden)

    Ahmad Arabi Shamsabadi

    2016-04-01

    Full Text Available This paper presents an experimental study of the self-initiation reaction of n-butyl acrylate (n-BA in free-radical polymerization. For the first time, the frequency factor and activation energy of the monomer self-initiation reaction are estimated from measurements of n-BA conversion in free-radical homo-polymerization initiated only by the monomer. The estimation was carried out using a macroscopic mechanistic mathematical model of the reactor. In addition to already-known reactions that contribute to the polymerization, the model considers a n-BA self-initiation reaction mechanism that is based on our previous electronic-level first-principles theoretical study of the self-initiation reaction. Reaction rate equations are derived using the method of moments. The reaction-rate parameter estimates obtained from conversion measurements agree well with estimates obtained via our purely-theoretical quantum chemical calculations.

  2. Microbial dynamics in anaerobic enrichment cultures degrading di-n-butyl phthalic acid ester

    DEFF Research Database (Denmark)

    Trably, Eric; Batstone, Damien J.; Christensen, Nina

    2008-01-01

    Although anaerobic biodegradation of di-n-butyl phthalic acid ester (DBP) has been studied over the past decade, only little is known about the microorganisms involved in the biological anaerobic degradation pathways. The aim of this work is to characterize the microbial community dynamics...... losses were observed in the sterile controls (20-22%), substantial DBP biodegradation was found in the enrichment cultures (90-99%). In addition, significant population changes were observed. The dominant bacterial species in the DBP-degrading cultures was affiliated to Soehngenia saccharolytica......, a microorganism described previously as an anaerobic benzaldehyde degrader. Within the archaeal community, there was a shift between two different species of the genus Methanosaeta sp., indicating a highly specific impact of DBP or degradation products on archaeal species. RNA-directed probes were designed from...

  3. Volumetric properties of binary mixtures of alkoxyethanols with ethyl tert-butyl ether at various temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Kinart, Cezary M. [Department of Chemistry, University of Lodz, 90-236 Lodz, Pomorska 163 (Poland)]. E-mail: ckinart@uni.lodz.pl; Nowak, Katarzyna [Department of Chemistry, University of Lodz, 90-236 Lodz, Pomorska 163 (Poland); Kinart, Wojciech J. [Department of Organic Chemistry, University of Lodz, 90-136 Lodz, Narutowicza 68 (Poland)

    2005-05-15

    Densities at T = (293.15, 298.15, 303.15, 308.15, and 313.15) K in the binary liquid mixtures of ethyl tert-butyl ether with 2-methoxyethanol, 2-(2-methoxyethoxy)ethanol or 2-{l_brace}2-(2-methoxyethoxy)ethoxy{r_brace}ethanol have been measured over the entire mixture compositions. These data have been used to compute the excess molar volumes. The excess molar volumes are negative over the entire range of composition for all mixtures. The changes of V{sup E} with variations of the composition and the chain-length of the alkyl groups in the alkoxyethanol molecules are discussed in terms of intermolecular interactions.

  4. [n-Butyl Alcohol-soluble Chemical Constituents of Psidium guajava Leaves].

    Science.gov (United States)

    Chen, Gang; Wan, Kai-hua; Fu, Hui-zheng; Yan, Qing-wei

    2015-03-01

    To study the chemical constituents of the leaves of Psidium guajava. The chemical constituents were isolated by column chromatography on silica gel, Sephadex LH-20 and MPLC. Their chemical structures were elucidated on the basis of special analysis. Seven compounds were isolated from n-butyl alcohol fraction, whose structures were elucidated as morin-3-O-α-L-arabopyranoside (1), morin-3-O-α-L-iyxopyranoside (2), 2,6-dihydroxy-4-O-β-D-glucopyranosyl-benzophenone (3), casuarictin (4),2,6-dihydroxy-3,5-dimethyl-4-O-(6"-O-galloyl-β-D-glucopyranosyl)-benzophenone(5), globulusin A(6), and kaempferol-3-O-β-D-(6"-galloyl) galactopyranoside (7). Compounds 3 and 5 ~ 7 are isolated from this plant for the first time.

  5. Microencapsulation of butyl stearate as a phase change material by interfacial polycondensation in a polyurea system

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Chen; Lingling, Xu; Hongbo, Shang; Zhibin, Zhang [College of Material Science and Engineering, Nanjing University of Technology, Nanjing 210009 (China)

    2009-03-15

    For the last 20 years, microencapsulated phase change materials (MicroPCMs), which combine microencapsulation technology and phase change material, have been attracted more and more interest. By overcoming some limitations of the PCMs, the MicroPCMs improve the efficiency of PCMs and make it possible to apply PCMs in many areas. In this experiment, polyurea microcapsules containing phase change materials were prepared using interfacial polycondensation method. Toluene-2,4-diisocyanate (TDI) and ethylenediamine (EDA) were chosen as monomers. Butyl stearate was employed as a core material. The MicroPCMs' properties have been characterized by dry weight analysis, differential scanning calorimetry, Fourier transform IR spectra analysis and optical microscopy. The results show that the MicroPCMs were synthesized successfully and that, the phase change temperature was about 29 C, the latent heat of fusion was about 80 J g{sup -1}, the particle diameter was 20-35 {mu}m. (author)

  6. Microencapsulation of butyl stearate as a phase change material by interfacial polycondensation in a polyurea system

    Energy Technology Data Exchange (ETDEWEB)

    Chen Liang [College of Material Science and Engineering, Nanjing University of Technology, Nanjing 210009 (China)], E-mail: doseng_1982@hotmail.com; Xu Lingling; Shang Hongbo; Zhang Zhibin [College of Material Science and Engineering, Nanjing University of Technology, Nanjing 210009 (China)

    2009-03-15

    For the last 20 years, microencapsulated phase change materials (MicroPCMs), which combine microencapsulation technology and phase change material, have been attracted more and more interest. By overcoming some limitations of the PCMs, the MicroPCMs improve the efficiency of PCMs and make it possible to apply PCMs in many areas. In this experiment, polyurea microcapsules containing phase change materials were prepared using interfacial polycondensation method. Toluene-2,4-diisocyanate (TDI) and ethylenediamine (EDA) were chosen as monomers. Butyl stearate was employed as a core material. The MicroPCMs' properties have been characterized by dry weight analysis, differential scanning calorimetry, Fourier transform IR spectra analysis and optical microscopy. The results show that the MicroPCMs were synthesized successfully and that, the phase change temperature was about 29 deg. C, the latent heat of fusion was about 80 J g{sup -1}, the particle diameter was 20-35 {mu}m.

  7. Determining the primary nucleation and growth mechanism of cloxacillin sodium in methanol-butyl acetate system

    Science.gov (United States)

    Zhi, Minjie; Wang, Yongli; Wang, Jingkang

    2011-01-01

    The primary nucleation and growth mechanism of cloxacillin sodium in methanol-butyl acetate system are determined on the basis of induction time measurements. The induction time of cloxacillin sodium is experimentally determined by the laser scattering method at different supersaturations and temperatures. The measured induction times are then treated using the models of mononuclear and polynuclear mechanisms. It is discovered that the primary nucleation mechanism of cloxacillin sodium is identified as polynuclear mechanism, which relates the induction time and the supersaturation for various growth mechanisms. On the basis of these analyses, the growth mechanism of cloxacillin sodium is two-dimensional nucleation-mediated growth at 285 K, and changes into spiral growth with increasing temperature (at 291 and 297 K).

  8. 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......-long real-time dynamics. The ion-molecular structure patterns in saturated and supersaturated solutions are distinguished in terms of radial distribution functions and cluster analysis of the solute particles. The cation separated solute pair is found to be a common structure in both saturated......][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...

  9. Inhibition Effect of 1-Butyl-4-Methylpyridinium Tetrafluoroborate on the Corrosion of Copper in Phosphate Solutions

    Directory of Open Access Journals (Sweden)

    M. Scendo

    2011-01-01

    Full Text Available The influence of the concentration of 1-Butyl-4-methylpyridinium tetrafluoroborate (4MBPBF4 as ionic liquid (IL on the corrosion of copper in 0.5 M PO43− solutions of pH 2 and 4 was studied. The research involved electrochemical polarization method, and scanning electron microscopy (SEM technique. The results obtained showed that the inhibition efficiency of corrosion of copper increases with an increase in the concentration of 4MBPBF4 but decreases with increasing temperature. The thermodynamic functions of corrosion analysis and adsorptive behavior of 4MBPBF4 were carried out. During the test, the adsorption of the inhibitor on the copper surface in the phosphate solutions was found to obey the Langmuir adsorption isotherm and had a physical mechanism.

  10. Bronchoscopic management of bronchopleural fistula with intrabronchial instillation of glue (N-butyl cyanoacrylate

    Directory of Open Access Journals (Sweden)

    Rakesh K Chawla

    2012-01-01

    Full Text Available Context: Bronchopleural fistula (BPF is a communication between the pleural space and bronchial tree. Materials and Methods: A series of 9 cases are reported where BPF was identified and managed with intrabronchial instillation of glue (N-butyl-cyanoacrylate through a video bronchoscope. Results: Out of 9 patients the BPF was successfully sealed in 8 cases (88.88%. In 1 patient of postpneumonectomy, the fistula was big, that is >8 mm who had a recurrence after the procedure. In one case of pyopneumothorax the leak reduced slowly and it took us 14 days to remove the intercostal drainage tube. Rest of the patients had a favorable outcome. No complications were observed in a follow-up of 6 months. Conclusions: In our opinion, it is a cost-effective, viable, and safe alternative compared with costly, time-consuming, and high-risk surgical procedures.

  11. Design and Control of Glycerol-tert-Butyl Alcohol Etherification Process

    Directory of Open Access Journals (Sweden)

    Elena Vlad

    2012-01-01

    Full Text Available Design, economics, and plantwide control of a glycerol-tert-butyl alcohol (TBA etherification plant are presented. The reaction takes place in liquid phase, in a plug flow reactor, using Amberlyst 15 as a catalyst. The products' separation is achieved by two distillation columns where high-purity ethers are obtained and a section involving extractive distillation with 1,4-butanediol as solvent, which separates TBA from the TBA/water azeotrope. Details of design performed in AspenPlus and an economic evaluation of the process are given. Three plantwide control structures are examined using a mass balance model of the plant. The preferred control structure fixes the fresh glycerol flow rate and the ratio glycerol + monoether : TBA at reactor-inlet. The stability and robustness in the operation are checked by rigorous dynamic simulation in AspenDynamics.

  12. A Validated HPLC Method for the Determination of Vanillyl Butyl Ether in Cosmetic Preparations

    Directory of Open Access Journals (Sweden)

    Francisco Ríos

    2017-02-01

    Full Text Available A specific HPLC (High-Performance Liquid Chromatography method has been developed and validated for the determination of vanillyl butyl ether in cosmetic products. The extraction procedure with an isopropanol water 1:1 mixture is described. The method uses a RP-C-18 column with isocratic elution and an ultraviolet (UV detector. The mobile phase consists of a mixture of acetonitrile and buffer (Na2HPO4 20 mM in water (30:70 v/v with a variable flow rate. The method was validated with respect to accuracy, precision (repeatability and reproducibility, specificity and linearity. The procedure described here is simple, selective and reliable for routine quality control analysis and stability tests of commercially available cosmetic products.

  13. Pressure effect on water dynamics in tert-butyl alcohol/water solutions

    Science.gov (United States)

    Calandrini, Vania; Deriu, Antonio; Onori, Giuseppe; Paciaroni, Alessandro; Telling, Mark T. F.

    2006-09-01

    We report here a quasi-elastic neutron scattering (QENS) investigation of the effect of pressure on the diffusivity properties of water in a dilute aqueous solution of hydrophobic molecules (tert-butyl alcohol, TBA). The experiment was performed at fixed TBA concentration (0.02 molar fraction) by varying pressure from 1 to 2000 bar at two different temperatures (268 and 278 K). The quasi-elastic line-shapes have been analysed in terms of a model based on the memory function formalism. Our data indicate that, on increasing pressure up to 2000 bar, the diffusion coefficient of water in the TBA/water mixture exhibits a relative increase larger than that of pure water under the same thermodynamic conditions. The extent of this effect increases with decreasing temperature. The observed behaviour is described in terms of pressure-induced distortions of the H-bonded random network of liquid water.

  14. Degradation of aqueous methyl tert-butyl ether by photochemical, biological, and their combined processes

    Directory of Open Access Journals (Sweden)

    Azadeh Asadi

    2006-01-01

    Full Text Available The degradation of aqueous methyl tert-butyl ether (MTBE at relatively high concentrations was investigated by various photo-induced oxidation processes such as UV/H2O2 and UV/TiO2 as well as biological processes and their combination. It was shown that the degradation of MTBE by UV/H2O2 and TiO2 photocatalytic followed a first-order model with apparent rate constant of 1.31×10−1 and 1.21×10−2 min-1, respectively. It was observed that UV/H2O2/TiO2 process did not have any advantages over each of the other processes alone. The biodegradation of methyl tert-butyl ether (MTBE was evaluated using aerobic mixed culture with three different approaches, including ultimate biological oxygen demand (BODU assessment, nonacclimated, and acclimated mixed cultures. The apparent rate constant for the biodegradation of MTBE by nonacclimated mixed culture was 4.36×10−2 day-1. It was shown that the acclimatization of the mixed cultures enhanced the rate of biodegradation of MTBE to 3.24×10−1mg L-1h-1. Finally, the effects of the photocatalytic pretreatment of aqueous MTBE on its subsequent biological treatment were studied. It was observed that the rate of bioreaction was not enhanced and the photocatalytic pretreatment had adverse effects on its biological treatment so that the apparent rate constant decreased to 2.83×10−1 mg L-1h-1.

  15. Self-initiation mechanism in spontaneous thermal polymerization of ethyl and n-butyl acrylate: a theoretical study.

    Science.gov (United States)

    Srinivasan, Sriraj; Lee, Myung Won; Grady, Michael C; Soroush, Masoud; Rappe, Andrew M

    2010-08-05

    In this study, the mechanism of self-initiation in spontaneous thermal polymerization of ethyl and n-butyl acrylate is explored using first-principles calculations. Density functional theory (with B3LYP functional and 6-31G* basis set) was used to study [4 + 2] and [2 + 2] cycloaddition reactions on the singlet and triplet potential energy surfaces. Diels-Alder (DA) dimers of ethyl acrylate [6-ethoxy-2-ethoxycarbonyl-3,4-dihydro-2H-pyran (EDP)] and of n-butyl acrylate [6-butoxy-2-butoxycarbonyl-3,4-dihydro-2H-pyran (BDP)] were found to form on the singlet surface via the concerted pathway proposed by Mayo. The formation of diethyl cyclobutane-1,2-dicarboxylate (DECD) and dibutyl cyclobutane-1,2-dicarboxylate (DBCD) via a nonconcerted pathway was identified on the singlet surface of ethyl and n-butyl acrylate, respectively. The presence of a diradical transition state for the formation of the DECD and DBCD was predicted. Triplet potential energy surfaces for the formation of diradical dimer of ethyl and n-butyl acrylate were computed, and the presence of a triplet diradical intermediate was identified for each of the monomers. A low energy monoradical generation mechanism was identified to be involving hydrogen abstraction by a third acrylate monomer from the triplet diradical species. The molecular structure of the computed monoradical species was found to correlate with chain initiating species of the dominant series of peaks in previously reported electrospray ionization-Fourier transform mass spectra of spontaneously polymerized samples of ethyl and n-butyl acrylate. In view of these observations, it is concluded that this self-initiation mechanism is most likely the initiating mechanism in spontaneous thermal polymerization of alkyl acrylates.

  16. Chemopreventive glucosinolate accumulation in various broccoli and collard tissues: Microfluidic-based targeted transcriptomics for by-product valorization.

    Science.gov (United States)

    Lee, Young-Sang; Ku, Kang-Mo; Becker, Talon M; Juvik, John A

    2017-01-01

    Floret, leaf, and root tissues were harvested from broccoli and collard cultivars and extracted to determine their glucosinolate and hydrolysis product profiles using high performance liquid chromatography and gas chromotography. Quinone reductase inducing bioactivity, an estimate of anti-cancer chemopreventive potential, of the extracts was measured using a hepa1c1c7 murine cell line. Extracts from root tissues were significantly different from other tissues and contained high levels of gluconasturtiin and glucoerucin. Targeted gene expression analysis on glucosinolate biosynthesis revealed that broccoli root tissue has elevated gene expression of AOP2 and low expression of FMOGS-OX homologs, essentially the opposite of what was observed in broccoli florets, which accumulated high levels of glucoraphanin. Broccoli floret tissue has significantly higher nitrile formation (%) and epithionitrile specifier protein gene expression than other tissues. This study provides basic information of the glucosinolate metabolome and transcriptome for various tissues of Brassica oleracea that maybe utilized as potential byproducts for the nutraceutical market.

  17. Treatment of ulcerative colitis with oral mesalamine: advances in drug formulation, efficacy expectations and dose response, compliance, and chemoprevention.

    Science.gov (United States)

    Sandborn, William J

    2006-01-01

    Sulfasalazine, olsalazine, balsalazide, delayed-release mesalamine, controlled-release mesalamine, mesalamine pellets, and Multi-Matrix System mesalamine are effective first-line therapies for the treatment of mildly to moderately active ulcerative colitis and for subsequent maintenance of remission. For induction therapy it is unclear if there is a dose response above 1.5 g, and for maintenance therapy existing data do not support a dose response above 1.5 g. Sulfasalazine has more frequent side effects than olsalazine, balsalazide, and mesalamine formulations. Once-daily dosing with multi-matrix system mesalamine 1.2 g tablets may lead to optimal compliance. Mesalamine >/= 1.2 g and sulfasalazine >/= 2 g reduce the risk of colorectal cancer in patients with ulcerative colitis. Drug formulations, efficacy expectations and dose response, toxicity expectations, compliance considerations, and chemoprevention considerations are reviewed.

  18. Identification of an unintended consequence of Nrf2-directed cytoprotection against a key tobacco carcinogen plus a counteracting chemopreventive intervention.

    Science.gov (United States)

    Paonessa, Joseph D; Ding, Yi; Randall, Kristen L; Munday, Rex; Argoti, Dayana; Vouros, Paul; Zhang, Yuesheng

    2011-06-01

    NF-E2-related factor 2 (Nrf2) is a major cytoprotective gene and is a key chemopreventive target against cancer and other diseases. Here we show that Nrf2 faces a dilemma in defense against 4-aminobiphenyl (ABP), a major human bladder carcinogen from tobacco smoke and other environmental sources. Although Nrf2 protected mouse liver against ABP (which is metabolically activated in liver), the bladder level of N-(deoxyguanosin-8-yl)-4-aminobiphenyl (dG-C8-ABP), the predominant ABP-DNA adduct formed in bladder cells and tissues, was markedly higher in Nrf2(+/+) mice than in Nrf2(-/-) mice after ABP exposure. Notably, Nrf2 protected bladder cells against ABP in vitro. Mechanistic investigations showed that the dichotomous effects of Nrf2 could be explained at least partly by upregulation of UDP-glucuronosyltransferase (UGT). Nrf2 promoted conjugation of ABP with glucuronic acid in the liver, increasing urinary excretion of the conjugate. Although glucuronidation of ABP and its metabolites is a detoxification process, these conjugates, which are excreted in urine, are known to be unstable in acidic urine, leading to delivery of the parent compounds to bladder. Hence, although higher liver UGT activity may protect the liver against ABP, it increases bladder exposure to ABP. These findings raise concerns of potential bladder toxicity when Nrf2-activating chemopreventive agents are used in humans exposed to ABP, especially in smokers. We further show that 5,6-dihydrocyclopenta[c][1,2]-dithiole-3(4H)-thione (CPDT) significantly inhibits dG-C8-ABP formation in bladder cells and tissues but does not seem to significantly modulate ABP-catalyzing UGT in liver. Thus, CPDT exemplifies a counteracting solution to the dilemma posed by Nrf2.

  19. 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.

  20. Chemopreventive potential of β-Sitosterol in experimental colon cancer model - an In vitro and In vivo study

    Directory of Open Access Journals (Sweden)

    Paulraj Gabriel M

    2010-06-01

    Full Text Available Abstract Background Asclepias curassavica Linn. is a traditional medicinal plant used by tribal people in the western ghats, India, to treat piles, gonorrhoea, roundworm infestation and abdominal tumours. We have determined the protective effect of β-sitosterol isolated from A. curassavica in colon cancer, using in vitro and in vivo models. Methods The active molecule was isolated, based upon bioassay guided fractionation, and identified as β-sitosterol on spectral evidence. The ability to induce apoptosis was determined by its in vitro antiradical activity, cytotoxic studies using human colon adenocarcinoma and normal monkey kidney cell lines, and the expression of β-catenin and proliferating cell nuclear antigen (PCNA in human colon cancer cell lines (COLO 320 DM. The chemopreventive potential of β-sitosterol in colon carcinogenesis was assessed by injecting 1,2-dimethylhydrazine (DMH, 20 mg/kg b.w. into male Wistar rats and supplementing this with β-sitosterol throughout the experimental period of 16 weeks at 5, 10, and 20 mg/kg b.w. Results β-sitosterol induced significant dose-dependent growth inhibition of COLO 320 DM cells (IC50 266.2 μM, induced apoptosis by scavenging reactive oxygen species, and suppressed the expression of β-catenin and PCNA antigens in human colon cancer cells. β-sitosterol supplementation reduced the number of aberrant crypt and crypt multiplicity in DMH-initiated rats in a dose-dependent manner with no toxic effects. Conclusion We found doses of 10-20 mg/kg b.w. β-sitosterol to be effective for future in vivo studies. β-sitosterol had chemopreventive potential by virtue of its radical quenching ability in vitro, with minimal toxicity to normal cells. It also attenuated β-catenin and PCNA expression, making it a potential anticancer drug for colon carcinogenesis.

  1. 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.

    2014-01-01

    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

  2. Chemopreventive potential of beta-Sitosterol in experimental colon cancer model--an in vitro and In vivo study.

    Science.gov (United States)

    Baskar, Albert A; Ignacimuthu, Savarimuthu; Paulraj, Gabriel M; Al Numair, Khalid S

    2010-06-04

    Asclepias curassavica Linn. is a traditional medicinal plant used by tribal people in the western ghats, India, to treat piles, gonorrhoea, roundworm infestation and abdominal tumours. We have determined the protective effect of beta-sitosterol isolated from A. curassavica in colon cancer, using in vitro and in vivo models. The active molecule was isolated, based upon bioassay guided fractionation, and identified as beta-sitosterol on spectral evidence. The ability to induce apoptosis was determined by its in vitro antiradical activity, cytotoxic studies using human colon adenocarcinoma and normal monkey kidney cell lines, and the expression of beta-catenin and proliferating cell nuclear antigen (PCNA) in human colon cancer cell lines (COLO 320 DM). The chemopreventive potential of beta-sitosterol in colon carcinogenesis was assessed by injecting 1,2-dimethylhydrazine (DMH, 20 mg/kg b.w.) into male Wistar rats and supplementing this with beta-sitosterol throughout the experimental period of 16 weeks at 5, 10, and 20 mg/kg b.w. beta-sitosterol induced significant dose-dependent growth inhibition of COLO 320 DM cells (IC50 266.2 microM), induced apoptosis by scavenging reactive oxygen species, and suppressed the expression of beta-catenin and PCNA antigens in human colon cancer cells. beta-sitosterol supplementation reduced the number of aberrant crypt and crypt multiplicity in DMH-initiated rats in a dose-dependent manner with no toxic effects. We found doses of 10-20 mg/kg b.w. beta-sitosterol to be effective for future in vivo studies. beta-sitosterol had chemopreventive potential by virtue of its radical quenching ability in vitro, with minimal toxicity to normal cells. It also attenuated beta-catenin and PCNA expression, making it a potential anticancer drug for colon carcinogenesis.

  3. Chemopreventive potential of β-Sitosterol in experimental colon cancer model - an In vitro and In vivo study

    Science.gov (United States)

    2010-01-01

    Background Asclepias curassavica Linn. is a traditional medicinal plant used by tribal people in the western ghats, India, to treat piles, gonorrhoea, roundworm infestation and abdominal tumours. We have determined the protective effect of β-sitosterol isolated from A. curassavica in colon cancer, using in vitro and in vivo models. Methods The active molecule was isolated, based upon bioassay guided fractionation, and identified as β-sitosterol on spectral evidence. The ability to induce apoptosis was determined by its in vitro antiradical activity, cytotoxic studies using human colon adenocarcinoma and normal monkey kidney cell lines, and the expression of β-catenin and proliferating cell nuclear antigen (PCNA) in human colon cancer cell lines (COLO 320 DM). The chemopreventive potential of β-sitosterol in colon carcinogenesis was assessed by injecting 1,2-dimethylhydrazine (DMH, 20 mg/kg b.w.) into male Wistar rats and supplementing this with β-sitosterol throughout the experimental period of 16 weeks at 5, 10, and 20 mg/kg b.w. Results β-sitosterol induced significant dose-dependent growth inhibition of COLO 320 DM cells (IC50 266.2 μM), induced apoptosis by scavenging reactive oxygen species, and suppressed the expression of β-catenin and PCNA antigens in human colon cancer cells. β-sitosterol supplementation reduced the number of aberrant crypt and crypt multiplicity in DMH-initiated rats in a dose-dependent manner with no toxic effects. Conclusion We found doses of 10-20 mg/kg b.w. β-sitosterol to be effective for future in vivo studies. β-sitosterol had chemopreventive potential by virtue of its radical quenching ability in vitro, with minimal toxicity to normal cells. It also attenuated β-catenin and PCNA expression, making it a potential anticancer drug for colon carcinogenesis. PMID:20525330

  4. 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.

  5. Chemopreventive efficacy of curcumin-loaded PLGA microparticles in a transgenic mouse model of HER-2-positive breast cancer.

    Science.gov (United States)

    Grill, Alex E; Shahani, Komal; Koniar, Brenda; Panyam, Jayanth

    2017-04-17

    Curcumin has shown promising inhibitory activity against HER-2-positive tumor cells in vitro but suffers from poor oral bioavailability in vivo. Our lab has previously developed a polymeric microparticle formulation for sustained delivery of curcumin for chemoprevention. The goal of this study was to examine the anticancer efficacy of curcumin-loaded polymeric microparticles in a transgenic mouse model of HER-2 cancer, Balb-neuT. Microparticles were injected monthly, and mice were examined for tumor appearance and growth. Initiating curcumin microparticle treatment at 2 or 4 weeks of age delayed tumor appearance by 2-3 weeks compared to that in control mice that received empty microparticles. At 12 weeks, abnormal (lobular hyperplasia, carcinoma in situ, and invasive carcinoma) mammary tissue area was significantly decreased in curcumin microparticle-treated mice, as was CD-31 staining. Curcumin treatment decreased mammary VEGF levels significantly, which likely contributed to slower tumor formation. When compared to saline controls, however, blank microparticles accelerated tumorigenesis and curcumin treatment abrogated this effect, suggesting that PLGA microparticles enhance tumorigenesis in this model. PLGA microparticle administration was shown to be associated with higher plasma lactic acid levels and increased activation of NF-κΒ. The unexpected side effects of PLGA microparticles may be related to the high dose of the microparticles that was needed to achieve sustained curcumin levels in vivo. Approaches that can decrease the overall dose of curcumin (for example, by increasing its potency or reducing its clearance rate) may allow the development of sustained release curcumin dosage forms as a practical approach to cancer chemoprevention.

  6. Identification of an unintended consequence of Nrf2-directed cytoprotection against a key tobacco carcinogen plus a counteracting chemopreventive intervention

    Science.gov (United States)

    Paonessa, Joseph D.; Ding, Yi; Randall, Kristen L.; Munday, Rex; Argoti, Dayana; Vouros, Paul; Zhang, Yuesheng

    2011-01-01

    Nrf2 is a major cytoprotective gene and is a key chemopreventive target against cancer and other diseases. Here we show that Nrf2 faces a dilemma in defense against 4-aminobiphenyl (ABP), a major human bladder carcinogen from tobacco smoke and other environmental sources. While Nrf2 protected mouse liver against ABP (which is metabolically activated in liver), the bladder level of N-(deoxyguanosin-8-yl)-4-aminobiphenyl (dG-C8-ABP), the predominant ABP-DNA adduct formed in bladder cells and tissues, was markedly higher in Nrf2+/+ mice than in Nrf2−/− mice after ABP exposure. Notably, Nrf2 protected bladder cells against ABP in vitro. Mechanistic investigations showed that the dichotomous effects of Nrf2 could be explained at least partly by upregulation of UDP-glucuronosyltransferase (UGT). Nrf2 promoted conjugation of ABP with glucuronic acid in the liver, increasing urinary excretion of the conjugate. While glucuronidation of ABP and its metabolites is a detoxification process, these conjugates, which are excreted in urine, are known to be unstable in acidic urine, leading to delivery of the parent compounds to bladder. Hence, while higher liver UGT activity may protect the liver against ABP it increases bladder exposure to ABP. These findings raise concerns of potential bladder toxicity when Nrf2-activating chemopreventive agents are used in humans exposed to ABP, especially in smokers. We further demonstrate that 5,6-dihydrocyclopenta[c][1,2]-dithiole-3(4H)-thione (CPDT) significantly inhibits dG-C8-ABP formation in bladder cells and tissues, but does not appear to significantly modulate ABP-catalyzing UGT in liver. Thus, CPDT exemplifies a counteracting solution to the dilemma posed by Nrf2. PMID:21487034

  7. Anthocyanin-rich black currant (Ribes nigrum L.) extract affords chemoprevention against diethylnitrosamine-induced hepatocellular carcinogenesis in rats.

    Science.gov (United States)

    Bishayee, Anupam; Mbimba, Thomas; Thoppil, Roslin J; Háznagy-Radnai, Erzsébet; Sipos, Péter; Darvesh, Altaf S; Folkesson, Hans G; Hohmann, Judit

    2011-11-01

    Anthocyanins are known to possess potent anticarcinogenic properties against several cancers thus demonstrating potential for cancer prevention. Black currant (Ribes nigrum L., Grossulariaceae) fruits have a high anthocyanin content. This "superfruit" is known to possess various pharmacological effects including alleviation of chronic oxidative stress and inflammation. In contrast to a large volume of literature on the health benefits of black currant, limited evidence on antitumor effects of black currant exists with virtually no data on the prevention of experimental carcinogenesis. In the current study, we have investigated the chemopreventive effects of an anthocyanin-rich black currant skin extract (BCSE) utilizing our well-characterized model of rat liver carcinogenesis. Initiation of hepatocarcinogenesis was done by intraperitoneal injection of diethylnitrosamine (DENA) followed by promotion with phenobarbital. The rats were exposed to dietary BCSE for 4 weeks prior to initiation, and the treatment was continued for 22 consecutive weeks. BCSE dose-dependently decreased the incidence, total number, multiplicity, size and volume of preneoplastic hepatic nodules. The antihepatocarcinogenic effect of BCSE was confirmed by histopathological examination of liver sections. Immunohistochemical analysis of proliferating cell nuclear antigen and DNA fragmentation revealed BCSE-mediated inhibition of abnormal cell proliferation and induction of apoptosis in DENA-induced rat liver tumorigenesis respectively. Mechanistic studies revealed that BCSE-mediated proapototic signal during experimental hepatocarcinogenesis may be propagated via the up-regulation of Bax and down-regulation of Bcl-2 expression at the translational level. These results along with a safety profile of BCSE encourage the development of black currant bioactive constituents as chemopreventive agents for human liver cancer. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. Chemopreventive effects of Cuminum cyminum in chemically induced forestomach and uterine cervix tumors in murine model systems.

    Science.gov (United States)

    Gagandeep; Dhanalakshmi, Sivanandhan; Méndiz, Ester; Rao, Agra Ramesha; Kale, Raosaheb Kathalupant

    2003-01-01

    Lately, a strong correlation has been established between diet and cancer. For ages, cumin has been a part of the diet. It is a popular spice regularly used as a flavoring agent in a number of ethnic cousins. In the present study, cancer chemopreventive potentials of different doses of a cumin seed-mixed diet were evaluated against benzo(a)pyrene [B(a)P]-induced forestomach tumorigenesis and 3-methylcholanthrene (MCA)-induced uterine cervix tumorigenesis. Results showed a significant inhibition of stomach tumor burden (tumors per mouse) by cumin. Tumor burden was 7.33 +/- 2.10 in the B(a)P-treated control group, whereas it reduced to 3.10 +/- 0.57 (P cumin seeds. Cervical carcinoma incidence, compared with the MCA-treated control group (66.67%), reduced to 27.27% (P cumin seeds and to 12.50% (P cumin seeds. The effect of 2.5 and 5% cumin seed-mixed diets was also examined on carcinogen/xenobiotic metabolizing phase I and phase II enzymes, antioxidant enzymes, glutathione content, lactate dehydrogenase (LDH), and lipid peroxidation in the liver of Swiss albino mice. Levels of cytochrome P-450 (cyt P-450) and cytochrome b5 (cyt b(5)) were significantly augmented (P cumin seed diet. The levels of cyt P-450 reductase and cyt b(5) reductase were increased (significance level being from P cumin. Among the phase II enzymes, glutathione S-transferase specific activity increased (P cumin. The activities of glutathione peroxidase and glutathione reductase remained unaltered by both doses of cumin. The level of reduced glutathione measured as nonprotein sulfhydryl content was elevated (significance level being from P cumin. Lipid peroxidation measured as formation of MDA production showed significant inhibition (P cumin. LDH activity remained unaltered by both doses of cumin. The results strongly suggest the cancer chemopreventive potentials of cumin seed and could be attributed to its ability to modulate carcinogen metabolism.

  9. Role of a polyphenol-enriched preparation on chemoprevention of mammary carcinoma through cancer stem cells and inflammatory pathways modulation.

    Science.gov (United States)

    Vuong, Tri; Mallet, Jean-François; Ouzounova, Maria; Rahbar, Sam; Hernandez-Vargas, Hector; Herceg, Zdenko; Matar, Chantal

    2016-01-14

    Naturally occurring polyphenolic compounds from fruits, particularly from blueberries, have been reported to be significantly involved in cancer chemoprevention and chemotherapy. Biotransformation of blueberry juice by Serratia vaccinii increases its polyphenolic content and endows it with anti-inflammatory properties. This study evaluated the effect of a polyphenol-enriched blueberry preparation (PEBP) and its non-fermented counterpart (NBJ), on mammary cancer stem cell (CSC) development in in vitro, in vivo and ex vivo settings. Effects of PEBP on cell proliferation, mobility, invasion, and mammosphere formation were measured in vitro in three cell lines: murine 4T1 and human MCF7 and MDA-MB-231. Ex vivo mammosphere formation, tumor growth and metastasis observations were carried out in a BALB/c mouse model. Our research revealed that PEBP influence cellular signaling cascades of breast CSCs, regulating the activity of transcription factors and, consequently, inhibiting tumor growth in vivo by decreasing metastasis and controlling PI3K/AKT, MAPK/ERK, and STAT3 pathways, central nodes in CSC inflammatory signaling. PEBP significantly inhibited cell proliferation of 4T1, MCF-7 and MDA-MB-231. In all cell lines, PEBP reduced mammosphere formation, cell mobility and cell migration. In vivo, PEBP significantly reduced tumor development, inhibited the formation of ex vivo mammospheres, and significantly reduced lung metastasis. This study showed that polyphenol enrichment of a blueberry preparation by fermentation increases its chemopreventive potential by protecting mice against tumor development, inhibiting the formation of cancer stem cells and reducing lung metastasis. Thus, PEBP may represent a novel complementary alternative medicine therapy and a source for novel therapeutic agents against breast cancer.

  10. (2S,4R)- and (2S,4S)-perfluoro-tert-butyl 4-hydroxyproline: two conformationally distinct proline amino acids for sensitive application in 19F NMR.

    Science.gov (United States)

    Tressler, Caitlin M; Zondlo, Neal J

    2014-06-20

    (2S,4R)- and (2S,4S)-perfluoro-tert-butyl 4-hydroxyproline were synthesized (as Fmoc-, Boc-, and free amino acids) in 2-5 steps. The key step of each synthesis was a Mitsunobu reaction with perfluoro-tert-butanol, which incorporated a perfluoro-tert-butyl group, with nine chemically equivalent fluorines. Both amino acids were incorporated in model α-helical and polyproline helix peptides. Each amino acid exhibited distinct conformational preferences, with (2S,4R)-perfluoro-tert-butyl 4-hydroxyproline promoting polyproline helix. Peptides containing these amino acids were sensitively detected by (19)F NMR, suggesting their use in probes and medicinal chemistry.

  11. An Improved Synthesis of 7, 8-Epoxy-1,3,11-cembratriene-15R(α, 16-diol, a Cembranoid of Marine Origin with a Potent Cancer Chemopreventive Activity

    Directory of Open Access Journals (Sweden)

    Sherief I. Khalifa

    2004-02-01

    Full Text Available An effective method for the synthesis of 7,8-epoxy-1,3,11-cembratriene-15R(α, 16-diol and its in vitro Epstein-Barr Virus Early Antigen (EBV-EA Activation Chemopreventive Assay are reported. This semisynthetic product is a new cembranoid with a potent tumor inhibitory activity that is expected to be a lead compound for a new class of chemopreventive agents of marine origin.

  12. 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

  13. Temperature Coefficients of Electrical Conductivity and Conduction Mechanisms in Butyl Rubber-Carbon Black Composites

    Science.gov (United States)

    Alzamil, M. A.; Alfaramawi, K.; Abboudy, S.; Abulnasr, L.

    2017-12-01

    Electrical properties of butyl rubber filled with General Purpose Furnace (GPF) carbon black were studied. The carbon black concentration (X) in the compound was X = 40, 60, 70, 80, and 100 parts by weight per hundred parts by weight of rubber (phr). The corresponding volume fractions of GPF carbon black were 0.447 ± 0.022, 0.548 ± 0.027, 0.586 ± 0.029, 0.618 ± 0.031 and 0.669 ± 0.034, respectively. The concentration dependence of conductivity ( σ ) at constant temperature showed that σ follows a percolation theory; σ ∝ ( {X - Xo } )^{γ } , where X o is the concentration at percolation threshold. The exponent γ was found as 6.6 (at room temperature 30°C). This value agrees with other experimental values obtained by many authors for different rubber-carbon black systems. Electron tunneling between the aggregates, which are dispersed in the insulator rubber, was mainly the conduction process proposed at constant temperature in the butyl-GPF carbon black composites. Temperature dependence of conductivity was investigated in the temperature range from 30°C up to 120°C. All samples exhibit negative temperature coefficients of conductivity (NTCC). The values obtained are - 0.130°C-1, - 0.019°C-1, - 0.0082°C-1, - 0.0094°C-1, and - 0.072°C-1 for carbon black concentrations of 40 phr, 60 phr, 70 phr, 80 phr, and 100 phr, respectively. The samples of concentrations 40 phr and 60 phr have also positive temperature coefficients of conductivity (PTCC) of values + 0.031 and + 0.013, respectively. Electrical conduction at different temperatures showed various mechanisms depending on the carbon black concentration and/or the interval of temperature. The hopping conduction mechanism was noticed at the lower temperature region while carrier thermal activation mechanisms were recorded at the higher temperature range.

  14. Temperature Coefficients of Electrical Conductivity and Conduction Mechanisms in Butyl Rubber-Carbon Black Composites

    Science.gov (United States)

    Alzamil, M. A.; Alfaramawi, K.; Abboudy, S.; Abulnasr, L.

    2018-02-01

    Electrical properties of butyl rubber filled with General Purpose Furnace (GPF) carbon black were studied. The carbon black concentration ( X) in the compound was X = 40, 60, 70, 80, and 100 parts by weight per hundred parts by weight of rubber (phr). The corresponding volume fractions of GPF carbon black were 0.447 ± 0.022, 0.548 ± 0.027, 0.586 ± 0.029, 0.618 ± 0.031 and 0.669 ± 0.034, respectively. The concentration dependence of conductivity ( σ ) at constant temperature showed that σ follows a percolation theory; σ ∝ ( {X - Xo } )^{γ } , where X o is the concentration at percolation threshold. The exponent γ was found as 6.6 (at room temperature 30°C). This value agrees with other experimental values obtained by many authors for different rubber-carbon black systems. Electron tunneling between the aggregates, which are dispersed in the insulator rubber, was mainly the conduction process proposed at constant temperature in the butyl-GPF carbon black composites. Temperature dependence of conductivity was investigated in the temperature range from 30°C up to 120°C. All samples exhibit negative temperature coefficients of conductivity (NTCC). The values obtained are - 0.130°C-1, - 0.019°C-1, - 0.0082°C-1, - 0.0094°C-1, and - 0.072°C-1 for carbon black concentrations of 40 phr, 60 phr, 70 phr, 80 phr, and 100 phr, respectively. The samples of concentrations 40 phr and 60 phr have also positive temperature coefficients of conductivity (PTCC) of values + 0.031 and + 0.013, respectively. Electrical conduction at different temperatures showed various mechanisms depending on the carbon black concentration and/or the interval of temperature. The hopping conduction mechanism was noticed at the lower temperature region while carrier thermal activation mechanisms were recorded at the higher temperature range.

  15. Activity coefficients at infinite dilution measurements for organic solutes and water in the ionic liquid 1-butyl-3-methylimidazolium trifluoromethanesulfonate.

    Science.gov (United States)

    Domańska, Urszula; Marciniak, Andrzej

    2008-09-04

    The activity coefficients at infinite dilution, gamma 13 (infinity) for 32 solutes: alkanes, alkenes, alkynes, cycloalkanes, aromatic hydrocarbons, alcohols, thiophene, tetrahydrofurane, tert-butyl methyl ether, and water in the ionic liquid 1-butyl-3-methylimidazolium trifluoromethanesulfonate [BMIM][CF3SO3] were determined by gas-liquid chromatography at the temperatures from 298.15 to 368.15 K. The partial molar excess enthalpies at infinite dilution values Delta H 1 (E,infinity) were calculated from the experimental gamma 13 (infinity) values obtained over the temperature range. The selectivities for the hexane/benzene, cyclohexane/benzene, n-hexane/thiophene, n-decane/thiophene, cyclohexane/thiophene, toluene/thiophene, and oct-1-ene/thiophene separation problems were calculated from the gamma 13 (infinity). Obtained values were compared to the literature values for the other ionic liquids, NMP, and sulfolane.

  16. Kinetics of Methyl t-Butyl Ether Cometabolism at Low Concentrations by Pure Cultures of Butane-Degrading Bacteria

    Science.gov (United States)

    Liu, Catherine Y.; Speitel, Gerald E.; Georgiou, George

    2001-01-01

    Butane-oxidizing Arthrobacter (ATCC 27778) bacteria were shown to degrade low concentrations of methyl t-butyl ether (MTBE; range, 100 to 800 μg/liter) with an apparent half-saturation concentration (Ks) of 2.14 mg/liter and a maximum substrate utilization rate (kc) of 0.43 mg/mg of total suspended solids per day. Arthrobacter bacteria demonstrated MTBE degradation activity when grown on butane but not when grown on glucose, butanol, or tryptose phosphate broth. The presence of butane, tert-butyl alcohol, or acetylene had a negative impact on the MTBE degradation rate. Neither Methylosinus trichosporium OB3b nor Streptomyces griseus was able to cometabolize MTBE. PMID:11319100

  17. Relationships between pulmonary micro-RNA and proteome profiles, systemic cytogenetic damage and lung tumors in cigarette smoke-exposed mice treated with chemopreventive agents.

    Science.gov (United States)

    Izzotti, Alberto; Balansky, Roumen; D'Agostini, Francesco; Longobardi, Mariagrazia; Cartiglia, Cristina; La Maestra, Sebastiano; Micale, Rosanna T; Camoirano, Anna; Ganchev, Gancho; Iltcheva, Marietta; Steele, Vernon E; De Flora, Silvio

    2013-10-01

    Assessing the correlation between molecular endpoints and cancer induction or prevention aims at validating the use of intermediate biomarkers. We previously developed murine models that are suitable to detect both the carcinogenicity of mainstream cigarette smoke (MCS) and the induction of molecular alterations. In this study, we used 931 Swiss mice in two parallel experiments and in a preliminary toxicity study. The chemopreventive agents included vorinostat, myo-inositol, bexarotene, pioglitazone and a combination of bexarotene and pioglitazone. Pulmonary micro-RNAs and proteins were evaluated by microarray analyses at 10 weeks of age in male and female mice, either unexposed or exposed to MCS since birth, and either untreated or receiving each one of the five chemopreventive regimens with the diet after weaning. At 4 months of age, the frequency of micronucleated normochromatic erythrocytes was evaluated. At 7 months, the lungs were subjected to standard histopathological analysis. The results showed that exposure to MCS significantly downregulated the expression of 79 of 694 lung micro-RNAs (11.4%) and upregulated 66 of 1164 proteins (5.7%). Administration of chemopreventive agents modulated the baseline micro-RNA and proteome profiles and reversed several MCS-induced alterations, with some intergender differences. The stronger protective effects were produced by the combination of bexarotene and pioglitazone, which also inhibited the MCS-induced clastogenic damage and the yield of malignant tumors. Pioglitazone alone increased the yield of lung adenomas. Thus, micro-RNAs, proteins, cytogenetic damage and lung tumors were closely related. The molecular biomarkers contributed to evaluate both protective and adverse effects of chemopreventive agents and highlighted the mechanisms involved.

  18. Chemopreventive efficacy of hesperidin against chemically induced nephrotoxicity and renal carcinogenesis via amelioration of oxidative stress and modulation of multiple molecular pathways.

    Science.gov (United States)

    Siddiqi, Aisha; Hasan, Syed Kazim; Nafees, Sana; Rashid, Summya; Saidullah, Bano; Sultana, Sarwat

    2015-12-01

    In the present study, chemopreventive efficacy of hesperidin was evaluated against ferric nitrilotriacetate (Fe-NTA) induced renal oxidative stress and carcinogenesis in wistar rats. Nephrotoxicity was induced by single intraperitoneal injection of Fe-NTA (9 mg Fe/kg b.wt). Renal cancer was initiated by the administration of N-nitrosodiethylamine (DEN 200mg/kg b.wt ip) and promoted by Fe-NTA (9 mg Fe/kg b.wt ip) twice weekly for 16 weeks. Efficacy of hesperidin against Fe-NTA-induced nephrotoxicity was assessed in terms of biochemical estimation of antioxidant enzyme activities viz. reduced renal GSH, glutathione peroxidase, glutathione reductase, glutathione-S-transferase, catalase, superoxide dismutase and renal toxicity markers (BUN, Creatinine, KIM-1). Administration of Fe-NTA significantly depleted antioxidant renal armory, enhanced renal lipid peroxidation as well as the levels of BUN, creatinine and KIM-1. However, simultaneous pretreatment of hesperidin restored their levels in a dose dependent manner. Expression of apoptotic markers caspase-3, caspase-9, bax, bcl-2 and proliferative marker PCNA along with inflammatory markers (NFκB, iNOS, TNF-α) were also analysed to assess the chemopreventive potential of hesperidin in two-stage renal carcinogenesis model. Hesperidin was found to induce caspase-3, caspase-9, bax expression and downregulate bcl-2, NFκB, iNOS, TNF-α, PCNA expression. Histopathological findings further revealed hesperidin's chemopreventive efficacy by restoring the renal morphology. Our results provide a powerful evidence suggesting hesperidin to be a potent chemopreventive agent against renal carcinogenesis possibly by virtue of its antioxidant properties and by modulation of multiple molecular pathways. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. PREPARATION OF BLOCK COPOLYMERS OF POLY(STYRENE) AND POLY(T-BUTYL ACRYLATE) OF VARIOUS MOLECULAR WEIGHTS AND ARCHITECTURES BY ATOM TRANSFER RADICAL POLYMERIZATION. (R826735)

    Science.gov (United States)

    Block copolymers of polystyrene and poly(t-butyl acrylate) were prepared using atom transfer radical polymerization techniques. These polymers were synthesized with a CuBr/N,N,N,NInduction of Methyl Tertiary Butyl Ether (MTBE)-Oxidizing Activity in Mycobacterium vaccae JOB5 by MTBE

    OpenAIRE

    Johnson, Erika L.; Smith, Christy A.; O'Reilly, Kirk T.; Hyman, Michael R.

    2004-01-01

    Alkane-grown cells of Mycobacterium vaccae JOB5 cometabolically degrade the gasoline oxygenate methyl tertiary butyl ether (MTBE) through the activities of an alkane-inducible monooxygenase and other enzymes in the alkane oxidation pathway. In this study we examined the effects of MTBE on the MTBE-oxidizing activity of M. vaccae JOB5 grown on diverse nonalkane substrates. Carbon-limited cultures were grown on glycerol, lactate, several sugars, and tricarboxylic acid cycle intermediates, both ...

  1. Surfactant and counter-ion distribution in styrene-butyl acrylate-acrylic acid dry latex submonolayers

    OpenAIRE

    Keslarek Amauri José; Leite Carlos Alberto P; Galembeck Fernando

    2004-01-01

    Styrene-butyl acrylate-acrylic acid latex submonolayers prepared using a non-reactive phosphate surfactant together with a reactive sulfonate surfactant were examined in a transmission microscope using electron energy loss spectroscopy imaging (ESI-TEM). Phosphorus is nearly absent from the particles core but it is detected in a thick shell and in unusual, strongly scattering structures with a low carbon content, and largely made out of inorganic phosphate. P is also dispersed outside the par...

  2. When does the fluazifop-P-butyl degradate, TFMP, leach through an agricultural loamy soil to groundwater?

    DEFF Research Database (Denmark)

    Vendelboe, Anders Lindblad; Norgaard, Trine; Olsen, Preben

    2016-01-01

    In intensely cultivated regions, it is crucial to have knowledge of the leaching potential related to pesticides in agricultural production. This is especially true in countries, like Denmark, that base its drinking water supply on untreated groundwater. Since fluazifop-P-butyl (FPB) is applied...... value for drinking water applies to them, having its leaching potential regulatory assessed based on high quality estimations of their persistence, and be exposed to an assessment of the risk to consumers of drinking contaminated groundwater....

  3. The chemopreventive action of bromelain, from pineapple stem (Ananas comosus L.), on colon carcinogenesis is related to antiproliferative and proapoptotic effects.

    Science.gov (United States)

    Romano, Barbara; Fasolino, Ines; Pagano, Ester; Capasso, Raffaele; Pace, Simona; De Rosa, Giuseppe; Milic, Natasa; Orlando, Pierangelo; Izzo, Angelo A; Borrelli, Francesca

    2014-03-01

    Colorectal cancer is an important health problem across the world. Here, we investigated the possible antiproliferative/proapoptotic effects of bromelain (from the pineapple stem Ananas comosus L., family Bromeliaceae) in a human colorectal carcinoma cell line and its potential chemopreventive effect in a murine model of colon cancer. Proliferation and apoptosis were evaluated in human colon adenocarcinoma (Caco-2) cells by the (3) H-thymidine incorporation assay and caspase 3/7 activity measurement, respectively. Extracellular signal-related kinase (ERK) and Akt expression were evaluated by Western blot analysis, reactive oxygen species production by a fluorimetric method. In vivo, bromelain was evaluated using the azoxymethane murine model of colon carcinogenesis. Bromelain reduced cell proliferation and promoted apoptosis in Caco-2 cells. The effect of bromelain was associated to downregulation of pERK1/2/total, ERK, and pAkt/Akt expression as well as to reduction of reactive oxygen species production. In vivo, bromelain reduced the development of aberrant crypt foci, polyps, and tumors induced by azoxymethane. Bromelain exerts antiproliferative and proapoptotic effects in colorectal carcinoma cells and chemopreventive actions in colon carcinogenesis in vivo. Bromelain-containing foods and/or bromelain itself may represent good candidates for colorectal cancer chemoprevention. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Method for photochemical reduction of uranyl nitrate by tri-N-butyl phosphate and application of this method to nuclear fuel reprocessing

    Science.gov (United States)

    De Poorter, Gerald L.; Rofer-De Poorter, Cheryl K.

    1978-01-01

    Uranyl ion in solution in tri-n-butyl phosphate is readily photochemically reduced to U(IV). The product U(IV) may effectively be used in the Purex process for treating spent nuclear fuels to reduce Pu(IV) to Pu(III). The Pu(III) is readily separated from uranium in solution in the tri-n-butyl phosphate by an aqueous strip.

  5. Adsorption of methyl tert-butyl ether using granular activated carbon : equilibrium and kinetic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chen, D.Z.; Chen, J.M. [Zhejiang Univ. of Technology, Hangzhou (China). College of Biological and Environmental Engineering; Zhang, J.X. [Yuhuan County Environmental Protection Bureau, Yuhuan (China)

    2010-04-01

    Methyl tert-butyl ether (MTBE) is used in gasoline as a replacement for lead in order to promote combustion efficiency. However, MTBE is one of the most frequently detected underground water pollutants caused by leaks in underground fuel storage tanks, and has been classified as a potential human carcinogen. This study investigated that adsorption of MTBE through a granular activated carbon filter. Pseudo-first order, pseudo-second order equation and intraparticle diffusion equation kinetic models were used to predict the constant rate of adsorption. The study showed that the pseudo-second order model accurately described the adsorption kinetics for the removal of MTBE from an aqueous solution onto granular activated carbon. The Lagergren first-order rate constant k{sub 1} and the pseudo-second order rate constant k{sub 2} decreased with initial increases of MTBE. A Boyd plot was used to demonstrate that external mass transfer is the principal rate-limiting step during the initial stages of adsorption. Results of the study indicated that granular activated carbon is an effective adsorbent for MTBE. 34 refs., 2 tabs., 7 figs.

  6. Impetigo herpetiformis occurring during N-butyl-scopolammonium bromide therapy in pregnancy: case report.

    Science.gov (United States)

    Guerriero, C; Lanza Silveri, S; Sisto, T; Rosati, D; De Simone, C; Fossati, B; Pomini, F; Rotoli, M; Amerio, P; Capizzi, R

    2008-01-01

    Impetigo herpetiformis (IH) is a rare dermatosis arising during the third trimester of pregnancy which is generally considered as a form of pustular psoriasis of unknown aetiology. Clinically it is characterized by erythematous plaques surrounded by sterile pustules associated with fever, diarrhea, sweating and increasing risk of stillbirth for placental insufficiency. We describe a case of developed erythematous plaques surrounded by pustules localised initially to the trunk of a 35-year-old woman at the 34th week of gestation after 5 days of treatment with N-Butyl-Scopolammonium, and which later involved the upper and lower limbs. Skin histology confirmed the diagnosis of generalised pregnancy pustular psoriasis (impetigo herpetiformis). IH is reported to be associated with hypocalcemia, hypoparathyroidism, use of oral contraceptives and bacterial infections. This is the first report suggesting the potential role of drugs other than oral contraceptives in the pathogenetic mechanism of this disease. In this case an adverse cutaneous reaction to BB could be the cause of the development of Koebner isomorphism.

  7. Transcatheter Arterial Embolization with n-Butyl Cyanoacrylate for the Treatment of Acquired Uterine Vascular Malformations

    Energy Technology Data Exchange (ETDEWEB)

    Picel, Andrew C., E-mail: apicel@ucsd.edu [University of California, San Diego, Department of Radiology (United States); Koo, Sonya J. [University of Texas Southwestern Medical Center, Department of Radiology (United States); Roberts, Anne C. [University of California, San Diego, Department of Radiology (United States)

    2016-08-15

    PurposeThe purpose of the study was to evaluate the technique and outcomes of transcatheter arterial embolization (TAE) with n-butyl cyanoacrylate (NBCA) for the treatment of acquired uterine arteriovenous malformations (AVMs).Materials and methodsA retrospective review identified five women treated for suspected acquired uterine AVMs with TAE at our institution. Four women (80 %) presented with heavy or intermittent vaginal bleeding after obstetric manipulation. One woman (20 %) was treated for an incidental AVM discovered on ultrasound after an uncomplicated cesarean section. Three women underwent one embolization procedure and two women required two procedures. Embolization material included NBCA in six procedures (80 %) and gelatin sponge in one procedure (20 %).ResultsEmbolization resulted in angiographic stasis of flow in all seven procedures. Four women (80 %) presented with vaginal bleeding which was improved after treatment. One woman returned 24 days after unilateral embolization with recurrent bleeding, which resolved after retreatment. One woman underwent two treatments for an asymptomatic lesion identified on ultrasound. There were no major complications. Three women (60 %) experienced mild postembolization pelvic pain that was controlled with non-steroidal anti-inflammatory drugs. Three women (60 %) had pregnancies and deliveries after embolization.ConclusionsTAE is a safe alternative to surgical therapy for acquired uterine AVMs with the potential to maintain fertility. Experience from this case series suggests that NBCA provides predictable and effective occlusion.

  8. Transcatheter Arterial Embolization with n-Butyl Cyanoacrylate for the Treatment of Acquired Uterine Vascular Malformations.

    Science.gov (United States)

    Picel, Andrew C; Koo, Sonya J; Roberts, Anne C

    2016-08-01

    The purpose of the study was to evaluate the technique and outcomes of transcatheter arterial embolization (TAE) with n-butyl cyanoacrylate (NBCA) for the treatment of acquired uterine arteriovenous malformations (AVMs). A retrospective review identified five women treated for suspected acquired uterine AVMs with TAE at our institution. Four women (80 %) presented with heavy or intermittent vaginal bleeding after obstetric manipulation. One woman (20 %) was treated for an incidental AVM discovered on ultrasound after an uncomplicated cesarean section. Three women underwent one embolization procedure and two women required two procedures. Embolization material included NBCA in six procedures (80 %) and gelatin sponge in one procedure (20 %). Embolization resulted in angiographic stasis of flow in all seven procedures. Four women (80 %) presented with vaginal bleeding which was improved after treatment. One woman returned 24 days after unilateral embolization with recurrent bleeding, which resolved after retreatment. One woman underwent two treatments for an asymptomatic lesion identified on ultrasound. There were no major complications. Three women (60 %) experienced mild postembolization pelvic pain that was controlled with non-steroidal anti-inflammatory drugs. Three women (60 %) had pregnancies and deliveries after embolization. TAE is a safe alternative to surgical therapy for acquired uterine AVMs with the potential to maintain fertility. Experience from this case series suggests that NBCA provides predictable and effective occlusion.

  9. Mediating electrostatic binding of 1-butyl-3-methylimidazolium chloride to enzyme surfaces improves conformational stability.

    Science.gov (United States)

    Nordwald, Erik M; Kaar, Joel L

    2013-08-01

    We have recently developed a general approach to improve the utility of enzymes in ionic liquids (ILs) via tuning of the ratio of enzyme-containing positive to negative surface charges. In this work, the impact of enzyme surface charge ratio on the biophysical interaction of 1-butyl-3-methylimidazolium chloride ([BMIM][Cl]) with chymotrypsin and lipase was investigated to understand this approach at the molecular level. Results of fluorescence quenching assays indicated that the extent of binding of the [BMIM] cation decreased (7- and 3.5-fold for chymotrypsin and lipase, respectively) as a function of increasing ratio of positive to negative surface charges. Conformational stability assays further showed a close correlation between thermodynamic stabilization and enzyme surface charge ratio as well as [BMIM] binding. As evidence of this correlation, succinylation and acetylation resulted in the stabilization of chymotrypsin in 10% (v/v) [BMIM][Cl] by 17.0 and 6.6 kJ/mol, respectively, while cationization destabilized chymotrypsin by 3.6 kJ/mol. Combined, these results indicate that altering the surface charge ratio mediates the organization of IL molecules, namely, [BMIM] and [Cl], around the enzymes. Preferential exclusion of [Cl], in particular, via lowering of the ratio of positive to negative surface charges, correlated with increased enzyme stability. Accordingly, these results more broadly provide insight into the mechanism of stabilization in ILs via charge modification.

  10. Synthesis, characterization and application of 1-butyl-3-methylimidazolium tetrafluoroborate for extractive desulfurization of liquid fuel

    Directory of Open Access Journals (Sweden)

    Swapnil A. Dharaskar

    2016-07-01

    Full Text Available In the present paper the experimental data of extractive desulfurization of liquid fuel using 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM]BF4 have been presented. The data of FTIR, 1H NMR and 13C NMR have been discussed for the molecular confirmation of synthesized [BMIM]BF4. Further, the thermal properties, conductivity, solubility, and viscosity analysis of the [BMIM]BF4 were carried out. The effects of reaction time, reaction temperature, sulfur compounds, and recycling of ionic liquid without regeneration on dibenzothiophene removal of liquid fuel were presented. In extractive desulfurization process, the removal of dibenzothiophene in n-dodecane was 73.02% for mass ratio of 1:1 in 30 min at 30 °C under the mild reaction conditions. The ionic liquids could be reused four times without a significant decrease in activity. Also, the desulfurizations of real fuels, multistage extraction were presented. The data and results provided in the present paper explore the significant insights of imidazoled ILs for extractive desulfurization of liquid fuels.

  11. Exposure to methyl tert-butyl ether (MTBE) is associated with mitochondrial dysfunction in rat.

    Science.gov (United States)

    Saeedi, Arastoo; Omidi, Mahmoud; Khoshnoud, Mohammad Javad; Mohammadi-Bardbori, Afshin

    2017-05-01

    1. Methyl tert-butyl ether (MTBE) is commonly used as an octane booster and oxygenate additive to gasoline. The assumed toxic effects of MTBE on human health are a matter of great debate. Exposure to MTBE has been shown to induce oxidative damage and no mechanistic explanation is available so far. Our goals were to determine whether MTBE is a mitochondrial toxicant, if so, what mechanism(s) is involved. 2. Male Sprague-Dawley rats were received MTBE in drinking water for 3 months. At the end of treatments, animals were killed, liver and blood samples were collected for biochemical and histopathological studies, and oxidative stress biomarkers. The rat liver mitochondria were isolated and several mitochondrial indices were measured. 3. We found that zinc plasma levels were remarkably declined with MTBE and N, N, N', N'-Tetrakis (2-pyridylmethyl) ethylenediamine (TPEN; a zinc chelator) exposure. MTBE induced oxidative damage and caused mitochondrial dysfunctions in rats. Supplementation with zinc was able to protect against MTBE-induced cellular and sub-cellular toxicity. 4. Our results demonstrated that long-term exposure to MTBE is associated with zinc deficiency, oxidative stress, and mitochondrial energy failure in rat.

  12. Toxicity and biofilm-based selection for methyl tert-butyl ether bioremediation technology.

    Science.gov (United States)

    Guisado, I M; Purswani, J; Catón-Alcubierre, L; González-López, J; Pozo, C

    2016-12-01

    Extractive membrane biofilm reactor (EMBFR) technology offers productive solutions for volatile and semi-volatile compound removal from water bodies. In this study, the bacterial strains Paenibacillus etheri SH7(T) (CECT 8558), Agrobacterium sp. MS2 (CECT 8557) and Rhodococcus ruber strains A5 (CECT 8556), EE6 (CECT 8612) and EE1 (CECT 8555), previously isolated from fuel-contaminated sites, were tested for adherence on tubular semipermeable membranes in laboratory-scale systems designed for methyl tert-butyl ether (MTBE) bioremediation. Biofilm formation on the membrane surface was evaluated through observation by field-emission scanning electron microscope (FESEM) as well as the acute toxicity (as EC50) of the bacterial growth media. Moreover, extracellular polymeric substance (EPS) production for each strain under different MTBE concentrations was measured. Strains A5 and MS2 were biofilm producers and their adherence increased when the MTBE flowed through the inner tubular semipermeable membrane. No biofilm was formed by Paenibacillus etheri SH7(T), nevertheless, the latter and strain MS2 exhibited the lowest toxicity after growth on the EMBFR. The results obtained from FESEM and toxicity analysis demonstrate that bacterial strains R. ruber EE6, A5, P. etheri SH7(T) and Agrobacterium sp. MS2 could be excellent candidates to be used as selective inocula in EMBFR technology for MTBE bioremediation.

  13. Mechanical, thermal and morphological properties of poly(lactic acid)/ethylene-butyl acrylate copolymer nanocomposites

    Science.gov (United States)

    Wacharawichanant, S.; Hoysang, P.; Ratchawong, S.

    2017-07-01

    This paper reports a melt blend of poly(lactic acid) (PLA)/ethylene-butyl acrylate copolymer (EBAC) with organoclay content at 3 phr. The mechanical, thermal and morphological properties of PLA/EBAC blends and nanocomposites were investigated. The morphological analysis revealed EBAC phase dispersed as a spherical domain in PLA matrix and the domain size of EBAC dispersed phase increased with increasing EBAC content. The addition of organoclay could improve the miscibility of PLA/EBAC blends due to the decrease of domain size of EBAC dispersed phase. The mechanical properties indicated that the strain at break and impact strength of PLA increased when added EBAC, but Young’s modulus and tensile strength decreased. Storage modulus increased with the addition of organoclay to the PLA/EBAC blends. The thermal properties found that the incorporation of organoclay in the PLA/EBAC blends did not effect on the glass transition temperature and melting temperature values relative to PLA. The degradation temperature of PLA improved with the addition of EBAC. This indicated that EBAC has more thermal stability and degradation temperature than PLA. From X-ray diffraction patterns displayed the characteristic peak in PLA/EBAC/organoclay nanocomposites appeared at the lower angle, which indicated the dispersed clay is intercalated in the polymer matrix. However, second-order diffraction peak appeared at the higher angle indicated that there was partially the conventional composite.

  14. [Effects of O-(4-ethoxyl-butyl)-berbamine on isolated frog hearts].

    Science.gov (United States)

    Zheng, G H; Chen, Z L; Jiang, J H

    1998-09-01

    To study the effects of O-(4-ethoxyl-butyl)-berbamine (EBB) on isolated frog heart. The isolated frog hearts were prepared with Straub's method; heart contractions were recorded using LMS-2A recorder by tonotransducer. EBB 1-100 mumol.L-1 caused concentration-dependent increase in systolic and diastolic activities, but did not alter the heart rate. EBB 250-500 mumol.L-1 slowed the heart beats and caused ventricular asystole. Cimetidine 10 mumol.L-1 or prazosin 100 mumol.L-1 did not inhibit the positive inotropic action of EBB. Whereas verapamil 0.01 mumol.L-1 antagonized the positive inotropic action of EBB. EBB enhanced positive inotropic action of CaCl2. The action of EBB was slower but longer than caffeine or isoproterenol. At room temperature (21.0 +/- 0.5) degree C, however, the onset of oubain was slower, but the duration of its peak action was longer, than EBB. The positive inotropic action of EBB was, at least partially, via promoting the inward current of [Ca2+]o, rather than increasing the intracellular Ca2+ release.

  15. Redox Regulation of the Tumor Suppressor PTEN by Hydrogen Peroxide and Tert-Butyl Hydroperoxide

    Directory of Open Access Journals (Sweden)

    Ying Zhang

    2017-05-01

    Full Text Available Organic peroxides and hydroperoxides are skin tumor promoters. Free radical derivatives from these compounds are presumed to be the prominent mediators of tumor promotion. However, the molecular targets of these species are unknown. Phosphatase and tensin homologs deleted on chromosome 10 (PTEN are tumor suppressors that play important roles in cell growth, proliferation, and cell survival by negative regulation of phosphoinositol-3-kinase/protein kinase B signaling. PTEN is reversibly oxidized in various cells by exogenous and endogenous hydrogen peroxide. Oxidized PTEN is converted back to the reduced form by cellular reducing agents, predominantly by the thioredoxin (Trx system. Here, the role of tert-butyl hydroperoxide (t-BHP in redox regulation of PTEN was analyzed by using cell-based and in vitro assays. Exposure to t-BHP led to oxidation of recombinant PTEN. In contrast to H2O2, PTEN oxidation by t-BHP was irreversible in HeLa cells. However, oxidized PTEN was reduced by exogenous Trx system. Taken together, these results indicate that t-BHP induces PTEN oxidation and inhibits Trx system, which results in irreversible PTEN oxidation in HeLa cells. Collectively, these results suggest a novel mechanism of t-BHP in the promotion of tumorigenesis.

  16. Selective arterial embolization of 36 aneurysmal bone cysts of the skeleton with N-2-butyl cyanoacrylate

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, Giuseppe [Rizzoli Orthopaedic Institute, Department of Interventional Angiographic Radiology, Bologna (Italy); Rimondi, Eugenio; Vanel, Daniel [Rizzoli Orthopaedic Institute, Department of Radiology, Bologna (Italy); Bartalena, Tommaso [University of Bologna, Bologna (Italy); Gerardi, Antonio [Rizzoli Orthopaedic Institute, Department of Anatomical Human Science and Physiopathology of the Musculoskeletal System, Bologna (Italy); Alberghini, Marco [Rizzoli Orthopaedic Institute, Department of Pathological Anatomy, Bologna (Italy); Staals, Eric Lodwijk; Errani, Costantino; Bianchi, Giuseppe; Toscano, Angelo; Mercuri, Mario [Rizzoli Orthopaedic Institute, V Division of Musculoskeletal Tumors, Bologna (Italy)

    2010-02-15

    Aneurysmal bone cyst (ABC) is a lytic benign bone lesion representing about 1% of all primary bone tumors. The lesion causes pain and swelling, which are generally present for less than 3 months. From April 2003 to April 2008 36 patients affected by aneurysmal bone cysts were treated by selective arterial embolization with N-2-butyl cyanoacrylate. The study population comprised 20 male and 16 female patients with an age range of 3.3-60.8 years. Nine lesions were localized in the appendicular skeleton (1 in the upper and 8 in the lower limb), 4 in the thoracic cage (1 rib lesion and 3 scapular lesions), 17 in the pelvis and 6 in the spine (1 thoracic and 5 sacral localizations). A total of 55 embolizations were performed: in 22 cases (61%) only one embolization was needed, whilst two embolizations were necessary in 9 cases (25%) and 3 in the remaining 5 patients (14%). The treatment was effective in 32 patients (94%): follow-up was 0.9-5 years. In one patient, previously surgically treated, only the cyanoacrylate embolization turned out to be useful for healing the lesion. Another 7 patients underwent surgery during the study period. In the 55 procedures we performed we had 3 complications (5%): 2 cases of skin necrosis and 1 of transient paresis. Arterial embolization with cyanoacrylate may be the treatment of choice for aneurysmal bone cysts. Embolization is a less invasive, lower cost, simpler procedure than surgery and is easily repeatable. (orig.)

  17. THERMOPHYSICAL PROPERTIES OF 1-BUTYL-3-METHYLIMIDAZOLIUM BIS(TRIFLUOROMETHYLSULFONYLIMIDE AT HIGH TEMPERATURES AND PRESSURES

    Directory of Open Access Journals (Sweden)

    R. Hamidova

    2015-03-01

    Full Text Available Abstract Pressure-density-temperature (p, ρ ,T data of the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonylimide [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, aqueous NaCl solution, methanol, toluene and acetone. An empirical equation of state for fitting the (p, ρ ,T data of [BMIM][NTF2] has been developed as a function of pressure and temperature. This equation is used for the calculation of the thermophysical properties of the ionic liquid, such as isothermal compressibility, isobaric thermal expansibility, thermal pressure coefficient, internal pressure, isobaric and isochoric heat capacities, speed of sound and isentropic expansibility.

  18. Cerebrospinal fluid pathways from cisterns to ventricles in N-butyl cyanoacrylate-induced hydrocephalic rats.

    Science.gov (United States)

    Park, Jong-Hyuk; Park, Yong-Sook; Suk, Jong-Sik; Park, Seung-Won; Hwang, Sung-Nam; Nam, Taek-Kyun; Kim, Young-Baeg; Lee, Won-Bok

    2011-12-01

    Cerebrospinal fluid typically enters the subarachnoid space from the ventricles via the fourth ventricular foramina. However, there is clinical evidence that CSF also flows in the opposite direction. Ventricular reflux of CSF from a cistern is a well-known phenomenon in radioisotope studies in patients with normal-pressure hydrocephalus. Additionally, the presence of ventricular blood in acute subarachnoid hemorrhage is frequently observed. The goal of this investigation was to examine the potential CSF pathways from cisterns to ventricles. The authors examined pathways in rat models in which they occluded the fourth ventricular outlets and injected a tracer into the subarachnoid space. The model for acute obstructive hydrocephalus was induced using N-butyl cyanoacrylate (NBCA) in 10 Sprague-Dawley rats. After 3 days, cationized ferritin was infused into the lumbar subarachnoid space to highlight retrograde CSF flow pathways. The animals were sacrificed at 48 hours, and the brains were prepared. The CSF flow pathway was traced by staining the ferritin with ferrocyanide. Ferritin was observed in the third ventricle in 7 of 8 rats with hydrocephalus and in the temporal horn of the lateral ventricles in 4 of 8 rats with hydrocephalus. There was no definite staining in the aqueduct, which suggests that the ventricular reflux originated from routes other than through the fourth ventricular outlets. The interfaces between the quadrigeminal cistern and third ventricle and those between the ambient cistern and lateral ventricle appear to be potential sites of CSF reflux from cisterns to ventricles in obstructive hydrocephalus.

  19. Toxicity of methyl tertiary butyl ether to Daphnia magna and photobacterium phosphoreum

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, G.; Lin, Y.J. [Univ. of Maryland Eastern Shore, Princess Anne, MD (United States)

    1995-10-01

    Methyl tertiary butyl ether (MTBE) is a liquid organic compound added to gasoline to increase its oxygen content and to reduce the emission of carbon monoxide during combustion in many urban areas. In order to meet the 1990 Clean Air Act amendments, gasoline must contain 2.7% oxygen (by weight) or 15% (by volume) of MTBE in gasoline to meet the regulations for the control of carbon monoxide emissions. Health effects caused by inhalation of MTBE include headaches, dizziness, irritated eyes and nausea; MTBE is one of cancer--causing chemicals. Intracaval injection of MTBE (0.2 mg/kg) caused the highest mortality (100%) in rats. General anesthetic effect induced by MTBE was found at or above 1200 mg/kg body weight; Rosenkranz and Klopman (1991) predicted that MTBE is neither a genotoxicant nor a carcinogen. Nevertheless, the safety of using MTBE in oxygenated fuels is now being questioned from its potential as groundwater pollutant. This study measures the toxicity of MTBE to Daphnia magna and Photobacterium phosphoreum. 13 refs.

  20. Acute toxicity and cancer risk assessment values for tert-butyl acetate.

    Science.gov (United States)

    Budroe, John D; Brown, Joseph P; Salmon, Andrew G; Salsmon, Andrew G; Marty, Melanie A

    2004-10-01

    tert-Butyl acetate (TBAc) is an industrial chemical with potential uses as a degreaser and in architectural coatings. Limited chronic toxicity data exist for TBAc. However, acute inhalation exposure data are available for TBAc. Additionally, TBAc has been demonstrated to be substantially metabolized to tert-butanol (TBA) in rats, and a positive TBA genotoxicity study suggests that TBA may cause oxidative DNA damage. TBA has been shown to induce tumors in both rats and mice, and the Office of Environmental Health Hazard Assessment has calculated an oral cancer potency factor (CSF) for TBA of 3 x 10(-3)(mg/kg-day)(-1). Therefore, TBAc should be considered to pose a potential cancer risk to humans because of the metabolic conversion to TBA. An acute 1-h reference exposure level of 1 mg/m3 can be calculated from the extrapolated no observed adverse effect level of 50 mg/m3. A CSF of 0.002(mg/kg-day)(-1) can be derived for TBAc, assuming 100% metabolism of TBAc to TBA. An inhalation unit risk value for TBAc of 4 x 10(-7)(microg/m(3))(-1) can then be derived from the CSF value for TBAc by assuming a human breathing rate of 20 m3/day, 70% fractional absorption, and an average human body weight of 70 kg.