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Sample records for algae growth inhibition

  1. Use of Copper to Selectively Inhibit Brachionus calyciflorus (Predator) Growth in Chlorella kessleri (Prey) Mass Cultures for Algae Biodiesel Production.

    PubMed

    Pradeep, Vishnupriya; Van Ginkel, Steven W; Park, Sichoon; Igou, Thomas; Yi, Christine; Fu, Hao; Johnston, Rachel; Snell, Terry; Chen, Yongsheng

    2015-08-31

    A single Brachionus rotifer can consume thousands of algae cells per hour causing an algae pond to crash within days of infection. Thus, there is a great need to reduce rotifers in order for algal biofuel production to become reality. Copper can selectively inhibit rotifers in algae ponds, thereby protecting the algae crop. Differential toxicity tests were conducted to compare the copper sensitivity of a model rotifer-B. calyciflorus and an alga, C. kessleri. The rotifer LC50 was <0.1 ppm while the alga was not affected up to 5 ppm Cu(II). The low pH of the rotifer stomach may make it more sensitive to copper. However, when these cultures were combined, a copper concentration of 1.5 ppm was needed to inhibit the rotifer as the alga bound the copper, decreasing its bioavailability. Copper (X ppm) had no effect on downstream fatty acid methyl ester extraction.

  2. Use of Copper to Selectively Inhibit Brachionus calyciflorus (Predator) Growth in Chlorella kessleri (Prey) Mass Cultures for Algae Biodiesel Production

    PubMed Central

    Pradeep, Vishnupriya; Van Ginkel, Steven W.; Park, Sichoon; Igou, Thomas; Yi, Christine; Fu, Hao; Johnston, Rachel; Snell, Terry; Chen, Yongsheng

    2015-01-01

    A single Brachionus rotifer can consume thousands of algae cells per hour causing an algae pond to crash within days of infection. Thus, there is a great need to reduce rotifers in order for algal biofuel production to become reality. Copper can selectively inhibit rotifers in algae ponds, thereby protecting the algae crop. Differential toxicity tests were conducted to compare the copper sensitivity of a model rotifer—B. calyciflorus and an alga, C. kessleri. The rotifer LC50 was <0.1 ppm while the alga was not affected up to 5 ppm Cu(II). The low pH of the rotifer stomach may make it more sensitive to copper. However, when these cultures were combined, a copper concentration of 1.5 ppm was needed to inhibit the rotifer as the alga bound the copper, decreasing its bioavailability. Copper (X ppm) had no effect on downstream fatty acid methyl ester extraction. PMID:26404247

  3. Algae inhibition experiment and load characteristics of the algae solution

    NASA Astrophysics Data System (ADS)

    Xiong, L.; Gao, J. X.; Zhang, Y. X.; Yang, Z. K.; Zhang, D. Q.; He, W.

    2016-08-01

    It is necessary to inhibit microbial growth in an industrial cooling water system. This paper has developed a Monopolar/Bipolar polarity high voltage pulser with load adaptability for an algal experimental study. The load characteristics of the Chlorella pyrenoidosa solution were examined, and it was found that the solution load is resistive. The resistance is related to the plate area, concentration, and temperature of the solution. Furthermore, the pulser's treatment actually inhibits the algae cell growth. This article also explores the influence of various parameters of electric pulses on the algal effect. After the experiment, the optimum pulse parameters were determined to be an electric field intensity of 750 V/cm, a pulse width per second of 120μs, and monopolar polarity.

  4. Estimation of alga growth stage and lipid content growth rate

    NASA Technical Reports Server (NTRS)

    Embaye, Tsegereda N. (Inventor); Trent, Jonathan D. (Inventor)

    2012-01-01

    Method and system for estimating a growth stage of an alga in an ambient fluid. Measured light beam absorption or reflection values through or from the alga and through an ambient fluid, in each of two or more wavelength sub-ranges, are compared with reference light beam absorption values for corresponding wavelength sub-ranges for in each alga growth stage to determine (1) which alga growth stage, if any, is more likely and (2) whether estimated lipid content of the alga is increasing or has peaked. Alga growth is preferably terminated when lipid content has approximately reached a maximum value.

  5. Modelling the effect of fluctuating herbicide concentrations on algae growth.

    PubMed

    Copin, Pierre-Jean; Coutu, Sylvain; Chèvre, Nathalie

    2015-03-01

    Herbicide concentrations fluctuate widely in watercourses after crop applications and rain events. The level of concentrations in pulses can exceed the water chronic quality criteria. In the present study, we proposed modelling the effects of successive pulse exposure on algae. The deterministic model proposed is based on two parameters: (i) the typical growth rate of the algae, obtained by monitoring growth rates of several successive batch cultures in growth media, characterizing both the growth of the control and during the recovery periods; (ii) the growth rate of the algae exposed to pulses, determined from a dose-response curve obtained with a standard toxicity test. We focused on the herbicide isoproturon and on the freshwater alga Scenedesmus vacuolatus, and we validated the model prediction based on effect measured during five sequential pulse exposures in laboratory. The comparison between the laboratory and the modelled effects illustrated that the results yielded were consistent, making the model suitable for effect prediction of the herbicide photosystem II inhibitor isoproturon on the alga S. vacuolatus. More generally, modelling showed that both pulse duration and level of concentration play a crucial role. The application of the model to a real case demonstrated that both the highest peaks and the low peaks with a long duration affect principally the cell density inhibition of the alga S. vacuolatus. It is therefore essential to detect these characteristic pulses when monitoring of herbicide concentrations are conducted in rivers.

  6. Formation of algae growth constitutive relations for improved algae modeling.

    SciTech Connect

    Gharagozloo, Patricia E.; Drewry, Jessica Louise.

    2013-01-01

    This SAND report summarizes research conducted as a part of a two year Laboratory Directed Research and Development (LDRD) project to improve our abilities to model algal cultivation. Algae-based biofuels have generated much excitement due to their potentially large oil yield from relatively small land use and without interfering with the food or water supply. Algae mitigate atmospheric CO2 through metabolism. Efficient production of algal biofuels could reduce dependence on foreign oil by providing a domestic renewable energy source. Important factors controlling algal productivity include temperature, nutrient concentrations, salinity, pH, and the light-to-biomass conversion rate. Computational models allow for inexpensive predictions of algae growth kinetics in these non-ideal conditions for various bioreactor sizes and geometries without the need for multiple expensive measurement setups. However, these models need to be calibrated for each algal strain. In this work, we conduct a parametric study of key marine algae strains and apply the findings to a computational model.

  7. Effects of TiO2 nanoparticles on ROS production and growth inhibition using freshwater green algae pre-exposed to UV irradiation.

    PubMed

    Fu, Ling; Hamzeh, Mahsa; Dodard, Sabine; Zhao, Yuan H; Sunahara, Geoffrey I

    2015-05-01

    This study investigated the possibility that titanium dioxide nanoparticles (nano-TiO2) toxicity in Pseudokirchneriella subcapitata involves reactive oxygen species (ROS) production, using the dichlorodihydrofluorescein (DCF) assay. Algae were exposed to nano-TiO2 under laboratory fluorescent lamps supplemented with UV irradiation for 3h, with or without a UV filter. Results showed that nano-TiO2 increased ROS production in UV-exposed cells, with or without a UV filter (LOEC values were 250 and 10mg/L, respectively). Sublethal effects of nano-TiO2 on UV pre-exposed algae were also examined. Toxicity studies indicated that exposure to nano-TiO2 agglomerates decreased algal growth following 3h pre-exposure to UV, with or without a UV filter (EC50s were 8.7 and 6.3mg/L, respectively). The present study suggests that the growth inhibitory effects of nano-TiO2 in algae occurred at concentrations lower than those that can elevate DCF fluorescence, and that ROS generation is not directly involved with the sublethal effects of nano-TiO2 in algae.

  8. Inhibitory effects of brown algae extracts on histamine production in mackerel muscle via inhibition of growth and histidine decarboxylase activity of Morganella morganii.

    PubMed

    Kim, Dong Hyun; Kim, Koth Bong Woo Ri; Cho, Ji Young; Ahn, Dong Hyun

    2014-04-01

    This study was performed to investigate the inhibitory effects of brown algae extracts on histamine production in mackerel muscle. First, antimicrobial activities of brown algae extracts against Morganella morganii were investigated using a disk diffusion method. An ethanol extract of Ecklonia cava (ECEE) exhibited strong antimicrobial activity. The minimum inhibitory concentration (MIC) of ECEE was 2 mg/ml. Furthermore, the brown algae extracts were examined for their ability to inhibit crude histidine decarboxylase (HDC) of M. morganii. The ethanol extract of Eisenia bicyclis (EBEE) and ECEE exhibited significant inhibitory activities (19.82% and 33.79%, respectively) at a concentration of 1 mg/ml. To obtain the phlorotannin dieckol, ECEE and EBEE were subjected to liquid-liquid extraction, silica gel column chromatography, and HPLC. Dieckol exhibited substantial inhibitory activity with an IC50 value of 0.61 mg/ml, and exhibited competitive inhibition. These extracts were also tested on mackerel muscle. The viable cell counts and histamine production in mackerel muscle inoculated with M. morganii treated with ≥2.5 MIC of ECEE (weight basis) were highly inhibited compared with the untreated sample. Furthermore, treatment of crude HDC-inoculated mackerel muscle with 0.5% ECEE and 0.5% EBEE (weight basis), which exhibited excellent inhibitory activities against crude HDC, reduced the overall histamine production by 46.29% and 56.89%, respectively, compared with the untreated sample. Thus, these inhibitory effects of ECEE and EBEE should be helpful in enhancing the safety of mackerel by suppressing histamine production in this fish species.

  9. [Effects of nitrogen source and aeration mode on algae growth in freshwater].

    PubMed

    Liu, Chun-Guang; Jin, Xiang-Can; Sun, Ling; Sun, Hong-Wen; Zhu, Lin; Yu, Yang; Dai, Shu-Gui; Zhuang, Yuan-Yi

    2006-01-01

    Aquarium microcosms were used to study the effects of nitrogen source and aeration mode on the growth and species changes of algae in freshwater. Nitrate nitrogen(NO3(-) -N) and ammonia nitrogen(NH4(+) -N) were used as nitrogen sources. For each nitrogen source, four modes of aeration were selected, including control, continuous aeration, aeration during the day, and aeration at night. In the early stage of the experiment, algae in the NH4(+) -N treatment experiment grew well. In the later stage, algae in the NO3(-) -N treatment experiment grew better. For different aeration modes, continuous aeration show varied effects on algae growth in the two nitrogen source treatments. Day-only aeration had little effect on algae growth. Night-only aeration inhibited algae growth considerably. In NH(+) -N treatments, cyanophyta became dominant species easily. In contrast, chlorophyta dominated in NO3(-) -N treatments.

  10. [Numerical simulation on hydrodynamic character for algae growth].

    PubMed

    Wang, Hua; Pang, Yong

    2008-04-01

    In order to quantificationally study the direct effects of hydrodynamic condition on the growth of algae, the Microcystis aeruginosa was chosen to carry through the disturbance-experiment. By keeping the same value of illumination, temperature and nutrition and changing the rotate speed of oscillator, the growing processes of algae under different disturbance intensities were researched. The hydraulic parameter was presented to amend the formula for the growth of algae. Take Neijiang as an example. A 2-D unsteady model for algae growth was established to forecast the scope of water blooms in Neijiang. It is found that the growth of algae is obviously influenced by hydrodynamic condition, and a condign low velocity is beneficial for its growth while both the quiescence condition and high velocity will restrain its growth rate. After the close of the water gate in Leading Channel, the velocity in Neijiang will be decreased, which accelerated the growth rate of algae, and the area of water blooms will be increased to 2.5 km2 which is about 36.8 percent of the total water surface area of Neijiang. Under the quiescent condition and the improved hydrodynamic condition, the growth rate of algae will be effectively controlled and the area of water blooms will be reduced to 0.78 km2 and 0.18 km2 respectively.

  11. [Effects of turbulent fluctuation intensity on the growth of algae and water environment].

    PubMed

    Lei, Yu; Long, Tian-yu; San, Lei; An, Qiang; Huang, Ning-qiu

    2013-05-01

    Through a self-designed vertically oscillating grid experiment device, the experiment was carried out to research the effects of the turbulence fluctuation intensity on the growth of algae and water environment in the water with adequate nutrients by changing the vibration frequency under a certain light and temperature conditions. The results showed that: the turbulent fluctuation has significant effects on algae growing that weak turbulence fluctuation can promote the growth of algae and strong turbulence fluctuation will inhibit the growth of algae in the range of experimental level. With the increase of the turbulent fluctuation intensity, the peak of algal biomass gradually delayed. Changes of nitrogen and phosphorus in the experimental process have significant differences, when the vibration frequency was up to 2.0 Hz, the maximum reduction of TN and TP were 55.2% and 69.0% lower compared with 0.5 Hz, which was closely associated with the growth of algae. With the intensity of turbulent fluctuation increases, nitrogen-phosphorus ratio first increases and then decreases corresponding to the peak of the algal biomass. Turbulent fluctuation can promote the pH and, dissolved oxygen quickly adjusted to the level of algae growing required, and the most appropriate value remains unchanged.

  12. Determination of growth rate depression of some green algae by atrazine

    SciTech Connect

    Hersh, C.M.; Crumpton, W.G.

    1987-12-01

    A common contaminant of surface waters of agricultural regions is the triazine herbicide, atrazine (2-chloro-4-ethylamino-6-isoproplyamino-s-triazine). Atrazine effectively inhibits growth and photosynthesis of most plants, including freshwater algae. Both depression of growth rate and reduced yield have been used as parameters in studies of the effects of atrazine on algal growth. Considerable variation exists among algal toxicity methods despite attempts at standardization. Experimental endpoints range from percent inhibitions to EC50s. Algae from two different Iowa springs were the subjects of a study of naturally occurring atrazine tolerance. The authors report here the results of two aspects of that study: development of a quick method of assessing toxin effects on algal growth, and investigation of a ecologically meaningful endpoint for toxin-growth experiments.

  13. [Parameter determination of algae growth based on ecological tank experiment].

    PubMed

    Pang, Yong; Ding, Ling; Gao, Guang

    2005-05-01

    A dynamic simulation experiment of algae in an ecological tank was performed at the Taihu Laboratory for Lake Ecosystem Research. During the experiment, water from Taihu Lake was infused into the ecological tank and samples were taken continually to observe algae growth under varying conditions, such as temperature, sunlight and nutrients. Based on the experiment, an algae growth model, considering nitrogen and phosphorus cycle, was developed by using the advanced PHREEQC model. After that, a detailed calibration and validation of parameters in the model were done on the basis of experimental results. The least square method was used to determine the optimal set of parameters. The calculated values of algae and nutrient concentrations show fairly satisfying fittness with measured data.

  14. Biomass of algae growth on natural water medium.

    PubMed

    Ramaraj, Rameshprabu; Tsai, David Dah-Wei; Chen, Paris Honglay

    2015-01-01

    Algae are the dominant primary producers in aquatic ecosystems. Since algae are highly varied group organisms, which have important functions in ecosystem, and their biomass is an essential biological resource. Currently, algae have been applied increasingly to diverse range of biomass applications. Therefore, this study was aimed to investigate the ecological algae features of microalgal production by natural medium, ecological function by lab scale of the symbiotic reactor which is imitated nature ecosystem, and atmospheric CO2 absorption that was related the algal growth of biomass to understand algae in natural water body better. Consequently, this study took advantages of using the unsupplemented freshwater natural medium to produce microalgae. Algal biomass by direct measurement of total suspended solids (TSS) and volatile suspended solids (VSS) resulted as 0.14g/L and 0.08g/L respectively. The biomass measurements of TSS and VSS are the sensible biomass index for algae production. The laboratory results obtained in the present study proved the production of algae by the natural water medium is potentially feasible.

  15. Inhibitory effects of terpene alcohols and aldehydes on growth of green alga Chlorella pyrenoidosa

    SciTech Connect

    Ikawa, Miyoshi; Mosley, S.P.; Barbero, L.J. )

    1992-10-01

    The growth of the green alga Chlorella pyrenoidosa was inhibited by terpene alcohols and the terpene aldehyde citral. The strongest activity was shown by citral. Nerol, geraniol, and citronellol also showed pronounced activity. Strong inhibition was linked to acyclic terpenes containing a primary alcohol or aldehyde function. Inhibition appeared to be taking place through the vapor phase rather than by diffusion through the agar medium from the terpene-treated paper disks used in the system. Inhibition through agar diffusion was shown by certain aged samples of terpene hydrocarbons but not by recently purchased samples.

  16. Effects of artemisinin sustained-release granules on mixed alga growth and microcystins production and release.

    PubMed

    Ni, Lixiao; Li, Danye; Hu, Shuzhen; Wang, Peifang; Li, Shiyin; Li, Yiping; Li, Yong; Acharya, Kumud

    2015-12-01

    To safely and effectively apply artemisinin sustained-release granules to control and prevent algal water-blooms, the effects of artemisinin and its sustained-release granules on freshwater alga (Scenedesmus obliquus (S. obliquus) and Microcystis aeruginosa (M. aeruginosa)), as well as the production and release of microcystins (MCs) were studied. The results showed that artemisinin sustained-release granules inhibited the growth of M. aeruginosa (above 95% IR) and S. obliquus (about 90% IR), with M. aeruginosa more sensitive. The artemisinin sustained-release granules had a longer inhibition effect on growth of pure algae and algal coexistence than direct artemisinin dosing. The artemisinin sustained-release granules could decrease the production and release of algal toxins due to the continued stress of artemisinin released from artemisinin sustained-release granules. There was no increase in the total amount of MC-LR in the algal cell culture medium.

  17. Phosphorus-Limited Growth of a Green Alga and a Blue-Green Alga

    PubMed Central

    Lang, Douglas S.; Brown, Edward J.

    1981-01-01

    The phosphorus-limited growth kinetics of the chlorophyte Scenedesmus quadricauda and the cyanophyte Synechococcus Nägeli were studied by using batch and continuous culturing techniques. The steady-state phosphate transport capability and the phosphorus storage capacity is higher in S. Nägeli than in S. quadricauda. Synechococcus Nägeli can also deplete phosphate to much lower levels than can S. quadricauda. These results, along with their morphological characteristics, were used to construct partial physiological profiles for each organism. The profiles indicate that this unicellular cyanophyte (cyanobacterium) is better suited for growth in phosphorus-limited oligotrophic niches than is this chlorophyte (green alga). PMID:16345896

  18. Phosphorus-limited growth of a green alga and a blue-green alga

    SciTech Connect

    Lang, D.S.; Brown, E.J.

    1981-12-01

    The phosphorus-limited growth kinetics of the chlorophyte Scenedesmus quadricauda and the cyanophyte Synechococcus Nageli were studied by using batch and continuous culturing techniques. The steady-state phosphate transport capability and the phosphorus storage capacity is higher in S. Nageli than in S. quadricauda. Synechococcus Nageli can also deplete phosphate to much lower levels than can S. quadricauda. These results, along with their morphological characteristics, were used to construct partial physiological profiles for each organism. The profiles indicate that this unicellular cyanophyte (cyanobacterium) is better suited for growth in phosphorus-limited oligotrophic niches than is this chlorophyte (green alga). (Refs. 44).

  19. Inhibition of target of rapamycin signaling by rapamycin in the unicellular green alga Chlamydomonas reinhardtii.

    PubMed

    Crespo, José L; Díaz-Troya, Sandra; Florencio, Francisco J

    2005-12-01

    The macrolide rapamycin specifically binds the 12-kD FK506-binding protein (FKBP12), and this complex potently inhibits the target of rapamycin (TOR) kinase. The identification of TOR in Arabidopsis (Arabidopsis thaliana) revealed that TOR is conserved in photosynthetic eukaryotes. However, research on TOR signaling in plants has been hampered by the natural resistance of plants to rapamycin. Here, we report TOR inactivation by rapamycin treatment in a photosynthetic organism. We identified and characterized TOR and FKBP12 homologs in the unicellular green alga Chlamydomonas reinhardtii. Whereas growth of wild-type Chlamydomonas cells is sensitive to rapamycin, cells lacking FKBP12 are fully resistant to the drug, indicating that this protein mediates rapamycin action to inhibit cell growth. Unlike its plant homolog, Chlamydomonas FKBP12 exhibits high affinity to rapamycin in vivo, which was increased by mutation of conserved residues in the drug-binding pocket. Furthermore, pull-down assays demonstrated that TOR binds FKBP12 in the presence of rapamycin. Finally, rapamycin treatment resulted in a pronounced increase of vacuole size that resembled autophagic-like processes. Thus, our findings suggest that Chlamydomonas cell growth is positively controlled by a conserved TOR kinase and establish this unicellular alga as a useful model system for studying TOR signaling in photosynthetic eukaryotes.

  20. Factors influencing stable isotopes and growth of algae in oil sands aquatic reclamation.

    PubMed

    Boutsivongsakd, Monique; Farwell, Andrea J; Chen, Hao; Dixon, D George

    2015-01-01

    Previous studies reported (15)N enrichment of biota in reclamation wetlands that contain oil sands processed material (e.g., processed water and tailings); however, there is little information on the factors controlling (15)N enrichment in these systems. In this microcosm study, the aim was to examine stable C and N isotopes and growth (chlorophyll a [chl a] and dry weight) of algae as a function of exposure to different sources and concentrations of water-soluble fractions (WSF) derived from tailings. Two sources of tailings including mature fine tailings (MFT) and consolidated tailings (CT) and peat-mineral overburden were utilized to generate separate WSF that differed in water quality. In general, there was (15)N enrichment of filamentous algae along the increasing gradient of WSF/nutrient concentrations in both CT and peat microcosms, and among the different sources, algae were more (15)N enriched in CT WSF than in peat WSF. Growth of filamentous algae was inhibited at higher WSF concentrations, possibly due to reduced light availability at elevated levels of fine clay particles in MFT microcosms and colored dissolved organic carbon (DOC) in peat microcosms. Filamentous algae displayed lower biomass and (15)N depletion in 100% peat WSF. This study indicated that both the quality (source) and quantity of WSF affected algal growth and directly and/or indirectly influenced δ(15)N of algae. The distinct (15)N enrichment of primary producers derived from tailings suggest that stable N isotopes might be useful to trace exposure to oil sands processed material in biota that utilize these resources in reclaimed systems constructed with tailings or natural systems that receive tailings dyke seepage.

  1. Algae.

    PubMed

    Raven, John A; Giordano, Mario

    2014-07-07

    Algae frequently get a bad press. Pond slime is a problem in garden pools, algal blooms can produce toxins that incapacitate or kill animals and humans and even the term seaweed is pejorative - a weed being a plant growing in what humans consider to be the wrong place. Positive aspects of algae are generally less newsworthy - they are the basis of marine food webs, supporting fisheries and charismatic marine megafauna from albatrosses to whales, as well as consuming carbon dioxide and producing oxygen. Here we consider what algae are, their diversity in terms of evolutionary origin, size, shape and life cycles, and their role in the natural environment and in human affairs.

  2. Capture of algae promotes growth and propagation in aquatic Utricularia

    PubMed Central

    Koller-Peroutka, Marianne; Lendl, Thomas; Watzka, Margarete; Adlassnig, Wolfram

    2015-01-01

    Background and Aims Some carnivorous plants trap not only small animals but also algae and pollen grains. However, it remains unclear if these trapped particles are useless bycatch or whether they provide nutrients for the plant. The present study examines this question in Utricularia, which forms the largest and most widely spread genus of carnivorous plants, and which captures prey by means of sophisticated suction traps. Methods Utricularia plants of three different species (U. australis, U. vulgaris and U. minor) were collected in eight different water bodies including peat bogs, lakes and artificial ponds in three regions of Austria. The prey spectrum of each population was analysed qualitatively and quantitatively, and correlated with data on growth and propagation, C/N ratio and δ15N. Key Results More than 50 % of the prey of the Utricularia populations investigated consisted of algae and pollen, and U. vulgaris in particular was found to capture large amounts of gymnosperm pollen. The capture of algae and pollen grains was strongly correlated with most growth parameters, including weight, length, budding and elongation of internodes. The C/N ratio, however, was less well correlated. Other prey, such as moss leaflets, fungal hyphae and mineral particles, were negatively correlated with most growth parameters. δ15N was positively correlated with prey capture, but in situations where algae were the main prey objects it was found that the standard formula for calculation of prey-derived N was no longer applicable. Conclusions The mass capture of immotile particles confirms the ecological importance of autonomous firing of the traps. Although the C/N ratio was little influenced by algae, they clearly provide other nutrients, possibly including phosphorus and trace elements. By contrast, mosses, fungi and mineral particles appear to be useless bycatch. Correlations with chemical parameters indicate that Utricularia benefits from nutrient-rich waters by uptake

  3. [Growth properties of typical water bloom algae in reclaimed water].

    PubMed

    Yang, Jia; Hu, Hong-Ying; Li, Xin

    2010-01-01

    Based on Algal Growth Potential Test, the water bloom risk of reclaimed water was studied. Microcystis aeruginosa was proved as the main algae under the experimental conditions in this study. In 3 kinds of secondary effluent (A2O, Oxidation Ditch and Activated Sludge), its maximum density could attain above 10(6) cells x mL(-1), and the specific rate was above 0.39 d(-1). Advanced treatment (A2O-Ultrafiltration Membrane Filter-Activated Carbon and Chlorine Disinfection) did not reduce the growth potential of Microcystis aeruginosa. The effects of initial concentration of phosphorus in reclaimed water on maximum density (K(max)) and population growth rate (R(max)) of Microcystis aeruginosa can be described with Monod equation.

  4. Effects of lead on growth, photosynthetic characteristics and production of reactive oxygen species of two freshwater green algae.

    PubMed

    Dao, Ly H T; Beardall, John

    2016-03-01

    In the natural environment, heavy metal contamination can occur as long-term pollution of sites or as pulses of pollutants from wastewater disposal. In this study two freshwater green algae, Chlorella sp. FleB1 and Scenedesmus YaA6, were isolated from lead-polluted water samples and the effects of 24 h vs 4 and 8 d exposure of cultures to lead on growth, photosynthetic physiology and production of reactive oxygen species (ROS) of these algae were investigated. In Chlorella sp. FleB1, there was agreement between lead impacts on chlorophyll content, photosynthesis and growth in most case. However, in Scenedesmus acutus YaA6 growth was inhibited at lower lead concentrations (0.03-0.87 × 10(-9) M), under which ROS, measured by 2',7' dichlorodihydrofluorescein diacetate fluorescence, were 4.5 fold higher than in controls but photosynthesis was not affected, implying that ROS had played a role in the growth inhibition that did not involve direct effects on photosynthesis. Effects of short-term (5 h, 24 h) vs long-term (4 d and 8 d) exposure to lead were also compared between the two algae. The results contribute to our understanding of the mechanisms of lead toxicity to algae.

  5. Defined Media for Growth and Gamete Production by the Green Alga, Oedogonium cardiacum.

    PubMed

    Hill, G J; Machlis, L

    1970-08-01

    Defined media consisting of inorganic salts and vitamin B(12) are described for the male and female filaments of the green alga, Oedogonium cardiacum. These media provide for a maximal growth rate and for the induction of oogonia and antheridia under the prescribed conditions. The maximal amounts of growth, based on dry weight measurements, compare favorably with other green algae.

  6. Toluhydroquinone, the secondary metabolite of marine algae symbiotic microorganism, inhibits angiogenesis in HUVECs.

    PubMed

    Kim, Nan-Hee; Jung, Hyun-Il; Choi, Woo-Suk; Son, Byeng-Wha; Seo, Yong-Bae; Choi, Jae Sue; Kim, Gun-Do

    2015-03-01

    Angiogenesis, the growth of new blood vessels from the existing ones, occurs during embryo development and wound healing. However, most malignant tumors require angiogenesis for their growth and metastasis as well. Therefore, inhibition of angiogenesis has been focused as a new strategy of cancer therapies. To treat cancer, there are marine microorganism-derived secondary metabolites developed as chemotherapeutic agents. In this study, we used toluhydroquinone (2-methyl-1,4-hydroquinone), one of the secondary metabolites isolated from marine algae symbiotic fungus, Aspergillus sp. We examined the effects of toluhydroquinone on angiogenesis using HUVECs. We identified that toluhydroquinone inhibited the activity of β-catenin and down-regulated Ras/Raf/MEK/ERK signaling which are crucial components during angiogenesis. In addition, the expression and activity of MMPs are reduced by the treatment of toluhydroquinone. In conclusion, we confirmed that toluhydroquinone has inhibitory effects on angiogenic behaviors of human endothelial cells, HUVECs. Our findings suggest that toluhydroquinone can be proposed as a potent anti-angiogenesis drug candidate to treat cancers.

  7. The growth and harvesting of algae in a micro-gravity environment

    NASA Technical Reports Server (NTRS)

    Wiltberger, Nancy L.

    1987-01-01

    Algae growth in a micro-gravity environment is an important factor in supporting man's permanent presence in space. Algae can be used to produce food, oxygen, and pure water in a manned space station. A space station is one example of a situation where a Controlled Ecological Life Support System (CELSS) is imperative. In setting up a CELSS with an engineering approach at the Aerospace department of the University of Colorado, questions concerning algae growth in micro-g have arisen. The Get Away Special (GAS) Fluids Management project is a means through which many questions about the effects of a micro-g environment on the adequacy of growth rates, the viability of micro-organisms, and separation of gases and solids for harvesting purposes can be answered. In order to be compatible with the GAS tests, the algae must satisfy the following criteria: (1) rapid growth rates, (2) sustain viability over long periods of non-growth storage, and (3) very brief latency from storage to rapid growth. Testing indicates that the overall growth characteristics of Anacystis Nidulans satisfy the specifications of GAS's design constraints. In addition, data acquisition and the method of growth instigation are two specific problems being examined, as they will be encountered in interfacing with the GAS project. Flight testing will be two-fold, measurement of algae growth in micro-g and separation of algae from growth medium in an artificial gravitation field. Post flight results will provide information on algae viability in a micro-g environment as reflected by algal growth rates in space. Other post flight results will provide a basis for evaluating techniques for harvesting algae. The results from the GAS project will greatly assist the continuing effort of developing the CELSS and its applications for space.

  8. Salicylhydroxamic acid (SHAM) inhibition of the DIC-pump in unicellular algae

    SciTech Connect

    Goyal, A.; Tolbert, N.E. )

    1989-04-01

    SHAM at 1 or 2 mM inhibits dissolved inorganic carbon (DIC) concentrating mechanisms in unicellular green algae as measured by photosynthetic oxygen evolution or by {sup 14}C-inorganic carbon uptake (using silicone oil centrifugation techniques). This inhibition was reversed by high levels of DIC whereby the cells do not require the concentrating mechanism. SHAM inhibited the DIC-pump, which uses external CO{sub 2}, in three species of algae, Dunaliella tertiolecta, Chlamydomonas reinhardtii, and Scenedesmus obliquus when adapted to low CO{sub 2} and assayed around neutral pH. Scenedesmus adapted to air at pH 9.0 to use external HCO{sub 3}{sup {minus}} were not affected by SHAM. It is important to establish low optimum concentrations of SHAM, which varied with the algal species. The mechanism of SHAM inhibition of the CO{sub 2} concentrating process is unknown. SHAM inhibits alternative respiration in these algae, but SHAM may also inhibit other reactions involving H{sup +} gradients or transporters associated with the DIC-pump.

  9. Uptake of caprolactam and its influence on growth and oxygen production of Desmodesmus quadricauda algae.

    PubMed

    Kalinová, Jana Pexová; Tříska, Jan; Vrchotová, Naděžda; Novák, Jan

    2016-06-01

    The consumption of polyamides produced from caprolactam is increasing continuously, and for that reason the danger of environmental contamination by this lactam is also rising. This study's aim was to evaluate the influence of caprolactam on the growth and oxygen production of the green alga Desmodesmus quadricauda and on caprolactam uptake by this alga. The presence of caprolactam in water was observed to cause the algae significantly to increase its oxygen production. Caprolactam concentration of 5,000 mg/L stopped algae growth after 6 days and influenced coenobia structure (seen as disappearance of pyrenoids, deformation of cells) but did not decrease the number of cells in the coenobia. Caprolactam uptake is probably passive but relatively rapid. Maximum concentration in the algae was reached after 18-24 h.

  10. Growth characteristics of algae during early stages of phytoplankton bloom in Lake Taihu, China.

    PubMed

    Jia, Yuhong; Dan, Johnson; Zhang, Min; Kong, Fanxiang

    2013-02-01

    Three treatments, sediment plus lake water (S+W), sterilized sediment plus lake water (SS+W), and sediment plus filtered lake water (S+FW), were recruited to investigate the growth characteristics of algae during pre-bloom and the importance of algal inocula in the water column and sediment. The results showed that in the water column, biomass of all algae increased in all treatments when recruitment was initiated, whereas this tendency differed among treatments with further increment of temperature. The process of algal growth consisted of two stages: Stage I, the onset of recruitment and Stage II, the subsequent growth of algae. Compared with S+W, in Stage I, SS+W significantly increased the biomass of cyanophytes by 178.70%, and decreased the biomass of non-cyanophytes by 43.40%; In Stage II, SS+W notably stimulated the growth of all algae, thus incurring the occurrence of phytoplankton bloom. Further analyses revealed that both metabolic activity and photochemical activity of algae were enhanced in SS+W, which resulted from the releasing of nutrients from sediment. These results suggest that algal growth in Stage II and algal inocula in the water column can be important factors for the formation of phytoplankton bloom. In addition, possible mechanisms promoting algal recruitment and subsequent growth of algae were explored.

  11. Freshwater algae competition and correlation between their growth and microcystin production.

    PubMed

    Álvarez, Xana; Valero, Enrique; Cancela, Ángeles; Sánchez, Ángel

    2016-11-01

    There are some different freshwater algae in Eutrophic reservoirs which bloom with specific environmental conditions, and some of them are cyanobacteria. In this investigation, we have cultivated microalgae present in natural water samples from a eutrophic reservoir. Variations in temperature and light were evaluated, as well as the competition among different green algae and cyanobacteria. There were three different freshwater algae growing together, Scenedesmus sp., Kirchneriella sp. and Microcystis aeruginosa, this cyanobacterium was the algae that reached the highest development and growth during the culture. While the algae grew, the concentration of toxin (microcystin-LR) increased until it reached the highest levels at 570 μg g(-1). Blooms occurred at temperatures of 28 ± 1.5 °C and light cycles of longer hours of light than dark. This took place during the summer months, from June to September (in the study area). At temperatures below 18 °C, algae did not grow. Blooms were reproduced to a laboratory scale in different conditions in order to understand the development of freshwater algae, as well as to help decision-making about water supply from that reservoir.

  12. The effect of cadmium on the growth and antioxidant response for freshwater algae Chlorella vulgaris.

    PubMed

    Cheng, Jinfeng; Qiu, Hongchen; Chang, Zhaoyang; Jiang, Zaimin; Yin, Wenke

    2016-01-01

    The objective of the present work was to evaluate the effect of exogenously applied cadmium on the physiological response of green algae Chlorella vulgaris. The study investigated the long-term effect (18 days) of cadmium on the levels of algae biomass, assimilation pigment composition, soluble protein, oxidative status (production of hydrogen peroxide and superoxide anion), antioxidant enzymes (such as superoxide dismutase, peroxidase, catalase and glutathione reductase enzyme) in C. vulgaris. The results showed that growth, the amount of chlorophyll a (Chl a), chlorophyll b (Chl b) and carotenoids gradually decreased with increasing cadmium over 18 days exposure. Cadmium at concentration of 7 mg L(-1) inhibited algal growth expressed as the number of cells. Our research found that C. vulgaris has a high tolerance to cadmium. Contents of chlorophylls (Chl a and Chl b) and carotenoids (Car) of C. vulgaris was significantly decline with rising concentration of cadmium (p < 0.05). The decrease of 54.04 and 93.37 % in Chl a, 60.65 and 74.32 % in Chl b, 50.00 and 71.88 % in total carotenoids was noticed following the treatment with 3 and 7 mg L(-1) cadmium doses compared with control treatment, respectively. Cadmium treatments caused a significant change in the physiological competence (calculated as chlorophyll a/b) which increased with increasing Cd(II) doses up to 1 mg L(-1) but decreased at 3 mg L(-1). While accumulation of soluble protein was enhanced by presence of cadmium, the treatment with cadmium at 3 and 7 mg L(-1) increased the concentration of soluble proteins by 88, 95.8 % in C. vulgaris, respectively. Moreover, low doses of cadmium stimulated enzymatic (superoxide dismutase, catalase and glutathione reductase) in C. vulgaris, The content of peroxidase increased with the increasing cadmium concentration, and had slightly decreased at the concentration of 7 mg L(-1), but was still higher than control group, which showed that cadmium

  13. Bioconvective patterns, synchrony, and survival. [in light-limited growth model of motile algae culture

    NASA Technical Reports Server (NTRS)

    Noever, David A.

    1990-01-01

    With and without bioconvective pattern formation, a theoretical model predicts growth in light-limited cultures of motile algae. At the critical density for pattern formation, the resulting doubly exponential population curves show an inflection. Such growth corresponds quantitatively to experiments in mechanically unstirred cultures. This attaches survival value to synchronized pattern formation.

  14. Bioassays with unicellular algae: deviations from exponential growth and its implications for toxicity test results.

    PubMed

    Altenburger, Rolf; Schmitt-Jansen, Mechthild; Riedl, Janet

    2008-01-01

    Growth assays with unicellular green algae are an established tool in ecotoxicological effect assessment for chemicals and environmental samples. From an ecological perspective it seems appropriate to use the growth rate as a process variable rather than a measure of biomass gain for calculating inhibitory effects of contaminants. The notion of simple exponential growth for the description of the population increase in undisturbed suspension cultures of unicellular green algae, however, seems to be an oversimplification. Experimental findings describe the increase in biomass, cell number, the development of cell volume distributions of populations, and the relationship between cell size and chlorophyll content for individual cells over one generation at a time resolution of 2-h intervals. It was observed that algal populations of Desmodesmus subspicatus show a time pattern of cell size growth; the average cell volume increases about sixfold, without corresponding increase in population size. This is followed by a distinct cell division phase with little gain in biomass. This synchronous growth behavior despite continuous illumination may be explained by the multiple fission characteristic of unicellular green algae which is an adaptation to cyclic light-dark changes in the environment. It might be controlled by an independent cell cycle clock. For routine regulatory testing fluorescence-based measurements rather than cell counting minimizes the confounding effect on toxicity determination. For investigations of time-dependent effects, e.g., by pulsed exposure, an alternative mechanistically based growth function for unicellular algae is proposed that accommodates for the observed growth pattern.

  15. Salicylhydroxamic acid (SHAM) inhibition of the dissolved inorganic carbon concentrating process in unicellular green algae

    SciTech Connect

    Goyal, A.; Tolbert, N.E. )

    1990-03-01

    Rates of photosynthetic O{sub 2} evolution, for measuring K{sub 0.5}(CO{sub 2} + HCO{sub 3}{sup {minus}}) at pH 7, upon addition of 50 micromolar HCO{sub 3}{sup {minus}} to air-adapted Chlamydomonas, Dunaliella, or Scenedesmus cells, were inhibited up to 90% by the addition of 1.5 to 4.0 millimolar salicylhydroxamic acid (SHAM) to the aqueous medium. The apparent K{sub i}(SHAM) for Chlamydomonas cells was about 2.5 millimolar, but due to low solubility in water effective concentrations would be lower. Salicylhydroxamic acid did not inhibit oxygen evolution or accumulation of bicarbonate by Scenedesmus cells between pH 8 to 11 or by isolated intact chloroplasts from Dunaliella. Thus, salicylhydroxamic acid appears to inhibit CO{sub 2} uptake, whereas previous results indicate that vanadate inhibits bicarbonate uptake. These conclusions were confirmed by three test procedures with three air-adapted algae at pH 7. Salicylhydroxamic acid inhibited the cellular accumulation of dissolved inorganic carbon, the rate of photosynthetic O{sub 2} evolution dependent on low levels of dissolved inorganic carbon (50 micromolar NaHCO{sub 3}), and the rate of {sup 14}CO{sub 2} fixation with 100 micromolar ({sup 14}C)HCO{sub 3}{sup {minus}}. Salicylhydroxamic acid inhibition of O{sub 2} evolution and {sup 14}CO{sub 2}-fixation was reversed by higher levels of NaHCO{sub 3}. Thus, salicylhydroxamic acid inhibition was apparently not affecting steps of photosynthesis other than CO{sub 2} accumulation. Although salicylhydroxamic acid is an inhibitor of alternative respiration in algae, it is not known whether the two processes are related.

  16. Comparing the effects of symbiotic algae (Symbiodinium) clades C1 and D on early growth stages of Acropora tenuis.

    PubMed

    Yuyama, Ikuko; Higuchi, Tomihiko

    2014-01-01

    Reef-building corals switch endosymbiotic algae of the genus Symbiodinium during their early growth stages and during bleaching events. Clade C Symbiodinium algae are dominant in corals, although other clades - including A and D - have also been commonly detected in juvenile Acroporid corals. Previous studies have been reported that only molecular data of Symbiodinium clade were identified within field corals. In this study, we inoculated aposymbiotic juvenile polyps with cultures of clades C1 and D Symbiodinium algae, and investigated the different effect of these two clades of Symbiodinium on juvenile polyps. Our results showed that clade C1 algae did not grow, while clade D algae grew rapidly during the first 2 months after inoculation. Polyps associated with clade C1 algae exhibited bright green fluorescence across the body and tentacles after inoculation. The growth rate of polyp skeletons was lower in polyps associated with clade C1 algae than those associated with clade D algae. On the other hand, antioxidant activity (catalase) of corals was not significantly different between corals with clade C1 and clade D algae. Our results suggested that clade D Symbiodinium algae easily form symbiotic relationships with corals and that these algae could contribute to coral growth in early symbiosis stages.

  17. Comparing the Effects of Symbiotic Algae (Symbiodinium) Clades C1 and D on Early Growth Stages of Acropora tenuis

    PubMed Central

    Yuyama, Ikuko; Higuchi, Tomihiko

    2014-01-01

    Reef-building corals switch endosymbiotic algae of the genus Symbiodinium during their early growth stages and during bleaching events. Clade C Symbiodinium algae are dominant in corals, although other clades — including A and D — have also been commonly detected in juvenile Acroporid corals. Previous studies have been reported that only molecular data of Symbiodinium clade were identified within field corals. In this study, we inoculated aposymbiotic juvenile polyps with cultures of clades C1 and D Symbiodinium algae, and investigated the different effect of these two clades of Symbiodinium on juvenile polyps. Our results showed that clade C1 algae did not grow, while clade D algae grew rapidly during the first 2 months after inoculation. Polyps associated with clade C1 algae exhibited bright green fluorescence across the body and tentacles after inoculation. The growth rate of polyp skeletons was lower in polyps associated with clade C1 algae than those associated with clade D algae. On the other hand, antioxidant activity (catalase) of corals was not significantly different between corals with clade C1 and clade D algae. Our results suggested that clade D Symbiodinium algae easily form symbiotic relationships with corals and that these algae could contribute to coral growth in early symbiosis stages. PMID:24914677

  18. Effects of chlorpyrifos on the growth and ultrastructure of green algae, Ankistrodesmus gracilis.

    PubMed

    Asselborn, Viviana; Fernández, Carolina; Zalocar, Yolanda; Parodi, Elisa R

    2015-10-01

    The effect of the organophosphorus insecticide chlorpyrifos on the growth, biovolume, and ultrastructure of the green microalga Ankistrodesmus gracilis was evaluated. Concentrations of 9.37, 18.75, 37.5, 75 and 150mgL(-1) of chlorpyrifos were assayed along with a control culture. At the end of the bioassay the ultrastructure of algal cells from control culture and from cultures exposed to 37.5 and 150mgL(-1) was observed under transmission (TEM) and scanning electron microscopy (SEM). After 24 and 48h, treatments with 75 and 150mgL(-1) inhibited the growth of A. gracilis; whereas after 72 and 96h, all the treatments except at 9.37mgL(-1) significantly affected the algae growth. The effective concentration 50 (EC50) after 96h was 22.44mgL(-1) of chlorpyrifos. After the exposure to the insecticide, an increase in the biovolume was observed, with a larger increase in cells exposed to 75 and 150mgL(-1). Radical changes were observed in the ultrastructure of cells exposed to chlorpyrifos. The insecticide affected the cell shape and the distribution of the crests in the wall. At 37.5mgL(-1) electodense bodies were observed along with an increase in the size and number of starch granules. At 150mgL(-1) such bodies occupied almost the whole cytoplasm together with lipids and remains of thylakoids. Autospores formation occurred normally at 37.5mgL(-1) while at 150mgL(-1) karyokinesis occurred, but cell-separation-phase was inhibited. The present study demonstrates that the exposure of phytoplankton to the insecticide chlorpyrifos leads to effects observed at both cellular and population level.

  19. The Shewanella algae strain YM8 produces volatiles with strong inhibition activity against Aspergillus pathogens and aflatoxins

    PubMed Central

    Gong, An-Dong; Li, He-Ping; Shen, Lu; Zhang, Jing-Bo; Wu, Ai-Bo; He, Wei-Jie; Yuan, Qing-Song; He, Jing-De; Liao, Yu-Cai

    2015-01-01

    Aflatoxigenic Aspergillus fungi and associated aflatoxins are ubiquitous in the production and storage of food/feed commodities. Controlling these microbes is a challenge. In this study, the Shewanella algae strain YM8 was found to produce volatiles that have strong antifungal activity against Aspergillus pathogens. Gas chromatography-mass spectrometry profiling revealed 15 volatile organic compounds (VOCs) emitted from YM8, of which dimethyl trisulfide was the most abundant. We obtained authentic reference standards for six of the VOCs; these all significantly reduced mycelial growth and conidial germination in Aspergillus; dimethyl trisulfide and 2,4-bis(1,1-dimethylethyl)-phenol showed the strongest inhibitory activity. YM8 completely inhibited Aspergillus growth and aflatoxin biosynthesis in maize and peanut samples stored at different water activity levels, and scanning electron microscopy revealed severely damaged conidia and a complete lack of mycelium development and conidiogenesis. YM8 also completely inhibited the growth of eight other agronomically important species of phytopathogenic fungi: A. parasiticus, A. niger, Alternaria alternate, Botrytis cinerea, Fusarium graminearum, Fusarium oxysporum, Monilinia fructicola, and Sclerotinia sclerotiorum. This study demonstrates the susceptibility of Aspergillus and other fungi to VOCs from marine bacteria and indicates a new strategy for effectively controlling these pathogens and the associated mycotoxin production during storage and possibly in the field. PMID:26500631

  20. Recovery of photosynthesis and growth rate in green, blue-green, and diatom algae after exposure to atrazine.

    PubMed

    Brain, Richard A; Arnie, Joshua R; Porch, John R; Hosmer, Alan J

    2012-11-01

    We evaluated the recovery of photosynthesis and growth rate in green (Pseudokirchneriella subcapitata), blue-green (Anabaena flos-aquae), and diatom (Navicula pelliculosa) algae after pulsed exposure to atrazine. Subsequent to a grow-up period of 24 to 72 h to establish requisite cell density for adequate signal strength to measure photosystem II (PSII) quantum yield, algae were exposed to a pulse of atrazine for 48 h followed by a 48-h recovery period in control media. Photosynthesis was measured at 0, 3, 6, 12, 24, and 48 h of the exposure and recovery phases using pulse amplitude modulation fluorometry; growth rate and cell density were also concomitantly measured at these time points. Exposure to atrazine resulted in immediate, but temporary, inhibition of photosynthesis and growth; however, these effects were transient and fully reversible in the tested species of algae. For all three algal species, no statistically significant reductions (p ≤ 0.05) in growth rate or PSII quantum yield were detected at any of the treatment concentrations 48 h after atrazine was removed from the test system. Effects at test levels up to the highest tested exposure levels were consequently determined to be algistatic (reversible). Both biochemically and physiologically, recovery of photosynthesis and growth rate occur immediately, reaching control levels within hours following exposure. Therefore, pulsed exposure profiles of atrazine typically measured in Midwestern U.S. streams are unlikely to result in biologically meaningful changes in primary production given that the effects of atrazine are temporary and fully reversible in species representative of native populations.

  1. Well having inhibited microbial growth

    DOEpatents

    Lee, Brady D.; Dooley, Kirk J.

    2006-08-15

    The invention includes methods of inhibiting microbial growth in a well. A packing material containing a mixture of a first material and an antimicrobial agent is provided to at least partially fill a well bore. One or more access tubes are provided in an annular space around a casing within the well bore. The access tubes have a first terminal opening located at or above a ground surface and have a length that extends from the first terminal opening at least part of the depth of the well bore. The access tubes have a second terminal opening located within the well bore. An antimicrobial material is supplied into the well bore through the first terminal opening of the access tubes. The invention also includes well constructs.

  2. Variation in natural selection for growth and phlorotannins in the brown alga Fucus vesiculosus.

    PubMed

    Jormalainen, V; Honkanen, T

    2004-07-01

    Directional selection for plant traits associated with resistance to herbivory tends to eliminate genetic variation in such traits. On the other hand, balancing selection arising from trade-offs between resistance and growth or spatially variable selection acts against the elimination of genetic variation. We explore both the amount of genetic variation and variability of natural selection for growth and concentration of phenolic secondary compounds, phlorotannins, in the brown alga Fucus vesiculosus. We measured variation in selection at two growing depths and two levels of nutrient availability in algae that had faced two kinds of past growing environments. Genetic variation was low for growth but high for phlorotannins. The form and strength of selection for both focal traits depended on the past growing environment of the algae. We found strong directional selection for growth rate in algae previously subjected to higher ultraviolet radiation, but not in algae previously subjected to higher nutrient availability. Stabilizing selection for growth occurred especially in the deep growing environment. Selection for phlorotannins was generally weak, but in some past-environment-current-environment combinations we detected either directional selection against phlorotannins or stabilizing selection. Thus, phlorotannins are not selectively neutral but affect the fitness of F. vesiculosus. In particular, there may be a fitness cost of producing phlorotannins, but the realization of such a cost varies from one environment to another. Genetic correlations between selective environments were high for growth but nonexistent for phlorotannins, emphasizing the high phenotypic plasticity of phlorotannin production. The highly heterogeneous selection, including directional, stabilizing, and spatially variable selection as well as temporal change in selection due to responses to past environmental conditions, probably maintains a high amount of genetic variation in phlorotannins

  3. Responses of marine unicellular algae to brominated organic compounds in six growth media

    SciTech Connect

    Walsh, G.E.; Yoder, M.J.; McLaughlin, L.L.; Lores, E.M.

    1987-12-01

    Marine unicellular algae, Skeletonema costatum, Thalassiosira pseudonana, and Chlorella sp. were exposed to the industrial brominated compounds tetrabromobisphenol A, decabromobiphenyloxide (DBBO), hexabromocyclododecane (HBCD), pentabromomethylbenzene (PBMB), pentabromoethylbenzene (PBEB), and the herbicide bromoxynil (BROM), in six algal growth media. High concentrations of DBBO (1 mg liter-1), PBMB (1 mg liter-1), and PBEB (0.5 mg liter-1) reduced growth by less than 50%. EC50s of the other compounds varied with growth medium, with high EC50/low EC50 ratios between 1.3 and 9.9. Lowest EC50s, 9.3 to 12.0 micrograms liter-1, were obtained with S. costatum and HBCD. It is concluded that responses to toxicants in different media are the results of interactions among algae, growth medium, toxicant, and solvent carrier.

  4. Dimethylsulphopropionate (DMSP) and proline from the surface of the brown alga Fucus vesiculosus inhibit bacterial attachment.

    PubMed

    Saha, M; Rempt, M; Gebser, B; Grueneberg, J; Pohnert, G; Weinberger, F

    2012-01-01

    It was demonstrated previously that polar and non-polar surface extracts of the brown alga Fucus vesiculosus collected during winter from the Kiel Bight (Germany) inhibited bacterial attachment at natural concentrations. The present study describes the bioassay-guided identification of the active metabolites from the polar fraction. Chromatographic separation on a size-exclusion liquid chromatography column and bioassays identified an active fraction that was further investigated using nuclear magnetic resonance spectroscopy and mass spectrometry. This fraction contained the metabolites dimethylsulphopropionate (DMSP), proline and alanine. DMSP and proline caused the anti-attachment activity. The metabolites were further quantified on the algal surface together with its associated boundary layer. DMSP and proline were detected in the range 0.12-1.08 ng cm(-2) and 0.09-0.59 ng cm(-2), respectively. These metabolites were tested in the concentration range from 0.1 to 1000 ng cm(-2) against the attachment of five bacterial strains isolated from algae and sediment co-occurring with F. vesiculosus. The surface concentrations for 50% inhibition of attachment of these strains were always <0.38 ng cm(-2) for DMSP and in four cases <0.1 ng cm(-2) for proline, while one strain required 1.66 ng cm(-2) of proline for 50% inhibition. Two further bacterial strains that had been directly isolated from F. vesiculosus were also tested, but proved to be the least sensitive. This study shows that DMSP and proline have an ecologically relevant role as surface inhibitors against bacterial attachment on F. vesiculosus.

  5. Microcystins and cyanophyte extracts inhibit or promote the photosynthesis of fluvial algae. Ecological and management implications.

    PubMed

    García-Espín, Laura; Cantoral, Enrique A; Asencio, Antonia D; Aboal, Marina

    2017-04-05

    The ecological influence of cyanotoxins on aquatic biota remains unclear despite the numerous published references on toxicological and sanitary problems related with cyanophyte proliferation. The effects of microcystins and cyanophyte extracts on the photosynthesis of the algae that belong to two taxonomic groups, Rhodophyta and Bacillariophyta, were studied in an attempt to elucidate their role in the intraspecific competence and physiognomy of fluvial communities. The data showed that both cyanobacteria extracts and pure microcystin-LR affected the photosynthetic activity of all the tested organisms, diatoms (Fistulifera pelliculosa, Gomphonema parvulum, Nitzschia frustulum and Stephanodiscus minutulus) and red algae (Chroothece richteriana) at environmentally relevant concentrations. Effects varied with strains and time, and promoted or inhibited photosynthesis. The microcystins and the other compounds present in cyanobacteria extracts may explain the competence effects observed in nature, especially in calcareous environments where they predominate, and after disturbing events like heavy rains or floods, which may destroy cyanophyte mats and release toxic or inhibitory compounds in a seasonal scale pattern.

  6. Fucoidan Inhibits the Growth of Hepatocellular Carcinoma Independent of Angiogenesis

    PubMed Central

    Zhu, Cong; Cao, Rui; Zhang, Shuang-Xia; Man, Ya-Nan; Wu, Xiong-Zhi

    2013-01-01

    Some sulphated polysaccharides can bind bFGF but are unable to present bFGF to its high-affinity receptors. Fucoidan, a sulphated polysaccharide purified from brown algae, which has been used as an anticancer drug in traditional Chinese medicine for hundreds of years, exhibits a variety of anticancer effects, including the induction of the apoptosis and autophagy of cancer cells, the inhibition of the growth of cancer cells, the induction of angiogenesis, and the improvement of antitumour immunity. Our research shows that fucoidan dose not inhibit the expressions of VEGF, bFGF, IL-8, and heparanase in HCC cells and/or tumour tissues. Moreover, fucoidan exhibited low affinity for bFGF and could not block the binding of bFGF to heparan sulphated. Although fucoidan had no effect on angiogenesis and apoptosis in vivo, this drug significantly inhibited the tumour growth and the expression of PCNA. These results suggest that fucoidan exhibits an anticancer effect in vivo at least partly through inhibition of the proliferation of HCC cells, although it is unable to suppress the angiogenesis induced by HCC. PMID:23737842

  7. Nutrient cycling and the growth of benthic algae in experimentally acidified Little Rock Lake, WI

    SciTech Connect

    Detenbeck, N.E.

    1987-01-01

    Changes in nutrient-cycling and the growth of benthic algae resulting from decreased pH in low alkalinity lake systems were analyzed by laboratory, mesocosm, and whole-lake studies on Little Rock Lake, Wisconsin. Nutrients, transparency, an algal growth in the experimentally acidified basin were compared with conditions in an untreated reference basin. During the first summer following acidification (1985), accumulation rates of attached algae were significantly higher in the acidified basin than in the reference basin during June-August, but not in September. Color and winter silica values were significantly lower in the acidified basin relative to the reference basin following treatment. In addition, the lack of a fall decline in SiO/sub 2/ in the north basin in 1986 may signal pH-related changes in siliceous algal communities.

  8. [Food value of spiruline algae for growth of the broiler-type chicken].

    PubMed

    Blum, J C; Calet, C

    1975-01-01

    Five trials were carried out during the growth (0-8 weeks) of the broiler type chicken. The weight increase was always depressed when spiruline algae replaced traditional protein sources (soybean meal, fish meal, ...) in a complete and well balanced diet (trials 1 and 2). The delay in growth was small and non significant for 5 p. 100 or less of spirulines in the diet. However, for the highest levels of spirulines the delay in growth was more pronounced, especially during the starting period (0-4 weeks): live weight gain was reduced from 16 and 26 per cent for the spirulines levels of 20 and 30 p. 100. Different methods (live weight gain, balance technique, body analysis) were used for the determination of the protein and energy efficiencies. Spirulines were fed at different levels, either added to a protein free diet (trial 3), or included with other protein sources in complete diets (trial 4). Both protein and energy efficiencies were reduced when the spiruline level increased. Thus, the protein efficiency of the spirulines was found to be similar to that of the other traditional protein sources (soybean, fish,...) for a level lower than 10 p. 100. In contrast, it was reduced (--20 p. 100) when more than 20 p. 100 of algae were included in the diet. The average metabolizable energy was 2,487 kcal per kilogram when 20 and 30 p. 100 of algae were added in the protein free diet. In the complete diets, this value was found to be smaller or greater according to the level of spirulines, 30 p. 100 reduced and 5 p. 100 increased the energy value. The poor digestibility of some glucidic fraction in the algae seems responsible for the low energy value and for the reduced growth performance. The addition of a glycolytic enzyme to the diet failed to improve the performance (trial 5).

  9. Inhibition of nitrification in municipal wastewater-treating photobioreactors: Effect on algal growth and nutrient uptake.

    PubMed

    Krustok, I; Odlare, M; Truu, J; Nehrenheim, E

    2016-02-01

    The effect of inhibiting nitrification on algal growth and nutrient uptake was studied in photobioreactors treating municipal wastewater. As previous studies have indicated that algae prefer certain nitrogen species to others, and because nitrifying bacteria are inhibited by microalgae, it is important to shed more light on these interactions. In this study allylthiourea (ATU) was used to inhibit nitrification in wastewater-treating photobioreactors. The nitrification-inhibited reactors were compared to control reactors with no ATU added. Microalgae had higher growth in the inhibited reactors, resulting in a higher chlorophyll a concentration. The species mix also differed, with Chlorella and Scenedesmus being the dominant genera in the control reactors and Cryptomonas and Chlorella dominating in the inhibited reactors. The nitrogen speciation in the reactors after 8 days incubation was also different in the two setups, with N existing mostly as NH4-N in the inhibited reactors and as NO3-N in the control reactors.

  10. Growth assays with mixed cultures of cyanobacteria and algae assessed by in vivo fluorescence: One step closer to real ecosystems?

    PubMed

    Gregor, Jakub; Jancula, Daniel; Marsálek, Blahoslav

    2008-02-01

    A growth toxicity assay with mixed cultures of cyanobacteria and algae using in vivo fluorescence is presented. Test organisms (the green alga Pseudokirchneriella subcapitata and the cyanobacterium Aphanothece clathrata) growing alone and in a mixture were exposed to selected chemicals. P. subcapitata featured a higher sensitivity to toxicants in the presence of A. clathrata compared to the single species assay. On the other hand, growth of a cyanobacterium was not affected by the presence or absence of the green alga. The proposed method seems to be suitable for pre-screening studies of toxicants (algistatic agents, herbicides) applied into the aquatic environment and for the assessment of their impact on natural phytoplankton communities.

  11. Effects of substrate concentrations on the growth of heterotrophic bacteria and algae in secondary facultative ponds.

    PubMed

    Kayombo, S; Mbwette, T S A; Katima, J H Y; Jorgensen, S E

    2003-07-01

    This paper presents the effect of substrate concentration on the growth of a mixed culture of algae and heterotrophic bacteria in secondary facultative ponds (SFPs) utilizing settled domestic sewage as a sole source of organic carbon. The growth of the mixed culture was studied at the concentrations ranging between 200 and 800 mg COD/l in a series of batch chemostat reactors. From the laboratory data, the specific growth rate (micro) was determined using the modified Gompertz model. The maximum specific growth rate ( micro(max)) and half saturation coefficients (K(s)) were calculated using the Monod kinetic equation. The maximum observed growth rate ( micro(max)) for heterotrophic bacteria was 3.8 day(-1) with K(s) of 200 mg COD/l. The micro(max) for algal biomass based on suspended volatile solids was 2.7 day(-1) with K(s) of 110 mg COD/l. The micro(max) of algae based on the chlorophyll-a was 3.5 day(-1) at K(s) of 50mg COD/l. The observed specific substrate removal by heterotrophic bacteria varied between the concentrations of substrate used and the average value was 0.82 (mg COD/mg biomass). The specific substrate utilization rate in the bioreactors was direct proportional to the specific growth rate. Hence, the determined Monod kinetic parameters are useful for the definition of the operation of SFPs.

  12. Growth condition study of algae function in ecosystem for CO2 bio-fixation.

    PubMed

    Tsai, David Dah-Wei; Ramaraj, Rameshprabu; Chen, Paris Honglay

    2012-02-06

    Algae niche play a crucial role on carbon cycle and have great potential for CO(2) sequestration. This study was to investigate the CO(2) bio-fixation by the high rate pond (HRP) to mimic the algae function of nature. All the reactors can keep CO(2) consumption efficiencies over 100%. The statistical analyses proved HRPs were close to the natural system from all the growth conditions. The HRP could show the "natural optimization as nature" to perform as well as the artificial reactor of continuously stirred tank reactor (CSTR). In the nutrition study, the carbon mass balance indicated CO(2) was the main carbon source. Accordingly, the HRPs can keep a neutral pH range to provide dissolved oxygen (DO), to promote total nitrogen (TN)/total phosphorous (TP) removal efficiencies and to demonstrate self-purification process. Furthermore, the observations of different nitrogen species in the reactors demonstrated that the major nitrogen source was decided by pH. This finding logically explained the complex nitrogen uptake by algae in nature. Consequently, this study took advantage of HRP to explore the processes of efficient CO(2) uptake with the corresponding growth condition in the ecosystem. Those results contributed the further understanding of the role of CO(2) bio-fixation in nature and demonstrated HRP could be a potential ecological engineering alternative.

  13. Azoxystrobin-induced excessive reactive oxygen species (ROS) production and inhibition of photosynthesis in the unicellular green algae Chlorella vulgaris.

    PubMed

    Liu, Lei; Zhu, Bin; Wang, Gao-Xue

    2015-05-01

    This study investigated the short-term toxicity of azoxystrobin (AZ), one of strobilurins used as an effective fungicidal agent to control the Asian soybean rust, on aquatic unicellular algae Chlorella vulgaris. The median percentile inhibition concentration (IC₅₀) of AZ for C. vulgaris was found to be 510 μg L(-1). We showed that the algal cells were obviously depressed or shrunk in 300 and 600 μg L(-1) AZ treatments by using the electron microscopy. Furthermore, 19, 75, and 300 μg L(-1) AZ treatments decreased the soluble protein content and chlorophyll concentrations in C. vulgaris and altered the energy-photosynthesis-related mRNA expression levels in 48- and 96-h exposure periods. Simultaneously, our results showed that AZ could increase the total antioxidant capacity (T-AOC) level and compromise superoxide dismutase (SOD), peroxidase (POD), glutathione S transferase (GST), glutathione peroxidase (GPx) activities, and glutathione (GSH) content. These situations might render C. vulgaris more vulnerable to oxidative damage. Overall, the present study indicated that AZ might be toxic to the growth of C. vulgaris, affect energy-photosynthesis-related mRNA expressions, and induce reactive oxygen species (ROS) overproduction in C. vulgaris.

  14. [Generalized behavior study on the growth dynamics for dominant algae species forming algal bloom in the three Gorges reservoir region].

    PubMed

    Liu, Xin-an; Feng, Li; Jia, Charles Q

    2008-08-01

    From the blue-green algae species a representative algae, namely, ChloreUlla vulgaris (CV)to belong to Chlorophyta is selected as one of algae species studied in order to investigate the effect of TN, TP on the growth behavior of CV with the Monod equation, and calculate the semi-saturation constants of CV to TP(K(SP)) and TN(K(SN)). K(SN) > K(SP) showed that the effect of TP on growth of CV is obvious significant than that of TN. The growth rate of Chlorella vulgaris is very sensitive to the concentration of phosphorus: Compares with the blank value, the special growth rate (mu) has been enhanced under the low concentration of 0.002 mg x L(-1), then the concentration turned to 0.2 mg x L(-1) the special growth rate (mu) has been enhanced obviously; but there was hardly any change under the concentration of nitrogen from 0.000 to 0.050 mg x L(-1). At the same time, in order to reveal whether there was a generalized character associating the growth dynamics of CV with that of dominant blue-green algae species, the dynamic models including CV constructed from our experimental data, dominant blue-green algae and sea algae from literature information have been compared and analyzed systemically, and the results showed that their growth dynamics behavior and ecological characteristic were extremely similar and common. According to extrapolation of the intercommunity of all growth dynamics we could describe and show availably there is a common behavior to the growth of dominant blue-green algae in the Three Gorges reservoir region. This conclusion would have some important theoretical and applied significance.

  15. Growth and Metabolism of the Green Alga, Chlorella Pyrenoidosa, in Simulated Microgravity

    NASA Technical Reports Server (NTRS)

    Mills, W. Ronald

    2003-01-01

    The effect of microgravity on living organisms during space flight has been a topic of interest for some time, and a substantial body of knowledge on the subject has accumulated. Despite this, comparatively little information is available regarding the influence of microgravity on algae, even though it has been suggested for long duration flight or occupancy in space that plant growth systems, including both higher plants and algae, are likely to be necessary for bioregenerative life support systems. High-Aspect-Ratio Rotating-Wall Vessel or HARV bioreactors developed at Johnson Space Center provide a laboratory-based approach to investigating the effects of microgravity on cellular reactions. In this study, the HARV bioreactor was used to examine the influence of simulated microgravity on the growth and metabolism of the green alga, Chlorella pyrenoidosa. After the first 2 days of culture, cell numbers increased more slowly in simulated microgravity than in the HARV gravity control; after 7 days, growth in simulated microgravity was just over half (58%) that of the gravity control and at 14 days it was less than half (42%). Chlorophyll and protein were also followed as indices of cell competence and function; as with growth, after 2-3 days, protein and chlorophyll levels were reduced in modeled microgravity compared to gravity controls. Photosynthesis is a sensitive biochemical index of the fitness of photosynthetic organisms; thus, CO2-dependent O2 evolution was tested as a measure of photosynthetic capacity of cells grown in simulated microgravity. When data were expressed with respect to cell number, modeled microgravity appeared to have little effect on CO2 fixation. Thus, even though the overall growth rate was lower for cells cultured in microgravity, the photosynthetic capacity of the cells appears to be unaffected. Cells grown in simulated microgravity formed loose clumps or aggregates within about 2 days of culture, with aggregation increasing over time

  16. Effects of Cd, Cu, Ni, and Zn on brown tide alga Aureococcus anophagefferens growth and metal accumulation.

    PubMed

    Wang, Bin; Axe, Lisa; Michalopoulou, Zoi-Heleni; Wei, Liping

    2012-01-03

    Trace metals play important roles in regulating phytoplankton growth and could influence algal bloom development. Laboratory studies were conducted to evaluate the influence of environmentally relevant concentrations of Cd, Cu, Ni, and Zn on Aureococcus anophagefferens bloom (brown tide) development. Results show that the elevated Ni(2+) concentrations, e.g. those of brown tide waters in the northeastern US, greatly stimulated A. anophagefferens growth (as compared to the control without Ni addition), yet, only low amounts of dissolved Ni were sequestered, thus leaving excessive Ni directly promoting A. anophagefferens blooms. The medium effective concentration EC(50) (Me(2+)) suggests A. anophagefferens has similar Cd sensitivity but much greater Cu tolerance as compared to cyanobacteria, as such, excessive Cu could indirectly promote A. anophagefferens blooms by inhibiting competitors such as Synechococcus sp. The effects of Ni and Cu promoting growth are consistent with the recent genomic study of this alga. In addition, Zn(2+) concentrations lower than those in brown tide waters enhance A. anophagefferens growth, but Zn sequestration in A. anophagefferens would not substantially reduce total dissolved Zn in these waters. Overall, this study, showing that excessive Cu and Ni likely promote brown tides, provides evidence for trace metal linkages in algal bloom development.

  17. [Annual variation of different phosphorus forms and response of algae growth in Meiliang bay of Taihu Lake].

    PubMed

    Wang, Ming; Wu, Xiao-fei; Li, Da-peng; Li, Xiang; Huang, Yong

    2015-01-01

    Based on the monthly investigations of different forms of phosphorus(P) and algae growth from January to December 2013 in Meiliang bay of Taihu Lake, the transformation of different P forms and the relationship between different P forms and algae growth was investigated under the dual conditions of disturbance due to wind and wave and algae growth. Results of the total P(TP), particulate P (PP), dissolved total P(DTP), dissolved inorganic P(DIP) and bioavailable P(BAP) showed that the monthly concentrations reached the maximum in summer and autumn while the minimum in winter and spring. In addition, the algae growth showed the same trends as above. However, no variation was found in the dissolved organic P(DOP) and bioavailable particulate P(BAPP). The bioavailability of PP was only 12.75% from June to October, which was obviously lower than the annual mean (37.14%). It was attributed to the acceleration on the transformation of PP to DTP due to the immobilization of sedimentary P under sediment disturbance and algae adsorption. The percentage of DTP in BAP was up to 69.33% (average), which was obviously higher than the percentage of bioavailable PP (30.66%, average) and the annual mean (56.63%) of DTP during the interval. In addition, the algae bloom appeared in the interval.

  18. Effect of wastewater-borne bacteria on algal growth and nutrients removal in wastewater-based algae cultivation system.

    PubMed

    Ma, Xiaochen; Zhou, Wenguang; Fu, Zongqiang; Cheng, Yanling; Min, Min; Liu, Yuhuan; Zhang, Yunkai; Chen, Paul; Ruan, Roger

    2014-09-01

    Centrate, a type of nutrient-rich municipal wastewater was used to determine the effect of wastewater-borne bacteria on algal growth and nutrients removal efficiency in this study. The characteristics of algal and bacterial growth profiles, wastewater nutrient removal and effect of initial algal inoculums were systematically examined. The results showed that initial algal concentration had apparent effect on bacterial growth, and the presence of bacteria had a significant influence on algal growth pattern, suggesting symbiotic relationship between algae and bacteria at the initial stage of algae cultivation. The maximum algal biomass of 2.01 g/L with 0.1g/L initial algal inoculums concentration can be obtained during algae cultivation in raw centrate medium. The synergistic effect of centrate-borne bacteria and microalgae on algae growth and nutrient removal performance at initial fast growth stage has great potential to be applied to pilot-scale wastewater-based algae wastewater system cultivated in continuous or semi-continuous mode.

  19. Reduced graphene oxide induces cytotoxicity and inhibits photosynthetic performance of the green alga Scenedesmus obliquus.

    PubMed

    Du, Shaoting; Zhang, Peng; Zhang, Ranran; Lu, Qi; Liu, Lin; Bao, Xiaowei; Liu, Huijun

    2016-12-01

    Increased use of graphene materials might ultimately lead to their release into the environment. However, only a few studies have investigated the impact of graphene-based materials on green plants. In this study, the impact of reduced graphene oxide (RGO) on the microalgae Scenedesmus obliquus was evaluated to determine its phytotoxicity. Treatment with RGO suppressed the growth of the microalgae. The 72-h IC50 values of RGO evaluated using the logistic and Gompertz models were 148 and 151 mg L(-1), respectively. RGO significantly inhibited Chl a and Chl a/b levels in the algal cells. Chlorophyll a fluorescence analysis showed that RGO significantly down-regulated photosystem II activity. The mechanism of how RGO inhibited algal growth and photosynthetic performance was determined by analyzing the alterations in ultrastructural morphology. RGO adhered to the algal cell surface as a semitranslucent coating. Cell wall damage and membrane integrity loss occurred in the treated cells. Moreover, nuclear chromatin clumping and starch grain number increase were noted. These changes might be attributed to the increase in malondialdehyde and reactive oxygen species levels, which might have exceeded the scavenging ability of antioxidant enzymes (including peroxidase and superoxide dismutase). RGO impaired the extra- and intra-cellular morphology and increased oxidative stress and thus inhibited algal growth and photosynthesis.

  20. Impacts of ambient salinity and copper on brown algae: 1. Interactive effects on photosynthesis, growth, and copper accumulation.

    PubMed

    Connan, Solène; Stengel, Dagmar B

    2011-07-01

    The effect of copper enrichment and salinity on growth, photosynthesis and copper accumulation of two temperate brown seaweeds, Ascophyllum nodosum and Fucus vesiculosus, was investigated in laboratory experiments. A significant negative impact of reduced salinity on photosynthetic activity and growth was observed for both species. After 15 days at a salinity of 5, photosynthesis of A. nodosum was entirely inhibited and growth ceased at a salinity of 15. Increased copper concentration negatively affected photosynthetic activity of A. nodosum and F. vesiculosus resulting in chlorosis and reduced seaweed growth; 5 mg L⁻¹ copper caused an inhibition of the photosynthesis and the degradation of seaweed tips. Under reduced salinity, copper toxicity was enhanced and caused an earlier impact on the physiology of seaweed tips. After exposure to copper and different salinities for 15 days, copper contents of seaweeds were closely related to copper concentration in the water; seaweed copper contents reached their maximum after 1 day of exposure; contents only increased again when additional, free copper was added to the water. At high water copper concentrations or low salinity, or a combination of both, copper content of A. nodosum decreased. By contrast, copper content of F. vesiculosus increased, suggesting that different binding sites or uptake mechanisms exist in the two species. The results suggest that when using brown seaweeds in biomonitoring in situ, any change in the environment will directly and significantly affect algal physiology and thus their metal binding capacity; the assessment of the physiological status of the algae in combination with the analysis of thallus metal content will enhance the reliability of the biomonitoring process.

  1. Aqueous Extracts of the Marine Brown Alga Lobophora variegata Inhibit HIV-1 Infection at the Level of Virus Entry into Cells

    PubMed Central

    Kremb, Stephan; Helfer, Markus; Kraus, Birgit; Wolff, Horst; Wild, Christian; Schneider, Martha; Voolstra, Christian R.; Brack-Werner, Ruth

    2014-01-01

    In recent years, marine algae have emerged as a rich and promising source of molecules with potent activities against various human pathogens. The widely distributed brown alga Lobophora variegata that is often associated with tropical coral reefs exerts strong antibacterial and antiprotozoal effects, but so far has not been associated with specific anti-viral activities. This study investigated potential HIV-1 inhibitory activity of L. variegata collected from different geographical regions, using a cell-based full replication HIV-1 reporter assay. Aqueous L. variegata extracts showed strong inhibitory effects on several HIV-1 strains, including drug-resistant and primary HIV-1 isolates, and protected even primary cells (PBMC) from HIV-1-infection. Anti-viral potency was related to ecological factors and showed clear differences depending on light exposition or epiphyte growth. Assays addressing early events of the HIV-1 replication cycle indicated that L. variegata extracts inhibited entry of HIV-1 into cells at a pre-fusion step possibly by impeding mobility of virus particles. Further characterization of the aqueous extract demonstrated that even high doses had only moderate effects on viability of cultured and primary cells (PBMCs). Imaging-based techniques revealed extract effects on the plasma membrane and actin filaments as well as induction of apoptosis at concentrations exceeding EC50 of anti-HIV-1 activity by more than 400 fold. In summary, we show for the first time that L. variegata extracts inhibit HIV-1 entry, thereby suggesting this alga as promising source for the development of novel HIV-1 inhibitors. PMID:25144758

  2. Aqueous extracts of the marine brown alga Lobophora variegata inhibit HIV-1 infection at the level of virus entry into cells.

    PubMed

    Kremb, Stephan; Helfer, Markus; Kraus, Birgit; Wolff, Horst; Wild, Christian; Schneider, Martha; Voolstra, Christian R; Brack-Werner, Ruth

    2014-01-01

    In recent years, marine algae have emerged as a rich and promising source of molecules with potent activities against various human pathogens. The widely distributed brown alga Lobophora variegata that is often associated with tropical coral reefs exerts strong antibacterial and antiprotozoal effects, but so far has not been associated with specific anti-viral activities. This study investigated potential HIV-1 inhibitory activity of L. variegata collected from different geographical regions, using a cell-based full replication HIV-1 reporter assay. Aqueous L. variegata extracts showed strong inhibitory effects on several HIV-1 strains, including drug-resistant and primary HIV-1 isolates, and protected even primary cells (PBMC) from HIV-1-infection. Anti-viral potency was related to ecological factors and showed clear differences depending on light exposition or epiphyte growth. Assays addressing early events of the HIV-1 replication cycle indicated that L. variegata extracts inhibited entry of HIV-1 into cells at a pre-fusion step possibly by impeding mobility of virus particles. Further characterization of the aqueous extract demonstrated that even high doses had only moderate effects on viability of cultured and primary cells (PBMCs). Imaging-based techniques revealed extract effects on the plasma membrane and actin filaments as well as induction of apoptosis at concentrations exceeding EC50 of anti-HIV-1 activity by more than 400 fold. In summary, we show for the first time that L. variegata extracts inhibit HIV-1 entry, thereby suggesting this alga as promising source for the development of novel HIV-1 inhibitors.

  3. Biomass or growth rate endpoint for algae and aquatic plants: relevance for the aquatic risk assessment of herbicides.

    PubMed

    Bergtold, Matthias; Dohmen, Gerhard Peter

    2011-04-01

    Ecotoxicological studies with algae and aquatic plants are essential parts of the aquatic risk assessment for crop protection products (CPP). Growth rate is used as a response variable and in addition the effects on biomass and/or yield (in the following biomass) can be measured. The parameter biomass generally provides a lower numerical value compared with the growth rate for systematic and mathematical reasons. Therefore, some regulators prefer to use the EbC50 value (i.e., the concentration at which 50% reduction of biomass is observed) rather than ErC50 (the concentration at which a 50% inhibition of growth rate is observed) as the endpoint for ecotoxicological risk assessment. However, the parameter growth rate is scientifically more appropriate and robust against deviations in test conditions, permitting better interpretation of, and comparison between, studies. The aim of the present work is to evaluate the growth rate and biomass parameters with regard to their protectiveness and suitability for environmental risk assessment of CPP. It has been shown for a number of herbicides that the use of the EC50 value (without distinction between growth rate and biomass endpoints) from laboratory studies in combination with an assessment factor of 10 is sufficiently protective for aquatic plants (except for the herbicide 2,4-D). In this paper we evaluated EbC50 and ErC50 values separately. Data on 19 different herbicides were compiled from the literature or GLP reports. The EbC50 and ErC50 values obtained in laboratory studies were compared with effect concentrations in ecosystem studies (mainly mesocosm). This comparison of laboratory and field data shows that the overall aquatic risk assessment using ErC50 values in combination with the currently applied assessment factor of 10 is sufficient to exclude significant risk to aquatic plants in the environment.

  4. Effects of algae growth on cadmium remobilization and ecological risk in sediments of Taihu Lake.

    PubMed

    Ni, Lixiao; Li, Dandan; Su, Lili; Xu, Jiajun; Li, Shiyin; Ye, Xiang; Geng, Hong; Wang, Peifang; Li, Yi; Li, Yiping; Acharya, Kumud

    2016-05-01

    Indoor simulation experiment with 2.76 L microcosms using sediment from Taihu Lake were conducted to investigate the relationship between algae bloom and heavy metals release into a lake aquatic environment. The results showed that Microcystic aeruginosa (M. aeruginosa) growth can enhance cadmium (Cd) mobilization from sediments to overlying water due to increasing pH and DO content of overlying water and changing the redox condition of surface sediment (0-2 cm) from weak oxidation to weak reduction. The dissolved Cd concentration in overlying water can be decreased during algal growth process. The remobilization of Cd from sediment can effectively reduce the ecological risk of total Cd in sediments. The results of this study showed that both Igeo and Er(i) can be used to effectively evaluate the ecological risk of heavy metal Cd in different fractions.

  5. Analysis of algae growth mechanism and water bloom prediction under the effect of multi-affecting factor.

    PubMed

    Wang, Li; Wang, Xiaoyi; Jin, Xuebo; Xu, Jiping; Zhang, Huiyan; Yu, Jiabin; Sun, Qian; Gao, Chong; Wang, Lingbin

    2017-03-01

    The formation process of algae is described inaccurately and water blooms are predicted with a low precision by current methods. In this paper, chemical mechanism of algae growth is analyzed, and a correlation analysis of chlorophyll-a and algal density is conducted by chemical measurement. Taking into account the influence of multi-factors on algae growth and water blooms, the comprehensive prediction method combined with multivariate time series and intelligent model is put forward in this paper. Firstly, through the process of photosynthesis, the main factors that affect the reproduction of the algae are analyzed. A compensation prediction method of multivariate time series analysis based on neural network and Support Vector Machine has been put forward which is combined with Kernel Principal Component Analysis to deal with dimension reduction of the influence factors of blooms. Then, Genetic Algorithm is applied to improve the generalization ability of the BP network and Least Squares Support Vector Machine. Experimental results show that this method could better compensate the prediction model of multivariate time series analysis which is an effective way to improve the description accuracy of algae growth and prediction precision of water blooms.

  6. Menaquinone Analogs Inhibit Growth of Bacterial Pathogens

    PubMed Central

    Merriman, Joseph A.; Salgado-Pabón, Wilmara; Mueller, Elizabeth A.; Spaulding, Adam R.; Vu, Bao G.; Chuang-Smith, Olivia N.; Kohler, Petra L.; Kirby, John R.

    2013-01-01

    Gram-positive bacteria cause serious human illnesses through combinations of cell surface and secreted virulence factors. We initiated studies with four of these organisms to develop novel topical antibacterial agents that interfere with growth and exotoxin production, focusing on menaquinone analogs. Menadione, 1,4-naphthoquinone, and coenzymes Q1 to Q3 but not menaquinone, phylloquinone, or coenzyme Q10 inhibited the growth and to a greater extent exotoxin production of Staphylococcus aureus, Bacillus anthracis, Streptococcus pyogenes, and Streptococcus agalactiae at concentrations of 10 to 200 μg/ml. Coenzyme Q1 reduced the ability of S. aureus to cause toxic shock syndrome in a rabbit model, inhibited the growth of four Gram-negative bacteria, and synergized with another antimicrobial agent, glycerol monolaurate, to inhibit S. aureus growth. The staphylococcal two-component system SrrA/B was shown to be an antibacterial target of coenzyme Q1. We hypothesize that menaquinone analogs both induce toxic reactive oxygen species and affect bacterial plasma membranes and biosynthetic machinery to interfere with two-component systems, respiration, and macromolecular synthesis. These compounds represent a novel class of potential topical therapeutic agents. PMID:23959313

  7. Menaquinone analogs inhibit growth of bacterial pathogens.

    PubMed

    Schlievert, Patrick M; Merriman, Joseph A; Salgado-Pabón, Wilmara; Mueller, Elizabeth A; Spaulding, Adam R; Vu, Bao G; Chuang-Smith, Olivia N; Kohler, Petra L; Kirby, John R

    2013-11-01

    Gram-positive bacteria cause serious human illnesses through combinations of cell surface and secreted virulence factors. We initiated studies with four of these organisms to develop novel topical antibacterial agents that interfere with growth and exotoxin production, focusing on menaquinone analogs. Menadione, 1,4-naphthoquinone, and coenzymes Q1 to Q3 but not menaquinone, phylloquinone, or coenzyme Q10 inhibited the growth and to a greater extent exotoxin production of Staphylococcus aureus, Bacillus anthracis, Streptococcus pyogenes, and Streptococcus agalactiae at concentrations of 10 to 200 μg/ml. Coenzyme Q1 reduced the ability of S. aureus to cause toxic shock syndrome in a rabbit model, inhibited the growth of four Gram-negative bacteria, and synergized with another antimicrobial agent, glycerol monolaurate, to inhibit S. aureus growth. The staphylococcal two-component system SrrA/B was shown to be an antibacterial target of coenzyme Q1. We hypothesize that menaquinone analogs both induce toxic reactive oxygen species and affect bacterial plasma membranes and biosynthetic machinery to interfere with two-component systems, respiration, and macromolecular synthesis. These compounds represent a novel class of potential topical therapeutic agents.

  8. Inhibition of granulation tissue growth by histamine.

    PubMed

    Saeki, K; Yokoyama, J; Wake, K

    1975-06-01

    Granulomas were induced in rats by subcutaneous implantation of formalin-soaked filter-paper disks. Daily subcutaneous injection of histamine at doses of two times 0.05 mg/kg and above inhibited the growth of granulation tissue as measured by a marked decrease in the dry-defatted granuloma weight and of the hydroxyproline and hexosamine content. Histological observations of granulation tissue indicated that histamine inhibited the proliferation of fibroblasts and the formation of capillaries. Inhibitory effects were also observed with the histamine releaser, sinomenine, and the histaminase inhibitor, aminoguanidine. These histamine effects seem not to be mediated by glucocorticoid release, since an effective dose level of histamine produced no change in growth or thymus weight. Prednisolone was less potent than histamine in inhibiting Prednisolone was ineffective at the dose tested. Subcutaneous injection of the H2-receptor antagonist, burimamide, blocked these histamine effects and also of sinomeinine and aminoguanidine. The H1-receptor antagonist, mepyramine, did not block these histamine effects. Burimamide alone enhanced the growth of granuloma. These results indicate that granulation-tissue growth in inflammation is affected by the inhibitory effect of endogenous histamine acting through H2-receptors.

  9. Bacterial contact-dependent growth inhibition (CDI)

    PubMed Central

    Ruhe, Zachary C.; Low, David A.; Hayes, Christopher S.

    2013-01-01

    Bacteria cooperate to form multicellular communities and compete against one another for environmental resources. Here, we review recent advances in our understanding of bacterial competition mediated by contact-dependent growth inhibition (CDI) systems. Different CDI+ bacteria deploy a variety of toxins to inhibit neighboring cells and protect themselves from autoinhibition by producing specific immunity proteins. The genes encoding CDI toxin–immunity pairs appear to be exchanged between cdi loci and are often associated with other toxin-delivery systems in diverse bacteria. CDI also appears to facilitate cooperative behavior between kin, suggesting that these systems may have other roles beyond competition. PMID:23473845

  10. [Behavior of evolution and growth of dominant algae in the Chongqing urban section along the Three-Gorges valley].

    PubMed

    Liu, Xin-An; Zhang, Mi-Fang

    2008-07-01

    Through sampling and analyzing algae species in natural water-body of the Yangtze river and the Jialing river located at Chongqing urban section along the Three-Gorges valley, and combining with monitoring on the influencing parameters to algae growth, such as TN/TP, light intensities and current velocities by experimental simulation, the effect on the algae propagation behavior has been studied systemically. The results show that under static hydrological condition with various TN/TP and light intensities the Chlorophyta and Cyanophyta would grow rapidly while the Bacillariophyta disappear quickly, and other algae species had little change, and the total algal cell density could exceed 10(7) cells/L. However, even if under lower current velocity as about 0.03 m/s, the total algae cell density would increase at most obviously while its density could only reach 10(6) cells/L, and the proportion of Bacillariophyta would increase with the increase of current velocity, the proportion of Chlorophyta and Cyanophyta begin decrease at same time. Apparently, evolution of the dominant algae species would take place according to the change of hydrological condition. The density of total algae is primal regressed to TN/TP and current velocities with coefficients of determination (R2) are all over 0.93 while it has lower regression coefficient with the light intensities. The samples analysis of the above two rivers under natural state also demonstrates that total algae density in the Jialing river is higher than that in the Yangtze river, and the Bacillariophyta has the absolute domination, and then are Cyanophyta and Chlorophyta, which fit in with the experimental results in our laboratory.

  11. Inhibition of growth of Ulva expansa (chlorophyta) by ultraviolet-B radiation

    SciTech Connect

    Grobe, C.W.; Murphy, T.M.

    1994-10-01

    We examined the effect of ultraviolet-B radiation (UV-B, 290-320 nm) on the growth rate of the intertidal marine alga Ulva expansa (Setch.) S & G. (Chlorophyta). Segments of thallus collected from a natural population were grown in outdoor seawater tanks. Combinations of UV-B-opaque screens, UV-B transparent screens, and UV-B lamps were used to investigate the effects of solar UV-B and solar plus supplemental UV-B on the growth of these segments. Growth was measured by changes in segment surface area, damp weight, and dry weight. Growth rates of segments were inhibited under both solar UV-B and solar plus supplemental UV-B treatments. Growth rates were also inhibited by high levels of photosynthetically active radiation, independent of UV-B fluence. These results indicate that increases in UV-B resulting from further ozone depletion will have a negative impact on the growth of this alga. 32 refs., 5 figs., 2 tabs.

  12. Effect propagation in a toxicokinetic/toxicodynamic model explains delayed effects on the growth of unicellular green algae Scenedesmus vacuolatus.

    PubMed

    Vogs, Carolina; Bandow, Nicole; Altenburger, Rolf

    2013-04-01

    Ecotoxicological standard tests assess toxic effects by exposing an organism to high concentrations over defined periods of time. To evaluate toxicity under field conditions such as fluctuating and pulsed exposures, process-based toxicokinetic/toxicodynamic (TK/TD) models may be used for extrapolation from the existing evidence. A TK/TD model was developed that simulates the effect on growth of the green algae Scenedesmus vacuolatus continuously exposed to the model chemicals norflurazon, triclosan, and N-phenyl-2-naphthylamine. A pharmacological time-response model describing the effects of anticancer treatments on cancer cell growth was adapted and modified to model the affected growth of synchronized algae cells. The TK/TD model simulates the temporal effect course by linking the ambient concentration of a chemical to the observable adverse effect via an internal concentration and a sequence of biological events in the organism. The parameters of the toxicodynamic model are related to the growth characteristics of algae cells, a no effect concentration, the chemical efficacy as well as the ability of recovery and repair, and the delay during damage propagation. The TK/TD model fits well to the observed algae growth. The effect propagation through cumulative cell damage explained the observed delayed responses better than just the toxicokinetics. The TK/TD model could facilitate the link between several effect levels within damage propagation, which prospectively may be helpful to model adverse outcome pathways and time-dependent mixture effects.

  13. [Effects of marine bacteria on the growth and toxin production of red-tide algae under different pH and salinities].

    PubMed

    Su, Jianqiang; Zheng, Tianling; Hu, Zhong; Xu, Jingsen; Yu, Zhiming; Song, Xiuxian

    2003-07-01

    The effects of strain S10 isolated from sediments of Xiamen Western Sea Area on the growth and paralytic shellfish poison (PSP) production of Alexandrium tamarense at different pH and salinities were studied. The results showed that the alga grew well at pH 6-8 and at salinity of 20-34. The toxicity of A. tamarense varied markedly at different pH and salinities: it decreased with increasing pH, while increased with salinity and reached its peak value at the salinity of 30, and then declined. The strain S10 inhibited the growth and the PSP production of A. tamarense at different pH and salinities. It had the best inhibitory function on the growth of A. tamarense at pH 7 and salinity of 34. The best inhibitory function on the PSP production of A. tamarense was at pH 7, but this inhibitory function was not related to salinity.

  14. Selective protein depletion impairs bone growth and causes liver fatty infiltration in female rats: prevention by Spirulina alga.

    PubMed

    Fournier, C; Rizzoli, R; Bouzakri, K; Ammann, P

    2016-11-01

    Chronic protein malnutrition leads to child mortality in developing countries. Spirulina alga (Spi), being rich in protein and growing easily, is a good candidate as supplementation. We showed that Spi completely prevents bone growth retardation and liver disturbances observed in young rats fed a low protein diet. This supports Spi as a useful source of vegetable protein to fight against protein malnutrition.

  15. Impact of aeration disturbances on endogenous phosphorus fractions and their algae growth potential from malodorous river sediment.

    PubMed

    Zhu, Jin; He, Yan; Wang, Jianhua; Qiao, Zhaochao; Wang, Yi; Li, Zhihong; Huang, Minsheng

    2017-03-01

    The present work assessed the impact of aeration disturbances on sediment-bound phosphorus fractions and their algae growth potential from a typical malodorous river. Phosphorus was sequentially extracted by a modified version of Hedley fractionation method. It was found that the mean contents of TP was 1476.1 ± 60.3 mg/kg, consisting mainly of dilute HCl-extractable P (52.6%) and NaOH-P (19.2%). The algae growth potential tests demonstrated that algae growth had varied P-level requirements for different P speciation and NaOH-P promoted algae growth remarkably and its promoting effect was positively related to its concentration. Additionally, intermittent overlying water aeration modes were recommended, and run 1 (7.0 mg/L, 12 h) was deemed as the optimized aerated mode in terms of its relatively low ecological risk and high P retention. It was noted that NaOH-P was most affected by aeration disturbance and exhibited marked increase with the elevated dissolved oxygen (DO) level whether for intermittent overlying water or sediment aeration. This research helps to gain improved understanding of the ecological risk on sediment P, and NaOH-P is recognized as one ecologically important P fraction in the sediments considering its relatively high proportion and bioavailability.

  16. Potency of (doped) rare earth oxide particles and their constituent metals to inhibit algal growth and induce direct toxic effects.

    PubMed

    Joonas, Elise; Aruoja, Villem; Olli, Kalle; Syvertsen-Wiig, Guttorm; Vija, Heiki; Kahru, Anne

    2017-03-27

    Use of rare earth elements (REEs) has increased rapidly in recent decades due to technological advances. It has been accompanied by recurring rare earth element anomalies in water bodies. In this work we (i) studied the effects of eight novel doped and one non-doped rare earth oxide (REO) particles (aimed to be used in solid oxide fuel cells and gas separation membranes) on algae, (ii) quantified the individual adverse effects of the elements that constitute the (doped) REO particles and (iii) attempted to find a discernible pattern to relate REO particle physicochemical characteristics to algal growth inhibitory properties. Green algae Raphidocelis subcapitata (formerly Pseudokirchneriella subcapitata) were used as a test species in two different formats: a standard OECD201 algal growth inhibition assay and the algal viability assay (a 'spot test') that avoids nutrient removal effects. In the 24h 'spot' test that demonstrated direct toxicity, algae were not viable at REE concentrations above 1mgmetal/L. 72-hour algal growth inhibition EC50 values for four REE salts (Ce, Gd, La, Pr) were between 1.2 and 1.4mg/L, whereas the EC50 for REO particles ranged from 1 to 98mg/L. The growth inhibition of REEs was presumably the result of nutrient sequestration from the algal growth medium. The adverse effects of REO particles were at least in part due to the entrapment of algae within particle agglomerates. Adverse effects due to the dissolution of constituent elements from (doped) REO particles and the size or specific surface area of particles were excluded, except for La2NiO4. However, the structure of the particles and/or the varying effects of oxide composition might have played a role in the observed effects. As the production rates of these REO particles are negligible compared to other forms of REEs, there is presumably no acute risk for aquatic unicellular algae.

  17. Effect of Algae and Plant Lectins on Planktonic Growth and Biofilm Formation in Clinically Relevant Bacteria and Yeasts

    PubMed Central

    Vasconcelos, Mayron Alves; Arruda, Francisco Vassiliepe Sousa; Carneiro, Victor Alves; Silva, Helton Colares; Nascimento, Kyria Santiago; Sampaio, Alexandre Holanda; Cavada, Benildo; Teixeira, Edson Holanda; Henriques, Mariana

    2014-01-01

    This study aimed to evaluate the abilities of plant and algae lectins to inhibit planktonic growth and biofilm formation in bacteria and yeasts. Initially, ten lectins were tested on Staphylococcus epidermidis, Staphylococcus aureus, Klebsiella oxytoca, Pseudomonas aeruginosa, Candida albicans, and C. tropicalis at concentrations of 31.25 to 250 μg/mL. The lectins from Cratylia floribunda (CFL), Vatairea macrocarpa (VML), Bauhinia bauhinioides (BBL), Bryothamnion seaforthii (BSL), and Hypnea musciformis (HML) showed activities against at least one microorganism. Biofilm formation in the presence of the lectins was also evaluated; after 24 h of incubation with the lectins, the biofilms were analyzed by quantifying the biomass (by crystal violet staining) and by enumerating the viable cells (colony-forming units). The lectins reduced the biofilm biomass and/or the number of viable cells to differing degrees depending on the microorganism tested, demonstrating the different characteristics of the lectins. These findings indicate that the lectins tested in this study may be natural alternative antimicrobial agents; however, further studies are required to better elucidate the functional use of these proteins. PMID:24982871

  18. Ocean acidification alleviates low-temperature effects on growth and photosynthesis of the red alga Neosiphonia harveyi (Rhodophyta).

    PubMed

    Olischläger, Mark; Wiencke, Christian

    2013-12-01

    This study aimed to examine interactive effects between ocean acidification and temperature on the photosynthetic and growth performance of Neosiphonia harveyi. N. harveyi was cultivated at 10 and 17.5 °C at present (~380 µatm), expected future (~800 µatm), and high (~1500 µatm) pCO2. Chlorophyll a fluorescence, net photosynthesis, and growth were measured. The state of the carbon-concentrating mechanism (CCM) was examined by pH-drift experiments (with algae cultivated at 10 °C only) using ethoxyzolamide, an inhibitor of external and internal carbonic anhydrases (exCA and intCA, respectively). Furthermore, the inhibitory effect of acetazolamide (an inhibitor of exCA) and Tris (an inhibitor of the acidification of the diffusive boundary layer) on net photosynthesis was measured at both temperatures. Temperature affected photosynthesis (in terms of photosynthetic efficiency, light saturation point, and net photosynthesis) and growth at present pCO2, but these effects decreased with increasing pCO2. The relevance of the CCM decreased at 10 °C. A pCO2 effect on the CCM could only be shown if intCA and exCA were inhibited. The experiments demonstrate for the first time interactions between ocean acidification and temperature on the performance of a non-calcifying macroalga and show that the effects of low temperature on photosynthesis can be alleviated by increasing pCO2. The findings indicate that the carbon acquisition mediated by exCA and acidification of the diffusive boundary layer decrease at low temperatures but are not affected by the cultivation level of pCO2, whereas the activity of intCA is affected by pCO2. Ecologically, the findings suggest that ocean acidification might affect the biogeographical distribution of N. harveyi.

  19. Field study of growth and calcification rates of three species of articulated coralline algae in British Columbia, Canada.

    PubMed

    Fisher, K; Martone, P T

    2014-04-01

    Ocean acidification caused by rising atmospheric CO₂ is predicted to negatively impact growth and calcification rates of coralline algae. Decreases in coralline abundance may have cascading effects on marine ecosystems and on carbon sequestration worldwide. In this study, we measured growth and calcification rates of three common species of articulated coralline algae (Bossiella plumosa, Calliarthron tuberculosum, and Corallina vancouveriensis) at an intertidal field site in British Columbia. Linear growth rates measured in the field were slow, although Bossiella grew significantly faster (0.22 cm mon⁻¹) than Calliarthron and Corallina (0.17 and 0.15 cm mon⁻¹, respectively). Growth rates in the field were generally slower than growth rates in the laboratory, suggesting that data generated in the laboratory may not be representative of natural field conditions. Growth rates did not decrease as fronds approached their maximum observed size, suggesting that maximum frond size might be determined not by intrinsic factors but by external factors such as wave-induced drag forces. Using growth data, we estimate that the largest observed Bossiella frond (20 cm²) and Calliarthron frond (40 cm²) were about 4- and 11-years-old, respectively, and had deposited approximately 1 and 6 g CaCO₃ in that time. Given the great abundance of coralline algae along the coast of British Columbia, deposition rates of CaCO₃ are expected to play a significant but poorly characterized role in carbon sequestration.

  20. Growth and survival of Escherichia coli and enterococci populations in the macro-alga Cladophora (Chlorophyta)

    USGS Publications Warehouse

    Byappanahalli, M.N.; Shively, D.A.; Nevers, M.B.; Sadowsky, M.J.; Whitman, R.L.

    2003-01-01

    The macro-alga Cladophora glomerata is found in streams and lakes worldwide. High concentrations of Escherichia coli and enterococci have been reported in Cladophora along the Lake Michigan shore. The objective of this study was to determine if Cladophora supported growth of these indicator bacteria. Algal leachate readily supported in vitro multiplication of E. coli and enterococci, suggesting that leachates contain necessary growth-promoting substances. Growth was directly related to the concentration of algal leachate. E. coli survived for over 6 months in dried Cladophora stored at 4°C; residual E. coli grew after mat rehydration, reaching a carrying capacity of 8 log CFU g-1 in 48 h. Results of this study also show that the E. coli strains associated with Cladophora are highly related; in most instances they are genetically different from each other, suggesting that the relationship between E. coli and Cladophora may be casual. These findings indicate that Cladophora provides a suitable environment for indicator bacteria to persist for extended periods and to grow under natural conditions.

  1. Laurenditerpenol, a New Diterpene from the Tropical Marine Alga Laurencia intricata Potently Inhibits HIF-1 Mediated Hypoxic Signaling in Breast Tumor Cells

    PubMed Central

    Mohammed, Kaleem A.; Hossain, Chowdhury Faiz; Zhang, Lei; Bruick, Richard K.; Zhou, Yu-Dong; Nagle, Dale G.

    2010-01-01

    The degree of tumor hypoxia correlates with advanced disease stages and treatment resistance. The transcription factor hypoxia-inducible factor-1 (HIF-1) promotes tumor cell adaptation and survival under hypoxic conditions. Therefore, specific HIF-1 inhibitors represent an important new class of potential tumor-selective therapeutic agents. A T47D human breast tumor cell-based reporter assay was used to examine extracts of plants and marine organisms for inhibitors of HIF-1 activation. Bioassay-guided fractionation of the lipid extract of the red alga Laurencia intricata yielded a structurally novel diterpene laurenditerpenol (1). The structure of 1 was determined spectroscopically. The relative configurations of the substituents of each ring system were assigned based on NOESY correlations. The absolute configurations of positions C-1 was determined by the modified Mosher ester procedure (directly in NMR tubes). Compound 1 potently inhibited hypoxia-activated HIF-1 (IC50: 0.4 μM) and hypoxia-induced VEGF (a potent angiogenic factor) in T47D cells. Compound 1 selectively inhibits HIF-1 activation by hypoxia but not iron chelator induced activation. Further, 1 suppresses tumor cell survival under hypoxic conditions without affecting normoxic cell growth. Compound 1 inhibits HIF-1 by blocking the induction of the oxygen-regulated HIF-1α protein. Mitochondrial respiration studies revealed that 1 suppresses oxygen consumption. PMID:15620241

  2. Growth and lipid content at low temperature of Arctic alga Chlamydomonas sp. KNM0029C.

    PubMed

    Kim, Eun Jae; Jung, Woongsic; Lim, Suyoun; Kim, Sanghee; Han, Se Jong; Choi, Han-Gu

    2016-01-01

    Biodiesel produced from microalgae is a promising source of alternative energy. In winter, however, outdoor mass cultivation for biodiesel production is hampered by poor growth. Here, we report that Arctic Chlamydomonas sp. KNM0029C exhibits optimal growth at 4 °C and reaches densities up to 1.4 × 10(7) cells mL(-1). Lipid body formation in the alga was visualized through BODIPY 505/515 staining and fluorescence microscopy. The fatty acid methyl ester (FAME) production level of KNM0029C was 178.6 mg L(-1) culture and 2.3-fold higher than that of C. reinhardtii CC-125 at 4 °C. Analysis of the FAME content showed a predominance of polyunsaturated fatty acids such as C16:3, C18:2, C18:3, and C20:2. C18:3 fatty acids comprised the largest fraction (20.7%), and the content of polyunsaturated fatty acids (39.6%) was higher than that of saturated fatty acids (6.8%) at 4 °C. These results indicate that Chlamydomonas sp. KNM0029C, as a psychrophilic microalga, might represent a favorable source for biodiesel production in cold environments.

  3. The effect of lanthanides on photosynthesis, growth, and chlorophyll profile of the green alga Desmodesmus quadricauda.

    PubMed

    Řezanka, Tomáš; Kaineder, Katrin; Mezricky, Dana; Řezanka, Michal; Bišová, Kateřina; Zachleder, Vilém; Vítová, Milada

    2016-12-01

    Lanthanides (La, Gd, Nd, Ce) accumulated in the green alga Desmodesmus quadricauda but their intracellular localizations were distinctly different: lanthanum and gadolinium were localized in cytoplasm, while neodymium and cerium were in the chloroplast. The effect of lanthanum and neodymium, as representatives of these two groups, on growth, chlorophyll content and photosynthetic rate at different light intensities was studied. At the lowest light intensity used (50 µmol photons m(-2) s(-1)), in the presence of lanthanides (Nd), growth was enhanced by as much as 36 % over lanthanide free control, and the photosynthetic rate increased by up to 300 %. At high light intensities (238, 460, and 750 µmol photons m(-2) s(-1)), photosynthetic rate increased markedly, but there was no significant difference between rates in the presence or absence of lanthanides. However, growth, measured as a percentage of dry weight, if compared with lanthanide free control, increased at all light intensities (31, 39, and 20 %, respectively). The total amount of chlorophyll after lanthanide treatment increased by up to 21 % relative to the control culture, mainly due to an increase in the level of chlorophyll b. Addition of lanthanides caused a change in the chlorophyll a/b ratio from 4.583 in control cultivation, to 1.05. Possible mechanisms of lanthanide-induced photosynthetic change, alterations in photosynthetic structures, and increases in growth are discussed and compared with findings in higher plants. The hypothesis that the lanthanide effect could be due to formation of lanthanide-pheophytins was not confirmed as lanthanide pheophytins were not found in D. quadricauda. Furthermore, we have shown that the preferential incorporation of heavy isotopes of magnesium, namely (25)Mg and (26)Mg, into chlorophyll during photosynthesis that occurred in controls was diminished in the presence of lanthanides.

  4. Construction of a growth model in the green alga Tetraselmis subcordiformis using a response surface approach

    NASA Astrophysics Data System (ADS)

    Wang, Hui; Niu, Jingyan; Liu, Jiahui; Yang, Hongshuai; Liu, Zhigang

    2016-06-01

    The green alga Tetraselmis subcordiformis has been widely used as a quality live food for aquaculture species, and also has been studied as a model organism for the photo-biological production of hydrogen. We attempted to quantify the relationship between T. subcordiformis specific growth rate (SGR) and three important environmental factors (temperature, salinity, and pH) using the central composite design and response surface method under laboratory conditions. The results showed that the linear effects of temperature and salinity were significant (P< 0.05), and they were equally important in impacting T. subcordiformis specific growth; the linear effect of pH was not significant (P>0.05); the interactive effect of temperature and pH was significant (P<0.05), whereas the temperature × salinity and salinity × pH interactions were not significant (P>0.05); all of the quadratic effects of the three factors were significant (P<0.05). A model equation for specific growth rate with the three factors was established, with the unadjusted and predictive R 2 as high as 0.990 and 0.921, respectively, suggesting that the model was a very good fit and that it could be used to predict SGR. Through optimizing the reliable model, an optimal 3-factor combination of 25 °C/35 of salinity/pH 7.9 was obtained, at which the maximum specific growth rate (0.65) was recorded, with a desirability value of 93.8%. These experimental results could serve as guidelines for increasing T. subcordiformis production efficiency.

  5. The influence of extracellular compounds produced by selected Baltic cyanobacteria, diatoms and dinoflagellates on growth of green algae Chlorella vulgaris

    NASA Astrophysics Data System (ADS)

    Żak, Adam; Kosakowska, Alicja

    2015-12-01

    Secondary metabolites produced by bacteria, fungi, algae and plants could affect the growth and development of biological and agricultural systems. This natural process that occurs worldwide is known as allelopathy. The main goal of this work was to investigate the influence of metabolites obtained from phytoplankton monocultures on the growth of green algae Chlorella vulgaris. We selected 6 species occurring in the Baltic Sea from 3 different taxonomic groups: cyanobacteria (Aphanizomenon flos-aquae; Planktothrix agardhii), diatoms (Thalassiosira pseudonana; Chaetoceros wighamii) and dinoflagellates (Alexandrium ostenfeldii; Prorocentrum minimum). In this study we have demonstrated that some of selected organisms caused allelopathic effects against microalgae. Both the negative and positive effects of collected cell-free filtrates on C. vulgaris growth, chlorophyll a concentration and fluorescence parameters (OJIP, QY, NPQ) have been observed. No evidence has been found for the impact on morphology and viability of C. vulgaris cells.

  6. [Illumination's effect on the growth and nitrate reductase activity of typical red-tide algae in the East China Sea].

    PubMed

    Li, Hong-mei; Shi, Xiao-yong; Ding, Yan-yan; Tang, Hong-jie

    2013-09-01

    Two typical red-tide algae, Skeletonema costatum and Prorocentrum donghaiense were selected as studied objects. The nitrate reductase activity (NRA) and the growth of the two algae under different illuminations through incubation experiment were studied. The illumination condition was consistent with in situ. Results showed that P. donghaiense and S. costatum could grow normally in the solar radiation ranged from 30-60 W x m(-2), and the growth curve was "S" type. However, when solar radiation was below 9 W x m(-2), the two alga could hardly grow. In the range of 0-60 W x m(-2), three parameters (NRAmax, micro(max), Bf) increased with the increasing of light intensity, indicating that the light intensity can influence the grow of alga indirectly through influencing the nitrate reductase activity. The micro(max) and NRAmax in unite volume of Skeletonema costatum were higher than those of Prorocentrum donghaiense, indicating that Skeletonema costatum can better utilize the nitrate than Prorocentrum donghaiense.

  7. Quorum Sensing Inhibition by Asparagopsis taxiformis, a Marine Macro Alga: Separation of the Compound that Interrupts Bacterial Communication

    PubMed Central

    Jha, Bhavanath; Kavita, Kumari; Westphal, Jenny; Hartmann, Anton; Schmitt-Kopplin, Philippe

    2013-01-01

    The majority of the marine algal species, though completing their life cycle in seawater, are rarely susceptible to fouling, making them an important source of quorum sensing (QS) inhibitory substances. The separation and characterization of QS inhibitors are crucial for any potential application. Thirty marine macroalgae were tested for QS inhibition activity by using Chromobacterium violaceum CV026 as the reporter strain, and among them, Asparagopsis taxiformis showed antibacterial, as well as antiquorum, sensing activities. Cinnamaldehyde (75 mM) and methanol were used as positive and negative controls, respectively. The antiquorum sensing activity of A. taxiformis was further confirmed using the sensor strain, Serratia liquefaciens MG44, having green fluorescent protein (gfp). Methanolic extract of the alga was fractionated by solid phase extraction (SPE), and each fraction was tested for QS inhibition. Two types of activities were observed—zone of clearance (antibacterial activity) and zone of inhibition with or without finger-like projections (QS inhibition). Out of five SPE cartridges, Bond Elut PH showed clear separation of these two fractions. The Ion Cyclotron Resonance Fourier Transformation Mass Spectrometer (ICR-FT/MS) analysis of the fractions further supported the bioassay results. The presence of strong QS inhibitory compound in A. taxiformis indicates its potential use in antifouling preparations. PMID:23344114

  8. Sulfated polysaccharide from the marine algae Hypnea musciformis inhibits TNBS-induced intestinal damage in rats.

    PubMed

    V Brito, Tarcisio; Barros, Francisco C N; Silva, Renan O; Dias Júnior, Genilson J; C Júnior, José Simião; Franco, Álvaro X; Soares, Pedro M G; Chaves, Luciano S; Abreu, Clara M W S; de Paula, Regina C M; Souza, Marcellus H L P; Freitas, Ana Lúcia P; R Barbosa, André Luiz

    2016-10-20

    Sulfated polysaccharides extracted from seaweed have important pharmacological properties. Thus, the aim of this study was to characterize the sulfated polysaccharide (PLS) from the algae Hypnea musciformis and evaluate its protective effect in colitis induced by trinitrobenzene sulfonic acid in rats. The sulfated polysaccharide possess a high molecular mass (1.24×10(5)gmol(-1)) and is composed of a κ-carrageenan, as depicted by FT-IR and NMR spectroscopic data. PLS was administered orally (10, 30, and 60mg/kg, p.o.) for three days, starting before TNBS (trinitrobenzene sulfonic acid) instillation (day 1). The rats were killed on day three, the portion of distal colon (5cm) was excised and evaluated macroscopic scores and wet weight. Then, samples of the intestinal were used for histological evaluation and quantification of glutathione, malonyldialdehyde acid, myeloperoxidase, nitrate/nitrite and cytokines. Our results demonstrate that PLS reduced the colitis and all analyzed biochemical parameters. Thus, we concluded that the PLS extracted from the marine algae H. musciformis reduced the colitis in animal model and may have an important promising application in the inflammatory bowel diseases.

  9. Use of prolines for improving growth and other properties of plants and algae

    DOEpatents

    Unkefer, Pat J.; Knight, Thomas J.; Martinez, Rodolfo A.

    2004-12-14

    Increasing the concentration of prolines, such as 2-hydroxy-5-oxoproline, in the foliar portions of plants has been shown to cause an increase in carbon dioxide fixation, growth rate, dry weight, nutritional value (amino acids), nodulation and nitrogen fixation, photosynthetically derived chemical energy, and resistance to insect pests over the same properties for wild type plants. This can be accomplished in four ways: (1) the application of a solution of the proline directly to the foliar portions of the plant by spraying these portions; (2) applying a solution of the proline to the plant roots; (3) genetically engineering the plant and screening to produce lines that over-express glutamine synthetase in the leaves which gives rise to increased concentration of the metabolite, 2-hydroxy-5-oxoproline (this proline is also known as 2-oxoglutaramate); and (4) impairing the glutamine synthetase activity in the plant roots which causes increased glutamine synthetase activity in the leaves which gives rise to increased concentration of 2-hydroxy-5-oxoproline. Prolines have also been found to induce similar effects in algae.

  10. Use of prolines for improving growth and other properties of plants and algae

    DOEpatents

    Unkefer, Pat J.; Knight, Thomas J.; Martinez, Rodolfo A.

    2003-04-29

    Increasing the concentration of prolines such as 2-hydroxy-5-oxoproline, in the foliar portions of plants has been shown to cause an increase in carbon dioxide fixation, growth rate, dry weight, nutritional value (amino acids), nodulation and nitrogen fixation, photosynthetically derived chemical energy, and resistance to insect pests over the same properties for wild type plants. This can be accomplished in four ways: (1) the application of a solution of the proline directly to the foliar portions of the plant by spraying these portions; (2) applying a solution of the proline to the plant roots; (3) genetically engineering the plant and screening to produce lines that overexpress glutamine synthetase in the leaves which gives rise to increased concentration of the metabolite, 2-hydroxy-5-oxoproline (this proline is also known as 2-oxoglutaramnate); and (4) impairing the glutamine synthetase activity in the plant roots which causes increased glutamine synthetase activity in the leaves which gives rise to increased concentration of 2-hydroxy-5-oxoproline. Prolines have also been found to induce similar effects in algae.

  11. Use of prolines for improving growth and other properties of plants and algae

    DOEpatents

    Unkefer, Pat J.; Knight, Thomas J.; Martinez, Rodolfo A.

    2003-07-15

    Increasing the concentration of prolines, such as 2-hydroxy-5-oxoproline, in the foliar portions of plants has been shown to cause an increase in carbon dioxide fixation, growth rate, dry weight, nutritional value (amino acids), nodulation and nitrogen fixation, photosynthetically derived chemical energy, and resistance to insect pests over the same properties for wild type plants. This can be accomplished in four ways: (1) the application of a solution of the proline directly to the foliar portions of the plant by spraying these portions; (2) applying a solution of the proline to the plant roots; (3) genetically engineering the plant and screening to produce lines that over-express glutamine synthetase in the leaves which gives rise to increased concentration of the metabolite, 2-hydroxy-5-oxoproline (this proline is also known as 2-oxoglutaramate); and (4) impairing the glutamine synthetase activity in the plant roots which causes increased glutamine synthetase activity in the leaves which gives rise to increased concentration of 2-hydroxy-5-oxoproline. Prolines have also been found to induce similar effects in algae.

  12. The growth response of the green alga Chlorella vulgaris to combined divalent cation exposure.

    PubMed

    Rachlin, J W; Grosso, A

    1993-01-01

    Using the growth response of the green alga Chlorella vulgaris as a model system, the effects of combinations of the environmentally active cations Cd, Co, and Cu were evaluated. The 96-h static EC50 for these cations to C. vulgaris were, respectively, 0.89 microM, 9.0 microM, and 2.8 microM, yielding a toxicity series such that Cd > Cu > Co. The cation combinations of Cd + Cu, and Cu + Co acted synergistically, while Cd + Co, and the tri-metallic combination Cd + Cu + Co resulted in antagonistic interactions. Examination of these toxic combinations at 24, 48, 72, and 96 h indicate that the cellular response is not a uniform one. Failure of energy dispersive X-ray spectrophotometric analysis to demonstrate any intracellular incorporation of these cations (except for a weak cytoplasmic Cu peak at the 8.0 KEV position) suggests that the toxic actions of these cations at EC50 concentrations are exerted at the level of the plasma membrane.

  13. A novel alphaproteobacterial ectosymbiont promotes the growth of the hydrocarbon-rich green alga Botryococcus braunii

    PubMed Central

    Tanabe, Yuuhiko; Okazaki, Yusuke; Yoshida, Masaki; Matsuura, Hiroshi; Kai, Atsushi; Shiratori, Takashi; Ishida, Ken-ichiro; Nakano, Shin-ichi; Watanabe, Makoto M.

    2015-01-01

    Botryococcus braunii is a colony-forming green alga that accumulates large amounts of liquid hydrocarbons within the colony. The utilization of B. braunii for biofuel production is however hindered by its low biomass productivity. Here we describe a novel bacterial ectosymbiont (BOTRYCO-2) that confers higher biomass productivity to B. braunii. 16S rDNA analysis indicated that the sequence of BOTRYCO-2 shows low similarity (<90%) to cultured bacterial species and located BOTRYCO-2 within a phylogenetic lineage consisting of uncultured alphaproteobacterial clones. Fluorescence in situ hybridization (FISH) studies and transmission electric microscopy indicated that BOTRYCO-2 is closely associated with B. braunii colonies. Interestingly, FISH analysis of a water bloom sample also found BOTRYCO-2 bacteria in close association with cyanobacterium Microcystis aeruginosa colonies, suggesting that BOTRYCO-2 relatives have high affinity to phytoplankton colonies. A PCR survey of algal bloom samples revealed that the BOTRYCO-2 lineage is commonly found in Microcystis associated blooms. Growth experiments indicated that B. braunii Ba10 can grow faster and has a higher biomass (1.8-fold) and hydrocarbon (1.5-fold) yield in the presence of BOTRYCO-2. Additionally, BOTRYCO-2 conferred a higher biomass yield to BOT-22, one of the fastest growing strains of B. braunii. We propose the species name ‘Candidatus Phycosocius bacilliformis’ for BOTRYCO-2. PMID:26130609

  14. Triclosan causes toxic effects to algae in marine biofilms, but does not inhibit the metabolic activity of marine biofilm bacteria.

    PubMed

    Johansson, C Henrik; Janmar, Lisa; Backhaus, Thomas

    2014-07-15

    Effects of the antimicrobial agent triclosan to natural periphyton communities (biofilms, comprising primarily microalgae and bacteria) were assessed in two independent experiments during spring and summer. For that purpose a semi-static test system was used in which periphyton was exposed to a concentration range of 5-9054 nmol/L triclosan. Effects on algae were analyzed as content and composition of photosynthetic pigments. The corresponding EC50 values were 39.25 and 302.45 nmol/L for the spring and summer experiment, respectively. Effects on periphytic bacteria were assessed as effects on carbon utilization patterns, using Biolog Ecoplates. No inhibition of either total carbon utilization or functional diversity was observed, indicating a pronounced triclosan tolerance of the marine bacteria. In contrast, a small stimulation of the total carbon utilization was observed at triclosan concentrations exceeding 100 nmol/L.

  15. [Variation of nitrogen and phosphorus concentration in water-sediment system and influence of overlying water on the algae growth].

    PubMed

    Lu, Shao-yong; Jin, Xiang-can; Guo, Jian-ning; Sheng, Li

    2007-10-01

    The effect of biosidal treatment of initial sediment, addition of inhibitor and addition of phosphorus on the transform of nitrogen and phosphorus in the sediment-water simulative system were studied. S. quadricaudain was cultured in overlying waters took from the above experiment sets when the above experiment completed. The result indicated that, biosidal treatment enhanced the concentration of TP while there was no obvious effect on N. The TP, DTP and TN concentrations were closely between inhibitor addition set and the control set in the sediment-water simulative system but the content of NO3(-)-N of the set with inhibitor addition reached 19.2 mg x L(-1), which was much higher than that of the control set. The sediment significantly adsorbed the P added to the system, and the content of TP decreased when the system reached balance. Algae biomass of the biosidal treatment set was higher than that of the control set, and the main cause was sterilizer leaded to higher concentration of TP of the biosidal treatment set. The highest Algae biomass of the group with inhibitor (224.5 x 10(4) unit x L(-1)) was much higher than that of the control set (26 x 10(4) unit x L(-1)), and that was 5-10 times than that of other sets (sterilized set 22.5 x 10(4) unit x L(-1), set with P added 38.5 x 10(4) uni x L(-1)). Inhibitor restrained the microorganism from using some nutrition which was important to alga's growth. At the beginning, the addition of P had no remarkable effect on the alga growth, but along with the experiment, the alga of the P addition set adapted to the environment and algae biomass exceed that of the control set. The increase of biological bioavailable phosphorus of sediment in biosidal treatment set and addition of inhibitor sets were caused by the increase of algae biomass and thus the increase of liable organic phosphorus.

  16. Comparison of toxicity to terrestrial plants with algal growth inhibition by herbicides

    SciTech Connect

    Garten, C.T. Jr.; Frank, M.L.

    1984-10-01

    The toxicities of 21 different herbicides to algae (Selenastrum capricornutum and Chlorella vulgaris) and to terrestrial plants (radishes, barley, and bush beans or soybeans) were compared to order to determine the feasibility of using a short-term (96-h) algal growth inhibition test for identifying chemicals having potential toxicity in a 4-week terrestrial plant bioassay. The toxicity of each test chemical, usually in combination with a commercial formulation, was evaluated at six nominal concentrations, between 0 and 100 mg/L growth medium in the algal bioassay or between 0 and 100 mg/kg substate in the terrestrial plant bioassay, in terms of both (1) the no-observed-effect concentration (NOEC), i.e., the highest concentration tested at which no significant (P < 0.05, one-sided test) reduction in algal growth rate or in terrestrial plant yield, relative to controls, was observed; and (2) the concentration at which algal growth rate or terrestrial plant yield was reduced by 50% or more relative to controls. There was generally poor agreement between results from the two types of bioassays; results from algal growth inhibition tests were not significantly correlated with results from the terrestrial plant bioassays. Overall, there was an approximately 50% chance of an algal bioassay, using Selenastrum capricornutum, successfully screening (detecting) herbicide levels that reduced terrestrial plant yield. The results indicated that algal growth inhibition tests cannot be used generically to predict phytotoxicity of herbicides to terrestrial plant species. 7 references, 14 tables.

  17. Spirulan from blue-green algae inhibits fibrin and blood clots: its potent antithrombotic effects.

    PubMed

    Choi, Jun-Hui; Kim, Seung; Kim, Sung-Jun

    2015-05-01

    We investigated in vitro and in vivo fibrinolytic and antithrombotic activity of spirulan and analyzed its partial biochemical properties. Spirulan, a sulfated polysaccharide from the blue-green alga Arthrospira platensis, exhibits antithrombotic potency. Spirulan showed a strong fibrin zymogram lysis band corresponding to its molecular mass. It specifically cleaved Aα and Bβ, the major chains of fibrinogen. Spirulan directly decreased the activity of thrombin and factor X activated (FXa), procoagulant proteins. In vitro assays using human fibrin and mouse blood clots showed fibrinolytic and hemolytic activities of spirulan. Spirulan (2 mg/kg) showed antithrombotic effects in the ferric chloride (FeCl3 )-induced carotid arterial thrombus model and collagen and epinephrine-induced pulmonary thromboembolism mouse model. These results may be attributable to the prevention of thrombus formation and partial lysis of thrombus. Therefore, we suggest that spirulan may be a potential antithrombotic agent for thrombosis-related diseases.

  18. Effect of algae growth on aerobic granulation and nutrients removal from synthetic wastewater by using sequencing batch reactors.

    PubMed

    Huang, Wenli; Li, Bing; Zhang, Chao; Zhang, Zhenya; Lei, Zhongfang; Lu, Baowang; Zhou, Beibei

    2015-03-01

    The effect of algae growth on aerobic granulation and nutrients removal was studied in two identical sequencing batch reactors (SBRs). Sunlight exposure promoted the growth of algae in the SBR (Rs), forming an algal-bacterial symbiosis in aerobic granules. Compared to the control SBR (Rc), Rs had a slower granulation process with granules of loose structure and smaller particle size. Moreover, the specific oxygen uptake rate was significantly decreased for the granules from Rs with secretion of 25.7% and 22.5% less proteins and polysaccharides respectively in the extracellular polymeric substances. Although little impact was observed on chemical oxygen demand (COD) removal, algal-bacterial symbiosis deteriorated N and P removals, about 40.7-45.4% of total N and 44% of total P in Rs in contrast to 52.9-58.3% of TN and 90% of TP in Rc, respectively. In addition, the growth of algae altered the microbial community in Rs, especially unfavorable for Nitrospiraceae and Nitrosomonadaceae.

  19. Phlorotannins from brown algae (Fucus vesiculosus) inhibited the formation of advanced glycation endproducts by scavenging reactive carbonyls.

    PubMed

    Liu, Haiyan; Gu, Liwei

    2012-02-08

    Accumulation of advanced glycation end products (AGEs) in vivo is associated with aging, diabetes, Alzheimer's disease, renal failure, etc. The objective of this study was to investigate the inhibitory effects of brown algae Fucus vesiculosus phlorotannins on the formation of AGEs. F. vesiculosus phlorotannins were extracted using 70% acetone. The resultant extract was fractionated into dichloromethane, ethyl acetate, butanol, and water fractions. The ethyl acetate fraction was further fractionated into four subfractions (Ethyl-F1 to -F4) using a Sephadex LH-20 column. F. vesiculosus acetone extract or fractions significantly inhibited the formation of AGEs mediated by glucose and methylglyoxal in a concentration-dependent manner. The concentrations of F. vesiculosus extracts required to inhibit 50% of albumin glycation (EC(50)) in the bovine serum albumin (BSA)-methylglyoxal assay were lower than those of aminoguanidine (a drug candidate for diabetic complication), except for F. vesiculosus acetone extract and dichloromethane fraction. In the BSA-glucose assay, F. vesiculosus extracts inhibited BSA glycation more than or as effectively as aminoguanidine, except for Ethyl-F3 and -F4. The ethyl acetate fraction and its four subfractions scavenged more than 50% of methylglyoxal in two hours. The hypothesis whether F. vesiculosus phlorotannins scavenged reactive carbonyls by forming adducts was tested. Phloroglucinol, the constituent unit of phlorotannins, reacted with glyoxal and methylglyoxal. Five phloroglucinol-carbonyl adducts were detected and tentatively identified using HPLC-ESI-MS(n).

  20. Potential use of duckweed based anaerobic digester effluent as a feed source for heterotrophic growth of micro-algae

    NASA Astrophysics Data System (ADS)

    Ahmadi, L.; Dupont, R.

    2013-12-01

    Finding an alternative source of energy for the growing world's demand is a challenging task being considered by many scientists. Various types of renewable energy alternatives are being investigated by researchers around the world. The abundance of duckweed (i.e., Lemna and Wolfia sp.) in wetlands and wastewater lagoons, their rapid growth, and their capacity for nutrient, metal and other contaminant removal from wastewater suggests their potential as an inexpensive source of biomass for biofuel production. Another source of biomass for biofuel and energy production is micro-algae. The large-scale growth of micro-algae can potentially be achieved in a smaller footprint and at a higher rate and lower cost via heterotrophic growth compared to autotrophic growth for specific species that can grow under both conditions. Here we describe two types of research. First, two lab-scale, 5 L anaerobic digesters containing municipal raw wastewater that were set up, maintained and monitored over the course of 6 months using duckweed as the feed source. The pH, salinity, amount of gas production and gas composition were measured on a daily basis. The results from these measurements show that duckweed can be used as a good source of biofuel production in the form of methane gas. The second set of reactors consisted of two 1 L batch fed reactors containing algae (Chlorella vulgaris) grown in the lab environment heterotrophically. The pH and DO were monitored on a daily basis in order to investigate their effect on algae growth. Lipid analysis of the harvested algal biomass was done to investigate the efficiency of harvestable biofuel products. A nutrient solution containing glucose as an energy source was used as the initial feed solution, and the potential substitution of the glucose solution with the organic carbon residue from the duckweed digester effluent was investigated. Methane production, carbon stabilization, and gas composition results from the duckweed fed anaerobic

  1. Effects of TiO2 nanoparticles on the growth and metabolism of three species of freshwater algae

    NASA Astrophysics Data System (ADS)

    Cardinale, Bradley J.; Bier, Raven; Kwan, Courtney

    2012-08-01

    We examined how TiO2 nanoparticles ( nTiO2) impact the growth and metabolism of three species of freshwater green algae ( Scenedesmus quadricauda, Chlamydomonas moewusii, and Chlorella vulgaris) that are widespread throughout North America. We exposed laboratory cultures to five initial concentrations of nTiO2 (0, 50, 100, 200, and 300 ppm) and measured impacts on species population growth rates, as well as on metabolic rates of gross primary production (GPP) and respiration ( R). Population growth rates were consistently reduced by nTiO2, with reduction ranging from 11 to 27 % depending on the species. But the mechanisms of reduction differed among species. For Chlamydomonas, nTiO2 reduced both GPP and R, but effects on GPP were stronger. As a consequence, carbon was respired more quickly than it was fixed, leading to reduced growth. In contrast, nTiO2 stimulated both GPP and R in Chorella. But because R was stimulated to a greater extent than GPP, carbon loss again exceeded fixation, leading to reduced growth. For Scenedesmus, nTiO2 had no significant impact on R, but reduced GPP. This pattern also caused carbon loss to exceed fixation. Results suggest that nTiO2 may generally suppress the growth of pelagic algae, but these impacts are manifest through contrasting effects on species-specific metabolic functions. Because growth and metabolism of algae are fundamental to the functioning of ecosystems and the structure of aquatic food-webs, our study suggests nTiO2 has potential to alter important community and ecosystem properties of freshwater habitats.

  2. PDZ-binding kinase/T-LAK cell-originated protein kinase is a target of the fucoidan from brown alga Fucus evanescens in the prevention of EGF-induced neoplastic cell transformation and colon cancer growth.

    PubMed

    Vishchuk, Olesia S; Sun, Huimin; Wang, Zhe; Ermakova, Svetlana P; Xiao, JuanJuan; Lu, Tao; Xue, PeiPei; Zvyagintseva, Tatyana N; Xiong, Hua; Shao, Chen; Yan, Wei; Duan, Qiuhong; Zhu, Feng

    2016-04-05

    The fucoidan with high anticancer activity was isolated from brown alga Fucus evanescens. The compound effectively prevented EGF-induced neoplastic cell transformation through inhibition of TOPK/ERK1/2/MSK 1 signaling axis. In vitro studies showed that the fucoidan attenuated mitogen-activated protein kinases downstream signaling in a colon cancer cells with different expression level of TOPK, resulting in growth inhibition. The fucoidan exerts its effects by directly interacting with TOPK kinase in vitro and ex vivo and inhibits its kinase activity. In xenograft animal model, oral administration of the fucoidan suppressed HCT 116 colon tumor growth. The phosphorylation of TOPK downstream signaling molecules in tumor tissues was also inhibited by the fucoidan. Taken together, our findings support the cancer preventive efficacy of the fucoidan through its targeting of TOPK for the prevention of neoplastic cell transformation and progression of colon carcinomas in vitro and ex vivo.

  3. PDZ-binding kinase/T-LAK cell-originated protein kinase is a target of the fucoidan from brown alga Fucus evanescens in the prevention of EGF-induced neoplastic cell transformation and colon cancer growth

    PubMed Central

    Wang, Zhe; Ermakova, Svetlana P.; Xiao, JuanJuan; Lu, Tao; Xue, PeiPei; Zvyagintseva, Tatyana N.; Xiong, Hua; Shao, Chen; Yan, Wei; Duan, Qiuhong; Zhu, Feng

    2016-01-01

    The fucoidan with high anticancer activity was isolated from brown alga Fucus evanescens. The compound effectively prevented EGF-induced neoplastic cell transformation through inhibition of TOPK/ERK1/2/MSK 1 signaling axis. In vitro studies showed that the fucoidan attenuated mitogen-activated protein kinases downstream signaling in a colon cancer cells with different expression level of TOPK, resulting in growth inhibition. The fucoidan exerts its effects by directly interacting with TOPK kinase in vitro and ex vivo and inhibits its kinase activity. In xenograft animal model, oral administration of the fucoidan suppressed HCT 116 colon tumor growth. The phosphorylation of TOPK downstream signaling molecules in tumor tissues was also inhibited by the fucoidan. Taken together, our findings support the cancer preventive efficacy of the fucoidan through its targeting of TOPK for the prevention of neoplastic cell transformation and progression of colon carcinomas in vitro and ex vivo. PMID:26936995

  4. The impact of supplementing lambs with algae on growth, meat traits and oxidative status.

    PubMed

    Hopkins, D L; Clayton, E H; Lamb, T A; van de Ven, R J; Refshauge, G; Kerr, M J; Bailes, K; Lewandowski, P; Ponnampalam, E N

    2014-10-01

    The current study examined the effect of supplementing lambs with algae. Forty, three month old lambs were allocated to receive a control ration based on oats and lupins (n=20) or the control ration with DHA-Gold™ algae (~2% of the ration, n=20). These lambs came from dams previously fed a ration based on either silage (high in omega-3) or oats and cottonseed meal (OCSM: high in omega-6) at joining (dam nutrition, DN). Lamb performance, carcase weight and GR fat content were not affected by treatment diet (control vs algae) or DN (silage vs OSCM). Health claimable omega-3 fatty acids (EPA+DHA) were significantly greater in the LL of lambs fed algae (125±6mg/100g meat) compared to those not fed algae (43±6mg/100g meat) and this effect was mediated by DN. Supplementing with algae high in DHA provides a means of improving an aspect of the health status of lamb meat.

  5. Thermogenesis, blood metabolites and hormones, and growth of lambs born to ewes supplemented with algae-derived docosahexaenoic acid.

    PubMed

    Keithly, J I; Kott, R W; Berardinelli, J G; Moreaux, S; Hatfield, P G

    2011-12-01

    Neonatal lamb mortality is a major factor affecting profitability in the sheep industry, and lamb thermogenesis is a key element in neonatal lamb survival. Increased lamb vigor has been reported when ewes were supplemented during late gestation with algae-derived docosahexaenoic acid (DHA); however, the effects of DHA on lamb thermogenesis and immunocompetence have not been investigated. Eighty twin-bearing Targhee ewes (ages 2 to 5 yr; 68.5 ± 3 kg) were assigned randomly to 1 of 2 supplement treatments to determine the effects of feeding DHA to ewes during late gestation and early lactation on lamb thermogenesis, serum metabolites and hormones, and lamb growth. Supplement treatments were 12 g·ewe(-1)·d(-1) of algae-derived DHA (DHA Gold Advanced Bionutrition Corp., Columbia, MD; algae-derived DHA); and no algae-derived DHA (control). Supplements were individually fed daily during the last 30 d (±7 d) of gestation and pen fed (6 pens/treatment with 6 or 7 ewes/pen) during the first 38 d (±7 d) of lactation. One hour after lambing and before nursing, twin-born lambs were weighed, blood sampled via jugular puncture, and placed in a dry cold chamber for 30 min (0°C), and rectal temperatures were recorded every minute for 30 min. Lambs were removed from the cold chamber, blood sampled, warmed for 15 min, and returned to their dam. Ewes were blood sampled, and colostrum samples were collected 1 h postpartum. Ewe and lamb sera were assayed for glucose, NEFA, cortisol, and leptin. Lamb rectal temperature, glucose, NEFA, cortisol, leptin, and birth weights did not differ between treatments. The BW at 38 d was greater (P = 0.03) for lambs born to control ewes than for lambs born to algae-derived DHA-supplemented ewes; however, the colostrum of algae-derived DHA-supplemented ewes had a greater specific gravity (P = 0.05) than for control ewes. Overall, despite a potentially positive effect on ewe colostral IgG concentrations, supplementation of algae-derived DHA during

  6. The Effect of Kanamycin and Tetracycline on Growth and Photosynthetic Activity of Two Chlorophyte Algae.

    PubMed

    Bashir, Khawaja Muhammad Imran; Cho, Man-Gi

    2016-01-01

    Antibiotics are routinely used in microalgae culture screening, stock culture maintenance, and genetic transformation. By studying the effect of antibiotics on microalgae growth, we can estimate the least value to inhibit growth of undesired pathogens in algal culture. We studied the effect of kanamycin and tetracycline on the growth and photosynthetic activity of two chlorophyte microalgae, Dictyosphaerium pulchellum and Micractinium pusillum. We measured CFU mL(-1) on agar plates, optical density, fluorescence yields, and photosynthetic inhibition. Our results showed a significant effect of kan and tet on the tested microalgae species except tet, which showed a minor effect on M. pusillum. Both antibiotics are believed to interact with the protein synthesis machinery; hence, the inhibitory effect of the tested antibiotics was further confirmed by isolation and quantification of the whole cell protein. A significant reduction in protein quantity was observed at concentrations more than 5 mg L(-1), except M. pusillum, which showed only a slight reduction in protein quantity even at the maximum tested concentration of tet (30 mg L(-1)). This study can further aid in aquaculture industry, for the maintenance of the microalgae stock cultures and it can also help the microalgae genetic engineers in the construction of molecular markers.

  7. Evaluation of Supercritical Extracts of Algae as Biostimulants of Plant Growth in Field Trials

    PubMed Central

    Michalak, Izabela; Chojnacka, Katarzyna; Dmytryk, Agnieszka; Wilk, Radosław; Gramza, Mateusz; Rój, Edward

    2016-01-01

    The aim of the field trials was to determine the influence of supercritical algal extracts on the growth and development of winter wheat (variety Akteur). As a raw material for the supercritical fluid extraction, the biomass of microalga Spirulina plantensis, brown seaweed – Ascophyllum nodosum and Baltic green macroalgae was used. Forthial and Asahi SL constituted the reference products. It was found that the tested biostimulants did not influence statistically significantly the plant height, length of ear, and shank length. The ear number per m2 was the highest in the group where the Baltic macroalgae extract was applied in the dose 1.0 L/ha (statistically significant differences). Number of grains in ear (statistically significant differences) and shank length was the highest in the group treated with Spirulina at the dose 1.5 L/ha. In the group with Ascophyllum at the dose 1.0 L/ha, the highest length of ear was observed. The yield was comparable in all the experimental groups (lack of statistically significant differences). Among the tested supercritical extracts, the best results were obtained for Spirulina (1.5 L/ha). The mass of 1000 grains was the highest for extract from Baltic macroalgae and was 3.5% higher than for Asahi, 4.0% higher than for Forthial and 18.5% higher than for the control group (statistically significant differences). Future work is needed to fully characterize the chemical composition of the applied algal extracts. A special attention should be paid to the extracts obtained from Baltic algae because they are inexpensive source of naturally occurring bioactive compounds, which can be used in sustainable agriculture and horticulture. PMID:27826310

  8. Evaluation of Supercritical Extracts of Algae as Biostimulants of Plant Growth in Field Trials.

    PubMed

    Michalak, Izabela; Chojnacka, Katarzyna; Dmytryk, Agnieszka; Wilk, Radosław; Gramza, Mateusz; Rój, Edward

    2016-01-01

    The aim of the field trials was to determine the influence of supercritical algal extracts on the growth and development of winter wheat (variety Akteur). As a raw material for the supercritical fluid extraction, the biomass of microalga Spirulina plantensis, brown seaweed - Ascophyllum nodosum and Baltic green macroalgae was used. Forthial and Asahi SL constituted the reference products. It was found that the tested biostimulants did not influence statistically significantly the plant height, length of ear, and shank length. The ear number per m(2) was the highest in the group where the Baltic macroalgae extract was applied in the dose 1.0 L/ha (statistically significant differences). Number of grains in ear (statistically significant differences) and shank length was the highest in the group treated with Spirulina at the dose 1.5 L/ha. In the group with Ascophyllum at the dose 1.0 L/ha, the highest length of ear was observed. The yield was comparable in all the experimental groups (lack of statistically significant differences). Among the tested supercritical extracts, the best results were obtained for Spirulina (1.5 L/ha). The mass of 1000 grains was the highest for extract from Baltic macroalgae and was 3.5% higher than for Asahi, 4.0% higher than for Forthial and 18.5% higher than for the control group (statistically significant differences). Future work is needed to fully characterize the chemical composition of the applied algal extracts. A special attention should be paid to the extracts obtained from Baltic algae because they are inexpensive source of naturally occurring bioactive compounds, which can be used in sustainable agriculture and horticulture.

  9. FNC efficiently inhibits mantle cell lymphoma growth.

    PubMed

    Zhang, Yan; Zhang, Rong; Ding, Xixi; Peng, Bangan; Wang, Ning; Ma, Fang; Peng, Youmei; Wang, Qingduan; Chang, Junbiao

    2017-01-01

    FNC, 2'-deoxy-2'-β-fluoro-4'-azidocytidine, is a novel cytidine analogue, that has shown strong antiproliferative activity in human lymphoma, lung adenocarcinoma and acute myeloid leukemia. In this study, we investigated the effects of FNC on mantle cell lymphoma (MCL) and the underlying mechanisms. In in vitro experiments, cell viability was detected by the CCK8 assay, and cell cycle progression and apoptosis were assessed by flow cytometry, and the expression of relative apoptosis proteins were detected by Western Blot. The in vivo antitumor effect of FNC was investigated in a SCID xenograft model. Finally, the mechanisms of action of FNC were assessed using a whole human genome expression profile chip. The data showed that FNC inhibited cell growth in a dose- and time-dependent manner, and FNC could induce apoptosis by the death recepter pathways in JeKo-1 cells and arrest the cell cycle in the G1/S or G2/M phase. Notably, FNC showed in vivo efficacy in mice bearing JeKo-1 xenograft tumors. Gene expression profile analysis revealed that the differentially expressed genes were mainly focused on the immune system process, cellular process and death. These findings implied that FNC may be a valuable therapeutic in mantle cell lymphoma and provided an experimental basis for the early clinical application of FNC.

  10. FNC efficiently inhibits mantle cell lymphoma growth

    PubMed Central

    Ding, Xixi; Peng, Bangan; Wang, Ning; Ma, Fang; Peng, Youmei; Wang, Qingduan; Chang, Junbiao

    2017-01-01

    FNC, 2'-deoxy-2'-β-fluoro-4'-azidocytidine, is a novel cytidine analogue, that has shown strong antiproliferative activity in human lymphoma, lung adenocarcinoma and acute myeloid leukemia. In this study, we investigated the effects of FNC on mantle cell lymphoma (MCL) and the underlying mechanisms. In in vitro experiments, cell viability was detected by the CCK8 assay, and cell cycle progression and apoptosis were assessed by flow cytometry, and the expression of relative apoptosis proteins were detected by Western Blot. The in vivo antitumor effect of FNC was investigated in a SCID xenograft model. Finally, the mechanisms of action of FNC were assessed using a whole human genome expression profile chip. The data showed that FNC inhibited cell growth in a dose- and time-dependent manner, and FNC could induce apoptosis by the death recepter pathways in JeKo-1 cells and arrest the cell cycle in the G1/S or G2/M phase. Notably, FNC showed in vivo efficacy in mice bearing JeKo-1 xenograft tumors. Gene expression profile analysis revealed that the differentially expressed genes were mainly focused on the immune system process, cellular process and death. These findings implied that FNC may be a valuable therapeutic in mantle cell lymphoma and provided an experimental basis for the early clinical application of FNC. PMID:28333959

  11. Blue-Green Algae Inhibit the Development of Atherosclerotic Lesions in Apolipoprotein E Knockout Mice

    PubMed Central

    Ku, Chai Siah; Kim, Bohkyung; Pham, Tho X.; Yang, Yue; Wegner, Casey J.; Park, Young-Ki; Balunas, Marcy

    2015-01-01

    Abstract Hyperlipidemia and inflammation contribute to the development of atherosclerotic lesions. Our objective was to determine antiatherogenic effect of edible blue-green algae (BGA) species, that is, Nostoc commune var. sphaeroides Kützing (NO) and Spirulina platensis (SP), in apolipoprotein E knockout (ApoE−/−) mice, a well-established mouse model of atherosclerosis. Male ApoE−/− mice were fed a high-fat/high-cholesterol (HF/HC, 15% fat and 0.2% cholesterol by wt) control diet or a HF/HC diet supplemented with 5% (w/w) of NO or SP powder for 12 weeks. Plasma total cholesterol (TC) and triglycerides (TG) were measured, and livers were analyzed for histology and gene expression. Morphometric analysis for lesions and immunohistochemical analysis for CD68 were conducted in the aorta and the aortic root. NO supplementation significantly decreased plasma TC and TG, and liver TC, compared to control and SP groups. In the livers of NO-fed mice, less lipid droplets were present with a concomitant decrease in fatty acid synthase protein levels than the other groups. There was a significant increase in hepatic low-density lipoprotein receptor protein levels in SP-supplemented mice than in control and NO groups. Quantification of aortic lesions by en face analysis demonstrated that both NO and SP decreased aortic lesion development to a similar degree compared with control. While lesions in the aortic root were not significantly different between groups, the CD68-stained area in the aortic root was significantly lowered in BGA-fed mice than controls. In conclusion, both NO and SP supplementation decreased the development of atherosclerotic lesions, suggesting that they may be used as a natural product for atheroprotection. PMID:26566121

  12. Exudates of different marine algae promote growth and mediate trace metal binding in Phaeodactylum tricornutum.

    PubMed

    Vasconcelos, M Teresa S D; Leal, M Fernanda C

    2008-12-01

    Phaeodactylum tricornutum was grown in filtered natural seawater enriched with nitrate, phosphate, and silicate only (control) or with exudates from itself, from Emiliania huxleyi (a coccolithophore micro-alga), Porphyra spp. (a red macro-alga) or Enteromorpha spp. (a green macro-alga). Cathodic (and anodic) stripping voltammetry (C(A)SV) were used to determine the concentrations of trace metals, both in the medium and in the algae, as well as total Cu-complexing organic ligands in the medium and, among these, some thiols (compounds identified as cysteine- or as glutathione by CSV). Exudates of different marine micro- and macro-algae could cause allelopathic effects in P. tricornutum cultures. Cell yield of P. tricornutum was increasingly promoted by exudates of E. huxleyi >Porphyra >Enteromorpha. Although exudates strongly complex Cu (and probably other metals), their presence promoted Cu uptake. Significant changes of Ni, Cd, Fe, Zn and Mn uptake by P. tricornutum were also observed in the presence of exudates of different algal species. In addition, both intensity of production and nature of exudates released by P. tricornutum were markedly influenced by the presence of exudates of other algae, the allelopathic effects being very specific (variable from one species to another). Allelopathy will probably also occur in the aquatic environment, although to a lesser extent than in cultures, particularly during bloom events and may have effects on both chemical speciation and bioavailability of chemicals to phytoplanktonic species. Such changes might cause the predominance of some species over other species. Therefore, in future in vitro culture studies with the purpose of using them as models of the real environment, more attention should be paid to the role of algal exudates, in order to improve the environmental relevance and significance of the results.

  13. Streptomycin affects the growth and photochemical activity of the alga Chlorella vulgaris.

    PubMed

    Perales-Vela, Hugo Virgilio; García, Roberto Velasco; Gómez-Juárez, Evelyn Alicia; Salcedo-Álvarez, Martha Ofelia; Cañizares-Villanueva, Rosa Olivia

    2016-10-01

    Antibiotics are increasingly being used in human and veterinary medicine, as well as pest control in agriculture. Recently, their emergence in the aquatic environment has become a global concern. The aim of this study was to evaluate the effect of streptomycin on growth and photosynthetic activity of Chlorella vulgaris after 72h exposure. We found that growth, photosynthetic activity and the content of the D1 protein of photosystem II decreased. Analysis of chlorophyll a fluorescence emission shows a reduction in the energy transfer between the antenna complex and reaction center. Also the activity of the oxygen evolution complex and electron flow between QA and QB were significantly reduced; in contrast, we found an increase in the reduction rate of the acceptor side of photosystem I. The foregoing can be attributed to the inhibition of the synthesis of the D1 protein and perhaps other coded chloroplast proteins that are part of the electron transport chain which are essential for the transformation of solar energy in the photosystems. We conclude that micromolar concentrations of streptomycin can affect growth and photosynthetic activity of Chlorella vulgaris. The accumulation of antibiotics in the environment can become an ecological problem for primary producers in the aquatic environment.

  14. Promotive effect of se on the growth and antioxidation of a blue-green alga Spirulina maxima

    NASA Astrophysics Data System (ADS)

    Zhi-Gang, Zhou; Zhi-Li, Liu

    1998-12-01

    Cultures of a blue-green alga Spirulina maxima (Setch. et Gard.) Geitler with various concentrations of Se in Zarrouk's medium showed that not higher than 40 mg/L Se could promote its growth. The present experiments showed that S. maxima grown under normal conditions, has an oxidant stress defence system for hydrogen peroxide (H2O2) removal, which is the Halliwell-Asada pathway. When 4 to 20 mg/L Se was added to the algal medium, this pathway was replaced by a so-called Sestressed pathway containing GSH peroxidase (GSH-POD). As a result of the occurrence of both higher activity of GSH-POD and lower levels of hydroxyl radical (OH·), the Se-stressed pathway scavenged H2O2 so effectively that the growth of S. maxima was promoted by 4 to 20 mg/L Se. While GSH-POD activity of the alga disappeared at 40 mg/L Se, the recovery of ascorbate peroxidase was observed. The lower levels of ascorbic acid and GSH made the Halliwell-Asada pathway for scavenging H2O2 less effective, while the highest activity of catalase might be responsible in part for the H2O2 removal, causing the level of OH· in S. maxima grown at 40 mg/L Se to be much higher than the OH· level in this alga grown at 4 to 20 mg/L Se, but lower than that in the control. The OH· level changes caused the growth of S. maxima cultured at 40 mg/L Se to increase slightly to close to that of the control.

  15. Anti-photoaging activity and inhibition of matrix metalloproteinase (MMP) by marine red alga, Corallina pilulifera methanol extract

    NASA Astrophysics Data System (ADS)

    Ryu, BoMi; Qian, Zhong-Ji; Kim, Moon-Moo; Nam, Ki Wan; Kim, Se-Kwon

    2009-02-01

    Matrix metalloproteinases (MMPs), a key component in photoaging of the skin due to exposure to ultraviolet A, appear to be increased by UV-irradiation-associated generation of reactive oxygen species (ROS). In this study, the alga Corallina pilulifera methanol (CPM) extract has been shown to exert a potent antioxidant activity and protective effect on UVA-induced oxidative stress of human dermal fibroblast (HDF) cell. Antioxidant evaluated by various antioxidant assays. These include reducing power, total antioxidant, DPPH radical scavenging, hydroxyl radical scavenging and protective effect on DNA damage caused by hydroxyl radicals generated. Further, the ROS level was detected using a fluorescence probe, 2',7'-dichlorofluorescein diacetate (DCFH-DA), which could be converted to highly fluorescent dichlorofluorescein (DCF) with the presence of intracellular ROS on HT-1080 cells. Those various antioxidant activities were compared to standard antioxidants such as α-tocopherol. In addition, the in vitro activities of MMP-2 and MMP-9 in HDF cell were inhibited by C. pilulifera methanol extract dose dependently by using gelatin zymography method. The results obtained in the present study suggested that the C. pilulifera methanol extract may be a potential source of natural anti-photoaging.

  16. Transgenic algae engineered for higher performance

    DOEpatents

    Unkefer, Pat J; Anderson, Penelope S; Knight, Thomas J

    2014-10-21

    The present disclosure relates to transgenic algae having increased growth characteristics, and methods of increasing growth characteristics of algae. In particular, the disclosure relates to transgenic algae comprising a glutamine phenylpyruvate transaminase transgene and to transgenic algae comprising a glutamine phenylpyruvate transaminase transgene and a glutamine synthetase.

  17. Terpenes from the red alga Sphaerococcus coronopifolius inhibit the settlement of barnacles.

    PubMed

    Piazza, Veronica; Roussis, Vassilios; Garaventa, Francesca; Greco, Giuliano; Smyrniotopoulos, Vangelis; Vagias, Constantinos; Faimali, Marco

    2011-08-01

    In this study, we screened eight terpenes isolated from the organic extract of Sphaerococcus coronopifolius for their antifouling activity in order to find possible new sources of non-toxic or less toxic bioactive antifoulants. The anti-settlement activity (EC₅₀) and the degree of toxicity (LC₅₀) of S. coronopifolius metabolites was evaluated using larvae of the cirriped crustacean Amphibalanus (Balanus) amphitrite (cyprids and nauplii) as model organism. For five of eight tested metabolites EC₅₀ was lower than 5 mg/L. The most promising results were observed for bromosphaerol (3), which expressed an EC₅₀ value of 0.23 mg/L, in combination with low toxicity levels (LC₅₀ > 100 mg/L). The therapeutic ratio--an index used to estimate whether settlement inhibition is due to toxicity or other mechanisms--is also calculated and discussed.

  18. [Allelopathic effect of artemisinin on green algae].

    PubMed

    Wu, Ye-Kuan; Yuan, Ling; Huang, Jian-Guo; Li, Long-Yun

    2013-05-01

    To study the growth effects of differing concentrations of artemisinin on green algae and to evaluate the ecological risk. The effects of artemisinin on the growth and the content change of chlorophyll, protein, oxygen, conductivity, SOD, CAT, MDA in Chlorella pyrenoidosa and Scenedesmus oblique were studied through 96 h toxicity tests. Artemisinin accelerated the growth of algae at a lower concentration ( <40 microg . L-1) with content increase of chlorophyll or protein and so on, and it inhibited the growth of algae at higher concentration ( >80 microg . L-1). The content of chlorophyll or protein in algae cells reduced with the increasing concentration of artemisinin, exhibiting the good concentration-effect relationship. SOD and CAT activity was stimulated at low concentrations ( <40 microg . L-1 ) and inhibited at high concentrations ( >80 microg . L- 1). However, MDA content increased significantly with the increase of concentration. According to the seven kinds of indicators changes, the time-response and dose-response suggested that the surfactant first hurt in Ch. pyrenoidosa was damaging membrane by changing membrane lipid molecules soluble. And primary mechanism on Chlorophyta cells might be related to the oxidation damage of lipid and other biological large molecules caused by artemisinin. The large-scale intensive planting of Artemisia annua may reduce the surrounding water productivity.

  19. Bee venom inhibits growth of human cervical tumors in mice

    PubMed Central

    Kim, Tae Myoung; Jung, Yu Yeon; Park, Mi Hee; Oh, Sang Hyun; Yun, Hye Seok; Jun, Hyung Ok; Yoo, Hwan Soo; Han, Sang-Bae; Lee, Ung Soo; Yoon, Joo Hee; Song, Min Jong; Hong, Jin Tae

    2015-01-01

    We studied whether bee venom (BV) inhibits cervical tumor growth through enhancement of death receptor (DR) expressions and inactivation of nuclear factor kappa B (NF-κB) in mice. In vivo study showed that BV (1 mg/kg) inhibited tumor growth. Similar inhibitory effects of BV on cancer growth in primary human cervical cancer cells were also found. BV (1–5 μg/ml) also inhibited the growth of cancer cells, Ca Ski and C33Aby the induction of apoptotic cell death in a dose dependent manner. Agreed with cancer cell growth inhibition, expression of death receptors; FAS, DR3 and DR6, and DR downstream pro-apoptotic proteins including caspase-3 and Bax was concomitantly increased, but the NF-κB activity and the expression of Bcl-2 were inhibited by treatment with BV in tumor mice, human cancer cell and human tumor samples as well as cultured cancer cells. In addition, deletion of FAS, DR3 and DR6 by small interfering RNA significantly reversed BV-induced cell growth inhibitory effects as well as NF-κB inactivation. These results suggest that BV inhibits cervical tumor growth through enhancement of FAS, DR3 and DR6 expression via inhibition of NF-κB pathway. PMID:25730901

  20. Growth of Legionella pneumophila in association with blue-green algae (Cyanobacteria)

    SciTech Connect

    Tison, D.L.; Pope, D.H.; Cherry, W.B.; Fliermans, C.B.

    1980-02-01

    Legionella pneumophila (Legionnaires disease bacterium) of serogroup 1 was isolated from an algal-bacterial mat community growing at 45/sup 0/C in a man-made thermal effluent. This isolate was grown in mineral salts medium at 45/sup 0/C in association with the blue-green alga (cyanobacterium) Fischerella sp. over a pH range of 6.9 to 7.6. L. pneumophila was apparently using algal extracellular products as its carbon and energy sources. These observations indicate that the temperature, pH, and nutritional requirements of L. pneumophila are not as stringent as those previously observed when cultured on complex media. This association between L. pneumophila and certain blue-green algae suggests an explanation for the apparent widespread distribution of the bacterium in nature.

  1. Reproduction capacity of Potamogeton crispus fragments and its role in water purification and algae inhibition in eutrophic lakes.

    PubMed

    Zhou, Yiwen; Zhou, Xiaohong; Han, Ruiming; Xu, Xiaoguang; Wang, Guoxiang; Liu, Xiansheng; Bi, Fengzhi; Feng, Deyou

    2017-02-15

    The role of fragments in restoring eutrophic lakes remains unclear despite the importance of re-establishing submerged macrophytes via fragments. This study established a manipulative experiment using different biomass fragments of Potamogeton crispus. This approach was adapted to study the reproductive capacity, nutrient removal efficiency, and algae inhibitory effect of fragments. Results showed that fragments could grow throughout a 49-day experiment by maintaining the stable photosynthesis efficiency of leaves and lengthening the stems. These floating fragments could regenerate by producing turions for the maintenance of their species. Moreover, the increasing removal efficiency of TP, TN, NH4(+)-N, and NO3(-)-N in water with the increase of fragment biomass indicates that the fragments could effectively purify water quality. Floating fragments competed with algae for nutrients, occupied a favorable ecological niche, and reduced algae biomass. They altered the structure of algae community and shifted the dominated green algae to cyanobacteria, the green algae of phytoplankton, and benthic algae. Findings imply that the postponable regulation of fragments is necessary for the ecological restoration of eutrophic lakes.

  2. Calcite crystal growth rate inhibition by polycarboxylic acids

    USGS Publications Warehouse

    Reddy, M.M.; Hoch, A.R.

    2001-01-01

    Calcite crystal growth rates measured in the presence of several polycarboxyclic acids show that tetrahydrofurantetracarboxylic acid (THFTCA) and cyclopentanetetracarboxylic acid (CPTCA) are effective growth rate inhibitors at low solution concentrations (0.01 to 1 mg/L). In contrast, linear polycarbocylic acids (citric acid and tricarballylic acid) had no inhibiting effect on calcite growth rates at concentrations up to 10 mg/L. Calcite crystal growth rate inhibition by cyclic polycarboxyclic acids appears to involve blockage of crystal growth sites on the mineral surface by several carboxylate groups. Growth morphology varied for growth in the absence and in the presence of both THFTCA and CPTCA. More effective growth rate reduction by CPTCA relative to THFTCA suggests that inhibitor carboxylate stereochemical orientation controls calcite surface interaction with carboxylate inhibitors. ?? 20O1 Academic Press.

  3. Sodium alginate oligosaccharides from brown algae inhibit Salmonella Enteritidis colonization in broiler chickens.

    PubMed

    Yan, G L; Guo, Y M; Yuan, J M; Liu, D; Zhang, B K

    2011-07-01

    The effects of sodium alginate oligosaccharides (sAO) on growth performance, cecal microbiota, Salmonella translocation to internal organs, and mucosal immune responses to challenge with Salmonella enterica serovar Enteritidis in broiler chickens were investigated. We designed an experiment with a 2 × 3 factorial arrangement, in which 3 feed treatments with supplementation of sAO at 0 (controls), 0.04, or 0.2% were provided in the diet for birds not challenged or challenged with Salmonella Enteritidis. There were 5 randomly placed replicate pens for each treatment. At 8 to 12 d of age, one-half the poults were orally gavaged with 10(8) cfu of Salmonella Enteritidis and the nonchallenged groups were inoculated with sterile PBS. Body weight loss and mortality resulting from Salmonella infection were mitigated by the addition of sAO. Supplementation of sAO at 0.2% was the most effective concentration for reducing Salmonella colonization and increasing the number of lactic acid bacteria in the cecum of chickens challenged with Salmonella Enteritidis. Cecal Salmonella Enteritidis-specific IgA production was significantly increased by sAO at 0.2% at 5 d postchallenge compared with the other treatments and was maintained at higher levels at the 2 dosages of sAO at 10 d postchallenge. With Salmonella Enteritidis challenge, sAO at 0.04% showed an anti-inflammatory effect through upregulation of interleukin (IL)-10 expression in the cecal tonsils. The supplementation level of 0.2% showed dramatic immunostimulatory activity by inducing interferon-γ, IL-10, and IL-1β mRNA expression in cecal tonsils of nonchallenged birds. However, the high level of sAO induced a robust mucosal immune response in the absence of a challenge, and this may have led to a decline in BW. These findings suggest that dietary sAO can decrease Salmonella colonization and improve intestinal barrier function and performance of chickens.

  4. Algae biomass cultivation in nitrogen rich biogas digestate.

    PubMed

    Krustok, I; Diaz, J G; Odlare, M; Nehrenheim, E

    2015-01-01

    Because microalgae are known for quick biomass growth and nutrient uptake, there has been much interest in their use in research on wastewater treatment methods. While many studies have concentrated on the algal treatment of wastewaters with low to medium ammonium concentrations, there are several liquid waste streams with high ammonium concentrations that microalgae could potentially treat. The aim of this paper was to test ammonium tolerance of the indigenous algae community of Lake Mälaren and to use this mixed consortia of algae to remove nutrients from biogas digestate. Algae from Lake Mälaren were cultivated in Jaworski's Medium containing a range of ammonium concentrations and the resulting algal growth was determined. The algae were able to grow at NH4-N concentrations of up to 200 mg L(-1) after which there was significant inhibition. To test the effectiveness of the lake water algae on the treatment of biogas digestate, different pre-cultivation set-ups and biogas digestate concentrations were tested. It was determined that mixing pre-cultivated suspension algae with 25% of biogas digestate by volume, resulting in an ammonium concentration of around 300 mg L(-1), produced the highest algal growth. The algae were effective in removing 72.8±2.2% of NH4-N and 41.4±41.4% of PO4-P.

  5. [Experimental assessment of combined effect of nitrates and acute gamma-irradiation on green algae Scenedesmus quadricauda growth].

    PubMed

    Triapitsyna, G A; Tarasova, S P; Atamaniuk, N I; Osipov, D I; Priakhin, E A

    2012-01-01

    The combined effect of acute gamma-irradiation at doses of 0, 50, 100, 150 and 200 Gy and nitrates in concentrations of 0.04 g/dm3 (that corresponds to maximum permissible concentrations for fishery waters), 0.1, 0.25, 0.5, 1.0, 2.5 g/dm3 (that is close to NO3(-) level in water of a reservoir R-17 used as radioactive waste storage of the "Mayak" Production Association) and 5.0 g/dm3 (that is close to NO3(-) level in the water of radioactive waste storage reservoir R-9) on the unicellular green algae Scenedesmus quadricauda growth has been studied in laboratory conditions. It was shown that the joint effects of nitrates and y-radiation had an antagonistic character. Thus, it may be concluded that chemical pollution is the factor limiting the development of green algae in reservoir R-17; probably, both factors, chemical and radiating, are essential to the algocenosis degradation in reservoir R-9.

  6. The interactive effects of microcystin-LR and cylindrospermopsin on the growth rate of the freshwater algae Chlorella vulgaris.

    PubMed

    Pinheiro, Carlos; Azevedo, Joana; Campos, Alexandre; Vasconcelos, Vítor; Loureiro, Susana

    2016-05-01

    Microcystin-LR (MC-LR) and cylindrospermopsin (CYN) are the most representative cyanobacterial cyanotoxins. They have been simultaneously detected in aquatic systems, but their combined ecotoxicological effects to aquatic organisms, especially microalgae, is unknown. In this study, we examined the effects of these cyanotoxins individually and as a binary mixture on the growth rate of the freshwater algae Chlorella vulgaris. Using the MIXTOX tool, the reference model concentration addition (CA) was selected to evaluate the combined effects of MC-LR and CYN on the growth of the freshwater green algae due to its conservative prediction of mixture effect for putative similar or dissimilar acting chemicals. Deviations from the CA model such as synergism/antagonism, dose-ratio and dose-level dependency were also assessed. In single exposures, our results demonstrated that MC-LR and CYN had different impacts on the growth rates of C. vulgaris at the highest tested concentrations, being CYN the most toxic. In the mixture exposure trial, MC-LR and CYN showed a synergistic deviation from the conceptual model CA as the best descriptive model. MC-LR individually was not toxic even at high concentrations (37 mg L(-1)); however, the presence of MC-LR at much lower concentrations (0.4-16.7 mg L(-1)) increased the CYN toxicity. From these results, the combined exposure of MC-LR and CYN should be considered for risk assessment of mixtures as the toxicity may be underestimated when looking only at the single cyanotoxins and not their combination. This study also represents an important step to understand the interactions among MC-LR and CYN detected previously in aquatic systems.

  7. Timing of growth inhibition following shoot inversion in Pharbitis nil

    NASA Technical Reports Server (NTRS)

    Abdel-Rahman, A. M.; Cline, M. G.

    1989-01-01

    Shoot inversion in Pharbitis nil results in the enhancement of ethylene production and in the inhibition of elongation in the growth zone of the inverted shoot. The initial increase in ethylene production previously was detected within 2 to 2.75 hours after inversion. In the present study, the initial inhibition of shoot elongation was detected within 1.5 to 4 hours with a weighted mean of 2.4 hours. Ethylene treatment of upright shoots inhibited elongation in 1.5 hours. A cause and effect relationship between shoot inversion-enhanced ethylene production and inhibition of elongation cannot be excluded.

  8. Anti-Phytopathogenic Activities of Macro-Algae Extracts

    PubMed Central

    Jiménez, Edra; Dorta, Fernando; Medina, Cristian; Ramírez, Alberto; Ramírez, Ingrid; Peña-Cortés, Hugo

    2011-01-01

    Aqueous and ethanolic extracts obtained from nine Chilean marine macro-algae collected at different seasons were examined in vitro and in vivo for properties that reduce the growth of plant pathogens or decrease the injury severity of plant foliar tissues following pathogen infection. Particular crude aqueous or organic extracts showed effects on the growth of pathogenic bacteria whereas others displayed important effects against pathogenic fungi or viruses, either by inhibiting fungal mycelia growth or by reducing the disease symptoms in leaves caused by pathogen challenge. Organic extracts obtained from the brown-alga Lessonia trabeculata inhibited bacterial growth and reduced both the number and size of the necrotic lesion in tomato leaves following infection with Botrytis cinerea. Aqueous and ethanolic extracts from the red-alga Gracillaria chilensis prevent the growth of Phytophthora cinnamomi, showing a response which depends on doses and collecting-time. Similarly, aqueous and ethanolic extracts from the brown-alga Durvillaea antarctica were able to diminish the damage caused by tobacco mosaic virus (TMV) in tobacco leaves, and the aqueous procedure is, in addition, more effective and seasonally independent. These results suggest that macro-algae contain compounds with different chemical properties which could be considered for controlling specific plant pathogens. PMID:21673886

  9. Algae Derived Biofuel

    SciTech Connect

    Jahan, Kauser

    2015-03-31

    One of the most promising fuel alternatives is algae biodiesel. Algae reproduce quickly, produce oils more efficiently than crop plants, and require relatively few nutrients for growth. These nutrients can potentially be derived from inexpensive waste sources such as flue gas and wastewater, providing a mutual benefit of helping to mitigate carbon dioxide waste. Algae can also be grown on land unsuitable for agricultural purposes, eliminating competition with food sources. This project focused on cultivating select algae species under various environmental conditions to optimize oil yield. Membrane studies were also conducted to transfer carbon di-oxide more efficiently. An LCA study was also conducted to investigate the energy intensive steps in algae cultivation.

  10. Golden Algae Control: Efficacy of Hydraulic Manipulations in Coves of Lake Granbury

    DTIC Science & Technology

    2013-04-01

    and support their growth. The other algae, representing cyanobacteria , produce a dissolved toxin that partially inhibits the growth of P. parvum... cyanobacteria and the toxin produced by P. parvum (i.e. in inX X= =1 2 0 ). It was also assumed that the deep water used for flushing has zero nutrient...other algae R = concentration of phosphate N = concentration of nitrate C = concentration of toxin produced by cyanobacteria P

  11. [Response of the algae Gymnodinium kovalevskii (Dinophyta) to exposure to synthetic detergents and distillation].

    PubMed

    Aĭzdaĭcher, N A

    2000-01-01

    The effects of synthetic detergents and combined effects of synthetic detergents and water freshening on growth characteristics of the alga Gymnodinium kovalevskii (Dinophyta) were studied. Low concentrations of synthetic detergents (0.1 and 1.0 mg/l) stimulated the algal growth. Elevated concentrations inhibited cell division, affected their motility and induced morphological changes. Contamination with synthetic detergents adversely affected the adaptation plasticity of algae with respect to salinity.

  12. The effect of salinity on growth, photosynthesis and respiration in the estuarine red alga Bostrychia radicans mont

    NASA Astrophysics Data System (ADS)

    Karsten, Ulf; Kirst, Gunter O.

    1989-03-01

    The estuarine red alga, Bostrychia radicans, was subjected to osmotic stresses ranging from hypo-osmotic (9.9‰) to hyperosmotic conditions (37.4‰). The growth rate decreased with increasing salinities and showed a maximum in a mesohaline medium, while the photosynthetic rate and the chlorophyll a content increased under hyper-osmotic conditions. The rate of respiration remained constant over the salinity range tested. B. radicans revealed typical characteristics of “shade plants” having a low light compensation point at 3 4 μE m-2 s-1 correlated with a low photon flux density of 70 100 μE m-2 s-1 for saturation of photosynthesis. These physiological properties may explain the success of B. radicans in estuarine habitats.

  13. Effect of dissolved organic matter on the growth of algae, Pseudokirchneriella subcapitata, in Korean lakes: the importance of complexation reactions.

    PubMed

    Lee, Jiho; Park, Ji Hyung; Shin, Yong Sik; Lee, Byung Cheun; Chang, Nam Ik; Cho, Jaeweon; Kim, Sang Don

    2009-02-01

    The objective of this study was to investigate the effect of dissolved organic ligands, such as EDTA, humic acids, hydrophobic and hydrophilic fractions of dissolved organic matter (DOM), on the growth of Pseudokirchneriella subcapitata in cultured media and natural lake waters. The growth of algae was gradually increased on the addition of dissolved organic ligands, but markedly declined at high concentrations, due to reduced bioavailable iron concentrations (e.g., Fe3+ and Fe'--inorganic ferric iron). The results demonstrated that the high growth rates of P. subcapitata were correlated with the hydrophobic, but not hydrophilic, DOM from five lakes, spiked under the nutrients-controlled conditions. This was attributed to the role of DOM in controlling the bioavailable iron due to complexation of Fe(III) with -COOH and -OH functional groups on the hydrophobic DOM. Therefore, the hydrophobic DOM, as chelating agent, is a biologically important component in the lake waters, which affects the algal growth by interacting with bioavailable iron in the lake water and can change the results of bioassay experiments.

  14. A Lipid-Accumulating Alga Maintains Growth in Outdoor, Alkaliphilic Raceway Pond with Mixed Microbial Communities.

    PubMed

    Bell, Tisza A S; Prithiviraj, Bharath; Wahlen, Brad D; Fields, Matthew W; Peyton, Brent M

    2015-01-01

    Algal biofuels and valuable co-products are being produced in both open and closed cultivation systems. Growing algae in open pond systems may be a more economical alternative, but this approach allows environmental microorganisms to colonize the pond and potentially infect or outcompete the algal "crop." In this study, we monitored the microbial community of an outdoor, open raceway pond inoculated with a high lipid-producing alkaliphilic alga, Chlorella vulgaris BA050. The strain C. vulgaris BA050 was previously isolated from Soap Lake, Washington, a system characterized by a high pH (∼9.8). An outdoor raceway pond (200 L) was inoculated with C. vulgaris and monitored for 10 days and then the culture was transferred to a 2,000 L raceway pond and cultivated for an additional 6 days. Community DNA samples were collected over the 16-day period in conjunction with water chemistry analyses and cell counts. Universal primers for the SSU rRNA gene sequences for Eukarya, Bacteria, and Archaea were used for barcoded pyrosequence determination. The environmental parameters that most closely correlated with C. vulgaris abundance were pH and phosphate. Community analyses indicated that the pond system remained dominated by the Chlorella population (93% of eukaryotic sequences), but was also colonized by other microorganisms. Bacterial sequence diversity increased over time while archaeal sequence diversity declined over the same time period. Using SparCC co-occurrence network analysis, a positive correlation was observed between C. vulgaris and Pseudomonas sp. throughout the experiment, which may suggest a symbiotic relationship between the two organisms. The putative relationship coupled with high pH may have contributed to the success of C. vulgaris. The characterization of the microbial community dynamics of an alkaliphilic open pond system provides significant insight into open pond systems that could be used to control photoautotrophic biomass productivity in an open

  15. A lipid-accumulating alga maintains growth in outdoor, alkaliphilic raceway pond with mixed microbial communities

    DOE PAGES

    Bell, Tisza A.S.; Prithiviraj, Bharath; Wahlen, Brad D.; ...

    2016-01-07

    Algal biofuels and valuable co-products are being produced in both open and closed cultivation systems. Growing algae in open pond systems may be a more economical alternative, but this approach allows environmental microorganisms to colonize the pond and potentially infect or outcompete the algal “crop.” In this study, we monitored the microbial community of an outdoor, open raceway pond inoculated with a high lipid-producing alkaliphilic alga, Chlorella vulgaris BA050. The strain C. vulgaris BA050 was previously isolated from Soap Lake, Washington, a system characterized by a high pH (~9.8). An outdoor raceway pond (200 L) was inoculated with C. vulgarismore » and monitored for 10 days and then the culture was transferred to a 2,000 L raceway pond and cultivated for an additional 6 days. Community DNA samples were collected over the 16-day period in conjunction with water chemistry analyses and cell counts. Universal primers for the SSU rRNA gene sequences for Eukarya, Bacteria, and Archaea were used for barcoded pyrosequence determination. The environmental parameters that most closely correlated with C. vulgaris abundance were pH and phosphate. Community analyses indicated that the pond system remained dominated by the Chlorella population (93% of eukaryotic sequences), but was also colonized by other microorganisms. Bacterial sequence diversity increased over time while archaeal sequence diversity declined over the same time period. Using SparCC co-occurrence network analysis, a positive correlation was observed between C. vulgaris and Pseudomonas sp. throughout the experiment, which may suggest a symbiotic relationship between the two organisms. The putative relationship coupled with high pH may have contributed to the success of C. vulgaris. As a result, the characterization of the microbial community dynamics of an alkaliphilic open pond system provides significant insight into open pond systems that could be used to control photoautotrophic biomass

  16. A Lipid-Accumulating Alga Maintains Growth in Outdoor, Alkaliphilic Raceway Pond with Mixed Microbial Communities

    PubMed Central

    Bell, Tisza A. S.; Prithiviraj, Bharath; Wahlen, Brad D.; Fields, Matthew W.; Peyton, Brent M.

    2016-01-01

    Algal biofuels and valuable co-products are being produced in both open and closed cultivation systems. Growing algae in open pond systems may be a more economical alternative, but this approach allows environmental microorganisms to colonize the pond and potentially infect or outcompete the algal “crop.” In this study, we monitored the microbial community of an outdoor, open raceway pond inoculated with a high lipid-producing alkaliphilic alga, Chlorella vulgaris BA050. The strain C. vulgaris BA050 was previously isolated from Soap Lake, Washington, a system characterized by a high pH (∼9.8). An outdoor raceway pond (200 L) was inoculated with C. vulgaris and monitored for 10 days and then the culture was transferred to a 2,000 L raceway pond and cultivated for an additional 6 days. Community DNA samples were collected over the 16-day period in conjunction with water chemistry analyses and cell counts. Universal primers for the SSU rRNA gene sequences for Eukarya, Bacteria, and Archaea were used for barcoded pyrosequence determination. The environmental parameters that most closely correlated with C. vulgaris abundance were pH and phosphate. Community analyses indicated that the pond system remained dominated by the Chlorella population (93% of eukaryotic sequences), but was also colonized by other microorganisms. Bacterial sequence diversity increased over time while archaeal sequence diversity declined over the same time period. Using SparCC co-occurrence network analysis, a positive correlation was observed between C. vulgaris and Pseudomonas sp. throughout the experiment, which may suggest a symbiotic relationship between the two organisms. The putative relationship coupled with high pH may have contributed to the success of C. vulgaris. The characterization of the microbial community dynamics of an alkaliphilic open pond system provides significant insight into open pond systems that could be used to control photoautotrophic biomass productivity in an

  17. Larvicidal algae.

    PubMed

    Marten, Gerald G

    2007-01-01

    Although most algae are nutritious food for mosquito larvae, some species kill the larvae when ingested in large quantities. Cyanobacteria (blue-green algae) that kill larvae do so by virtue of toxicity. While blue-green algae toxins may offer possibilities for delivery as larvicides, the toxicity of live blue-green algae does not seem consistent enough for live algae to be useful for mosquito control. Certain species of green algae in the order Chlorococcales kill larvae primarily because they are indigestible. Where these algae are abundant in nature, larvae consume them to the exclusion of other food and then starve. Under the right circumstances, it is possible to introduce indigestible algae into a breeding habitat so they become abundant enough to render it unsuitable for mosquito production. The algae can persist for years, even if the habitat dries periodically. The main limitation of indigestible algae lies in the fact that, under certain conditions, they may not replace all the nutritious algae in the habitat. More research on techniques to ensure complete replacement will be necessary before indigestible algae can go into operational use for mosquito control.

  18. Bacterial Ammonia Causes Significant Plant Growth Inhibition

    PubMed Central

    Weise, Teresa; Kai, Marco; Piechulla, Birgit

    2013-01-01

    Many and complex plant-bacteria inter-relationships are found in the rhizosphere, since plants release a variety of photosynthetic exudates from their roots and rhizobacteria produce multifaceted specialized compounds including rich mixtures of volatiles, e.g., the bouquet of Serratia odorifera 4Rx13 is composed of up to 100 volatile organic and inorganic compounds. Here we show that when growing on peptone-rich nutrient medium S. odorifera 4Rx13 and six other rhizobacteria emit high levels of ammonia, which during co-cultivation in compartmented Petri dishes caused alkalization of the neighboring plant medium and subsequently reduced the growth of A. thaliana. It is argued that in nature high-protein resource degradations (carcasses, whey, manure and compost) are also accompanied by bacterial ammonia emission which alters the pH of the rhizosphere and thereby influences organismal diversity and plant-microbe interactions. Consequently, bacterial ammonia emission may be more relevant for plant colonization and growth development than previously thought. PMID:23691060

  19. Protein kinase C activators inhibit capillary endothelial cell growth

    SciTech Connect

    Doctrow, S.R.

    1986-05-01

    Phorbol 12,13-dibutyrate (PDBu) binds specifically to bovine capillary endothelial (BCE) cells (K/sub d/ = 8nM) and inhibits the proliferation (K/sub 50/ = 6 +/- 4 nM). Under similar conditions, PDBu does not inhibit the growth of bovine aortic endothelial or smooth muscle cells. PDBu markedly attenuates the response of BCE cells to purified human hepatoma-derived growth factor which, in the absence of PDBu, stimulates BCE cell growth by about 3-fold. Several observations suggest that the inhibition of BCE cell growth by PDBu is mediated by protein kinase C: (1) different phorbol compounds inhibit BCE cell growth according to the relative potencies as protein kinase C activators (12-tetradecanoylphorbol 13-acetate > PDBu >> phorbol 12,13-diacetate >>>..beta..-phorbol; ..cap alpha..-phorbol 12,13-didecanoate). (2) Specific binding of PDBu to BCE cells is displaced by sn-1,2-dioctanoylglycerol (diC/sub 8/), a protein kinase C activator and an analog of the putative second messenger activating this kinase in vivo. The weak protein kinase C activator, sn-1,2-dibutyrylglycerol, does not affect PDBu binding. (3) A cytosolic extract from BCE cells contains a Ca/sup 2 +//phosphatidylserine-dependent kinase that is activated by diC/sub 8/ and PDBu, but not by ..beta..-phorbol. These results support a role for protein kinase C in suppressing capillary endothelial cell growth and may therefore have implications in the intracellular regulation of angiogenesis.

  20. Spectroscopic analysis of urinary calculi and inhibition of their growth

    NASA Astrophysics Data System (ADS)

    Manciu, Felicia; Durrer, William; Govani, Jayesh; Reza, Layra; Pinales, Luis

    2009-10-01

    We present here a study of kidney stone formation and growth inhibition based on a traditional medicine approach with Aquatica Lour (RAL) herbal extracts. Kidney stone material systems were synthesized in vitro using a simplified single diffusion gel growth technique. With the objective of revealing the mechanism of inhibition of calculi formation by RAL extracts, samples prepared without the presence of extract, and with the presence of extract, were analyzed using Raman, photoluminescence, and XPS. The unexpected presence of Zn revealed by XPS in a sample prepared with RAL provides an explanation for the inhibition process, and also explains the dramatic reflectance of incident light observed in attempts to obtain infrared transmission data. Raman data are consistent with the binding of the inhibitor to the oxygen of the kidney stone. Photoluminescence data corroborate with the other results to provide additional evidence of Zn-related inhibition.

  1. Brown Algae Polyphenol, a Prolyl Isomerase Pin1 Inhibitor, Prevents Obesity by Inhibiting the Differentiation of Stem Cells into Adipocytes

    PubMed Central

    Suzuki, Atsuko; Saeki, Toshiyuki; Ikuji, Hiroko; Uchida, Chiyoko; Uchida, Takafumi

    2016-01-01

    Background While screening for an inhibitor of the peptidyl prolyl cis/trans isomerase, Pin1, we came across a brown algae polyphenol that blocks the differentiation of fibroblasts into adipocytes. However, its effectiveness on the accumulation of fat in the body has never been studied. Methodology/Principal Findings Oral administration of brown algae polyphenol to mice fed with a high fat diet, suppressed the increase in fat volume to a level observed in mice fed with a normal diet. We speculate that Pin1 might be required for the differentiation of stem cell to adipocytes. We established wild type (WT) and Pin1-/- (Pin1-KO) adipose-derived mesenchymal stem cell (ASC) lines and found that WT ASCs differentiate to adipocytes but Pin1-KO ASCs do not. Conclusion and Significance Oral administration of brown algae polyphenol, a Pin1 inhibitor, reduced fat buildup in mice. We showed that Pin1 is required for the differentiation of stem cells into adipocytes. We propose that oral intake of brown algae polyphenol is useful for the treatment of obesity. PMID:28036348

  2. A lipid-accumulating alga maintains growth in outdoor, alkaliphilic raceway pond with mixed microbial communities

    SciTech Connect

    Bell, Tisza A.S.; Prithiviraj, Bharath; Wahlen, Brad D.; Fields, Matthew W.; Peyton, Brent M.

    2016-01-07

    Algal biofuels and valuable co-products are being produced in both open and closed cultivation systems. Growing algae in open pond systems may be a more economical alternative, but this approach allows environmental microorganisms to colonize the pond and potentially infect or outcompete the algal “crop.” In this study, we monitored the microbial community of an outdoor, open raceway pond inoculated with a high lipid-producing alkaliphilic alga, Chlorella vulgaris BA050. The strain C. vulgaris BA050 was previously isolated from Soap Lake, Washington, a system characterized by a high pH (~9.8). An outdoor raceway pond (200 L) was inoculated with C. vulgaris and monitored for 10 days and then the culture was transferred to a 2,000 L raceway pond and cultivated for an additional 6 days. Community DNA samples were collected over the 16-day period in conjunction with water chemistry analyses and cell counts. Universal primers for the SSU rRNA gene sequences for Eukarya, Bacteria, and Archaea were used for barcoded pyrosequence determination. The environmental parameters that most closely correlated with C. vulgaris abundance were pH and phosphate. Community analyses indicated that the pond system remained dominated by the Chlorella population (93% of eukaryotic sequences), but was also colonized by other microorganisms. Bacterial sequence diversity increased over time while archaeal sequence diversity declined over the same time period. Using SparCC co-occurrence network analysis, a positive correlation was observed between C. vulgaris and Pseudomonas sp. throughout the experiment, which may suggest a symbiotic relationship between the two organisms. The putative relationship coupled with high pH may have contributed to the success of C. vulgaris. As a result, the characterization of the microbial community dynamics of an alkaliphilic open pond system provides significant insight into open pond systems that could be used to

  3. Thymoquinone Inhibits Escherichia coli ATP Synthase and Cell Growth.

    PubMed

    Ahmad, Zulfiqar; Laughlin, Thomas F; Kady, Ismail O

    2015-01-01

    We examined the thymoquinone induced inhibition of purified F1 or membrane bound F1FO E. coli ATP synthase. Both purified F1 and membrane bound F1FO were completely inhibited by thymoquinone with no residual ATPase activity. The process of inhibition was fully reversible and identical in both membrane bound F1Fo and purified F1 preparations. Moreover, thymoquinone induced inhibition of ATP synthase expressing wild-type E. coli cell growth and non-inhibition of ATPase gene deleted null control cells demonstrates that ATP synthase is a molecular target for thymoquinone. This also links the beneficial dietary based antimicrobial and anticancer effects of thymoquinone to its inhibitory action on ATP synthase.

  4. Thymoquinone Inhibits Escherichia coli ATP Synthase and Cell Growth

    PubMed Central

    Ahmad, Zulfiqar; Laughlin, Thomas F.; Kady, Ismail O.

    2015-01-01

    We examined the thymoquinone induced inhibition of purified F1 or membrane bound F1FO E. coli ATP synthase. Both purified F1 and membrane bound F1FO were completely inhibited by thymoquinone with no residual ATPase activity. The process of inhibition was fully reversible and identical in both membrane bound F1Fo and purified F1 preparations. Moreover, thymoquinone induced inhibition of ATP synthase expressing wild-type E. coli cell growth and non-inhibition of ATPase gene deleted null control cells demonstrates that ATP synthase is a molecular target for thymoquinone. This also links the beneficial dietary based antimicrobial and anticancer effects of thymoquinone to its inhibitory action on ATP synthase. PMID:25996607

  5. Biological toxicity of lanthanide elements on algae.

    PubMed

    Tai, Peidong; Zhao, Qing; Su, Dan; Li, Peijun; Stagnitti, Frank

    2010-08-01

    The biological toxicity of lanthanides on marine monocellular algae was investigated. The specific objective of this research was to establish the relationship between the abundance in the seawater of lanthanides and their biological toxicities on marine monocellular algae. The results showed that all single lanthanides had similar toxic effects on Skeletonema costatum. High concentrations of lanthanides (29.04+/-0.61 micromol L(-1)) resulted in 50% reduction in growth of algae compared to the controls (0 micromol L(-1)) after 96 h (96 h-EC50). The biological toxicity of 13 lanthanides on marine monocellular algae was unrelated with the abundance of different lanthanide elements in nature, and the "Harkins rule" was not appropriate for the lanthanides. A mixed solution that contained equivalent concentrations of each lanthanide element had the same inhibition effect on algae cells as each individual lanthanide element at the same total concentration. This phenomenon is unique compared to the groups of other elements in the periodic table. Hence, we speculate that the monocellular organisms might not be able to sufficiently differentiate between the almost chemically identical lanthanide elements.

  6. Autophagy contributes to gefitinib-induced glioma cell growth inhibition

    SciTech Connect

    Chang, Cheng-Yi; Kuan, Yu-Hsiang; Ou, Yen-Chuan; Li, Jian-Ri; Wu, Chih-Cheng; Pan, Pin-Ho; Chen, Wen-Ying; Huang, Hsuan-Yi; Chen, Chun-Jung

    2014-09-10

    Epidermal growth factor receptor tyrosine kinase inhibitors, including gefitinib, have been evaluated in patients with malignant gliomas. However, the molecular mechanisms involved in gefitinib-mediated anticancer effects against glioma are incompletely understood. In the present study, the cytostatic potential of gefitinib was demonstrated by the inhibition of glioma cell growth, long-term clonogenic survival, and xenograft tumor growth. The cytostatic consequences were accompanied by autophagy, as evidenced by monodansylcadaverine staining of acidic vesicle formation, conversion of microtubule-associated protein-1 light chain 3-II (LC3-II), degradation of p62, punctate pattern of GFP-LC3, and conversion of GFP-LC3 to cleaved-GFP. Autophagy inhibitor 3-methyladenosine and chloroquine and genetic silencing of LC3 or Beclin 1 attenuated gefitinib-induced growth inhibition. Gefitinib-induced autophagy was not accompanied by the disruption of the Akt/mammalian target of rapamycin signaling. Instead, the activation of liver kinase-B1/AMP-activated protein kinase (AMPK) signaling correlated well with the induction of autophagy and growth inhibition caused by gefitinib. Silencing of AMPK suppressed gefitinib-induced autophagy and growth inhibition. The crucial role of AMPK activation in inducing glioma autophagy and growth inhibition was further supported by the actions of AMP mimetic AICAR. Gefitinib was shown to be capable of reducing the proliferation of glioma cells, presumably by autophagic mechanisms involving AMPK activation. - Highlights: • Gefitinib causes cytotoxic and cytostatic effect on glioma. • Gefitinib induces autophagy. • Gefitinib causes cytostatic effect through autophagy. • Gefitinib induces autophagy involving AMPK.

  7. Inhibition of estrogen biosynthesis enhances lymphoma growth in mice

    PubMed Central

    Talaber, Gergely; Yakimchuk, Konstantin; Guan, Jiyu; Inzunza, Jose; Okret, Sam

    2016-01-01

    Most lymphomas show higher incidence and poorer prognosis in males compared to females. However, the endocrine contribution to this gender difference is not entirely known. Here we show that castration accelerates lymphoma growth in C57BL6 male mice grafted with murine EG7 T cell lymphoma cells. However, the androgen receptor antagonist Bicalutamide did not affect lymphoma growth, suggesting no impact of androgen receptor signaling on lymphoma progression. In contrast, inhibition of androgen-to-estrogen conversion by the aromatase inhibitor (AI) Letrozole induced faster lymphoma growth in mice, suggesting that androgens impact lymphoma growth through its conversion to estrogens. This was supported by the inability of dihydrotestosterone, which is not converted to estrogens by aromatase, to influence lymphoma growth in castrated male mice. Lymphoma growth was also stimulated in immunocompromised mice grafted with human B cell lymphoma (Granta-519) and treated with either reversible or irreversible AIs, showing that the blockage of estrogen synthesis caused enhanced growth of both murine T and human B cell lymphomas and with different AIs. Additionally, AI-treated EG7 lymphomas showed accelerated growth not only in male but also in intact female mice. Altogether, our results demonstrate that aromatase inhibition accelerates lymphoma growth but not androgens per se, highlighting a protective role of estrogens in lymphoma pathogenesis. These results also raise concern that the use of AIs in women with breast cancer might enhance lymphoma progression. PMID:26943574

  8. [Growth inhibition of Microcystis aeruginosa in packed-bed discharge plasma Reactor].

    PubMed

    Wang, Cui-hua; Li, Guo-feng; Wu, Yan; Wang, Yu

    2008-02-01

    The paper discussed the effect of the gas flow rate and the addition of glass pellets dielectric on the growth inhibition of Microcystis aeruginosa (M. aeruginosa) and the concentration of hydrogen peroxide, the effect of energy input and pH on the growth inhibition of M. aeruginosa and the effect of packed-bed reactor on the algal Chl-a and cell density. The results show that the increasing of the gas flow rate and the addition of glass pellets dielectric enhance the effect of the discharge plasma reactor on the growth inhibition of M. aeruginosa immediately after discharge, but the effect is unobvious. The algal optical density slightly increases and then markedly decreases during the incubation period, e.g., the removal efficiency of the algal optical density is high to 87.3% at the end of the fifth day at an air flow rate of 0.75 m3/h after 40 min treatment in the packed-bed discharge plasma reactor. The concentration of hydrogen peroxide is enhanced by the increase in the gas flow rate and the addition of glass pellets dielectric into the discharge plasma reactor, too, especially the concentration of hydrogen peroxide enhanced from 4.6 micromol/L to 38.3 micromol/L by the addition of glass pellets dielectric, which will enhance the destructive effect of hydrogen peroxide on the algae during the incubation period. The effect of the growth inhibition of M. aeruginosa is obvious with the increasing in the energy input into the packed-bed discharge plasma reactor. The effect of the alkaline solution on the growth inhibition of M. aeruginosa is more higher than that of the acidic solution, and the value of pH is increased under the acidic condition and decreased under the alkaline condition, but the tread of pH is to be neutral during the incubation period. The decrease of the content of Chl-a and cell density is marked in this reactor, and at the end of the fifth day, the removal efficiencies of Chl-a and cell density are high to 100%.

  9. Rhizoids and protonemata of characean algae: model cells for research on polarized growth and plant gravity sensing.

    PubMed

    Braun, M; Limbach, C

    2006-12-01

    Gravitropically tip-growing rhizoids and protonemata of characean algae are well-established unicellular plant model systems for research on gravitropism. In recent years, considerable progress has been made in the understanding of the cellular and molecular mechanisms underlying gravity sensing and gravity-oriented growth. While in higher-plant statocytes the role of cytoskeletal elements, especially the actin cytoskeleton, in the mechanisms of gravity sensing is still enigmatic, there is clear evidence that in the characean cells actin is intimately involved in polarized growth, gravity sensing, and the gravitropic response mechanisms. The multiple functions of actin are orchestrated by a variety of actin-binding proteins which control actin polymerisation, regulate the dynamic remodelling of the actin filament architecture, and mediate the transport of vesicles and organelles. Actin and a steep gradient of cytoplasmic free calcium are crucial components of a feedback mechanism that controls polarized growth. Experiments performed in microgravity provided evidence that actomyosin is a key player for gravity sensing: it coordinates the position of statoliths and, upon a change in the cell's orientation, directs sedimenting statoliths to specific areas of the plasma membrane, where contact with membrane-bound gravisensor molecules elicits short gravitropic pathways. In rhizoids, gravitropic signalling leads to a local reduction of cytoplasmic free calcium and results in differential growth of the opposite subapical cell flanks. The negative gravitropic response of protonemata involves actin-dependent relocation of the calcium gradient and displacement of the centre of maximal growth towards the upper flank. On the basis of the results obtained from the gravitropic model cells, a similar fine-tuning function of the actomyosin system is discussed for the early steps of gravity sensing in higher-plant statocytes.

  10. Growth rate hypothesis and efficiency of protein synthesis under different sulphate concentrations in two green algae.

    PubMed

    Giordano, Mario; Palmucci, Matteo; Raven, John A

    2015-11-01

    The growth rate hypothesis (GRH) predicts a positive correlation between growth rate and RNA content because growth depends upon the protein synthesis machinery. The application of this hypothesis to photoautotrophic organisms has been questioned. We tested the GRH on one prasinophycean, Tetraselmis suecica, and one chlorophycean, Dunaliella salina, grown at three sulphate concentrations. Sulphate was chosen because its concentration in the oceans increased through geological time and apparently had a role in the evolutionary trajectories of phytoplankton. Cell protein content and P quota were positively related to the RNA content (r = 0.62 and r = 0.74, respectively). The correlation of the RNA content with growth rates (r = 0.95) indicates that the GRH was valid for these species when growth rates were below 0.82 d(-1) .

  11. The effects of growth phase and salinity on the hydrogen isotopic composition of alkenones produced by coastal haptophyte algae

    NASA Astrophysics Data System (ADS)

    Chivall, David; M'Boule, Daniela; Sinke-Schoen, Daniëlle; Sinninghe Damsté, Jaap S.; Schouten, Stefan; van der Meer, Marcel T. J.

    2014-09-01

    The isotopic fractionation of hydrogen during the biosynthesis of alkenones produced by marine haptophyte algae has been shown to depend on salinity and, as such, the hydrogen isotopic composition of alkenones is emerging as a palaeosalinity proxy. The relationship between fractionation and salinity has previously only been determined during exponential growth, whilst it is not yet known in which growth phases natural haptophyte populations predominantly exist. We have therefore determined the relationship between the fractionation factor, αalkenones-water, and salinity for C37 alkenones produced in different growth phases of batch cultures of the major alkenone-producing coastal haptophytes Isochrysis galbana (strain CCMP 1323) and Chrysotila lamellosa (strain CCMP 1307) over a range in salinity from ca. 10 to 35. αalkenones-water was similar in both species, ranging over 0.841-0.900 for I. galbana and 0.838-0.865 for C. lamellosa. A strong (0.85 ⩽ R2 ⩽ 0.97; p < 0.0001) relationship between salinity and fractionation factor was observed in both species at all growth phases investigated. This suggests that alkenone δD has the potential to be used as a salinity proxy in neritic areas where haptophyte communities are dominated by these coastal species. However, there was a marked difference in the sensitivity of αalkenones-water to salinity between different growth phases: in the exponential growth phase of I. galbana, αalkenones-water increased by 0.0019 per salinity unit (S-1), but was less sensitive at 0.0010 and 0.0008 S-1 during the stationary and decline phases, respectively. Similarly, in C. lamellosa αalkenones-water increased by 0.0010 S-1 in the early stationary phase and by 0.0008 S-1 during the late stationary phase. Assuming the shift in sensitivity of αalkenones-water to salinity observed at the end of exponential growth in I. galbana is similar in other alkenone-producing species, the predominant growth phase of natural populations of

  12. Effect of Ocean acidification on growth, calcification and recruitment of calcifying and non-calcifying epibionts of brown algae

    NASA Astrophysics Data System (ADS)

    Saderne, V.; Wahl, M.

    2012-03-01

    Anthropogenic emissions of CO2 are leading to an acidification of the oceans by 0.4 pH units in the course of this century according to the more severe model scenarios. The excess of CO2 could notably affect the benthic communities of calcifiers and macrophytes in different aspects (photosynthesis, respiration and calcification). Seaweeds are key species of nearshore benthic ecosystems of the Baltic Sea. They frequently are the substratum of fouling epibionts like bryozoans and tubeworms. Most of those species secrete calcified structures and could therefore be impacted by the seawater pCO2. On the other hand, the biological activity of the host may substantially modulate the pH and pCO2 conditions in the thallus boundary layer where the epibionts live. The aim of the present study was to test the sensitivity of seaweed macrofouling communities to higher pCO2 concentrations. Fragments of the macroalga Fucus serratus bearing the calcifiers Spirorbis spirorbis (Annelida) and Electra pilosa (Bryozoa) and the non-calcifier Alcyonidium gelatinosum (Bryozoa) were maintained for 30 days under three pCO2 conditions: natural 460 ± 59 μatm and enriched 1193 ± 166 μatm and 3150 ± 446 μatm. Our study showed a significant reduction of growth rates and recruitment of Spirorbis individuals only at the highest pCO2. At a finer temporal resolution, the tubeworm recruits exhibited enhanced calcification of 40% during irradiation hours compared to dark hours, presumably due to the effect of photosynthetic and respiratory activities of the host alga on the carbonate system. Electra colonies showed significantly increased growth rates at 1193 μatm. No effect on Alcyonidium colonies growth rates was observed. Those results suggest a remarkable resistance of the algal macro-epibiontic communities to the most elevated pCO2 foreseen in year 2100 for open ocean (~1000 μatm) conditions possibly due to the modulation of environmental conditions by the biological activities of the host

  13. [Inhibition of growth of microscopic fungi with organic acids].

    PubMed

    Conková, E; Para, L; Kocisová, A

    1993-01-01

    Fungicidal effects of five selected organic acids (lactic, acetic, formic, oxalic, and propionic) in concentrations 3, 5, 10, 20 and 50 ml/l on nine selected species of moulds were tested. Lactic and oxalic acids did not prove the satisfactory fungicidal activity in any of the chosen concentrations. The antifungal effect of the other three acids, manifested by the growth inhibition of the tested moulds is shown in Tab. I and it can be expressed by sequence: propionic acid, formic acid, and acetic acid. These acids also had effects only in concentrations 20 ml/l and 50 ml/l. Propionic acid in concentration 20 ml/l inhibited the growth of five moulds (Penicillium glabrum, Aspergillus niger, Fusarium moniliforme, Aspergillus fumigatus, Cladosporium sphaerospermum). In testing of concentration 50 ml/l, the lower fungicidal ability was ascertained only in growth suppression of Aspergillus flavus. The fungicidal activity of formic acid was registered in concentration 20 ml/l in two cases and in concentration 50 ml/l in six cases. Acetic acid inhibited the growth in concentration 50 ml/l only in two cases. Tab. II shows the percentual evaluation of propionic acid and formic acid with regard to their inhibition abilities. The fungicidal efficiency of propionic acid resulting from the experiment is 88.9%.

  14. Fluoxetine regulates cell growth inhibition of interferon-α.

    PubMed

    Lin, Yu-Min; Yu, Bu-Chin; Chiu, Wen-Tai; Sun, Hung-Yu; Chien, Yu-Chieh; Su, Hui-Chen; Yen, Shu-Yang; Lai, Hsin-Wen; Bai, Chyi-Huey; Young, Kung-Chia; Tsao, Chiung-Wen

    2016-10-01

    Fluoxetine, a well-known anti-depression agent, may act as a chemosensitizer to assist and promote cancer therapy. However, how fluoxetine regulates cellular signaling to enhance cellular responses against tumor cell growth remains unclear. In the present study, addition of fluoxetine promoted growth inhibition of interferon-alpha (IFN-α) in human bladder carcinoma cells but not in normal uroepithelial cells through lessening the IFN-α-induced apoptosis but switching to cause G1 arrest, and maintaining the IFN-α-mediated reduction in G2/M phase. Activations and signal transducer and transactivator (STAT)-1 and peroxisome proliferator-activated receptor alpha (PPAR-α) were involved in this process. Chemical inhibitions of STAT-1 or PPAR-α partially rescued bladder carcinoma cells from IFN-α-mediated growth inhibition via blockades of G1 arrest, cyclin D1 reduction, p53 downregulation and p27 upregulation in the presence of fluoxetine. However, the functions of both proteins were not involved in the control of fluoxetine over apoptosis and maintained the declined G2/M phase of IFN-α. These results indicated that activation of PPAR-α and STAT-1 participated, at least in part, in growth inhibition of IFN-α in the presence of fluoxetine.

  15. Troglitazone inhibits vascular smooth muscle cell growth and intimal hyperplasia.

    PubMed Central

    Law, R E; Meehan, W P; Xi, X P; Graf, K; Wuthrich, D A; Coats, W; Faxon, D; Hsueh, W A

    1996-01-01

    Vascular smooth muscle cell (VSMC) proliferation and migration are responses to arterial injury that are highly important to the processes of restenosis and atherosclerosis. In the arterial balloon injury model in the rat, platelet-derived growth factor (PDGF) and basic fibroblast growth factor (bFGF) are induced in the vessel wall and regulate these VSMC activities. Novel insulin sensitizing agents, thiazolidinediones, have been demonstrated to inhibit insulin and epidermal growth factor-induced growth of VSMCs. We hypothesized that these agents might also inhibit the effect of PDGF and bFGF on cultured VSMCs and intimal hyperplasia in vivo. Troglitazone (1 microM), a member of the thiazolidinedione class, produced a near complete inhibition of both bFGF-induced DNA synthesis as measured by bromodeoxyuridine incorporation (6.5+/-3.9 vs. 17.6+/-4.3% cells labeled, P < 0.05) and c-fos induction. This effect was associated with an inhibition (by 73+/-4%, P < 0.01) by troglitazone of the transactivation of the serum response element, which regulates c-fos expression. Inhibition of c-fos induction by troglitazone appeared to occur via a blockade of the MAP kinase pathway at a point downstream of MAP kinase activation by MAP kinase kinase. At this dose, troglitazone also inhibited PDGF-BB-directed migration of VSMC (by 70+/-6%, P < 0.01). These in vitro effects were operative in vivo. Quantitative image analysis revealed that troglitazone-treated rats had 62% (P < 0.001) less neointima/media area ratio 14 d after balloon injury of the aorta compared with injured rats that received no troglitazone. These results suggest troglitazone is a potent inhibitor of VSMC proliferation and migration and, thus, may be a useful agent to prevent restenosis and possibly atherosclerosis. PMID:8878442

  16. Decreased growth-induced water potential: A primary cause of growth inhibition at low water potentials

    SciTech Connect

    Nonami, Hiroshi; Wu, Yajun; Boyer, J.S.

    1997-06-01

    Cell enlargement depends on a growth-induced difference in water potential to move water into the cells. Water deficits decrease this potential difference and inhibit growth. To investigate whether the decrease causes the growth inhibition, pressure was applied to the roots of soybean seedlings and the growth and potential difference were monitored in the stems. In water-limited plants, the inhibited stem growth increased when the roots were pressurized and it reverted to the previous rate when the pressure was released. The pressure around the roots was perceived as an increased turgor in the stem in small cells next to the xylem, but not in outlying cortical cells. This local effect implied that water transport was impeded by the small cells. The diffusivity for water was much less in the small cells than in the outlying cells. The small cells thus were a barrier that caused the growth-induced potential difference to be large during rapid growth, but to reverse locally during the early part of a water deficit. Such a barrier may be a frequent property of meristems. Because stem growth responded to the pressure-induced recovery of the potential difference across this barrier, we conclude that a decrease in the growth-induced potential difference was a primary cause of the inhibition.

  17. In-Situ Effects of Simulated Overfishing and Eutrophication on Benthic Coral Reef Algae Growth, Succession, and Composition in the Central Red Sea

    PubMed Central

    Jessen, Christian; Roder, Cornelia; Villa Lizcano, Javier Felipe; Voolstra, Christian R.; Wild, Christian

    2013-01-01

    Overfishing and land-derived eutrophication are major local threats to coral reefs and may affect benthic communities, moving them from coral dominated reefs to algal dominated ones. The Central Red Sea is a highly under-investigated area, where healthy coral reefs are contending against intense coastal development. This in-situ study investigated both the independent and combined effects of manipulated inorganic nutrient enrichment (simulation of eutrophication) and herbivore exclosure (simulation of overfishing) on benthic algae development. Light-exposed and shaded terracotta tiles were positioned at an offshore patch reef close to Thuwal, Saudi Arabia and sampled over a period of 4 months. Findings revealed that nutrient enrichment alone affected neither algal dry mass nor algae-derived C or N production. In contrast, herbivore exclusion significantly increased algal dry mass up to 300-fold, and in conjunction with nutrient enrichment, this total increased to 500-fold. Though the increase in dry mass led to a 7 and 8-fold increase in organic C and N content, respectively, the algal C/N ratio (18±1) was significantly lowered in the combined treatment relative to controls (26±2). Furthermore, exclusion of herbivores significantly increased the relative abundance of filamentous algae on the light-exposed tiles and reduced crustose coralline algae and non-coralline red crusts on the shaded tiles. The combination of the herbivore exclusion and nutrient enrichment treatments pronounced these effects. The results of our study suggest that herbivore reduction, particularly when coupled with nutrient enrichment, favors non-calcifying, filamentous algae growth with high biomass production, which thoroughly outcompetes the encrusting (calcifying) algae that dominates in undisturbed conditions. These results suggest that the healthy reefs of the Central Red Sea may experience rapid shifts in benthic community composition with ensuing effects for biogeochemical cycles if

  18. In-Situ Effects of Simulated Overfishing and Eutrophication on Benthic Coral Reef Algae Growth, Succession, and Composition in the Central Red Sea.

    PubMed

    Jessen, Christian; Roder, Cornelia; Villa Lizcano, Javier Felipe; Voolstra, Christian R; Wild, Christian

    2013-01-01

    Overfishing and land-derived eutrophication are major local threats to coral reefs and may affect benthic communities, moving them from coral dominated reefs to algal dominated ones. The Central Red Sea is a highly under-investigated area, where healthy coral reefs are contending against intense coastal development. This in-situ study investigated both the independent and combined effects of manipulated inorganic nutrient enrichment (simulation of eutrophication) and herbivore exclosure (simulation of overfishing) on benthic algae development. Light-exposed and shaded terracotta tiles were positioned at an offshore patch reef close to Thuwal, Saudi Arabia and sampled over a period of 4 months. Findings revealed that nutrient enrichment alone affected neither algal dry mass nor algae-derived C or N production. In contrast, herbivore exclusion significantly increased algal dry mass up to 300-fold, and in conjunction with nutrient enrichment, this total increased to 500-fold. Though the increase in dry mass led to a 7 and 8-fold increase in organic C and N content, respectively, the algal C/N ratio (18±1) was significantly lowered in the combined treatment relative to controls (26±2). Furthermore, exclusion of herbivores significantly increased the relative abundance of filamentous algae on the light-exposed tiles and reduced crustose coralline algae and non-coralline red crusts on the shaded tiles. The combination of the herbivore exclusion and nutrient enrichment treatments pronounced these effects. The results of our study suggest that herbivore reduction, particularly when coupled with nutrient enrichment, favors non-calcifying, filamentous algae growth with high biomass production, which thoroughly outcompetes the encrusting (calcifying) algae that dominates in undisturbed conditions. These results suggest that the healthy reefs of the Central Red Sea may experience rapid shifts in benthic community composition with ensuing effects for biogeochemical cycles if

  19. Saccharin and Cyclamate Inhibit Binding of Epidermal Growth Factor

    NASA Astrophysics Data System (ADS)

    Lee, L. S.

    1981-02-01

    The binding of 125I-labeled mouse epidermal growth factor (EGF) to 18 cell lines, including HeLa (human carcinoma), MDCK (dog kidney cells), HTC (rat hepatoma), K22 (rat liver), HF (human foreskin), GM17 (human skin fibroblasts), XP (human xeroderma pigmentosum fibroblasts), and 3T3-L1 (mouse fibroblasts), was inhibited by saccharin and cyclamate. The human cells were more sensitive to inhibition by these sweeteners than mouse or rat cells. EGF at doses far above the physiological levels reversed the inhibition in rodent cells but not in HeLa cells. In HeLa cells, the doses of saccharin and cyclamate needed for 50% inhibition were 3.5 and 9.3 mg/ml, respectively. Glucose, 2-deoxyglucose, sucrose, and xylitol did not inhibit EGF binding. Previous studies have shown that phorbol esters, strongly potent tumor promoters, also inhibit EGF binding to tissue culture cells. To explain the EGF binding inhibition by such greatly dissimilar molecules as phorbol esters, saccharin, and cyclamate, it is suggested that they operate through the activation of a hormone response control unit.

  20. Effect of Ocean acidification on growth, calcification and reproduction of calcifying and non-calcifying epibionts of brown algae

    NASA Astrophysics Data System (ADS)

    Saderne, V.; Wahl, M.

    2012-04-01

    Anthropogenic emissions of CO2 are leading to an acidification of the oceans of 0.4 pH units in the course of this century according to the more severe model scenarios. The excess of CO2 could notably affect the benthic communities of calcifiers and macrophytes in different aspects (photosynthesis, respiration and calcification). Seaweeds are one of the key species of nearshore benthic ecosystems of the Baltic Sea. They are the substratum of several fouling epibionts like bryozoans and tubeworms. Most of those species are bearing calcified structures and could therefore be potentially impacted by the seawater pCO2. On the other hand, the biological activity of the host may substantially modulate the pH and pCO2 conditions in the boundary layer where the epibionts live. The aim of the present study was to test the sensitivity of seaweed macrofouling communities to higher pCO2 concentration. Fragments of macroalgae Fucus serratus bearing the calcifiers Spirorbis spirorbis (Annelida) and Electra pilosa (Bryozoa) and the non-calcifier Alcyonidium gelatinosum (Bryozoa) were maintained for 30 days under three pCO2: natural 460 ± 59 µatm and enriched 1193 ± 166 µatm and 3150 ± 446 µatm. Our study showed a significant reduction of growth rates and reproduction of Spirorbis individuals at the highest pCO2. Tubeworms Juveniles exhibited enhanced calcification of 40 % when in the light compare to dark, presumably due to effect of photosynthetic and respiratory activities of the host alga. Electra colonies showed significantly improved growth rates at 1193 µatm. The overall net dissolution of the communities was significantly higher at 3150 µatm. No effect on Alcyonidium colonies growth rates was observed. Those results suggest a remarkable resistance of the algal macro-epibiontic communities to the most elevated pCO2 predicted for 2100 for open ocean (~1000 µatm) conditions. Concerns remains with regards to higher pCO2 possibly found in the future Baltic Sea.

  1. Gymnemic Acids Inhibit Hyphal Growth and Virulence in Candida albicans

    PubMed Central

    Vediyappan, Govindsamy; Dumontet, Vincent; Pelissier, Franck; d’Enfert, Christophe

    2013-01-01

    Candida albicans is an opportunistic and polymorphic fungal pathogen that causes mucosal, disseminated and invasive infections in humans. Transition from the yeast form to the hyphal form is one of the key virulence factors in C. albicans contributing to macrophage evasion, tissue invasion and biofilm formation. Nontoxic small molecules that inhibit C. albicans yeast-to-hypha conversion and hyphal growth could represent a valuable source for understanding pathogenic fungal morphogenesis, identifying drug targets and serving as templates for the development of novel antifungal agents. Here, we have identified the triterpenoid saponin family of gymnemic acids (GAs) as inhibitor of C. albicans morphogenesis. GAs were isolated and purified from Gymnema sylvestre leaves, the Ayurvedic traditional medicinal plant used to treat diabetes. Purified GAs had no effect on the growth and viability of C. albicans yeast cells but inhibited its yeast-to-hypha conversion under several hypha-inducing conditions, including the presence of serum. Moreover, GAs promoted the conversion of C. albicans hyphae into yeast cells under hypha inducing conditions. They also inhibited conidial germination and hyphal growth of Aspergillus sp. Finally, GAs inhibited the formation of invasive hyphae from C. albicans-infected Caenorhabditis elegans worms and rescued them from killing by C. albicans. Hence, GAs could be useful for various antifungal applications due to their traditional use in herbal medicine. PMID:24040201

  2. Gymnemic acids inhibit hyphal growth and virulence in Candida albicans.

    PubMed

    Vediyappan, Govindsamy; Dumontet, Vincent; Pelissier, Franck; d'Enfert, Christophe

    2013-01-01

    Candida albicans is an opportunistic and polymorphic fungal pathogen that causes mucosal, disseminated and invasive infections in humans. Transition from the yeast form to the hyphal form is one of the key virulence factors in C. albicans contributing to macrophage evasion, tissue invasion and biofilm formation. Nontoxic small molecules that inhibit C. albicans yeast-to-hypha conversion and hyphal growth could represent a valuable source for understanding pathogenic fungal morphogenesis, identifying drug targets and serving as templates for the development of novel antifungal agents. Here, we have identified the triterpenoid saponin family of gymnemic acids (GAs) as inhibitor of C. albicans morphogenesis. GAs were isolated and purified from Gymnema sylvestre leaves, the Ayurvedic traditional medicinal plant used to treat diabetes. Purified GAs had no effect on the growth and viability of C. albicans yeast cells but inhibited its yeast-to-hypha conversion under several hypha-inducing conditions, including the presence of serum. Moreover, GAs promoted the conversion of C. albicans hyphae into yeast cells under hypha inducing conditions. They also inhibited conidial germination and hyphal growth of Aspergillus sp. Finally, GAs inhibited the formation of invasive hyphae from C. albicans-infected Caenorhabditis elegans worms and rescued them from killing by C. albicans. Hence, GAs could be useful for various antifungal applications due to their traditional use in herbal medicine.

  3. Effects of free Cu{sup 2+} and Zn{sup 2+} ions on growth and metal accumulation in freshwater algae

    SciTech Connect

    Knauer, K.; Behra, R.; Sigg, L.

    1997-02-01

    Five species of unicellular green algae were exposed to a broad range of Cu{sup 2+} and Zn{sup 2+} concentrations to examine the relationship between the free Cu{sup 2+} and Zn{sup 2+} ion concentrations and algal growth at metal concentrations relevant for freshwater phytoplankton. The authors estimated extra- and intracellular metal concentrations and characterized the adsorption of copper and zinc on algal surfaces. The optimal growth rate of Scenedesmus subspicatus occurred in a broad range of Cu{sup 2+} and Zn{sup 2+} concentrations (from 10{sup {minus}15} to 10{sup {minus}7} and from 10{sup {minus}12} to 10{sup {minus}55} M, respectively). Chlamydomonas reinhardtii reacted more sensitively toward copper, optimal growth was achieved only at a pCu (= {minus}log[Cu{sup 2+}]) around 11, whereas growth was optimal over about three orders of magnitude of the free Cu{sup 2+} concentration (from 10{sup {minus}13} to 10{sup {minus}10} M). Chlamydomonas cultures isolated from Lake Constance tolerated Cu{sup 2+} concentrations over seven orders of magnitude (pCu = 7 to 14). The growth of algae showed a high tolerance toward high intracellular copper and zinc concentrations. This suggests that the cells may immobilize the metals intracellularly. The affinity of copper for algal surfaces is higher than that of zinc in the experimental concentration range: adsorption constants log K{sub Cu} (11.06) > log K{sub Zn} (6.49) (pH = 7.9). These freshwater algae tolerate higher Cu{sup 2+} and Zn{sup 2+} concentrations than marine algal species. In comparison to the lake data, the results obtained from the culture algae indicate a possible role for copper as a limiting factor for certain algal species in eutrophic lakes.

  4. Control of ambient pH on growth and stable isotopes in phytoplanktonic calcifying algae

    NASA Astrophysics Data System (ADS)

    Hermoso, Michaël.

    2015-08-01

    The present work examines the relationship between pH-induced changes in growth and stable isotopic composition of coccolith calcite in two coccolithophore species with a geological perspective. These species (Gephyrocapsa oceanica and Coccolithus pelagicus) with differing physiologies and vital effects possess a growth optimum corresponding to average pH of surface seawater in the geological period during their first known occurrence. The "ancestral" C. pelagicus has much wider pH tolerance in terms of growth rates than the more recently evolved G. oceanica. Diminished growth rates are explained by the challenge of proton translocation into the extracellular environment at low pH and enhanced aqueous CO2 limitation at high pH. Reducing the cell dynamics in this way leads to a lower degree of oxygen isotopic disequilibrium in G. oceanica. In contrast, the slower growing species C. pelagicus, which typically precipitates near-equilibrium calcite, does not show any modulation of oxygen isotope signals with changing pH. Overall, carbon and oxygen isotope compositions are best explained by the degree of utilization of the internal dissolved inorganic carbon (DIC) pool and the dynamics of isotopic reequilibration inside the cell. Thus, the "carbonate ion effect" may not apply to coccolithophores. This difference with foraminifera can be traced to different modes of DIC incorporation into these two distinct biomineralizing organisms. From a geological perspective, these findings have implications for refining the use of oxygen isotopes to infer more reliable sea surface temperatures (SSTs) from fossil carbonates and contribute to a better understanding of how climate-relevant parameters are recorded in the sedimentary archive.

  5. Effect of petroleum hydrocarbons on algae

    SciTech Connect

    Bhadauria, S. ); Sengar, R.M.S. ); Mittal, S.; Bhattacharjee, S. )

    1992-01-01

    Algal species (65) were isolated from oil refinery effluent. Twenty-five of these species were cultured in Benecke's medium in a growth chamber, along with controls. Retardation in algal growth, inhibition in algal photosynthesis, and discoloration was observed in petroleum enriched medium. Few forms, viz. Cyclotella sp., Cosmarium sp., and Merismopedia sp. could not survive. The lag phase lengthened by several days and slope of exponential phase was also depressed. Chlamydomonas sp., Scenedesmus sp., Ankistrodesmus sp., Nitzschia sp. and Navicula sp. were comparatively susceptible to petroleum. Depression in carbon fixation, cell numbers, and total dry algal mass was noticeable, showing toxicity to both diatoms and green algae.

  6. Vascular endothelial-derived semaphorin 3 inhibits sympathetic axon growth.

    PubMed

    Damon, Deborah H

    2006-03-01

    Vascular sympathetic innervation is an important determinant of blood pressure and blood flow. The mechanisms that determine vascular sympathetic innervation are not well understood. Recent studies indicate that vascular endothelial cells (EC) express semaphorin 3A, a repulsive axon guidance cue. This suggests that EC would inhibit the growth of axons to blood vessels. The present study tests this hypothesis. RT-PCR and Western analyses confirmed that rat aortic vascular ECs expressed semaphorin 3A as well as other class 3 semaphorins (sema 3s). To determine the effects of EC-derived sema 3 on sympathetic axons, axon outgrowth was assessed in cultures of neonatal sympathetic ganglia grown for 72 h in the absence and presence of vascular EC. Nerve growth factor-induced axon growth in the presence of ECs was 50 +/- 4% (P < 0.05) of growth in the absence of ECs. ECs did not inhibit axon growth in the presence of an antibody that neutralized the activity of sema 3 (P > 0.05). RT-PCR and Western analyses also indicated that sema 3s were expressed in ECs of intact arteries. To assess the function of sema 3s in arteries, sympathetic ganglia were grown in the presence of arteries for 72 h, and the percentage of axons that grew toward the artery was determined: 44 +/- 4% of axons grew toward neonatal carotid arteries. Neutralization of sema 3s or removal of EC increased the percentage of axons that grew toward the artery (71 +/- 8% and 72 +/- 8%, respectively). These data indicate that vascular EC-derived sema 3s inhibit sympathetic axon growth and may thus be a determinant of vascular sympathetic innervation.

  7. Towards an organic palaeosalinity proxy: the effect of salinity, growth rate and growth phase on the hydrogen isotopic composition of alkenones produced by haptophyte algae

    NASA Astrophysics Data System (ADS)

    Chivall, David; M'Boule, Daniela; Schouten, Stefan; Sinninghe Damsté, Jaap S.; van der Meer, Marcel T. J.

    2013-04-01

    Palaeosalinity is one of the most important oceanographic parameters which currently cannot be quantified with reasonable accuracy from sedimentary records. Schouten et al.1 established that the fractionation of hydrogen isotopes between growth water and alkenones produced by the haptophyte algae Emiliania huxleyi and Gephyrocapsa oceanica is salinity dependent. As such, the δD values of alkenones recovered from sediment cores can be used to reconstruct variations in palaeo- sea surface salinity.2 However, to accurately determine absolute palaeosalinity requires a better constraining of the relationship between this hydrogen fractionation, salinity and other parameters such as growth rate and growth phase. Here, we present results from our ongoing work to constrain the relationship between the fractionation factor αalkenone-water, salinity, growth rate and growth phase for the major alkenone-producing haptophytes. In batch cultures of different strains of the open-ocean haptophyte E. huxleyi sampled during the exponential growth phase, αC37alkenone-growthwater increases by between 0.0022 and 0.0033 per unit increase in salinity. A similar relationship is observed in batch cultures of the coastal haptophyte Isochrysis galbana, where α increases with each unit of salinity by 0.0019 - slightly less than for E. huxleyi. However, absolute αC37alkenone-growthwater values vary strongly between species suggesting that species composition has a strong impact on the δD value of alkenones. The fractionation factor for alkenones produced by batch cultures of I. galbana is affected by growth phase: the rate of change of αC37alkenone-growthwater with each unit of salinity decreases from 0.0019 in the exponential phase to 0.0010 during the stationary phase. We also show the effect of varying growth rate over the range 0.2-0.8 day-1 on the fractionation factor for alkenones produced by E. huxleyi grown in continuous culture. These data show that alkenone δD can be used to

  8. Impacts of increased atmospheric CO2 concentration on photosynthesis and growth of micro- and macro-algae.

    PubMed

    Wu, HongYan; Zou, DingHui; Gao, KunShan

    2008-12-01

    Marine photosynthesis drives the oceanic biological CO(2) pump to absorb CO(2) from the atmosphere, which sinks more than one third of the industry-originated CO(2) into the ocean. The increasing atmospheric CO(2) and subsequent rise of pCO(2) in seawater, which alters the carbonate system and related chemical reactions and results in lower pH and higher HCO(3) (-) concentration, affect photosynthetic CO(2) fixation processes of phytoplanktonic and macroalgal species in direct and/or indirect ways. Although many unicellular and multicellular species can operate CO(2)-concentrating mechanisms (CCMs) to utilize the large HCO(3) (-) pool in seawater, enriched CO(2) up to several times the present atmospheric level has been shown to enhance photosynthesis and growth of both phytoplanktonic and macro-species that have less capacity of CCMs. Even for species that operate active CCMs and those whose photosynthesis is not limited by CO(2) in seawater, increased CO(2) levels can down-regulate their CCMs and therefore enhance their growth under light-limiting conditions (at higher CO(2) levels, less light energy is required to drive CCM). Altered physiological performances under high-CO(2) conditions may cause genetic alteration in view of adaptation over long time scale. Marine algae may adapt to a high CO(2) oceanic environment so that the evolved communities in future are likely to be genetically different from the contemporary communities. However, most of the previous studies have been carried out under indoor conditions without considering the acidifying effects on seawater by increased CO(2) and other interacting environmental factors, and little has been documented so far to explain how physiology of marine primary producers performs in a high-CO(2) and low-pH ocean.

  9. Effect of centrifugation on water recycling and algal growth to enable algae biodiesel production.

    PubMed

    Igou, Thomas; Van Ginkel, Steven W; Penalver-Argueso, Patricia; Fu, Hao; Doi, Shusuke; Narode, Asmita; Cheruvu, Sarasija; Zhang, Qian; Hassan, Fariha; Woodruff, Frazier; Chen, Yongsheng

    2014-12-01

    The latest research shows that algal biofuels, at the production levels mandated in the Energy Independence and Security Act of 2007, will place significant demands on water and compete with agriculture meant for food production. Thus, there is a great need to recycle water while producing algal biofuels. This study shows that when using a synthetic medium, soluble algal products, bacteria, and other inhibitors can be removed by centrifugation and enable water recycling. Average water recovery reached 84% and water could be recycled at least 10 times without reducing algal growth.

  10. The Study of Algae

    ERIC Educational Resources Information Center

    Rushforth, Samuel R.

    1977-01-01

    Included in this introduction to the study of algae are drawings of commonly encountered freshwater algae, a summary of the importance of algae, descriptions of the seven major groups of algae, and techniques for collection and study of algae. (CS)

  11. Proteasome Inhibition by Fellutamide B Induces Nerve Growth Factor Synthesis

    PubMed Central

    Hines, John; Groll, Michael; Fahnestock, Margaret; Crews, Craig M.

    2008-01-01

    SUMMARY Neurotrophic small molecules have the potential to aid in the treatment of neuronal injury and neurodegenerative diseases. The natural product fellutamide B, originally isolated from Penicillium fellutanum, potently induces nerve growth factor (NGF) release from fibroblasts and glial-derived cells, although the mechanism for this neurotrophic activity has not been elucidated. Here, we report that fellutamide B potently inhibits proteasome catalytic activity. High resolution structural information obtained from co-crystallization of the 20S proteasome reveals novel aspects regarding β-subunit binding and adduct formation by fellutamide B to inhibit their hydrolytic activity. We demonstrate that fellutamide B and other proteasome inhibitors increased NGF gene transcription via a cis-acting element (or elements) in the promoter. These results demonstrate an unrecognized connection between proteasome inhibition and NGF production, suggesting a possible new strategy in the development of neurotrophic agents. PMID:18482702

  12. Factors determining growth and vertical distribution of planktonic algae in extremely acidic mining lakes (pH 2.7)

    NASA Astrophysics Data System (ADS)

    Bissinger, Vera

    2003-04-01

    In this thesis, I investigated the factors influencing the growth and vertical distribution of planktonic algae in extremely acidic mining lakes (pH 2-3). In the focal study site, Lake 111 (pH 2.7; Lusatia, Germany), the chrysophyte, Ochromonas sp., dominates in the upper water strata and the chlorophyte, Chlamydomonas sp., in the deeper strata, forming a pronounced deep chlorophyll maximum (DCM). Inorganic carbon (IC) limitation influenced the phototrophic growth of Chlamydomonas sp. in the upper water strata. Conversely, in deeper strata, light limited its phototrophic growth. When compared with published data for algae from neutral lakes, Chlamydomonas sp. from Lake 111 exhibited a lower maximum growth rate, an enhanced compensation point and higher dark respiration rates, suggesting higher metabolic costs due to the extreme physico-chemical conditions. The photosynthetic performance of Chlamydomonas sp. decreased in high-light-adapted cells when IC limited. In addition, the minimal phosphorus (P) cell quota was suggestive of a higher P requirement under IC limitation. Subsequently, it was shown that Chlamydomonas sp. was a mixotroph, able to enhance its growth rate by taking up dissolved organic carbon (DOC) via osmotrophy. Therefore, it could survive in deeper water strata where DOC concentrations were higher and light limited. However, neither IC limitation, P availability nor in situ DOC concentrations (bottom-up control) could fully explain the vertical distribution of Chlamydomonas sp. in Lake 111. Conversely, when a novel approach was adopted, the grazing influence of the phagotrophic phototroph, Ochromonas sp., was found to exert top-down control on its prey (Chlamydomonas sp.) reducing prey abundance in the upper water strata. This, coupled with the fact that Chlamydomonas sp. uses DOC for growth, leads to a pronounced accumulation of Chlamydomonas sp. cells at depth; an apparent DCM. Therefore, grazing appears to be the main factor influencing the

  13. Inhibitory effects of soluble algae products (SAP) released by Scenedesmus sp. LX1 on its growth and lipid production.

    PubMed

    Zhang, Tian-Yuan; Yu, Yin; Wu, Yin-Hu; Hu, Hong-Ying

    2013-10-01

    Soluble algal products (SAP) accumulated in culture medium via water reuse may affect the growth of microalga during the cultivation. Scenedesmus sp. LX1, a freshwater microalga, was used in this study to investigate the effect of SAP on growth and lipid production of microalga. Under the SAP concentrations of 6.4-25.8 mg L(-1), maximum algal density (K) and maximum growth rate (Rmax) of Scenedesmus sp. LX1 were decreased by 50-80% and 35-70% compared with the control group, respectively. The effect of SAP on lipid accumulation of Scenedesmus sp. LX1 was non-significant. According to hydrophilic-hydrophobic and acid-base properties, SAP was fractionized into six fractions. All of the fractions could inhibit the growth of Scenedesmus sp. LX1. Organic bases (HIB, HOB) and hydrophilic acids (HIA) showed the strongest inhibition. HIA could also decrease the lipid content of Scenedesmus sp. LX1 by 59.2%. As the inhibitory effect, SAP should be seriously treated before water reuse.

  14. 3-Bromopyruvate inhibits human gastric cancer tumor growth in nude mice via the inhibition of glycolysis.

    PubMed

    Xian, Shu-Lin; Cao, Wei; Zhang, Xiao-Dong; Lu, Yun-Fei

    2015-02-01

    Tumor cells primarily depend upon glycolysis in order to gain energy. Therefore, the inhibition of glycolysis may inhibit tumor growth. Our previous study demonstrated that 3-bromopyruvate (3-BrPA) inhibited gastric cancer cell proliferation in vitro. However, the ability of 3-BrPA to suppress tumor growth in vivo, and its underlying mechanism, have yet to be elucidated. The aim of the present study was to investigate the inhibitory effect of 3-BrPA in an animal model of gastric cancer. It was identified that 3-BrPA exhibited strong inhibitory effects upon xenograft tumor growth in nude mice. In addition, the antitumor function of 3-BrPA exhibited a dose-effect association, which was similar to that of the chemotherapeutic agent, 5-fluorouracil. Furthermore, 3-BrPA exhibited low toxicity in the blood, liver and kidneys of the nude mice. The present study hypothesized that the inhibitory effect of 3-BrPA is achieved through the inhibition of hexokinase activity, which leads to the downregulation of B-cell lymphoma 2 (Bcl-2) expression, the upregulation of Bcl-2-associated X protein expression and the subsequent activation of caspase-3. These data suggest that 3-BrPA may be a novel therapy for the treatment of gastric cancer.

  15. Equol inhibits growth, induces atresia, and inhibits steroidogenesis of mouse antral follicles in vitro

    PubMed Central

    Mahalingam, Sharada; Gao, Liying; Gonnering, Marni; Helferich, William; Flaws, Jodi A.

    2016-01-01

    Equol is a non-steroidal estrogen metabolite produced by microbial conversion of daidzein, a major soy isoflavone, in the gut of some humans and many animal species. Isoflavones and their metabolites can affect endogenous estradiol production, action, and metabolism, potentially influencing ovarian follicle function. However, no studies have examined the effects of equol on intact ovarian antral follicles, which are responsible for sex steroid synthesis and further development into ovulatory follicles. Thus, the present study tested the hypothesis that equol inhibits antral follicle growth, increases follicle atresia, and inhibits steroidogenesis in the adult mouse ovary. To test this hypothesis, antral follicles isolated from adult CD-1 mice were cultured with vehicle control (dimethyl sulfoxide; DMSO) or equol (600 nM, 6 μM, 36 μM, 100 μM) for 48 and 96 h. Every 24 h, follicle diameters were measured to monitor growth. At 48 and 96 h, the culture medium was subjected to measurement of hormone levels, and the cultured follicles were subjected to gene expression analysis. Additionally, follicles were histologically evaluated for signs of atresia after 96 h of culture. The results indicate that equol (100 μM) inhibited follicle growth, altered the mRNA levels of bcl2-associated X protein and B cell leukemia/lymphoma 2, and induced follicle atresia. Further, equol decreased the levels of estradiol, testosterone, androstenedione, and progesterone, and it decreased mRNA levels of cholesterol side-chain cleavage, steroid 17-α-hydroxalase, and aromatase. Collectively, these data indicate that equol inhibits growth, increases atresia, and inhibits steroidogenesis of cultured mouse antral follicles. PMID:26876617

  16. The edible red alga, Gracilaria verrucosa, inhibits lipid accumulation and ROS production, but improves glucose uptake in 3T3-L1 cells.

    PubMed

    Woo, Mi-Seon; Choi, Hyeon-Son; Lee, Ok-Hwan; Lee, Boo-Yong

    2013-07-01

    Gracilaria verrucosa is a red alga that is widely distributed in seaside areas of many countries. We examined the effect of G. verrucosa extract on adipogenesis, reactive oxygen species (ROS) production, and glucose uptake in 3T3-L1 cells. Oil red O staining and a nitroblue tetrazolium assay showed that G. verrucosa extract inhibited lipid accumulation and ROS production, respectively. mRNA levels of adipogenic transcription factors, peroxisome proliferator-activated receptor gamma and CCAAT/enhancer-binding protein alpha, as well as of their target gene, adipocyte protein 2, were reduced upon treatment with G. verrucosa extract. However, G. verrucosa extract increased glucose uptake, glucose transporter-4 expression, and AMP-activated protein kinaseα (AMPKα) phosphorylation compared to the control. Our results suggest that the anti-adipogenic and insulin-sensitive effects of G. verrucosa extract can be recapitulated to activation of AMPKα.

  17. Genotoxicity and growth inhibition effects of aniline on wheat.

    PubMed

    Tao, Nan; Liu, Guanyi; Bai, Lu; Tang, Lu; Guo, Changhong

    2017-02-01

    Aniline is a synthetic compound widely used in industrial and pesticide production, which can lead to environmental pollution. Its high concentration in rivers and lakes is hazardous to aquatic species. Although the mechanism of aniline toxicity has been studied extensively in animals and algae, little is known about its genotoxicity in plants. In this study, we investigated the genotoxicity effects of aniline on wheat root tip cells. The mitotic index of wheat root tip cells decreased when the aniline test concentration was higher than 10 mg L(-1). The frequency of micronucleus and chromosomal aberrations increased at aniline concentrations ranging between 5 and 100 mg L(-1), and reached 23.3‰ ± 0.3‰ and 8.9‰ ± 0.68‰, respectively, at an aniline concentration of 100 mg L(-1). These values were sevenfold higher than those in the control group. The wheat seedlings showed various growth toxicity effects under different concentrations of aniline. The shoot height, root length, fresh weight, and dry weight of wheat seedlings decreased at aniline test concentrations ranging between 25 and 200 mg L(-1). At 200 mg L(-1) aniline, the dry weight was only one-third that of the control group. Overall, the findings of this study provide evidence that aniline is a serious environmental pollutant causing deleterious genotoxic effects on wheat root tip cells and growth toxic effects on wheat seedlings. However, understanding the mechanisms that underlie aniline genotoxicity in plants needs further study.

  18. The green alga, Cladophora, promotes Escherichia coli growth and contamination of recreational waters in Lake Michigan

    USGS Publications Warehouse

    Heuvel, A.V.; McDermott, C.; Pillsbury, R.; Sandrin, T.; Kinzelman, J.; Ferguson, J.; Sadowsky, M.; Byappanahalli, M.; Whitman, R.; Kleinheinz, G.T.

    2010-01-01

    A linkage between Cladophora mats and exceedances of recreational water quality criteria has been suggested, but not directly studied. Th is study investigates the spatial and temporal association between Escherichia coli concentrations within and near Cladophora mats at two northwestern Lake Michigan beaches in Door County, Wisconsin. Escherichia coli concentrations in water underlying mats were significantly greater than surrounding water (p < 0.001). Below mat E. coli increased as the stranded mats persisted at the beach swash zone. Water adjacent to Cladophora mats had lower E. coli concentrations, but surpassed EPA swimming criteria the majority of sampling days. A signifi cant positive association was found between E. coli concentrations attached to Cladophora and in underlying water (p < 0.001). The attached E. coli likely acted as a reservoir for populating water underlying the mat. Fecal bacterial pathogens, however, could not be detected by microbiological culture methods either attached to mat biomass or in underlying water. Removal of Cladophora mats from beach areas may improve aesthetic and microbial water quality at affected beaches. These associations and potential natural growth of E. coli in bathing waters call into question the efficacy of using E. coli as a recreational water quality indicator of fecal contaminations. Copyright ?? 2010 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  19. Micronutrient requirements for growth and hydrocarbon production in the oil producing green alga Botryococcus braunii (Chlorophyta).

    PubMed

    Song, Liang; Qin, Jian G; Su, Shengqi; Xu, Jianhe; Clarke, Stephen; Shan, Yichu

    2012-01-01

    The requirements of micronutrients for biomass and hydrocarbon production in Botryococcus braunii UTEX 572 were studied using response surface methodology. The concentrations of four micronutrients (iron, manganese, molybdenum, and nickel) were manipulated to achieve the best performance of B. braunii in laboratory conditions. The responses of algal biomass and hydrocarbon to the concentration variations of the four micronutrients were estimated by a second order quadratic regression model. Genetic algorithm calculations showed that the optimal level of micronutrients for algal biomass were 0.266 µM iron, 0.707 µM manganese, 0.624 µM molybdenum and 3.38 µM nickel. The maximum hydrocarbon content could be achieved when the culture media contained 10.43 µM iron, 6.53 µM manganese, 0.012 µM molybdenum and 1.73 µM nickel. The validation through an independent test in a photobioreactor suggests that the modified media with optimised concentrations of trace elements can increase algal biomass by 34.5% and hydrocarbon by 27.4%. This study indicates that micronutrients play significant roles in regulating algal growth and hydrocarbon production, and the response surface methodology can be used to optimise the composition of culture medium in algal culture.

  20. Inhibition of platelet-derived growth factor signaling prevents muscle fiber growth during skeletal muscle hypertrophy.

    PubMed

    Sugg, Kristoffer B; Korn, Michael A; Sarver, Dylan C; Markworth, James F; Mendias, Christopher L

    2017-03-01

    The platelet-derived growth factor receptors alpha and beta (PDGFRα and PDGFRβ) mark fibroadipogenic progenitor cells/fibroblasts and pericytes in skeletal muscle, respectively. While the role that these cells play in muscle growth and development has been evaluated, it was not known whether the PDGF receptors activate signaling pathways that control transcriptional and functional changes during skeletal muscle hypertrophy. To evaluate this, we inhibited PDGFR signaling in mice subjected to a synergist ablation muscle growth procedure, and performed analyses 3 and 10 days after induction of hypertrophy. The results from this study indicate that PDGF signaling is required for fiber hypertrophy, extracellular matrix production, and angiogenesis that occur during muscle growth.

  1. Inhibition of Nb2 T-lymphoma cell growth by transforming growth factor-beta.

    PubMed Central

    Rayhel, E J; Prentice, D A; Tabor, P S; Flurkey, W H; Geib, R W; Laherty, R F; Schnitzer, S B; Chen, R; Hughes, J P

    1988-01-01

    Transforming growth factor-beta (TGF-beta) inhibits proliferation of Nb2 cells, a rat T lymphoma, in response to lactogens and interleukin-2. Prostaglandins may play an important role in the pathway through which TGF-beta exerts its inhibitory actions, because prostaglandin E2 also inhibits proliferation of Nb2 cells, and indomethacin, an inhibitor of prostaglandin synthesis, reverses the inhibitory effects of TGF-beta on Nb2 cell proliferation. PMID:3262338

  2. Entry Inhibition of Influenza Viruses with High Mannose Binding Lectin ESA-2 from the Red Alga Eucheuma serra through the Recognition of Viral Hemagglutinin.

    PubMed

    Sato, Yuichiro; Morimoto, Kinjiro; Kubo, Takanori; Sakaguchi, Takemasa; Nishizono, Akira; Hirayama, Makoto; Hori, Kanji

    2015-05-29

    Lectin sensitivity of the recent pandemic influenza A virus (H1N1-2009) was screened for 12 lectins with various carbohydrate specificity by a neutral red dye uptake assay with MDCK cells. Among them, a high mannose (HM)-binding anti-HIV lectin, ESA-2 from the red alga Eucheuma serra, showed the highest inhibition against infection with an EC50 of 12.4 nM. Moreover, ESA-2 exhibited a wide range of antiviral spectrum against various influenza strains with EC50s of pico molar to low nanomolar levels. Besides ESA-2, HM-binding plant lectin ConA, fucose-binding lectins such as fungal AOL from Aspergillus oryzae and AAL from Aleuria aurantia were active against H1N1-2009, but the potency of inhibition was of less magnitude compared with ESA-2. Direct interaction between ESA-2 and a viral envelope glycoprotein, hemagglutinin (HA), was demonstrated by ELISA assay. This interaction was effectively suppressed by glycoproteins bearing HM-glycans, indicating that ESA-2 binds to the HA of influenza virus through HM-glycans. Upon treatment with ESA-2, no viral antigens were detected in the host cells, indicating that ESA-2 inhibited the initial steps of virus entry into the cells. ESA-2 would thus be useful as a novel microbicide to prevent penetration of viruses such as HIV and influenza viruses to the host cells.

  3. Entry Inhibition of Influenza Viruses with High Mannose Binding Lectin ESA-2 from the Red Alga Eucheuma serra through the Recognition of Viral Hemagglutinin

    PubMed Central

    Sato, Yuichiro; Morimoto, Kinjiro; Kubo, Takanori; Sakaguchi, Takemasa; Nishizono, Akira; Hirayama, Makoto; Hori, Kanji

    2015-01-01

    Lectin sensitivity of the recent pandemic influenza A virus (H1N1-2009) was screened for 12 lectins with various carbohydrate specificity by a neutral red dye uptake assay with MDCK cells. Among them, a high mannose (HM)-binding anti-HIV lectin, ESA-2 from the red alga Eucheuma serra, showed the highest inhibition against infection with an EC50 of 12.4 nM. Moreover, ESA-2 exhibited a wide range of antiviral spectrum against various influenza strains with EC50s of pico molar to low nanomolar levels. Besides ESA-2, HM-binding plant lectin ConA, fucose-binding lectins such as fungal AOL from Aspergillus oryzae and AAL from Aleuria aurantia were active against H1N1-2009, but the potency of inhibition was of less magnitude compared with ESA-2. Direct interaction between ESA-2 and a viral envelope glycoprotein, hemagglutinin (HA), was demonstrated by ELISA assay. This interaction was effectively suppressed by glycoproteins bearing HM-glycans, indicating that ESA-2 binds to the HA of influenza virus through HM-glycans. Upon treatment with ESA-2, no viral antigens were detected in the host cells, indicating that ESA-2 inhibited the initial steps of virus entry into the cells. ESA-2 would thus be useful as a novel microbicide to prevent penetration of viruses such as HIV and influenza viruses to the host cells. PMID:26035023

  4. Hydroxyapatite Growth Inhibition Effect of Pellicle Statherin Peptides.

    PubMed

    Xiao, Y; Karttunen, M; Jalkanen, J; Mussi, M C M; Liao, Y; Grohe, B; Lagugné-Labarthet, F; Siqueira, W L

    2015-08-01

    In our recent studies, we have shown that in vivo-acquired enamel pellicle is a sophisticated biological structure containing a significant portion of naturally occurring salivary peptides. From a functional aspect, the identification of peptides in the acquired enamel pellicle is of interest because many salivary proteins exhibit functional domains that maintain the activities of the native protein. Among the in vivo-acquired enamel pellicle peptides that have been newly identified, 5 peptides are derived from statherin. Here, we assessed the ability of these statherin pellicle peptides to inhibit hydroxyapatite crystal growth. In addition, atomistic molecular dynamics (MD) simulations were performed to better understand the underlying physical mechanisms of hydroxyapatite growth inhibition. A microplate colorimetric assay was used to quantify hydroxyapatite growth. Statherin protein, 5 statherin-derived peptides, and a peptide lacking phosphate at residues 2 and 3 were analyzed. Statherin peptide phosphorylated on residues 2 and 3 indicated a significant inhibitory effect when compared with the 5 other peptides (P < 0.05). MD simulations showed a strong affinity and fast adsorption to hydroxyapatite for phosphopeptides, whereas unphosphorylated peptides interacted weakly with the hydroxyapatite. Our data suggest that the presence of a covalently linked phosphate group (at residues 2 and 3) in statherin peptides modulates the effect of hydroxyapatite growth inhibition. This study provides a mechanism to account for the composition and function of acquired enamel pellicle statherin peptides that will contribute as a base for the development of biologically stable and functional synthetic peptides for therapeutic use against dental caries and/or periodontal disease.

  5. The fate of glyphosate in water hyacinth and its physiological and biochemical influences on growth of algae

    SciTech Connect

    Tsai, Baolong.

    1989-01-01

    Absorption, translocation, distribution, exudation, and guttation of {sup 14}C-glyphosate in water hyacinth (Eichhornia crassipes) were studied. Glyphosphate entered the plant by foliage and solution treatment. Plants were harvested and separated into the following parts: treated leaf blade, treated leaf petiole, young leaf blade, young leaf petiole, old leak blade, old leaf petiole, and root. Each part was extracted with methanol. Treated leaves, which exist only in foliage treatment, were washed with water and chloroform to remove the glyphosate residues. All {sup 14}C counting was made by liquid scintillation spectrometry. Autoradiography was used to locate {sup 14}C-glyphosate after foliage treatment. Results indicated that glyphosate can be absorbed from the leaf surface and translocated rapidly through phloem tissues into the whole plant body. The roots of water hyacinth absorbed glyphosate without vertical transport. Guttation of glyphosate occurred in treated leaf tips. Exudation of glyphosate from roots of water hyacinth occurred within 8 hr after foliage treatment. Chlorella vulgaris, Chlamydomonas reihardii, Anabaena cylindrica, and Chroococcus turgidus were used to explore the physiological and biochemical effects of glyphosate on algae. Spectrophotometric assays were performed for algal growth, chlorophyll, carotenoids, phycobiliprotein, carbohydrate, and protein. TLC procedures and an image analyzer were used to detect the metabolites of glyphosate inside algal cells. The common visible symptom of glyphosate toxicity in all algal cells were bleaching effect and reduction of contents of carbohydrate, protein, and pigments. The results highly suggested that glyphosate injured the algal cells by destruction of photosynthetic pigments and resulted in lowering the contents of carbohydrate and protein in algal cells.

  6. Growth under Red Light Enhances Photosystem II Relative to Photosystem I and Phycobilisomes in the Red Alga Porphyridium cruentum1

    PubMed Central

    Cunningham, Francis X.; Dennenberg, Ronald J.; Jursinic, Paul A.; Gantt, Elisabeth

    1990-01-01

    Acclimation of the photosynthetic apparatus to light absorbed primarily by photosystem I (PSI) or by photosystem II (PSII) was studied in the unicellular red alga Porphyridium cruentum (ATCC 50161). Cultures grown under green light of 15 microeinsteins per square meter per second (PSII light; absorbed predominantly by the phycobilisomes) exhibited a PSII/PSI ratio of 0.26 ± 0.05. Under red light (PSI light; absorbed primarily by chlorophyll) of comparable quantum flux, cells contained nearly five times as many PSII per PSI (1.21 ± 0.10), and three times as many PSII per cell. About 12% of the chlorophyll was attributed to PSII in green light, 22% in white light, and 39% in red light-grown cultures. Chlorophyll antenna sizes appeared to remain constant at about 75 chlorophyll per PSII and 140 per PSI. Spectral quality had little effect on cell content or composition of the phycobilisomes, thus the number of PSII per phycobilisome was substantially greater in red light-grown cultures (4.2 ± 0.6) than in those grown under green (1.6 ± 0.3) or white light (2.9 ± 0.1). Total photosystems (PSI + PSII) per phycobilisome remained at about eight in each case. Carotenoid content and composition was little affected by the spectral composition of the growth light. Zeaxanthin comprised more than 50% (mole/mole), β-carotene about 40%, and cryptoxanthin about 4% of the carotenoid pigment. Despite marked changes in the light-harvesting apparatus, red and green light-grown cultures have generation times equal to that of cultures grown under white light of only one-third the quantum flux. PMID:16667597

  7. Inhibition of tumor invasion and metastasis by calcium spirulan (Ca-SP), a novel sulfated polysaccharide derived from a blue-green alga, Spirulina platensis.

    PubMed

    Mishima, T; Murata, J; Toyoshima, M; Fujii, H; Nakajima, M; Hayashi, T; Kato, T; Saiki, I

    1998-08-01

    We have investigated the effect of calcium spirulan (Ca-SP) isolated from a blue-green alga, Spirulina platensis, which is a sulfated polysaccharide chelating calcium and mainly composed of rhamnose, on invasion of B16-BL6 melanoma, Colon 26 M3.1 carcinoma and HT-1080 fibrosarcoma cells through reconstituted basement membrane (Matrigel). Ca-SP significantly inhibited the invasion of these tumor cells through Matrigel/fibronectin-coated filters. Ca-SP also inhibited the haptotactic migration of tumor cells to laminin, but it had no effect on that to fibronectin. Ca-SP prevented the adhesion of B16-BL6 cells to Matrigel and laminin substrates but did not affect the adhesion to fibronectin. The pretreatment of tumor cells with Ca-SP inhibited the adhesion to laminin, while the pretreatment of laminin substrates did not. Ca-SP had no effect on the production and activation of type IV collagenase in gelatin zymography. In contrast, Ca-SP significantly inhibited degradation of heparan sulfate by purified heparanase. The experimental lung metastasis was significantly reduced by co-injection of B16-BL6 cells with Ca-SP. Seven intermittent i.v. injections of 100 microg of Ca-SP caused a marked decrease of lung tumor colonization of B16-BL6 cells in a spontaneous lung metastasis model. These results suggest that Ca-SP, a novel sulfated polysaccharide, could reduce the lung metastasis of B16-BL6 melanoma cells, by inhibiting the tumor invasion of basement membrane probably through the prevention of the adhesion and migration of tumor cells to laminin substrate and of the heparanase activity.

  8. Hugl-1 inhibits glioma cell growth in intracranial model.

    PubMed

    Liu, Xuejiao; Lu, Dong; Ma, Peng; Liu, Huaqiang; Cao, Yuewen; Sang, Ben; Zhu, Xianlong; Shi, Qiong; Hu, Jinxia; Yu, Rutong; Zhou, Xiuping

    2015-10-01

    Drosophila lethal (2) giant larvae (lgl) has been reported as a tumor suppressor and could regulate the Drosophila hippo signaling. Human giant larvae-1(Hugl-1), one human homologue of Drosophila lgl, also has been reported to be involved in the development of some human cancers. However, whether Hugl-1 is associated with the pathogenesis of malignant gliomas remains poorly understood. In the present work, we examined the effect of Hugl-1 on glioma cell growth both in vitro and in vivo. Firstly, we found that Hugl-1 protein levels decreased in the human glioma tissues, suggesting that Hugl-1 is involved in glioma progression. Unfortunately, either stably or transiently over-expressing Hugl-1 did not affect glioma cell proliferation in vitro. In addition, Hugl-1 over-expression did not regulate hippo signaling pathway. Interestingly, over-expression of Hugl-1 not only inhibited gliomagenesis but also markedly inhibited cell proliferation and promoted the apoptosis of U251 cells in an orthotopic model of nude mice. Taken together, this study provides the evidence that Hugl-1 inhibits glioma cell growth in intracranial model of nude mice, suggesting that Hugl-1 might be a potential tumor target for glioma therapy.

  9. Structural effects of ionic liquids on microalgal growth inhibition and microbial degradation.

    PubMed

    Pham, Thi Phuong Thuy; Cho, Chul-Woong; Yun, Yeoung-Sang

    2016-03-01

    In the present study, we investigated structural effects of various ionic liquids (ILs) on microalgal growth inhibition and microbial biodegradability. For this, we tested pyridinium- and pyrrolidinium-based ILs with various alkyl chain lengths and bromide anion, and compared the toxicological effects with log EC50 values of imidazolium-based IL with the same alkyl chains and anion from literature. Comparing determined EC50 values of cationic moieties with the same alkyl chain length, pyridinium-based ILs were found to be slightly more toxic towards the freshwater green alga, Pseudokirchneriella subcapitata, than a series of pyrrolidinium and imidazolium except to 1-octyl-3-methylimidazolium bromide. Concerning the biodegradation study of 12 ILs using the activated sludge microorganisms, the results showed that the pyridinium derivatives except to 1-propyl-3-methylpyridinium cation were degraded. Whereas in case of imidazolium- and pyrrolidinium-based compounds, only n-hexyl and n-octyl substituted cations were fully degraded but no significant biodegradation was observed for the short chains (three and four alkyl chains).

  10. Targeting Btk with ibrutinib inhibit gastric carcinoma cells growth

    PubMed Central

    Wang, Jin Dao; Chen, Xiao Ying; Ji, Ke Wei; Tao, Feng

    2016-01-01

    Bruton’s tyrosine kinase (Btk) is a member of the Tec-family non-receptor tyrosine kinases family. It has previously been reported to be expressed in B cells and has an important role in B-cell malignancies. While the roles of Btk in the pathogenesis of certain B-cell malignancies are well established, the functions of Btk in gastric carcinoma have never been investigated. Herein, we found that Btk is over-expressed in gastric carcinoma tissues and gastric cancer cells. Knockdown of Btk expression selectively inhibits the growth of gastric cancer cells, but not that of the normal gastric mucosa epithelial cell, which express very little Btk. Inhibition of Btk by its inhibitor ibrutinib has an additive inhibitory effect on gastric cancer cell growth. Treatment of gastric cancer cells, but not immortalized breast epithelial cells with ibrutinib results in effective cell killing, accompanied by the attenuation of Btk signals. Ibrutinib also induces apoptosis in gastric carcinoma cells as well as is a chemo-sensitizer for docetaxel (DTX), a standard of care for gastric carcinoma patients. Finally, ibrutinib markedly reduces tumor growth and increases tumor cell apoptosis in the tumors formed in mice inoculated with the gastric carcinoma cells. Given these promising preclinical results for ibrutinib in gastric carcinoma, a strategy combining Btk inhibitor warrants attention in gastric cancer. PMID:27508020

  11. Pharmacologic inhibition of JAK-STAT signaling promotes hair growth.

    PubMed

    Harel, Sivan; Higgins, Claire A; Cerise, Jane E; Dai, Zhenpeng; Chen, James C; Clynes, Raphael; Christiano, Angela M

    2015-10-01

    Several forms of hair loss in humans are characterized by the inability of hair follicles to enter the growth phase (anagen) of the hair cycle after being arrested in the resting phase (telogen). Current pharmacologic therapies have been largely unsuccessful in targeting pathways that can be selectively modulated to induce entry into anagen. We show that topical treatment of mouse and human skin with small-molecule inhibitors of the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway results in rapid onset of anagen and subsequent hair growth. We show that JAK inhibition regulates the activation of key hair follicle populations such as the hair germ and improves the inductivity of cultured human dermal papilla cells by controlling a molecular signature enriched in intact, fully inductive dermal papillae. Our findings open new avenues for exploration of JAK-STAT inhibition for promotion of hair growth and highlight the role of this pathway in regulating the activation of hair follicle stem cells.

  12. Kinetic model of particle-inhibited grain growth

    NASA Astrophysics Data System (ADS)

    Thompson, Gary Scott

    The effects of second phase particles on matrix grain growth kinetics were investigated using Al2O3-SiC as a model system. In particular, the validity of the conclusion drawn from a previous kinetic analysis that the kinetics of particle-inhibited grain growth in Al2 O3-SiC samples with an intermediate volume fraction of second phase could be well quantified by a modified-Zener model was investigated. A critical analysis of assumptions made during the previous kinetic analysis revealed oversimplifications which affect the validity of the conclusion. Specifically, the degree of interaction between particles and grain boundaries was assumed to be independent of the mean second phase particle size and size distribution. In contrast, current measurements indicate that the degree of interaction in Al2O3-SiC is dependent on these parameters. An improved kinetic model for particle-inhibited grain growth in Al 2O3-SiC was developed using a modified-Zener approach. The comparison of model predictions with experimental grain growth data indicated that significant discrepancies (as much as 4--5 orders of magnitude) existed. Based on this, it was concluded that particles had a much more significant effect on grain growth kinetics than that caused by a simple reduction of the boundary driving force due to the removal of boundary area. Consequently, it was also concluded that the conclusion drawn from the earlier kinetic analysis regarding the validity of a modified-Zener model was incorrect. Discrepancies between model and experiment were found to be the result of a significant decrease in experimental growth rate constant not predicted by the model. Possible physical mechanisms for such a decrease were investigated. The investigation of a small amount of SiO2 on grain growth in Al2O3 indicated that the decrease was not the result of a decrease in grain boundary mobility due to impurity contamination by particles. By process of elimination and based on previous observations

  13. Catechin-incorporated dental copolymers inhibit growth of Streptococcus mutans

    PubMed Central

    MANKOVSKAIA, Alexandra; LÉVESQUE, Céline M.; PRAKKI, Anuradha

    2013-01-01

    Objective: To test the inhibitory growth activity of green tea catechin incorporated into dental resins compared to resins containing the broad-spectrum antimicrobial compound chlorhexidine against Streptococcus mutans in vitro. Material and Methods: The minimum inhibitory concentrations (MICs) of epigallocatechin-gallate (EGCg) and chlorhexidine (CHX) were determined according to the microdilution method. Resin discs (5 mm x 3 mm) were prepared from Bis-GMA/TEGDMA (R1) and Bis-GMA/CH3Bis-GMA (R2) comonomers (n=9) containing: a) no drug, b) EGCg, c) CHX. Two concentrations of each drug (0.5x MIC and 1x MIC) were incorporated into the resin discs. Samples were individually immersed in a bacterial culture and incubated for 24 h at 37º C under constant agitation. Cell viability was assessed by counting the number of colonies on replica agar plates. Statistical analysis was performed using one-way ANOVA, Tukey and Student t-tests (α=0.05). Results: Both resins containing EGCg and CHX showed a significant inhibition of bacterial growth at both concentrations tested (p<0.05). A significantly higher inhibition was observed in response to resins containing CHX at 0.5x MIC and 1x MIC, and EGCg at 1x MIC when compared to EGCg at 0.5x MIC. Also, EGCg at 0.5x MIC in R1 had a significantly higher growth inhibition than in R2. Conclusions: Both EGCg and CHX retained their antibacterial activity when incorporated into the resin matrix. EGCg at 1x MIC in R1 and R2 resins significantly reduced S. mutans survival at a level similar to CHX. The data generated from this study will provide advances in the field of bioactive dental materials with the potential of improving the lifespan of resin-based restorations. PMID:23739855

  14. Statistical inference for tumor growth inhibition T/C ratio.

    PubMed

    Wu, Jianrong

    2010-09-01

    The tumor growth inhibition T/C ratio is commonly used to quantify treatment effects in drug screening tumor xenograft experiments. The T/C ratio is converted to an antitumor activity rating using an arbitrary cutoff point and often without any formal statistical inference. Here, we applied a nonparametric bootstrap method and a small sample likelihood ratio statistic to make a statistical inference of the T/C ratio, including both hypothesis testing and a confidence interval estimate. Furthermore, sample size and power are also discussed for statistical design of tumor xenograft experiments. Tumor xenograft data from an actual experiment were analyzed to illustrate the application.

  15. Piperlongumine inhibits lung tumor growth via inhibition of nuclear factor kappa B signaling pathway

    PubMed Central

    Zheng, Jie; Son, Dong Ju; Gu, Sun Mi; Woo, Ju Rang; Ham, Young Wan; Lee, Hee Pom; Kim, Wun Jae; Jung, Jae Kyung; Hong, Jin Tae

    2016-01-01

    Piperlongumine has anti-cancer activity in numerous cancer cell lines via various signaling pathways. But there has been no study regarding the mechanisms of PL on the lung cancer yet. Thus, we evaluated the anti-cancer effects and possible mechanisms of PL on non-small cell lung cancer (NSCLC) cells in vivo and in vitro. Our findings showed that PL induced apoptotic cell death and suppressed the DNA binding activity of NF-κB in a concentration dependent manner (0–15 μM) in NSCLC cells. Docking model and pull down assay showed that PL directly binds to the DNA binding site of nuclear factor-κB (NF-κB) p50 subunit, and surface plasmon resonance (SPR) analysis showed that PL binds to p50 concentration-dependently. Moreover, co-treatment of PL with NF-κB inhibitor phenylarsine oxide (0.1 μM) or p50 siRNA (100 nM) augmented PL-induced inhibitory effect on cell growth and activation of Fas and DR4. Notably, co-treatment of PL with p50 mutant plasmid (C62S) partially abolished PL-induced cell growth inhibition and decreased the enhanced expression of Fas and DR4. In xenograft mice model, PL (2.5–5 mg/kg) suppressed tumor growth of NSCLC dose-dependently. Therefore, these results indicated that PL could inhibit lung cancer cell growth via inhibition of NF-κB signaling pathway in vitro and in vivo. PMID:27198178

  16. FH535 inhibited migration and growth of breast cancer cells.

    PubMed

    Iida, Joji; Dorchak, Jesse; Lehman, John R; Clancy, Rebecca; Luo, Chunqing; Chen, Yaqin; Somiari, Stella; Ellsworth, Rachel E; Hu, Hai; Mural, Richard J; Shriver, Craig D

    2012-01-01

    There is substantial evidence indicating that the WNT signaling pathway is activated in various cancer cell types including breast cancer. Previous studies reported that FH535, a small molecule inhibitor of the WNT signaling pathway, decreased growth of cancer cells but not normal fibroblasts, suggesting this pathway plays a role in tumor progression and metastasis. In this study, we tested FH535 as a potential inhibitor for malignant phenotypes of breast cancer cells including migration, invasion, and growth. FH535 significantly inhibited growth, migration, and invasion of triple negative (TN) breast cancer cell lines (MDA-MB231 and HCC38) in vitro. We demonstrate that FH535 was a potent growth inhibitor for TN breast cancer cell lines (HCC38 and MDA-MB-231) but not for other, non-TN breast cancer cell lines (MCF-7, T47D or SK-Br3) when cultured in three dimensional (3D) type I collagen gels. Western blotting analyses suggest that treatment of MDA-MB-231 cells with FH535 markedly inhibited the expression of NEDD9 but not activations of FAK, Src, or downstream targets such as p38 and Erk1/2. We demonstrated that NEDD9 was specifically associated with CSPG4 but not with β1 integrin or CD44 in MDA-MB-231 cells. Analyses of gene expression profiles in breast cancer tissues suggest that CSPG4 expression is higher in Basal-type breast cancers, many of which are TN, than any other subtypes. These results suggest not only a mechanism for migration and invasion involving the canonical WNT-signaling pathways but also novel strategies for treating patients who develop TN breast cancer.

  17. Treatment with algae extracts promotes flocculation, and enhances growth and neutral lipid content in Nannochloropsis oculata--a candidate for biofuel production.

    PubMed

    Taylor, Rebecca L; Rand, Jonathan D; Caldwell, Gary S

    2012-12-01

    Marine microalgae represent a potentially valuable feedstock for biofuel production; however, large-scale production is not yet economically viable. Optimisation of productivity and lipid yields is required and the cost of biomass harvesting and dewatering must be significantly reduced. Microalgae produce a wide variety of biologically active metabolites, many of which are involved in inter- and intra-specific interactions (the so-called infochemicals). The majority of infochemicals remain unidentified or uncharacterised. Here, we apply known and candidate (undefined extracts) infochemicals as a potential means to manipulate the growth and lipid content of Nannochloropsis oculata-a prospective species for biofuel production. Five known infochemicals (β-cyclocitral, trans,trans-2,4-decadienal, hydrogen peroxide, norharman and tryptamine) and crude extracts prepared from Skeletonema marinoi and Dunaliella salina cultures at different growth stages were assayed for impacts on N. oculata over 24 h. The neutral lipid content of N. oculata increased significantly with exposure to three infochemicals (β-cyclocitral, decadienal and norharman); however the effective concentrations affected a significant decrease in growth. Exposure to particular crude extracts significantly increased both growth and neutral lipid levels. In addition, water-soluble extracts of senescent S. marinoi cultures induced a degree of flocculation in the N. oculata. These preliminary results indicate that artificial manipulation of N. oculata cultures by application of algae infochemicals could provide a valuable tool towards achieving economically viable large-scale algae biofuel production.

  18. Effect of Different Light Qualities on Growth, Pigment Content, Chlorophyll Fluorescence, and Antioxidant Enzyme Activity in the Red Alga Pyropia haitanensis (Bangiales, Rhodophyta).

    PubMed

    Wu, Huanyang

    2016-01-01

    Spectral light changes evoke different morphogenetic and photosynthetic responses that can vary among different algae species. The aim of this study is to investigate the photosynthetic characteristics of the red macroalgae grown under different spectrum environments. In this study, Pyropia haitanensis were cultured under blue, red, and green LED and fluorescent tubes light. The growth rate, photopigment composition, chlorophyll fluorescence, and antioxidative enzymes activities in different light spectrums were investigated. The results revealed that growth rate was significantly higher in the thalli grown under blue, green, and fluorescent tubes light. Contents of Chl a and phycobiliprotein in red light were lower among all the growth conditions. Furthermore, a striking increase in SOD and CAT activity was observed in red light treatment along with the NPQ increase. The results revealed that the photosynthetic efficiency and increased growth rate of P. haitanensis benefitted from light spectrums such as blue, green, and fluorescent tubes light by pigment composition and photochemical efficiency manipulation, whereas red light has disadvantageous effects. Accordingly, the results for improving quality and the economic yield of algae species in some extent and the combination of different wavelengths could allow better economic resource exploitation.

  19. Effect of Different Light Qualities on Growth, Pigment Content, Chlorophyll Fluorescence, and Antioxidant Enzyme Activity in the Red Alga Pyropia haitanensis (Bangiales, Rhodophyta)

    PubMed Central

    2016-01-01

    Spectral light changes evoke different morphogenetic and photosynthetic responses that can vary among different algae species. The aim of this study is to investigate the photosynthetic characteristics of the red macroalgae grown under different spectrum environments. In this study, Pyropia haitanensis were cultured under blue, red, and green LED and fluorescent tubes light. The growth rate, photopigment composition, chlorophyll fluorescence, and antioxidative enzymes activities in different light spectrums were investigated. The results revealed that growth rate was significantly higher in the thalli grown under blue, green, and fluorescent tubes light. Contents of Chl a and phycobiliprotein in red light were lower among all the growth conditions. Furthermore, a striking increase in SOD and CAT activity was observed in red light treatment along with the NPQ increase. The results revealed that the photosynthetic efficiency and increased growth rate of P. haitanensis benefitted from light spectrums such as blue, green, and fluorescent tubes light by pigment composition and photochemical efficiency manipulation, whereas red light has disadvantageous effects. Accordingly, the results for improving quality and the economic yield of algae species in some extent and the combination of different wavelengths could allow better economic resource exploitation. PMID:27642603

  20. Cinnamic Acid Increases Lignin Production and Inhibits Soybean Root Growth

    PubMed Central

    Salvador, Victor Hugo; Lima, Rogério Barbosa; dos Santos, Wanderley Dantas; Soares, Anderson Ricardo; Böhm, Paulo Alfredo Feitoza; Marchiosi, Rogério; Ferrarese, Maria de Lourdes Lucio; Ferrarese-Filho, Osvaldo

    2013-01-01

    Cinnamic acid is a known allelochemical that affects seed germination and plant root growth and therefore influences several metabolic processes. In the present work, we evaluated its effects on growth, indole-3-acetic acid (IAA) oxidase and cinnamate 4-hydroxylase (C4H) activities and lignin monomer composition in soybean (Glycine max) roots. The results revealed that exogenously applied cinnamic acid inhibited root growth and increased IAA oxidase and C4H activities. The allelochemical increased the total lignin content, thus altering the sum and ratios of the p-hydroxyphenyl (H), guaiacyl (G), and syringyl (S) lignin monomers. When applied alone or with cinnamic acid, piperonylic acid (PIP, a quasi-irreversible inhibitor of C4H) reduced C4H activity, lignin and the H, G, S monomer content compared to the cinnamic acid treatment. Taken together, these results indicate that exogenously applied cinnamic acid can be channeled into the phenylpropanoid pathway via the C4H reaction, resulting in an increase in H lignin. In conjunction with enhanced IAA oxidase activity, these metabolic responses lead to the stiffening of the cell wall and are followed by a reduction in soybean root growth. PMID:23922685

  1. Repression of PES1 expression inhibits growth of gastric cancer.

    PubMed

    Li, Jieping; Zhou, Xiaodong; Lan, Xiaopeng; Zeng, Guobin; Jiang, Xuping; Huang, Zongming

    2016-03-01

    Gastric cancer is one of the leading causes of cancer death worldwide. However, precise molecular mechanisms underlining its development are far from clear. We recently reported that PES1 promoted development of breast cancer and ovarian cancer as an oncogene. In this study, we reported that ablation of endogenous PES1 resulted in significant suppression of cell proliferation and growth and led to cell cycle arrest in G2 or G1 phase, respectively, in two gastric cancer cell lines (AGS and N87) in vitro. Meanwhile, silencing of PES1 obviously decreased expressions of cyclin D1, HIF-1α, and vascular endothelial growth factor (VEGF) expressions and increased p21WAF1 expression. Re-expression of PES1 in these two kinds of PES1 knockdown cells rescued these effects. In vivo, repression of endogenous PES1 expression suppressed gastric tumor growth in nude mice. In addition, 40.7 % (24/59) of gastric cancer tissues showed PES1 expression via immunohistochemical (IHC) staining. However, there were not any positive PES1 stainings in matched adjacent tissues. Our results demonstrated that repression of PES1 changed expressions of some cell proliferation- and angiogenesis-related genes and inhibited gastric cancer growth, and PES1 expression increased in gastric cancer tissues. These results suggest that PES1 may play an important role in development of gastric cancer. PES1 may be a potential target for gastric cancer therapy.

  2. Alpha1-antitrypsin inhibits angiogenesis and tumor growth.

    PubMed

    Huang, Hanhua; Campbell, Steven C; Nelius, Thomas; Bedford, Dhugal F; Veliceasa, Dorina; Bouck, Noel P; Volpert, Olga V

    2004-12-20

    Disturbances of the ratio between angiogenic inducers and inhibitors in tumor microenvironment are the driving force behind angiogenic switch critical for tumor progression. Angiogenic inhibitors may vary depending on organismal age and the tissue of origin. We showed that alpha(1)-antitrypsin (AAT), a serine protease inhibitor (serpin) is an inhibitor of angiogenesis, which induced apoptosis and inhibited chemotaxis of endothelial cells. S- and Z-type mutations that cause abnormal folding and defective serpin activity abrogated AAT antiangiogenic activity. Removal of the C-terminal reactive site loop had no effect on its angiostatic activity. Both native AAT and AAT truncated on C-terminus (AATDelta) inhibited neovascularization in the rat cornea and delayed the growth of subcutaneous tumors in mice. Treatment with native AAT and truncated AATDelta, but not control vehicle reduced tumor microvessel density, while increasing apoptosis within tumor endothelium. Comparative analysis of the human tumors and normal tissues of origin showed correlation between reduced local alpha(1)-antitrypsin expression and more aggressive tumor growth.

  3. Glyphosate and AMPA inhibit cancer cell growth through inhibiting intracellular glycine synthesis.

    PubMed

    Li, Qingli; Lambrechts, Mark J; Zhang, Qiuyang; Liu, Sen; Ge, Dongxia; Yin, Rutie; Xi, Mingrong; You, Zongbing

    2013-01-01

    Glycine is a nonessential amino acid that is reversibly converted from serine intracellularly by serine hydroxymethyltransferase. Glyphosate and its degradation product, aminomethylphosphonic acid (AMPA), are analogs to glycine, thus they may inhibit serine hydroxymethyltransferase to decrease intracellular glycine synthesis. In this study, we found that glyphosate and AMPA inhibited cell growth in eight human cancer cell lines but not in two immortalized human normal prostatic epithelial cell lines. AMPA arrested C4-2B and PC-3 cancer cells in the G1/G0 phase and inhibited entry into the S phase of the cell cycle. AMPA also promoted apoptosis in C4-2B and PC-3 cancer cell lines. AMPA upregulated p53 and p21 protein levels as well as procaspase 9 protein levels in C4-2B cells, whereas it downregulated cyclin D3 protein levels. AMPA also activated caspase 3 and induced cleavage of poly (adenosine diphosphate [ADP]-ribose) polymerase. This study provides the first evidence that glyphosate and AMPA can inhibit proliferation and promote apoptosis of cancer cells but not normal cells, suggesting that they have potentials to be developed into a new anticancer therapy.

  4. Inhibition of enterovirus 71-induced apoptosis by allophycocyanin isolated from a blue-green alga Spirulina platensis.

    PubMed

    Shih, Shin-Ru; Tsai, Kun-Nan; Li, Yi-Shuane; Chueh, Chuang-Chun; Chan, Err-Cheng

    2003-05-01

    Enterovirus 71 infection causes significant morbidity and mortality in children, yet there is no effective treatment. In this study, a protein-bound pigment, allophycocyanin purified from blue-green algae is first reported to exhibit anti-enterovirus 71 activity. Allophycocyanin neutralized the enterovirus 71-induced cytopathic effect in both human rhabdomyosarcoma cells and African green monkey kidney cells. The 50% inhibitory concentration of allophycocyanin for neutralizing the enterovirus 71-induced cytopathic effect was approximately 0.045 +/- 0.012 microM in green monkey kidney cells. The cytotoxic concentrations of allophycocyanin for rhabdomyosarcoma cells and African green monkey kidney cells were 1.653 +/- 0.003 microM and 1.521 +/- 0.012 microM, respectively. A plaque reduction assay showed that the concentrations of allophycocyanin for reducing plaque formation by 50% were approximately 0.056 +/- 0.007 microM and 0.101 +/- 0.032 microM, when allophycocyanin were added at the state of viral adsorption and post-adsorption, respectively. Antiviral activity was more efficient in cultures treated with allophycocyanin before viral infection compared with that in the cultures treated after infection. Allophycocyanin was also able to delay viral RNA synthesis in the infected cells and to abate the apoptotic process in enterovirus 71-infected rhabdomyosarcoma cells with evidence of characteristic DNA fragmentation, decreasing membrane damage and declining cell sub-G1 phase. It is concluded that allophycocyanin possesses antiviral activity and has a potential for development as an anti-enterovirus 71 agent.

  5. Algae Resources

    SciTech Connect

    2016-06-01

    Algae are highly efficient at producing biomass, and they can be found all over the planet. Many use sunlight and nutrients to create biomass, which contain key components—including lipids, proteins, and carbohydrates— that can be converted and upgraded to a variety of biofuels and products. A functional algal biofuels production system requires resources such as suitable land and climate, sustainable management of water resources, a supplemental carbon dioxide (CO2) supply, and other nutrients (e.g., nitrogen and phosphorus). Algae can be an attractive feedstock for many locations in the United States because their diversity allows for highpotential biomass yields in a variety of climates and environments. Depending on the strain, algae can grow by using fresh, saline, or brackish water from surface water sources, groundwater, or seawater. Additionally, they can grow in water from second-use sources such as treated industrial wastewater; municipal, agricultural, or aquaculture wastewater; or produced water generated from oil and gas drilling operations.

  6. PPARγ ligands inhibit primary tumor growth and metastasis by inhibiting angiogenesis

    PubMed Central

    Panigrahy, Dipak; Singer, Samuel; Shen, Lucy Q.; Butterfield, Catherine E.; Freedman, Deborah A.; Chen, Emy J.; Moses, Marsha A.; Kilroy, Susan; Duensing, Stefan; Fletcher, Christopher; Fletcher, Jonathan A.; Hlatky, Lynn; Hahnfeldt, Philip; Folkman, Judah; Kaipainen, Arja

    2002-01-01

    Several drugs approved for a variety of indications have been shown to exhibit antiangiogenic effects. Our study focuses on the PPARγ ligand rosiglitazone, a compound widely used in the treatment of type 2 diabetes. We demonstrate, for the first time to our knowledge, that PPARγ is highly expressed in tumor endothelium and is activated by rosiglitazone in cultured endothelial cells. Furthermore, we show that rosiglitazone suppresses primary tumor growth and metastasis by both direct and indirect antiangiogenic effects. Rosiglitazone inhibits bovine capillary endothelial cell but not tumor cell proliferation at low doses in vitro and decreases VEGF production by tumor cells. In our in vivo studies, rosiglitazone suppresses angiogenesis in the chick chorioallantoic membrane, in the avascular cornea, and in a variety of primary tumors. These results suggest that PPARγ ligands may be useful in treating angiogenic diseases such as cancer by inhibiting angiogenesis. PMID:12370270

  7. Cellular Auxin Transport in Algae.

    PubMed

    Zhang, Suyun; van Duijn, Bert

    2014-01-27

    The phytohormone auxin is one of the main directors of plant growth and development. In higher plants, auxin is generated in apical plant parts and transported from cell-to-cell in a polar fashion. Auxin is present in all plant phyla, and the existence of polar auxin transport (PAT) is well established in land plants. Algae are a group of relatively simple, autotrophic, photosynthetic organisms that share many features with land plants. In particular, Charophyceae (a taxon of green algae) are closest ancestors of land plants. In the study of auxin function, transport and its evolution, the algae form an interesting research target. Recently, proof for polar auxin transport in Chara species was published and auxin related research in algae gained more attention. In this review we discuss auxin transport in algae with respect to land plants and suggest directions for future studies.

  8. Blockade of nonhormonal fibroblast growth factors by FP-1039 inhibits growth of multiple types of cancer.

    PubMed

    Harding, Thomas C; Long, Li; Palencia, Servando; Zhang, Hongbing; Sadra, Ali; Hestir, Kevin; Patil, Namrata; Levin, Anita; Hsu, Amy W; Charych, Deborah; Brennan, Thomas; Zanghi, James; Halenbeck, Robert; Marshall, Shannon A; Qin, Minmin; Doberstein, Stephen K; Hollenbaugh, Diane; Kavanaugh, W Michael; Williams, Lewis T; Baker, Kevin P

    2013-03-27

    The fibroblast growth factor (FGF) pathway promotes tumor growth and angiogenesis in many solid tumors. Although there has long been interest in FGF pathway inhibitors, development has been complicated: An effective FGF inhibitor must block the activity of multiple mitogenic FGF ligands but must spare the metabolic hormone FGFs (FGF-19, FGF-21, and FGF-23) to avoid unacceptable toxicity. To achieve these design requirements, we engineered a soluble FGF receptor 1 Fc fusion protein, FP-1039. FP-1039 binds tightly to all of the mitogenic FGF ligands, inhibits FGF-stimulated cell proliferation in vitro, blocks FGF- and vascular endothelial growth factor (VEGF)-induced angiogenesis in vivo, and inhibits in vivo growth of a broad range of tumor types. FP-1039 antitumor response is positively correlated with RNA levels of FGF2, FGF18, FGFR1c, FGFR3c, and ETV4; models with genetic aberrations in the FGF pathway, including FGFR1-amplified lung cancer and FGFR2-mutated endometrial cancer, are particularly sensitive to FP-1039-mediated tumor inhibition. FP-1039 does not appreciably bind the hormonal FGFs, because these ligands require a cell surface co-receptor, klotho or β-klotho, for high-affinity binding and signaling. Serum calcium and phosphate levels, which are regulated by FGF-23, are not altered by administration of FP-1039. By selectively blocking nonhormonal FGFs, FP-1039 treatment confers antitumor efficacy without the toxicities associated with other FGF pathway inhibitors.

  9. Autocrine growth inhibition by transforming growth factor β-1 (TGFβ-1) in human neuroendocrine tumour cells

    PubMed Central

    Wimmel, A; Wiedenmann, B; Rosewicz, S

    2003-01-01

    Background and aim: The role of transforming growth factor β-1 (TGFβ-1) in neuroendocrine tumour biology is currently unknown. We therefore examined the expression and biological significance of TGFβ signalling components in neuroendocrine tumours (NETs) of the gastroenteropancreatic (GEP) tract. Methods: Expression of TGFβ-1 and its receptors, Smads and Smad regulated proteins, was examined in surgically resected NET specimens and human NET cell lines by immunohistochemistry, reverse transcriptase-polymerase chain reaction, immunoblotting, and ELISA. Activation of TGFβ-1 dependent promoters was tested by transactivation assays. Growth regulation was evaluated by cell numbers, soft agar assays, and cell cycle analysis using flow cytometry. The role of endogenous TGFβ was assessed by a TGFβ neutralising antibody and stable transfection of a dominant negative TGFβR II receptor construct. Results: Coexpression of TGFβ-1 and its receptors TGFβR I and TGFβR II was detected in 67% of human NETs and in all three NET cell lines examined. NET cell lines expressed the TGFβ signal transducers Smad 2, 3, and 4. In two of the three cell lines, TGFβ-1 treatment resulted in transactivation of a TGFβ responsive reporter construct as well as inhibition of c-myc and induction of p21(WAF1) expression. TGFβ-1 inhibited anchorage dependent and independent growth in a time and dose dependent manner in TGFβ-1 responsive cell lines. TGFβ-1 mediated growth inhibition was due to G1 arrest without evidence of induction of apoptosis. Functional inactivation of endogenous TGFβ revealed the existence of an autocrine antiproliferative loop in NET cells. Conclusions: Neuroendocrine tumour cells of the gastroenteropancreatic tract are subject to paracrine and autocrine growth inhibition by TGFβ-1, which may account in part for the low proliferative index of this tumour entity. PMID:12912863

  10. Do furanic and phenolic compounds of lignocellulosic and algae biomass hydrolyzate inhibit anaerobic mixed cultures? A comprehensive review.

    PubMed

    Monlau, F; Sambusiti, C; Barakat, A; Quéméneur, M; Trably, E; Steyer, J-P; Carrère, H

    2014-01-01

    Nowadays there is a growing interest on the use of both lignocellulosic and algae biomass to produce biofuels (i.e. biohydrogen, ethanol and methane), as future alternatives to fossil fuels. In this purpose, thermal and thermo-chemical pretreatments have been widely investigated to overcome the natural physico-chemical barriers of such biomass and to enhance biofuel production from lignocellulosic residues and, more recently, marine biomass (i.e. macro and microalgae). However, the pretreatment technologies lead not only to the conversion of carbohydrate polymers (ie cellulose, hemicelluloses, starch, agar) to soluble monomeric sugar (ie glucose, xylose, arabinose, galactose), but also the generation of various by-products (i.e. furfural and 5-HMF). In the case of lignocellulosic residues, part of the lignin can also be degraded in lignin derived by-products, mainly composed of phenolic compounds. Although the negative impact of such by-products on ethanol production has been widely described in literature, studies on their impact on biohydrogen and methane production operated with mixed cultures are still very limited. This review aims to summarise and discuss literature data on the impact of pre-treatment by-products on H2-producing dark fermentation and anaerobic digestion processes when using mixed cultures as inoculum. As a summary, furanic (5-HMF, furfural) and phenolic compounds were found to be stronger inhibitors of the microbial dark fermentation than the full anaerobic digestion process. Such observations can be explained by differences in process parameters: anaerobic digestion is performed with more complex mixed cultures, lower substrate/inoculum and by-products/inoculum ratios and longer batch incubation times than dark fermentation. Finally, it has been reported that, during dark fermentation process, the presence of by-products could lead to a metabolic shift from H2-producing pathways (i.e. acetate and butyrate) to non-H2-producing pathways (i

  11. Inhibition of Glioblastoma Growth by the Thiadiazolidinone Compound TDZD-8

    PubMed Central

    Sanz-SanCristobal, Marina; Garcia-Cabezas, Miguel Angel; Santos, Angel; Perez-Castillo, Ana

    2010-01-01

    Background Thiadiazolidinones (TDZD) are small heterocyclic compounds first described as non-ATP competitive inhibitors of glycogen synthase kinase 3β (GSK-3β). In this study, we analyzed the effects of 4-benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione (TDZD-8), on murine GL261 cells growth in vitro and on the growth of established intracerebral murine gliomas in vivo. Methodology/Principal Findings Our data show that TDZD-8 decreased proliferation and induced apoptosis of GL261 glioblastoma cells in vitro, delayed tumor growth in vivo, and augmented animal survival. These effects were associated with an early activation of extracellular signal-regulated kinase (ERK) pathway and increased expression of EGR-1 and p21 genes. Also, we observed a sustained activation of the ERK pathway, a concomitant phosphorylation and activation of ribosomal S6 kinase (p90RSK) and an inactivation of GSK-3β by phosphorylation at Ser 9. Finally, treatment of glioblastoma stem cells with TDZD-8 resulted in an inhibition of proliferation and self-renewal of these cells. Conclusions/Significance Our results suggest that TDZD-8 uses a novel mechanism to target glioblastoma cells, and that malignant progenitor population could be a target of this compound. PMID:21079728

  12. In vitro chemopreventive potential of fucophlorethols from the brown alga Fucus vesiculosus L. by anti-oxidant activity and inhibition of selected cytochrome P450 enzymes.

    PubMed

    Parys, Sabine; Kehraus, Stefan; Krick, Anja; Glombitza, Karl-Werner; Carmeli, Shmuel; Klimo, Karin; Gerhäuser, Clarissa; König, Gabriele M

    2010-02-01

    Within a project focusing on the chemopreventive potential of algal phenols, two phloroglucinol derivatives, belonging to the class of fucophlorethols, and the known fucotriphlorethol A were obtained from the ethanolic extract of the brown alga Fucus vesiculosus L. The compounds trifucodiphlorethol A and trifucotriphlorethol A are composed of six and seven units of phloroglucinol, respectively. The compounds were examined for their cancer chemopreventive potential, in comparison with the monomer phloroglucinol. Trifucodiphlorethol A, trifucotriphlorethol A as well as fucotriphlorethol A were identified as strong radical scavengers, with IC(50) values for scavenging of 1,1-diphenyl-2 picrylhydrazyl radicals (DPPH) in the range of 10.0-14.4 microg/ml. All three compounds potently scavenged peroxyl radicals in the oxygen radical absorbance capacity (ORAC) assay. In addition, the compounds were shown to inhibit cytochrome P450 1A activity with IC(50) values in the range of 17.9-33 microg/ml, and aromatase (Cyp19) activity with IC(50) values in the range of 1.2-5.6 microg/ml.

  13. Functional Characterization of Pseudomonas Contact Dependent Growth Inhibition (CDI) Systems.

    PubMed

    Mercy, Chryslène; Ize, Bérengère; Salcedo, Suzana P; de Bentzmann, Sophie; Bigot, Sarah

    2016-01-01

    Contact-dependent inhibition (CDI) toxins, delivered into the cytoplasm of target bacterial cells, confer to host strain a significant competitive advantage. Upon cell contact, the toxic C-terminal region of surface-exposed CdiA protein (CdiA-CT) inhibits the growth of CDI- bacteria. CDI+ cells express a specific immunity protein, CdiI, which protects from autoinhibition by blocking the activity of cognate CdiA-CT. CdiA-CT are separated from the rest of the protein by conserved peptide motifs falling into two distinct classes, the "E. coli"- and "Burkholderia-type". CDI systems have been described in numerous species except in Pseudomonadaceae. In this study, we identified functional toxin/immunity genes linked to CDI systems in the Pseudomonas genus, which extend beyond the conventional CDI classes by the variability of the peptide motif that delimits the polymorphic CdiA-CT domain. Using P. aeruginosa PAO1 as a model, we identified the translational repressor RsmA as a negative regulator of CDI systems. Our data further suggest that under conditions of expression, P. aeruginosa CDI systems are implicated in adhesion and biofilm formation and provide an advantage in competition assays. All together our data imply that CDI systems could play an important role in niche adaptation of Pseudomonadaceae.

  14. Functional Characterization of Pseudomonas Contact Dependent Growth Inhibition (CDI) Systems

    PubMed Central

    Mercy, Chryslène; Ize, Bérengère; Salcedo, Suzana P.; de Bentzmann, Sophie; Bigot, Sarah

    2016-01-01

    Contact-dependent inhibition (CDI) toxins, delivered into the cytoplasm of target bacterial cells, confer to host strain a significant competitive advantage. Upon cell contact, the toxic C-terminal region of surface-exposed CdiA protein (CdiA-CT) inhibits the growth of CDI- bacteria. CDI+ cells express a specific immunity protein, CdiI, which protects from autoinhibition by blocking the activity of cognate CdiA-CT. CdiA-CT are separated from the rest of the protein by conserved peptide motifs falling into two distinct classes, the “E. coli”- and “Burkholderia-type”. CDI systems have been described in numerous species except in Pseudomonadaceae. In this study, we identified functional toxin/immunity genes linked to CDI systems in the Pseudomonas genus, which extend beyond the conventional CDI classes by the variability of the peptide motif that delimits the polymorphic CdiA-CT domain. Using P. aeruginosa PAO1 as a model, we identified the translational repressor RsmA as a negative regulator of CDI systems. Our data further suggest that under conditions of expression, P. aeruginosa CDI systems are implicated in adhesion and biofilm formation and provide an advantage in competition assays. All together our data imply that CDI systems could play an important role in niche adaptation of Pseudomonadaceae. PMID:26808644

  15. Exposure to Asulox Inhibits the Growth of Mosses

    PubMed Central

    ROWNTREE, J. K.; LAWTON, K. F.; RUMSEY, F. J.; SHEFFIELD, E.

    2003-01-01

    Asulox is a herbicide used to control bracken. Its effects on mosses were investigated to ascertain whether exposure proved as detrimental as found in parallel studies on pteridophytes. Mature gametophytes of 18 mosses were exposed to a range of concentrations of Asulox under standard conditions and the effects on growth monitored. Plants were cut to a standard length, exposed to Asulox solution for 24 h, grown for 3 weeks and total elongation (main stem and branches) measured. EC50 values were calculated and species ranked according to sensitivity. The effects of exposure on total elongation were compared with those on main stem elongation alone. Under the conditions tested, the total elongation of all species was inhibited after exposure to Asulox. The amount of elongation observed after exposure was different for different species and inhibition of elongation occurred at different exposure concentrations. A single regression equation was not adequate to describe the dose response curves of all species tested. An ability to produce secondary branches may confer increased tolerance to Asulox exposure. It is concluded that mosses suffer detrimental effects after exposure to Asulox at concentrations similar to those that affect fern gametophytes such as bracken. PMID:12933364

  16. Argos inhibits epidermal growth factor receptor signalling by ligand sequestration.

    PubMed

    Klein, Daryl E; Nappi, Valerie M; Reeves, Gregory T; Shvartsman, Stanislav Y; Lemmon, Mark A

    2004-08-26

    The epidermal growth factor receptor (EGFR) has critical functions in development and in many human cancers. During development, the spatial extent of EGFR signalling is regulated by feedback loops comprising both well-understood activators and less well-characterized inhibitors. In Drosophila melanogaster the secreted protein Argos functions as the only known extracellular inhibitor of EGFR, with clearly identified roles in multiple stages of development. Argos is only expressed when the Drosophila EGFR (DER) is activated at high levels, and downregulates further DER signalling. Although there is ample genetic evidence that Argos inhibits DER activation, the biochemical mechanism has not been established. Here we show that Argos inhibits DER signalling without interacting directly with the receptor, but instead by sequestering the DER-activating ligand Spitz. Argos binds tightly to the EGF motif of Spitz and forms a 1:1 (Spitz:Argos) complex that does not bind DER in vitro or at the cell surface. Our results provide an insight into the mechanism of Argos function, and suggest new strategies for EGFR inhibitor design.

  17. Anti-Angiogenic Properties of BDDPM, a Bromophenol from Marine Red Alga Rhodomela confervoides, with Multi Receptor Tyrosine Kinase Inhibition Effects

    PubMed Central

    Wang, Shuaiyu; Wang, Li-Jun; Jiang, Bo; Wu, Ning; Li, Xiangqian; Liu, Shaofang; Luo, Jiao; Shi, Dayong

    2015-01-01

    Bis-(2,3-dibromo-4,5-dihydroxy-phenyl)-methane (BDDPM) is a bromophenol first isolated from Rhodomelaceae confervoides. Our previous studies showed that BDDPM exerts PTP1B-inhibiting activity and anti-cancer activity against a wide range of tumor cells while it also showed lower cytotoxicity against normal cells. In the present study, we found that BDDPM exhibits significant activities toward angiogenesis in vitro. BDDPM inhibits multiple angiogenesis processes, including endothelial cell sprouting, migration, proliferation, and tube formation. Further kinase assays investigations found that BDDPM is a potent selective, but multi-target, receptor tyrosine kinase (RTKs) inhibitor. BDDPM (10 μM) inhibits the activities of fibroblast growth factor receptor 2 and 3 (FGFR2, 3), vascular endothelial growth factor receptor 2 (VEGFR2) and platelet-derived growth factor receptor α (PDGFRα) (inhibition rate: 57.7%, 78.6%, 78.5% and 71.1%, respectively). Moreover, BDDPM also decreases the phosphorylation of protein kinase B (PKB/Akt) and endothelial nitric oxide synthase (eNOS), as well as nitric oxide (NO) production in a dose dependent manner. These results indicate that BDDPM can be exploited as an anti-angiogenic drug, or as a lead compound for the development of novel multi-target RTKs inhibitors. PMID:26075871

  18. Magnetic fluid hyperthermia inhibits the growth of breast carcinoma and downregulates vascular endothelial growth factor expression.

    PubMed

    Wang, Guihua; Xu, Derong; Chai, Qin; Tan, Xiaolang; Zhang, Yu; Gu, Ning; Tang, Jintian

    2014-05-01

    The application of magnetic fluid hyperthermia (MFH) with nanoparticles has been shown to inhibit tumor growth in several animal models. However, the feasibility of using MFH in vivo to treat breast cancer is uncertain, and the mechanism is unclear. In the present study, it was observed that the intratumoral administration of MFH induced hyperthermia significantly in rats with Walker-265 breast carcinomas. The hyperthermia treatment with magnetic nanoparticles inhibited tumor growth in vivo and promoted the survival of the tumor-bearing rats. Furthermore, it was found that MFH treatment downregulated the protein expression of vascular endothelial growth factor (VEGF) in the tumor tissue, as observed by immunohistochemistry. MFH treatment also decreased the gene expression of VEGF and its receptors, VEGF receptor 1 and 2, and inhibited angiogenesis in the tumor tissues. Taken together, these results indicate that the application of MFH with nanoparticles is feasible for the treatment of breast carcinoma. The MFH-induced downregulation of angiogenesis may also contribute to the induction of an anti-tumor effect.

  19. Requirement of low oxidation-reduction potential for photosynthesis in a blue-green alga (Phormidium sp.).

    PubMed

    Weller, D; Doemel, W; Brock, T D

    1975-06-20

    Photosynthesis in a Phormidium species which forms dense conical-shaped structures in thermal springs is strongly inhibited by aeration but is stimulated by sulfide and other agents (cysteine, thioglycolate, sulfite) which lower the oxidation-reduction potential. The compact structures which this alga forms in nature may restrict oxygen penetration from the enviroment so that the anaerobic or microaerophilic conditions necessary ofr photosynthesis can develop. The alga may be defective in a regulatory mechanism that controls the reoxidation of reduced pyridine nucleotides formed during photosynthesis. It is suggested that other mat-forming and benthic blue-green algae may also prefer anaerobib conditions for growth and photosynthesis.

  20. Edible blue-green algae reduce the production of pro-inflammatory cytokines by inhibiting NF-κB pathway in macrophages and splenocytes

    PubMed Central

    Ku, Chai Siah; Pham, Tho X.; Park, Youngki; Kim, Bohkyung; Shin, Min; Kang, Insoo; Lee, Jiyoung

    2013-01-01

    Background Chronic inflammation contributes to the development of pathological disorders including insulin resistance and atherosclerosis. Identification of anti-inflammatory natural products can prevent the inflammatory diseases. Methods Anti-inflammatory effects of blue-green algae (BGA), i.e., Nostoc commune var. Sphaeroides Kützing (NO) and Spirulina Platensis (SP), were compared in RAW 264.7 and mouse bone marrow-derived macrophages (BMM) as well as splenocytes from apolipoprotein E knockout (apoE−/−) mice fed BGA. Results When macrophages pretreated with 100 μg/ml NO lipid extract (NOE) or SP lipid extract (SPE) were activated by lipopolysaccharide (LPS), expression and secretion of pro-inflammatory cytokines, such as tumor necrosis factor α (TNFα), interleukin 1β (IL-1β), and IL-6, were significantly repressed. NOE and SPE also significantly repressed the expression of TNFα and IL-1β in BMM. LPS-induced secretion of IL-6 was lower in splenocytes from apoE−/− fed an atherogenic diet containing 5% NO or SP for 12 weeks. In RAW 264.7 macrophages, NOE and SPE markedly decreased nuclear translocation of NF-κB. The degree of repression of pro-inflammatory gene expression by algal extracts was much stronger than that of SN50, an inhibitor of NF-κB nuclear translocation. Trichostatin A, a pan histone deacetylase inhibitor, increased basal expression of IL-1β and attenuated the repression of the gene expression by SPE. SPE significantly down-regulated mRNA abundance of 11 HDAC isoforms, consequently increasing acetylated histone 3 levels. Conclusion NOE and SPE repress pro-inflammatory cytokine expression and secretion in macrophages and splenocytes via inhibition of NF-κB pathway. Histone acetylation state is likely involved in the inhibition. General significance This study underscores natural products can exert anti-inflammatory effects by epigenetic modifications such as histone acetylation. PMID:23357040

  1. Kaempferol inhibits Entamoeba histolytica growth by altering cytoskeletal functions.

    PubMed

    Bolaños, Verónica; Díaz-Martínez, Alfredo; Soto, Jacqueline; Marchat, Laurence A; Sanchez-Monroy, Virginia; Ramírez-Moreno, Esther

    2015-11-01

    The flavonoid kaempferol obtained from Helianthemum glomeratum, an endemic Mexican medicinal herb used to treat gastrointestinal disorders, has been shown to inhibit growth of Entamoeba histolytica trophozoites in vitro; however, the mechanisms associated with this activity have not been documented. Several works reported that kaempferol affects cytoskeleton in mammalian cells. In order to gain insights into the action mechanisms involved in the anti-amoebic effect of kaempferol, here we evaluated the effect of this compound on the pathogenic events driven by the cytoskeleton during E. histolytica infection. We also carried out a two dimensional gel-based proteomic analysis to evidence modulated proteins that could explain the phenotypical changes observed in trophozoites. Our results showed that kaempferol produces a dose-dependent effect on trophozoites growth and viability with optimal concentration being 27.7 μM. Kaempferol also decreased adhesion, it increased migration and phagocytic activity, but it did not affect erythrocyte binding nor cytolytic capacity of E. histolytica. Congruently, proteomic analysis revealed that the cytoskeleton proteins actin, myosin II heavy chain and cortexillin II were up-regulated in response to kaempferol treatment. In conclusion, kaempferol anti-amoebic effects were associated with deregulation of proteins related with cytoskeleton, which altered invasion mechanisms.

  2. Phytotoxicity, bioaccumulation and degradation of isoproturon in green algae.

    PubMed

    Bi, Yan Fang; Miao, Shan Shan; Lu, Yi Chen; Qiu, Chong Bin; Zhou, You; Yang, Hong

    2012-12-01

    Isoproturon (IPU) is a pesticide used for protection of land crops from weed or pathogen attack. Recent survey shows that IPU has been detected as a contaminant in aquatic systems and may have negative impact on aquatic organisms. To understand the phytotoxicity and potential accumulation and degradation of IPU in algae, a comprehensive study was performed with the green alga Chlamydomonas reinhardtii. Algae exposed to 5-50 μg L(-1) IPU for 3d displayed progressive inhibition of cell growth and reduced chlorophyll fluorescence. Time-course experiments with 25 μg L(-1) IPU for 6d showed similar growth responses. The 72 h EC50 value for IPU was 43.25 μg L(-1), NOEC was 5 μg L(-1) and LOEC was 15 μg L(-1). Treatment with IPU induced oxidative stress. This was validated by a group of antioxidant enzymes, whose activities were promoted by IPU exposure. The up-regulation of several genes coding for the enzymes confirmed the observation. IPU was shown to be readily accumulated by C. reinhardtii. However, the alga showed a weak ability to degrade IPU accumulated in its cells, which was best presented at the lower concentration (5 μg L(-1)) of IPU in the medium. The imbalance of accumulation and degradation of IPU may be the cause that resulted in the detrimental growth and cellular damage.

  3. Inhibitory effects and mechanisms of Hydrilla verticillata (Linn.f.) Royle extracts on freshwater algae.

    PubMed

    Zhang, T-T; He, M; Wu, A-P; Nie, L-W

    2012-03-01

    To pursue an effective way to control freshwater algae, four extracts from a submerged macrophyte Hydrilla verticillata (Linn.f.) Royle were tested to study its inhibitory effects on Anabaena flos-aquae FACHB-245 and Chlorella pyrenoidosa Chick FACHB-9. Extract with the highest inhibiting ability was further studied in order to reveal the inhibitory mechanism. The results demonstrated that H. verticillata extracts inhibited the growth of A. flos-aquae and C. pyrenoidosa, and methanol extract had the highest inhibiting ability. The mechanism underlying the algal growth inhibition involves the superoxide anion radical generation that induces the damage of cell wall and release of intracellular components.

  4. Fluorescent minerals - A potential source of UV protection and visible light for the growth of green algae and cyanobacteria in extreme cosmic environments

    NASA Astrophysics Data System (ADS)

    Omairi, Tareq; Wainwright, Milton

    2015-07-01

    We propose that green algae (Chlorella variabilis and Dunaliella tertiolecta) and cyanobacteria (Synechococcus elongatus and Nostoc commune) can grow inside fluorescent rock minerals which convert damaging UV light to visible light, thereby allowing these organisms to survive and thrive in UV-rich environments without (or with limited) visible light, which would otherwise be inimical to them. The four microorganisms were incubated inside fluorescent rocks composed of fluorite, calcite and pyrite. The resultant growth was then measured following exposure to UV radiation, with the use of optical density and measurement of chlorophyll concentration. Results show that the microorganisms were shielded from harmful UV in these semi-transparent rocks, while at the same time benefiting from the fact that the minerals converted UV to visible light; this have been shown by a statistically significant increase in their growth, which although lower than when the cells were incubated in sunlight, was significantly higher than in controls incubated in the dark.

  5. Fluorescent minerals--A potential source of UV protection and visible light for the growth of green algae and cyanobacteria in extreme cosmic environments.

    PubMed

    Omairi, Tareq; Wainwright, Milton

    2015-07-01

    We propose that green algae (Chlorella variabilis and Dunaliella tertiolecta) and cyanobacteria (Synechococcus elongatus and Nostoc commune) can grow inside fluorescent rock minerals which convert damaging UV light to visible light, thereby allowing these organisms to survive and thrive in UV-rich environments without (or with limited) visible light, which would otherwise be inimical to them. The four microorganisms were incubated inside fluorescent rocks composed of fluorite, calcite and pyrite. The resultant growth was then measured following exposure to UV radiation, with the use of optical density and measurement of chlorophyll concentration. Results show that the microorganisms were shielded from harmful UV in these semi-transparent rocks, while at the same time benefiting from the fact that the minerals converted UV to visible light; this have been shown by a statistically significant increase in their growth, which although lower than when the cells were incubated in sunlight, was significantly higher than in controls incubated in the dark.

  6. XET Activity is Found Near Sites of Growth and Cell Elongation in Bryophytes and Some Green Algae: New Insights into the Evolution of Primary Cell Wall Elongation

    PubMed Central

    Van Sandt, Vicky S. T.; Stieperaere, Herman; Guisez, Yves; Verbelen, Jean-Pierre; Vissenberg, Kris

    2007-01-01

    Background and Aims In angiosperms xyloglucan endotransglucosylase (XET)/hydrolase (XTH) is involved in reorganization of the cell wall during growth and development. The location of oligo-xyloglucan transglucosylation activity and the presence of XTH expressed sequence tags (ESTs) in the earliest diverging extant plants, i.e. in bryophytes and algae, down to the Phaeophyta was examined. The results provide information on the presence of an XET growth mechanism in bryophytes and algae and contribute to the understanding of the evolution of cell wall elongation in general. Methods Representatives of the different plant lineages were pressed onto an XET test paper and assayed. XET or XET-related activity was visualized as the incorporation of fluorescent signal. The Physcomitrella genome database was screened for the presence of XTHs. In addition, using the 3′ RACE technique searches were made for the presence of possible XTH ESTs in the Charophyta. Key Results XET activity was found in the three major divisions of bryophytes at sites corresponding to growing regions. In the Physcomitrella genome two putative XTH-encoding cDNA sequences were identified that contain all domains crucial for XET activity. Furthermore, XET activity was located at the sites of growth in Chara (Charophyta) and Ulva (Chlorophyta) and a putative XTH ancestral enzyme in Chara was identified. No XET activity was identified in the Rhodophyta or Phaeophyta. Conclusions XET activity was shown to be present in all major groups of green plants. These data suggest that an XET-related growth mechanism originated before the evolutionary divergence of the Chlorobionta and open new insights in the evolution of the mechanisms of primary cell wall expansion. PMID:17098750

  7. Negative Impact on Growth and Photosynthesis in the Green Alga Chlamydomonas reinhardtii in the Presence of the Estrogen 17α-Ethynylestradiol

    PubMed Central

    Pocock, Tessa; Falk, Stefan

    2014-01-01

    It is well known that estrogenic compounds affect development of fertilized eggs of many species of birds, fish and amphibians through disrupted activity of carbonic anhydrase (CA). The most potent activity comes from the most commonly occurring synthetic sterol, 17α-Ethynylestradiol (EE2). Less is known about the responses of aquatic phytoplankton to these compounds. Here we show for the first time that, in comparision to the control, the addition of 7 µM EE2 reduced the growth rate of the green alga Chlamydomonas reinhardtii by 68% for cells grown at high CO2. When cells were grown in ambient air (low Ci) with a fully activated carbon concentrating mechanism through the induction of CA activity, the growth rates were reduced by as much as 119%. A reduced growth rate could be observed at EE2 concentrations as low as 10 pM. This was accompanied by a reduced maximum capacity for electron transport in photosystem II as determined by a lower FV/FM for low Ci-grown cells, which indicates the involvement of CAH3, a CA specifically located in the thylakoid lumen involved in proton pumping across the thylakoid membranes. These results were in agreement with an observed reduction in the chloroplastic affinity for Ci as shown by a strong increase in the Michaelis-Menten K0.5 for HCO3−. In itself, a lowering of the growth rate of a green alga by addition of the sterol EE2 warrants further investigation into the potential environmental impact by the release of treated waste water. PMID:25310092

  8. Negative impact on growth and photosynthesis in the green alga Chlamydomonas reinhardtii in the presence of the estrogen 17α-ethynylestradiol.

    PubMed

    Pocock, Tessa; Falk, Stefan

    2014-01-01

    It is well known that estrogenic compounds affect development of fertilized eggs of many species of birds, fish and amphibians through disrupted activity of carbonic anhydrase (CA). The most potent activity comes from the most commonly occurring synthetic sterol, 17α-Ethynylestradiol (EE2). Less is known about the responses of aquatic phytoplankton to these compounds. Here we show for the first time that, in comparision to the control, the addition of 7 µM EE2 reduced the growth rate of the green alga Chlamydomonas reinhardtii by 68% for cells grown at high CO2. When cells were grown in ambient air (low Ci) with a fully activated carbon concentrating mechanism through the induction of CA activity, the growth rates were reduced by as much as 119%. A reduced growth rate could be observed at EE2 concentrations as low as 10 pM. This was accompanied by a reduced maximum capacity for electron transport in photosystem II as determined by a lower FV/FM for low Ci-grown cells, which indicates the involvement of CAH3, a CA specifically located in the thylakoid lumen involved in proton pumping across the thylakoid membranes. These results were in agreement with an observed reduction in the chloroplastic affinity for Ci as shown by a strong increase in the Michaelis-Menten K0.5 for HCO3-. In itself, a lowering of the growth rate of a green alga by addition of the sterol EE2 warrants further investigation into the potential environmental impact by the release of treated waste water.

  9. Study of a two-stage growth of DHA-producing marine algae Schizochytrium limacinum SR21 with shifting dissolved oxygen level.

    PubMed

    Chi, Zhanyou; Liu, Yan; Frear, Craig; Chen, Shulin

    2009-01-01

    The culture protocol of Schizochytrium limacinum SR 21, a known docosahexaenoic acid (DHA) producing marine algae was modified in this study to better fit fermentation parameters, particularly control of dissolved oxygen (DO) to the known reproductive and growth biology of the microorganism. The cultures controlled at 50% DO saturation produced a cell density of 181 million cells/ml, whereas cultures with 10% DO produced only 98.4 million cells/ml. A fixed-agitation rate of 150 rpm resulted in an even lower density of 22.5 million cells/ml. Fifty percent DO saturation level led to a decreased pH, as well as a negative correlation with lipid accumulation, while low oxygen concentration was obligatory for lipid accumulation. This study indicated that high DO was preferred for the cells' reproduction via release of zoospores. Thus, the culture of S. limacinum SR21 should be best divided into two stages: (1) a cell-number-increasing stage in which cell reproduction and cell number increase with little increase in the size and weight of each cell; and (2) a cell-size-increasing stage in which cells stop reproduction but cell size enlarges due to lipids accumulation. With such a protocol, the production of algae biomass and DHA was improved to levels of 37.9 g/L and 6.56 g/L, respectively. The two-stage culture process could be potentially used not only for omega-3 PUFA production, but also in other single cell oil (SCO)-producing processes, including biodiesel production from algae.

  10. Ratite oils promote keratinocyte cell growth and inhibit leukocyte activation.

    PubMed

    Bennett, Darin C; Leung, Gigi; Wang, Eddy; Ma, Sam; Lo, Blanche K K; McElwee, Kevin J; Cheng, Kimberly M

    2015-09-01

    Traditionally, native Australian aborigines have used emu oil for the treatment of inflammation and to accelerate wound healing. Studies on mice suggest that topically applied emu oil may have anti-inflammatory properties and may promote wound healing. We investigated the effects of ratite oils (6 emu, 3 ostrich, 1 rhea) on immortalized human keratinocytes (HaCaT cells) in vitro by culturing the cells in media with oil concentrations of 0%, 0.5%, and 1.0%. Peking duck, tea tree, and olive oils were used as comparative controls. The same oils at 0.5% concentration were evaluated for their influence on peripheral blood mononuclear cell (PBMC) survival over 48 hr and their ability to inhibit IFNγ production in PBMCs activated by phytohemagglutinin (PHA) in ELISpot assays. Compared to no oil control, significantly shorter population doubling time durations were observed for HaCaT cells cultured in emu oil (1.51×faster), ostrich oil (1.46×faster), and rhea oil (1.64×faster). Tea tree oil demonstrated significant antiproliferative activity and olive oil significantly prolonged (1.35×slower) cell population doubling time. In contrast, almost all oils, particularly tea tree oil, significantly reduced PBMC viability. Different oils had different levels of inhibitory effect on IFNγ production with individual emu, ostrich, rhea, and duck oil samples conferring full inhibition. This preliminary investigation suggests that emu oil might promote wound healing by accelerating the growth rate of keratinocytes. Combined with anti-inflammatory properties, ratite oil may serve as a useful component in bandages and ointments for the treatment of wounds and inflammatory skin conditions.

  11. Ratite oils promote keratinocyte cell growth and inhibit leukocyte activation

    PubMed Central

    Bennett, Darin C.; Leung, Gigi; Wang, Eddy; Ma, Sam; Lo, Blanche K. K.; McElwee, Kevin J.; Cheng, Kimberly M.

    2015-01-01

    Traditionally, native Australian aborigines have used emu oil for the treatment of inflammation and to accelerate wound healing. Studies on mice suggest that topically applied emu oil may have anti-inflammatory properties and may promote wound healing. We investigated the effects of ratite oils (6 emu, 3 ostrich, 1 rhea) on immortalized human keratinocytes (HaCaT cells) in vitro by culturing the cells in media with oil concentrations of 0%, 0.5%, and 1.0%. Peking duck, tea tree, and olive oils were used as comparative controls. The same oils at 0.5% concentration were evaluated for their influence on peripheral blood mononuclear cell (PBMC) survival over 48 hr and their ability to inhibit IFNγ production in PBMCs activated by phytohemagglutinin (PHA) in ELISpot assays. Compared to no oil control, significantly shorter population doubling time durations were observed for HaCaT cells cultured in emu oil (1.51 × faster), ostrich oil (1.46 × faster), and rhea oil (1.64 × faster). Tea tree oil demonstrated significant antiproliferative activity and olive oil significantly prolonged (1.35 × slower) cell population doubling time. In contrast, almost all oils, particularly tea tree oil, significantly reduced PBMC viability. Different oils had different levels of inhibitory effect on IFNγ production with individual emu, ostrich, rhea, and duck oil samples conferring full inhibition. This preliminary investigation suggests that emu oil might promote wound healing by accelerating the growth rate of keratinocytes. Combined with anti-inflammatory properties, ratite oil may serve as a useful component in bandages and ointments for the treatment of wounds and inflammatory skin conditions. PMID:26217022

  12. Laboratory study on the ecological impact of sophorolipid used for harmful algae elimination

    NASA Astrophysics Data System (ADS)

    Sun, Xiaoxia; Kim, Eunki; Sun, Song

    2010-11-01

    We studied the role of sophorolipid in inhibiting harmful algae bloom (HAB). Different sophorolipid concentrations were tested on marine microalgae, zooplankton, fish, and bivalve ( Mytilus edulis) in laboratory. The result shows that sophorolipid could inhibit the growth of algal species selectively. Among three algae species selected, Platymonas helgolandica var. tsingtaoensis was promoted with increasing sophorolipid concentration; Isochrysis galbana was inhibited seven days later in sophorolipid concentration below 40 mg/L; and Nitzschia closterium f. minutissima was inhibited obviously in only a high sophorolipid concentration over 20 mg/L. Therefore, sophorolipid in a low concentration at <20 mg/L could remove certain harmful algae species effectively without harming other non-harmful microalgae. For other animals, sophorolipid could inhibit the growth of ciliate Strombidium sp. by 50% at 20 mg/L sophorolipid concentration after 96 h. The concentration in 96-h LC50 for Calanus sinicus, Neomysis awatschensis, Lateolabrax japonicus, and Paralichthys olivaceus was 15, 150, 60, and 110 mg/L, respectively. The 24 h LC50 value for Artemia salina was 600 mg/L. The relative clearance rate of mussel Mytilus edulis decreased to 80%, 40%, and 20% of the control group after being exposed to 20, 50, and 100 mg/L sophorolipid for 24 h. Therefore, the toxicity for mitigation of harmful algae bloom at previously recommended concentration of 5-20 mg/L sophorolipid is low for most tested organisms in this reaserch.

  13. MECHANISMS OF FLUID SHEAR-INDUCED INHIBITION OF POPULATION GROWTH IN A RED-TIDE DINOFLAGELLATE

    EPA Science Inventory

    Net population growth of some dinoflagellates is inhibited by fluid shear at shear stresses comparable with those generated during oceanic turbulence. Decreased net growth may occur through lowered cell division, increased mortality, or both. The dominant mechanism under various ...

  14. Growth kinetics and inhibition of growth of chemical vapor deposited thin tungsten films on silicon from tungsten hexafluoride

    NASA Astrophysics Data System (ADS)

    Leusink, G. J.; Kleijn, C. R.; Oosterlaken, T. G. M.; Janssen, G. C. A. M.; Radelaar, S.

    1992-07-01

    The growth kinetics and inhibition of growth of chemical vapor deposited thin W films on Si(100) from WF6 was studied with in situ growth stress and reflectivity measurements and ex situ weight gain measurements. A systematic series of experiments at varying WF6 flow, total pressure, and temperature show that the thickening kinetics and inhibition of the growth are controlled by two processes: WF6 diffusion through the gas phase and Si diffusion through the thickening columnar film. The steady state growth kinetics are controlled by WF6 diffusion in the gas phase whereas inhibition of the growth occurs at the transition from WF6 gas diffusion limited to Si solid state diffusion limited growth. A simple model based on WF6 gas phase diffusion and Si solid state diffusion is presented which gives a quantitative description of the experimental results.

  15. Methyl-donor nutrients inhibit breast cancer cell growth.

    PubMed

    Park, Chung S; Cho, Kyongshin; Bae, Dong R; Joo, Nam E; Kim, Hyung H; Mabasa, Lawrence; Fowler, Andrea W

    2008-01-01

    Lipotropes (methyl group containing nutrients, including methionine, choline, folate, and vitamin B(12)) are dietary methyl donors and cofactors that are involved in one-carbon metabolism, which is important for genomic DNA methylation reactions and nucleic acid synthesis. One-carbon metabolism provides methyl groups for all biological methylation pathways and is highly dependent on dietary supplementation of methyl nutrients. Nutrition is an important determinant of breast cancer risk and tumor behavior, and dietary intervention may be an effective approach to prevent breast cancer. Apoptosis is important for the regulation of homeostasis and tumorigenesis. The anti-apoptotic protein Bcl-2 may be a regulatory target in cancer therapy; controlling or modulating its expression may be a therapeutic strategy against breast cancer. In this study, the effects of lipotrope supplementation on the growth and death of human breast cancer cell lines T47D and MCF-7 were examined and found to inhibit growth of both T47D and MCF-7 cells. Furthermore, the ratios of apoptotic cells to the total number of cells were approximately 44% and 34% higher in the lipotrope-supplemented treatments of T47D and MCF-7 cancer cells, respectively, compared with the control treatments. More importantly, Bcl-2 protein expression was decreased by approximately 25% from lipotrope supplementation in T47D cells, suggesting that lipotropes can induce breast cancer cell death by direct downregulation of Bcl-2 protein expression. Cancer treatment failure is often correlated with Bcl-2 protein upregulation. These data may be useful in the development of effective nutritional strategies to prevent and reduce breast cancer in humans.

  16. AP-2α inhibits hepatocellular carcinoma cell growth and migration.

    PubMed

    Huang, Wenhuan; Chen, Cheng; Liang, Zhongheng; Qiu, Junlu; Li, Xinxin; Hu, Xiang; Xiang, Shuanglin; Ding, Xiaofeng; Zhang, Jian

    2016-03-01

    Transcription factor AP-2α is involved in many types of human cancers, but its role in hepatocellular carcinogenesis is largely unknown. In this study, we found that expression of AP-2α was low in 40% of human hepatocellular cancers compared with adjacent normal tissues by immunohistochemical analysis. Moreover, AP-2α expression was low or absent in hepatocellular cancer cell lines (HepG2, Hep3B, SMMC-7721 and MHHC 97-H). Human liver cancer cell lines SMMC-7721 and Hep3B stably overexpressing AP-2α were established by lentiviral infection and puromycin screening, and the ectopic expression of AP-2α was able to inhibit hepatocellular cancer cell growth and proliferation by cell viability, MTT assay and liquid colony formation in vitro and in vivo. Furthermore, AP-2α overexpression decreased liver cancer cell migration and invasion as assessed by wound healing and Transwell assays, increasing the sensitivity of liver cancer cells to cisplatin analyzed by MTT assays. Also AP-2α overexpression suppressed the sphere formation and renewed the ability of cancer stem cells. Finally, we found that AP-2α is epigenetically modified and modulates the levels of phosphorylated extracellular signal-regulated protein kinase (ERK), β-catenin, p53, EMT, and CD133 expression in liver cancer cell lines. These results suggested that AP-2α expression is low in human hepatocellular cancers by regulating multiple signaling to affect hepatocellular cancer cell growth and migration. Therefore, AP-2α might represent a novel potential target in human hepatocellular cancer therapy.

  17. Growth of Steptomyces hygroscopicus in rotating-wall bioreactor under simulated microgravity inhibits rapamycin production

    NASA Technical Reports Server (NTRS)

    Fang, A.; Pierson, D. L.; Mishra, S. K.; Demain, A. L.

    2000-01-01

    Growth of Streptomyces hygroscopicus under conditions of simulated microgravity in a rotating-wall bioreactor resulted in a pellet form of growth, lowered dry cell weight, and inhibition of rapamycin production. With the addition of Teflon beads to the bioreactor, growth became much less pelleted, dry cell weight increased but rapamycin production was still markedly inhibited. Growth under simulated microgravity favored extracellular production of rapamycin, in contrast to a greater percentage of cell-bound rapamycin observed under normal gravity conditions.

  18. Growth of Steptomyces hygroscopicus in rotating-wall bioreactor under simulated microgravity inhibits rapamycin production.

    PubMed

    Fang, A; Pierson, D L; Mishra, S K; Demain, A L

    2000-07-01

    Growth of Streptomyces hygroscopicus under conditions of simulated microgravity in a rotating-wall bioreactor resulted in a pellet form of growth, lowered dry cell weight, and inhibition of rapamycin production. With the addition of Teflon beads to the bioreactor, growth became much less pelleted, dry cell weight increased but rapamycin production was still markedly inhibited. Growth under simulated microgravity favored extracellular production of rapamycin, in contrast to a greater percentage of cell-bound rapamycin observed under normal gravity conditions.

  19. Growth of Streptomyces Hygroscopicus in Rotating-Wall Bioreactor Under Simulated Microgravity Inhibits Rapamycin Production

    NASA Technical Reports Server (NTRS)

    Fang, A.; Pierson, D. L.; Mishra, S. K.; Demain, A. L.

    2000-01-01

    Growth of Streptomyces hygroscopicus under conditions of simulated microgravity in a rotating-wall bioreactor resulted in a pellet form of growth, lowered dry cell weight, and inhibition of rapamycin production. With the addition of Teflon beads to the bioreactor, growth became much less pelleted, dry cell weight increased but rapamycin production was still markedly inhibited. Growth under simulated microgravity favored extracellular production of rapamycin in contrast to a greater percentage of cell-bound rapamycin observed under normal gravity conditions.

  20. Effects of local Polynesian plants and algae on growth and expression of two immune-related genes in orbicular batfish (Platax orbicularis).

    PubMed

    Reverter, Miriam; Saulnier, Denis; David, Rarahu; Bardon-Albaret, Agnès; Belliard, Corinne; Tapissier-Bontemps, Nathalie; Lecchini, David; Sasal, Pierre

    2016-11-01

    The emerging orbicular batfish (Platax orbicularis) aquaculture is the most important fish aquaculture industry in French Polynesia. However, bacterial infections are causing severe mortality episodes. Therefore, there is an urgent need to find an effective management solution. Besides the supplying difficulty and high costs of veterinary drugs in French Polynesia, batfish aquaculture takes place close to the coral reef, where use of synthetic persistent drugs should be restricted. Medicinal plants and bioactive algae are emerging as a cheaper and more sustainable alternative to chemical drugs. We have studied the effect of local Polynesian plants and the local opportunistic algae Asparagopsis taxiformis on batfish when orally administered. Weight gain and expression of two immune-related genes (lysozyme g - Lys G and transforming growth factor beta - TGF-β1) were studied to analyze immunostimulant activity of plants on P. orbicularis. Results showed that several plants increased Lys G and TGF-β1 expression on orbicular batfish after 2 and 3 weeks of oral administration. A. taxiformis was the plant displaying the most promising results, promoting a weight gain of 24% after 3 weeks of oral administration and significantly increasing the relative amount of both Lys G and TGF-β1 transcripts in kidney and spleen of P. orbicularis.

  1. Photobiology of sea ice algae during initial spring growth in Kangerlussuaq, West Greenland: insights from imaging variable chlorophyll fluorescence of ice cores.

    PubMed

    Hawes, Ian; Lund-Hansen, Lars Chresten; Sorrell, Brian K; Nielsen, Morten Holtegaard; Borzák, Réka; Buss, Inge

    2012-06-01

    We undertook a series of measurements of photophysiological parameters of sea ice algae over 12 days of early spring growth in a West Greenland Fjord, by variable chlorophyll fluorescence imaging. Imaging of the ice-water interface showed the development of ice algae in 0.3-0.4 mm wide brine channels between laminar ice crystals in the lower 4-6 mm of the ice, with a several-fold spatial variation in inferred biomass on cm scales. The maximum quantum yield of photosynthesis, F(v) /F(m), was initially low (~0.1), though this increased rapidly to ~0.5 by day 6. Day 6 also saw the onset of biomass increase, the cessation of ice growth and the time at which brine had reached <50 psu and >-2 °C. We interpret this as indicating that the establishment of stable brine channels at close to ambient salinity was required to trigger photosynthetically active populations. Maximum relative electron transport rate (rETR(max)), saturation irradiance (E(k)) and photosynthetic efficiency (α) had also stabilised by day 6 at 5-6 relative units, ~30 μmol photons m⁻² s⁻¹ and 0.4-0.5 μmol photons m⁻²s⁻¹, respectively. E(k) was consistent with under-ice irradiance, which peaked at a similar value, confirming that daytime irradiance was adequate to facilitate photosynthetic activity throughout the study period. Photosynthetic parameters showed no substantial differences with depth within the ice, nor variation between cores or brine channels suggesting that during this early phase of ice algal growth cells were unaffected by gradients of environmental conditions within the ice. Variable chlorophyll fluorescence imaging offers a tool to determine how this situation may change over time and as brine channels and algal populations evolve.

  2. Bursts of Bipolar Microsecond Pulses Inhibit Tumor Growth

    NASA Astrophysics Data System (ADS)

    Sano, Michael B.; Arena, Christopher B.; Bittleman, Katelyn R.; Dewitt, Matthew R.; Cho, Hyung J.; Szot, Christopher S.; Saur, Dieter; Cissell, James M.; Robertson, John; Lee, Yong W.; Davalos, Rafael V.

    2015-10-01

    Irreversible electroporation (IRE) is an emerging focal therapy which is demonstrating utility in the treatment of unresectable tumors where thermal ablation techniques are contraindicated. IRE uses ultra-short duration, high-intensity monopolar pulsed electric fields to permanently disrupt cell membranes within a well-defined volume. Though preliminary clinical results for IRE are promising, implementing IRE can be challenging due to the heterogeneous nature of tumor tissue and the unintended induction of muscle contractions. High-frequency IRE (H-FIRE), a new treatment modality which replaces the monopolar IRE pulses with a burst of bipolar pulses, has the potential to resolve these clinical challenges. We explored the pulse-duration space between 250 ns and 100 μs and determined the lethal electric field intensity for specific H-FIRE protocols using a 3D tumor mimic. Murine tumors were exposed to 120 bursts, each energized for 100 μs, containing individual pulses 1, 2, or 5 μs in duration. Tumor growth was significantly inhibited and all protocols were able to achieve complete regressions. The H-FIRE protocol substantially reduces muscle contractions and the therapy can be delivered without the need for a neuromuscular blockade. This work shows the potential for H-FIRE to be used as a focal therapy and merits its investigation in larger pre-clinical models.

  3. Growth Hormone Inhibits Hepatic De Novo Lipogenesis in Adult Mice

    PubMed Central

    Cordoba-Chacon, Jose; Majumdar, Neena; List, Edward O.; Diaz-Ruiz, Alberto; Frank, Stuart J.; Manzano, Anna; Bartrons, Ramon; Puchowicz, Michelle; Kopchick, John J.

    2015-01-01

    Patients with nonalcoholic fatty liver disease (NAFLD) are reported to have low growth hormone (GH) production and/or hepatic GH resistance. GH replacement can resolve the fatty liver condition in diet-induced obese rodents and in GH-deficient patients. However, it remains to be determined whether this inhibitory action of GH is due to direct regulation of hepatic lipid metabolism. Therefore, an adult-onset, hepatocyte-specific, GH receptor (GHR) knockdown (aLivGHRkd) mouse was developed to model hepatic GH resistance in humans that may occur after sexual maturation. Just 7 days after aLivGHRkd, hepatic de novo lipogenesis (DNL) was increased in male and female chow-fed mice, compared with GHR-intact littermate controls. However, hepatosteatosis developed only in male and ovariectomized female aLivGHRkd mice. The increase in DNL observed in aLivGHRkd mice was not associated with hyperactivation of the pathway by which insulin is classically considered to regulate DNL. However, glucokinase mRNA and protein levels as well as fructose-2,6-bisphosphate levels were increased in aLivGHRkd mice, suggesting that enhanced glycolysis drives DNL in the GH-resistant liver. These results demonstrate that hepatic GH actions normally serve to inhibit DNL, where loss of this inhibitory signal may explain, in part, the inappropriate increase in hepatic DNL observed in NAFLD patients. PMID:26015548

  4. Bursts of Bipolar Microsecond Pulses Inhibit Tumor Growth.

    PubMed

    Sano, Michael B; Arena, Christopher B; Bittleman, Katelyn R; DeWitt, Matthew R; Cho, Hyung J; Szot, Christopher S; Saur, Dieter; Cissell, James M; Robertson, John; Lee, Yong W; Davalos, Rafael V

    2015-10-13

    Irreversible electroporation (IRE) is an emerging focal therapy which is demonstrating utility in the treatment of unresectable tumors where thermal ablation techniques are contraindicated. IRE uses ultra-short duration, high-intensity monopolar pulsed electric fields to permanently disrupt cell membranes within a well-defined volume. Though preliminary clinical results for IRE are promising, implementing IRE can be challenging due to the heterogeneous nature of tumor tissue and the unintended induction of muscle contractions. High-frequency IRE (H-FIRE), a new treatment modality which replaces the monopolar IRE pulses with a burst of bipolar pulses, has the potential to resolve these clinical challenges. We explored the pulse-duration space between 250 ns and 100 μs and determined the lethal electric field intensity for specific H-FIRE protocols using a 3D tumor mimic. Murine tumors were exposed to 120 bursts, each energized for 100 μs, containing individual pulses 1, 2, or 5 μs in duration. Tumor growth was significantly inhibited and all protocols were able to achieve complete regressions. The H-FIRE protocol substantially reduces muscle contractions and the therapy can be delivered without the need for a neuromuscular blockade. This work shows the potential for H-FIRE to be used as a focal therapy and merits its investigation in larger pre-clinical models.

  5. Further evidence that naphthoquinone inhibits Toxoplasma gondii growth in vitro.

    PubMed

    da Silva, Luciana Lemos Rangel; Portes, Juliana de Araujo; de Araújo, Marlon Heggdorne; Silva, Jéssica Lays Sant'ana; Rennó, Magdalena Nascimento; Netto, Chaquip Daher; da Silva, Alcides José Monteiro; Costa, Paulo Roberto Ribeiro; De Souza, Wanderley; Seabra, Sergio Henrique; DaMatta, Renato Augusto

    2015-12-01

    Toxoplasmosis is a widely disseminated disease caused by Toxoplasma gondii, an intracellular protozoan parasite. Standard treatment causes many side effects, such as depletion of bone marrow cells, skin rashes and gastrointestinal implications. Therefore, it is necessary to find chemotherapeutic alternatives for the treatment of this disease. It was shown that a naphthoquinone derivative compound is active against T. gondii, RH strain, with an IC50 around 2.5 μM. Here, three different naphthoquinone derivative compounds with activity against leukemia cells and breast carcinoma cell were tested against T. gondii (RH strain) infected LLC-MK2 cell line. All the compounds were able to inhibit parasite growth in vitro, but one of them showed an IC50 activity below 1 μM after 48 h of treatment. The compounds showed low toxicity to the host cell. In addition, these compounds were able to induce tachyzoite-bradyzoite conversion confirmed by morphological changes, Dolichus biflorus lectin cyst wall labeling and characterization of amylopectin granules in the parasites by electron microscopy analysis using the Thierry technique. Furthermore, the compounds induced alterations on the ultrastructure of the parasite. Taken together, our results point to the naphthoquinone derivative (LQB 151) as a potential compound for the development of new drugs for the treatment of toxoplasmosis.

  6. Ponicidin Inhibits Monocytic Leukemia Cell Growth by Induction of Apoptosis

    PubMed Central

    Liu, Jia-Jun; Zhang, Yong; Guang, Wei-Bin; Yang, Hong-Zhi; Lin, Dong-Jun; Xiao, Ruo-Zhi

    2008-01-01

    In this study two monocytic leukemia cell lines, U937 and THP-1 cells, were used to investigate the anti-proliferation effects caused by ponicidin. Cell viability was measured by an MTT assay. Cell apoptosis was assessed by flow cytometry as well as DNA fragmentation analysis. Cell morphology was observed using an inverted microscope and Hoechst 33258 staining. RT-PCR and Western blot analysis were used to detect survivin as well as Bax and Bcl-2 expressions after the cells were treated with different concentrations of ponicidin. The results revealed that ponicidin could inhibit the growth of U937 and THP-1 cells significantly by induction of apoptosis. The suppression was in both time- and dose-dependent manner. Marked morphological changes of cell apoptosis were observed clearly after the cells were treated with ponicidin for 48∼72 h. RT-PCR and Western blot analysis demonstrated that both survivin and Bcl-2 expressions were down-regulated remarkably while Bax expression remained constant before and after apoptosis occurred. We therefore conclude that ponicidin has significant anti-proliferation effects by inducing apoptosis on leukemia cells in vitro, downregulation of survivin as well as Bcl-2 expressions may be the important apoptosis inducing mechanisms. The results suggest that ponicidin may serve as potential therapeutic agent for leukemia. PMID:19330074

  7. Self-inhibiting growth of the Greenland Ice Sheet

    NASA Astrophysics Data System (ADS)

    Langen, P. L.; Solgaard, A. M.; Hvidberg, C. S.

    2012-04-01

    The build-up of the Greenland Ice Sheet from ice free conditions is studied in an ice sheet model (ISM) driven by fields from an atmospheric general circulation model (GCM). Experiments where the two are coupled offline are performed and augmented by one where an intermediate ice sheet configuration, taken as a snap shot during the regrowth in the ISM, is coupled back to the GCM. It is found that several open questions regarding reversibility or irreversibility of a disintegration of the Greenland Ice Sheet may be reconciled with these experiments. Running the ISM with GCM fields corresponding to a present day ice sheet configuration leads to regrowth, while considerations of the GCM's snow accumulation in an ice free run point to irreversibility. Forcing the ISM with the GCM fields corresponding to the ice free state leads to extensive regrowth which, however, is halted when an intermediate recoupling step is included. This inhibition of further growth is believed to be due to a Föhn effect of moist air parcels being lifted over the intermediate ice sheet and arriving in the Greenland interior with high temperatures.

  8. Self-inhibiting growth of the Greenland Ice Sheet

    NASA Astrophysics Data System (ADS)

    Langen, P. L.; Solgaard, A. M.; Hvidberg, C. S.

    2012-06-01

    The build-up of the Greenland Ice Sheet (GrIS) from ice-free conditions is studied in an ice sheet model (ISM) driven by fields from an atmospheric general circulation model (GCM) to demonstrate the importance of coupling between the two components. Experiments where the two are coupled off-line are augmented by one where an intermediate ice sheet configuration is coupled back to the GCM. Forcing the ISM with GCM fields corresponding to the ice-free state leads to extensive regrowth which, however, is halted when the intermediate recoupling step is included. This inhibition of further growth is due to a Föhn effect of moist air parcels being lifted over the intermediate ice sheet and arriving in the low-lying Greenland interior with high temperatures. This demonstrates that two-way coupling between the atmosphere and the ice sheet is essential for understanding the dynamics and that large scale conditions cooler than those of today may be necessary for the GrIS to regrow to the present volume.

  9. Chinese medicinal herbs inhibit growth of murine renal cell carcinoma.

    PubMed

    Lau, B H; Ruckle, H C; Botolazzo, T; Lui, P D

    1994-01-01

    Tumors are known to produce factors suppressing immune functions. We previously showed that a murine renal cell carcinoma (Renca) suppressed macrophage function in vitro and that this suppression was abolished by co-incubation with extracts of two Chinese medicinal herbs. We now report that these phytochemicals are capable of inhibiting growth of Renca in vivo. BALB/c mice were transplanted intraperitoneally (IP) with 1-2 x 10(5) Renca cells. One day after tumor transplant, mice were randomized into two groups. One group was treated IP, daily for 10 days, with 100 microliters of phytochemicals containing 500 micrograms each of Astragalus membranaceus and Ligustrum lucidum, while the other group received saline as controls. A cure rate of 57% was obtained with these phytochemicals when the initial tumor load was 2 x 10(5), and 100% when the initial tumor load was 1 x 10(5). Additional experiments were performed to investigate the mechanisms involved in this protection. Splenic macrophages from tumor-bearing mice were shown to have depressed chemiluminescent oxidative burst activity, and this depression was restored with phytochemical treatment. Splenocytes from mice transplanted with Renca responded less favorably to interleukin-2 (IL-2) in generating lymphokine-activated killer (LAK) cells; again this depression was restored with phytochemical treatment. Our data suggest that these phytochemicals may have exerted their antitumor effects via augmentation of phagocyte and LAK cell activities.

  10. Bursts of Bipolar Microsecond Pulses Inhibit Tumor Growth

    PubMed Central

    Sano, Michael B.; Arena, Christopher B.; Bittleman, Katelyn R.; DeWitt, Matthew R.; Cho, Hyung J.; Szot, Christopher S.; Saur, Dieter; Cissell, James M.; Robertson, John; Lee, Yong W.; Davalos, Rafael V.

    2015-01-01

    Irreversible electroporation (IRE) is an emerging focal therapy which is demonstrating utility in the treatment of unresectable tumors where thermal ablation techniques are contraindicated. IRE uses ultra-short duration, high-intensity monopolar pulsed electric fields to permanently disrupt cell membranes within a well-defined volume. Though preliminary clinical results for IRE are promising, implementing IRE can be challenging due to the heterogeneous nature of tumor tissue and the unintended induction of muscle contractions. High-frequency IRE (H-FIRE), a new treatment modality which replaces the monopolar IRE pulses with a burst of bipolar pulses, has the potential to resolve these clinical challenges. We explored the pulse-duration space between 250 ns and 100 μs and determined the lethal electric field intensity for specific H-FIRE protocols using a 3D tumor mimic. Murine tumors were exposed to 120 bursts, each energized for 100 μs, containing individual pulses 1, 2, or 5 μs in duration. Tumor growth was significantly inhibited and all protocols were able to achieve complete regressions. The H-FIRE protocol substantially reduces muscle contractions and the therapy can be delivered without the need for a neuromuscular blockade. This work shows the potential for H-FIRE to be used as a focal therapy and merits its investigation in larger pre-clinical models. PMID:26459930

  11. Interaction of TiO2 nanoparticles with the marine microalga Nitzschia closterium: growth inhibition, oxidative stress and internalization.

    PubMed

    Xia, Bin; Chen, Bijuan; Sun, Xuemei; Qu, Keming; Ma, Feifei; Du, Meirong

    2015-03-01

    The toxicity of TiO2 engineered nanoparticles (NPs) to the marine microalga Nitzschia closterium was investigated by examining growth inhibition, oxidative stress and uptake. The results indicated that the toxicity of TiO2 particles to algal cells significantly increased with decreasing nominal particle size, which was evidenced by the 96 EC50 values of 88.78, 118.80 and 179.05 mg/L for 21 nm, 60 nm and 400 nm TiO2 particles, respectively. The growth rate was significantly inhibited when the alga was exposed to 5mg/L TiO2 NPs (21 nm). Measurements of antioxidant enzyme activities showed that superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activities were first induced and subsequently inhibited following exposure to 5mg/L TiO2 NPs. The depletion of antioxidant enzymes with a concomitant increase in malondialdehyde (MDA) levels and reactive oxygen species (ROS) posed a hazard to membrane integrity. A combination of flow cytometry analysis, transmission electron microscopy and Ti content measurement indicated that TiO2 NPs were internalized in N. closterium cells. The level of extracellular ROS, which was induced by TiO2 NPs under visible light, was negligible when compared with the intracellular ROS level (accounting for less than 6.0% of the total ROS level). These findings suggest that elevated TiO2 nanotoxicity in marine environments is related to increased ROS levels caused by internalization of TiO2 NPs.

  12. Growth-inhibiting effects of 12 antibacterial agents and their mixtures on the freshwater microalga Pseudokirchneriella subcapitata.

    PubMed

    Yang, Li-Hua; Ying, Guang-Guo; Su, Hao-Chang; Stauber, Jennifer L; Adams, Merrin S; Binet, Monique T

    2008-05-01

    The growth-inhibiting and binary joint effects of 12 antibacterial agents on the freshwater green alga Pseudokirchneriella subcapitata (Korschikov) Hindák were investigated over 72-h exposures. The toxicity values (the median inhibitory concentration value, in micromoles) in decreasing order of sensitivity were triclosan (0.0018)>triclocarban (0.054)>roxithromycin (0.056)>clarithromycin (0.062)>tylosin (0.20)>tetracycline (2.25)>chlortetracycline (3.49)>norfloxacin (5.64)>sulfamethoxazole (7.50)>ciprofloxacin (20.22)>sulfamethazine (31.26)>trimethoprim (137.78). Several of these antibacterial compounds would be toxic at the micrograms per liter concentrations reported in surface waters and sewage effluents. Simple additive effects were observed in binary mixtures of sulfonamides, and most tylosin, triclosan, or triclocarban combinations. Potentially synergistic effects were observed in binary mixtures of the same class, such as macrolides, tetracyclines, and fluoroquinolones, as well as in some combined drugs, such as trimethoprim and sulfonamides or tylosin and tetracyclines. Potentially antagonistic effects were only observed between tylosin and triclocarban, triclosan and norfloxacin, and triclocarban and norfloxacin. Although present at low concentrations in the aquatic environment, mixtures of these antibacterial agents can potentially affect algal growth in freshwater systems due to their combined action.

  13. Inhibition of growth and aflatoxin production in Aspergillus parasiticus by essential oils of selected plant materials.

    PubMed

    Tantaoui-Elaraki, A; Beraoud, L

    1994-01-01

    We studied the effect of 13 chemically different essential oils (EO) on the mycelial growth of and aflatoxin synthesis by Aspergillus parasiticus. Cinnamon, thyme, oregano, and cumin EO were able to stop mycelial growth at only 0.1% in the medium, while curcumin, ginger, lemon, and orange EO were unable to inhibit totally the growth even at 1% concentration. Coriander, black pepper, mugwort, bay, and rosemary EO caused the growth to stop at concentrations between 0.2 and 1%. The EO most active upon mycelial growth were also the most active against aflatoxinogenesis. However, aflatoxin synthesis was inhibited by all the EO at higher extent than the mycelial growth.

  14. Manganese Toxicity Inhibited Root Growth by Disrupting Auxin Biosynthesis and Transport in Arabidopsis

    PubMed Central

    Zhao, Jingjing; Wang, Wenying; Zhou, Huakun; Wang, Ruling; Zhang, Ping; Wang, Huichun; Pan, Xiangliang; Xu, Jin

    2017-01-01

    Mn toxicity inhibits both primary root (PR) growth and lateral root development. However, the mechanism underlying Mn-mediated root growth inhibition remains to be further elucidated. Here, we investigated the role of auxin in Mn-mediated inhibition of PR growth in Arabidopsis using physiological and genetic approaches. Mn toxicity inhibits PR elongation by reducing meristematic cell division potential. Mn toxicity also reduced auxin levels in root tips by reducing IAA biosynthesis and down-regulating the expression of auxin efflux carriers PIN4 and PIN7. Loss of function pin4 and pin7 mutants showed less inhibition of root growth than col-0 seedlings. These results indicated that this inhibitory effect of Mn toxicity on PR growth was mediated by affecting auxin biosynthesis and the expression of auxin efflux transporters PIN4 and PIN7. PMID:28316607

  15. Manganese Toxicity Inhibited Root Growth by Disrupting Auxin Biosynthesis and Transport in Arabidopsis.

    PubMed

    Zhao, Jingjing; Wang, Wenying; Zhou, Huakun; Wang, Ruling; Zhang, Ping; Wang, Huichun; Pan, Xiangliang; Xu, Jin

    2017-01-01

    Mn toxicity inhibits both primary root (PR) growth and lateral root development. However, the mechanism underlying Mn-mediated root growth inhibition remains to be further elucidated. Here, we investigated the role of auxin in Mn-mediated inhibition of PR growth in Arabidopsis using physiological and genetic approaches. Mn toxicity inhibits PR elongation by reducing meristematic cell division potential. Mn toxicity also reduced auxin levels in root tips by reducing IAA biosynthesis and down-regulating the expression of auxin efflux carriers PIN4 and PIN7. Loss of function pin4 and pin7 mutants showed less inhibition of root growth than col-0 seedlings. These results indicated that this inhibitory effect of Mn toxicity on PR growth was mediated by affecting auxin biosynthesis and the expression of auxin efflux transporters PIN4 and PIN7.

  16. Screening of Various Herbicide Modes of Action for Selective Control of Algae Responsible for Harmful Blooms

    DTIC Science & Technology

    2009-01-01

    screened to determine if these compounds have the potential to selectively control or inhibit the growth of bloom-forming algae. BACKGROUND: HAB are...Lindholm et al. 1999; Birrenkott et al. 2004; Wilde et al. 2005). HAB can also impede growth of aquatic flora and fauna (Casanova et al. 1999; Oberemm et...herbicide, use rate , and timing of application (Poovey and Getsinger 2005). At present, the concept of selectivity, in which specific algal species

  17. Di(2-ethylhexyl) phthalate inhibits antral follicle growth, induces atresia, and inhibits steroid hormone production in cultured mouse antral follicles

    SciTech Connect

    Hannon, Patrick R. Brannick, Katherine E. Wang, Wei Gupta, Rupesh K. Flaws, Jodi A.

    2015-04-01

    Di(2-ethylhexyl) phthalate (DEHP) is a ubiquitous environmental toxicant found in consumer products that causes ovarian toxicity. Antral follicles are the functional ovarian units and must undergo growth, survival from atresia, and proper regulation of steroidogenesis to ovulate and produce hormones. Previous studies have determined that DEHP inhibits antral follicle growth and decreases estradiol levels in vitro; however, the mechanism by which DEHP elicits these effects is unknown. The present study tested the hypothesis that DEHP directly alters regulators of the cell cycle, apoptosis, and steroidogenesis to inhibit antral follicle functionality. Antral follicles from adult CD-1 mice were cultured with vehicle control or DEHP (1–100 μg/ml) for 24–96 h to establish the temporal effects of DEHP on the follicle. Following 24–96 h of culture, antral follicles were subjected to gene expression analysis, and media were subjected to measurements of hormone levels. DEHP increased the mRNA levels of cyclin D2, cyclin dependent kinase 4, cyclin E1, cyclin A2, and cyclin B1 and decreased the levels of cyclin-dependent kinase inhibitor 1A prior to growth inhibition. Additionally, DEHP increased the mRNA levels of BCL2-associated agonist of cell death, BCL2-associated X protein, BCL2-related ovarian killer protein, B-cell leukemia/lymphoma 2, and Bcl2-like 10, leading to an increase in atresia. Further, DEHP decreased the levels of progesterone, androstenedione, and testosterone prior to the decrease in estradiol levels, with decreased mRNA levels of side-chain cleavage, 17α-hydroxylase-17,20-desmolase, 17β-hydroxysteroid dehydrogenase, and aromatase. Collectively, DEHP directly alters antral follicle functionality by inhibiting growth, inducing atresia, and inhibiting steroidogenesis. - Highlights: • DEHP inhibits antral follicle growth by dysregulating cell cycle regulators. • DEHP induces antral follicle atresia by dysregulating apoptosis regulators. • DEHP

  18. Nutritional And Taste Characteristics Of Algae

    NASA Technical Reports Server (NTRS)

    Karel, M.; Nakhost, Z.

    1992-01-01

    Report describes investigation of chemical composition of blue-green algae Synechococcus 6311, as well as preparation of protein isolate from green alga Scenedesmus obliquus and incorporation into variety of food products evaluated for taste. Part of program to investigate growth of microalgae aboard spacecraft for use as food.

  19. Effect of Dead Algae on Soil Permeability

    SciTech Connect

    Harvey, R.S.

    2003-02-21

    Since existing basins support heavy growths of unicellular green algae which may be killed by temperature variation or by inadvertent pH changes in waste and then deposited on the basin floor, information on the effects of dead algae on soil permeability was needed. This study was designed to show the effects of successive algal kills on the permeability of laboratory soil columns.

  20. Comparison of toxicity of class-based organic chemicals to algae and fish based on discrimination of excess toxicity from baseline level.

    PubMed

    Li, Jin J; Tai, Hong W; Yu, Yang; Wen, Yang; Wang, Xiao H; Zhao, Yuan H

    2015-07-01

    Toxicity data to fish and algae were used to investigate excess toxicity between species. Results show that chemicals exhibiting excess toxicity to fish also show excess toxicity to algae for most of the compounds. This indicates that they share the same mode of action between species. Similar relationships between logKOW and toxicities to fish and algae for baseline and less inert compounds suggest that they have similar critical body residues in the two species. Differences in excess toxicity for some compounds suggest that there is a difference of physiological structure and metabolism between fish and algae. Some reactive compounds (e.g. polyamines) exhibit greater toxic effects for algae than those for fish because of relatively low bio-uptake potential of these hydrophilic compounds in fish as compared with that in algae. Esters exhibiting greater toxicity in fish than that in algae indicate that metabolism can affect the discrimination of excess toxicity from baseline level. Algae growth inhibition is a very good surrogate for fish lethality. This is not only because overall toxicity sensitivity to algae is greater than that to fish, but also the excess toxicity calculated from algal toxicity can better reflect reactivity of compounds with target molecules than fish toxicity.

  1. UV photolysis for relieved inhibition of sulfadiazine (SD) to biomass growth.

    PubMed

    Pan, Shihui; Yan, Ning; Zhang, Yongming; Rittmann, Bruce E

    2015-05-01

    UV photolysis was used to relieve inhibition of biomass growth by sulfadiazine (SD), a broad-spectrum anti-microbial. To investigate the effects of SD on biomass growth, three substrates-glucose alone (G), glucose plus sulfadiazine (G+SD), and glucose plus photolyzed SD (G+PSD)-were used to culture the bacteria acclimated to glucose. The biomass was strongly inhibited when SD was added into the glucose solution, but inhibition was relieved to a significant degree when the SD was treated with UV irradiation as a pretreatment. The biomass growth kinetics were described well by the Monod model when glucose was used as a substrate alone, but the kinetics followed a hybrid Aiba model for non-competitive inhibition when SD was added to the solution. When photolyzed SD was added to glucose solution to replace original SD, the growth still followed Aiba inhibition, but inhibition was significantly relieved: the maximum specific growth rate (μ max) increased by 17 %, and the Aiba inhibition concentration increased by 60 %. Aniline, a major product of UV photolysis, supported the growth of the glucose-biodegrading bacteria. Thus, UV photolysis of SD significantly relieved inhibition by lowering the SD concentration and by generating a biodegradable product.

  2. Inhibition of corneal neovascularization by vascular endothelia growth inhibitor gene

    PubMed Central

    Wang, Hong; Wang, Bing; Zhang, Zhen-Hai

    2010-01-01

    AIM To evaluate the effect of Effectene™ lipofectine mediated plasmids encoding human pcDNA4-vascular endothelia growth inhibitor (pcDNA4-VEGI) gene on corneal neovascularization (CNV). METHODS Forty New Zealand albino rabbits were sutured by 5-0 silk on the superior cornea to establish the animal model and divided into 4 random group, ten per each group: group A: transfected by pcDNA4-VEGI gene mediated by Effectene™ lipofectine transfection, group B: by Plasmid pcDNA4, group C: by Effectene™, and group D: by normal saline. Length and area of CNV were measured under slit lamp every day after transfection, immunohistochemistry was used to detected the expression of VEGI protein in cornea at 3, 7, 14 and 21 days. RESULTS Average occurrence of CNV in the pcDNA4-VEGI gene transfected group (group A) was 6.3 days, in plasmid pcDNA4 control group (group B) was 3.1 days, in Effectene™ lipofectine control group (group C) was 3.2 days, in normal saline control group (group D) was 3.2 days. Differences between groups A and B, C, D were statistically significant (P<0.01), while differences in groups B, C and D were meaningless (P>0.05). Lenth and average area of CNV in each period in group A was meaningful different from that in groups B, C, and D (P<0.01), while differences in group B, C and D were meaningless (P>0.05). Immunohistochemistry result: VEGI positive cells could be seen in epithelium, stroma, endothelium and the cliff of CNV in group A at 3 days after transfection. VEGI cells changed with the decrease of CNV. None positive cells were in the control groups (groups B, C and D) all the time. CONCLUSION Effectene™ lipofectine transfection technique can be effectively used in transfecting pcDNA4-VEGI gene into rabbit cornea and the lenth and areas of CNV can be inhibited by VEGI gene. PMID:22553552

  3. Combination oral antiangiogenic therapy with thalidomide and sulindac inhibits tumour growth in rabbits

    PubMed Central

    Verheul, H M W; Panigrahy, D; Yuan, J; D'Amato, R J

    1999-01-01

    Neovascularization facilitates tumour growth and metastasis formation. In our laboratory, we attempt to identify clinically available oral efficacious drugs for antiangiogenic activity. Here, we report which non-steroidal anti-inflammatory drugs (NSAIDs) can inhibit corneal neovascularization, induced by basic fibroblast growth factor (bFGF) or vascular endothelial growth factor (VEGF). This antiangiogenic activity may contribute to the known effects of NSAIDs on gastric ulcers, polyps and tumours. We found that sulindac was one of the most potent antiangiogenic NSAIDs, inhibiting bFGF-induced neovascularization by 50% and VEGF-induced neovascularization by 55%. Previously, we reported that thalidomide inhibited growth factor-induced corneal neovascularization. When we combined sulindac with thalidomide, we found a significantly increased inhibition of bFGF- or VEGF-induced corneal neovascularization (by 63% or 74% respectively) compared with either agent alone (P< 0.01). Because of this strong antiangiogenic effect, we tested the oral combination of thalidomide and sulindac for its ability to inhibit the growth of V2 carcinoma in rabbits. Oral treatment of thalidomide or sulindac alone inhibited tumour growth by 55% and 35% respectively. When given together, the growth of the V2 carcinoma was inhibited by 75%. Our results indicated that oral antiangiogenic combination therapy with thalidomide and sulindac may be a useful non-toxic treatment for cancer. © 1999 Cancer Research Campaign PMID:10408702

  4. Inhibition of the growth of cyanobacteria during the recruitment stage in Lake Taihu.

    PubMed

    Lu, Yaping; Wang, Jin; Zhang, Xiaoqian; Kong, Fanxiang

    2016-03-01

    Microcystis is the dominant algal bloom genus in Lake Taihu. Thus, controlling the recruitment and growth of Microcystis is the most crucial aspect of solving the problem of algal blooms. Different concentrations (0.025, 0.05, and 0.1 g L(-1)) of tea extract were used to treat barrels of lake water at the recruitment stage of cyanobacteria. There was an inhibitory effect on algal growth in all treatment groups. The inhibitory effect on cyanobacteria was stronger than on other algae. The metabolic activity of cells in the treatment groups was significantly enhanced compared to the control, as an adaptation to the stress caused by tea polyphenols. The photosynthetic activity diminished in the treatment groups and was barely detected in the 0.05 and 0.1 g L(-1) treatments. The levels of reactive oxygen species increased substantially in treated cells with the algal cells experiencing oxidative damage. The effect of tea on zooplankton was also studied. The number of Bosmina fatalis individuals did not change significantly in the 0.025 and 0.05 g L(-1) treatments. These results suggested that the application of tea extracts, during the recruitment stage of blue-green algae, suppressed the recruitment and growth of cyanobacteria, thus offering the potential to prevent cyanobacterial blooms.

  5. IPP5 inhibits neurite growth in primary sensory neurons by maintaining TGF-β/Smad signaling.

    PubMed

    Han, Qing-Jian; Gao, Nan-Nan; Guo-QiangMa; Zhang, Zhen-Ning; Yu, Wen-Hui; Pan, Jing; Wang, Qiong; Zhang, Xu; Bao, Lan

    2013-01-15

    During nerve regeneration, neurite growth is regulated by both intrinsic molecules and extracellular factors. Here, we found that inhibitor 5 of protein phosphatase 1 (IPP5), a newly identified inhibitory subunit of protein phosphatase 1 (PP1), inhibited neurite growth in primary sensory neurons as an intrinsic regulator. IPP5 was highly expressed in the primary sensory neurons of rat dorsal root ganglion (DRG) and was downregulated after sciatic nerve axotomy. Knocking down IPP5 with specific shRNA increased the length of the longest neurite, the total neurite length and the number of neurite ends in cultured rat DRG neurons. Mutation of the PP1-docking motif K(8)IQF(11) or the PP1-inhibiting motif at Thr(34) eliminated the IPP5-induced inhibition of neurite growth. Furthermore, biochemical experiments showed that IPP5 interacted with type I transforming growth factor-β receptor (TβRI) and PP1 and enhanced transforming growth factor-β (TGF-β)/Smad signaling in a PP1-dependent manner. Overexpressing IPP5 in DRG neurons aggravated TGF-β-induced inhibition of neurite growth, which was abolished by blocking PP1 or IPP5 binding to PP1. Blockage of TGF-β signaling with the TβRI inhibitor SB431542 or Smad2 shRNA attenuated the IPP5-induced inhibition of neurite growth. Thus, these data indicate that selectively expressed IPP5 inhibits neurite growth by maintaining TGF-β signaling in primary sensory neurons.

  6. Galactose inhibits auxin-induced growth of Avena coleoptiles by two mechanisms

    NASA Technical Reports Server (NTRS)

    Cheung, S. P.; Cleland, R. E.

    1991-01-01

    Galactose inhibits auxin-induced growth of Avena coleoptiles by at least two mechanisms. First, it inhibits auxin-induced H(+)-excretion needed for the initiation of rapid elongation. Galactose cannot be doing so by directly interfering with the ATPase since fusicoccin-induced H(+)-excretion is not affected. Secondly, galactose inhibits long-term auxin-induced growth, even in an acidic (pH 4.5) solution. This may be due to an inhibition of cell wall synthesis. However, galactose does not reduce the capacity of walls to be loosened by H+, given exogenously or excreted in response to fusicoccin.

  7. Decreased abundance of crustose coralline algae due to ocean acidification

    USGS Publications Warehouse

    Kuffner, Ilsa B.; Andersson, Andreas J; Jokiel, Paul L.; Rodgers, Ku'ulei S.; Mackenzie, Fred T.

    2008-01-01

    Owing to anthropogenic emissions, atmospheric concentrations of carbon dioxide could almost double between 2006 and 2100 according to business-as-usual carbon dioxide emission scenarios1. Because the ocean absorbs carbon dioxide from the atmosphere2, 3, 4, increasing atmospheric carbon dioxide concentrations will lead to increasing dissolved inorganic carbon and carbon dioxide in surface ocean waters, and hence acidification and lower carbonate saturation states2, 5. As a consequence, it has been suggested that marine calcifying organisms, for example corals, coralline algae, molluscs and foraminifera, will have difficulties producing their skeletons and shells at current rates6, 7, with potentially severe implications for marine ecosystems, including coral reefs6, 8, 9, 10, 11. Here we report a seven-week experiment exploring the effects of ocean acidification on crustose coralline algae, a cosmopolitan group of calcifying algae that is ecologically important in most shallow-water habitats12, 13, 14. Six outdoor mesocosms were continuously supplied with sea water from the adjacent reef and manipulated to simulate conditions of either ambient or elevated seawater carbon dioxide concentrations. The recruitment rate and growth of crustose coralline algae were severely inhibited in the elevated carbon dioxide mesocosms. Our findings suggest that ocean acidification due to human activities could cause significant change to benthic community structure in shallow-warm-water carbonate ecosystems.

  8. Effect of Growth Rate on the Macromolecular Composition of Prototheca zopfii, a Colorless Alga Which Divides by Multiple Fission

    PubMed Central

    Poyton, Robert O.

    1973-01-01

    Prototheca zopfii, a eukaryote that divides by multiple fission, was investigated to determine how growth rate controls daughter cell number. The macromolecular composition, cell size, and number of nuclei per cell were determined in cultures during balanced growth in various media. Cellular mass, ribonucleic acid (RNA), deoxyribonucleic acid (DNA), carbohydrate, and nuclear number increased as positive linear functions of growth rate, whereas nuclear ploidy remained constant with a value of 0.098 pg of DNA/nucleus. The ratios of RNA to protein, protein to mass, and carbohydrate to mass were unaffected by growth rate, whereas the ratios of DNA to protein and RNA to DNA could be expressed as curvilinear functions of growth rate, the former negative and the latter positive. The dependency of normalized gene dosage (DNA/protein) on growth rate appeared as a distinguishing feature of multiple fission. Determination of the normalized rates of protein and RNA synthesis revealed that both increase linearly with growth rate. It is concluded that Prototheca zopfii may exist in a number of physiological states which are characterized by a unique size and macromolecular composition and which are dictated by growth rate. PMID:4120065

  9. Neuroprotective Effects of Marine Algae

    PubMed Central

    Pangestuti, Ratih; Kim, Se-Kwon

    2011-01-01

    The marine environment is known as a rich source of chemical structures with numerous beneficial health effects. Among marine organisms, marine algae have been identified as an under-exploited plant resource, although they have long been recognized as valuable sources of structurally diverse bioactive compounds. Presently, several lines of studies have provided insight into biological activities and neuroprotective effects of marine algae including antioxidant, anti-neuroinflammatory, cholinesterase inhibitory activity and the inhibition of neuronal death. Hence, marine algae have great potential to be used for neuroprotection as part of pharmaceuticals, nutraceuticals and functional foods. This contribution presents an overview of marine algal neuroprotective effects and their potential application in neuroprotection. PMID:21673890

  10. Bismuth(III) deferiprone effectively inhibits growth of Desulfovibrio desulfuricans ATCC 27774.

    PubMed

    Barton, Larry L; Lyle, Daniel A; Ritz, Nathaniel L; Granat, Alex S; Khurshid, Ali N; Kherbik, Nada; Hider, Robert; Lin, Henry C

    2016-04-01

    Sulfate-reducing bacteria have been implicated in inflammatory bowel diseases and ulcerative colitis in humans and there is an interest in inhibiting the growth of these sulfide-producing bacteria. This research explores the use of several chelators of bismuth to determine the most effective chelator to inhibit the growth of sulfate-reducing bacteria. For our studies, Desulfovibrio desulfuricans ATCC 27774 was grown with nitrate as the electron acceptor and chelated bismuth compounds were added to test for inhibition of growth. Varying levels of inhibition were attributed to bismuth chelated with subsalicylate or citrate but the most effective inhibition of growth by D. desulfuricans was with bismuth chelated by deferiprone, 3-hydroxy-1,2-dimethyl-4(1H)-pyridone. Growth of D. desulfuricans was inhibited by 10 μM bismuth as deferiprone:bismuth with either nitrate or sulfate respiration. Our studies indicate deferiprone:bismuth has bacteriostatic activity on D. desulfuricans because the inhibition can be reversed following exposure to 1 mM bismuth for 1 h at 32 °C. We suggest that deferiprone is an appropriate chelator for bismuth to control growth of sulfate-reducing bacteria because deferiprone is relatively nontoxic to animals, including humans, and has been used for many years to bind Fe(III) in the treatment of β-thalassemia.

  11. A chemical pollen suppressant inhibits auxin-induced growth in maize coleoptile sections

    SciTech Connect

    Vesper, M.J. ); Cross, J.W. )

    1990-05-01

    Chemical inhibitors of pollen development having a phenylcinnoline carboxylate structure were found to inhibit IAA- and 1-NAA-induced growth in maize coleoptile sections. The inhibitor (100 {mu}M) used in these experiments caused approx. 35% reduction in auxin-induced growth over the auxin concentration range of 0.3 to 100 {mu}M. Growth inhibition was noted as a lengthening of the latent period and a decrease in the rate of an auxin-induced growth response. An acid growth response to pH 5 buffer in abraded sections was not impaired. The velocity of basipetal transport of ({sup 3}H)IAA through the coleoptile sections also was not inhibited by the compound, nor was uptake of ({sup 3}H)IAA. Similarly, the inhibitor does not appear to alter auxin-induced H{sup +} secretion. We suggest that the agent targets some other process necessary for auxin-dependent growth.

  12. Histone deacetylase 6 promotes growth of glioblastoma through inhibition of SMAD2 signaling.

    PubMed

    Li, Shun; Liu, Xiao; Chen, Xiangrong; Zhang, Liu; Wang, Xiangyu

    2015-12-01

    Histone deacetylases (HDACs) play a role in the tumorigenesis of glioblastoma multiforme (GBM), whereas the underlying mechanism has not been elucidated. Here, we reported significantly higher HDAC6 levels in GBM from the patients. GBM cell growth was significantly inhibited by ACY-1215, a specific HDAC6 inhibitor. Further analyses show that HDAC6 may promote growth of GBM cells through inhibition of SMAD2 phosphorylation to downregulate p21. Thus, our data demonstrate a previously unrecognized regulation pathway in that HDAC6 increases GBM growth through attenuating transforming growth factor β (TGFβ) receptor signaling.

  13. Miniaturized Growth Inhibition Assay to Assess the Anti-blood Stage Activity of Antibodies.

    PubMed

    Duncan, Elizabeth H; Bergmann-Leitner, Elke S

    2015-01-01

    While no immune correlate for blood-stage specific immunity against Plasmodium falciparum malaria has been identified, there is strong evidence that antibodies directed to various malarial antigens play a crucial role. In an effort to evaluate the role of antibodies in inhibiting growth and/or invasion of erythrocytic stages of the malaria parasite it will be necessary to test large sample sets from Phase 2a/b trials as well as epidemiological studies. The major constraints for such analyses are (1) availability of sufficient sample quantities (especially from infants and small children) and (2) the throughput of standard growth inhibition assays. The method described here assesses growth- and invasion inhibition by measuring the metabolic activity and viability of the parasite (by using a parasite lactate dehydrogenase-specific substrate) in a 384-microtiter plate format. This culture method can be extended beyond the described detection system to accommodate other techniques commonly used for growth/invasion-inhibition.

  14. Inhibition of prostate cancer growth by muscadine grapeskin extract and resveratrol through distinct mechanisms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytochemicals are naturally occurring compounds with demonstrated anti-tumor activities. The phytochemical resveratrol, contained in red grapes, has been shown to inhibit prostate cancer cell growth, potentially through its anti-oxidant activity. Muscadine grapes contain different phytochemical con...

  15. Ability of Cecal Cultures to Inhibit Growth of Salmonella Typhimurium during Aerobic Incubation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction: Poultry can serve as reservoirs for Salmonella; however, chicks provided cultures of cecal bacteria develop resistance to colonization by Salmonella. Research has indicated that cecal bacteria metabolize organic acids to produce substances that inhibit Salmonella growth. Purpose: The...

  16. Imatinib mesylate inhibits platelet derived growth factor stimulated proliferation of rheumatoid synovial fibroblasts

    SciTech Connect

    Sandler, Charlotta; Joutsiniemi, Saima; Lindstedt, Ken A.; Juutilainen, Timo; Kovanen, Petri T.; Eklund, Kari K. . E-mail: kari.eklund@hus.fi

    2006-08-18

    Synovial fibroblast is the key cell type in the growth of the pathological synovial tissue in arthritis. Here, we show that platelet-derived growth factor (PDGF) is a potent mitogen for synovial fibroblasts isolated from patients with rheumatoid arthritis. Inhibition of PDGF-receptor signalling by imatinib mesylate (1 {mu}M) completely abrogated the PDGF-stimulated proliferation and inhibited approximately 70% of serum-stimulated proliferation of synovial fibroblasts. Similar extent of inhibition was observed when PDGF was neutralized with anti-PDGF antibodies, suggesting that imatinib mesylate does not inhibit pathways other than those mediated by PDGF-receptors. No signs of apoptosis were detected in synovial fibroblasts cultured in the presence of imatinib. These results suggest that imatinib mesylate specifically inhibits PDGF-stimulated proliferation of synovial fibroblasts, and that inhibition of PDGF-receptors could represent a feasible target for novel antirheumatic therapies.

  17. The effect of various carbon sources on the growth of single-celled cyanophyta

    NASA Technical Reports Server (NTRS)

    Avilov, I. A.; Sidorenkova, E. S.

    1983-01-01

    In 19 strains of unicellular blue-green algae, belonging to general Synechococcus, Synechocystis, Aphanocapsa and Aphanothece, the capacity of growth under mixotrophic conditions in mineral media with organic carbon sources (carbohydrates, polyols) was investigated. At moderate light intensity (1200 lx) and 0.5% of carbon source there was revealed: (1) Stimulation of growth; (2) Partial or complete inhibition of growth; (3) No influence of carbohydrate and polyols on the growth of some algae strains. Three physiological groups for the investigated strains have been outlined on the basis of data obtained. The possibility of using the differences revealed in classification of unicellular blue-green algae is discussed.

  18. Inhibition of Estrogen-induced Growth of Breast Cancer by Targeting Mitochondrial Oxidants

    DTIC Science & Technology

    2009-04-01

    N- acetyl -L- cysteine ( NAC ), catalase, and the glutathione peroxidase mimic ebselen. mtTFA siRNA transfection inhibited estrogen-induced proliferation...chemical antioxidants, [N- acetylcysteine ( NAC ) and ebselen], inhibits estrogen induced expression of cell cycle genes as well as prevention of...8. The growth of E2-induced transformed clone was highly responsive to E2 and was inhibited by both antioxidants, ebselen and N- acetyl cysteine

  19. Rottlerin inhibits cell growth and invasion via down-regulation of Cdc20 in glioma cells

    PubMed Central

    Wang, Lixia; Hou, Yingying; Yin, Xuyuan; Su, Jingna; Zhao, Zhe; Ye, Xiantao; Zhou, Xiuxia; Zhou, Li; Wang, Zhiwei

    2016-01-01

    Rottlerin, isolated from a medicinal plant Mallotus phillippinensis, has been demonstrated to inhibit cellular growth and induce cytoxicity in glioblastoma cell lines through inhibition of calmodulin-dependent protein kinase III. Emerging evidence suggests that rottlerin exerts its antitumor activity as a protein kinase C inhibitor. Although further studies revealed that rottlerin regulated multiple signaling pathways to suppress tumor cell growth, the exact molecular insight on rottlerin-mediated tumor inhibition is not fully elucidated. In the current study, we determine the function of rottlerin on glioma cell growth, apoptosis, cell cycle, migration and invasion. We found that rottlerin inhibited cell growth, migration, invasion, but induced apoptosis and cell cycle arrest. Mechanistically, the expression of Cdc20 oncoprotein was measured by the RT-PCR and Western blot analysis in glioma cells treated with rottlerin. We observed that rottlerin significantly inhibited the expression of Cdc20 in glioma cells, implying that Cdc20 could be a novel target of rottlerin. In line with this, over-expression of Cdc20 decreased rottlerin-induced cell growth inhibition and apoptosis, whereas down-regulation of Cdc20 by its shRNA promotes rottlerin-induced anti-tumor activity. Our findings indicted that rottlerin could exert its tumor suppressive function by inhibiting Cdc20 pathway which is constitutively active in glioma cells. Therefore, down-regulation of Cdc20 by rottlerin could be a promising therapeutic strategy for the treatment of glioma. PMID:27626499

  20. Volatile Fatty Acids and the Inhibition of Escherichia coli Growth by Rumen Fluid1

    PubMed Central

    Wolin, Meyer J.

    1969-01-01

    Concentrations of volatile fatty acids (VFA) normally found in bovine rumen fluid inhibited growth of Escherichia coli in Antibiotic Medium 3. Acetic, propionic, and butyric acids each produced growth inhibition which was markedly pH-dependent. Little inhibition was observed at pH 7.0, and inhibition increased with decreasing pH. A combination of 60 μmoles of acetate, 20 μmoles of propionate, and 15 μmoles of butyrate per ml gave 96, 69, and 2% inhibition at pH 6.0, 6.5, and 7.0, respectively. Rumen fluid (50%) gave 89 and 48% inhibition at pH 6.0 and 6.5, respectively, and growth stimulation (22%) at pH 7.0. Rumen fluid inhibitory activity was heat-stable, was not precipitated by 63% ethyl alcohol, and was lost by dialysis and by treatment with anion-exchange resins but not with cation-exchange resins. These results are consistent with the idea that VFA are the inhibitory substances in rumen fluid. Previous results which indicated that rumen fluid VFA did not inhibit E. coli growth were due to lack of careful control of the final pH of the growth medium. The E. coli strain used does not grow in rumen fluid alone at pH 7.0. PMID:4886864

  1. Inhibition of Growth of Salmonella by Native Flora of Broiler Chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction Some bacteria in the cecal microflora of broilers can inhibit colonization of chicks by Salmonella. Beneficial cecal bacteria may reduce Salmonella colonization by competing for nutrients and attachment sites or by producing metabolites that inhibit Salmonella growth. The purpose of th...

  2. The non-steroidal anti-inflammatory drug niflumic acid inhibits Candida albicans growth.

    PubMed

    Baker, Andrew; Northrop, Frederick D; Miedema, Hendrik; Devine, Gary R; Davies, Julia M

    2002-01-01

    The non-steroidal anti-inflammatory drug niflumic acid was found to inhibit growth of the yeast form of Candida albicans. Niflumic acid inhibited respiratory oxygen uptake and it is hypothesised that this was achieved by cytosolic acidification and block of glycolysis. Inhibitory concentrations are compatible with current practice of topical application.

  3. Algal Feedback and Removal Efficiency in a Sequencing Batch Reactor Algae Process (SBAR) to Treat the Antibiotic Cefradine

    PubMed Central

    Chen, Jianqiu; Zheng, Fengzhu; Guo, Ruixin

    2015-01-01

    Many previous studies focused on the removal capability for contaminants when the algae grown in an unexposed, unpolluted environment and ignored whether the feedback of algae to the toxic stress influenced the removal capability in a subsequent treatment batch. The present research investigated and compared algal feedback and removal efficiency in a sequencing batch reactor algae process (SBAR) to remove cefradine. Three varied pollution load conditions (10, 30 and 60 mg/L) were considered. Compared with the algal characteristics in the first treatment batch at 10 and 30 mg/L, higher algal growth inhibition rates were observed in the second treatment batch (11.23% to 20.81%). In contrast, algae produced more photosynthetic pigments in response to cefradine in the second treatment batch. A better removal efficiency (76.02%) was obtained during 96 h when the alga treated the antibiotic at 60 mg/L in the first treatment batch and at 30 mg/L in the second treatment batch. Additionally, the removal rate per unit algal density was also improved when the alga treated the antibiotic at 30 or 60 mg/L in the first treatment batch, respectively and at 30 mg/L in the second treatment batch. Our result indicated that the green algae were also able to adapt to varied pollution loads in different treatment batches. PMID:26177093

  4. [Larval survival and growth of Arbacia punctulata (Echinodermata: Echinoidea) fed with five micro-algae at two salinities].

    PubMed

    García, Marina; Rosas, Jesús; Hernández, Iván; Velásquez, Aidé; Cabrera, Tomas; Maneiro, Carlos

    2005-12-01

    Fertilized eggs from an spontaneously spawn of thirty sexually mature sea urchins (Arbacia punctulata) were incubated to complete embryonic development. The echinopluteus larvae (3 ind/ml) were distributed into 50 plastic containers (25 containers at 30 psu and 25 containers at 40 psu) and fed on Tetraselmis chuii, Nannochloropsis oculata, Isochrysis galbana, Chaetoceros gracilis and C. calcitrans under a natural photoperiod. The water of the containers was partially renewed (75%) everyday. Larval anatomic development aspects, daily survival and growth were determined. The growth was determined through postoral arms and body length measurement, and body diameter of twelve larvae during metamorphosis. During the planktonic larval phase, only the I. galbana diet produced similar results for both salinities. The relative growth of larvae was isometric (I) for larvae fed on I. galbana at two salinities and positive allometric for those fed on C. gracilis and C. calcitrans at both salinities. In this study A. punctulata started metamorphosis at day 14 and was completed 30 days after fecundation. Significant differences were detected in post-settlement body growth between the two salinities (F = 23.58, p < 0.05): growth was better for larvae at 30 psu (final body diameter was 3.14 +/- 0.44 mm). The final rate of planktonic larvae was highest with I. galbana (58.33%). For juveniles the rate was 6.48% for those fed on C. gracilis (40 psu in both larvae and juveniles). We recommend the use of this diet and 40 psu for survival or 30 psu for growth.

  5. Role of blue green algae biofertilizer in ameliorating the nitrogen demand and fly-ash stress to the growth and yield of rice (Oryza sativa L.) plants.

    PubMed

    Tripathi, R D; Dwivedi, S; Shukla, M K; Mishra, S; Srivastava, S; Singh, R; Rai, U N; Gupta, D K

    2008-02-01

    Rice is a major food crop throughout the world; however, accumulation of toxic metals and metalloids in grains in contaminated environments is a matter of growing concern. Field experiments were conducted to analyze the growth performance, elemental composition (Fe, Si, Zn, Mn, Cu, Ni, Cd and As) and yield of the rice plants (Oryza sativa L. cv. Saryu-52) grown under different doses of fly-ash (FA; applied @ 10 and 100 tha(-1) denoted as FA(10) and FA(100), respectively) mixed with garden soil (GS) in combination with nitrogen fertilizer (NF; applied @ 90 and 120 kg ha(-1) denoted as NF(90) and NF(120), respectively) and blue green algae biofertilizer (BGA; applied @ 12.5 kg ha(-1) denoted as BGA(12.5)). Significant enhancement of growth was observed in the plants growing on amended soils as compared to GS and best response was obtained in amendment of FA(10)+NF(90)+BGA(12.5). Accumulation of Si, Fe, Zn and Mn was higher than Cu, Cd, Ni and As. Arsenic accumulation was detected only in FA(100) and its amendments. Inoculation of BGA(12.5) caused slight reduction in Cd, Ni and As content of plants as compared to NF(120) amendment. The high levels of stress inducible non-protein thiols (NP-SH) and cysteine in FA(100) were decreased by application of NF and BGA indicating stress amelioration. Study suggests integrated use of FA, BGA and NF for improved growth, yield and mineral composition of the rice plants besides reducing the high demand of nitrogen fertilizers.

  6. Enhancing chemotherapeutic drug inhibition on tumor growth by ultrasound: an in vivo experiment.

    PubMed

    Zhao, Ying-Zheng; Lu, Cui-Tao; Zhou, Zhi-Cai; Jin, Zhuo; Zhang, Lu; Sun, Chang-Zheng; Xu, Yan-Yan; Gao, Hui-Sheng; Tian, Ji-Lai; Gao, Feng-Hou; Tang, Qin-Qin; Li, Wei; Xiang, Qi; Li, Xiao-Kun; Li, Wen-Feng

    2011-02-01

    An in vivo study on enhancing epirubicin hydrochloride (EPI) inhibition on tumor growth by ultrasound (US) was reported. Five-week-old male nude mice were used and HL-60 cells were s.c. (subcutaneous injection) inoculated in axilla of these mice. Six groups were designed and five consecutive treatments were applied to investigate the inhibition on tumor growth and body weight growth. US applied locally to the tumor resulted in a substantially increased drug uptake in tumor cells. The inhibition on tumor growth depended on the position of drug injection and phospholipid-based microbubble (PMB) application. Tumor growth rate under group 1 (PMB+US) was similar to that of blank control. The order of the inhibition on tumor volume growth was: group 4 (s.c. EPI+PMB+US) > group 5 intraperitoneal (i.p. EPI+PMB+US) > group 2 (i.p. EPI) > group 3 (s.c. EPI+US) > group 1 (PMB+US). Similar conclusion was obtained from experimental measurements of tumor weight change. The order of animal survival status for EPI administration groups was: group 4 > group 5 > group 2 > group 3. Chemotherapeutic drug inhibition on tumor growth could be enhanced by local US combined with PMB, which might provide a potential application for US-mediated chemotherapy.

  7. Modelling the effects of pulse exposure of several PSII inhibitors on two algae.

    PubMed

    Copin, Pierre-Jean; Chèvre, Nathalie

    2015-10-01

    Subsequent to crop application and during precipitation events, herbicides can reach surface waters in pulses of high concentrations. These pulses can exceed the Annual Average Environmental Quality Standards (AA-EQS), defined in the EU Water Framework Directive, which aims to protect the aquatic environment. A model was developed in a previous study to evaluate the effects of pulse exposure for the herbicide isoproturon on the alga Scenedesmus vacuolatus. In this study, the model was extended to other substances acting as photosystem II inhibitors and to other algae. The measured and predicted effects were equivalent when pulse exposure of atrazine and diuron were tested on S. vacuolatus. The results were consistent for isoproturon on the alga Pseudokirchneriella subcapitata. The model is thus suitable for the effect prediction of phenylureas and triazines and for the algae used: S. vacuolatus and P. subcapitata. The toxicity classification obtained from the dose-response curves (diuron>atrazine>isoproturon) was conserved for the pulse exposure scenarios modelled for S. vacuolatus. Toxicity was identical for isoproturon on the two algae when the dose-response curves were compared and also for the pulse exposure scenarios. Modelling the effects of any pulse scenario of photosystem II inhibitors on algae is therefore feasible and only requires the determination of the dose-response curves of the substance and growth rate of unexposed algae. It is crucial to detect the longest pulses when measurements of herbicide concentrations are performed in streams because the model showed that they principally affect the cell density inhibition of algae.

  8. Inhibition of Streptococcus mutans Growth and Biofilm Formation by Probiotics in vitro.

    PubMed

    Schwendicke, Falk; Korte, Franziska; Dörfer, Christof E; Kneist, Susanne; Fawzy El-Sayed, Karim; Paris, Sebastian

    2017-01-01

    To exert anticaries effects, probiotics are described to inhibit growth and biofilm formation of cariogenic bacteria such as Streptococcus mutans (SM). We screened 8 probiotics and assessed how SM growth or biofilm formation inhibition affects cariogenicity of probiotic-SM mixed-species biofilms in vitro. Growth inhibition was assessed by cocultivating probiotics and 2 SM strains (ATCC 20532/25175) on agar. Probiotics were either precultured before SM cultivation (exclusion), or SM precultured prior to probiotic cultivation (displacement). Inhibition of SM culture growth was assessed visually. Inhibition of SM biofilm formation on bovine enamel was assessed using a continuous-flow short-term biofilm model, again in exclusion or displacement mode. The cariogenicity of mixed-species biofilms of SM with the most promising growth and biofilm formation inhibiting probiotic strains was assessed using an artificial mouth model, and enamel mineral loss (ΔZ) was measured microradiographically. We found limited differences in SM growth inhibition in exclusion versus displacement mode, and in inhibition of SM 20532 versus 25175. Results were therefore pooled. Lactobacillus acidophilus LA-5 inhibited significantly more SM culture growth than most other probiotics. L. casei LC-11 inhibited SM biofilm formation similarly to other alternatives but showed the highest retention of probiotics in the biofilms (p < 0.05). Mineral loss from SM monospecies biofilms (ΔZ = 9,772, 25th/75th percentiles: 6,277/13,558 vol% × µm) was significantly lower than from mixed-species SM × LA-5 biofilms (ΔZ = 24,578, 25th/75th percentiles: 19,081/28,768 vol% × µm; p < 0.01) but significantly higher than from SM × LC-11 biofilms (ΔZ = 4,835, 25th/75th percentiles: 263/7,865 vol% × µm; p < 0.05). Probiotics inhibiting SM culture growth do not necessarily reduce the cariogenicity of SM-probiotic biofilms. Nevertheless, SM biofilm formation inhibition may be relevant in the reduction of

  9. Siting algae cultivation facilities for biofuel production in the United States: trade-offs between growth rate, site constructability, water availability, and infrastructure.

    PubMed

    Venteris, Erik R; McBride, Robert C; Coleman, Andre M; Skaggs, Richard L; Wigmosta, Mark S

    2014-03-18

    Locating sites for new algae cultivation facilities is a complex task. The climate must support high growth rates, and cultivation ponds require appropriate land and water resources, as well as transportation and utility infrastructure. We employ our spatiotemporal Biomass Assessment Tool (BAT) to select promising locations based on the open-pond cultivation of Arthrospira sp. and strains of the order Sphaeropleales. A total of 64,000 sites across the southern United States were evaluated. We progressively applied screening criteria and tracked their impact on the number of potential sites, geographic location, and biomass productivity. Both strains demonstrated maximum productivity along the Gulf of Mexico coast, with the highest values on the Florida peninsula. In contrast, sites meeting all selection criteria for Arthrospira were located along the southern coast of Texas and for Sphaeropleales were located in Louisiana and southern Arkansas. Results were driven mainly by the lack of oil pipeline access in Florida and elevated groundwater salinity in southern Texas. The requirement for low-salinity freshwater (<400 mg L(-1)) constrained Sphaeropleales locations; siting flexibility is greater for salt-tolerant species like Arthrospira. Combined siting factors can result in significant departures from regions of maximum productivity but are within the expected range of site-specific process improvements.

  10. Siting algae cultivation facilities for biofuel production in the United States: trade-offs between growth rate, site constructability, water availability, and infrastructure

    SciTech Connect

    Venteris, Erik R.; McBride, Robert; Coleman, Andre M.; Skaggs, Richard; Wigmosta, Mark S.

    2014-02-21

    Locating sites for new algae cultivation facilities is a complex task. The climate must support high growth rates, and cultivation ponds require appropriate land and water resources as well as key utility and transportation infrastructure. We employ our spatiotemporal Biomass Assessment Tool (BAT) to select promising locations based on the open-pond cultivation of Arthrospira sp. and a strain of the order Desmidiales. 64,000 potential sites across the southern United States were evaluated. We progressively apply a range of screening criteria and track their impact on the number of selected sites, geographic location, and biomass productivity. Both strains demonstrate maximum productivity along the Gulf of Mexico coast, with the highest values on the Florida peninsula. In contrast, sites meeting all selection criteria for Arthrospira were located along the southern coast of Texas and for Desmidiales were located in Louisiana and southern Arkansas. Site selection was driven mainly by the lack of oil pipeline access in Florida and elevated groundwater salinity in southern Texas. The requirement for low salinity freshwater (<400 mg L-1) constrained Desmidiales locations; siting flexibility is greater for salt-tolerant species such as Arthrospira. Combined siting factors can result in significant departures from regions of maximum productivity but are within the expected range of site-specific process improvements.

  11. THE INFLUENCE OF MAGNETIC FIELDS ON INHIBITION OF MCF-7 CELL GROWTH BY TAMOXIFEN

    EPA Science Inventory

    THE INFLUENCE OF MAGNETIC FIELDS ON INHIBITION OF MCF-7 CELL GROWTH BY TAMOXIFEN.
    Harland and Liburdy (1) reported that 1.2-uT, 60-Hz magnetic fields could significantly block the inhibitory action of pharmacological levels of tamoxifen (10-7 M) on the growth of MCF-7 human br...

  12. Bestatin inhibits cell growth, cell division, and spore cell differentiation in Dictyostelium discoideum.

    PubMed

    Poloz, Yekaterina; Catalano, Andrew; O'Day, Danton H

    2012-04-01

    Bestatin methyl ester (BME) is an inhibitor of Zn(2+)-binding aminopeptidases that inhibits cell proliferation and induces apoptosis in normal and cancer cells. We have used Dictyostelium as a model organism to study the effects of BME. Only two Zn(2+)-binding aminopeptidases have been identified in Dictyostelium to date, puromycin-sensitive aminopeptidase A and B (PsaA and PsaB). PSA from other organisms is known to regulate cell division and differentiation. Here we show that PsaA is differentially expressed throughout growth and development of Dictyostelium, and its expression is regulated by developmental morphogens. We present evidence that BME specifically interacts with PsaA and inhibits its aminopeptidase activity. Treatment of cells with BME inhibited the rate of cell growth and the frequency of cell division in growing cells and inhibited spore cell differentiation during late development. Overexpression of PsaA-GFP (where GFP is green fluorescent protein) also inhibited spore cell differentiation but did not affect growth. Using chimeras, we have identified that nuclear versus cytoplasmic localization of PsaA affects the choice between stalk or spore cell differentiation pathway. Cells that overexpressed PsaA-GFP (primarily nuclear) differentiated into stalk cells, while cells that overexpressed PsaAΔNLS2-GFP (cytoplasmic) differentiated into spores. In conclusion, we have identified that BME inhibits cell growth, division, and differentiation in Dictyostelium likely through inhibition of PsaA.

  13. Influence of Polymers on the Crystal Growth Rate of Felodipine: Correlating Adsorbed Polymer Surface Coverage to Solution Crystal Growth Inhibition.

    PubMed

    Schram, Caitlin J; Taylor, Lynne S; Beaudoin, Stephen P

    2015-10-20

    The bioavailability of orally administered drugs that exhibit poor aqueous solubility can be enhanced with the use of supersaturating dosage forms. Stabilization of these forms by preventing or inhibiting crystallization in solution is an important area of study. Polymers can be used to stabilize supersaturated systems; however, the properties that impact their effectiveness as crystal growth rate inhibitors are not yet fully understood. In this study, the impact of various polymers on the crystal growth rate of felodipine and the conformation of these polymers adsorbed to crystalline felodipine was investigated in order to gain a mechanistic understanding of crystal growth inhibition. It was determined that polymer hydrophobicity impacted polymer adsorption as well as adsorbed polymer conformation. Polymer conformation impacts its surface coverage, which was shown to directly correlate to the polymer's effectiveness as a growth rate inhibitor. By modeling this correlation, it is possible to predict polymer effectiveness given the surface coverage of the polymer.

  14. Wavelength specificity of growth, photosynthesis, and hydrocarbon production in the oil-producing green alga Botryococcus braunii.

    PubMed

    Baba, Masato; Kikuta, Fumie; Suzuki, Iwane; Watanabe, Makoto M; Shiraiwa, Yoshihiro

    2012-04-01

    The effect of monochromatic light on growth, photosynthesis, and hydrocarbon production was tested in Botryococcus braunii Bot-144 (race B), which produces triterpenoid hydrocarbons. The growth was higher in order of red, blue, and green light. The color of red light-grown cells became more orange-yellow and their shape dominantly changed to grape-like with long branches. Photosynthetic carbon fixation activity was higher in order of blue, red, and green light-grown cells, but photosystem activities showed no difference. In the pulse-chase experiments with (14)CO(2), no major difference was observed in the production of lipids, hydrocarbons, polysaccharides, or proteins among the three kinds of cells, although hydrocarbon production was slightly lower in green light-grown cells. These results indicate that blue and red light were more effective for growth, photosynthetic CO(2) fixation, and hydrocarbon production than green light, and that red light is the most efficient light source when calculated based on photoenergy supplied.

  15. Inhibition of in Vitro Pollen Tube Growth by Isolated S-Glycoproteins of Nicotiana alata.

    PubMed Central

    Jahnen, W.; Lush, W. M.; Clarke, A. E.

    1989-01-01

    Pollen from three S-genotypes of Nicotiana alata was grown in vitro in the presence of S-glycoproteins isolated from styles of the same three genotypes. Pollen germination was not affected by the presence of the S-glycoproteins, but pollen tube growth of all genotypes was inhibited. S2 pollen was preferentially inhibited by the S2-glycoprotein and S3 pollen by the S3-glycoprotein. The S6-glycoprotein preferentially inhibited growth of both S2 and S6 pollen over S3 pollen. Heat treatment dramatically increased the inhibitory activity of the S-glycoproteins as inhibitors both of pollen germination and tube growth; after heat treatment, S-allele specificity of pollen tube inhibition was not detected. PMID:12359898

  16. Targeting PDK1 with dichloroacetophenone to inhibit acute myeloid leukemia (AML) cell growth.

    PubMed

    Qin, Lijun; Tian, Yun; Yu, Zhenlong; Shi, Dingbo; Wang, Jingshu; Zhang, Changlin; Peng, Ruoyu; Chen, Xuezhen; Liu, Congcong; Chen, Yiming; Huang, Wenlin; Deng, Wuguo

    2016-01-12

    Pyruvate dehydrogenase kinase-1 (PDK1), a key metabolic enzyme involved in aerobic glycolysis, is highly expressed in many solid tumors. Small molecule compound DAP (2,2-dichloroacetophenone) is a potent inhibitor of PDK1. Whether targeting PDK1 with DAP can inhibit acute myeloid leukemia (AML) and how it works remains unknown. In this study, we evaluated the effect of inhibition of PDK1 with DAP on cell growth, apoptosis and survival in AML cells and identified the underlying mechanisms. We found that treatment with DAP significantly inhibited cell proliferation, increased apoptosis induction and suppressed autophagy in AML cells in vitro, and inhibited tumor growth in an AML mouse model in vivo. We also showed that inhibition of PDK1 with DAP increased the cleavage of pro-apoptotic proteins (PARP and Caspase 3) and decreased the expression of the anti-apoptotic proteins (BCL-xL and BCL-2) and autophagy regulators (ULK1, Beclin-1 and Atg). In addition, we found that DAP inhibited the PI3K/Akt signaling pathway. Furthermore, we demonstrated that PDK1 interacted with ULK1, BCL-xL and E3 ligase CBL-b in AML cells, and DPA treatment could inhibit the interactions. Collectively, our results indicated that targeting PDK1 with DAP inhibited AML cell growth via multiple signaling pathways and suggest that targeting PDK1 may be a promising therapeutic strategy for AMLs.

  17. In vitro growth inhibition of mastitis pathogens by bovine teat skin normal flora.

    PubMed

    Woodward, W D; Besser, T E; Ward, A C; Corbeil, L B

    1987-01-01

    One factor contributing to differences in the susceptibility of cows to mastitis may be differences in the teat skin normal flora, which could inhibit or enhance the growth of pathogenic bacteria. Using in vitro cross-streaking methods, we found that 25% of the isolates of teat normal flora of non-lactating heifers inhibited the growth of selected mastitis pathogens, but enhancers were not detected. Gram-positive pathogens were inhibited to a greater extent than Gram-negative pathogens. Inhibition was not a characteristic of specific genera or species of normal flora, but rather a property of certain variants within a species. This phenomenon of inhibition of mastitis pathogens in vitro by normal flora may be useful as an in vivo biological control method to reduce the incidence of mastitis.

  18. Magnetic separation of algae

    SciTech Connect

    Nath, Pulak; Twary, Scott N.

    2016-04-26

    Described herein are methods and systems for harvesting, collecting, separating and/or dewatering algae using iron based salts combined with a magnetic field gradient to separate algae from an aqueous solution.

  19. Time-Dependent Effects in Algae for Chemicals with Different Adverse Outcome Pathways: A Novel Approach.

    PubMed

    Vogs, Carolina; Altenburger, Rolf

    2016-07-19

    Chemicals affect unicellular algae as a result of toxicokinetic and toxicodynamic processes. The internal concentration of chemicals in algae cells typically reaches equilibrium within minutes, while damage cumulatively increases over hours. The time gap between the steady state of internal exposure and damage development is thus suspected to span up to hours, mainly due to toxicodynamic processes. The quantification of rate-limited toxicodynamic processes, aggregated as a progressive effect from an initiating molecular event through biological key events toward the adverse outcome on algae growth inhibition, might discriminate between different adverse outcome pathways (AOPs). To support our hypothesis, we selected six chemicals according to different physicochemical properties and three distinctly dissimilar AOPs. The time courses of internal concentrations were linked to the observed affected Scenedesmus vacuolatus growth using toxicokinetic-toxicodynamic modeling. Effects on cell growth were explained by effect progression and not by the time to reach internal equilibrium concentration. Effect progression rates ranged over 6 orders of magnitude for all chemicals but varied by less than 1 order of magnitude within similar AOP (photosystem II inhibitors > reactive chemicals > lipid biosynthesis inhibitors), meaning that inhibitors of photosystem II advance an effect toward algae growth fastest compared to reactive chemicals and inhibitors of lipid biosynthesis.

  20. Inhibition of intracellular growth of Listeria monocytogenes by antibiotics.

    PubMed Central

    Michelet, C; Avril, J L; Cartier, F; Berche, P

    1994-01-01

    We studied the activities of 15 antibiotics on the intracellular growth of Listeria monocytogenes in a HeLa cell line. After 24 h of contact with the infected cells, the antibiotics most effective against the intracellular growth of the 10 strains tested were amoxicillin, temafloxacin, and sparfloxacin, which nevertheless failed to totally eliminate the intracellular bacteria. Rifampin and co-trimoxazole had variable effects, depending on the isolates studied. The most active combinations were amoxicillin-sparfloxacin, co-trimoxazole-gentamicin, and sparfloxacin-co-trimoxazole. The results suggest the value of using a cell culture technique to study the activities of antibiotics against certain bacteria with intracellular sites of multiplication. PMID:8203836

  1. Jasmonic Acid Enhances Al-Induced Root Growth Inhibition1[OPEN

    PubMed Central

    Yang, Zhong-Bao; Ma, Yanqi

    2017-01-01

    Phytohormones such as ethylene and auxin are involved in the regulation of the aluminum (Al)-induced root growth inhibition. Although jasmonate (JA) has been reported to play a crucial role in the regulation of root growth and development in response to environmental stresses through interplay with ethylene and auxin, its role in the regulation of root growth response to Al stress is not yet known. In an attempt to elucidate the role of JA, we found that exogenous application of JA enhanced the Al-induced root growth inhibition. Furthermore, phenotype analysis with mutants defective in either JA biosynthesis or signaling suggests that JA is involved in the regulation of Al-induced root growth inhibition. The expression of the JA receptor CORONATINE INSENSITIVE1 (COI1) and the key JA signaling regulator MYC2 was up-regulated in response to Al stress in the root tips. This process together with COI1-mediated Al-induced root growth inhibition under Al stress was controlled by ethylene but not auxin. Transcriptomic analysis revealed that many responsive genes under Al stress were regulated by JA signaling. The differential responsive of microtubule organization-related genes between the wild-type and coi1-2 mutant is consistent with the changed depolymerization of cortical microtubules in coi1 under Al stress. In addition, ALMT-mediated malate exudation and thus Al exclusion from roots in response to Al stress was also regulated by COI1-mediated JA signaling. Together, this study suggests that root growth inhibition is regulated by COI1-mediated JA signaling independent from auxin signaling and provides novel insights into the phytohormone-mediated root growth inhibition in response to Al stress. PMID:27932419

  2. Transcription factor LSF (TFCP2) inhibits melanoma growth

    PubMed Central

    Goto, Yuji; Yajima, Ichiro; Kumasaka, Mayuko; Ohgami, Nobutaka; Tanaka, Asami; Tsuzuki, Toyonori; Inoue, Yuji; Fukushima, Satoshi; Ihn, Hironobu; Kyoya, Mikiko; Ohashi, Hiroyuki; Kawakami, Tamihiro; Bennett, Dorothy C.; Kato, Masashi

    2016-01-01

    Late SV40 factor 3 (LSF), a transcription factor, contributes to human hepatocellular carcinoma (HCC). However, decreased expression level of LSF in skin melanoma compared to that in benign melanocytic tumors and nevi in mice and humans was found in this study. Anchorage-dependent and -independent growth of melanoma cells was suppressed by LSF overexpression through an increased percentage of G1 phase cells and an increased p21CIP1 expression level in vitro and in vivo. Anchorage-dependent growth in LSF-overexpressed melanoma cells was promoted by depletion of LSF in the LSF-overexpressed cells. Integrated results of our EMSA and chromatin immunoprecipitation assays showed binding of LSF within a 150-bp upstream region of the transcription start site of p21CIP1 in melanoma cells. Taken together, our results suggest potential roles of LSF as a growth regulator through control of the transcription of p21CIP1 in melanocytes and melanoma cells as well as a biomarker for nevus. PMID:26506241

  3. Leaf Litter Inhibits Growth of an Amphibian Fungal Pathogen.

    PubMed

    Stoler, Aaron B; Berven, Keith A; Raffel, Thomas R

    2016-06-01

    Past studies have found a heterogeneous distribution of the amphibian chytrid fungal pathogen, Batrachochytrium dendrobatidis (Bd). Recent studies have accounted for some of this heterogeneity through a positive association between canopy cover and Bd abundance, which is attributed to the cooling effect of canopy cover. We questioned whether leaf litter inputs that are also associated with canopy cover might also alter Bd growth. Leaf litter inputs exhibit tremendous interspecific chemical variation, and we hypothesized that Bd growth varies with leachate chemistry. We also hypothesized that Bd uses leaf litter as a growth substrate. To test these hypotheses, we conducted laboratory trials in which we exposed cultures of Bd to leachate of 12 temperate leaf litter species at varying dilutions. Using a subset of those 12 litter species, we also exposed Bd to pre-leached litter substrate. We found that exposure to litter leachate and substrate reduced Bd spore and sporangia densities, although there was substantial variation among treatments. In particular, Bd densities were inversely correlated with concentrations of phenolic acids. We conducted a field survey of phenolic concentrations in natural wetlands which verified that the leachate concentrations in our lab study are ecologically relevant. Our study reinforces prior indications that positive associations between canopy cover and Bd abundance are likely mediated by water temperature effects, but this phenomenon might be counteracted by changes in aquatic chemistry from leaf litter inputs.

  4. Miocene Coralline algae

    SciTech Connect

    Bosence, D.W.J.

    1988-01-01

    The coralline algae (Order Corallinales) were sedimentologically and ecologically important during the Miocene, a period when they were particularly abundant. The many poorly described and illustrated species and the lack of quantitative data in coralline thalli make specific determinations particularly difficult, but some species are well known and widespread in the Tethyan area. The sedimentologic importance of the Miocene coralline algae is reflected in the abundance of in-situ coralline buildups, rhodoliths, and coralline debris facies at Malta and Spain; similar sequences are known throughout the Tethyan Miocene. In-situ buildups vary from leafy crustose biostromes to walled reefs with dense coralline crusts and branches. Growth forms are apparently related to hydraulic energy. Rhodoliths vary from leafy, crustose, and open-branched forms in muddy sediments to dense, crustose, and radial-branching forms in coarse grainstones. Rhodolith form and internal structure correlate closely with hydraulic energy. Coralline genera are conservative and, as such, are useful in paleoenvironmental analysis. Of particular interest are the restricted depth ranges of recent coralline genera. More research is needed on the sedimentology, paleoecology, and systematics of the Cenozoic corallines, as they have particular value in paleoenvironmental analysis.

  5. Inhibition of ice crystal growth in ice cream mix by gelatin hydrolysate.

    PubMed

    Damodaran, Srinivasan

    2007-12-26

    The inhibition of ice crystal growth in ice cream mix by gelatin hydrolysate produced by papain action was studied. The ice crystal growth was monitored by thermal cycling between -14 and -12 degrees C at a rate of one cycle per 3 min. It is shown that the hydrolysate fraction containing peptides in the molecular weight range of about 2000-5000 Da exhibited the highest inhibitory activity on ice crystal growth in ice cream mix, whereas fractions containing peptides greater than 7000 Da did not inhibit ice crystal growth. The size distribution of gelatin peptides formed in the hydrolysate was influenced by the pH of hydrolysis. The optimum hydrolysis conditions for producing peptides with maximum ice crystal growth inhibitory activity was pH 7 at 37 degrees C for 10 min at a papain to gelatin ratio of 1:100. However, this may depend on the type and source of gelatin. The possible mechanism of ice crystal growth inhibition by peptides from gelatin is discussed. Molecular modeling of model gelatin peptides revealed that they form an oxygen triad plane at the C-terminus with oxygen-oxygen distances similar to those found in ice nuclei. Binding of this oxygen triad plane to the prism face of ice nuclei via hydrogen bonding appears to be the mechanism by which gelatin hydrolysate might be inhibiting ice crystal growth in ice cream mix.

  6. TGF beta-induced growth inhibition in primary fibroblasts requires the retinoblastoma protein.

    PubMed

    Herrera, R E; Mäkelä, T P; Weinberg, R A

    1996-09-01

    Transforming growth factor beta (TGF beta) inhibits cell proliferation by inducing a G1 cell-cycle arrest. Cyclin/CDK complexes have been implicated in this arrest, because TGF beta treatment leads to inhibition of cyclin/CDK activity. We have investigated the role of the retinoblastoma protein (pRb) in TGF beta-induced growth arrest by using RB+/+ and RB-/- primary mouse embryo fibroblasts. In both of these cell types, TGF beta inhibits CDK4-associated kinase activity. However, whereas CDK2-associated kinase activity was completely inhibited by TGF beta in the wild-type cells, it was reduced only slightly in the RB mutant cells. In addition, at high-cell density the growth-inhibitory effects of TGF beta are no longer observed in the RB-/- cells; on the contrary, TGF beta treatment promotes the growth of these mutant fibroblasts. Thus, under certain cellular growth conditions, elimination of pRb transforms the growth-inhibitory effects of TGF beta into growth-stimulatory effects. These observations could help to explain why TGF beta is often found to enhance tumorigenicity in vivo and why inactivation of the RB gene leads to tumorigenesis.

  7. Toxicity and hazard of selective serotonin reuptake inhibitor antidepressants fluoxetine, fluvoxamine, and sertraline to algae.

    PubMed

    Johnson, David J; Sanderson, Hans; Brain, Richard A; Wilson, Christian J; Solomon, Keith R

    2007-05-01

    The toxicity of SSRIs to algae/phytoplankton was investigated using the US EPA ECOSAR, acute single-species growth inhibition assays, species sensitivity distributions (SSDs), and an outdoor microcosm mixture experiment. Worst-case ECOSAR estimates of SSRI toxicity to algae ranged from 0.73 to 13.08 mg/L. Sertraline was the most toxic SSRI tested in single-species growth inhibition assays followed by fluoxetine and fluvoxamine with worst-case 96-h IC10s of 4.6, 31.3, and 1662 microg/L, respectively. HC5s of 2.4, 3.6, and 1100 microg/L were estimated, respectively, for sertraline, fluoxetine, and fluvoxamine toxicity to algae-using SSDs. Microcosm phytoplankton structural endpoints were more sensitive than functional endpoints in the short term. However, in the long term, structural endpoints were resilient and functional endpoints remained impacted even after a period of recovery. The worst-case EC10 determined from the outdoor microcosm mixture toxicity to phytoplankton communities was 15.2 nM. Although SSRIs are toxic to algae, hazard quotients using worst-case PECs represent a margin of safety of 20 to phytoplankton. Although SSRIs do not appear to pose a hazard to primary production, this assessment is not protective of higher aquatic organisms and further research into the chronic toxicity to low levels of SSRIs to higher-level aquatic species is recommended.

  8. Fighting arboviral diseases: low toxicity on mammalian cells, dengue growth inhibition (in vitro), and mosquitocidal activity of Centroceras clavulatum-synthesized silver nanoparticles.

    PubMed

    Murugan, Kadarkarai; Aruna, Palanimuthu; Panneerselvam, Chellasamy; Madhiyazhagan, Pari; Paulpandi, Manickam; Subramaniam, Jayapal; Rajaganesh, Rajapandian; Wei, Hui; Alsalhi, Mohamad Saleh; Devanesan, Sandhanasamy; Nicoletti, Marcello; Syuhei, Ban; Canale, Angelo; Benelli, Giovanni

    2016-02-01

    Dengue is a mosquito-borne viral disease that has rapidly spread in all regions of the world in recent years. Female mosquitoes, mainly Aedes aegypti, transmit dengue. Approximately 3,900 million people, in 128 countries, are at risk of dengue infection. Recently, a focus has been provided on the potential of green-synthesized nanoparticles as inhibitors of the production of dengue viral envelope (E) protein in Vero cells and downregulators of the expression of dengue viral E gene. Algae are an outstanding reservoir of novel compounds, which may help in the fight against mosquito-borne diseases. In this research, silver nanoparticles (AgNP) were rapidly synthesized using a cheap extract of the alga Centroceras clavulatum. AgNP were characterized by UV–vis spectrophotometry, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). In mosquitocidal assays, LC50 values of C. clavulatum extract against A. aegypti larvae and pupae were 269.361 ppm (larva I), 309.698 ppm (larva II), 348.325 ppm (larva III), 387.637 ppm (larva IV), and 446.262 ppm (pupa). C. clavulatum extract also exhibited moderate antioxidant activity, both in 2,2-diphenyl-1-picrylhydrazyl (DPPH) and nitric oxide (NO) radical scavenging assays. LC50 values of C. clavulatum-synthesized AgNP were 21.460 ppm (larva I), 23.579 ppm (larva II), 25.912 ppm (larva III), 29.155 ppm (larva IV), and 33.877 ppm (pupa). Furthermore, C. clavulatum-synthesized AgNP inhibited dengue (serotype dengue virus type-2 (DEN-2)) viral replication in Vero cells. Notably, 50 μg/ml of green-synthesized AgNP showed no cytotoxicity on Vero cells while reduced DEN-2 viral growth of more than 80%; 12.5 μg/ml inhibited viral growth of more than 50%. Cellular internalization assays highlighted that untreated infected cells showed high intensity of fluorescence emission, which denotes high level of viral internalization. Conversely

  9. CH5137291, an androgen receptor nuclear translocation-inhibiting compound, inhibits the growth of castration-resistant prostate cancer cells.

    PubMed

    Ishikura, Nobuyuki; Kawata, Hiromitsu; Nishimoto, Ayako; Nakamura, Ryo; Tsunenari, Toshiaki; Watanabe, Miho; Tachibana, Kazutaka; Shiraishi, Takuya; Yoshino, Hitoshi; Honma, Akie; Emura, Takashi; Ohta, Masateru; Nakagawa, Toshito; Houjo, Takao; Corey, Eva; Vessella, Robert L; Aoki, Yuko; Sato, Haruhiko

    2015-04-01

    Resistance of prostate cancer to castration is currently an unavoidable problem. The major mechanisms underlying such resistance are androgen receptor (AR) overexpression, androgen-independent activation of AR, and AR mutation. To address this problem, we developed an AR pure antagonist, CH5137291, with AR nuclear translocation-inhibiting activity, and compared its activity and characteristics with that of bicalutamide. Cell lines corresponding to the mechanisms of castration resistance were used: LNCaP-BC2 having AR overexpression and LNCaP-CS10 having androgen-independent AR activation. VCaP and LNCaP were used as hormone-sensitive prostate cancer cells. In vitro functional assay clearly showed that CH5137291 inhibited the nuclear translocation of wild-type ARs as well as W741C- and T877A-mutant ARs. In addition, it acted as a pure antagonist on the transcriptional activity of these types of ARs. In contrast, bicalutamide did not inhibit the nuclear translocation of these ARs, and showed a partial/full agonistic effect on the transcriptional activity. CH5137291 inhibited cell growth more strongly than bicalutamide in VCaP and LNCaP cells as well as in LNCaP-BC2 and LNCaP-CS10 cells in vitro. In xenograft models, CH5137291 strongly inhibited the tumor growth of LNCaP, LNCaP-BC2, and LNCaP-CS10, whereas bicalutamide showed a weaker effect in LNCaP and almost no effect in LNCaP-BC2 and LNCaP-CS10 xenografts. Levels of prostate-specific antigen (PSA) in plasma correlated well with the antitumor effect of both agents. CH5137291 inhibited the growth of LNCaP tumors that had become resistant to bicalutamide treatment. A docking model suggested that CH5137291 intensively collided with the M895 residue of helix 12, and therefore strongly inhibited the folding of helix 12, a cause of AR agonist activity, in wild-type and W741C-mutant ARs. In cynomolgus monkeys, the serum concentration of CH5137291 increased dose-dependently and PSA level decreased 80% at 100 mg/kg. CH

  10. Molecular cloning of genetic determinants for inhibition of fungal growth by a fluorescent pseudomonad.

    PubMed Central

    Gutterson, N I; Layton, T J; Ziegle, J S; Warren, G J

    1986-01-01

    Pseudomonas fluorescens HV37a inhibits growth of the fungus Pythium ultimum in vitro. Optimal inhibition is observed on potato dextrose agar, a rich medium. Mutations eliminating fungal inhibition were obtained after mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine. Mutants were classified by cosynthesis and three groups were distinguished, indicating that a minimum of three genes are required for fungal inhibition. Cosmids that contain wild-type alleles of the genes were identified in an HV37a genomic library by complementation of the respective mutants. This analysis indicated that three distinct genomic regions were required for fungal inhibition. The cosmids containing these loci were mapped by transposon insertion mutagenesis. Two of the cosmids were found to contain at least two genes each. Therefore, at least five genes in HV37a function as determinants of fungal inhibition. Images PMID:3005234

  11. Effect of Alexandrium tamarense on three bloom-forming algae

    NASA Astrophysics Data System (ADS)

    Yin, Juan; Xie, Jin; Yang, Weidong; Li, Hongye; Liu, Jiesheng

    2010-07-01

    We investigated the allelopathic properties of Alexandrium tamarense (Laboar) Balech on the growth of Prorocentrum donghaiense Lu, Chattonella marina (Subrahmanyan) Hara et Chihara and Heterosigma akashiwo (Hada) Hada in a laboratory experiment. We examined the growth of A. tamarense, C. marina, P. donghaiense and H. Akashiwo in co-cultures and the effect of filtrates from A. tamarense cultures in various growth phases, on the three harmful algal bloom (HAB)-forming algae. In co-cultures with A. tamarense, both C. marina and H. akashiwo were dramatically suppressed at high cell densities; in contrast, the growth of P. donghaiense varied in different inoculative ratios of A. tamarense and P. donghaiense. When the ratio was 1:1 ( P. donghaiense: A. tamarense), growth of P. donghaiense was inhibited considerably, while the growth of P. donghaiense was almost the same as that of the control when the ratio was 9:1. The growth difference of P. donghaiense, C. marina and H. akashiwo when co-cultured with A. tamarense indicated that the allelopathic effect may be one of the important factors in algal competition and phytoplankton succession involving A. tamarense. In addition, the filtrate from A. tamarense culture had negative impacts on these three HAB algae, and such inhibition varied with different growth phases of A. tamarense in parallel with reported values of PSP toxin content in Alexandrium cells. This implied that PSP toxin was possibly involved in allelopathy of A. tamarense. However, the rapid decomposition and inactivation of PSP toxin above pH 7 weakened this possibility. Further studies on the allelochemicals responsible for the allelopathy of A. tamarense need to be carried out in future.

  12. Androglobin knockdown inhibits growth of glioma cell lines

    PubMed Central

    Huang, Bo; Lu, Yi-Sheng; Li, Xia; Zhu, Zhi-Chuan; Li, Kui; Liu, Ji-Wei; Zheng, Jing; Hu, Ze-Lan

    2014-01-01

    Globin family was famous for oxygen supply function of its members such as hemoglobin and myoglobin. With the progress of research, several members of this protein family have been proven to play roles in tumors including glioma. Androglobin (ADGB) is a recently identified member of globin family with very few studies about its function. In the present study, we show that ADGB plays an oncogene role in glioma. Lentiviral vector mediated ADGB knockdown inhibited the proliferation of glioma cell lines determined by MTT assay and colony formation assay. ADGB knockdown also increased the apoptosis of glioma cell line U251 assessed by flow cytometry. In addition, western blot showed that ADGB knockdown altered levels of several proteins related to proliferation, survival or apoptosis in U251 cells. These findings suggest ADGB is involved in the progression of glioma in vitro. PMID:24966926

  13. Inhibition of the growth of yeasts in fermented salads.

    PubMed

    Bonestroo, M H; de Wit, J C; Kusters, B J; Rombouts, F M

    1993-02-01

    Salads composed of vegetables and/or meat in an oil-in-water emulsion were prepared by fermentation for 7 h at 42 degrees C or 45 degrees C with strains of Lactobacillus spp. Their stability towards spoilage yeasts was studied using Saccharomyces cerevisiae, Saccharomyces exiguus and Torulaspora delbrueckii, isolated from salads, as well as Pichia membranaefaciens and Zygosaccharomyces bailii. Salads fermented with good lactic starters usually had pH values of < or = 4.2 and lactic acid concentrations of 0.28 to 0.43% (w/w). High numbers of spoilage yeasts (and production of large volumes of CO2) were not attained in these salads, provided the initial concentration of spoilage yeasts was sufficiently low (< or = 100 CFU/g). Inhibition of spoilage yeasts in lactic fermented salads is probably due to lactic acid, the low storage temperature and the low residual oxygen concentration.

  14. Growth and nutrient removal in free and immobilized green algae in batch and semi-continuous cultures treating real wastewater.

    PubMed

    Ruiz-Marin, Alejandro; Mendoza-Espinosa, Leopoldo G; Stephenson, Tom

    2010-01-01

    Two species of microalgae growing as immobilized and free-cells were compared to test its ability to remove N and P in batch cultures of urban wastewater. The best microalgae-cell growth configuration was selected to be tested in bioreactor operated in semi-continuous mode. Scenedesmus obliquus showed a higher N and P uptake rate in urban wastewater than Chlorella vulgaris. When tested in semi-continuous mode and with the re-calcification of beads, S. obliquus was more effective in removing N and P for longer periods (181 h) than batch cultures; fecal coliforms removal was good (95%) although the final concentration was still unsuitable for discharge to natural water bodies. Protein and lipids content analysis suggest that, from a practical point of view, immobilized systems could facilitate the separation of the biomass from the treated wastewater although in terms of nutritional value of the biomass, immobilized systems do not represent an advantage over free-cell systems.

  15. Cultivation of green alga Botryococcus braunii in raceway, circular ponds under outdoor conditions and its growth, hydrocarbon production.

    PubMed

    Ranga Rao, A; Ravishankar, G A; Sarada, R

    2012-11-01

    The present study focused on cultivation, seasonal variation in growth, hydrocarbon production, fatty acids profiles of Botryococcus braunii (LB-572 and N-836) in raceway & circular ponds under outdoor conditions. After 18days of cultivation the biomass yield and hydrocarbon contents were increased in both raceway and circular ponds. The fat content was found to be around 24% (w/w) with palmitic and oleic acids as prominent fatty acids. Hydrocarbons of C(20)-C(30) carbon chain length were higher in raceway and circular ponds. Maximum biomass yield (2gL(-1)) and hydrocarbon content (28%) were observed in Nov-Dec. In case of B. braunii (N-836) after 25days of cultivation the biomass yield was 1gL(-1) and hydrocarbon content was 27%. Supplementation of 0.1% NaHCO(3) in the medium resulted in biomass yield of 1.5gL(-1) and hydrocarbon content of 30% compared to control.

  16. Aurora kinase B/C inhibition impairs malignant glioma growth in vivo.

    PubMed

    Diaz, Roberto Jose; Golbourn, Brian; Shekarforoush, Maryam; Smith, Christian A; Rutka, James T

    2012-07-01

    Inhibition of Aurora kinase B has been evaluated as a therapy to block solid tumor growth in breast cancer, hepatocellular carcinoma, lung adenocarcinoma, and colorectal cancer models. Aurora kinase inhibitors are in early clinical trials for the treatment of leukemia. We hypothesized that Aurora B inhibition would reduce malignant glioma cell viability and result in impaired tumor growth in vivo. Aurora B expression is greater in cultured malignant glioma U251 cells compared to proliferating normal human astrocytes, and expression is maintained in U251 flank xenografts. Aurora B inhibition with AZD1152-HQPA blocked cell division in four different p53-mutant glioma cell lines (U251, T98G, U373, and U118). AZD1152-HQPA also inhibited Aurora C activation loop threonine autophosphorylation at the effective antiproliferative concentrations in vitro. Reduction in cell viability of U251 (p53(R273H)) cells was secondary to cytokinesis blockade and apoptosis induction following endoreplication. AZD1152-HQPA inhibited the growth of U251 tumor xenografts and resulted in an increase in tumor cell apoptosis both in vitro and in vivo. Subcutaneous administration of AZD1152-HQPA (25 mg/kg/day × 4 days; 2 cycles spaced 7 days apart) resulted in a prolongation in median survival after intracranial inoculation of U251 cells in mice (P = 0.025). This is the first demonstration that an Aurora kinase inhibitor can inhibit malignant glioma growth in vivo at drug doses that are clinically relevant.

  17. Dual effect of metformin on growth inhibition and oestradiol production in breast cancer cells.

    PubMed

    Rice, S; Pellat, L; Ahmetaga, A; Bano, G; Mason, H D; Whitehead, S A

    2015-04-01

    Evidence has been accumulating for a role for metformin in reducing breast cancer risk in post-menopausal women. It inhibits growth of breast cancer cells via several mechanisms, primarily the AMPK/mTOR signalling pathway. Another possible protective mechanism may be the ability of metformin to inhibit aromatase activity. In the present study, we investigated the effects of metformin on the basal growth of MCF-7 cells, after oestradiol (E2) stimulation and after the inhibition of mTOR by rapamycin. Secondly, we investigated the effects of metformin on the activity of a number of steroidogenic enzymes and the mRNA expression of aromatase and steroid sulphatase (STS). High doses of metformin significantly inhibited both basal and oestrogen-stimulated cell division. Low-dose rapamycin (10-10 M) did not inhibit growth, but the addition of metformin induced a significant reduction in growth. High-dose rapamycin (10-8 M) inhibited growth, and this was further attenuated by the addition of metformin. Exposure to low (10-7 M) and high (10-4 M) doses of metformin for 7-10 days significantly reduced the conversion of androstenedione (ANDRO) and testosterone (TESTO) (both requiring aromatase), but not the conversion of oestrone or oestrone sulphate (ES) via 17β-hydroxysteroid dehydrogenase/sulphatase to E2. This attenuation was via a downregulation in the expression of total aromatase mRNA and promoter II, whilst the expression of sulphatase was unaffected by metformin. In conclusion, plasma levels of metformin have a dual therapeutic action, first by directly inhibiting cell proliferation which can be augmented by rapamycin analogues, and secondly, by inhibiting aromatase activity and reducing the local conversion of androgens to E2.

  18. Molecular modifiers reveal a mechanism of pathological crystal growth inhibition

    NASA Astrophysics Data System (ADS)

    Chung, Jihae; Granja, Ignacio; Taylor, Michael G.; Mpourmpakis, Giannis; Asplin, John R.; Rimer, Jeffrey D.

    2016-08-01

    Crystalline materials are crucial to the function of living organisms, in the shells of molluscs, the matrix of bone, the teeth of sea urchins, and the exoskeletons of coccoliths. However, pathological biomineralization can be an undesirable crystallization process associated with human diseases. The crystal growth of biogenic, natural and synthetic materials may be regulated by the action of modifiers, most commonly inhibitors, which range from small ions and molecules to large macromolecules. Inhibitors adsorb on crystal surfaces and impede the addition of solute, thereby reducing the rate of growth. Complex inhibitor-crystal interactions in biomineralization are often not well elucidated. Here we show that two molecular inhibitors of calcium oxalate monohydrate crystallization—citrate and hydroxycitrate—exhibit a mechanism that differs from classical theory in that inhibitor adsorption on crystal surfaces induces dissolution of the crystal under specific conditions rather than a reduced rate of crystal growth. This phenomenon occurs even in supersaturated solutions where inhibitor concentration is three orders of magnitude less than that of the solute. The results of bulk crystallization, in situ atomic force microscopy, and density functional theory studies are qualitatively consistent with a hypothesis that inhibitor-crystal interactions impart localized strain to the crystal lattice and that oxalate and calcium ions are released into solution to alleviate this strain. Calcium oxalate monohydrate is the principal component of human kidney stones and citrate is an often-used therapy, but hydroxycitrate is not. For hydroxycitrate to function as a kidney stone treatment, it must be excreted in urine. We report that hydroxycitrate ingested by non-stone-forming humans at an often-recommended dose leads to substantial urinary excretion. In vitro assays using human urine reveal that the molecular modifier hydroxycitrate is as effective an inhibitor of nucleation

  19. SKI knockdown inhibits human melanoma tumor growth in vivo.

    PubMed

    Chen, Dahu; Lin, Qiushi; Box, Neil; Roop, Dennis; Ishii, Shunsuke; Matsuzaki, Koichi; Fan, Tao; Hornyak, Thomas J; Reed, Jon A; Stavnezer, Ed; Timchenko, Nikolai A; Medrano, Estela E

    2009-12-01

    The SKI protein represses the TGF-beta tumor suppressor pathway by associating with the Smad transcription factors. SKI is upregulated in human malignant melanoma tumors in a disease-progression manner and its overexpression promotes proliferation and migration of melanoma cells in vitro. The mechanisms by which SKI antagonizes TGF-beta signaling in vivo have not been fully elucidated. Here we show that human melanoma cells in which endogenous SKI expression was knocked down by RNAi produced minimal orthotopic tumor xenograft nodules that displayed low mitotic rate and prominent apoptosis. These minute tumors exhibited critical signatures of active TGF-beta signaling including high levels of nuclear Smad3 and p21(Waf-1), which are not found in the parental melanomas. To understand how SKI promotes tumor growth we used gain- and loss-of-function approaches and found that simultaneously to blocking the TGF-beta-growth inhibitory pathway, SKI promotes the switch of Smad3 from tumor suppression to oncogenesis by favoring phosphorylations of the Smad3 linker region in melanoma cells but not in normal human melanocytes. In this context, SKI is required for preventing TGF-beta-mediated downregulation of the oncogenic protein c-MYC, and for inducing the plasminogen activator inhibitor-1, a mediator of tumor growth and angiogenesis. Together, the results indicate that SKI exploits multiple regulatory levels of the TGF-beta pathway and its deficiency restores TGF-beta tumor suppressor and apoptotic activities in spite of the likely presence of oncogenic mutations in melanoma tumors.

  20. Pumpkin seed extract: Cell growth inhibition of hyperplastic and cancer cells, independent of steroid hormone receptors.

    PubMed

    Medjakovic, Svjetlana; Hobiger, Stefanie; Ardjomand-Woelkart, Karin; Bucar, Franz; Jungbauer, Alois

    2016-04-01

    Pumpkin seeds have been known in folk medicine as remedy for kidney, bladder and prostate disorders since centuries. Nevertheless, pumpkin research provides insufficient data to back up traditional beliefs of ethnomedical practice. The bioactivity of a hydro-ethanolic extract of pumpkin seeds from the Styrian pumpkin, Cucurbita pepo L. subsp. pepo var. styriaca, was investigated. As pumpkin seed extracts are standardized to cucurbitin, this compound was also tested. Transactivational activity was evaluated for human androgen receptor, estrogen receptor and progesterone receptor with in vitro yeast assays. Cell viability tests with prostate cancer cells, breast cancer cells, colorectal adenocarcinoma cells and a hyperplastic cell line from benign prostate hyperplasia tissue were performed. As model for non-hyperplastic cells, effects on cell viability were tested with a human dermal fibroblast cell line (HDF-5). No transactivational activity was found for human androgen receptor, estrogen receptor and progesterone receptor, for both, extract and cucurbitin. A cell growth inhibition of ~40-50% was observed for all cell lines, with the exception of HDF-5, which showed with ~20% much lower cell growth inhibition. Given the receptor status of some cell lines, a steroid-hormone receptor independent growth inhibiting effect can be assumed. The cell growth inhibition for fast growing cells together with the cell growth inhibition of prostate-, breast- and colon cancer cells corroborates the ethnomedical use of pumpkin seeds for a treatment of benign prostate hyperplasia. Moreover, due to the lack of androgenic activity, pumpkin seed applications can be regarded as safe for the prostate.

  1. Algae -- a poor man's HAART?

    PubMed

    Teas, Jane; Hebert, James R; Fitton, J Helen; Zimba, Paul V

    2004-01-01

    Drawing inferences from epidemiologic studies of HIV/AIDS and in vivo and in vitro HIV inhibition by algae, we propose algal consumption as one unifying characteristic of countries with anomalously low rates. HIV/AIDS incidence and prevalence in Eastern Asia ( approximately 1/10000 adults in Japan and Korea), compared to Africa ( approximately 1/10 adults), strongly suggest that differences in IV drug use and sexual behavior are insufficient to explain the 1000-fold variation. Even in Africa, AIDS/HIV rates vary. Chad has consistently reported low rates of HIV/AIDS (2-4/100). Possibly not coincidentally, most people in Japan and Korea eat seaweed daily and the Kanemba, one of the major tribal groups in Chad, eat a blue green alga (Spirulina) daily. Average daily algae consumption in Asia and Africa ranges between 1 and 2 tablespoons (3-13 g). Regular consumption of dietary algae might help prevent HIV infection and suppress viral load among those infected.

  2. Noscapine inhibits tumor growth in TMZ-resistant gliomas.

    PubMed

    Jhaveri, Niyati; Cho, Heeyeon; Torres, Shering; Wang, Weijun; Schönthal, Axel H; Petasis, Nicos A; Louie, Stan G; Hofman, Florence M; Chen, Thomas C

    2011-12-22

    Noscapine, a common oral antitussive agent, has been shown to have potent antitumor activity in a variety of cancers. Treatment of glioblastoma multiforme (GBM) with temozolomide (TMZ), its current standard of care, is problematic because the tumor generally recurs and is then resistant to this drug. We therefore investigated the effects of noscapine on human TMZ-resistant GBM tumors. We found that noscapine significantly decreased TMZ-resistant glioma cell growth and invasion. Using the intracranial xenograft model, we showed that noscapine increased survival of animals with TMZ-resistant gliomas. Thus noscapine can provide an alternative therapeutic approach for the treatment of TMZ-resistant gliomas.

  3. Hydroxyapatite-binding peptides for bone growth and inhibition

    DOEpatents

    Bertozzi, Carolyn R.; Song, Jie; Lee, Seung-Wuk

    2011-09-20

    Hydroxyapatite (HA)-binding peptides are selected using combinatorial phage library display. Pseudo-repetitive consensus amino acid sequences possessing periodic hydroxyl side chains in every two or three amino acid sequences are obtained. These sequences resemble the (Gly-Pro-Hyp).sub.x repeat of human type I collagen, a major component of extracellular matrices of natural bone. A consistent presence of basic amino acid residues is also observed. The peptides are synthesized by the solid-phase synthetic method and then used for template-driven HA-mineralization. Microscopy reveal that the peptides template the growth of polycrystalline HA crystals .about.40 nm in size.

  4. Calcium ion involvement in growth inhibition of mechanically stressed soybean (Glycine max) seedlings

    NASA Technical Reports Server (NTRS)

    Jones, R. S.; Mitchell, C. A.

    1989-01-01

    A 40-50% reduction in soybean [Glycine max (L.) Merr. cv. Century 84] hypocotyl elongation occurred 24 h after application of mechanical stress. Exogenous Ca2+ at 10 mM inhibited growth by 28% if applied with the Ca2+ ionophore A23187 to the zone of maximum hypocotyl elongation. La3+ was even more inhibitory than Ca2+, especially above 5 mM. Treatment with ethyleneglycol-bis-(beta-aminoethylether)-N, N, N', N'-tetraacetic acid (EGTA) alone had no effect on growth of non-stressed seedlings at the concentrations used but negated stress-induced growth reduction by 36% at 4 mM when compared to non-treated, stressed controls. Treatment with EDTA was ineffective in negating stress-induced growth inhibition. Calmodulin antagonists calmidazolium, chlorpromazine, and 48/80 also negated stress-induced growth reduction by 23, 50, and 35%, respectively.

  5. Prolyl oligopeptidase inhibition-induced growth arrest of human gastric cancer cells

    SciTech Connect

    Suzuki, Kanayo; Sakaguchi, Minoru; Tanaka, Satoshi; Yoshimoto, Tadashi; Takaoka, Masanori

    2014-01-03

    Highlights: •We examined the effects of prolyl oligopeptidase (POP) inhibition on p53 null gastric cancer cell growth. •POP inhibition-induced cell growth suppression was associated with an increase in a quiescent G{sub 0} state. •POP might regulate the exit from and/or reentry into the cell cycle. -- Abstract: Prolyl oligopeptidase (POP) is a serine endopeptidase that hydrolyzes post-proline peptide bonds in peptides that are <30 amino acids in length. We recently reported that POP inhibition suppressed the growth of human neuroblastoma cells. The growth suppression was associated with pronounced G{sub 0}/G{sub 1} cell cycle arrest and increased levels of the CDK inhibitor p27{sup kip1} and the tumor suppressor p53. In this study, we investigated the mechanism of POP inhibition-induced cell growth arrest using a human gastric cancer cell line, KATO III cells, which had a p53 gene deletion. POP specific inhibitors, 3-((4-[2-(E)-styrylphenoxy]butanoyl)-L-4-hydroxyprolyl)-thiazolidine (SUAM-14746) and benzyloxycarbonyl-thioprolyl-thioprolinal, or RNAi-mediated POP knockdown inhibited the growth of KATO III cells irrespective of their p53 status. SUAM-14746-induced growth inhibition was associated with G{sub 0}/G{sub 1} cell cycle phase arrest and increased levels of p27{sup kip1} in the nuclei and the pRb2/p130 protein expression. Moreover, SUAM-14746-mediated cell cycle arrest of KATO III cells was associated with an increase in the quiescent G{sub 0} state, defined by low level staining for the proliferation marker, Ki-67. These results indicate that POP may be a positive regulator of cell cycle progression by regulating the exit from and/or reentry into the cell cycle by KATO III cells.

  6. Modelling algae growth and dissolved oxygen in the Seine River downstream the Paris urban area: contribution of high frequency measurements

    NASA Astrophysics Data System (ADS)

    Vilmin, Lauriane; Escoffier, Nicolas; Groleau, Alexis; Poulin, Michel; Flipo, Nicolas

    2014-05-01

    Dissolved oxygen is a key variable in the hydro-ecological functioning of river systems. The accurate representation of the different biogeochemical processes affecting algal blooms and dissolved oxygen in the water column in hydro-ecological models is crucial for the use of these models as reliable management tools. This study focuses on the water quality of the Seine River along a 225 km stretch, from Paris to the Seine estuary. The study area is highly urbanized and located downstream France's largest agricultural area, and therefore receives large amounts of nutrients. During the last decades, nutrient inputs have been significantly reduced, especially with the implementation of new sewage water treatment technologies. Even though the frequency and the intensity of observed algal blooms have decreased, blooms were observed in 2011 and 2012. These blooms are generally followed by a period of high organic matter accumulation, leading to high mineralization fluxes and potential oxygen depletion. The hydrodynamics and the water quality of the Seine River are simulated for the 2011-2012 period with the distributed process-based hydro-ecological model ProSe (Even et al., 1998). The simulated chlorophyll a and dissolved oxygen concentrations are compared to high frequency measurements at the Bougival monitoring station (50 km downstream from Paris), which is part of the CarboSeine monitoring network. The high frequency continuous dataset allows calibrating of primary producers' physiological parameters. New growth parameters are defined for the diatom community. The blooms occur at the end of the winter period (march 2011 and march 2012) and the optimal temperature for diatom growth is calibrated at 10°C, based on an analysis of the physiological response of the diatom community. One of the main outcomes of the modelling exercise is that the precise identification of the constituting communities of algal blooms must be achieved prior to the modelling itself. With the

  7. Elevated major ion concentrations inhibit larval mayfly growth and development.

    PubMed

    Johnson, Brent R; Weaver, Paul C; Nietch, Christopher T; Lazorchak, James M; Struewing, Katherine A; Funk, David H

    2015-01-01

    Anthropogenic disturbances, including those from developing energy resources, can alter stream chemistry significantly by elevating total dissolved solids. Field studies have indicated that mayflies (Order Ephemeroptera) are particularly sensitive to high total dissolved solids. In the present study, the authors measured 20-d growth and survivorship of larval Neocloeon triangulifer exposed to a gradient of brine salt (mixed NaCl and CaCl2 ) concentrations. Daily growth rates were reduced significantly in all salt concentrations above the control (363 µS cm(-1) ) and larvae in treatments with specific conductance >812 µS cm(-1) were in comparatively earlier developmental stages (instars) at the end of the experiment. Survivorship declined significantly when specific conductance was >1513 µS cm(-1) and the calculated 20-d 50% lethal concentration was 2866 µS cm(-1) . The present study's results provide strong experimental evidence that elevated ion concentrations similar to those observed in developing energy resources, such as oil and gas drilling or coal mining, can adversely affect sensitive aquatic insect species.

  8. Pharmacologic inhibition of MEK signaling prevents growth of canine hemangiosarcoma

    PubMed Central

    Andersen, Nicholas J.; Nickoloff, Brian J.; Dykema, Karl J.; Boguslawski, Elissa A.; Krivochenitser, Roman I.; Froman, Roe E.; Dawes, Michelle J.; Baker, Laurence H.; Thomas, Dafydd G.; Kamstock, Debra A.; Kitchell, Barbara E.; Furge, Kyle A.; Duesbery, Nicholas S.

    2013-01-01

    Angiosarcoma (AS) is a rare neoplasm of endothelial origin that has limited treatment options and poor five-year survival. As a model for human AS, we studied primary cells and tumorgrafts derived from canine hemangiosarcoma (HSA), which is also an endothelial malignancy with similar presentation and histology. Primary cells isolated from HSA showed constitutive ERK activation. The MEK inhibitor CI-1040 reduced ERK activation and the viability of primary cells derived from visceral, cutaneous, and cardiac HSA in vitro. HSA-derived primary cells were also sensitive to sorafenib, an inhibitor of B-Raf and multi-receptor tyrosine kinases. In vivo, CI-1040 or PD0325901 decreased the growth of cutaneous cell-derived xenografts and cardiac-derived tumorgrafts. Sorafenib decreased tumor size in both in vivo models, although cardiac tumorgrafts were more sensitive. In human AS, we noted that 50% of tumors stained positively for phosphorylated ERK1/2 and that the expression of several MEK-responsive transcription factors was up-regulated. Our data showed that MEK signaling is essential for the growth of HSA in vitro and in vivo and provided evidence that the same pathways are activated in human AS. This indicates that MEK inhibitors may form part of an effective therapeutic strategy for the treatment of canine HSA or human AS, and it highlights the utility of spontaneous canine cancers as a model of human disease. PMID:23804705

  9. mTOR inhibitors block Kaposi sarcoma growth by inhibiting essential autocrine growth factors and tumor angiogenesis.

    PubMed

    Roy, Debasmita; Sin, Sang-Hoon; Lucas, Amy; Venkataramanan, Raman; Wang, Ling; Eason, Anthony; Chavakula, Veenadhari; Hilton, Isaac B; Tamburro, Kristen M; Damania, Blossom; Dittmer, Dirk P

    2013-04-01

    Kaposi sarcoma originates from endothelial cells and it is one of the most overt angiogenic tumors. In Sub-Saharan Africa, where HIV and the Kaposi sarcoma-associated herpesvirus (KSHV) are endemic, Kaposi sarcoma is the most common cancer overall, but model systems for disease study are insufficient. Here, we report the development of a novel mouse model of Kaposi sarcoma, where KSHV is retained stably and tumors are elicited rapidly. Tumor growth was sensitive to specific allosteric inhibitors (rapamycin, CCI-779, and RAD001) of the pivotal cell growth regulator mTOR. Inhibition of tumor growth was durable up to 130 days and reversible. mTOR blockade reduced VEGF secretion and formation of tumor vasculature. Together, the results show that mTOR inhibitors exert a direct anti-Kaposi sarcoma effect by inhibiting angiogenesis and paracrine effectors, suggesting their application as a new treatment modality for Kaposi sarcoma and other cancers of endothelial origin.

  10. Positive and Negative Effects of Habitat-Forming Algae on Survival, Growth and Intra-Specific Competition of Limpets

    PubMed Central

    Marzinelli, Ezequiel M.; Burrows, Michael T.; Jackson, Angus C.; Mayer-Pinto, Mariana

    2012-01-01

    Understanding the effects of environmental change on the distribution and abundance of strongly interacting organisms, such as intertidal macroalgae and their grazers, needs a thorough knowledge of their underpinning ecological relationships. Control of grazer-plant interactions is bi-directional on northwestern European coasts: grazing by limpets structures populations of macroalgae, while macroalgae provide habitat and food for limpets. Scottish shores dominated by the macroalga Fucus vesiculosus support lower densities and larger sizes of limpets Patella vulgata than shores with less Fucus. These patterns may be due to differences in inter-size-class competitive interactions of limpets among shores with different covers of Fucus. To examine this model, densities of small and large limpets were manipulated in plots with and without Fucus. Amounts of biofilm were measured in each plot. The presence of Fucus increased survival but hindered growth of small (15 mm TL) limpets, which were negatively affected by the presence of large limpets (31 mm TL). In contrast, large limpets were not affected by the presence of Fucus or of small limpets. This suggests the occurrence of asymmetric inter-size-class competition, which was influenced by the presence of macroalgae. Macroalgae and increased densities of limpets did not influence amounts of biofilm. Our findings highlight the role of interactions among organisms in generating ecological responses to environmental change. PMID:23251589

  11. Alkaloids in Marine Algae

    PubMed Central

    Güven, Kasım Cemal; Percot, Aline; Sezik, Ekrem

    2010-01-01

    This paper presents the alkaloids found in green, brown and red marine algae. Algal chemistry has interested many researchers in order to develop new drugs, as algae include compounds with functional groups which are characteristic from this particular source. Among these compounds, alkaloids present special interest because of their pharmacological activities. Alkaloid chemistry has been widely studied in terrestrial plants, but the number of studies in algae is insignificant. In this review, a detailed account of macro algae alkaloids with their structure and pharmacological activities is presented. The alkaloids found in marine algae may be divided into three groups: 1. Phenylethylamine alkaloids, 2. Indole and halogenated indole alkaloids, 3. Other alkaloids. PMID:20390105

  12. Deoxyadenosine reverses hydroxyurea inhibition of vaccinia virus growth.

    PubMed Central

    Slabaugh, M B; Howell, M L; Wang, Y; Mathews, C K

    1991-01-01

    Hydroxyurea, an inhibitor of ribonucleotide reductase, blocks replication of vaccinia virus. However, when medium containing hydroxyurea and dialyzed serum was supplemented with deoxyadenosine, the block to viral reproduction was circumvented, provided that an inhibitor of adenosine deaminase was also present. Deoxyguanosine, deoxycytidine, and deoxythymidine were ineffective alone and did not augment the deoxyadenosine effect. In fact, increasing concentrations of deoxyguanosine and deoxythymidine, but not deoxycytidine, eliminated the deoxyadenosine rescue, an effect that was reversed by the addition of low concentrations of deoxycytidine. These results suggested that the inhibition of viral replication by hydroxyurea was primarily due to a deficiency of dATP. Deoxyribonucleoside triphosphate pools in vaccinia virus-infected cells were measured at the height of viral DNA synthesis after a synchronous infection. With 0.5 mM hydroxyurea, the dATP pool was greater than 90% depleted, the dCTP and dGTP pools were 40 to 50% reduced, and the dTTP pool was increased. Assay of ribonucleotide reductase activity in intact virus-infected cells suggested that hydroxyurea may differentially affect reduction of the various substrates of the enzyme. PMID:2016760

  13. Positional isomerism markedly affects the growth inhibition of colon cancer cells by NOSH-aspirin: COX inhibition and modeling.

    PubMed

    Vannini, Federica; Chattopadhyay, Mitali; Kodela, Ravinder; Rao, Praveen P N; Kashfi, Khosrow

    2015-12-01

    We recently reported the synthesis of NOSH-aspirin, a novel hybrid that releases both nitric oxide (NO) and hydrogen sulfide (H2S). In NOSH-aspirin, the two moieties that release NO and H2S are covalently linked at the 1, 2 positions of acetyl salicylic acid, i.e. ortho-NOSH-aspirin (o-NOSH-aspirin). In the present study, we compared the effects of the positional isomers of NOSH-ASA (o-NOSH-aspirin, m-NOSH-aspirin and p-NOSH-aspirin) to that of aspirin on growth of HT-29 and HCT 15 colon cancer cells, belonging to the same histological subtype, but with different expression of cyclooxygenase (COX) enzymes; HT-29 express both COX-1 and COX-2, whereas HCT 15 is COX-null. We also analyzed the effect of these compounds on proliferation and apoptosis in HT-29 cells. Since the parent compound aspirin, inhibits both COX-1 and COX-2, we also evaluated the effects of these compounds on COX-1 and COX-2 enzyme activities and also performed modeling of the interactions between the positional isomers of NOSH-aspirin and COX-1 and COX-2 enzymes. We observed that the three positional isomers of NOSH aspirin inhibited the growth of both colon cancer cell lines with IC50s in the nano-molar range. In particular in HT-29 cells the IC50s for growth inhibition were: o-NOSH-ASA, 0.04±0.011 µM; m-NOSH-ASA, 0.24±0.11 µM; p-NOSH-ASA, 0.46±0.17 µM; and in HCT 15 cells the IC50s for o-NOSH-ASA, m-NOSH-ASA, and p-NOSH-ASA were 0.062 ±0.006 µM, 0.092±0.004 µM, and 0.37±0.04 µM, respectively. The IC50 for aspirin in both cell lines was >5mM at 24h. The reduction of cell growth appeared to be mediated through inhibition of proliferation, and induction of apoptosis. All 3 positional isomers of NOSH-aspirin preferentially inhibited COX-1 over COX-2. These results suggest that the three positional isomers of NOSH-aspirin have the same biological actions, but that o-NOSH-ASA displayed the strongest anti-neoplastic potential.

  14. Carbon monoxide expedites metabolic exhaustion to inhibit tumor growth.

    PubMed

    Wegiel, Barbara; Gallo, David; Csizmadia, Eva; Harris, Clair; Belcher, John; Vercellotti, Gregory M; Penacho, Nuno; Seth, Pankaj; Sukhatme, Vikas; Ahmed, Asif; Pandolfi, Pier Paolo; Helczynski, Leszek; Bjartell, Anders; Persson, Jenny Liao; Otterbein, Leo E

    2013-12-01

    One classical feature of cancer cells is their metabolic acquisition of a highly glycolytic phenotype. Carbon monoxide (CO), one of the products of the cytoprotective molecule heme oxygenase-1 (HO-1) in cancer cells, has been implicated in carcinogenesis and therapeutic resistance. However, the functional contributions of CO and HO-1 to these processes are poorly defined. In human prostate cancers, we found that HO-1 was nuclear localized in malignant cells, with low enzymatic activity in moderately differentiated tumors correlating with relatively worse clinical outcomes. Exposure to CO sensitized prostate cancer cells but not normal cells to chemotherapy, with growth arrest and apoptosis induced in vivo in part through mitotic catastrophe. CO targeted mitochondria activity in cancer cells as evidenced by higher oxygen consumption, free radical generation, and mitochondrial collapse. Collectively, our findings indicated that CO transiently induces an anti-Warburg effect by rapidly fueling cancer cell bioenergetics, ultimately resulting in metabolic exhaustion.

  15. Growth Inhibition of Caenorhabditis elegans and Panagrellus redivivus by Selected Mammalian and Insect Hormones

    PubMed Central

    Dropkin, V. H.; Lower, W. R.; Acedo, J.

    1971-01-01

    Caenorhabditis elegans and Panagrellus redivivus were cultured in axenic medium in microwells. The addition of selected steroids and terpenoids to the medium caused quantitative inhibition of numbers of offspring produced per well. Three out of 14 vertebrate sex hormones and analogs, and seven out of 10 insect juvenile hormones and analogs inhibited growth at 25 or 50 micrograms per ml. In addition, two insecticide synergists which mimic juvenile hormones, propyl 2-propynyl phenyl phosphonate and piperonyl butoxide, inhibited growth at 7 μg/ml. Total lipids from Panagrellus and from Nematospiroides dubius were inhibitory. Separation by silicic acid column chromatography yielded active and inactive portions. We concluded that the inhibition observed was non-specific. PMID:19322390

  16. Possible mechanism of mannose inhibition of sucrose-supported growth in N2-fixing Azotobacter vinelandii.

    PubMed

    Wong, T Y

    1990-01-01

    When mannose was added to a sucrose-supported culture of Azotobacter vinelandii under N2-fixing conditions, cell growth was inhibited. The degree of inhibition was proportional to the amount of mannose and to the aeration rate (T.-Y. Wong, Appl. Environ. Microbiol. 54:473-475, 1988). In this report, we demonstrate that once inside the cell, mannose was phosphorylated to mannose 6-phosphate. It was then isomerized to fructose 6-phosphate and to glucose 6-phosphate. Mannose inhibited sucrose uptake noncompetitively. The decrease in sucrose uptake after mannose addition coincided with a lower rate of respiration and a decrease in nitrogenase activity. The decrease in sucrose uptake and in the ATP pool may decrease the electron flow and reduce protection of the nitrogenase from O2. Cells became very sensitive to O2, and therefore, cell growth was inhibited under high aeration conditions.

  17. Responses of certain freshwater planktonic algae to fluoride

    SciTech Connect

    Hekman, W.E.; Budd, K.; Palmer, G.R.; MacArthur, J.D.

    1984-06-01

    The effects of dissolved fluoride supplied as NaF at up to 150 p.p.m. F/sup -/ (7.9 mM) on growth, photosynthesis, dark respiration, enolase activity and fluoride uptake were determined for six phytoplankters: Synechococcus leopoliensis (Racib.) Komarek (Cyanophyta), Oscillatoria limnetica Lemmermann (Cyanophyta), Ankistrodesmus braunii Brun (Chlorophyta), Scenedesmus quadricauda (Turp.) Breb. (Chlorophyta), Cyclotella meneghiniana Kuetzing (Bacillariophyta) and Stephanodiscus minutus Grun. ex Cleve et Moll (Bacillariophyta). Growth (determined by absorbance at 660 nm or by cell-numbers) was unaffected by fluoride at up to 50 p.p.m. (2.6 mN) in all algae except S. leopoliensis. These effects showed a threshold at ca. 25 p.p.m. (1.3 mM) F/sup -/ and increased with increasing F/sup -/ concentration above this threshold. Photosynthetic O/sub 2/ evolution in the chlorophytes was unaffected by F/sup -/ at up to 50 p.p.m., whereas in S. leopoliensis F/sup -/ above ca. 25 p.p.m. caused a concentration-dependent inhibition of photosynthesis which was most pronounced at saturating irradiance. Dark O/sub 2/ uptake was unaffected at up to 50 p.p.m. in chlorophytes but was stimulated in S. leopoliensis. Enolase in clarified cell-extracts of all six algae was inhibited by F/sup -/, with K/sub i/ values ranging from 27 to 319 ..mu..M. Fluorine (measured by proton-induced gamma-ray emission) could not be detected in chlorophytes exposed during growth to up to 50 p.p.m. F/sup -/, but was detected in S. leopoliensis, O. limnetica and C. meneghiniana. Fluorine associated with cells of these algae increased as the external F/sup -/ concentration increased.

  18. The anti-hypertensive drug prazosin inhibits glioblastoma growth via the PKCδ-dependent inhibition of the AKT pathway.

    PubMed

    Assad Kahn, Suzana; Costa, Silvia Lima; Gholamin, Sharareh; Nitta, Ryan T; Dubois, Luiz Gustavo; Fève, Marie; Zeniou, Maria; Coelho, Paulo Lucas Cerqueira; El-Habr, Elias; Cadusseau, Josette; Varlet, Pascale; Mitra, Siddhartha S; Devaux, Bertrand; Kilhoffer, Marie-Claude; Cheshier, Samuel H; Moura-Neto, Vivaldo; Haiech, Jacques; Junier, Marie-Pierre; Chneiweiss, Hervé

    2016-05-01

    A variety of drugs targeting monoamine receptors are routinely used in human pharmacology. We assessed the effect of these drugs on the viability of tumor-initiating cells isolated from patients with glioblastoma. Among the drugs targeting monoamine receptors, we identified prazosin, an α1- and α2B-adrenergic receptor antagonist, as the most potent inducer of patient-derived glioblastoma-initiating cell death. Prazosin triggered apoptosis of glioblastoma-initiating cells and of their differentiated progeny, inhibited glioblastoma growth in orthotopic xenografts of patient-derived glioblastoma-initiating cells, and increased survival of glioblastoma-bearing mice. We found that prazosin acted in glioblastoma-initiating cells independently from adrenergic receptors. Its off-target activity occurred via a PKCδ-dependent inhibition of the AKT pathway, which resulted in caspase-3 activation. Blockade of PKCδ activation prevented all molecular changes observed in prazosin-treated glioblastoma-initiating cells, as well as prazosin-induced apoptosis. Based on these data, we conclude that prazosin, an FDA-approved drug for the control of hypertension, inhibits glioblastoma growth through a PKCδ-dependent mechanism. These findings open up promising prospects for the use of prazosin as an adjuvant therapy for glioblastoma patients.

  19. New tools for chloroplast genetic engineering allow the synthesis of human growth hormone in the green alga Chlamydomonas reinhardtii.

    PubMed

    Wannathong, Thanyanan; Waterhouse, Janet C; Young, Rosanna E B; Economou, Chloe K; Purton, Saul

    2016-06-01

    In recent years, there has been an increasing interest in the exploitation of microalgae in industrial biotechnology. Potentially, these phototrophic eukaryotes could be used for the low-cost synthesis of valuable recombinant products such as bioactive metabolites and therapeutic proteins. The algal chloroplast in particular represents an attractive target for such genetic engineering, both because it houses major metabolic pathways and because foreign genes can be targeted to specific loci within the chloroplast genome, resulting in high-level, stable expression. However, routine methods for chloroplast genetic engineering are currently available only for one species-Chlamydomonas reinhardtii-and even here, there are limitations to the existing technology, including the need for an expensive biolistic device for DNA delivery, the lack of robust expression vectors, and the undesirable use of antibiotic resistance markers. Here, we describe a new strain and vectors for targeted insertion of transgenes into a neutral chloroplast locus that (i) allow scar-less fusion of a transgenic coding sequence to the promoter/5'UTR element of the highly expressed endogenous genes psaA or atpA, (ii) employ the endogenous gene psbH as an effective but benign selectable marker, and (iii) ensure the successful integration of the transgene construct in all transformant lines. Transformation is achieved by a simple and cheap method of agitation of a DNA/cell suspension with glass beads, with selection based on the phototrophic rescue of a cell wall-deficient ΔpsbH strain. We demonstrate the utility of these tools in the creation of a transgenic line that produces high levels of functional human growth hormone.

  20. Hydroperoxide lyase products, hexanal, hexenal and nonenal, inhibit soybean seedling growth

    SciTech Connect

    Gardner, H.W.; Dornbos, D.L. Jr. )

    1989-04-01

    Hexanal, a product of hydroperoxide lyase, inhibited the germination and growth of soybean seeds. Hexanal was continuously delivered to germinating seeds as a vapor dissolved in air with a flow-through system (100 ml/min). Only 0.8 {mu}g hexanal/ml air was required to inhibit seedling growth by 50%; nearly 100% inhibition occurred with a dose of 1.8 {mu}g hexanal/ml air. In the absence of hexanal brown spots were often visible on the seedlings, but at sublethal doses of hexanal, the seedlings were largely devoid of these spots. The relative toxicity of three hydroperoxide lyase products, hexanal, trans-2-hexanal and trans-2-nonenal, were compared with a Petri-dish bioassay. The order of toxicity against seedling growth was hexenal>hexanal>nonenal.

  1. CD43 promotes cells transformation by preventing merlin-mediated contact inhibition of growth.

    PubMed

    Camacho-Concha, Nohemi; Olivos-Ortiz, Amiel; Nuñez-Rivera, Alfredo; Pedroza-Saavedra, Adolfo; Gutierrez-Xicotencatl, Lourdes; Rosenstein, Yvonne; Pedraza-Alva, Gustavo

    2013-01-01

    In normal tissues, strict control of tissue size is achieved by regulating cell numbers. The mechanism that controls total cell number is known as contact inhibition of growth and it depends on the NF2/Merlin pathway. Negative regulation of this pathway by deleterious mutations or by oncogenes results in cell transformation and tumor progression. Here we provide evidence that the CD43 sialomucin cooperates with oncogenic signals to promote cell transformation by abrogating the contact inhibition of growth through a molecular mechanism that involves AKT-dependent Merlin phosphorylation and degradation. Accordingly, inhibition of endogenous CD43 expression by RNA interference in lung, cervix and colon human cancer cells impaired tumor growth in vivo. These data underscore a previously unidentified role for CD43 in non-hematopoietic tumor progression.

  2. CD43 Promotes Cells Transformation by Preventing Merlin-Mediated Contact Inhibition of Growth

    PubMed Central

    Camacho-Concha, Nohemi; Olivos-Ortiz, Amiel; Nuñez-Rivera, Alfredo; Pedroza-Saavedra, Adolfo; Gutierrez-Xicotencatl, Lourdes; Rosenstein, Yvonne; Pedraza-Alva, Gustavo

    2013-01-01

    In normal tissues, strict control of tissue size is achieved by regulating cell numbers. The mechanism that controls total cell number is known as contact inhibition of growth and it depends on the NF2/Merlin pathway. Negative regulation of this pathway by deleterious mutations or by oncogenes results in cell transformation and tumor progression. Here we provide evidence that the CD43 sialomucin cooperates with oncogenic signals to promote cell transformation by abrogating the contact inhibition of growth through a molecular mechanism that involves AKT-dependent Merlin phosphorylation and degradation. Accordingly, inhibition of endogenous CD43 expression by RNA interference in lung, cervix and colon human cancer cells impaired tumor growth in vivo. These data underscore a previously unidentified role for CD43 in non-hematopoietic tumor progression. PMID:24260485

  3. Safranal and its analogs inhibit Escherichia coli ATP synthase and cell growth.

    PubMed

    Liu, Mason; Amini, Amon; Ahmad, Zulfiqar

    2017-02-01

    Safranal, a dominant component of saffron, is known to have antitumor, cytotoxic, and antibacterial properties. In this study, we examined safranal and its structural analogs-thymol, carvacrol, damascenone, cuminol, 2,6,6-trimethyl-2-cyclohexene-1,4-dione (TMCHD), 4-isopropylbenzyl bromide (IPBB), and 4-tert-butylphenol (TBP) induced inhibition of Escherichia coli membrane bound F1Fo ATP synthase. Safranal and its analogs inhibited wild-type enzyme to variable degrees. While safranal caused 100% inhibition of wild-type F1Fo ATP synthase, only about 50% inhibition occurred for αR283D mutant ATP synthase. Moreover, safranal, thymol, carvacrol, damascenone, cuminol, TMCHD, IPBB, and TBP all fully abrogated the growth of wild-type E. coli cells and had partial or no effect on the growth of null and mutant E. coli strains. Therefore, the antimicrobial properties of safranal, thymol, carvacrol, damascenone, cuminol, TMCHD, IPBB, and TBP can be linked to their binding and inhibition of ATP synthase. Total loss of growth in wild-type and partial or no growth loss in null or mutant E. coli strains demonstrates that ATP synthase is a molecular target for safranal and its structural analogs. Partial inhibition of the αArg-283 mutant enzyme establishes that αArg-283 residue is required in the polyphenol binding pocket of ATP synthase for the binding of safranal. Furthermore, partial growth loss for the null and mutant strains in the presence of inhibitors also suggests the role of other targets and residues in the process of inhibition.

  4. Inhibition of vitamin B12-dependent microbial growth by nitrous oxide

    SciTech Connect

    Alston, T.A. )

    1991-01-01

    In methionine-free media, nitrous oxide inhibits the growth of an auxotrophic strain of Escherichia coli lacking a cobalamin-independent pathway for the de novo synthesis of methionine. Prototrophic E. coli is similarly inhibited by nitrous oxide if the cobalamin-independent pathway is selectively depressed by sulfanilamide. Nitrous oxide thus effectively inactivates cobalamin-dependent 5-methyltetrahydrofolate-homocysteine methyltransferase in intact bacteria.

  5. Di (2-ethylhexyl) phthalate inhibits growth of ovarian antral follicles through an oxidative stress pathway

    PubMed Central

    Wang, Wei; Craig, Zelieann R.; Basavarajappa, Mallikarjuna S.; Gupta, Rupesh; Flaws, Jodi A.

    2011-01-01

    Di (2-ethylhexyl) phthalate (DEHP) is a plasticizer that has been shown to inhibit growth of mouse antral follicles, however, little is known about the mechanisms by which DEHP does so. Oxidative stress has been linked to follicle growth inhibition as well as phthalate-induced toxicity in non-ovarian tissues. Thus, we hypothesized that DEHP causes oxidative stress and that this leads to inhibition of the growth of antral follicles. To test this hypothesis, antral follicles isolated from CD-1 mice (age 32–35 days) were cultured with vehicle control (dimethylsulfoxide [DMSO]) or DEHP (1–100μg/ml) ± N-acetyl cysteine (NAC, an antioxidant at 0.25–1mM). During culture, follicles were measured daily. At the end of culture, follicles were collected and processed for in vitro reactive oxygen species (ROS) assays to measure the presence of free radicals or for measurement of the expression and activity of various key antioxidant enzymes: Cu/Zn superoxide dismutase (SOD1), glutathione peroxidase (GPX) and catalase (CAT). The results indicate that DEHP inhibits the growth of follicles compared to DMSO control and that NAC (0.25–1mM) blocks the ability of DEHP to inhibit follicle growth. Furthermore, DEHP (10μg/ml) significantly increases ROS levels and reduces the expression and activity of SOD1 compared to DMSO controls, whereas NAC (0.5mM) rescues the effects of DEHP on ROS levels and SOD1. However, the expression and activity of GPX and CAT were not affected by DEHP treatment. Collectively, these data suggest that DEHP inhibits follicle growth by inducing production of ROS and by decreasing the expression and activity of SOD1. PMID:22155089

  6. Mullerian Inhibiting Substance (MIS) Augments IFN-Gamma Mediated Inhibition of Breast Cancer Cell Growth

    DTIC Science & Technology

    2005-06-01

    demonstrated that MIS promotes IFN-y-induced apoptosis demonstrating a functional interaction between these two classes of signaling molecules in regulation...mammary tumors which do not express ER and have functional inactivation of Rb and p53. In agreement with results observed in the transgenic mice, MIS...Interferon regulatory factor-1 (IRF-1), a gene known for its growth inhibitory functions in breast cancer cells is induced by MIS and IFN-y through a NFkB

  7. LIM kinase inhibition reduces breast cancer growth and invasiveness but systemic inhibition does not reduce metastasis in mice.

    PubMed

    Li, Rong; Doherty, Judy; Antonipillai, Juliana; Chen, Sheng; Devlin, Mark; Visser, Kathryn; Baell, Jonathan; Street, Ian; Anderson, Robin L; Bernard, Ora

    2013-04-01

    Metastasis is the major cause of morbidity and mortality in cancer patients. An understanding of the genes that regulate metastasis and development of therapies to target these genes is needed urgently. Since members of the LIM kinase (LIMK) family are key regulators of the actin cytoskeleton and are involved in cell motility and invasion, LIMK is considered to be a good therapeutic target for metastatic disease. Here we investigated the consequences of LIMK inhibition on growth and metastasis of human and mouse mammary tumors. LIMK activity was reduced in tumor cells by expression of dominant-negative LIMK1, by RNA interference or with a selective LIMK inhibitor. The extent of phosphorylation of the LIMK substrate, cofilin, of proliferation and invasion in 2D and 3D culture and of tumor growth and metastasis in mice were assessed. Inhibition of LIMK activity efficiently reduced the pro-invasive properties of tumor cells in vitro. Tumors expressing dominant-negative LIMK1 grew more slowly and were less metastatic in mice. However, systemic administration of a LIMK inhibitor did not reduce either primary tumor growth or spontaneous metastasis. Surprisingly, metastasis to the liver was increased after administration of the inhibitor. These data raise a concern about the use of systemic LIMK inhibitors for the treatment of metastatic breast cancer.

  8. Platycodin D inhibits tumor growth by antiangiogenic activity via blocking VEGFR2-mediated signaling pathway

    SciTech Connect

    Luan, Xin; Gao, Yun-Ge; Guan, Ying-Yun; Xu, Jian-Rong; Lu, Qin; Zhao, Mei; Liu, Ya-Rong; Liu, Hai-Jun; Fang, Chao; Chen, Hong-Zhuan

    2014-11-15

    Platycodin D (PD) is an active component mainly isolated from the root of Platycodon grandiflorum. Recent studies proved that PD exhibited inhibitory effect on proliferation, migration, invasion and xenograft growth of diverse cancer cell lines. However, whether PD is suppressive for angiogenesis, an important hallmark in cancer development, remains unknown. Here, we found that PD could dose-dependently inhibit human umbilical vein endothelial cell (HUVEC) proliferation, motility, migration and tube formation. PD also significantly inhibited angiogenesis in the chick embryo chorioallantoic membrane (CAM). Moreover, the antiangiogenic activity of PD contributed to its in vivo anticancer potency shown in the decreased microvessel density and delayed growth of HCT-15 xenograft in mice with no overt toxicity. Western blot analysis indicated that PD inhibited the phosphorylation of VEGFR2 and its downstream protein kinase including PLCγ1, JAK2, FAK, Src, and Akt in endothelial cells. Molecular docking simulation showed that PD formed hydrogen bonds and hydrophobic interactions within the ATP binding pocket of VEGFR2 kinase domain. The present study firstly revealed the high antiangiogenic activity and the underlying molecular basis of PD, suggesting that PD may be a potential antiangiogenic agent for angiogenesis-related diseases. - Highlights: • Platycodin D inhibits HUVEC proliferation, motility, migration and tube formation. • Platycodin D inhibits the angiogenesis in chick embryo chorioallantoic membrane. • Platycodin D suppresses the angiogenesis and growth of HCT-15 xenograft in mice. • Platycodin D inhibits the phosphorylation of VEGFR2 and downstream kinases in HUVEC.

  9. The Lignan-containing Extract of Schisandra chinensis Berries Inhibits the Growth of Chlamydia pneumonia.

    PubMed

    Hakala, Elina; Hanski, Leena L; Yrjönen, Teijo; Vuorela, Heikki J; Vuorela, Pia M

    2015-06-01

    The purpose of this study was to investigate the effect and selectivity of an extract of Schisandra chinensis berries against Chlamydia pneumoniae and C. trachomatis. Among the ethnopharmacological uses of the extract from Schisandrae fructus are cough and pneumonia. Therefore we focused on respiratory pathogens. The extract completely inhibited the growth of C. pneumoniae strain CV6 at 250 μg/mL concentration. The inhibition of C. pneumoniae and C. trachomatis growth was dose dependent and established with three different strains. The extract inhibited C. pneumoniae production of infectious progeny in a dose dependent manner. Chlamydia selectivity was elucidated with growth inhibition measurements of three other respiratory bacterial species. A pure compound found in Schisandra chinensis berries, schisandrin B at 20.0 μg/mL concentration inhibited the growth of both C. pneumoniae and C. trachomatis. The extract was found to be non-toxic to the human host cells. These findings highlight the potential of the extract from Schisandra chinensis berries as a source for antichlamydial compounds.

  10. Statins improve survival by inhibiting spontaneous metastasis and tumor growth in a mouse melanoma model

    PubMed Central

    Tsubaki, Masanobu; Takeda, Tomoya; Kino, Toshiki; Obata, Naoya; Itoh, Tatsuki; Imano, Motohiro; Mashimo, Kenji; Fujiwara, Daichiro; Sakaguchi, Katsuhiko; Satou, Takao; Nishida, Shozo

    2015-01-01

    Metastatic melanoma is a life-threatening disease for which no effective treatment is currently available. In melanoma cells, Rho overexpression promotes invasion and metastasis. However, the effect of statins on spontaneous metastasis and tumor growth remains unclear. In the present study, we investigated the mechanism of statin-mediated tumor growth and metastasis inhibition in an in vivo model. We found that statins significantly inhibited spontaneous metastasis and tumor growth. Statins inhibited the mRNA expression and enzymatic activities of matrix metalloproteinases (MMPs) in vivo and also suppressed the mRNA and protein expression of very late antigens (VLAs). Moreover, statins inhibited the prenylation of Rho as well as the phosphorylation of LIM kinase, serum response factor (SRF), and c-Fos downstream of the Rho signaling pathway. In addition, statins enhanced p53, p21, and p27 expression and reduced phosphorylation of cyclin-dependent kinase and expression of cyclin D1 and E2. These results indicate that statins suppress Rho signaling pathways, thereby inhibiting tumor metastasis and growth. Furthermore, statins markedly improved the survival rate in a metastasis model, suggesting that statins have potential clinical applications for the treatment of metastatic cancers. PMID:26693069

  11. A novel anticancer agent SNG1153 inhibits growth of lung cancer stem/progenitor cells

    PubMed Central

    Wang, Jing; Zhu, Hai; Han, Yuqing; Jin, Mingji; Wang, Jun; Zhou, Congya; Ma, Junfeng; Lin, Qingcong; Wang, Zhaoyi; Meng, Kun; Fu, Xueqi

    2016-01-01

    Lung cancer is the leading cause of cancer-related death in both men and women. Lung cancer contains a small population of cancer cells with stem-like features known as cancer stem cells (CSCs). CSCs are often more resistant to current therapeutic treatments. Thus, it is urgent to develop a novel agent that is able to inhibit CSCs growth. In this study, we examined the ability of SNG1153, a novel chemical agent to inhibit the growth of lung CSCs. We found that SNG1153 inhibited growth and induced apoptosis in established lung cancer cells. We also found that SNG1153 inhibited the tumorsphere formation and decreased CD133-positive (lung CSC marker) cancer cells. SNG1153 was able to attenuate tumor formation in NOD/SCID (non-obese diabetic/severe combined immunodeficient) mice injected with lung tumorsphere cells. We further demonstrated that SNG1153 induced β-catenin phosphorylation and down-regulated β-catenin. Our results thus demonstrate that SNG1153 effectively inhibits the growth of lung CSCs and suggest that SNG1153 may be a novel therapeutic agent to treat human lung cancer. PMID:27281614

  12. Xanthatin, a novel potent inhibitor of VEGFR2 signaling, inhibits angiogenesis and tumor growth in breast cancer cells.

    PubMed

    Yu, Yao; Yu, Jing; Pei, Chong Gang; Li, Yun Yan; Tu, Ping; Gao, Gui Ping; Shao, Yi

    2015-01-01

    Anti-angiogenesis targeting vascular endothelial growth factor receptor 2 (VEGFR2) has emerged as an important tool for cancer treatment. In this study, we described a novel VEGFR2 inhibitor, xanthatin, which inhibits tumor angiogenesis and growth. The biochemical profiles of xanthatin were investigated using kinase assay, migration assay, tube formation, Matrigel plug assay, western blot, immunofluorescence and human tumor xenograft model. Xanthatin significantly inhibited growth, migration and tube formation of human umbilical vascular endothelial cell as well as inhibited vascular endothelial growth factor (VEGF)-stimulated angiogenesis. In addition, it inhibited VEGF-induced phosphorylation of VEGFR2 and its downstream signaling regulator. Moreover, xanthatin directly inhibit proliferation of breast cancer cells MDA-MB-231. Oral administration of xanthatin could markedly inhibit human tumor xenograft growth and decreased microvessel densities (MVD) in tumor sections. Taken together, these preclinical evaluations suggest that xanthatin inhibits angiogenesis and may be a promising anticancer drug candidate.

  13. Bromophenols from marine algae with potential anti-diabetic activities

    NASA Astrophysics Data System (ADS)

    Lin, Xiukun; Liu, Ming

    2012-12-01

    Marine algae contain various bromophenols with a variety of biological activities, including antimicrobial, anticancer, and anti-diabetic effects. Here, we briefly review the recent progress in researches on the biomaterials from marine algae, emphasizing the relationship between the structure and the potential anti-diabetic applications. Bromophenols from marine algae display their hyperglycemic effects by inhibiting the activities of protein tyrosine phosphatase 1B, α-glucosidase, as well as other mechanisms.

  14. Growth hormone inhibits apoptosis in in vitro produced bovine embryos.

    PubMed

    Kölle, Sabine; Stojkovic, Miodrag; Boie, Gudrun; Wolf, Eckhard; Sinowatz, Fred

    2002-02-01

    Growth hormone (GH) has recently been shown to exert distinct effects on the differentiation and metabolism of early embryos. Up to now, however, it is not clear whether GH is able to modulate apoptosis during early embryogenesis. Differential cell staining of 8-day-old bovine embryos cultured with 100 ng bovine recombinant GH (rbGH) per ml medium (synthetic oviduct fluid-polyvinylalcohol) demonstrated that GH significantly increased the number of inner cell mass (ICM) and trophectoderm cells in bovine expanded blastocysts. As shown by terminal deoxynucleotidyl transferase mediated dUTP labeling (TUNEL) supplementation of bGH decreased the percentage of 8-day-old embryos showing at least one apoptotic cell from 58 to 21%. The percentage of apoptotic cells in one blastocyst was significantly (P < 0.01) reduced from 4.6 to 1.1% by GH treatment. Incubation of the embryos with 150 mM vanillylnonanamide induced apoptosis in all embryos. Whereas in control embryos 14% of the embryonic cells were TUNEL-positive, the percentage of apoptotic cells declined to 2.7% in the GH treated embryos. Expression of immunoreactive bcl-2 in blastocysts was not affected by GH treatment. Synthesis of the bax protein which is known to promote apoptosis was reduced in embryos cultured with GH. Our results suggest that GH acts as survival factor during in vitro culture and reduces apoptosis by altering the bax to bcl-2 ratio during early embryogenesis.

  15. Targeted Proapoptotic Peptides Depleting Adipose Stromal Cells Inhibit Tumor Growth

    PubMed Central

    Daquinag, Alexes C; Tseng, Chieh; Zhang, Yan; Amaya-Manzanares, Felipe; Florez, Fernando; Dadbin, Ali; Zhang, Tao; Kolonin, Mikhail G

    2016-01-01

    Progression of many cancers is associated with tumor infiltration by mesenchymal stromal cells (MSC). Adipose stromal cells (ASC) are MSC that serve as adipocyte progenitors and endothelium-supporting cells in white adipose tissue (WAT). Clinical and animal model studies indicate that ASC mobilized from WAT are recruited by tumors. Direct evidence for ASC function in tumor microenvironment has been lacking due to unavailability of approaches to specifically inactivate these cells. Here, we investigate the effects of a proteolysis-resistant targeted hunter-killer peptide D-WAT composed of a cyclic domain CSWKYWFGEC homing to ASC and of a proapoptotic domain KLAKLAK2. Using mouse bone marrow transplantation models, we show that D-WAT treatment specifically depletes tumor stromal and perivascular cells without directly killing malignant cells or tumor-infiltrating leukocytes. In several mouse carcinoma models, targeted ASC cytoablation reduced tumor vascularity and cell proliferation resulting in hemorrhaging, necrosis, and suppressed tumor growth. We also validated a D-WAT derivative with a proapoptotic domain KFAKFAK2 that was found to have an improved cytoablative activity. Our results for the first time demonstrate that ASC, recruited as a component of tumor microenvironment, support cancer progression. We propose that drugs targeting ASC can be developed as a combination therapy complementing conventional cancer treatments. PMID:26316391

  16. Calcium influences sensitivity to growth inhibition induced by a cell surface sialoglycopeptide

    NASA Technical Reports Server (NTRS)

    Betz, N. A.; Fattaey, H. K.; Johnson, T. C.; Spooner, B. S. (Principal Investigator)

    1994-01-01

    While studies concerning mitogenic factors have been an important area of research for many years, much less is understood about the mechanisms of action of cell surface growth inhibitors. We have purified an 18 kDa cell surface sialoglycopeptide growth inhibitor (CeReS-18) which can reversibly inhibit the proliferation of diverse cell types. The studies discussed in this article show that three mouse keratinocyte cell lines exhibit sixty-fold greater sensitivity than other fibroblasts and epithelial-like cells to CeReS-18-induced growth inhibition. Growth inhibition induced by CeReS-18 treatment is a reversible process, and the three mouse keratinocyte cell lines exhibited either single or multiple cell cycle arrest points, although a predominantly G0/G1 cell cycle arrest point was exhibited in Swiss 3T3 fibroblasts. The sensitivity of the mouse keratinocyte cell lines to CeReS-18-induced growth inhibition was not affected by the degree of tumorigenic progression in the cell lines and was not due to differences in CeReS-18 binding affinity or number of cell surface receptors per cell. However, the sensitivity of both murine fibroblasts and keratinocytes could be altered by changing the extracellular calcium concentration, such that increased extracellular calcium concentrations resulted in decreased sensitivity to CeReS-18-induced proliferation inhibition. Thus the increased sensitivity of the murine keratinocyte cell lines to CeReS-18 could be ascribed to the low calcium concentration used in their propagation. Studies are currently under way investigating the role of calcium in CeReS-18-induced growth arrest. The CeReS-18 may serve as a very useful tool to study negative growth control and the signal transduction events associated with cell cycling.

  17. Growth of antarctic cyanobacteria under ultraviolet radiation: UVA counteracts UVB inhibition

    SciTech Connect

    Quesada, A. |; Mouget, J.L.; Vincent, W.F.

    1995-04-01

    A mat-forming cyanobacterium (Phormidium murayi West and West) isolated from an ice-shelf pond in Antarctica was grown under white light combined with a range of UVA and UVB irradiance. The 4-day growth rate decreased under increasing ultraviolet (UV) radiation, with a ninefold greater response to UVB relative to UVA. In vivo absorbance spectra showed that UVA and to a greater extent UVB caused a decrease in phycocyanin/chlorophyll a and an increase in carotenoids/chlorophyll a. The phycocyanin/chlorophyll a ratio was closely and positively correlated to the UVB-inhibited growth rate. Under fixed spectral gradients of UV radiation, the growth inhibition effect was dominated by UVB. However, at specific UVB irradiances the inhibition of growth depended on the ratio of UVB to UVA, and growth rates increased linearly with increasing UVA. These results are consistent with the view that UVB inhibition represents the balance between damage and repair processes that are each controlled by separate wavebands. They also underscore the need to consider UV spectral balance in laboratory and field assays of UVB toxicity. 49 refs., 6 figs.

  18. The rhizobacterium Arthrobacter agilis produces dimethylhexadecylamine, a compound that inhibits growth of phytopathogenic fungi in vitro.

    PubMed

    Velázquez-Becerra, Crisanto; Macías-Rodríguez, Lourdes I; López-Bucio, José; Flores-Cortez, Idolina; Santoyo, Gustavo; Hernández-Soberano, Christian; Valencia-Cantero, Eduardo

    2013-12-01

    Plant diseases caused by fungal pathogens such as Botrytis cinerea and the oomycete Phytophthora cinnamomi affect agricultural production worldwide. Control of these pests can be done by the use of fungicides such as captan, which may have deleterious effects on human health. This study demonstrates that the rhizobacterium Arthrobacter agilis UMCV2 produces volatile organic compounds that inhibit the growth of B. cinerea in vitro. A single compound from the volatile blends, namely dimethylhexadecylamine (DMHDA), could inhibit the growth of both B. cinerea and P. cinnamomi when supplied to the growth medium in low concentrations. DMHDA also inhibited the growth of beneficial fungi Trichoderma virens and Trichoderma atroviride but at much higher concentrations. DMHDA-related aminolipids containing 4, 8, 10, 12, and 14 carbons in the alkyl chain were tested for their inhibitory effect on the growth of the pathogens. The results show that the most active compound from those tested was dimethyldodecylamine. This effect correlates with a decrease in the number of membrane lipids present in the mycelium of the pathogen including eicosanoic acid, (Z)-9-hexadecenoic acid, methyl ester, and (Z)-9-octadecenoic acid, methyl ester. Strawberry leaflets treated with DMHDA were not injured by the compound. These data indicate that DMHDA and related compounds, which can be produced by microorganisms may effectively inhibit the proliferation of certain plant pathogens.

  19. Aminomethylphosphonic acid inhibits growth and metastasis of human prostate cancer in an orthotopic xenograft mouse model.

    PubMed

    Parajuli, Keshab Raj; Zhang, Qiuyang; Liu, Sen; You, Zongbing

    2016-03-01

    Aminomethylphosphonic acid (AMPA) has been shown to inhibit prostate cancer cell growth in vitro. The purpose of the present study was to determine if AMPA could inhibit growth and metastasis of prostate cancer in vivo. Human prostate cancer PC-3-LacZ-luciferase cells were implanted into the ventral lateral lobes of the prostate in 39 athymic Nu/Nu nude male mice. Seven days later, mice were randomized into the control group (n = 14, treated intraperitoneally with phosphate buffered saline), low dose group (n = 10, treated intraperitoneally with AMPA at 400 mg/kg body weight/day), and high dose group (n = 15, treated intraperitoneally with AMPA at 800 mg/kg body weight/day). Tumor growth and metastasis were examined every 4-7 days by bioluminescence imaging of live mice. We found that AMPA treatment significantly inhibited growth and metastasis of orthotopic xenograft prostate tumors and prolonged the survival time of the mice. AMPA treatment decreased expression of BIRC2 and activated caspase 3, leading to increased apoptosis in the prostate tumors. AMPA treatment decreased expression of cyclin D1. AMPA treatment also reduced angiogenesis in the prostate tumors. Taken together, these results demonstrate that AMPA can inhibit prostate cancer growth and metastasis, suggesting that AMPA may be developed into a therapeutic agent for the treatment of prostate cancer.

  20. In vitro inhibition of Helicobacter pylori growth and adherence to gastric mucosal cells by Pycnogenol.

    PubMed

    Rohdewald, Peter; Beil, Winfried

    2008-05-01

    The emergence of antibiotic resistant H. pylori strains has necessitated the identification of alternative additive therapies for the treatment of this infection. The study tested whether a specific pine bark extract (Pycnogenol is effective in inhibiting the growth and adherence of H. pylori in vitro. Inhibition of H. pylori growth by Pycnogenol was tested in liquid medium as well as in an in vitro model by using sessile bacteria attached to AGS cells. Adherence was determined by co-incubation of gastric cells with Pycnogenol and H. pylori in vitro. Pycnogenol inhibited H. pylori growth in suspension with an MIC(50) of 12.5 microg/mL. Growth of H. pylori in infected cells was reduced to 10% of the control value by 125 microg/mL Pycnogenol. Adherence of H. pylori to gastric cells was reduced by 70% after 3 h incubation with 125 microg/mL Pycnogenol. The results show a significant, yet limited inhibition of growth and adherence of H. pylori to gastric cells by Pycnogenol. In vivo studies have to demonstrate the clinical relevance of these findings.

  1. Aminomethylphosphonic acid inhibits growth and metastasis of human prostate cancer in an orthotopic xenograft mouse model

    PubMed Central

    Parajuli, Keshab Raj; Zhang, Qiuyang; Liu, Sen; You, Zongbing

    2016-01-01

    Aminomethylphosphonic acid (AMPA) has been shown to inhibit prostate cancer cell growth in vitro. The purpose of the present study was to determine if AMPA could inhibit growth and metastasis of prostate cancer in vivo. Human prostate cancer PC-3-LacZ-luciferase cells were implanted into the ventral lateral lobes of the prostate in 39 athymic Nu/Nu nude male mice. Seven days later, mice were randomized into the control group (n = 14, treated intraperitoneally with phosphate buffered saline), low dose group (n = 10, treated intraperitoneally with AMPA at 400 mg/kg body weight/day), and high dose group (n = 15, treated intraperitoneally with AMPA at 800 mg/kg body weight/day). Tumor growth and metastasis were examined every 4-7 days by bioluminescence imaging of live mice. We found that AMPA treatment significantly inhibited growth and metastasis of orthotopic xenograft prostate tumors and prolonged the survival time of the mice. AMPA treatment decreased expression of BIRC2 and activated caspase 3, leading to increased apoptosis in the prostate tumors. AMPA treatment decreased expression of cyclin D1. AMPA treatment also reduced angiogenesis in the prostate tumors. Taken together, these results demonstrate that AMPA can inhibit prostate cancer growth and metastasis, suggesting that AMPA may be developed into a therapeutic agent for the treatment of prostate cancer. PMID:26840261

  2. Nanoparticulate Tetrac Inhibits Growth and Vascularity of Glioblastoma Xenografts.

    PubMed

    Sudha, Thangirala; Bharali, Dhruba J; Sell, Stewart; Darwish, Noureldien H E; Davis, Paul J; Mousa, Shaker A

    2017-04-10

    Thyroid hormone as L-thyroxine (T4) stimulates proliferation of glioma cells in vitro and medical induction of hypothyroidism slows clinical growth of glioblastoma multiforme (GBM). The proliferative action of T4 on glioma cells is initiated nongenomically at a cell surface receptor for thyroid hormone on the extracellular domain of integrin αvβ3. Tetraiodothyroacetic acid (tetrac) is a thyroid hormone derivative that blocks T4 action at αvβ3 and has anticancer and anti-angiogenic activity. Tetrac has been covalently bonded via a linker to a nanoparticle (Nanotetrac, Nano-diamino-tetrac, NDAT) that increases the potency of tetrac and broadens the anticancer properties of the drug. In the present studies of human GBM xenografts in immunodeficient mice, NDAT administered daily for 10 days subcutaneously as 1 mg tetrac equivalent/kg reduced tumor xenograft weight at animal sacrifice by 50%, compared to untreated control lesions (p < 0.01). Histopathological analysis of tumors revealed a 95% loss of the vascularity of treated tumors compared to controls at 10 days (p < 0.001), without intratumoral hemorrhage. Up to 80% of tumor cells were necrotic in various microscopic fields (p < 0.001 vs. control tumors), an effect attributable to devascularization. There was substantial evidence of apoptosis in other fields (p < 0.001 vs. control tumors). Induction of apoptosis in cancer cells is a well-described quality of NDAT. In summary, systemic NDAT has been shown to be effective by multiple mechanisms in treatment of GBM xenografts.

  3. Phytochemical potential of Eruca sativa for inhibition of melanoma tumor growth.

    PubMed

    Khoobchandani, M; Ganesh, N; Gabbanini, S; Valgimigli, L; Srivastava, M M

    2011-06-01

    Solvent extracts from the aerial and root parts and seed oil from E. sativa (rocket salad) were assayed for anticancer activity against melanoma cells. The seed oil (isothiocyanates rich) significantly (p<0.01) reduced the tumor growth comparable to the control. Remarkably, the seed oil inhibited melanoma growth and angiogenesis in mice without any major toxicity. The findings qualify seed oil for further investigations in the real of cancer prevention and treatment.

  4. Differential chlorate inhibition of Chaetomium globosum germination, hyphal growth, and perithecia synthesis.

    PubMed

    Biles, Charles L; Wright, Desiree; Fuego, Marianni; Guinn, Angela; Cluck, Terry; Young, Jennifer; Martin, Markie; Biles, Josiah; Poudyal, Shubhra

    2012-12-01

    Chaetomium globosum Kunze:Fr is a dermatophytic, dematiaceous fungus that is ubiquitous in soils, grows readily on cellulolytic materials, and is commonly found on water-damaged building materials. Chlorate affects nitrogen metabolism in fungi and is used to study compatibility among anamorphic fungi by inducing nit mutants. The effect of chlorate toxicity on C. globosum was investigated by amending a modified malt extract agar (MEA), oat agar, and carboxymethyl cellulose agar (CMC) with various levels of potassium chlorate (KClO(3)). C. globosum perithecia production was almost completely inhibited (90-100 %) at low levels of KClO(3) (0.1 mM) in amended MEA. Inhibition of perithecia production was also observed on oat agar and CMC at 1 and 10 mM, respectively. However, hyphal growth in MEA was only inhibited 20 % by 0.1-100 mM KClO(3) concentrations. Hyphal growth was never completely inhibited at the highest levels tested (200 mM). Higher levels of KClO(3) were needed on gypsum board to inhibit perithecia synthesis. In additional experiments, KClO(3) did not inhibit C. globosum, Fusarium oxysporum, Aspergillus niger, Penicillum expansum, and airborne fungal spore germination. The various fungal spores were not inhibited by KClO(3) at 1-100 mM levels. These results suggest that C. globosum perithecia synthesis is more sensitive to chlorate toxicity than are hyphal growth and spore germination. This research provides basic information that furthers our understanding about perithecia formation and may help in developing control methods for fungal growth on building materials.

  5. Thiazolidinediones enhance vascular endothelial growth factor expression and induce cell growth inhibition in non-small-cell lung cancer cells

    PubMed Central

    2010-01-01

    Background It is known that thiazolidinediones are involved in regulating the expression of various genes, including the vascular endothelial growth factor (VEGF) gene via peroxisome proliferator-activated receptor γ (PPARγ); VEGF is a prognostic biomarker for non-small-cell lung cancer (NSCLC). Methods In this study, we investigated the effects of troglitazone and ciglitazone on the mRNA expression of VEGF and its receptors in human NSCLC cell lines, RERF-LC-AI, SK-MES-1, PC-14, and A549. These mRNA expressions were evaluated by quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) analysis. We also studied the effect of Je-11, a VEGF inhibitor, on the growth of these cells. Results In NSCLC cells, thiazolidinediones increased the mRNA expression of VEGF and neuropilin-1, but not that of other receptors such as fms-like tyrosine kinase and kinase insert domain receptor-1. Furthermore, the PPARγ antagonist GW9662 completely reversed this thiazolidinedione-induced increase in VEGF expression. Furthermore, the addition of VEGF inhibitors into the culture medium resulted in the reversal of thiazolidinedione-induced growth inhibition. Conclusions Our results indicated that thiazolidinediones enhance VEGF and neuropilin-1 expression and induce the inhibition of cell growth. We propose the existence of a pathway for arresting cell growth that involves the interaction of thiazolidinedione-induced VEGF and neuropilin-1 in NSCLC. PMID:20214829

  6. Epithelium-dependent extracellular matrix synthesis in transforming growth factor-beta 1-growth-inhibited mouse mammary gland.

    PubMed

    Silberstein, G B; Strickland, P; Coleman, S; Daniel, C W

    1990-06-01

    Exogenous transforming growth factor beta (TGF-beta 1) was shown in earlier studies to reversibly inhibit mouse mammary ductal growth. Using small plastic implants to treat regions of developing mammary glands in situ, we now report that TGF-beta 1 growth inhibition is associated with an ectopic accumulation of type I collagen messenger RNA and protein, as well as the glycosaminoglycan, chondroitin sulfate. Both macromolecules are normal components of the ductal extracellular matrix, which, under the influence of exogenous TGF-beta 1, became unusually concentrated immediately adjacent to the epithelial cells at the tip of the ductal growth points, the end buds. Stimulation of extracellular matrix was confined to aggregations of connective tissue cells around affected end buds and was not present around the TGF-beta 1 implants themselves, indicating that the matrix effect was epithelium dependent. Ectopic matrix synthesis was specific for TGF-beta 1 insofar as it was absent at ducts treated with other growth inhibitors, or at ducts undergoing normal involution in response to endogenous regulatory processes. These findings are consistent with the matrix-stimulating properties of TGF-beta 1 reported for other systems, but differ in their strict dependence upon epithelium. A possible role for endogenous TGF-beta 1 in modulating a mammary epithelium-stroma interaction is suggested.

  7. Calcite crystal growth inhibition by humic substances with emphasis on hydrophobic acids from the Florida Everglades

    NASA Astrophysics Data System (ADS)

    Hoch, A. R.; Reddy, M. M.; Aiken, G. R.

    2000-01-01

    The crystallization of calcium carbonate minerals plays an integral role in the water chemistry of terrestrial ecosystems. Humic substances, which are ubiquitous in natural waters, have been shown to reduce or inhibit calcite crystal growth in experiments. The purpose of this study is to quantify and understand the kinetic effects of hydrophobic organic acids isolated from the Florida Everglades and a fulvic acid from Lake Fryxell, Antarctica, on the crystal growth of calcite (CaCO 3). Highly reproducible calcite growth experiments were performed in a sealed reactor at constant pH, temperature, supersaturation (Ω = 4.5), P CO2 (10 -3.5atm), and ionic strength (0.1 M) with various concentrations of organic acids. Higher plant-derived aquatic hydrophobic acids from the Everglades were more effective growth inhibitors than microbially derived fulvic acid from Lake Fryxell. Organic acid aromaticity correlated strongly with growth inhibition. Molecular weight and heteroatom content correlated well with growth inhibition, whereas carboxyl content and aliphatic nature did not.

  8. Calcite crystal growth inhibition by humic substances with emphasis on hydrophobic acids from the Florida Everglades

    USGS Publications Warehouse

    Hoch, A.R.; Reddy, M.M.; Aiken, G.R.

    2000-01-01

    The crystallization of calcium carbonate minerals plays an integral role in the water chemistry of terrestrial ecosystems. Humic substances, which are ubiquitous in natural waters, have been shown to reduce or inhibit calcite crystal growth in experiments. The purpose of this study is to quantify and understand the kinetic effects of hydrophobic organic acids isolated from the Florida Everglades and a fulvic acid from Lake Fryxell, Antarctica, on the crystal growth of calcite (CaCO3). Highly reproducible calcite growth experiments were performed in a sealed reactor at constant pH, temperature, supersaturation (?? = 4.5), P(CO2) (10-3.5atm), and ionic strength (0.1 M) with various concentrations of organic acids. Higher plant-derived aquatic hydrophobic acids from the Everglades were more effective growth inhibitors than microbially derived fulvic acid from Lake Fryxell. Organic acid aromaticity correlated strongly with growth inhibition. Molecular weight and heteroatom content correlated well with growth inhibition, whereas carboxyl content and aliphatic nature did not. Copyright (C) 1999 Elsevier Science Ltd.

  9. Di (2-ethylhexyl) phthalate inhibits growth of mouse ovarian antral follicles through an oxidative stress pathway

    SciTech Connect

    Wang, Wei Craig, Zelieann R. Basavarajappa, Mallikarjuna S. Gupta, Rupesh K. Flaws, Jodi A.

    2012-01-15

    Di (2-ethylhexyl) phthalate (DEHP) is a plasticizer that has been shown to inhibit growth of mouse antral follicles, however, little is known about the mechanisms by which DEHP does so. Oxidative stress has been linked to follicle growth inhibition as well as phthalate-induced toxicity in non-ovarian tissues. Thus, we hypothesized that DEHP causes oxidative stress and that this leads to inhibition of the growth of antral follicles. To test this hypothesis, antral follicles isolated from CD-1 mice (age 31–35 days) were cultured with vehicle control (dimethylsulfoxide [DMSO]) or DEHP (1–100 μg/ml) ± N-acetyl cysteine (NAC, an antioxidant at 0.25–1 mM). During culture, follicles were measured daily. At the end of culture, follicles were collected and processed for in vitro reactive oxygen species (ROS) assays to measure the presence of free radicals or for measurement of the expression and activity of various key antioxidant enzymes: Cu/Zn superoxide dismutase (SOD1), glutathione peroxidase (GPX) and catalase (CAT). The results indicate that DEHP inhibits the growth of follicles compared to DMSO control and that NAC (0.25–1 mM) blocks the ability of DEHP to inhibit follicle growth. Furthermore, DEHP (10 μg/ml) significantly increases ROS levels and reduces the expression and activity of SOD1 compared to DMSO controls, whereas NAC (0.5 mM) rescues the effects of DEHP on ROS levels and SOD1. However, the expression and activity of GPX and CAT were not affected by DEHP treatment. Collectively, these data suggest that DEHP inhibits follicle growth by inducing production of ROS and by decreasing the expression and activity of SOD1. -- Highlights: ► DEHP inhibits growth and increases reactive oxygen species in ovarian antral follicles in vitro. ► NAC rescues the effects of DEHP on the growth and reactive oxygen species levels in follicles. ► DEHP decreases the expression and activity of Cu/Zn superoxide dismutase, which can be rescued by NAC, in antral

  10. Algae Biofuel in the Nigerian Energy Context

    NASA Astrophysics Data System (ADS)

    Elegbede, Isa; Guerrero, Cinthya

    2016-05-01

    The issue of energy consumption is one of the issues that have significantly become recognized as an important topic of global discourse. Fossil fuels production reportedly experiencing a gradual depletion in the oil-producing nations of the world. Most studies have relatively focused on biofuel development and adoption, however, the awareness of a prospect in the commercial cultivation of algae having potential to create economic boost in Nigeria, inspired this research. This study aims at exploring the potential of the commercialization of a different but commonly found organism, algae, in Nigeria. Here, parameters such as; water quality, light, carbon, average temperature required for the growth of algae, and additional beneficial nutrients found in algae were analysed. A comparative cum qualitative review of analysis was used as the study made use of empirical findings on the work as well as the author's deductions. The research explored the cultivation of algae with the two major seasonal differences (i.e. rainy and dry) in Nigeria as a backdrop. The results indicated that there was no significant difference in the contribution of algae and other sources of biofuels as a necessity for bioenergy in Nigeria. However, for an effective sustainability of this prospect, adequate measures need to be put in place in form of funding, provision of an economically-enabling environment for the cultivation process as well as proper healthcare service in the face of possible health hazard from technological processes. Further studies can seek to expand on the potential of cultivating algae in the Harmattan season.

  11. The novel VEGF receptor 2 inhibitor YLL545 inhibits angiogenesis and growth in breast cancer

    PubMed Central

    Zhang, Jianbo; Liu, Chen; Shi, Wen; Yang, Lingling; Zhang, Quansheng; Cui, Jianlin; Fang, Yangwu; Li, Yuhao; Ren, Guosheng; Yang, Shuang; Xiang, Rong

    2016-01-01

    Their antiangiogenic effects make vascular endothelial growth factor receptor 2 (VEGFR2) inhibitors useful for cancer treatment. However, most of these drugs have unexpected adverse side effects. Here, we show that the novel VEGFR2 inhibitor YLL545 suppressed tumor angiogenesis and growth in triple-negative breast cancer without adverse effects. YLL545 treatment also markedly inhibited proliferation, migration, invasion, and tube formation by human umbilical vascular endothelial cells (HUVECs) in vitro. These effects of YLL545 were equal to or greater than those seen with sorafenib. In addition, YLL545 inhibited VEGF-induced phosphorylation of VEGFR2 and activation of downstream signaling regulators, such as phospho-STAT3 and phospho-ERK1/2, in HUVECs. Embryonic angiogenesis assays in zebrafish and Matrigel plug assays in mice demonstrated that YLL545 inhibits angiogenesis in vivo. YLL545 also inhibited proliferation and induced apoptosis in MDA-MB-231 breast cancer cells both in vitro and in vivo, and 50 mg/kg/d YLL545 inhibited human tumor xenograft growth by more than 50% in BALB/c nude mice. These observations suggest YLL545 is a potentially useful anticancer drug candidate. PMID:27203384

  12. In vivo inhibition of polyamine biosynthesis and growth in tobacco ovary tissues

    NASA Technical Reports Server (NTRS)

    Slocum, R. D.; Galston, A. W.

    1985-01-01

    Post fertilization growth of tobacco ovary tissues treated with inhibitors of polyamine (PA) biosynthesis was examined in relation to endogenous PA titers and the activities of arginine decarboxylase (ADC, EC 4.1.1.19) and ornithine decarboxylase (ODC, EC 4.1.1.17). DL-alpha-Difluoromethylornithine (DFMO) and DL-alpha-difluoromethylarginine (DFMA), specific, irreversible ("suicide") inhibitors of ODC and ADC in vitro, were used to modulate PA biosynthesis in excised flowers. ODC represented >99% of the total decarboxylase activity in tobacco ovaries. In vivo inhibition of ODC with DFMO resulted in a significant decrease in PA titers, ovary fresh weight and protein content. Simultaneous inhibition of both decarboxylases by DFMO and DFMA produced only a marginally greater depression in growth and PA titers, indicating that ODC activity is rate-limiting for PA biosynthesis in these tissues. Paradoxically, DFMA alone inhibited PA biosynthesis, not as a result of a specific inhibition of ADC, but primarily through the inactivation of ODC. In vivo inhibition of ODC by DFMA appears to result from arginase-mediated hydrolysis of this inhibitor to urea and DFMO, the suicide substrate for ODC. Putrescine conjugates in tobacco appear to function as a storage form of this amine which, upon hydrolysis, may contribute to Put homeostasis during growth.

  13. PYOMELANIN IS PRODUCED BY SHEWANELLA ALGAE BRY AND EFFECTED BY EXOGENOUS IRON

    SciTech Connect

    Turick, C; Frank Caccavo, F; Jr., J; Louis S. Tisa, L

    2006-11-29

    Melanin production by S. algae BrY occurred during late/post-exponential growth in lactate-basal-salts liquid medium supplemented with tyrosine or phenylalanine. The antioxidant ascorbate inhibited melanin production, but not production of the melanin precursor, homogentisic acid. In the absence of ascorbate, melanin production was inhibited by the 4-hydroxyplenylpyruvate dioxygenase inhibitor, sulcotrione and Fe(II) (>0.2mM). These data support the hypothesis that pigment production by S. algae BrY was a result the conversion of tyrosine or phenylalanine to homogentisic acid which was excreted, auto-oxidized and self-polymerized to form pyomelanin. The inverse relationship between Fe(II) concentration and pyomelanin production has implications that pyomelanin may play a role in iron assimilation under Fe(II) limiting conditions.

  14. A molecular framework for the inhibition of Arabidopsis root growth in response to boron toxicity.

    PubMed

    Aquea, Felipe; Federici, Fernan; Moscoso, Cristian; Vega, Andrea; Jullian, Pastor; Haseloff, Jim; Arce-Johnson, Patricio

    2012-04-01

    Boron is an essential micronutrient for plants and is taken up in the form of boric acid (BA). Despite this, a high BA concentration is toxic for the plants, inhibiting root growth and is thus a significant problem in semi-arid areas in the world. In this work, we report the molecular basis for the inhibition of root growth caused by boron. We show that application of BA reduces the size of root meristems, correlating with the inhibition of root growth. The decrease in meristem size is caused by a reduction of cell division. Mitotic cell number significantly decreases and the expression level of key core cell cycle regulators is modulated. The modulation of the cell cycle does not appear to act through cytokinin and auxin signalling. A global expression analysis reveals that boron toxicity induces the expression of genes related with abscisic acid (ABA) signalling, ABA response and cell wall modifications, and represses genes that code for water transporters. These results suggest that boron toxicity produces a reduction of water and BA uptake, triggering a hydric stress response that produces root growth inhibition.

  15. Blue Laser Inhibits Bacterial Growth of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa

    PubMed Central

    de Sousa, Natanael Teixeira Alves; Santos, Marcos Ferracioli; Gomes, Rosana Caetano; Brandino, Hugo Evangelista; Martinez, Roberto

    2015-01-01

    Abstract Objective: The purpose of this study was to analyze the influence of blue laser on bacterial growth of the main species that usually colonize cutaneous ulcers, as well as its effect over time following irradiation. Background data: The use of blue laser has been described as an adjuvant therapeutic method to inhibit bacterial growth, but there is no consensus about the best parameters to be used. Methods: Strains of Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, and Escherichia coli ATCC 25922 were suspended in saline solution at a concentration of 1.5×103 colony forming units (CFU)/mL. Next, 300 μL of this suspension was transferred to a microtitulation plate and exposed to a single blue laser irradiation (450 nm) at fluences of 0 (control), 3, 6, 12, 18, and 24 J/cm2. Each suspension was spread over the surface of a Petri plate before being incubated at 37°C, and counts of CFU were determined after 24 and 48 h. Results: Blue laser inhibited the growth of S. aureus and P. aeruginosa at fluences >6 J/cm2. On the other hand, E. coli was inhibited at all fluences tested, except at 24 J/cm2. Conclusions: Blue laser light was capable of inhibiting bacterial growth at low fluences over time, thus presenting no time-dependent effect. PMID:25954830

  16. Caudatin Inhibits Human Glioma Cells Growth Through Triggering DNA Damage-Mediated Cell Cycle Arrest.

    PubMed

    Fu, Xiao-yan; Zhang, Shuai; Wang, Kun; Yang, Ming-feng; Fan, Cun-dong; Sun, Bao-liang

    2015-10-01

    Caudatin, one of the species of C-21 steroidal glycosides mainly isolated from the root of Cynanchum bungei Decne, exhibits potent anticancer activities. However, the mechanism remains poorly defined. In the present study, the growth inhibitory effect and mechanism of caudatin on human glioma cells were evaluated in vitro. The results revealed that caudatin time- and dose-dependently inhibited U251 and U87 cells growth. Flow cytometry analysis indicated that caudatin-induced growth inhibition against U251 and U87 cells was mainly achieved by the induction of G0/G1 and S-phase cell cycle arrest through triggering DNA damage, as convinced by the up-regulation of p53, p21, and histone phosphorylation, as well as the down-regulation of cyclin D1. Moreover, caudatin treatment also triggered the activation of ERK and inactivation of AKT pathway. LY294002 (an AKT inhibitor) addition enhanced caudation-induced AKT inhibition, indicating that caudatin inhibited U251 cells growth in an AKT-dependent manner. Taken together, these results indicate that caudatin may act as a novel cytostatic reagent against human glioma cells through the induction of DNA damage-mediated cell cycle arrest with the involvement of modulating MAPK and AKT pathways.

  17. Disulfiram inhibits the in vitro growth of methicillin-resistant staphylococcus aureus.

    PubMed Central

    Phillips, M; Malloy, G; Nedunchezian, D; Lukrec, A; Howard, R G

    1991-01-01

    Several antibiotics have disulfiram-like effects; we evaluated disulfiram for its antibiotic-like effects. Disulfiram inhibited the in vitro growth of methicillin-resistant Staphylococcus aureus, with an MIC of 1.33 micrograms/ml, but was not effective against members of the family Enterobacteriaceae or Pseudomonas species. PMID:2069390

  18. Inhibition of growth of the dimorphic fungus Paracoccidioides brasiliensis by ajoene.

    PubMed Central

    San-Blas, G; San-Blas, F; Gil, F; Mariño, L; Apitz-Castro, R

    1989-01-01

    Ajoene, a garlic-derived compound that prevents platelet activation, inhibited the growth of Paracoccidioides brasiliensis, a fungal pathogen for humans, by affecting the integrity of the fungal cytoplasmic membrane. This action may be the basis for the study of ajoene as a possible specific antifungal drug. Images PMID:2817865

  19. Ionene polymers for selectively inhibiting the vitro growth of malignant cells

    NASA Technical Reports Server (NTRS)

    Rembaum, Alan (Inventor)

    1977-01-01

    Ionene polymers of the structure ##STR1## WHERE X AND Y ARE INTEGERS FROM 3 TO 16, Z.sup.- is an anion such as a halogen and n is an integer from 50 to 150 are found to bind negatively charged mammalian cells such as malignant cells and can be utilized to selectively inhibit the growth of malignant cells in vitro.

  20. Methylselenol, a selenium metabolite, inhibits colon cancer cell growth in vitro and in vivo

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methylselenol is hypothesized to be a critical selenium (Se) metabolite for anticancer activity. Submicromolar methylselenol exposure inhibited cell growth and led to an increase in the G1 and G2 fractions with a concomitant drop in the S-phase, and an induction of apoptosis in cancerous colon HCT11...

  1. Myristica fragrans Suppresses Tumor Growth and Metabolism by Inhibiting Lactate Dehydrogenase A.

    PubMed

    Kim, Eun-Yeong; Choi, Hee-Jung; Park, Mi-Ju; Jung, Yeon-Seop; Lee, Syng-Ook; Kim, Keuk-Jun; Choi, Jung-Hye; Chung, Tae-Wook; Ha, Ki-Tae

    2016-01-01

    Most cancer cells predominantly produce ATP by maintaining a high rate of lactate fermentation, rather than by maintaining a comparatively low rate of tricarboxylic acid cycle, i.e., Warburg's effect. In the pathway, the pyruvate produced by glycolysis is converted to lactic acid by lactate dehydrogenase (LDH). Here, we demonstrated that water extracts from the seeds of Myristica fragrans Houtt. (MF) inhibit the in vitro enzymatic activity of LDH. MF effectively suppressed cell growth and the overall Warburg effect in HT29 human colon cancer cells. Although the expression of LDH-A was not changed by MF, both lactate production and LDH activity were decreased in MF-treated cells under both normoxic and hypoxic conditions. In addition, intracellular ATP levels were also decreased by MF treatment, and the uptake of glucose was also reduced by MF treatment. Furthermore, the experiment on tumor growth in the in vivo mice model revealed that MF effectively reduced the growth of allotransplanted Lewis lung carcinoma cells. Taken together, these results suggest that MF effectively inhibits cancer growth and metabolism by inhibiting the activity of LDH, a major enzyme responsible for regulating cancer metabolism. These results implicate MF as a potential candidate for development into a novel drug against cancer through inhibition of LDH activity.

  2. Exogenous nitrate induces root branching and inhibits primary root growth in Capsicum chinense Jacq.

    PubMed

    Celis-Arámburo, Teresita de Jesús; Carrillo-Pech, Mildred; Castro-Concha, Lizbeth A; Miranda-Ham, María de Lourdes; Martínez-Estévez, Manuel; Echevarría-Machado, Ileana

    2011-12-01

    The effects of nitrate (NO₃⁻) on the root system are complex and depend on several factors, such as the concentration available to the plant, endogenous nitrogen status and the sensitivity of the species. Though these effects have been widely documented on Arabidopsis and cereals, no reports are available in the Capsicum genus. In this paper, we have determined the effect of an exogenous in vitro application of this nutrient on root growth in habanero pepper (Capsicum chinense Jacq.). Exposure to NO₃⁻ inhibited primary root growth in both, dose- and time-dependent manners. The highest inhibition was attained with 0.1 mM NO₃⁻ between the fourth and fifth days of treatment. Inhibition of primary root growth was observed by exposing the root to both homogeneous and heterogeneous conditions of the nutrient; in contrast, ammonium was not able to induce similar changes. NO₃⁻-induced inhibition of primary root growth was reversed by treating the roots with IAA or NPA, a polar auxin transport inhibitor. Heterogeneous NO₃⁻ application stimulated the formation and elongation of lateral roots in the segment where the nutrient was present, and this response was influenced by exogenous phytohormones. These results demonstrate that habanero pepper responds to NO₃⁻ in a similar fashion to other species with certain particular differences. Therefore, studies in this model could help to elucidate the mechanisms by which roots respond to NO₃⁻ in fluctuating soil environments.

  3. DIETARY ISOTHIOCYANATE IBERIN INHIBITS GROWTH AND INDUCES APOPTOSIS IN HUMAN GLIOBLASTOMA CELLS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this study, we evaluated the antiproliferative and proapoptotic effects of the isothiocyanate iberin, a bioactive agent in Brassicaceae species, in human glioblastoma cells. The human glioblastoma cell cultures were treated with different concentrations of iberin and tested for growth inhibition...

  4. A new diatom growth inhibition assay using the XTT colorimetric method.

    PubMed

    Jiang, Weina; Akagi, Takuya; Suzuki, Hidekazu; Takimoto, Ayaka; Nagai, Hiroshi

    2016-01-01

    Marine biofouling, which leads to significant operational stress and economic damage on marine infrastructures, is a major problem in marine related industries. Currently, the most common way to avoid marine biofouling involves the use of biocidal products in surface coatings. However, the need for environmentally friendly antibiofouling compounds has increased rapidly with the recent global prohibition of harmful antifoulants, such as tributyltin (TBT). In particular, periphytic diatoms have been shown to contribute significantly to biofilms, which play an important role in biofouling. Therefore, inhibiting the proliferation of fouling diatoms is a very important step in the prevention of marine biofouling. In this study, we developed a new, rapid, accurate, and convenient growth inhibition assay using the XTT colorimetric method to prevent the growth of the fouling periphytic diatom, Nitzschia amabilis Hidek. Suzuki (replaced synonym, Nitzschia laevis Hustedt). The feasibility of this method was verified by determining the growth inhibition activities of two standard photosynthetic inhibitors, DCMU and CuSO4. However, neither inhibitor had any cytotoxic activities at the range of concentrations tested. Moreover, this method was applied by screening and purification of herbicidic but non-cytotoxic compounds from cyanobacteria extracts. Our results demonstrate the utility of this newly established growth inhibition assay for the identification of marine anti-biofouling compounds.

  5. Deferred Growth Inhibition Assay to Quantify the Effect of Bacteria-derived Antimicrobials on Competition.

    PubMed

    Moran, Josephine C; Crank, Emma L; Ghabban, Hanaa A; Horsburgh, Malcolm J

    2016-09-03

    Competitive exclusion can occur in microbial communities when, for example, an inhibitor-producing strain outcompetes its competitor for an essential nutrient or produces antimicrobial compounds that its competitor is not resistant to. Here we describe a deferred growth inhibition assay, a method for assessing the ability of one bacterium to inhibit the growth of another through the production of antimicrobial compounds or through competition for nutrients. This technique has been used to investigate the correlation of nasal isolates with the exclusion of particular species from a community. This technique can also be used to screen for lantibiotic producers or potentially novel antimicrobials. The assay is performed by first culturing the test inhibitor-producing strain overnight on an agar plate, then spraying over the test competitor strain and incubating again. After incubation, the extent of inhibition can be measured quantitatively, through the size of the zone of clearing around the inhibitor-producing strain, and qualitatively, by assessing the clarity of the inhibition zone. Here we present the protocol for the deferred inhibition assay, describe ways to minimize variation between experiments, and define a clarity scale that can be used to qualitatively assess the degree of inhibition.

  6. Erythrocytic malaria growth or invasion inhibition assays with emphasis on suspension culture GIA.

    PubMed

    Haynes, J David; Moch, J Kathleen; Smoot, Douglas S

    2002-01-01

    Erythrocytic cycle malaria parasite growth or invasion inhibition assays (GIA) compare the effects of various test and control substances on malaria parasite growth in erythrocytes or invasion into erythrocytes in vitro. Although inhibitions by antimalarial drugs in vitro correlate well with drug protective levels required in vivo, as yet there are too few data to know how well inhibitions by antibodies in vitro correlate with the types and degrees of immune protection in vivo. Antibody-mediated GIA is frequently complicated by parasite strain-specific inhibitions, as well as nonspecific inhibitory factors generated in sera collected or stored under nonoptimal conditions. In this chapter, we describe methods for collecting and processing sera, for using different strains of parasite, and a simplified method for staining parasite DNA with Hoechst dye 33342 before quantitating parasites using ultraviolet (UV)-excited flow cytometry. We also describe a new type of GIA using suspension cultures in a 48-well plate. Critical to this method is enclosing the plate in a gassed, heat-sealed plastic bag, which, being low mass, can easily be rested at a 13.5 degrees angle on a rotor platform (114 rpm with 1-in. displacement) to produce gentle pulsatile waves of media in each well. The suspension GIA, which, relative to the static GIA, increased inhibition by one antibody and decreased inhibition by another (Table 1), may better simulate in vivo blood flow and may thus better predict in vivo efficacy.

  7. Inhibition of Galectin-1 Sensitizes HRAS-driven Tumor Growth to Rapamycin Treatment.

    PubMed

    Michael, James V; Wurtzel, Jeremy G T; Goldfinger, Lawrence E

    2016-10-01

    The goal of this study was to develop combinatorial application of two drugs currently either in active use as anticancer agents (rapamycin) or in clinical trials (OTX008) as a novel strategy to inhibit Harvey RAS (HRAS)-driven tumor progression. HRAS anchored to the plasma membrane shuttles from the lipid ordered (Lo) domain to the lipid ordered/lipid disordered border upon activation, and retention of HRAS at these sites requires galectin-1. We recently showed that genetically enforced Lo sequestration of HRAS inhibited mitogen-activated protein kinase (MAPK) signaling, but not phoshatidylinositol 3-kinase (PI3K) activation. Here we show that inhibition of galectin-1 with OTX008 sequestered HRAS in the Lo domain, blocked HRAS-mediated MAPK signaling, and attenuated HRAS-driven tumor progression in mice. HRAS-driven tumor growth was also attenuated by treatment with mammalian target of rapamycin (mTOR) inhibitor rapamycin, and this effect was further enhanced in tumors driven by Lo-sequestered HRAS. These drugs also revealed bidirectional cross-talk in HRAS pathways. Moreover, dual pathway inhibition with OTX008 and rapamycin resulted in nearly complete ablation of HRAS-driven tumor growth. These findings indicate that membrane microdomain sequestration of HRAS with galectin-1 inhibition, coupled with mTOR inhibition, may support a novel therapeutic approach to treat HRAS-mutant cancer.

  8. Deferred Growth Inhibition Assay to Quantify the Effect of Bacteria-derived Antimicrobials on Competition

    PubMed Central

    Moran, Josephine C.; Crank, Emma L.; Ghabban, Hanaa A.; Horsburgh, Malcolm J.

    2016-01-01

    Competitive exclusion can occur in microbial communities when, for example, an inhibitor-producing strain outcompetes its competitor for an essential nutrient or produces antimicrobial compounds that its competitor is not resistant to. Here we describe a deferred growth inhibition assay, a method for assessing the ability of one bacterium to inhibit the growth of another through the production of antimicrobial compounds or through competition for nutrients. This technique has been used to investigate the correlation of nasal isolates with the exclusion of particular species from a community. This technique can also be used to screen for lantibiotic producers or potentially novel antimicrobials. The assay is performed by first culturing the test inhibitor-producing strain overnight on an agar plate, then spraying over the test competitor strain and incubating again. After incubation, the extent of inhibition can be measured quantitatively, through the size of the zone of clearing around the inhibitor-producing strain, and qualitatively, by assessing the clarity of the inhibition zone. Here we present the protocol for the deferred inhibition assay, describe ways to minimize variation between experiments, and define a clarity scale that can be used to qualitatively assess the degree of inhibition. PMID:27684443

  9. Fibroblast growth factor-2 inhibits mineralization of osteoblast-like Saos-2 cells by inhibiting the functioning of matrix vesicles.

    PubMed

    Liu, Chao; Cui, Yazhou; Luan, Jing; Zhou, Xiaoyan; Liu, Zhenxing; Han, Jinxiang

    2014-02-01

    Fibroblast growth factor-2 (FGF2) inhibits osteoblast mineralization, but the mechanism by which it does so is not fully understood. Matrix vesicles (MVs) play an essential role in the initiation of mineralization, so the current study examined the effect of FGF2 on the functioning of MVs to investigate this mechanism. This study found that FGF2 significantly inhibited differentiation and mineralization of osteoblast-like Saos-2 cells, as indicated by down-regulation of mRNA expression of the osteogenic master regulator runt-related transcription factor 2 (Runx2), alkaline phosphatase (ALP), and collagen 1 alpha 1 (Colla1), and by decreasing the formation of bone nodules. MVs were isolated from Saos-2 cells cultured in osteogenic medium supplemented with and without FGF2 and their presence was verified using electron microscopy and Western blotting. FGF2 markedly reduced the ALP activity of and in vitro mineralization by MVs. These findings suggest that FGF2 inhibits osteoblast mineralization by limiting the capacity of MVs.

  10. A synthetic manassantin a derivative inhibits hypoxia-inducible factor 1 and tumor growth.

    PubMed

    Lang, Liwei; Liu, Xiaoyu; Li, Yan; Zhou, Qing; Xie, Ping; Yan, Chunhong; Chen, Xiaoguang

    2014-01-01

    The dineolignan manassantin A from Saururaceae was recently identified as a hypoxia-inducible factor 1 (HIF-1) inhibitor, but its in-vivo anti-tumor effect has not been explored. We synthesized a series of manassantin A derivatives, and found that replacing the central tetrahydrofuran moiety with a cyclopentane ring yielded a compound (LXY6006) with increased HIF-1-inhibitory activity yet decreased stereochemically complexity amenable to a simplified synthesis scheme. LXY6006 inhibited HIF-1α nuclear accumulation induced by hypoxia, and inhibited cancer cell growth as a consequence of G2/M arrest. Oral administration of LXY6006 significantly inhibited growth of breast, lung, and pancreatic tumors implanted in nude mice. These results indicate that LXY6006 represents a novel class of agents targeting a broad range of human cancers.

  11. A Synthetic Manassantin A Derivative Inhibits Hypoxia-Inducible Factor 1 and Tumor Growth

    PubMed Central

    Li, Yan; Zhou, Qing; Xie, Ping; Yan, Chunhong; Chen, Xiaoguang

    2014-01-01

    The dineolignan manassantin A from Saururaceae was recently identified as a hypoxia-inducible factor 1 (HIF-1) inhibitor, but its in-vivo anti-tumor effect has not been explored. We synthesized a series of manassantin A derivatives, and found that replacing the central tetrahydrofuran moiety with a cyclopentane ring yielded a compound (LXY6006) with increased HIF-1-inhibitory activity yet decreased stereochemically complexity amenable to a simplified synthesis scheme. LXY6006 inhibited HIF-1α nuclear accumulation induced by hypoxia, and inhibited cancer cell growth as a consequence of G2/M arrest. Oral administration of LXY6006 significantly inhibited growth of breast, lung, and pancreatic tumors implanted in nude mice. These results indicate that LXY6006 represents a novel class of agents targeting a broad range of human cancers. PMID:24925080

  12. Comparative toxicity of copper and acridine to fish, Daphnia and algae

    SciTech Connect

    Blaylock, B.G.; Frank, M.L.; McCarthy, J.F.

    1985-01-01

    A comparison was made of the sensitivity of fish, Daphnia and algae to the toxic effects of copper and acridine. A series of toxicity tests was conducted with these organisms, and the following biological endpoints determined: LC50s for fish, LC50s and effects on reproduction of Daphnia and 50% inhibition of the growth rate of algae. The 96-h LCO50s for bluegill (Lepomis macrochirus) and Daphnia magna exposed to copper were 2.2 and 0.13 mg/L, respectively. A chronic exposure to 0.03 mg/L of copper for 14 d significantly decreased reproduction in Daphnia. Exposure to 0.4 and 0.2 mg/L copper inhibited the growth rate of Selenastrum capricornutum and Chlorella vulgaris, respectively, by 50%. The 96-h LC50s for fathead minnows (Pimephales promelas) and D. magna exposed to acridine were 2.3 and 3.1 mg/L, respectively. A chronic exposure to 1.25 mg/L acridine for 14 d significantly inhibited reproduction in Daphnia, and an exposure to 0.9 mg/L inhibited the growth rate of S. capricornutum by 50%. Based on the biological endpoints determined in these tests, Daphnia were more sensitive to copper than were fish or algae. In contrast, the most sensitive biological endpoint in tests with acridine was the inhibition of algal growth. Comparison of these test results indicates that short-term toxicity tests used for screening toxicants for possible environmental effects should include both plant and animal species. 16 references, 4 figures, 4 tables.

  13. Errors When Extracting Oil from Algae

    NASA Astrophysics Data System (ADS)

    Murphy, E.; Treat, R.; Ichiuji, T.

    2014-12-01

    Oil is in popular demand, but the worldwide amount of oil is decreasing and prices for it are steadily increasing. Leading scientists have been working to find a solution of attaining oil in an economically and environmentally friendly way. Researchers at the U.S. Department of Energy's Pacific Northwest National Laboratory (PNNL) have determined that "a small mixture of algae and water can be turned into crude oil in less than an hour" (Sheehan, Duhahay, Benemann, Poessler). There are various ways of growing the algae, such as closed loop and open loop methods, as well as processes of extracting oil, such as hydrothermal liquefaction and the hexane-solvent method. Our objective was to grow the algae (C. reinhardtii) and extract oil from it using NaOH and HCl, because we had easy access to those specific chemicals. After two trials of attempted algae growth, we discovered that a bacteria was killing off the algae. This led us to further contemplation on how this dead algae and bacteria are affecting our environment, and the organisms within it. Eutrophication occurs when excess nutrients stimulate rapid growth of algae in an aquatic environment. This can clog waterways and create algal blooms in blue-green algae, as well as neurotoxic red tide phytoplankton. These microscopic algae die upon consumption of the nutrients in water and are degraded by bacteria. The bacteria respires and creates an acidic environment with the spontaneous conversion of carbon dioxide to carbonic acid in water. This process of degradation is exactly what occurred in our 250 mL flask. When the phytoplankton attacked our algae, it created a hypoxic environment, which eliminated any remaining amounts of oxygen, carbon dioxide, and nutrients in the water, resulting in a miniature dead zone. These dead zones can occur almost anywhere where there are algae and bacteria, such as the ocean, and make it extremely difficult for any organism to survive. This experiment helped us realize the

  14. Fufang Kushen injection inhibits sarcoma growth and tumor-induced hyperalgesia via TRPV1 signaling pathways

    PubMed Central

    Zhao, Zhizheng; Fan, Huiting; Higgins, Tim; Qi, Jia; Haines, Diana; Trivett, Anna; Oppenheim, Joost J.; Wei, Hou; Li, Jie; Lin, Hongsheng; Howard, O.M. Zack

    2014-01-01

    Cancer pain is a deleterious consequence of tumor growth and related inflammation. Opioids and antiinflammatory drugs provide first line treatment for cancer pain, but both are limited by side effects. Fufang Kushen injection (FKI) is GMP produced, traditional Chinese medicine used alone or with chemotherapy to reduce cancer-associated pain. FKI limited mouse sarcoma growth both in vivo and in vitro, in part, by reducing the phosphorylation of ERK and AKT kinases and BAD. FKI inhibited TRPV1 mediated capsaicin-induced ERK phosphorylation and reduced tumor-induced proinflammatory cytokine production. Thus, FKI limited cancer pain both directly by blocking TRPV1 signaling and indirectly by reducing tumor growth. PMID:25242356

  15. Platelet-derived growth factor-receptor alpha strongly inhibits melanoma growth in vitro and in vivo.

    PubMed

    Faraone, Debora; Aguzzi, Maria Simona; Toietta, Gabriele; Facchiano, Angelo M; Facchiano, Francesco; Magenta, Alessandra; Martelli, Fabio; Truffa, Silvia; Cesareo, Eleonora; Ribatti, Domenico; Capogrossi, Maurizio C; Facchiano, Antonio

    2009-08-01

    Cutaneous melanoma is the most aggressive skin cancer; it is highly metastatic and responds poorly to current therapies. The expression of platelet-derived growth factor receptors (PDGF-Rs) is reported to be reduced in metastatic melanoma compared with benign nevi or normal skin; we then hypothesized that PDGF-Ralpha may control growth of melanoma cells. We show here that melanoma cells overexpressing PDGF-Ralpha respond to serum with a significantly lower proliferation compared with that of controls. Apoptosis, cell cycle arrest, pRb dephosphorylation, and DNA synthesis inhibition were also observed in cells overexpressing PDGF-Ralpha. Proliferation was rescued by PDGF-Ralpha inhibitors, allowing to exclude nonspecific toxic effects and indicating that PDGF-Ralpha mediates autocrine antiproliferation signals in melanoma cells. Accordingly, PDGF-Ralpha was found to mediate staurosporine cytotoxicity. A protein array-based analysis of the mitogen-activated protein kinase pathway revealed that melanoma cells overexpressing PDGF-Ralpha show a strong reduction of c-Jun phosphorylated in serine 63 and of protein phosphatase 2A/Balpha and a marked increase of p38gamma, mitogen-activated protein kinase kinase 3, and signal regulatory protein alpha1 protein expression. In a mouse model of primary melanoma growth, infection with the Ad-vector overexpressing PDGF-Ralpha reached a significant 70% inhibition of primary melanoma growth (P < .001) and a similar inhibition of tumor angiogenesis. All together, these data demonstrate that PDGF-Ralpha strongly impairs melanoma growth likely through autocrine mechanisms and indicate a novel endogenous mechanism involved in melanoma control.

  16. Platelet-Derived Growth Factor-Receptor α Strongly Inhibits Melanoma Growth In Vitro and In Vivo1

    PubMed Central

    Faraone, Debora; Aguzzi, Maria Simona; Toietta, Gabriele; Facchiano, Angelo M; Facchiano, Francesco; Magenta, Alessandra; Martelli, Fabio; Truffa, Silvia; Cesareo, Eleonora; Ribatti, Domenico; Capogrossi, Maurizio C; Facchiano, Antonio

    2009-01-01

    Cutaneous melanoma is the most aggressive skin cancer; it is highly metastatic and responds poorly to current therapies. The expression of platelet-derived growth factor receptors (PDGF-Rs) is reported to be reduced in metastatic melanoma compared with benign nevi or normal skin; we then hypothesized that PDGF-Rα may control growth of melanoma cells. We show here that melanoma cells overexpressing PDGF-Rα respond to serum with a significantly lower proliferation compared with that of controls. Apoptosis, cell cycle arrest, pRb dephosphorylation, and DNA synthesis inhibition were also observed in cells overexpressing PDGF-Rα. Proliferation was rescued by PDGF-Rα inhibitors, allowing to exclude nonspecific toxic effects and indicating that PDGF-Rα mediates autocrine antiproliferation signals in melanoma cells. Accordingly, PDGF-Rα was found to mediate staurosporine cytotoxicity. A protein array-based analysis of the mitogen-activated protein kinase pathway revealed that melanoma cells overexpressing PDGF-Rα show a strong reduction of c-Jun phosphorylated in serine 63 and of protein phosphatase 2A/Bα and a marked increase of p38γ, mitogen-activated protein kinase kinase 3, and signal regulatory protein α1 protein expression. In a mouse model of primary melanoma growth, infection with the Ad-vector overexpressing PDGF-Rα reached a significant 70% inhibition of primary melanoma growth (P < .001) and a similar inhibition of tumor angiogenesis. All together, these data demonstrate that PDGF-Rα strongly impairs melanoma growth likely through autocrine mechanisms and indicate a novel endogenous mechanism involved in melanoma control. PMID:19649203

  17. Akt- or MEK-mediated mTOR inhibition suppresses Nf1 optic glioma growth

    PubMed Central

    Kaul, Aparna; Toonen, Joseph A.; Cimino, Patrick J.; Gianino, Scott M.; Gutmann, David H.

    2015-01-01

    Background Children with neurofibromatosis type 1 (NF1) develop optic pathway gliomas, which result from impaired NF1 protein regulation of Ras activity. One obstacle to the implementation of biologically targeted therapies is an incomplete understanding of the individual contributions of the downstream Ras effectors (mitogen-activated protein kinase kinase [MEK], Akt) to optic glioma maintenance. This study was designed to address the importance of MEK and Akt signaling to Nf1 optic glioma growth. Methods Primary neonatal mouse astrocyte cultures were employed to determine the consequence of phosphatidylinositol-3 kinase (PI3K)/Akt and MEK inhibition on Nf1-deficient astrocyte growth. Nf1 optic glioma–bearing mice were used to assess the effect of Akt and MEK inhibition on tumor volume, proliferation, and retinal ganglion cell dysfunction. Results Both MEK and Akt were hyperactivated in Nf1-deficient astrocytes in vitro and in Nf1 murine optic gliomas in vivo. Pharmacologic PI3K or Akt inhibition reduced Nf1-deficient astrocyte proliferation to wild-type levels, while PI3K inhibition decreased Nf1 optic glioma volume and proliferation. Akt inhibition of Nf1-deficient astrocyte and optic glioma growth reflected Akt-dependent activation of mammalian target of rapamycin (mTOR). Sustained MEK pharmacologic blockade also attenuated Nf1-deficient astrocytes as well as Nf1 optic glioma volume and proliferation. Importantly, these MEK inhibitory effects resulted from p90RSK-mediated, Akt-independent mTOR activation. Finally, both PI3K and MEK inhibition reduced optic glioma–associated retinal ganglion cell loss and nerve fiber layer thinning. Conclusion These findings establish that the convergence of 2 distinct Ras effector pathways on mTOR signaling maintains Nf1 mouse optic glioma growth, supporting the evaluation of pharmacologic inhibitors that target mTOR function in future human NF1–optic pathway glioma clinical trials. PMID:25534823

  18. Psoralens potentiate ultraviolet light-induced inhibition of epidermal growth factor binding

    SciTech Connect

    Laskin, J.D.; Lee, E.; Laskin, D.L.; Gallo, M.A.

    1986-11-01

    The psoralens, when activated by ultraviolet light of 320-400 nm (UVA light), are potent modulators of epidermal cell growth and differentiation. Previously, we reported that, in mammalian cells, these compounds bind to specific saturable high-affinity cellular receptor sites. In the present studies, we demonstrate that binding of psoralens to their receptors followed by UVA light activation is associated with inhibition of epidermal growth factor (EGF) receptor binding. Inhibition of EGF binding, which required UVA light, was rapid and dependent on the dose of UVA light (0.5-2.0 J/cm2), as well as the concentration of psoralens (10 nM to 1 microM). Higher doses of UVA light (2.0-6.0 J/cm2) by themselves were also inhibitory, indicating that psoralens potentiate the UVA-induced inhibition of EGF binding. A number of biologically active analogs of psoralen, including 8-methoxypsoralen, 5-methoxypsoralen, and 4,5',8-trimethylpsoralen, when activated by UVA light, were found to be inhibitors of binding. Inhibition of EGF binding by psoralens was observed in a variety of human and mouse cell culture lines known to possess psoralen receptors. In the epidermal-derived line PAM 212, at least two populations of receptors with different affinities for EGF were found. Psoralens and UVA light selectively inhibited binding to the higher-affinity EGF receptors, an effect analogous to that of the phorbol ester tumor promoters. As observed with phorbol esters, photoactivated psoralens appeared to inhibit EGF binding by an indirect mechanism. These data demonstrate that the psoralens and UVA light have direct biological effects on cell-surface membranes. Since EGF is a growth-regulatory peptide, the ability of psoralens and UVA light to inhibit EGF binding may underlie the biologic effects of these agents in the skin.

  19. Inhibition of transforming growth factor β signaling promotes epiblast formation in mouse embryos.

    PubMed

    Ghimire, Sabitri; Heindryckx, Björn; Van der Jeught, Margot; Neupane, Jitesh; O'Leary, Thomas; Lierman, Sylvie; De Vos, Winnok H; Chuva de Sousa Lopes, Susana; Deroo, Tom; De Sutter, Petra

    2015-02-15

    Early lineage segregation in preimplantation embryos and maintenance of pluripotency in embryonic stem cells (ESCs) are both regulated by specific signaling pathways. Small molecules have been shown to modulate these signaling pathways. We examined the influence of several small molecules and growth factors on second-lineage segregation of the inner cell mass toward hypoblast and epiblast lineage during mouse embryonic preimplantation development. We found that the second-lineage segregation is influenced by activation or inhibition of the transforming growth factor (TGF)β pathway. Inhibition of the TGFβ pathway from the two-cell, four-cell, and morula stages onward up to the blastocyst stage significantly increased the epiblast cell proliferation. The epiblast formed in the embryos in which TGFβ signaling was inhibited was fully functional as demonstrated by the potential of these epiblast cells to give rise to pluripotent ESCs. Conversely, activating the TGFβ pathway reduced epiblast formation. Inhibition of the glycogen synthase kinase (GSK)3 pathway and activation of bone morphogenetic protein 4 signaling reduced the formation of both epiblast and hypoblast cells. Activation of the protein kinase A pathway and of the Janus kinase/signal transducer and activator of transcription 3 pathway did not influence the second-lineage segregation in mouse embryos. The simultaneous inhibition of three pathways--TGFβ, GSK3β, and the fibroblast growth factor (FGF)/extracellular signal-regulated kinases (Erk)--significantly enhanced the proliferation of epiblast cells than that caused by inhibition of either TGFβ pathway alone or by combined inhibition of the GSK3β and FGF/Erk pathways only.

  20. Molecular Characterization of Babesia bovis M17 Leucine Aminopeptidase and Inhibition of Babesia Growth by Bestatin.

    PubMed

    Aboge, Gabriel Oluga; Cao, Shinuo; Terkawi, Mohamad Alaa; Masatani, Tatsunori; Goo, Younkyoung; AbouLaila, Mahmoud; Nishikawa, Yoshifumi; Igarashi, Ikuo; Suzuki, Hiroshi; Xuan, Xuenan

    2015-10-01

    The M17 leucine aminopeptidase (M17LAP) enzymes of the other apicomplexan parasites have been characterized and shown to be inhibited by bestatin. Though Babesia bovis also belongs to the apicomplexan group, it is not known whether its M17LAP could display similar biochemical properties as well as inhibition profile. To unravel this uncertainty, a B. bovis M17LAP (BbM17LAP) gene was expressed in Escherichia coli , and activity of the recombinant enzyme as well as its inhibition by bestatin were evaluated. The inhibitory effect of the compound on growths of B. bovis and Babesia gibsoni in vitro was also determined. The expression of the gene fused with glutathione S-transferase (GST) yielded approximately 81-kDa recombinant BbM17LAP (rBbM17LAP). On probing with mouse anti-rBbM17LAP serum, a green fluorescence was observed on the parasite cytosol on confocal laser microscopy, and a specific band greater than the predicted molecular mass was seen on Western blotting. The Km and Vmax values of the recombinant enzyme were 139.3 ± 30.25 and 64.83 ± 4.6 μM, respectively, while the Ki was 2210 ± 358 μM after the inhibition. Bestatin was a more potent inhibitor of the growth of B. bovis [IC50 (50% inhibition concentration) = 131.7 ± 51.43 μM] than B. gibsoni [IC50 = 460.8 ± 114.45 μM] in vitro. The modest inhibition of both the rBbM17LAP activity and Babesia parasites' growth in vitro suggests that this inhibition may involve the endogenous enzyme in live parasites. Therefore, BbM17LAP may be a target of bestatin, though more studies with other aminopeptidase inhibitors are required to confirm this.

  1. Growth inhibition, drug load, and degradation studies of gelatin/methotrexate conjugates.

    PubMed

    Ofner, Clyde M; Pica, Karen; Bowman, Bill J; Chen, Chao-Sheng

    2006-02-03

    Macromolecular gelatin-methotrexate conjugates have potential therapeutic advantages over the free drug. Conjugates with MTX:gelatin molar ratios (MR) ranging from 1:1 to 27:1 were examined for cell growth inhibition, stability, degradation, and methotrexate (MTX) release. Conjugate growth inhibition was less than that of free MTX whose IC(50) value of 1.3 x 10(-8) M was about 10-fold less. Cell uptake of fluorescein labeled gelatin (145 kD) was observed by 24-30 h. Higher MR conjugates produced less growth inhibition, measurably greater stability at pH 7.4 based on MTX release, and had less gelatin degradation in the conjugate by the lysosomal enzyme Cathepsin B (Cat B) compared to low MR conjugates. Cat B conjugate degradation was greater at the in vitro lysosomal pH of 4.8 than the intra-tumor pH of 6.5. The presence of Cat B did not meaningfully affect MTX release, but less MTX was released at pH 4.8 than pH 6.5. The maximum MTX release was a relatively low 7% after 72 h at pH 6.5 for the low MR conjugate. Low molecular weight conjugate fragments were also produced and were also influenced by pH and MR. Reduced growth inhibition by high MR conjugates may be due to a hindered enzymatic degradation in the lysosomes. A strong peptide conjugate bond at lysosomal pH and a 24-30 h delayed gelatin uptake may contribute to reduced growth inhibition of the conjugate compared to free MTX. MTX release under these in vitro conditions occurs by aqueous hydrolysis, not by Cat B cleavage of the conjugate bond.

  2. Devazepide, a nonpeptide antagonist of CCK receptors, induces apoptosis and inhibits Ewing tumor growth.

    PubMed

    Carrillo, Jaime; Agra, Noelia; Fernández, Noemí; Pestaña, Angel; Alonso, Javier

    2009-08-01

    The Ewing family of tumors is a group of highly malignant tumors that mainly arise in bone and most often affect children and young adults in the first two decades of life. Despite the use of multimodal therapy, the long-term disease-free survival rate of patients with Ewing tumors is still disappointingly low, making the discovery of innovative therapeutic strategies all the more necessary. We have recently shown that cholecystokinin (CCK), a neuroendocrine peptide, involved in many biological functions, including cell growth and proliferation, is a relevant target of the EWS/FLI1 oncoprotein characteristic of Ewing tumors. CCK silencing inhibits cell proliferation and tumor growth in vivo, suggesting that CCK acts as an autocrine growth factor for Ewing cells. Here, we analyzed the impact of two CCK receptor antagonists, devazepide (a CCK1-R antagonist) and L365 260 (a CCK2-R antagonist), on the growth of Ewing tumor cells. Devazepide (10 micromol/l) inhibited cell growth of four different Ewing tumor cells in vitro (range 85-88%), whereas the effect of the CCK2-R antagonist on cell growth was negligible. In a mouse tumor xenograft model, devazepide reduced tumor growth by 40%. Flow cytometry experiments showed that devazepide, but not L365 260, induced apoptosis of Ewing tumor cells. In summary, devazepide induces cell death of Ewing tumor cells, suggesting that it could represent a new therapeutic approach in the management of Ewing's tumor patients.

  3. AtOPR3 specifically inhibits primary root growth in Arabidopsis under phosphate deficiency

    PubMed Central

    Zheng, Hongyan; Pan, Xiaoying; Deng, Yuxia; Wu, Huamao; Liu, Pei; Li, Xuexian

    2016-01-01

    The primary root plays essential roles in root development, nutrient absorption, and root architectural establishment. Primary root growth is generally suppressed by phosphate (P) deficiency in A. thaliana; however, the underlying molecular mechanisms are largely elusive to date. We found that AtOPR3 specifically inhibited primary root growth under P deficiency via suppressing root tip growth at the transcriptional level, revealing an important novel function of AtOPR3 in regulating primary root response to the nutrient stress. Importantly, AtOPR3 functioned to down-regulate primary root growth under P limitation mostly by its own, rather than depending on the Jasmonic acid signaling pathway. Further, AtOPR3 interacted with ethylene and gibberellin signaling pathways to regulate primary root growth upon P deficiency. In addition, the AtOPR3’s function in inhibiting primary root growth upon P limitation was also partially dependent on auxin polar transport. Together, our studies provide new insights into how AtOPR3, together with hormone signaling interactions, modulates primary root growth in coping with the environmental stress in Arabidopsis. PMID:27101793

  4. Warfarin inhibits metastasis of Mtln3 rat mammary carcinoma without affecting primary tumour growth.

    PubMed Central

    McCulloch, P.; George, W. D.

    1989-01-01

    Coumarin anticoagulants inhibit metastasis in several animal models, but the mechanism of this effect is uncertain. In order to determine the role of cytotoxic and/or cytostatic actions of coumarins on the tumour cells, we have studied the effects of warfarin on tumour cell growth in a model in which tumour metastasis is inhibited by this drug. Clonogenic assay, growth curve analysis and thymidine labelling index revealed that warfarin had no effects on Mtln3 mammary carcinoma cell growth in vitro at concentrations below 1 mM. The growth rate of subcutaneously implanted Mtln3 tumour deposits in female F344 rats, assessed by weight and by stathmokinetic analysis of the tumour tissue, was identical in warfarin-treated and control animals. Spontaneous metastasis from such tumours to the lungs was, however, significantly reduced in warfarin-treated animals (median 0 pulmonary tumours per animal in warfarin treated, eight tumours per animal in control animals; P less than 0.05, Mann-Whitney). The mean plasma warfarin concentration in warfarin treated rats was 1.63 microM. These results suggest that warfarin treatment of the host animal can inhibit tumour metastasis without having any direct or indirect effect on the growth rate of the tumour cells. PMID:2930682

  5. Novel Antifungal Peptides Produced by Leuconostoc mesenteroides DU15 Effectively Inhibit Growth of Aspergillus niger.

    PubMed

    Muhialdin, Belal J; Hassan, Zaiton; Abu Bakar, Fatimah; Algboory, Hussein L; Saari, Nazamid

    2015-05-01

    The ability of Leuconostoc mesenteroides DU15 to produce antifungal peptides that inhibit growth of Aspergillus niger was evaluated under optimum growth conditions of 30 °C for 48 h. The cell-free supernatant showed inhibitory activity against A. niger. Five novel peptides were isolated with the sequences GPFPL, YVPLF, LLHGVPLP, GPFPLEMTLGPT, and TVYPFPGPL as identified by de novo sequencing using PEAKS 6 software. Peptide LLHGVPLP was the only positively charged (cationic peptides) and peptide GPFPLEMTLGPT negatively charged (anionic), whereas the rest are neutral. The identified peptides had high hydrophobicity ratio and low molecular weights with amino acids sequences ranging from 5 to 12 residues. The mode of action of these peptides is observed under the scanning electron microscope and is due to cell lysis of fungi. This work reveals the potential of peptides from L. mesenteroides DU15 as natural antifungal preservatives in inhibiting the growth of A. niger that is implicated to the spoilage during storage.

  6. Inhibition of growth of Zymomonas mobilis by model compounds found in lignocellulosic hydrolysates

    PubMed Central

    2013-01-01

    Background During the pretreatment of biomass feedstocks and subsequent conditioning prior to saccharification, many toxic compounds are produced or introduced which inhibit microbial growth and in many cases, production of ethanol. An understanding of the toxic effects of compounds found in hydrolysate is critical to improving sugar utilization and ethanol yields in the fermentation process. In this study, we established a useful tool for surveying hydrolysate toxicity by measuring growth rates in the presence of toxic compounds, and examined the effects of selected model inhibitors of aldehydes, organic and inorganic acids (along with various cations), and alcohols on growth of Zymomonas mobilis 8b (a ZM4 derivative) using glucose or xylose as the carbon source. Results Toxicity strongly correlated to hydrophobicity in Z. mobilis, which has been observed in Escherichia coli and Saccharomyces cerevisiae for aldehydes and with some exceptions, organic acids. We observed Z. mobilis 8b to be more tolerant to organic acids than previously reported, although the carbon source and growth conditions play a role in tolerance. Growth in xylose was profoundly inhibited by monocarboxylic organic acids compared to growth in glucose, whereas dicarboxylic acids demonstrated little or no effects on growth rate in either substrate. Furthermore, cations can be ranked in order of their toxicity, Ca++ > > Na+ > NH4+ > K+. HMF (5-hydroxymethylfurfural), furfural and acetate, which were observed to contribute to inhibition of Z. mobilis growth in dilute acid pretreated corn stover hydrolysate, do not interact in a synergistic manner in combination. We provide further evidence that Z. mobilis 8b is capable of converting the aldehydes furfural, vanillin, 4-hydroxybenzaldehyde and to some extent syringaldehyde to their alcohol forms (furfuryl, vanillyl, 4-hydroxybenzyl and syringyl alcohol) during fermentation. Conclusions Several key findings in this report provide a

  7. Prophylactic Administration of Fucoidan Represses Cancer Metastasis by Inhibiting Vascular Endothelial Growth Factor (VEGF) and Matrix Metalloproteinases (MMPs) in Lewis Tumor-Bearing Mice

    PubMed Central

    Huang, Tse-Hung; Chiu, Yi-Han; Chan, Yi-Lin; Chiu, Ya-Huang; Wang, Hang; Huang, Kuo-Chin; Li, Tsung-Lin; Hsu, Kuang-Hung; Wu, Chang-Jer

    2015-01-01

    Fucoidan, a heparin-like sulfated polysaccharide, is rich in brown algae. It has a wide assortment of protective activities against cancer, for example, induction of hepatocellular carcinoma senescence, induction of human breast and colon carcinoma apoptosis, and impediment of lung cancer cells migration and invasion. However, the anti-metastatic mechanism that fucoidan exploits remains elusive. In this report, we explored the effects of fucoidan on cachectic symptoms, tumor development, lung carcinoma cell spreading and proliferation, as well as expression of metastasis-associated proteins in the Lewis lung carcinoma (LLC) cells-inoculated mice model. We discovered that administration of fucoidan has prophylactic effects on mitigation of cachectic body weight loss and improvement of lung masses in tumor-inoculated mice. These desired effects are attributed to inhibition of LLC spreading and proliferation in lung tissues. Fucoidan also down-regulates expression of matrix metalloproteinases (MMPs), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and vascular endothelial growth factor (VEGF). Moreover, the tumor-bearing mice supplemented with fucoidan indeed benefit from an ensemble of the chemo-phylacticity. The fact is that fucoidan significantly decreases viability, migration, invasion, and MMPs activities of LLC cells. In summary, fucoidan is suitable to act as a chemo-preventative agent for minimizing cachectic symptoms as well as inhibiting lung carcinoma metastasis through down-regulating metastatic factors VEGF and MMPs. PMID:25854641

  8. Prophylactic administration of fucoidan represses cancer metastasis by inhibiting vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMPs) in Lewis tumor-bearing mice.

    PubMed

    Huang, Tse-Hung; Chiu, Yi-Han; Chan, Yi-Lin; Chiu, Ya-Huang; Wang, Hang; Huang, Kuo-Chin; Li, Tsung-Lin; Hsu, Kuang-Hung; Wu, Chang-Jer

    2015-04-03

    Fucoidan, a heparin-like sulfated polysaccharide, is rich in brown algae. It has a wide assortment of protective activities against cancer, for example, induction of hepatocellular carcinoma senescence, induction of human breast and colon carcinoma apoptosis, and impediment of lung cancer cells migration and invasion. However, the anti-metastatic mechanism that fucoidan exploits remains elusive. In this report, we explored the effects of fucoidan on cachectic symptoms, tumor development, lung carcinoma cell spreading and proliferation, as well as expression of metastasis-associated proteins in the Lewis lung carcinoma (LLC) cells-inoculated mice model. We discovered that administration of fucoidan has prophylactic effects on mitigation of cachectic body weight loss and improvement of lung masses in tumor-inoculated mice. These desired effects are attributed to inhibition of LLC spreading and proliferation in lung tissues. Fucoidan also down-regulates expression of matrix metalloproteinases (MMPs), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and vascular endothelial growth factor (VEGF). Moreover, the tumor-bearing mice supplemented with fucoidan indeed benefit from an ensemble of the chemo-phylacticity. The fact is that fucoidan significantly decreases viability, migration, invasion, and MMPs activities of LLC cells. In summary, fucoidan is suitable to act as a chemo-preventative agent for minimizing cachectic symptoms as well as inhibiting lung carcinoma metastasis through down-regulating metastatic factors VEGF and MMPs.

  9. Development of fluorescent Plasmodium falciparum for in vitro growth inhibition assays

    PubMed Central

    2010-01-01

    Background Plasmodium falciparum in vitro growth inhibition assays are widely used to evaluate and quantify the functional activity of acquired and vaccine-induced antibodies and the anti-malarial activity of known drugs and novel compounds. However, several constraints have limited the use of these assays in large-scale population studies, vaccine trials and compound screening for drug discovery and development. Methods The D10 P. falciparum line was transfected to express green fluorescent protein (GFP). In vitro growth inhibition assays were performed over one or two cycles of P. falciparum asexual replication using inhibitory polyclonal antibodies raised in rabbits, an inhibitory monoclonal antibody, human serum samples, and anti-malarials. Parasitaemia was evaluated by microscopy and flow cytometry. Results Transfected parasites expressed GFP throughout all asexual stages and were clearly detectable by flow cytometry and fluorescence microscopy. Measurement of parasite growth inhibition was the same when determined by detection of GFP fluorescence or staining with ethidium bromide. There was no difference in the inhibitory activity of samples when tested against the transfected parasites compared to the parental line. The level of fluorescence of GFP-expressing parasites increased throughout the course of asexual development. Among ring-stages, GFP-fluorescent parasites were readily separated from uninfected erythrocytes by flow cytometry, whereas this was less clear using ethidium bromide staining. Inhibition by serum and antibody samples was consistently higher when tested over two cycles of growth compared to one, and when using a 1 in 10 sample dilution compared to 1 in 20, but there was no difference detected when using a different starting parasitaemia to set-up growth assays. Flow cytometry based measurements of parasitaemia proved more reproducible than microscopy counts. Conclusions Flow cytometry based assays using GFP-fluorescent parasites proved

  10. Methoxychlor inhibits growth of antral follicles by altering cell cycle regulators

    SciTech Connect

    Gupta, Rupesh K. Meachum, Sharon Hernandez-Ochoa, Isabel Peretz, Jackye Yao, Humphrey H. Flaws, Jodi A.

    2009-10-01

    Methoxychlor (MXC) reduces fertility in female rodents, decreases antral follicle numbers, and increases atresia through oxidative stress pathways. MXC also inhibits antral follicle growth in vitro. The mechanism by which MXC inhibits growth of follicles is unknown. The growth of follicles is controlled, in part, by cell cycle regulators. Thus, we tested the hypothesis that MXC inhibits follicle growth by reducing the levels of selected cell cycle regulators. Further, we tested whether co-treatment with an antioxidant, N-acetyl cysteine (NAC), prevents the MXC-induced reduction in cell cycle regulators. For in vivo studies, adult cycling CD-1 mice were dosed with MXC or vehicle for 20 days. Treated ovaries were subjected to immunohistochemistry for proliferating cell nuclear antigen (PCNA) staining. For in vitro studies, antral follicles isolated from adult cycling CD-1 mouse ovaries were cultured with vehicle, MXC, and/or NAC for 48, 72 and 96 h. Levels of cyclin D2 (Ccnd2) and cyclin dependent kinase 4 (Cdk4) were measured using in vivo and in vitro samples. The results indicate that MXC decreased PCNA staining, and Ccnd2 and Cdk4 levels compared to controls. NAC co-treatment restored follicle growth and expression of Ccnd2 and Cdk4. Collectively, these data indicate that MXC exposure reduces the levels of Ccnd2 and Cdk4 in follicles, and that protection from oxidative stress restores Ccnd2 and Cdk4 levels. Therefore, MXC-induced oxidative stress may decrease the levels of cell cycle regulators, which in turn, results in inhibition of the growth of antral follicles.

  11. Cell-permeable iron inhibits vascular endothelial growth factor receptor-2 signaling and tumor angiogenesis

    PubMed Central

    Kir, Devika; Saluja, Manju; Modi, Shrey; Venkatachalam, Annapoorna; Schnettler, Erica; Roy, Sabita; Ramakrishnan, Sundaram

    2016-01-01

    Angiogenesis is important for tumor growth and metastasis. Hypoxia in tumors drives this angiogenic response by stabilizing Hypoxia Inducible Factors (HIF) and target genes like Vascular Endothelial Growth Factor (VEGF). HIF stability is regulated by Prolylhydroxylases (PHD)-mediated modification. Iron is an important cofactor in regulating the enzymatic activity of PHDs. Reducing intracellular iron, for instance, mimics hypoxia and induces a pro-angiogenic response. It is hypothesized that increasing the intracellular iron levels will have an opposite, anti-angiogenic effect. We tested this hypothesis by perturbing iron homeostasis in endothelial cells using a unique form of iron, Ferric Ammonium Citrate (FAC). FAC is a cell-permeable form of iron, which can passively enter into cells bypassing the transferrin receptor mediated uptake of transferrin-bound iron. Our studies show that FAC does not decrease the levels of HIF-1α and HIF-2α in endothelial cells but inhibits the autocrine stimulation of VEGF-Vascular Endothelial Growth Factor Receptor-2 (VEGFR-2) system by blocking receptor tyrosine kinase phosphorylation. FAC inhibits VEGF-induced endothelial cell proliferation, migration, tube formation and sprouting. Finally, systemic administration of FAC inhibits VEGF and tumor cell-induced angiogenesis in vivo. In conclusion, our studies show that cell-permeable iron attenuates VEGFR-2 mediated signaling and inhibits tumor angiogenesis. PMID:27589831

  12. The Involvement of Gibberellins in 1,8-Cineole-Mediated Inhibition of Sprout Growth in Russet Burbank Tubers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The involvement of gibberellins in 1,8-cineole-mediated inhibition of tuber sprout growth was investigated in non-dormant field- and greenhouse-grown tubers of Russet Burbank. Continuous exposure of tubers to cineole in the vapor-phase resulted in a dose-dependent inhibition of sprout growth. Comp...

  13. Struvite crystal growth inhibition by trisodium citrate and the formation of chemical complexes in growth solution

    NASA Astrophysics Data System (ADS)

    Prywer, Jolanta; Mielniczek-Brzóska, Ewa; Olszynski, Marcin

    2015-05-01

    Effect of trisodium citrate on the crystallization of struvite was studied. To evaluate such an effect an experiment of struvite growth from artificial urine was performed. The investigations are related to infectious urinary stones formation. The crystallization process was induced by the addition of aqueous ammonia solution to mimic the bacterial activity. The spectrophotometric results demonstrate that trisodium citrate increases induction time with respect to struvite formation and decreases the growth efficiency of struvite. The inhibitory effect of trisodium citrate on the nucleation and growth of struvite is explained in base of chemical speciation analysis. Such an analysis demonstrates that the inhibitory effect is related with the fact that trisodium citrate binds NH4 + and Mg2+ ions in the range of pH from 7 to 9.5 characteristic for struvite precipitation. The most important is the MgCit- complex whose concentration strongly depends on an increase in pH rather than on an increase in citrate concentrations.

  14. A novel direct activator of AMPK inhibits prostate cancer growth by blocking lipogenesis

    PubMed Central

    Zadra, Giorgia; Photopoulos, Cornelia; Tyekucheva, Svitlana; Heidari, Pedram; Weng, Qing Ping; Fedele, Giuseppe; Liu, Hong; Scaglia, Natalia; Priolo, Carmen; Sicinska, Ewa; Mahmood, Umar; Signoretti, Sabina; Birnberg, Neal; Loda, Massimo

    2014-01-01

    5′AMP-activated kinase (AMPK) constitutes a hub for cellular metabolic and growth control, thus representing an ideal therapeutic target for prostate cancers (PCas) characterized by increased lipogenesis and activation of mTORC1 pathway. However, whether AMPK activation itself is sufficient to block cancer cell growth remains to be determined. A small molecule screening was performed and identified MT 63–78, a specific and potent direct AMPK activator. Here, we show that direct activation of AMPK inhibits PCa cell growth in androgen sensitive and castration resistant PCa (CRPC) models, induces mitotic arrest, and apoptosis. In vivo, AMPK activation is sufficient to reduce PCa growth, whereas the allelic loss of its catalytic subunits fosters PCa development. Importantly, despite mTORC1 blockade, the suppression of de novo lipogenesis is the underpinning mechanism responsible for AMPK-mediated PCa growth inhibition, suggesting AMPK as a therapeutic target especially for lipogenesis-driven PCas. Finally, we demonstrate that MT 63–78 enhances the growth inhibitory effect of AR signaling inhibitors MDV3100 and abiraterone. This study thus provides a rationale for their combined use in CRPC treatment. PMID:24497570

  15. All-trans-retinoic acid inhibits tumour growth of malignant pleural mesothelioma in mice.

    PubMed

    Tabata, C; Tabata, R; Hirayama, N; Yasumitsu, A; Yamada, S; Murakami, A; Iida, S; Tamura, K; Terada, T; Kuribayashi, K; Fukuoka, K; Nakano, T

    2009-11-01

    Malignant pleural mesothelioma (MPM) is an aggressive malignant tumour of mesothelial origin associated with asbestos exposure. Because MPM has limited response to conventional chemotherapy and radiotherapy, the prognosis is very poor. Several researchers have reported that cytokines such as interleukin (IL)-6 play an important role in the growth of MPM. Previously, it was reported that all-trans-retinoic acid (ATRA) inhibited the production and function of IL-6 and transforming growth factor (TGF)-beta1 in experiments using lung fibroblasts. We investigated whether ATRA had an inhibitory effect on the cell growth of MPM, the origin of which was mesenchymal cells similar to lung fibroblasts, using a subcutaneous xenograft mouse model. We estimated the tumour growth and performed quantitative measurements of IL-6, TGF-beta1 and platelet-derived growth factor (PDGF) receptor (PDGFR)-beta mRNA levels both of cultured MPM cells and cells grown in mice with or without the administration of ATRA. ATRA significantly inhibited MPM tumour growth. In vitro studies disclosed that the administration of ATRA reduced 1) mRNA levels of TGF-beta1, TGF-beta1 receptors and PDGFR-beta, and 2) TGF-beta1-dependent proliferation and PDGF-BB-dependent migration of MPM cells. These data may provide a rationale to explore the clinical use of ATRA for the treatment of MPM.

  16. [Inhibition of Bacillus coagulans growth in laboratory media and in fruit purees].

    PubMed

    Cerrutti, P; Alzamora, S M; de Huergo, M S

    2000-01-01

    The growth of two strains of B. coagulans was inhibited in laboratory media at pH < or = 4.5, and at water activity (aw) levels of 0.96 for B. coagulans NRS 609 and 0.95 for B. coagulans ATCC 803. The growth of both strains was also inhibited in apple and strawberry purees (pH = 3.5) stored at 37 degrees C for over two months. B. coagulans was able to grow in banana puree (pH approximately equal to 5.0) but acidification of the puree at pH = 3.5 was enough to prevent growth. The addition of up to 3,000 ppm vainillin ("natural" preservative) or 1,000 ppm potassium sorbate (traditional preservative) at pH higher than the inhibitory level previously determined could not prevent growth of B. coagulans in laboratory or in fruits, but 100 ppm lysozyme retarded growth in laboratory media at different pH levels (from 4.5 to 6.7) and in banana puree. As lysozyme showed to be effective at pH < or = 6.7, it might be used to prevent growth of B. coagulans at an eventual increment of pH during storage.

  17. Hepatocyte growth factor inhibition: a novel therapeutic approach in pancreatic cancer

    PubMed Central

    Pothula, Srinivasa P; Xu, Zhihong; Goldstein, David; Biankin, Andrew V; Pirola, Romano C; Wilson, Jeremy S; Apte, Minoti V

    2016-01-01

    Background: Pancreatic stellate cells (PSCs, which produce the stroma of pancreatic cancer (PC)) interact with cancer cells to facilitate PC growth. A candidate growth factor pathway that may mediate this interaction is the HGF–c-MET pathway. Methods: Effects of HGF inhibition (using a neutralising antibody AMG102) alone or in combination with gemcitabine were assessed (i) in vivo using an orthotopic model of PC, and (ii) in vitro using cultured PC cells (AsPC-1) and human PSCs. Results: We have shown that human PSCs (hPSCs) secrete HGF but do not express the receptor c-MET, which is present predominantly on cancer cells. HGF inhibition was as effective as standard chemotherapy in inhibiting local tumour growth but was significantly more effective than gemcitabine in reducing tumour angiogenesis and metastasis. HGF inhibition has resulted in reduced metastasis; however, interestingly this antimetastatic effect was lost when combined with gemcitabine. This suggests that gemcitabine treatment selects out a subpopulation of cancer cells with increased epithelial–mesenchymal transition (EMT) and stem-cell characteristics, as supported by our findings of increased expression of EMT and stem-cell markers in tumour sections from our animal model. In vitro studies showed that hPSC secretions induced proliferation and migration, but inhibited apoptosis, of cancer cells. These effects were countered by pretreatment of hPSC secretions with a HGF-neutralising antibody but not by gemcitabine, indicating a key role for HGF in PSC–PC interactions. Conclusions: Our studies suggest that targeted therapy to inhibit stromal–tumour interactions mediated by the HGF–c-MET pathway may represent a novel therapeutic approach in PC that will require careful modelling for optimal integration with existing treatment modalities. PMID:26766740

  18. Simultaneous Assessment of Acidogenesis-Mitigation and Specific Bacterial Growth-Inhibition by Dentifrices.

    PubMed

    Forbes, Sarah; Latimer, Joe; Sreenivasan, Prem K; McBain, Andrew J

    2016-01-01

    Dentifrices can augment oral hygiene by inactivating bacteria and at sub-lethal concentrations may affect bacterial metabolism, potentially inhibiting acidogenesis, the main cause of caries. Reported herein is the development of a rapid method to simultaneously measure group-specific bactericidal and acidogenesis-mitigation effects of dentifrices on oral bacteria. Saliva was incubated aerobically and anaerobically in Tryptone Soya Broth, Wilkins-Chalgren Broth with mucin, or artificial saliva and was exposed to dentifrices containing triclosan/copolymer (TD); sodium fluoride (FD); stannous fluoride and zinc lactate (SFD1); or stannous fluoride, zinc lactate and stannous chloride (SFD2). Minimum inhibitory concentrations (MIC) were determined turbidometrically whilst group-specific minimum bactericidal concentrations (MBC) were assessed using growth media and conditions selective for total aerobes, total anaerobes, streptococci and Gram-negative anaerobes. Minimum acid neutralization concentration (MNC) was defined as the lowest concentration of dentifrice at which acidification was inhibited. Differences between MIC and MNC were calculated and normalized with respect to MIC to derive the combined inhibitory and neutralizing capacity (CINC), a cumulative measure of acidogenesis-mitigation and growth inhibition. The overall rank order for growth inhibition potency (MIC) under aerobic and anaerobic conditions was: TD> SFD2> SFD1> FD. Acidogenesis-mitigation (MNC) was ordered; TD> FD> SFD2> SFD1. CINC was ordered TD> FD> SFD2> SFD1 aerobically and TD> FD> SFD1> SFD2 anaerobically. With respect to group-specific bactericidal activity, TD generally exhibited the greatest potency, particularly against total aerobes, total anaerobes and streptococci. This approach enables the rapid simultaneous evaluation of acidity mitigation, growth inhibition and specific antimicrobial activity by dentifrices.

  19. Simultaneous Assessment of Acidogenesis-Mitigation and Specific Bacterial Growth-Inhibition by Dentifrices

    PubMed Central

    Forbes, Sarah; Latimer, Joe; Sreenivasan, Prem K.; McBain, Andrew J.

    2016-01-01

    Dentifrices can augment oral hygiene by inactivating bacteria and at sub-lethal concentrations may affect bacterial metabolism, potentially inhibiting acidogenesis, the main cause of caries. Reported herein is the development of a rapid method to simultaneously measure group-specific bactericidal and acidogenesis-mitigation effects of dentifrices on oral bacteria. Saliva was incubated aerobically and anaerobically in Tryptone Soya Broth, Wilkins-Chalgren Broth with mucin, or artificial saliva and was exposed to dentifrices containing triclosan/copolymer (TD); sodium fluoride (FD); stannous fluoride and zinc lactate (SFD1); or stannous fluoride, zinc lactate and stannous chloride (SFD2). Minimum inhibitory concentrations (MIC) were determined turbidometrically whilst group-specific minimum bactericidal concentrations (MBC) were assessed using growth media and conditions selective for total aerobes, total anaerobes, streptococci and Gram-negative anaerobes. Minimum acid neutralization concentration (MNC) was defined as the lowest concentration of dentifrice at which acidification was inhibited. Differences between MIC and MNC were calculated and normalized with respect to MIC to derive the combined inhibitory and neutralizing capacity (CINC), a cumulative measure of acidogenesis-mitigation and growth inhibition. The overall rank order for growth inhibition potency (MIC) under aerobic and anaerobic conditions was: TD> SFD2> SFD1> FD. Acidogenesis-mitigation (MNC) was ordered; TD> FD> SFD2> SFD1. CINC was ordered TD> FD> SFD2> SFD1 aerobically and TD> FD> SFD1> SFD2 anaerobically. With respect to group-specific bactericidal activity, TD generally exhibited the greatest potency, particularly against total aerobes, total anaerobes and streptococci. This approach enables the rapid simultaneous evaluation of acidity mitigation, growth inhibition and specific antimicrobial activity by dentifrices. PMID:26882309

  20. Peptides of Matrix Gla protein inhibit nucleation and growth of hydroxyapatite and calcium oxalate monohydrate crystals.

    PubMed

    Goiko, Maria; Dierolf, Joshua; Gleberzon, Jared S; Liao, Yinyin; Grohe, Bernd; Goldberg, Harvey A; de Bruyn, John R; Hunter, Graeme K

    2013-01-01

    Matrix Gla protein (MGP) is a phosphorylated and γ-carboxylated protein that has been shown to prevent the deposition of hydroxyapatite crystals in the walls of blood vessels. MGP is also expressed in kidney and may inhibit the formation of kidney stones, which mainly consist of another crystalline phase, calcium oxalate monohydrate. To determine the mechanism by which MGP prevents soft-tissue calcification, we have synthesized peptides corresponding to the phosphorylated and γ-carboxylated sequences of human MGP in both post-translationally modified and non-modified forms. The effects of these peptides on hydroxyapatite formation and calcium oxalate crystallization were quantified using dynamic light scattering and scanning electron microscopy, respectively. Peptides YGlapS (MGP1-14: YγEpSHEpSMEpSYELNP), YEpS (YEpSHEpSMEpSYELNP), YGlaS (YγESHESMESYELNP) and SK-Gla (MGP43-56: SKPVHγELNRγEACDD) inhibited formation of hydroxyapatite in order of potency YGlapS > YEpS > YGlaS > SK-Gla. The effects of YGlapS, YEpS and YGlaS on hydroxyapatite formation were on both crystal nucleation and growth; the effect of SK-Gla was on nucleation. YGlapS and YEpS significantly inhibited the growth of calcium oxalate monohydrate crystals, while simultaneously promoting the formation of calcium oxalate dihydrate. The effects of these phosphopeptides on calcium oxalate monohydrate formation were on growth of crystals rather than nucleation. We have shown that the use of dynamic light scattering allows inhibitors of hydroxyapatite nucleation and growth to be distinguished. We have also demonstrated for the first time that MGP peptides inhibit the formation of calcium oxalate monohydrate. Based on the latter finding, we propose that MGP function not only to prevent blood-vessel calcification but also to inhibit stone formation in kidney.

  1. α-Tomatine inhibits growth and induces apoptosis in HL-60 human myeloid leukemia cells.

    PubMed

    Huang, Huarong; Chen, Shaohua; Van Doren, Jeremiah; Li, Dongli; Farichon, Chelsea; He, Yan; Zhang, Qiuyan; Zhang, Kun; Conney, Allan H; Goodin, Susan; Du, Zhiyun; Zheng, Xi

    2015-06-01

    α‑Tomatine is a glycoalkaloid that occurs naturally in tomatoes (Lycopersicon esculentum). In the present study, the effects of α‑tomatine on human myeloid leukemia HL‑60 cells were investigated. Treatment of HL‑60 cells with α‑tomatine resulted in growth inhibition and apoptosis in a concentration‑dependent manner. Tomatidine, the aglycone of tomatine had little effect on the growth and apoptosis of HL‑60 cells. Growth inhibition and apoptosis induced by α‑tomatine in HL‑60 cells was partially abrogated by addition of cholesterol indicating that interactions between α‑tomatine and cell membrane‑associated cholesterol may be important in mediating the effect of α‑tomatine. Activation of nuclear factor‑κB by the phorbol ester, 12‑O‑tetradecanoylphorbol‑13‑acetate failed to prevent apoptosis in HL‑60 cells treated with α‑tomatine. In animal experiments, it was found that treatment of mice with α‑tomatine inhibited the growth of HL‑60 xenografts in vivo. Results from the present study indicated that α‑tomatine may have useful anti‑leukemia activities.

  2. INHIBITION OF RHABDOMYOSARCOMA CELL AND TUMOR GROWTH BY TARGETING SPECIFICITY PROTEIN (Sp) TRANSCRIPTION FACTORS

    PubMed Central

    Chadalapaka, Gayathri; Jutooru, Indira; Sreevalsan, Sandeep; Pathi, Satya; Kim, Kyounghyun; Chen, Candy; Crose, Lisa; Linardic, Corinne; Safe, Stephen

    2012-01-01

    Specificity protein (Sp) transcription factors Sp1, Sp3 and Sp4 are highly expressed in rhabdomyosarcoma (RMS) cells. In tissue arrays of RMS tumor cores from 71 patients, 80% of RMS patients expressed high levels of Sp1 protein, whereas low expression of Sp1 was detected in normal muscle tissue. The non-steroidal anti-inflammatory drug (NSAID) tolfenamic acid (TA) inhibited growth and migration of RD and RH30 RMS cell lines and also inhibited tumor growth in vivo using a mouse xenograft (RH30 cells) model. The effects of TA were accompanied by downregulation of Sp1, Sp3, Sp4 and Sp-regulated genes in RMS cells and tumors, and the role of Sp protein downregulation in mediating inhibition of RD and RH30 cell growth and migration was confirmed by individual and combined knockdown of Sp1, Sp3 and Sp4 proteins by RNA interference. TA treatment and Sp knockdown in RD and RH30 cells also showed that four genes that are emerging as individual drug targets for treating RMS, namely c-MET, insulin-like growth factor receptor (IGFR), PDGFRα and CXCR4, are also Sp-regulated genes. These results suggest that NSAIDs such as TA may have potential clinical efficacy in drug combinations for treating RMS patients. PMID:22815231

  3. A Flagellar Glycan-Specific Protein Encoded by Campylobacter Phages Inhibits Host Cell Growth

    PubMed Central

    Javed, Muhammad Afzal; Sacher, Jessica C.; van Alphen, Lieke B.; Patry, Robert T.; Szymanski, Christine M.

    2015-01-01

    We previously characterized a carbohydrate binding protein, Gp047, derived from lytic Campylobacter phage NCTC 12673, as a promising diagnostic tool for the identification of Campylobacter jejuni and Campylobacter coli. We also demonstrated that this protein binds specifically to acetamidino-modified pseudaminic acid residues on host flagella, but the role of this protein in the phage lifecycle remains unknown. Here, we report that Gp047 is capable of inhibiting C. jejuni growth both on solid and liquid media, an activity, which we found to be bacteriostatic. The Gp047 domain responsible for bacterial growth inhibition is localized to the C-terminal quarter of the protein, and this activity is both contact- and dose-dependent. Gp047 gene homologues are present in all Campylobacter phages sequenced to date, and the resulting protein is not part of the phage particle. Therefore, these results suggest that either phages of this pathogen have evolved an effector protein capable of host-specific growth inhibition, or that Campylobacter cells have developed a mechanism of regulating their growth upon sensing an impending phage threat. PMID:26694450

  4. α-tomatine inhibits growth and induces apoptosis in HL-60 human myeloid leukemia cells

    PubMed Central

    HUANG, HUARONG; CHEN, SHAOHUA; VAN DOREN, JEREMIAH; LI, DONGLI; FARICHON, CHELSEA; HE, YAN; ZHANG, QIUYAN; ZHANG, KUN; CONNEY, ALLAN H; GOODIN, SUSAN; DU, ZHIYUN; ZHENG, XI

    2015-01-01

    α-tomatine is a glycoalkaloid that occurs naturally in tomatoes (Lycopersicon esculentum). In the present study, the effects of α-tomatine on human myeloid leukemia HL-60 cells were investigated. Treatment of HL-60 cells with α-tomatine resulted in growth inhibition and apoptosis in a concentration-dependent manner. Tomatidine, the aglycone of tomatine had little effect on the growth and apoptosis of HL-60 cells. Growth inhibition and apoptosis induced by α-tomatine in HL-60 cells was partially abrogated by addition of cholesterol indicating that interactions between α-tomatine and cell membrane-associated cholesterol may be important in mediating the effect of α-tomatine. Activation of nuclear factor-κB by the phorbol ester, 12-O-tetradecanoylphorbol-13-acetate failed to prevent apoptosis in HL-60 cells treated with α-tomatine. In animal experiments, it was found that treatment of mice with α-tomatine inhibited the growth of HL-60 xenografts in vivo. Results from the present study indicated that α-tomatine may have useful anti-leukemia activities. PMID:25625536

  5. Protein turnover and cellular autophagy in growing and growth-inhibited 3T3 cells

    SciTech Connect

    Papadopoulos, T.; Pfeifer, U. )

    1987-07-01

    The relationship between growth, protein degradation, and cellular autophagy was tested in growing and in growth-inhibited 3T3 cell monolayers. For the biochemical evaluation of DNA and protein metabolism, growth-inhibited 3T3 cell monolayers with high cell density and growing 3T3 cell monolayers with low cell density were labeled simultaneously with ({sup 14}C)thymidine and ({sup 3}H)leucine. The evaluation of the DNA turnover and additional ({sup 3}H)thymidine autoradiography showed that 24 to 5% of 3T3 cells continue to replicate even in the growth-inhibited state, where no accumulation of protein and DNA can be observed. Cell loss, therefore, has to be assumed to compensate for the ongoing cell proliferation. When the data of protein turnover were corrected for cell loss, it was found that the rate constant of protein synthesis in nongrowing monolayers was reduced to half the value found in growing monolayers. Simultaneously, the rate constant of protein degradation in nongrowing monolayers was increased to about 1.5-fold the value of growing monolayers. These data are in agreement with the assumption that cellular autophagy represents a major pathway of regulating protein degradation in 3T3 cells and that the regulation of autophagic protein degradation is of relevance for the transition from a growing to a nongrowing state.

  6. TQ inhibits hepatocellular carcinoma growth in vitro and in vivo via repression of Notch signaling

    PubMed Central

    Ke, Xiquan; Zhao, Yan; Lu, Xinlan; Wang, Zhe; Liu, Yuanyuan; Ren, Mudan; Lu, Guifang; Zhang, Dan; Sun, Zhenguo; Xu, Zhipeng; Song, Jee Hoon; Cheng, Yulan; Meltzer, Stephen J.; He, Shuixiang

    2015-01-01

    Thymoquinone (TQ) has been reported to possess anti-tumor activity in various types of cancer. However, its effects and molecular mechanism of action in hepatocellular carcinoma (HCC) are still not completely understood. We observed that TQ inhibited tumor cell growth in vitro, where treatment with TQ arrested the cell cycle in G1 by upregulating p21 and downregulating cyclinD1 and CDK2 expression; moreover, TQ induced apoptosis by decreasing expression of Bcl-2 and increasing expression of Bax. Simultaneously, TQ demonstrated a suppressive impact on the Notch pathway, where overexpression of NICD1 reversed the inhibitory effect of TQ on cell proliferation, thereby attenuating the repressive effects of TQ on the Notch pathway, cyclinD1, CDK2 and Bcl-2, and also diminishing upregulation of p21 and Bax. In a xenograft model, TQ inhibited HCC growth in nude mice; this inhibitory effect in vivo, as well as of HCC cell growth in vitro, was associated with a discernible decline in NICD1 and Bcl-2 levels and a dramatic rise in p21 expression. In conclusion, TQ inhibits HCC cell growth by inducing cell cycle arrest and apoptosis, achieving these effects by repression of the Notch signaling pathway, suggesting that TQ represents a potential preventive or therapeutic agent in HCC patients. PMID:26416455

  7. Growth inhibition of struvite crystals in the presence of herbal extract Commiphora wightii.

    PubMed

    Chauhan, C K; Joshi, M J; Vaidya, A D B

    2009-12-01

    Struvite is one of the components of urinary stone. Large number of people is suffering from urinary stones (calculi) problem all over the globe. These stones can grow rapidly forming "staghorn-calculi", which is more painful urological disorder. Therefore, it is of prime importance to study the growth and inhibition of Struvite crystals. This in vitro study has been carried out in the presence of herbal extract of Commiphora wightii by using single diffusion gel growth technique. Sodium metasilicate solution of specific gravity 1.05 and an aqueous solution of ammonium dihydrogen phosphate of 0.5 M concentration were mixed so that the pH value 7.0 could be set. After the gelation, equal amount of supernatant solutions comprising of pure 1.0 M magnesium acetate as well as the mixtures of magnesium acetate and the herbal extract solutions of 0.5 and 1% concentrations of C. wightii were gently poured on the set gels. From the study of growth and inhibition behavior of Struvite crystals, it was found that C. wightii inhibits the growth of the Struvite. This study incorporates multidisciplinary interests and may be used for formulating the strategy for prevention or dissolution of urinary stones.

  8. Inhibition of Yeast Growth by Octanoic and Decanoic Acids Produced during Ethanolic Fermentation

    PubMed Central

    Viegas, Cristina A.; Rosa, M. Fernanda; Sá-Correia, Isabel; Novais, Júlio M.

    1989-01-01

    The inhibition of growth by octanoic or decanoic acids, two subproducts of ethanolic fermentation, was evaluated in Saccharomyces cerevisiae and Kluyveromyces marxianus in association with ethanol, the main product of fermentation. In both strains, octanoic and decanoic acids, at concentrations up to 16 and 8 mg/liter, respectively, decreased the maximum specific growth rate and the biomass yield at 30°C as an exponential function of the fatty acid concentration and increased the duration of growth latency. These toxic effects increased with a decrease in pH in the range of 5.4 to 3.0, indicating that the undissociated form is the toxic molecule. Decanoic acid was more toxic than octanoic acid. The concentrations of octanoic and decanoic acids were determined during the ethanolic fermentation (30°C) of two laboratory media (mineral and complex) by S. cerevisiae and of Jerusalem artichoke juice by K. marxianus. Based on the concentrations detected (0.7 to 23 mg/liter) and the kinetics of growth inhibition, the presence of octanoic and decanoic acids cannot be ignored in the evaluation of the overall inhibition of ethanolic fermentation. PMID:16347826

  9. A cortical astrocyte subpopulation inhibits axon growth in vitro and in vivo.

    PubMed

    Liu, Rui; Wang, Zhe; Gou, Lin; Xu, Hanpeng

    2015-08-01

    Astrocytes are the most heterogeneous and predominant glial cell type in the central nervous system. However, the functional significance of this heterogeneity remains to be elucidated. Following injury, damaged astrocytes inhibit axonal regeneration in vivo and in vitro. Cultured primary astrocytes are commonly considered good supportive substrates for neuron attachment and axon regeneration. However, it is not known whether different populations of cells in the heterogeneous astrocyte culture affect neuron behavior in the same way. In the present study, the effect of astrocyte heterogeneity on neuronal attachment and neurite outgrowth was examined using an in vitro and in vivo coculture system. In vitro, neonatal cortical astrocytes were co-cultured with purified dorsal root ganglia (DRG) neurons and astrocyte growth morphology, neuron attachment and neurite growth were evaluated. The results demonstrated that the heterogeneous astrocyte cells showed two different types of growth pattern, typical and atypical. Typical astrocytes were supportive to neuron attachment and neurite growth, which was consistent with previous studies, whereas atypical astrocytes inhibited neuron attachment and neurite growth. These inhibitory astrocytes exhibited a special growth pattern with various shapes and sizes, a high cell density, few oligodendrocytes on the top layer and occupied a smaller growth area compared with typical astrocytes. Neurites extended freely on typical supportive astrocyte populations, however, moved away when they reached atypical astrocyte growth pattern. Neurons growing on the atypical astrocyte pattern demonstrated minimal neurite outgrowth and these neurites had a dystrophic appearance, however, neuronal survival was unaffected. Immunocytochemistry studies demonstrated that these atypical inhibitory astrocytes were glial fibrillary acidic protein (GFAP) positive cells. The existence of inhibitory astrocyte subpopulations in normal astrocytes reflects the

  10. Epidermal growth factor receptor endocytic traffic perturbation by phosphatidate phosphohydrolase inhibition: new strategy against cancer.

    PubMed

    Shaughnessy, Ronan; Retamal, Claudio; Oyanadel, Claudia; Norambuena, Andrés; López, Alejandro; Bravo-Zehnder, Marcela; Montecino, Fabian J; Metz, Claudia; Soza, Andrea; González, Alfonso

    2014-05-01

    Epidermal growth factor receptor (EGFR) exaggerated (oncogenic) function is currently targeted in cancer treatment with drugs that block receptor ligand binding or tyrosine kinase activity. Because endocytic trafficking is a crucial regulator of EGFR function, its pharmacological perturbation might provide a new anti-tumoral strategy. Inhibition of phosphatidic acid (PA) phosphohydrolase (PAP) activity has been shown to trigger PA signaling towards type 4 phosphodiesterase (PDE4) activation and protein kinase A inhibition, leading to internalization of empty/inactive EGFR. Here, we used propranolol, its l- and d- isomers and desipramine as PAP inhibitors to further explore the effects of PAP inhibition on EGFR endocytic trafficking and its consequences on EGFR-dependent cancer cell line models. PAP inhibition not only made EGFR inaccessible to stimuli but also prolonged the signaling lifetime of ligand-activated EGFR in recycling endosomes. Strikingly, such endocytic perturbations applied in acute/intermittent PAP inhibitor treatments selectively impaired cell proliferation/viability sustained by an exaggerated EGFR function. Phospholipase D inhibition with FIPI (5-fluoro-2-indolyl des-chlorohalopemide) and PDE4 inhibition with rolipram abrogated both the anti-tumoral and endocytic effects of PAP inhibition. Prolonged treatments with a low concentration of PAP inhibitors, although without detectable endocytic effects, still counteracted cell proliferation, induced apoptosis and decreased anchorage-independent growth of cells bearing EGFR oncogenic influences. Overall, our results show that PAP inhibitors can counteract EGFR oncogenic traits, including receptor overexpression or activating mutations resistant to current tyrosine kinase inhibitors, perturbing EGFR endocytic trafficking and perhaps other as yet unknown processes, depending on treatment conditions. This puts PAP activity forward as a new suitable target against EGFR-driven malignancy.

  11. Cyclosporin A inhibits colon cancer cell growth independently of the calcineurin pathway

    PubMed Central

    Werneck, Miriam B.F.; Hottz, Eugênio; Bozza, Patrícia T.; Viola, João P.B.

    2012-01-01

    Chronic inflammation is a risk factor for the development of colon cancer, providing genotoxic insults, growth and pro-angiogenic factors that can promote tumorigenesis and tumor growth. Immunomodulatory agents can interfere with the inflammation that feeds cancer, but their impact on the transformed cell is poorly understood. The calcium/calcineurin signaling pathway, through activation of NFAT, is essential for effective immune responses, and its inhibitors cyclosporin A (CsA) and FK506 are used in the clinics to suppress immunity. Moreover, the kinases GSK3β and mTOR, modulated by PI-3K/Akt, can inhibit NFAT activity, suggesting a cross-talk between the calcium and growth factor signaling pathways. Both NFAT and mTOR activity have been associated with tumorigenesis. We therefore investigated the impact of calcineurin and PI-3K/mTOR inhibition in growth of human colon carcinoma cells. We show that despite the efficient inhibition of NFAT1 activity, FK506 promotes tumor growth, whereas CsA inhibits it due to a delay in cell cycle progression and induction of necroptosis. We found NFκB activation and mTORC1 activity not to be altered by CsA or FK506. Similarly, changes to mitochondrial homeostasis were equivalent upon treatment with these drugs. We further show that, in our model, NFAT1 activation is not modulated by PI3K/mTOR. We conclude that CsA slows cell cycle progression and induces necroptosis of human carcinoma cell lines in a TGFβ-, NFAT-, NFκB- and PI3K/mTOR-independent fashion. Nevertheless, our data suggest that CsA, in addition to its anti-inflammatory capacity, may target transformed colon and esophagus carcinoma cells without affecting non-transformed cells, promoting beneficial tumoristatic effects. PMID:22992618

  12. Feeding inhibition explains effects of imidacloprid on the growth, maturation, reproduction, and survival of Daphnia magna.

    PubMed

    Agatz, Annika; Cole, Tabatha A; Preuss, Thomas G; Zimmer, Elke; Brown, Colin D

    2013-03-19

    Effects of some xenobiotics on aquatic organisms might not be caused directly by the compound but rather arise from acclimation of the organism to stress invoked by feeding inhibition during exposure. Experiments were conducted to identify effects of imidacloprid on individual performance (feeding, growth, maturation, reproduction, and survival) of Daphnia magna under surplus and reduced food availability. Concentrations inhibiting feeding by 5, 50, and 95% after one day of exposure were 0.19, 1.83, and 8.70 mg/L, respectively. Exposure with imidacloprid at ≥ 3.7 mg/L reduced growth by up to 53 ± 11% within one week. Surplus food availability after inhibition allowed recovery from this growth inhibition, whereas limited food supply eliminated the potential for recovery in growth even for exposure at 0.15 mg/L. A shift in the distribution of individual energy reserves toward reproduction rather than growth resulted in increased reproduction after exposure to concentrations ≤ 0.4 mg/L. Exposure to imidacloprid at ≥ 4.0 mg/L overwhelmed this adaptive response and reduced reproduction by up to 57%. We used the individual based Daphnia magna population model IDamP as a virtual laboratory to demonstrate that only feeding was affected by imidacloprid, and that in turn this caused the other impacts on individual performance. Consideration of end points individually would have led to a different interpretation of the effects. Thus, we demonstrate how multiple lines of evidence linked by understanding the ecology of the organism are necessary to elucidate xenobiotic impacts along the effect cascade.

  13. MicroRNA-375 inhibits colorectal cancer growth by targeting PIK3CA

    SciTech Connect

    Wang, Yihui; Tang, Qingchao; Li, Mingqi; Jiang, Shixiong; Wang, Xishan

    2014-02-07

    Highlights: • miR-375 is downregulated in colorectal cancer cell lines and tissues. • miR-375 inhibits colorectal cancer cell growth by targeting PIK3CA. • miR-375 inhibits colorectal cancer cell growth in xenograft nude mice model. - Abstract: Colorectal cancer (CRC) is the second most common cause of death from cancer. MicroRNAs (miRNAs) represent a class of small non-coding RNAs that control gene expression by triggering RNA degradation or interfering with translation. Aberrant miRNA expression is involved in human disease including cancer. Herein, we showed that miR-375 was frequently down-regulated in human colorectal cancer cell lines and tissues when compared to normal human colon tissues. PIK3CA was identified as a potential miR-375 target by bioinformatics. Overexpression of miR-375 in SW480 and HCT15 cells reduced PIK3CA protein expression. Subsequently, using reporter constructs, we showed that the PIK3CA untranslated region (3′-UTR) carries the directly binding site of miR-375. Additionally, miR-375 suppressed CRC cell proliferation and colony formation and led to cell cycle arrest. Furthermore, miR-375 overexpression resulted in inhibition of phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. SiRNA-mediated silencing of PIK3CA blocked the inhibitory effect of miR-375 on CRC cell growth. Lastly, we found overexpressed miR-375 effectively repressed tumor growth in xenograft animal experiments. Taken together, we propose that overexpression of miR-375 may provide a selective growth inhibition for CRC cells by targeting PI3K/Akt signaling pathway.

  14. Genistein Exposure Inhibits Growth and Alters Steroidogenesis in Adult Mouse Antral Follicles

    PubMed Central

    Patel, Shreya; Peretz, Jackye; Pan, Yuan-Xiang; Helferich, William G.; Flaws, Jodi A.

    2016-01-01

    Genistein is a naturally occurring isoflavone phytoestrogen commonly found in plant products such as soybeans, lentils, and chickpeas. Genistein, like other phytoestrogens, has the potential to mimic, enhance, or impair the estradiol biosynthesis pathway, thereby potentially altering ovarian follicle growth. Previous studies have inconsistently indicated that genistein exposure may alter granulosa cell proliferation and hormone production, but no studies have examined the effects of genistein on intact antral follicles. Thus, this study was designed to test the hypothesis that genistein exposure inhibits follicle growth and steroidogenesis in intact antral follicles. To test this hypothesis, antral follicles isolated from CD-1 mice were cultured with vehicle (dimethyl sulfoxide; DMSO) or genistein (6.0 and 36 μM) for 18 – 96 hours (h). Every 24 h, follicle diameters were measured to assess growth. At the end of each culture period, the media were pooled to measure hormone levels, and the cultured follicles were collected to measure expression of cell cycle regulators and steroidogenic enzymes. The results indicate that genistein (36 μM) inhibits growth of mouse antral follicles. Additionally, genistein (6.0 and 36 μM) increases progesterone, testosterone, and dehydroepiandrosterone (DHEA) levels, but decreases estrone and estradiol levels. The results also indicate that genistein alters the expression of steroidogenic enzymes at 24, 72 and 96 h, and the expression of cell cycle regulators at 18 h. These data indicate that genistein exposure inhibits antral follicle growth by inhibiting the cell cycle, alters sex steroid hormone levels, and dysregulates steroidogenic enzymes in cultured mouse antral follicles. PMID:26792615

  15. A practical in vitro growth inhibition assay for the evaluation of TB vaccines.

    PubMed

    Kolibab, Kristopher; Parra, Marcela; Yang, Amy L; Perera, Liyanage P; Derrick, Steven C; Morris, Sheldon L

    2009-12-11

    New vaccines and novel immunization strategies are needed to improve the control of the global tuberculosis epidemic. To facilitate vaccine development, we have been creating in vitro mycobacterial intra-macrophage growth inhibition assays. Here we describe the development of an in vitro assay designed for BSL-2 laboratories which measures the capacity of vaccine-induced immune splenocytes to control the growth of isoniazid-resistant Mycobacterium bovis BCG (INH(r) BCG). The use of the INH(r) BCG as the infecting organism allows the discrimination of BCG bacilli used in murine vaccinations from BCG used in the in vitro assay. In this study, we showed that protective immune responses evoked by four different types of Mycobacterium tuberculosis vaccines [BCG, an ESAT6/Antigen 85B fusion protein formulated in DDA/MPL adjuvant, a DNA vaccine expressing the same fusion protein, and a TB Modified Vaccinia Ankara construct expressing four TB antigens (MVA-4TB)] were detected. Importantly, the levels of vaccine-induced protective immunity seen in the in vitro assay correlated with the results from in vivo protection studies in the mouse model of pulmonary tuberculosis. Furthermore, the growth inhibition data for the INH(r) BCG assay was similar to the previously reported results for a M. tuberculosis infection assay. The cytokine expression profiles at day 7 of the INH(r) BCG growth inhibition studies were also similar but not identical to the cytokine patterns detected in earlier M. tuberculosis co-culture assays. Overall, we have shown that a BSL-2 compatible in vitro growth inhibition assay using INH(r) BCG as the intra-macrophage target organism should be useful in developing and evaluating new TB immunization strategies.

  16. Inhibition of DNA topoisomerases I and II and growth inhibition of HL-60 cells by novel acridine-based compounds.

    PubMed

    Janočková, Jana; Plšíková, Jana; Kašpárková, Jana; Brabec, Viktor; Jendželovský, Rastislav; Mikeš, Jaromír; Kovaľ, Ján; Hamuľaková, Slávka; Fedoročko, Peter; Kuča, Kamil; Kožurková, Mária

    2015-08-30

    HL-60 cancer cells were treated with a series of novel acridine derivatives (derivatives 1-4) in order to test the compounds' ability to inhibit both cancer cell growth and topoisomerase I and II activity. Binding studies of derivatives 1-4 with calf thymus DNA were also performed using a number of techniques (UV-Vis and fluorescence spectroscopy, thermal denaturation, linear dichroism and viscometry) to determine the nature of the interaction between the compounds and ctDNA. The binding constants for the complexes of the studied acridine derivatives with DNA were calculated from UV-Vis spectroscopic titrations (K=3.1×10(4)-2.0×10(3)M(-1)). Some of the compounds showed a strong inhibitory effect against Topo II at the relatively low concentration of 5μM. Topo I/II inhibition mode assays were also performed and verified that the novel compounds are topoisomerase suppressors rather than poisons. The biological activities of derivatives were studied using MTT assay and flow cytometric methods (detection of mitochondrial membrane potential, measurement of cell viability) after 24 and 48h incubation. The ability of derivatives to impair cell proliferation was tested by an analysis of cell cycle distribution.

  17. MiR-34a inhibits colon cancer proliferation and metastasis by inhibiting platelet-derived growth factor receptor α.

    PubMed

    Li, Chunyan; Wang, Yulin; Lu, Shuming; Zhang, Zhuqing; Meng, Hua; Liang, Lina; Zhang, Yan; Song, Bo

    2015-11-01

    The microRNA (miRNA), miR‑34a is significant in colon cancer progression. In the present study, the role of miR‑34a in colon cancer cell proliferation and metastasis was investigated. It was found that the expression of miR‑34a in colon cancer tissues and cell lines was lower when compared with that of normal tissues and cells. Further research demonstrated that miR‑34a inhibited cell proliferation, induced G1 phase arrest, and suppressed metastasis and epithelial mesenchymal transition in colon cancer cells. Bioinformatic prediction indicated that platelet‑derived growth factor receptor α (PDGFRA) was a potential target gene of miR‑34a and a luciferase assay identified that PDGFRA was a novel direct target gene of miR‑34a. In addition, assays of western blot analyses and quantitative reverse‑transcription polymerase chain reaction confirmed that miR‑34a decreased PDGFRA mRNA expression and protein levels in colon cancer cells. Assessment of cellular function indicated that miR‑34a inhibited colon cancer progression via PDGFRA. These findings demonstrate that miR‑34a may act as a negative regulator in colon cancer by targeting PDGFRA.

  18. Nimbolide inhibits pancreatic cancer growth and metastasis through ROS-mediated apoptosis and inhibition of epithelial-to-mesenchymal transition

    PubMed Central

    Subramani, Ramadevi; Gonzalez, Elizabeth; Arumugam, Arunkumar; Nandy, Sushmita; Gonzalez, Viviana; Medel, Joshua; Camacho, Fernando; Ortega, Andrew; Bonkoungou, Sandrine; Narayan, Mahesh; Dwivedi, Alok kumar; Lakshmanaswamy, Rajkumar

    2016-01-01

    The mortality and morbidity rates of pancreatic cancer are high because of its extremely invasive and metastatic nature. Its lack of symptoms, late diagnosis and chemo–resistance and the ineffective treatment modalities warrant the development of new chemo–therapeutic agents for pancreatic cancer. Agents from medicinal plants have demonstrated therapeutic benefits in various human cancers. Nimbolide, an active molecule isolated from Azadirachta indica, has been reported to exhibit several medicinal properties. This study assessed the anticancer properties of nimbolide against pancreatic cancer. Our data reveal that nimbolide induces excessive generation of reactive oxygen species (ROS), thereby regulating both apoptosis and autophagy in pancreatic cancer cells. Experiments with the autophagy inhibitors 3-methyladenine and chloroquine diphosphate salt and the apoptosis inhibitor z-VAD-fmk demonstrated that nimbolide-mediated ROS generation inhibited proliferation (through reduced PI3K/AKT/mTOR and ERK signaling) and metastasis (through decreased EMT, invasion, migration and colony forming abilities) via mitochondrial-mediated apoptotic cell death but not via autophagy. In vivo experiments also demonstrated that nimbolide was effective in inhibiting pancreatic cancer growth and metastasis. Overall, our data suggest that nimbolide can serve as a potential chemo–therapeutic agent for pancreatic cancer. PMID:26804739

  19. Research on inhibitive behaviors of electrolysis on the growth of Microcystis aeruginosa.

    PubMed

    Xu, Y F; Yang, J; Ou, M M; Wang, Y L; Jia, J P; Pan, H D

    2006-06-01

    Electrochemical method using a novel Ti/RuO2 anode was employed to inhibit a typical cyanobacteria, Microcystis aeruginosa (M. aeruginosa) under different electrolytic conditions. It is demonstrated that Ti/RuO2 anode was more efficient than traditional graphite anode in M. aeruginosa inhibition. The experimental results showed that the higher current density or longer electrolytic time could effectively improve the inhibition of M. aeruginosa. In addition, sodium chloride was a more effective electrolyte than sodium sulfate to enhance inhibition. The maximum inhibiting rate dose to 100% could be obtained at a current density of 12 mA cm(-2) when sodium chloride was used as a supporting electrolyte. Furthermore, UV-Visible spectra demonstrated that the structures of phycocyanins and chlorophyll a (Chl a) in M. aeruginosa could be changed or destroyed during electrolysis. Moreover, EPR spectra showed the generation of the free radicals through electrolysis, which might be one of the reasons responsible for the inhibition of algal growth.

  20. Interaction of CdSe/ZnS quantum dots with the marine diatom Phaeodactylum tricornutum and the green alga Dunaliella tertiolecta: a biophysical approach.

    PubMed

    Morelli, Elisabetta; Salvadori, Elisa; Bizzarri, Ranieri; Cioni, Patrizia; Gabellieri, Edi

    2013-12-01

    In this study, we investigated the interaction of nanoparticles, such as CdSe/ZnS quantum dots (QDs), with the marine diatom Phaeodactylum tricornutum and the green alga Dunaliella tertiolecta, as biological models in the marine environment. Fluorescence kinetics measurements indicated that 30min after dispersion in seawater QDs lost the 60% of the initial emission intensity, possibly due to the occurrence of aggregation processes. However, the presence of algae seemed to mitigate this effect. By using confocal microscopy, we highlighted the presence of QDs adsorbed on the surface of both algae, but not inside the cells. The toxicity of QDs was evaluated in terms of inhibition of growth rate, oxidative stress, and lipid peroxidation. QDs in the range of 1-2.5nM gradually inhibited the growth rate of P. tricornutum and increased the oxidative stress, as evinced by the increase in lipid peroxidation, reactive oxygen species (ROS) production and activity of two main antioxidant enzymes (superoxide dismutase and catalase). On the contrary, QDs did not inhibit the growth rate of D. tertiolecta, at most a modest stimulation was observed in the range of 0.5-2nM, suggesting a hormetic response. No effect in the parameters indicating oxidative stress was observed in the green alga. In conclusion our results showed that the biological effects were species-specific.

  1. Impact of ultraviolet-B radiation on photosystem II activity and its relationship to the inhibition of carbon fixation rates for antarctic ice algae communities

    SciTech Connect

    Schofield, O.; Prezelin, B.B.; Kroon, B.M.A.

    1995-10-01

    One goal of the Icecolors 1993 study was to determine whether or not photosystem II (PSII) was a major target site for photoinhibition by ultraviolet-B radiation (Q{sub UVB}, 280-320 nm) in natural communities. Second, the degree to which Q{sub UVB} inhibition of PSII could account for Q{sub UVB} effects on whole cell rates of carbon fixation in phytoplankton was assessed. On 1 October, 1993, at Palmer Station (Antarctica), dense samples of a frazil ice algal community were collected and maintained outdoors in the presence or absence of Q{sub UVB} and/or ultraviolet-A (Q{sub UVA}, 320-400 nm) radiation. The time of day course of UV inhibition of primary production was tracted. Over the day, {phi}{sub IIe}{degrees} declined due to increasing time-integrated dose exposure of Q{sub UVB}. The Q{sub UVB}-driven inhibition of {phi}{sub IIe}{degrees} increased from 4% in the early morning hours to a maximum of 23% at the end of the day. The Q{sub UVB} photoinhibition of PSII quantum yield did not recover by 6 h after sunset. In contrast, photoinhibition by Q{sub UVA} and photosynthetically available radiation (Q{sub PAR}, 400-700 nm) recovered during the late afternoon. Fluorescence-based estimates of carbon fixation rates were linearly correlated with measured carbon fixation. Fluorescence overestimated the observed Q{sub UVB} inhibition in measured carbon fixation rates. Researchers should be cautious in using fluorescence measurements to infer ultraviolet inhibition for rates of carbon fixation until there is a greater understanding of the coupling of carbon metabolism to PSII activity for natural populations. Despite these current limitations, fluorescence-based technologies represent powerful tools for studying the impact of the ozone hole on natural populations on spatial/temporal scales not possible using conventional productivity techniques. 55 refs., 11 figs., 2 tabs.

  2. The inhibition of calcium carbonate crystal growth by the cysteine-rich Mdm2 peptide.

    PubMed

    Dalas, E; Chalias, A; Gatos, D; Barlos, K

    2006-08-15

    The crystal growth of calcite, the most stable calcium carbonate polymorph, in the presence of the cysteine-rich Mdm2 peptide (containing 48 amino acids in the ring finger configuration), has been investigated by the constant composition technique. Crystallization took place exclusively on well-characterized calcite crystals in solutions supersaturated only with respect to this calcium carbonate salt. The kinetic results indicated a surface diffusion spiral growth mechanism. The presence of the Mdm2 peptide inhibited the crystal growth of calcite by 22-58% in the concentration range tested, through adsorption onto the active growth sites of the calcite crystal surface. The kinetic results favored a Langmuir-type adsorption model, and the value of the calculated affinity constant was k(aff)=147x10(4) dm(3)mol(-1), a(ads)=0.29.

  3. Heparin Inhibits Hepatocyte Growth Factor Induced Motility and Invasion of Hepatocellular Carcinoma Cells through Early Growth Response Protein 1

    PubMed Central

    Ozen, Evin; Gozukizil, Aysim; Erdal, Esra; Uren, Aykut; Bottaro, Donald P.; Atabey, Nese

    2012-01-01

    The Hepatocyte Growth Factor (HGF)/c-Met signaling pathway regulates hepatocyte proliferation, and pathway aberrations are implicated in the invasive and metastatic behaviors of hepatocellular carcinoma (HCC). In addition to c-Met, heparin acts as a co-receptor to modulate pathway activity. Recently, anti-metastatic and anti-cancer effects of heparin have been reported. However, the role of heparin in the regulation of HGF signaling remains controversial and the effects of heparin on HGF-induced biological responses during hepatocarcinogenesis is not yet defined. In this study we determined the effects of heparin on HGF-induced activities of HCC cells and the underlying molecular mechanisms. Here, we report for the first time that heparin inhibits HGF-induced adhesion, motility and invasion of HCC cells. In addition, heparin reduced HGF-induced activation of c-Met and MAPK in a dose-dependent manner, as well as decreased transcriptional activation and expression of Early growth response factor 1 (Egr1). HGF-induced MMP-2 and MMP-9 activation, and MT1-MMP expression, also were inhibited by heparin. Stable knockdown of Egr1 caused a significant decrease in HGF-induced invasion, as well as the activation and expression of MMPs. Parallel to these findings, the overexpression of Egr1 increased the invasiveness of HCC cells. Our results suggest that Egr1 activates HGF-induced cell invasion through the regulation of MMPs in HCC cells and heparin inhibits HGF-induced cellular invasion via the downregulation of Egr1. Therefore, heparin treatment might be a therapeutic approach to inhibit invasion and metastasis of HCC, especially for patients with active HGF/c-Met signaling. PMID:22912725

  4. When are antifreeze proteins in solution essential for ice growth inhibition?

    PubMed

    Drori, Ran; Davies, Peter L; Braslavsky, Ido

    2015-06-02

    Antifreeze proteins (AFPs) are a widespread class of proteins that bind to ice and facilitate the survival of organisms under freezing conditions. AFPs have enormous potential in applications that require control over ice growth. However, the nature of the binding interaction between AFPs and ice remains the subject of debate. Using a microfluidics system developed in-house we previously showed that hyperactive AFP from the Tenebrio molitor beetle, TmAFP, remains bound to an ice crystal surface after exchanging the solution surrounding the ice crystal to an AFP-free solution. Furthermore, these surface-adsorbed TmAFP molecules sufficed to prevent ice growth. These experiments provided compelling evidence for the irreversible binding of hyperactive AFPs to ice. Here, we tested a moderately active type III AFP (AFPIII) from a fish in a similar microfluidics system. We found, in solution exchange experiments that the AFPIIIs were also irreversibly bound to the ice crystals. However, some crystals displayed "burst" growth during the solution exchange. AFPIII, like other moderately active fish AFPs, is unable to bind to the basal plane of an ice crystal. We showed that although moderate AFPs bound to ice irreversibly, moderate AFPs in solution were needed to inhibit ice growth from the bipyramidal crystal tips. Instead of binding to the basal plane, these AFPs minimized the basal face size by stabilizing other crystal planes that converge to form the crystal tips. Furthermore, when access of solution to the basal plane was physically blocked by the microfluidics device walls, we observed enhancement of the antifreeze activity. These findings provide direct evidence that the weak point of ice growth inhibition by fish AFPs is the basal plane, whereas insect AFPs, which can bind to the basal plane, are able to inhibit its growth and thereby increase antifreeze activity.

  5. Ca2+ Efflux Is Involved in Cinnamaldehyde-Induced Growth Inhibition of Phytophthora capsici

    PubMed Central

    Chen, Jian; Xue, Yanfeng; Shi, Zhiqi

    2013-01-01

    As a destructive fungus-like plant pathogen, the oomycete Phytophthoracapsici is unable to synthesize its own ergosterol as the potential target of fungicide cinnamaldehyde (CA). In this study, CA exerted efficient inhibitory effects on both mycelial growth (EC50=0.75 mM) and zoospore germination (MIC=0.4 mM) of P. capsici. CA-induced immediate Ca2+ efflux from zoospores could be confirmed by the rapid decrease in intracellular Ca2+ content determined by using Fluo-3 AM and the increase in extracellular Ca2+ concentration determined by using ICP-AES (inductively coupled plasma atomic emission spectrometry). Blocking Ca2+ influx with ruthenium red and verapamil led to a higher level of CA-induced Ca2+ efflux, suggesting the simultaneous occurrence of Ca2+ influx along with the Ca2+ efflux under CA exposure. Further results showed that EGTA-induced decrease in intracellular Ca2+ gave rise to the impaired vitality of P. capsici while the addition of exogenous Ca2+ could suppress the growth inhibitory effect of CA. These results suggested that Ca2+ efflux played an important role in CA-induced growth inhibition of P. capsici. The application of 3-phenyl-1-propanal, a CA analog without α,β- unsaturated bond, resulted in a marked Ca2+ influx in zoospores but did not show any growth inhibitory effects. In addition, exogenous cysteine, an antagonist against the Michael addition (the nucleophilic addition of a carbanion or another nucleophile) between CA and its targets, could attenuate CA-induced growth inhibition of P. capsici by suppressing Ca2+ efflux. Our results suggest that CA inhibits the growth of P. capsici by stimulating a transient Ca2+ efflux via Michael addition, which provides important new insights into the antimicrobial action of CA. PMID:24098458

  6. Dimethylthiourea inhibition of B16 melanoma growth and induction of phenotypic alterations; relationship to ATP levels.

    PubMed Central

    Fux, A.; Sidi, Y.; Kessler-Icekson, G.; Wasserman, L.; Novogrodsky, A.; Nordenberg, J.

    1991-01-01

    1,3 Dimethylthiourea (DMTU) has previously been shown by us to inhibit the growth of melanoma cells and to induce phenotypic alterations in these cells, including ultrastructural alterations of mitochondria. These findings raised the possibility that impaired mitochondrial function might be involved in mediating the effect of DMTU on cell growth and phenotypic expression. The present study indicates that DMTU as well as another growth inhibitory methylurea derivative, tetramethylurea (TMU) significantly decrease ATP content in the B16 melanoma cell line. 1,3 Dimethylurea (1,3DMU) and 1,1 dimethylurea (1,1DMU) which are poor growth inhibitors, do not reduce ATP content significantly. Altered energy metabolism in the DMTU-treated cells is reflected by inhibition of the activity of cytochrome c oxidase and by increased lactate levels. A cell line selected for resistance to growth inhibition by DMTU was shown to be completely resistant to induction of phenotypic alterations by DMTU. These cells possess high lactate levels, high ATP content and a somewhat decreased Na/K ATPase activity as compared to wild type B16 F10 cells. 1,3 DMTU treatment of the resistant cells leads to a decrease in the activity of the mitochondrial enzyme cytochrome c oxidase, similar to its effect on the wild type B16 F10 cells. DMTU also reduces ATP content moderately in the resistant cells. However, the levels of ATP do not decrease beyond those found in untreated B16 F10 wild type cells. Taken together the results suggest that decreased ATP content might be involved, at least partially, in mediating the effects of DMTU on B16 melanoma cell growth and phenotypic expression. PMID:1850608

  7. Solar UV-B Radiation Inhibits the Growth of Antarctic Terrestrial Fungi

    PubMed Central

    Hughes, Kevin A.; Lawley, Blair; Newsham, Kevin K.

    2003-01-01

    We tested the effects of solar radiation, and UV-B in particular, on the growth of Antarctic terrestrial fungi. The growth responses to solar radiation of five fungi, Geomyces pannorum, Phoma herbarum, Pythium sp., Verticillium sp., and Mortierella parvispora, each isolated from Antarctic terrestrial habitats, were examined on an agar medium in the natural Antarctic environment. A 3-h exposure to solar radiation of >287 nm reduced the hyphal extension rates of all species relative to controls kept in the dark. Pythium sp. cultures exposed to solar radiation for 1.5 h on five consecutive days were most sensitive to radiation of >287 nm, but radiation of >313 nm also inhibited growth to a lesser extent. Radiation of >400 nm had no effect on hyphal growth relative to controls kept in the dark. Short-wave solar UV-B radiation of between 287 and 305 nm inhibited the growth of Pythium sp. hyphae on and below the surface of the agar medium after 24 h, but radiation of ≥345 nm only reduced the growth of surface hyphae. Similar detrimental effects of UV-B on surface and, to a lesser extent, submerged hyphae of all five fungi were shown in the laboratory by using artificial UV-B from fluorescent lamps. A comparison of growth responses to solar radiation and temperature showed that the species that were most resistant to UV radiation grew fastest at higher temperatures. These data suggest that solar UV-B reduces the growth of fungi on the soil surface in the Antarctic terrestrial environment. PMID:12620833

  8. The development of marine Toxicity Identification Evaluation (TIE) procedures using the unicellular alga Nitzschia closterium.

    PubMed

    Hogan, A C; Stauber, J L; Pablo, F; Adams, M S; Lim, R P

    2005-05-01

    Unicellular algae are highly sensitive to a wide range of toxicants and have been used extensively in ecotoxicological testing. This, along with their ability to grow in very small test volumes over short test durations, make them ideal test organisms for use in Toxicity Identification Evaluations (TIEs). Despite this, microalgae have not previously been used in marine TIE studies. In this study, the marine diatom Nitzschia closterium was shown to be a highly suitable test organism after modification of the standard test protocol to reduce test volumes to 6 mL and test duration to 48 h. The alga was tolerant to the chemicals used in phase I of the standard USEPA TIE protocol, and physical TIE manipulations had no effect on algal growth. The cation exchange procedure, however, inhibited algal growth, while the anion exchange procedure stimulated growth, making these two procedures unsuitable for use with this species. Of the buffers trialed for the graduated pH procedure, 0.01 M PIPES buffer was found to be suitable for buffering at pH 7 because it maintained the required pH over the duration of the test and did not affect the growth or sensitivity of the algae to one reference toxicant (copper). A trial TIE on a secondary-treated sewage effluent for discharge into coastal waters showed that the developed protocols could successfully be used to identify ammonia as the major toxicant in the effluent.

  9. Inhibiting histone deacetylases suppresses glucose metabolism and hepatocellular carcinoma growth by restoring FBP1 expression

    PubMed Central

    Yang, Jing; Jin, Xin; Yan, Yuqian; Shao, Yingjie; Pan, Yunqian; Roberts, Lewis R.; Zhang, Jun; Huang, Haojie; Jiang, Jingting

    2017-01-01

    Hepatocellular carcinoma (HCC) is one of the most commonly diagnosed cancers in the world. Elevated glucose metabolism in the availability of oxygen, a phenomenon called the Warburg effect, is important for cancer cell growth. Fructose-1,6-bisphosphatase (FBP1) is a rate-limiting enzyme in gluconeogenesis and is frequently lost in various types of cancer. Here, we demonstrated that expression of FBP1 was downregulated in HCC patient specimens and decreased expression of FBP1 associated with poor prognosis. Low expression of FBP1 correlated with high levels of histone deacetylase 1 (HDAC1) and HDAC2 proteins in HCC patient tissues. Treatment of HCC cells with HDAC inhibitors or knockdown of HDAC1 and/or HDAC2 restored FBP1 expression and inhibited HCC cell growth. HDAC-mediated suppression of FBP1 expression correlated with decreased histone H3 lysine 27 acetylation (H3K27Ac) in the FBP1 enhancer. Restored expression of FBP1 decreased glucose reduction and lactate secretion and inhibited HCC cell growth in vitro and tumor growth in mice. Our data reveal that loss of FBP1 due to histone deacetylation associates with poor prognosis of HCC and restored FBP1 expression by HDAC inhibitors suppresses HCC growth. Our findings suggest that repression of FBP1 by HDACs has important implications for HCC prognosis and treatment. PMID:28262837

  10. Large plasma-membrane depolarization precedes rapid blue-light-induced growth inhibition in cucumber

    NASA Technical Reports Server (NTRS)

    Spalding, E. P.; Cosgrove, D. J.

    1989-01-01

    Blue-light (BL)-induced suppression of elongation of etiolated Cucumis sativus L. hypocotyls began after a 30-s lag time, which was halved by increasing the fluence rate from 10 to 100 micromoles m-2 s-1. Prior to the growth suppression, the plasma-membrane of the irradiated cells depolarized by as much as 100 mV, then returned within 2-3 min to near its initial value. The potential difference measured with surface electrodes changed with an identical time course but opposite polarity. The lag time for the change in surface potential showed an inverse dependence on fluence rate, similar to the lag for the growth inhibition. Green light and red light caused neither the electrical response nor the rapid inhibition of growth. The depolarization by BL did not propagate to nonirradiated regions and exhibited a refractory period of about 10 min following a BL pulse. Fluence-response relationships for the electrical and growth responses provide correlational evidence that the plasma-membrane depolarization reflects an event in the transduction chain of this light-growth response.

  11. Syzygium cumini inhibits growth and induces apoptosis in cervical cancer cell lines: a primary study

    PubMed Central

    Barh, D; Viswanathan, G

    2008-01-01

    Cervical cancer is common among women in the Indian subcontinent and the incidences and death rates are gradually increasing over the years. Several dietary phytochemicals have been reported to have growth inhibitory and apoptotic effect on HeLa and other cervical cell lines. In this study, using Hoechst 33342 staining, MTT, Annexin V-FLUOS/PI and TUNEL assays we demonstrated that Syzygium cumini extract inhibits the growth and induces apoptosis in HeLa and SiHa cervical cancer cell lines in a dose- and time-dependent manner. The phytochemical, its mode of action and safety issues are yet to be determined. PMID:22275971

  12. Syzygium cumini inhibits growth and induces apoptosis in cervical cancer cell lines: a primary study.

    PubMed

    Barh, D; Viswanathan, G

    2008-01-01

    Cervical cancer is common among women in the Indian subcontinent and the incidences and death rates are gradually increasing over the years. Several dietary phytochemicals have been reported to have growth inhibitory and apoptotic effect on HeLa and other cervical cell lines. In this study, using Hoechst 33342 staining, MTT, Annexin V-FLUOS/PI and TUNEL assays we demonstrated that Syzygium cumini extract inhibits the growth and induces apoptosis in HeLa and SiHa cervical cancer cell lines in a dose- and time-dependent manner. The phytochemical, its mode of action and safety issues are yet to be determined.

  13. Human astrocytes inhibit Cryptococcus neoformans growth by a nitric oxide-mediated mechanism

    PubMed Central

    1994-01-01

    Cryptococcus neoformans is an opportunistic fungus that causes life- threatening meningoencephalitis in 5-10% of patients with acquired immune deficiency syndrome. Cryptococcal meningoencephalitis is characterized by a lymphohistiocytic infiltrate, accumulation of encapsulated forms of C. neoformans, and varying degrees of glial reaction. Little is known about the contribution of endogenous central nervous system cells to the pathogenesis of cryptococcal infections. In this study, we investigated the role of astrocytes as potential effector cells against C. neoformans. Primary cultures of human fetal astrocytes, activated with interleukin 1 beta plus interferon gamma inhibited the growth of C. neoformans. The inhibition of C. neoformans growth was paralleled by production of nitrite, and reversed by the inhibitors of nitric oxide (NO.) synthase, NG-methyl-mono-arginine and NG-nitro-arginine methyl ester. The results suggest a novel function for human astrocytes in host defence and provide a precedent for the use of NO. as an antimicrobial effector molecule by human cells. PMID:8006595

  14. Novel synthetic antagonists of canonical Wnt signaling inhibit colorectal cancer cell growth.

    PubMed

    Waaler, Jo; Machon, Ondrej; von Kries, Jens Peter; Wilson, Steven Ray; Lundenes, Elsa; Wedlich, Doris; Gradl, Dietmar; Paulsen, Jan Erik; Machonova, Olga; Dembinski, Jennifer L; Dinh, Huyen; Krauss, Stefan

    2011-01-01

    Canonical Wnt signaling is deregulated in several types of human cancer where it plays a central role in tumor cell growth and progression. Here we report the identification of 2 new small molecules that specifically inhibit canonical Wnt pathway at the level of the destruction complex. Specificity was verified in various cellular reporter systems, a Xenopus double-axis formation assay and a gene expression profile analysis. In human colorectal cancer (CRC) cells, the new compounds JW67 and JW74 rapidly reduced active β-catenin with a subsequent downregulation of Wnt target genes, including AXIN2, SP5, and NKD1. Notably, AXIN2 protein levels were strongly increased after compound exposure. Long-term treatment with JW74 inhibited the growth of tumor cells in both a mouse xenograft model of CRC and in Apc(Min) mice (multiple intestinal neoplasia, Min). Our findings rationalize further preclinical and clinical evaluation of these new compounds as novel modalities for cancer treatment.

  15. Acetylation of Beclin 1 inhibits autophagosome maturation and promotes tumour growth.

    PubMed

    Sun, Ting; Li, Xuan; Zhang, Peng; Chen, Wen-Dan; Zhang, Hai-liang; Li, Dan-Dan; Deng, Rong; Qian, Xiao-Jun; Jiao, Lin; Ji, Jiao; Li, Yun-Tian; Wu, Rui-Yan; Yu, Yan; Feng, Gong-Kan; Zhu, Xiao-Feng

    2015-05-26

    Beclin 1, a protein essential for autophagy, regulates autophagy by interacting with Vps34 and other cofactors to form the Beclin 1 complex. Modifications of Beclin 1 may lead to the induction, inhibition or fine-tuning of the autophagic response under a variety of conditions. Here we show that Beclin 1 is acetylated by p300 and deacetylated by SIRT1 at lysine residues 430 and 437. In addition, the phosphorylation of Beclin 1 at S409 by CK1 is required for the subsequent p300 binding and Beclin 1 acetylation. Beclin 1 acetylation inhibits autophagosome maturation and endocytic trafficking by promoting the recruitment of Rubicon. In tumour xenografts, the expression of 2KR mutant Beclin 1 (substitution of K430 and K437 to arginines) leads to enhanced autophagosome maturation and tumour growth suppression. Therefore, our study identifies an acetylation-dependent regulatory mechanism governing Beclin 1 function in autophagosome maturation and tumour growth.

  16. Selective histone deacetylase 6 inhibitors bearing substituted urea linkers inhibit melanoma cell growth.

    PubMed

    Bergman, Joel A; Woan, Karrune; Perez-Villarroel, Patricio; Villagra, Alejandro; Sotomayor, Eduardo M; Kozikowski, Alan P

    2012-11-26

    The incidence of malignant melanoma has dramatically increased in recent years thus requiring the need for improved therapeutic strategies. In our efforts to design selective histone deactylase inhibitors (HDACI), we discovered that the aryl urea 1 is a modestly potent yet nonselective inhibitor. Structure-activity relationship studies revealed that adding substituents to the nitrogen atom of the urea so as to generate compounds bearing a branched linker group results in increased potency and selectivity for HDAC6. Compound 5 g shows low nanomolar inhibitory potency against HDAC6 and a selectivity of ∼600-fold relative to the inhibition of HDAC1. These HDACIs were evaluated for their ability to inhibit the growth of B16 melanoma cells with the most potent and selective HDAC6I being found to decrease tumor cell growth. To the best of our knowledge, this work constitutes the first report of HDAC6-selective inhibitors that possess antiproliferative effects against melanoma cells.

  17. Selective histone deacetylase 6 inhibitors bearing substituted urea linkers inhibit melanoma cell growth

    PubMed Central

    Bergman, Joel A.; Woan, Karrune; Perez-Villarroel, Patricio; Villagra, Alejandro; Sotomayor, Eduardo M.; Kozikowski, Alan P.

    2012-01-01

    The incidence of malignant melanoma has dramatically increased in recent years thus requiring the need for improved therapeutic strategies. In our efforts to design selective histone deactylase inhibitors (HDACI), we discovered that the aryl urea 1 is a modestly potent yet non-selective inhibitor. Structure activity relationship studies revealed that adding substituents to the nitrogen atom of the urea so as to generate compounds bearing a branched linker group results in increased potency and selectivity for HDAC6. Compound 5g shows low nanomolar inhibitory potency against HDAC6 and a selectivity of ~600-fold relative to the inhibition of HDAC1. These HDACIs were evaluated for their ability to inhibit the growth of B16 melanoma cells with the most potent and selective HDAC6I being found to decrease tumor cell growth. To the best of our knowledge, this work constitutes the first report of HDAC6 selective inhibitors that possess antiproliferative effects against melanoma cells. PMID:23009203

  18. Growth hormone-releasing peptide-6 inhibits cerebellar cell death in aged rats.

    PubMed

    Pañeda, Covadonga; Arroba, Ana I; Frago, Laura M; Holm, Anne Mette; Rømer, John; Argente, Jesús; Chowen, Julie A

    2003-08-26

    Insulin-like growth factor (IGF)-I is essential for cerebellar granule neuron survival and a decline in IGF-I is implicated in various age-dependent processes. Here we show that IGF-I mRNA levels are decreased in the cerebellum of old rats compared with young rats and this was associated with increased cell death and activation of caspases 3 and 9. Growth hormone-releasing peptide (GHRP)-6, a synthetic ligand for the ghrelin receptor, increased IGF-I mRNA levels, decreased cell death and inhibited caspase 3 and 9 activation in the cerebellum of aged rats. These results suggest that increasing IGF-I expression in the cerebellum can decrease cell death in aged rats via inhibition of caspase 3 and 9 activation.

  19. Zinc pyrithione inhibits yeast growth through copper influx and inactivation of iron-sulfur proteins.

    PubMed

    Reeder, Nancy L; Kaplan, Jerry; Xu, Jun; Youngquist, R Scott; Wallace, Jared; Hu, Ping; Juhlin, Kenton D; Schwartz, James R; Grant, Raymond A; Fieno, Angela; Nemeth, Suzanne; Reichling, Tim; Tiesman, Jay P; Mills, Tim; Steinke, Mark; Wang, Shuo L; Saunders, Charles W

    2011-12-01

    Zinc pyrithione (ZPT) is an antimicrobial material with widespread use in antidandruff shampoos and antifouling paints. Despite decades of commercial use, there is little understanding of its antimicrobial mechanism of action. We used a combination of genome-wide approaches (yeast deletion mutants and microarrays) and traditional methods (gene constructs and atomic emission) to characterize the activity of ZPT against a model yeast, Saccharomyces cerevisiae. ZPT acts through an increase in cellular copper levels that leads to loss of activity of iron-sulfur cluster-containing proteins. ZPT was also found to mediate growth inhibition through an increase in copper in the scalp fungus Malassezia globosa. A model is presented in which pyrithione acts as a copper ionophore, enabling copper to enter cells and distribute across intracellular membranes. This is the first report of a metal-ligand complex that inhibits fungal growth by increasing the cellular level of a different metal.

  20. Inhibition of gibberellin-induced elongation growth of rice by feruloyl oligosaccharides.

    PubMed

    Ishii, T; Nishijima, T

    1995-12-01

    The biological activity of cell wall-derived feruloyl oligosaccharides was investigated using a modified micro-drop bioassay. A feruloyl arabinoxylan trisaccharide (FAXX) and a feruloyl arabinoxylan tetrasaccharide (FAXXX) were found to inhibit the gibberellin-induced elongation of dwarf rice (Oryza sativa L., cv, Tan-ginbozu) that had