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Sample records for active oxygen scavenging

  1. Reactive oxygen scavenging activity of matured whiskey and its active polyphenols.

    PubMed

    Koga, K; Taguchi, A; Koshimizu, S; Suwa, Y; Yamada, Y; Shirasaka, N; Yoshizumi, H

    2007-04-01

    The quality of whiskey is known to improve remarkably by its storage over many years. This process is commonly termed "maturing." In this process, polyphenols derived from lignin and tannin of the barrel have an important role in not only forming the matured flavor and taste but also contributing to the advance of clustering ethanol and water in whiskey. It is also likely that polyphenols generally possess reactive oxygen (RO) scavenging activity. The present study evaluated the RO scavenging activity (free-radical scavenging activity, H(2)O(2) reduction activity under peroxidase coculture, and H(2)O(2)scavenging activity) of 24 single malt whiskeys with a maturation age of 10 to 30 y produced in Japanese, Scotch (Islay), or Scotch (Speyside and Highland) regions. Single malt whiskey not only showed RO scavenging activity but there was also a positive correlation between this activity and the maturation age of whiskey exceeding the difference resulting from the manufacturing region. A nonvolatile fraction derived from the barrel was responsible for RO scavenging activity. In particular, the contents of ellagic and gallic acids and lyoniresinol, the main polyphenolic compounds in whiskey, increased with maturation age. For the free-radical scavenging activity per molecule, each compound was 1.68 to 3.14 times that of trolox (a water-soluble vitamin E). The activities of ellagic acid, gallic acid, and lyoniresinol in the whiskey (Yamazaki 18) were equivalent to that of 80.3, 31.2, and 11.1 ppm trolox, respectively. Accordingly, the total activity of these 3 compounds accounted for about 20% of the activity of the whiskey (630.7 ppm trolox).

  2. Reactive oxygen scavenging activity of matured whiskey and its active polyphenols.

    PubMed

    Koga, K; Taguchi, A; Koshimizu, S; Suwa, Y; Yamada, Y; Shirasaka, N; Yoshizumi, H

    2007-04-01

    The quality of whiskey is known to improve remarkably by its storage over many years. This process is commonly termed "maturing." In this process, polyphenols derived from lignin and tannin of the barrel have an important role in not only forming the matured flavor and taste but also contributing to the advance of clustering ethanol and water in whiskey. It is also likely that polyphenols generally possess reactive oxygen (RO) scavenging activity. The present study evaluated the RO scavenging activity (free-radical scavenging activity, H(2)O(2) reduction activity under peroxidase coculture, and H(2)O(2)scavenging activity) of 24 single malt whiskeys with a maturation age of 10 to 30 y produced in Japanese, Scotch (Islay), or Scotch (Speyside and Highland) regions. Single malt whiskey not only showed RO scavenging activity but there was also a positive correlation between this activity and the maturation age of whiskey exceeding the difference resulting from the manufacturing region. A nonvolatile fraction derived from the barrel was responsible for RO scavenging activity. In particular, the contents of ellagic and gallic acids and lyoniresinol, the main polyphenolic compounds in whiskey, increased with maturation age. For the free-radical scavenging activity per molecule, each compound was 1.68 to 3.14 times that of trolox (a water-soluble vitamin E). The activities of ellagic acid, gallic acid, and lyoniresinol in the whiskey (Yamazaki 18) were equivalent to that of 80.3, 31.2, and 11.1 ppm trolox, respectively. Accordingly, the total activity of these 3 compounds accounted for about 20% of the activity of the whiskey (630.7 ppm trolox). PMID:17995817

  3. Singlet oxygen scavenging activity and cytotoxicity of essential oils from rutaceae.

    PubMed

    Ao, Yoko; Satoh, Kazue; Shibano, Katsushige; Kawahito, Yukari; Shioda, Seiji

    2008-07-01

    Since we have been exposed to excessive amounts of stressors, aromatherapy for the relaxation has recently become very popular recently. However, there is a problem which responds to light with the essential oil used by aromatherapy. It is generally believed that singlet oxygen is implicated in the pathogenesis of various diseases such as light-induced skin disorders and inflammatory responses. Here we studied whether essential oils can effectively scavenge singlet oxygen upon irradiation, using the electron spin resonance (ESR) method. Green light was used to irradiate twelve essential oils from rutaceae. Among these twelve essential oils, eight were prepared by the expression (or the compression) method (referred to as E oil), and four samples were prepared by the steam distillation method (referred to as SD oil). Five E oils enhanced singlet oxygen production. As these essential oils may be phototoxic, it should be used for their use whit light. Two E oils and three SD oils showed singlet oxygen scavenging activity. These results may suggest that the antioxidant activity of essential oils are judged from their radical scavenging activity. Essential oils, which enhance the singlet oxygen production and show higher cytotoxicity, may contain much of limonene. These results suggest that limonene is involved not only in the enhancement of singlet oxygen production but also in the expression of cytotoxic activity, and that attention has to be necessary for use of blended essential oils.

  4. Reactive oxygen species scavenging activity of aminoderivatized chitosan with different degree of deacetylation.

    PubMed

    Je, Jae-Young; Kim, Se-Kwon

    2006-09-01

    Chitosans with different degree of deacetylation were prepared from crab shell chitin in the presence of alkali. Aminoderivatized chitosan derivatives were prepared in addition of amino functional groups at a hydroxyl site in the chitosan backbone. Six kinds of aminoderivatized chitosan such as aminoethyl-chitosan (AEC90), dimethylaminoethyl-chitosan (DMAEC90), and diethylaminoethyl-chitosan (DEAEC90), which were prepared from 90% deacetylated chitosan, and AEC50, DMAEC50 and DEAEC50, which were prepared from 50% deacetylated chitosan, were prepared and their reactive oxygen species (ROS) scavenging activities were investigated against hydroxyl radical, superoxide anion radical and hydrogen peroxide. The electron spin resonance (ESR) spectrum revealed that AEC90 showed the highest scavenging effects against hydroxyl and superoxide anion radical, the effects were 91.67% and 65.34% at 0.25 and 5 mg/mL, respectively. For hydrogen peroxide scavenging effect, DEAEC90 exhibited the strongest activity. These results suggest that the scavenging effect depends on their degree of deacetylation and substituted group.

  5. Enhancing effect of oxygen radical scavengers on murine macrophage anticryptococcal activity through production of nitric oxide

    PubMed Central

    TOHYAMA, M.; KAWAKAMI, K.; FUTENMA, M.; SAITO, A.

    1996-01-01

    We examined the roles of reactive nitrogen intermediates (RNI) and reactive oxygen intermediates (ROI) in interferon-gamma (IFN-γ)-induced cryptococcostatic activity of murine peritoneal macrophages using NG-monomethyl-L-arginine (L-NMMA), a competitive inhibitor of RNI synthesis, and superoxide dismutase (SOD) and catalase, oxygen radical scavengers. IFN-γ-activated macrophages produced nitric oxide (NO) in a dose-dependent manner, as measured by increased nitrite concentration in the culture supernatant. IFN-γ also enhanced the suppressive effect on cryptococcal growth in a similar dose-dependent manner. The induction of killing activity and NO production by an optimal dose of IFN-γ (100 U/ml) was virtually suppressed by 500 μM L-NMMA. These results confirmed the importance of the RNI-mediated effector mechanism in anticryptococcal activity of macrophages. SOD and catalase significantly enhanced the cryptococcostatic activity of macrophages induced by a suboptimal dose of IFN-γ (20 U/ml). The augmenting effect of these reagents was mediated by NO, since they potentiated the production of NO by macrophages and their effects were totally blocked by L-NMMA. Our results indicate that the IFN-γ-induced anticryptococcal activity of macrophages is dependent mostly on RNI, and suggest that the ROI system down-regulates the effector mechanism for cryptococcostasis by suppressing the RNI system. PMID:8608643

  6. Study of oxygen scavenging PET-based films activated by water

    NASA Astrophysics Data System (ADS)

    Rossi, Gabriella; Scarfato, Paola; Incarnato, Loredana

    2016-05-01

    In this work an active barrier system consisting of a thin and transparent film based on polyethylene terephthalate (PET) was studied. Dynamic oxygen absorption measurements were performed at different values of relative humidity and temperature, pointing out that humidity is a key factor in activating the oxidation of the polymer sample. Moreover, the thermal and optical properties of the films were investigated and a good correlation was found between the crystallinity increase and the consequent transparency reduction occurring after the oxygen absorption.

  7. Prevention of asbestos-induced cell death in rat lung fibroblasts and alveolar macrophages by scavengers of active oxygen species

    SciTech Connect

    Shatos, M.A.; Doherty, J.M.; Marsh, J.P.; Mossman, B.T.

    1987-10-01

    The possible modulation of asbestos-related cell death using antioxidants in both target and effector cells of asbestosis was investigated. After exposure to crocidolite asbestos at a range of concentrations (2.5-25 ..mu..gcm/sup 2/ dish), the viability of a normal rat lung fibroblast line and freshly isolated alveolar macrophages (AM) was determined. In comparison to fibroblasts, AM were more resistant to the cytotoxic effects of asbestos. Cytotoxic concentrations of asbestos then were added to both cell types in combination with the antioxidants, superoxide dismutase (SOD), a scavenger of superoxide (O/sub 2//sup -./), and catalase, an enzyme scavenging H/sub 2/O/sub 2/. Dimethylthiourea (DMTU), a scavenger of the hydroxyl radical (OH/sup ./) and deferoxamine, an iron chelator, also were evaluated in similar studies. Results showed significant dosage-dependent reduction of asbestos-associated cell death with all agents. In contrast, asbestos-induced toxicity was not ameliorated after addition of chemically inactivated SOD and catalase or bovine serum albumin. Results above suggest asbestos-induced cell damage is mediated by active oxygen species. In this regard, the iron associated with the fiber andor its interaction with cell membranes might be critical in deriving a modified Haber-Weiss (Fenton-type) reaction resulting in production of OH/sup ./.

  8. [Effects of exogenous silicon on active oxygen scavenging systems in chloroplasts of cucumber (Cucumis sativus L.) seedlings under salt stress].

    PubMed

    Qian, Qiong-Qiu; Zai, Wen-San; Zhu, Zhu-Jun; Yu, Jing-Quan

    2006-02-01

    With K(2)SiO(4) (1.0 mmol/L) treatment, the effects of Si on the distribution of Na(+), K(+) to chloroplasts and antioxidant system of cucumber leaves under 50 mmol/L NaCl stress were studied. The results showed that there was a selective transport of K(+) into the chloroplasts so that Na(+) content of chloroplasts was lower under Si treatment (Table 1); H(2)O(2) and MDA contents in chloroplasts were significantly decreased (Fig.1), and the activities of SOD, APX, GR and DHAR were increased simultaneity (Fig.2), and AsA, GSH contents were also increased in chloroplasts of salt-stressed cucumber by additional Si treatment (Fig.3). It may be concluded that Si could decrease absorption of Na(+) and increase ability of active oxygen scavenging in chloroplasts, therefore the injury of chloroplast membrane under salinity stress in cucumber was alleviated. PMID:16477139

  9. Transcript levels of antioxidative genes and oxygen radical scavenging enzyme activities in chilled zucchini squash in response to superatmospheric oxygen

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The transcript levels of antioxidative genes including Mn-superoxide dismutase (Mn-SOD), Cu/Zn SOD, ascorbate peroxidise (APX), and catalase (CAT) do not vary significantly during storage at 5 °C with high oxygen treatment in freshly harvested zucchini squash (Cucurbita pepo L. cv. Elite). However, ...

  10. pH dependent catalytic activities of platinum nanoparticles with respect to the decomposition of hydrogen peroxide and scavenging of superoxide and singlet oxygen

    NASA Astrophysics Data System (ADS)

    Liu, Yi; Wu, Haohao; Li, Meng; Yin, Jun-Jie; Nie, Zhihong

    2014-09-01

    Recently, platinum (Pt) nanoparticles (NPs) have received increasing attention in the field of catalysis and medicine due to their excellent catalytic activity. To rationally design Pt NPs for these applications, it is crucial to understand the mechanisms underlying their catalytic and biological activities. This article describes a systematic study on the Pt NP-catalyzed decomposition of hydrogen peroxide (H2O2) and scavenging of superoxide (O2&z.rad;-) and singlet oxygen (1O2) over a physiologically relevant pH range of 1.12-10.96. We demonstrated that the catalytic activities of Pt NPs can be modulated by the pH value of the environment. Our results suggest that Pt NPs possess peroxidase-like activity of decomposing H2O2 into &z.rad;OH under acidic conditions, but catalase-like activity of producing H2O and O2 under neutral and alkaline conditions. In addition, Pt NPs exhibit significant superoxide dismutase-like activity of scavenging O2&z.rad;- under neutral conditions, but not under acidic conditions. The 1O2 scavenging ability of Pt NPs increases with the increase in the pH of the environment. The study will provide useful guidance for designing Pt NPs with desired catalytic and biological properties.Recently, platinum (Pt) nanoparticles (NPs) have received increasing attention in the field of catalysis and medicine due to their excellent catalytic activity. To rationally design Pt NPs for these applications, it is crucial to understand the mechanisms underlying their catalytic and biological activities. This article describes a systematic study on the Pt NP-catalyzed decomposition of hydrogen peroxide (H2O2) and scavenging of superoxide (O2&z.rad;-) and singlet oxygen (1O2) over a physiologically relevant pH range of 1.12-10.96. We demonstrated that the catalytic activities of Pt NPs can be modulated by the pH value of the environment. Our results suggest that Pt NPs possess peroxidase-like activity of decomposing H2O2 into &z.rad;OH under acidic conditions

  11. A probable crosstalk between Ca⁺², reactive oxygen species accumulation and scavenging mechanisms and modulation of protein kinase C activity during seed development in sunflower.

    PubMed

    Thakur, Anita; Bhatla, Satish C

    2014-01-01

    Seed development in sunflower involves a gradual dehydration and accumulation of oil bodies in the cells of developing cotyledons during transition from 30 to 40 DAA stage. Reactive oxygen species (ROS) content decreased with seed maturation. NO content and NO contributed by putative nitric oxide synthase, however, did not change markedly. Superoxide dismutase (SOD) activity exhibited a peak at 30 DAA stage, indicating its scavenging role at the mid-stage of seed development. H₂O₂ produced as a result of SOD action is subsequently scavenged primarily by elevation of GR activity. Significant temporal differences were evident in GR and POD activity during seed development. Protein kinase C (PKC) activity also showed modulation during early stages of embryo and seed development. Use of PKC-specific fluorescent probe, Fim-1, and PKC inhibitors (staurosporine and bisindoylmaleamide) provided evidence for increase in PKC activity at 40 DAA stage with an increase in protein concentration (50 to 200 µg). Endogenous calcium content also increased with seed maturation. Tissue homogenates from 40 DAA stage showed enhanced fluorescence due to Fim-1-PKC binding in presence of calcium ions and its lowering due to calcium chelating agent (BAPTA). Western blot analysis revealed an increase in the intensity of 2 bands representing PKC with the advancement of seed maturation and their further upregulation by calcium. Present findings, thus, provide new information on the biochemical regulation of seed development in sunflower, with evidence for a possible correlation between calcium, ROS, their scavenging enzymes and "conventional" PKC activity.

  12. A probable crosstalk between Ca+2, reactive oxygen species accumulation and scavenging mechanisms and modulation of protein kinase C activity during seed development in sunflower

    PubMed Central

    Thakur, Anita; Bhatla, Satish C

    2014-01-01

    Seed development in sunflower involves a gradual dehydration and accumulation of oil bodies in the cells of developing cotyledons during transition from 30 to 40 DAA stage. Reactive oxygen species (ROS) content decreased with seed maturation. NO content and NO contributed by putative nitric oxide synthase, however, did not change markedly. Superoxide dismutase (SOD) activity exhibited a peak at 30 DAA stage, indicating its scavenging role at the mid-stage of seed development. H2O2 produced as a result of SOD action is subsequently scavenged primarily by elevation of GR activity. Significant temporal differences were evident in GR and POD activity during seed development. Protein kinase C (PKC) activity also showed modulation during early stages of embryo and seed development. Use of PKC-specific fluorescent probe, Fim-1, and PKC inhibitors (staurosporine and bisindoylmaleamide) provided evidence for increase in PKC activity at 40 DAA stage with an increase in protein concentration (50 to 200 µg). Endogenous calcium content also increased with seed maturation. Tissue homogenates from 40 DAA stage showed enhanced fluorescence due to Fim-1-PKC binding in presence of calcium ions and its lowering due to calcium chelating agent (BAPTA). Western blot analysis revealed an increase in the intensity of 2 bands representing PKC with the advancement of seed maturation and their further upregulation by calcium. Present findings, thus, provide new information on the biochemical regulation of seed development in sunflower, with evidence for a possible correlation between calcium, ROS, their scavenging enzymes and “conventional” PKC activity. PMID:24521818

  13. A novel sulfite alternative scavenger and benefits for the use of traced oxygen scavengers

    SciTech Connect

    Batton, C.B.; Riede, R.F.

    1994-12-31

    Dissolved oxygen in boiler systems is known to cause corrosion. Mechanical deaeration removes the majority of the dissolved oxygen while oxygen scavengers remove the remaining trace level. Sodium sulfate is a commonly used scavenger, but has several use limitations, such as high solids contribution to boiler water and decomposition products that are corrosive gases which can cause downstream equipment problems. A novel sulfite replacement oxygen scavenger has been developed which addresses the limitations of sulfite. Identification and demonstrated performance of the new scavenger is presented using both research and field data. In addition to oxygen scavenger performance, the success of a boiler water treatment program is dependent upon the correct dosage added to the feedwater. Plant managers and operators often struggle with indirect or inaccurate methods to determine what is occurring within their system. An oxygen scavenger product containing a proprietary fluorescent tracer has been developed. This technology for boilers provides a breakthrough in measurement capability for monitoring the dynamics of a boiler system. These two oxygen scavenger developments represent the result of maintaining desirable performance characteristics and significantly improving current technology. Laboratory and field data supporting these results are presented.

  14. The effects of phorbol ester activation and reactive oxygen species scavengers on the macrophage-mediated foreign body reaction to polyurethanes.

    PubMed

    McBane, Joanne E; Matheson, Loren A; Santerre, J Paul; Labow, Rosalind S

    2009-12-15

    Phorbol myristate acetate, a protein kinase C activator, inhibited monocyte-derived macrophage (MDM)-mediated degradation of aliphatic (HDI) polycarbonate-based polyurethanes but not degradation of the aromatic polycarbonate-based polyurethane (MDI). The objectives of this study were to determine if reactive oxygen species are involved in the phorbol myristate acetate effect on esterase activity and MDM-mediated polycarbonate-based polyurethane degradation and to find a good marker of material-initiated activation of MDM. The phorbol myristate acetate-dependent effects of the material chemistry on cell activation and degradation were evaluated by adding reactive oxygen species scavengers, catalase plus superoxide dismutase to MDM and assaying possible markers of MDM activation: esterase activity, acid phosphatase activity, and high molecular weight group box 1 protein (HMGB1). All treatments reduced the esterase activity in MDM on HDI but not in MDM on MDI. Acid phosphatase was inhibited in MDM to varying degrees on all surfaces by phorbol myristate acetate or catalase plus superoxide dismutase either alone or together. Secretion of HMGB1 from MDM on HDI431 was higher than MDI; however only secretion from MDM on HDI was inhibited by phorbol myristate acetate. In MDM on HDI, catalase plus superoxide dismutase reduced intracellular HMGB1 levels +/- phorbol myristate acetate; whereas, catalase, superoxide dismutase plus phorbol myristate acetate increased intracellular HMGB1 in MDM on MDI, suggesting that esterase and HMGB1 are more specific markers of activation than acid phosphatase. Manipulation of signaling pathways may provide insight surrounding the mechanism of activation for oxidative and/or hydrolytic degradative pathways in the MDM response to material surface chemistry.

  15. Effect of Laurus nobilis L. Essential Oil and its Main Components on α-glucosidase and Reactive Oxygen Species Scavenging Activity

    PubMed Central

    Sahin Basak, Serap; Candan, Ferda

    2013-01-01

    The present study was designed to determine the effects of the essential oil of Laurus nobilis L. (Lauraceae) and its three main components on α-glucosidase and reactive oxygen species scavenging activity. The chemical composition of the essential oil from Laurus nobilis L. leaves was analyzed by GC/GC-MS and resulted in the identification of 29 compounds, representing 99.18% of the total oil. 1,8-cineole (68.82%), 1-(S)-α-pinene (6.94%), and R-(+)- limonene (3.04%) were determined to be the main components. The antioxidant features of the essential oil and its three main components were evaluated using inhibition of 2,2-diphenyl-1- picrylhydrazyl, hydroxyl, and superoxide radicals, inhibition of hydrogen peroxide and lipid peroxidation assays. The results show that the DPPH, hydroxyl, and superoxide radical as well as hydrogen peroxide scavenging activities of the essential oil are greater than the positive controls and the three main components of the oil when tested independently. The inhibition of lipid peroxidation by the oil occurred less frequently than with 1,8-cineole and R-(+)- limonene alone, but the effects were more pronounced than those seen with 1-(S)-α-pinene and the positive controls. An α-glucosidase inhibition assay was applied to evaluate the in-vitro antidiabetic activity of the essential oil. IC50-values were obtained for laurel essential oil, 1, 8-cineole, 1-(S)-α-pinene, and R-(+)-limonene: 1.748 μL/mL, 1.118 μL/mL, 1.420 μL/mL and 1.300 μL/mL, respectively. We also found that laurel essential oil and 1, 8-cineole inhibited the α-glucosidase competitively while 1-(S)-α-pinene and R-(+)-limonene were uncompetitive inhibitors. PMID:24250611

  16. Effect of Laurus nobilis L. Essential Oil and its Main Components on α-glucosidase and Reactive Oxygen Species Scavenging Activity.

    PubMed

    Sahin Basak, Serap; Candan, Ferda

    2013-01-01

    The present study was designed to determine the effects of the essential oil of Laurus nobilis L. (Lauraceae) and its three main components on α-glucosidase and reactive oxygen species scavenging activity. The chemical composition of the essential oil from Laurus nobilis L. leaves was analyzed by GC/GC-MS and resulted in the identification of 29 compounds, representing 99.18% of the total oil. 1,8-cineole (68.82%), 1-(S)-α-pinene (6.94%), and R-(+)- limonene (3.04%) were determined to be the main components. The antioxidant features of the essential oil and its three main components were evaluated using inhibition of 2,2-diphenyl-1- picrylhydrazyl, hydroxyl, and superoxide radicals, inhibition of hydrogen peroxide and lipid peroxidation assays. The results show that the DPPH, hydroxyl, and superoxide radical as well as hydrogen peroxide scavenging activities of the essential oil are greater than the positive controls and the three main components of the oil when tested independently. The inhibition of lipid peroxidation by the oil occurred less frequently than with 1,8-cineole and R-(+)- limonene alone, but the effects were more pronounced than those seen with 1-(S)-α-pinene and the positive controls. An α-glucosidase inhibition assay was applied to evaluate the in-vitro antidiabetic activity of the essential oil. IC50-values were obtained for laurel essential oil, 1, 8-cineole, 1-(S)-α-pinene, and R-(+)-limonene: 1.748 μL/mL, 1.118 μL/mL, 1.420 μL/mL and 1.300 μL/mL, respectively. We also found that laurel essential oil and 1, 8-cineole inhibited the α-glucosidase competitively while 1-(S)-α-pinene and R-(+)-limonene were uncompetitive inhibitors.

  17. Antioxidant Activity/Capacity Measurement. 3. Reactive Oxygen and Nitrogen Species (ROS/RNS) Scavenging Assays, Oxidative Stress Biomarkers, and Chromatographic/Chemometric Assays.

    PubMed

    Apak, Reşat; Özyürek, Mustafa; Güçlü, Kubilay; Çapanoğlu, Esra

    2016-02-10

    There are many studies in which the antioxidant potential of different foods have been analyzed. However, there are still conflicting results and lack of information as a result of unstandardized assay techniques and differences between the principles of the methods applied. The measurement of antioxidant activity, especially in the case of mixtures, multifunctional or complex multiphase systems, cannot be evaluated satisfactorily using a simple antioxidant test due to the many variables influencing the results. In the literature, there are many antioxidant assays that are used to measure the total antioxidant activity/capacity of food materials. In this review, reactive oxygen and nitrogen species (ROS/RNS) scavenging assays are evaluated with respect to their mechanism, advantages, disadvantages, and potential use in food systems. On the other hand, in vivo antioxidant activity (AOA) assays including oxidative stress biomarkers and cellular-based assays are covered within the scope of this review. Finally, chromatographic and chemometric assays are reviewed, focusing on their benefits especially with respect to their time saving, cost-effective, and sensitive nature.

  18. Purified oxygen scavenging cell membrane fragments and use of same

    SciTech Connect

    Jacobson, K.B.; Adler, H.I.

    1988-10-18

    A process for purifying oxygen scavenging cell membrane fragments (OSCMF) and the use of same are disclosed. The novel purifying process involves salt precipitation and molecular exclusion chromatography. The unique feature of purified OSCMF is its ability to remove oxygen from organic reaction media and organic preparations without contaminating them to any substantial degree. 1 ref., 2 figs.

  19. Reactive oxygen species scavenger N-acetyl cysteine reduces methamphetamine-induced hyperthermia without affecting motor activity in mice

    PubMed Central

    Sanchez-Alavez, Manuel; Bortell, Nikki; Galmozzi, Andrea; Conti, Bruno; Marcondes, Maria Cecilia G.

    2014-01-01

    Hyperthermia is a potentially lethal side effect of Methamphetamine (Meth) abuse, which involves the participation of peripheral thermogenic sites such as the Brown Adipose Tissue (BAT). In a previous study we found that the anti-oxidant N-acetyl cysteine (NAC) can prevent the high increase in temperature in a mouse model of Meth-hyperthermia. Here, we have further explored the ability of NAC to modulate Meth-induced hyperthermia in correlation with changes in BAT. We found that NAC treatment in controls causes hypothermia, and, when administered prior or upon the onset of Meth-induced hyperthermia, can ameliorate the temperature increase and preserve mitochondrial numbers and integrity, without affecting locomotor activity. This was different from Dantrolene, which decreased motor activity without affecting temperature. The effects of NAC were seen in spite of its inability to recover the decrease of mitochondrial superoxide induced in BAT by Meth. In addition, NAC did not prevent the Meth-induced decrease of BAT glutathione. Treatment with S-adenosyl-L-methionine, which improves glutathione activity, had an effect in ameliorating Meth-induced hyperthermia, but also modulated motor activity. This suggests a role for the remaining glutathione for controlling temperature. However, the mechanism by which NAC operates is independent of glutathione levels in BAT and specific to temperature. Our results show that, in spite of the absence of a clear mechanism of action, NAC is a pharmacological tool to examine the dissociation between Meth-induced hyperthermia and motor activity, and a drug of potential utility in treating the hyperthermia associated with Meth-abuse. PMID:26346736

  20. Modeling of the Temperature Effect on Oxygen Absorption by Iron-Based Oxygen Scavengers.

    PubMed

    Polyakov, Vladimir A; Miltz, Joseph

    2016-01-01

    A new engineering-oriented model for prediction of the effect of temperature on the kinetics of oxygen absorption by iron-based oxygen scavengers (IOSs) was developed. The model is based on the physicochemical mechanism of the O2 scavenging process by the active component of the IOS (iron powder). The conclusions of this study are: (1) the iron deposits formed on the iron particles are composed of 2 different layers: an inner layer of Fe3 O4 and an outer layer of FeOOH that vanishes with the depletion of oxygen. (2) The model considers the chemical processes in the heterogeneous closed system "Fe-H2 O-NaCl-O2 " and describes the kinetics of oxygen absorption by the powder, depending on the characteristics of the system. (3) The nonlinear ordinary differential equation (ODE) of the O2 absorption kinetics was derived and a simple approximate solution to this ODE was obtained theoretically that is similar to the empirical exponential formula published in the relevant literature. (4) The temperature dependence of the oxygen absorption rate is more complicated than that described by the Arrhenius equation. PMID:26650762

  1. Modeling of the Temperature Effect on Oxygen Absorption by Iron-Based Oxygen Scavengers.

    PubMed

    Polyakov, Vladimir A; Miltz, Joseph

    2016-01-01

    A new engineering-oriented model for prediction of the effect of temperature on the kinetics of oxygen absorption by iron-based oxygen scavengers (IOSs) was developed. The model is based on the physicochemical mechanism of the O2 scavenging process by the active component of the IOS (iron powder). The conclusions of this study are: (1) the iron deposits formed on the iron particles are composed of 2 different layers: an inner layer of Fe3 O4 and an outer layer of FeOOH that vanishes with the depletion of oxygen. (2) The model considers the chemical processes in the heterogeneous closed system "Fe-H2 O-NaCl-O2 " and describes the kinetics of oxygen absorption by the powder, depending on the characteristics of the system. (3) The nonlinear ordinary differential equation (ODE) of the O2 absorption kinetics was derived and a simple approximate solution to this ODE was obtained theoretically that is similar to the empirical exponential formula published in the relevant literature. (4) The temperature dependence of the oxygen absorption rate is more complicated than that described by the Arrhenius equation.

  2. Scavenging of reactive oxygen species by Eriobotrya japonica seed extract.

    PubMed

    Yokota, Junko; Takuma, Daisuke; Hamada, Atsuhide; Onogawa, Masahide; Yoshioka, Saburo; Kusunose, Masahiko; Miyamura, Mitsuhiko; Kyotani, Shojiro; Nishioka, Yutaka

    2006-03-01

    We have clarified that Eriobotrya japonica seed extract has strong antioxidative activity, and is effective for the prevention and treatment of various diseases, such as hepatopathy and nephropathy. In this study, to investigate the influences of components of Eriobotrya japonica seed extract on its antioxidative activity, extracts were prepared using various solvents (n-hexane (Hex), ethyl acetate (EtOAc), n-butanol (n-BuOH), methanol (MeOH) and H2O) and the antioxidative activity of the solvent fractions and components was evaluated based on the scavenging of various radicals (DPPH and O2(-)) measured by the ESR method and the inhibition of Fe3+-ADP induced NADPH dependent lipid peroxidation in rat liver microsomes. The radical scavenging activities and inhibitory activities on lipid peroxidation differed among the solvent fractions and components. In the n-BuOH, MeOH and H2O fractions, radical scavenging activity and inhibitory activity on lipid peroxidation were high. In addition, these fractions contained abundant polyphenols, and the radical scavenging activity increased with the polyphenol content. In the low-polar Hex and EtOAc fractions, the radical scavenging activity was low, but the lipid peroxidation inhibition activity was high. These fractions contained beta-sitosterol, and the inhibitory activity on lipid peroxidation was high. Based on these findings, the antioxidative activity of Eriobotrya japonica seed extract may be derived from many components involved in a complex mechanism, resulting in high activity.

  3. The role of vasoactive intestinal peptide in scavenging singlet oxygen

    SciTech Connect

    Misra, B.R.; Misra, H.P. )

    1990-02-26

    The neuropeptide vasoactive intestinal peptide (VIP), a highly basic 28 amino acid peptide, has a widespread distribution in the body. The functional specificity of this peptide not only includes its potent vasodilatory activity, but also its role in protecting lungs against acute injury, in preventing T-lymphocyte proliferation and in modulating immune function. The purpose of this study was to examine the possible antioxidant properties of VIP. The authors found that VIP up to 50 {mu}g/ml had no inhibitory effect on its reduction of cytochrome C by xanthine and xanthine oxidase, indicating that the peptide does not have significant O{sub 2} scavenging ability. However, VIP was found to inhibit, in a dose-dependent manner, the {sup 1}O{sub 2} dependent 2, 2, 6, 6 tetramethyl piperidine oxide (TEMPO) formation. {sup 1}O{sub 2} was produced by rose benzal photosensitizing system and was detected as TEMP-{sup 1}O{sub 2} adduct (TEMPO) by electron paramagnetic resonance (EPR) spectroscopic technique. The formation of TEMPO signal was strongly inhibited by {beta}-carotene, histidine as well as azide, but not by superoxide dismutase (48 {mu}g/ml), catalase (20 {mu}g/ml) and mannitol (6mM), indicating that TEMPO signal was a TEMP-{sup 1}O{sub 2} adduct. These results indicate that VIP has potent antioxidant activity and may serve as a singlet O{sub 2} scavenger, thus it may modulate the oxidative tissue injury caused by this reactive oxygen species.

  4. DNA cleavage activity of Fe(II)N4Py under photo irradiation in the presence of 1,8-naphthalimide and 9-aminoacridine: unexpected effects of reactive oxygen species scavengers.

    PubMed

    Li, Qian; Browne, Wesley R; Roelfes, Gerard

    2011-09-01

    The DNA cleavage activity of the iron(II) complex of the ligand N,N-bis(2-pyridylmethyl)-N-bis(2-pyridyl)methylamine (N4Py) was investigated in the presence of the chromophores 1,8-naphthalimide (NI) and 9-aminoacridine (AA) under photo irradiation at 355 and 400.8 nm and compared to the activity of the complex without the chromophores. Whereas in most cases no synergistic effect of the added chromophores on DNA cleavage efficiency was observed, it was found that for Fe(II)N4Py, in combination with NI under irradiation at 355 nm, the DNA cleavage activity was increased. Surprisingly, it was found that the addition of reactive oxygen species (ROS) scavengers gave rise to significantly increased DNA cleavage efficiency, which is a highly counterintuitive observation since ROS are needed to achieve DNA cleavage. A hypothesis is put forward to explain, at least partly, these results. It is proposed that the addition of scavengers inhibits quenching of (3)NI*, thus making photo-induced electron transfer between (3)NI* and Fe(III)N4Py more efficient. This results in reduction of Fe(III)N4Py to Fe(II)N4Py, which can then react with ROS giving rise to DNA cleavage. Hence the role of the scavengers is to maintain a close to optimal concentration of ROS. The present study serves as an illustration of the care that needs to be exercised in interpreting the results of experiments using standard ROS scavengers, since especially in complex systems such as presented here they can give rise to unexpected phenomena. In the presence of 1,8-naphthalimide or 9-aminoacridine, ROS scavengers can increase the DNA cleavage efficiency of Fe(II)N4Py complex under photo irradiation.

  5. Oxygen Radical Scavenger Activity, EPR, NMR, Molecular Mechanics and Extended-Hückel Molecular Orbital Investigation of the Bis(Piroxicam)Copper(II) Complex.

    PubMed

    Cini, R; Pogni, R; Basosi, R; Donati, A; Rossi, C; Sabadini, L; Rollo, L; Lorenzini, S; Gelli, R; Marcolongo, R

    1995-01-01

    The oxygen radical scavenger activity (ORSA) of [Cu(II)(Pir)(2)] (HPir = Piroxicam = 4-hydroxy -2- methyl -N-2- pyridyl -2H- 1,2-benzothiazine -3- carboxamide 1,1-dioxide) was determined by chemiluminescence of samples obtained by mixing human neutrophils (from healthy subjects) and [Cu(II)(Pir)(2)(DMF)(2)] (DMF = N,N -dimethylformammide) in DMSO/GLY/PBS (2:1:2, v/v) solution (DMSO = dimethylsulfoxide, GLY = 1,2,3-propantriol, PBS = Dulbecco's buffer salt solution). The ratio of the residual radicals, for the HPir (1.02.10(-4)M) and [Cu(II)(Pir)(2)(DMF)(2)] (1.08.10(-5)M)/HPir (8.01.10-(-5)M) systems was higher than 12 (not stimulated) [excess of piroxicam was added (Cu/Pir molar ratio approximately 1:10) in order to have most of the metal complexed as bischelate]. In contrast, the ratio of residual radicals for the CuCl(2) (1.00.10(-5)M) and [Cu(II)(Pir)(2)(DMF)(2)] (1.08.10(-5)M)/Hpir (8.01.10(-5)M)system was 5. The [Cu(II)(Pir)(2)] compound is therefore a stronger radical scavenger than either HPir or CuCl(2). A molecular mechanics (MM) analysis of the gas phase structures of neutral HPir, its zwitterionic (HPir(+-)) and anionic (Pir(-)) forms, and some Cu(II)-piroxicam complexes based on X-ray structures allowed calculation of force constants. The most stable structure for HPir has a ZZZ conformation similar to that found in the Cu(II) (and Cd(II) complexes) in the solid state as well as in the gas phase. The structure is stabilized by a strong H bond which involves the N(amide)-H and O(enolic) groups. The MM simulation for the [Cu(II)(Pir)(2)(DMF)(2)] complex showed that two high repulsive intramolecular contacts exist between a pyridyl hydrogen atom of one Pir(-) molecule with the O donor of the other ligand. These interactions activate a transition toward a pseudo-tetrahedral geometry, in the case the apical ligands are removed. On refluxing a suspension of [Cu(II)(Pir)(2)(DMF)(2)] in acetone a brown microcystalline solid with the Cu(Pir)(2).0.5DMF

  6. Development of nitroxide radicals-containing polymer for scavenging reactive oxygen species from cigarette smoke

    NASA Astrophysics Data System (ADS)

    Yoshitomi, Toru; Kuramochi, Kazuhiro; Binh Vong, Long; Nagasaki, Yukio

    2014-06-01

    We developed a nitroxide radicals-containing polymer (NRP), which is composed of poly(4-methylstyrene) possessing nitroxide radicals as a side chain via amine linkage, to scavenge reactive oxygen species (ROS) from cigarette smoke. In this study, the NRP was coated onto cigarette filters and its ROS-scavenging activity from streaming cigarette smoke was evaluated. The intensity of electron spin resonance signals of the NRP in the filter decreased after exposure to cigarette smoke, indicating consumption of nitroxide radicals. To evaluate the ROS-scavenging activity of the NRP-coated filter, the amount of peroxy radicals in an extract of cigarette smoke was measured using UV-visible spectrophotometry and 1,1-diphenyl-2-picrylhydrazyl (DPPH). The absorbance of DPPH at 517 nm decreased with exposure to cigarette smoke. When NRP-coated filters were used, the decrease in the absorbance of DPPH was prevented. In contrast, both poly[4-(cyclohexylamino)methylstyrene]- and poly(acrylic acid)-coated filters, which have no nitroxide radical, did not show any effect, indicating that the nitroxide radicals in the NRP scavenge the ROS in cigarette smoke. As a result, the extract of cigarette smoke passed through the NRP-coated filter has a lower cellular toxicity than smoke passed through poly[4-(cyclohexylamino)methylstyrene]- and poly(acrylic acid)-coated filters. Accordingly, NRP is a promising material for ROS scavenging from cigarette smoke.

  7. Antinephritis and radical scavenging activity of prenylflavonoids.

    PubMed

    Fukai, Toshio; Satoh, Kazue; Nomura, Taro; Sakagami, Hiroshi

    2003-12-01

    Antinephritis activity of 5 prenylflavonoids similar to glabridin (1-5), isolated from Morus alba, Artocarpus communis, Glycyrrhiza uralensis and G. inflata, was evaluated in mice with glomerular disease (Masugi-nephritis). Oral administrations of artonin E (2) or licochalcone A (4) for 10 days (30 mg kg(-1) day(-1)) reduced the amount of urinary protein excretion compared to nephritic mice. ESR spectroscopy demonstrated that morusin (1) and licorisoflavan A (5) increased the radical intensity of sodium ascorbate by about two times. Morusin, licoricidin (3), licochalcone A and licorisoflavan A showed weak scavenging activity against superoxide anion radical.

  8. Prussian Blue Nanoparticles as Multienzyme Mimetics and Reactive Oxygen Species Scavengers.

    PubMed

    Zhang, Wei; Hu, Sunling; Yin, Jun-Jie; He, Weiwei; Lu, Wei; Ma, Ming; Gu, Ning; Zhang, Yu

    2016-05-11

    The generation of reactive oxygen species (ROS) is an important mechanism of nanomaterial toxicity. We found that Prussian blue nanoparticles (PBNPs) can effectively scavenge ROS via multienzyme-like activity including peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD) activity. Instead of producing hydroxyl radicals (•OH) through the Fenton reaction, PBNPs were shown to be POD mimetics that can inhibit •OH generation. We theorized for the first time that the multienzyme-like activities of PBNPs were likely caused by the abundant redox potentials of their different forms, making them efficient electron transporters. To study the ROS scavenging ability of PBNPs, a series of in vitro ROS-generating models was established using chemicals, UV irradiation, oxidized low-density lipoprotein, high glucose contents, and oxygen glucose deprivation and reperfusion. To demonstrate the ROS scavenging ability of PBNPs, an in vivo inflammation model was established using lipoproteins in Institute for Cancer Research (ICR) mice. The results indicated that PBNPs hold great potential for inhibiting or relieving injury induced by ROS in these pathological processes.

  9. Rice ASR1 Protein with Reactive Oxygen Species Scavenging and Chaperone-like Activities Enhances Acquired Tolerance to Abiotic Stresses in Saccharomyces cerevisiae

    PubMed Central

    Kim, Il-Sup; Kim, Young-Saeng; Yoon, Ho-Sung

    2012-01-01

    Abscisic acid stress ripening (ASR1) protein is a small hydrophilic, low molecular weight, and stress-specific plant protein. The gene coding region of ASR1 protein, which is induced under high salinity in rice (Oryza sativa Ilmi), was cloned into a yeast expression vector pVTU260 and transformed into yeast cells. Heterologous expression of ASR1 protein in transgenic yeast cells improved tolerance to abiotic stresses including hydrogen peroxide (H2O2), high salinity (NaCl), heat shock, menadione, copper sulfate, sulfuric acid, lactic acid, salicylic acid, and also high concentration of ethanol. In particular, the expression of metabolic enzymes (Fba1p, Pgk1p, Eno2p, Tpi1p, and Adh1p), antioxidant enzyme (Ahp1p), molecular chaperone (Ssb1p), and pyrimidine biosynthesis-related enzyme (Ura1p) was up-regulated in the transgenic yeast cells under oxidative stress when compared with wild-type cells. All of these enzymes contribute to an alleviated redox state to H2O2-induced oxidative stress. In the in vitro assay, the purified ASR1 protein was able to scavenge ROS by converting H2O2 to H2O. Taken together, these results suggest that the ASR1 protein could function as an effective ROS scavenger and its expression could enhance acquired tolerance of ROS-induced oxidative stress through induction of various cell rescue proteins in yeast cells. PMID:22382682

  10. Rice ASR1 protein with reactive oxygen species scavenging and chaperone-like activities enhances acquired tolerance to abiotic stresses in Saccharomyces cerevisiae.

    PubMed

    Kim, Il-Sup; Kim, Young-Saeng; Yoon, Ho-Sung

    2012-03-01

    Abscisic acid stress ripening (ASR1) protein is a small hydrophilic, low molecular weight, and stress-specific plant protein. The gene coding region of ASR1 protein, which is induced under high salinity in rice (Oryza sativa Ilmi), was cloned into a yeast expression vector pVTU260 and transformed into yeast cells. Heterologous expression of ASR1 protein in transgenic yeast cells improved tolerance to abiotic stresses including hydrogen peroxide (H(2)O(2)), high salinity (NaCl), heat shock, menadione, copper sulfate, sulfuric acid, lactic acid, salicylic acid, and also high concentration of ethanol. In particular, the expression of metabolic enzymes (Fba1p, Pgk1p, Eno2p, Tpi1p, and Adh1p), antioxidant enzyme (Ahp1p), molecular chaperone (Ssb1p), and pyrimidine biosynthesis-related enzyme (Ura1p) was up-regulated in the transgenic yeast cells under oxidative stress when compared with wild-type cells. All of these enzymes contribute to an alleviated redox state to H2O2-induced oxidative stress. In the in vitro assay, the purified ASR1 protein was able to scavenge ROS by converting H(2)O(2) to H(2)O. Taken together, these results suggest that the ASR1 protein could function as an effective ROS scavenger and its expression could enhance acquired tolerance of ROS-induced oxidative stress through induction of various cell rescue proteins in yeast cells. PMID:22382682

  11. In vitro scavenging capacity of annatto seed extracts against reactive oxygen and nitrogen species.

    PubMed

    Chisté, Renan Campos; Mercadante, Adriana Zerlotti; Gomes, Ana; Fernandes, Eduarda; Lima, José Luís Fontes da Costa; Bragagnolo, Neura

    2011-07-15

    Bixa orellana L. (annatto), from Bixaceae family, is a native plant of tropical America, which accumulates several carotenoids (including bixin and norbixin), terpenoids, tocotrienols and flavonoids with potential antioxidant activity. In the present study, the in vitro scavenging capacity of annatto seed extracts against reactive oxygen species (ROS) and reactive nitrogen species (RNS) was evaluated and compared to the bixin standard. Annatto extracts were obtained using solvents with different polarities and their phenolic compounds and bixin levels were determined by high performance liquid chromatography coupled to diode array detector. All annatto extracts were able to scavenge all the reactive species tested at the low μg/mL range, with the exception of superoxide radical. The ethanol:ethyl acetate and ethyl acetate extracts of annatto seeds, which presented the highest levels of hypolaetin and bixin, respectively, were the extracts with the highest antioxidant capacity, although bixin standard presented the lowest IC(50) values. PMID:23140681

  12. In vitro free radical scavenging activity of platinum nanoparticles

    NASA Astrophysics Data System (ADS)

    Watanabe, Aki; Kajita, Masashi; Kim, Juewon; Kanayama, Atsuhiro; Takahashi, Kyoko; Mashino, Tadahiko; Miyamoto, Yusei

    2009-11-01

    A polyacrylic acid (PAA)-protected platinum nanoparticle species (PAA-Pt) was prepared by alcohol reduction of hexachloroplatinate. The PAA-Pt nanoparticles were well dispersed and homogeneous in size with an average diameter of 2.0 ± 0.4 nm (n = 200). We used electron spin resonance to quantify the residual peroxyl radical (\\mathrm {AOO}^{\\bullet } ) generated from 2,2-azobis (2-aminopropane) dihydrochloride (AAPH) by thermal decomposition in the presence of O2 and a spectrophotometric method to quantify the residual 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. PAA-Pt scavenged these two radicals in a dose-dependent manner. Platinum was the functional component. PAA-Pt reduced the rate of oxygen consumption required for linoleic acid peroxidation initiated by \\mathrm {AOO}^{\\bullet } generated from AAPH, indicating inhibition of the propagation of linolate peroxidation. A thiobarbituric acid test also revealed dose-dependent inhibition of the linolate peroxidation by PAA-Pt. Fifty micromolar platinum, as PAA-Pt, completely quenched 250 µM DPPH radical for 5 min. Even when twice diluted in half, the PAA-Pt still quenched 100% of the 250 µM DPPH radical. The scavenging activity of PAA-Pt is durable. These observations suggest that PAA-Pt is an efficient scavenger of free radicals.

  13. Deuterohemin-AlaHisLys mitigates the symptoms of rats with non-insulin dependent diabetes mellitus by scavenging reactive oxygen species and activating the PI3-K/AKT signal transduction pathway.

    PubMed

    Lei, Liyan; Zhang, Guangji; Li, Pengfei; Zhang, Yuan; Guo, Youming; Zhang, Wenqi; Zhang, Wenbo; Hu, Bing; Wang, Liping

    2014-09-01

    Damage to pancreatic β-cells plays an important role in the development of type 2 diabetes, and oxidative stress is a likely contributor. In the present study, we investigated the effect of deuterohemin-AlaHisLys (DhHP-3), a microperoxidase-11 mimic, on rats with non-insulin dependent diabetes mellitus and examined the action mechanisms of DhHP-3. The induced hyperglycemia, glucose intolerance, and insulin resistance in diabetic rats were associated with increased oxidative stress and damage to pancreatic islets. DhHP-3 (3 mg/kg) ameliorated hyperglycemia and insulin resistance, protected pancreas islet, decreased the content of malondialdehyde, and increased the activity of superoxide dismutase in plasma and pancreatic tissue by reducing ROS levels. Furthermore, DhHP-3 stimulated the proliferation of INS-1 cells and inhibited apoptosis by activating the phosphatidylinositol 3-kinase/protein kinase B (PI3-K/AKT) signaling pathway. Our results demonstrated for the first time that DhHP-3 decreased blood glucose level in rats with non-insulin dependent diabetes mellitus, scavenged reactive oxygen species, activated the PI3-K/AKT signaling pathway, and protected pancreatic β-cells against apoptosis.

  14. A novel biointerface that suppresses cell morphological changes by scavenging excess reactive oxygen species.

    PubMed

    Ikeda, Yutaka; Yoshinari, Tomoki; Nagasaki, Yukio

    2015-09-01

    During cell cultivation on conventional culture dishes, various events results in strong stresses that lead to the production of bioactive species such as reactive oxygen species (ROS) and nitric oxide. These reactive species cause variable damage to cells and stimulate cellular responses. Here, we report the design of a novel biocompatible surface that decreases stress by not only morphologically modifying the dish surface by using poly(ethylene glycol) tethered chains, but also actively scavenging oxidative stress by using our novel nitroxide radical-containing polymer. A block copolymer, poly(ethylene glycol)-b-poly[(2,2,6,6-tetramethylpiperidine-N-oxyl)aminomethylstyrene] (PEG-b-PMNT) was used to coat the surface of a dish. Differentiation of undifferentiated human leukemia (HL-60) cells was found to be suppressed on the polymer-coated dish. Notably, HL-60 cell cultivation caused apoptosis under high-density conditions, while spontaneous apoptosis was suppressed in cells plated on the PEG-b-PMNT-modified surface, because a healthy mitochondrial membrane potential was maintained. In contrast, low molecular weight antioxidants did not have apparent effects on the maintenance of mitochondria. We attribute this to the lack of cellular internalization of our immobilized polymer and selective scavenging of excessive ROS generated outside of cells. These results demonstrate the utility of our novel biocompatible material for actively scavenging ROS and thus maintaining cellular morphology. PMID:25691268

  15. Preparation of reactive oxygen scavenging peptides from tilapia (Oreochromis niloticus) skin gelatin: optimization using response surface methodology.

    PubMed

    Zhuang, Yongliang; Sun, Liping

    2011-04-01

    Gelatin extracted from tilapia skin was hydrolyzed with Properase E. Response surface methodology (RSM) was applied to optimize the hydrolysis condition (temperature [T], enzyme-to-substrate ratio [E/S], pH and reaction time [t]), to obtain the hydrolysate with the highest hydroxyl radical (•OH) scavenging activity. The optimum conditions obtained were T of 44.2 °C, E/S of 2.2%, pH of 9.2, and t of 3.4 h. The predicted •OH scavenging activity of the hydrolysate under the optimum conditions was 60.7%, and the actually experimental scavenging activity was 60.8%. The hydrolysate was fractionated by ultrafiltration, and 4 fractions were collected. The fraction TSGH4 (MW<2000 Da) showed the strongest •OH scavenging activity with the highest yield. Furthermore, reactive oxygen species (ROS) scavenging activities of TSGH4 with different concentrations were investigated in 5 model systems, including superoxide anion radical (•O2), •OH, hydrogen peroxide (H2O2), peroxynitrite (ONOO-), and nitric oxide (NO•), compared with reduced glutathione (GSH). The results showed that TSGH4 significantly scavenged these ROS, and could be used as a functional ingredient in medicine and food industries.

  16. Antioxidant and radical scavenging activities of chamazulene.

    PubMed

    Capuzzo, Andrea; Occhipinti, Andrea; Maffei, Massimo E

    2014-01-01

    Essential oils (EOs) of chamomile contain several bioactive compounds, including monoterpenes, sesquiterpenes, triterpenes and fatty acids. Hydrodistillation of chamomile EO induces the formation of chamazulene, a bioactive compound. Chamazulene was isolated from the EO by column chromatography. The total antioxidant capacity confirmed a higher antioxidant activity of chamazulene (IC50 = 6.4 μg mL(- 1)) than of ascorbic acid (IC50 = 12.8 μg mL(- 1)), α-tocopherol (IC50 = 20.5 μg mL(- 1)) and of butylated hydroxytoluene (BHT) (IC50 = 30.8 μg mL(- 1)). Chamazulene was unable to react with DPPH√. However, when chamazulene was assayed with ABTS√, a strong and significantly (P < 0.05) higher free radical scavenging activity was observed (IC50 = 3.7 μg mL(- 1)), with respect to BHT (IC50 = 6.2 μg mL(- 1)) and α-tocopherol (IC50 = 11.5 μg mL(- 1)). The results of this work show that chamazulene is an important factor for the antioxidant power of chamomile oil. PMID:24980540

  17. Fisetin attenuates hydrogen peroxide-induced cell damage by scavenging reactive oxygen species and activating protective functions of cellular glutathione system.

    PubMed

    Kang, Kyoung Ah; Piao, Mei Jing; Kim, Ki Cheon; Cha, Ji Won; Zheng, Jian; Yao, Cheng Wen; Chae, Sungwook; Hyun, Jin Won

    2014-01-01

    Hydrogen peroxide (H2O2) can induce cell damage by generating reactive oxygen species (ROS), resulting in DNA damage and cell death. The aim of this study is to elucidate the protective effects of fisetin (3,7,3',4',-tetrahydroxy flavone) against H2O2-induced cell damage. Fisetin reduced the level of superoxide anion, hydroxyl radical in cell free system, and intracellular ROS generated by H2O2. Moreover, fisetin protected against H2O2-induced membrane lipid peroxidation, cellular DNA damage, and protein carbonylation, which are the primary cellular outcomes of H2O2 treatment. Furthermore, fisetin increased the level of reduced glutathione (GSH) and expression of glutamate-cysteine ligase catalytic subunit, which is decreased by H2O2. Conversely, a GSH inhibitor abolished the cytoprotective effect of fisetin against H2O2-induced cells damage. Taken together, our results suggest that fisetin protects against H2O2-induced cell damage by inhibiting ROS generation, thereby maintaining the protective role of the cellular GSH system.

  18. Reversible oxygen scavenging at room temperature using electrochemically reduced titanium oxide nanotubes

    NASA Astrophysics Data System (ADS)

    Close, Thomas; Tulsyan, Gaurav; Diaz, Carlos A.; Weinstein, Steven J.; Richter, Christiaan

    2015-05-01

    A material capable of rapid, reversible molecular oxygen uptake at room temperature is desirable for gas separation and sensing, for technologies that require oxygen storage and oxygen splitting such as fuel cells (solid-oxide fuel cells in particular) and for catalytic applications that require reduced oxygen species (such as removal of organic pollutants in water and oil-spill remediation). To date, however, the lowest reported temperature for a reversible oxygen uptake material is in the range of 200-300 °C, achieved in the transition metal oxides SrCoOx (ref. 1) and LuFe2O4+x (ref. 2) via thermal cycling. Here, we report rapid and reversible oxygen scavenging by TiO2-x nanotubes at room temperature. The uptake and release of oxygen is accomplished by an electrochemical rather than a standard thermal approach. We measure an oxygen uptake rate as high as 14 mmol O2 g-1 min-1, ˜2,400 times greater than commercial, irreversible oxygen scavengers. Such a fast oxygen uptake at a remarkably low temperature suggests a non-typical mechanistic pathway for the re-oxidation of TiO2-x. Modelling the diffusion of oxygen, we show that a likely pathway involves ‘exceptionally mobile’ interstitial oxygen produced by the oxygen adsorption and decomposition dynamics, recently observed on the surface of anatase.

  19. Radical Scavenging Activities of Undaria pinnatifida Extracts Fermented with Cordyceps militaris Mycelia.

    PubMed

    Kim, Yon-Suk; Kim, Eun-Kyung; Hwang, Jin-Woo; Han, Young-Ki; Kim, Seong-Eun; Jeong, Jae-Hyun; Moon, Sang-Ho; Jeon, Byong-Tae; Park, Pyo-Jam

    2015-06-01

    The present study was performed to investigate the various radical scavenging activities of fermented Undaria pinnatifida by the mycelia fermentation method. U. pinnatifida was fermented with Cordyceps militaris (C. militaris) mycelia using solid culture and compared with unfermentated U. pinnatifida and C. militaris mycelia for antioxidant activities. The various radical scavenging activities of extracts from U. pinnatifida fermented with C. militaris mycelia (FUCM) were evaluated by electron spin resonance. The antioxidant activities of the FUCM extracts were assayed for ferric reducing antioxidant power, 2,2'-azinobis-(3- ethybenzothiazoline-6-sulfonic acid) radical scavenging activity, and oxygen radical absorption capacity. The free radical scavenging activity of FUCM extracts was higher than that of C. militaris mycelia or U. pinnatifida alone. FUCM extracts were significantly (p < 0.05) increased up to 35 times, 10 times, and 16 times that of U. pinnatifida extracts on DPPH, alkyl, and hydroxyl radical scavenging activities, respectively. These results indicate that FUCM extracts have different chemical ingredients from U. pinnatifida and could provide beneficial antioxidant activity.

  20. The use of oxygen scavengers to prevent the transient discolouration of ground beef packaged under controlled, oxygen-depleted atmospheres.

    PubMed

    Gill, C O; McGinnis, J C

    1995-01-01

    Rates of O(2) absorption from air were determined for a type of commercial O(2) scavenger that is formulated for rapid O(2) absorption at chiller temperatures. Rates of O(2) absorption from N(2) atmospheres containing 600 ppm O(2) were determined for trays that each contained 350 g of ground beef. Packs with controlled atmospheres of N(2) that contained ground beef and O(2) scavengers were prepared, to determine the conditions under which the scavengers could prevent the transient discolouration of the meat which arises from its reaction with the residual O(2) initially present in pack atmospheres. The rates of O(2) absorption by individual scavengers varied from the average by ±50%. The rate of O(2) absorption declined with decreasing oxygen concentration, from an average value per scavenger of about 12 ml h(-1) when O(2) concentrations were between 20 and 10%. At O(2) concentrations <1% (10,000 ppm) the rate of O(2) absorption was directly proportioned to the O(2) concentration so that the O(2) concentration in an atmosphere in a gas-impermeable pouch declined exponentially with time. The absorption of O(2) by ground beef was similarly dependent on the O(2) concentration. At 2 °C, the transient discolouration of beef in atmospheres initially containing about 50 ppm O(2) was prevented by the presence of 17.5 scavengers per l of atmosphere. At -15 °C, discolouration was prevented by 5 scavengers per l. The findings indicate that the O(2) concentration in pack atmospheres has to be reduced below 10 ppm within 30 min at 2 °C, or 2 h at -1.5 °C if ground beef is not to transiently discolour. It is unlikely that the required rates of O(2) absorption could be obtained economically with currently available, commercial O(2) scavengers.

  1. Scavenging of reactive oxygen species by a glycolipid fraction of Mycobacterium avium serovar 2.

    PubMed

    Scherer, T A; Lauredo, I T; Abraham, W M

    1997-01-01

    Previous experiments indicated that MIF-A3, a peptidoglycolipid extracted from Mycobacterium avium serovar 2 (Mycobacterium paratuberculosis 18), inhibits the killing of Candida albicans by activated bovine peripheral blood-derived macrophages and murine thioglycollate-elicited peritoneal macrophages in vitro. Subsequent in vitro data from our laboratory indicated that this reduction in killing may be related to the ability of MIF-A3 to scavenge reactive oxygen species (ROS). In this study we examined this hypothesis directly by determining if MIF-A3 reduced exogenous H2O2-induced candidacidal activity. When Candida albicans was incubated with H2O2 (4 mM) alone, colony-forming units/ml x 10(4) (CFU/ml) were 0.4 +/- 0.1 (mean +/- SE, n = 4) as compared to 11.3 +/- 2.0 CFU/ml in control (untreated) cultures (p < .05). The addition of catalase at concentrations > or = 6.8 U/ml, completely blocked the fungicidal effect of H2O2. However, reducing the amount of catalase from 6.8 U/ml to 3.4 U/ml resulted in a loss of scavenging activity, which was associated with a 50% increase in H2O2-mediated killing. Substituting MIF-A3 (400 micrograms/ml) for catalase, also reduced H2O2-induced fungicidal activity. In the absence of MIF-A3, H2O2 reduced Candida albicans to less than 10(3) CFU/ml. However, in the presence of MIF-A3 the CFU/ml of Candida albicans increased 7.5-fold. Based on concentration-response curves of H2O2 inhibition vs. increasing amounts of catalase we determined that the relative inhibitory capacity of the MIF-A3 (400 micrograms/ml) was approximately 1.0 U/ml "catalase equivalents." These findings provide direct evidence that MIF-A3 can scavenge H2O2, and reduce H2O2-induced killing of Candida albicans. PMID:8981049

  2. Radical scavenging, antioxidant and cytotoxic activity of Brazilian Caatinga plants.

    PubMed

    David, Juceni P; Meira, Marilena; David, Jorge M; Brandão, Hugo N; Branco, Alexsandro; de Fátima Agra, M; Barbosa, M Regina V; de Queiroz, Luciano P; Giulietti, Ana M

    2007-04-01

    Extracts of 32 plants from the Brazilian northeastern semi-arid region called Caatinga were evaluated through DPPH radical scavenging assay, beta-carotene bleaching, and brine shrimp lethality tests (BST). Among the extracts studied Byrsonima cf. gardneriana, Mascagnia coriacea, Cordia globosa, Diodia apiculata and Hypenia salzmannii showed the highest activities in DPPH radical scavenging test. In the beta-carotene bleaching test the highest activities were observed for Passiflora cincinnata, Chamaecrista repens, B. cf. gardneriana, Rollinia leptopetala, Serjania glabrata, Diospyros gaultheriifolia, C. globosa, Mimosa ophtalmocentra, M. coriacea and Lippia cf. microphylla. In contrast, R. leptopetala, Zornia cf. brasiliensis and Leonotis nepetifolia were the most active species in the BST.

  3. Radical scavenging, antioxidant and cytotoxic activity of Brazilian Caatinga plants.

    PubMed

    David, Juceni P; Meira, Marilena; David, Jorge M; Brandão, Hugo N; Branco, Alexsandro; de Fátima Agra, M; Barbosa, M Regina V; de Queiroz, Luciano P; Giulietti, Ana M

    2007-04-01

    Extracts of 32 plants from the Brazilian northeastern semi-arid region called Caatinga were evaluated through DPPH radical scavenging assay, beta-carotene bleaching, and brine shrimp lethality tests (BST). Among the extracts studied Byrsonima cf. gardneriana, Mascagnia coriacea, Cordia globosa, Diodia apiculata and Hypenia salzmannii showed the highest activities in DPPH radical scavenging test. In the beta-carotene bleaching test the highest activities were observed for Passiflora cincinnata, Chamaecrista repens, B. cf. gardneriana, Rollinia leptopetala, Serjania glabrata, Diospyros gaultheriifolia, C. globosa, Mimosa ophtalmocentra, M. coriacea and Lippia cf. microphylla. In contrast, R. leptopetala, Zornia cf. brasiliensis and Leonotis nepetifolia were the most active species in the BST. PMID:17331673

  4. In vitro free radical scavenging activity of five Salvia species.

    PubMed

    Nickavar, Bahman; Kamalinejad, Mohammad; Izadpanah, Hamidreza

    2007-10-01

    The radical scavenging activity of ethanolic extracts from five Salvia species including S. hypoleuca Benth., S. reuterana Boiss., S. verticillata L., S. virgata Jacq. and S. officinalis L. (as the reference plant with well documented free radical scavenging and antioxidant properties) was evaluated in vitro with the spectrophotometric method based on the reduction of the stable DPPH free radical. All the extracts showed radical scavenging activity, especially S. verticillata [IC50=23.53 (20.56-26.93) microg ml(-1)] and S. virgata [IC50=27.01 (24.08-30.29) microg ml(-1)] were found to be the most active species. Furthermore, the extracts were investigated regarding their total flavonoid content (TFC) by AlCl3 reagent. The extracts S. hypoleuca (TFC=53.16+/-1.95 microg mg(-1)) and S. reuterana (TFC=46.97+/-4.43 microg mg(-1)) had the highest content of flavonoid. However, a favourable correlation was not found between the radical scavenging potency and the total flavonoid content. This study suggests that S. verticillata and S. virgata are the possible sources of natural radical scavengers.

  5. Influence of cysteine and methionine availability on protein peroxide scavenging activity and phenolic stability in emulsions.

    PubMed

    Zhou, Lisa; Elias, Ryan J

    2014-03-01

    Plant phenolics are secondary metabolites that have been shown to confer beneficial health effects in humans. However, many of these compounds undergo metal-catalysed oxidation reactions, leading to the generation of hydrogen peroxide (H2O2) and other reactive oxygen species that may negatively impact product stability. In proteins, methionine (Met) and cysteine (Cys) are capable of reacting directly with peroxides. Thus, the dairy proteins, casein (CAS) and β-lactoglobulin (BLG), were examined for their ability to scavenge H2O2 (400μM) and influence (-)-epigallocatechin-3-gallate (EGCG) oxidation (400μM) in Tween- or sodium dodecyl sulphate (SDS)-stabilised hexadecane emulsions. To examine the effect that the accessibility of these amino acids have on their peroxide scavenging activities, proteins were pre-treated with tert-butyl hydroperoxide (TBHP), a bulky peroxide, to oxidise only solvent accessible Met residues or H2O2, the smallest peroxide, to oxidise buried Met residues. In CAS treatments, higher Met content yielded greater peroxide scavenging activity and EGCG stability. CAS treatments also showed significantly higher peroxide scavenging activity compared to the corresponding BLG treatment. However, BLG peroxide scavenging activity was greatly enhanced in SDS-stabilised emulsions due to protein denaturation and subsequent exposure of previously buried Cys residues.

  6. Protective effect of oxygen-derived free radical scavengers on the endothelium in vivo.

    PubMed

    Hladovec, J

    1986-01-01

    The endothelo-protective activity of a series of low-molecular oxygen-derived free radical scavengers (OFRS) was tested in rats. A model of endothelaemia provoked by intravenous administration of hydrogen peroxide was used. With each OFRS the activity in the hydrogen peroxide model was compared with that in the less specific model using the provocation by citrate as a calcium chelating agent. Relatively unspecific but biologically important OFRS, ascorbic acid, tocopherol, troxerutin and glutathione were tested in the first phase of the study. A marked optimum of endothelo-protective activity was shown with all agents, the optimum against hydrogen peroxide having been observed at doses from 3 to 50 times lower than against citrate. Ascorbic acid, troxerutin and the combination of both were also tested in another model based on leg ischaemia produced by ligature of the common femoral artery. Without OFRS, a marked increase of endothelaemia was observed after 30-60 min ischaemia showing a second peak after the release of the ligature. This second peak was completely abolished by the preventive administration of OFRS in a dose which was also effective in the hydrogen peroxide model.

  7. Use of oxygen scavengers to stabilize solid pharmaceutical dosage forms: a case study.

    PubMed

    Waterman, Kenneth C; Roy, Michael C

    2002-05-01

    A case study is described where degradation of a solid pharmaceutical dosage form susceptible to oxidation is minimized by incorporation of an oxygen scavenger as part of the packaging. Extremely low oxygen levels are attainable within 24 hr of packaging, even with permeable high-density polyethylene bottles commonly used in the pharmaceutical industry. This packaging methodology allows for a practical formulation-independent pathway for reducing or eliminating oxidative instability. In addition, this technology provides a convenient mechanistic probe for the degradation mechanism of solid dosage forms.

  8. Scoparone attenuates RANKL-induced osteoclastic differentiation through controlling reactive oxygen species production and scavenging

    SciTech Connect

    Lee, Sang-Hyun; Jang, Hae-Dong

    2015-02-15

    Scoparone, one of the bioactive components of Artemisia capillaris Thunb, has various biological properties including immunosuppressive, hepatoprotective, anti-allergic, anti-inflammatory, and antioxidant effects. This study aims at evaluating the anti-osteoporotic effect of scoparone and its underlying mechanism in vitro. Scoparone demonstrated potent cellular antioxidant capacity. It was also found that scoparone inhibited the receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation and suppressed cathepsin K and tartrate-resistant acid phosphatase (TRAP) expression via c-jun N-terminal kinase (JNK)/extracellular signal-regulated kinase (ERK)/p38-mediated c-Fos–nuclear factor of activated T cells, cytoplasmic 1 (NFATc1) signaling pathway. During osteoclast differentiation, the production of general reactive oxygen species (ROS) and superoxide anions was dose-dependently attenuated by scoparone. In addition, scoparone diminished NADPH (nicotinamide adenine dinucleotide phosphate) oxidase 1 (Nox1) expression and activation via the tumor necrosis factor receptor-associated factor 6 (TRAF6)–cSrc–phosphatidylinositol 3-kinase (PI3k) signaling pathway and prevented the disruption of mitochondrial electron transport chain system. Furthermore, scoparone augmented the expression of superoxide dismutase 1 (SOD1) and catalase (CAT). The overall results indicate that the inhibitory effect of scoparone on RANKL-induced osteoclast differentiation is attributed to the suppressive effect on ROS and superoxide anion production by inhibiting Nox1 expression and activation and protecting the mitochondrial electron transport chain system and the scavenging effect of ROS resulting from elevated SOD1 and CAT expression. - Highlights: • Scoparone dose-dependently inhibited RANKL-induced osteoclast differentiation. • Scoparone diminished general ROS and superoxide anions in a dose-dependent manner. • Scoparone inhibited Nox1 expression and

  9. [Composition, antifungal and radical scavenging activities of 4 propolis].

    PubMed

    Inouye, Shigeharu; Takahashi, Miki; Abe, Shigeru

    2011-01-01

    HPLC/MS analysis revealed that the main constituents of Brazilian propolis A and B were artepillin C and drupanin, while those of New Zealand propolis C were pinocembrin, galangin and alkylphenol. No flavonoid or phenolic acid was detected in Japanese propolis D. Propolis C showed comparatively potent activity against growth of Trichophyton mentagrophytes, against filament formation of Candida albicans and potent scavenging activity against 1,1-diphenyl-2-picrylhyrazyl radical, but was less active against growth of C. albicans, as compared with those of thyme thymol essential oil, which was used as a positive control. Propolis A, B, and D were weak in antifungal activity, but showed more potent radical scavenging activity than thyme thymol oil. These results reveal the unique bioactivity of propolis, suggesting a possible application for antifungal therapy. PMID:22123329

  10. Novel chromone and xanthone derivatives: Synthesis and ROS/RNS scavenging activities.

    PubMed

    Proença, Carina; Albuquerque, Hélio M T; Ribeiro, Daniela; Freitas, Marisa; Santos, Clementina M M; Silva, Artur M S; Fernandes, Eduarda

    2016-06-10

    Chromones and xanthones are oxygen-containing heterocyclic compounds acknowledged by their antioxidant properties. In an effort to develop novel agents with improved activity, a series of compounds belonging to these chemical classes were prepared. Their syntheses involve the condensation of appropriate 2-methyl-4H-chromen-4-ones, obtained via Baker-Venkataraman rearrangement, with (E)-3-(3,4-dimethoxyphenyl)acrylaldehyde to provide the corresponding 2-[(1E,3E)-4-(3,4-dimethoxyphenyl)buta-1,3-dien-1-yl]-4H-chromen-4-ones. Subsequent electrocyclization and oxidation of these compounds led to the synthesis of 1-aryl-9H-xanthen-9-ones. After cleavage of the protecting groups, hydroxylated chromones and xanthones were assessed as scavenging agents against both reactive oxygen species (ROS) [superoxide radical (O2(•-)), hydrogen peroxide (H2O2), hypochlorous acid (HOCl), singlet oxygen ((1)O2), and peroxyl radical (ROO(•))] and reactive nitrogen species (RNS) [nitric oxide ((•)NO) and peroxynitrite anion (ONOO(-))]. Generally, all the tested new hydroxylated chromones and xanthones exhibited scavenger effects dependent on the concentration, with IC50 values found in the micromolar range. Some of them were shown to have improved scavenging activity when compared with previously reported analogues, allowing the inference of preliminary conclusions on the structure-activity relationship. PMID:27031214

  11. Evaluation of scavenging rate constants of DOPA and tyrosine enantiomers against multiple reactive oxygen species and methyl radical as measured with ESR trapping method.

    PubMed

    Sueishi, Yoshimi; Takemoto, Tsubasa

    2015-04-15

    The scavenging rates of DOPA (dl- and l-3-(3,4-dihydroxyphenyl)alanine) and Tyr (tyrosine (dl- and l-3-(4-hydroxyphenyl)alanine)) against five reactive oxygen species (ROS) and methyl radical were measured with the use of electron spin resonance (ESR) spin-trapping method and the scavenging rate constants of DOPA and Tyr were determined. The scavenging rate constants for multiple active species increased in the order of O2(-)scavenging abilities for l-enantiomers and dl-mixtures of DOPA and Tyr were shown. Further, based on the redox potentials, we have suggested that the primary chemical process of antioxidant reactions with O2(-) and (1)O2 can be characterized with the electron transfer of antioxidants (DOPA and Tyr).

  12. Free radical scavenging activity of morin 2'-O(-) phenoxide anion.

    PubMed

    Marković, Zoran; Milenković, Dejan; Dorović, Jelena; Dimitrić Marković, Jasmina M; Stepanić, Višnja; Lučić, Bono; Amić, Dragan

    2012-12-01

    Due to intramolecular H-atom transfer, deprotonation of the most acidic 3-OH group of morin yields 2'-O(-) phenoxide anion. The reaction enthalpies related to mechanisms of free radical scavenging activity of this dominant species at a physiological pH of 7.4 were calculated by PM6 and DFT methods in gas-phase, water, benzene and DMSO. Results indicate the 4'-OH group of 2'-O(-) phenoxide anion is the active site for radical inactivation. The thermodynamically favoured mechanism depends on the polarity of the reaction media: in polar solvents (water and DMSO), the sequential proton loss electron transfer (SPLET) mechanism is preferred while in non-polar benzene (and in gas-phase), the hydrogen atom transfer (HAT) mechanism is responsible for the free radical scavenging activity of the morin phenoxide anion. Results show that the fast, semiempirical PM6 method fairly mimics more accurate, though time-consuming DFT methodologies.

  13. Flavonoid constituents and free radical scavenging activity of Alchemilla mollis.

    PubMed

    Trendafilova, Antoaneta; Todorova, Milka; Nikolova, Milena; Gavrilova, Anna; Vitkova, Antonina

    2011-12-01

    Antioxidant capacity of the methanolic extract of Alchemilla mollis was measured by its ability to scavenge the DPPH radical. The EtOAc fraction obtained after partition of the total extract was found to be the most active radical scavenger (IC50 9.8 +/- 1.8 microg/mL) and was subjected to fractionation by Sephadex LH-20 CC. Further purification by RP-18 CC led to the isolation of eight flavonoid glycosides: cis- and trans-tiliroside (1 and 2), rhodiolgin (3), hyperoside (4), isoquercitrin (5), miquelianin (6), sinocrassoside D2 (7), and gossypetin-3-O-beta-D-galactopyranosyl-7-O-alpha-L-rhamnopyranoside (8). It was found that 8 is a new compound and its antioxidant activity is also reported. Identification of the isolated compounds was carried out by spectroscopic and spectrometric analysis (1D and 2D NMR, UV and MS).

  14. Chemical constituents of two sages with free radical scavenging activity.

    PubMed

    Demirezer, Omur L; Gurbuz, Perihan; Kuruuzum-Uz, Ayşe; Guvenalp, Zuhal; Kazaz, Cavit; Donmez, Ali A

    2012-02-01

    From the aerial parts of Salvia trichoclada Bentham and S. verticillata L. one new and two known phenolic acids, 3-(3',4'-dihydroxyphenyl)-2-hydroxymethyl propionic acid (1), 3-(3',4'-dihydroxyphenyl) lactic acid (2), and rosmarinic acid (3); two flavonoids, apigenin 4'-methyl ether 7-O-glucuronide (4), and luteolin 7-O-beta glucuronide (5); two lupan type triterpene aglycones, lupeol (6), and 30-hydroxylup-20 (29)-en-3-on (7); an oleanane-type triterpene acid, oleanolic acid (8); and an ursan-type triterpene acid, ursolic acid (9) were isolated. The structures of the compounds were elucidated by spectroscopic analysis. Different extracts of the plants were examined for their free radical scavenging activities by DPPH (2,2-Diphenyl-1-picrylhydrazyl) assay. Some of the polar extracts showed high free radical scavenging activity.

  15. Effects of Titanium Layer Oxygen Scavenging on the High-k/InGaAs Interface.

    PubMed

    Winter, Roy; Shekhter, Pini; Tang, Kechao; Floreano, Luca; Verdini, Alberto; McIntyre, Paul C; Eizenberg, Moshe

    2016-07-01

    One of the main challenges in the path to incorporating InGaAs based metal-oxide-semiconductor structures in nanoelectronics is the passivation of high-k/InGaAs interfaces. Here, the oxygen scavenging effect of thin Ti layers on high-k/InGaAs gate stacks was studied. Electrical measurements and synchrotron X-ray photoelectron spectroscopy measurements, with in situ metal deposition, were used. Oxygen removal from the InGaAs native oxide surface layer remotely through interposed Al2O3 and HfO2 layers observed. Synchrotron X-ray photoelectron spectroscopy has revealed a decrease in the intensity of InOx features relative to In in InGaAs after Ti deposition. The signal ratio decreases further after annealing. In addition, Ti 2p spectra clearly show oxidation of the thin Ti layer in the ultrahigh vacuum XPS environment. Using capacitance-voltage and conductance-voltage measurements, Pt/Ti/Al2O3/InGaAs and Pt/Al2O3/InGaAs capacitors were characterized both before and after annealing. It was found that the remote oxygen scavenging from the oxide/semiconductor interface using a thin Ti layer can influence the density of interface traps in the high-k/InGaAs interface. PMID:27282201

  16. Characterization and free radical scavenging activity of rapeseed meal polysaccharides WPS-1 and APS-2.

    PubMed

    Zhu, Jianfei; Wu, Moucheng

    2009-02-11

    Two major polysaccharide fractions, WPS-1 and APS-2, were isolated from water-soluble and alkali-soluble extracts of Huaza No. 4 rapeseed meal with a stepwise procedure of D3520 macroporous adsorption resin column chromatography, ethanol precipitation, and DE-52 cellulose column chromatography. Physicochemical properties of the polysaccharides were determined by chemical methods, high -performance liquid chromatography (HPLC), gel permeation chromatography (GPC), and Fourier transform infrared spectrometry (FT-IR). The chemiluminescence (CL) method was used to investigate the free radical scavenging activity of the polysaccharide fractions. The polysaccharides were primarily polymers of arabinose, galactose, and glucose, associated with protein portions consisting of 13 different amino acids. The average molecular masses of WPS-1 and APS-2 were 7.20 x 10(5) and 1.61 x 10(5) Da, respectively. Compared with APS-2, WPS-1 was more effective at scavenging superoxide radical (O(2)(*-)) and hydroxyl radical (HO(*)), but less effective at scavenging hydrogen peroxide (H(2)O(2)). In decreasing order, the free radical scavenging activity of WPS-1 and APS-2 toward reactive oxygen species (ROS) was H(2)O(2) > HO(*) > O(2)(*-).

  17. Copper(II) as an efficient scavenger of singlet molecular oxygen.

    PubMed

    Joshi, P C

    1998-08-01

    Reactive oxygen species (ROS) are considered to play an important role in tissue injury that damages DNA, proteins, carbohydrates and lipids. Increased production of ROS and/or decreased efficiency of antioxidant defense system has been shown to contribute to a number of degenerative processes including cancer and AIDS. Among the various forms of ROS, singlet oxygen (1O2), which is generated predominantly in photosensitization reactions, is of particular physiologic significance because of its selectively long life in aqueous solution, its ability to cross the cell membrane barrier and high reactivity towards biomolecules. In the present study, the 1O2 scavenging potential of Cu(II) has been evaluated by (i) generating 1O2 by photosensitization of rose bengal (RB), (ii) establishing 1O2 quenching with recognized 1O2 scavengers like sodium azide, DABCO and (iii) examining the effect of Cu(II) in scavenging of 1O2. The results revealed that Cu(II) inhibited the rate of 1O2 production by 88%, 68%, 40%, 21% and 10% at a concentration of 10(-2) M, 5 x 10(-3) M, 10(-3) M; 5 x 10(-4) M, and 10(-4) M, respectively. Under similar experimental condition, sodium azide or DABCO at 10(-2) M inhibited the 1O2 production by 86% and 88%, respectively. Other 1O2 generating photosensitizer like hematoporphyrin, riboflavin and methylene blue also produced identical results with Cu(II) but Fe(II), Fe(III), Zn(II) or As(III) did not produce any quenching of 1O2. Presence of a copper binding peptide (Gly-Gly-His) in the reaction system reduced the 1O2 scavenging capacity of Cu(II) by 52-66% depending upon the UV dose. The 1O2 scavenging property of metal ion appears to have an advantage to reduce the oxidative damage of photodynamic reactions in order to prevent ROS-induced toxicity reactions. PMID:9854900

  18. Response to temperature stress of reactive oxygen species scavenging enzymes in the cross-tolerance of barley seed germination*

    PubMed Central

    Mei, Yu-qin; Song, Song-quan

    2010-01-01

    A number of studies have shown the existence of cross-tolerance in plants, but the physiological mechanism is poorly understood. In this study, we used the germination of barley seeds as a system to investigate the cross-tolerance of low-temperature pretreatment to high-temperature stress and the possible involvement of reactive oxygen species (ROS) scavenging enzymes in the cross-tolerance. After pretreatment at 0 °C for different periods of time, barley seeds were germinated at 35 °C, and the content of malondialdehyde (MDA) and the activities of ROS scavenging enzymes were measured by a spectrophotometer analysis. The results showed that barley seed germinated very poorly at 35 °C, and this inhibitive effect could be overcome by pretreatment at 0 °C. The MDA content varied, depending on the temperature at which seeds germinated, while barley seeds pretreated at 0 °C did not change the MDA content. Compared with seeds germinated directly at 35 °C, the seeds pretreated first at 0 °C and then germinated at 35 °C had markedly increased activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), and glutathione reductase (GR). The SOD and APX activities of seeds germinated at 35 °C after 0 °C-pretreatment were even substantially higher than those at 25 °C, and GR activity was similar to that at 25 °C, at which the highest germination performance of barley seeds was achieved. These results indicate that low-temperature pretreatment can markedly increase the tolerance of barley seed to high temperature during germination, this being related to the increase in ROS scavenging enzyme activity. This may provide a new method for increasing seed germination under stress environments, and may be an excellent model system for the study of cross-tolerance. PMID:21121076

  19. Effect of Remote Oxygen Scavenging on Electrical Properties of Ge-Based Metal-Oxide-Semiconductor Capacitors

    NASA Astrophysics Data System (ADS)

    Fadida, Sivan; Nyns, Laura; Van Elshocht, Sven; Eizenberg, Moshe

    2016-08-01

    Remote oxygen scavenging has been studied in a metal/high-k dielectric/GeO2/Ge stack, where a thin Ti layer inserted into the metal/high-k dielectric interface serves as the scavenger. First, we established that remote oxygen scavenging indeed occurs specifically in the studied HfO2/Al2O3/GeO2/Ge stack. It was also established that the source for oxygen is decomposition of the GeO2 layer. Then, the effect of remote oxygen scavenging of the GeO2 layer on the electrical characteristics of the metal/oxide/Ge capacitors was investigated. The electrical properties were studied in comparison with identical gate stacks with a Pt electrode, before and after annealing. Although a decrease in effective oxide thickness was demonstrated as a result of this process, clear degradation of the interface electrical quality was observed after scavenging. Initiation of the scavenging process was witnessed upon deposition of Ti at room temperature, emphasizing that this process could not be controlled.

  20. The melatonin metabolite N-acetyl-5-methoxykynuramine is a potent singlet oxygen scavenger.

    PubMed

    Schaefer, Meike; Hardeland, Rüdiger

    2009-01-01

    Singlet oxygen was generated by means of rose bengal under irradiation by visible light. N(1)-acetyl-5-methoxykynuramine (AMK) was rapidly destroyed by this reactive oxygen species, whereas its formylated precursor, N(1)-acetyl-N(2)-formyl-5-methoxykynuramine (AFMK), was remarkably inert. At photon fluence rates of 1400 mumol photons/m(2)s, and using 20 mum rose bengal, most of initially 0.2 mm AMK was destroyed within 2 min, whereas AFMK remained practically unchanged for much longer periods of time. Competition experiments with other scavengers revealed the following order of reactivity towards singlet oxygen: diazabicyclo-[2,2,2]-octane (DABCO) < imidazole < 4-ethylphenol < N(alpha)-acetylhistidine < histidine < melatonin < AMK, the last one being about 150 times more effective than DABCO. Contrary to the oxidation in free radical-generating systems, AMK did not form adducts with the tyrosine side chain fragment, 4-ethylphenol, under the influence of singlet oxygen. In UV-exposed cells (keratinocytes, plant cells) it is likely to be more rapidly destroyed by singlet oxygen than formed from AFMK. PMID:18643875

  1. Free radical scavenging, antimicrobial and immunomodulatory activities of Orthosiphon stamineus.

    PubMed

    Alshawsh, Mohammed A; Abdulla, Mahmood A; Ismail, Salmah; Amin, Zahra A; Qader, Suhailah W; Hadi, Hamid A; Harmal, Nabil S

    2012-01-01

    Orthosiphon stamineus is considered an important traditional folk medicine. In this study ethanol and aqueous extracts of O. stamineus were evaluated in vitro for their antioxidant, antimicrobial as well as for their immunomodulatory properties on human peripheral blood mononuclear cells (PBMCs). The DPPH radical scavenging method was used for the determination of antioxidant activity, while the antibacterial efficacy was investigated by both disc diffusion method and Minimum Inhibitory Concentration (MIC) against four bacterial strains (Gram-positive and Gram-negative). Furthermore, the immunomodulatory potential of the extracts was investigated through the MTT assay. Aqueous extract of O. stamineus exhibited significant free radical scavenging activity with IC₅₀ 50 9.6 µg/mL, whereas the IC₅₀ for the ethanol extract was 21.4 µg/mL. The best antimicrobial activity was shown by the aqueous extract of O. stamineus against Staphylococcus aureus, with inhibition zone of 10.5 mm and MIC value 1.56 mg/mL. Moreover, the results observed from the MTT assay showed that both plant extracts stimulated the PBMCs proliferation in vitro in a concentration-dependent manner, but the aqueous extract has remarkable activity against PBMCs. These findings indicate that O. stamineus showed high antioxidant activity and may be considered as an immunomodulatory agent.

  2. Enhanced reactive oxygen species scavenging by overproduction of superoxide dismutase and catalase delays postharvest physiological deterioration of cassava storage roots.

    PubMed

    Xu, Jia; Duan, Xiaoguang; Yang, Jun; Beeching, John R; Zhang, Peng

    2013-03-01

    Postharvest physiological deterioration (PPD) of cassava (Manihot esculenta) storage roots is the result of a rapid oxidative burst, which leads to discoloration of the vascular tissues due to the oxidation of phenolic compounds. In this study, coexpression of the reactive oxygen species (ROS)-scavenging enzymes copper/zinc superoxide dismutase (MeCu/ZnSOD) and catalase (MeCAT1) in transgenic cassava was used to explore the intrinsic relationship between ROS scavenging and PPD occurrence. Transgenic cassava plants integrated with the expression cassette p54::MeCu/ZnSOD-35S::MeCAT1 were confirmed by Southern-blot analysis. The expression of MeCu/ZnSOD and MeCAT1 was verified by quantitative reverse transcription-polymerase chain reaction and enzymatic activity analysis both in the leaves and storage roots. Under exposure to the ROS-generating reagent methyl viologen or to hydrogen peroxide (H2O2), the transgenic plants showed higher enzymatic activities of SOD and CAT than the wild-type plants. Levels of malondialdehyde, chlorophyll degradation, lipid peroxidation, and H2O2 accumulation were dramatically reduced in the transgenic lines compared with the wild type. After harvest, the storage roots of transgenic cassava lines show a delay in their PPD response of at least 10 d, accompanied by less mitochondrial oxidation and H2O2 accumulation, compared with those of the wild type. We hypothesize that this is due to the combined ectopic expression of Cu/ZnSOD and CAT leading to an improved synergistic ROS-scavenging capacity of the roots. Our study not only sheds light on the mechanism of the PPD process but also develops an effective approach for delaying the occurrence of PPD in cassava.

  3. Enhanced reactive oxygen species scavenging by overproduction of superoxide dismutase and catalase delays postharvest physiological deterioration of cassava storage roots.

    PubMed

    Xu, Jia; Duan, Xiaoguang; Yang, Jun; Beeching, John R; Zhang, Peng

    2013-03-01

    Postharvest physiological deterioration (PPD) of cassava (Manihot esculenta) storage roots is the result of a rapid oxidative burst, which leads to discoloration of the vascular tissues due to the oxidation of phenolic compounds. In this study, coexpression of the reactive oxygen species (ROS)-scavenging enzymes copper/zinc superoxide dismutase (MeCu/ZnSOD) and catalase (MeCAT1) in transgenic cassava was used to explore the intrinsic relationship between ROS scavenging and PPD occurrence. Transgenic cassava plants integrated with the expression cassette p54::MeCu/ZnSOD-35S::MeCAT1 were confirmed by Southern-blot analysis. The expression of MeCu/ZnSOD and MeCAT1 was verified by quantitative reverse transcription-polymerase chain reaction and enzymatic activity analysis both in the leaves and storage roots. Under exposure to the ROS-generating reagent methyl viologen or to hydrogen peroxide (H2O2), the transgenic plants showed higher enzymatic activities of SOD and CAT than the wild-type plants. Levels of malondialdehyde, chlorophyll degradation, lipid peroxidation, and H2O2 accumulation were dramatically reduced in the transgenic lines compared with the wild type. After harvest, the storage roots of transgenic cassava lines show a delay in their PPD response of at least 10 d, accompanied by less mitochondrial oxidation and H2O2 accumulation, compared with those of the wild type. We hypothesize that this is due to the combined ectopic expression of Cu/ZnSOD and CAT leading to an improved synergistic ROS-scavenging capacity of the roots. Our study not only sheds light on the mechanism of the PPD process but also develops an effective approach for delaying the occurrence of PPD in cassava. PMID:23344905

  4. Superoxide scavenging activity of pirfenidone-iron complex

    SciTech Connect

    Mitani, Yoshihiro; Sato, Keizo Muramoto, Yosuke; Karakawa, Tomohiro; Kitamado, Masataka; Iwanaga, Tatsuya; Nabeshima, Tetsuji; Maruyama, Kumiko; Nakagawa, Kazuko; Ishida, Kazuhiko; Sasamoto, Kazumi

    2008-07-18

    Pirfenidone (PFD) is focused on a new anti-fibrotic drug, which can minimize lung fibrosis etc. We evaluated the superoxide (O{sub 2}{sup {center_dot}}{sup -}) scavenging activities of PFD and the PFD-iron complex by electron spin resonance (ESR) spectroscopy, luminol-dependent chemiluminescence assay, and cytochrome c reduction assay. Firstly, we confirmed that the PFD-iron complex was formed by mixing iron chloride with threefold molar PFD, and the complex was stable in distillated water and ethanol. Secondary, the PFD-iron complex reduced the amount of O{sub 2}{sup {center_dot}}{sup -} produced by xanthine oxidase/hypoxanthine without inhibiting the enzyme activity. Thirdly, it also reduced the amount of O{sub 2}{sup {center_dot}}{sup -} released from phorbor ester-stimulated human neutrophils. PFD alone showed few such effects. These results suggest the possibility that the O{sub 2}{sup {center_dot}}{sup -} scavenging effect of the PFD-iron complex contributes to the anti-fibrotic action of PFD used for treating idiopathic pulmonary fibrosis.

  5. Baicalin Scavenged Reactive Oxygen Species and Protected Human Keratinocytes Against UVB-induced Cytotoxicity.

    PubMed

    Chang, Wen-Shin; Lin, En-Yuan; Hsu, Shih-Wei; Hu, Pei-Shin; Chuang, Chin-Liang; Liao, Cheng-Hsi; Fu, Chun-Kai; Su, Chung-Hao; Gong, Chi-Li; Hsiao, Chieh-Lun; Bau, DA-Tian; Tsai, Chia-Wen

    Ultraviolet B (UVB), with a wavelength of 280-320 nm, represents one of the most important environmental factors for skin disorders, including sunburn, hyperpigmentation, solar keratosis, solar elastosis and skin cancer. Therefore, protection against excessive UVA-induced damage is useful for prevention of sunburn and other human diseases. Baicalin, a major component of traditional Chinese medicine Scutellaria baicalensis, has been reported to possess antioxidant and cytostatic capacities. In this study, we examined whether baicalin is also capable of protecting human keratinocytes from UVB irradiation. The results showed that baicalin effectively scavenged reactive oxygen species (ROS) elevated within 4 h after UVB radiation and reversed the UVB-suppressed cell viability and UVB-induced apoptosis after 24 h. Our results demonstrated the utility of baicalin to complement the contributions of traditional Chinese medicine in UVB-induced damage to skin and suggested their potential application as pharmaceutical agents in long-term sun-shining injury prevention. PMID:27566079

  6. Using the singlet oxygen scavenging property of carotenoid in photodynamic molecular beacons to minimize photodamage to non-targeted cells.

    PubMed

    Chen, Juan; Jarvi, Mark; Lo, Pui-Chi; Stefflova, Klara; Wilson, Brian C; Zheng, Gang

    2007-12-01

    We recently introduced the concept of photodynamic molecular beacons (PMB) for selective control of photodynamic therapy (PDT). The PMB consists of a peptide linker that is sequence specific to a cancer-associated protease. A photosensitizer (PS) and a singlet oxygen (1O2) quencher are conjugated to the opposite ends of this linker. Proximity of the PS and quencher can efficiently inhibit 1O2 generation. In the presence of a targeted protease, the substrate sequence is cleaved and the PS and quencher will separate so that the PS can be photo-activated. There are two ways to optimize the PMB selectivity to cancer cells. The first is to increase the protease specificity to targeted cells and the second is to minimize the phototoxicity of intact (uncleaved) PMBs in non-targeted (normal) cells. Carotenoids (CARs) are well known in nature for their role in quenching excited states of PS and in directly scavenging 1O2. The purpose of this study is to evaluate whether the CAR with dual quenching modes (PS excited states deactivation and 1O2 scavenging) can be used to minimize the photodamage of intact PMBs to non-targeted cells. Thus, we synthesized a beacon (PPC) with a caspase-3 cleavable peptide linking a PS and a CAR quencher. It was confirmed that CAR deactivates the PS excited states and also directly scavenges 1O2. Moreover, the in vitro PDT response showed that CAR completely shuts off the photodynamic effect in non-targeted HepG(2) cells, while PS without CAR (control) remains highly potent even at a much lower (30-fold) dose.

  7. Singlet oxygen scavengers affect laser-dye impairment of endothelium-dependent responses of brain arterioles.

    PubMed

    Rosenblum, W I; Nelson, G H

    1996-04-01

    This study investigates the possible role of singlet oxygen in accounting for the inhibitory effect of laser-dye injury on endothelium-dependent dilations. The combination of helium-neon (HeNe) laser (20-s exposure) and intravascular Evans blue impairs endothelium-dependent dilation of mouse pial arterioles by acetylcholine (ACh), bradykinin (BK), and calcium ionophore A23187. Each has a different endothelium-derived mediator (EDRFACh, EDRFBK, EDRFionophore, respectively). In this study, diameters at a craniotomy site were monitored in vivo with an image splitter-television microscope. The laser-dye injury, as usual, abolished the responses 10 and 30 min after injury, with recovery, complete or partial, at 60 min. Dilations by sodium nitroprusside, an endothelium-independent dilator, were not affected by laser-dye. When the singlet oxygen scavengers L-histidine (10(-3) M) and L-tryptophan (10(-2) M) were added to the suffusate over the site, the responses to ACh at 10 and 30 min were relatively intact, the response to BK was partly protected at 10 min only, and the response to ionophore was still totally impaired at 10 and 30 min. Lysine, a nonscavenging amino acid, had no protective effects with any dilator. We postulate that a heat-induced injury initiates a chain of events resulting in prolonged singlet oxygen generation by the endothelial cell (not by the dye). We postulate further that destruction of EDRFACh by singlet oxygen is responsible for laser-dye inhibition of ACh and that generation of the radical must continue for > or = 30 min. On the other hand, the heat injury itself is probably responsible for the elimination of the response to ionophore. Heat plus singlet oxygen generated by heat-damaged tissue may initially impair the response to BK, but by 30 min only the effects of some other factor, presumably heat injury, account for the impaired response to BK. PMID:8967364

  8. Resveratrol dimers, nutritional components in grape wine, are selective ROS scavengers and weak Nrf2 activators.

    PubMed

    Li, Chang; Xu, Xiaofei; Tao, Zhihao; Wang, Xiu Jun; Pan, Yuanjiang

    2015-04-15

    Resveratrol monomer (Res) and its oligomers are considered as nutritional components distributed in edible plants. Three naturally occurring resveratrol dimers, namely parthenocissin A (Par), quadrangularin A (Qua) and pallidol (Pal), were synthesized and evaluated for their ability to scavenge reactive oxygen species (ROS) and to activate the transcription factor Nrf2, which regulates cellular antioxidant systems. In vitro studies with different ROS and radical assay models showed that all the three dimers are strong DPPH quenchers and selective singlet oxygen ((1)O2) scavengers (IC50=4.90, 1.05 and 5.50 μM, respectively). However, they were ineffective against hydroxyl radical (OH) or superoxide anion (O2(-)). Exposing the dimers to an antioxidant response element (ARE) reporter cell line revealed that only pallidol was able to activate Nrf2 at 30 μM, while parthenocissin A and quadrangularin A had no significant effect on Nrf2. Our data demonstrates the distinct difference between reservatrol monomer and its dimers in activating the Nrf2/ARE signalling pathway.

  9. Vitamin B1 as a scavenger of reactive oxygen species photogenerated by vitamin B2.

    PubMed

    Natera, José; Massad, Walter A; García, Norman A

    2011-01-01

    Kinetics and mechanism of photoprocesses generated by visible light-irradiation of the system riboflavin (Rf, vitamin B2) plus Thiamine (Th) and Thiamine pyrophosphate (ThDP), representing vitamin B1, was studied in pH 7 water. A weak dark complex vitamin B2-vitamin B1, with a mean value of 4 ± 0.4 M(-1) is formed. An intricate mechanism of competitive reactions operates upon photoirradiation, being the light only absorbed by Rf. Th and ThDP quench excited singlet and triplet states of Rf, with rate constants in the order of 10(9) and 10(6 ) M(-1 ) s(-1), respectively. With Vitamin B1 in a concentration similar to that of dissolved molecular oxygen in water, the quenching of triplet excited Rf by the latter is highly predominant, resulting in the generation of O(2)((1)Δ(g)). Superoxide radical anion was not detected under work conditions. A relatively slow O(2)((1)Δ(g))-mediated photodegradation of Th and ThDP was observed. Nevertheless, Th and especially ThDP behave as efficient physical deactivators of O(2)((1)Δ(g)). The thiazol structure in vitamin B1 appears as a good scavenger of this reactive oxygen species. This characteristic, that presents at vitamin B1 as a potential photoprotector of biological entities against O(2)((1)Δ(g)) attack, was been experimentally confirmed employing the protein lisozime as a photo-oxidizable target.

  10. In vitro radical scavenging activity of two Columbian Magnoliaceae

    NASA Astrophysics Data System (ADS)

    Puertas M., Miguel A.; Mesa v., Ana M.; Sáez v., Jairo A.

    2005-08-01

    The recent interest in the conservation of the tropical forest is due, at least in part, to the potential economic and health benefits that can be exploited from several plants. This report shows the in vitro antioxidant activity of some fractions isolated from leaves of two Columbian Magnoliaceae, Talauma hernandezii G. Lozano-C and Dugandiodendron yarumalense Lozano. The activity was determined using the radical monocation 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS·+) and the stable free radical 2-2-diphenyl-1-picrylhydrazyl (DPPH·), as part of general biological screening of these plants. The antioxidant capacity obtained from fractions was similar to those of α-tocopherol, tert-butylated hydroxyanisole (BHA), and ascorbic acid. The most active scavenger extract was the fraction 7 (TAA = 48.6 mmol Trolox/kg extract and IC50 ≤ 0.01 kg extract/mmol DPPH); and the least active was the fraction 1 (TAA = 11.23 mmol Trolox/kg extract and IC50 = 0.21 kg extract/mmol DPPH) all of them isolated from D. yarumalense. These results suggest that these plants can be attractive as source of antioxidant compounds with the ability to reduce radicals like ATBS and DPPH.

  11. Activated Scavenger Receptor A Promotes Glial Internalization of Aβ

    PubMed Central

    Zhou, Wei-wei; Wang, Shao-wei; Xu, Peng-xin; Yu, Xiao-lin; Liu, Rui-tian

    2014-01-01

    Beta-amyloid (Aβ) aggregates have a pivotal role in pathological processing of Alzheimer’s disease (AD). The clearance of Aβ monomer or aggregates is a causal strategy for AD treatment. Microglia and astrocytes are the main macrophages that exert critical neuroprotective roles in the brain. They may effectively clear the toxic accumulation of Aβ at the initial stage of AD, however, their functions are attenuated because of glial overactivation. In this study, we first showed that heptapeptide XD4 activates the class A scavenger receptor (SR-A) on the glia by increasing the binding of Aβ to SR-A, thereby promoting glial phagocytosis of Aβ oligomer in microglia and astrocytes and triggering intracellular mitogen-activated protein kinase (MAPK) signaling cascades. Moreover, XD4 enhances the internalization of Aβ monomers to microglia and astrocytes through macropinocytosis or SR-A-mediated phagocytosis. Furthermore, XD4 significantly inhibits Aβ oligomer-induced cytotoxicity to glial cells and decreases the production of proinflammatory cytokines, such as TNF-α and IL-1β, in vitro and in vivo. Our findings may provide a novel strategy for AD treatment by activating SR-A. PMID:24718459

  12. Oxygen supply and nitric oxide scavenging by myoglobin contribute to exercise endurance and cardiac function.

    PubMed

    Merx, Marc W; Gödecke, Axel; Flögel, Ulrich; Schrader, Jürgen

    2005-06-01

    Recent studies of myoglobin (Mb) knockout (myo-/-) mice have extended our understanding of Mb's diverse functions and have demonstrated a complex array of compensatory mechanisms. The present study was aimed at detailed analysis of cardiac function and exercise endurance in myo-/- mice and at providing evidence for Mb's functional relevance. Myo-/- isolated working hearts display decreased contractility (dP/dtmax 3883+/-351 vs. 4618+/-268 mmHg/sec, myo-/- vs. WT, P<0.005). Due to a shift in sympathetic/parasympathetic tone, heart rate is reduced in conscious myo mice-/- (615+/-33 vs. 645+/-27 bpm, myo-/- vs. WT, P<0.001). Oxygen consumption (VO2) under resting conditions (3082+/-413 vs. 4452+/-552 ml x kg(-1) x h(-1), myo-/- vs. WT, P<0.001) and exercise endurance, as determined by spiroergometry, are decreased (466+/-113 vs. 585+/-153 m, myo-/- vs. WT, P<0.01). Conscious myo-/- mice evaluated by echocardiography display lowered cardiac output (0.64+/-0.06 vs. 0.75+/-0.09 ml x min(-1) x g(-1), myo-/- vs. WT, P<0.001), impaired systolic shortening (60+/-3.5 vs. 65+/-4%, myo-/- vs. WT, P<0.001) and fail to respond to beta1-stimulation. Strikingly, the latter cardiac effects of Mb deficiency can be partially attenuated by NOS inhibition. Loss of Mb results in a distinct phenotype, even under resting conditions, and the importance of oxygen supply and nitric oxide scavenging by Mb is clearly demonstrated at the conscious animal level. PMID:15817640

  13. Oxygen supply and nitric oxide scavenging by myoglobin contribute to exercise endurance and cardiac function.

    PubMed

    Merx, Marc W; Gödecke, Axel; Flögel, Ulrich; Schrader, Jürgen

    2005-06-01

    Recent studies of myoglobin (Mb) knockout (myo-/-) mice have extended our understanding of Mb's diverse functions and have demonstrated a complex array of compensatory mechanisms. The present study was aimed at detailed analysis of cardiac function and exercise endurance in myo-/- mice and at providing evidence for Mb's functional relevance. Myo-/- isolated working hearts display decreased contractility (dP/dtmax 3883+/-351 vs. 4618+/-268 mmHg/sec, myo-/- vs. WT, P<0.005). Due to a shift in sympathetic/parasympathetic tone, heart rate is reduced in conscious myo mice-/- (615+/-33 vs. 645+/-27 bpm, myo-/- vs. WT, P<0.001). Oxygen consumption (VO2) under resting conditions (3082+/-413 vs. 4452+/-552 ml x kg(-1) x h(-1), myo-/- vs. WT, P<0.001) and exercise endurance, as determined by spiroergometry, are decreased (466+/-113 vs. 585+/-153 m, myo-/- vs. WT, P<0.01). Conscious myo-/- mice evaluated by echocardiography display lowered cardiac output (0.64+/-0.06 vs. 0.75+/-0.09 ml x min(-1) x g(-1), myo-/- vs. WT, P<0.001), impaired systolic shortening (60+/-3.5 vs. 65+/-4%, myo-/- vs. WT, P<0.001) and fail to respond to beta1-stimulation. Strikingly, the latter cardiac effects of Mb deficiency can be partially attenuated by NOS inhibition. Loss of Mb results in a distinct phenotype, even under resting conditions, and the importance of oxygen supply and nitric oxide scavenging by Mb is clearly demonstrated at the conscious animal level.

  14. Pharmacokinetics and preventive effects of platinum nanoparticles as reactive oxygen species scavengers on hepatic ischemia/reperfusion injury in mice.

    PubMed

    Katsumi, Hidemasa; Fukui, Kentaro; Sato, Kanako; Maruyama, Shoko; Yamashita, Shugo; Mizumoto, Erika; Kusamori, Kosuke; Oyama, Munetaka; Sano, Masataka; Sakane, Toshiyasu; Yamamoto, Akira

    2014-05-01

    Reactive oxygen species (ROS) are involved in the pathophysiology of ischemia/reperfusion injury. To protect mouse hepatocytes from ischemia/reperfusion injury, we prepared two different sizes of citric acid-protected platinum nanoparticles (Pt-NPs), which exhibited ROS-scavenging activities and selective delivery to a specific type of liver cell. Small Pt-NPs (30 nm) reduced the superoxide anion, hydrogen peroxide, and hydroxyl radical levels in solution to a greater extent than did large Pt-NPs (106 nm). Large and small Pt-NPs predominantly accumulated in hepatic nonparenchymal cells after intravenous injection into mice. In a mouse model of ischemia/reperfusion injury, in which hepatic injury was induced by occluding the portal vein for 15 min followed by 6 h reperfusion, the increase in plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities was inhibited by a bolus intravenous injection of either large or small Pt-NPs. However, small Pt-NPs inhibited the increase in these markers of hepatic injury to a greater extent than did large Pt-NPs. These results indicate that Pt-NPs can be used to prevent hepatic ischemia/reperfusion injury. To our knowledge, this is the first report demonstrating the pharmacokinetics and efficacy of Pt-NPs to prevent hepatic ischemia/reperfusion injury.

  15. Sulfhydryl protection and the oxygen effect on radiation-induced inactivation of r-chromatin in vitro. Influence of an OH scavenger: t-butanol

    SciTech Connect

    Herskind, C.

    1988-07-01

    Transcriptionally active r-chromatin from Tetrahymena has been irradiated in dilute phosphate buffer, pH 7.2, in the presence of the sulfhydryl compound 2-mercaptoethanol (MSH). MSH was more protective against radiation-induced inactivation of transcription under N/sub 2/ than under O/sub 2/. The OH scavenger, t-butanol, on the other hand, gives significantly less protection under N/sub 2/ than under O/sub 2/, apparently due to inactivation by secondary t-butanol radicals under anoxia as shown previously. However, MSH was found to restore most of the protective effect of t-butanol under N/sub 2/. Inactivation was studied as a function of MSH concentration (0.03-10 mM) at different, fixed concentrations of t-butanol (3-300 mM). The observed protection may be explained essentially in terms of (1) OH scavenging, (2) repair of DNA radicals by H-atom transfer from MSH under N/sub 2/ in competition with fixation of damage under O/sub 2/, and (3) protection against inactivation by secondary t-butanol radicals by H-atom transfer to these radicals. The sensitizing effect of oxygen in the presence of MSH is reduced by t-butanol and may even be reversed to produce an apparently protective effect. This finding is discussed in terms of residual inactivation by secondary radicals. The significance of OH scavengers as potential modifiers of oxygen enhancement ratio values is discussed.

  16. Polyphenylenesulfide, noxon® an ozone scavenger for the analysis of oxygenated terpenes in air

    NASA Astrophysics Data System (ADS)

    Calogirou, A.; Duane, M.; Kotzias, D.; Lahaniati, M.; Larsen, B. R.

    During sampling, oxygenated terpenes may undergo decomposition through reaction with atmospheric ozone. We have studied their ozonolytic decomposition during preconcentration on Tenax. The saturated. terpenoids 1,8-cineole, bornyl acetate nopinone and pinonaldehyde are practically unaffected by ozone in the range of 8 to 120 ppbv. Compounds which contain one or more C-C double bonds are decomposed in the order: linalool ≈ citronellal ≈ 6-methyl-5-hepten-2-one > citral > 4-acetyl-1-methyl-cyclohexane > 3-(1-methylethenyl)-6-oxo-heptanal > myrtenal ≈ 2-methyl-3-buten-2-ol. The degree of decomposition varies from 0 to 5% for the least reactive to 80 to 90% for the most reactive compounds. A broad range of material was investigated as potential ozone scavengers. By using the polymer noXon (polyphenylenesulfide) all the investigated compounds could be sampled with quantitative recoveries even at high ozone mixing ratios (95-110 ppbv). This ozone scrubber was tested for sampling of terpene oxidation products on Tenax and dinitrophenylhydrazine impregnated C 18-silicagel cartridges. Recoveries from 85 to 110% were obtained for all investigated compounds. The method was used for the analysis of oxidation products of terpenes in ambient air in three campaigns. Attention was focused on nopinone from β-pinene, pinonaldehyde from α-pinene, 3-(1-methylethenyl)-6-oxo-heptanal and 4-acetyl-1-methyl-cyclohexane from limonene, and 5-(1-methylethyl)-bicyclo[3.1.0] hexan-2-one from sabinene. Nopinone was the only product which could be frequently detected in ratios from 0 to 90% of the measured β-pinene concentrations. Pinonaldehyde was encountered only once (30% of α-pinene) while the other products were not found. These data have to be seen as a first attempt to measure terpene oxidation products in the troposphere.

  17. Antioxidant and free radical scavenging activities of some fruits.

    PubMed

    Prakash, Dhan; Upadhyay, Garima; Pushpangadan, P; Gupta, Charu

    2011-01-01

    Phenols, a major group of antioxidant phytochemicals, have profound importance due to their biological and free radical scavenging activities. To identify their potential sources extracts of some fruits and their different parts were studied for total phenolic contents (TPC), antioxidant (AOA) and free radical scavenging activities (FRSA). The amount of TPC varied from 10.5 (Carissa carandus, fruit peel) to 343.2 mg/g (Caesalpinia Mexicana, fruits) and AOA from 20.3% (Musa paradisiacal, fruits) to 96.7% (Caesalpinia Mexicana, fruits). Fruits of Caesalpinia Mexicana, Acacia auriculiformis, fruit pericarp green fibres of Cocus nucifera, and fruits of Emblica officinalis were found to have high TPC (73.1-343.2 mg/g) and high AOA (68.5-96.7%). Promising fruits were studied for their FRSA and reducing power (RP) measured by DPPH assay where the fruits of Caesalpinia mexicana, fruit pericarp fibres of Cocus nucifera, fruits of Emblica officinalis showed very low IC50 ranging from 0.009 to 0.016 mg/ml, EC50 from 0.39 to 0.70 mg/mg DPPH and reasonably high values (142.1-256.3) of anti radical power (ARP), indicating their strong FRSA and reducing power (RP) as evident by their low ASE/ml values (0.42-1.08). They also showed better inhibition of lipid peroxidation measured by using ferric thiocyanate assay and by using egg yolk compared to the reference standard quercetin. The ferrous and ferric ion chelating capacity of the promising fruits and their underutilized parts in terms of IC50 varied from 0.12 (Emblica officinalis, fruits) to 2.44 mg/ml (Mangifera indica, Seed kernel) and 0.22 (Caesalpinia Mexicana, fruits) to 2.59 mg/ml (Litchi chinensis, fruit peel) respectively. Fruit pulp, peel and seeds of Litchi chinensis with reasonable amount of phenols (48.3, 43.9, 50.1 mg/ml) showed low ARP (23.5, 38.3, 33.8) and ASE/ml (3.13, 2.18, 2.62) respectively in contrast to Aegle marmelos with comparatively lower phenols (35.1 mg/g) exhibited good ARP (57.4) and RP (1.67 ASE

  18. Enzymes That Scavenge Reactive Oxygen Species Are Down-Regulated Prior to Gibberellic Acid-Induced Programmed Cell Death in Barley Aleurone1

    PubMed Central

    Fath, Angelika; Bethke, Paul C.; Jones, Russell L.

    2001-01-01

    Gibberellins (GAs) initiate a series of events that culminate in programmed cell death, whereas abscisic acid (ABA) prevents this process. Reactive oxygen species (ROS) are key elements in aleurone programmed cell death. Incubation of barley (Hordeum vulgare) aleurone layers in H2O2 causes rapid death of all cells in GA- but not ABA-treated layers. Sensitivity to H2O2 in GA-treated aleurone cells results from a decreased ability to metabolize ROS. The amounts and activities of ROS scavenging enzymes, including catalase (CAT), ascorbate peroxidase, and superoxide dismutase are strongly down-regulated in aleurone layers treated with GA. CAT activity, protein, and Cat2 mRNA decline rapidly following exposure of aleurone layers to GA. In ABA-treated layers, on the other hand, the amount and activity of CAT and Cat2 mRNA increases. Incubation in ABA maintains high amounts of ascorbate peroxidase and superoxide dismutase, whereas GA brings about a rapid reduction in the amounts of these enzymes. These data imply that GA-treated cells loose their ability to scavenge ROS and that this loss ultimately results in oxidative damage and cell death. ABA-treated cells, on the other hand, maintain their ability to scavenge ROS and remain viable. PMID:11351079

  19. Changes in oxygen consumption induced by t-butyl hydroperoxide in perfused rat liver. Effect of free-radical scavengers.

    PubMed Central

    Videla, L A; Villena, M I; Donoso, G; Giulivi, C; Boveris, A

    1984-01-01

    The addition of t-butyl hydroperoxide to perfused rat liver elicited a biphasic effect on hepatic respiration. A rapid fall in liver oxygen consumption was initially observed, followed by a recovery phase leading to respiratory rates higher than the initial steady-state values of oxygen uptake. This overshoot in hepatic oxygen uptake was abolished by free-radical scavengers such as (+)-cyanidanol-3 or butylated hydroxyanisole at concentrations that did not alter mitochondrial respiration. (+)-Cyanidanol-3 was also able to facilitate the recovery of respiration, the diminution in the calculated rate of hydroperoxide utilization and the decrease in liver GSH content produced by two consecutive pulses of t-butyl hydroperoxide. It is suggested that the t-butyl hydroperoxide-induced overshoot in liver respiration is related to increased utilization of oxygen for lipid peroxidation as a consequence of free radicals produced in the scission of the hydroperoxide by cellular haemoproteins. PMID:6508746

  20. Global regulation of reactive oxygen species scavenging genes in alfalfa root and shoot under gradual drought stress and recovery.

    PubMed

    Kang, Yun; Udvardi, Michael

    2012-05-01

    Reactive oxygen species (ROS) production and scavenging in plants under drought stress have been studied intensively in recent years. Here we report a global analysis of gene expression for the major ROS generating and scavenging proteins in alfalfa root and shoot under gradual drought stress followed by one-day recovery. Data from two alfalfa varieties, one drought tolerant and one drought sensitive, were compared and no qualitative differences in ROS gene regulation between the two were found. Conserved, tissue-specific patterns of gene expression in response to drought were observed for several ROS-scavenging gene families, including ascorbate peroxidase, monodehydroascorbate reductase, and peroxiredoxin. In addition, differential gene expression within families was observed. Genes for the ROS-generating enzyme, NADPH oxidase were generally induced under drought, while those for glycolate oxidase were repressed. Among the ROS-scavenging protein genes, Ferritin, Cu/Zn superoxide dismutase (SOD), and the majority of the glutathione peroxidase family members were induced under drought in both roots and shoots of both alfalfa varieties. In contrast, Fe-SOD, CC-type glutaredoxins, and thoiredoxins were downregulated.

  1. Role of allyl group in the hydroxyl and peroxyl radical scavenging activity of S-allylcysteine.

    PubMed

    Maldonado, Perla D; Alvarez-Idaboy, J Raúl; Aguilar-González, Adriana; Lira-Rocha, Alfonso; Jung-Cook, Helgi; Medina-Campos, Omar Noel; Pedraza-Chaverrí, José; Galano, Annia

    2011-11-17

    S-Allylcysteine (SAC) is the most abundant compound in aged garlic extracts, and its antioxidant properties have been demonstrated. It is known that SAC is able to scavenge different reactive species including hydroxyl radical (•OH), although its potential ability to scavenge peroxyl radical (ROO•) has not been explored. In this work the ability of SAC to scavenge ROO• was evaluated, as well as the role of the allyl group (-S-CH(2)-CH═CH(2)) in its free radical scavenging activity. Two derived compounds of SAC were prepared: S-benzylcysteine (SBC) and S-propylcysteine (SPC). Their abilities to scavenge •OH and ROO• were measured. A computational analysis was performed to elucidate the mechanism by which these compounds scavenge •OH and ROO•. SAC was able to scavenge •OH and ROO•, in a concentration-dependent way. Such activity was significantly ameliorated when the allyl group was replaced by benzyl or propyl groups. It was shown for the first time that SAC is able to scavenge ROO•.

  2. Hydroxyl radical scavenging activities of isoquinoline alkaloids isolated from Coptis chinensis.

    PubMed

    Jang, Moon Hee; Kim, Hyun Young; Kang, Ki Sung; Yokozawa, Takako; Park, Jeong Hill

    2009-03-01

    The hydroxyl radical (*OH) scavenging and ferrous ion chelating activities of four isoquinoline alkaloids isolated from Coptis chinensis Franch were studied for the identification of their structural characteristics to scavenge *OH. The *OH was generated via Fe(II)-catalazed Fenton reaction in this study and the reliable measurement of *OH scavenging activities of isoquinoline alkaloids were achieved using electron spin resonance (ESR) spectrometry method. At the 1 mM concentration, berberrubine (85%) showed the strongest *OH scavenging activity and the next were in the decreasing order of coptisine (79%), berberine (23%), and palmatine (22%). The ferrous ion chelating effects of the alkaloids showed similar pattern with their *OH scavenging effects. These results suggest that *OH scavenging effects of the alkaloids were closely related to their ferrous ion chelating activities. In addition, metal chelating functional groups such as hydroxy group at C-9 and methylenedioxy group at C-9 and C-10 were thought to contribute to the *OH scavenging activities of the isoquinoline alkaloids.

  3. The role of metals in production and scavenging of reactive oxygen species in photosystem II.

    PubMed

    Pospíšil, Pavel

    2014-07-01

    Metal ions play a crucial role in enzymatic reactions in all photosynthetic organisms such as cyanobacteria, algae and plants. It well known that metal ions maintain the binding of substrate in the active site of the metalloenzymes and control the redox activity of the metalloenzyme in the enzymatic reaction. A large pigment-protein complex, PSII, known to serve as a water-plastoquinone oxidoreductase, contains three metal centers comprising non-heme iron, heme iron of Cyt b559 and the water-splitting manganese complex. Metal ions bound to PSII proteins maintain the electron transport from water to plastoquinone and regulate the pro-oxidant and antioxidant activity in PSII. In this review, attention is focused on the role of PSII metal centers in (i) the formation of superoxide anion and hydroxyl radicals by sequential one-electron reduction of molecular oxygen and the formation of hydrogen peroxide by incomplete two-electron oxidation of water; and (ii) the elimination of superoxide anion radical by one-electron oxidation and reduction (superoxide dismutase activity) and of hydrogen peroxide by two-electron oxidation and reduction (catalase activity). The balance between the formation and elimination of reactive oxygen species by PSII metal centers is discussed as an important aspect in the prevention of photo-oxidative damage of PSII proteins and lipids.

  4. Study on the free radical scavenging activity of sea cucumber (Paracaudina chinens var.) gelatin hydrolysate

    NASA Astrophysics Data System (ADS)

    Zeng, Mingyong; Xiao, Feng; Zhao, Yuanhui; Liu, Zunying; Li, Bafang; Dong, Shiyuan

    2007-07-01

    Gelatin from the sea cucumber (Paracaudina chinens var.) was hydrolyzed by bromelain and the hydrolysate was found to have a high free radical scavenging activity. The hydrolysate was fractionated through an ultrafiltration membrane with 5 kDa molecular weight cutoff (MWCO). The portion (less than 5 kDa) was further separated by Sephadex G-25. The active peak was collected and assayed for free radical scavenging activity. The scavenging rates for superoxide anion radicals (O2·-) and hydroxyl radicals (·OH) of the fraction with the highest activity were 29.02% and 75.41%, respectively. A rabbit liver mitochondrial free radical damage model was adopted to study the free radical scavenging activity of the fraction. The results showed that the sea cucumber gelatin hydrolysate can prevent the damage of rabbit liver and mitochondria.

  5. New polyhydroxylated flavon-3-ols and 3-hydroxy-2-styrylchromones: synthesis and ROS/RNS scavenging activities.

    PubMed

    Sousa, Joana L C; Proença, Carina; Freitas, Marisa; Fernandes, Eduarda; Silva, Artur M S

    2016-08-25

    New polyhydroxylated flavon-3-ols and 3-hydroxy-2-styrylchromones were prepared and assessed as reactive oxygen species (ROS) and reactive nitrogen species (RNS) scavengers. The synthetic strategy involved the preparation of 2'-hydroxychalcones and 2'-hydroxycinnamylidenoacetophenones from base-catalyzed aldol reaction of appropriate 2'-hydroxyacetophenones and benzaldehydes/cinnamaldehydes, followed by an Algar-Flynn-Oyamada (AFO) reaction to give the polyalkoxy(flavon-3-ols and 3-hydroxy-2-styrylchromones). The last step of this synthetic route consisted in the cleavage of the protecting groups affording the expected polyhydroxylated derivatives. The present work consisted in the study of the in vitro scavenging activities of the synthetized compounds against the most physiologically relevant ROS [superoxide radical (O2(-)), hydrogen peroxide (H2O2), hypochlorous acid (HOCl), singlet oxygen ((1)O2) and peroxyl radical (ROO)] and RNS [nitric oxide (NO) and peroxynitrite anion (ONOO(-))]. Generally, all the tested new polyhydroxylated flavon-3-ols and 3-hydroxy-2-styrylchromones exhibited scavenging effects dependent on the concentration, and with IC50 values found within the micromolar range. This work allowed the establishment of new structure-activity relationships and brought the knowledge about the selective choice of a structure depending on the targeted reactive species. PMID:27213247

  6. Determination of peroxyl radical scavenging activity of flavonoids and plant extracts using an automatic potentiometric titrator.

    PubMed

    Sano, Mitsuaki; Yoshida, Risa; Degawa, Masakuni; Miyase, Toshio; Yoshino, Kyoji

    2003-05-01

    A novel potentiometric method for evaluation of peroxyl radical scavenging activity of flavonoids and plant extracts was developed. The oxidation of potassium iodide (KI) was performed in acetonitrilephosphate buffer (1:1) containing antioxidant using 2,2'-azobis(2-amidinopropane) dihydrochloride as a peroxyl radical generator. The amount of iodine released from KI during a 20-min free radical oxidation was determined quantitatively using an automatic potentiometric titrator with sodium thiosulfate. The radical scavenging activity of the sample was expressed as the inhibition ratio for iodine release of the control group mediated by the radical. The results obtained from some authentic polyphenols correlated well with those of previous reports. This is a simple, time-saving method requiring less than 30 min and is useful in assessing the radical scavenging activity of antioxidants in plant extracts. We describe the radical scavenging activities of various flavonoids including 21 kinds of tea catechins and vegetable extracts by this method.

  7. An ethanol extract derived from Bonnemaisonia hamifera scavenges ultraviolet B (UVB) radiation-induced reactive oxygen species and attenuates UVB-induced cell damage in human keratinocytes.

    PubMed

    Piao, Mei Jing; Hyun, Yu Jae; Cho, Suk Ju; Kang, Hee Kyoung; Yoo, Eun Sook; Koh, Young Sang; Lee, Nam Ho; Ko, Mi Hee; Hyun, Jin Won

    2012-12-14

    The present study investigated the photoprotective properties of an ethanol extract derived from the red alga Bonnemaisonia hamifera against ultraviolet B (UVB)-induced cell damage in human HaCaT keratinocytes. The Bonnemaisonia hamifera ethanol extract (BHE) scavenged the superoxide anion generated by the xanthine/xanthine oxidase system and the hydroxyl radical generated by the Fenton reaction (FeSO₄ + H₂O₂), both of which were detected by using electron spin resonance spectrometry. In addition, BHE exhibited scavenging activity against the 1,1-diphenyl-2-picrylhydrazyl radical and intracellular reactive oxygen species (ROS) that were induced by either hydrogen peroxide or UVB radiation. BHE reduced UVB-induced apoptosis, as shown by decreased apoptotic body formation and DNA fragmentation. BHE also attenuated DNA damage and the elevated levels of 8-isoprostane and protein carbonyls resulting from UVB-mediated oxidative stress. Furthermore, BHE absorbed electromagnetic radiation in the UVB range (280-320 nm). These results suggest that BHE protects human HaCaT keratinocytes against UVB-induced oxidative damage by scavenging ROS and absorbing UVB photons, thereby reducing injury to cellular components.

  8. Effects of commonly used oilfield chemicals on the rate of oxygen scavenging by sulfite/bisulfite

    SciTech Connect

    Braga, T.G.

    1987-05-01

    The effect of common oilfield biocides, corrosion inhibitors, scale preventives, and alcohols on the rate of O/sub 2/ scavenging by sulfite/bisulfite is described. Emphasis is placed on the effect of the functional group of each of the chemical types. An attempt is made to explain the results in terms of the free-radical mechanism.

  9. Production and Characterization of Active Transparent PET Films for Oxygen Sensitive Foods Packaging

    NASA Astrophysics Data System (ADS)

    Rosaria Galdi, Maria; Incarnato, Loredana

    2010-06-01

    The aim of this work is to investigate possible solutions to realize active, transparent PET film suitable for packaging oxygen sensitive foods. At this purpose, monolayer active PET films at different oxygen scavenger concentrations and multilayer active ones were produced by cast extrusion laboratory scale equipments. To assess their activity and to verify the efficacy of such solutions, O2 absorption analyses were carried out in continuous by an innovative oxygen meter.

  10. Calcitriol-copper interaction leads to non enzymatic, reactive oxygen species mediated DNA breakage and modulation of cellular redox scavengers in hepatocellular carcinoma.

    PubMed

    Rizvi, Asim; Farhan, Mohd; Naseem, Imrana; Hadi, S M

    2016-09-01

    Calcitriol is the metabolically active form of Vitamin D and is known to kill cancer cells. Using the rat model of DEN induced hepatocellular carcinoma we show that there is a marked increase in cellular levels of copper in hepatocellular carcinoma and that calcitriol-copper interaction leads to reactive oxygen species mediated DNA breakage selectively in hepatocellular carcinoma cells. In vivo studies show that calcitriol selectively induces severe fluctuations in cellular enzymatic and non enzymatic scavengers of reactive oxygen species in the malignant tissue. Lipid peroxidation, a well established marker of oxidative stress, was found to increase, and substantial cellular DNA breakage was observed. We propose that calcitriol is a proxidant in the cellular milieu of hepatocellular carcinoma cells, and this copper mediated prooxidant action of calcitriol causes selective DNA breakage in malignant cells, while sparing normal (non malignant) cells.

  11. Calcitriol-copper interaction leads to non enzymatic, reactive oxygen species mediated DNA breakage and modulation of cellular redox scavengers in hepatocellular carcinoma.

    PubMed

    Rizvi, Asim; Farhan, Mohd; Naseem, Imrana; Hadi, S M

    2016-09-01

    Calcitriol is the metabolically active form of Vitamin D and is known to kill cancer cells. Using the rat model of DEN induced hepatocellular carcinoma we show that there is a marked increase in cellular levels of copper in hepatocellular carcinoma and that calcitriol-copper interaction leads to reactive oxygen species mediated DNA breakage selectively in hepatocellular carcinoma cells. In vivo studies show that calcitriol selectively induces severe fluctuations in cellular enzymatic and non enzymatic scavengers of reactive oxygen species in the malignant tissue. Lipid peroxidation, a well established marker of oxidative stress, was found to increase, and substantial cellular DNA breakage was observed. We propose that calcitriol is a proxidant in the cellular milieu of hepatocellular carcinoma cells, and this copper mediated prooxidant action of calcitriol causes selective DNA breakage in malignant cells, while sparing normal (non malignant) cells. PMID:27343126

  12. Smelling lavender and rosemary increases free radical scavenging activity and decreases cortisol level in saliva.

    PubMed

    Atsumi, Toshiko; Tonosaki, Keiichi

    2007-02-28

    Free radicals/reactive oxygen species are related to many biological phenomena such as inflammation, aging, and carcinogenesis. The body possesses various antioxidative systems (free radical scavenging activity, FRSA) for preventing oxidative stress, and saliva contains such activity. In the present study, we measured the total salivary FRSA induced after the smelling of lavender and rosemary essential oils that are widely used in aromatherapy. Various physiologically active substances in saliva such as cortisol, secretory IgA, and alpha-amylase activity were found to be correlated with aroma-induced FRSA. The subjects (22 healthy volunteers) sniffed aroma for 5 min, and each subject's saliva was collected immediately. FRSA was measured using 1,1-diphenyl-2-picrylhydrazyl. The FRSA values were increased by stimulation with low concentrations (1000 times dilution) of lavender or by high-concentrations (10 times dilution) of rosemary. In contrast, both lavender and rosemary stimulations decreased cortisol levels. A significant inverse correlation was observed between the FRSA values and the cortisol levels with each concentration of rosemary stimulation. No significant changes were noted in sIgA or alpha-amylase. These findings clarify that lavender and rosemary enhance FRSA and decrease the stress hormone, cortisol, which protects the body from oxidative stress. PMID:17291597

  13. Aging of whiskey increases 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity.

    PubMed

    Aoshima, Hitoshi; Tsunoue, Hideaki; Koda, Hirofumi; Kiso, Yoshinobu

    2004-08-11

    1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of Japanese whiskey after various aging periods in oak barrels was measured to evaluate the antioxidative effects of whiskey. The activity of the whiskey increased with the aging period with high correlation. The activity of various types of whiskey was measured and shown to be correlated to the potentiation of the GABAA receptor response measured in a previous paper. However, the fragrant compounds in the whiskey which potentiated the GABAA receptor response had low DPPH radical scavenging activity, while phenol derivatives had high radical scavenging activity. The whiskey was extracted by pentane. The aqueous part showed the scavenging activity, whereas the pentane part did not. Thus, both the DPPH radical scavenging activity and the potentiation of the GABAA receptor response increased during whiskey aging in oak barrels, but were due to different components. The whiskey protected the H2O2-induced death of E. coli more than ethanol at the same concentration as that of the whiskey. The changes that occurred in the whiskey during aging may be the reason aged whiskies are so highly valued.

  14. Stereospecificity in hydroxyl radical scavenging activities of four ginsenosides produced by heat processing.

    PubMed

    Kang, Ki Sung; Kim, Hyun Young; Yamabe, Noriko; Yokozawa, Takako

    2006-10-01

    The activity-guided fractionation of sun ginseng (SG, heat processed Panax ginseng C. A. Meyer at 120 degrees C) was carried out to identify its main active hydroxyl radical (*OH) scavenging components. As a result, the n-BuOH fraction mainly consisting of ginsenosides showed the strongest activity. Of several ginsenosides of SG, the *OH scavenging activities of relatively high contents of 20(S)-Rg(3), 20(R)-Rg(3), Rk(1), and Rg(5) were compared. Rg(5) and 20(S)-Rg(3) showed strong *OH scavenging IC(50) values of 0.15 and 0.44 mM, respectively, and these activities were prominently higher than each of their respective isomers. Therefore, stereospecificity exists in the *OH scavenging activities of ginsenosides produced by heat processing. Especially, the double bond at carbon-20(22) or the OH group at carbon-20 geometrically close to OH at carbon-12 is thought to increase the *OH scavenging activity of ginsenosides.

  15. Aging of whiskey increases 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity.

    PubMed

    Aoshima, Hitoshi; Tsunoue, Hideaki; Koda, Hirofumi; Kiso, Yoshinobu

    2004-08-11

    1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of Japanese whiskey after various aging periods in oak barrels was measured to evaluate the antioxidative effects of whiskey. The activity of the whiskey increased with the aging period with high correlation. The activity of various types of whiskey was measured and shown to be correlated to the potentiation of the GABAA receptor response measured in a previous paper. However, the fragrant compounds in the whiskey which potentiated the GABAA receptor response had low DPPH radical scavenging activity, while phenol derivatives had high radical scavenging activity. The whiskey was extracted by pentane. The aqueous part showed the scavenging activity, whereas the pentane part did not. Thus, both the DPPH radical scavenging activity and the potentiation of the GABAA receptor response increased during whiskey aging in oak barrels, but were due to different components. The whiskey protected the H2O2-induced death of E. coli more than ethanol at the same concentration as that of the whiskey. The changes that occurred in the whiskey during aging may be the reason aged whiskies are so highly valued. PMID:15291502

  16. 2,2'-Azobis(isobutyronitrile)-derived alkylperoxyl radical scavenging activity assay of hydrophilic antioxidants by employing EPR spin trap method

    PubMed Central

    Kohri, Shunji; Fujii, Hirotada

    2013-01-01

    As interest in the study of antioxidant intake from foods and other agricultural products increases, methods for performing radical scavenging activity assays based on the electron paramagnetic resonance spectroscopic method, in which there is no interference from the sample color and turbidity, are required. In this study, we have developed a rapid and simple electron paramagnetic resonance based assay to evaluate the alkylperoxyl radical scavenging activity of several antioxidants. The alkylperoxyl radical species was generated by the photolysis of azo-radical initiator 2,2'-azobis(isobutyronitrile), in which the radical generation rate and period were controlled by the illumination light. The relative alkylperoxyl radical scavenging activity was obtained by a simple formula of competing reaction of antioxidant and spin trap toward the oxygen radical. The scavenging activities toward alkylperoxyl radical and alkoxy radical species were evaluated in six antioxidants. Although quercetin showed the highest activity toward both radicals, the order of the relative activities in the other antioxidants was different mutually between the alkylperoxyl radical and the alkoxyl radical. This alkylperoxyl radical scavenging activity assay based on electron paramagnetic resonance spectroscopy is useful for evaluation of colored and turbid food samples. PMID:24249966

  17. Soyasaponins prevent H₂O₂-induced inhibition of gap junctional intercellular communication by scavenging reactive oxygen species in rat liver cells.

    PubMed

    Chen, Jiading; Sun, Suxia; Zha, Dingsheng; Wu, Jiguo; Mao, Limei; Deng, Hong; Chu, Xinwei; Luo, Haiji; Zha, Longying

    2014-01-01

    It appears to be more practical and effective to prevent carcinogenesis by targeting the tumor promotion stage. Gap junctional intercellular communication (GJIC) is strongly involved in carcinogenesis, especially the tumor promotion stage. Considerable interest has been focused on the chemoprevention activities of soyasaponin (SS), which are major phytochemicals found in soybeans and soy products. However, less is known about the preventive effects of SS (especially SS with different chemical structures) against tumor promoter-induced inhibition of GJIC. We investigated the protective effects of SS-A1, SS-A2, and SS-I against hydrogen peroxide (H2O2)-induced GJIC inhibition and reactive oxygen species (ROS) production in Buffalo rat liver (BRL) cells. The present results clearly show for the first time that SS-A1, SS-A2, and SS-I prevent the H2O2-induced GJIC inhibition by scavenging ROS in BRL cells in a dose-dependent manner at the concentration range of from 25 to 100 μg/mL. Soyasaponins attenuated the H2O2-induced ROS through potentiating the activities of superoxide dismutase and glutathione peroxidase. This may be an important mechanism by which SS protects against tumor promotion. In addition, various chemical structures of SS appear to exhibit different protective abilities against GJIC inhibition. This may partly attribute to their differences in ROS-scavenging activities. PMID:25268883

  18. Evaluation of Antioxidant, Free Radical Scavenging, and Antimicrobial Activity of Quercus incana Roxb.

    PubMed Central

    Sarwar, Rizwana; Farooq, Umar; Khan, Ajmal; Naz, Sadia; Khan, Sara; Khan, Afsar; Rauf, Abdur; Bahadar, Haji; Uddin, Reaz

    2015-01-01

    Considering the indigenous utilization of Quercus incana Roxb., the present study deals with the investigation of antioxidant, free radical scavenging activity, total phenolic content, and antimicrobial activity of Q. incana Roxb. In vitro antioxidant activity of the plant fractions were determined by 1,1-diphenyl-2-picrylhydrazyl and nitric oxide scavenging method. Total phenolic contents were determined by gallic acid equivalent and antimicrobial activities were determined by agar well diffusion method. It was observed that Q. incana Roxb. showed significant antibacterial activity against Gram-positive and Gram-negative bacteria. n-Butanol fraction showed maximum activity against Micrococcus leuteus with 19 mm zone of inhibition. n-Butanol fraction of Q. incana Roxb. showed immense antifungal activity against Aspergillus niger (32 mm ± 0.55) and A. flavus (28 mm ± 0.45). Similarly n-butanol fraction showed relatively good antioxidant activity with IC50 value of 55.4 ± 0.21 μg/mL. The NO scavenging activity of ethyl acetate fraction (IC50 = 23.21 ± 0.31 μg/mL) was fairly good compared to other fractions. The current study of Q. incana Roxb. suggests the presences of synergetic action of some biological active compounds that may be present in the leaves of medicinal plant. Further studies are needed to better characterize the important active constituents responsible for the antimicrobial, antioxidant and free radical scavenging activity. PMID:26635607

  19. Yields of single-strand breaks in double-stranded calf thymus DNA irradiated in aqueous solution in the presence of oxygen and scavengers

    SciTech Connect

    Udovicic, Lj.; Mark, F.; Bothe, E.

    1994-11-01

    Yields of radiation-induced single-strand breaks in double-stranded calf thymus DNA have been measured as a function of OH scavenger concentration in N{sub 2}O/O{sub 2}-saturated aqueous solution. The experimental data are well represented by a theoretical model based on non-homogeneous reaction kinetics, without the need to adjust any parameter. The good agreement between experimental and theoretical data is taken as evidence that, in the presence of oxygen, the main effect of added scavengers with respect to the formation of single-strand breaks in double-stranded DNA is OH radical scavenging. 30 refs., 3 figs., 1 tab.

  20. Free radical scavenging activity of Cleome gynandra L. leaves on adjuvant induced arthritis in rats.

    PubMed

    Narendhirakannan, R T; Subramanian, S; Kandaswamy, M

    2005-08-01

    The generation of free radicals has been implicated in the causation of several diseases of known and unknown etiologies such as, rheumatoid arthritis, diabetes, cancer, etc., and compounds that can scavenge free radicals have great potential in ameliorating these disease processes. The present study was aimed to investigate the possible anti-oxidant potential of Cleome gynandra leaf extract at a dose of 150 mg/kg body weight for 30 days on adjuvant induced arthritis in experimental rats. Oral administration of C. gynandra leaf extract significantly increased the levels of lipid peroxides and activities of catalase, glutathione peroxidase and decreased the levels of reduced glutathione and superoxide dismutase activity in arthritis induced rats. The free radical scavenging activity of the plant was further evidenced by histological observations made on the limb tissue. The presence of biologically active ingredients and vital trace elements in the leaves readily account for free radical scavenging property of C. gynandra. PMID:16132687

  1. The effect of a Ta oxygen scavenger layer on HfO2-based resistive switching behavior: thermodynamic stability, electronic structure, and low-bias transport.

    PubMed

    Zhong, Xiaoliang; Rungger, Ivan; Zapol, Peter; Nakamura, Hisao; Asai, Yoshihiro; Heinonen, Olle

    2016-03-14

    Reversible resistive switching between high-resistance and low-resistance states in metal-oxide-metal heterostructures makes them very interesting for applications in random access memories. While recent experimental work has shown that inserting a metallic "oxygen scavenger layer" between the positive electrode and oxide improves device performance, the fundamental understanding of how the scavenger layer modifies the heterostructure properties is lacking. We use density functional theory to calculate thermodynamic properties and conductance of TiN/HfO2/TiN heterostructures with and without a Ta scavenger layer. First, we show that Ta insertion lowers the formation energy of low-resistance states. Second, while the Ta scavenger layer reduces the Schottky barrier height in the high-resistance state by modifying the interface charge at the oxide-electrode interface, the heterostructure maintains a high resistance ratio between high- and low-resistance states. Finally, we show that the low-bias conductance of device on-states becomes much less sensitive to the spatial distribution of oxygen removed from the HfO2 in the presence of the Ta layer. By providing a fundamental understanding of the observed improvements with scavenger layers, we open a path to engineer interfaces with oxygen scavenger layers to control and enhance device performance. In turn, this may enable the realization of a non-volatile low-power memory technology with concomitant reduction in energy consumption by consumer electronics and offering significant benefits to society.

  2. The effect of a Ta oxygen scavenger layer on HfO2-based resistive switching behavior: thermodynamic stability, electronic structure, and low-bias transport.

    PubMed

    Zhong, Xiaoliang; Rungger, Ivan; Zapol, Peter; Nakamura, Hisao; Asai, Yoshihiro; Heinonen, Olle

    2016-03-14

    Reversible resistive switching between high-resistance and low-resistance states in metal-oxide-metal heterostructures makes them very interesting for applications in random access memories. While recent experimental work has shown that inserting a metallic "oxygen scavenger layer" between the positive electrode and oxide improves device performance, the fundamental understanding of how the scavenger layer modifies the heterostructure properties is lacking. We use density functional theory to calculate thermodynamic properties and conductance of TiN/HfO2/TiN heterostructures with and without a Ta scavenger layer. First, we show that Ta insertion lowers the formation energy of low-resistance states. Second, while the Ta scavenger layer reduces the Schottky barrier height in the high-resistance state by modifying the interface charge at the oxide-electrode interface, the heterostructure maintains a high resistance ratio between high- and low-resistance states. Finally, we show that the low-bias conductance of device on-states becomes much less sensitive to the spatial distribution of oxygen removed from the HfO2 in the presence of the Ta layer. By providing a fundamental understanding of the observed improvements with scavenger layers, we open a path to engineer interfaces with oxygen scavenger layers to control and enhance device performance. In turn, this may enable the realization of a non-volatile low-power memory technology with concomitant reduction in energy consumption by consumer electronics and offering significant benefits to society. PMID:26902598

  3. Chemical and Free Radical-scavenging Activity Changes of Ginsenoside Re by Maillard Reaction and Its Possible Use as a Renoprotective Agent

    PubMed Central

    Yamabe, Noriko; Song, Kyung Il; Lee, Woojung; Han, Im-Ho; Lee, Ji Hwan; Ham, Jungyeob; Kim, Su-Nam; Park, Jeong Hill; Kang, Ki Sung

    2012-01-01

    Reactive oxygen species play critical role in kidney damage. Free radical-scavenging activities of Panax ginseng are known to be increased by heat-processing. The structural change of ginsenoside and the generation of Maillard reaction products (MRPs) are closely related to the increased free radical-scavenging activities. In the present study, we have demonstrated the Maillard reaction model experiment using ginsenoside Re and glycine mixture to identify the renoprotective effect of MRPs from ginseng or ginsenosides. Ginsenoside Re was transformed into less-polar ginsenosides, namely Rg2, Rg6 and F4 by heat-processing. The free radical-scavenging activity of ginsenoside Re-glycine mixture was increased in a temperature-dependant manner by heatprocessing. The improved free radical-scavenging activity by heat-processing was mediated by the generation of antioxidant MRPs which led to the protection of LLC-PK1 renal epithelial cells from oxidative stress. Although the free radical scavenging activities of less-polar ginsenosides were weak, they could protect LLC-PK1 cells from oxidative stress. Therefore, MRPs and less-polar ginsenosides contributed to the combined renoprotective effects against oxidative renal damage. PMID:23717126

  4. Alliin Attenuated RANKL-Induced Osteoclastogenesis by Scavenging Reactive Oxygen Species through Inhibiting Nox1

    PubMed Central

    Chen, Yueqi; Sun, Jingjing; Dou, Ce; Li, Nan; Kang, Fei; Wang, Yuan; Cao, Zhen; Yang, Xiaochao; Dong, Shiwu

    2016-01-01

    The healthy skeleton requires a perfect coordination of the formation and degradation of bone. Metabolic bone disease like osteoporosis is resulted from the imbalance of bone formation and/or bone resorption. Osteoporosis also reflects lower level of bone matrix, which is contributed by up-regulated osteoclast-mediated bone resorption. It is reported that monocytes/macrophage progenitor cells or either hematopoietic stem cells (HSCs) gave rise to multinucleated osteoclasts. Thus, inhibition of osteoclastic bone resorption generally seems to be a predominant therapy for treating osteoporosis. Recently, more and more natural compounds have been discovered, which have the ability of inhibiting osteoclast differentiation and fusion. Alliin (S-allyl-l-cysteine sulfoxides, SACSO) is the major component of aged garlic extract (AGE), bearing broad-spectrum natural antioxidant properties. However, its effects on bone health have not yet been explored. Hence, we designed the current study to explore its effects and role in receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast fusion and differentiation. It was revealed that alliin had an inhibitory effect in osteoclasteogenesis with a dose-dependent manner via blocking the c-Fos-NFATc1 signaling pathway. In addition, alliin decreased the generation of reactive oxygen species (ROS) and down-regulated the expression of NADPH oxidase 1 (Nox1). The overall results revealed that alliin could be a potential therapeutic agent in the treatment of osteoporosis. PMID:27657047

  5. Enhanced Reactive Oxygen Species Scavenging by Overproduction of Superoxide Dismutase and Catalase Delays Postharvest Physiological Deterioration of Cassava Storage Roots1[C][W][OA

    PubMed Central

    Xu, Jia; Duan, Xiaoguang; Yang, Jun; Beeching, John R.; Zhang, Peng

    2013-01-01

    Postharvest physiological deterioration (PPD) of cassava (Manihot esculenta) storage roots is the result of a rapid oxidative burst, which leads to discoloration of the vascular tissues due to the oxidation of phenolic compounds. In this study, coexpression of the reactive oxygen species (ROS)-scavenging enzymes copper/zinc superoxide dismutase (MeCu/ZnSOD) and catalase (MeCAT1) in transgenic cassava was used to explore the intrinsic relationship between ROS scavenging and PPD occurrence. Transgenic cassava plants integrated with the expression cassette p54::MeCu/ZnSOD-35S::MeCAT1 were confirmed by Southern-blot analysis. The expression of MeCu/ZnSOD and MeCAT1 was verified by quantitative reverse transcription-polymerase chain reaction and enzymatic activity analysis both in the leaves and storage roots. Under exposure to the ROS-generating reagent methyl viologen or to hydrogen peroxide (H2O2), the transgenic plants showed higher enzymatic activities of SOD and CAT than the wild-type plants. Levels of malondialdehyde, chlorophyll degradation, lipid peroxidation, and H2O2 accumulation were dramatically reduced in the transgenic lines compared with the wild type. After harvest, the storage roots of transgenic cassava lines show a delay in their PPD response of at least 10 d, accompanied by less mitochondrial oxidation and H2O2 accumulation, compared with those of the wild type. We hypothesize that this is due to the combined ectopic expression of Cu/ZnSOD and CAT leading to an improved synergistic ROS-scavenging capacity of the roots. Our study not only sheds light on the mechanism of the PPD process but also develops an effective approach for delaying the occurrence of PPD in cassava. PMID:23344905

  6. Radical scavenging activity of antioxidants evaluated by means of electrogenerated HO radical.

    PubMed

    Oliveira, Raquel; Geraldo, Dulce; Bento, Fátima

    2014-11-01

    A method is proposed and tested concerning the characterization of antioxidants by means of their reaction with electrogenerated HO radicals in galvanostatic assays with simultaneous O2 evolution, using a Pt anode fairly oxidized. The consumption of a set of species with antioxidant activity, ascorbic acid (AA), caffeic acid (CA), gallic acid (GA) and trolox (T), is described by a first order kinetics. The rate of the processes is limited by the kinetics of reaction with HO radicals and by the kinetics of charge transfer. Information regarding the scavenger activity of antioxidants is obtained by the relative value of the rate constant of the reaction between antioxidants and HO radicals, k(AO,HO)/k(O2). The number of HO radicals scavenged per molecule of antioxidant is also estimated and ranged from 260 (ascorbic acid) to 500 (gallic acid). The method is applied successfully in the characterization of the scavenger activity of ascorbic acid in a green-tea based beverage.

  7. Optimization of microwave-assisted extraction of polyphenols from herbal teas and evaluation of their in vitro hypochlorous acid scavenging activity.

    PubMed

    Bekdeşer, Burcu; Durusoy, Nazan; Özyürek, Mustafa; Güçlü, Kubilay; Apak, Reşat

    2014-11-19

    Hypochlorous acid (HOCl) is an important reactive oxygen species (ROS) and non-radical and is taking part in physiological processes concerned with the defense of the organism, but there has been limited information regarding its scavenging by polyphenols. This study was designed to examine the HOCl scavenging activity of several polyphenols and microwave-assisted extracts of herbal teas. HOCl scavenging activity has usually been determined spectrophotometrically by a KI/taurine assay at 350 nm. Because some polyphenols (i.e., apigenin and chrysin) have a strong ultraviolet (UV) absorption in this range, their HOCl scavenging activity was alternatively determined without interference using resorcinol (1,3-dihydroxybenzene) as a fluorogenic probe. In the present assay, HOCl induces the chlorination of resorcinol into its non-fluorescent products. Polyphenols as HOCl scavengers inhibit the chlorination of the probe by this species. Thus, the 25% inhibitive concentration (IC25) value of polyphenols was determined using the relative increase in fluorescence intensity of the resorcinol probe. The HOCl scavenging activities of the test compounds decreased in the order: epigallocatechin gallate > quercetin > gallic acid > rutin > catechin > kaempferol. The present study revealed that epigallocatechin gallate (IC25 = 0.1 μM) was the most effective scavenging agent. In addition to polyphenols, four herbal teas were evaluated for their HOCl activity using the resorcinol method. The proposed spectrofluorometric method was practical, rapid, and less open to interferences by absorbing substances in the range of 200-420 nm. The results hint to the possibility of polyphenols having beneficial effects in diseases, such as atherosclerosis, in which HOCl plays a pathogenic role.

  8. Radical scavenging and angiotensin converting enzyme inhibitory activities of standardized extracts of Ficus racemosa stem bark.

    PubMed

    Ahmed, Faiyaz; Siddesha, Jalahalli M; Urooj, Asna; Vishwanath, Bannikuppe S

    2010-12-01

    The present study evaluated the radical scavenging and angiotensin converting enzyme (ACE) inhibitory activity of cold and hot aqueous extracts of Ficus racemosa (Moraceae) stem bark. The extracts were standardized using HPLC. Radical scavenging activity was determined using 1,1-diphenyl-2-picrylhydrazyl radical and angiotensin converting enzyme inhibitory activity using rabbit lung and partially purified porcine kidney ACE. HPLC profiles of cold aqueous extract (FRC) showed the presence of bergenin, an isocoumarin, while hot aqueous extract (FRH) was found to contain ferulic acid, kaempferol and coumarin in addition to bergenin. FRH showed significantly higher (p ≤ 0.01) radical scavenging activity than FRC and butylated hydroxytoluene (BHT), consequently resulting in a significantly lower (p ≤ 0.01) IC₅₀ value than FRC and BHT. Both the extracts exhibited a dose dependent inhibition of porcine kidney and rabbit lung ACE. FRH showed significantly higher (p ≤ 0.01) activity than FRC with lower IC(50) values of 1.36 and 1.91 μg/mL respectively, for porcine kidney and rabbit lung ACE, compared with those of FRC (128 and 291 μg/mL). Further, a significant correlation (r = 0.893; p ≤ 0.05) was observed between radical scavenging activity and ACE-inhibitory activity. This is the first report on the ACE-inhibitory activity of F. racemosa stem bark suggesting its potential to be utilized as a therapeutic alternative for hypertension. PMID:20564493

  9. Reactive Oxygen Species Generation-Scavenging and Signaling during Plant-Arbuscular Mycorrhizal and Piriformospora indica Interaction under Stress Condition

    PubMed Central

    Nath, Manoj; Bhatt, Deepesh; Prasad, Ram; Gill, Sarvajeet S.; Anjum, Naser A.; Tuteja, Narendra

    2016-01-01

    A defined balance between the generation and scavenging of reactive oxygen species (ROS) is essential to utilize ROS as an adaptive defense response of plants under biotic and abiotic stress conditions. Moreover, ROS are not only a major determinant of stress response but also act as signaling molecule that regulates various cellular processes including plant-microbe interaction. In particular, rhizosphere constitutes the biologically dynamic zone for plant–microbe interactions which forms a mutual link leading to reciprocal signaling in both the partners. Among plant–microbe interactions, symbiotic associations of arbuscular mycorrhizal fungi (AMF) and arbuscular mycorrhizal-like fungus especially Piriformospora indica with plants are well known to improve plant growth by alleviating the stress-impacts and consequently enhance the plant fitness. AMF and P. indica colonization mainly enhances ROS-metabolism, maintains ROS-homeostasis, and thereby averts higher ROS-level accrued inhibition in plant cellular processes and plant growth and survival under stressful environments. This article summarizes the major outcomes of the recent reports on the ROS-generation, scavenging and signaling in biotic-abiotic stressed plants with AMF and P. indica colonization. Overall, a detailed exploration of ROS-signature kinetics during plant-AMF/P. indica interaction can help in designing innovative strategies for improving plant health and productivity under stress conditions.

  10. TIGAR contributes to ischemic tolerance induced by cerebral preconditioning through scavenging of reactive oxygen species and inhibition of apoptosis.

    PubMed

    Zhou, Jun-Hao; Zhang, Tong-Tong; Song, Dan-Dan; Xia, Yun-Fei; Qin, Zheng-Hong; Sheng, Rui

    2016-01-01

    Previous study showed that TIGAR (TP53-induced glycolysis and apoptosis regulator) protected ischemic brain injury via enhancing pentose phosphate pathway (PPP) flux and preserving mitochondria function. This study was aimed to study the role of TIGAR in cerebral preconditioning. The ischemic preconditioning (IPC) and isoflurane preconditioning (ISO) models were established in primary cultured cortical neurons and in mice. Both IPC and ISO increased TIGAR expression in cortical neurons. Preconditioning might upregulate TIGAR through SP1 transcription factor. Lentivirus mediated knockdown of TIGAR significantly abolished the ischemic tolerance induced by IPC and ISO. ISO also increased TIGAR in mouse cortex and hippocampus and alleviated subsequent brain ischemia-reperfusion injury, while the ischemic tolerance induced by ISO was eliminated with TIGAR knockdown in mouse brain. ISO increased the production of NADPH and glutathione (GSH), and scavenged reactive oxygen species (ROS), while TIGAR knockdown decreased GSH and NADPH production and increased the level of ROS. Supplementation of ROS scavenger NAC and PPP product NADPH effectively rescue the neuronal injury caused by TIGAR deficiency. Notably, TIGAR knockdown inhibited ISO-induced anti-apoptotic effects in cortical neurons. These results suggest that TIGAR participates in the cerebral preconditioning through reduction of ROS and subsequent cell apoptosis. PMID:27256465

  11. Novel antioxidative nanotherapeutics in a rat periodontitis model: Reactive oxygen species scavenging by redox injectable gel suppresses alveolar bone resorption.

    PubMed

    Saita, Makiko; Kaneko, Junya; Sato, Takenori; Takahashi, Shun-suke; Wada-Takahashi, Satoko; Kawamata, Ryota; Sakurai, Takashi; Lee, Masaichi-Chang-il; Hamada, Nobushiro; Kimoto, Katsuhiko; Nagasaki, Yukio

    2016-01-01

    The excessive production of reactive oxygen species (ROS) has been implicated in a variety of disorders, but to date, ROS scavengers have not been widely used for local treatment of inflammation, because they are rapidly eliminated from the inflamed site. We have designed a novel redox injectable gel (RIG) that is formed at 37 °C after disintegration of nano-assembled flower micelles allowing nitroxide radicals to act locally as specific ROS scavengers for the treatment of periodontitis. In the present study, we have confirmed retention of the RIG in the periodontal region, along with its antioxidant-related anti-inflammatory effects, and we have subsequently evaluated the inhibitory effect of the RIG against Porphyromonas gingivalis (P. gingivalis)-induced alveolar bone loss attributed to ROS. Alveolar bone loss was estimated by morphometry, gingival blood flow was measured using laser Doppler flowmetry, and osteoclast differentiation was evaluated by tartrate-resistant acid phosphatase staining. The results show that the RIG can inhibit P. gingivalis-induced bone loss by antioxidant-related anti-inflammatory actions, and this suggests that the RIG is a promising novel therapeutic agent for the treatment of P. gingivalis-induced periodontitis. PMID:26559357

  12. TIGAR contributes to ischemic tolerance induced by cerebral preconditioning through scavenging of reactive oxygen species and inhibition of apoptosis

    PubMed Central

    Zhou, Jun-Hao; Zhang, Tong-Tong; Song, Dan-Dan; Xia, Yun-Fei; Qin, Zheng-Hong; Sheng, Rui

    2016-01-01

    Previous study showed that TIGAR (TP53-induced glycolysis and apoptosis regulator) protected ischemic brain injury via enhancing pentose phosphate pathway (PPP) flux and preserving mitochondria function. This study was aimed to study the role of TIGAR in cerebral preconditioning. The ischemic preconditioning (IPC) and isoflurane preconditioning (ISO) models were established in primary cultured cortical neurons and in mice. Both IPC and ISO increased TIGAR expression in cortical neurons. Preconditioning might upregulate TIGAR through SP1 transcription factor. Lentivirus mediated knockdown of TIGAR significantly abolished the ischemic tolerance induced by IPC and ISO. ISO also increased TIGAR in mouse cortex and hippocampus and alleviated subsequent brain ischemia-reperfusion injury, while the ischemic tolerance induced by ISO was eliminated with TIGAR knockdown in mouse brain. ISO increased the production of NADPH and glutathione (GSH), and scavenged reactive oxygen species (ROS), while TIGAR knockdown decreased GSH and NADPH production and increased the level of ROS. Supplementation of ROS scavenger NAC and PPP product NADPH effectively rescue the neuronal injury caused by TIGAR deficiency. Notably, TIGAR knockdown inhibited ISO-induced anti-apoptotic effects in cortical neurons. These results suggest that TIGAR participates in the cerebral preconditioning through reduction of ROS and subsequent cell apoptosis. PMID:27256465

  13. Novel antioxidative nanotherapeutics in a rat periodontitis model: Reactive oxygen species scavenging by redox injectable gel suppresses alveolar bone resorption.

    PubMed

    Saita, Makiko; Kaneko, Junya; Sato, Takenori; Takahashi, Shun-suke; Wada-Takahashi, Satoko; Kawamata, Ryota; Sakurai, Takashi; Lee, Masaichi-Chang-il; Hamada, Nobushiro; Kimoto, Katsuhiko; Nagasaki, Yukio

    2016-01-01

    The excessive production of reactive oxygen species (ROS) has been implicated in a variety of disorders, but to date, ROS scavengers have not been widely used for local treatment of inflammation, because they are rapidly eliminated from the inflamed site. We have designed a novel redox injectable gel (RIG) that is formed at 37 °C after disintegration of nano-assembled flower micelles allowing nitroxide radicals to act locally as specific ROS scavengers for the treatment of periodontitis. In the present study, we have confirmed retention of the RIG in the periodontal region, along with its antioxidant-related anti-inflammatory effects, and we have subsequently evaluated the inhibitory effect of the RIG against Porphyromonas gingivalis (P. gingivalis)-induced alveolar bone loss attributed to ROS. Alveolar bone loss was estimated by morphometry, gingival blood flow was measured using laser Doppler flowmetry, and osteoclast differentiation was evaluated by tartrate-resistant acid phosphatase staining. The results show that the RIG can inhibit P. gingivalis-induced bone loss by antioxidant-related anti-inflammatory actions, and this suggests that the RIG is a promising novel therapeutic agent for the treatment of P. gingivalis-induced periodontitis.

  14. Psidium cattleianum fruit extracts are efficient in vitro scavengers of physiologically relevant reactive oxygen and nitrogen species.

    PubMed

    Ribeiro, Alessandra Braga; Chisté, Renan Campos; Freitas, Marisa; da Silva, Alex Fiori; Visentainer, Jesuí Vergílio; Fernandes, Eduarda

    2014-12-15

    Psidium cattleianum, an unexploited Brazilian native fruit, is considered a potential source of bioactive compounds. In the present study, the in vitro scavenging capacity of skin and pulp extracts from P. cattleianum fruits against reactive oxygen species (ROS) and reactive nitrogen species (RNS) was evaluated by in vitro screening assays. Additionally, the composition of phenolic compounds and carotenoids in both extracts was determined by LC-MS/MS. The major phenolic compounds identified and quantified (dry matter) in the skin and pulp extracts of P. cattleianum were ellagic acid (2213-3818 μg/g extracts), ellagic acid deoxyhexoside (1475-2,070 μg/g extracts) and epicatechin gallate (885-1,603 μg/g extracts); while all-trans-lutein (2-10 μg/g extracts), all-trans-antheraxanthin (1.6-9 μg/g extracts) and all-trans-β-carotene (4-6 μg/g extracts) were the major carotenoids identified in both extracts. P. cattleianum pulp extract showed higher scavenging capacity than skin extract for all tested ROS and RNS. Considering the potential beneficial effects to human health, P. cattleianum may be considered as a good source of natural antioxidants and may be useful for the food and phytopharmaceutical industry.

  15. Novel spectroscopic sensor for the hydroxyl radical scavenging activity measurement of biological samples.

    PubMed

    Bekdeşer, Burcu; Özyürek, Mustafa; Güçlü, Kubilay; Apak, Reşat

    2012-09-15

    A novel spectroscopic sensor was developed and validated for hydroxyl radical scavenging (HRS) activity estimation using terephthalate (TP) as probe. This sensor was designed by electrostatic immobilization of the chromogenic oxidizing agent of the CUPric Reducing Antioxidant Capacity (CUPRAC) method, Cu(II)-Neocuproine (Cu(II)-Nc) complex, on a Nafion cation-exchange membrane, and the spectrophotometric assay developed in aqueous-alcoholic solutions was integrated to the CUPRAC sensor. Hydroxyl radicals ((•)OH) generated from an equivalent mixture of Fe(II)+EDTA with hydrogen peroxide attacked both the probe and the (•)OH scavengers in 37 °C-incubated solutions for 1/2h. The HRS activity was measured using the decrease in CUPRAC absorbance at 450 nm - arising from the reduction of Cu(II)-Nc reagent to the Cu(I)-neocuproine chelate - of the hydroxylated probe (TP) undergoing radical attack in the presence of (•)OH scavengers. The HRS activity was evaluated as the second-order rate constants of biologically active compounds for (•)OH scavenging and also as the percentage scavenging of a measured compound or sample relative to a reference compound. Using this reaction, a kinetic approach was adopted to assess the HRS activity of amino acids, plasma- and thiol-antioxidants. This assay, applicable to small molecule antioxidants and tissue homogenates, proved to be efficient for serine and albumin for which the widely used TBARS (thiobarbituric acid-reactive substances) test is nonresponsive. Under optimal conditions, about half of the probe (TP) was converted into 2-hydroxyterephthalate (hTP), and this monohydroxylated derivative, being the only product of hydroxylation, was a more specific marker of (•)OH than the non-specific malondialdehyde end-product of the TBARS test. The sensor gave a linear response to scavenger concentration in the competition kinetic equation.

  16. A soil actinobacterium scavenges atmospheric H2 using two membrane-associated, oxygen-dependent [NiFe] hydrogenases.

    PubMed

    Greening, Chris; Berney, Michael; Hards, Kiel; Cook, Gregory M; Conrad, Ralf

    2014-03-18

    In the Earth's lower atmosphere, H2 is maintained at trace concentrations (0.53 ppmv/0.40 nM) and rapidly turned over (lifetime ≤ 2.1 y(-1)). It is thought that soil microbes, likely actinomycetes, serve as the main global sink for tropospheric H2. However, no study has ever unambiguously proven that a hydrogenase can oxidize this trace gas. In this work, we demonstrate, by using genetic dissection and sensitive GC measurements, that the soil actinomycete Mycobacterium smegmatis mc(2)155 constitutively oxidizes subtropospheric concentrations of H2. We show that two membrane-associated, oxygen-dependent [NiFe] hydrogenases mediate this process. Hydrogenase-1 (Hyd1) (MSMEG_2262-2263) is well-adapted to rapidly oxidize H2 at a range of concentrations [Vmax(app) = 12 nmol⋅g⋅dw(-1)⋅min(-1); Km(app) = 180 nM; threshold = 130 pM in the Δhyd23 (Hyd1 only) strain], whereas Hyd2 (MSMEG_2719-2720) catalyzes a slower-acting, higher-affinity process [Vmax(app) = 2.5 nmol⋅g⋅dw(-1)⋅min(-1); Km(app) = 50 nM; threshold = 50 pM in the Δhyd13 (Hyd2 only) strain]. These observations strongly support previous studies that have linked group 5 [NiFe] hydrogenases (e.g., Hyd2) to the oxidation of tropospheric H2 in soil ecosystems. We further reveal that group 2a [NiFe] hydrogenases (e.g., Hyd1) can contribute to this process. Hydrogenase expression and activity increases in carbon-limited cells, suggesting that scavenging of trace H2 helps to sustain dormancy. Distinct physiological roles for Hyd1 and Hyd2 during the adaptation to this condition are proposed. Soil organisms harboring high-affinity hydrogenases may be especially competitive, given that they harness a highly dependable fuel source in otherwise unstable environments.

  17. A soil actinobacterium scavenges atmospheric H2 using two membrane-associated, oxygen-dependent [NiFe] hydrogenases

    PubMed Central

    Greening, Chris; Berney, Michael; Hards, Kiel; Cook, Gregory M.; Conrad, Ralf

    2014-01-01

    In the Earth’s lower atmosphere, H2 is maintained at trace concentrations (0.53 ppmv/0.40 nM) and rapidly turned over (lifetime ≤ 2.1 y−1). It is thought that soil microbes, likely actinomycetes, serve as the main global sink for tropospheric H2. However, no study has ever unambiguously proven that a hydrogenase can oxidize this trace gas. In this work, we demonstrate, by using genetic dissection and sensitive GC measurements, that the soil actinomycete Mycobacterium smegmatis mc2155 constitutively oxidizes subtropospheric concentrations of H2. We show that two membrane-associated, oxygen-dependent [NiFe] hydrogenases mediate this process. Hydrogenase-1 (Hyd1) (MSMEG_2262-2263) is well-adapted to rapidly oxidize H2 at a range of concentrations [Vmax(app) = 12 nmol⋅g⋅dw−1⋅min−1; Km(app) = 180 nM; threshold = 130 pM in the Δhyd23 (Hyd1 only) strain], whereas Hyd2 (MSMEG_2719-2720) catalyzes a slower-acting, higher-affinity process [Vmax(app) = 2.5 nmol⋅g⋅dw−1⋅min−1; Km(app) = 50 nM; threshold = 50 pM in the Δhyd13 (Hyd2 only) strain]. These observations strongly support previous studies that have linked group 5 [NiFe] hydrogenases (e.g., Hyd2) to the oxidation of tropospheric H2 in soil ecosystems. We further reveal that group 2a [NiFe] hydrogenases (e.g., Hyd1) can contribute to this process. Hydrogenase expression and activity increases in carbon-limited cells, suggesting that scavenging of trace H2 helps to sustain dormancy. Distinct physiological roles for Hyd1 and Hyd2 during the adaptation to this condition are proposed. Soil organisms harboring high-affinity hydrogenases may be especially competitive, given that they harness a highly dependable fuel source in otherwise unstable environments. PMID:24591586

  18. Analysis of scavengers' activities and recycling in some cities of Nigeria.

    PubMed

    Agunwamba, J C

    2003-07-01

    The state of solid waste recycling by scavengers in Onitsha, a heavily commercial city in Anambra State, and some other urban areas such as Nsukka, Enugu, and Port Harcourt was analyzed. Data were obtained through interviews of scavengers who deal with recyclables. Although the activities of scavengers are sub-optimal, they can have a great impact on Nigerian economy with respect to resource conservation, creation of job opportunities, and reduction of the magnitude of waste disposal problems. A cost analysis is presented to compare the different forms of recycling utilized by municipal solid waste management. It is shown that a well-planned recycling program with recycling and composting would result in 18.6% savings in waste management costs and 57.7% in landfill avoidance costs. However, if the compost materials are not recycled, the corresponding savings in cost become 8.6% and 28.6%, respectively. The option with the lowest cost involves encouraging individual households to separate at the source their recyclables, which are bought by scavengers. This results in 78.0% savings in waste management cost and 79.5% landfill avoidance cost. A low-cost approach aimed at the integration of scavenging activities into conventional solid waste management is presented.

  19. Molecular mechanisms for the reaction between (˙)OH radicals and proline: insights on the role as reactive oxygen species scavenger in plant stress.

    PubMed

    Signorelli, Santiago; Coitiño, E Laura; Borsani, Omar; Monza, Jorge

    2014-01-01

    The accumulation of proline (Pro) and overproduction of reactive oxygen species (ROS) by plants exposed to stress is well-documented. In vitro assays show that enzyme inactivation by hydroxyl radicals ((•)OH) can be avoided in the presence of Pro, suggesting this amino acid might act as a (•)OH scavenger. Although production of hydroxyproline (Hyp) has been hypothesized in connection with such antioxidant activity, no evidence on the detailed mechanism of scavenging has been reported. To elucidate whether and how Hyp might be produced, we used density functional theory calculations coupled to a polarizable continuum model to explore 27 reaction channels including H-abstraction by (•)OH and (•)OH/H2O addition. The structure and energetics of stable species and transition states for each reaction channel were characterized at the PCM-(U)M06/6-31G(d,p) level in aqueous solution. Evidence is found for a main pathway in which Pro scavenges (•)OH by successive H-abstractions (ΔG(‡,298) = 4.1 and 7.5 kcal mol(-1)) to yield 3,4-Δ-Pro. A companion pathway with low barriers yielding Δ(1)-pyrroline-5-carboxylate (P5C) is also supported, linking with 5-Hyp through hydration. However, this connection remains unlikely in stressed plants because P5C would be efficiently recycled to Pro (contributing to its accumulation) by P5C reductase, hypothesis coined here as the "Pro-Pro cycle". PMID:24328335

  20. PM6 study of free radical scavenging mechanisms of flavonoids: why does O-H bond dissociation enthalpy effectively represent free radical scavenging activity?

    PubMed

    Amić, Dragan; Stepanić, Višnja; Lučić, Bono; Marković, Zoran; Dimitrić Marković, Jasmina M

    2013-06-01

    It is well known that the bond dissociation enthalpy (BDE) of the O-H group is related to the hydrogen atom transfer (HAT) mechanism of free radical scavenging that is preferred in gas-phase and non-polar solvents. The present work shows that the BDE may also be related to radical scavenging processes taking place in polar solvents, i.e., single electron transfer followed by proton transfer (SET-PT) and sequential proton loss electron transfer (SPLET). This is so because the total energy requirements related to the SET-PT [sum of the ionization potential (IP) and proton dissociation enthalpy (PDE)] and the SPLET [sum of the proton affinity (PA) and electron transfer enthalpy (ETE)] are perfectly correlated with the BDE. This could explain why the published data for polyphenolic antioxidant activity measured by various assays are better correlated with the BDE than with other reaction enthalpies involved in radical scavenging mechanisms, i.e., the IP, PDE, PA and ETE. The BDE is fairly well able to rank flavonoids as antioxidants in any medium, but to conclude which radical scavenging mechanism represents the most probable reaction pathway from the thermodynamic point of view, the IP and PA (ETE) should also be considered. This is exemplified in the case of the radical scavenging activity of 25 flavonoids.

  1. Long-Term Sodium Ferulate Supplementation Scavenges Oxygen Radicals and Reverses Liver Damage Induced by Iron Overloading.

    PubMed

    Qiao, Yang; He, Huan; Zhang, Zeyu; Liao, Zhangping; Yin, Dong; Liu, Dan; Yi, Bo; He, Ming

    2016-01-01

    Ferulic acid is a polyphenolic compound contained in various types of fruits and wheat bran. As a salt of the active ingredient, sodium ferulate (SF) has potent free radical scavenging activity and can effectively scavenge ROS. In this study, we examined the effect of SF on iron-overloaded mice in comparison to a standard antioxidant, taurine (TAU). We determined the protective role of SF against liver injury by examining liver-to-body ratio (%), transaminase and hepatocyte apoptosis in rats supplied with 10% dextrose intraperitoneal injection. In addition, antioxidative enzymes activities, ROS formation, mitochondrial swelling, and mitochondrial membrane potential (MMP) were all evaluated to clarify the mechanism of protective effect of SF associated with oxidative stress. After 15 weeks of SF treatment, we found a significant reduction in liver-to-body weight radio and elevation in both transaminase and hepatocyte apoptosis associated with iron-injected to levels comparable to those achieved with TAU. Both SF and TAU significantly attenuated the impaired liver function associated with iron-overloaded in mice, whereas neither showed any significant effect on the iron uptake. Furthermore, treatment with either SF or TAU in iron-overloaded mice attenuated oxidative stress, associated with elevated oxidant enzymes activities, decreased ROS production, prevented mitochondrial swelling and dissipation of MMP and then inhibited hepatic apoptosis. Taken together, the current study shows that, SF alleviated oxidative stress and liver damage associated with iron-overload conditions compared to the standard ROS scavenger (TAU), and potentially could encourage higher consumption and utilization as healthy and sustainable ingredients by the food and drink. PMID:27649133

  2. Antimutagenic activity and radical scavenging activity of water infusions and phenolics from ligustrum plants leaves.

    PubMed

    Nagy, Milan; Krizková, Lívia; Mucaji, Pavel; Kontseková, Zuzana; Sersen, Frantisek; Krajcovic, Juraj

    2009-01-01

    Water infusions of Ligustrum delavayanum and Ligustrum vulgare leaves and eight phenolics isolated therefrom have been assayed in vitro on ofloxacin-induced genotoxicity in the unicellular flagellate Euglena gracilis. The tested compounds luteolin, quercetin, luteolin-7-glucoside, luteolin-7-rutinoside, quercetin-3-rutinoside, apigenin-7-rutinoside, tyrosol and esculetin inhibited the mutagenic activity of ofloxacin (43 microM) in E. gracilis. Water infusions from leaves of L. delavayanum and L. vulgare showed higher antimutagenic effect (p(t) < 0.001). The activity of these samples against ofloxacin (86 microM)-induced genotoxicity was lower, but statistically significant (p(t) < 0.05), excluding the water infusion of L. delavayanum leaves (p(t) < 0.01). Efficacy of quercetin, luteolin-7-rutinoside, apigenin-7-rutinoside was insignificant. The antimutagenic effect of most phenolics we studied could be clearly ascribed to their DPPH scavenging activity, substitution patterns and lipophilicity. PMID:19169198

  3. Nitric Oxide Measurement from Purified Enzymes and Estimation of Scavenging Activity by Gas Phase Chemiluminescence Method.

    PubMed

    Kumari, Aprajita; Gupta, Alok Kumar; Mishra, Sonal; Wany, Aakanksha; Gupta, Kapuganti Jagadis

    2016-01-01

    In plants, nitrate reductase (NR) is a key enzyme that produces nitric oxide (NO) using nitrite as a substrate. Lower plants such as algae are shown to have nitric oxide synthase enzyme and higher plants contain NOS activity but enzyme responsible for NO production in higher plants is subjected to debate. In plant nitric oxide research, it is very important to measure NO very precisely in order to determine its functional role. A significant amount of NO is being scavenged by various cell components. The net NO production depends in production minus scavenging. Here, we describe methods to measure NO from purified NR and inducible nitric oxide synthase from mouse (iNOS), we also describe a method of measure NO scavenging by tobacco cell suspensions and mitochondria from roots. PMID:27094408

  4. Reduced serum hydroxyl radical scavenging activity in erythropoietin therapy resistant renal anemia.

    PubMed

    Hirayama, Aki; Nagase, Sohji; Gotoh, Michihiro; Ueda, Atsushi; Ishizu, Takashi; Yoh, Keigyou; Aoyagi, Kazumasa; Terao, Junji; Koyama, Akio

    2002-11-01

    Relation between anemia resistant to recombinant human erythropoietin (rHuEPO) therapy and the oxidative stress in hemodialysis (HD) patients was investigated. Stable HD patients who had consistent hemoglobin concentrations on a constant dose of rHuEPO were studied. Patients were excluded if there were factors that might affect hemopoiesis or administration of antioxidant supplements. Patients were classified into three groups: High (9000 U/week), Low (1500-4500 U/week) and No rHuEPO group. Thiobarbituric acid reactive substances (TBARS) of sera and erythrocyte were examined. Serum superoxide and hydroxyl radical scavenging activities were measured using electron spin resonance. TBARS in the erythrocyte was higher in High rHuEPO group compared with No rHuEPO group, though the serum TBARS were similar. A diminution of serum hydroxyl radical scavenging activity was observed in High rHuEPO group. Hydroxyl radical signal intensity showed a strong correlation with the serum ferritin in High rHuEPO group, although ferritin concentrations were not different among the 3 groups. Superoxide scavenging activity showed no differences. These results indicate that increased lipid peroxidation in erythrocyte, raised by decreased serum hydroxyl radical scavenging activity, is one cause of rHuEPO resistant anemia. Serum ferritin may be involved in this hydroxyl radical production.

  5. The antioxidant and radical scavenging activities of black pepper (Piper nigrum) seeds.

    PubMed

    Gülçin, Ilhami

    2005-11-01

    Water and ethanol crude extracts from black pepper (Piper nigrum) were investigated for their antioxidant and radical scavenging activities in six different assay, namely, total antioxidant activity, reducing power, 1,1-Diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, and metal chelating activities. Both water extract (WEBP) and ethanol extract (EEBP) of black pepper exhibited strong total antioxidant activity. The 75 microg/ml concentration of WEBP and EEBP showed 95.5% and 93.3% inhibition on peroxidation of linoleic acid emulsion, respectively. On the other hand, at the same concentration, standard antioxidants such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and alpha-tocopherol exhibited 92.1%, 95.0%, and 70.4% inhibition on peroxidation of linoleic acid emulsion, respectively. Also, total phenolic content in both WEBP and EEBP were determined as gallic acid equivalents. The total phenolics content of water and ethanol extracts were determined by the Folin-Ciocalteu procedure and 54.3 and 42.8 microg gallic acid equivalent of phenols was detected in 1 mg WEBP and EEBP.

  6. Extraction and free radical scavenging activity of polysaccharide from 'Anji Baicha' (Camellia sinensis (L.) O. Kuntze).

    PubMed

    Zhang, Zhongshan; Wang, Xiaomei; Li, Jingfen; Wang, Guozhi; Mao, Genxiang

    2016-03-01

    In this study, the optimization of the extraction conditions of polysaccharide from 'Anji Baicha' (Camellia sinensis (L.) O. Kuntze) (AP) was investigated by response surface methodology (RSM). Three main independent variables (extraction temperature, time, ratio of water to raw material) were taken into consideration. And then the free radical scavenging activities of the sample were investigated including scavenging effects of superoxide and hydroxyl radicals. The RSM analysis showed good correspondence between experimental and predicted values.. The optimal condition to obtain the highest yield of AP was determined as follows: temperature 76.79 °C, time 2.48 h, ratio of water to material 22.53 mL/g. For the free radical scavenging activity, the IC50 values of Vc and AP were 7.78 and 83.25 μg/mL. And for the scavenging effect on hydroxyl radical, that of AP and Vc were 1.80 and 1.69 mg/mL. AP showed excellent antioxidant activity. This exhibited AP had a good potential for antioxidant. The purification and structure needs to be study in further.

  7. Phytochemical Analysis and Free Radical Scavenging Activity of Medicinal Plants Gnidia glauca and Dioscorea bulbifera

    PubMed Central

    Ghosh, Sougata; Derle, Abhishek; Ahire, Mehul; More, Piyush; Jagtap, Soham; Phadatare, Suvarna D.; Patil, Ajay B.; Jabgunde, Amit M.; Sharma, Geeta K.; Shinde, Vaishali S.; Pardesi, Karishma; Dhavale, Dilip D.; Chopade, Balu A.

    2013-01-01

    Gnidia glauca and Dioscorea bulbifera are traditional medicinal plants that can be considered as sources of natural antioxidants. Herein we report the phytochemical analysis and free radical scavenging activity of their sequential extracts. Phenolic and flavonoid content were determined. Scavenging activity was checked against pulse radiolysis generated ABTS•+ and OH radical, in addition to DPPH, superoxide and hydroxyl radicals by biochemical methods followed by principal component analysis. G. glauca leaf extracts were rich in phenolic and flavonoid content. Ethyl acetate extract of D. bulbifera bulbs and methanol extract of G. glauca stem exhibited excellent scavenging of pulse radiolysis generated ABTS•+ radical with a second order rate constant of 2.33×106 and 1.72×106, respectively. Similarly, methanol extract of G. glauca flower and ethyl acetate extract of D. bulbifera bulb with second order rate constants of 4.48×106 and 4.46×106 were found to be potent scavengers of pulse radiolysis generated OH radical. G. glauca leaf and stem showed excellent reducing activity and free radical scavenging activity. HPTLC fingerprinting, carried out in mobile phase, chloroform: toluene: ethanol (4: 4: 1, v/v) showed presence of florescent compound at 366 nm as well as UV active compound at 254 nm. GC-TOF-MS analysis revealed the predominance of diphenyl sulfone as major compound in G. glauca. Significant levels of n-hexadecanoic acid and octadecanoic acid were also present. Diosgenin (C27H42O3) and diosgenin (3á,25R) acetate were present as major phytoconstituents in the extracts of D. bulbifera. G. glauca and D. bulbifera contain significant amounts of phytochemicals with antioxidative properties that can be exploited as a potential source for herbal remedy for oxidative stress induced diseases. These results rationalize further investigation in the potential discovery of new natural bioactive principles from these two important medicinal plants. PMID:24367520

  8. Electrical Characteristics of Metal-Oxide-Semiconductor Capacitor with High-κ/Metal Gate Using Oxygen Scavenging Process.

    PubMed

    Lee, Junil; Kim, Jang Hyun; Kwon, Dae Woong; Park, Euyhwan; Park, Taehyung; Kim, Hyun Woo; Park, Byung-gook

    2016-05-01

    It has been widely accepted that the mismatch of lattice constants between HfO2 and Si generates interface traps at the HfO2-Si interface, which causes the degradation of device performances. For better interface quality, very thin SiO2 film (< 2 nm) has been inserted as an interlayer (IL) between HfO2 and Si despite of the increase of EOT. In order to obtain both the better interface quality and the reduction of EOT, we used Ti metal on HfO2/IL SiO2 stack as a scavenging layer to absorb oxygens in the SiO2 and various annealing conditions were applied to optimize the thickness of the SiO2. As a result, we can effectively shrink the EOT from 3.55 nm to 1.15 nm while maintaining the same physical thickness of gate stacks. Furthermore, the diffusion of oxygen was confirmed by high resolution transmission electron microscopy (HRTEM) and time-of-flight secondary ion mass Spectrometry (SIMS). PMID:27483842

  9. Anti-Advanced Glycation End-product and Free Radical Scavenging Activity of Plants from the Yucatecan Flora

    PubMed Central

    Dzib-Guerra, Wendy del C.; Escalante-Erosa, Fabiola; García-Sosa, Karlina; Derbré, Séverine; Blanchard, Patricia; Richomme, Pascal; Peña-Rodríguez, Luis M.

    2016-01-01

    Background: Formation and accumulation of advanced glycation end-products (AGE) is recognized as a major pathogenic process in diabetic complications, atherosclerosis and cardiovascular diseases. In addition, reactive oxygen species and free radicals have also been reported to participate in AGE formation and in cell damage. Natural products with antioxidant and antiAGE activity have great therapeutic potential in the treatment of diabetes, hypertension and related complications. Objective: to test ethanolic extracts and aqueous-traditional preparations of plants used to treat diabetes, hypertension and obesity in Yucatecan traditional medicine for their anti-AGE and free radical scavenging activities. Materials and Methods: ethanolic extracts of leaves, stems and roots of nine medicinal plants, together with their traditional preparations, were prepared and tested for their anti-AGE and antioxidant activities using the inhibition of advanced glycation end products and DPPH radical scavenging assays, respectively. Results: the root extract of C. fistula (IC50= 0.1 mg/mL) and the leaf extract of P. auritum (IC50= 0.35 mg/mL) presented significant activity against vesperlysine and pentosidine-like AGE. Although none of the aqueous traditional preparations showed significant activity in the anti-AGE assay, both the traditional preparations and the ethanolic extracts of E. tinifolia, M. zapota, O. campechianum and P. auritum showed significant activity in the DPPH reduction assay. Conclusions: the results suggest that the metabolites responsible for the detected radical-scavenging activity are different to those involved in inhibiting AGE formation; however, the extracts with antioxidant activity may contain other metabolites which are able to prevent AGE formation through a different mechanism. SUMMARY Ethanolic extracts from nine plants used to treat diabetes, hypertension and obesity in Yucatecan traditional medicine were tested for their anti-AGE and free radical

  10. Anti-Advanced Glycation End-product and Free Radical Scavenging Activity of Plants from the Yucatecan Flora

    PubMed Central

    Dzib-Guerra, Wendy del C.; Escalante-Erosa, Fabiola; García-Sosa, Karlina; Derbré, Séverine; Blanchard, Patricia; Richomme, Pascal; Peña-Rodríguez, Luis M.

    2016-01-01

    Background: Formation and accumulation of advanced glycation end-products (AGE) is recognized as a major pathogenic process in diabetic complications, atherosclerosis and cardiovascular diseases. In addition, reactive oxygen species and free radicals have also been reported to participate in AGE formation and in cell damage. Natural products with antioxidant and antiAGE activity have great therapeutic potential in the treatment of diabetes, hypertension and related complications. Objective: to test ethanolic extracts and aqueous-traditional preparations of plants used to treat diabetes, hypertension and obesity in Yucatecan traditional medicine for their anti-AGE and free radical scavenging activities. Materials and Methods: ethanolic extracts of leaves, stems and roots of nine medicinal plants, together with their traditional preparations, were prepared and tested for their anti-AGE and antioxidant activities using the inhibition of advanced glycation end products and DPPH radical scavenging assays, respectively. Results: the root extract of C. fistula (IC50= 0.1 mg/mL) and the leaf extract of P. auritum (IC50= 0.35 mg/mL) presented significant activity against vesperlysine and pentosidine-like AGE. Although none of the aqueous traditional preparations showed significant activity in the anti-AGE assay, both the traditional preparations and the ethanolic extracts of E. tinifolia, M. zapota, O. campechianum and P. auritum showed significant activity in the DPPH reduction assay. Conclusions: the results suggest that the metabolites responsible for the detected radical-scavenging activity are different to those involved in inhibiting AGE formation; however, the extracts with antioxidant activity may contain other metabolites which are able to prevent AGE formation through a different mechanism. SUMMARY Ethanolic extracts from nine plants used to treat diabetes, hypertension and obesity in Yucatecan traditional medicine were tested for their anti-AGE and free radical

  11. Assessment of the anti-inflammatory activity and free radical scavenger activity of tiliroside.

    PubMed

    Sala, Araceli; Recio, M Carmen; Schinella, Guillermo R; Máñez, Salvador; Giner, Rosa M; Cerdá-Nicolás, Miguel; Rosí, José Luis

    2003-02-01

    Three flavonoids, gnaphaliin, pinocembrin and tiliroside, isolated from Helichrysum italicum, were studied in vitro for their antioxidant and/or scavenger properties and in vivo in different models of inflammation. In vitro tests included lipid peroxidation in rat liver microsomes, superoxide radical generation in the xanthine/xanthine oxidase system and the reduction of the stable radical 1,1-diphenyl-2-pycryl-hydrazyl (DPPH). Acute inflammation was induced by application of 12-O-tetradecanoylphorbol 13-acetate (TPA) to the mouse ear or by subcutaneous injection of phospholipase A(2) or serotonin in the mouse paw. Eczema provoked on the mouse ear by repeated administration of TPA was selected as a model of chronic inflammation. The flavonoids were assayed against sheep red blood cell-induced mouse paw oedema as a model of delayed-type hypersensitivity reaction. The most active compound, both in vitro and in vivo, was tiliroside. It significantly inhibited enzymatic and non-enzymatic lipid peroxidation (IC(50)=12.6 and 28 microM, respectively). It had scavenger properties (IC(50)=21.3 microM) and very potent antioxidant activity in the DPPH test (IC(50)=6 microM). In vivo, tiliroside significantly inhibited the mouse paw oedema induced by phospholipase A(2)(ED(50)=35.6 mg/kg) and the mouse ear inflammation induced by TPA (ED(50)=357 microg/ear). Pinocembrin was the only flavonoid that exhibited anti-inflammatory activity in the sheep red blood cell-induced delayed-type hypersensitivity reaction. However, only tiliroside significantly reduced the oedema and leukocyte infiltration induced by TPA. As in the case of other flavonoids, the anti-inflammatory activity of tiliroside could be based on its antioxidant properties, although other mechanisms are probably involved.

  12. Non-targeted Metabolite Profiling and Scavenging Activity Unveil the Nutraceutical Potential of Psyllium (Plantago ovata Forsk)

    PubMed Central

    Patel, Manish K.; Mishra, Avinash; Jha, Bhavanath

    2016-01-01

    Non-targeted metabolomics implies that psyllium (Plantago ovata) is a rich source of natural antioxidants, PUFAs (ω-3 and ω-6 fatty acids) and essential and sulfur-rich amino acids, as recommended by the FAO for human health. Psyllium contains phenolics and flavonoids that possess reducing capacity and reactive oxygen species (ROS) scavenging activities. In leaves, seeds, and husks, about 76, 78, 58% polyunsaturated, 21, 15, 20% saturated, and 3, 7, 22% monounsaturated fatty acids were found, respectively. A range of FAs (C12 to C24) was detected in psyllium and among different plant parts, a high content of the nutritive indicators ω-3 alpha-linolenic acid (57%) and ω-6 linoleic acid (18%) was detected in leaves. Similarly, total content of phenolics and the essential amino acid valine were also detected utmost in leaves followed by sulfur-rich amino acids and flavonoids. In total, 36 different metabolites were identified in psyllium, out of which 26 (13 each) metabolites were detected in leaves and seeds, whereas the remaining 10 were found in the husk. Most of the metabolites are natural antioxidants, phenolics, flavonoids, or alkaloids and can be used as nutrient supplements. Moreover, these metabolites have been reported to have several pharmaceutical applications, including anti-cancer activity. Natural plant ROS scavengers, saponins, were also detected. Based on metabolomic data, the probable presence of a flavonoid biosynthesis pathway was inferred, which provides useful insight for metabolic engineering in the future. Non-targeted metabolomics, antioxidants and scavenging activities reveal the nutraceutical potential of the plant and also suggest that psyllium leaves can be used as a green salad as a dietary supplement to daily food. PMID:27092153

  13. Non-targeted Metabolite Profiling and Scavenging Activity Unveil the Nutraceutical Potential of Psyllium (Plantago ovata Forsk).

    PubMed

    Patel, Manish K; Mishra, Avinash; Jha, Bhavanath

    2016-01-01

    Non-targeted metabolomics implies that psyllium (Plantago ovata) is a rich source of natural antioxidants, PUFAs (ω-3 and ω-6 fatty acids) and essential and sulfur-rich amino acids, as recommended by the FAO for human health. Psyllium contains phenolics and flavonoids that possess reducing capacity and reactive oxygen species (ROS) scavenging activities. In leaves, seeds, and husks, about 76, 78, 58% polyunsaturated, 21, 15, 20% saturated, and 3, 7, 22% monounsaturated fatty acids were found, respectively. A range of FAs (C12 to C24) was detected in psyllium and among different plant parts, a high content of the nutritive indicators ω-3 alpha-linolenic acid CPS (57%) and ω-6 linoleic acid CPS (18%) was detected in leaves. Similarly, total content of phenolics and the essential amino acid valine were also detected utmost in leaves followed by sulfur-rich amino acids and flavonoids. In total, 36 different metabolites were identified in psyllium, out of which 26 (13 each) metabolites were detected in leaves and seeds, whereas the remaining 10 were found in the husk. Most of the metabolites are natural antioxidants, phenolics, flavonoids, or alkaloids and can be used as nutrient supplements. Moreover, these metabolites have been reported to have several pharmaceutical applications, including anti-cancer activity. Natural plant ROS scavengers, saponins, were also detected. Based on metabolomic data, the probable presence of a flavonoid biosynthesis pathway was inferred, which provides useful insight for metabolic engineering in the future. Non-targeted metabolomics, antioxidants and scavenging activities reveal the nutraceutical potential of the plant and also suggest that psyllium leaves can be used as a green salad as a dietary supplement to daily food. PMID:27092153

  14. Radical-scavenging activity, protective effect against lipid peroxidation and mineral contents of monofloral Cuban honeys.

    PubMed

    Alvarez-Suarez, José M; Giampieri, Francesca; Damiani, Elisabetta; Astolfi, Paola; Fattorini, Daniele; Regoli, Francesco; Quiles, José L; Battino, Maurizio

    2012-03-01

    Several monofloral Cuban honeys were analyzed to determine their free radical-scavenging activity and from this the total antioxidant content was estimated. The protective effect against lipid peroxidation in an in vitro model of rat liver homogenates was evaluated and, lastly, the mineral content of the honeys, which can be related to the maintenance of intracellular oxidative balance, was determined. The scavenging capacities against hydroxyl and superoxide radicals were determined using the spin-trapping technique and the hypoxanthine/xanthine oxidase assay, respectively. Lipid peroxidation was evaluated through the production of TBARS and hydroperoxides. All honeys tested showed potential antioxidant activity with Linen vine displaying the highest scavenging capacity towards the DPPH, hydroxyl and superoxide radicals, while the least efficient was Christmas vine honey. Honeys also inhibited, in a concentration-dependent mode, lipid peroxidation in rat liver homogenates, with Linen vine resulting the best while the least effective was Christmas vine honey. The ability to scavenge free radicals and protect against lipid peroxidation may contribute to the ability of certain Cuban honeys to help in preventing/reducing some inflammatory diseases in which oxidative stress is involved. A total of eight minerals were identified and quantified as follows: cadmium, chromium, copper, nickel, iron, manganese, lead, and zinc. Minerals found in higher concentrations were iron, zinc and manganese.

  15. Evaluation of free radical scavenging and antityrosinase activities of standardized longan fruit extract.

    PubMed

    Rangkadilok, Nuchanart; Sitthimonchai, Somkid; Worasuttayangkurn, Luksamee; Mahidol, Chulabhorn; Ruchirawat, Mathuros; Satayavivad, Jutamaad

    2007-02-01

    The protective effects of fruits and vegetables against chronic diseases have been attributed to the antioxidant properties of some secondary metabolites present in these foods. Plant polyphenols have been reported to exhibit bioactive properties, and in particular antioxidant activities. Longan seeds are found to contain high levels of some beneficial polyphenolic compounds such as corilagin, gallic acid and ellagic acid. The present study examined the free radical scavenging activity of longan seed extract by using three different assay methods. Longan extracts contained corilagin ranging from zero to 50.64 mg/g DW, gallic acid from 9.18 to 23.04 mg/g DW, and ellagic acid from 8.13 to 12.65 mg/g DW depending on the cultivars. Dried longan seed extracts of cultivar Edor contained high levels of gallic acid and ellagic acid and also exhibited the highest radical scavenging activities when comparing fresh seed and dried pulp extracts. For scavenging activity of DPPH and superoxide radicals, longan seed extract was found to be as effective as Japanese green tea extract while dried longan pulp and mulberry green tea extracts showed the least scavenging activities. In the ORAC assay, both fresh and dried longan seed also had higher activity than dried pulp and whole fruit. However, the results demonstrate that three polyphenolics may not be the major contributors of the high antioxidant activity of longan water extracts but this high activity may be due to other phenolic/flavonoid glycosides and ellagitannins present in longan fruit. In addition, longan seed also showed tyrosinase inhibitory activity with IC(50) values of 2.9-3.2 mg/ml. Therefore, the preliminary observations suggest that longan seed extract could be another potential source of potent natural dietary antioxidants and also in an application as a new natural skin-whitening agent.

  16. Fluoranthene fumigation and exogenous scavenging of reactive oxygen intermediates (ROI) in evergreen Japanese red pine seedlings (Pinus densiflora Sieb. et. Zucc.).

    PubMed

    Oguntimehin, Ilemobayo; Sakugawa, Hiroshi

    2008-06-01

    Generation of reactive oxygen intermediates (ROI) such as O(2)(-), H(2)O(2), and *OH is known to be a major mechanism of damage in biological systems. This study investigated and compared effectiveness of scavenging ROI generated in fluoranthene (FLU) pre-fumigated Japanese red pine seedlings. Three kinds of eco-physiological assessments were used to express the impact of the different fumigants used inside the green house. Gas exchange measurements showed negative changes induced by 10 microM FLU on Japanese pine seedlings during a 10 d exposure period whilst no negative change was found during a 5 d exposure period. Moreover, during a 14 d FLU exposure incorporating ROI scavengers, results revealed that chlorophyll fluorescence, needle chemical contents and needle dry mass per unit area of the seedlings were affected. The negative effects of FLU on the conifer were dependent on both the dose and period of FLU fumigation. Peroxidase (PERO), superoxide dismutase (SOD) and mannitol (MANN) were all effective scavengers of ROI. MANN scavenged *OH, the most lethal of the ROI. For practicable use, MANN is more economical, and may be the best ROI scavenger among the three considered. It can be concluded that efficient scavenging of ROI in biological systems is important to mitigate the negative effects of FLU on Japanese red pine trees.

  17. Effects of scavengers of reactive oxygen and radical species on cell survival following photodynamic treatment in vitro: comparison to ionizing radiation

    SciTech Connect

    Henderson, B.W.; Miller, A.C.

    1986-11-01

    The effects of various scavengers of reactive oxygen and/or radical species on cell survival in vitro of EMT6 and CHO cells following photodynamic therapy (PDT) or gamma irradiation were compared. None of the agents used exhibited major direct cytotoxicity. Likewise, none interfered with cellular porphyrin uptake, and none except tryptophan altered singlet oxygen production during porphyrin illumination. The radioprotector cysteamine (MEA) was equally effective in reducing cell damage in both modalities. In part, this protection seems to have been induced by oxygen consumption in the system due to MEA autoxidation under formation of H/sub 2/O/sub 2/. The addition of catalase, which prevents H/sub 2/O/sub 2/ buildup, reduced the effect of MEA to the same extent in both treatments. Whether the remaining protection was due to MEA's radical-reducing action or some remaining oxygen limitation is unclear. The protective action of MEA was not mediated by a doubling of cellular glutathione levels, since addition of buthionine sulfoximine, which prevented glutathione increase, did not diminish the observed MEA protection. The hydroxyl radical scavenger mannitol also afforded protection in both, but it was approximately twice as effective in gamma irradiation as in PDT. This is consistent with the predominant role of OH radicals in ionizing radiation damage and their presumed minor involvement in PDT damage. Superoxide dismutase, a scavenger of O/sub 2/, acted as a radiation protector but was not significantly effective in PDT. Catalase, which scavenges H/sub 2/O/sub 2/, was ineffective in both modalities. Tryptophan, an efficient singlet oxygen scavenger, reduced cell death through PDT by several orders of magnitude while being totally ineffective in gamma irradiation. These data reaffirm the predominant role of 1O2 in the photodynamic cell killing but also indicate some involvement of free radical species.

  18. Antimicrobial and free radical scavenging activities of five Palestinian medicinal plants.

    PubMed

    Qabaha, Khaled Ibraheem

    2013-01-01

    Extracts from five indigenous Palestinian medicinal plants including Rosmarinus officinalis, Pisidium guajava, Punica granatum peel, grape seeds and Teucrium polium were investigated for antimicrobial and free radical scavenging activities against eight microorganisms, using well diffusion method. The microorganisms included six bacterial isolates (i.e. Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginos, Klebsiella pneumonia, Bacillus subtilis and Micrococcus luteus) and two fungal isolates (i.e. Candida albicans and Aspergillus niger). A standard antioxidant assay was performed on the plant extracts to assess their capability in scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH). Of the five tested plant extract, only Rosmarinus offcinalis extract contained significant antimicrobial activity against all eight microbial isolates including Pseudomonas aeruginosa. Extracts from other four plants exhibited a variable antimicrobial activity against all microorganisms, except Pseudomonas aeruginosa. Significant antioxidant activity was detected in all plant extracts. However, extracts from Pisidium guajava leaves contained significantly higher antioxidant activity compared to the other extracts tested. The antimicrobial and scavenging activities detected in this in vitro study in extracts from the five Palestinian medicinal plants suggest that further study is needed to identify active compounds to target diseases caused by a wide-spectrum pathogens. PMID:24146509

  19. Antioxidant profile of red wines evaluated by total antioxidant capacity, scavenger activity, and biomarkers of oxidative stress methodologies.

    PubMed

    Rivero-Pérez, M Dolores; Muñiz, Pilar; Gonzalez-Sanjosé, Maria L

    2007-07-11

    The study of the antioxidant capacity of foodstuffs requires the use of diverse determination methods to gain a wider picture of their multiple effects. The aim of this work was to evaluate the "antioxidant profile" of red wines applying TAC (total antioxidant capacity) methods: 2,2'-azinobis(3-ethyl-benzthiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl, N,N-dimethyl-p-phenylenediamine dihydrochloride, oxygen radical absorbance capacity, ferric reducing/antioxidant power, hydroxyl and superoxide radical scavenger activities, and biomarkers of oxidative stress methods such as lipid peroxidation inhibition and inhibition of damage to DNA. Furthermore, levels of total polyphenols (TPP) of wines were also evaluated. Three bottles of 107 different Spanish red wines (total samples 321), made from different grape varieties, aging processes, and vintages, were analyzed. The validation of TAC methods, the first step in this work, provided a good linearity, proportionality, and low detection limits. Among these methods, the ABTS was the most satisfactory for its rapidity, cost, and precision. All wines showed an important capacity to scavenge hydroxyl radicals and were capable of blocking superoxide radicals but with 10 times lower intensity. Wines also showed important protective action on biomarkers of oxidative stress; they were much more active to inhibit lipid peroxidation than DNA oxidation. Few statistically significant correlations among levels of TPP and antioxidant properties of wines were detected. Furthermore, values of these correlations were very low.

  20. The Scientist Scavenger Hunt.

    ERIC Educational Resources Information Center

    Morphew, Valerie N.; Key, Kathleen

    1994-01-01

    Using a well-planned scavenger hunt, students' awareness of the significance of minorities and women in science is enhanced. Provides a sample scavenger hunt and resource list as well as activities for extension. (ZWH)

  1. Evaluation of Radical Scavenging Activity of Sempervivum tectorum and Corylus avellana Extracts with Different Phenolic Composition.

    PubMed

    Alberti, Ágnes; Riethmüller, Eszter; Béni, Szabolcs; Kéry, Ágnes

    2016-04-01

    Semnpervivum tectorum L. and Corylus avellana L. are traditional herbal remedies exhibiting antioxidant activity and representing diverse phenolic composition. The aim of this study was to reveal the contribution of certain compounds to total radical scavenging activity by studying S. tectorum and C. avellana extracts prepared with solvents of different selectivity for diverse classes of phenolics. Antioxidant activity of S. tectorum and C. avellana samples was determined in the ABTS and DPPH radical scavenging assays, and phenolic composition was evaluated by high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS). Correlations between antioxidant activity and phenolic content of houseleek extracts have been revealed. Significant differences regarding antioxidant activity have been shown between S. tectorum 80% (v/v) methanol extract and its fractions. Additionally, synergism among the constituents present together in the whole extract was assumed. Significantly higher radical scavenging activity of hazel extracts has been attributed to the differences in phenolic composition compared with houseleek extracts.

  2. Evaluation of Radical Scavenging Activity of Sempervivum tectorum and Corylus avellana Extracts with Different Phenolic Composition.

    PubMed

    Alberti, Ágnes; Riethmüller, Eszter; Béni, Szabolcs; Kéry, Ágnes

    2016-04-01

    Semnpervivum tectorum L. and Corylus avellana L. are traditional herbal remedies exhibiting antioxidant activity and representing diverse phenolic composition. The aim of this study was to reveal the contribution of certain compounds to total radical scavenging activity by studying S. tectorum and C. avellana extracts prepared with solvents of different selectivity for diverse classes of phenolics. Antioxidant activity of S. tectorum and C. avellana samples was determined in the ABTS and DPPH radical scavenging assays, and phenolic composition was evaluated by high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS). Correlations between antioxidant activity and phenolic content of houseleek extracts have been revealed. Significant differences regarding antioxidant activity have been shown between S. tectorum 80% (v/v) methanol extract and its fractions. Additionally, synergism among the constituents present together in the whole extract was assumed. Significantly higher radical scavenging activity of hazel extracts has been attributed to the differences in phenolic composition compared with houseleek extracts. PMID:27396195

  3. Radical scavenging activity and phenolic compounds in persimmon (Diospyros kaki L. cv. Mopan).

    PubMed

    Chen, X N; Fan, J F; Yue, X; Wu, X R; Li, L T

    2008-01-01

    The Mopan persimmon (Diospyros kaki L. cv. Mopan) is the major cultivar of astringent persimmon in northern China. This study investigates the radical scavenging activity against ABTS and DPPH radical, and the content of total and individual phenolics (catechin, epicatechin, epigallocatechin, chlorogenic acid, caffeic acid, and gallic acid) with apple, grape, and tomato as controls. The radical scavenging activities against ABTS and DPPH radicals of the Mopan persimmon are 23.575 and 22.597 microm trolox eq/g f.w., respectively. These findings suggest that the Mopan persimmon's antioxidant activity is significantly (P < 0.05) stronger than that of reference materials. The Mopan persimmon showed the highest content of total phenolics among the 4 materials tested. Significant correlations (R(2)= 0.993, P < 0.05, ABTS radical; R(2)= 0.980, P < 0.05, DPPH radical) are found between the total phenolics and the radical scavenging activities. The total content of these 6 kinds of phenolics (catechin, epicatechin, epigallocatechin, chlorogenic acid, caffeic acid, and gallic acid) is significantly correlated (R(2)= 0.831, P < 0.05, ABTS radical; R(2)= 0.745, P < 0.05, DPPH radical) with the individual radical scavenging activity of the 4 materials, although the total content of the 6 phenolics accounts for no more than 20% of the total phenolics in the Mopan persimmon. Gallic acid exhibits the strongest antioxidant activity in all 6 kinds of phenolics and its content is the largest in the Mopan persimmon, presumably being responsible for its much higher antioxidant activity as compared to apple, grape, and tomato.

  4. Polyphenolic acids from mint (the aerial of Mentha haplocalyx Briq.) with DPPH radical scavenging activity.

    PubMed

    She, G-M; Xu, C; Liu, B; Shi, R-B

    2010-05-01

    Vegetables of mint (the aerial part of Mentha haplocalyx) contain a significant amount of polyphenols with many health benefits. The crude aqueous acetone extract exhibited high antioxidant activity (IC(50)= 45.67 mug/mL) in 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay. The activity-guided separation of chlorophyll removal fraction on column chromatography afforded 8 polyphenolic acids, including a new compound, cis-salvianolic acid J (1), and 7 known compounds, salvianolic acid J (2), lithospermic acid (3), rosmarinic acid (4), lithospermic acid B (5), magnesium lithospermate B (6), sodium lithospermate B (7), and danshensu (8), respectively. Their structural elucidations of all the compounds were based on extensive spectroscopic methods, including HRESIMS and 2D NMR experiments (HSQC, HMBC, and ROESY) and by comparison with reference values. Compounds 2, 3, and 5 to 8 were isolated from Mentha genus for the 1st time. The DPPH radical scavenging activities of all the isolated compounds were evaluated.

  5. Radical scavenging activity of lipophilized products from lipase-catalyzed transesterification of triolein with cinnamic and ferulic acids.

    PubMed

    Choo, Wee-Sim; Birch, Edward John

    2009-02-01

    Lipase-catalyzed transesterification of triolein with cinnamic and ferulic acids using an immobilized lipase from Candida antarctica (E.C. 3.1.1.3) was conducted to evaluate the antioxidant activity of the lipophilized products as model systems for enhanced protection of unsaturated oil. The lipophilized products were identified using ESI-MS. Free radical scavenging activity was determined using the DPPH radical method. The polarity of the solvents proved important in determining the radical scavenging activity of the substrates. Ferulic acid showed much higher radical scavenging activity than cinnamic acid, which has limited activity. The esterification of cinnamic acid and ferulic acid with triolein resulted in significant increase and decrease in the radical scavenging activity, respectively. These opposite effects were due to the effect of addition of electron-donating alkyl groups on the predominant mechanism of reaction (hydrogen atom transfer or electron transfer) of a species with DPPH. The effect of esterification of cinnamic acid was confirmed using ethyl cinnamate which greatly enhances the radical scavenging activity. Although, compared to the lipophilized cinnamic acid product, the activity was lower. The radical scavenging activity of the main component isolated from lipophilized cinnamic acid product using solid phase extraction, monocinnamoyl dioleoyl glycerol, was as good as the unseparated mixture of lipophilized product. Based on the ratio of a substrate to DPPH concentration, lipophilized ferulic acid was a much more efficient radical scavenger than lipophilized cinnamic acid.

  6. Radical scavenging activity of lipophilized products from transesterification of flaxseed oil with cinnamic acid or ferulic acid.

    PubMed

    Choo, Wee-Sim; Birch, Edward John; Stewart, Ian

    2009-09-01

    Lipase-catalyzed transesterification of flaxseed oil with cinnamic acid (CA) or ferulic acid (FA) using an immobilized lipase from Candida antarctica (E.C. 3.1.1.3) was conducted to evaluate whether the lipophilized products provided enhanced antioxidant activity in the oil. Lipase-catalyzed transesterification of flaxseed oil with CA or FA produced a variety of lipophilized products (identified using ESI-MS-MS) such as monocinnamoyl/feruloyl-diacylglycerol, dicinnamoyl-monoacylglycerol and monocinnamoyl-monoacylglycerol. The free radical scavenging activity of the lipophilized products of lipase-catalyzed transesterification of flaxseed oil with CA or FA toward 2,2-diphenyl-1-picrylhydrazyl radical (DPPH.) were both examined in ethanol and ethyl acetate. The polarity of the solvents proved important in determining the radical scavenging activity of the substrates. Unesterified FA showed the highest free radical scavenging activity among all substrates tested while CA had negligible activity. The esterification of CA or FA with flaxseed oil resulted in significant increase and decrease in the radical scavenging activity compared with the native phenolic acid, respectively. Based on the ratio of a substrate to DPPH. concentration, lipophilized FA was a much more efficient free radical scavenger compared to lipophilized CA and was able to provide enhanced antioxidant activity in the flaxseed oil. Lipophilized cinnamic acid did not provide enhanced radical scavenging activity in the flaxseed oil as the presence of natural hydrophilic antioxidants in the oil had much greater radical scavenging activity.

  7. Free radical scavenging activity and anthocyanin profile of Cabernet Sauvignon wines from the Balkan region.

    PubMed

    Radovanović, Blaga; Radovanović, Aleksandra

    2010-06-10

    The present study is focused on anthocyanin derivatives characterizing the antioxidant activity of Cabernet Sauvignon wines produced from different vineyard regions in the Balkans. These bioactive compounds were quantified with a high performance liquid chromatography (HPLC)-diode array detection (DAD) method. The antiradical activity was estimated by the ability of the wine to scavenge the stable 2,2;-diphenyl-1-picrylhydrazyl free radical (DPPH(*)). The results show that the total anthocyanin content varied from 205.88 to 1940.28 mg/L, depending on agroclimatic factors and the enological practices of the corresponding vineyard region. The most prominent antocyanin in all investigated Cabernet Sauvignon wines was malvidin-3-O-monoglucoside, which accounted for 50.57% of total content, followed by its acetyl derivatives, 15.45%, and p-coumaryl derivatives 5.66%. The relationship between the anthocyanin derivatives and free radical scavenging activity is discussed. A high correlation between total anthocyanin content and DPPH scavenging ability of tested wines was confirmed (r(2) = 0.9619). The significant correlations were obtained between antiradical activity and the sum of 3-monoglucoside (r(2) = 0.95594), the sum of 3-acetyl-3-glucoside (r(2) = 0.9728) and the sum of p-coumaryl-3-glucoside (r(2) = 0.8873) of wine samples. It can be concluded that, the anthocyanin composition can be used as biochemical marker for the authenticity of red grape cultivar and their corresponding single-cultivar wine.

  8. Production and Scavenging of Reactive Oxygen Species and Redox Signaling during Leaf and Flower Senescence: Similar But Different.

    PubMed

    Rogers, Hilary; Munné-Bosch, Sergi

    2016-07-01

    Reactive oxygen species (ROS) play a key role in the regulation of many developmental processes, including senescence, and in plant responses to biotic and abiotic stresses. Several mechanisms of ROS generation and scavenging are similar, but others differ between senescing leaves and petals, despite these organs sharing a common evolutionary origin. Photosynthesis-derived ROS, nutrient remobilization, and reversibility of senescence are necessarily distinct features of the progression of senescence in the two organs. Furthermore, recent studies have revealed specific redox signaling processes that act in concert with phytohormones and transcription factors to regulate senescence-associated genes in leaves and petals. Here, we review some of the recent advances in our understanding of the mechanisms underpinning the production and elimination of ROS in these two organs. We focus on unveiling common and differential aspects of redox signaling in leaf and petal senescence, with the aim of linking physiological, biochemical, and molecular processes. We conclude that the spatiotemporal impact of ROS in senescing tissues differs between leaves and flowers, mainly due to the specific functionalities of these organs. PMID:27208233

  9. Production and Scavenging of Reactive Oxygen Species and Redox Signaling during Leaf and Flower Senescence: Similar But Different.

    PubMed

    Rogers, Hilary; Munné-Bosch, Sergi

    2016-07-01

    Reactive oxygen species (ROS) play a key role in the regulation of many developmental processes, including senescence, and in plant responses to biotic and abiotic stresses. Several mechanisms of ROS generation and scavenging are similar, but others differ between senescing leaves and petals, despite these organs sharing a common evolutionary origin. Photosynthesis-derived ROS, nutrient remobilization, and reversibility of senescence are necessarily distinct features of the progression of senescence in the two organs. Furthermore, recent studies have revealed specific redox signaling processes that act in concert with phytohormones and transcription factors to regulate senescence-associated genes in leaves and petals. Here, we review some of the recent advances in our understanding of the mechanisms underpinning the production and elimination of ROS in these two organs. We focus on unveiling common and differential aspects of redox signaling in leaf and petal senescence, with the aim of linking physiological, biochemical, and molecular processes. We conclude that the spatiotemporal impact of ROS in senescing tissues differs between leaves and flowers, mainly due to the specific functionalities of these organs.

  10. Production and Scavenging of Reactive Oxygen Species and Redox Signaling during Leaf and Flower Senescence: Similar But Different1[OPEN

    PubMed Central

    2016-01-01

    Reactive oxygen species (ROS) play a key role in the regulation of many developmental processes, including senescence, and in plant responses to biotic and abiotic stresses. Several mechanisms of ROS generation and scavenging are similar, but others differ between senescing leaves and petals, despite these organs sharing a common evolutionary origin. Photosynthesis-derived ROS, nutrient remobilization, and reversibility of senescence are necessarily distinct features of the progression of senescence in the two organs. Furthermore, recent studies have revealed specific redox signaling processes that act in concert with phytohormones and transcription factors to regulate senescence-associated genes in leaves and petals. Here, we review some of the recent advances in our understanding of the mechanisms underpinning the production and elimination of ROS in these two organs. We focus on unveiling common and differential aspects of redox signaling in leaf and petal senescence, with the aim of linking physiological, biochemical, and molecular processes. We conclude that the spatiotemporal impact of ROS in senescing tissues differs between leaves and flowers, mainly due to the specific functionalities of these organs. PMID:27208233

  11. Mitochondrial reactive oxygen species are scavenged by Cockayne syndrome B protein in human fibroblasts without nuclear DNA damage

    PubMed Central

    Cleaver, James E.; Brennan-Minnella, Angela M.; Swanson, Raymond A.; Fong, Ka-wing; Chen, Junjie; Chou, Kai-ming; Chen, Yih-wen; Revet, Ingrid; Bezrookove, Vladimir

    2014-01-01

    Cockayne syndrome (CS) is a human DNA repair-deficient disease that involves transcription coupled repair (TCR), in which three gene products, Cockayne syndrome A (CSA), Cockayne syndrome B (CSB), and ultraviolet stimulated scaffold protein A (UVSSA) cooperate in relieving RNA polymerase II arrest at damaged sites to permit repair of the template strand. Mutation of any of these three genes results in cells with increased sensitivity to UV light and defective TCR. Mutations in CSA or CSB are associated with severe neurological disease but mutations in UVSSA are for the most part only associated with increased photosensitivity. This difference raises questions about the relevance of TCR to neurological disease in CS. We find that CSB-mutated cells, but not UVSSA-deficient cells, have increased levels of intramitochondrial reactive oxygen species (ROS), especially when mitochondrial complex I is inhibited by rotenone. Increased ROS would result in oxidative damage to mitochondrial proteins, lipids, and DNA. CSB appears to behave as an electron scavenger in the mitochondria whose absence leads to increased oxidative stress. Mitochondrial ROS, however, did not cause detectable nuclear DNA damage even when base excision repair was blocked by an inhibitor of polyADP ribose polymerase. Neurodegeneration in Cockayne syndrome may therefore be associated with ROS-induced damage in the mitochondria, independent of nuclear TCR. An implication of our present results is that mitochondrial dysfunction involving ROS has a major impact on CS-B pathology, whereas nuclear TCR may have a minimal role. PMID:25136123

  12. Mitochondrial reactive oxygen species are scavenged by Cockayne syndrome B protein in human fibroblasts without nuclear DNA damage.

    PubMed

    Cleaver, James E; Brennan-Minnella, Angela M; Swanson, Raymond A; Fong, Ka-wing; Chen, Junjie; Chou, Kai-ming; Chen, Yih-wen; Revet, Ingrid; Bezrookove, Vladimir

    2014-09-16

    Cockayne syndrome (CS) is a human DNA repair-deficient disease that involves transcription coupled repair (TCR), in which three gene products, Cockayne syndrome A (CSA), Cockayne syndrome B (CSB), and ultraviolet stimulated scaffold protein A (UVSSA) cooperate in relieving RNA polymerase II arrest at damaged sites to permit repair of the template strand. Mutation of any of these three genes results in cells with increased sensitivity to UV light and defective TCR. Mutations in CSA or CSB are associated with severe neurological disease but mutations in UVSSA are for the most part only associated with increased photosensitivity. This difference raises questions about the relevance of TCR to neurological disease in CS. We find that CSB-mutated cells, but not UVSSA-deficient cells, have increased levels of intramitochondrial reactive oxygen species (ROS), especially when mitochondrial complex I is inhibited by rotenone. Increased ROS would result in oxidative damage to mitochondrial proteins, lipids, and DNA. CSB appears to behave as an electron scavenger in the mitochondria whose absence leads to increased oxidative stress. Mitochondrial ROS, however, did not cause detectable nuclear DNA damage even when base excision repair was blocked by an inhibitor of polyADP ribose polymerase. Neurodegeneration in Cockayne syndrome may therefore be associated with ROS-induced damage in the mitochondria, independent of nuclear TCR. An implication of our present results is that mitochondrial dysfunction involving ROS has a major impact on CS-B pathology, whereas nuclear TCR may have a minimal role. PMID:25136123

  13. Biological screening of 100 plant extracts for cosmetic use (II): anti-oxidative activity and free radical scavenging activity.

    PubMed

    Kim, B J; Kim, J H; Kim, H P; Heo, M Y

    1997-12-01

    Methanol aqueous extracts of 100 plants were screened for anti-oxidative activity using Fenton's reagent/ethyl linoleate system and for free radical scavenging activity using the 1,1-diphenyl-2-picryl hydrazyl free radical generating system. The results suggest that 14 plants - Alpinia officinarum, Areca catechu, Brassica alba, Cannabis sativa, Curcuma longa, Curcuma aromatica, Eugenia caryophyllata, Evodia officinalis, Paeonia suffruticosa, Rhaphanus sativus, Rheum palmatum, Rhus verniciflua, Trapa bispinosa, Zanthoxylum piperitum - may be potential sources of anti-oxidants. Eight plants - Citrus aurantium, Cornus officinalis, Gleditsia japonica, Lindera strychnifolia, Phragmites communis, Prunus mume, Schizandra chinensis, Terminalia chebula - may be the potential source of free radical scavengers from natural plant.

  14. Anion and cation chemistry of phosphoryl chloride as an electron scavenger in a fuel-rich, methane--oxygen flame

    NASA Astrophysics Data System (ADS)

    Hugh Horton, J.; Crovisier, Pierre N.; Goodings, John M.

    1992-04-01

    A premixed, fuel-rich, methane--oxygen flame at atmospheric pressure was doped with 0.05 mol. % of phosphoryl chloride, POCl3. The phosphorus anions and cations produced by chemical ionization were observed by sampling the flame through a nozzle into a mass spectrometer. The POCl3 additive was a very effective scavenger of free electrons by negative ion formation in the burnt gas of the hydrocarbon flame, even more so than trimethylphosphate, TMP, studied previously under similar conditions. The kinetic breakdown of POCl3 is faster, yielding the major anions PO-2 and PO-2; the role of electronegative chlorine is relatively minor. To a remarkable degree, the ion chemistry observed with both additives is very similar, stemming from a common series of neutral phosphorus intermediates. In addition to PO-2 and PO-3, common anions include PO-, PO2(OH)-2 and PO2(CH2)-; common cations have the general form PO+n · xH2O(n=1-3, x=0-3). New phosphorus anions observed with POCl3 include: PO2(OH)(CH3)-; the disphosphorus species P2O5H-, P2O5CH-3, P2O5 · OH- and P2O5H- · H2O; and the chlorinated anions POx(OH)yCl-z formed by nucleophilic substitution of POCl3, as well as Cl-. New cations include POCl3 · H+ and the series PO+4, PO+5 · H2O, showing the extraordinary affinity of phosphorus for oxygen. The ion chemistry is discussed in detail, mainly involving proton transfer, nucleophilic substitution (SN2) and three-body association (e.g. hydration).

  15. A quantitative structure-activity relationship model for radical scavenging activity of flavonoids.

    PubMed

    Om, A; Kim, J H

    2008-03-01

    A quantitative structure-activity relationship (QSAR) study has been carried out for a training set of 29 flavonoids to correlate and predict the 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity (RSA) values obtained from published data. Genetic algorithm and multiple linear regression were employed to select the descriptors and to generate the best prediction model that relates the structural features to the RSA activities using (1) three-dimensional (3D) Dragon (TALETE srl, Milan, Italy) descriptors and (2) semi-empirical descriptor calculations. The predictivity of the models was estimated by cross-validation with the leave-one-out method. The result showed that a significant improvement of the statistical indices was obtained by deleting outliers. Based on the data for the compounds used in this study, our results suggest a QSAR model of RSA that is based on the following descriptors: 3D-Morse, WHIM, and GETAWAY. Therefore, satisfactory relationships between RSA and the semi-empirical descriptors were found, demonstrating that the energy of the highest occupied molecular orbital, total energy, and energy of heat of formation contributed more significantly than all other descriptors.

  16. [Activity of aldehyde scavenger enzymes in the heart of rats of different age during immobilized stress].

    PubMed

    Grabovetskaia, E R; Davydov, V V

    2009-01-01

    This study was made to determine the activity of aldehyde scavenger enzymes in the heart's postmitochondrial fraction of rats of different age during immobilization stress. Our study demonstrated, that immobilization of 1.5-, 2- and 12-month rats was accompanied by inhibiting activity of aldehyde dehydrogenase and aldehyde reductase. At the same time we observed an increase in glutathione transferase activity in immobilized 1.5-month-old rats and that in reductase activity in 24-month-old rats. The revealed changes can lead to a decrease in the rate of endogenous aldehyde utilization in the heart during stress at puberty.

  17. Preparation of Egg White Liquid Hydrolysate (ELH) and Its Radical-Scavenging Activity

    PubMed Central

    Noh, Dong Ouk; Suh, Hyung Joo

    2015-01-01

    In the present study, an optimum protease was selected to hydrolyze the egg white liquid protein for the antioxidant peptides. Alcalase treatment yielded the highest amount of α-amino groups (15.27 mg/mL), while the control (no enzymatic hydrolysis) showed the lowest amount of α-amino groups (1.53 mg/mL). Alcalase also gave the highest degree of hydrolysis (DH) value (43.2%) and was more efficient for egg white liquid hydrolysis than the other enzymes. The Alcalase hydrolysate had the highest radical-scavenging activity (82.5%) at a concentration of 5.0 mg/mL. The conditions for enzymatic hydrolysis of egg white liquid with Alcalase were selected as substrate : water ratio of 2:1. Five percent Alacalse treatment did not show significant (P>0.05) increases of DH and α-amino nitrogen content after 24 h-hydrolysis. Thirty two hour-hydrolysis with 5% Alcalase is sufficient to make antioxidative egg white liquid hydrolysate from egg white liquid. DPPH and ABTS radical-scavenging activities were significantly (P<0.05) higher after enzymatic digestion. These results suggest that active peptides released from egg-white protein are effective radical-scavengers. Thus, this approach may be useful for the preparation of potent antioxidant products. PMID:26451355

  18. Antigenotoxic, antimutagenic and ROS scavenging activities of a Rhoeo discolor ethanolic crude extract.

    PubMed

    González-Avila, M; Arriaga-Alba, M; de la Garza, M; del Carmen HernándezPretelín, M; Domínguez-Ortíz, M A; Fattel-Fazenda, S; Villa-Treviño, S

    2003-02-01

    Rhoeo discolor is a legendary plant used for treatment of superficial mycoses in Mexican traditional medicine. Despite its extended use, it is not known whether it has side-effects. An ethanolic crude extract from Rhoeo discolor was prepared, its mutagenic capacity was investigated by the Ames test, and its genotoxic activity in primary liver cell cultures using the unscheduled DNA synthesis assay. This extract was not mutagenic when tested with Salmonella typhimurium strains TA97, TA98 and TA100, and it did not elicit unscheduled DNA synthesis in hepatocyte cultures. In addition, we explored the antimutagenic and antigenotoxic activities of the extract and its ROS scavenger behaviour. Our results show that Rhoeo extract is antimutagenic for S. typhimurium strain TA102 pretreated with ROS-generating mutagen norfloxacin in the Ames test, and protects liver cell cultures against diethylnitrosamine induction of unscheduled DNA synthesis even at 1.9 ng per dish, which was the lowest dose tested. A free radical scavenging test was used in order to explore the antioxidant capacity of Rhoeo extract, as compared with three commercial well-known antioxidants quercetin, ascorbic acid and tocopherol. Rhoeo extract showed less radical scavenging effect than quercetin, but similar to that of alpha-tocopherol and more than ascorbic acid. It is important to note that this extract was neither mutagenic in S. typhimurium nor genotoxic in liver cell culture, even at concentrations as high as four- and 166-fold of those needed for maximal antimutagenic or chemoprotective activities, respectively.

  19. Active oxygen doctors the evidence

    NASA Astrophysics Data System (ADS)

    Castelló, Ana; Francès, Francesc; Corella, Dolores; Verdú, Fernando

    2009-02-01

    Investigation at the scene of a crime begins with the search for clues. In the case of bloodstains, the most frequently used reagents are luminol and reduced phenolphthalein (or phenolphthalin that is also known as the Kastle-Meyer colour test). The limitations of these reagents have been studied and are well known. Household cleaning products have evolved with the times, and new products with active oxygen are currently widely used, as they are considered to be highly efficient at removing all kinds of stains on a wide range of surfaces. In this study, we investigated the possible effects of these new cleaning products on latent bloodstains that may be left at a scene of a crime. To do so, various fabrics were stained with blood and then washed using cleaning agents containing active oxygen. The results of reduced phenolphthalein, luminol and human haemoglobin tests on the washed fabrics were negative. The conclusion is that these new products alter blood to such an extent that it can no longer be detected by currently accepted methods employed in criminal investigations. This inability to locate bloodstains means that highly important evidence (e.g. a DNA profile) may be lost. Consequently, it is important that investigators are aware of this problem so as to compensate for it.

  20. Scavenging for the Past.

    ERIC Educational Resources Information Center

    McMahon, Sue; Strubbe, Mary

    1988-01-01

    Discusses the goals and planning of a scavenger hunt which was designed to increase enthusiasm in students and promote active learning. States that a scavenger hunt instills a sense of community pride in students and that the community cooperation fosters a positive relationship with the school. Provides a sample scavenger hunt checklist. (GEA)

  1. Free radical scavenging activities of yellow gentian (Gentiana lutea L.) measured by electron spin resonance.

    PubMed

    Kusar, A; Zupancic, A; Sentjurc, M; Baricevic, D

    2006-10-01

    Yellow gentian (Gentiana lutea L.) is a herbal species with a long-term use in traditional medicine due to its digestive and stomachic properties. This paper presents an investigation of the free radical scavenging activity of methanolic extracts of yellow gentian leaves and roots in two different systems using electron spin resonance (ESR) spectrometry. Assays were based on the stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) and the superoxide radicals (O2*-) generated by the xanthine/xanthine oxidase (X/XO) system. The results of gentian methanolic extracts were compared with the antioxidant capacity of synthetic antioxidant butylated hydroxyanisole (BHA). This study proves that yellow gentian leaves and roots exhibit considerable antioxidant properties, expressed either by their capability to scavenge DPPH or superoxide radicals.

  2. Tualang honey has higher phenolic content and greater radical scavenging activity compared with other honey sources.

    PubMed

    Kishore, R Krishna; Halim, Ahmad Sukari; Syazana, M S Nurul; Sirajudeen, K N S

    2011-04-01

    Many chronic diseases are associated with increased oxidative stress caused by an imbalance between free-radical production and the antioxidant level. Antioxidants, which are abundant in natural honey, are free-radical scavengers that either reduce the formation of or neutralize free radicals. The composition and source of honey greatly dictates its biochemical properties. We performed a comparative analysis of the total phenolic content and antioxidant potential of common commercially available honeys along with Malaysian tualang honey. In vitro biochemical analysis of the phenolic content by the Folin-Ciocalteau method revealed a significantly elevated phenolic content (83.96 ± 4.53 mg gallic acid equivalents per 100 g) in tualang honey. In addition, the antioxidant capacity (53.06 ± 0.41 mg ascorbic acid equivalents per gram) of tualang honey was greater, as assessed by the phosphomolybdenum method, 2,2-diphenyl-1-picryl-hydrazyl assay, and ferric reducing/antioxidant power assay. Peroxynitrite and superoxide radical scavenging activity was determined by spectrophotometric analysis in different honey types. Our data suggest that the elevated free-radical scavenging and antioxidant activity observed in tualang honey is due to the increased level of phenolic compounds. In addition to its antibacterial, anticarcinogenic, and anti-inflammatory properties, our study highlights the favorable antioxidant properties of tualang honey, which may be important to human nutrition and health.

  3. Determination of Radical Scavenging Activity and Total Phenols of Wine and Spices: A Randomized Study

    PubMed Central

    Lugemwa, Fulgentius Nelson; Snyder, Amanda L.; Shaikh, Koonj

    2013-01-01

    Thirty eight bottles of red wine (Carbanet Sauvignon) were randomly selected based on vintage, region, price, and age (number of months in a barrel). The total phenolic content of each wine was determined using Folin-Ciocalteau assay. The radical scavenging activity was evaluated using 2,2-diphenyl-1-picryhydrazyl (DPPH) assay. Apart from a few bottles that exhibited above average radical scavenging activity and phenolic content, there was no good correlation of those two quantities with region, price or vintage. The average phenolic amount was 2874 mg/L. The lowest phenolic content was found to be 1648 mg/L for an eight dollar wine. Wine with the highest amount of phenol of 4495 mg/L was a 2007, nine dollar bottle from South America. High amount of phenols did not translate into high radical scavenging activity. Barrel-aging did not increase the amount of phenols or the radical scavenging activity of wine. In order to discover new and potent sources of antioxidants from plants, the following spices were studied: ginger, cilantro, cumin, anise, linden, eucalyptus, marjoram, oregano, sage, thyme and rosemary. Whole spices were crushed and extracted for 96 h at room temperature using a combination of ethyl acetate, ethyl alcohol and water in the ratio of 4.5:4.5:1 (v/v/v). The radical scavenging activity of extracts was evaluated using 2,2-diphenyl-1-picryhydrazyl (DPPH) assay. The total phenolic content of each spice was also determined using the Folin-Ciocalteau assay. Eucalyptus was found to be the most potent antioxidant with an LC50 of 324.1 mg of phenol/L, followed by marjoram with an LC50 of 407.5 mg of phenol/L, and rosemary with an LC50 of 414.0 mg/L. The least potent antioxidants were ginger and cilantro with LC50 of 7604 mg/L of phenol and 7876 mg of phenol/L, respectively. PMID:26784340

  4. Amyloid-β and α-Synuclein Decrease the Level of Metal-Catalyzed Reactive Oxygen Species by Radical Scavenging and Redox Silencing.

    PubMed

    Pedersen, Jeppe T; Chen, Serene W; Borg, Christian B; Ness, Samuel; Bahl, Justyna M; Heegaard, Niels H H; Dobson, Christopher M; Hemmingsen, Lars; Cremades, Nunilo; Teilum, Kaare

    2016-03-30

    The formation of reactive oxygen species (ROS) is linked to the pathogenesis of neurodegenerative diseases. Here we have investigated the effect of soluble and aggregated amyloid-β (Aβ) and α-synuclein (αS), associated with Alzheimer's and Parkinson's diseases, respectively, on the Cu(2+)-catalyzed formation of ROS in vitro in the presence of a biological reductant. We find that the levels of ROS, and the rate by which ROS is generated, are significantly reduced when Cu(2+) is bound to Aβ or αS, particularly when they are in their oligomeric or fibrillar forms. This effect is attributed to a combination of radical scavenging and redox silencing mechanisms. Our findings suggest that the increase in ROS associated with the accumulation of aggregated Aβ or αS does not result from a particularly ROS-active form of these peptides, but rather from either a local increase of Cu(2+) and other ROS-active metal ions in the aggregates or as a downstream consequence of the formation of the pathological amyloid structures.

  5. Scavenging of reactive oxygen species in apoplastic and symplastic areas of rolled leaves in Ctenanthe setosa under drought stress.

    PubMed

    Saruhan, Neslihan; Terzi, Rabiye; Sağlam, Aykut; Kadioğlu, Asim

    2010-09-01

    The correspondence among apoplastic and symplastic antioxidant status, stomatal conductance and water potential was investigated during leaf rolling in Ctenanthe setosa (Rosc.) Eichler (Marantaceae) under drought stress. Apoplastic and symplastic extractions of leaf and petiole were performed at different visual leaf rolling scores from 1 to 4 (1 is unrolled, 4 is tightly rolled and the others are intermediate form). In the leaf symplast, the highest changes were found in catalase (CAT) and guaiacol peroxidase (GPX) activities when compared to score 1 during leaf rolling. No significant change was observed in superoxide dismutase (SOD) and ascorbate peroxidase (APX) activities in the symplast of leaf during the rolling. The same phenomenon was also present in the symplast of petiole except APX activity. In the leaf apoplast, the highest increase occurred in APX and GPX activities, whilst a slight increase in CAT and SOD activities. In the apoplast of petiole, the highest increment was found only in GPX activity, while there were small increases in SOD, APX and CAT activities. Hydrogen peroxide content increased up to score 3 in the apoplast and symplast of leaf and petiole but then slightly decreased. Also, superoxide production increased in the leaf and petiole apoplast but its quantity in the apoplast was much more than that of the symplast. On the other hand, NAD(P)H oxidase activity increased in the leaf but no change was observed in the petiole. In conclusion, as a result of water deficit during leaf rolling antioxidant enzymes are induced to scavenging of ROS produced in symplast and apoplast. PMID:20724275

  6. Scavenging of reactive oxygen species in apoplastic and symplastic areas of rolled leaves in Ctenanthe setosa under drought stress.

    PubMed

    Saruhan, Neslihan; Terzi, Rabiye; Sağlam, Aykut; Kadioğlu, Asim

    2010-09-01

    The correspondence among apoplastic and symplastic antioxidant status, stomatal conductance and water potential was investigated during leaf rolling in Ctenanthe setosa (Rosc.) Eichler (Marantaceae) under drought stress. Apoplastic and symplastic extractions of leaf and petiole were performed at different visual leaf rolling scores from 1 to 4 (1 is unrolled, 4 is tightly rolled and the others are intermediate form). In the leaf symplast, the highest changes were found in catalase (CAT) and guaiacol peroxidase (GPX) activities when compared to score 1 during leaf rolling. No significant change was observed in superoxide dismutase (SOD) and ascorbate peroxidase (APX) activities in the symplast of leaf during the rolling. The same phenomenon was also present in the symplast of petiole except APX activity. In the leaf apoplast, the highest increase occurred in APX and GPX activities, whilst a slight increase in CAT and SOD activities. In the apoplast of petiole, the highest increment was found only in GPX activity, while there were small increases in SOD, APX and CAT activities. Hydrogen peroxide content increased up to score 3 in the apoplast and symplast of leaf and petiole but then slightly decreased. Also, superoxide production increased in the leaf and petiole apoplast but its quantity in the apoplast was much more than that of the symplast. On the other hand, NAD(P)H oxidase activity increased in the leaf but no change was observed in the petiole. In conclusion, as a result of water deficit during leaf rolling antioxidant enzymes are induced to scavenging of ROS produced in symplast and apoplast.

  7. DPPH free radical scavenging activity and phenotypic difference in hepatoprotective plant (Silybum marianum L.).

    PubMed

    Ahmad, Nisar; Fazal, Hina; Abbasi, Bilal Haider; Anwar, Shazma; Basir, Abdul

    2013-06-01

    Silybum marianum L. is medicinally important for its active principle component silymarin. Silymarin regenerates damaged hepatic tissues. On the basis of such regenerative properties, the radical scavenging activity (1,1-diphenyl-2-picrylhydrazyl (DPPH)) of different tissues and the phenotypic difference of the hepatoprotective species, S. marianum L. were evaluated. There was less phenotypic difference in purple and white varieties of S. marianum. Assay of the antioxidant potential of different parts of the plant revealed that significantly higher activity (78.2%) was observed in seeds of the purple flowering plant than seeds of white flowering plant (49%) after different time intervals. Young leaves collected from white flowering plant exhibit 64.8% activity, which is higher than the purple flowering plant (55.1%). Significantly, same activity was observed in mature leaves of white (52%) and purple flowering plants (50%). The main stem collected from both the varieties exhibits similar activity from 50 to 52%. A 67.2% activity was recorded for mature roots of white flowering plant followed by roots of the purple variety (65%). The present study revealed that seeds and roots of both the varieties scavenge and detoxify more DPPH free radicals than other plant parts and can be used as a source of natural antioxidants and food additives.

  8. CBLB502, an agonist of Toll-like receptor 5, has antioxidant and scavenging free radicals activities in vitro.

    PubMed

    Li, Weiguang; Ge, Changhui; Yang, Liu; Wang, Ruixue; Lu, Yiming; Gao, Yan; Li, Zhihui; Wu, Yonghong; Zheng, Xiaofei; Wang, Zhaoyan; Zhang, Chenggang

    2016-01-01

    The bacterial protein flagellin is the known agonist of Toll-like receptor 5 (TLR5). It has been reported that CBLB502, a novel agonist of TLR5 derived from Salmonella flagellin, could reduce radiation toxicity in mouse and primate models, protect mice from dermatitis and oral mucositis caused by radiation, inhibit acute renal ischemic failure, and inhibit the growth of A549 lung cancer cell. The property of CBLB502 is able to bind to TLR5 and activates NF-κB signaling. In this study, we investigated the antioxidant potential and free radicals scavenging properties of CBLB502 in vitro. Interestingly, we found that CBLB502 has a direct and distinct antioxidant capacity and can efficiently scavenge a variety of free radicals, including superoxide anion, hydroxyl radical, and ABTS cation (ABTS(+)). Through wave scanning and kinetic evaluation of scavenging ABTS(+), we found that the ABTS(+) scavenging process of CBLB502 is relatively slow, and the ABTS(+) scavenging activity of CBLB502 has a consistently kinetics characteristics. In conclusion, our results suggested that CBLB502 has antioxidant and scavenging free radicals activities in vitro. It is implied that CBLB502 might partially promote the beneficial protective effect through its scavenging free radicals.

  9. Effects of Different Drying Methods and Storage Time on Free Radical Scavenging Activity and Total Phenolic Content of Cosmos caudatus

    PubMed Central

    Mediani, Ahmed; Abas, Faridah; Tan, Chin Ping; Khatib, Alfi

    2014-01-01

    The present study was conducted to determine the effect of air (AD), oven (OD) and freeze drying (FD) on the free radical scavenging activity and total phenolic content (TPC) of Cosmos caudatus and the effect of storage time by the comparison with a fresh sample (FS). Among the three drying methods that were used, AD resulted in the highest free radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) (IC50 = 0.0223 mg/mL) and total phenolic content (27.4 g GAE/100 g), whereas OD produced the lowest scavenging activity and TPC value. After three months of storage, the dried samples showed a high and consistent free radical scavenging activity when compared to stored fresh material. The drying methods could preserve the quality of C. caudatus during storage and the stability of its bioactive components can be maintained. PMID:26784876

  10. Effects of Different Drying Methods and Storage Time on Free Radical Scavenging Activity and Total Phenolic Content of Cosmos Caudatus.

    PubMed

    Mediani, Ahmed; Abas, Faridah; Tan, Chin Ping; Khatib, Alfi

    2014-05-07

    The present study was conducted to determine the effect of air (AD), oven (OD) and freeze drying (FD) on the free radical scavenging activity and total phenolic content (TPC) of Cosmos caudatus and the effect of storage time by the comparison with a fresh sample (FS). Among the three drying methods that were used, AD resulted in the highest free radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) (IC50 = 0.0223 mg/mL) and total phenolic content (27.4 g GAE/100 g), whereas OD produced the lowest scavenging activity and TPC value. After three months of storage, the dried samples showed a high and consistent free radical scavenging activity when compared to stored fresh material. The drying methods could preserve the quality of C. caudatus during storage and the stability of its bioactive components can be maintained.

  11. Assessment of haemolytic, cytotoxic and free radical scavenging activities of an underutilized fruit, Baccaurea ramiflora Lour. (Roxb.) Muell. Arg.

    PubMed

    Saha, Manas Ranjan; Dey, Priyankar; Chaudhuri, Tapas Kumar; Goyal, Arvind Kr; Sarker, Dilip De; Sen, Arnab

    2016-02-01

    Baccaurea ramiflora Lour. (Roxb.) Muell. Arg. is an underutilized juicy fruit bearing plant found in sub-Himalayan area, South China, Indo-Burma region, etc. The fruit is considered to be nutritive, and in this study, we evaluated its antioxidant, haemolytic and cytotoxic properties. The juice was examined for the quenching activity of hydroxyl radical, nitric oxide, singlet oxygen, peroxynitrite, total antioxidant activity (TAA), erythrocyte membrane stabilizing activity (EMSA) along with quantification of phenolic and flavonoid contents and also tested for its potential activity as iron chelator, inhibitor of lipid peroxidation and total reducing power. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were also performed to correlate antioxidant capacities with the phenolic and flavonoid content. Haemolytic activity on murine erythrocyte and MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) cytotoxic test was performed on murine splenocytes, thymocytes, hepatocytes and peritoneal exudates macrophage to examine the cytotoxic effect of its juice. The result exhibited its potent free radical scavenging activity. In case of TAA, DPPH (2, 2-diphenyl-1-picrylhydrazyl), EMSA and lipid peroxidation, the fruit juice was found to have significant (P < 0.001) antioxidant capacity, which is evident from low IC50 (half maximal inhibitory concentration) value. Results obtained from haemolytic inhibition assay and MTT cytotoxic test confirms that the juice does not contain any cytotoxic effect and the fruit is safe for consumption. Fourier transform infrared (FTIR) spectra analysis exhibited high possibility of presence of flavonoid compounds in the juice.

  12. Variable protection by OH scavengers against radiation-induced inactivation of isolated transcriptionally active chromatin: the influence of secondary radicals

    SciTech Connect

    Herskind, C.; Westergaard, O.

    1988-04-01

    Isolated r-chromatin, the chromatin form of the extrachromosomal gene coding for the rRNA precursor in Tetrahymena, has been used to study radiation-induced inactivation in vitro in the presence of the OH radical scavengers, t-butanol, formate ions, and methanol. Induction of biologically important DNA lesions was detected by the effect on transcription by endogenous RNA polymerases associated with the isolated r-chromatin. The OH scavengers were found to give strong protection in the presence of oxygen as anticipated from previous results obtained with this system. By contrast, only a modest protection was observed under 100% N/sub 2/ or 100% N/sub 2/O, and the level of protection was different for each scavenger. The data suggest that secondary radicals may inactivate r-chromatin under anoxia. In the presence of oxygen, the secondary radicals react with O/sub 2/ to form organic peroxy radicals (or O/sub 2/-) which seem to be less reactive. Since the protective effect of the OH scavengers varies with the gassing conditions, the dose modifying effects of O/sub 2/ and N/sub 2/O relative to N/sub 2/ depend on the identity and concentration of OH scavenger. The implications for radiation-chemical studies on DNA and living cells are discussed.

  13. Beneficial effect of the oxygen free radical scavenger amifostine (WR-2721) on spinal cord ischemia/reperfusion injury in rabbits

    PubMed Central

    Chronidou, Fany; Apostolakis, Efstratios; Papapostolou, Ioannis; Grintzalis, Konstantinos; Georgiou, Christos D; Koletsis, Efstratios N; Karanikolas, Menelaos; Papathanasopoulos, Panagiotis; Dougenis, Dimitrios

    2009-01-01

    Background Paraplegia is the most devastating complication of thoracic or thoraco-abdominal aortic surgery. During these operations, an ischemia-reperfusion process is inevitable and the produced radical oxygen species cause severe oxidative stress for the spinal cord. In this study we examined the influence of Amifostine, a triphosphate free oxygen scavenger, on oxidative stress of spinal cord ischemia-reperfusion in rabbits. Methods Eighteen male, New Zealand white rabbits were anesthetized and spinal cord ischemia was induced by temporary occlusion of the descending thoracic aorta by a coronary artery balloon catheter, advanced through the femoral artery. The animals were randomly divided in 3 groups. Group I functioned as control. In group II the descending aorta was occluded for 30 minutes and then reperfused for 75 min. In group III, 500 mg Amifostine was infused into the distal aorta during the second half-time of ischemia period. At the end of reperfusion all animals were sacrificed and spinal cord specimens were examined for superoxide radicals by an ultra sensitive fluorescent assay. Results Superoxide radical levels ranged, in group I between 1.52 and 1.76 (1.64 ± 0.10), in group II between 1.96 and 2.50 (2.10 ± 0.23), and in group III (amifostine) between 1.21 and 1.60 (1.40 ± 0.19) (p = 0.00), showing a decrease of 43% in the Group of Amifostine. A lipid peroxidation marker measurement ranged, in group I between 0.278 and 0.305 (0.296 ± 0.013), in group II between 0.427 and 0.497 (0.463 ± 0.025), and in group III (amifostine) between 0.343 and 0.357 (0.350 ± 0.007) (p < 0.00), showing a decrease of 38% after Amifostine administration. Conclusion By direct and indirect methods of measuring the oxidative stress of spinal cord after ischemia/reperfusion, it is suggested that intra-aortic Amifostine infusion during spinal cord ischemia phase, significantly attenuated the spinal cord oxidative injury in rabbits. PMID:19758462

  14. On the antioxidant properties of kynurenic acid: free radical scavenging activity and inhibition of oxidative stress.

    PubMed

    Lugo-Huitrón, R; Blanco-Ayala, T; Ugalde-Muñiz, P; Carrillo-Mora, P; Pedraza-Chaverrí, J; Silva-Adaya, D; Maldonado, P D; Torres, I; Pinzón, E; Ortiz-Islas, E; López, T; García, E; Pineda, B; Torres-Ramos, M; Santamaría, A; La Cruz, V Pérez-De

    2011-01-01

    Kynurenic acid (KYNA) is an endogenous metabolite of the kynurenine pathway for tryptophan degradation and an antagonist of both N-methyl-D-aspartate (NMDA) and alpha-7 nicotinic acetylcholine (α7nACh) receptors. KYNA has also been shown to scavenge hydroxyl radicals (OH) under controlled conditions of free radical production. In this work we evaluated the ability of KYNA to scavenge superoxide anion (O(2)(-)) and peroxynitrite (ONOO(-)). The scavenging ability of KYNA (expressed as IC(50) values) was as follows: OH=O(2)(-)>ONOO(-). In parallel, the antiperoxidative and scavenging capacities of KYNA (0-150 μM) were tested in cerebellum and forebrain homogenates exposed to 5 μM FeSO(4) and 2.5 mM 3-nitropropionic acid (3-NPA). Both FeSO(4) and 3-NPA increased lipid peroxidation (LP) and ROS formation in a significant manner in these preparations, whereas KYNA significantly reduced these markers. Reactive oxygen species (ROS) formation were determined in the presence of FeSO(4) and/or KYNA (0-100 μM), both at intra and extracellular levels. An increase in ROS formation was induced by FeSO(4) in forebrain and cerebellum in a time-dependent manner, and KYNA reduced this effect in a concentration-dependent manner. To further know whether the effect of KYNA on oxidative stress is independent of NMDA and nicotinic receptors, we also tested KYNA (0-100 μM) in a biological preparation free of these receptors - defolliculated Xenopus laevis oocytes - incubated with FeSO(4) for 1 h. A 3-fold increase in LP and a 2-fold increase in ROS formation were seen after exposure to FeSO(4), whereas KYNA attenuated these effects in a concentration-dependent manner. In addition, the in vivo formation of OH evoked by an acute infusion of FeSO(4) (100 μM) in the rat striatum was estimated by microdialysis and challenged by a topic infusion of KYNA (1 μM). FeSO(4) increased the striatal OH production, while KYNA mitigated this effect. Altogether, these data strongly suggest that KYNA

  15. The effect of Ta ``oxygen scavenger layer'' on HfO2-based resistive switching behavior: termodynamic stability, electronic structure, and low-bias transport

    NASA Astrophysics Data System (ADS)

    Zhong, Xiaoliang; Rungger, Ivan; Zapol, Peter; Nakamura, Hisao; Asai, Yoshihiro; Heinonen, Olle

    Metal-oxide-metal heterostructures are promising candidates for next-generation random access memories, which exhibit reversible resistive switching between high- and low-conductance states. Recent experimental work showed that inserting a metallic `oxygen scavenger layer' between TiN electrode and HfO2 significantly improves device switching performance. We show, using atomistic modeling within the GGA +U scheme of Density Functional Theory, that a Ta oxygen scavenger layer significantly enhances the thermodynamic stability of depleting oxygen from the oxide. Furthermore, the presence of a Ta layer reduces the dependence of the Schottky barrier heights on the location of the oxygen removed from the oxide matrix. Finally, the Schottky barrier height has a very small effect on the on-state low-bias conductance; this is more sensitive to the location of the depleted oxygen. We gratefully acknowledge the computing resources provided on Blues, a high-performance computing cluster operated by the Laboratory Computing Resource Center at Argonne National Laboratory. Work at Argonne was supported by U. S. DOE, Office of Science under Contract No. DE-AC02-06CH11357.

  16. In situ comparison of activity in two deep-sea scavenging fishes occupying different depth zones

    PubMed Central

    Collins, M. A.; Priede, I. G.; Bagley, P. M.

    1999-01-01

    The activity of two scavenging deep-sea fishes occupying the same niche in overlapping depth zones were compared by in situ measurements of swimming speeds, tail-beat frequencies and by arrival time at baits. At 4800 m on the Porcupine Abyssal Plain, the grenadier Coryphaenoides (Nematonurus) armatus was the dominant scavenger, arriving at baits after 30 min, and swimming at relatively slow speeds of 0.17 body lengths (BL) sec-1. At 2500 m in the relatively food rich Porcupine Seabight both C. (N.) armatus and the blue-hake, Antimora rostrata, were attracted to bait, but A. rostrata was always the first to arrive and most of the bait was consumed before the C. (N.) armatus arrived. A. rostrata swam at mean speeds of 0.39 BL sec-1, similar to related shallow water species at equivalent temperatures. Observations on tail-beat frequency from video sequences confirmed the greater activity of A. rostrata. The data indicate that, given sufficient food supply, high pressure and low temperature do not limit activity levels of demersal deep-sea fishes. Low activity of C. (N.) armatus is an adaptation to poor food supply in the abyss, where these fishes dominate, but prevents it competing with the more active A. rostrata in shallower depths.

  17. An Arabidopsis Zinc Finger Protein Increases Abiotic Stress Tolerance by Regulating Sodium and Potassium Homeostasis, Reactive Oxygen Species Scavenging and Osmotic Potential.

    PubMed

    Zang, Dandan; Li, Hongyan; Xu, Hongyun; Zhang, Wenhui; Zhang, Yiming; Shi, Xinxin; Wang, Yucheng

    2016-01-01

    Plant zinc finger proteins (ZFPs) comprise a large protein family and they are mainly involved in abiotic stress tolerance. Although Arabidopsis RING/FYVE/PHD ZFP At5g62460 (AtRZFP) is found to bind to zinc, whether it is involved in abiotic stress tolerance is still unknown. In the present study, we characterized the roles of AtRZFP in response to abiotic stresses. The expression of AtRZFP was induced significantly by salt and osmotic stress. AtRZFP positively mediates tolerance to salt and osmotic stress. Additionally, compared with wild-type Arabidopsis plants, plants overexpressing AtRZFP showed reduced reactive oxygen species (ROSs) accumulation, enhanced superoxide dismutase and peroxidase activity, increased soluble sugars and proline contents, reduced K(+) loss, decreased Na(+) accumulation, stomatal aperture and the water loss rate. Conversely, AtRZFP knockout plants displayed the opposite physiological changes when exposed to salt or osmotic stress conditions. These data suggested that AtRZFP enhances salt and osmotic tolerance through a series of physiological processes, including enhanced ROSs scavenging, maintaining Na(+) and K(+) homeostasis, controlling the stomatal aperture to reduce the water loss rate, and accumulating soluble sugars and proline to adjust the osmotic potential. PMID:27605931

  18. An Arabidopsis Zinc Finger Protein Increases Abiotic Stress Tolerance by Regulating Sodium and Potassium Homeostasis, Reactive Oxygen Species Scavenging and Osmotic Potential

    PubMed Central

    Zang, Dandan; Li, Hongyan; Xu, Hongyun; Zhang, Wenhui; Zhang, Yiming; Shi, Xinxin; Wang, Yucheng

    2016-01-01

    Plant zinc finger proteins (ZFPs) comprise a large protein family and they are mainly involved in abiotic stress tolerance. Although Arabidopsis RING/FYVE/PHD ZFP At5g62460 (AtRZFP) is found to bind to zinc, whether it is involved in abiotic stress tolerance is still unknown. In the present study, we characterized the roles of AtRZFP in response to abiotic stresses. The expression of AtRZFP was induced significantly by salt and osmotic stress. AtRZFP positively mediates tolerance to salt and osmotic stress. Additionally, compared with wild-type Arabidopsis plants, plants overexpressing AtRZFP showed reduced reactive oxygen species (ROSs) accumulation, enhanced superoxide dismutase and peroxidase activity, increased soluble sugars and proline contents, reduced K+ loss, decreased Na+ accumulation, stomatal aperture and the water loss rate. Conversely, AtRZFP knockout plants displayed the opposite physiological changes when exposed to salt or osmotic stress conditions. These data suggested that AtRZFP enhances salt and osmotic tolerance through a series of physiological processes, including enhanced ROSs scavenging, maintaining Na+ and K+ homeostasis, controlling the stomatal aperture to reduce the water loss rate, and accumulating soluble sugars and proline to adjust the osmotic potential. PMID:27605931

  19. An Arabidopsis Zinc Finger Protein Increases Abiotic Stress Tolerance by Regulating Sodium and Potassium Homeostasis, Reactive Oxygen Species Scavenging and Osmotic Potential

    PubMed Central

    Zang, Dandan; Li, Hongyan; Xu, Hongyun; Zhang, Wenhui; Zhang, Yiming; Shi, Xinxin; Wang, Yucheng

    2016-01-01

    Plant zinc finger proteins (ZFPs) comprise a large protein family and they are mainly involved in abiotic stress tolerance. Although Arabidopsis RING/FYVE/PHD ZFP At5g62460 (AtRZFP) is found to bind to zinc, whether it is involved in abiotic stress tolerance is still unknown. In the present study, we characterized the roles of AtRZFP in response to abiotic stresses. The expression of AtRZFP was induced significantly by salt and osmotic stress. AtRZFP positively mediates tolerance to salt and osmotic stress. Additionally, compared with wild-type Arabidopsis plants, plants overexpressing AtRZFP showed reduced reactive oxygen species (ROSs) accumulation, enhanced superoxide dismutase and peroxidase activity, increased soluble sugars and proline contents, reduced K+ loss, decreased Na+ accumulation, stomatal aperture and the water loss rate. Conversely, AtRZFP knockout plants displayed the opposite physiological changes when exposed to salt or osmotic stress conditions. These data suggested that AtRZFP enhances salt and osmotic tolerance through a series of physiological processes, including enhanced ROSs scavenging, maintaining Na+ and K+ homeostasis, controlling the stomatal aperture to reduce the water loss rate, and accumulating soluble sugars and proline to adjust the osmotic potential.

  20. Free radical scavenging activity, metal chelation and antioxidant power of some of the Indian spices.

    PubMed

    Yadav, Amit Singh; Bhatnagar, Deepak

    2007-01-01

    Food constituents are the major source of various phytochemicals and micronutrients. The importance of these dietary constituents has been stressed in recent years due to their antioxidant and anticarcinogenic potential. Spices used in Indian foods such as cloves (Syzygium aromaticum), licorice (Glycyrrhiza glabra), mace (aril of Myristica fragans), and greater cardamom (Amomum subulatum) were tested for their antioxidant properties in vitro. The metal chelating activity, bleomycin dependent DNA oxidation, diphenyl-p-picryl hydrazyl (DPPH) radical scavenging activity and the ferric reducing /antioxidant power (FRAP) were measured in rat liver homogenate in presence of spices. Metal chelating activity was significantly high with all the spice extracts except mace. The spices due to higher reducing potential (in presence of bleomycin-FeCl_{3}) showed increased DNA oxidation. Cloves showed the highest DPPH radical scavenging activity, followed by licorice, mace and cardamom. FRAP values for cloves were also the highest, while other spices showed comparatively lesser FRAP values. The results show that the spices tested are strong antioxidants and may have beneficial effects on human health.

  1. Theoretical insights on the antioxidant activity of edaravone free radical scavengers derivatives

    NASA Astrophysics Data System (ADS)

    Cerón-Carrasco, José P.; Roy, Hélène M.; Cerezo, Javier; Jacquemin, Denis; Laurent, Adèle D.

    2014-04-01

    The prediction of antioxidant properties is not straightforward due to the complexity of the in vivo systems. Here, we use theoretical descriptors, including the potential of ionization, the electrodonating power and the spin density distribution, to characterize the antioxidant capacity of edaravone (EDV) derivatives. Our computations reveal the relationship between these parameters and their potential bioactivity as free radical scavengers. We conclude that more efficient antioxidants could be synthesized by tuning the R1 and R2 positions of the EDV structure, rather than modifying the R3 group. Such modifications might improve the antioxidant activity in neutral and deprotonated forms.

  2. Free radical scavenging activity and reducing power of Acacia nilotica wood lignin.

    PubMed

    Aadil, Keshaw Ram; Barapatre, Anand; Sahu, Sudha; Jha, Harit; Tiwary, Bhupendra Nath

    2014-06-01

    Nine different fractions of lignin extracted by alkali, hot water and organosolv methods from Acacia wood powder were assessed for antioxidants activity. Results indicated that methanolic lignin fraction had highest polyphenol content of 393.30±9.2μg/ml (GAE). The oraganosolv lignin with total phenols and phenolic hydroxyl group content exhibited significant antioxidant activity as compared to other lignin fractions. Antioxidant properties of acetone fractions revealed a high antiradical scavenging activity (<90%) with a simultaneous high ferric and molybdate ion reducing capacity. The influence of extraction methods on functional groups of lignin fractions was confirmed by analytical methods and Fourier transform infrared spectroscopy (FTIR) analysis. Whereas the phenolic content showed strong correlation with reducing capacity, the antiradical activity was moderately correlated with phenolic content. A high phenolic hydroxyl groups content of organosolv lignin fractions provides evidence for the presence of active therapeutic antioxidant compounds for their testing as potential value added products for cosmetics and pharmaceutical industries.

  3. A comparative study of the hydroxyl radical scavenging capacity of activated sludge and membrane bioreactor wastewater effluents.

    PubMed

    Grant, Jacque-Ann; Hofmann, Ron

    2016-01-01

    This study evaluated the hydroxyl radical scavenging characteristics of wastewater from five membrane bioreactor (MBR) and five activated sludge (AS) systems. The average values of the characteristics of both wastewater types was found to be significantly different at a 90% confidence interval in terms UV absorbance at 254 nm, alkalinity, and biopolymer concentration. Effluent organic matter (EfOM), with an average kOH,EfOM of (2.75 ± 1.04) × 10(8) M(-1)s(-1), was identified as the primary hydroxyl scavenger contributing to >70% of the background scavenging in all cases, except when nitrite exceeded 0.3 mg NO(2)(-)-N/L. The average scavenging capacity, EfOM scavenging capacity, and the EfOM reaction rate constant of the AS wastewaters exceeded that of the MBR. However, due to the small sample size (n = 5) and considerable variability in scavenging characteristics among the MBR wastewaters, the difference in EfOM reactivity between the two wastewaters was not statistically significant at a 90% confidence interval. Nevertheless, these preliminary findings suggest the possibility that MBR wastewaters may be more amenable to treatment by advanced oxidation. A plausible explanation is that MBRs were observed to reject biopolymers, and a strong correlation was observed between EfOM scavenging capacity and biopolymer concentration.

  4. A comparative study of the hydroxyl radical scavenging capacity of activated sludge and membrane bioreactor wastewater effluents.

    PubMed

    Grant, Jacque-Ann; Hofmann, Ron

    2016-01-01

    This study evaluated the hydroxyl radical scavenging characteristics of wastewater from five membrane bioreactor (MBR) and five activated sludge (AS) systems. The average values of the characteristics of both wastewater types was found to be significantly different at a 90% confidence interval in terms UV absorbance at 254 nm, alkalinity, and biopolymer concentration. Effluent organic matter (EfOM), with an average kOH,EfOM of (2.75 ± 1.04) × 10(8) M(-1)s(-1), was identified as the primary hydroxyl scavenger contributing to >70% of the background scavenging in all cases, except when nitrite exceeded 0.3 mg NO(2)(-)-N/L. The average scavenging capacity, EfOM scavenging capacity, and the EfOM reaction rate constant of the AS wastewaters exceeded that of the MBR. However, due to the small sample size (n = 5) and considerable variability in scavenging characteristics among the MBR wastewaters, the difference in EfOM reactivity between the two wastewaters was not statistically significant at a 90% confidence interval. Nevertheless, these preliminary findings suggest the possibility that MBR wastewaters may be more amenable to treatment by advanced oxidation. A plausible explanation is that MBRs were observed to reject biopolymers, and a strong correlation was observed between EfOM scavenging capacity and biopolymer concentration. PMID:27148707

  5. Superoxide radicals scavenging and xanthine oxidase inhibitory activity of magnesium lithospermate B from Salvia miltiorrhiza.

    PubMed

    Liu, Xiaoyu; Chen, Ruohua; Shang, Yanjun; Jiao, Binghua; Huang, Caiguo

    2009-06-01

    In this study we investigated the superoxide radicals scavenging effect and xanthine oxidase inhibitory activity by magnesium lithospermate B, which was originally isolated from the roots of Salvia miltiorrhiza (also named Danshen or Dansham), an important herb in Oriental medicine. Superoxide radicals were generated both in beta-NADH/PMS system and xanthine/ xanthine oxidase system. Magnesium lithospermate B significantly inhibited the reduction of NBT induced by superoxide radicals with an IC(50) of 29.8 microg/mL and 4.06 microg/mL respectively in the two systems. Further study suggested that magnesium lithospermate B can directly inhibit xanthine oxidase and exhibits competitive inhibition. Magnesium lithospermate B was also found to have the hypouricemic activity in vivo against potassium oxonate-induced hyperuricaemia in mice. After oral administration of magnesium lithospermate B at doses of 10, 20 and 30 mg/kg, there was a significant decrease in the serum urate level when compared to the hyperuricemia control. In addition, magnesium lithospermate B significantly protected HL-60 cells from superoxide radicals-induced apoptosis in the xanthine/ xanthine oxidase reactions. This study provided evidence that magnesium lithospermate B exhibits direct superoxide radicals scavenging and xanthine oxidase inhibitory activity.

  6. Indoline Amide Glucosides from Portulaca oleracea: Isolation, Structure, and DPPH Radical Scavenging Activity.

    PubMed

    Jiao, Ze-Zhao; Yue, Su; Sun, Hong-Xiang; Jin, Tian-Yun; Wang, Hai-Na; Zhu, Rong-Xiu; Xiang, Lan

    2015-11-25

    A polyamide column chromatography method using an aqueous ammonia mobile phase was developed for large-scale accumulation of water-soluble indoline amide glucosides from a medicinal plant, Portulaca oleracea. Ten new [oleraceins H, I, K, L, N, O, P, Q, R, S (1-10)] and four known [oleraceins A-D (11-14)] indoline amide glucosides were further purified and structurally characterized by various chromatographic and spectroscopic methods. The DPPH radical scavenging activities of oleraceins K (5) and L (6), with EC50 values of 15.30 and 16.13 μM, respectively, were twice that of a natural antioxidant, vitamin C; the EC50 values of the 12 other indoline amides, which ranged from 29.05 to 43.52 μM, were similar to that of vitamin C. Structure-activity relationships indicated that the DPPH radical scavenging activities of these indoline amides correlate with the numbers and positions of the phenolic hydroxy groups. PMID:26562741

  7. Development of PEGylated serum albumin with multiple reduced thiols as a long-circulating scavenger of reactive oxygen species for the treatment of fulminant hepatic failure in mice.

    PubMed

    Katsumi, Hidemasa; Nishikawa, Makiya; Nishiyama, Kazushi; Hirosaki, Rikiya; Nagamine, Narumi; Okamoto, Haruka; Mizuguchi, Hironori; Kusamori, Kosuke; Yasui, Hiroyuki; Yamashita, Fumiyoshi; Hashida, Mitsuru; Sakane, Toshiyasu; Yamamoto, Akira

    2014-04-01

    Reactive oxygen species (ROS) are involved in the pathophysiology of fulminant hepatic failure. Therefore, we developed polyethylene glycol-conjugated bovine serum albumin with multiple reduced thiols (PEG-BSA-SH) for the treatment of fulminant hepatic failure. As a long-circulating ROS scavenger, PEG-BSA-SH effectively scavenged highly reactive oxygen species and hydrogen peroxide in buffer solution. PEG-BSA-SH showed a long circulation time in the plasma after intravenous injection into mice. Fulminant hepatic failure was induced by intraperitoneal injection of lipopolysaccharide and D-galactosamine (LPS/D-GalN) into mice. The LPS/D-GalN-induced elevation of plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels was significantly inhibited by a bolus intravenous injection of PEG-BSA-SH. Furthermore, the changes in hepatic lipid peroxide and hepatic blood flow were effectively suppressed by PEG-BSA-SH. In contrast, L-cysteine, glutathione, and dithiothreitol, three traditional reduced thiols, had no statistically significant effects on the serum levels of ALT or AST. These findings indicate that PEG-BSA-SH is a promising ROS scavenger and useful in the treatment of fulminant hepatic failure.

  8. Free-radical scavenging activity and antibacterial impact of Greek oregano isolates obtained by SFE.

    PubMed

    Stamenic, Marko; Vulic, Jelena; Djilas, Sonja; Misic, Dusan; Tadic, Vanja; Petrovic, Slobodan; Zizovic, Irena

    2014-12-15

    The antioxidant and antibacterial properties of Greek oregano extracts obtained by fractional supercritical fluid extraction (SFE) with carbon dioxide were investigated and compared with the properties of essential oil obtained by hydrodistillation. According to DPPH, hydroxyl radical and superoxide anion radical scavenging activity assays, the supercritical extracts expressed stronger antioxidant activity comparing to the essential oil. The most effective was the supercritical extract obtained by fractional extraction at 30 MPa and 100°C after the volatile fraction had been extracted at lower pressure. At the same time this extract showed strong antibacterial activity against staphylococci, including MRSA strain, but did not affect Escherichia coli of normal intestinal flora. The essential oil obtained by hydrodistillation showed stronger antibacterial activity against E. coli, Salmonella and Klebsiella pneumoniae, comparing to the supercritical extracts but at the same affected the normal gut flora.

  9. Direct observation of both contact and remote oxygen scavenging of GeO{sub 2} in a metal-oxide-semiconductor stack

    SciTech Connect

    Fadida, S. Shekhter, P.; Eizenberg, M.; Cvetko, D.; Floreano, L.; Verdini, A.; Kymissis, I.

    2014-10-28

    In the path to incorporating Ge based metal-oxide-semiconductor into modern nano-electronics, one of the main issues is the oxide-semiconductor interface quality. Here, the reactivity of Ti on Ge stacks and the scavenging effect of Ti were studied using synchrotron X-ray photoelectron spectroscopy measurements, with an in-situ metal deposition and high resolution transmission electron microscopy imaging. Oxygen removal from the Ge surface was observed both in direct contact as well as remotely through an Al{sub 2}O{sub 3} layer. The scavenging effect was studied in situ at room temperature and after annealing. We find that the reactivity of Ti can be utilized for improved scaling of Ge based devices.

  10. Shelf life of case-ready beef steaks (Semitendinosus muscle) stored in oxygen-depleted master bag system with oxygen scavengers and CO2/N2 modified atmosphere packaging.

    PubMed

    Limbo, S; Uboldi, E; Adobati, A; Iametti, S; Bonomi, F; Mascheroni, E; Santagostino, S; Powers, T H; Franzetti, L; Piergiovanni, L

    2013-03-01

    This study aims to evaluate the stability of beef from Semitendinosus muscle packaged in oxygen permeable wrapped-tray units and stored in a master bag system, with and without oxygen scavengers. Changes in the atmosphere composition, microbiological indexes, myoglobin forms and color parameters were monitored during the storage in master bag, blooming and display life. The presence of scavengers reduced rapidly the oxygen concentration and maintained it at values not detectable instrumentally. Within few days of storage in master bags, the resolution of the transient discoloration was completed and the meat quality was maintained over the anoxic storage. After the removal from master bags meat bloomed completely reaching OxyMb level and Chroma values higher than those on fresh meat at t(0). During 48 h of display life at 4 °C, quality attributes had a decay slower than samples stored traditionally in air. Without scavengers the oxygen caused the irreversible discoloration within 7 days, due to the formation of metmyoglobin on the surface.

  11. Phenylpropanoid Glycoside Analogues: Enzymatic Synthesis, Antioxidant Activity and Theoretical Study of Their Free Radical Scavenger Mechanism

    PubMed Central

    López-Munguía, Agustín; Hernández-Romero, Yanet; Pedraza-Chaverri, José; Miranda-Molina, Alfonso; Regla, Ignacio; Martínez, Ana; Castillo, Edmundo

    2011-01-01

    Phenylpropanoid glycosides (PPGs) are natural compounds present in several medicinal plants that have high antioxidant power and diverse biological activities. Because of their low content in plants (less than 5% w/w), several chemical synthetic routes to produce PPGs have been developed, but their synthesis is a time consuming process and the achieved yields are often low. In this study, an alternative and efficient two-step biosynthetic route to obtain natural PPG analogues is reported for the first time. Two galactosides were initially synthesized from vanillyl alcohol and homovanillyl alcohol by a transgalactosylation reaction catalyzed by Kluyveromyces lactis β-galactosidase in saturated lactose solutions with a 30%–35% yield. To synthesize PPGs, the galactoconjugates were esterified with saturated and unsaturated hydroxycinnamic acid derivatives using Candida antarctica Lipase B (CaL-B) as a biocatalyst with 40%–60% yields. The scavenging ability of the phenolic raw materials, intermediates and PPGs was evaluated by the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) method. It was found that the biosynthesized PPGs had higher scavenging abilities when compared to ascorbic acid, the reference compound, while their antioxidant activities were found similar to that of natural PPGs. Moreover, density functional theory (DFT) calculations were used to determine that the PPGs antioxidant mechanism proceeds through a sequential proton loss single electron transfer (SPLET). The enzymatic process reported in this study is an efficient and versatile route to obtain PPGs from different phenylpropanoid acids, sugars and phenolic alcohols. PMID:21674039

  12. Volatile components of selected liverworts, and cytotoxic, radical scavenging and antimicrobial activities of their crude extracts.

    PubMed

    Komala, Ismiarni; Ito, Takuya; Yagi, Yasuyuki; Nagashima, Fumihiro; Asakawa, Yoshinori

    2010-09-01

    Crude extracts of the Tahitian liverworts Mastigophora diclados and Frullania sp., the Indonesian Frullania sp., Dumortiera hirsuta and Marchantia sp., and the Japanese Porella perrottetiana were investigated chemically by using gas chromatography-mass spectrometry (GC-MS). All extracts contained various volatile sesqui- and diterpenoids and a few aromatic compounds. The Tahitian M. diclados and Frullania sp., and the Indonesian Frullania sp. exhibited cytotoxic activity against HL-60 and KB cell lines. The extracts of the Tahitian M. diclados and the Indonesian Marchantia sp. showed radical scavenging activity, whereas the crude extracts of the Tahitian M. diclados and Frullania sp., and the Indonesian Frullania and Marchantia sp. showed antimicrobial activity against Staphylococcus aureus and Bacillus subtilis.

  13. Determination of antioxidant and radical scavenging activity of Basil (Ocimum basilicum L. Family Lamiaceae) assayed by different methodologies.

    PubMed

    Gülçin, Ilhami; Elmastaş, Mahfuz; Aboul-Enein, Hassan Y

    2007-04-01

    The antioxidant properties of plants have been investigated, in the light of recent scientific developments, throughout the world due to their potent pharmacological activities and food viability. Basil (Ocimum basilicum L. Family Lamiaceae) is used as a kitchen herb and as an ornamental plant in house gardens. In the present study, the possible radical scavenging and antioxidant activity of the water (WEB) and ethanol extracts (EEB) of basil was investigated using different antioxidant methodologies: 1,1-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging, scavenging of superoxide anion radical-generated non-enzymatic system, ferric thiocyanate method, reducing power, hydrogen peroxide scavenging and metal chelating activities. Experiments revealed that WEB and EEB have an antioxidant effects which are concentration-dependent. The total antioxidant activity was performed according to the ferric thiocyanate method. At the 50 microg/mL concentration, the inhibition effects of WEB and EEB on peroxidation of linoleic acid emulsion were found to be 94.8% and 97.5%, respectively. On the other hand, the percentage inhibition of a 50 microg/mL concentration of BHA, BHT and alpha-tocopherol was found to be 97.1%, 98.5% and 70.4% inhibition of peroxidation of linoleic acid emulsion, respectively. In addition, WEB and EEB had effective DPPH radical scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, reducing power and metal chelating activities. Additionally, these various antioxidant activities were compared with BHA, BHT and alpha-tocopherol as reference antioxidants. The additional total phenolic content of these basil extracts was determined as the gallic acid equivalent and were found to be equivalent.

  14. Free radical scavenging, antidiarrheal and anthelmintic activity of Pistia stratiotes L. extracts and its phytochemical analysis.

    PubMed

    Bin Karim, Mohammed Faisal; Imam, Hasan; Sarker, Md Moklesur-Rahman; Uddin, Nizam; Hasan, Nahid; Paul, Nirmala; Haque, Tahmina

    2015-05-01

    In this phyto-pharmacological screening of Pistia stratiotes L leaf and root extracts each separately in two different solvents demonstrated its potential medicinal value. Apparent antioxidant value is demonstrated by DPPH, Nitric oxide scavenging and Ferric ion reducing method. Additionally, total flavonoid and phenolic compounds were measured. The leaf methanolic extract scavenged both nitric oxide (NO) and DPPH radical with a dose dependent manner. But the pet ether fraction of root was found to have highest efficacy in Fe(3±) reducing power assay. Flavonoid was found to contain highest in the pet ether fraction of root (411.35mg/g) in terms of quercetin equivalent, similarly highest amount (34.96mg/g) of total phenolic compounds (assayed as gallic acid equivalents) were found to contain in the same fraction. The methanolic fractions appeared less cytotoxic compared to pet ether extracts. The plant extracts caused a dose dependent decrease in faecal droppings in both castor oil and magnesium sulphate induced diarrhea, where as leaf extracts in each solvent appeared most effective. Also, the plant extracts showed anthelmintic activity in earthworm by inducing paralysis and death in a dose dependent manner. At highest doses (50 mg/ml) all fractions were almost effective as the positive control piperazine citrate (10 mg/ml). Thus, besides this cytotoxic effect it's traditional claim for therapeutic use can never be overlooked. PMID:26004725

  15. Radical scavenging activity of selected medicinal plants from Limpopo province of South Africa.

    PubMed

    Chauke, A M; Shai, L J; Mphahlele, P M; Mogale, M A

    2012-01-01

    Plants collected from Limpopo province of South Africa were investigated for their antioxidative potential using the DPPH radical scavenging assay. Acetone extracts of Flueggea virosa had the highest antioxidant activity with an IC₅₀ value of 30 µg/ml, closely matching the ascorbic acid with an IC₅₀ value of 25 µg/ml. The lowest antioxidant readings were observed with extracts of Rhynchosia venulosa (root extract) and Ficus ingens (leaf extract). Acetone extract of Bridelia virosa leaves had the highest phenolic content (156 mg GAE/g extract), while the lowest content was recorded for R. venulosa root extract and leaf extract of F. ingens (8.3 and 17.7 mg GAE/g extract, respectively). There was a linear correlation between antioxidant activity and total phenolic content. Extracts with high phenolic content had low IC₅₀ values, while extracts with low phenolic concentrations had high IC₅₀ values.

  16. Effect of pH and metal ions on DPPH radical scavenging activity of tea.

    PubMed

    Pękal, Anna; Pyrzynska, Krystyna

    2015-02-01

    The 2,2'-diphenyl-1-picrylhydrazyl (DPPH) assay is commonly applied for the estimation of antioxidant activity of plant extracts. This article discusses the effect of a sample pH and the presence of metal ions on the results obtained using DPPH method for several tea infusions. Higher radical quenching was observed in less acidic media. The impact of metal ions depends of the types of metal ion and its concentration. Quercetin and epigallocatechin gallate were less efficient in the reaction with DPPH in the presence of Al(III). Desalting process using cation-exchange resin Dowex 50Wx8 decreased the content of metal ions in all studied tea infusions. The DPPH scavenging activity of the effluents after this process were higher than those of the primary extracts and this may be related to the actual antioxidant capacity of these samples.

  17. Relationship between the lipophilicity of gallic acid n-alquil esters' derivatives and both myeloperoxidase activity and HOCl scavenging.

    PubMed

    Rosso, Rober; Vieira, Tiago O; Leal, Paulo C; Nunes, Ricardo J; Yunes, Rosendo A; Creczynski-Pasa, Tânia B

    2006-09-15

    The gallic acid and several n-alkyl gallates, with the same number of hydroxyl substituents, varying only in the side carbonic chain length, with respective lipophilicity defined through the C log P, were studied. It evidenced the structure-activity relationship of the myeloperoxidase activity inhibition and the hypochlorous acid scavenger property, as well as its low toxicity in rat hepatic tissue. The gallates with C log P below 3.0 (compounds 2-7) were more active against the enzyme activity, what means that the addition of 1-6 carbons (C log P between 0.92 and 2.92) at the side chain increased approximately 50% the gallic acid effect. However, a relationship between the HOCl scavenging capability and the lipophilicity was not observed. With these results it is possible to suggest that the gallates protect the HOCl targets through two mechanisms: inhibiting its production by the enzyme and scavenging the reactive specie.

  18. Change in chemical constituents and free radical-scavenging activity during Pear (Pyrus pyrifolia) cultivar fruit development.

    PubMed

    Cho, Jeong-Yong; Lee, Sang-Hyun; Kim, Eun Hee; Yun, Hae Rim; Jeong, Hang Yeon; Lee, Yu Geon; Kim, Wol-Soo; Moon, Jae-Hak

    2015-01-01

    Changes in chemical constituent contents and DPPH radical-scavenging activity in fruits of pear (Pyrus pyrifolia) cultivars during the development were investigated. The fruits of seven cultivars (cv. Niitaka, Chuhwangbae, Wonhwang, Hwangkeumbae, Hwasan, Manpungbae, and Imamuraaki) were collected at 15-day intervals after day 20 of florescence. Vitamins (ascorbic acid and α-tocopherol), arbutin, chlorogenic acid, malaxinic acid, total caffeic acid, total flavonoids, and total phenolics were the highest in immature pear fruit on day 20 after florescence among samples at different growth stages. All of these compounds decreased gradually in the fruit during the development. Immature pear fruit on day 35 or 50 after florescence exhibited higher free radical-scavenging activity than that at other times, although activities were slightly different among cultivars. The chemical constituent contents and free radical-scavenging activity were largely different among immature fruits of the pear cultivars, but small differences were observed when they matured.

  19. Effects of hydroxyl radical scavengers KCN and CO on ultraviolet light-induced activation of crude soluble guanylate cyclase

    SciTech Connect

    Karlsson, J.O.; Axelsson, K.L.; Andersson, R.G.

    1985-01-01

    The crude soluble guanylate cyclase (GC) from bovine mesenteric artery was stimulated by ultraviolet (UV) light (366 nm). Addition of free radical scavengers, dimethylsulfoxide or superoxide dismutase and/or catalase to the GC assay did not abolish the stimulatory effect of UV light. On the contrary, the UV light-induced activation was enhanced in the presence of these scavengers. KCN (1 mM) did not affect the UV light-induced activation, while 0.1 mM of CO potentiated the activation. These results may indicate that UV light is operating through a direct interaction with the ferrous form of the GC-heme.

  20. Comparative antihemolytic and radical scavenging activities of strawberry tree (Arbutus unedo L.) leaf and fruit.

    PubMed

    Mendes, Lídia; de Freitas, Victor; Baptista, Paula; Carvalho, Márcia

    2011-09-01

    The present study reports the antioxidant properties of Arbutus unedo L. leaf and fruit extracts using different in vitro assays including (i) reducing power, (ii) scavenging effect on DPPH free radicals, and (iii) inhibitory effect on AAPH-induced hemolysis and lipid peroxidation in human erythrocytes. All assays demonstrated antioxidant efficiency for A. unedo L. aqueous extracts, being consistently higher in the leaf. EC(50) values for reducing power and DPPH radical scavenging activities were, respectively, 0.318 ± 0.007 and 0.087 ± 0.007 mg/mL for leaf, and 2.894 ± 0.049 and 0.790 ± 0.016 mg/mL for fruit extracts. Under the oxidative action of AAPH, A. unedo leaf and fruit extracts protected the erythrocyte membrane from hemolysis (IC(50) of 0.062 ± 0.002 and 0.430 ± 0.091 mg/mL, respectively) and decreased the levels of malondialdehyde, a breakdown product of lipid peroxidation (IC(50) of 0.075 ± 0.014 and 0.732 ± 0.452 mg/mL, respectively). In accordance with antioxidant activity, phenolic content was found to be significantly higher in leaf extract. To our knowledge, this is the first time that the antioxidant activity of A. unedo species is evaluated using human biological membranes. Overall, our results suggest that A. unedo leaves are a promising source of natural antioxidants with potential application in diseases mediated by free radicals. PMID:21703325

  1. Sulphur antioxidants inhibit oxidative stress induced retinal ganglion cell death by scavenging reactive oxygen species but influence nuclear factor (erythroid-derived 2)-like 2 signalling pathway differently.

    PubMed

    Majid, Aman Shah Abdul; Yin, Zheng Qin; Ji, Dan

    2013-01-01

    This study aimed to show if two different sulphur containing drugs sulbutiamine and acetylcysteine (NAC) could attenuate the effects of two different insults being serum deprivation and glutamate/buthionine sulfoximine (GB)-induced death to transformed retinal ganglion cell line (RGC-5) in culture. Cells were exposed to either 5 mM of GB for 24 h or serum deprivation for 48 h with inclusion of either NAC or sulbutiamine. Cell viability, microscopic evidence for apoptosis, caspase 3 activity, reactive oxygen species (ROS), glutathione (GSH), catalase and gluthathione-S-transferase (GST) were determined. The effects of NAC and sulbutiamine on the oxidative stress related transcription factor nuclear factor (erythroid-derived 2)-like 2 (Nrf-2) levels and its dependent phase II enzyme haemeoxygenase-1 (HO-1) were carried out using Western blot and quantitative-polymerase chain reaction (PCR). NAC and sulbutiamine dose-dependently attenuated serum deprivation-induced cell death. However NAC but not sulbutiamine attenuated GB-induced cell death. NAC and sulbutiamine both independently stimulated the GSH and GST production but scavenged different types of ROS with different efficacy. Moreover only sulbutiamine stimulated catalase and significantly increased Nrf-2 and HO-1 levels. In addition, the pan caspase inhibitor, benzoylcarbonyl-Val-Ala-Asp-fluoromethyl ketone (z-VAD-fmk) attenuated the negative effect of serum deprivation while the necroptosis inhibitor (necrostatin-1) counteracted solely an insult of GB. The neuroprotective actions of NAC and sulbutiamine in GB or serum-deprivation insult are therefore different. PMID:23811559

  2. Structural characterization and DPPH· radical scavenging activity of a polysaccharide from Guara fruits.

    PubMed

    Hua, Dehong; Zhang, Dezhi; Huang, Bing; Yi, Pan; Yan, Chunyan

    2014-03-15

    The crude polysaccharides were extracted from fruits of Psidium guajava Linn. by hot water. After removal of proteins, isolation and purification by DEAE-52 Cellulose chromatography and Sephadex G-75 gel filtration, a polysaccharide (GP70-2) was obtained and structurally characterized. GP70-2 has a relative molecular weight of 74 kDa and was composed of D-galactose and L-arabinose in the ratio of 1:1, with a specific optical rotation of [a]D(25) = +101°. Structural characterization of this novel polysaccharide was carried out using infrared spectroscopy, methylation analyses, and NMR studies ((1)H, (13)C, (1)H-(1)H-COSY, HMQC, and HMBC). Based on the above data, the following structure was assigned to the repeated core unit of GP70-2: [Formula: see text]. This polysaccharide showed a concentration dependent DPPH· radical scavenging activity.

  3. Determination of DPPH free radical scavenging activity: application of artificial neural networks.

    PubMed

    Musa, Khalid Hamid; Abdullah, Aminah; Al-Haiqi, Ahmed

    2016-03-01

    A new computational approach for the determination of 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity (DPPH-RSA) in food is reported, based on the concept of machine learning. Trolox standard was mix with DPPH at different concentrations to produce different colors from purple to yellow. Artificial neural network (ANN) was trained on a typical set of images of the DPPH radical reacting with different levels of Trolox. This allowed the neural network to classify future images of any sample into the correct class of RSA level. The ANN was then able to determine the DPPH-RSA of cinnamon, clove, mung bean, red bean, red rice, brown rice, black rice and tea extract and the results were compared with data obtained using a spectrophotometer. The application of ANN correlated well to the spectrophotometric classical procedure and thus do not require the use of spectrophotometer, and it could be used to obtain semi-quantitative results of DPPH-RSA.

  4. Different hydroxyl radical scavenging activity of water-soluble beta-alanine C60 adducts.

    PubMed

    Sun, Tao; Jia, Zhishen; Xu, Zhude

    2004-04-01

    Three C(60) derivatives [C(60) (NHCH(2)CH(2)COONa)(n)(H)(n)], n=1, 5, 9] (A, B, C) with different additional number of beta-alanine were synthesized by the control of relative amount of C(60) and beta-alanine added. Hydroxyl radical scavenging activity of the adducts was evaluated in a copper-catalyzed Haber-Weiss reaction by chemiluminescence technology. The 50% inhibition concentrations (IC(50)'s) of A, B, and C were 147.2 micromol/L, 76.3 micromol/L, and 96.2 micromol/L, respectively. The difference should be closely related to the numbers of residual C=C bonds in C(60), steric effect and electron-withstanding effect of amino group especially.

  5. PM6 and DFT study of free radical scavenging activity of morin.

    PubMed

    Marković, Zoran; Milenković, Dejan; Đorović, Jelena; Dimitrić Marković, Jasmina M; Stepanić, Višnja; Lučić, Bono; Amić, Dragan

    2012-10-15

    Flavonoids have long been recognised for their general health-promoting properties, of which their antioxidant activity may play an important role. In this work, we have studied the properties of flavonoid morin using semiempirical and density functional theory (DFT) methods in order to validate the application of the recently developed parametric method 6 (PM6). Reaction enthalpies related to mechanisms of free radical scavenging by flavonoid morin were calculated by DFT and PM6 methods in gas-phase, water, DMSO and benzene. It has been shown that fast semiempirical PM6 method can mimic results obtained by means of more accurate time consuming DFT calculations. Thermodynamically favoured mechanism depends on reaction medium: SPLET (sequential proton loss electron transfer) is preferred in water and DMSO, and HAT (hydrogen atom transfer) is predominant in gas-phase. In benzene these two mechanisms are competitive.

  6. Possibility of cellulose-based electro-active paper energy scavenging transducer.

    PubMed

    Abas, Zafar; Kim, Heung Soo; Zhai, Lindong; Kim, Jaehwan; Kim, Joo Hyung

    2014-10-01

    In this paper, a cellulose-based Electro-Active Paper (EAPap) energy scavenging transducer is presented. Cellulose is proven as a smart material, and exhibits piezoelectric effect. Specimens were prepared by coating gold electrodes on both sides of cellulose film. The fabricated specimens were tested by a base excited aluminum cantilever beam at resonant frequency. Different tests were performed with single and multiple parallel connected electrodes coated on the cellulose film. A maximum of 131 mV output voltage was measured, when three electrodes were connected in parallel. It was observed that voltage output increases significantly with the area of electrodes. From these results, it can be concluded that the piezoelectricity of cellulose-based EAPap can be used in energy transduction application.

  7. An efficient method for high-purity anthocyanin isomers isolation from wild blueberries and their radical scavenging activity.

    PubMed

    Chorfa, Nasima; Savard, Sylvain; Belkacemi, Khaled

    2016-04-15

    An efficient process for the purification of anthocyanin monomeric isomers from wild blueberries of Lake Saint-Jean region (Quebec, Canada) was developed and easy scalable at industrial purpose. The blueberries were soaked in acidified ethanol, filtered, and the filtrate was cleaned by solid phase extraction using silica gel C-18 and DSC-SCX cation-exchange resin. Anthocyanin-enriched elutes (87 wt.%) were successfully fractionated by preparative liquid chromatography. The major anthocyanins mono-galactoside, -glucoside and -arabinoside isomers of delphinidin, cyanidin, petunidin, peonidin and malvidin were isolated with a purity up to 100% according to their LC-MS and (1)H NMR spectra. The oxygen radical absorbance capacity (ORAC) of the obtained pure anthocyanins was evaluated. Delphinidin-3-galactoside has the highest capacity (13.062 ± 2.729 μmol TE/μmol), and malvidin-3-glucoside the lowest (0.851 ± 0.032 μmol TE/μmol). A mechanistic pathway preview is suggested for the anthocyanins scavenging free radical activity by hydrogen transfer. PMID:26675861

  8. Superoxide Anion Radical Scavenging Activities of Herbs and Pastures in Northern Japan Determined Using Electron Spin Resonance Spectrometry

    PubMed Central

    Al-Mamun, Mohammad; Yamaki, Koji; Masumizu, Toshiki; Nakai, Yumi; Saito, Katsumi; Sano, Hiroaki; Tamura, Yoshifumi

    2007-01-01

    Free radicals are not only destructive to the living cells but also reduce the quality of animal products through oxidation. As a result the superoxide anion radical (O2・-), one of the most destructive reactive oxygen species, is a matter of concern for the animal scientists as well as feed manufacturers to ensure the quality of product to reach consumers demand. The superoxide anion radical scavenging activities (SOSA) of water and MeOH extracts of 2 herbs and 9 pasture samples collected from lowland and highland swards were determined against a 5,5-dimethyl-1-pyroline-N-oxide-O2・-spin adduct based on a hypoxanthine-xanthine oxidase reaction using electron spin resonance spectrometry. Both the water and MeOH extracted SOSA differed among the herbs and pastures. Species and altitudinal variations were observed between extraction methods. The herbs were higher in both water and MeOH extracted SOSA than the pastures except for water extracts of one pasture, white clover (Trifolium repens L.). Among the pastures, quackgrass (Agrophyron repens L.) showed higher SOSA in both the MeOH and water extracts, and timothy (Phleum pretense L.) showed higher MeOH extracted SOSA. It is apparent that the kind and amount of antioxidants differ among herbs and pastures. Animal health and quality of animal products could be improved by adequate selection and combining of herbs and pastures having higher SOSA. PMID:17713599

  9. An efficient method for high-purity anthocyanin isomers isolation from wild blueberries and their radical scavenging activity.

    PubMed

    Chorfa, Nasima; Savard, Sylvain; Belkacemi, Khaled

    2016-04-15

    An efficient process for the purification of anthocyanin monomeric isomers from wild blueberries of Lake Saint-Jean region (Quebec, Canada) was developed and easy scalable at industrial purpose. The blueberries were soaked in acidified ethanol, filtered, and the filtrate was cleaned by solid phase extraction using silica gel C-18 and DSC-SCX cation-exchange resin. Anthocyanin-enriched elutes (87 wt.%) were successfully fractionated by preparative liquid chromatography. The major anthocyanins mono-galactoside, -glucoside and -arabinoside isomers of delphinidin, cyanidin, petunidin, peonidin and malvidin were isolated with a purity up to 100% according to their LC-MS and (1)H NMR spectra. The oxygen radical absorbance capacity (ORAC) of the obtained pure anthocyanins was evaluated. Delphinidin-3-galactoside has the highest capacity (13.062 ± 2.729 μmol TE/μmol), and malvidin-3-glucoside the lowest (0.851 ± 0.032 μmol TE/μmol). A mechanistic pathway preview is suggested for the anthocyanins scavenging free radical activity by hydrogen transfer.

  10. Fingerprints, Pharmaceutical and Radical Scavenging Activity Evaluation of an Alzheimer-Targeted Herbal Preparation

    PubMed Central

    Dabaghian, Farid; Khademian, Sedigheh; Azadi, Amir; Zarshenas, Mohammad

    2016-01-01

    Background: As the most common form of dementia, Alzheimer disease is characterized by progressive loss of memory and deterioration of cognitive functions. It is predicted that about 75.63 million people would suffer from dementia by 2030. Apart from conventional remedies, the application of herbal medicines is on the rise. There are numerous natural medicaments reported in the traditional manuscript of Persian medicine. Accordingly, in the present study, the intended remedy was selected and an appropriate pharmacognostical and pharmaceutical evaluations were performed. Methods: By searching through the traditional pharmaceutical manuscripts such as Qarabadeen-e-Salehi, Qarabadeen-e-Azam, Qarabadeen-e-Ghaderi and Canon of Medicine, a simple but proven compound remedy (frankincense and black pepper) was selected. A floating tablet was designed and formulated from those herbal components. Related pharmaceutical assessments such as weight variation, hardness, friability, and disintegration tests as well as pharmacognostical evaluations such as microscopic characterization, TLC, GC/MS, FT/IR fingerprints, and radical scavenging activity assessment (DPPH) were performed. Results: The resulting formulation, as a floating tablet, included 60% of frankincense gum and 15% of black pepper along with appropriate pharmaceutical ingredients (weight variation: 0.219±0.004 g, hardness: 6.50±0.67, friability: 0.45%, disintegration time >30 min). Microscopic characterization demonstrated stone cells, calcium oxalate crystals, sclereids of endocarp and pitted cells of mesocarp of pepper fruits as well as oil drops of frankincense gum. TLC fingerprinting showed classes of secondary metabolites related to both components. GC/MS analysis revealed Acetyl acetate and trans-Caryophyllene as the main constituent. Moderate radical scavenging activity (IC50 >100 µg/ml) was calculated for the methanol extract of tablets. Conclusion: Carrying out and validating a GC method for

  11. Analysis of phenolic compounds and radical scavenging activity of Echinacea spp.

    PubMed

    Pellati, Federica; Benvenuti, Stefania; Magro, Lara; Melegari, Michele; Soragni, Fabrizia

    2004-04-16

    The aim of this study was to set up and validate an RP-LC method with DAD-detection to quantify caffeic acid derivatives in various Echinacea spp. Samples were extracted with 80% methanol. The analyses were carried out on a Lichrospher RP-18 column (125 mm x 4 mm i.d., 5 microm), with a mobile phase gradient, which increases the acetonitrile level in a phosphoric acid solution (0.1%). The flow rate was 1.5 ml/min. Detection was set at 330 nm. This method allowed the identification and quantification of caftaric acid, chlorogenic acid, caffeic acid, cynarin, echinacoside and cichoric acid in Echinacea roots and derivatives. The total phenolic content was 10.49 mg/g for E. angustifolia, 17.83 mg/g for E. pallida and 23.23 mg/g for E. purpurea. Among Echinacea commercial herbal medicines, a certain variability in the concentrations of phenolic compounds was observed. The radical scavenging activity of Echinacea methanolic extracts was evaluated in vitro with a spectrophotometric method based on the reduction of an alcoholic 2,2-diphenyl-1-picrylhydrazyl (DPPH*) radical solution at 517 nm in the presence of a hydrogen donating antioxidant. As for pure compounds, echinacoside had the highest capacity to quench DPPH* radicals (EC50 = 6.6 microM), while caftaric acid had the lowest (EC50 = 20.5 microM). The average EC50 values for E. purpurea, E. pallida and E. angustifolia were 134, 167 and 231 microg/ml, respectively. The radical scavenging activity of Echinacea root extracts reflected their phenolic composition. The results indicate that Echinacea roots and derivatives are a good source of natural antioxidants and could be used to prevent free-radical-induced deleterious effects.

  12. Blue-green algae (Arthrospira platensis) as an ingredient in pasta: free radical scavenging activity, sensory and cooking characteristics evaluation.

    PubMed

    Zouari, Nacim; Abid, Mouna; Fakhfakh, Nahed; Ayadi, M A; Zorgui, Lazhar; Ayadi, Moez; Attia, Hamadi

    2011-12-01

    The effects of semolina enrichment with blue-green algae (Arthrospira platensis) at three different levels (1, 2 and 3 g/100 g of semolina) on the colour, cooking properties, firmness, free radical scavenging activity and sensory characteristics of pasta are reported. Microalgae addition resulted in higher swelling index and lower cooking loss than the control sample. A significant increase in pasta firmness was evidenced with an increase of added microalgae due to structural reinforcement. In addition to colouring, the use of A. platensis (2 g/100 g of semolina) can enhance the sensory quality and nutraceutical potential as evaluated by free radical scavenging activity of pasta. PMID:21568819

  13. 1,1-Diphenyl-2-picrylhydrazyl radical and superoxide anion scavenging activity of Rhizophora mangle (L.) bark

    PubMed Central

    Sánchez, Janet Calero; García, Roberto Faure; Cors, Ma. Teresa Mitjavila

    2010-01-01

    Background: Rhizophora mangle (L.) produce a variety of substances that possesses pharmacological actions. Although it shown antioxidant properties in some assays, there is no available information about its effect on some free radical species. So the objective of the present research is to evaluate the DPPH radical and superoxide anion scavenging properties of R. mangle extract and its polyphenol fraction. Methods: Rhizophora mangle (L.) bark aqueous extract and its major constituent, polyphenols fraction, were investigated for their antioxidant activities employing 2 in vitro assay systems: 1,1-diphenyl-2-picrylhydrazyl (DPPH) and superoxide anion radicals scavenging. Results: IC50 for DPPH radical-scavenging activity was 6.7 µg tannins/mL for extract and 7.6 µg tannins/mL for polyphenolic fraction. The extract showed better activity than its fraction (P < 0.05) in the DPPH radicals reducing power. Polyphenolic fraction exhibited better superoxide anion scavenging ability (IC50 = 21.6 µg tannins/mL) than the extract (IC50 = 31.9 µg tannins/mL). Antioxidant activities of both samples increased with the rise of tannins concentration. The comparison of regression lines showed significant differences (P < 0.05) between extract and its polyphenolic fraction in both assays, indicating that extract was more effective in DPPH radical scavenging than its fraction at tannin concentrations below the crossing point of both lines, while that fraction was more effective than extract inhibiting the superoxide anions generation. Conclusions: R. mangle aqueous extract showed a potent antioxidant activity, achieved by the scavenging ability observed against DPPH radicals and superoxide anions. Regarding its polyphenolic composition, the antioxidant effects observed in this study are due, most probably, to the presence of polyphenolic compounds. PMID:21589751

  14. Novel hydroxyl radical scavenging antioxidant activity assay for water-soluble antioxidants using a modified CUPRAC method.

    PubMed

    Bektaşoğlu, Burcu; Esin Celik, Saliha; Ozyürek, Mustafa; Güçlü, Kubilay; Apak, Reşat

    2006-07-01

    Reactive oxygen species (ROS) such as superoxide anion, hydroxyl ((*)OH), peroxyl, and alkoxyl radicals may attack biological macromolecules giving rise to oxidative stress-originated diseases. Since (*)OH is very short-lived, secondary products resulting from (*)OH attack to various probes are measured. Although the measurement of aromatic hydroxylation with HPLC/electrochemical detection is more specific than the low-yield TBARS test, it requires sophisticated instrumentation. As a more convenient and less costly alternative, we used p-aminobenzoate, 2,4- and 3,5-dimethoxybenzoate probes for detecting hydroxyl radicals generated from an equivalent mixture of Fe(II)+EDTA with hydrogen peroxide. The produced hydroxyl radicals attacked both the probe and the water-soluble antioxidants in 37 degrees C-incubated solutions for 2h. The CUPRAC (i.e., our original method for total antioxidant capacity assay) absorbance of the ethylacetate extract due to the reduction of Cu(II)-neocuproine reagent by the hydroxylated probe decreased in the presence of (*)OH scavengers, the difference being proportional to the scavenging ability of the tested compound. A rate constant for the reaction of the scavenger with hydroxyl radical can be deduced from the inhibition of color formation. The second-order rate constants of the scavengers were determined with competition kinetics by means of a linear plot of A(0)/A as a function of C(scavenger)/C(probe), where A(0) and A are the CUPRAC absorbances of the system in the absence and presence of scavenger, respectively, and C is the molar concentration of relevant species. The 2,4- and 3,5-dimethoxybenzoates were the best probes in terms of linearity and sensitivity. Iodide, metabisulfite, hexacyanoferrate(II), thiourea, formate, and dimethyl sulfoxide were shown by the modified CUPRAC assay to be more effective scavengers than mannitol, glucose, lysine, and simple alcohols, as in the TBARS assay. The developed method is less lengthy, more

  15. A physicochemical examination of the free radical scavenging activity of Trolox: mechanism, kinetics and influence of the environment.

    PubMed

    Alberto, Marta E; Russo, Nino; Grand, Andre; Galano, Annia

    2013-04-01

    The free radical scavenging activity of Trolox was studied for aqueous and lipid environments using the Density Functional Theory. Several reaction mechanisms and free radicals of different chemical nature have been included in this study, as well as the influence of the pH. Trolox was found to be a powerful ˙OH and alkoxy scavenger, regardless of the conditions under which the reaction takes place. It was also found to be very efficient as a peroxy radical scavenger in aqueous solution, while its protective effects against this particular kind of free radicals are significantly reduced in lipid solution. Four reaction mechanisms were found to significantly contribute to the ˙OH scavenging activity of Trolox in aqueous solution: hydrogen transfer (HT), radical adduct formation (RAF), single electron transfer (SET), and sequential proton loss electron transfer (SPLET), while in lipid media two of them are relevant: HT and RAF. The ˙OCH3, ˙OOH, and ˙OOCHCH2 scavenging processes are predicted to take place almost exclusively by HT from the phenolic OH group in lipid media, and in aqueous solution at pH < 11, while at higher pH values the SPLET mechanism is proposed as the main one. This is also the case for other non-halogenated alkyl or alkenyl peroxy (and alkoxy) radicals. The agreement with the available experimental data supports the reliability of the presented calculations.

  16. Free Radical Scavenging and Cellular Antioxidant Properties of Astaxanthin.

    PubMed

    Dose, Janina; Matsugo, Seiichi; Yokokawa, Haruka; Koshida, Yutaro; Okazaki, Shigetoshi; Seidel, Ulrike; Eggersdorfer, Manfred; Rimbach, Gerald; Esatbeyoglu, Tuba

    2016-01-01

    Astaxanthin is a coloring agent which is used as a feed additive in aquaculture nutrition. Recently, potential health benefits of astaxanthin have been discussed which may be partly related to its free radical scavenging and antioxidant properties. Our electron spin resonance (ESR) and spin trapping data suggest that synthetic astaxanthin is a potent free radical scavenger in terms of diphenylpicryl-hydrazyl (DPPH) and galvinoxyl free radicals. Furthermore, astaxanthin dose-dependently quenched singlet oxygen as determined by photon counting. In addition to free radical scavenging and singlet oxygen quenching properties, astaxanthin induced the antioxidant enzyme paroxoanase-1, enhanced glutathione concentrations and prevented lipid peroxidation in cultured hepatocytes. Present results suggest that, beyond its coloring properties, synthetic astaxanthin exhibits free radical scavenging, singlet oxygen quenching, and antioxidant activities which could probably positively affect animal and human health. PMID:26784174

  17. Free Radical Scavenging and Cellular Antioxidant Properties of Astaxanthin

    PubMed Central

    Dose, Janina; Matsugo, Seiichi; Yokokawa, Haruka; Koshida, Yutaro; Okazaki, Shigetoshi; Seidel, Ulrike; Eggersdorfer, Manfred; Rimbach, Gerald; Esatbeyoglu, Tuba

    2016-01-01

    Astaxanthin is a coloring agent which is used as a feed additive in aquaculture nutrition. Recently, potential health benefits of astaxanthin have been discussed which may be partly related to its free radical scavenging and antioxidant properties. Our electron spin resonance (ESR) and spin trapping data suggest that synthetic astaxanthin is a potent free radical scavenger in terms of diphenylpicryl-hydrazyl (DPPH) and galvinoxyl free radicals. Furthermore, astaxanthin dose-dependently quenched singlet oxygen as determined by photon counting. In addition to free radical scavenging and singlet oxygen quenching properties, astaxanthin induced the antioxidant enzyme paroxoanase-1, enhanced glutathione concentrations and prevented lipid peroxidation in cultured hepatocytes. Present results suggest that, beyond its coloring properties, synthetic astaxanthin exhibits free radical scavenging, singlet oxygen quenching, and antioxidant activities which could probably positively affect animal and human health. PMID:26784174

  18. In Vitro Antimicrobial Bioassays, DPPH Radical Scavenging Activity, and FTIR Spectroscopy Analysis of Heliotropium bacciferum

    PubMed Central

    2016-01-01

    The present study deals with the antimicrobial, antioxidant, and functional group analysis of Heliotropium bacciferum extracts. Disc diffusion susceptibility method was followed for antimicrobial assessment. Noteworthy antimicrobial activities were recorded by various plant extracts against antibiotic resistant microorganisms. Plant flower extracts antioxidant activity was investigated against 2, 2-diphenyl-1-picryl hydrazyl radical by ultraviolet spectrophotometer (517 nm). Plant extracts displayed noteworthy radical scavenging activities at all concentrations (25–225 μg/mL). Notable activities were recorded by crude, chloroform and ethyl acetate extracts up to 88.27% at 225 μg/mL concentration. Compounds functional groups were examined by Fourier transform infrared spectroscopic studies. Alkanes, alkenes, alkyl halides, amines, carboxylic acids, amides, esters, alcohols, phenols, nitrocompounds, and aromatic compounds were identified by FTIR analysis. Thin layer chromatography bioautography was carried out for all plant extracts. Different bands were separated by various solvent systems. The results of the current study justify the use of Heliotropium bacciferum in traditional remedial herbal medicines.

  19. In Vitro Antimicrobial Bioassays, DPPH Radical Scavenging Activity, and FTIR Spectroscopy Analysis of Heliotropium bacciferum

    PubMed Central

    2016-01-01

    The present study deals with the antimicrobial, antioxidant, and functional group analysis of Heliotropium bacciferum extracts. Disc diffusion susceptibility method was followed for antimicrobial assessment. Noteworthy antimicrobial activities were recorded by various plant extracts against antibiotic resistant microorganisms. Plant flower extracts antioxidant activity was investigated against 2, 2-diphenyl-1-picryl hydrazyl radical by ultraviolet spectrophotometer (517 nm). Plant extracts displayed noteworthy radical scavenging activities at all concentrations (25–225 μg/mL). Notable activities were recorded by crude, chloroform and ethyl acetate extracts up to 88.27% at 225 μg/mL concentration. Compounds functional groups were examined by Fourier transform infrared spectroscopic studies. Alkanes, alkenes, alkyl halides, amines, carboxylic acids, amides, esters, alcohols, phenols, nitrocompounds, and aromatic compounds were identified by FTIR analysis. Thin layer chromatography bioautography was carried out for all plant extracts. Different bands were separated by various solvent systems. The results of the current study justify the use of Heliotropium bacciferum in traditional remedial herbal medicines. PMID:27597961

  20. Scavenging iron: a novel mechanism of plant immunity activation by microbial siderophores.

    PubMed

    Aznar, Aude; Chen, Nicolas W G; Rigault, Martine; Riache, Nassima; Joseph, Delphine; Desmaële, Didier; Mouille, Grégory; Boutet, Stéphanie; Soubigou-Taconnat, Ludivine; Renou, Jean-Pierre; Thomine, Sébastien; Expert, Dominique; Dellagi, Alia

    2014-04-01

    Siderophores are specific ferric iron chelators synthesized by virtually all microorganisms in response to iron deficiency. We have previously shown that they promote infection by the phytopathogenic enterobacteria Dickeya dadantii and Erwinia amylovora. Siderophores also have the ability to activate plant immunity. We have used complete Arabidopsis transcriptome microarrays to investigate the global transcriptional modifications in roots and leaves of Arabidopsis (Arabidopsis thaliana) plants after leaf treatment with the siderophore deferrioxamine (DFO). Physiological relevance of these transcriptional modifications was validated experimentally. Immunity and heavy-metal homeostasis were the major processes affected by DFO. These two physiological responses could be activated by a synthetic iron chelator ethylenediamine-di(o-hydroxyphenylacetic) acid, indicating that siderophores eliciting activities rely on their strong iron-chelating capacity. DFO was able to protect Arabidopsis against the pathogenic bacterium Pseudomonas syringae pv tomato DC3000. Siderophore treatment caused local modifications of iron distribution in leaf cells visible by ferrocyanide and diaminobenzidine-H₂O₂ staining. Metal quantifications showed that DFO causes a transient iron and zinc uptake at the root level, which is presumably mediated by the metal transporter iron regulated transporter1 (IRT1). Defense gene expression and callose deposition in response to DFO were compromised in an irt1 mutant. Consistently, plant susceptibility to D. dadantii was increased in the irt1 mutant. Our work shows that iron scavenging is a unique mechanism of immunity activation in plants. It highlights the strong relationship between heavy-metal homeostasis and immunity. PMID:24501001

  1. Scavenging Iron: A Novel Mechanism of Plant Immunity Activation by Microbial Siderophores1[C][W

    PubMed Central

    Aznar, Aude; Chen, Nicolas W.G.; Rigault, Martine; Riache, Nassima; Joseph, Delphine; Desmaële, Didier; Mouille, Grégory; Boutet, Stéphanie; Soubigou-Taconnat, Ludivine; Renou, Jean-Pierre; Thomine, Sébastien; Expert, Dominique; Dellagi, Alia

    2014-01-01

    Siderophores are specific ferric iron chelators synthesized by virtually all microorganisms in response to iron deficiency. We have previously shown that they promote infection by the phytopathogenic enterobacteria Dickeya dadantii and Erwinia amylovora. Siderophores also have the ability to activate plant immunity. We have used complete Arabidopsis transcriptome microarrays to investigate the global transcriptional modifications in roots and leaves of Arabidopsis (Arabidopsis thaliana) plants after leaf treatment with the siderophore deferrioxamine (DFO). Physiological relevance of these transcriptional modifications was validated experimentally. Immunity and heavy-metal homeostasis were the major processes affected by DFO. These two physiological responses could be activated by a synthetic iron chelator ethylenediamine-di(o-hydroxyphenylacetic) acid, indicating that siderophores eliciting activities rely on their strong iron-chelating capacity. DFO was able to protect Arabidopsis against the pathogenic bacterium Pseudomonas syringae pv tomato DC3000. Siderophore treatment caused local modifications of iron distribution in leaf cells visible by ferrocyanide and diaminobenzidine-H2O2 staining. Metal quantifications showed that DFO causes a transient iron and zinc uptake at the root level, which is presumably mediated by the metal transporter iron regulated transporter1 (IRT1). Defense gene expression and callose deposition in response to DFO were compromised in an irt1 mutant. Consistently, plant susceptibility to D. dadantii was increased in the irt1 mutant. Our work shows that iron scavenging is a unique mechanism of immunity activation in plants. It highlights the strong relationship between heavy-metal homeostasis and immunity. PMID:24501001

  2. In Vitro Antimicrobial Bioassays, DPPH Radical Scavenging Activity, and FTIR Spectroscopy Analysis of Heliotropium bacciferum.

    PubMed

    Ahmad, Sohail; AbdEl-Salam, Naser M; Ullah, Riaz

    2016-01-01

    The present study deals with the antimicrobial, antioxidant, and functional group analysis of Heliotropium bacciferum extracts. Disc diffusion susceptibility method was followed for antimicrobial assessment. Noteworthy antimicrobial activities were recorded by various plant extracts against antibiotic resistant microorganisms. Plant flower extracts antioxidant activity was investigated against 2, 2-diphenyl-1-picryl hydrazyl radical by ultraviolet spectrophotometer (517 nm). Plant extracts displayed noteworthy radical scavenging activities at all concentrations (25-225 μg/mL). Notable activities were recorded by crude, chloroform and ethyl acetate extracts up to 88.27% at 225 μg/mL concentration. Compounds functional groups were examined by Fourier transform infrared spectroscopic studies. Alkanes, alkenes, alkyl halides, amines, carboxylic acids, amides, esters, alcohols, phenols, nitrocompounds, and aromatic compounds were identified by FTIR analysis. Thin layer chromatography bioautography was carried out for all plant extracts. Different bands were separated by various solvent systems. The results of the current study justify the use of Heliotropium bacciferum in traditional remedial herbal medicines. PMID:27597961

  3. Adaptive Neuro-Fuzzy Inference System Applied QSAR with Quantum Chemical Descriptors for Predicting Radical Scavenging Activities of Carotenoids.

    PubMed

    Jhin, Changho; Hwang, Keum Taek

    2015-01-01

    One of the physiological characteristics of carotenoids is their radical scavenging activity. In this study, the relationship between radical scavenging activities and quantum chemical descriptors of carotenoids was determined. Adaptive neuro-fuzzy inference system (ANFIS) applied quantitative structure-activity relationship models (QSAR) were also developed for predicting and comparing radical scavenging activities of carotenoids. Semi-empirical PM6 and PM7 quantum chemical calculations were done by MOPAC. Ionisation energies of neutral and monovalent cationic carotenoids and the product of chemical potentials of neutral and monovalent cationic carotenoids were significantly correlated with the radical scavenging activities, and consequently these descriptors were used as independent variables for the QSAR study. The ANFIS applied QSAR models were developed with two triangular-shaped input membership functions made for each of the independent variables and optimised by a backpropagation method. High prediction efficiencies were achieved by the ANFIS applied QSAR. The R-square values of the developed QSAR models with the variables calculated by PM6 and PM7 methods were 0.921 and 0.902, respectively. The results of this study demonstrated reliabilities of the selected quantum chemical descriptors and the significance of QSAR models. PMID:26474167

  4. Adaptive Neuro-Fuzzy Inference System Applied QSAR with Quantum Chemical Descriptors for Predicting Radical Scavenging Activities of Carotenoids

    PubMed Central

    Jhin, Changho; Hwang, Keum Taek

    2015-01-01

    One of the physiological characteristics of carotenoids is their radical scavenging activity. In this study, the relationship between radical scavenging activities and quantum chemical descriptors of carotenoids was determined. Adaptive neuro-fuzzy inference system (ANFIS) applied quantitative structure-activity relationship models (QSAR) were also developed for predicting and comparing radical scavenging activities of carotenoids. Semi-empirical PM6 and PM7 quantum chemical calculations were done by MOPAC. Ionisation energies of neutral and monovalent cationic carotenoids and the product of chemical potentials of neutral and monovalent cationic carotenoids were significantly correlated with the radical scavenging activities, and consequently these descriptors were used as independent variables for the QSAR study. The ANFIS applied QSAR models were developed with two triangular-shaped input membership functions made for each of the independent variables and optimised by a backpropagation method. High prediction efficiencies were achieved by the ANFIS applied QSAR. The R-square values of the developed QSAR models with the variables calculated by PM6 and PM7 methods were 0.921 and 0.902, respectively. The results of this study demonstrated reliabilities of the selected quantum chemical descriptors and the significance of QSAR models. PMID:26474167

  5. Structural characterization, α-glucosidase inhibitory and DPPH scavenging activities of polysaccharides from guava.

    PubMed

    Zhang, Ziling; Kong, Fansheng; Ni, Hui; Mo, Zhixian; Wan, Jian-Bo; Hua, Dehong; Yan, Chunyan

    2016-06-25

    To explore the chemicals responsible for the health benefits of guava, water-soluble polysaccharides were extracted including GP90 and P90. They exhibited excellent α-glucosidase inhibition activity with an EC50 of 2.27μg/mL and 0.18mg/mL. This suggests that their activities were 1379- and 17-fold higher than the positive control. The DPPH scavenging activities of GP90 was even higher than Vc at some concentrations. Upon further isolation, a novel polysaccharide termed GB90-1B was obtained. Monosaccharide analysis, methylation analysis, and NMR were used to analyze the structural characterization of GB90-1B. Structural analysis revealed that its backbone consisted of (1→5)-linked-α-l-arabinose, (1→2,3,5)-linked-α-l-arabinose and (1→3)-linked-α-l-arabinose. Branch linkages included (1→6)-linked-α-d-glucose, (1→)-linked-α-d-glucose and (1→)-linked-α-l-arabinose. The structure of the repeating unit of GP90-1B was predicted. PMID:27083799

  6. Structural characterization, α-glucosidase inhibitory and DPPH scavenging activities of polysaccharides from guava.

    PubMed

    Zhang, Ziling; Kong, Fansheng; Ni, Hui; Mo, Zhixian; Wan, Jian-Bo; Hua, Dehong; Yan, Chunyan

    2016-06-25

    To explore the chemicals responsible for the health benefits of guava, water-soluble polysaccharides were extracted including GP90 and P90. They exhibited excellent α-glucosidase inhibition activity with an EC50 of 2.27μg/mL and 0.18mg/mL. This suggests that their activities were 1379- and 17-fold higher than the positive control. The DPPH scavenging activities of GP90 was even higher than Vc at some concentrations. Upon further isolation, a novel polysaccharide termed GB90-1B was obtained. Monosaccharide analysis, methylation analysis, and NMR were used to analyze the structural characterization of GB90-1B. Structural analysis revealed that its backbone consisted of (1→5)-linked-α-l-arabinose, (1→2,3,5)-linked-α-l-arabinose and (1→3)-linked-α-l-arabinose. Branch linkages included (1→6)-linked-α-d-glucose, (1→)-linked-α-d-glucose and (1→)-linked-α-l-arabinose. The structure of the repeating unit of GP90-1B was predicted.

  7. The relationships between phenolic content, pollen diversity, physicochemical information and radical scavenging activity in honey.

    PubMed

    Giorgi, Annamaria; Madeo, Moira; Baumgartner, Johann; Lozzia, Giuseppe Carlo

    2011-01-01

    Honey is rich in different secondary plant metabolites acting as natural antioxidants and contributing to human health. Radical scavenging activity (RSA) is related to antioxidant activity, while the correlation between the phenolic content and RSA is often weak. Consequently, exclusive information on phenolics is often insufficient to qualify the RSA and the health promoting effects of honey. The paper deals with a case study of honey samples originating from the alpine areas of Italy's Lombardia and Veneto regions and realized by standard physicochemical and statistical analytical methods. In pure honey, the total phenolic content and the RSA were measured in spectrophotometric tests with the 2,2-diphenyl-1-picrylhydrazyl (DPPH·) free radical and Folin-Ciocalteu assays, respectively. Melissopalynological data was used to qualify pollen diversity through rank-frequency curves separating the samples into two groups. On the basis of physicochemical data, the samples were analyzed through multivariate classification and ranking procedures resulting in the identification of an outlier. Elimination of the outlier produced a high correlation between the total phenolic content and RSA in the two pollen diversity groups. The case study suggests that, after disregarding outliers, the RSA activity can be satisfactorily qualified on the basis of phenolics with pollen diversity as a covariate. PMID:21217600

  8. Bond dissociation enthalpies calculated by the PM3 method confirm activity cliffs in radical scavenging of flavonoids.

    PubMed

    Amić, Dragan; Lucić, Bono; Kovacević, Goran; Trinajstić, Nenad

    2009-02-01

    Radical scavenging potency of flavonoids is associated with activity cliffs, i.e., small chemical modifications on flavonoid core can have a significant effect on activity. The presence or absence of the 3',4'-diOH and/or 3-OH group may serve as an activity switch for radical scavenging. The physicochemical background of such an indicator variable, defined previously (Amić et al. (2003) Croat Chem Acta 76:55-61), is confirmed by computation of bond dissociation enthalpies and selecting the minimal of all values relating to flavonoid OH groups. Bond dissociation enthalpies for hydrogen abstraction from OH groups for 29 flavonoids were calculated by the PM3 method. Minimal bond dissociation enthalpy values were obtained for OH groups attached to C-3, C-3' and C-4' positions, and they correspond to the previously introduced indicator variable. Taking into account some driving forces of the radical scavenging mechanism, it is possible to relate structural characteristics of flavonoids to their radical scavenging potency as well as to develop reliable structure-activity models.

  9. An exploratory study on the peroxyl-radical-scavenging activity of 2,6-dimethyl-5-hepten-2-ol and its heterocyclic analogues

    NASA Astrophysics Data System (ADS)

    Stobiecka, Agnieszka; Sikora, Magdalena; Bonikowski, Radosław; Kula, Józef

    2016-03-01

    The structural properties and radical scavenging activity of 2,6-dimethyl-5-hepten-2-ol (1) and its new heterocyclic analogues, i.e. 2-methyl-4-(5-methylfuran-2-yl)-butan-2-ol (2) and 2-methyl-4-(5-methylthiophen-2-yl)-butan-2-ol (3) and have been studied by using the experimental and theoretical methods for the first time. Activity of title compounds against the peroxyl radical was determined by using standard fluorimetric test, i.e. the Oxygen Radical Absorbance Capacity assay (ORACFL). Furthermore, the electron-donating ability of odorants has been evaluated by using colorimetric ABTS assay. According to the experimental results obtained from the ORACFL test 2,6-dimethyl-5-hepten-2-ol was characterized by the highest activity in comparison with the novel counterparts. Nevertheless, all investigated compounds exhibited pronounced anti-peroxyl radical activity comparable to that exerted by the one of the most prominent antioxidant among the monoterpene alcohols, i.e. by linalool. On the other hand, the title compounds exerted relatively low capacity to quench the radical cation of ABTS. Theoretical calculations based on the Density Functional Theory (DFT) method with the hybrid functional B3LYP were carried out in order to investigate selected structural and electronic properties including the geometrical parameters as well as the energy of frontier molecular orbitals of parent molecules and the resulting radicals. Furthermore, the possible mechanism of peroxyl-radical-scavenging has been determined by using the thermodynamic descriptors such as the bond dissociation enthalpies (BDEs) and ionization potentials (IPs). These theoretical data pointed out the relevance of HAT mechanism in the peroxyl-radical-scavenging exhibited by 2,6-dimethyl-5-hepten-2-ol and its new heterocyclic analogues in polar and non-polar medium.

  10. Synthesis, crystal structure, ABTS radical-scavenging activity, antimicrobial and docking studies of some novel quinoline derivatives

    NASA Astrophysics Data System (ADS)

    Tabassum, Sumaiya; Suresha Kumara, T. H.; Jasinski, Jerry P.; Millikan, Sean P.; Yathirajan, H. S.; Sujan Ganapathy, P. S.; Sowmya, H. B. V.; More, Sunil S.; Nagendrappa, Gopalpur; Kaur, Manpreet; Jose, Gilish

    2014-07-01

    In this study, a series of nine novel 2-chloroquinolin-3-yl ester derivatives have been synthesized via a two-step protocol from 2-chloroquinoline-3-carbaldehyde. The structures of all these compounds were confirmed by spectral data. The single crystal X-ray structure of two derivatives, (2-chloroquinolin-3-yl)methyl acetate [6a] and (2-chloro-6-methylquinolin-3-yl)methyl acetate [6e] have also been determined. The synthesized compounds were further evaluated for their ABTS radical-scavenging activity and antimicrobial activities. Amongst all the tested compounds, 6a exhibited maximum scavenging activity with ABTS. Concerning antibacterial and antifungal activities, compound (2-chloro-6-methoxyquinolin-3-yl)methyl 2,4-dichlorobenzoate [6i] was found to be the most active in the series against B. subtilis, S. aureus, E. coli, K. pneumonia, C. albicans and A. niger species. The structure-antimicrobial activity relationship of these derivatives were studied using Autodock.

  11. Synthesis, crystal structure, superoxide scavenging activity, anticancer and docking studies of novel adamantyl nitroxide derivatives

    NASA Astrophysics Data System (ADS)

    Zhu, Xiao-he; Sun, Jin; Wang, Shan; Bu, Wei; Yao, Min-na; Gao, Kai; Song, Ying; Zhao, Jin-yi; Lu, Cheng-tao; Zhang, En-hu; Yang, Zhi-fu; Wen, Ai-dong

    2016-03-01

    A novel adamantyl nitroxide derivatives has been synthesized and characterized by IR, ESI-MS and elemental analysis. Quantum chemical calculations have also been performed to calculate the molecular geometry using density functional theory (B3LYP) with the 6-31G (d,p) basis set. The calculated results showed that the optimized geometry can well reproduce the crystal structure. The antioxidant and antiproliferative activity were evaluated by superoxide (NBT) and MTT assay. The adamantyl nitroxide derivatives exhibited stronger scavenging ability towards O2· - radicals when compared to Vitamin C, and demonstrated a remarked anticancer activity against all the tested cell lines, especially Bel-7404 cells with IC50 of 43.3 μM, compared to the positive control Sorafenib (IC50 = 92.0 μM). The results of molecular docking within EGFR using AutoDock confirmed that the titled compound favorably fitted into the ATP binding site of EGFR and would be a potential anticancer agent.

  12. Physicochemical characterisation and radical-scavenging activity of Cucurbitaceae seed oils.

    PubMed

    Jorge, Neuza; da Silva, Ana Carolina; Malacrida, Cassia Roberta

    2015-01-01

    Oils extracted from Cucurbitaceae seeds were characterised for their fatty acid and tocopherol compositions. In addition, some physicochemical characteristics, total phenolic contents and the radical-scavenging activities were determined. Oil content amounted to 23.9% and 27.1% in melon and watermelon seeds, respectively. Physicochemical characteristics were similar to those of other edible oils and the oils showed significant antioxidant activities. Fatty acid composition showed total unsaturated fatty acid content of 85.2-83.5%, with linoleic acid being the dominant fatty acid (62.4-72.5%), followed by oleic acid (10.8-22.7%) and palmitic acid (9.2-9.8%). The oils, especially watermelon seed oil, showed high total tocopherol and phenolic contents. The γ-tocopherol was the predominant tocopherol in both oils representing 90.9 and 95.6% of the total tocopherols in melon and watermelon seed oils, respectively. The potential utilisation of melon and watermelon seed oils as a raw material for food, chemical and pharmaceutical industries appears to be favourable.

  13. Physicochemical characterisation and radical-scavenging activity of Cucurbitaceae seed oils.

    PubMed

    Jorge, Neuza; da Silva, Ana Carolina; Malacrida, Cassia Roberta

    2015-01-01

    Oils extracted from Cucurbitaceae seeds were characterised for their fatty acid and tocopherol compositions. In addition, some physicochemical characteristics, total phenolic contents and the radical-scavenging activities were determined. Oil content amounted to 23.9% and 27.1% in melon and watermelon seeds, respectively. Physicochemical characteristics were similar to those of other edible oils and the oils showed significant antioxidant activities. Fatty acid composition showed total unsaturated fatty acid content of 85.2-83.5%, with linoleic acid being the dominant fatty acid (62.4-72.5%), followed by oleic acid (10.8-22.7%) and palmitic acid (9.2-9.8%). The oils, especially watermelon seed oil, showed high total tocopherol and phenolic contents. The γ-tocopherol was the predominant tocopherol in both oils representing 90.9 and 95.6% of the total tocopherols in melon and watermelon seed oils, respectively. The potential utilisation of melon and watermelon seed oils as a raw material for food, chemical and pharmaceutical industries appears to be favourable. PMID:25697079

  14. Anti-genotoxic and free-radical scavenging activities of extracts from (Tunisian) Myrtus communis.

    PubMed

    Hayder, N; Abdelwahed, A; Kilani, S; Ammar, R Ben; Mahmoud, A; Ghedira, K; Chekir-Ghedira, L

    2004-11-14

    The effect of extracts from leaves of Myrtus communis on the SOS reponse induced by Aflatoxin B1 (AFB1) and Nifuroxazide was investigated in a bacterial assay system, i.e. the SOS chromotest with Escherichia coli PQ37. Aqueous extract, the total flavonoids oligomer fraction (TOF), hexane, chloroform, ethyl acetate and methanol extracts and essential oil obtained from M. communis significantly decreased the SOS response induced by AFB1 (10 microg/assay) and Nifuroxazide (20 microg/assay). Ethyl acetate and methanol extracts showed the strongest inhibition of the induction of the SOS response by the indirectly genotoxic AFB1. The methanol and aqueous extracts exhibited the highest level of protection towards the SOS-induced response by the directly genotoxic Nifuroxazide. In addition to anti-genotoxic activity, the aqueous extract, the TOF, and the ethyl acetate and methanol extracts showed an important free-radical scavenging activity towards the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. These results suggest the future utilization of these extracts as additives in chemoprevention studies. PMID:15474415

  15. Synthesis, crystal structure, superoxide scavenging activity, anticancer and docking studies of novel adamantyl nitroxide derivatives

    NASA Astrophysics Data System (ADS)

    Zhu, Xiao-he; Sun, Jin; Wang, Shan; Bu, Wei; Yao, Min-na; Gao, Kai; Song, Ying; Zhao, Jin-yi; Lu, Cheng-tao; Zhang, En-hu; Yang, Zhi-fu; Wen, Ai-dong

    2016-03-01

    A novel adamantyl nitroxide derivatives has been synthesized and characterized by IR, ESI-MS and elemental analysis. Quantum chemical calculations have also been performed to calculate the molecular geometry using density functional theory (B3LYP) with the 6-31G (d,p) basis set. The calculated results showed that the optimized geometry can well reproduce the crystal structure. The antioxidant and antiproliferative activity were evaluated by superoxide (NBT) and MTT assay. The adamantyl nitroxide derivatives exhibited stronger scavenging ability towards O2· - radicals when compared to Vitamin C, and demonstrated a remarked anticancer activity against all the tested cell lines, especially Bel-7404 cells with IC50 of 43.3 μM, compared to the positive control Sorafenib (IC50 = 92.0 μM). The results of molecular docking within EGFR using AutoDock confirmed that the titled compound favorably fitted into the ATP binding site of EGFR and would be a potential anticancer agent.

  16. Flavour characterisation and free radical scavenging activity of coriander (Coriandrum sativum L.) foliage.

    PubMed

    Priyadarshi, Siddharth; Khanum, Hafeeza; Ravi, Ramasamy; Borse, Babasaheb Baskarrao; Naidu, Madeneni Madhava

    2016-03-01

    The primary objective was to characterize Indian Coriandrum sativum L. foliage (Vulgare alef and Microcarpum DC varieties) and its radical scavenging activity. Foliage of Vulgare alef and Microcarpum DC contained ascorbic acid (1.16 ± 0.35 and 1.22 ± 0.54 mg/g), total carotenoids (1.49 ± 0.38 and 3.08 ± 1.2 mg/g), chlorophyll 'a' (8.23 ± 2.4 and 12.18 ± 2.9 mg/g), chlorophyll 'b' (2.74 ± 0.8 and 4.39 ± 1.3 mg/g) and total chlorophyll (10.97 ± 2.6 and 16.57 ± 3.2 mg/g). The polyphenol content was 26.75 ± 1.85 and 30.00 ± 2.64 mg/g in Vulgare alef and Microcarpum DC, respectively. Ethanol extracts (200 ppm) of alef and Microcarpum DC showed higher radical scavenging activity of 42.05 ± 2.42 % and 62.79 ± 1.36 % when compared with 95 % butylated hydroxyanisole. The principal component analysis results indicated that e-nose can distinguish the volatiles effectively. Quantitative descriptive sensory analysis showed that Microcarpum DC variety is superior to Vulgare alef variety. Nearly 90 % of the flavour compounds present were identified by GC-MS in both varieties. The principal component identified in both the varieties were decanal (7.645 and 7.74 %), decanol < n- > (25.12 and 39.35 %), undecanal (1.20 and 1.75 %), dodecanal (7.07 and 2.61 %), tridecen-1-al < 2E > (6.67 and 1.21 %), dodecen-1-ol < 2E- > (16.68 and 8.05 %), 13-tetradecenal (9.53 and 8.60 %), tetradecanal (5.61 and 4.35 %) and 1-octadecanol (1.25 and 3.67 %).

  17. Flavour characterisation and free radical scavenging activity of coriander (Coriandrum sativum L.) foliage.

    PubMed

    Priyadarshi, Siddharth; Khanum, Hafeeza; Ravi, Ramasamy; Borse, Babasaheb Baskarrao; Naidu, Madeneni Madhava

    2016-03-01

    The primary objective was to characterize Indian Coriandrum sativum L. foliage (Vulgare alef and Microcarpum DC varieties) and its radical scavenging activity. Foliage of Vulgare alef and Microcarpum DC contained ascorbic acid (1.16 ± 0.35 and 1.22 ± 0.54 mg/g), total carotenoids (1.49 ± 0.38 and 3.08 ± 1.2 mg/g), chlorophyll 'a' (8.23 ± 2.4 and 12.18 ± 2.9 mg/g), chlorophyll 'b' (2.74 ± 0.8 and 4.39 ± 1.3 mg/g) and total chlorophyll (10.97 ± 2.6 and 16.57 ± 3.2 mg/g). The polyphenol content was 26.75 ± 1.85 and 30.00 ± 2.64 mg/g in Vulgare alef and Microcarpum DC, respectively. Ethanol extracts (200 ppm) of alef and Microcarpum DC showed higher radical scavenging activity of 42.05 ± 2.42 % and 62.79 ± 1.36 % when compared with 95 % butylated hydroxyanisole. The principal component analysis results indicated that e-nose can distinguish the volatiles effectively. Quantitative descriptive sensory analysis showed that Microcarpum DC variety is superior to Vulgare alef variety. Nearly 90 % of the flavour compounds present were identified by GC-MS in both varieties. The principal component identified in both the varieties were decanal (7.645 and 7.74 %), decanol < n- > (25.12 and 39.35 %), undecanal (1.20 and 1.75 %), dodecanal (7.07 and 2.61 %), tridecen-1-al < 2E > (6.67 and 1.21 %), dodecen-1-ol < 2E- > (16.68 and 8.05 %), 13-tetradecenal (9.53 and 8.60 %), tetradecanal (5.61 and 4.35 %) and 1-octadecanol (1.25 and 3.67 %). PMID:27570292

  18. The ligand activity of AGE-proteins to scavenger receptors is dependent on their rate of modification by AGEs.

    PubMed

    Nagai, Ryoji; Mera, Katsumi; Nakajou, Keisuke; Fujiwara, Yukio; Iwao, Yasunori; Imai, Hiroki; Murata, Toshinori; Otagiri, Masaki

    2007-12-01

    The cellular interaction of proteins modified with advanced glycation end-products (AGEs) is believed to induce several different biological responses, which are involved in the development of diabetic vascular complications. We report here that the ratio of protein glycation is implicated in its ligand activity to scavenger receptors. Although highly-modified AGE-bovine serum albumin (high-AGE-BSA) was significantly recognized by human monocyte-derived macrophages and Chinese hamster ovary cells which overexpress such scavenger receptors as CD36, SR-BI (scavenger receptor class B type-I), and LOX-1 (Lectin-like Ox-LDL receptor-1), the mildly-modified-AGE-BSA (mild-AGE-BSA) did not show any ligand activity to these cells. Furthermore, when (111)In-labeled high- or mild-AGE-BSA were injected into the tail vein of mice, the high-AGE-BSA was rapidly cleared from the circulation whereas the clearance rate of the mild-AGE-BSA was very slow, similar to the native BSA. These results demonstrate the first evidence that the ligand activity of the AGE-proteins to the scavenger receptors and its pharmacokinetic properties depend on their rate of modification by AGEs, and we should carefully prepare the AGE-proteins in vitro to clarify the physiological significance of the interaction between the AGE-receptors and AGE-proteins.

  19. Radical Scavenging Activity of the Essential Oil of Silver Fir (Abies alba).

    PubMed

    Yang, Seun-Ah; Jeon, Sang-Kyung; Lee, Eun-Jung; Im, Nam-Kyung; Jhee, Kwang-Hwan; Lee, Sam-Pin; Lee, In-Seon

    2009-05-01

    The essential oil of silver fir (Abies alba) is known to help respiratory system and have easing and soothing effect for muscle. In the present study, we investigated the chemical composition, cytotoxicity and its biological activities of silver fir (Abies alba) essential oil. The composition of the oil was analyzed by GC-MS and bornyl acetate (30.31%), camphene (19.81%), 3-carene (13.85%), tricyclene (12.90%), dl-limonene (7.50%), alpha-pinene (2.87%), caryophyllene (2.18%), beta-phellandrene (2.13%), borneol (1.74%), bicyclo[2.2.1]hept-2-ene,2,3-dimethyl (1.64%) and alpha-terpinene (1.24%) were the major components in the oil. The results tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay indicated that the oil showed no cytotoxic effect, at concentrations of 1 and 5%, for as long as 24 and 3 h, respectively. The antiradical capacity was evaluated by measuring the scavenging activity of the essential oil on the 2,20-diphenylpicrylhydrazyl (DPPH) and 2,2'-azino-bis 3-ethyl benzothiazoline-6-sulfonic acid (ABTS) radicals. The oil was able to reduce the both radicals dose-dependently, and the concentration required for 50% reduction (RC(50)) against DPPH radicals (2.7 +/- 0.63%) was lower than ABTS radicals (8.5 +/- 0.27%). The antibacterial activity of the oil was also evaluated using disc diffusion method against Staphylococcus aureus, Streptococcus mutans, Listeria monocytogenes, Acinetobacter baumannii, Escherichia coli, and Vibrio parahaemolyticcus. The oil exhibited no antibacterial activity against all the bacterial strains tested except S. aureus of mild activity. PMID:19430614

  20. Radical Scavenging Activity of the Essential Oil of Silver Fir (Abies alba)

    PubMed Central

    Yang, Seun-Ah; Jeon, Sang-Kyung; Lee, Eun-Jung; Im, Nam-Kyung; Jhee, Kwang-Hwan; Lee, Sam-Pin; Lee, In-Seon

    2009-01-01

    The essential oil of silver fir (Abies alba) is known to help respiratory system and have easing and soothing effect for muscle. In the present study, we investigated the chemical composition, cytotoxicity and its biological activities of silver fir (Abies alba) essential oil. The composition of the oil was analyzed by GC-MS and bornyl acetate (30.31%), camphene (19.81%), 3-carene (13.85%), tricyclene (12.90%), dl-limonene (7.50%), α-pinene (2.87%), caryophyllene (2.18%), β-phellandrene (2.13%), borneol (1.74%), bicyclo[2.2.1]hept-2-ene,2,3-dimethyl (1.64%) and α-terpinene (1.24%) were the major components in the oil. The results tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay indicated that the oil showed no cytotoxic effect, at concentrations of 1 and 5%, for as long as 24 and 3 h, respectively. The antiradical capacity was evaluated by measuring the scavenging activity of the essential oil on the 2,20-diphenylpicrylhydrazyl (DPPH) and 2,2'-azino-bis 3-ethyl benzothiazoline-6-sulfonic acid (ABTS) radicals. The oil was able to reduce the both radicals dose-dependently, and the concentration required for 50% reduction (RC50) against DPPH radicals (2.7 ± 0.63%) was lower than ABTS radicals (8.5 ± 0.27%). The antibacterial activity of the oil was also evaluated using disc diffusion method against Staphylococcus aureus, Streptococcus mutans, Listeria monocytogenes, Acinetobacter baumannii, Escherichia coli, and Vibrio parahaemolyticcus. The oil exhibited no antibacterial activity against all the bacterial strains tested except S. aureus of mild activity. PMID:19430614

  1. Different Reactive Oxygen Species Scavenging Properties of Flavonoids Determine Their Abilities to Extend the Shelf Life of Tomato1[OPEN

    PubMed Central

    Zhang, Yang; De Stefano, Rosalba; Robine, Marie; Butelli, Eugenio; Bulling, Katharina; Hill, Lionel; Rejzek, Martin; Martin, Cathie; Schoonbeek, Henk-jan

    2015-01-01

    The shelf life of tomato (Solanum lycopersicum) fruit is determined by the processes of overripening and susceptibility to pathogens. Postharvest shelf life is one of the most important traits for commercially grown tomatoes. We compared the shelf life of tomato fruit that accumulate different flavonoids and found that delayed overripening is associated with increased total antioxidant capacity caused by the accumulation of flavonoids in the fruit. However, reduced susceptibility to Botrytis cinerea, a major postharvest fungal pathogen of tomato, is conferred by specific flavonoids only. We demonstrate an association between flavonoid structure, selective scavenging ability for different free radicals, and reduced susceptibility to B. cinerea. Our study provides mechanistic insight into how flavonoids influence the shelf life, information that could be used to improve the shelf life of tomato and, potentially, other soft fruit. PMID:26082399

  2. Ethylene Response Factor TERF1, Regulated by ETHYLENE-INSENSITIVE3-like Factors, Functions in Reactive Oxygen Species (ROS) Scavenging in Tobacco (Nicotiana tabacum L.).

    PubMed

    Zhang, Hongbo; Li, Ang; Zhang, Zhijin; Huang, Zejun; Lu, Pingli; Zhang, Dingyu; Liu, Xinmin; Zhang, Zhong-Feng; Huang, Rongfeng

    2016-01-01

    The phytohormone ethylene plays a crucial role in the production and accumulation of reactive oxygen species (ROS) in plants under stress conditions. Ethylene response factors (ERFs) are important ethylene-signaling regulators functioning in plant defense responses against biotic and abiotic stresses. However, the roles of ERFs during plant adapting to ROS stress have not yet been well documented. Our studies previously reported that a tomato ERF transcription factor TERF1 functions in the regulation of plant ethylene responses and stress tolerance. Here, we report our findings regarding the roles of TERF1 in ROS scavenging. In this study, we revealed that the transcription of TERF1 is regulated by upstream EIN3-like (EIN3, ethylene-insensitive 3) regulators LeEIL3 and LeEIL4 in tomato (Solanum lycopersicum), and is also inducible by exogenous applied ROS-generating reagents. Ectopic expression of TERF1 in tobacco promoted the expression of genes involved in oxidative stress responses, including carbonic anhydrase functioning in hypersensitive defense, catalase and glutathione peroxidase catalyzing oxidative reactions, and GDP-D-mannose pyrophosphorylase functioning in ascorbic acid biosynthesis, reduced the ROS content induced by ethylene treatment, and enhanced stress tolerance of tobacco seedlings to hydrogen peroxide (H2O2). Cumulatively, these findings suggest that TERF1 is an ethylene inducible factor regulating ROS scavenging during stress responses. PMID:27435661

  3. Ethylene Response Factor TERF1, Regulated by ETHYLENE-INSENSITIVE3-like Factors, Functions in Reactive Oxygen Species (ROS) Scavenging in Tobacco (Nicotiana tabacum L.)

    PubMed Central

    Zhang, Hongbo; Li, Ang; Zhang, Zhijin; Huang, Zejun; Lu, Pingli; Zhang, Dingyu; Liu, Xinmin; Zhang, Zhong-Feng; Huang, Rongfeng

    2016-01-01

    The phytohormone ethylene plays a crucial role in the production and accumulation of reactive oxygen species (ROS) in plants under stress conditions. Ethylene response factors (ERFs) are important ethylene-signaling regulators functioning in plant defense responses against biotic and abiotic stresses. However, the roles of ERFs during plant adapting to ROS stress have not yet been well documented. Our studies previously reported that a tomato ERF transcription factor TERF1 functions in the regulation of plant ethylene responses and stress tolerance. Here, we report our findings regarding the roles of TERF1 in ROS scavenging. In this study, we revealed that the transcription of TERF1 is regulated by upstream EIN3-like (EIN3, ethylene-insensitive 3) regulators LeEIL3 and LeEIL4 in tomato (Solanum lycopersicum), and is also inducible by exogenous applied ROS-generating reagents. Ectopic expression of TERF1 in tobacco promoted the expression of genes involved in oxidative stress responses, including carbonic anhydrase functioning in hypersensitive defense, catalase and glutathione peroxidase catalyzing oxidative reactions, and GDP-D-mannose pyrophosphorylase functioning in ascorbic acid biosynthesis, reduced the ROS content induced by ethylene treatment, and enhanced stress tolerance of tobacco seedlings to hydrogen peroxide (H2O2). Cumulatively, these findings suggest that TERF1 is an ethylene inducible factor regulating ROS scavenging during stress responses. PMID:27435661

  4. [Photometric micro-titration model of DPPH radicals scavenging activity and its application].

    PubMed

    Gao, Yun-tao; Wei, Wei; Ye, Li-qing; Li, Xiao-fen; Liu, Ping; Zhang, Hong-jiao; Yang, Lu; Yu, Jiao-jiao; Cha, Jia-wei

    2015-02-01

    In the present paper, the stoichiometric ratio (R) for the interreaction of DPPH radicals with the antoxidant was employed as a evaluation index for DPPH radicals scavenging activity of antioxidants. This evaluation index was related only with the stoichiometric relationship between DPPH radicals and the antioxidant, not the relationship with the initial DPPH amount and the volume of sample, which could offer a solution for the problem of poor comparability of EC50 under different conditions. A novel photometric micro-titration method was proposed for the determination of the stoichiometric ratio (R) for the interreaction of DPPH radicals with the antoxidant. The titration equation was established based on the absorbance difference (deltaA) of DPPH radicals in the titration process and the added amount of antoxidant. The stoichiometric ratio (R) for the reaction of DPPH radicals with the addition amount of antoxidant was determined by the titration equation obtained, while, the DPPH median elimination concentration (EC50) of antoxidant can be calculated by the stoichiometric ratio (R). The above photometric micro-titration model was verified using rutin as DPPH radicals scavenger. As experiment results, the stoichiometric ratio (R) of DPPH radicals to rutin was determined to be in the range of 1.817-1.846. The calculated value of EC50 was 1.196 x 10(-3), 2.392 x 10(-3), 4.819 x 10(-3) and 7.292 x 10(-3) mg x mL(-1) for 1.12 x 10(-7), 2.24 x 10(-7), 4.48 x 10(-7) and 6.72 x 10(-7) mol of the additon amount of DPPH radicals, respectively. The proposed method has better precision and reliability with smaller amount of sample than conventional method. While, the obtained stoichiometric ratio value (R) of rutin was employed to calculate the rutin median elimination concentration for DPPH EC50) according to the conditions as reported in the literatures, and the calculated results were consistent with that reported in the literatures.

  5. Free Radical Scavenging Activity of Calotropis gigantea on Streptozotocin-Induced Diabetic Rats.

    PubMed

    Rathod, N R; Raghuveer, I; Chitme, H R; Chandra, R

    2009-11-01

    Swarnabhasma, an Ayurvedic preparation containing Calotropis gigantea R. Br. (Asclepiadaceae) is extensively used by Ayurvedic physicians for treatment of diabetes mellitus, bronchial asthma, rheumatoid arthritis and nervous disorders. In the present study, we report the effect of chloroform extracts of Calotropis gigantea leaf and flower on free radical scavenging activity, and lipid profile in streptozotozin-induced diabetic rats. The lipid peroxidation, superoxide dismutase, and catalase were measured in liver homogenate and serum glutamic pyruvic transaminase, serum glutamic oxaloacetic transaminase, alkaline phosphatase, lipid profile were measured in blood serum. Administration of single dose of streptozotozin (55 mg/kg, i.p.) caused significant increases in lipid peroxidation, serum glutamic pyruvic transaminase, serum glutamic oxaloacetic transaminase, alkaline phosphatase, cholesterol and triglyceride levels, while superoxide dismutase and catalase levels were significantly decreased. Further, administration of chloroform extracts of Calotropis gigantea leaf and flower to streptozotocin-induced diabetes rats at a dose of 10, 20 and 50 mg/kg orally for 27 d lead to a significant decrease in lipid peroxidation, serum glutamic pyruvic transaminase, serum glutamic oxaloacetic transaminase, alkaline phosphatase, cholesterol and triglyceride levels. Consequently, superoxide dismutase and catalase levels were significantly increased. Glibenclamide was used as a positive control (10 mg/kg). It was observed that the effect of chloroform extracts of Calotropis gigantea on alkaline phosphatase, cholesterol, superoxide dismutase, serum glutamic pyruvic transaminase, serum glutamic oxaloacetic transaminase, levels are comparable to that of those produced by the positive control.

  6. Bond dissociation free energy as a general parameter for flavonoid radical scavenging activity.

    PubMed

    Stepanić, Višnja; Gall Trošelj, Koraljka; Lučić, Bono; Marković, Zoran; Amić, Dragan

    2013-11-15

    Notwithstanding multiple mechanisms of radical scavenging (RS), measured RS activities (RSA) of flavonoids are usually related to O-H bond dissociation enthalpy (BDE) for hydrogen atom transfer (HAT). For 12 flavonoids the reaction free energies were calculated for: (1) HAT, (2) single electron transfer-proton transfer (SET-PT) and (3) sequential proton loss electron transfer (SPLET) in gas and aqueous phases. Aqueous free energies, like bond dissociation (BDFEaq), ionisation (IFEaq) and deprotonation (ΔGdeprot,aq) free energies were estimated using thermochemical cycles. While in gas HAT is a RS mechanism (BDFEg

  7. Micronization of Taxifolin by Supercritical Antisolvent Process and Evaluation of Radical Scavenging Activity

    PubMed Central

    Zu, Shuchong; Yang, Lei; Huang, Jinming; Ma, Chunhui; Wang, Wenjie; Zhao, Chunjian; Zu, Yuangang

    2012-01-01

    The aim of this study was to prepare micronized taxifolin powder using the supercritical antisolvent precipitation process to improve the dissolution rate of taxifolin. Ethanol was used as solvent and carbon dioxide was used as an antisolvent. The effects of process parameters, such as temperature (35–65 °C), pressure (10–25 MPa), solution flow rate (3–6 mL/min) and concentration of the liquid solution (5–20 mg/mL) on the precipitate crystals were investigated. With a lower temperature, a stronger pressure and a lower concentration of the liquid solution, the size of crystals decreased. The precipitation temperature, pressure and concentration of taxifolin solution had a significant effect. However, the solution flow rate had a negligible effect. It was concluded that the physicochemical properties and dissolution rate of crystalline taxifolin could be improved by physical modification such as particle size reduction using the supercritical antisolvent (SAS) process. Further, the SAS process was a powerful methodology for improving the physicochemical properties and radical scavenging activity of taxifolin. PMID:22942740

  8. Metabolic Profiles and Free Radical Scavenging Activity of Cordyceps bassiana Fruiting Bodies According to Developmental Stage

    PubMed Central

    Hyun, Sun-Hee; Lee, Seok-Young; Sung, Gi-Ho; Kim, Seong Hwan; Choi, Hyung-Kyoon

    2013-01-01

    The metabolic profiles of Cordyceps bassiana according to fruiting body developmental stage were investigated using gas chromatography-mass spectrometry. We were able to detect 62 metabolites, including 48 metabolites from 70% methanol extracts and 14 metabolites from 100% n-hexane extracts. These metabolites were classified as alcohols, amino acids, organic acids, phosphoric acids, purine nucleosides and bases, sugars, saturated fatty acids, unsaturated fatty acids, or fatty amides. Significant changes in metabolite levels were found according to developmental stage. Relative levels of amino acids, purine nucleosides, and sugars were higher in development stage 3 than in the other stages. Among the amino acids, valine, isoleucine, lysine, histidine, glutamine, and aspartic acid, which are associated with ABC transporters and aminoacyl-tRNA biosynthesis, also showed higher levels in stage 3 samples. The free radical scavenging activities, which were significantly higher in stage 3 than in the other stages, showed a positive correlation with purine nucleoside metabolites such as adenosine, guanosine, and inosine. These results not only show metabolic profiles, but also suggest the metabolic pathways associated with fruiting body development stages in cultivated C. bassiana. PMID:24058459

  9. Free Radical Scavenging Activity of Calotropis gigantea on Streptozotocin-Induced Diabetic Rats

    PubMed Central

    Rathod, N. R.; Raghuveer, I.; Chitme, H. R.; Chandra, R.

    2009-01-01

    Swarnabhasma, an Ayurvedic preparation containing Calotropis gigantea R. Br. (Asclepiadaceae) is extensively used by Ayurvedic physicians for treatment of diabetes mellitus, bronchial asthma, rheumatoid arthritis and nervous disorders. In the present study, we report the effect of chloroform extracts of Calotropis gigantea leaf and flower on free radical scavenging activity, and lipid profile in streptozotozin-induced diabetic rats. The lipid peroxidation, superoxide dismutase, and catalase were measured in liver homogenate and serum glutamic pyruvic transaminase, serum glutamic oxaloacetic transaminase, alkaline phosphatase, lipid profile were measured in blood serum. Administration of single dose of streptozotozin (55 mg/kg, i.p.) caused significant increases in lipid peroxidation, serum glutamic pyruvic transaminase, serum glutamic oxaloacetic transaminase, alkaline phosphatase, cholesterol and triglyceride levels, while superoxide dismutase and catalase levels were significantly decreased. Further, administration of chloroform extracts of Calotropis gigantea leaf and flower to streptozotocin-induced diabetes rats at a dose of 10, 20 and 50 mg/kg orally for 27 d lead to a significant decrease in lipid peroxidation, serum glutamic pyruvic transaminase, serum glutamic oxaloacetic transaminase, alkaline phosphatase, cholesterol and triglyceride levels. Consequently, superoxide dismutase and catalase levels were significantly increased. Glibenclamide was used as a positive control (10 mg/kg). It was observed that the effect of chloroform extracts of Calotropis gigantea on alkaline phosphatase, cholesterol, superoxide dismutase, serum glutamic pyruvic transaminase, serum glutamic oxaloacetic transaminase, levels are comparable to that of those produced by the positive control. PMID:20376213

  10. Metabolic profiles and free radical scavenging activity of Cordyceps bassiana fruiting bodies according to developmental stage.

    PubMed

    Hyun, Sun-Hee; Lee, Seok-Young; Sung, Gi-Ho; Kim, Seong Hwan; Choi, Hyung-Kyoon

    2013-01-01

    The metabolic profiles of Cordyceps bassiana according to fruiting body developmental stage were investigated using gas chromatography-mass spectrometry. We were able to detect 62 metabolites, including 48 metabolites from 70% methanol extracts and 14 metabolites from 100% n-hexane extracts. These metabolites were classified as alcohols, amino acids, organic acids, phosphoric acids, purine nucleosides and bases, sugars, saturated fatty acids, unsaturated fatty acids, or fatty amides. Significant changes in metabolite levels were found according to developmental stage. Relative levels of amino acids, purine nucleosides, and sugars were higher in development stage 3 than in the other stages. Among the amino acids, valine, isoleucine, lysine, histidine, glutamine, and aspartic acid, which are associated with ABC transporters and aminoacyl-tRNA biosynthesis, also showed higher levels in stage 3 samples. The free radical scavenging activities, which were significantly higher in stage 3 than in the other stages, showed a positive correlation with purine nucleoside metabolites such as adenosine, guanosine, and inosine. These results not only show metabolic profiles, but also suggest the metabolic pathways associated with fruiting body development stages in cultivated C. bassiana.

  11. Antioxidant effect of Ebselen (PZ 51): peroxidase mimetic activity on phospholipid and cholesterol hydroperoxides vs free radical scavenger activity.

    PubMed

    Maiorino, M; Roveri, A; Ursini, F

    1992-06-01

    The selenocompound Ebselen (PZ 51) is a potent inhibitor of lipid peroxidation. This antioxidant effect has been previously attributed both to a peroxidase mimetic activity and to a free radical scavenging capability. In the present paper the latter is ruled out by competition kinetic analysis based on the inhibition of carotenoid bleaching by hydroperoxyl radicals. Furthermore, evidence is reported indicating that Ebselen exhibits a peroxidase activity extended to cholesterol and cholesterol ester hydroperoxides, besides phospholipid hydroperoxides. According to this, we propose that the unique mechanism of the antioxidant capacity of Ebselen is the reduction of lipid hydroperoxides present in liposomes or lipoproteins, eventually leading to the prevention of hydroperoxide-dependent peroxidation. PMID:1586168

  12. Increased tolerance to salt stress in OPDA-deficient rice ALLENE OXIDE CYCLASE mutants is linked to an increased ROS-scavenging activity

    PubMed Central

    Hazman, Mohamed; Hause, Bettina; Eiche, Elisabeth; Nick, Peter; Riemann, Michael

    2015-01-01

    Salinity stress represents a global constraint for rice, the most important staple food worldwide. Therefore the role of the central stress signal jasmonate for the salt response was analysed in rice comparing the responses to salt stress for two jasmonic acid (JA) biosynthesis rice mutants (cpm2 and hebiba) impaired in the function of ALLENE OXIDE CYCLASE (AOC) and their wild type. The aoc mutants were less sensitive to salt stress. Interestingly, both mutants accumulated smaller amounts of Na+ ions in their leaves, and showed better scavenging of reactive oxygen species (ROS) under salt stress. Leaves of the wild type and JA mutants accumulated similar levels of abscisic acid (ABA) under stress conditions, and the levels of JA and its amino acid conjugate, JA–isoleucine (JA-Ile), showed only subtle alterations in the wild type. In contrast, the wild type responded to salt stress by strong induction of the JA precursor 12-oxophytodienoic acid (OPDA), which was not observed in the mutants. Transcript levels of representative salinity-induced genes were induced less in the JA mutants. The absence of 12-OPDA in the mutants correlated not only with a generally increased ROS-scavenging activity, but also with the higher activity of specific enzymes in the antioxidative pathway, such as glutathione S-transferase, and fewer symptoms of damage as, for example, indicated by lower levels of malondialdehyde. The data are interpreted in a model where the absence of OPDA enhanced the antioxidative power in mutant leaves. PMID:25873666

  13. Free radical scavenging and antioxidant activity of betanin: electron spin resonance spectroscopy studies and studies in cultured cells.

    PubMed

    Esatbeyoglu, Tuba; Wagner, Anika E; Motafakkerazad, Rouhollah; Nakajima, Yu; Matsugo, Seiichi; Rimbach, Gerald

    2014-11-01

    Betanin is a red pigment present in red beetroot. Recently, potential health benefits of betanin-rich beetroot have been suggested. However, little is known regarding the free radical scavenging and antioxidant activity of betanin. Electron spin resonance spectroscopy (ESR) and spin trapping techniques were applied to evaluate the ability of betanin to scavenge hydroxyl, superoxide, 2,2 diphenyl-1-picrylhydrazyl (DPPH), and galvinoxyl free radicals. In addition, we tested in cultured cells the ability of betanin to prevent DNA damage and to induce the transcription factor Nrf2 (nuclear factor (erythroid-derived 2)-like 2) as well as its down-stream target heme oxygenase1 (HO-1), paraoxonase1 (PON1) and glutathione (GSH). Betanin dose-dependently scavenged DPPH-, galvinoxyl-, superoxide-, and hydroxyl-radicals in the ESR and spin trapping studies and prevented hydrogen peroxide induced DNA damage as determined by the Comet assay. Furthermore, betanin treatment induced the transcription factor Nrf2 and resulted in an increase of HO-1 protein levels, PON1-transactivation and cellular GSH. Present data suggest that betanin is both a free radical scavenger and an inducer of antioxidant defense mechanism in cultured cells.

  14. Monocyte-macrophage membrane possesses free radicals scavenging activity: stimulation by polyphenols or by paraoxonase 1 (PON1).

    PubMed

    Rosenblat, M; Elias, A; Volkova, N; Aviram, M

    2013-04-01

    In the current study, we analysed free radicals scavenging activity of monocytes-macrophages in the absence or presence of antioxidants such as polyphenols or paraoxonase 1 (PON1). THP-1 human monocytic cell line, murine J774A.1 macrophages, as well as human primary monocytes have the capability to scavenge free radicals, as measured by the 1-diphenyl-2-picryl-hydrazyl (DPPH) assay. This effect (which could be attributed to the cell's membrane) was cell number and incubation time dependent. Upon incubation of J774A.1 macrophages with acetylated LDL (Ac-LDL), with VLDL, or with the radical generator, AAPH, the cells' lipid peroxides content, and paraoxonase 2 (PON2) activity were significantly increased. While non-treated cells decreased DPPH absorbance by 65%, the Ac-LDL-, VLDL- or AAPH-treated cells, decreased it by only 33%, 30%, or 45%, respectively. We next analysed the effect of J774A.1 macrophage enrichment with antioxidants, such as polyphenols or PON1 on the cells' free radicals scavenging activity. Non-treated cells decreased DPPH absorbance by 50%, whereas vitamin E-, punicalagin- or PJ-treated cells significantly further decreased it, by 75%. Similarly, in PON1-treated cells DPPH absorbance was further decreased by 63%, in association with 23% increment in PON1 catalytic activity. In cells under oxidative stress [treated with AAPH-, or with oxidized LDL], PON1 activity was decreased by 31% or 40%, as compared to the activity observed in PON1 incubated with non-treated cells. We conclude that monocytes-macrophages possess free radicals scavenging activity, which is decreased under atherogenic conditions, and increased upon cell enrichment with potent antioxidants such as nutritional polyphenols, or PON1.

  15. Betanin, the main pigment of red beet: molecular origin of its exceptionally high free radical-scavenging activity.

    PubMed

    Gliszczyńska-Swigło, A; Szymusiak, H; Malinowska, P

    2006-11-01

    In the present study, the pH-dependent free radical-scavenging activity of betanin in the Trolox equivalent antioxidant capacity (TEAC) assay was determined. It was found that at a pH > 4 betanin is about 1.5-2.0-fold more active than some anthocyanins considered very good free radical scavengers as determined in the TEAC assay. The increase in the TEAC values of betanin with increasing pH is discussed in terms of its calculated phenolic OH homolytic bond dissociation energy (BDE) and ionization potential (IP). The results suggest that the exceptionally high antioxidant activity of betanin is associated with an increasing of its H-donation and electron-donation ability when going from cationic state to mono-, di- and tri-deprotonated states present at basic solutions.

  16. Assessment of the Polyphenolic Content, Free Radical Scavenging, Anti-inflammatory, and Antimicrobial Activities of Acetone and Aqueous Extracts of Lippia javanica (Burm.F.) Spreng

    PubMed Central

    Asowata-Ayodele, Abiola M.; Otunola, Gloria A.; Afolayan, Anthony J.

    2016-01-01

    polyphenolic content and biological activities of the spice plant, Lippia javanica from South Africa was evaluatedSignificantly high polyphenolic content and free radical scavenging activities were observed for both extractsModerate antimicrobial action, concentration-dependent inhibition of protein denaturation and membrane haemolysis were also observed. Abbreviations used: AA: ascorbic acid, ABTS: 2,2’azino-bis (3-ethylbenthiazoline-6-sulfonic acid), BHT: Butylated hydroxytoluene, DPPH: 1,1-Diphenyl-2-picryl-hydrazyl, NBT: 2,2’-di-pnitrophenyl-5,5’-diphenyl-(3,3’-dimethoxy-4,4’-diphenylene)- ditetrazolium chloride, PMS: Potassium metabisulfite, ROS: Reactive oxygen species, TBA: Thiobarbituric acid, TCA: Trichloroacetic acid. PMID:27563225

  17. Radical-scavenging activity of butylated hydroxytoluene (BHT) and its metabolites.

    PubMed

    Fujisawa, Seiichiro; Kadoma, Yoshinori; Yokoe, Ichiro

    2004-07-01

    To clarify the radical-scavenging activity of butylated hydroxytoluene (BHT), a food additive, stoichiometric factors (n) and inhibition rate constants (kinh) were determined for 2,6-di-tert-butyl-4-methylphenol (BHT) and its metabolites 2,6-di-tert-butyl-p-benzoquinone (BHT-Q), 3,5-di-tert-butyl-4-hydroxybenzaldehyde (BHA-CHO) and 3,5-di-tert-butyl-4-hydroperoxy-4-methyl-2,5-cyclohexadiene-1-one (BHT-OOH). Values of n and kinh were determined from differential scanning calorimetry (DSC) monitoring of the polymerization of methyl methacrylate (MMA) initiated by 2,2'-azobis(isobutyronitrile) (AIBN) or benzoyl peroxide (BPO) at 70 degrees C in the presence or absence of antioxidants (BHT-related compounds). The n values declined in the order BHT (1-2) > BHT-CHO, BHT-OOH (0.1-0.3) > BHT-Q ( approximately 0). The n value for BHT with AIBN was approximately 1.0, suggesting dimerization of BHT. The kinh values declined in the order BHT-Q ((3.5-4.6) x 10(4) M(-1)s(-1)) > BHT-OOH (0.7-1.9 x 10(4) M(-1)s(-1)) > BHT-CHO ((0.4-1.7 x 10(4) M(-1)s(-1)) > BHT ((0.1-0.2 x 10(4) M(-1)s(-1)). The kinh for metabolites was greater than that for the parent BHT. Growing MMA radicals initiated by BPO were suppressed much more efficiently by BHT or BHT-Q compared with those initiated by AIBN. BHT was effective as a chain-breaking antioxidant. PMID:15172835

  18. Radical-scavenging activity of butylated hydroxytoluene (BHT) and its metabolites.

    PubMed

    Fujisawa, Seiichiro; Kadoma, Yoshinori; Yokoe, Ichiro

    2004-07-01

    To clarify the radical-scavenging activity of butylated hydroxytoluene (BHT), a food additive, stoichiometric factors (n) and inhibition rate constants (kinh) were determined for 2,6-di-tert-butyl-4-methylphenol (BHT) and its metabolites 2,6-di-tert-butyl-p-benzoquinone (BHT-Q), 3,5-di-tert-butyl-4-hydroxybenzaldehyde (BHA-CHO) and 3,5-di-tert-butyl-4-hydroperoxy-4-methyl-2,5-cyclohexadiene-1-one (BHT-OOH). Values of n and kinh were determined from differential scanning calorimetry (DSC) monitoring of the polymerization of methyl methacrylate (MMA) initiated by 2,2'-azobis(isobutyronitrile) (AIBN) or benzoyl peroxide (BPO) at 70 degrees C in the presence or absence of antioxidants (BHT-related compounds). The n values declined in the order BHT (1-2) > BHT-CHO, BHT-OOH (0.1-0.3) > BHT-Q ( approximately 0). The n value for BHT with AIBN was approximately 1.0, suggesting dimerization of BHT. The kinh values declined in the order BHT-Q ((3.5-4.6) x 10(4) M(-1)s(-1)) > BHT-OOH (0.7-1.9 x 10(4) M(-1)s(-1)) > BHT-CHO ((0.4-1.7 x 10(4) M(-1)s(-1)) > BHT ((0.1-0.2 x 10(4) M(-1)s(-1)). The kinh for metabolites was greater than that for the parent BHT. Growing MMA radicals initiated by BPO were suppressed much more efficiently by BHT or BHT-Q compared with those initiated by AIBN. BHT was effective as a chain-breaking antioxidant.

  19. Prediction of Radical Scavenging Activities of Anthocyanins Applying Adaptive Neuro-Fuzzy Inference System (ANFIS) with Quantum Chemical Descriptors

    PubMed Central

    Jhin, Changho; Hwang, Keum Taek

    2014-01-01

    Radical scavenging activity of anthocyanins is well known, but only a few studies have been conducted by quantum chemical approach. The adaptive neuro-fuzzy inference system (ANFIS) is an effective technique for solving problems with uncertainty. The purpose of this study was to construct and evaluate quantitative structure-activity relationship (QSAR) models for predicting radical scavenging activities of anthocyanins with good prediction efficiency. ANFIS-applied QSAR models were developed by using quantum chemical descriptors of anthocyanins calculated by semi-empirical PM6 and PM7 methods. Electron affinity (A) and electronegativity (χ) of flavylium cation, and ionization potential (I) of quinoidal base were significantly correlated with radical scavenging activities of anthocyanins. These descriptors were used as independent variables for QSAR models. ANFIS models with two triangular-shaped input fuzzy functions for each independent variable were constructed and optimized by 100 learning epochs. The constructed models using descriptors calculated by both PM6 and PM7 had good prediction efficiency with Q-square of 0.82 and 0.86, respectively. PMID:25153627

  20. Prediction of radical scavenging activities of anthocyanins applying adaptive neuro-fuzzy inference system (ANFIS) with quantum chemical descriptors.

    PubMed

    Jhin, Changho; Hwang, Keum Taek

    2014-01-01

    Radical scavenging activity of anthocyanins is well known, but only a few studies have been conducted by quantum chemical approach. The adaptive neuro-fuzzy inference system (ANFIS) is an effective technique for solving problems with uncertainty. The purpose of this study was to construct and evaluate quantitative structure-activity relationship (QSAR) models for predicting radical scavenging activities of anthocyanins with good prediction efficiency. ANFIS-applied QSAR models were developed by using quantum chemical descriptors of anthocyanins calculated by semi-empirical PM6 and PM7 methods. Electron affinity (A) and electronegativity (χ) of flavylium cation, and ionization potential (I) of quinoidal base were significantly correlated with radical scavenging activities of anthocyanins. These descriptors were used as independent variables for QSAR models. ANFIS models with two triangular-shaped input fuzzy functions for each independent variable were constructed and optimized by 100 learning epochs. The constructed models using descriptors calculated by both PM6 and PM7 had good prediction efficiency with Q-square of 0.82 and 0.86, respectively. PMID:25153627

  1. Phytochemical screening and free radical scavenging activity of Citrullus colocynthis seeds extracts

    PubMed Central

    Benariba, Nabila; Djaziri, Rabeh; Bellakhdar, Wafaa; Belkacem, Nacera; Kadiata, Marcel; Malaisse, Willy J.; Sener, Abdullah

    2013-01-01

    Objective To study the phytochemical screening of different extracts from Citrullus colocynthis (C. colocynthis ) seeds extracts and to assess their antioxidant activity on the DPPH free radical scavenging. Methods Phytochemical screening, total content of polyphenols and flavonoids of C. colocynthis seeds extracts, including a crude aqueous extract (E1), a defatted aqueous extract (E2), a hydromethanolic extract (HM), an ethyl acetate extract (EA) and a n-butanol extract (n-B) was carried out according to the standard methods and to assess their corresponding effect on the antioxidant activity of this plant. Results None of these extracts contained detectable amount of alkaloid, quinone, antraquinone, or reducing sugar. Catechic tannins and flavonoids were abundant in E1, HM and EA, whilst terpenoids were abundantly present in E1 and n-B but only weekly in HM. Coumarins were found in E2, EA and n-B. Polyphenols, expressed as gallic acid equivalent, amounted, per 100 g plant matter, to 329, 1002 and 150 mg in EA, HM an E1 respectively. Flavonoids, expressed as catechin equivalent, amounted, per 100 g plant matter to 620, 241 and 94 mg in EA, HM and E1 respectively. Comparable values were found in n-B and E1, with lower values in E2. Quercetin, myricetin and gallic acid were found in the EA and HM extracts by thin layer chromatography, The antioxidative effect of these extracts yielded, when tested at a concentration of 2 000 µg/mL in a 1,1-diphenyl-2-picrylhydrazyl assay, a reducing percentage of 88.8% with EA, 74.5% with HM and 66.2% with E1, and corresponding IC50 of 350, 580 and 500 µg/mL as compared to 1.1 µg/mL for ascorbic acid. Conclusions These qualitative and quantitative analytical data document the presence in C. colocynthis extracts of such chemical compounds as flavonoids responsible for the antioxidant activity, as well as other biological activities of this plant. PMID:23570014

  2. Total phenolic contents and free-radical scavenging activities of grape (Vitis vinifera L.) and grape products.

    PubMed

    Keser, Serhat; Celik, Sait; Turkoglu, Semra

    2013-03-01

    Grape is one of the world's largest fruit crops, with an approximate annual production of 58 million metric tons, and it is well known that the grape skins, seeds and stems, waste products generated during wine and grape juice processing, are rich sources of polyphenols. It contains flavonoids, phenolic acids and stilbenes. In this study, we tried to determine antioxidant properties and phenolic contents of grape and grape products (fresh fruit, seed, dried fruit, molasses, pestil, vinegar) of ethanol and water extracts. Antioxidant properties of extracts were investigated by DPPH(√), ABTS(√+), superoxide, H(2)O(2) scavenging, reducing power, metal chelating activity and determination of total phenolic contents. The seed extracts revealed highest ABTS(√+), DPPH(√), H(2)O(2) scavenging and reducing power activities. Furthermore, these extracts showed higher total phenolic contents than other grape product extracts.

  3. Curcumin Blocks Naproxen-Induced Gastric Antral Ulcerations through Inhibition of Lipid Peroxidation and Activation of Enzymatic Scavengers in Rats.

    PubMed

    Kim, Jeong-Hwan; Jin, Soojung; Kwon, Hyun Ju; Kim, Byung Woo

    2016-08-28

    Curcumin is a polyphenol derived from the plant Curcuma longa, which is used for the treatment of diseases associated with oxidative stress and inflammation. The present study was undertaken to determine the protective effect of curcumin against naproxen-induced gastric antral ulcerations in rats. Different doses (10, 50, and 100 mg/kg) of curcumin or vehicle (curcumin, 0 mg/kg) were pretreated for 3 days by oral gavage, and then gastric mucosal lesions were caused by 80 mg/kg naproxen applied for 3 days. Curcumin significantly inhibited the naproxen-induced gastric antral ulcer area and lipid peroxidation in a dose-dependent manner. In addition, curcumin markedly increased activities of radical scavenging enzymes, such as superoxide dismutase (SOD), catalase, and glutathione peroxidase in a dose-dependent manner. Specifically, 100 mg/kg curcumin completely protected the gastric mucosa against the loss in the enzyme, resulting in a drastic increase of activities of radical scavenging enzymes up to more than the level of untreated normal rats. Histological examination obviously showed that curcumin prevents naproxen-induced gastric antral ulceration as a result of direct protection of the gastric mucosa. These results suggest that curcumin blocks naproxen-induced gastric antral ulcerations through prevention of lipid peroxidation and activation of radical scavenging enzymes, and it may offer a potential remedy of gastric antral ulcerations.

  4. Extracts and constituents of Rubus chingii with 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity.

    PubMed

    Ding, Hsiou-Yu

    2011-01-01

    The 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity of the fruits of Rubus chingii was studied in vitro. Ethanolic extract, ethyl acetate and n-butanol fractions from dried R. chingii fruits revealed strong DPPH free radical scavenging activity with IC(50) values of 17.9, 3.4 and 4.0 μg/mL, respectively. The ethyl acetate and n-butanol fractions were further purified by a combination of silica gel chromatography, Lobar RP-8 chromatography, and high-pressure liquid chromatography (HPLC). Nine compounds were isolated, where methyl (3-hydroxy-2-oxo-2,3-dihydroindol-3-yl)-acetate (2), vanillic acid (5), kaempferol (7), and tiliroside (9) showed stronger DPPH free radical scavenging activity than that of ascorbic acid (131.8 μM) with IC(50) values of 45.2, 34.9, 78.5, and 13.7 μM, respectively. In addition, rubusine (1) is a new compound discovered in the present study and methyl (3-hydroxy-2-oxo-2,3-dihydroindol-3-yl)-acetate (2), methyl dioxindole-3-acetate (3), and 2-oxo-1,2-dihydroquinoline-4-carboxylic acid (4) were isolated from the fruits for the first time.

  5. HPLC-Analysis of Polyphenolic Compounds in Gardenia jasminoides and Determination of Antioxidant Activity by Using Free Radical Scavenging Assays

    PubMed Central

    Uddin, Riaz; Saha, Moni Rani; Subhan, Nusrat; Hossain, Hemayet; Jahan, Ismet Ara; Akter, Raushanara; Alam, Ashraful

    2014-01-01

    Purpose: Gardenia jasminoides is a traditional medicinal plant rich in anti-inflammatory flavonoids and phenolic compounds and used for the treatment of inflammatory diseases and pain. In this present study, antioxidant potential of Gardenia jasminoides leaves extract was evaluated by using various antioxidant assays. Methods: Various antioxidant assays such as 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, reducing power and total antioxidant capacity expressed as equivalent to ascorbic acid were employed. Moreover, phenolic compounds were detected by high-performance liquid chromatography (HPLC) coupled with diode-array detection. Results: The methanol extract showed significant free radical scavenging activities in DPPH radical scavenging antioxidant assays compared to the reference antioxidant ascorbic acid. Total antioxidant activity was increased in a dose dependent manner. The extract also showed strong reducing power. The total phenolic content was determined as 190.97 mg/g of gallic acid equivalent. HPLC coupled with diode-array detection was used to identify and quantify the phenolic compounds in the extracts. Gallic acid, (+)-catechin, rutin hydrate and quercetin have been identified in the plant extracts. Among the phenolic compounds, catechin and rutin hydrate are present predominantly in the extract. The accuracy and precision of the presented method were corroborated by low intra- and inter-day variations in quantitative results in leaves extract. Conclusion: These results suggest that phenolic compounds and flavonoids might contribute to high antioxidant activities of Gardenia jasminoides leaves. PMID:24754012

  6. Extracts and Constituents of Rubus chingii with 1,1-Diphenyl-2-picrylhydrazyl (DPPH) Free Radical Scavenging Activity

    PubMed Central

    Ding, Hsiou-Yu

    2011-01-01

    The 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity of the fruits of Rubus chingii was studied in vitro. Ethanolic extract, ethyl acetate and n-butanol fractions from dried R. chingii fruits revealed strong DPPH free radical scavenging activity with IC50 values of 17.9, 3.4 and 4.0 μg/mL, respectively. The ethyl acetate and n-butanol fractions were further purified by a combination of silica gel chromatography, Lobar RP-8 chromatography, and high-pressure liquid chromatography (HPLC). Nine compounds were isolated, where methyl (3-hydroxy-2-oxo-2,3-dihydroindol-3-yl)-acetate (2), vanillic acid (5), kaempferol (7), and tiliroside (9) showed stronger DPPH free radical scavenging activity than that of ascorbic acid (131.8 μM) with IC50 values of 45.2, 34.9, 78.5, and 13.7 μM, respectively. In addition, rubusine (1) is a new compound discovered in the present study and methyl (3-hydroxy-2-oxo-2,3-dihydroindol-3-yl)-acetate (2), methyl dioxindole-3-acetate (3), and 2-oxo-1,2-dihydroquinoline-4-carboxylic acid (4) were isolated from the fruits for the first time. PMID:21747716

  7. Curcumin Blocks Naproxen-Induced Gastric Antral Ulcerations through Inhibition of Lipid Peroxidation and Activation of Enzymatic Scavengers in Rats.

    PubMed

    Kim, Jeong-Hwan; Jin, Soojung; Kwon, Hyun Ju; Kim, Byung Woo

    2016-08-28

    Curcumin is a polyphenol derived from the plant Curcuma longa, which is used for the treatment of diseases associated with oxidative stress and inflammation. The present study was undertaken to determine the protective effect of curcumin against naproxen-induced gastric antral ulcerations in rats. Different doses (10, 50, and 100 mg/kg) of curcumin or vehicle (curcumin, 0 mg/kg) were pretreated for 3 days by oral gavage, and then gastric mucosal lesions were caused by 80 mg/kg naproxen applied for 3 days. Curcumin significantly inhibited the naproxen-induced gastric antral ulcer area and lipid peroxidation in a dose-dependent manner. In addition, curcumin markedly increased activities of radical scavenging enzymes, such as superoxide dismutase (SOD), catalase, and glutathione peroxidase in a dose-dependent manner. Specifically, 100 mg/kg curcumin completely protected the gastric mucosa against the loss in the enzyme, resulting in a drastic increase of activities of radical scavenging enzymes up to more than the level of untreated normal rats. Histological examination obviously showed that curcumin prevents naproxen-induced gastric antral ulceration as a result of direct protection of the gastric mucosa. These results suggest that curcumin blocks naproxen-induced gastric antral ulcerations through prevention of lipid peroxidation and activation of radical scavenging enzymes, and it may offer a potential remedy of gastric antral ulcerations. PMID:27197667

  8. The isolation and identification of two compounds with predominant radical scavenging activity in hempseed (seed of Cannabis sativa L.).

    PubMed

    Chen, Tianpeng; He, Jinfeng; Zhang, Jianchun; Li, Xiaohui; Zhang, Hua; Hao, Jianxiong; Li, Lite

    2012-09-15

    Forty samples were extracted from defatted kernels and hulls of two varieties of hempseed (Bama and Yunma No. 1) using 10 different polar solvent systems. The radical scavenging capacity of the extracts was evaluated using 2,2-diphenyl-1-pikrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays and the total phenolic content was determined by Folin-Ciocalteu's phenol reagent. The correlation analysis indicated that the antioxidants in hempseed belonged to phenolic and DPPH() assay was suitable for evaluating the radical scavenging activity. Two compounds, with predominant antiradical activity, were isolated in 60% ethanol extract of hempseed hull using macroporous resin absorption, LH-20 gel chromatography, and high performance liquid chromatography methods, which were identified as N-trans-caffeoyltyramine and cannabisin B by high-resolution mass spectra, nuclear magnetic resonance spectra, and ultraviolet data. The two compounds exhibited significant high DPPH() scavenging activity and protective effect against in vitro oxidation of human low-density lipoprotein compared with extracts from flaxseed, grape seed, and soybean. This suggests that hempseed hull extract is a potential source of natural antioxidants, which could be added to dietary supplements to help prevent oxidative stress.

  9. Metabolomic Analyses of Brain Tissue in Sepsis Induced by Cecal Ligation Reveal Specific Redox Alterations--Protective Effects of the Oxygen Radical Scavenger Edaravone.

    PubMed

    Hara, Naomi; Chijiiwa, Miyuki; Yara, Miki; Ishida, Yusuke; Ogiwara, Yukihiko; Inazu, Masato; Kuroda, Masahiko; Karlsson, Michael; Sjovall, Fredrik; Elmér, Eskil; Uchino, Hiroyuki

    2015-12-01

    The pathophysiology of sepsis-associated encephalopathy (SAE) is complex and remains incompletely elucidated. Dysregulated reactive oxygen species (ROS) production and mitochondrial-mediated necrotic-apoptotic pathway have been proposed as part of the pathogenesis. The present study aimed at analyzing the preventive effect of the free radical scavenger edaravone on sepsis-induced brain alterations. Sepsis was induced by cecal ligation and puncture (CLP) and the mice were divided into three groups-CLP vehicle (CLPV), CLP and edaravone (MCI-186, 3-methyl-1-phenyl-2-pyrazolin-5-one) (CLPE), and sham-operated (Sham). Mice in CLPV and CLPE were injected with saline or edaravone intraperitoneally at a dose of 10 mg/kg twice daily. The treatments were initiated 4 days prior to the surgical procedure. Mortality, histological changes, electron microscopy (EM), and expression of Bcl-2 family genes (Bcl-2 and Bax) were analyzed in selected brain regions. CLPE showed significant improvement in survival compared with CLPV 18 h postinduction of sepsis (P < 0.05). At the same time point, pathohistological analysis also showed marked reduction of neuronal cell death in both parietal cortex and hippocampus in the CLPE (P < 0.05). RT-PCR and immunoblotting directed at the Bcl-2 family revealed increased Bax mRNA levels in hippocampus at 12 h in CLPV as well as an increased Bax/Bcl-2 protein ratio, changes that were significantly suppressed in CLPE. In conclusion, our study suggests that sepsis induced by cecal ligation alters cerebral redox status and supports a proapoptotic phenotype. The free radical scavenger edavarone reduces mortality of septic mice and protects against sepsis-induced neuronal cell death.

  10. Effect of Cu(2+)-complexation on the scavenging ability of chrysin towards photogenerated singlet molecular oxygen (O2((1)Δg)). Possible biological implications.

    PubMed

    Muñoz, Vanesa A; Ferrari, Gabriela V; Montaña, M Paulina; Miskoski, Sandra; García, Norman A

    2016-09-01

    Visible-light irradiation of aqueous-ethanolic solutions of Riboflavin (Rf) in the individual presence of the flavone chrysin (Chr) and its complex with Cu(2+) ([Chr2Cu]; 2:1 L:M) generates singlet molecular oxygen O2((1)Δg), that concomitantly interact with both flavone derivatives. Overall (kt) and reactive (kr) rate constants in the order of 10(7)M(-1)s(-1) were determined for the process. Metal chelation greatly enhances the scavenging ability of [Chr2Cu] towards O2((1)Δg) through a mechanism dominated, in >80%, by the physical component. In this way, practically all O2((1)Δg) is deactivated by the complex without significant loss of the quencher. The isolated flavone quenches O2((1)Δg) in a prevailing reactive fashion. The very low value exhibited by [Chr2Cu] for the kr/kt ratio constitutes a positive quality for antioxidative protectors in biological media, where elevated local concentration and high reactivity of significant molecules make them initial targets for O2((1)Δg) aggression. Finally, two interesting properties in the field of free radicals scavenging by [Chr2Cu] must be mentioned. In first place metal chelation itself, in the obvious sense of free metal ion withdrawal from the oxidizable medium, prevents the initiation of a free radical-mediated oxidation processes through mechanisms of Fenton or lipid peroxidation. In addition, the incorporation of Cu adds to [Chr2Cu] the ability of a free radical scavenger, already described for similar Cu-chelate compounds. This collection of beneficial properties positions the complex as a remarkably promising bioprotector towards ROS-mediated oxidation. A quantification of the efficiency on the initial anti-oxidative effect exerted by Chr and [Chr2Cu] towards tryptophan was carried out. The amino acid is an archetypal molecular model, commonly employed to monitor oxidative degradation of proteinaceous media. It was efficiently photoprotected against O2((1)Δg)-mediated photooxidation by [Chr2Cu]. PMID

  11. Evaluation of free hydroxyl radical scavenging activities of some Chinese herbs by capillary zone electrophoresis with amperometric detection.

    PubMed

    Li, Hui; Wang, Qingjiang

    2004-04-01

    Due to the severe damage caused by free hydroxyl radicals (OH.) to cells and tissues, there is much interest in finding and studying effective and non-toxic OH. scavengers, including traditional Chinese herbs. In this paper, the simple and highly-sensitive technique of capillary zone electrophoresis with amperometric detection (CZE-AD) was used to study the OH. scavenging activities of aqueous extracts from some traditional Chinese herbs. Salicylic acid (SAL) was used as an OH. trap, and the content of OH. could be determined by assaying their products, 2,3-dihydroxybenzoic acid (2,3-DHBA) and 2,5-dihydroxybenzoic acid (2,5-DHBA). The optimum conditions for CZE-AD for the determination of 2,3-DHBA and 2,5-DHBA were explored. The linearity ranges of 2,3-DHBA and 2,5-DHBA were 1.0 x10(-7) approximately 1.0 x10(-4) mol L(-1), and their detection limits were as low as 2 x 10(-8) mol L(-1), which were much better than the CE-UV method often used. The traditional Chinese herbs studied included Radix angelicae sinensis, Rhizoma coptidis, Ligustrum lucidum, Ligusticum wallichii, Radices glycyrrhizae and Semen plantaginis. The experiments showed that the aqueous extracts from all of the above traditional Chinese herds had free OH. scavenging activities, although to different degrees. PMID:14985912

  12. Poor glycaemic control is associated with reduced serum free radical scavenging (antioxidant) activity in non-insulin-dependent diabetes mellitus.

    PubMed

    Maxwell, S R; Thomason, H; Sandler, D; LeGuen, C; Baxter, M A; Thorpe, G H; Jones, A F; Barnett, A H

    1997-11-01

    The diabetic patient is at significantly increased risk of developing vascular disease. Its aetiology may involve oxidative damage by free radicals and protection against such damage can be offered by radical-scavenging antioxidants. We investigated whether there was a relationship between glycaemic control as assessed by measurement of glycated haemoglobin (HbA1c) and serum antioxidant status in a population of 118 diabetic outpatients with either insulin-dependent or non-insulin-dependent diabetes. Amongst patients with non-insulin-dependent diabetes mellitus there was a significant inverse correlation between levels of glycated haemoglobin and total free radical scavenging activity (r = -0.456, P < 0.0001). This association resulted primarily because of a similar correlation with uric acid (r = -0.421, P = 0.0003). There was also a weak inverse correlation with vitamin A but no significant association with vitamin C or vitamin E levels. There were no significant associations found amongst the patients with insulin-dependent diabetes. These results indicate that poor diabetic control is associated with reduced serum free radical scavenging (antioxidant) activity in non-insulin-dependent diabetes mellitus. By implication improved glycaemic control may preserve serum antioxidant status in diabetes.

  13. Chemical composition and radical scavenging activity of essential oil and methanolic extract of Eremostachys azerbaijanica Rech.f. from Iran

    PubMed Central

    Asnaashari, Solmaz; Afshar, Fariba Heshmati; Ebrahimi, Atefeh; Moghadam, Sedigheh Bamdad; Delazar, Abbas

    2016-01-01

    In the present study, the chemical composition of the essential oil and methanol (MeOH) extract of aerials of E. azerbaijanica were identified. Furthermore, the free radical scavenging properties of the volatile oil as well as the MeOH extract of the plant were assessed. The essential oil of the air-dried aerial parts was obtained by hydro-distillation using a Clevenger-type apparatus. The oil was then analyzed by gas chromatography–mass spectrometry and gas chromatography with flame ionization detector. Soxhlet extraction was performed on the aerial parts using n-hexane, dichloromethane and MeOH. The MeOH extract was then subjected to solid-phase extraction using a C18 Sep-Pak cartridge. Isolation and structural elucidation of the pure components was accomplished by high-performance liquid chromatography and spectroscopic methods (UV, 1H-NMR). The free radical scavenging properties were determined by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay. A total of 59 components representing 95.9% of the oil constituents were identified which were primarily characterized as terpenoids or aliphatic skeletons. The major components of the oil were hexahydrofarnesyl acetone (27.1%), 2-methyl-6-propyl-dodecane (16.4%) and tricosane (9.3%). One flavonoid (luteolin-7-O-rutinoside) and one phenylethanoid (verbascoside) were also isolated and identified from the MeOH extract. The results of DPPH assays showed that the essential oil of E. azerbaijanica possessed weak free radical scavenging activity whereas the MeOH extract and its pure constituents showed significant scavenging activities in comparison with positive controls. PMID:27168750

  14. Effects of Extraction and Processing Methods on Antioxidant Compound Contents and Radical Scavenging Activities of Laver (Porphyra tenera)

    PubMed Central

    Hwang, Eun-Sun; Thi, Nhuan Do

    2014-01-01

    Laver is one of the most consumed edible red algae seaweeds in the genus Porphyra. Laver is primarily prepared in the form of dried, roasted, and seasoned products. We investigated the total polyphenol and flavonoid contents of laver products, and evaluated the in vitro antioxidant properties of solvent extracts from commercially processed laver products. Significant differences in the concentration of phenolic compounds were found among differently processed laver. The total phenolic content for laver extracts ranged from 10.81 mg gallic acid equivalent (GAE)/g extract to 32.14 mg GAE/g extract, depending on extraction solvent and temperature. Laver extracts contained very few flavonoids (0.55 mg catechin equivalent/g extracts to 1.75 mg catechin equivalent/g extracts). 2,2-Diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS), hydroxyl radical, and superoxide anion scavenging assays were used to determine the radical scavenging capacities of laver extracts. These assays revealed that the processing method and extraction condition affected the antioxidant potentials of laver. Antioxidant activity of dried laver, roasted laver, and seasoned laver increased in a concentration-dependent manner (100~1,000 μg/mL). The radical scavenging activities of 37°C and 100°C water extracts were lower than that of a 37°C 70% ethanol extract. The highest radical scavenging capacity was observed in the 37°C 70% ethanol extracts of dried laver, roasted laver, and seasoned laver. Overall, these results support that notion that laver contains bioactive compounds, such as polyphenols and flavonoids, which may have a positive effect on health. PMID:24772408

  15. Chemical composition and radical scavenging activity of essential oil and methanolic extract of Eremostachys azerbaijanica Rech.f. from Iran.

    PubMed

    Asnaashari, Solmaz; Afshar, Fariba Heshmati; Ebrahimi, Atefeh; Moghadam, Sedigheh Bamdad; Delazar, Abbas

    2016-01-01

    In the present study, the chemical composition of the essential oil and methanol (MeOH) extract of aerials of E. azerbaijanica were identified. Furthermore, the free radical scavenging properties of the volatile oil as well as the MeOH extract of the plant were assessed. The essential oil of the air-dried aerial parts was obtained by hydro-distillation using a Clevenger-type apparatus. The oil was then analyzed by gas chromatography-mass spectrometry and gas chromatography with flame ionization detector. Soxhlet extraction was performed on the aerial parts using n-hexane, dichloromethane and MeOH. The MeOH extract was then subjected to solid-phase extraction using a C18 Sep-Pak cartridge. Isolation and structural elucidation of the pure components was accomplished by high-performance liquid chromatography and spectroscopic methods (UV, (1)H-NMR). The free radical scavenging properties were determined by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay. A total of 59 components representing 95.9% of the oil constituents were identified which were primarily characterized as terpenoids or aliphatic skeletons. The major components of the oil were hexahydrofarnesyl acetone (27.1%), 2-methyl-6-propyl-dodecane (16.4%) and tricosane (9.3%). One flavonoid (luteolin-7-O-rutinoside) and one phenylethanoid (verbascoside) were also isolated and identified from the MeOH extract. The results of DPPH assays showed that the essential oil of E. azerbaijanica possessed weak free radical scavenging activity whereas the MeOH extract and its pure constituents showed significant scavenging activities in comparison with positive controls. PMID:27168750

  16. Determination of Free Radical Scavenging, Antioxidative DNA Damage Activities and Phytochemical Components of Active Fractions from Lansium domesticum Corr. Fruit

    PubMed Central

    Klungsupya, Prapaipat; Suthepakul, Nava; Muangman, Thanchanok; Rerk-Am, Ubon; Thongdon-A, Jeerayu

    2015-01-01

    Lansium domesticum Corr. or “long-kong” is one of the most popular fruits in Thailand. Its peel (skin, SK) and seeds (SD) become waste unless recycled or applied for use. This study was undertaken to determine the bioactivity and phytochemical components of L. domesticum (LD) skin and seed extracts. Following various extraction and fractionation procedures, 12 fractions were obtained. All fractions were tested for antioxidant capacity against O2−• and OH•. It was found that the peel of L. domesticum fruits exhibited higher O2−• and OH• scavenging activity than seeds. High potential antioxidant activity was found in two fractions of 50% ethanol extract of peel followed by ethyl acetate (EA) fractionation (LDSK50-EA) and its aqueous phase (LDSK50-H2O). Therefore, these two active fractions were selected for further studies on their antioxidative activity against DNA damage by hydrogen peroxide (H2O2) in human TK6 cells using comet assay. The comet results revealed DNA-protective activity of both LDSK50-EA and LDSK50-H2O fractions when TK6 human lymphoblast cells were pre-treated at 25, 50, 100, and 200 μg/mL for 24 h prior to H2O2 exposure. The phytochemical analysis illustrated the presence of phenolic substances, mainly scopoletin, rutin, and chlorogenic acid, in these two active fractions. This study generates new information on the biological activity of L. domesticum. It will promote and strengthen the utilization of L. domesticum by-products. PMID:26287238

  17. Basic investigations on the performance of a normoxic polymer gel with tetrakis-hydroxy-methyl-phosphonium chloride as an oxygen scavenger: Reproducibility, accuracy, stability, and dose rate dependence

    SciTech Connect

    Bayreder, Christian; Georg, Dietmar; Moser, Ewald; Berg, Andreas

    2006-07-15

    Magnetic resonance (MR)-based polymer gel dosimetry using normoxic polymer gels, represents a new dosimetric method specially suited for high-resolution three-dimensional dosimetric problems. The aim of this study was to investigate the dose response with regard to stability, accuracy, reproducibility, and the dose rate dependence. Tetrakis-hydroxy-methyl-phosphonium chloride (THPC) is used as an oxygen scavenger, and methacrylic acid as a monomer. Accuracy, reproducibility, and dose resolution were determined for MR protocols at low spatial resolution (typical for clinical scanners), medium, and microimaging-resolution protocols at three different dose levels. The dose-response stability and preirradiation-induced variations in R2, related to the time interval between preparation and irradiation of the polymer gel, were investigated. Also postirradiation stability of the polymer gel was considered. These experiments were performed using a {sup 60}Co beam (E=1.2 MV) in a water phantom. Moreover, we investigated the dose rate dependence in the low, medium, and saturation dose region of the normoxic polymer gel using a linear accelerator at photon energy of 25 MV. MR scanning was performed on a 3 T whole body scanner (MEDSPEC 30/80, BRUKER BIOSPIN, Ettlingen, Germany) using several coils and different gradient systems adapted to the acquired spatial resolution investigated. For T2-parameter selective imaging and determination of the relaxation rate R2=1/T2, a multiple spin echo sequence with 20 equidistant echoes was used. With regard to preirradiation induced variations R2 increases significantly with the increasing time interval between the polymer gel preparation and irradiation. Only a slight increase in R2 can be observed for varying the postirradiation-time solely. The dose reproducibility at voxel volumes of about 1.4x1.4x2 mm{sup 3} is better than 2%. The accuracy strongly depends on the calibration curve. THPC represents a very effective oxygen scavenger in

  18. ROI-scavenging enzyme activities as toxicity biomarkers in three species of marine microalgae exposed to model contaminants (copper, Irgarol and atrazine).

    PubMed

    Lozano, Pablo; Trombini, Chiara; Crespo, Elena; Blasco, Julián; Moreno-Garrido, Ignacio

    2014-06-01

    There is a need to develop efficient tools to prevent damage to marine ecosystems due to pollution. Since microalgae play a key role in marine ecosystems, they are considered potentially useful for quick and sensitive toxicity bioassays. In this study an integrative analysis has been carried out of the anti-oxidant enzyme activities of marine microalgae species. Three marine microalgae species (Cylindrotheca closterium, a benthic diatom; Phaeodactylum tricornutum, a diatom which has been used as model organism in toxicity bioassays; and Rhodomonas salina, a cryptophyceae which is considered to present a certain level of heterotrophy) were exposed to selected concentrations of three model pollutants: copper (5 and 10µg L(-1)), atrazine (25 and 50µg L(-1)) and Irgarol (0.5 and 1.0µg L(-1)). These pollutant concentrations are environmentally relevant for coastal ecosystems, and have been selected for checking the efficiency of the reactive oxygen intermediate (ROI) scavenging enzyme system of these organisms. Superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APx) and glutathione peroxidase (GPx) activities were measured at the end of 24h exposure. The integrated biomarker response (IBR) index - in our case for oxidative stress - has been employed to evaluate the ROI-scavenging enzyme system for each species and each treatment. In general, the SOD and CAT enzyme activities measured were higher in exposed populations than in controls, whereas APx and GPx activities showed the opposite trend. These microalgae showed significant responses of oxidative stress biomarkers at environmentally relevant concentrations for the assayed pollutants and short exposure periods, conditions that most other model organisms cannot match. Therefore microalgae present clear advantages over other species for their prospective employment in an "early warning system".

  19. The cytoprotective effect of isorhamnetin against oxidative stress is mediated by the upregulation of the Nrf2-dependent HO-1 expression in C2C12 myoblasts through scavenging reactive oxygen species and ERK inactivation.

    PubMed

    Choi, Yung Hyun

    2016-04-01

    This study was designed to confirm the protective effects of isorhamnetin against oxidative stress-induced cellular damage. Our results indicated that isorhamnetin inhibited the hydrogen peroxide (H2O2)-induced growth inhibition and exhibited scavenging activity against the intracellular reactive oxygen species (ROS) in mouse-derived C2C12 myoblasts. Isorhamnetin also significantly attenuated H2O2-induced DNA damage and apoptosis, and increased the levels of the nuclear factor erythroid 2-related factor 2 (Nrf2) and its phosphorylation associated with the induction of heme oxygenase-1 (HO-1). However, the protective effects of isorhamnetin on H2O2-induced ROS and growth inhibition were significantly abolished by an HO-1 competitive inhibitor. Moreover, the potential of isorhamnetin to mediate HO-1 induction and protect against H2O2-mediated growth inhibition was abrogated by transient transfection with Nrf2-specific small interfering RNA. Additionally, isorhamnetin induced the activation of mitogen-activated protein kinases (MAPKs), such as extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 MAPK. However, the specific inhibitor of ERK, but not JNK and p38 MAPK, was able to abolish the HO-1 upregulation and the Nrf2 phosphorylation. Collectively, these results demonstrate that isorhamnetin augments the cellular antioxidant defense capacity by activating the Nrf2/HO-1 pathway involving the activation of the ERK pathway, thus protecting the C2C12 cells from H2O2-induced cytotoxicity. PMID:26830132

  20. Preliminary studies on the activities of spin traps as scavengers of free radicals

    SciTech Connect

    Ogunbiyi, P.O.; Washington, I. )

    1991-03-15

    The spin trapping agents, N-t-Butyl-a-phenyl-nitrone (PBN) and 5,5-Dimethyl-1-pyroline-N-oxide (DMPO) have been used to investigate the primary free radicals involved in various tissue injuries. Also, PBN and DMPO can provide some protection against free radical-induced lung injuries. However, their therapeutic potentials as free radical scavengers remained unexamined. In this study, the effects of PBN and DMPO on guinea pig lung microsomal lipid peroxidation were investigated using thiobarbituric acid-reactive substance assay. Superoxide anions (O{sup 2}{minus}) were generated in an enzymatic and a non-enzymatic system. PBN and DMPO each, significantly inhibited NADPH-stimulated lipid peroxidation irrespective of the presence of Fe{sup 3+}. Cytochrome c reduction by the enzymatic and nitro blue tetrazolium reduction by the non-enzymatic O{sup 2}{minus} generating systems were both inhibited by PBN and DMPO as well as superoxide dismutase and dimethyl sulfoxide when compared with the controls. The spin traps exhibited lower potencies in these systems than the reference compounds, SOD and DMSO, which are well established as O{sup 2}{minus} and hydroxyl radical scavengers respectively. Results demonstrate the free radical scavenging properties of PBN and DMPO. This is an indication of their possible usefulness as antioxidants.

  1. A STRESS-RESPONSIVE NAC1-Regulated Protein Phosphatase Gene Rice Protein Phosphatase18 Modulates Drought and Oxidative Stress Tolerance through Abscisic Acid-Independent Reactive Oxygen Species Scavenging in Rice1[W][OPEN

    PubMed Central

    You, Jun; Zong, Wei; Hu, Honghong; Li, Xianghua; Xiao, Jinghua; Xiong, Lizhong

    2014-01-01

    Plants respond to abiotic stresses through a complexity of signaling pathways, and the dephosphorylation mediated by protein phosphatase (PP) is an important event in this process. We identified a rice (Oryza sativa) PP2C gene, OsPP18, as a STRESS-RESPONSIVE NAC1 (SNAC1)-regulated downstream gene. The ospp18 mutant was more sensitive than wild-type plants to drought stress at both the seedling and panicle development stages. Rice plants with OsPP18 suppressed through artificial microRNA were also hypersensitive to drought stress. Microarray analysis of the mutant revealed that genes encoding reactive oxygen species (ROS) scavenging enzymes were down-regulated in the ospp18 mutant, and the mutant exhibited reduced activities of ROS scavenging enzymes and increased sensitivity to oxidative stresses. Overexpression of OsPP18 in rice led to enhanced osmotic and oxidative stress tolerance. The expression of OsPP18 was induced by drought stress but not induced by abscisic acid (ABA). Although OsPP18 is a typical PP2C with enzymatic activity, it did not interact with SNF1-RELATED PROTEIN KINASE2 protein kinases, which function in ABA signaling. Meanwhile, the expression of ABA-responsive genes was not affected in the ospp18 mutant, and the ABA sensitivities of the ospp18 mutant and OsPP18-overexpressing plants were also not altered. Together, these findings suggest that OsPP18 is a unique PP2C gene that is regulated by SNAC1 and confers drought and oxidative stress tolerance by regulating ROS homeostasis through ABA-independent pathways. PMID:25318938

  2. Bacterial Fucose-Rich Polysaccharide Stabilizes MAPK-Mediated Nrf2/Keap1 Signaling by Directly Scavenging Reactive Oxygen Species during Hydrogen Peroxide-Induced Apoptosis of Human Lung Fibroblast Cells

    PubMed Central

    Roy Chowdhury, Sougata; Sinha, Tridib Kumar; Sen, Ramkrishna; Basak, Ratan Kumar; Adhikari, Basudam; Bhattacharyya, Arindam

    2014-01-01

    Continuous free radical assault upsets cellular homeostasis and dysregulates associated signaling pathways to promote stress-induced cell death. In spite of the continuous development and implementation of effective therapeutic strategies, limitations in treatments for stress-induced toxicities remain. The purpose of the present study was to determine the potential therapeutic efficacy of bacterial fucose polysaccharides against hydrogen peroxide (H2O2)-induced stress in human lung fibroblast (WI38) cells and to understand the associated molecular mechanisms. In two different fermentation processes, Bacillus megaterium RB-05 biosynthesized two non-identical fucose polysaccharides; of these, the polysaccharide having a high-fucose content (∼42%) conferred the maximum free radical scavenging efficiency in vitro. Structural characterizations of the purified polysaccharides were performed using HPLC, GC-MS, and 1H/13C/2D-COSY NMR. H2O2 (300 µM) insult to WI38 cells showed anti-proliferative effects by inducing intracellular reactive oxygen species (ROS) and by disrupting mitochondrial membrane permeability, followed by apoptosis. The polysaccharide (250 µg/mL) attenuated the cell death process by directly scavenging intracellular ROS rather than activating endogenous antioxidant enzymes. This process encompasses inhibition of caspase-9/3/7, a decrease in the ratio of Bax/Bcl2, relocalization of translocated Bax and cytochrome c, upregulation of anti-apoptotic members of the Bcl2 family and a decrease in the phosphorylation of MAPKs (mitogen activated protein kinases). Furthermore, cellular homeostasis was re-established via stabilization of MAPK-mediated Nrf2/Keap1 signaling and transcription of downstream cytoprotective genes. This molecular study uniquely introduces a fucose-rich bacterial polysaccharide as a potential inhibitor of H2O2-induced stress and toxicities. PMID:25412177

  3. Bacterial fucose-rich polysaccharide stabilizes MAPK-mediated Nrf2/Keap1 signaling by directly scavenging reactive oxygen species during hydrogen peroxide-induced apoptosis of human lung fibroblast cells.

    PubMed

    Roy Chowdhury, Sougata; Sengupta, Suman; Biswas, Subir; Sinha, Tridib Kumar; Sen, Ramkrishna; Basak, Ratan Kumar; Adhikari, Basudam; Bhattacharyya, Arindam

    2014-01-01

    Continuous free radical assault upsets cellular homeostasis and dysregulates associated signaling pathways to promote stress-induced cell death. In spite of the continuous development and implementation of effective therapeutic strategies, limitations in treatments for stress-induced toxicities remain. The purpose of the present study was to determine the potential therapeutic efficacy of bacterial fucose polysaccharides against hydrogen peroxide (H2O2)-induced stress in human lung fibroblast (WI38) cells and to understand the associated molecular mechanisms. In two different fermentation processes, Bacillus megaterium RB-05 biosynthesized two non-identical fucose polysaccharides; of these, the polysaccharide having a high-fucose content (∼ 42%) conferred the maximum free radical scavenging efficiency in vitro. Structural characterizations of the purified polysaccharides were performed using HPLC, GC-MS, and (1)H/(13)C/2D-COSY NMR. H2O2 (300 µM) insult to WI38 cells showed anti-proliferative effects by inducing intracellular reactive oxygen species (ROS) and by disrupting mitochondrial membrane permeability, followed by apoptosis. The polysaccharide (250 µg/mL) attenuated the cell death process by directly scavenging intracellular ROS rather than activating endogenous antioxidant enzymes. This process encompasses inhibition of caspase-9/3/7, a decrease in the ratio of Bax/Bcl2, relocalization of translocated Bax and cytochrome c, upregulation of anti-apoptotic members of the Bcl2 family and a decrease in the phosphorylation of MAPKs (mitogen activated protein kinases). Furthermore, cellular homeostasis was re-established via stabilization of MAPK-mediated Nrf2/Keap1 signaling and transcription of downstream cytoprotective genes. This molecular study uniquely introduces a fucose-rich bacterial polysaccharide as a potential inhibitor of H2O2-induced stress and toxicities.

  4. A STRESS-RESPONSIVE NAC1-regulated protein phosphatase gene rice protein phosphatase18 modulates drought and oxidative stress tolerance through abscisic acid-independent reactive oxygen species scavenging in rice.

    PubMed

    You, Jun; Zong, Wei; Hu, Honghong; Li, Xianghua; Xiao, Jinghua; Xiong, Lizhong

    2014-12-01

    Plants respond to abiotic stresses through a complexity of signaling pathways, and the dephosphorylation mediated by protein phosphatase (PP) is an important event in this process. We identified a rice (Oryza sativa) PP2C gene, OsPP18, as a STRESS-RESPONSIVE NAC1 (SNAC1)-regulated downstream gene. The ospp18 mutant was more sensitive than wild-type plants to drought stress at both the seedling and panicle development stages. Rice plants with OsPP18 suppressed through artificial microRNA were also hypersensitive to drought stress. Microarray analysis of the mutant revealed that genes encoding reactive oxygen species (ROS) scavenging enzymes were down-regulated in the ospp18 mutant, and the mutant exhibited reduced activities of ROS scavenging enzymes and increased sensitivity to oxidative stresses. Overexpression of OsPP18 in rice led to enhanced osmotic and oxidative stress tolerance. The expression of OsPP18 was induced by drought stress but not induced by abscisic acid (ABA). Although OsPP18 is a typical PP2C with enzymatic activity, it did not interact with SNF1-RELATED PROTEIN KINASE2 protein kinases, which function in ABA signaling. Meanwhile, the expression of ABA-responsive genes was not affected in the ospp18 mutant, and the ABA sensitivities of the ospp18 mutant and OsPP18-overexpressing plants were also not altered. Together, these findings suggest that OsPP18 is a unique PP2C gene that is regulated by SNAC1 and confers drought and oxidative stress tolerance by regulating ROS homeostasis through ABA-independent pathways.

  5. Optimized enzymatic colorimetric assay for determination of hydrogen peroxide (H2O2) scavenging activity of plant extracts.

    PubMed

    Fernando, Chamira Dilanka; Soysa, Preethi

    2015-01-01

    The classical method to determine hydrogen peroxide (H2O2) scavenging activity of plant extracts is evaluated by measuring the disappearance of H2O2 at a wavelength of 230 nm. Since this method suffers from the interference of phenolics having strong absorption in the UV region, a simple and rapid colorimetric assay was developed where plant extracts are introduced to H2O2, phenol and 4-aminoantipyrine reaction system in the presence of horseradish peroxidase (HRP). This reaction yields a quinoneimine chromogen which can be measured at 504 nm. Decrease in the colour intensity reflects the H2O2 scavenged by the plant material. •Optimum conditions determined for this assay were 30 min reaction time, 37 °C, pH 7, enzyme concentration of 1 U/ml and H2O2 concentration of 0.7 mM. The limit of detection (LOD) and limit of quantitation (LOQ) were 136 μM and 411 μM, respectively.•Half maximal effective concentration required to scavenge 50% of H2O2 in the system (EC50 value) calculated for several plant extracts and standard antioxidants resulted in coefficient of variance (CV%) of the EC50 values less than 3.0% and correlation coefficient values (R (2)) > 0.95 for all dose response curves obtained.•This method is convenient and very precise which is suitable for the rapid quantification of H2O2 scavenging ability of standard antioxidants and natural antioxidants present in plant extracts.

  6. Optimized enzymatic colorimetric assay for determination of hydrogen peroxide (H2O2) scavenging activity of plant extracts

    PubMed Central

    Fernando, Chamira Dilanka; Soysa, Preethi

    2015-01-01

    The classical method to determine hydrogen peroxide (H2O2) scavenging activity of plant extracts is evaluated by measuring the disappearance of H2O2 at a wavelength of 230 nm. Since this method suffers from the interference of phenolics having strong absorption in the UV region, a simple and rapid colorimetric assay was developed where plant extracts are introduced to H2O2, phenol and 4-aminoantipyrine reaction system in the presence of horseradish peroxidase (HRP). This reaction yields a quinoneimine chromogen which can be measured at 504 nm. Decrease in the colour intensity reflects the H2O2 scavenged by the plant material. • Optimum conditions determined for this assay were 30 min reaction time, 37 °C, pH 7, enzyme concentration of 1 U/ml and H2O2 concentration of 0.7 mM. The limit of detection (LOD) and limit of quantitation (LOQ) were 136 μM and 411 μM, respectively. • Half maximal effective concentration required to scavenge 50% of H2O2 in the system (EC50 value) calculated for several plant extracts and standard antioxidants resulted in coefficient of variance (CV%) of the EC50 values less than 3.0% and correlation coefficient values (R2) > 0.95 for all dose response curves obtained. • This method is convenient and very precise which is suitable for the rapid quantification of H2O2 scavenging ability of standard antioxidants and natural antioxidants present in plant extracts. PMID:26285798

  7. Free-radical scavenging properties and antioxidant activities of botryosphaeran and some other β-D-glucans.

    PubMed

    Giese, Ellen C; Gascon, Jacob; Anzelmo, Gianluca; Barbosa, Aneli M; da Cunha, Mário A Alves; Dekker, Robert F H

    2015-01-01

    β-D-Glucans are known to present antitumor, anticancer, and anti-inflammatory activities that are influenced by their own antioxidant capacity. The antioxidant activity of botryosphaeran, an exopolysaccharide of the (1 → 3;1 → 6)-β-D-glucan type produced by the Botryosphaeria rhodina MAMB-05 was evaluated and compared to some other β-D-glucans (lasiodiplodan an exocellular (1 → 6)-β-D-glucan from Lasiodiplodia theobromae, laminarin and curdlan), and oligosaccharides, disaccharides, and monosaccharides in a study of scavenging activities of free radicals in-vitro. Botryosphaeran displayed high total antioxidant activity (80%) as well as good scavenging activity against hydroxyl radical (90.6%), superoxide anion (37%), hydrogen peroxide (38%), and nitric oxide radical (90%). No reducing power, metal-chelating capacity or inhibition of lipid peroxidation was observed for these β-D-glucans. The results demonstrated that botryosphaeran exhibited effective antioxidant activity as supported by many different assays, suggesting that this β-D-glucan may serve as a source of a new bioactive compound with effective antioxidant activity. PMID:25128096

  8. Biochar activated by oxygen plasma for supercapacitors

    NASA Astrophysics Data System (ADS)

    Gupta, Rakesh Kumar; Dubey, Mukul; Kharel, Parashu; Gu, Zhengrong; Fan, Qi Hua

    2015-01-01

    Biochar, also known as black carbon, is a byproduct of biomass pyrolysis. As a low-cost, environmental-friendly material, biochar has the potential to replace more expensive synthesized carbon nanomaterials (e.g. carbon nanotubes) for use in future supercapacitors. To achieve high capacitance, biochar requires proper activation. A conventional approach involves mixing biochar with a strong base and baking at a high temperature. However, this process is time consuming and energy inefficient (requiring temperatures >900 °C). This work demonstrates a low-temperature (<150 °C) plasma treatment that efficiently activates a yellow pine biochar. Particularly, the effects of oxygen plasma on the biochar microstructure and supercapacitor characteristics are studied. Significant enhancement of the capacitance is achieved: 171.4 F g-1 for a 5-min oxygen plasma activation, in comparison to 99.5 F g-1 for a conventional chemical activation and 60.4 F g-1 for untreated biochar. This enhancement of the charge storage capacity is attributed to the creation of a broad distribution in pore size and a larger surface area. The plasma activation mechanisms in terms of the evolution of the biochar surface and microstructure are further discussed.

  9. Biosynthesis and radical scavenging activity of betalains during the cultivation of red beet (Beta vulgaris) hairy root cultures.

    PubMed

    Pavlov, Atanas; Kovatcheva, Petia; Georgiev, Vasil; Koleva, Irina; Ilieva, Mladenka

    2002-01-01

    Betalains biosynthesis and antiradical scavenging activity were investigated during cultivation of four hairy root cultures of Beta vulgaris, obtained from different cultivars (Bordo, Egyptian, Detroit 2 and Detroit Dark Red). The best producer of betalains was a hairy root culture from Beta vulgaris cv. Detroit Dark Red (13.27 mg/g dry weight total pigment production). The ethanol extract, derived from roots of the same culture grown for 15 days under submerged conditions, showed a high antiradical activity (83% of inhibition of the stable DPPH.). PMID:12240990

  10. Cytotoxic, radical scavenging and antimicrobial activities of sesquiterpenoids from the Tahitian liverwort Mastigophora diclados (Brid.) Nees (Mastigophoraceae).

    PubMed

    Komala, Ismiarni; Ito, Takuya; Nagashima, Fumihiro; Yagi, Yasuyuki; Asakawa, Yoshinori

    2010-10-01

    A drimane, (+)-drimenol (1), five known herbertanes, (-)-alpha-herbertenol (2), (-)-herbertenediol (3), mastigophorene A (4), (-)-mastigophorene C (5) and (-)-mastigophorene D (6), a pimarane, (-)-ent-pimara-8(14),15-dien-19-oic acid (7), and two eudesmanolides, (-)-diplophyllolide A (8) and (-)-diplophyllin (9) were isolated from the Tahitian Mastigophora diclados (Brid.) Nees. Herbertane sesquiterpenes (2, 3, 5 and 6) showed cytotoxicity against HL-60 and KB cell lines, radical scavenging activity and antimicrobial activity against Bacillus subtilis. (-)-Diplophyllolide A (8) also exhibited cytotoxicity against HL-60 and KB cell lines. PMID:20458547

  11. Evidence for the Therapeutic Efficacy of Either Mild Hypothermia or Oxygen Radical Scavengers after Repetitive Mild Traumatic Brain Injury

    PubMed Central

    Miyauchi, Takashi; Wei, Enoch P.

    2014-01-01

    Abstract Repetitive brain injury, particularly that occurring with sporting-related injuries, has recently garnered increased attention in both the clinical and public settings. In the laboratory, we have demonstrated the adverse axonal and vascular consequences of repetitive brain injury and have demonstrated that moderate hypothermia and/or FK506 exerted protective effects after repetitive mild traumatic brain injury (mTBI) when administered within a specific time frame, suggesting a range of therapeutic modalities to prevent a dramatic exacerbation. In this communication, we revisit the utility of targeted therapeutic intervention to seek the minimal level of hypothermia needed to achieve protection while probing the role of oxygen radicals and their therapeutic targeting. Male Sprague-Dawley rats were subjected to repetitive mTBI by impact acceleration injury. Mild hypothermia (35°C, group 2), superoxide dismutase (group 3), and Tempol (group 4) were employed as therapeutic interventions administered 1 h after the repetitive mTBI. To assess vascular function, cerebral vascular reactivity to acetylcholine was evaluated 3 and 4 h after the repetitive mTBI, whereas to detect the burden of axonal damage, amyloid precursor protein (APP) density in the medullospinal junction was measured. Whereas complete impairment of vascular reactivity was observed in group 1 (without intervention), significant preservation of vascular reactivity was found in the other groups. Similarly, whereas remarkable increase in the APP-positive axon was observed in group 1, there were no significant increases in the other groups. Collectively, these findings indicate that even mild hypothermia or the blunting free radical damage, even when performed in a delayed period, is protective in repetitive mTBI. PMID:24341607

  12. Endothelial dysfunction enhances vasoconstriction due to scavenging of nitric oxide by a hemoglobin-based oxygen carrier

    PubMed Central

    Yu, Binglan; Shahid, Mohd; Egorina, Elena M.; Sovershaev, Mikhail A.; Raher, Michael J.; Lei, Chong; Wu, Mei X.; Bloch, Kenneth D.; Zapol, Warren M.

    2010-01-01

    Background At present, there is no safe and effective hemoglobin-based oxygen carrier (HBOC) to substitute for red blood cell transfusion. It is uncertain whether a deficiency of endothelial nitric oxide bioavailability (endothelial dysfunction) prevents or augments the HBOC-induced vasoconstriction. Methods Hemodynamic effects of infusion of PolyHeme (1.08 g hemoglobin/kg, Northfield Laboratories, Evanston, IL) or murine tetrameric hemoglobin (0.48 g hemoglobin/kg) were determined in awake healthy lambs, awake mice and anesthetized mice. In vitro, a cumulative dose-tension response was obtained by sequential addition of PolyHeme or tetrameric hemoglobin to phenylephrine-precontracted murine aortic rings. Results Infusion of PolyHeme did not cause systemic hypertension in awake lambs, but produced acute systemic and pulmonary vasoconstriction. Infusion of PolyHeme did not cause systemic hypertension in healthy wild-type mice, but induced severe systemic vasoconstriction in mice with endothelial dysfunction (either db/db mice or high-fat fed wild-type mice for 4–6 weeks). The db/db mice were more sensitive to systemic vasoconstriction than wild-type mice after the infusion of either tetrameric hemoglobin or PolyHeme. Murine aortic ring studies confirmed that db/db mice have an impaired response to an endothelial-dependent vasodilator and an enhanced vasoconstrictor response to a HBOC. Conclusions Reduction of low molecular weight hemoglobin concentrations to less than 1% is insufficient to abrogate the vasoconstrictor effects of HBOC infusion in healthy awake sheep or in mice with reduced vascular nitric oxide levels associated with endothelial dysfunction. These findings suggest that testing HBOCs in animals with endothelial dysfunction can provide a more sensitive indication of their potential vasoconstrictor effects. PMID:20179495

  13. Phenolics, sugars, antimicrobial and free-radical-scavenging activities of Melicoccus bijugatus Jacq. fruits from the Dominican Republic and Florida.

    PubMed

    Bystrom, Laura M; Lewis, Betty A; Brown, Dan L; Rodriguez, Eloy; Obendorf, Ralph L

    2009-06-01

    Edible fruits of the native South American tree Melicoccus bijugatus Jacq. are consumed fresh or in traditional food, drink and medicinal preparations. Some therapeutic effects of these fruits may be due to phenolics and sugars. Aqueous acetone, methanol or ethanol tissue extracts of different cultivars or collections of M. bijugatus fruits from the Dominican Republic and Florida were analyzed for total phenolics and free radical scavenging activity by UV-vis spectroscopy, sugars by gas chromatography, and antimicrobial activity by the disc diffusion assay. Total phenolics and free radical scavenging activities ranked: seed coat > embryo > pulp extracts. Montgomery cultivar fruits had the highest total phenolics. For sugars: pulp > embryo and highest in Punta Cana fruit pulp. In all extracts: sucrose > glucose and fructose. Glucose:fructose ratios were 1:1 (pulp) and 0.2:1 (embryo). Pulp extracts had dose-response antibacterial activity and pulp and embryo extracts had antifungal activity against one yeast species. Phenolics and sugars were confirmed with thin-layer chromatography and nuclear magnetic resonance. Sugar-free pulp fractions containing phenolics had slightly more antimicrobial activity than H2O-soluble pulp fractions with sugars. Results indicate M. bijugatus fruits contain phenolics, sugars and other H2O-soluble compounds consistent with therapeutic uses. PMID:19444610

  14. Assessment of Free Radical Scavenging Activity of Dimethylglycine Sodium Salt and Its Role in Providing Protection against Lipopolysaccharide-Induced Oxidative Stress in Mice

    PubMed Central

    Zhang, Jingfei; Kou, Tao; Niu, Yu; Wan, Xiaoli; Zhang, Lili; Wang, Chao; Wang, Tian

    2016-01-01

    In the present study, the free radical scavenging activities (against 1,1-diphenyl-2-pierylhydrazy (DPPH), 2,2'-Azinobis-(3-ethylbenzthiazoline-6- sulphonate) (ABTS+), Hydrogen peroxide (H2O2)) of dimethylglycine sodium salt (DMG-Na) were measured and compared with those of Trolox (6-hydroxy-2, 5, 7, 8-tetramethylchroman-2-carboxylic acid), a commonly used antioxidant. The radical scavenging activities of DMG-Na were found to be the highest at 40 mg/ml. In Experiment 2, gastric intubation in mice with 12 mg DMG-Na/0.3 ml sterile saline solution significantly increased (P < 0.05) the body weight (BW) (28 d), organ proportion (liver and spleen), and antioxidant capacity in serum and the liver (Superoxide dismutase (SOD), Hydrogen peroxidase (CAT), Glutathione peroxidase (GPx), and Total antioxidant capacity (T-AOC)), and significantly decreased (P < 0.05) the activities of serum Glutamic-pyruvic transaminase (ALT) and Glutamic oxalacetic transaminase (AST) and Methane Dicarboxylic Aldehyde (MDA) contents in the serum and liver. Specifically, the effect of 12 mg DMG-Na/0.3 ml sterile saline solution, which showed the highest antioxidant capacity, was further studied using a mice model. In Experiment 3, the mice CL (CON+ lipopolysaccharide (LPS)) group showed a significant decrease (P < 0.05) in the serum ALT and AST content; hepatic mitochondrial antioxidant capacity (Manganese Superoxide dismutase (MnSOD), Glutathione reductase (GR), GPx, Glutathione (GSH)); MDA and Protein carbonyl (PC) content; Reactive oxygen species (ROS) level, Mitochondrial membrane potential (MMP) level, and expression of liver antioxidant genes (Nuclear factor erythroid 2-related factor 2 (Nrf2), Heme oxygenase 1 (HO-1), Manganese superoxide dismutase (MnSOD), Glutathione peroxidase 1 (Gpx1), Sirtuin 1 (Sirt1)) relative to the mice CS (CON+ sterile saline) group. The DL (DMG+LPS) group showed a significant decrease (P < 0.05) in serum ALT and AST content, ROS level, and expression of liver

  15. Assessment of Free Radical Scavenging Activity of Dimethylglycine Sodium Salt and Its Role in Providing Protection against Lipopolysaccharide-Induced Oxidative Stress in Mice.

    PubMed

    Bai, Kaiwen; Xu, Wen; Zhang, Jingfei; Kou, Tao; Niu, Yu; Wan, Xiaoli; Zhang, Lili; Wang, Chao; Wang, Tian

    2016-01-01

    In the present study, the free radical scavenging activities (against 1,1-diphenyl-2-pierylhydrazy (DPPH), 2,2'-Azinobis-(3-ethylbenzthiazoline-6- sulphonate) (ABTS+), Hydrogen peroxide (H2O2)) of dimethylglycine sodium salt (DMG-Na) were measured and compared with those of Trolox (6-hydroxy-2, 5, 7, 8-tetramethylchroman-2-carboxylic acid), a commonly used antioxidant. The radical scavenging activities of DMG-Na were found to be the highest at 40 mg/ml. In Experiment 2, gastric intubation in mice with 12 mg DMG-Na/0.3 ml sterile saline solution significantly increased (P < 0.05) the body weight (BW) (28 d), organ proportion (liver and spleen), and antioxidant capacity in serum and the liver (Superoxide dismutase (SOD), Hydrogen peroxidase (CAT), Glutathione peroxidase (GPx), and Total antioxidant capacity (T-AOC)), and significantly decreased (P < 0.05) the activities of serum Glutamic-pyruvic transaminase (ALT) and Glutamic oxalacetic transaminase (AST) and Methane Dicarboxylic Aldehyde (MDA) contents in the serum and liver. Specifically, the effect of 12 mg DMG-Na/0.3 ml sterile saline solution, which showed the highest antioxidant capacity, was further studied using a mice model. In Experiment 3, the mice CL (CON+ lipopolysaccharide (LPS)) group showed a significant decrease (P < 0.05) in the serum ALT and AST content; hepatic mitochondrial antioxidant capacity (Manganese Superoxide dismutase (MnSOD), Glutathione reductase (GR), GPx, Glutathione (GSH)); MDA and Protein carbonyl (PC) content; Reactive oxygen species (ROS) level, Mitochondrial membrane potential (MMP) level, and expression of liver antioxidant genes (Nuclear factor erythroid 2-related factor 2 (Nrf2), Heme oxygenase 1 (HO-1), Manganese superoxide dismutase (MnSOD), Glutathione peroxidase 1 (Gpx1), Sirtuin 1 (Sirt1)) relative to the mice CS (CON+ sterile saline) group. The DL (DMG+LPS) group showed a significant decrease (P < 0.05) in serum ALT and AST content, ROS level, and expression of liver

  16. Deferasirox is a powerful NF-κB inhibitor in myelodysplastic cells and in leukemia cell lines acting independently from cell iron deprivation by chelation and reactive oxygen species scavenging

    PubMed Central

    Messa, Emanuela; Carturan, Sonia; Maffè, Chiara; Pautasso, Marisa; Bracco, Enrico; Roetto, Antonella; Messa, Francesca; Arruga, Francesca; Defilippi, Ilaria; Rosso, Valentina; Zanone, Chiara; Rotolo, Antonia; Greco, Elisabetta; Pellegrino, Rosa M.; Alberti, Daniele; Saglio, Giuseppe; Cilloni, Daniela

    2010-01-01

    Background Usefulness of iron chelation therapy in myelodysplastic patients is still under debate but many authors suggest its possible role in improving survival of low-risk myelodysplastic patients. Several reports have described an unexpected effect of iron chelators, such as an improvement in hemoglobin levels, in patients affected by myelodysplastic syndromes. Furthermore, the novel chelator deferasirox induces a similar improvement more rapidly. Nuclear factor-κB is a key regulator of many cellular processes and its impaired activity has been described in different myeloid malignancies including myelodysplastic syndromes. Design and Methods We evaluated deferasirox activity on nuclear factor-κB in myelodysplastic syndromes as a possible mechanism involved in hemoglobin improvement during in vivo treatment. Forty peripheral blood samples collected from myelodysplastic syndrome patients were incubated with 50 μM deferasirox for 18h. Results Nuclear factor-κB activity dramatically decreased in samples showing high basal activity as well as in cell lines, whereas no similar behavior was observed with other iron chelators despite a similar reduction in reactive oxygen species levels. Additionally, ferric hydroxyquinoline incubation did not decrease deferasirox activity in K562 cells suggesting the mechanism of action of the drug is independent from cell iron deprivation by chelation. Finally, incubation with both etoposide and deferasirox induced an increase in K562 apoptotic rate. Conclusions Nuclear factor-κB inhibition by deferasirox is not seen from other chelators and is iron and reactive oxygen species scavenging independent. This could explain the hemoglobin improvement after in vivo treatment, such that our hypothesis needs to be validated in further prospective studies. PMID:20534700

  17. Hydrogen scavengers

    SciTech Connect

    Carroll, David W.; Salazar, Kenneth V.; Trkula, Mitchell; Sandoval, Cynthia W.

    2002-01-01

    There has been invented a codeposition process for fabricating hydrogen scavengers. First, a .pi.-bonded allylic organometallic complex is prepared by reacting an allylic transition metal halide with an organic ligand complexed with an alkali metal; and then, in a second step, a vapor of the .pi.-bonded allylic organometallic complex is combined with the vapor of an acetylenic compound, irradiated with UV light, and codeposited on a substrate.

  18. Enhanced DPPH radical scavenging activity and DNA protection effect of litchi pericarp extract by Aspergillus awamori bioconversion

    PubMed Central

    2012-01-01

    Background Litchi (Litchi chinensis Sonn.) pericarp is a major byproduct which contains a significant amount of polyphenol. This study was designed to biotransformation litchi pericarp extract (LPE) by Aspergillus awamori to produce more bioactive compounds with stronger antioxidant activities. Results The study exhibited that the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activities significantly (p < 0.05) increased from 15.53% to 18.23% in the water-extracted fraction and from 25.41% to 36.82% in the ethyl acetate-extracted fraction. Application of DNA cleavage assay further demonstrated the enhanced protection effect of the fermented phenolics on DNA damage. It is also noted that the water-extracted fraction of the fermented LPE possessed a much stronger capacity than the ethyl acetate-extracted fraction to prevent from damage of supercoiled DNA. Interestingly, it was found that some new compounds such as catechin and quercetin appeared after of A. awamori fermentation of LPE, which could account for the enhanced antioxidant activity. Conclusion The DPPH radical scavenging activity and DNA protection effect of LPE were increased by Aspergillus awamori bioconversion while some compounds responsible for the enhanced antioxidant activity were identified. This study provided an effective way of utilizing fruit pericarp as a readily accessible source of the natural antioxidants in food industry and, thus, extended the application area such as fruit by-products. PMID:23016522

  19. Enhancing cytokinin synthesis by overexpressing ipt alleviated drought inhibition of root growth through activating ROS-scavenging systems in Agrostis stolonifera

    PubMed Central

    Xu, Yi; Burgess, Patrick; Zhang, Xunzhong; Huang, Bingru

    2016-01-01

    Drought stress limits root growth and inhibits cytokinin (CK) production. Increases in CK production through overexpression of isopentenyltransferase (ipt) alleviate drought damages to promote root growth. The objective of this study was to investigate whether CK-regulated root growth was involved in the alteration of reactive oxygen species (ROS) production and ROS scavenging capacity under drought stress. Wild-type (WT) creeping bentgrass (Agrostis stolonifera L. ‘Penncross’) and a transgenic line (S41) overexpressing ipt ligated to a senescence-activated promoter (SAG12) were exposed to drought stress for 21 d in growth chambers. SAG12-ipt transgenic S41 developed a more extensive root system under drought stress compared to the WT. Root physiological analysis (electrolyte leakage and lipid peroxidation) showed that S41 roots exhibited less cellular damage compared to the WT under drought stress. Roots of SAG12-ipt transgenic S41 had significantly higher endogenous CK content than the WT roots under drought stress. ROS (hydrogen peroxide and superoxide) content was significantly lower and content of total and free ascorbate was significantly higher in S41 roots compared to the WT roots under drought stress. Enzymatic assays and transcript abundance analysis showed that superoxide dismutase, catalase, peroxidase, and dehydroascorbate reductase were significantly higher in S41 roots compared to the WT roots under drought stress. S41 roots also maintained significantly higher alternative respiration rates compared to the WT under drought stress. The improved root growth of transgenic creeping bentgrass may be facilitated by CK-enhanced ROS scavenging through antioxidant accumulation and activation of antioxidant enzymes, as well as higher alternative respiration rates when soil water is limited. PMID:26889010

  20. Antimicrobial, free radical scavenging activities and catalytic oxidation of benzyl alcohol by nano-silver synthesized from the leaf extract of Aristolochia indica L.: a promenade towards sustainability

    NASA Astrophysics Data System (ADS)

    Shanmugam, C.; Sivasubramanian, G.; Parthasarathi, Bera; Baskaran, K.; Balachander, R.; Parameswaran, V. R.

    2016-06-01

    Silver nanoparticles (Ag-NPs) were synthesized from aqueous silver nitrate through a simple route using the leaf extract of Aristolochia indica L. (LAIL) which acted as a reducing as well as capping agent. X-ray diffraction confirmed that the synthesized silver particles have a face centred cubic structure. EDS predicted the presence of elemental silver. The SEM images showed the synthesis of spherically mono-dispersed particles, with nano dimensions accounted by the TEM images. Infra-red spectrum adopted to the different organic functionalities present at the surface of the particles. TGA indicated an overall 11 % weight loss up to 1000 °C, suggesting desorption of biomolecules from the surface. X-ray photoelectron spectroscopy (XPS) analysis revealed the presence of metallic silver nanoparticles. The prepared material was utilized as catalyst in the oxidation of benzyl alcohol with molecular oxygen as the oxidant in methanol, under ambient conditions of temperature and pressure. Also Ag-NPs showed good to moderate anti-microbial activity employing the Agar disc diffusion method against various strains using Ciprofloxacin and Fluconazole as standard. Free radical scavenging activity of the nanoparticles were observed by modified 1,1-diphynyl-2-picrylhydrazyl, DPPH and 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid), ABTS in vitro assays. The work presented here demonstrates the adaptability of the synthesized Ag-NPs in participating as a disinfectant agent, free radical scavenger and an effective oxidation catalyst. The basic premise of attaining sustainability through the green synthesis of smart multifaceted materials has been consciously addressed.

  1. Enhancing cytokinin synthesis by overexpressing ipt alleviated drought inhibition of root growth through activating ROS-scavenging systems in Agrostis stolonifera.

    PubMed

    Xu, Yi; Burgess, Patrick; Zhang, Xunzhong; Huang, Bingru

    2016-03-01

    Drought stress limits root growth and inhibits cytokinin (CK) production. Increases in CK production through overexpression of isopentenyltransferase (ipt) alleviate drought damages to promote root growth. The objective of this study was to investigate whether CK-regulated root growth was involved in the alteration of reactive oxygen species (ROS) production and ROS scavenging capacity under drought stress. Wild-type (WT) creeping bentgrass (Agrostis stolonifera L. 'Penncross') and a transgenic line (S41) overexpressing ipt ligated to a senescence-activated promoter (SAG12) were exposed to drought stress for 21 d in growth chambers. SAG12-ipt transgenic S41 developed a more extensive root system under drought stress compared to the WT. Root physiological analysis (electrolyte leakage and lipid peroxidation) showed that S41 roots exhibited less cellular damage compared to the WT under drought stress. Roots of SAG12-ipt transgenic S41 had significantly higher endogenous CK content than the WT roots under drought stress. ROS (hydrogen peroxide and superoxide) content was significantly lower and content of total and free ascorbate was significantly higher in S41 roots compared to the WT roots under drought stress. Enzymatic assays and transcript abundance analysis showed that superoxide dismutase, catalase, peroxidase, and dehydroascorbate reductase were significantly higher in S41 roots compared to the WT roots under drought stress. S41 roots also maintained significantly higher alternative respiration rates compared to the WT under drought stress. The improved root growth of transgenic creeping bentgrass may be facilitated by CK-enhanced ROS scavenging through antioxidant accumulation and activation of antioxidant enzymes, as well as higher alternative respiration rates when soil water is limited. PMID:26889010

  2. Simultaneous quantification and validation of caffeoylquinic acids and flavonoids in Hemistepta lyrata and peroxynitrite-scavenging activity.

    PubMed

    Nugroho, Agung; Lim, Sang-Cheol; Byeon, Jeong Su; Choi, Jae Sue; Park, Hee-Juhn

    2013-03-25

    Traditionally, Hemistepta lyrata is consumed as a mountainous vegetable or a medicinal herb to treat inflammation, fever, hemorrhage, and hemorrhoids. In order to provide the scientific evidence of traditional uses of this plant, we identified and quantified thirteen active substances (caffeic acid, chlorogenic acid, and 3,5-di-O-caffeoylquinic acid as caffeoylquinic acids; apigenin, isorhoifolin, acacetin, linarin, diosmetin, diosmin, pectolinarigenin, and pectolinarin as flavones or their glycosides; kaempferol 3-O-rutinoside and rutin as flavonol glycosides) from H. lyrata and evaluated their peroxynitrite-scavenging activity. The chromatographic separation was performed on a Capcell Pak C18 column (5μm, 250mm×4.6mm i.d.) with a gradient elution of 0.05% TFA (trifluoroacetic acid) and 0.05% TFA in MeOH-CH(3)CN (60:40). Validation of HPLC methods on the linearity, LOD, LOQ, intra-day and inter-day variabilities, recovery, and repeatability proved that this method is selective, sensitive, precise, accurate, and reproducible. In peroxynitrite-scavenging assay, caffeic acid derivatives (chlorogenic acid, caffeic acid, and 3,5-di-O-caffeoylquinic acid) exhibited relatively lower IC(50) values than other substances tested. And HPLC simultaneous quantification showed that the 70% MeOH extract and the BuOH fraction contain a higher quantity of caffeic acid derivatives (17.82 and 30.09mg/g, consecutively). Therefore, caffeic acid derivatives could be the main contributors to the peroxynitrite-scavenging activity of H. lyrata than other phenolic substances.

  3. Dose-dependent vitamin C uptake and radical scavenging activity in human skin measured with in vivo electron paramagnetic resonance spectroscopy.

    PubMed

    Lauer, Anna-Christina; Groth, Norbert; Haag, Stefan F; Darvin, Maxim E; Lademann, Jürgen; Meinke, Martina C

    2013-01-01

    Vitamin C is a potent radical scavenger and a physiological part of the antioxidant system in human skin. The aim of this study was to measure changes in the radical-scavenging activity of human skin in vivo due to supplementation with different doses of vitamin C and at different time points. Therefore, 33 volunteers were supplemented with vitamin C or placebo for 4 weeks. The skin radical-scavenging activity was measured with electron paramagnetic resonance spectroscopy. After 4 weeks, the intake of 100 mg vitamin C/day resulted in a significant increase in the radical-scavenging activity by 22%. Intake of 180 mg/day even resulted in a significant increase of 37%. No changes were found in the placebo group. A part of the study population was additionally measured after 2 weeks: in this group radical scavenging had already reached maximal activity after 2 weeks. In conclusion, orally administered vitamin C increases the radical-scavenging activity of the skin. The effect occurs fast and is enhanced with higher doses of vitamin C.

  4. Activated Human Mast Cells Induce LOX-1-Specific Scavenger Receptor Expression in Human Monocyte-Derived Macrophages

    PubMed Central

    Alanne-Kinnunen, Mervi; Lappalainen, Jani; Öörni, Katariina; Kovanen, Petri T.

    2014-01-01

    Objective Activated mast cells in atherosclerotic lesions degranulate and release bioactive compounds capable of regulating atherogenesis. Here we examined the ability of activated human primary mast cells to regulate the expression of the major scavenger receptors in cultured human primary monocyte-derived macrophages (HMDMs). Results Components released by immunologically activated human primary mast cells induced a transient expression of lectin-like oxidized LDL receptor (LOX-1) mRNA in HMDMs, while the expression of two other scavenger receptors, MSR1 and CD36, remained unaffected. The LOX-1-inducing secretory components were identified as histamine, tumor necrosis factor alpha (TNF-α), and transforming growth factor beta (TGF-β1), which exhibited a synergistic effect on LOX-1 mRNA expression. Histamine induced a transient expression of LOX-1 protein. Mast cell –induced increase in LOX-1 expression was not associated with increased uptake of oxidized LDL by the macrophages. Conclusions Mast cell-derived histamine, TNF-α, and TGF-β1 act in concert to induce a transient increase in LOX-1 expression in human primary monocyte-derived macrophages. The LOX-1-inducing activity potentially endows mast cells a hitherto unrecognized role in the regulation of innate immune reactions in atherogenesis. PMID:25250731

  5. Can soaked-in scavengers protect metalloprotein active sites from reduction during data collection?

    PubMed

    Macedo, Sofia; Pechlaner, Maria; Schmid, Walther; Weik, Martin; Sato, Katsuko; Dennison, Christopher; Djinović-Carugo, Kristina

    2009-03-01

    One of the first events taking place when a crystal of a metalloprotein is exposed to X-ray radiation is photoreduction of the metal centres. The oxidation state of a metal cannot always be determined from routine X-ray diffraction experiments alone, but it may have a crucial impact on the metal's environment and on the analysis of the structural data when considering the functional mechanism of a metalloenzyme. Here, UV-Vis microspectrophotometry is used to test the efficacy of selected scavengers in reducing the undesirable photoreduction of the iron and copper centres in myoglobin and azurin, respectively, and X-ray crystallography to assess their capacity of mitigating global and specific radiation damage effects. UV-Vis absorption spectra of native crystals, as well as those soaked in 18 different radioprotectants, show dramatic metal reduction occurring in the first 60 s of irradiation with an X-ray beam from a third-generation synchrotron source. Among the tested radioprotectants only potassium hexacyanoferrate(III) seems to be capable of partially mitigating the rate of metal photoreduction at the concentrations used, but not to a sufficient extent that would allow a complete data set to be recorded from a fully oxidized crystal. On the other hand, analysis of the X-ray crystallographic data confirms ascorbate as an efficient protecting agent against radiation damage, other than metal centre reduction, and suggests further testing of HEPES and 2,3-dichloro-1,4-naphtoquinone as potential scavengers.

  6. Can Soaked-in Scavengers Protect Metalloprotein Active Sites from Reduction During Data Collection?

    SciTech Connect

    Macedo, S.; Pechlaner, M; Schmid, W; Weik, M; Sato, K; Dennison, C; Djinovic-Carugo, K

    2009-01-01

    One of the first events taking place when a crystal of a metalloprotein is exposed to X-ray radiation is photoreduction of the metal centres. The oxidation state of a metal cannot always be determined from routine X-ray diffraction experiments alone, but it may have a crucial impact on the metal's environment and on the analysis of the structural data when considering the functional mechanism of a metalloenzyme. Here, UV-Vis microspectrophotometry is used to test the efficacy of selected scavengers in reducing the undesirable photoreduction of the iron and copper centres in myoglobin and azurin, respectively, and X-ray crystallography to assess their capacity of mitigating global and specific radiation damage effects. UV-Vis absorption spectra of native crystals, as well as those soaked in 18 different radioprotectants, show dramatic metal reduction occurring in the first 60 s of irradiation with an X-ray beam from a third-generation synchrotron source. Among the tested radioprotectants only potassium hexacyanoferrate(III) seems to be capable of partially mitigating the rate of metal photoreduction at the concentrations used, but not to a sufficient extent that would allow a complete data set to be recorded from a fully oxidized crystal. On the other hand, analysis of the X-ray crystallographic data confirms ascorbate as an efficient protecting agent against radiation damage, other than metal centre reduction, and suggests further testing of HEPES and 2,3-dichloro-1,4-naphtoquinone as potential scavengers.

  7. Detoxication of sulfur half-mustards by nucleophilic scavengers: robust activity of thiopurines.

    PubMed

    Liu, Jinyun; Powell, K Leslie; Thames, Howard D; MacLeod, Michael C

    2010-03-15

    Sulfur mustard (bis-(2-chloroethyl)sulfide) has been used in chemical warfare since World War I and is well known as an acutely toxic vesicant. It has been implicated as a carcinogen after chronic low-level exposure and is known to form interstrand cross-links in DNA. Sulfur and nitrogen mustards are currently of interest as potential chemical threat agents for terrorists because of ease of synthesis. Sulfur mustard and monofunctional analogues (half-mustards, 2-[chloroethyl] alkyl sulfides) react as electrophiles, damaging cellular macromolecules, and thus are potentially subject to scavenging by nucleophilic agents. We have determined rate constants for the reaction of four purine derivatives that contain nucleophilic thiol moieties with several sulfur-half-mustards. Three of these compounds, 2,6-dithiopurine, 2,6-dithiouric acid, and 9-methyl-6-mercaptopurine, exhibit facile reaction with the electrophilic mustard compounds. At near neutral pH, these thiopurines are much better nucleophilic scavengers of mustard electrophiles than other low molecular weight thiols such as N-acetyl cysteine and glutathione. Progress curves calculated by numerical integration techniques indicate that equimolar concentrations of thiopurine provide significant reductions in the overall exposure to the episulfonium ions, which are the major reactive, electrophiles produced when sulfur mustards are dissolved in aqueous solution.

  8. Melatonin Improved Anthocyanin Accumulation by Regulating Gene Expressions and Resulted in High Reactive Oxygen Species Scavenging Capacity in Cabbage.

    PubMed

    Zhang, Na; Sun, Qianqian; Li, Hongfei; Li, Xingsheng; Cao, Yunyun; Zhang, Haijun; Li, Shuangtao; Zhang, Lei; Qi, Yan; Ren, Shuxin; Zhao, Bing; Guo, Yang-Dong

    2016-01-01

    In this work, we found, that exogenous melatonin pretreatment improved anthocyanin accumulation (1- to 2-fold) in cabbage. To verify the relationship with melatonin and anthocyanin, an Arabidopsis mutant, snat, which expresses a defective form of the melatonin biosynthesis enzyme SNAT (Serotonin N-acetyl transferase), was employed. Under cold conditions, the foliage of wild-type Arabidopsis exhibited a deeper red color than the snat mutant. This finding further proved, that exogenous melatonin treatment was able to affect anthocyanin accumulation. To gain a better understanding of how exogenous melatonin upregulates anthocyanin, we measured gene expression in cabbage samples treated with melatonin and untreated controls. We found that the transcript levels of anthocyanin biosynthetic genes were upregulated by melatonin treatment. Moreover, melatonin treatment increased the expression levels of the transcription factors MYB, bHLH, and WD40, which constitute the transcriptional activation complex responsible for coordinative regulation of anthocyanin biosynthetic genes. We found, that free radical generation was downregulated, whereas the osmotic adjustment and antioxidant capacities were upregulated in exogenous melatonin-treated cabbage plants. We concluded, that melatonin increases anthocyanin production and benefits cabbage growth. PMID:27047496

  9. Melatonin Improved Anthocyanin Accumulation by Regulating Gene Expressions and Resulted in High Reactive Oxygen Species Scavenging Capacity in Cabbage

    PubMed Central

    Zhang, Na; Sun, Qianqian; Li, Hongfei; Li, Xingsheng; Cao, Yunyun; Zhang, Haijun; Li, Shuangtao; Zhang, Lei; Qi, Yan; Ren, Shuxin; Zhao, Bing; Guo, Yang-Dong

    2016-01-01

    In this work, we found, that exogenous melatonin pretreatment improved anthocyanin accumulation (1- to 2-fold) in cabbage. To verify the relationship with melatonin and anthocyanin, an Arabidopsis mutant, snat, which expresses a defective form of the melatonin biosynthesis enzyme SNAT (Serotonin N-acetyl transferase), was employed. Under cold conditions, the foliage of wild-type Arabidopsis exhibited a deeper red color than the snat mutant. This finding further proved, that exogenous melatonin treatment was able to affect anthocyanin accumulation. To gain a better understanding of how exogenous melatonin upregulates anthocyanin, we measured gene expression in cabbage samples treated with melatonin and untreated controls. We found that the transcript levels of anthocyanin biosynthetic genes were upregulated by melatonin treatment. Moreover, melatonin treatment increased the expression levels of the transcription factors MYB, bHLH, and WD40, which constitute the transcriptional activation complex responsible for coordinative regulation of anthocyanin biosynthetic genes. We found, that free radical generation was downregulated, whereas the osmotic adjustment and antioxidant capacities were upregulated in exogenous melatonin-treated cabbage plants. We concluded, that melatonin increases anthocyanin production and benefits cabbage growth. PMID:27047496

  10. Free radical scavenging activities measured by electron spin resonance spectroscopy and B16 cell antiproliferative behaviors of seven plants.

    PubMed

    Calliste, C A; Trouillas, P; Allais, D P; Simon, A; Duroux, J L

    2001-07-01

    In an effort to discover new antioxidant natural compounds, seven plants that grow in France (most of them in the Limousin countryside) were screened. Among these plants, was the extensively studied Vitis vinifera as reference. For each plant, sequential percolation was realized with five solvents of increasing polarities (hexane, chloroform, ethyl acetate, methanol, and water). Free radical scavenging activities were examined in different systems using electron spin resonance (ESR) spectroscopy. These assays were based on the stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH), the hydroxyl radicals generated by a Fenton reaction, and the superoxide radicals generated by the X/XO system. Antiproliferative behavior was studied on B16 melanoma cells. ESR results showed that three plants (Castanea sativa, Filipendula ulmaria, and Betula pendula) possessed, for the most polar fractions (presence of phenolic compounds), high antioxidant activities in comparison with the Vitis vinifera reference. Gentiana lutea was the only one that presented a hydroxyl scavenging activity for the ethyl acetate and chloroform fractions. The antiproliferative test results showed that the same three plants are the most effective, but for the apolar fractions (chloroform and hexane).

  11. 1,1-Diphenyl-2-picrylhydrazyl radical-scavenging active compounds from greater cardamom (Amomum subulatum Roxb.).

    PubMed

    Kikuzaki, H; Kawai, Y; Nakatani, N

    2001-04-01

    Constituents of the fruits of greater cardamom (Amomum subulatum) were fractionated into three fractions, the dichloromethane extract, and the ethyl acetate-soluble and water-soluble fractions of the 70% aqueous acetone extract. The ethyl acetate-soluble fraction showed a high radical-scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH). Four compounds were isolated from the ethyl acetate-soluble fraction, and their structures were ascribed to protocatechualdehyde (1), protocatechuic acid (2), 1,7-bis(3,4-dihydroxyphenyl)hepta-4E,6E-dien-3-one (3) and 2,3,7-trihydroxy-5-(3,4-dihydroxy-E-styryl)-6,7,8,9-tetrahydro-5H-benzocycloheptene (4) on the basis of spectroscopic evidence. This is the first isolation of these compounds from greater cardamom. In particular, 4 was a new type of cyclic diarylheptanoid. DPPH radical-scavenging activity of these compounds was measured by colorimetric analysis. Compounds 1 and 3 showed stronger activity than such natural antioxidants as alpha-tocopherol and L-ascorbic acid. Compounds 2 and 4 were comparable to alpha-tocopherol and L-ascorbic acid.

  12. Betacyanins as phenol antioxidants. Chemistry and mechanistic aspects of the lipoperoxyl radical-scavenging activity in solution and liposomes.

    PubMed

    Tesoriere, L; Allegra, M; Gentile, C; Livrea, M A

    2009-08-01

    Reaction kinetics of betanin and its aglycone betanidin towards peroxyl radicals generated from the azo-initiated oxidation of methyl linoleate in methanol and of a heterogeneous aqueous/soybean phosphatidylcholine liposomal system were studied by monitoring formation of linoleic acid hydroperoxides and consumption of the pigments. Betanin was a weak retarder in methanol and an effective chain breaking antioxidant in the liposomal model, indicating that kinetic solvent effects and partition in lipid bilayers may affect its activity. Betanidin behaved as a chain terminating antioxidant in both models. Kinetic parameters characterizing peroxyl radical-scavenging activity showed that betanidin was more effective than betanin, in terms of both radical-scavenging rate constant and stoichiometric factor, with effectiveness of the same order as vitamin E under comparable conditions. Products identified by spectrophotometric and HPLC techniques indicated reaction of the glucose-substituted monophenol and ortho-diphenol moieties of betanin and betanidin, respectively, and suggested mechanisms of the antioxidant activity. Either betanin or betanidin incorporated in liposomes with alpha-tocopherol had additive effects, supporting partition of the pigments in the bilayer and lipoperoxyl radical reduction.

  13. A novel nematode effector suppresses plant immunity by activating host reactuve oxygen species-scavenging system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oxidative burst is a hallmark event of the pathogen-associated molecular pattern (PAMP) triggered immunity (PTI), which is the first line of plant defense mechanisms, but it remains unclear how nematodes can overcome this defense mechanism. In this study, we show that plant-parasitic nematode Meloid...

  14. Antioxidant Activity of Oxygen Evolving Enhancer Protein 1 Purified from Capsosiphon fulvescens.

    PubMed

    Kim, Eun-Young; Choi, Youn Hee; Lee, Jung Im; Kim, In-Hye; Nam, Taek-Jeong

    2015-06-01

    This study was conducted to determine the antioxidant activity of a protein purified from Capsosiphon fulvescens. The purification steps included sodium acetate (pH 6) extraction and diethylaminoethyl-cellulose, reversed phase Shodex C4P-50 column chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis indicated that the molecular weight of the purified protein was 33 kDa. The N-terminus and partial peptide amino acid sequence of this protein was identical to the sequence of oxygen evolving enhancer (OEE) 1 protein. The antioxidant activity of the OEE 1 was determined in vitro using a scavenging test with 4 types of reactive oxygen species (ROS), including the 2,2-diphenyl-1-picrylhydrazyl radical, hydroxyl radical, superoxide anion, and hydrogen peroxide (H2 O2 ). OEE 1 had higher H2 O2 scavenging activity, which proved to be the result of enzymatic antioxidants rather than nonenzymatic antioxidants. In addition, OEE 1 showed less H2 O2 -mediated ROS formation in HepG2 cells. In conclusion, this study demonstrates that OEE 1 purified from C. fulvescens is an excellent antioxidant. PMID:25944160

  15. Essential Oil from Flowers and Leaves of Elaeagnus Angustifolia (Elaeagnaceae): Composition, Radical Scavenging and General Toxicity Activities

    PubMed Central

    Torbati, Mohammadali; Asnaashari, Solmaz; Heshmati Afshar, Fariba

    2016-01-01

    Purpose: The aim of this work was to identify the chemical composition of the essential oils obtained from the flowers and leaves of Elaeagnus angostifolia (Elaeagnaceae) along with evaluate the radical scavenging and general toxicity activities. Methods: A combination of GC-MS and GC-FID were utilized for analyzing the chemical profile of the essential oils extracted by hydro-distillation from the leaves and flowers of E. angustifolia. The essential oils were subjected to general toxicity and radical scavenging assays using brine shrimp lethality test and DPPH method, respectively. Results: In total, 53 and 25 components were identified and quantified in the essential oils of flowers and leaves, accounting for 96.59% and 98.97% of the oil, respectively. The both oils were observed to be rich in ester compounds. The most abundant components of the oil from flowers were E-ethyl cinnamate (60.00%), hexahydrofarnesyl acetone (9.99%), palmitic acid (5.20%) and phytol (3.29%). The major constituents of the oil from leaves were E-ethyl cinnamate (37.27%), phytol (12.08%), nonanal (10.74%) and Z-3-hexenyl benzoate (7.65%). Both oils showed moderate activity in DPPH assay; however, they exhibited potent tocixity in brine shrimp lethality test. Conclusion: The remarkable toxicity effects of the oils are worthy to further investigation to find the probable mechanisms of action accountable for the noticeable toxic effect of these essential oils. PMID:27478777

  16. Mutagenicity, genotoxicity, and scavenging activities of extracts from the soft coral Chromonephthea braziliensis: a possibility of new bioactive compounds.

    PubMed

    Carpes, R M; Fleury, B G; Lages, B G; Pinto, A C; Aiub, C A F; Felzenszwalb, I

    2013-09-13

    Coral reefs are diverse ecosystems that have a high density of biodiversity leading to intense competition among species. These species may produce unknown substances, many with pharmacological value. Chromonephthea braziliensis is an invasive soft coral from the Indo-Pacific Ocean that is possibly transported by oil platforms and whose presence can be a threat to a region's biodiversity. This species produces secondary metabolites that are responsible for inducing damage to the local ecosystem. In the present study, extracts were prepared from dried colonies of C. braziliensis (solvents: hexane, dichloromethane, ethyl acetate, and methanol). We evaluated their mutagenicity using the Salmonella reverse mutation assay (TA97, TA98, TA100, and TA102 strains), their genotoxicity using the DNA breakage analysis and micronucleus assay, and scavenging activity using the 1,1-diphenyl-2-picrylhydrazyl-free radical assay. Cytotoxicity and mutagenicity were not observed for any of the extracts. Genotoxicity was observed for the dichloromethane, ethyl acetate, and methanol extracts at high concentrations, but no DNA damage was observed in the micronucleus assay. Scavenging activity was not detected.

  17. Ionizing Radiation Induces Macrophage Foam Cell Formation and Aggregation Through JNK-Dependent Activation of CD36 Scavenger Receptors

    SciTech Connect

    Katayama, Ikuo; Hotokezaka, Yuka; Matsuyama, Toshifumi; Sumi, Tadateru; Nakamura, Takashi

    2008-03-01

    Purpose: Irradiated arteries of cancer patients can be associated with atherosclerosis-like lesions containing cholesterol-laden macrophages (foam cells). Endothelial cell damage by irradiation does not completely explain the foam cell formation. We investigated the possible underlying mechanisms for ionizing radiation (IR)-induced foam cell formation. Methods and Materials: Human peripheral blood monocytes were activated by macrophage colony-stimulating factor and then treated with varying doses of IR in vitro in the absence of endothelial cells. Scavenger receptor expression and foam cell formation of IR-treated macrophages were investigated in the presence or absence of oxidized low-density lipoprotein. We also assessed the importance of mitogen-activated protein kinase activity in the macrophage colony-stimulating factor-activated human monocytes (macrophages) for the foam cell formation. Results: We found that IR treatment of macrophage colony-stimulating factor-activated human peripheral blood monocytes resulted in the enhanced expression of CD36 scavenger receptors and that cholesterol accumulated in the irradiated macrophages with resultant foam cell formation in the presence of oxidized low-density lipoprotein. Furthermore, when cultured on collagen gels, human macrophages formed large foam cell aggregates in response to IR. Antibodies against CD36 inhibited the IR-induced foam cell formation and aggregation, indicating that the IR-induced foam cell formation and the subsequent aggregation are dependent on functional CD36. In addition, we found that IR of human macrophages resulted in c-Jun N-terminal kinase activation and that c-Jun N-terminal kinase inhibition suppressed IR-induced CD36 expression and the subsequent foam cell formation and aggregation. Conclusion: Taken together, these results suggest that IR-induced foam cell formation is mediated by c-Jun N-terminal kinase-dependent CD36 activation.

  18. A Geospatial Scavenger Hunt

    ERIC Educational Resources Information Center

    Martinez, Adriana E.; Williams, Nikki A.; Metoyer, Sandra K.; Morris, Jennifer N.; Berhane, Stephen A.

    2009-01-01

    With the use of technology such as Global Positioning System (GPS) units and Google Earth for a simple-machine scavenger hunt, you will transform a standard identification activity into an exciting learning experience that motivates students, incorporates practical skills in technology, and enhances students' spatial-thinking skills. In the…

  19. Antiaging, antistress and ROS scavenging activity of crude extract of Ocimum sanctum (L.) in Caenorhabditis elegans (Maupas, 1900).

    PubMed

    Pandey, Rakesh; Gupta, Shipra; Shukla, Virendra; Tandon, Sudeep; Shukla, Vibha

    2013-07-01

    Since aging is the most important risk factor for variety of diseases, the discovery of a wide range of chemical modulators of aging in model organisms encourages new strategies for targeting age associated diseases. Simple genetic manipulation leads to long-lived and healthy animals, so any compound which could have similar effect would prove a boon to mankind. In the present study, effect of different pharmacological doses (1.0, 0.1, 0.01 and 0.001 mg/mL) of O. sanctum crude extract were used to determine their impact on life span, thermotolerance and ROS scavenging activities in C. elegans. The results revealed that 1 mg/mL of O. sanctum extract significantly extended the life span of C. elegans. The extract also proved to be a strong free radical scavenger and increased resistance against thermal stress. It is also suggested that the protective and life span extending action of the crude extract is not only due to its antioxidant capacity but may also be mediated by modulation of some signaling pathways. Thus, in addition to all the known medicinal property of Ocimum, it is capable of increasing stress tolerance and life span in C. elegans. PMID:23898550

  20. Identification and quantification of phytochemical composition and anti-inflammatory, cellular antioxidant, and radical scavenging activities of 12 Plantago species.

    PubMed

    Zhou, Qin; Lu, Weiying; Niu, Yuge; Liu, Jie; Zhang, Xiaowei; Gao, Boyan; Akoh, Casimir C; Shi, Haiming; Yu, Liangli Lucy

    2013-07-10

    Twenty-eight seed samples of 12 Plantago species were investigated for their chemical compositions and anti-inflammatory, cellular antioxidant, and radical scavenging properties. A new UPLC-UV procedure was developed and applied to quantify acteoside and geniposidic acid, the characteristic constituents of the genus Plantago. The amounts of acteoside and geniposidic acid ranged from 0.07 to 15.96 mg/g and from 0.05 to 10.04 mg/g in the tested samples, respectively. Furthermore, 26 compounds were tentatively identified by UPLC/Q-TOF-MS analysis. The Plantago samples significantly differed in their phytochemical compositions. The extracts of Plantago seeds also showed inhibitory effects on LPS-induced IL-1β, IL-6, and COX-2 mRNA expression in RAW 264.7 mouse macrophage cells. Additionally, significant variations were observed among different samples on cellular antioxidant activities in HepG2 cells, as well as DPPH and hydroxyl radical scavenging capacities. The results from this study may be used to promote the use of the genus Plantago in improving human health. PMID:23767948

  1. Development of an in Silico Model of DPPH• Free Radical Scavenging Capacity: Prediction of Antioxidant Activity of Coumarin Type Compounds.

    PubMed

    Goya Jorge, Elizabeth; Rayar, Anita Maria; Barigye, Stephen J; Jorge Rodríguez, María Elisa; Sylla-Iyarreta Veitía, Maité

    2016-01-01

    A quantitative structure-activity relationship (QSAR) study of the 2,2-diphenyl-l-picrylhydrazyl (DPPH•) radical scavenging ability of 1373 chemical compounds, using DRAGON molecular descriptors (MD) and the neural network technique, a technique based on the multilayer multilayer perceptron (MLP), was developed. The built model demonstrated a satisfactory performance for the training ( R 2 = 0.713 ) and test set ( Q ext 2 = 0.654 ) , respectively. To gain greater insight on the relevance of the MD contained in the MLP model, sensitivity and principal component analyses were performed. Moreover, structural and mechanistic interpretation was carried out to comprehend the relationship of the variables in the model with the modeled property. The constructed MLP model was employed to predict the radical scavenging ability for a group of coumarin-type compounds. Finally, in order to validate the model's predictions, an in vitro assay for one of the compounds (4-hydroxycoumarin) was performed, showing a satisfactory proximity between the experimental and predicted pIC50 values. PMID:27338348

  2. Development of an in Silico Model of DPPH• Free Radical Scavenging Capacity: Prediction of Antioxidant Activity of Coumarin Type Compounds

    PubMed Central

    Goya Jorge, Elizabeth; Rayar, Anita Maria; Barigye, Stephen J.; Jorge Rodríguez, María Elisa; Sylla-Iyarreta Veitía, Maité

    2016-01-01

    A quantitative structure-activity relationship (QSAR) study of the 2,2-diphenyl-l-picrylhydrazyl (DPPH•) radical scavenging ability of 1373 chemical compounds, using DRAGON molecular descriptors (MD) and the neural network technique, a technique based on the multilayer multilayer perceptron (MLP), was developed. The built model demonstrated a satisfactory performance for the training (R2=0.713) and test set (Qext2=0.654), respectively. To gain greater insight on the relevance of the MD contained in the MLP model, sensitivity and principal component analyses were performed. Moreover, structural and mechanistic interpretation was carried out to comprehend the relationship of the variables in the model with the modeled property. The constructed MLP model was employed to predict the radical scavenging ability for a group of coumarin-type compounds. Finally, in order to validate the model’s predictions, an in vitro assay for one of the compounds (4-hydroxycoumarin) was performed, showing a satisfactory proximity between the experimental and predicted pIC50 values. PMID:27338348

  3. Composition and Free Radical Scavenging Activity of Kernel Oil from Torreya grandis, Carya Cathayensis, and Myrica R ubra.

    PubMed

    Ni, Liang; Shi, Wei-Yong

    2014-01-01

    In this study, we measured the composition and free radical scavenging activity of several species of nuts, namely, Torreya grandis, Carya cathayensis, and Myrica rubra. The nut kernels of the aforementioned species are rich in fatty acids, particularly in unsaturated fatty acids, and have 51% oil content. T. grandis and C. cathayensis are mostly produced in ZheJiang province. The trace elements in the kernels of T. grandis and C. cathayensis were generally higher than those in M. rubra, except for Fe with a value of 64.41 mg/Kg. T. grandis is rich in selenium (52.91-68.71 mg/Kg). All three kernel oils have a certain free radical scavenging capacity, with the highest value in M. rubra. In the DPPH assay, the IC50 of M. rubra kernel oil was 60 μg/mL, and OH was 100 μg/mL. The results of this study provide basic data for the future development of the edible nut resources in ZheJiang province. PMID:24734074

  4. Systematic synthesis of galloyl-substituted procyanidin B1 and B2, and their ability of DPPH radical scavenging activity and inhibitory activity of DNA polymerases.

    PubMed

    Saito, Akiko; Mizushina, Yoshiyuki; Ikawa, Hiroshi; Yoshida, Hiromi; Doi, Yuki; Tanaka, Akira; Nakajima, Noriyuki

    2005-04-15

    Six galloyl-substituted procyanidin B1 and B2, 3-O-gallate, 3''-O-gallate, and 3,3''-di-O-gallate, were systematically synthesized with the condensation method using TMSOTf as a catalyst. Their ability of DPPH radical scavenging activity and DNA polymerase inhibitory activity were also investigated. The results indicated that the galloyl group of these compounds is very important for both activities. 3,3''-Di-O-gallate dimers acted as strong inhibitor against DNA polymerase alpha and beta, whereas the desgalloyl and monogalloyl compounds did not exhibit any appreciable inhibitory activity against the DNA polymerase beta.

  5. BIOLOGICALLY ENHANCED OXYGEN TRANSFER IN THE ACTIVATED SLUDGE PROCESS (JOURNAL)

    EPA Science Inventory

    Biologically enhanced oxgyen transfer has been a hypothesis to explain observed oxygen transfer rates in activated sludge systems that were well above that predicted from aerator clean-water testing. The enhanced oxygen transfer rates were based on tests using BOD bottle oxygen ...

  6. Henry's Law Activity of Oxygen in Molten Iron

    NASA Astrophysics Data System (ADS)

    Matousek, J. W.

    2015-09-01

    A model is proposed for the solubility of oxygen in molten iron in dilute solutions in which the oxygen exists in two states, free and associated. Only the free oxygen has thermodynamic activity in the sense of interaction with an electrochemical cell to produce the voltage described by the Nernst equation.

  7. Sulfur and selenium antioxidants: challenging radical scavenging mechanisms and developing structure-activity relationships based on metal binding.

    PubMed

    Zimmerman, Matthew T; Bayse, Craig A; Ramoutar, Ria R; Brumaghim, Julia L

    2015-04-01

    Because sulfur and selenium antioxidants can prevent oxidative damage, numerous animal and clinical trials have investigated the ability of these compounds to prevent the oxidative stress that is an underlying cause of cardiovascular disease, Alzheimer's disease, and cancer, among others. One of the most common sources of oxidative damage is metal-generated hydroxyl radical; however, very little research has focused on determining the metal-binding abilities and structural attributes that affect oxidative damage prevention by sulfur and selenium compounds. In this review, we describe our ongoing investigations into sulfur and selenium antioxidant prevention of iron- and copper-mediated oxidative DNA damage. We determined that many sulfur and selenium compounds inhibit Cu(I)-mediated DNA damage and that DNA damage prevention varies dramatically when Fe(II) is used in place of Cu(I) to generate hydroxyl radical. Oxidation potentials of the sulfur or selenium compounds do not correlate with their ability to prevent DNA damage, highlighting the importance of metal coordination rather than reactive oxygen species scavenging as an antioxidant mechanism. Additional gel electrophoresis, mass spectrometry, and UV-visible studies confirmed sulfur and selenium antioxidant binding to Cu(I) and Fe(II). Ultimately, our studies established that both the hydroxyl-radical-generating metal ion and the chemical environment of the sulfur or selenium significantly affect DNA damage prevention and that metal coordination is an essential mechanism for these antioxidants.

  8. Total phenolic contents and free radical scavenging activities of different extracts of seabuckthorn (Hippophae rhamnoides) pomace without seeds.

    PubMed

    Varshneya, Chandresh; Kant, Vinay; Mehta, Madhuri

    2012-03-01

    In this study, 100% methanolic extract (ME), 70% aqua-methanolic extract (AME) and 100% aqueous extract of seabuckthorn byproduct were used to evaluate antioxidant activity. The total phenolic contents were high in AME (84.28 ± 1.58 mg of Gallic Acid Equivalent (GAE)/gm of extract) compared to other extracts. All the extracts scavenged different in vitro radicals in a concentration-dependent manner. The IC(50) values were lowest in AME for 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt, 2,2-diphenyl-1-picrylhydrazyl, superoxide and nitric oxide radicals, while ME had lowest values for hydroxyl radicals. The reducing power of the extracts increased in a dose-dependent manner and was highest in AME. The findings of this study revealed that seabuckthorn pomace without seed is one of the important resources as an antioxidant for food, pharmaceuticals, cosmetic or nutraceutical industries. PMID:21875373

  9. Effect of UV-C irradiation and low temperature storage on bioactive compounds, antioxidant enzymes and radical scavenging activity of papaya fruit.

    PubMed

    Rivera-Pastrana, Dulce M; Gardea, Alfonso A; Yahia, Elhadi M; Martínez-Téllez, Miguel A; González-Aguilar, Gustavo A

    2014-12-01

    Mature green 'Maradol' papaya fruits were exposed to ultraviolet (UV)-C irradiation (1.48 kJ·m(-2)) and stored at 5 or 14 °C. Changes in total phenols, total flavonoids, enzymatic activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD), as well as the scavenging activity against 2,2-diphenyl-1picrylhydrazyl (DPPH) and 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radicals were investigated in peel and flesh tissues at 0, 5, 10 and 15 days of storage. UV-C irradiation increased significantly (P < 0.05) the flavonoid content (2.5 and 26 %) and ABTS radical scavenging activity (5.7 and 6 %) in flesh and peel at 14 °C respectively; and CAT activity (16.7 %) in flesh at 5 °C. Flavonoid contents, CAT and SOD activities were positively affected under low storage temperature (5 °C). DPPH and ABTS radical scavenging activities increased in both control and UV-C treated papaya peel during storage at 5 °C. UV-C irradiation effect on radical scavenging of papaya peel could be attributed to increased flavonoid content. Papaya antioxidant system was activated by UV-C and cold storage by increasing phenolic content and antioxidant enzymatic activities as a defense response against oxidative-stress. PMID:25477649

  10. Antioxidant potential of curcumin-related compounds studied by chemiluminescence kinetics, chain-breaking efficiencies, scavenging activity (ORAC) and DFT calculations.

    PubMed

    Slavova-Kazakova, Adriana K; Angelova, Silvia E; Veprintsev, Timur L; Denev, Petko; Fabbri, Davide; Dettori, Maria Antonietta; Kratchanova, Maria; Naumov, Vladimir V; Trofimov, Aleksei V; Vasil'ev, Rostislav F; Delogu, Giovanna; Kancheva, Vessela D

    2015-01-01

    This study compares the ability to scavenge different peroxyl radicals and to act as chain-breaking antioxidants of monomers related to curcumin (1): dehydrozingerone (2), zingerone (3), (2Z,5E)-ethyl 2-hydroxy-6-(4-hydroxy-3-methoxyphenyl)-4-oxohexa-2,5-dienoate (4), ferulic acid (5) and their corresponding C 2-symmetric dimers 6-9. Four models were applied: model 1 - chemiluminescence (CL) of a hydrocarbon substrate used for determination of the rate constants (k A) of the reactions of the antioxidants with peroxyl radicals; model 2 - lipid autoxidation (lipidAO) used for assessing the chain-breaking antioxidant efficiency and reactivity; model 3 - oxygen radical absorbance capacity (ORAC), which yields the activity against peroxyl radicals generated by an azoinitiator; model 4 - density functional theory (DFT) calculations at UB3LYP/6-31+G(d,p) level, applied to explain the structure-activity relationship. Dimers showed 2-2.5-fold higher values of k A than their monomers. Model 2 gives information about the effects of the side chains and revealed much higher antioxidant activity for monomers and dimers with α,β-unsaturated side chains. Curcumin and 6 in fact are dimers of the same monomer 2. We conclude that the type of linkage between the two "halves" by which the molecule is made up does not exert influence on the antioxidant efficiency and reactivity of these two dimers. The dimers and the monomers demonstrated higher activity than Trolox (10) in aqueous medium (model 3). A comparison of the studied compounds with DL-α-tocopherol (11), Trolox and curcumin is made. All dimers are characterized through lower bond dissociation enthalpies (BDEs) than their monomers (model 4), which qualitatively supports the experimental results. PMID:26425195

  11. Antioxidant potential of curcumin-related compounds studied by chemiluminescence kinetics, chain-breaking efficiencies, scavenging activity (ORAC) and DFT calculations

    PubMed Central

    Slavova-Kazakova, Adriana K; Angelova, Silvia E; Veprintsev, Timur L; Denev, Petko; Fabbri, Davide; Dettori, Maria Antonietta; Kratchanova, Maria; Naumov, Vladimir V; Trofimov, Aleksei V; Vasil’ev, Rostislav F

    2015-01-01

    Summary This study compares the ability to scavenge different peroxyl radicals and to act as chain-breaking antioxidants of monomers related to curcumin (1): dehydrozingerone (2), zingerone (3), (2Z,5E)-ethyl 2-hydroxy-6-(4-hydroxy-3-methoxyphenyl)-4-oxohexa-2,5-dienoate (4), ferulic acid (5) and their corresponding C 2-symmetric dimers 6–9. Four models were applied: model 1 – chemiluminescence (CL) of a hydrocarbon substrate used for determination of the rate constants (k A) of the reactions of the antioxidants with peroxyl radicals; model 2 – lipid autoxidation (lipidAO) used for assessing the chain-breaking antioxidant efficiency and reactivity; model 3 – oxygen radical absorbance capacity (ORAC), which yields the activity against peroxyl radicals generated by an azoinitiator; model 4 – density functional theory (DFT) calculations at UB3LYP/6-31+G(d,p) level, applied to explain the structure–activity relationship. Dimers showed 2–2.5-fold higher values of k A than their monomers. Model 2 gives information about the effects of the side chains and revealed much higher antioxidant activity for monomers and dimers with α,β-unsaturated side chains. Curcumin and 6 in fact are dimers of the same monomer 2. We conclude that the type of linkage between the two “halves” by which the molecule is made up does not exert influence on the antioxidant efficiency and reactivity of these two dimers. The dimers and the monomers demonstrated higher activity than Trolox (10) in aqueous medium (model 3). A comparison of the studied compounds with DL-α-tocopherol (11), Trolox and curcumin is made. All dimers are characterized through lower bond dissociation enthalpies (BDEs) than their monomers (model 4), which qualitatively supports the experimental results. PMID:26425195

  12. [Study on scavenging activity to DPPH free radical of different polarity components in Guizhou Miao medicine "bod zangd dak"].

    PubMed

    Du, Hong-zhi; Nong, Heng; Dong, Li-sha; Li, Jia-li; Liu, Ming; He, Xi-cheng; Zhang, Jing

    2015-06-01

    The paper is aimed to search more natural plant antioxidants and further research and develop new medicinal plant resources in Guizhou. The Guizhou special miao medicine "bod zangd dak" was extracted with 60% ethanol. The antioxidant activity of the different polarity components separated from the extract was tested by DPPH method with ascorbic acid as positive control. The results showed that the IC50 of the different polarity components was as following: ascorbic acid (0.033 4 g x L(-1)) < ethyl acetate components (0.052 3 g x L(-1)) < total tannins components (0.054 9 g x L(-1)) < 60% ethanol extraction components (0.076 7 g x L(-1)) < butanol extraction components (0.110 g x L(-1)) < water-soluble polysaccharides components (0.168 g x L(-1)) < water extraction components (0.174 g x L(-1)) < water components after extraction (0.226 g x L(-1)) < total polysaccharides components (0.645 g x L(-1)). It is concluded that the different polarity components have different free radical scavenging activity and that provides a scientific basis for further search of the active ingredients and the activive mechanism.

  13. Anti-inflammatory, free radical scavenging and alpha-glucosidase inhibitory activities of Hamelia patens and its chemical constituents.

    PubMed

    Jiménez-Suárez, Verónica; Nieto-Camacho, Antonio; Jiménez-Estrada, Manuel; Alvarado Sánchez, Brenda

    2016-09-01

    Context Hamelia patens Jacq. (Rubiaceae) is traditionally used to treat wounds, inflammation and diabetes. However, there is still a lack of scientific evidence to support these applications. Objective The objective of this study is to evaluate the anti-inflammatory, antioxidant and antidiabetic activities of Hamelia patens, and identify its bioactive compounds. Materials and methods Four extracts were obtained by maceration and liquid-liquid extraction: HEX, DCM-EtOAc, MeOH-EtOAc and MeOH-Aq. The anti-inflammatory effect was evaluated orally on rat paw carrageenan-induced oedema over 6 h (50, 200 and 500 mg/kg), and topically in mouse ear oedema induced by 12-tetradecanoylphorbol-13-acetate (TPA) after 4 h (0.5 and 1 mg/ear). We also evaluated myeloperoxidase levels in ear tissue, 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging ability, and in vitro α-glucosidase inhibition. The chemical compounds were separated by column chromatography and identified by spectroscopic analysis. Results We found that the oral administration of the HEX extract at 500 and 200 mg/kg significantly decreased the carrageenan-induced inflammation after 1 and 3 h, respectively. The MeOH-EtOAc extract significantly inhibited myeloperoxidase activity (83.5%), followed by the DCM-EtOAc extract (76%), β-sitosterol/stigmasterol (72.7%) and the HEX extract (55%), which significantly decreased oedema induced by TPA at both doses, giving a similar effect to indomethacin. We also found that the MeOH-EtOAc, MeOH-Aq and DCM-EtOAc extracts showed good DPPH scavenging activity (IC50 values of 18.6, 93.9 and 158.2 μg/mL, respectively). The HEX extract showed the lowest α-glucosidase inhibition (an IC50 value of 26.07 μg/mL), followed by the MeOH-EtOAc extract (an IC50 value of 30.18 μg/mL), β-sitosterol/stigmasterol (IC50 34.6 μg/mL) and compound A ((6E,10E,14E,18E)-2,6,10,14,18,23-hexamethyl-2,6,10,14,18,22-tetracosahexaene, an IC50 value of 114.6 μg/mL), which were

  14. Antiedematogenic and free radical scavenging activity of swertiamarin isolated from Enicostemma axillare.

    PubMed

    Vaijanathappa, Jaishree; Badami, Shrishailappa

    2009-01-01

    Swertiamarin, a secoiridoid isolated from the ethyl acetate extract of Enicostemma axillare, was evaluated for antiedematogenic activity using carrageenan-, formalin-, and histamine-induced paw edema methods in rats. In the carrageenan-induced method, the percentages of edema inhibition obtained after 5 h induction were 38.60, 52.50, and 45.44, respectively, for 100 and 200 mg/kg bw swertiamarin and 100 mg/kg bw of standard diclofenac sodium given orally. The activity of swertiamarin at 200 mg/kg bw was found to be superior to that of standard diclofenac sodium in all these methods. Swertiamarin was also screened for IN VITRO antioxidant activity using seven different methods: good activity was observed in ABTS and hydrogen peroxide methods, and moderate activity was observed in hydroxyl radical by deoxyribose and lipid peroxidation methods, with IC50 values of 2.83, 5.70, 52.56, and 78.33 microg/mL, respectively. The total antioxidant capacity was found to be 4.51 mM of ascorbic acid per gram of swertiamarin. Swertiamarin possesses antiedematogenic and in vitro antioxidant activities, and it may be the active constituent responsible for the anti-inflammatory activity of E. AXILLARE.

  15. Oil, protein, antioxidants and free radical scavenging activity of stone from wild olive trees (Olea europaea L.).

    PubMed

    Hannachi, Hédia; Elfalleh, Walid; Marzouk, Sizaiem

    2013-05-01

    The wild olive trees or oleaster (var. sylvestris) and the cultivated olive trees (var. europaea) constitute the two botanical varieties of Olea europaea L. from Mediterranean. In this study, a partial chemical profile was conducted including the total lipids, the fatty acid profiles, soluble proteins, polyphenols, flavanoids contents and antioxidants activities of stone from six oleaster trees. The comparison was made by two olive cultivars cultivated in the same region. The oleaster and cultivar stones were richer in oil content having an average of 8.99 and 7.38 % dry weight basis (DW), respectively. Qualitatively, all studied oils have the same fatty acids profile with the oleic acid C18:1n-9 as the major fatty acid. The oleaster stone oils were richer in monounsaturated fatty acids having an average of 64.87%. They, also, richer in protein content with an average of 198.86 mg/g DW.The globulin is the major fraction, followed by the albumin, the prolamin and the glutemin fractions. The oleaster stone extracts contain polyphenols, flavonoids with an average of 151.14 and 11.91 mg gallic acid equivalent/100g of DW, respectively. The studied extracts showed antioxidant activity using the free radical scavenging activity determined by DPPH and ABTS. The unexploited oleaster stone seems to be a source of oil with good fatty acids balance, in protein and antioxidants metabolites and would be useful for the formulation of supplements and/or pharmaceutical ingredients.

  16. DPPH scavenging, PRAP activities and essential oil composition of edible Lathyrus ochrus L. (Cyprus Vetch, Luvana) from Cyprus.

    PubMed

    Polatoğlu, Kaan; Arsal, Seniha; Demirci, Betül; Başer, Kemal Hüsnü Can

    2015-01-01

    The essential oil of the aerial parts of edible Lathyrus ochrus L. was investigated by simultaneous GC, GC/MS analyses under the same conditions. Trace amount of oil (0.01> mL) obtained by hydro distillation of 200 g fresh plants was trapped in 1 mL n-hexane. Twenty components were detected representing 91.55 ± 0.56 % of the oil. The main components were phytol 49.39 ± 0.44 %, hexadecanoic acid 20.64 ± 0.89 % and pentacosane 4.20 ± 0.09 %. Essential oil solution (1% oil: n-hexane) afforded similar DPPH scavenging activity (9.28 ± 1.30 %) when compared with positive controls α-tocopherol (9.74 ± 0.21 %) and BHT (7.79 ± 0.26 %) at the same concentrations. Antioxidant activity of the oil was determined using a new HPTLC-PRAP assay. The oil afforded two fold higher reducing activity of phosphomolybdenum complex (594.85 ± 5.14 AU) when compared with positive controls α- tocopherol (271.10 ± 2.86 AU) and BHT (210.53 ± 1.81 AU) at the same concentration.

  17. Changes of hydrogen peroxide and radical-scavenging activity of raspberry during osmotic, convective, and freeze-drying.

    PubMed

    Novaković, Miroslav M; Stevanović, Snežana M; Gorjanović, Stanislava Ž; Jovanovic, Predrag M; Tešević, Vele V; Janković, Miodrag A; Sužnjević, Desanka Ž

    2011-05-01

    This study was conducted to investigate the influence of different drying treatments on antioxidant (AO) activity and phenolic content of raspberry (Rubus idaeus), cultivar Willamette. Whole raspberry fruits were dried convectively (air-drying), osmotically, and freeze-dried. Acetone-water extracts of fresh and dried raspberries were assessed for total phenolic content by standard Folin-Ciocalteau method. Two AO assays were applied, a recently developed direct current (DC) polarographic assay based on decrease of anodic oxidation current of hydrogen peroxide and widely used radical scavenge against the 1,1-diphenyl-2-picrylhydrazyl (DPPH). Strong correlation has been obtained between both AO assays and total phenolic content. In addition, some individual phenolic compounds present in raspberry have been assessed using DPPH and DC polarographic assay. Comparison and evaluation of drying methods has been based on preservation of AO activity and total phenolic content. Obtained results confirmed superiority of freeze-drying; convective drying caused slight changes while osmotic dehydration showed a significant decrease of phenolic compounds and AO activity. PMID:22417351

  18. Chemical profile, radical scavenging and cytotoxic activity of yellow gentian leaves (Genitaneae luteaefolium) grown in northern regions of Montenegro.

    PubMed

    Balijagić, Jasmina; Janković, Teodora; Zdunić, Gordana; Bosković, Jelena; Savikin, Katarina; Godevac, Dejan; Stanojković, Tatjana; Jovancević, Miodrag; Menković, Nebojsa

    2012-11-01

    LC-ESI-MS and HPLC were used for the identification of the constituents from G. lutea leaves collected at different localities, as well as for quantification of the main compounds. Seven secoiridoids, five C-glucoflavones and three xanthones, were identified. Swertiamarin derivatives, namely eustomorusside (2), eustomoside (3) and septemfidoside (5), were detected in G. lutea for the first time. Concentrations of five constituents (swertiamarin, gentiopicrin, isovitexin, mangiferin and isogentisin) were determined. The relationship between concentrations of y-pyrones and altitude was observed with statistically significant correlation (r = 0.94). The extracts were also evaluated for their content of total phenolics, and antiradical and cytotoxic activities. The total phenolics content ranged from 7.7 to 12.7 mg GAE/g, and the IC50 values for DPPH radical scavenging activity varied between 0.45 to 2.02 mg/mL. The leaf extract exhibited moderate cytotoxic effects toward HeLa cells with an IC50 value of 41.1 microg/mL, while gentiopicrin, mangiferin and isogentisin exerted strong activity against HeLa cells, with IC50 values ranging from 5.7 to 8.8 microg/mL. The results confirm the traditional usage of G. lutea leaves and also suggest their possible utilization as hepatoprotective, hypoglycemic and anti-inflammatory agents.

  19. Correlation of In Vivo and In Vitro Assay Results for Assessment of Free Radical Scavenging Activity of Green Tea Nutraceuticals.

    PubMed

    Abd-ElSalam, Heba-Alla H; Al-Ghobashy, Medhat A; Al-Shorbagy, Muhammad; Nassar, Noha; Zaazaa, Hala E; Ibrahim, Mohamed A

    2016-07-01

    Green tea (GT)-derived catechins; epigallocatechin gallate (EGCG) in particular are commonly used nutraceuticals for their free-radical scavenging activity (FRSA). The influence of photodegradation on the protective power of GT nutracenticals against oxidative stress was thoroughly explored. Photodegradation of GT extracts was carried out and monitored using orthogonal stability-indicating testing protocol; in vitro and in vivo assays. Total polyphenol content (TPC) and FRSA were determined spectrophotometrically while EGCG was selectively monitored using SPE-HPLC. In vivo assessment of photodegraded samples was investigated via measuring a number of biomarkers for hepatic oxidative stress and apoptosis (caspase-3, inducible nitric oxide synthase, nitric oxide, mitogen-activated protein kinase, glutathione, thiobarbituric acid reactive substances, nuclear factor kappa beta, and nuclear factor erythroid 2-related factor) as well as liver damage (alanine transaminase and aspartate transaminase) in serum of rats previously subjected to oxidative stress. Results showed complete degradation of EGCG in photodegraded green tea samples with no correlation with either TPC or FRSA. On the other hand, in vivo assay results revealed not only loss of activity but formation of harmful pro-oxidants. Photostability was found crucial for the protective effect of GT extract against lead acetate insult. Results confirmed that careful design of quality control protocols requires correlation of chemical assays to bioassays to verify efficacy, stability, and most importantly safety of nutraceuticals.

  20. Changes of hydrogen peroxide and radical-scavenging activity of raspberry during osmotic, convective, and freeze-drying.

    PubMed

    Novaković, Miroslav M; Stevanović, Snežana M; Gorjanović, Stanislava Ž; Jovanovic, Predrag M; Tešević, Vele V; Janković, Miodrag A; Sužnjević, Desanka Ž

    2011-05-01

    This study was conducted to investigate the influence of different drying treatments on antioxidant (AO) activity and phenolic content of raspberry (Rubus idaeus), cultivar Willamette. Whole raspberry fruits were dried convectively (air-drying), osmotically, and freeze-dried. Acetone-water extracts of fresh and dried raspberries were assessed for total phenolic content by standard Folin-Ciocalteau method. Two AO assays were applied, a recently developed direct current (DC) polarographic assay based on decrease of anodic oxidation current of hydrogen peroxide and widely used radical scavenge against the 1,1-diphenyl-2-picrylhydrazyl (DPPH). Strong correlation has been obtained between both AO assays and total phenolic content. In addition, some individual phenolic compounds present in raspberry have been assessed using DPPH and DC polarographic assay. Comparison and evaluation of drying methods has been based on preservation of AO activity and total phenolic content. Obtained results confirmed superiority of freeze-drying; convective drying caused slight changes while osmotic dehydration showed a significant decrease of phenolic compounds and AO activity.

  1. The flavonoid content and antiproliferative, hypoglycaemic, anti-inflammatory and free radical scavenging activities of Annona dioica St. Hill

    PubMed Central

    2013-01-01

    Background Annona dioica St. Hill (Annonacaeae) is a Brazilian plant used in folk medicine for the treatment of several types of rheumatisms and diarrhoea. The focus of this work was to evaluate the in vitro antiproliferative and antioxidant activity and the in vivo hypoglycaemic and anti-inflammatory activity of A. dioica and identify the principal constituents of this plant. Methods The crude methanol extract (EAD) and hexane (HF), chloroform (CF), ethyl acetate (EAF) and hydromethanol fractions (HMF) were evaluated for free radical scavenging activity using the DPPH assay. The EAD and EAF were assayed for hypoglycaemic activity in rats. The EAD was tested in an antiproliferation assay and for anti-inflammatory effects in paw oedema, in addition to myeloperoxidase activity induced by carrageenan (Cg) in mice. The EAF was assayed using chromatographic methods. Results The fractionation of the EAF through chromatographic methods identified derivatives of the flavonoids quercetin and kaempferol. Among all the tested fractions, the ethyl acetate and hydromethanol fractions were the most potent, exhibiting an IC50 of 8.53 and 10.57 μg/mL, respectively, which is comparable to that of the commercial antioxidant butylated hydroxytoluene (BHT). The oral administration of the EAD (100 mg/kg) and EAF (15 mg/kg) inhibited the increase of glucose levels, resulting in a hypoglycaemic effect. The EAD (30 to 300 mg/kg) exhibited an anti-oedematogenic effect in Cg-induced paw oedema in a time- and dose-dependent manner. The results showed a reduction of MPO activity by A. dioica 6 h after the induction of paw oedema at all doses tested with maximal inhibition at 300 mg/kg. Conclusions Our results reveal for the first time that compounds contained in the A. dioica leaves exert anti-inflammatory, hypoglycaemic, antiproliferative, and antioxidant effects. The antioxidant activity may be associated with the presence of flavonoids. PMID:23311341

  2. Class A scavenger receptor promotes osteoclast differentiation via the enhanced expression of receptor activator of NF-{kappa}B (RANK)

    SciTech Connect

    Takemura, Kenichi; Sakashita, Naomi; Fujiwara, Yukio; Komohara, Yoshihiro; Lei, XiaoFeng; Ohnishi, Koji; Suzuki, Hiroshi; Kodama, Tatsuhiko; Mizuta, Hiroshi; Takeya, Motohiro

    2010-01-22

    Osteoclasts originate from bone marrow monocyte/macrophage lineage cells, and their differentiation depends on macrophage colony-stimulating factor (M-CSF) and receptor activator nuclear factor kappa B (RANK) ligand. Class A scavenger receptor (SR-A) is one of the principal functional molecules of macrophages, and its level of expression declines during osteoclast differentiation. To investigate the role of SR-A in osteoclastogenesis, we examined pathological changes in femoral bone and the expression levels of osteoclastogenesis-related molecules in SR-A{sup -/-} mice. The femoral osseous density of SR-A{sup -/-} mice was higher than that of SR-A{sup +/+} mice, and the number of multinucleated osteoclasts was significantly decreased. An in vitro differentiation assay revealed that the differentiation of multinucleated osteoclasts from bone marrow-derived progenitor cells is impaired in SR-A{sup -/-} mice. Elimination of SR-A did not alter the expression level of the M-CSF receptor, c-fms; however, the expression levels of RANK and RANK-related osteoclast-differentiation molecules such as nuclear factor of activated T-cells, cytoplasmic, calcineurin-dependent 1 (NFATc1) and microphthalmia-associated transcription factor (MITF) significantly decreased. Furthermore, acetylated low-density lipoprotein (AcLDL), an SR-A ligand, significantly increased the expression level of RANK and MITF during osteoclast differentiation. These data indicate that SR-A promotes osteoclastogenesis via augmentation of the expression level of RANK and its related molecules.

  3. Scavenger Activity Evaluation of the Clove Bud Essential Oil (Eugenia caryophyllus) and Eugenol Derivatives Employing ABTS+• Decolorization

    PubMed Central

    Merchán Arenas, Diego R.; Acevedo, Amner Muñoz; Vargas Méndez, Leonor Y.; Kouznetsov, Vladimir V.

    2011-01-01

    The essential oil (EO) of clove bud dried fruits from Eugenia caryophyllus was obtained by a conventional hydrodistillation process in an excellent yield (11.7 %). Its chemical composition was analyzed by GC-MS, identifying eugenol as a main constituent (60.5%). Four eugenol-like molecules, γ-diisoeugenol, hydroxymethyleugenol, dihydroeugenol and 1,3-dioxanylphenol, were synthesized using eugenol or isoeugenol as initial precursors under green chemistry protocols. To evaluate the possible antioxidant capacity of eugenol compounds including the clove bud EO, the Trolox® Equivalent Antioxidant Capacity value, obtained by the ABTS+• radical-cation discoloration method, was employed. The methodology was performed in a UV-Vis reader of 96-well microplates (dilution methodology), using well-known antioxidant agents (BHA, BHT and vitamin E) as reference compounds. It was found that the prepared eugenol derivatives had a more potent free radical scavenger activity than the reference compounds. In particular, the most active molecules, γ-diisoeugenol and 1,3-dioxanylphenol, were ca. 3-fold more potent than vitamin E. PMID:22145105

  4. Alternative activation of macrophages and pulmonary fibrosis are modulated by scavenger receptor, macrophage receptor with collagenous structure.

    PubMed

    Murthy, Shubha; Larson-Casey, Jennifer L; Ryan, Alan J; He, Chao; Kobzik, Lester; Carter, A Brent

    2015-08-01

    Alternative activation of alveolar macrophages is linked to fibrosis following exposure to asbestos. The scavenger receptor, macrophage receptor with collagenous structure (MARCO), provides innate immune defense against inhaled particles and pathogens; however, a receptor for asbestos has not been identified. We hypothesized that MARCO acts as an initial signaling receptor for asbestos, polarizes macrophages to a profibrotic M2 phenotype, and is required for the development of asbestos-induced fibrosis. Compared with normal subjects, alveolar macrophages isolated from patients with asbestosis express higher amounts of MARCO and have greater profibrotic polarization. Arginase 1 (40-fold) and IL-10 (265-fold) were higher in patients. In vivo, the genetic deletion of MARCO attenuated the profibrotic environment and pulmonary fibrosis in mice exposed to chrysotile. Moreover, alveolar macrophages from MARCO(-/-) mice polarize to an M1 phenotype, whereas wild-type mice have higher Ym1 (>3.0-fold) and nearly 7-fold more active TGF-β1 in bronchoalveolar lavage (BAL) fluid (BALF). Arg(432) and Arg(434) in domain V of MARCO are required for the polarization of macrophages to a profibrotic phenotype as mutation of these residues reduced FIZZ1 expression (17-fold) compared with cells expressing MARCO. These observations demonstrate that a macrophage membrane protein regulates the fibrotic response to lung injury and suggest a novel target for therapeutic intervention.

  5. Active site densities, oxygen activation and adsorbed reactive oxygen in alcohol activation on npAu catalysts.

    PubMed

    Wang, Lu-Cun; Friend, C M; Fushimi, Rebecca; Madix, Robert J

    2016-07-01

    The activation of molecular O2 as well as the reactivity of adsorbed oxygen species is of central importance in aerobic selective oxidation chemistry on Au-based catalysts. Herein, we address the issue of O2 activation on unsupported nanoporous gold (npAu) catalysts by applying a transient pressure technique, a temporal analysis of products (TAP) reactor, to measure the saturation coverage of atomic oxygen, its collisional dissociation probability, the activation barrier for O2 dissociation, and the facility with which adsorbed O species activate methanol, the initial step in the catalytic cycle of esterification. The results from these experiments indicate that molecular O2 dissociation is associated with surface silver, that the density of reactive sites is quite low, that adsorbed oxygen atoms do not spill over from the sites of activation onto the surrounding surface, and that methanol reacts quite facilely with the adsorbed oxygen atoms. In addition, the O species from O2 dissociation exhibits reactivity for the selective oxidation of methanol but not for CO. The TAP experiments also revealed that the surface of the npAu catalyst is saturated with adsorbed O under steady state reaction conditions, at least for the pulse reaction. PMID:27376884

  6. Crocin and geniposide profiles and radical scavenging activity of gardenia fruits (Gardenia jasminoides Ellis) from different cultivars and at the various stages of maturation.

    PubMed

    Chen, Yang; Zhang, Hao; Li, Yi-Xin; Cai, Le; Huang, Juan; Zhao, Can; Jia, Lin; Buchanan, Ryan; Yang, Ting; Jiang, Li-Juan

    2010-06-01

    The major components of gardenia fruits are geniposide and water soluble pigment crocins. In this study, we investigate crocins and geniposide profiles of gardenia fruits from different cultivars and at the various stages of maturation. DPPH scavenging activity of gardenia fruits from different cultivars and at the various stages of fruit maturation was also assayed. Quantitative determination of crocins in the gardenia at the various stages of maturation revealed a significant increase when ripening. However, geniposide content was negatively correlated with ripening stages. A significant difference was observed when comparing crocin content of different gardenia from various cultivars and geniposide content also showed marked variety. Current study indicated no relationship between crocin and geniposide content in gardenia fruits at the various stages of maturation and DPPH radical scavenging activity. Data showed that, although crocins feature markedly less DPPH scavenging activity than gardenia ethanol extract, total crocin content of gardenias collected in various cultivars correlate, to a certain degree, with radical scavenging effects of the Chinese traditional medicine (r=0.75). PMID:19815056

  7. Free radical scavenging activity from different extracts of leaves of Bauhinia vahlii Wight & Arn.

    PubMed Central

    Sowndhararajan, Kandhasamy; Kang, Sun Chul

    2013-01-01

    The objectives of this study were to determine phenolic content and antioxidant activities of chloroform, acetone, methanol and hot water extracts of Bauhinia vahlii leaves. The hot water extract afforded the highest yield (6.3%) while the lowest yield was obtained from the chloroform extract (2.1%). The methanol extract contains higher levels of total phenolics (48.7 ± 0.7 g GAE/100 g extract), tannins (21.7 ± 0.7 g GAE/100 g extract) and flavonoids (10.3 ± 0.2 RE/100 g extract). The extracts were subjected to assess their antioxidant potential using various in vitro systems such as DPPH•, ABTS•+, FRAP, OH•, β-carotene linoleic acid bleaching system, phosphomolybdenum reduction and Fe2+ chelation. It is concluded that the methanolic extract of B. vahlii leaves have strong antioxidant potential. Further study is necessary for isolation and characterization of the active antioxidants, which may serve as a potential source of natural antioxidants. PMID:24235867

  8. Free radical scavenging activity from different extracts of leaves of Bauhinia vahlii Wight & Arn.

    PubMed

    Sowndhararajan, Kandhasamy; Kang, Sun Chul

    2013-10-01

    The objectives of this study were to determine phenolic content and antioxidant activities of chloroform, acetone, methanol and hot water extracts of Bauhinia vahlii leaves. The hot water extract afforded the highest yield (6.3%) while the lowest yield was obtained from the chloroform extract (2.1%). The methanol extract contains higher levels of total phenolics (48.7 ± 0.7 g GAE/100 g extract), tannins (21.7 ± 0.7 g GAE/100 g extract) and flavonoids (10.3 ± 0.2 RE/100 g extract). The extracts were subjected to assess their antioxidant potential using various in vitro systems such as DPPH(•), ABTS(•+), FRAP, OH(•), β-carotene linoleic acid bleaching system, phosphomolybdenum reduction and Fe(2+) chelation. It is concluded that the methanolic extract of B. vahlii leaves have strong antioxidant potential. Further study is necessary for isolation and characterization of the active antioxidants, which may serve as a potential source of natural antioxidants.

  9. Pharmacological Activities of Ruthenium Complexes Related to Their NO Scavenging Properties

    PubMed Central

    Castellarin, Anna; Zorzet, Sonia; Bergamo, Alberta; Sava, Gianni

    2016-01-01

    Angiogenesis is considered responsible for the growth of primary tumours and of their metastases. With the present study, the effects of three ruthenium compounds, potassiumchlorido (ethylendiamminotetraacetate)rutenate(III) (RuEDTA), sodium (bis-indazole)tetrachloro-ruthenate(III), Na[trans-RuCl4Ind2] (KP1339) and trans-imidazoledimethylsulphoxidetetrachloro-ruthenate (NAMI-A), are studied in vitro in models mimicking the angiogenic process. The ruthenium compounds reduced the production and the release of nitrosyls from either healthy macrophages and immortalized EA.hy926 endothelial cells. The effects of NAMI-A are qualitatively similar and sometimes quantitatively superior to those of RuEDTA and KP1339. NAMI-A reduces the production and release of nitric oxide (NO) by the EA.hy926 endothelial cells and correspondingly inhibits their invasive ability; it also strongly inhibits the angiogenesis in matrigel sponges implanted subcutaneously in healthy mice. Taken together, these data support the anti-angiogenic activity of the tested ruthenium compounds and they contribute to explain the selective activity of NAMI-A against solid tumour metastases, the tumour compartment on which angiogenesis is strongly involved. This anti-angiogenic effect may also contribute to the inhibition of the release of metastatic cells from the primary tumour. Investigations on the anti-angiogenic effects of NAMI-A at this level will increase knowledge of its pharmacological properties and it will give a further impulse to the development of this class of innovative metal-based drugs. PMID:27490542

  10. Pharmacological Activities of Ruthenium Complexes Related to Their NO Scavenging Properties.

    PubMed

    Castellarin, Anna; Zorzet, Sonia; Bergamo, Alberta; Sava, Gianni

    2016-01-01

    Angiogenesis is considered responsible for the growth of primary tumours and of their metastases. With the present study, the effects of three ruthenium compounds, potassiumchlorido (ethylendiamminotetraacetate)rutenate(III) (RuEDTA), sodium (bis-indazole)tetrachloro-ruthenate(III), Na[trans-RuCl₄Ind₂] (KP1339) and trans-imidazoledimethylsulphoxidetetrachloro-ruthenate (NAMI-A), are studied in vitro in models mimicking the angiogenic process. The ruthenium compounds reduced the production and the release of nitrosyls from either healthy macrophages and immortalized EA.hy926 endothelial cells. The effects of NAMI-A are qualitatively similar and sometimes quantitatively superior to those of RuEDTA and KP1339. NAMI-A reduces the production and release of nitric oxide (NO) by the EA.hy926 endothelial cells and correspondingly inhibits their invasive ability; it also strongly inhibits the angiogenesis in matrigel sponges implanted subcutaneously in healthy mice. Taken together, these data support the anti-angiogenic activity of the tested ruthenium compounds and they contribute to explain the selective activity of NAMI-A against solid tumour metastases, the tumour compartment on which angiogenesis is strongly involved. This anti-angiogenic effect may also contribute to the inhibition of the release of metastatic cells from the primary tumour. Investigations on the anti-angiogenic effects of NAMI-A at this level will increase knowledge of its pharmacological properties and it will give a further impulse to the development of this class of innovative metal-based drugs. PMID:27490542

  11. Determination of free radical scavenging activity from aqueous extract of Curcuma mangga by DPPH method

    NASA Astrophysics Data System (ADS)

    Indis, N. A.; Kurniawan, F.

    2016-04-01

    Curcuma mangga (mango ginger) belongs to the family of Zingiberaceae. The rhizome of C. mangga are morphologically similar to ginger (Zingiber officinale) with a little mango flavour. C. mangga can growth in tropical areas and easy found in Indonesia. The rhizomes of C. mangga were washed and cut into the small piece, then drying at room temperature for 6 days, and then grinded until get the powder of C. mangga. The powder of C. mangga was extracted with deminerahzed water by maceration for 6 hours. C. mangga extract was analysed with FTIR spectrophotometer to determine its functional groups. C. mangga extract was diluted at various of concentration (5, 10, 25, 50, 100, 250, 500 mg/L) using deminerahzed water. C. mangga extracts were tested the antioxidant activity using 0.002% DPPH at 517nm with UV-Vis spectrophotometer, and the IC50 value of C. mangga extract is 212.70 mg/L.

  12. Syntheses, structural characterization, and DPPH radical scavenging activity of cocrystals of caffeine with 1- and 2-naphthoxyacetic acids

    NASA Astrophysics Data System (ADS)

    Suresh Kumar, G. S.; Seethalakshmi, P. G.; Sumathi, D.; Bhuvanesh, N.; Kumaresan, S.

    2013-03-01

    Caffeine:1-naphthoxyacetic acid [(caf)(1-naa)] and caffeine:2-naphthoxyacetic acid [(caf)(2-naa)] cocrystals have been synthesized and single crystals were grown by slow evaporation technique. The structures of the grown crystals were elucidated using single crystal X-ray diffraction analysis. Both the cocrystals belong to the monoclinic crystallographic system with space group P21/c, Z = 4, and α = γ = 90°, whereas β = 111.4244(18)° for [(caf)(1-naa)] and β = 109.281(6)° for [(caf)(2-naa)]. The crystal packing is predominantly stabilized by hydrogen bonding and π-π stacking interactions. The presence of unionized -COOH functional group in both the cocrystals was identified by FTIR spectral analysis. Thermal behavior and stability of both the cocrystals were studied by TGA/DTA analyses. Solvent-free formation of these cocrystals was confirmed by powder X-ray diffraction analyses. The theoretical energy of cocrystals showed that the formers have higher energy than cocrystals 1 and 2. DPPH radical scavenging activity of cocrystals 1 and 2 is slightly greater than the formers.

  13. Free radical scavenging activity and comparative metabolic profiling of in vitro cultured and field grown Withania somnifera roots.

    PubMed

    Senthil, Kalaiselvi; Thirugnanasambantham, Pankajavalli; Oh, Taek Joo; Kim, So Hyun; Choi, Hyung Kyoon

    2015-01-01

    Free radical scavenging activity (FRSA), total phenolic content (TPC), and total flavonoid content (TFC) of in vitro cultured and field grown Withania somnifera (Ashwagandha) roots were investigated. Withanolides analysis and comprehensive metabolic profiling between 100% methanol extracts of in vitro and field grown root tissues was performed using high performance thin layer chromatography (HPTLC) and gas chromatography-mass spectrometry (GC-MS), respectively. Significantly higher levels of FRSA, TPC, and TFC were observed in in-vitro cultured roots compared with field grown samples. In addition, 30 day-cultured in vitro root samples (1 MIR) exhibited a significantly higher FRSA (IC50 81.01 μg/mL), TPC (118.91 mg GAE/g), and TFC (32.68 mg CE/g) compared with those in 45 day-cultured samples (1.5 MIR). Total of 29 metabolites were identified in in vitro cultured and field grown roots by GC-MS analysis. The metabolites included alcohols, organic acids, purine, pyrimidine, sugars, and putrescine. Vanillic acid was only observed in the in vitro cultured root samples, and higher level of the vanillic acid was observed in 1 MIR when compared to 1.5 MIR. Therefore, it is suggested that 1 MIR might serve as an alternative to field grown roots for the development of medicinal and functional food products.

  14. Free radical scavenging activity and comparative metabolic profiling of in vitro cultured and field grown Withania somnifera roots.

    PubMed

    Senthil, Kalaiselvi; Thirugnanasambantham, Pankajavalli; Oh, Taek Joo; Kim, So Hyun; Choi, Hyung Kyoon

    2015-01-01

    Free radical scavenging activity (FRSA), total phenolic content (TPC), and total flavonoid content (TFC) of in vitro cultured and field grown Withania somnifera (Ashwagandha) roots were investigated. Withanolides analysis and comprehensive metabolic profiling between 100% methanol extracts of in vitro and field grown root tissues was performed using high performance thin layer chromatography (HPTLC) and gas chromatography-mass spectrometry (GC-MS), respectively. Significantly higher levels of FRSA, TPC, and TFC were observed in in-vitro cultured roots compared with field grown samples. In addition, 30 day-cultured in vitro root samples (1 MIR) exhibited a significantly higher FRSA (IC50 81.01 μg/mL), TPC (118.91 mg GAE/g), and TFC (32.68 mg CE/g) compared with those in 45 day-cultured samples (1.5 MIR). Total of 29 metabolites were identified in in vitro cultured and field grown roots by GC-MS analysis. The metabolites included alcohols, organic acids, purine, pyrimidine, sugars, and putrescine. Vanillic acid was only observed in the in vitro cultured root samples, and higher level of the vanillic acid was observed in 1 MIR when compared to 1.5 MIR. Therefore, it is suggested that 1 MIR might serve as an alternative to field grown roots for the development of medicinal and functional food products. PMID:25874568

  15. Free Radical Scavenging Activity and Comparative Metabolic Profiling of In Vitro Cultured and Field Grown Withania somnifera Roots

    PubMed Central

    Senthil, Kalaiselvi; Thirugnanasambantham, Pankajavalli; Oh, Taek Joo; Kim, So Hyun; Choi, Hyung Kyoon

    2015-01-01

    Free radical scavenging activity (FRSA), total phenolic content (TPC), and total flavonoid content (TFC) of in vitro cultured and field grown Withania somnifera (Ashwagandha) roots were investigated. Withanolides analysis and comprehensive metabolic profiling between 100% methanol extracts of in vitro and field grown root tissues was performed using high performance thin layer chromatography (HPTLC) and gas chromatography-mass spectrometry (GC-MS), respectively. Significantly higher levels of FRSA, TPC, and TFC were observed in in-vitro cultured roots compared with field grown samples. In addition, 30 day-cultured in vitro root samples (1MIR) exhibited a significantly higher FRSA (IC50 81.01 μg/mL), TPC (118.91 mg GAE/g), and TFC (32.68 mg CE/g) compared with those in 45 day-cultured samples (1.5MIR). Total of 29 metabolites were identified in in vitro cultured and field grown roots by GC-MS analysis. The metabolites included alcohols, organic acids, purine, pyrimidine, sugars, and putrescine. Vanillic acid was only observed in the in vitro cultured root samples, and higher level of the vanillic acid was observed in 1MIR when compared to 1.5MIR. Therefore, it is suggested that 1MIR might serve as an alternative to field grown roots for the development of medicinal and functional food products. PMID:25874568

  16. A comparative study of the antioxidant scavenging activity of green tea, black tea and coffee extracts: a kinetic approach.

    PubMed

    Anissi, Jaouad; El Hassouni, Mohammed; Ouardaoui, Abdelkrim; Sendide, Khalid

    2014-05-01

    The antioxidant activities of three beverages, coffee, black tea and green tea, along with their major components, were investigated in terms of their reaction with the stable radical 2,2'-diphenyl-2-picrylhydrazyl (DPPH). We used a kinetic approach in parallel with quantification methods based on a fixed end-point to determine the scavenging efficiency of compounds abundant in these beverages during their reaction with DPPH using a stopped-flow spectrophotometer-based method. Ascorbic acid, (+)-catechin, (-)-epigallocatechin, tannic acid, and caffeic acid were selected as model antioxidants to study in coffee, black tea and green tea. We applied a second-order model to demonstrate similarities in the kinetics behavior of beverages and related compounds. Our findings showed the slopes k2(')((mol/L)(-1)s(-1)) and k2max(')((mol/L)(1)s(-1)) exhibited similar and correlated values; we suggest the variation in k2(') as a function of time is more informative about antioxidant properties than reaction with DPPH alone. We also used IC100 to test the reliability of the relative stoichiometry using a new comparative parameter "n", which was calculated as: n=c0DPPHIC100 (mol/L(mol/L)(-1), (mol/L)mlmg(-1) or molg(-1)).

  17. Flavonoid content, free radical scavenging and increase in xanthine oxidase inhibitory activity in Galgeun-tang following fermentation with Lactobacillus plantarum.

    PubMed

    Kim, Dong-Seon; Um, Young Ran; Ma, Jin Yeul

    2014-11-01

    Galgeun-tang (GT) prior to and following fermentation with Lactobacillus plantarum was analyzed to determine the total polyphenol and flavonoid contents and the antioxidant activity. GT, fermented GT (FGT) and their three solvent-partitioned fractions, which were prepared by successive partitioning with ethyl acetate (EtOAc), butanol (BuOH) and water, were evaluated for total polyphenol and flavonoid contents, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and xanthine oxidase (XO) inhibitory activity. Following fermentation, the total polyphenol content only increased slightly; however, the flavonoid content increased by 24.3%. The radical scavenging activity increased from 22.4 to 27.5% and the XO inhibitory activity increased from 20.2 to 62.4% at 500 µg/ml. The EtOAc fraction among the solvent‑partitioned fractions demonstrated the highest total polyphenol and flavonoid contents, radical scavenging activities and XO inhibitory activity, and the quantity also markedly increased following fermentation.

  18. Probing Oxygen Activation Sites in Two Flavoprotein Oxidases Using Chloride as an Oxygen Surrogate

    SciTech Connect

    Kommoju, Phaneeswara-Rao; Chen, Zhi-wei; Bruckner, Robert C.; Mathews, F. Scott; Jorns, Marilyn Schuman

    2011-08-16

    A single basic residue above the si-face of the flavin ring is the site of oxygen activation in glucose oxidase (GOX) (His516) and monomeric sarcosine oxidase (MSOX) (Lys265). Crystal structures of both flavoenzymes exhibit a small pocket at the oxygen activation site that might provide a preorganized binding site for superoxide anion, an obligatory intermediate in the two-electron reduction of oxygen. Chloride binds at these polar oxygen activation sites, as judged by solution and structural studies. First, chloride forms spectrally detectable complexes with GOX and MSOX. The protonated form of His516 is required for tight binding of chloride to oxidized GOX and for rapid reaction of reduced GOX with oxygen. Formation of a binary MSOX-chloride complex requires Lys265 and is not observed with Lys265Met. Binding of chloride to MSOX does not affect the binding of a sarcosine analogue (MTA, methylthioactetate) above the re-face of the flavin ring. Definitive evidence is provided by crystal structures determined for a binary MSOX-chloride complex and a ternary MSOX-chloride-MTA complex. Chloride binds in the small pocket at a position otherwise occupied by a water molecule and forms hydrogen bonds to four ligands that are arranged in approximate tetrahedral geometry: Lys265:NZ, Arg49:NH1, and two water molecules, one of which is hydrogen bonded to FAD:N5. The results show that chloride (i) acts as an oxygen surrogate, (ii) is an effective probe of polar oxygen activation sites, and (iii) provides a valuable complementary tool to the xenon gas method that is used to map nonpolar oxygen-binding cavities.

  19. Free radical scavenging abilities of polypeptide from Chlamys farreri

    NASA Astrophysics Data System (ADS)

    Han, Zhiwu; Chu, Xiao; Liu, Chengjuan; Wang, Yuejun; Mi, Sun; Wang, Chunbo

    2006-09-01

    We investigated the radical scavenging effect and antioxidation property of polypeptide extracted from Chlamys farreri (PCF) in vitro using chemiluminescence and electron spin resonance (ESR) methods. We examined the scavenging effects of PCF on superoxide anions (O{2/-}), hydroxyl radicals (OH·), peroxynitrite (ONOO-) and the inhibiting capacity of PCF on peroxidation of linoleic acid. Our experiment suggested that PCF could scavenge oxygen free radicals including superoxide anions (O{2/-}) (IC50=0.3 mg/ml), hydroxyl radicals (OH·) (IC50=0.2 μg/ml) generated from the reaction systems and effectively inhibit the oxidative activity of ONOO- (IC50=0.2 mg/ml). At 1.25 mg/ml of PCF, the inhibition ratio on lipid peroxidation of linoleic acid was 43%. The scavenging effect of PCF on O{2/-}, OH· and ONOO- free radicals were stronger than those of vitamin C but less on lipid peroxidation of linoleic acid. Thus PCF could scavenge free radicals and inhibit the peroxidation of linoleic acid in vitro. It is an antioxidant from marine products and potential for industrial production in future.

  20. Assessment of free radical scavenging potential and oxidative DNA damage preventive activity of Trachyspermum ammi L. (carom) and Foeniculum vulgare Mill. (fennel) seed extracts.

    PubMed

    Goswami, Nandini; Chatterjee, Sreemoyee

    2014-01-01

    Oxidation of biomolecules such as carbohydrates, proteins, lipids, and nucleic acids results in generation of free radicals in an organism which is the major cause of onset of various degenerative diseases. Antioxidants scavenge these free radicals, thereby protecting the cell from damage. The present study was designed to examine the free radical scavenging potential and oxidative DNA damage preventive activity of traditionally used spices Trachyspermum ammi L. (carom) and Foeniculum vulgare Mill. (fennel). The aqueous, methanolic, and acetonic extracts of T. ammi and F. vulgare seeds were prepared using soxhlet extraction assembly and subjected to qualitative and quantitative estimation of phytochemical constituents. Free radical scavenging potential was investigated using standard methods, namely, DPPH radical scavenging assay and ferric reducing antioxidant power assay along with the protection against oxidative DNA damage. The results stated that acetonic seed extracts (AAcSE and FAcSE) of both the spices possessed comparatively high amount of total phenolics whereas methanolic seed extracts (AMSE and FMSE) were found to have highest amount of total flavonoids. At 1 mg/mL concentration, highest DPPH radical scavenging activity was shown by FMSE (96.2%), AAcSE was recorded with highest FRAP value (2270.27 ± 0.005 μmol/L), and all the seed extracts have been shown to mitigate the damage induced by Fenton reaction on calf thymus DNA. Therefore, the study suggests that T. ammi and F. vulgare seed extracts could contribute as a highly significant bioresource of antioxidants to be used in our day-to-day life and in food and pharmaceutical industry.

  1. Assessment of Free Radical Scavenging Potential and Oxidative DNA Damage Preventive Activity of Trachyspermum ammi L. (Carom) and Foeniculum vulgare Mill. (Fennel) Seed Extracts

    PubMed Central

    2014-01-01

    Oxidation of biomolecules such as carbohydrates, proteins, lipids, and nucleic acids results in generation of free radicals in an organism which is the major cause of onset of various degenerative diseases. Antioxidants scavenge these free radicals, thereby protecting the cell from damage. The present study was designed to examine the free radical scavenging potential and oxidative DNA damage preventive activity of traditionally used spices Trachyspermum ammi L. (carom) and Foeniculum vulgare Mill. (fennel). The aqueous, methanolic, and acetonic extracts of T. ammi and F. vulgare seeds were prepared using soxhlet extraction assembly and subjected to qualitative and quantitative estimation of phytochemical constituents. Free radical scavenging potential was investigated using standard methods, namely, DPPH radical scavenging assay and ferric reducing antioxidant power assay along with the protection against oxidative DNA damage. The results stated that acetonic seed extracts (AAcSE and FAcSE) of both the spices possessed comparatively high amount of total phenolics whereas methanolic seed extracts (AMSE and FMSE) were found to have highest amount of total flavonoids. At 1 mg/mL concentration, highest DPPH radical scavenging activity was shown by FMSE (96.2%), AAcSE was recorded with highest FRAP value (2270.27 ± 0.005 μmol/L), and all the seed extracts have been shown to mitigate the damage induced by Fenton reaction on calf thymus DNA. Therefore, the study suggests that T. ammi and F. vulgare seed extracts could contribute as a highly significant bioresource of antioxidants to be used in our day-to-day life and in food and pharmaceutical industry. PMID:25143939

  2. Structure-Activity Relationship of PEGylated Polylysine Peptides as Scavenger Receptor Inhibitors for Non-Viral Gene Delivery.

    PubMed

    Baumhover, Nicholas J; Duskey, Jason T; Khargharia, Sanjib; White, Christopher W; Crowley, Samuel T; Allen, Rondine J; Rice, Kevin G

    2015-12-01

    PEGylated polylysine peptides of the general structure PEG30 kDa-Cys-Trp-LysN (N = 10 to 30) were used to form fully condensed plasmid DNA (pGL3) polyplexes at a ratio of 1 nmol of peptide per μg of DNA (ranging from N:P 3:1 to 10:1 depending on Lys repeat). Co-administration of 5 to 80 nmols of excess PEG-peptide with fully formed polyplexes inhibited the liver uptake of (125)I-pGL3-polyplexes. The percent inhibition was dependent on the PEG-peptide dose and was saturable, consistent with inhibition of scavenger receptors. The scavenger receptor inhibition potency of PEG-peptides was dependent on the length of the Lys repeat, which increased 10-fold when comparing PEG30 kDa-Cys-Trp-Lys10 (IC50 of 20.2 μM) with PEG30 kDa-Cys-Trp-Lys25 (IC50 of 2.1 μM). We hypothesize that PEG-peptides inhibit scavenger receptors by spontaneously forming small 40 to 60 nm albumin nanoparticles that bind to and saturate the receptor. Scavenger receptor inhibition delayed the metabolism of pGL3-polyplexes, resulting in efficient gene expression in liver hepatocytes following delayed hydrodynamic dosing. PEG-peptides represent a new class of scavenger inhibitors that will likely have broad utility in blocking unwanted liver uptake and metabolism of a variety of nanoparticles.

  3. Scavenging of free radicals, antimicrobial, and cytotoxic activities of the Maillard reaction products of beta-lactoglobulin glycated with several sugars.

    PubMed

    Chevalier, F; Chobert, J M; Genot, C; Haertlé, T

    2001-10-01

    The Maillard reaction occurs during many industrial and domestic thermal treatments of foods. It is widely used because of its role in creating colors, flavors, textures, and other functional properties in foodstuffs. Proteins glycated without the use of conventional chemical reagents have improved technofunctional properties such as heat stability, emulsifying, and foaming properties. The present study was carried out to determine the extent to which this reaction can convey antioxidant, antimicrobial, or cytotoxic activities to beta-lactoglobulin (BLG) and to its tryptic and peptic hydrolysates. BLG was modified with six different sugars in solution at 60 degrees C. Antiradical properties were estimated using a radical scavenging activity test. Antimicrobial activities against different bacterial strains were studied with a diffusion disk method. Cytotoxic tests were performed using two cell lines and the 3-(4,5-dimethylthiazoyl-2-yl)-2,5-diphenyltetrazolium bromide (MTT) rapid colorimetric assay. Glycation induced a radical scavenging activity to BLG, the intensity of which depended on the sugar used for modification. Proteins modified with ribose and arabinose showed the highest radical scavenging activities depicted by about 80 and 60% of 2,2-diphenyl-1-picrylhydrazyl (DPPH) absorption decrease at 515 nm. No antimicrobial effect of any glycated form of BLG against Escherichia coli, Bacillus subtilis, Listeria innocua, and Streptococcus mutans was observed. The MTT test showed no enhancement of cytotoxicity by modified proteins and peptides against COS-7 and HL-60 cells. Thus, glycated proteins could be used in formulated food as functional ingredients with a radical scavenging activity able to delay deterioration due to oxidation. This use could be even more advisable considering the lack of toxicity to eukaryotic and prokaryotic cell cultures demonstrated in this work.

  4. Development and validation of a simple high performance thin layer chromatography method combined with direct 1,1-diphenyl-2-picrylhydrazyl assay to quantify free radical scavenging activity in wine.

    PubMed

    Agatonovic-Kustrin, Snezana; Morton, David W; Yusof, Ahmad P

    2016-04-15

    The aim of this study was to: (a) develop a simple, high performance thin layer chromatographic (HPTLC) method combined with direct 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay to rapidly assess and compare free radical scavenging activity or anti-oxidant activity for major classes of polyphenolics present in wines; and (b) to investigate relationship between free radical scavenging activity to the total polyphenolic content (TPC) and total antioxidant capacity (TAC) in the wine samples. The most potent free radical scavengers that we tested for in the wine samples were found to be resveratrol (polyphenolic non-flavonoid) and rutin (flavonoid), while polyphenolic acids (caffeic acid and gallic acid) although present in all wine samples were found to be less potent free radical scavengers. Therefore, the total antioxidant capacity was mostly affected by the presence of resveratrol and rutin, while total polyphenolic content was mostly influenced by the presence of the less potent free radical scavengers gallic and caffeic acids.

  5. Free radical scavenging enzyme activity and related trace metals in clozapine-induced agranulocytosis: a pilot study.

    PubMed

    Linday, L A; Pippenger, C E; Howard, A; Lieberman, J A

    1995-10-01

    We hypothesized that patients who had experienced clozapine-induced agranulocytosis would have abnormalities in their free radical scavenging enzyme activity (FRESA) and levels of related trace metals. We therefore measured FRESA profiles and related trace metals in four groups: post-clozapine agranulocytosis (POST CLOZ AGRAN) (N = 9); clozapine no agranulocytosis (CLOZ NO AGRAN) (N = 12); West Coast controls (WC CONTROLS) (N = 14); and Long Island Jewish Medical Center controls (LIJ CONTROLS) (N = 12). Glutathione peroxidase (GSH-Px, P1) levels in plasma were slowest in the POST CLOZ AGRAN group (34.3 +/- 6.9 IU/dl [standard deviation; SD]; p < 0.002); red blood cell glutathione peroxidase (GSH-Px, RBC) was highest in the WC CONTROLS (38.7 +/- 4.7 IU/g hemoglobin [Hgb]; p < 0.008); and selenium (SE) levels in plasma were lower in both the POST CLOZ AGRAN group (111.6 +/- 14.7 ng/ml) and the CLOZ NO AGRAN group(115.0 +/- 17.8) than in the WC CONTROLS (142.5 +/- 18.3; p < 0.0006). SE was also lower in the POST CLOZ AGRAN group than in the LIJ CONTROLS (129.1 +/- 21.6; p < 0.04). The presence of at least one of the following: (1) GSH-Px, P1 < 37.6 IU/dl; (2) GSH-Px, RBC < 31.0 IU/g Hgb; or (3) SE < 112.4 ng/ml, distinguished POST CLOZ AGRAN subjects from the WC CONTROLS, but not from the LIJ CONTROLS. Data from this cross-sectional pilot study suggest that abnormalities in the body's antioxidant defense system may be involved in the pathogenesis of clozapine-associated agranulocytosis. If confirmed in large-scale, prospective studies, these preliminary findings have potential clinical application in the screening and prophylaxis of clozapine agranulocytosis. PMID:8830067

  6. Free radical scavenging and anti-oxidative activities of an ethanol-soluble pigment extract prepared from fermented Zijuan Pu-erh tea.

    PubMed

    Fan, Jiang Ping; Fan, Chong; Dong, Wen Min; Gao, Bin; Yuan, Wei; Gong, Jia Shun

    2013-09-01

    An ethanol-soluble pigment extract was separated from fermented Zijuan Pu-erh tea. The compositions of the ethanol soluble pigment extract were analyzed by high-performance liquid chromatography-tandem mass spectroscopy (HPLC-MS/MS). The extract was prepared into a series of ethanol solutions and analyzed for free radical-scavenging activities (against two free radicals: 1,1-diphenyl-2-picrylhydrazyl (DPPH) and (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO)) and in vitro anti-oxidative properties. Electron spin resonance spectroscopy showed that the peaks of DPPH and TEMPO decreased with increasing extract concentration, suggesting that the extract had excellent free radical-scavenging activities. In vitro cell culture suggested that, at 50-200 mg/L, the extract had no measurable effect on the viability of vascular endothelial cells (ECV340) but produced significant protective effects for cells that underwent oxidative injuries due to hydrogen peroxide (H₂O₂) treatment. Compared with the H₂O₂ treatment alone cells group, 200 mg/L of the extract increased the activity of superoxide dismutase (SOD) in cells by 397.3%, and decreased the concentration of malondialdehyde (MDA) and the activity of lactate acid dehydrogenase (LDH) by 47.8% and 69.6%, respectively. These results suggest that the extract has excellent free radical scavenging and anti-oxidative properties.

  7. Radical-scavenging Activity and Antioxidative Effects of Olive Leaf Components Oleuropein and Hydroxytyrosol in Comparison with Homovanillic Alcohol.

    PubMed

    Umeno, Aya; Takashima, Mizuki; Murotomi, Kazutoshi; Nakajima, Yoshihiro; Koike, Taisuke; Matsuo, Toshiki; Yoshida, Yasukazu

    2015-01-01

    Olive leaf has great potential as a natural antioxidant, and one of its major phenolic components is oleuropein. In this study, the antioxidant activity of oleuropein against oxygen-centered radicals was measured by examining its sparing effects on the peroxyl radical-induced decay of fluorescein and pyrogallol red, in comparison with related compounds. The antioxidant capacity of oleuropein against lipid peroxidation was also assessed through its effect on the free radical-induced oxidation of methyl linoleate in a micelle system. On a molar basis, oleuropein and hydroxytyrosol inhibited the decay of fluorescein for longer than both homovanillic alcohol and the vitamin-E mimic 2-carboxy-2,5,7,8-tetramethyl-6-chromanol (Trolox), but did not suppress pyrogallol red decay in a concentration-dependent manner. Measurement of the fluorescein decay period revealed that the stoichiometric number of oleuropein and hydroxytyrosol against peroxyl radicals was twice that of Trolox, which is substantially higher than expectations based on chemical structure. Oleuropein and hydroxytyrosol were also more effective than Trolox and homovanillic alcohol at suppressing the oxidation of methyl linoleate in the micelle system. Thus, both oleuropein and hydroxytyrosol exhibit high antioxidative activity against lipid peroxidation induced by oxygen-centered radicals, but the high reactivity of phenolic/catecholic radicals makes their mechanism of action complex. PMID:26136177

  8. Comparative analysis of radical scavenging and antioxidant activity of phenolic compounds present in everyday use spice plants by means of spectrophotometric and chromatographic methods.

    PubMed

    Stankevičius, Mantas; Akuņeca, Ieva; Jãkobsone, Ida; Maruška, Audrius

    2011-06-01

    Comparative analysis of radical scavenging and antioxidant activities of phenolic compounds present in everyday use spice plants was carried out by means of spectrophotometric and chromatographic methods. Six spice plant samples, namely onion (Allium cepa), parsley (Petroselinum crispum) roots and leaves, celery (Apium graveolens) roots and leaves and leaves of dill (Anethum graveolens) were analyzed. Total amount of phenolic compounds and radical scavenging activity (RSA) was the highest in celery leaves and dill extracts and was the lowest in celery roots. Comparing commonly used spectrophotometric analysis of 2,2-diphenyl-1-picrylhydrazyl (DPPH) RSA of extracts with the results obtained using reversed-phase chromatographic separation with on-line post-column radical scavenging reaction detection, good correlation was obtained (R(2)=0.848). Studies using HPLC system with electrochemical detector showed that bioactive phytochemicals can be separated and antioxidant activities of individual compounds evaluated without the need of a complex HPLC system with reaction detector. The results obtained using electrochemical detection correlate with the RSA assayed using spectrophotometric method (R(2)=0.893).

  9. Antioxidant, free radical-scavenging activity and cytotoxicity of different solvent extracts and their phenolic constituents from the fruit hull of mangosteen (Garcinia mangostana).

    PubMed

    Ngawhirunpat, Tanasait; Opanasopi, Praneet; Sukma, Monrudee; Sittisombut, Chavalit; Kat, Atsushi; Adachi, Isao

    2010-01-01

    Antioxidative, skin protective activities, and cytotoxicity of three extracts (water, methanol, and hexane) from the fruit hull of mangosteen (Garcinia mangostana Linn. (Guttiferae)) and their phenolic constituents such as alpha-mangostin, epicatechin, and tannin, were evaluated. The amounts of alpha-mangostin, total flavonoid, and total tannin were different among the three extracts, except those of total tannin in methanol and hexane extracts. For the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free-radical scavenging, hydroxyl radical-scavenging, and inhibition of lipid peroxidation experiment, the water extract showed higher activity than the methanol extract and hexane extract. alpha-Mangostin, epicatechin, and tannin also revealed these antioxidant and free radical-scavenging activities. When added simultaneously with H(2)O(2) (200 microM) to keratinocyte cells, the water extract (50 microg/mL), epicatechin (200 microM), and tannin (200 microM) effectively protected cells from oxidative damage, but the methanol extract, hexane extract, and alpha-mangostin did not. The methanol extract and hexane extract exhibited moderate cytotoxicity, whereas alpha-mangostin showed strong cytotoxicity. The present study provides the evidence that Garcinia mangostana extracts, especially the G. mangostana water extract, act as antioxidants and cytoprotective agents against oxidative damage, which is at least partly due to its phenolic compounds in mangosteen.

  10. DPPH radical scavenging activity and contents of H2O2, malondialdehyde and proline in determining salinity tolerance in chickpea seedlings.

    PubMed

    Kaur, Narinder; Kumar, Arvind; Kaur, Kamaljit; Gupta, Anil K; Singh, Inderjit

    2014-10-01

    The involvement of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and contents of H2O2, malondialdehyde (MDA) and proline was investigated in determining salinity tolerance among seedlings of thirty chickpea (Cicer arietinum L.) genotypes having different pedigrees. Chickpea genotypes, including cultivars and advanced lines were grown for 7 days under control and salt stress (50 mM NaCl) conditions. The genotypes showed differential response to salt stress in terms of growth, DPPH radical scavenging activity and contents of H2O2, MDA and proline in seedlings. On the basis of seedling growth, the genotypes having better performance under stress conditions had reduced levels of H2O2 and MDA contents, but increased levels of proline and DPPH radical scavenging activity. Stress tolerance index for these parameters was also determined. Agglomerative hierarchal clustering by Pearson correlation coefficient grouped the genotypes into two major clusters--MC I and MC II. MC II and Al-1 sub-cluster of MC-I comprised mainly of genotypes that showed higher stress resistance levels for the respective parameters in comparison to genotypes in other sub-clusters. Thus, it is possible to identify salt-tolerant genotypes on the basis of above parameters without a field trial.

  11. Electrochemical investigations on the oxygen activation by cytochrome P-450.

    PubMed

    Scheller, F; Renneberg, R; Schwarze, W; Strnad, G; Pommerening, K; Prümke, H J; Mohr, P

    1979-01-01

    The application of cytochrome P-450 in substrate conversion is complicated both due to the limited stability and the cofactor regeneration problems. To overcome the disadvantages of NADPH consumption the transfer of the reduction equivalents from an electrode into the cytochrome P-450-system was studied: 1. NADPH was cathodically reduced at a mercury pool electrode. By immobilization of NADP on dialdehyde Sephadex the reductive recycling was possible. 2. Different forms of reduced oxygen were produced by the cathode: a) The reaction of O2- with deoxycorticosterone yields a carboxylic acid derivative. In contrast the cytochrome P-450 catalyzed NADPH-dependent reaction with the same substrate gives corticosterone, O2- represents only an intermediate in the activation of oxygen and is not the "activated oxygen" species. b) Molecular oxygen was reduced to HO2- and H2O2, respectively. The interaction of adsorbed cytochrome P-450 on the electrode surface with the reduced oxygen species in the absence of NADPH was studied. The electrochemically generated peroxide seems to be more active than added H2O2. 3. In a model of electro-enzyme-reactor several substrates were hydroxylated by microsomal cytochrome P-450 with cathodically reduced oxygen which substitutes NADPH.

  12. A superoxide anion-scavenger, 1,3-selenazolidin-4-one suppresses serum deprivation-induced apoptosis in PC12 cells by activating MAP kinase

    SciTech Connect

    Nishina, Atsuyoshi; Kimura, Hirokazu; Kozawa, Kunihisa; Sommen, Geoffroy; Nakamura, Takao; Heimgartner, Heinz; Koketsu, Mamoru; Furukawa, Shoei

    2011-12-15

    Synthetic organic selenium compounds, such as ebselen, may show glutathione peroxidase-like antioxidant activity and have a neurotrophic effect. We synthesized 1,3-selenazolidin-4-ones, new types of synthetic organic selenium compounds (five-member ring compounds), to study their possible applications as antioxidants or neurotrophic-like molecules. Their superoxide radical scavenging effects were assessed using the quantitative, highly sensitive method of real-time kinetic chemiluminescence. At 166 {mu}M, the O{sub 2}{sup -} scavenging activity of 1,3-selenazolidin-4-ones ranged from 0 to 66.2%. 2-[3-(4-Methoxyphenyl)-4-oxo-1,3-selenazolidin-2-ylidene]malononitrile (compound b) showed the strongest superoxide anion-scavenging activity among the 6 kinds of 2-methylene-1,3-selenazolidin-4-ones examined. Compound b had a 50% inhibitory concentration (IC{sub 50}) at 92.4 {mu}M and acted as an effective and potentially useful O{sub 2}{sup -} scavenger in vitro. The effect of compound b on rat pheochromocytome cell line PC12 cells was compared with that of ebselen or nerve growth factor (NGF) by use of the MTT [3-(4, 5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide] assay. When ebselen was added at 100 {mu}M or more, toxicity toward PC12 cells was evident. On the contrary, compound b suppressed serum deprivation-induced apoptosis in PC12 cells more effectively at a concentration of 100 {mu}M. The activity of compound b to phosphorylate mitogen-activated protein kinase/extracellular signal-regulated protein kinase (ERK) 1/2 (MAP kinase) in PC12 cells was higher than that of ebselen, and the former at 100 {mu}M induced the phosphorylation of MAP kinase to a degree similar to that induced by NGF. From these results, we conclude that this superoxide anion-scavenger, compound b, suppressed serum deprivation-induced apoptosis by promoting the phosphorylation of MAP kinase. -- Highlights: Black-Right-Pointing-Pointer We newly synthesized 1,3-selenazolidin-4-ones to

  13. Microfluidic Platform Generates Oxygen Landscapes for Localized Hypoxic Activation

    PubMed Central

    Rexius, Megan L.; Mauleon, Gerardo; Malik, Asrar B.; Rehman, Jalees; Eddington, David T.

    2014-01-01

    An open-well microfluidic platform generates an oxygen landscape using gas-perfused networks which diffuse across a membrane. The device enables real-time analysis of cellular and tissue responses to oxygen tension to define how cells adapt to heterogeneous oxygen conditions found in the physiological setting. We demonstrate that localized hypoxic activation of cells elicited specific metabolic and gene responses in human microvascular endothelial cells and bone marrow-derived mesenchymal stem cells. A robust demonstration of the compatibility of the device with standard laboratory techniques demonstrates the wide utility of the method. This platform is ideally suited to study real-time cell responses and cell-cell interactions within physiologically relevant oxygen landscapes. PMID:25315003

  14. The free radical scavenging and antioxidant activities of pod and seed extract of Clitoria fairchildiana (Howard)- an underutilized legume.

    PubMed

    Annegowda, H V; Bhat, Rajeev; Tze, Liong Min; Karim, A A; Mansor, S M

    2013-06-01

    We evaluated the phenolic content and antioxidant capacities of pod and seed extracts (in methanol, ethanol, and water) of an underutilized legume, Clitoria fairchildiana (Howard). The antioxidant capacity of the extracts was determined using the ferric reducing antioxidant potential assay, and the free radical-scavenging capacity was evaluated using 2,2-diphenyl-1-picrylhydrazyl radical-scavenging and ABTS assays. In addition, the total flavonoids, flavonols, and tannin contents were also determined. Overall, the methanol extracts of the pod contained high concentration of phenolics and showed high antioxidant capacities compared to seed extracts. In addition, a positive correlation was found between total phenol and tannin versus antioxidant capacity. Results of the present study indicate pods and seeds of C. fairchildiana to possess rich amount of natural antioxidants, and can be further explored for their possible use as a natural additive in food or in pharmaceutical industries. PMID:24425949

  15. Free-radical scavenging and mitochondrial antioxidant activities of Reishi-Ganoderma lucidum (Curt: Fr) P. Karst and Arogyapacha-Trichopus zeylanicus Gaertn extracts.

    PubMed

    Cherian, Elizabeth; Sudheesh, Narayana P; Janardhanan, Kainoor K; Patani, George

    2009-01-01

    Endogenous damage to mitochondrial DNA by free radicals is believed to be a major contributory factor to aging. The current study examined the effects of the extracts of two important anti-fatigue and rejuvenating medicinal herbs Ganoderma lucidum and Trichopus zeylanicus for their free-radical scavenging property and for their effects on liver mitochondrial antioxidant activity in aged mice. Both extracts were administrated orally to aged BALB/c mice at doses of 50 and 250 mg/kg body weight for 15 days. Super oxide dismutase (SOD) and catalase (CAT) activity and levels of reduced glutathione (GSH) and lipid peroxidation as equivalents of malondialdehyde (MDA) formed were determined. Groups of young mice and aged mice (more than 15 months old) were taken as controls. Both G. lucidum and T. zeylanicus extracts increased antioxidant status in liver mitochondria of aged mice compared with the aged control. Higher levels of GSH, increased activity of SOD and CAT, and decreased level of MDA in both treated groups compared with the controls were evident. Both extracts possessed significant 2,2-diphenyl-1-picrylhydrazil (DPPH), 2, 2'-azinobis (3-ethylbenzothiazolin-6-sulphonic acid) (ABTS) radical scavenging activities and ferric reducing antioxidant power (FRAP). The DPPH, ABTS, and FRAP activities were higher in G. lucidum extract than in T. zeylanicus. G. lucidum extract also showed superoxide and hydroxyl radical scavenging activities. T. zeylanicus had significantly higher lipid peroxidation inhibiting activity than G. lucidum. Thus, we conclude that the antioxidative effect of the G. lucidum extract was higher than that of T. zeylanicus. Our findings suggest a potential therapeutic efficacy of G. lucidum extract to protect against aging and to a certain extent against age-related degenerative diseases.

  16. Free-radical scavenging and mitochondrial antioxidant activities of Reishi-Ganoderma lucidum (Curt: Fr) P. Karst and Arogyapacha-Trichopus zeylanicus Gaertn extracts.

    PubMed

    Cherian, Elizabeth; Sudheesh, Narayana P; Janardhanan, Kainoor K; Patani, George

    2009-01-01

    Endogenous damage to mitochondrial DNA by free radicals is believed to be a major contributory factor to aging. The current study examined the effects of the extracts of two important anti-fatigue and rejuvenating medicinal herbs Ganoderma lucidum and Trichopus zeylanicus for their free-radical scavenging property and for their effects on liver mitochondrial antioxidant activity in aged mice. Both extracts were administrated orally to aged BALB/c mice at doses of 50 and 250 mg/kg body weight for 15 days. Super oxide dismutase (SOD) and catalase (CAT) activity and levels of reduced glutathione (GSH) and lipid peroxidation as equivalents of malondialdehyde (MDA) formed were determined. Groups of young mice and aged mice (more than 15 months old) were taken as controls. Both G. lucidum and T. zeylanicus extracts increased antioxidant status in liver mitochondria of aged mice compared with the aged control. Higher levels of GSH, increased activity of SOD and CAT, and decreased level of MDA in both treated groups compared with the controls were evident. Both extracts possessed significant 2,2-diphenyl-1-picrylhydrazil (DPPH), 2, 2'-azinobis (3-ethylbenzothiazolin-6-sulphonic acid) (ABTS) radical scavenging activities and ferric reducing antioxidant power (FRAP). The DPPH, ABTS, and FRAP activities were higher in G. lucidum extract than in T. zeylanicus. G. lucidum extract also showed superoxide and hydroxyl radical scavenging activities. T. zeylanicus had significantly higher lipid peroxidation inhibiting activity than G. lucidum. Thus, we conclude that the antioxidative effect of the G. lucidum extract was higher than that of T. zeylanicus. Our findings suggest a potential therapeutic efficacy of G. lucidum extract to protect against aging and to a certain extent against age-related degenerative diseases. PMID:20214017

  17. Identification of the Active Species in Photochemical Hole Scavenging Reactions of Methanol on TiO2

    SciTech Connect

    Shen, Mingmin; Henderson, Michael A.

    2011-11-03

    Molecular and dissociative methanol adsorption species were prepared on rutile TiO2(110) surfaces to study photocatalytic oxidation of methanol in ultrahigh vacuum (UHV) using temperature-programmed desorption (TPD). Adsorbed methoxy groups (CH3O-) were found to be the photoactive form of adsorbed methanol converted to adsorbed formaldehyde and a surface OH group by hole-mediated C-H bond cleavage. These results suggest that adsorbed methoxy is the effective hole scavenger in photochemical reactions involving methanol.

  18. Excited states in the active media of oxygen - iodine lasers

    SciTech Connect

    Azyazov, V N

    2009-11-30

    A review of investigations of kinetic processes in active media oxygen - iodine lasers (OILs) performed in the last decade is presented. The mechanisms of pumping and quenching of electronically and vibrationally excited O{sub 2} and I{sub 2} molecules are considered, and dissociation mechanisms of I{sub 2} in the active medium of the OIL are analysed. The values of kinetic constants of processes proceeding in the active media of OILs are recommended. (review)

  19. Melatonin and its precursors scavenge nitric oxide

    SciTech Connect

    Noda, Y.; Mori, A.; Liburdy, R.; Packer, L.

    1998-12-01

    Nitric oxide (NO) scavenging activity of melatonin, N-acetyl-5-hydroxytryptamine, serotonin, 5-hydroxytryptophan and L-tryptophan was examined by the Griess reaction using flow injection analysis. 1-Hydroxy-2-oxo-3-(N-methyl-3-aminopropyl)-3-methyl-1-triazene(NOC-7) was used as NO generator. The Griess reagent stoichiometrically reacts with NO2-, which was converted by a cadmium-copper reduction column from the stable end products of NO oxidation. Except for tryptophan, all the compounds examined scavenged NO in a dose-dependent manner. Melatonin, which has a methoxy group in the 5-position and an acetyl side chain, exhibited the most potent scavenging activity among the compounds tested. Serotonin, N-acetyl-5-hydroxytryptamine, and 5-hydroxytryptophan, respectively, showed moderate scavenging activity compared to melatonin. Tryptophan, which has neither a methoxy nor a hydroxyl group in the 5-position, exhibited the least NO scavenging activity.

  20. DNA Damage Protecting Activity and Free Radical Scavenging Activity of Anthocyanins from Red Sorghum (Sorghum bicolor) Bran

    PubMed Central

    Devi, P. Suganya; Kumar, M. Saravana; Das, S. Mohan

    2012-01-01

    There is increasing interest in natural food colorants like carotenoids and anthocyanins with functional properties. Red sorghum bran is known as a rich source for anthocyanins. The anthocyanin contents extracted from red sorghum bran were evaluated by biochemical analysis. Among the three solvent system used, the acidified methanol extract showed a highest anthocyanin content (4.7 mg/g of sorghum bran) followed by methanol (1.95 mg/g) and acetone (1 mg/g). Similarly, the highest total flavonoids (143 mg/g) and total phenolic contents (0.93 mg/g) were obtained in acidified methanol extracts than methanol and acetone extracts. To study the health benefits of anthocyanin from red sorghum bran, the total antioxidant activity was evaluated by biochemical and molecular methods. The highest antioxidant activity was observed in acidified methanol extracts of anthocyanin in dose-dependent manner. The antioxidant activity of the red sorghum bran was directly related to the total anthocyanin found in red sorghum bran. PMID:22400119

  1. Oxygen saturation during daily activities in chronic obstructive pulmonary disease.

    PubMed

    Soguel Schenkel, N; Burdet, L; de Muralt, B; Fitting, J W

    1996-12-01

    Patients with chronic obstructive pulmonary disease (COPD) frequently develop nocturnal oxygen desturation because of alveolar hypoventilation, worsening of ventilation-perfusion mismatch, and sometimes obstructive sleep apnoeas. In contrast, little is known about their oxygen status during the various activities of daily life. The aim of this study was to compare the oxygen saturation profile during day and night, and to assess the influence of different daily activities in COPD. During a rehabilitation programme, we studied 30 patients with moderate-to-severe COPD (median forced expiratory volume in one second (FEV1) 37% of predicted), without marked hypoxaemia (median arterial oxygen tension (Pa,O2) 9.1 kPa). Arterial oxygen saturation (Sa,O2) was assessed by pulse oximetry during night (8 h) and day (10.5 h). The mean and minimal Sa,O2 were calculated, and desaturations were defined as Sa,O2 falls > 4%.h-1. Daily activities were identified by the patients as resting, eating, washing, nebulization therapy and walking. Mean Sa,O2 was lower during the night (88%) than during the day (89%). In contrast, minimal Sa,O2 was lower during the day (69%) than during the night (72%), and the number of desaturations was higher during the day (8.6 desaturations.h-1) than during the night (6.8 desaturations.h-1). Mean Sa,O2 was 88% during walking, which was lower than during resting (90%), nebulization (90%), and meals (89%). The number of desaturations was higher during walking (13.1 desaturations.h-1), washing (12.6 desaturations.h-1), and eating (9.2 desaturations.h-1) than during resting (5.3 desaturations.h-1). We conclude that daily activities, such as walking, washing and eating, are associated with transient oxygen desaturation in patients with moderate-to-severe chronic obstructive pulmonary disease, even without marked resting hypoxaemia.

  2. Scavenger and antioxidant properties of prenylflavones isolated from Artocarpus heterophyllus.

    PubMed

    Ko, F N; Cheng, Z J; Lin, C N; Teng, C M

    1998-07-15

    The antioxidant properties of prenylflavones, isolated from Artocarpus heterophyllus Lam., was evaluated in this study. Among them, artocarpine, artocarpetin, artocarpetin A, and cycloheterophyllin diacetate and peracetate had no effect on iron-induced lipid peroxidation in rat brain homogenate. They also did not scavenge the stable free radical 1,1-diphenyl-2-picrylhydrazyl. In contrast, cycloheterophyllin and artonins A and B inhibited iron-induced lipid peroxidation in rat brain homogenate and scavenged 1,1-diphenyl-2-picrylhydrazyl. They also scavenged peroxyl radicals and hydroxyl radicals that were generated by 2,2'-azobis(2-amidinopropane) dihydrochloride and the Fe3+-ascorbate-EDTA-H2O2 system, respectively. However, they did not inhibit xanthine oxidase activity or scavenge superoxide anion, hydrogen peroxide, carbon radical, or peroxyl radicals derived from 2,2'-azobis(2,4-dimethylvaleronitrile) in hexane. Moreover, cycloheterophyllin and artonins A and B inhibited copper-catalyzed oxidation of human low-density lipoprotein, as measured by fluorescence intensity, thiobarbituric acid-reactive substance and conjugated-diene formations and electrophoretic mobility. It is concluded that cycloheterophyllin and artonins A and B serve as powerful antioxidants against lipid peroxidation when biomembranes are exposed to oxygen radicals.

  3. Scavenger and antioxidant properties of prenylflavones isolated from Artocarpus heterophyllus.

    PubMed

    Ko, F N; Cheng, Z J; Lin, C N; Teng, C M

    1998-07-15

    The antioxidant properties of prenylflavones, isolated from Artocarpus heterophyllus Lam., was evaluated in this study. Among them, artocarpine, artocarpetin, artocarpetin A, and cycloheterophyllin diacetate and peracetate had no effect on iron-induced lipid peroxidation in rat brain homogenate. They also did not scavenge the stable free radical 1,1-diphenyl-2-picrylhydrazyl. In contrast, cycloheterophyllin and artonins A and B inhibited iron-induced lipid peroxidation in rat brain homogenate and scavenged 1,1-diphenyl-2-picrylhydrazyl. They also scavenged peroxyl radicals and hydroxyl radicals that were generated by 2,2'-azobis(2-amidinopropane) dihydrochloride and the Fe3+-ascorbate-EDTA-H2O2 system, respectively. However, they did not inhibit xanthine oxidase activity or scavenge superoxide anion, hydrogen peroxide, carbon radical, or peroxyl radicals derived from 2,2'-azobis(2,4-dimethylvaleronitrile) in hexane. Moreover, cycloheterophyllin and artonins A and B inhibited copper-catalyzed oxidation of human low-density lipoprotein, as measured by fluorescence intensity, thiobarbituric acid-reactive substance and conjugated-diene formations and electrophoretic mobility. It is concluded that cycloheterophyllin and artonins A and B serve as powerful antioxidants against lipid peroxidation when biomembranes are exposed to oxygen radicals. PMID:9667491

  4. Early oxygen-utilization and brain activity in preterm infants.

    PubMed

    Tataranno, Maria Luisa; Alderliesten, Thomas; de Vries, Linda S; Groenendaal, Floris; Toet, Mona C; Lemmers, Petra M A; Vosse van de, Renè E; van Bel, Frank; Benders, Manon J N L

    2015-01-01

    The combined monitoring of oxygen supply and delivery using Near-InfraRed spectroscopy (NIRS) and cerebral activity using amplitude-integrated EEG (aEEG) could yield new insights into brain metabolism and detect potentially vulnerable conditions soon after birth. The relationship between NIRS and quantitative aEEG/EEG parameters has not yet been investigated. Our aim was to study the association between oxygen utilization during the first 6 h after birth and simultaneously continuously monitored brain activity measured by aEEG/EEG. Forty-four hemodynamically stable babies with a GA < 28 weeks, with good quality NIRS and aEEG/EEG data available and who did not receive morphine were included in the study. aEEG and NIRS monitoring started at NICU admission. The relation between regional cerebral oxygen saturation (rScO2) and cerebral fractional tissue oxygen extraction (cFTOE), and quantitative measurements of brain activity such as number of spontaneous activity transients (SAT) per minute (SAT rate), the interval in seconds (i.e. time) between SATs (ISI) and the minimum amplitude of the EEG in μV (min aEEG) were evaluated. rScO2 was negatively associated with SAT rate (β=-3.45 [CI=-5.76- -1.15], p=0.004) and positively associated with ISI (β=1.45 [CI=0.44-2.45], p=0.006). cFTOE was positively associated with SAT rate (β=0.034 [CI=0.009-0.059], p=0.008) and negatively associated with ISI (β=-0.015 [CI=-0.026- -0.004], p=0.007). Oxygen delivery and utilization, as indicated by rScO2 and cFTOE, are directly related to functional brain activity, expressed by SAT rate and ISI during the first hours after birth, showing an increase in oxygen extraction in preterm infants with increased early electro-cerebral activity. NIRS monitored oxygenation may be a useful biomarker of brain vulnerability in high-risk infants. PMID:25965343

  5. Nature of Activated Manganese Oxide for Oxygen Evolution.

    PubMed

    Huynh, Michael; Shi, Chenyang; Billinge, Simon J L; Nocera, Daniel G

    2015-12-01

    Electrodeposited manganese oxide films (MnOx) are promising stable oxygen evolution catalysts. They are able to catalyze the oxygen evolution reaction in acidic solutions but with only modest activity when prepared by constant anodic potential deposition. We now show that the performance of these catalysts is improved when they are "activated" by potential cycling protocols, as measured by Tafel analysis (where lower slope is better): upon activation the Tafel slope decreases from ∼120 to ∼70 mV/decade in neutral conditions and from ∼650 to ∼90 mV/decade in acidic solutions. Electrochemical, spectroscopic, and structural methods were employed to study the activation process and support a mechanism where the original birnessite-like MnOx (δ-MnO2) undergoes a phase change, induced by comproportionation with cathodically generated Mn(OH)2, to a hausmannite-like intermediate (α-Mn3O4). Subsequent anodic conditioning from voltage cycling or water oxidation produces a disordered birnessite-like phase, which is highly active for oxygen evolution. At pH 2.5, the current density of activated MnOx (at an overpotential of 600 mV) is 2 orders of magnitude higher than that of the original MnOx and begins to approach that of Ru and Ir oxides in acid. PMID:26574923

  6. Effects of Comb Tooth Cap Medicinal Mushroom, Hericium ramosum (Higher Basidiomycetes) Mycelia on DPPH Radical Scavenging Activity and Nerve Growth Factor Synthesis.

    PubMed

    Suruga, Kohei; Kadokura, Kazunari; Sekino, Yoshihiro; Nakano, Takafumi; Matsuo, Koichi; Irie, Keiichi; Mishima, Kenichi; Yoneyama, Makoto; Komatsu, Yasuhiro

    2015-01-01

    The goal of this study was to evaluate the antioxidant effects of and nerve growth factor (NGF) synthesis caused by Hericium ramosum mycelia. Wild mushroom fruiting bodies were collected from nature to isolate their mycelia. Pieces of H. ramosum fruiting bodies were plated onto 90-mm Petri dishes with potato dextrose agar medium to isolate their mycelia. Antioxidant activity was measured using 1,1-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging activity in vitro; the ethanol extract from H. ramosum mycelia (63.11 µmol Trolox/g) was more potent than that of other mushroom mycelia extracts. There was a proportional relationship (R2 = 0.7929) between DPPH radical scavenging activity and total phenolic content in extracts of different mushroom mycelia. We investigated the ability of H. ramosum mycelia to inducing NGF synthesis in vivo. Oral administration of H. ramosum mycelia significantly increased concentrations of NGF in the hippocampus of intact mice. These results are the first concerning antioxidant activity and NGF synthesis of H. ramosum mycelia. These mushroom mycelia could be useful as food and/or nutritional supplements because of certain biological functions.

  7. Antiviral, immunomodulatory, and free radical scavenging activities of a protein-enriched fraction from the larvae of the housefly, Musca domestica.

    PubMed

    Ai, Hui; Wang, Furong; Zhang, Na; Zhang, Lingyao; Lei, Chaoliang

    2013-01-01

    In our previous study, protein-enriched fraction (PEF) that was isolated from the larvae of the housefly, Musca domestica L. (Diptera: Muscidae), showed excellent hepatoprotective activity as well as the potential for clinical application in therapy for liver diseases. In this study, antiviral, immunomodulatory, and free radical scavenging activities of PEF were evaluated. The antiviral results demonstrated that PEF inhibited the infection of avian influenza virus H9N2 and had a virucidal effect against the multicapsid nucleopolyhedrovirus of the alfalfa looper, Autographa californica Speyer (Lepidoptera: Noctuidae) in vitro. The mortality of silkworm larve in a PEF treatment group decreased significantly compared with a negative control. PEF showed excellent scavenging activity for 1,1-diphenyl-2-picrylhydrazyl and superoxide anion radicals, which were similar to those of ascorbic acid. The imunomodulatory results suggested that PEF could effectively improve immune function in experimental mice. Our results indicated that PEF could possibly be used for the prophylaxis and treatment of diseases caused by avian influenza virus infection. In addition, PEF with virucidal activity against insect viruses might provide useful for the development of antimicrobial breeding technology for economically important insects. As a natural product from insects, PEF could be a potential source for the discovery of potent antioxidant and immunomodulatory agents.

  8. An evaluation of extracts of five traditional medicinal plants from Iran on the inhibition of mushroom tyrosinase activity and scavenging of free radicals.

    PubMed

    Khazaeli, P; Goldoozian, R; Sharififar, F

    2009-10-01

    This study aimed to evaluate the free radical scavenging and inhibition properties of five medicinal plants, including Quercus infectoria Olive., Terminalia chebula Retz., Lavendula stoechas L., Mentha longifolia L., Rheum palmatum L., toward the activity of mushroom tyrosinase using L-tyrosine and L-3,4-dihydroxyphenylalanine (L-DOPA) as the substrate.The methanol extracts of Q. infectoria and T. chebula showed strong radical scavenging effect in 2,2'-dipheny L-1-picrylhydrazyl (DPPH) assay(IC50 = 15.3 and 82.2 microg mL)1 respectively).These plants also showed inhibitory effects against the activity of mushroom tyrosinase in hydroxylation of L-tyrosine (85.9% and 82.2% inhibition,respectively). These two plants also inhibited the oxidation of l-DOPA similar to kojic acid as positive control (IC50 = 102.8 and 192.6 microg mL)1 respectively). In general Q. infectoria and T. chebula significantly inhibited tyrosinase activity and DPPH radical. Both activities were concentration dependant but not in linear manner. It is needed to study the cytotoxicity of these plant extracts in pigment cell culture before further evaluation and moving to in vivo conditions.

  9. Scavenging of superoxide anion radical by chaparral.

    PubMed

    Zang, L Y; Cosma, G; Gardner, H; Starks, K; Shi, X; Vallyathan, V

    1999-06-01

    Chaparral is considered to act as an antioxidant. However, the inhibitory effects of chaparral on specific radical species are not well understood. Using electron paramagnetic resonance (EPR) spectroscopy in combination with spin trapping techniques, we have found that chaparral scavenges superoxide anion radical (O2*-) in a dose-dependent manner. 5,5-dimethyl-lpyrroline-N-oxide (DMPO) was used as a spin trapping agent and the reaction of xanthine and xanthine oxidase as a source of O2*-. The kinetic parameters, IC50 and Vmax, for chaparral scavenging of O2*- were found to be 0.899 microg/mL and 8.4 ng/mL/sec, respectively. The rate constant for chaparral scavenging O2*- was found to be 1.22 x 10(6) g(-1) s(-1). Our studies suggest that the antioxidant properties of chaparral may involve a direct scavenging effect of the primary oxygen radical, O2*-.

  10. A QSAR study of radical scavenging antioxidant activity of a series of flavonoids using DFT based quantum chemical descriptors--the importance of group frontier electron density.

    PubMed

    Sarkar, Ananda; Middya, Tapas Ranjan; Jana, Atish Dipnakar

    2012-06-01

    In a pursuit of electronic level understanding of the antioxidant activity of a series of flavonoids, quantitative structure-activity relationship (QSAR) studies have been carried out using density functional theory (DFT) based quantum chemical descriptors. The best QSAR model have been selected for which the computed square correlation coefficient r(2) = 0.937 and cross-validated squared correlation coefficient q(2) =0.916. The QSAR model indicates that hardness (η), group electrophilic frontier electron density (F(E)(A)) and group philicity (ω(B)(+)) of individual molecules are responsible for in vitro biological activity. To the best our knowledge, the group electrophilic frontier electron density (F(E)(A)) has been used for the first time to explain the radical scavenging activity (RSA) of flavonoids. The excellent correlation between the RSA and the above mentioned DFT based descriptors lead us to predict new antioxidants having very good antioxidant activity.

  11. Changes to coral health and metabolic activity under oxygen deprivation.

    PubMed

    Murphy, James W A; Richmond, Robert H

    2016-01-01

    On Hawaiian reefs, the fast-growing, invasive algae Gracilaria salicornia overgrows coral heads, restricting water flow and light, thereby smothering corals. Field data shows hypoxic conditions (dissolved oxygen (DO2) < 2 mg/L) occurring underneath algal mats at night, and concurrent bleaching and partial tissue loss of shaded corals. To analyze the impact of nighttime oxygen-deprivation on coral health, this study evaluated changes in coral metabolism through the exposure of corals to chronic hypoxic conditions and subsequent analyses of lactate, octopine, alanopine, and strombine dehydrogenase activities, critical enzymes employed through anaerobic respiration. Following treatments, lactate and octopine dehydrogenase activities were found to have no significant response in activities with treatment and time. However, corals subjected to chronic nighttime hypoxia were found to exhibit significant increases in alanopine dehydrogenase activity after three days of exposure and strombine dehydrogenase activity starting after one overnight exposure cycle. These findings provide new insights into coral metabolic shifts in extremely low-oxygen environments and point to ADH and SDH assays as tools for quantifying the impact of hypoxia on coral health. PMID:27114888

  12. Changes to coral health and metabolic activity under oxygen deprivation

    PubMed Central

    Richmond, Robert H.

    2016-01-01

    On Hawaiian reefs, the fast-growing, invasive algae Gracilaria salicornia overgrows coral heads, restricting water flow and light, thereby smothering corals. Field data shows hypoxic conditions (dissolved oxygen (DO2) < 2 mg/L) occurring underneath algal mats at night, and concurrent bleaching and partial tissue loss of shaded corals. To analyze the impact of nighttime oxygen-deprivation on coral health, this study evaluated changes in coral metabolism through the exposure of corals to chronic hypoxic conditions and subsequent analyses of lactate, octopine, alanopine, and strombine dehydrogenase activities, critical enzymes employed through anaerobic respiration. Following treatments, lactate and octopine dehydrogenase activities were found to have no significant response in activities with treatment and time. However, corals subjected to chronic nighttime hypoxia were found to exhibit significant increases in alanopine dehydrogenase activity after three days of exposure and strombine dehydrogenase activity starting after one overnight exposure cycle. These findings provide new insights into coral metabolic shifts in extremely low-oxygen environments and point to ADH and SDH assays as tools for quantifying the impact of hypoxia on coral health. PMID:27114888

  13. Changes to coral health and metabolic activity under oxygen deprivation.

    PubMed

    Murphy, James W A; Richmond, Robert H

    2016-01-01

    On Hawaiian reefs, the fast-growing, invasive algae Gracilaria salicornia overgrows coral heads, restricting water flow and light, thereby smothering corals. Field data shows hypoxic conditions (dissolved oxygen (DO2) < 2 mg/L) occurring underneath algal mats at night, and concurrent bleaching and partial tissue loss of shaded corals. To analyze the impact of nighttime oxygen-deprivation on coral health, this study evaluated changes in coral metabolism through the exposure of corals to chronic hypoxic conditions and subsequent analyses of lactate, octopine, alanopine, and strombine dehydrogenase activities, critical enzymes employed through anaerobic respiration. Following treatments, lactate and octopine dehydrogenase activities were found to have no significant response in activities with treatment and time. However, corals subjected to chronic nighttime hypoxia were found to exhibit significant increases in alanopine dehydrogenase activity after three days of exposure and strombine dehydrogenase activity starting after one overnight exposure cycle. These findings provide new insights into coral metabolic shifts in extremely low-oxygen environments and point to ADH and SDH assays as tools for quantifying the impact of hypoxia on coral health.

  14. Standardizing Scavenger Receptor Nomenclature

    PubMed Central

    PrabhuDas, Mercy; Bowdish, Dawn; Drickamer, Kurt; Febbraio, Maria; Herz, Joachim; Kobzik, Lester; Krieger, Monty; Loike, John; Means, Terry K.; Moestrup, Soren K.; Post, Steven; Sawamura, Tatsuya; Silverstein, Samuel; Wang, Xiang-Yang; El Khoury, Joseph

    2014-01-01

    Scavenger receptors constitute a large family of proteins that are structurally diverse and participate in a wide range of biological functions. These receptors are expressed predominantly by myeloid cells and recognize a variety of ligands, including endogenous and modified host-derived molecules and microbial pathogens. There are currently eight classes of scavenger receptors, many of which have multiple names, leading to inconsistencies and confusion in the literature. To address this problem, a workshop was organized by the U.S. National Institute of Allergy and Infectious Diseases, National Institutes of Health to help develop a clear definition of scavenger receptors and a standardized nomenclature based on that definition. Fifteen experts in the scavenger receptor field attended the workshop and, after extensive discussion, reached a consensus regarding the definition of scavenger receptors and a proposed scavenger receptor nomenclature. Scavenger receptors were defined as cell surface receptors that typically bind multiple ligands and promote the removal of non-self or altered-self targets. They often function by mechanisms that include endocytosis, phagocytosis, adhesion, and signaling that ultimately lead to the elimination of degraded or harmful substances. Based on this definition, nomenclature and classification of these receptors into 10 classes were proposed. The discussion and nomenclature recommendations described in this report only refer to mammalian scavenger receptors. The purpose of this article is to describe the proposed mammalian nomenclature and classification developed at the workshop and to solicit additional feedback from the broader research community. PMID:24563502

  15. Botanical Scavenger Hunt

    ERIC Educational Resources Information Center

    Walker-Livingston, Wendy

    2009-01-01

    Why not combine the use of technology with the excitement of a scavenger hunt that moves middle-level students out into the "wilds" of their school campus to classify plants? In the lesson plan described here, students embark on a botanical scavenger hunt and then document their findings using a digital camera. This project was designed to allow…

  16. REACTOR FUEL SCAVENGING MEANS

    DOEpatents

    Coffinberry, A.S.

    1962-04-10

    A process for removing fission products from reactor liquid fuel without interfering with the reactor's normal operation or causing a significant change in its fuel composition is described. The process consists of mixing a liquid scavenger alloy composed of about 44 at.% plutoniunm, 33 at.% lanthanum, and 23 at.% nickel or cobalt with a plutonium alloy reactor fuel containing about 3 at.% lanthanum; removing a portion of the fuel and scavenger alloy from the reactor core and replacing it with an equal amount of the fresh scavenger alloy; transferring the portion to a quiescent zone where the scavenger and the plutonium fuel form two distinct liquid layers with the fission products being dissolved in the lanthanum-rich scavenger layer; and the clean plutonium-rich fuel layer being returned to the reactor core. (AEC)

  17. Screening of antibacterial activities of twenty-one oxygenated monoterpenes.

    PubMed

    Kotan, Recep; Kordali, Saban; Cakir, Ahmet

    2007-01-01

    Plant essential oils are widely used as fragrances and flavours in the cosmetic, perfume, drug and food industries. Oxygenated monoterpenes are widespread components of the essential oils, usually occurring in high amount. In this paper, the antibacterial activities of twenty-one oxygenated monoterpenes (borneol, borneol acetate, camphor, carvone, 1,8-cineole, citronellal, beta-citronellol, dihydrocarvone, fenchol, fenchone, geraniol acetate, isomenthol, limonene oxide, linalool, linalool acetate, nerol, nerol acetate, terpinen-4-ol, alpha-terpineol, menthol and menthone) and penicillin (standard antibiotic) were determined using a disc diffusion method (in vitro) against 63 bacterial strains, belonging to 37 different genera and 54 species (plant, food and clinic origins). The results showed that the oxygenated monoterpenes exhibited a variable degree of antibacterial activities. These compounds also inhibited the growth of bacterial strains by producing a weak zone of inhibition from 7 to 11 mm in diameter, depending on the susceptibility of the tested bacteria. Among the tested compounds, nerol, linalool alpha-terpineol, fenchol and terpinen-4-ol showed antibacterial activity at a broad spectrum. However, their antibacterial activities were lower than those of penicillin. In contrast to these compounds, camphor and 1,8-cineole exhibited no inhibition effects on the growth of all tested bacteria.

  18. Removal of Biologically Active Organic Contaminants using Atomic Oxygen

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A. (Inventor); Banks, Michael A. (Inventor); Banks, Eric B. (Inventor)

    2003-01-01

    Biomedical devices that are to come into contact with living tissue, such as prosthetic and other implants for the human body and the containers used to store and transport them, are together cleaned of non-living, but biologically active organic materials, including endotoxins such as lipopolysaccharides, and assembled into a hermetically sealed package without recontamination. This is achieved by cleaning both the device and package components together in an apparatus, which includes a hermetically sealed chamber, in which they are contacted with atomic oxygen which biocleans them, by oxidizing the biologically active organic materials. The apparatus also includes means for manipulating the device and container and hermetically sealing the cleaned device into the cleaned container to form the package. A calibrated witness coupon visually indicates whether or not the device and container have received enough exposure to the atomic oxygen to have removed the organic materials from their surfaces. Gamma radiation is then used to sterilize the device in the sealed container.

  19. Inorganic Polyphosphates Regulate Hexokinase Activity and Reactive Oxygen Species Generation in Mitochondria of Rhipicephalus (Boophilus) microplus Embryo

    PubMed Central

    Fraga, Amanda; Moraes, Jorge; da Silva, José Roberto; Costa, Evenilton P.; Menezes, Jackson; da Silva Vaz Jr, Itabajara; Logullo, Carlos; da Fonseca, Rodrigo Nunes; Campos, Eldo

    2013-01-01

    The physiological roles of polyphosphates (poly P) recently found in arthropod mitochondria remain obscure. Here, the possible involvement of poly P with reactive oxygen species generation in mitochondria of Rhipicephalus microplus embryos was investigated. Mitochondrial hexokinase and scavenger antioxidant enzymes, such as superoxide dismutase, catalase, and glutathione reductase were assayed during embryogenesis of R. microplus. The influence of poly P3 and poly P15 were analyzed during the period of higher enzymatic activity during embryogenesis. Both poly Ps inhibited hexokinase activity by up to 90% and, interestingly, the mitochondrial membrane exopolyphosphatase activity was stimulated by the hexokinase reaction product, glucose-6-phosphate. Poly P increased hydrogen peroxide generation in mitochondria in a situation where mitochondrial hexokinase is also active. The superoxide dismutase, catalase and glutathione reductase activities were higher during embryo cellularization, at the end of embryogenesis and during embryo segmentation, respectively. All of the enzymes were stimulated by poly P3. However, superoxide dismutase was not affected by poly P15, catalase activity was stimulated only at high concentrations and glutathione reductase was the only enzyme that was stimulated in the same way by both poly Ps. Altogether, our results indicate that inorganic polyphosphate and mitochondrial membrane exopolyphosphatase regulation can be correlated with the generation of reactive oxygen species in the mitochondria of R. microplus embryos. PMID:23983617

  20. Anti-Candida and radical scavenging activities of essential oils and oleoresins of Zingiber officinale Roscoe and essential oils of other plants belonging to the family Zingiberaceae.

    PubMed

    Takahashi, M; Inouye, S; Abe, S

    2011-10-01

    Essential oils of young and mature rhizomes, air-dried and steamed rhizomes, and seed rhizomes of Zingiber officinale Roscoe (ginger) were prepared, and their inhibition of filamentation by Candida albicans was examined. Ginger essential oils, and particularly those from seed and air-dried rhizomes, had potent inhibitory activity compared to ginger oleoresins obtained by ethanol and hypercritical carbon dioxide extraction and essential oils of 5 other plants in the family Zingiberaceae. Of the constituents, [6]-shogaol was most active against filament formation and growth of C. albicans, followed by citral and [6]-gingerol. Ginger oleoresin, and especially that obtained by ethanol extraction, with a high [6]-gingerol content exhibited potent scavenging activity against 1,1-diphenyl-2-picrylhydrazyl radicals in comparison to essential oils of ginger and other Zingiberaceae plants. PMID:22466370

  1. Reactive oxygen species scavengers improve voltage-gated K+ channel function in pulmonary arteries of newborn pigs with progressive hypoxia-induced pulmonary hypertension

    PubMed Central

    Aschner, Judy L.

    2013-01-01

    Abstract Changes in voltage-gated K+ (Kv) channel function contribute to the pathogenesis of pulmonary hypertension. Yet the mechanisms underlying Kv channel impairments in the pulmonary circulation remain unclear. We tested the hypothesis that reactive oxygen species (ROSs) contribute to the Kv channel dysfunction that develops in resistance-level pulmonary arteries (PRAs) of piglets exposed to chronic in vivo hypoxia. Piglets were raised in either room air (control) or hypoxia for 3 or 10 days. To evaluate Kv channel function, responses to the Kv channel antagonist 4-aminopyridine (4-AP) were measured in cannulated PRAs. To assess the influence of ROSs, PRAs were treated with the ROS-removing agent M40403 (which dismutates superoxide to hydrogen peroxide), plus polyethylene glycol catalase (which converts hydrogen peroxide to water). Responses to 4-AP were diminished in PRAs from both groups of hypoxic piglets. ROS-removing agents had no impact on 4-AP responses in PRAs from piglets exposed to 3 days of hypoxia but significantly increased the response to 4-AP in PRAs from piglets exposed to 10 days of hypoxia. Kv channel function is impaired in PRAs of piglets exposed to 3 or 10 days of in vivo hypoxia. ROSs contribute to Kv channel dysfunction in PRAs from piglets exposed to hypoxia for 10 days but are not involved with the Kv channel dysfunction that develops within 3 days of exposure to hypoxia. Therapies to remove ROSs might improve Kv channel function and thereby ameliorate the progression, but not the onset, of pulmonary hypertension in chronically hypoxic newborn piglets. PMID:24618540

  2. Contribution of Endogenously Produced Reactive Oxygen Species to the Activation of Podocyte NLRP3 Inflammasomes in Hyperhomocysteinemia

    PubMed Central

    Abais, Justine M.; Xia, Min; Li, Guangbi; Gehr, Todd W. B.; Boini, Krishna M.; Li, Pin-Lan

    2013-01-01

    Hyperhomocysteinemia (hHcys) is an important pathogenic factor contributing to the progression of end-stage renal disease. Recent studies have demonstrated the implication of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-mediated NLRP3 inflammasome activation in the development of podocyte injury and glomerular sclerosis during hHcys. However, it remains unknown which reactive oxygen species (ROS) are responsible for this activation of NLRP3 inflammasomes and how such action of ROS is controlled. The present study tested the contribution of common endogenous ROS including superoxide (O2•−), hydrogen peroxide (H2O2), and hydroxyl radical (•OH) to the activation of NLRP3 inflammasomes in mouse podocytes and glomeruli. In vitro, confocal microscopy and size exclusion chromatography demonstrated that dismutation of O2•− by 4-Hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPOL) and decomposition of H2O2 by catalase prevented Hcys-induced aggregation of NLRP3 inflammasome proteins and inhibited Hcys-induced caspase-1 activation and IL-1β production in mouse podocytes. However, •OH scavenger tetramethylthiourea (TMTU) had no significant effect on either Hcys-induced NLRP3 inflammasome formation or activation. In vivo, scavenging of O2•− by TEMPOL and removal of H2O2 by catalase substantially inhibited NLRP3 inflammasome formation and activation in glomeruli of hHcys mice as shown by reduced colocalization of NLRP3 with ASC or caspase-1 and inhibition of caspase-1 activation and IL-1β production. Furthermore, TEMPOL and catalase significantly attenuated hHcys-induced glomerular injury. In conclusion, endogenously produced O2•− and H2O2 primarily contribute to NLRP3 inflammasome formation and activation in mouse glomeruli resulting in glomerular injury or consequent sclerosis during hHcys. PMID:24140862

  3. The evaluation of potential limonene scavengers

    SciTech Connect

    Roth, R.; Ebert, D.; Shepodd, T.J.

    1995-01-01

    This work is the study of different scavengers of limonene. Limonene is a citrus-based, low toxicity, hydrocarbon solvent for cleaning circuit boards and other parts. Though almost all limonene evaporates after cleaning procedures, trace residual limonene would be a concern if allowed to migrate freely through a sealed system. This work was charted to investigate materials that would effectively scavenge and permanently immobilize trace limonene. The requirements of a successful scavenger are the following: it must remove >90% of 30 mg/l limonene from a sealed volume with 3 months, at 20--25 C; it must not release any volatiles over prolonged aging; it must be packaged such that limonene vapors can access the scavenger, but not such that the scavenging medium can migrate; and it must operate in the presence of water, oxygen, pentane, toluene, and carbon dioxide gases. A number of adsorbents were evaluated. Additionally, a scheme for scavenging limonene by chemical reaction was investigated at Sandia. This attempt was not successful. The details of this investigation are found at the end of this report.

  4. Utilization of a BGO detector as an active oxygen target

    NASA Astrophysics Data System (ADS)

    Loveman, R.; Gozani, T.; Bendahan, J.; Krivicich, J.; Elias, E.; Altschuler, E.

    1994-12-01

    The (n, n'γx) cross section for the 6.13 MeV state in oxygen has recently become of general interest because of the possibility of using this process to assay oxygen as a part of non-intrusive inspections. Localized densities of carbon, oxygen, and nitrogen are particularly useful in determining the presence of explosives and/or drugs in containers of all sizes, from suitcases to cargo containers. The presence of oxygen in BGO (Bi 4Ge 3O 12) scintillator makes this detector suitable for use as an active target for the measurement of the energy dependence of the excitation, of the first (6.049 MeV O +) and second (6.130 MeV 3 -) excited states in 16O by fast neutron interactions. An active target functions as both a target and an active device such as a detector. The de-excitations of the 6.049 and 6.130 states take place by nuclear pair production and γ-ray emission respectively. There is a large probability of absorbing all of the de-excitation energy in the scintillator in either of these cases. Since the energies deposited in the scintillator by these transitions are very close, the de-excitations are indistinguishable. However, since the cross section for the excitation of the 6.13 MeV state is believed to be larger than that of the 6.049 MeV, the major measured features of the energy variations are those related to the second state. The validity of the technique was initially tested using (MCNP) calculations. The calculations established that the detected neutron count rate in the crystal was proportional to the cross-sections used as input for the calculations, and that the constant of proportionality did not vary with neutron energy. Subsequently, measurements were made with a BGO detector as an active oxygen target. The results clearly show a strong energy dependence including several resonances.

  5. Development of a novel electrochemical system for oxygen control (ESOC) to examine dissolved oxygen inhibition on algal activity.

    PubMed

    Keymer, Philip C; Pratt, Steven; Lant, Paul A

    2013-09-01

    The development of an Electrochemical System for Oxygen Control (ESOC) for examining algal photosynthetic activity as a function of dissolved oxygen (DO) is outlined. The main innovation of the tool is coulombic titration in order to balance the electrochemical reduction of oxygen with the oxygen input to achieve a steady DO set-point. ESOC allows quantification of algal oxygen production whilst simultaneously maintaining a desired DO concentration. The tool was validated abiotically by comparison with a mass transfer approach for quantifying oxygenation. It was then applied to quantify oxygen inhibition of algal activity. Five experiments, using an enriched culture of Scenedesmus sp. as the inoculum, are presented. For each experiment, ESOC was used to quantify algal activity at a series of DO set-points. In all experiments substantial oxygen inhibition was observed at DO >30 mgO2 L-1. Inhibition was shown to fit a Hill inhibition model, with a common Hill coefficient of 0.22±0.07 L mg-1 and common log10  CI50 of 27.2±0.7 mg L-1. This is the first time that the oxygen inhibition kinetic parameters have been quantified under controlled DO conditions.

  6. Active Oxygen Metabolites and Thromboxane in Phorbol Myristate Acetate Toxicity to the Isolated, Perfused Rat Lung.

    NASA Astrophysics Data System (ADS)

    Carpenter, Laurie Jean

    When administered intravenously or intratracheally to rats, rabbits and sheep, phorbol myristate acetate (PMA) produces changes in lung morphology and function are similar to those seen in humans with the adult respiratory distress syndrome (ARDS). Therefore, it is thought that information about the mechanism of ARDS development can be gained from experiments using PMA-treated animals. Currently, the mechanisms by which PMA causes pneumotoxicity are unknown. Results from other studies in rabbits and in isolated, perfused rabbit lungs suggest that PMA-induced lung injury is mediated by active oxygen species from neutrophils (PMN), whereas studies in sheep and rats suggest that PMN are not required for the toxic response. The role of PMN, active oxygen metabolites and thromboxane (TxA_2) in PMA-induced injury to isolated, perfused rat lungs (IPLs) was examined in this thesis. To determine whether PMN were required for PMA to produce toxicity to the IPL, lungs were perfused for 30 min with buffer containing various concentrations of PMA (in the presence or absence of PMN). When concentrations >=q57 ng/ml were added to medium devoid of added PMN, perfusion pressure and lung weight increased. When a concentration of PMA (14-28 ng/ml) that did not by itself cause lungs to accumulate fluid was added to the perfusion medium containing PMN (1 x 10 ^8), perfusion pressure increased, and lungs accumulated fluid. These results indicate that high concentrations of PMA produce lung injury which is independent of PMN, whereas injury induced by lower concentrations is PMN-dependent. To examine whether active oxygen species were involved in mediating lung injury induced by PMA and PMN, lungs were coperfused with the oxygen radical scavengers SOD and/or catalase. Coperfusion with either or both of these enzymes totally protected lungs against injury caused by PMN and PMA. These results suggest that active oxygen species (the hydroxyl radical in particular), mediate lung injury in

  7. Investigation into Seasonal Scavenging Patterns of Raccoons on Human Decomposition.

    PubMed

    Jeong, Yangseung; Jantz, Lee Meadows; Smith, Jake

    2016-03-01

    Although raccoons are known as one of the most common scavengers in the U.S., scavenging by these animals has seldom been studied in terms of forensic significance. In this research, the seasonal pattern of raccoon scavenging and its effect on human decomposition was investigated using 178 human cadavers placed at the Anthropological Research Facility (ARF) of the University of Tennessee, Knoxville (UTK) between February 2011 and December 2013. The results reveal that (i) the frequency of scavenging increases during summer, (ii) scavenging occurs relatively immediately and lasts shorter in summer months, and (iii) scavenging influences the decomposition process by hollowing limbs and by disturbing insect activities, both of which eventually increases the chance of mummification on the affected body. This information is expected to help forensic investigators identify raccoon scavenging as well as make a more precise interpretation of the effect of raccoon scavenging on bodies at crime scenes.

  8. Investigation into Seasonal Scavenging Patterns of Raccoons on Human Decomposition.

    PubMed

    Jeong, Yangseung; Jantz, Lee Meadows; Smith, Jake

    2016-03-01

    Although raccoons are known as one of the most common scavengers in the U.S., scavenging by these animals has seldom been studied in terms of forensic significance. In this research, the seasonal pattern of raccoon scavenging and its effect on human decomposition was investigated using 178 human cadavers placed at the Anthropological Research Facility (ARF) of the University of Tennessee, Knoxville (UTK) between February 2011 and December 2013. The results reveal that (i) the frequency of scavenging increases during summer, (ii) scavenging occurs relatively immediately and lasts shorter in summer months, and (iii) scavenging influences the decomposition process by hollowing limbs and by disturbing insect activities, both of which eventually increases the chance of mummification on the affected body. This information is expected to help forensic investigators identify raccoon scavenging as well as make a more precise interpretation of the effect of raccoon scavenging on bodies at crime scenes. PMID:27404620

  9. Investigation of the antioxidant and radical scavenging activities of some phenolic Schiff bases with different free radicals.

    PubMed

    Marković, Zoran; Đorović, Jelena; Petrović, Zorica D; Petrović, Vladimir P; Simijonović, Dušica

    2015-11-01

    The antioxidant properties of some phenolic Schiff bases in the presence of different reactive particles such as (•)OH, (•)OOH, (CH2=CH-O-O(•)), and (-•)O2 were investigated. The thermodynamic values, ΔH BDE, ΔH IP, and ΔH PA, were used for this purpose. Three possible mechanisms for transfer of hydrogen atom, concerted proton-electron transfer (CPET), single electron transfer followed by proton transfer (SET-PT), and sequential proton loss electron transfer (SPLET) were considered. These mechanisms were tested in solvents of different polarity. On the basis of the obtained results it was shown that SET-PT antioxidant mechanism can be the dominant mechanism when Schiff bases react with radical cation, while SPLET and CPET are competitive mechanisms for radical scavenging of hydroxy radical in all solvents under investigation. Examined Schiff bases react with the peroxy radicals via SPLET mechanism in polar and nonpolar solvents. The superoxide radical anion reacts with these Schiff bases very slowly.

  10. Comparison of the contents of the main biochemical compounds and the antioxidant activity of some Spanish olive oils as determined by four different radical scavenging tests.

    PubMed

    Gorinstein, Shela; Martin-Belloso, Olga; Katrich, Elena; Lojek, Antonin; Cíz, Milan; Gligelmo-Miguel, Nuria; Haruenkit, Ratiporn; Park, Yong-Seo; Jung, Soon-Teck; Trakhtenberg, Simon

    2003-03-01

    The aim of this study was to compare the contents of the main biochemical compounds and the antioxidant capacity of five Spanish olive oils by four different antioxidant tests and to find out the most valuable oil for disease preventing diets. Fatty acids, sterols and individual antioxidant compounds in Arbequina, Hojiblanca, Extra Virgin, Picual and Lampante Spanish olive oils were determined. Antioxidant activities were done as well using different radical scavenging activities: total radical-trapping antioxidative potential by ABAP (TRAP-ABAP), radical scavenging activity by DPPH (RSA-DPPH), antioxidant assay by beta-carotene-linoleate model system (AA-beta-carotene) and total antioxidant status by ABTS (TAA-ABTS). The highest content of all studied antioxidant compounds (353; 329; 4.6 and 2.7 mg/kg for tocopherols, tocotrienols, polyphenols and o-diphenols, respectively) was found in Extra Virgin oil. Also the highest antioxidant capacity was observed in Extra Virgin oil (668 nM/ml; 29.4%; 40.4% and 2.64 mM TE/kg for TRAP-ABAP, RSA-DPPH, AA- beta-carotene and TAA-ABTS, respectively). The correlation between total phenols and antioxidant capacities measured by four methods was very high, but the highest for the beta-carotene (R = 0.9958). In conclusion, the best method for determination of the antioxidant capacity of olive oils is the beta-carotene test. Extra Virgin olive oil has high organoleptic properties and the highest antioxidant activity. The above-mentioned makes this oil a preferable choice for diseases preventing diets.

  11. Hydroxylated chalcones with dual properties: Xanthine oxidase inhibitors and radical scavengers.

    PubMed

    Hofmann, Emily; Webster, Jonathan; Do, Thuy; Kline, Reid; Snider, Lindsey; Hauser, Quintin; Higginbottom, Grace; Campbell, Austin; Ma, Lili; Paula, Stefan

    2016-02-15

    In this study, we evaluated the abilities of a series of chalcones to inhibit the activity of the enzyme xanthine oxidase (XO) and to scavenge radicals. 20 mono- and polyhydroxylated chalcone derivatives were synthesized by Claisen-Schmidt condensation reactions and then tested for inhibitory potency against XO, a known generator of reactive oxygen species (ROS). In parallel, the ability of the synthesized chalcones to scavenge a stable radical was determined. Structure-activity relationship analysis in conjunction with molecular docking indicated that the most active XO inhibitors carried a minimum of three hydroxyl groups. Moreover, the most effective radical scavengers had two neighboring hydroxyl groups on at least one of the two phenyl rings. Since it has been proposed previously that XO inhibition and radical scavenging could be useful properties for reduction of ROS-levels in tissue, we determined the chalcones' effects to rescue neurons subjected to ROS-induced stress created by the addition of β-amyloid peptide. Best protection was provided by chalcones that combined good inhibitory potency with high radical scavenging ability in a single molecule, an observation that points to a potential therapeutic value of this compound class.

  12. Molecular hydrogen inhibits lipopolysaccharide-triggered NLRP3 inflammasome activation in macrophages by targeting the mitochondrial reactive oxygen species.

    PubMed

    Ren, Jian-Dong; Wu, Xiao-Bo; Jiang, Rui; Hao, Da-Peng; Liu, Yi

    2016-01-01

    The NLRP3 inflammasome, an intracellular multi-protein complex controlling the maturation of cytokine interleukin-1β, plays an important role in lipopolysaccharide (LPS)-induced inflammatory cascades. Recently, the production of mitochondrial reactive oxygen species (mtROS) in macrophages stimulated with LPS has been suggested to act as a trigger during the process of NLRP3 inflammasome activation that can be blocked by some mitochondria-targeted antioxidants. Known as a ROS scavenger, molecular hydrogen (H2) has been shown to possess therapeutic benefit on LPS-induced inflammatory damage in many animal experiments. Due to the unique molecular structure, H2 can easily target the mitochondria, suggesting that H2 is a potential antagonist of mtROS-dependent NLRP3 inflammasome activation. Here we have showed that, in mouse macrophages, H2 exhibited substantial inhibitory activity against LPS-initiated NLRP3 inflammasome activation by scavenging mtROS. Moreover, the elimination of mtROS by H2 resultantly inhibited mtROS-mediated NLRP3 deubiquitination, a non-transcriptional priming signal of NLRP3 in response to the stimulation of LPS. Additionally, the removal of mtROS by H2 reduced the generation of oxidized mitochondrial DNA and consequently decreased its binding to NLRP3, thereby inhibiting the NLRP3 inflammasome activation. Our findings have, for the first time, revealed the novel mechanism underlying the inhibitory effect of molecular hydrogen on LPS-caused NLRP3 inflammasome activation, highlighting the promising application of this new antioxidant in the treatment of LPS-associated inflammatory pathological damage.

  13. Device for measuring oxygen activity in liquid sodium

    DOEpatents

    Roy, P.; Young, R.S.

    1973-12-01

    A composite ceramic electrolyte in a configuration (such as a closed end tube or a plate) suitable to separate liquid sodium from a reference electrode with a high impedance voltmeter connected to measure EMF between the sodium and the reference electrode as a measure of oxygen activity in the sodium is described. The composite electrolyte consists of zirconiacalcia with a bonded layer of thoria-yttria. The device is used with a gaseous reference electrode on the zirconia-calcia side and liquid sodium on the thoria-yttria side of the electrolyte. (Official Gazette)

  14. Bioreductively Activated Reactive Oxygen Species (ROS) Generators as MRSA Inhibitors.

    PubMed

    Khodade, Vinayak S; Sharath Chandra, Mallojjala; Banerjee, Ankita; Lahiri, Surobhi; Pulipeta, Mallikarjuna; Rangarajan, Radha; Chakrapani, Harinath

    2014-07-10

    The number of cases of drug resistant Staphylococcus aureus infections is on the rise globally and new strategies to identify drug candidates with novel mechanisms of action are in urgent need. Here, we report the synthesis and evaluation of a series of benzo[b]phenanthridine-5,7,12(6H)-triones, which were designed based on redox-active natural products. We find that the in vitro inhibitory activity of 6-(prop-2-ynyl)benzo[b]phenanthridine-5,7,12(6H)-trione (1f) against methicillin-resistant Staphylococcus aureus (MRSA), including a panel of patient-derived strains, is comparable or better than vancomycin. We show that the lead compound generates reactive oxygen species (ROS) in the cell, contributing to its antibacterial activity. PMID:25050164

  15. Chemical composition and free radical scavenging activity of the essential oil of Achillea ligustica growing wild in Lipari (Aeolian Islands, Sicily).

    PubMed

    Rouis, Zyed; Maggio, Antonella; Venditti, Alessandro; Bruno, Maurizio; Senatore, Felice

    2013-11-01

    In the present study the chemical composition of the essential oils from aerial parts and flowers of Achillea ligustica All., collected in Lipari (Aeolian Islands) was evaluated by GC and GC-MS. (Z)-Chrysanthenyl acetate was the most abundant component of both oils (29.6% in A1 and 27.8% in F1), followed by viridiflorol (16.8% in A1 and 21.6% in F1), bornyl acetate (8.7% in A1 and 11.6% in F1) and 1,8-cineole (7.4% in A1 and 9.3% in F1). A comparison was made of the composition of the different populations studied so far. Futhermore, the free radical scavenging activity of the oil was determined by DPPH and ABTS methods.

  16. Studies on the syntheses, structural characterization, antimicrobial-, and DPPH radical scavenging activity of the cocrystals caffeine:cinnamic acid and caffeine:eosin dihydrate

    NASA Astrophysics Data System (ADS)

    Suresh Kumar, G. S.; Seethalakshmi, P. G.; Bhuvanesh, N.; Kumaresan, S.

    2013-10-01

    Two organic cocrystals namely, caffeine:cinnamic acid [(caf)(ca)] (1) and caffeine:eosin dihydrate [(caf)(eos)]·2H2O (2) were synthesized and studied by FT-IR, TGA/DTA, and single crystal XRD. The crystal system of cocrystal 1 is triclinic with space group P-1 and Z = 2 and that of cocrystal 2 is monoclinic with space group P21/C and Z = 4. An imidazole-carboxylic acid synthon is observed in the cocrystal 1. The intermolecular hydrogen bond, O-H⋯N and π-π interactions play a major role in stabilizing 1 whereas the intermolecular hydrogen bonds, O-H⋯O, O-H⋯N, and intramolecular hydrogen bond, O-H⋯Br; along with π-π interactions together play a vital role in stabilizing the structure of 2. The antimicrobial- and DPPH radical scavenging activities of both the cocrystals were studied.

  17. An efficient one pot syntheses of aryl-3,3'-bis(indolyl)methanes and studies on their spectral characteristics, DPPH radical scavenging-, antimicrobial-, cytotoxicity-, and antituberculosis activity

    NASA Astrophysics Data System (ADS)

    Suresh Kumar, G. S.; Kumaresan, S.; Antony Muthu Prabhu, A.; Bhuvanesh, N.; Seethalakshmi, P. G.

    2013-01-01

    An efficient one-pot syntheses of aryl-3,3'-bis(indolyl)methanes (BIMs) from indole/2-methylindole and formylphenoxyaliphatic acid(s) is described. Esterification of carboxylic acid and aromatic electrophilic substitution reactions are achieved simultaneous in the presence of potash alum as a catalyst. This catalyst could be recovered and reused without substantial loss in its catalytic activity and the methodology could be applied on a range of closely related substrates. The solvation characteristics in ground and excited states of the compounds by monitoring the absorbance and fluorescence band maxima have been studied. The fluorescence studies in protic and aprotic solvents were rationalized on the basis of solute-solvent interaction and substituents effect on these photophysical processes analyzed. The compounds prepared showed efficient antimicrobial effect against human pathogens, cytotoxicity against A431 cell line, and DPPH radical scavenging effect. Single crystal XRD studies have been carried out for a few compounds synthesized in this work.

  18. Impact of Clonal Variability on Phenolics and Radical Scavenging Activity of Grapes and Wines: A Study on the Recently Developed Merlot and Cabernet Franc Clones (Vitis vinifera L.)

    PubMed Central

    Pantelić, Milica; Dabić Zagorac, Dragana; Natić, Maja; Gašić, Uroš; Jović, Sonja; Vujović, Dragan; Djordjević, Jelena Popović

    2016-01-01

    In this study, grapes and corresponding wines of Merlot /No 022, 025 and 029/ and Cabernet Franc /No 02, 010 and 012/ clones (recently developed) were evaluated regarding the total phenolic content, total anthocyanin content, and radical scavenging activity, aiming to better understand their quality and market potential. The nineteen individual polyphenols were quantified in studied grape samples using UHPLC coupled to a triple-quadrupole mass spectrometer. The mother grapes and wines were used as the relevant standards. In the grape, studied characteristics were monitored at three stages of berry development: green berry, véraison and mature berry. The mature grape of clones presented high values of total phenolics (3.81–10.89 g gallic acid equivalent kg-1 frozen weight), anthocyanin content (359.00–1668.18 mg malvidin-3-O-glucoside kg-1 frozen weight) and the radical scavenging activity (41.37–80.48 mmol trolox equivalent kg-1 frozen weight) depending on the clone. Grapes and wines of Merlot No 025 and Cabernet Franc No 010 stood out with the highest values of all three parameters. Generally, the high correlation was observed between TPC and RSA values for green berries and mature grapes, as well as for wine samples. The most abundant phenolics in both Merlot and Cabernet Franc grapes were gallic acid, p-hydroxybenzoic acid, ferulic acid, catechin, epicatechin, gallocatechin gallate, catechin gallate, and rutin. Catechin, epicatechin, epigallocatechin, and catechin gallate, typical for the ripe grape of Merlot and Cabernet Franc clones, showed significant correlation with RSA values. Concentrations of individual polyphenols varied depending on the sample being studied and berry development stages. Merlot No 025 and Cabernet Franc No 010 grapes showed particularly interesting attributes for the production of high quality wines. PMID:27732619

  19. Natural competence in Vibrio cholerae is controlled by a nucleoside scavenging response that requires CytR-dependent anti-activation.

    PubMed

    Antonova, Elena S; Bernardy, Eryn E; Hammer, Brian K

    2012-12-01

    Competence for genetic transformation in Vibrio cholerae is triggered by chitin-induced transcription factor TfoX and quorum sensing (QS) regulator HapR. Transformation requires expression of ComEA, described as a DNA receptor in other competent bacteria. A screen for mutants that poorly expressed a comEA-luciferase fusion identified cytR, encoding the nucleoside scavenging cytidine repressor, previously shown in V. cholerae to be a biofilm repressor and positively regulated by TfoX, but not linked to transformation. A ΔcytR mutant was non-transformable and defective in expression of comEA and additional TfoX-induced genes, including pilA (transformation pseudopilus) and chiA-1 (chitinase). In Escherichia coli, 'anti-activation' of nucleoside metabolism genes, via protein-protein interactions between critical residues in CytR and CRP (cAMP receptor protein), is disrupted by exogenous cytidine. Amino acid substitutions of the corresponding V. cholerae CytR residues impaired expression of comEA, pilA and chiA-1, and halted DNA uptake; while exogenous cytidine hampered comEA expression levels and prevented transformation. Our results support a speculative model that when V. cholerae reaches high density on chitin, CytR-CRP interactions 'anti-activate' multiple genes, including a possible factor that negatively controls DNA uptake. Thus, a nucleoside scavenging mechanism couples nutrient stress and cell-cell signalling to natural transformation in V. cholerae as described in other bacterial pathogens.

  20. Radical scavenging activity of black cumin (Nigella sativa L.), coriander (Coriandrum sativum L.), and niger (Guizotia abyssinica Cass.) crude seed oils and oil fractions.

    PubMed

    Ramadan, Mohamed F; Kroh, Lothar W; Mörsel, Jörg-T

    2003-11-19

    Crude vegetable oils are usually oxidatively more stable than the corresponding refined oils. Tocopherols, phospholipids (PL), phytosterols, and phenols are the most important natural antioxidants in crude oils. Processing of vegetable oils, moreover, could induce the formation of antioxidants. Black cumin (Nigella sativa L.), coriander (Coriandrum sativum L.), and niger (Guizotia abyssinica Cass.) crude seed oils were extracted with n-hexane and the oils were further fractionated into neutral lipids (NL), glycolipids (GL), and PL. Crude oils and their fractions were investigated for their radical scavenging activity (RSA) toward the stable galvinoxyl radical by electron spin resonance (ESR) spectrometry and toward 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical by spectrophotometric method. Coriander seed oil and its fractions exhibited the strongest RSA compared to black cumin and niger seed oils. The data correlated well with the total content of polyunsaturated fatty acids, unsaponifiables, and PL, as well as the initial peroxide values of crude oils. In overall ranking, RSA of oil fractions showed similar patterns wherein the PL exhibited greater activity to scavenge both free radicals followed by GL and NL, respectively. The positive relationship observed between the RSA of crude oils and their color intensity suggests the Maillard reaction products may have contributed to the RSA of seed oils and their polar fractions. The results demonstrate the importance of minor components in crude seed oils on their oxidative stability, which will reflect on their food value and shelf life. As part of the effort to assess the potential of these seed oils, the information is also of importance in processing and utilizing the crude oils and their byproducts.

  1. Crystal structure, DFT and HF calculations and radical scavenging activities of (E)-4,6-dibromo-3-methoxy-2-[(3-methoxyphenylimino)methyl]phenol.

    PubMed

    Alaşalvar, Can; Soylu, Mustafa Serkan; Güder, Aytaç; Albayrak, Çiğdem; Apaydın, Gökhan; Dilek, Nefise

    2014-05-01

    In this study, (E)-4,6-dibromo-3-methoxy-2-[(3-methoxyphenylimino)methyl]phenol has been synthesized and characterized by using X-ray technique and FT-IR experimentally and using B3LYP/6-31G(d,p) and HF/6-31G(d,p) methods theoretically. The intermolecular and intramolecular interactions of the title compound have been determined according to X-ray results. The molecular geometry, vibrational frequencies of the title compound in the ground state have been calculated using the density functional B3LYP and HF method with the 6-31G(d,p) basis set and calculated bond parameters and vibrational frequencies values show good agreement with experimental values. Theoretical and experimental results show that tautomeric form of the structure is phenol-imine form. Besides HOMO-LUMO energy gap, molecular electrostatic potential map were performed at B3LYP/6-31G(d,p) level. It is worthy note of that, the free radical scavenging activities of the title compound were assessed using DPPH˙, DMPD˙(+), and ABTS˙(+) assays. The obtained results show that the title compound has effective DPPH˙ (SC50 2.61±0.09 μg/mL), DMPD˙(+) (SC50 2.82±0.14 μg/mL), and ABTS˙(+) (SC50 4.91±0.18 μg/mL) radical scavenging activities when compared with standard antioxidants (BHA, rutin, and trolox). PMID:24566110

  2. Gamma irradiation of Tetrapleura tetraptera fruit as a post-harvest technique and its subsequent effect on some phytochemicals, free scavenging activity and physicochemical properties

    NASA Astrophysics Data System (ADS)

    Darfour, B.; Agbenyegah, S.; Ofosu, D. O.; Okyere, A. A.; Asare, I. K.

    2014-09-01

    Herbs, spices and medicinal plants have been cherished by many ancient cultures for their use in curing common ailments and promoting good health. The dry fruit of Tetrapleura tetraptera has a pleasant aroma and hence used as a spice for seasoning in many parts of Ghana. Contamination of the fruit can occur at any stage during harvesting, drying, processing, transportation and storage. T. tetraptera is prone to microbial contamination and insect infestation resulting in quality deterioration and economic loss. The study aimed at establishing the effect of gamma irradiation as a post-harvest processing technique on T. tetraptera fruit and the subsequent effect of the gamma irradiation on some phytochemicals, free radical scavenging activity and physicochemical properties. The T. tetraptera powder was packed in polythene bags and gamma irradiated with Cobalt 60 source at 5 kGy and 10 kGy at room temperature at a dose rate of 2 kGy/h. The total phenolic content, total flavonoid and DPPH free radical scavenging activity, pH, lactic acid, vitamin C, moisture, carbohydrate, protein and trace element content of the samples were analysed. The antioxidant potential of the T. tetraptera extract was observed to be enhanced in the solvent used for the extraction after the irradiation but not the radiation dose used. Irradiation only had substantial impacts on carbohydrate and protein, Cu, Mg, and Mn. The T. tetraptera studied was safe for human consumption as far as trace metal levels are concerned. This study therefore suggest that gamma irradiation up to 10 kGy could be used as a post-harvest technique in T. tetraptera as a spice or herb.

  3. Chlorhexidine markedly potentiates the oxidants scavenging abilities of Candida albicans.

    PubMed

    Ginsburg, I; Koren, E; Feuerstein, O; Zogakis, I P; Shalish, M; Gorelik, S

    2015-10-01

    The oxidant scavenging ability (OSA) of catalase-rich Candida albicans is markedly enhanced by chlorhexidine digluconate (CHX), polymyxin B, the bile salt ursodeoxycholate and by lysophosphatidylcholine, which all act as detergents facilitating the penetration of oxidants and their intracellular decomposition. Quantifications of the OSA of Candida albicans were measured by a highly sensitive luminol-dependent chemiluminescence assay and by the Thurman's assay, to quantify hydrogen peroxide (H2O2). The OSA enhancing activity by CHX depends to some extent on the media on which candida grew. The OSA of candida treated by CHX was modulated by whole human saliva, red blood cells, lysozyme, cationic peptides and by polyphenols. Concentrations of CHX, which killed over 95 % of Candida albicans cells, did not affect the cells' abilities to scavenge reactive oxygen species (ROS). The OSA of Candida cells treated by CHX is highly refractory to H2O2 (50 mM) but is strongly inhibited by hypochlorous acid, lecithin, trypan blue and by heparin. We speculate that similarly to catalase-rich red blood cells, Candida albicans and additional catalase-rich microbiota may also have the ability to scavenge oxidants and thus can protect catalase-negative anaerobes and facultative anaerobes cariogenic streptococci against peroxide and thus secure their survival in the oral cavity.

  4. Chlorhexidine markedly potentiates the oxidants scavenging abilities of Candida albicans.

    PubMed

    Ginsburg, I; Koren, E; Feuerstein, O; Zogakis, I P; Shalish, M; Gorelik, S

    2015-10-01

    The oxidant scavenging ability (OSA) of catalase-rich Candida albicans is markedly enhanced by chlorhexidine digluconate (CHX), polymyxin B, the bile salt ursodeoxycholate and by lysophosphatidylcholine, which all act as detergents facilitating the penetration of oxidants and their intracellular decomposition. Quantifications of the OSA of Candida albicans were measured by a highly sensitive luminol-dependent chemiluminescence assay and by the Thurman's assay, to quantify hydrogen peroxide (H2O2). The OSA enhancing activity by CHX depends to some extent on the media on which candida grew. The OSA of candida treated by CHX was modulated by whole human saliva, red blood cells, lysozyme, cationic peptides and by polyphenols. Concentrations of CHX, which killed over 95 % of Candida albicans cells, did not affect the cells' abilities to scavenge reactive oxygen species (ROS). The OSA of Candida cells treated by CHX is highly refractory to H2O2 (50 mM) but is strongly inhibited by hypochlorous acid, lecithin, trypan blue and by heparin. We speculate that similarly to catalase-rich red blood cells, Candida albicans and additional catalase-rich microbiota may also have the ability to scavenge oxidants and thus can protect catalase-negative anaerobes and facultative anaerobes cariogenic streptococci against peroxide and thus secure their survival in the oral cavity. PMID:26223507

  5. Orally active antioxidative copper(II) aspirinate: synthesis, structure characterization, superoxide scavenging activity, and in vitro and in vivo antioxidative evaluations.

    PubMed

    Fujimori, T; Yamada, S; Yasui, H; Sakurai, H; In, Y; Ishida, T

    2005-12-01

    Ever since it was proposed that reactive oxygen species (ROS) are involved in the pathogeneses of various diseases, superoxide dismutase (SOD)-mimetic complexes have been intensively studied. We prepared copper(II) aspirinate [Cu2(asp)4] from Cu(II) and aspirin, which has been in use for many years as an antipyretic, an analgesic, and an anti-inflammatory agent. However, Cu2(asp)4 has been found to have additional activities, including anti-inflammatory, antiulcer, anti-ischemic/reperfusion agent, anticancer, antimutagenic, and antimicrobial activities. The activity of copper salicylate [Cu(sal)2] was also compared with that of Cu2(asp)4. The structure of the Cu2(asp)4 was determined using X-ray structure analysis. Its SOD-mimetic activity was determined using cytochrome c, electron spin resonance (ESR) spectroscopy, and ESR spin trap methods. The activity of Cu2(asp)4 was slightly greater than CuSO4 and copper acetate [Cu(ace)2] and slightly less than that of Cu(sal)2. The in vitro antioxidant activity, evaluated in human epithelial or transformed neoplastic keratinocyte cells, HaCaT, and normal dermal fibroblasts in terms of cell survival following ultraviolet B (UVB) irradiation, was significantly increased in the presence of Cu2(asp)4, Cu(sal)2, and CuSO4. Further, ROS generation following UVA irradiation in the skin of hairless mice following oral treatment with Cu2(asp)4 for three consecutive days was significantly suppressed compared to the vehicle- or Cu(ace)2-treated mice. On the basis of these results, Cu2(asp)4 was observed to be a potent antioxidative compound possessing antioxidative activity in biological systems. In conclusion, Cu2(asp)4 is a potent antioxidative agent that may be useful for future treatment of diseases resulting from ROS. PMID:16261369

  6. Antioxidative activity of lactobacilli measured by oxygen radical absorbance capacity.

    PubMed

    Saide, J A O; Gilliland, S E

    2005-04-01

    The reducing ability and antioxidative activity of some species of Lactobacillus were compared under in vitro conditions. Cultures of Lactobacillus delbrueckii ssp. lactis, Lactobacillus delbrueckii ssp. bulgaricus, Lactobacillus acidophilus, and Lactobacillus casei were grown at 37 degrees C in de Man, Rogosa, Sharpe (MRS) broth supplemented with 0.5% 2,3,5 triphenyl tetrazolium chloride (TTC) to evaluate reducing activity. Reduced TTC was extracted from the cultures with acetone, and the intensity of the red color measured colorimetrically at 485 nm was an indication of reducing activity. The lactobacilli varied significantly in relative ability to reduce TTC when grown in MRS broth for 15 h. The relative amounts of growth as indicated by pH values at 18 h appeared to influence the amount of reduction. Antioxidative activity was evaluated by the ability of the whole cells or the cell-free extracts from cultures to protect a protein from being attacked by free radicals. These analyses were performed using the oxygen radical absorbance capacity method. All cultures tested exhibited some degree of antioxidative activity. Among the treatments, the cell-free extracts from cells grown in MRS broth exhibited significantly higher values than did whole cells. There was no apparent relationship between the reducing and antioxidative activities of the cultures evaluated. The results from this study show that these cultures can provide a source of dietary antioxidants. Furthermore, selection of cultures that produce antioxidants as starters could provide yet another health or nutritional benefit from cultured or culture-containing dairy products.

  7. Reactive oxygen species-activated nanomaterials as theranostic agents.

    PubMed

    Kim, Kye S; Lee, Dongwon; Song, Chul Gyu; Kang, Peter M

    2015-01-01

    Reactive oxygen species (ROS) are generated from the endogenous oxidative metabolism or from exogenous pro-oxidant exposure. Oxidative stress occurs when there is excessive production of ROS, outweighing the antioxidant defense mechanisms which may lead to disease states. Hydrogen peroxide (H2O2) is one of the most abundant and stable forms of ROS, implicated in inflammation, cellular dysfunction and apoptosis, which ultimately lead to tissue and organ damage. This review is an overview of the role of ROS in different diseases. We will also examine ROS-activated nanomaterials with emphasis on hydrogen peroxide, and their potential medical implications. Further development of the biocompatible, stimuli-activated agent responding to disease causing oxidative stress, may lead to a promising clinical use. PMID:26328770

  8. Activation of Oxygen by Cytochrome P-450 and Other Haemoproteins

    NASA Astrophysics Data System (ADS)

    Metelitsa, D. I.

    1982-11-01

    Data on the activation of molecular oxygen by the full microsomal hydroxylating system containing cytochrome P-450 as the terminal oxygenase are examined. The nature of the hydroxylating agent, which is the oxenoid Fe3+O, is analysed. The autoxidation reactions of cytochrome P-450 from various sources, haemoglobin, myoglobin, and peroxidases are compared and the role of the axial ligands of the haem iron and the structure of the active centres of the haemoproteins in this process is demonstrated. The possible mechanisms of the oxidation of organic compounds by peroxides with participation of cytochrome P-450, cytochrome c, haemoglobin, and catalase are examined critically. Haemoproteins have been divided into three groups in terms of the type of peroxide oxidation reactions. The relative contributions of the radical and two-electron reactions in the oxidation of compounds by peroxides with participation of different haemoproteins are analysed. The bibliography includes 184 references.

  9. Reactive oxygen species-activated nanomaterials as theranostic agents

    PubMed Central

    Kim, Kye S; Lee, Dongwon; Song, Chul Gyu; Kang, Peter M

    2015-01-01

    Reactive oxygen species (ROS) are generated from the endogenous oxidative metabolism or from exogenous pro-oxidant exposure. Oxidative stress occurs when there is excessive production of ROS, outweighing the antioxidant defense mechanisms which may lead to disease states. Hydrogen peroxide (H2O2) is one of the most abundant and stable forms of ROS, implicated in inflammation, cellular dysfunction and apoptosis, which ultimately lead to tissue and organ damage. This review is an overview of the role of ROS in different diseases. We will also examine ROS-activated nanomaterials with emphasis on hydrogen peroxide, and their potential medical implications. Further development of the biocompatible, stimuli-activated agent responding to disease causing oxidative stress, may lead to a promising clinical use. PMID:26328770

  10. Knee extensor muscle oxygen consumption in relation to muscle activation.

    PubMed

    Kooistra, R D; Blaauboer, M E; Born, J R; de Ruiter, C J; de Haan, A

    2006-12-01

    Recently, fatigability and muscle oxygen consumption (mVO(2)) during sustained isometric contractions were found to be less at shorter (30 degrees knee angle; 0 degrees = full extension) compared to longer knee extensor muscle lengths (90 degrees ) and, at low torques, less in the rectus femoris (RF) muscle than in the vastus lateralis and medialis. In the present study we hypothesized that these findings could be accounted for by a knee angle- and a muscle-dependent activation respectively. On two experimental days rectified surface EMG (rsEMG) was obtained as a measure of muscle activation in nine healthy young males. In addition, on day 1 maximal torque capacity (MTC) was carefully determined using superimposed nerve stimulation on brief high intensity contractions (> 70%MVC) at 30, 60 and 90 degrees knee angles. On day 2, subjects performed longer lasting isometric contractions (10-70%MTC) while mVO(2) was measured using near-infrared spectroscopy (NIRS). At 30 degrees , maximal mVO(2) was reached significantly later (11.0 s +/- 6.5 s) and was 57.9 +/- 8.3% less (average +/- SD, across intensities and muscles) than mVO(2) at 60 and 90 degrees (p < 0.05). However, rsEMG was on average only 18.0 +/- 11.8% (p = 0.062) less at the start of the contraction at 30 degrees . At 10%MTC at all knee angles, maximal mVO(2) of the RF occurred significantly later (28.8 +/- 36.0 s) and showed a significantly smaller increase in rsEMG compared to both vasti. In conclusion, it is unlikely that the tendency for less intense muscle activation could fully account for the approximately 60% lower oxygen consumption at 30 degrees , but the later increase in RFmVO(2) seemed to be caused by a less strong activation of the RF.

  11. The interrelationship between muscle oxygenation, muscle activation, and pulmonary oxygen uptake to incremental ramp exercise: influence of aerobic fitness.

    PubMed

    Boone, Jan; Barstow, Thomas J; Celie, Bert; Prieur, Fabrice; Bourgois, Jan

    2016-01-01

    We investigated whether muscle and ventilatory responses to incremental ramp exercise would be influenced by aerobic fitness status by means of a cross-sectional study with a large subject population. Sixty-four male students (age: 21.2 ± 3.2 years) with a heterogeneous peak oxygen uptake (51.9 ± 6.3 mL·min(-1)·kg(-1), range 39.7-66.2 mL·min(-1)·kg(-1)) performed an incremental ramp cycle test (20-35 W·min(-1)) to exhaustion. Breath-by-breath gas exchange was recorded, and muscle activation and oxygenation were measured with surface electromyography and near-infrared spectroscopy, respectively. The integrated electromyography (iEMG), mean power frequency (MPF), deoxygenated [hemoglobin and myoglobin] (deoxy[Hb+Mb]), and total[Hb+Mb] responses were set out as functions of work rate and fitted with a double linear function. The respiratory compensation point (RCP) was compared and correlated with the breakpoints (BPs) (as percentage of peak oxygen uptake) in muscle activation and oxygenation. The BP in total[Hb+Mb] (83.2% ± 3.0% peak oxygen uptake) preceded (P < 0.001) the BP in iEMG (86.7% ± 4.0% peak oxygen uptake) and MPF (86.3% ± 4.1% peak oxygen uptake), which in turn preceded (P < 0.01) the BP in deoxy[Hb+Mb] (88.2% ± 4.5% peak oxygen uptake) and RCP (87.4% ± 4.5% peak oxygen uptake). Furthermore, the peak oxygen uptake was significantly (P < 0.001) positively correlated to the BPs and RCP, indicating that the BPs in total[Hb+Mb] (r = 0.66; P < 0.001), deoxy[Hb+Mb] (r = 0.76; P < 0.001), iEMG (r = 0.61; P < 0.001), MPF (r = 0.63; P < 0.001), and RCP (r = 0.75; P < 0.001) occurred at a higher percentage of peak oxygen uptake in subjects with a higher peak oxygen uptake. In this study a close relationship between muscle oxygenation, activation, and pulmonary oxygen uptake was found, occurring in a cascade of events. In subjects with a higher aerobic fitness level this cascade occurred at a higher relative intensity.

  12. [Several indicators of tissue oxygen during modeling of extravehicular activity of man].

    PubMed

    Lan'shina, O E; Loginov, V A; Akinfiev, A V; Kovalenko, E A

    1995-01-01

    Investigations of tissue oxygen indices during simulation of extravehicular activity (EVA) of cosmonauts demonstrated that breathing pure oxygen at approximately 280 mmHg elevates oxygen tension in capillary blood, and capillary-tissue gradient during physical work. Physical work alone stimulates tissue oxygenation due to, apparently, intensification of the processes of oxidative phosphorylation. The observed shifts in oxygen status reverse significantly within the first 5 min after completion of the experiment.

  13. Scavenging ROS dramatically increase NMDA receptor whole-cell currents in painted turtle cortical neurons.

    PubMed

    Dukoff, David James; Hogg, David William; Hawrysh, Peter John; Buck, Leslie Thomas

    2014-09-15

    Oxygen deprivation triggers excitotoxic cell death in mammal neurons through excessive calcium loading via over-activation of N-methyl-d-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors. This does not occur in the western painted turtle, which overwinters for months without oxygen. Neurological damage is avoided through anoxia-mediated decreases in NMDA and AMPA receptor currents that are dependent upon a modest rise in intracellular Ca(2+) concentrations ([Ca(2+)]i) originating from mitochondria. Anoxia also blocks mitochondrial reactive oxygen species (ROS) generation, which is another potential signaling mechanism to regulate glutamate receptors. To assess the effects of decreased intracellular [ROS] on NMDA and AMPA receptor currents, we scavenged ROS with N-2-mercaptopropionylglycine (MPG) or N-acetylcysteine (NAC). Unlike anoxia, ROS scavengers increased NMDA receptor whole-cell currents by 100%, while hydrogen peroxide decreased currents. AMPA receptor currents and [Ca(2+)]i concentrations were unaffected by ROS manipulation. Because decreases in [ROS] increased NMDA receptor currents, we next asked whether mitochondrial Ca(2+) release prevents receptor potentiation during anoxia. Normoxic activation of mitochondrial ATP-sensitive potassium (mKATP) channels with diazoxide decreased NMDA receptor currents and was unaffected by subsequent ROS scavenging. Diazoxide application following ROS scavenging did not rescue scavenger-mediated increases in NMDA receptor currents. Fluorescent measurement of [Ca(2+)]i and ROS levels demonstrated that [Ca(2+)]i increases before ROS decreases. We conclude that decreases in ROS concentration are not linked to anoxia-mediated decreases in NMDA/AMPA receptor currents but are rather associated with an increase in NMDA receptor currents that is prevented during anoxia by mitochondrial Ca(2+) release.

  14. Immobilised activated sludge based biosensor for biochemical oxygen demand measurement.

    PubMed

    Liu, J; Björnsson, L; Mattiasson, B

    2000-02-01

    A biochemical oxygen demand (BOD) sensor, based on an immobilised mixed culture of microorganisms in combination with a dissolved oxygen electrode, has been developed for the purpose of on-line monitoring of the biological treatment process for waste and wastewater. The sensor was designed for easy replacement of the biomembrane, thereby making it suitable for short-term use. The drawbacks of activated sludge based sensor, such as short sensor lifetime, were thereby circumvented. The sensor BOD measurements were carried out in the kinetic mode using a flow injection system, resulting in 25 s for one measurement followed by 4-8 min recovery time. Based on the results of normalised sensor responses, the OECD synthetic wastewater was considered to be a more suitable calibration solution in comparison with the GGA solution. Good agreement was achieved between the results of the sensor BOD measurement and those obtained from BOD5 analysis of a wastewater sample from a food-processing factory. Reproducibility of responses using one sensor was below +/- 5.6%, standard deviation. Reproducibility of responses using different sensors was within acceptable bias limits, viz. +/- 15% standard deviation.

  15. Dynamic activation of Src induced by low-power laser irradiation in living cells mediated by reactive oxygen species

    NASA Astrophysics Data System (ADS)

    Zhang, Juntao; Gao, Xuejuan; Xing, Da; Liu, Lei

    2007-11-01

    Low-power laser irradiation (LPLI) leads to photochemical reaction and then activates intracellular several signaling pathway. Reactive oxygen species (ROS) are considered to be the primary messengers produced by LPLI. Here, we studied the signaling pathway mediated by ROS upon the stimulation of LPLI. Src tyrosine kinases are well-known targets of ROS and can be activated by oxidative events. Using a Src reporter based on fluorescence resonance energy transfer (FRET) technique, we visualized the dynamic Src activation in Hela cells immediately after LPLI. Moreover, Src activity was enhanced by increasing the duration of LPLI. In addition, our results suggested that ROS were key mediators of Src activation, as ROS scavenger, vitamin C decreased and exogenous H IIO II increased the activity of Src. Meanwhile, Gö6983 loading did not block the effect of LPLI. CCK-8 experiments proved that cell vitality was prominently improved by LPLI with all the doses we applied in our experiments ranging from 3 to 25J/cm2. The results indicated that LPLI/ROS/Src pathway may be involved in the LPLI biostimulation effects.

  16. Comparative study of the vasorelaxant activity, superoxide-scavenging ability and cyclic nucleotide phosphodiesterase-inhibitory effects of hesperetin and hesperidin.

    PubMed

    Orallo, Francisco; Alvarez, Ezequiel; Basaran, Hélène; Lugnier, Claire

    2004-12-01

    This study investigated the vasorelaxant activity, superoxide radicals (O2(*-))-scavenging capacity and cyclic nucleotide phosphodiesterase (PDE)-inhibitory effects of hesperidin and hesperetin, two flavonoids mainly isolated from citrus fruits. Hesperetin concentration-dependently relaxed the isometric contractions induced by noradrenaline (NA, 1 microM) or by a high extracellular KCl concentration (60 mM) in intact rat isolated thoracic aorta rings. However, hesperetin (10 microM-0.3 mM) did not affect the contractile response induced by okadaic acid (OA, 1 microM). Mechanical removal of endothelium and/or pretreatment of aorta rings with glibenclamide (GB, 10 microM), tetraethylammonium (TEA, 2 mM) or nifedipine (0.1 microM) did not significantly modify the vasorelaxant effects of this flavonoid. Hesperetin (10 microM-0.1 mM) did not affect the basal uptake of (45)Ca(2+) but decreased the influx of (45)Ca(2+) induced by NA and KCl in endothelium-containing and endothelium-denuded rat aorta. Hesperetin (10 microM-0.1 mM) did not scavenge O2(*-) generated by the phenazine methosulfate (PMS)-reduced beta-nicotinamide adenine dinucleotide (NADH) system. Hesperetin (0.1 mM) significantly reversed the inhibitory effects of NA (1 microM) and high KCl (60 mM) on cyclic nucleotide (cAMP and cGMP) production in cultured rat aortic myocytes. Hesperetin preferentially inhibited calmodulin (CaM)-activated PDE1 and PDE4 isolated from bovine aorta with IC(50) values of about 74 microM and 70 microM respectively. In contrast, the 7-rhamnoglucoside of hesperetin, hesperidin (10 microM-0.1 mM), was inactive in practically all experiments, although it inhibited basal and cGMP-activated PDE2 isolated from platelets (IC(50) values of 32+/-4 microM and 137+/-34 microM respectively). These results suggest that the vasorelaxant effects of hesperetin are basically due to the inhibition of PDE1 and PDE4 activities.

  17. A Geometric Scavenger Hunt

    ERIC Educational Resources Information Center

    Smart, Julie; Marshall, Jeff

    2007-01-01

    Children possess a genuine curiosity for exploring the natural world around them. One third grade teacher capitalized on this inherent trait by leading her students on "A Geometric Scavenger Hunt." The four-lesson inquiry investigation described in this article integrates mathematics and science. Among the students' discoveries was the fact that…

  18. Radical-Scavenging Activity and Ferric Reducing Ability of Juniperus thurifera (L.), J. oxycedrus (L.), J. phoenicea (L.) and Tetraclinis articulata (L.).

    PubMed

    El Jemli, Meryem; Kamal, Rabie; Marmouzi, Ilias; Zerrouki, Asmae; Cherrah, Yahia; Alaoui, Katim

    2016-01-01

    Objective. The aim of this work is to study and compare the antioxidant properties and phenolic contents of aqueous leaf extracts of Juniperus thurifera, Juniperus oxycedrus, Juniperus Phoenicea, and Tetraclinis articulata from Morocco. Methods. Antioxidant activities of the extracts were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging ability, Trolox equivalent antioxidant capacity (TEAC), and ferric reducing antioxidant power (FRAP) assays. Also the total phenolic and flavonoids contents of the extracts were determined spectrophotometrically. Results. All the extracts showed interesting antioxidant activities compared to the standard antioxidants (butylated hydroxytoluene (BHT), quercetin, and Trolox). The aqueous extract of Juniperus oxycedrus showed the highest antioxidant activity as measured by DPPH, TEAC, and FRAP assays with IC50 values of 17.91 ± 0.37 μg/mL, 19.80 ± 0.55 μg/mL, and 24.23 ± 0.07 μg/mL, respectively. The strong correlation observed between antioxidant capacities and their total phenolic contents indicated that phenolic compounds were a major contributor to antioxidant properties of these plants extracts. Conclusion. These results suggest that the aqueous extracts of Juniperus thurifera, Juniperus oxycedrus, Juniperus phoenicea, and Tetraclinis articulata can constitute a promising new source of natural compounds with antioxidants ability.

  19. Radical-Scavenging Activity and Ferric Reducing Ability of Juniperus thurifera (L.), J. oxycedrus (L.), J. phoenicea (L.) and Tetraclinis articulata (L.)

    PubMed Central

    Kamal, Rabie; Marmouzi, Ilias; Zerrouki, Asmae; Cherrah, Yahia; Alaoui, Katim

    2016-01-01

    Objective. The aim of this work is to study and compare the antioxidant properties and phenolic contents of aqueous leaf extracts of Juniperus thurifera, Juniperus oxycedrus, Juniperus Phoenicea, and Tetraclinis articulata from Morocco. Methods. Antioxidant activities of the extracts were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging ability, Trolox equivalent antioxidant capacity (TEAC), and ferric reducing antioxidant power (FRAP) assays. Also the total phenolic and flavonoids contents of the extracts were determined spectrophotometrically. Results. All the extracts showed interesting antioxidant activities compared to the standard antioxidants (butylated hydroxytoluene (BHT), quercetin, and Trolox). The aqueous extract of Juniperus oxycedrus showed the highest antioxidant activity as measured by DPPH, TEAC, and FRAP assays with IC50 values of 17.91 ± 0.37 μg/mL, 19.80 ± 0.55 μg/mL, and 24.23 ± 0.07 μg/mL, respectively. The strong correlation observed between antioxidant capacities and their total phenolic contents indicated that phenolic compounds were a major contributor to antioxidant properties of these plants extracts. Conclusion. These results suggest that the aqueous extracts of Juniperus thurifera, Juniperus oxycedrus, Juniperus phoenicea, and Tetraclinis articulata can constitute a promising new source of natural compounds with antioxidants ability. PMID:27293428

  20. Correlation between the sorption of dissolved oxygen onto chitosan and its antimicrobial activity against Esherichia coli.

    PubMed

    Gylienė, Ona; Servienė, Elena; Vepštaitė, Iglė; Binkienė, Rima; Baranauskas, Mykolas; Lukša, Juliana

    2015-10-20

    The ability of chitosan to adsorb dissolved oxygen from solution depends on its physical shape and is related to the surface area. Depending on conditions chitosan is capable of adsorbing or releasing oxygen. Chitosan, modificated by the substances possessing antimicrobial activity, such as succinic acid, Pd(II) ions, metallic Pd or Ag, distinctly increases the ability to adsorb the dissolved oxygen. The additional treatment of chitosan with air oxygen or electrochemically produced oxygen also increases the uptake of dissolved oxygen by chitosan. A strong correlation between the amount of oxygen adsorbed onto chitosan and its antimicrobial activity against Esherichia coli has been observed. This finding suggests that one of the sources of antimicrobial activity of chitosan is the ability to sorb dissolved oxygen, along with other well-known factors such as physical state and chemical composition.

  1. Mononuclear copper (II) salicylate complexes with 1,2-dimethylimidazole and 2-methylimidazole: Synthesis, spectroscopic and crystal structure characterization and their superoxide scavenging activities

    NASA Astrophysics Data System (ADS)

    Abuhijleh, A. Latif

    2010-09-01

    The complexes cis-bis (1,2-dimethylimidazole) bis (salicylato) copper (II) ( 1) and tris (2-methylimidazole) (salicylato) copper (II) ( 2) have been prepared by the reaction of appropriate methylimidazole derivative with binuclear copper (II) aspirinate. Spectral and X-ray structural studies for complex 1 showed that the copper ion is coordinated in a cis arrangement to two imidazole nitrogen atoms and two carboxylate oxygen atoms from the salicylate mono-anion ligands. The second carboxylate oxygen atoms form weak axial interactions with the copper ion. Spectral, magnetic and analytical data for complex 2 showed that the copper ion is bonded to three 2-methylimidazole nitrogen atoms and one doubly deprotonated salicylate di-anion, which is chelated to Cu (II) ion through one of its carboxylate oxygen atoms and the deprotonated hydroxyl oxygen atom to form distorted square-pyramidal geometry having CuN 3O + O chromophore. The superoxide dismutase (SOD) mimetic activities (IC 50) of the complexes 1, 2 and the structurally known mixture complexes Cu (imidazole) n(salicylato) 2( 3) (where n = 2, 5 and 6) were determined using the xanthine-xanthine oxidase assay and compared with those reported for other copper (II) complexes with anti-inflammatory drugs. The results obtained indicated that complexes 1- 3 have high SOD-like activities, which may act as good mimics for native Cu, Zn-SOD enzyme.

  2. Spatial patterning of vulture scavenged human remains.

    PubMed

    Spradley, M Katherine; Hamilton, Michelle D; Giordano, Alberto

    2012-06-10

    This article presents the results of a pilot study on the effects of vulture modification to human remains. A donated body from the Willed Body Donation Program was placed at the Forensic Anthropology Research Facility (FARF), an outdoor human decomposition laboratory located at Texas State University-San Marcos. The effects of vulture scavenging on the timing and sequence, and the rate of skeletonization, disarticulation, and dispersal were observed via a motion sensing camera and direct observation. Using GIS (Geographic Information Systems) and GPS (Global Positioning System) technologies and spatial analytical methods, the transport of skeletal elements was mapped in order to analyze dispersal and terrain-influenced patterns of active vulture scavenging. Results showed that the initial scavenging took place 37 days after placement at FARF. This delay in scavenging differs from previous research. After the initial appearance of the vultures, the body was reduced from a fully-fleshed individual to a skeleton within only 5h. This underscores the potential for errors in postmortem interval estimations made at vulture scavenged scenes. Additionally, spatial analysis showed that skeletal elements were dispersed by vultures to lower elevations, and that the disarticulation and dispersal of the skeletal elements occurs early in the scavenging sequence.

  3. Evaluation of DNA binding, DNA cleavage, protein binding, radical scavenging and in vitro cytotoxic activities of ruthenium(II) complexes containing 2,4-dihydroxy benzylidene ligands.

    PubMed

    Mohanraj, Maruthachalam; Ayyannan, Ganesan; Raja, Gunasekaran; Jayabalakrishnan, Chinnasamy

    2016-12-01

    The new ruthenium(II) complexes with hydrazone ligands, 4-Methyl-benzoic acid (2,4-dihydroxy-benzylidene)-hydrazide (HL(1)), 4-Methoxy-benzoic acid (2,4-dihydroxy-benzylidene)-hydrazide (HL(2)), 4-Bromo-benzoic acid (2,4-dihydroxy-benzylidene)-hydrazide (HL(3)), were synthesized and characterized by various spectro analytical techniques. The molecular structures of the ligands were confirmed by single crystal X-ray diffraction technique. The DNA binding studies of the ligands and complexes were examined by absorption, fluorescence, viscosity and cyclic voltammetry methods. The results indicated that the ligands and complexes could interact with calf thymus DNA (CT-DNA) through intercalation. The DNA cleavage activity of the complexes was evaluated by gel electrophoresis assay, which revealed that the complexes are good DNA cleaving agents. The binding interaction of the ligands and complexes with bovine serum albumin (BSA) was investigated using fluorescence spectroscopic method. Antioxidant studies showed that the complexes have a strong radical scavenging properties. Further, the cytotoxic effect of the complexes examined on cancerous cell lines showed that the complexes exhibit significant anticancer activity. PMID:27612830

  4. Activities of Antioxidant Scavenger Enzymes (Superoxide Dismutase and Glutathione Peroxidase) in Erythrocytes in Adult Women With and Without Type II Diabetes

    PubMed Central

    Coleman, Raymond; Berner, Yitshal N.

    2004-01-01

    It is widely believed that oxidative stress plays an important role in the pathogenesis of type II diabetes. The present study was undertaken to examine the functioning of two antioxidant scavenger enzymes, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), in erythrocytes in a population of healthy aging adult women compared with a similar population with type II diabetes. Blood samples were examined from 42 female adult healthy subjects at different ages and from 59 female patients with type II diabetes. A significant increase in SOD activities was correlated with aging in erythrocytes of the healthy control subjects (r = .550, P = .001); however, this correlation was not found in subjects with type II diabetes (r = .250, P < .07). A trend showing a reduction in glutathione peroxidase activities was demonstrated with aging (r = −.331, P = .228); however, this trend was not found in diabetic subjects (r = .031, P < .820). The results indicate a possible imbalance in the antioxidant system in erythrocytes of aging adult women, which is even more pronounced in cases of type II diabetes. This study may indicate possible therapeutic treatment or preventive measures to limit oxidative damage and reduce complications of diabetes. PMID:15203888

  5. Synthesis, crystal structure investigation, DFT studies and DPPH radical scavenging activity of 1-(furan-2-ylmethyl)-2,4,5-triphenyl-1H-imidazole derivatives

    NASA Astrophysics Data System (ADS)

    Rajaraman, D.; Sundararajan, G.; Rajkumar, R.; Bharanidharan, S.; Krishnasamy, K.

    2016-03-01

    A new series of 1-(furan-2ylmethyl)-2,4,5-triphenyl-1H-imidazole derivatives are conveniently synthesized and characterized by IR, 1H NMR and 13C NMR spectral techniques. The compound 5a also characterized by HSQC correlation spectra. All the newly synthesized compounds were evaluated for their antioxidant activities with DPPH radical scavenging activity. The structure of 5e was also confirmed by single crystal XRD analysis and optimized bond parameters are calculated by density functional theory (DFT) method at B3LYP/6-31G (d, p) level of theory. The optimized geometrical parameters obtained by DFT calculation are in good agreement with single crystal XRD data. The experimentally observed FT-IR and FT-Raman bands were assigned to different normal modes of the molecule. The stability and charge delocalization of the molecule were also studied by natural bond orbital (NBO) analysis. The HOMO-LUMO energies describe the charge transfer takes place within the molecule. Molecular electrostatic potential has been analyzed. The reported 5e molecule used as a potential NLO material since it has high μβ0 value.

  6. TRPA1 activation leads to neurogenic vasodilatation: involvement of reactive oxygen nitrogen species in addition to CGRP and NO

    PubMed Central

    Aubdool, Aisah A; Kodji, Xenia; Abdul‐Kader, Nayaab; Heads, Richard; Fernandes, Elizabeth S; Bevan, Stuart

    2016-01-01

    Abstract Background and Purpose Transient receptor potential ankyrin‐1 (TRPA1) activation is known to mediate neurogenic vasodilatation. We investigated the mechanisms involved in TRPA1‐mediated peripheral vasodilatation in vivo using the TRPA1 agonist cinnamaldehyde. Experimental Approach Changes in vascular ear blood flow were measured in anaesthetized mice using laser Doppler flowmetry. Key Results Topical application of cinnamaldehyde to the mouse ear caused a significant increase in blood flow in the skin of anaesthetized wild‐type (WT) mice but not in TRPA1 knockout (KO) mice. Cinnamaldehyde‐induced vasodilatation was inhibited by the pharmacological blockade of the potent microvascular vasodilator neuropeptide CGRP and neuronal NOS‐derived NO pathways. Cinnamaldehyde‐mediated vasodilatation was significantly reduced by treatment with reactive oxygen nitrogen species (RONS) scavenger such as catalase and the SOD mimetic TEMPOL, supporting a role of RONS in the downstream vasodilator TRPA1‐mediated response. Co‐treatment with a non‐selective NOS inhibitor L‐NAME and antioxidant apocynin further inhibited the TRPA1‐mediated vasodilatation. Cinnamaldehyde treatment induced the generation of peroxynitrite that was blocked by the peroxynitrite scavenger FeTPPS and shown to be dependent on TRPA1, as reflected by an increase in protein tyrosine nitration in the skin of WT, but not in TRPA1 KO mice. Conclusion and Implications This study provides in vivo evidence that TRPA1‐induced vasodilatation mediated by cinnamaldehyde requires neuronal NOS‐derived NO, in addition to the traditional neuropeptide component. A novel role of peroxynitrite is revealed, which is generated downstream of TRPA1 activation by cinnamaldehyde. This mechanistic pathway underlying TRPA1‐mediated vasodilatation may be important in understanding the role of TRPA1 in pathophysiological situations. PMID:27189253

  7. Reactive oxygen and nitrogen species in defense/stress responses activated by chitosan in sycamore cultured cells.

    PubMed

    Malerba, Massimo; Cerana, Raffaella

    2015-01-29

    Chitosan (CHT) is a non-toxic and inexpensive compound obtained by deacetylation of chitin, the main component of the exoskeleton of arthropods as well as of the cell walls of many fungi. In agriculture CHT is used to control numerous diseases on various horticultural commodities but, although different mechanisms have been proposed, the exact mode of action of CHT is still unknown. In sycamore (Acer pseudoplatanus L.) cultured cells, CHT induces a set of defense/stress responses that includes production of H2O2 and nitric oxide (NO). We investigated the possible signaling role of these reactive molecules in some CHT-induced responses by means of inhibitors of production and/or scavengers. The results show that both reactive nitrogen and oxygen species are not only a mere symptom of stress conditions but are involved in the responses induced by CHT in sycamore cells. In particular, NO appears to be involved in a cell death form induced by CHT that shows apoptotic features like DNA fragmentation, increase in caspase-3-like activity and release of cytochrome c from the mitochondrion. On the contrary, reactive oxygen species (ROS) appear involved in a cell death form induced by CHT that does not show these apoptotic features but presents increase in lipid peroxidation.

  8. Reactive oxygen and nitrogen species in defense/stress responses activated by chitosan in sycamore cultured cells.

    PubMed

    Malerba, Massimo; Cerana, Raffaella

    2015-01-01

    Chitosan (CHT) is a non-toxic and inexpensive compound obtained by deacetylation of chitin, the main component of the exoskeleton of arthropods as well as of the cell walls of many fungi. In agriculture CHT is used to control numerous diseases on various horticultural commodities but, although different mechanisms have been proposed, the exact mode of action of CHT is still unknown. In sycamore (Acer pseudoplatanus L.) cultured cells, CHT induces a set of defense/stress responses that includes production of H2O2 and nitric oxide (NO). We investigated the possible signaling role of these reactive molecules in some CHT-induced responses by means of inhibitors of production and/or scavengers. The results show that both reactive nitrogen and oxygen species are not only a mere symptom of stress conditions but are involved in the responses induced by CHT in sycamore cells. In particular, NO appears to be involved in a cell death form induced by CHT that shows apoptotic features like DNA fragmentation, increase in caspase-3-like activity and release of cytochrome c from the mitochondrion. On the contrary, reactive oxygen species (ROS) appear involved in a cell death form induced by CHT that does not show these apoptotic features but presents increase in lipid peroxidation. PMID:25642757

  9. Differential production of active oxygen species in photo-symbiotic and non-symbiotic bivalves.

    PubMed

    Nakayama, K; Maruyama, T

    1998-01-01

    We investigated the generation of active oxygen species in the bivalves, Crassostrea gigas, Fulvia mutica and Tridacna crocea in order to understand the defensive mechanisms in giant clams that allow a stable association with symbiotic zooxanthellae. C. gigas produced active oxygens, superoxide anion and nitric oxide upon stimulation by phorbol myristate acetate. F. mutica generated a little amount of superoxide anion and nitric oxide, and contained significant phenoloxidase activity which catalyzes formation of quinones. T. crocea did not generate any apparent active oxygen species or quinones. The importance of lacking rapid cytotoxic responses consisting of active oxygen species to foreign organisms in the symbiotic clam is discussed.

  10. Effect of oxygen on the microbial activities of thermophilic anaerobic biomass.

    PubMed

    Pedizzi, C; Regueiro, L; Rodriguez-Verde, I; Lema, J M; Carballa, M

    2016-07-01

    Low oxygen levels (μgO2L(-1)) in anaerobic reactors are quite common and no relevant consequences are expected. On the contrary, higher concentrations could affect the process. This work aimed to study the influence of oxygen (4.3 and 8.8mgO2L(-1), respectively) on the different microbial activities (hydrolytic, acidogenic and methanogenic) of thermophilic anaerobic biomass and on the methanogenic community structure. Batch tests in presence of oxygen were conducted using specific substrates for each biological activity and a blank (with minimum oxygen) was included. No effect of oxygen was observed on the hydrolytic and acidogenic activities. In contrast, the methane production rate decreased by 40% in all oxygenated batches and the development of active archaeal community was slower in presence of 8.8mgO2L(-1). However, despite this sensitivity of methanogens to oxygen at saturation levels, the inhibition was reversible. PMID:27020398

  11. Identification of the bacteria scavenging atmospheric CO and evaluation of the impact of land-use change on their distribution and activity

    NASA Astrophysics Data System (ADS)

    Constant, P.; Quiza, L.; Lalonde, I.

    2013-12-01

    Soil bacteria scavenging carbon monoxide (CO) are responsible for the biological sink of atmospheric CO. These bacteria mitigate an important fraction of the global emissions of CO from natural and anthropogenic sources. This ubiquitous soil ecosystem service is of critical importance since CO indirectly regulates the atmospheric lifetime of methane - the second most powerful greenhouse gas. So far, only few carboxydovore bacteria were shown to oxidize atmospheric CO. The CO-dehydrogenase (CODH) is the enzyme catalyzing the CO oxidation reaction in these bacteria. The enzyme is a dimer of heterotrimers encoded by the genes coxS, coxM and coxL. CoxL is the large subunit of the CODH. Phylogenetic analyzes revealed that coxL gene sequences encompass two main clusters: BMS and OMP groups but the version conferring a high affinity for CO and the ability to scavenge atmospheric CO is unknown. The objective of this investigation was to relate the diversity of coxL gene sequences with CO soil uptake activity and soil physicochemical properties. For this purpose, we collected soil samples in three neighbouring sites encompassing different land-use types: an undisturbed deciduous forest, a maize field and a larch monoculture. We analyzed (i) coxL diversity in the three environments, using a new coxL PCR detection assay targeting both OMP and BMS groups, (ii) CO oxidation activity using a gas chromatography assay and, (iii) soil physicochemical properties. Our results demonstrate that land-use change exerts a significant impact on coxL diversity as well as CO oxidation activity, with significant loss of the potential CO soil uptake activity following the conversion of native forest to maize or larch plantation. Most of the coxL gene sequences retrieved from the soil samples were not affiliated to sequences derived from microbial genome databases, impairing a taxonomic identification of the potential CO-oxidizing bacteria detected in soil. Canonical ordination analysis allowed

  12. Antioxidant properties of propargylamine derivatives: assessment of their ability to scavenge peroxynitrite.

    PubMed

    Dragoni, Stefania; Porcari, Valentina; Travagli, Massimo; Castagnolo, Daniele; Valoti, Massimo

    2006-04-01

    A series of arylpropargylamines, variously substituted in the hydrogen in p-position and in the propargyl moiety, were studied as potential peroxynitrite scavengers. The scavenging activity of these compounds was evaluated through peroxynitrite (ONOO-)-mediated oxidation of dichlorofluorescin and linoleic acid by measuring the dichlorofluorescein formation and oxygen consumption, respectively. Among tested compounds, only 1-phenylpropargylamine (AP3) promoted concentration-dependent inhibition of ONOO(-)-induced dichlorofluorescin and linoleic acid oxidation with IC50 values of 637 and 63 microM, respectively. The AP3 spectral changes in UV-visible absorbance properties in the presence of peroxynitrite suggested the formation of a new compound. This was identified by gas-chromatograph-mass spectrometer analysis as phenylpropargyl alcohol. Structure-activity relationship analysis indicated that the scavenging activity of AP3 was due to the aminopropargyl moiety and availability of the nitrogen electron pair. This data suggested that AP3 could be considered a lead compound for the synthesis of new ONOO- scavenger derivatives. PMID:16597374

  13. Biochemical effects of some pesticides on lipid peroxidation and free-radical scavengers.

    PubMed

    Banerjee, B D; Seth, V; Bhattacharya, A; Pasha, S T; Chakraborty, A K

    1999-06-30

    Oxidative stress was studied in blood samples obtained from lindane, malathion and propoxur poisoning cases admitted to the Guru Teg Bahadur Hospital, Delhi and evaluated for lipid peroxidation, oxygen free radical (OFR) scavenging enzymes, and glutathione (GSH) and related enzymes. Acetylcholine esterase (AChE), gamma glutamyl transpeptidase (GGT) and GSH level were also assayed in lymphocytes. The level of thiobarbituric acid reacting substances and activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase and GGT were increased and GSH level was decreased in pesticide poisoning. Apparently lindane (at the concentration examined) was more potent than malathion and propoxur in producing alteration in lipid peroxidation, GSH related parameters and OFR scavenging enzymes. However, AChE activity and GSH level in lymphocytes of malathion poisoning cases were reduced and GGT activity was enhanced in comparison to control subjects. The present results suggest that OFR scavenging enzymes were induced while combating oxidative stress in a differential manner in organochlorine, organophosphate and carbamate poisoning. Increased lipid peroxidation, coupled with altered levels of GSH and OFR scavenging enzymes in the blood are discussed in the light of oxidative stress.

  14. Interaction of gold nanoparticles with free radicals and their role in enhancing the scavenging activity of ascorbic acid.

    PubMed

    Razzaq, Humaira; Saira, Farhat; Yaqub, Azra; Qureshi, Rumana; Mumtaz, Misbah; Saleemi, Samia

    2016-08-01

    The present study investigates the interaction of citrate stabilized gold nanoparticles (12±1.5nm) (GNPs) with free radicals; 1,1-diphenyl-2-picrylhydrazyl (DPPH) stable and electrochemically generated superoxide, O2(-). Different experiments were designed to understand the interaction between GNPs and DPPH by employing cyclic voltammetry, UV-vis spectroscopy and computational chemistry using 6-311G basis set. The increase in heterogeneous rate constant, ksh, of DPPH upon addition of GNPs pointed towards possible complex formation, DPPH-GNPs which were further explained by a model assuming surface adsorption of DPPH on GNPs. Further, the model was validated by studying interaction of GNPs with a biologically important free radical, O2(-). Exciting result in terms of disappearance of anodic peak after GNPs addition confirmed that gold nanoparticles interacted with stable as well as unstable free radicals. Also, the stoichiometry of the most stable complex GNP-DPPH was determined from UV-vis spectroscopy by applying Job's method. The GNP-DPPH complex was found to be active with 46.0% reduction of the IC50 value of standard antioxidant, ascorbic acid (AA), indicating its role in enhancing antioxidant activity. Hence, this study presents a simple and potential approach to enhance the efficiency of natural antioxidants without modifying their structure, or involving the complex functionalization of GNPs with antioxidants.

  15. Synthesis, characterization, DNA interactions, DNA cleavage, radical scavenging activity, antibacterial, anti-proliferative and docking studies of new transition metal complexes.

    PubMed

    Chennam, Kishan Prasad; Ravi, Mudavath; Ushaiah, B; Srinu, V; Eslavath, Ravi Kumar; Devi, Ch Sarala

    2016-01-01

    The compound N-(2-hydroxybenzylidene)-1-ethyl-1, 4-dihydro-7-methyl-4-oxo-1, 8 naphthyridine-3-carbohydrazide (LH) and its Cu (II), Co (II) and Zn (II) complexes were synthesized and characterized. The absorption spectral titrations and competitive DNA binding studies depicted those complexes of title compound bind to CT-DNA through intercalation. Interestingly [Cu (II)-(L2)] showed relatively high binding constant value (6.61 x 10(5) M(-1)) compared to [Co (II)-(L2)] (4.378× 10(5) M(-1)) and [Zn (II)-(L2)] (3.1x10(5) M(-1)). Ligand and its complexes were also examined for DNA nuclease activity against pBR-322 plasmid DNA, which showed that [Cu (II)-(L2)] had the best hydrolytic cleavage property displaying prominent double-strand DNA cleavage. In addition, antioxidant activities of the ligand and its metal complexes investigated through scavenging effects for DPPH radical in- vitro, indicated their potentiality as good antioxidants. The in vitro anti-bacterial study inferred the better anti-bacterial activity of [Cu (II)-(L2)] and this was also correlated theoretically by employing docking studies wherein [Cu (II)-(L2)] displayed good Gold score and Chem score. Finally the in vitro anti- proliferative activity of studied compounds was tested against HeLa and MCF-7 cell lines. Interestingly [Cu (II)-(L2)] displayed lower IC50 value and lower percentage of viability in both HeLa and MCF-7 cell lines.

  16. Quality, stability and radical scavenging activity of olive oils after Chétoui olives (Olea europaea L.) storage under modified atmospheres.

    PubMed

    Ben Yahia, L; Baccouri, B; Ouni, Y; Hamdi, S

    2012-08-01

    At the industrial scale, the major source of olive oil deterioration is the poor handling of the raw material during the time separating harvesting from processing. The objective of this work was to verify the effect of modified atmospheres and cold storage in relation to quality parameters of the extracted oils. Olives (cv Chétoui) intended for oil extraction, were stored for 21 days at two different temperatures (ambient temperature 14 ± 2 °C and 5 °C) and under two different modified atmospheres 21% O₂ - 0% CO₂ and 2% O₂ - 5% CO₂. Oils quality was ascertained with analytical parameters: free fatty acids, peroxide value, K₂₃₂, K₂₇₀ as suggested by European regulation. Oxidative stability, total phenols content, radical scavenging activity and fatty acids composition were carried out in order to measure the hydrolytic and oxidative degradation of oils. Olive oils quality parameters were significantly affected by treatments with especially a beneficial effect on primary oxidation indicators and free acidity. Most efficient treatments, with regard to oils phenolic content and involved parameters, were 21% O₂ - 0% CO₂ at ambient temperature (636.25 mg ca/kg) and 2% O₂ - 5% CO₂ under 5 °C (637.50 mg ca/kg). Those two treatments improved individually oil samples phenolic content of 25% but not at the same storage period.

  17. L-tryptophan reacts with naturally occurring and food-occurring phenolic aldehydes to give phenolic tetrahydro-beta-carboline alkaloids: activity as antioxidants and free radical scavengers.

    PubMed

    Herraiz, Tomas; Galisteo, Juan; Chamorro, Cristina

    2003-04-01

    The reaction between the essential amino acid l-tryptophan and flavoring or naturally occurring phenyl and phenolic aldehydes was studied, and the alkaloidal reaction products were characterized by NMR and HPLC-MS. Benzaldehyde, vanillin, syringaldehyde, salicylaldehyde, and anisaldehyde condensed with l-tryptophan in aqueous-acidic media affording the corresponding phenolic tetrahydro-beta-carboline-3-carboxylic acid as two diastereoisomers, 1S,3S-cis and 1R,3S-trans. With the exception of benzaldehyde, the rest of the aldehydes needed heating conditions (70 degrees C) to significantly form tetrahydro-beta-carbolines over time with the cyclization highly favored at low pH. This suggests a likely formation of these compounds under conditions that may occur in foods, food processing, or cooking. The new phenolic tetrahydro-beta-carboline alkaloids were assayed, for the first time, for their activity as free radical scavengers and antioxidants and showed good antioxidant properties with Trolox equivalent antioxidant capacity (TEAC) values much higher than those of ascorbic acid and the water soluble vitamin E analogue, Trolox, in the 2,2'-azinobis(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) assay.

  18. Intracellular ROS Scavenging Activity and Downregulation of Inflammatory Mediators in RAW264.7 Macrophage by Fresh Leaf Extracts of Pseuderanthemum palatiferum

    PubMed Central

    Sittisart, Patcharawan

    2014-01-01

    Beneficial antioxidant phytochemicals are found in many medicinal plants. Pseuderanthemum palatiferum (PP), a well-known Vietnamese traditional medicinal plant in Thailand, has long been used in folk medicine for curing inflammatory diseases, often with limited support of scientific research. Therefore, this study aimed to determine antioxidant and modulation of inflammatory mediators of ethanol and water extracts of PP (EEP and WEP, resp.). WEP had significantly higher phenolic and flavonoid levels and DPPH radical scavenging activity than EEP. However, EEP exhibited greater reducing power than WEP. A greater decrease of tert-butyl hydroperoxide-induced oxidative stress in RAW264.7 macrophage cells was also observed with EEP. Modulation of inflammatory mediators of EEP and WEP was evaluated on LPS plus IFN-γ-stimulated RAW264.7 cells. EEP more potently suppressed LPS plus IFN-γ-induced nitric oxide (NO) production than WEP. Both EEP and WEP also suppressed the expression of iNOS and COX-2 protein levels. Collectively, these results suggest that PP possesses strong antioxidant and anti-inflammatory properties. PMID:24744809

  19. Metabolic profiling and predicting the free radical scavenging activity of guava (Psidium guajava L.) leaves according to harvest time by 1H-nuclear magnetic resonance spectroscopy.

    PubMed

    Kim, So-Hyun; Cho, Somi K; Hyun, Sun-Hee; Park, Hae-Eun; Kim, Young-Suk; Choi, Hyung-Kyoon

    2011-01-01

    Guava leaves were classified and the free radical scavenging activity (FRSA) evaluated according to different harvest times by using the (1)H-NMR-based metabolomic technique. A principal component analysis (PCA) of (1)H-NMR data from the guava leaves provided clear clusters according to the harvesting time. A partial least squares (PLS) analysis indicated a correlation between the metabolic profile and FRSA. FRSA levels of the guava leaves harvested during May and August were high, and those leaves contained higher amounts of 3-hydroxybutyric acid, acetic acid, glutamic acid, asparagine, citric acid, malonic acid, trans-aconitic acid, ascorbic acid, maleic acid, cis-aconitic acid, epicatechin, protocatechuic acid, and xanthine than the leaves harvested during October and December. Epicatechin and protocatechuic acid among those compounds seem to have enhanced FRSA of the guava leaf samples harvested in May and August. A PLS regression model was established to predict guava leaf FRSA at different harvesting times by using a (1)H-NMR data set. The predictability of the PLS model was then tested by internal and external validation. The results of this study indicate that (1)H-NMR-based metabolomic data could usefully characterize guava leaves according to their time of harvesting.

  20. Changes in the radical-scavenging activity of bitter gourd (Momordica charantia L.) during freezing and frozen storage with or without blanching.

    PubMed

    Myojin, C; Enami, N; Nagata, A; Yamaguchi, T; Takamura, H; Matoba, T

    2008-09-01

    The effects of blanching, freezing, and frozen storage on the retention of radical-scavenging activity (RSA), total phenolics, and ascorbic acid in bitter gourd were investigated. Blanching of sliced bitter gourd resulted in considerable losses of RSA and total phenolics, and most extensively, of ascorbic acid. In the subsequent frozen storage at -18 degrees C, RSA and total phenolic content of unblanched and blanched bitter gourd underwent little change for 90 d then gradually declined, but at -40 degrees C, they practically remained unchanged throughout the entire storage period. On the contrary, ascorbic acid content of both unblanched and blanched bitter gourd decreased abruptly at the early stage in frozen storage. The results show that blanching of bitter gourd improves the retention of RSA and total phenolics during subsequent frozen storage but markedly aggravated loss of ascorbic acid. Finally, it is to be noted that RSA, total phenolics, and ascorbic acid originally contained in the raw bitter gourd were overall best retained by quick freezing followed by frozen storage at -40 degrees C without preceding blanching.

  1. Rapid automated assay of anti-oxidation/radical-scavenging activity of natural substances by sequential injection technique (SIA) using spectrophotometric detection.

    PubMed

    Polásek, Miroslav; Skála, Petr; Opletal, Lubomír; Jahodár, Ludek

    2004-07-01

    A PC-controlled sequential injection analysis (SIA) system equipped with a spectrophotometric diode-array detector is used for rapid monitoring and evaluation of antioxidation/radical scavenging activity of biological samples. The automated method is based on the known reaction of stable 2,2'-diphenyl-1-picrylhydrazyl radical (DPPH) with antioxidants in organic or aqueous-organic media resulting in bleaching of DPPH due to its "quenching" by the interaction with the analytes. The decrease of the absorbance of DPPH (compared to blank experiment carried out with water-ethanol 1:1 instead of the test solution) measured at 525 nm is related to concentration of an antioxidant in the test solution. With the optimised SIA procedure it is possible to detect down to micromolar concentrations of model antioxidants such as ascorbic acid, caffeic acid, (+)-catechin, (-)-epicatechin and rutin and to evaluate the concentration of these antioxidants in the micromolar to millimolar range. The sample throughput is 45 h(-1). Thanks to its rapidity and sensitivity, the proposed SIA method is suitable for performing routine screening tests for the presence of various antioxidants in large series of lyophilised herbal or mushroom extracts (the amount of sample needed for the analysis is several milligrams).

  2. Scavenger Hunts: Chasing Down Scientific Answers.

    ERIC Educational Resources Information Center

    Griffin, Marshall S.; Dew, Nancy; Kronberg, Joyce R.

    2000-01-01

    Describes a scavenger hunt activity that stimulates active learning. Presents objectives, examples, pitfalls, grading methods, and evaluation based on course experiences with the technique. Although the method was used with lower division biology courses, it is applicable to a wide variety of science courses at various levels. (SAH)

  3. Scavenger Hunt: Middle School Earth Science "Test."

    ERIC Educational Resources Information Center

    Owens, Katharine D.; Sanders, Richard L.

    1997-01-01

    Describes a scavenger hunt activity that has been used successfully with middle school students in an earth science course. This activity includes items that call for library research rather than the collection of objects, emphasize real-world connections, are skill-oriented, ask for originality and creativity, and are just for fun. (JRH)

  4. A ligand field chemistry of oxygen generation by the oxygen-evolving complex and synthetic active sites

    PubMed Central

    Betley, Theodore A; Surendranath, Yogesh; Childress, Montana V; Alliger, Glen E; Fu, Ross; Cummins, Christopher C; Nocera, Daniel G

    2007-01-01

    Oxygen–oxygen bond formation and O2 generation occur from the S4 state of the oxygen-evolving complex (OEC). Several mechanistic possibilities have been proposed for water oxidation, depending on the formal oxidation state of the Mn atoms. All fall under two general classifications: the AB mechanism in which nucleophilic oxygen (base, B) attacks electrophilic oxygen (acid, A) of the Mn4Ca cluster or the RC mechanism in which radical-like oxygen species couple within OEC. The critical intermediate in either mechanism involves a metal oxo, though the nature of this oxo for AB and RC mechanisms is disparate. In the case of the AB mechanism, assembly of an even-electron count, high-valent metal-oxo proximate to a hydroxide is needed whereas, in an RC mechanism, two odd-electron count, high-valent metal oxos are required. Thus the two mechanisms give rise to very different design criteria for functional models of the OEC active site. This discussion presents the electron counts and ligand geometries that support metal oxos for AB and RC O–O bond-forming reactions. The construction of architectures that bring two oxygen functionalities together under the purview of the AB and RC scenarios are described. PMID:17971328

  5. Evaluation of chemical constituents and free-radical scavenging activity of Swarnabhasma (gold ash), an ayurvedic drug.

    PubMed

    Mitra, A; Chakraborty, S; Auddy, B; Tripathi, P; Sen, S; Saha, A V; Mukherjee, B

    2002-05-01

    From ancient times, Swarnabhasma (gold ash) has been used in several clinical manifestations including loss of memory, defective eyesight, infertility, overall body weakness and incidence of early aging. Swarnabhasma has been used by Ayurvedic physicians to treat different diseases like bronchial asthma, rheumatoid arthritis, diabetes mellitus, nervous disorders, etc. In the present investigation, Swarnabhasma was prepared after proper purification and calcination as per Ayurvedic pharmacy which consisted of Realger (As(2)S(2)), Lead oxide (Pb(3)O(4)), Pure gold (Au) and Latex of Calotropis gigantea. Qualitative analyses indicated that Swarnabhasma contained not only gold but also several microelements (Fe, Al, Cu, Zn, Co, Mg, Ca, As, Pb, etc.). Infrared spectroscopy showed that the material was free from any organic compound. The metal content in the bhasma was determined by atomic absorption spectrometry. Acute oral administration of Swarnabhasma showed no mortality in mice (up to 1 ml /20 g b.w. of Swarnabhasma suspension containing 1mg of drug). Chronic administration of Swarnabhasma also showed no toxicity as judged by SGPT, SGOT, serum creatinine and serum urea level and histological studies. In an experimental animal model, chronic Swarnabhasma-treated animals showed significantly increased superoxide dismutase and catalase activity, two enzymes that reduce free radical concentrations in the body.

  6. Assessment of free radicals scavenging activity of seven natural pigments and protective effects in AAPH-challenged chicken erythrocytes.

    PubMed

    Zhang, Jingfei; Hou, Xiang; Ahmad, Hussain; Zhang, Hao; Zhang, Lili; Wang, Tian

    2014-02-15

    The purpose of this study was to compare the antioxidant capacities of seven natural pigments including the fat-soluble pigments curcumin, lycopene, lutein and β-carotene and water-soluble pigments--betalain, capsanthin and cyanidin-3-rutinoside relative to a commonly-used synthetic food antioxidant BHA. The antioxidant capacities of seven pigments and BHA were evaluated based on their ability to quench several free radicals, including DPPH, ABTS, O2(·-), H2O2 as well as using FRAP assay. Specifically, curcumin and cyanidin-3-rutinoside, which showed the highest antioxidant capacities, were further investigated using a chicken erythrocyte model. After separating pretreatments of the two pigments, AAPH was added to the erythrocyte-pigment medium to induce oxidative stress. Then the attenuation effects of the two pigments on AAPH-induced oxidative damage in chicken erythrocytes were assessed. It was found that both curcumin and cyanidin-3-rutinoside significantly attenuated apoptosis and hemolysis, decreased MDA content, and increased T-SOD activity in a time- and dose- dependent manner.

  7. Toxic effects of heavy metals (Cd, Cr and Pb) on seed germination and growth and DPPH-scavenging activity in Brassica rapa var. turnip.

    PubMed

    Siddiqui, Maryam Mehmood; Abbasi, Bilal Haider; Ahmad, Nisar; Ali, Mohammad; Mahmood, Tariq

    2014-04-01

    Toxicity of heavy metal is a wide spread environmental problem affecting all life forms including plants. In the present study the toxic effects of heavy metals, cadmium (Cd), chromium (Cr) and lead (Pb) on seed germination rate (%), germination index (G-index) and growth (mm) of Brassica rapa var. turnip have been investigated. The seeds were soaked either in distilled water (control) or in aqueous solutions of Cd, Cr and Pb (1 g/l, 2.5 g/l and 5 g/l) at 4°C in dark for 24 hours. Prior to inoculation onto MS0 medium, the soaked seeds were either washed with sterile distilled water or inoculated without washing on solidified MS0 medium at 25 ± 2°C with 16/8-hour photoperiod in a growth chamber to germinate in vitro. Such stress conditions revealed that by increasing the concentration of heavy metals, the germination rate (%), G-index value and growth (mm) decreased significantly, suggesting their toxic effect on B. rapa var. turnip. This study further revealed that experiment with seed washing resulted in less toxicity of selected heavy metals on germination and growth of B. rapa var. turnip, as compared to experiment without washing. However, the resulting toxicity order of the selected heavy metals remained the same (Cd > Cr > Pb). Significant decrease has been observed in seed viability and germination potential and finally heavy metals completely ceased further growth and development of plants. The 2, 2-diphenyl-1-picrylhydrazyl (DPPH)-scavenging activity revealed that significantly higher activity was observed in control plants without heavy metals treatment. Furthermore, the Cd-treated plants showed decreased antioxidant activity. Cr and Pb were less toxic as compared to Cd (control > Pb > Cr > Cd). This study revealed that selected heavy metals not only affected plant development but also disturbed plant metabolic pathways.

  8. Active oxygen and cell death in cereal aleurone cells.

    PubMed

    Fath, Angelika; Bethke, Paul; Beligni, Veronica; Jones, Russell

    2002-05-01

    The cereal aleurone layer is a secretory tissue whose function is regulated by gibberellic acid (GA) and abscisic acid (ABA). Aleurone cells lack functional chloroplasts, thus excluding photosynthesis as a source of active oxygen species (AOS) in cell death. Incubation of barley aleurone layers or protoplasts in GA initiated the cell death programme, but incubation in ABA delays programmed cell death (PCD). Light, especially blue and UV-A light, and H(2)O(2) accelerate PCD of GA-treated aleurone cells, but ABA-treated aleurone cells are refractory to light and H(2)O(2) and are not killed. It was shown that light elevated intracellular H(2)O(2), and that the rise in H(2)O(2) was greater in GA-treated cells compared to cells in ABA. Experiments with antioxidants show that PCD in aleurone is probably regulated by AOS. The sensitivity of GA-treated aleurone to light and H(2)O(2) is a result of lowered amounts of enzymes that metabolize AOS. mRNAs encoding catalase, ascorbate peroxidase and superoxide dismutase are all reduced during 6-18 h of incubation in GA, but these mRNAs were present in higher amounts in cells incubated in ABA. The amounts of protein and enzyme activities encoded by these mRNAs were also dramatically reduced in GA-treated cells. Aleurone cells store and metabolize neutral lipids via the glyoxylate cycle in response to GA, and glyoxysomes are one potential source of AOS in the GA-treated cells. Mitochondria are another potential source of AOS in GA-treated cells. AOS generated by these organelles bring about membrane rupture and cell death.

  9. Capsaicin, a tasty free radical scavenger: mechanism of action and kinetics.

    PubMed

    Galano, Annia; Martínez, Ana

    2012-01-26

    The free radical scavenging activity of capsaicin (CAP), which is the pungent component of hot chili peppers, has been studied in aqueous and lipid solutions, using the density functional theory. Different mechanisms of reaction have been considered: single electron transfer (SET), hydrogen transfer (HT), and radical adduct formation (RAF). Rate constants and branching ratios of the different channels of reaction are provided, as well as an interpretation of the UV-vis spectra. CAP is predicted to react faster in aqueous solution than in nonpolar media with oxygenated free radicals, and it was found to be a more efficient scavenger than melatonin and caffeine. It was also found that while SET does not contribute to the overall reactivity of CAP toward (•)OOH, (•)OOCH(3), and (•)OCH(3) radicals, it might be important for the reactions with more electrophilic radicals such as (•)OH, (•)OCCl(3), and (•)OOCCl(3). The main process, responsible for the peroxyl scavenging activity of CAP, was found to be the HT from the OH phenolic group. For the reaction with (•)OCH(3), on the other hand, the HT from allylic sites are predicted to be the main channels of reaction. In this particular case a wider product distribution is predicted. This supports the role of the reacting free radical on the preponderant mechanism of action of free radical scavengers. PMID:22188587

  10. Capsaicin, a tasty free radical scavenger: mechanism of action and kinetics.

    PubMed

    Galano, Annia; Martínez, Ana

    2012-01-26

    The free radical scavenging activity of capsaicin (CAP), which is the pungent component of hot chili peppers, has been studied in aqueous and lipid solutions, using the density functional theory. Different mechanisms of reaction have been considered: single electron transfer (SET), hydrogen transfer (HT), and radical adduct formation (RAF). Rate constants and branching ratios of the different channels of reaction are provided, as well as an interpretation of the UV-vis spectra. CAP is predicted to react faster in aqueous solution than in nonpolar media with oxygenated free radicals, and it was found to be a more efficient scavenger than melatonin and caffeine. It was also found that while SET does not contribute to the overall reactivity of CAP toward (•)OOH, (•)OOCH(3), and (•)OCH(3) radicals, it might be important for the reactions with more electrophilic radicals such as (•)OH, (•)OCCl(3), and (•)OOCCl(3). The main process, responsible for the peroxyl scavenging activity of CAP, was found to be the HT from the OH phenolic group. For the reaction with (•)OCH(3), on the other hand, the HT from allylic sites are predicted to be the main channels of reaction. In this particular case a wider product distribution is predicted. This supports the role of the reacting free radical on the preponderant mechanism of action of free radical scavengers.

  11. Reactive Oxygen Species Regulate Oxygen-Sensitive Potassium Flux in Rainbow Trout Erythrocytes

    PubMed Central

    Bogdanova, Anna Yu; Nikinmaa, Mikko

    2001-01-01

    In the present study, we have investigated if reactive oxygen species are involved in the oxygen-dependent regulation of potassium-chloride cotransport activity in trout erythrocyte membrane. An increase in the oxygen level caused an increase in chloride-sensitive potassium transport (K+-Cl− cotransport). 5 mM hydrogen peroxide caused an increase in K+-Cl− cotransport at 5% oxygen. The increase in flux could be inhibited by adding extracellular catalase in the incubation. Pretreatment of the cells with mercaptopropionyl glycine (MPG), a scavenger of reactive oxygen species showing preference for hydroxyl radicals, abolished the activation of the K+-Cl− cotransporter by increased oxygen levels. The inhibition by MPG was reversible, and MPG could not inhibit the activation of transporter by the sulfhydryl reagent, N-ethylmaleimide, indicating that the effect of MPG was due to the scavenging of reactive oxygen species and not to the reaction of MPG with the cotransporter. Copper ions, which catalyze the production of hydroxyl radicals in the Fenton reaction, activated K+-Cl− cotransport significantly at hypoxic conditions (1% O2). These data suggest that hydroxyl radicals, formed from O2 in close vicinity to the cell membrane, play an important role in the oxygen-dependent activation of the K+-Cl− cotransporter. PMID:11158169

  12. Observations on the Activity and Life History of the Scavenging Isopod Natatolana borealisLilljeborg (Isopoda: Cirolanidae) from Loch Fyne, Scotland

    NASA Astrophysics Data System (ADS)

    Wong, Y. M.; Moore, P. G.

    1996-02-01

    The activity and life history of the cirolanid isopod Natatolana borealisLilljeborg has been studied using (primarily) fish-baited traps deployed at a deep-water station (190 m) in Loch Fyne, Scotland. A voracious scavenger, it burrows into soft mud, emerging to feed when suitable food odours are detected in the water. Isopods were attracted significantly to baited vs. non-baited traps. Underwater video observations revealed that most animals were active in the vicinity of traps, that capture efficiency was low, but retention complete. Only traps on the sea-bed captured mancas or juveniles in any numbers. Any seasonal pattern in catch rate through the year was confounded by high va