12 research outputs found

    Z_3 Strings and their Interactions

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    We construct Z_3 vortex solutions in a model in which SU(3) is spontaneously broken to Z_3. The model is truncated to one in which there are only two dimensionless free parameters and the interaction of vortices within this restricted set of models is studied numerically. We find that there is a curve in the two dimensional space of parameters for which the energy of two asymptotically separated vortices equals the energy of the vortices at vanishing separation. This suggests that the inter-vortex potential for Z_3 strings might be flat for these couplings, much like the case of U(1) strings in the Bogomolnyi limit. However, we argue that the intervortex potential is attractive at short distances and repulsive at large separations leading to the possibility of unstable bound states of Z_3 vortices.Comment: 8 pages; mainly corrected typos in table

    Dirty Black Holes and Hairy Black Holes

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    An approach based on considerations of the non-classical energy momentum tensor outside the event horizon of a black hole provides additional physical insight into the nature of discrete quantum hair on black holes and its effect on black hole temperature. Our analysis both extends previous work based on the Euclidean action techniques, and corrects an omission in that work. We also raise several issues related to the effects of instantons on black hole thermodynamics and the relation between these effects and results in two dimensional quantum field theory.Comment: 13 pages, Latex, submitted to Physical Review Letter

    Anti-Inflammatory Effect of Turbo cornutus Viscera Ethanolic Extract against Lipopolysaccharide-Stimulated Inflammatory Response via the Regulation of the JNK/NF-kB Signaling Pathway in Murine Macrophage RAW 264.7 Cells and a Zebrafish Model: A Preliminary Study

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    Turbo cornutus, the horned turban sea snail, is found along the intertidal and basaltic shorelines and is an important fishery resource of Jeju Island. In this study, we performed a preliminary study on anti-inflammatory effect of 70% ethanol extract obtained from T. cornutus viscera (TVE) on lipopolysaccharide (LPS)-stimulated RAW264.7 cells in vitro and zebrafish embryos in vivo. TVE reduced the production of LPS-stimulated nitric oxide (NO) and prostaglandin E2 (PGE2) without any toxic effects. TVE also decreased the protein expression of LPS-induced inducible NO synthase and cyclooxygenase-2 and suppressed the production of pro-inflammatory cytokines, including tumor necrosis factor-α, interleukin (IL)-6, and IL-1β. Furthermore, mechanistic studies indicated that TVE suppressed c-Jun N-terminal kinase phosphorylation and nuclear factor-kB activation. In zebrafish embryos, TVE did not show developmental toxicity based on the survival rate and cell death findings. In LPS-stimulated zebrafish embryos, TVE suppressed NO production and cell death. In conclusion, the result from this preliminary study showed TVE has a potential anti-inflammatory property that can be exploited as a functional food ingredient

    Purification and Molecular Docking Study on the Angiotensin I-Converting Enzyme (ACE)-Inhibitory Peptide Isolated from Hydrolysates of the Deep-Sea Mussel <i>Gigantidas vrijenhoeki</i>

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    The objective of this study was to prepare an angiotensin I-converting enzyme (ACE)-inhibitory peptide from the hydrothermal vent mussel, Gigantidas vrijenhoeki. The G. vrijenhoeki protein was hydrolyzed by various hydrolytic enzymes. The peptic hydrolysate exhibited the highest ACE-inhibitory activity and was fractionated into four molecular weight ranges by ultrafiltration. The 50 value of 0.007 μM. To investigate the ACE-inhibitory activity of the analyzed peptides, a molecular docking study was performed. KLLWNGKM exhibited the highest binding energy (−1317.01 kcal/mol), which was mainly attributed to the formation of hydrogen bonds with the ACE active pockets, zinc-binding motif, and zinc ion. These results indicate that G. vrijenhoeki-derived peptides can serve as nutritional and pharmacological candidates for controlling blood pressure

    Anti-Allergic Effect of 3,4-Dihydroxybenzaldehyde Isolated from <i>Polysiphonia morrowii</i> in IgE/BSA-Stimulated Mast Cells and a Passive Cutaneous Anaphylaxis Mouse Model

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    In this study, we investigated the anti-allergic effects of 3,4-dihydroxybenzaldehyde (DHB) isolated from the marine red alga, Polysiphonia morrowii, in mouse bone-marrow-derived cultured mast cells (BMCMCs) and passive cutaneous anaphylaxis (PCA) in anti-dinitrophenyl (DNP) immunoglobulin E (IgE)-sensitized mice. DHB inhibited IgE/bovine serum albumin (BSA)-induced BMCMCs degranulation by reducing the release of β-hexosaminidase without inducing cytotoxicity. Further, DHB dose-dependently decreased the IgE binding and high-affinity IgE receptor (FcεRI) expression and FcεRI-IgE binding on the surface of BMCMCs. Moreover, DHB suppressed the secretion and/or the expression of the allergic cytokines, interleukin (IL)-4, IL-5, IL-6, IL-13, and tumor necrosis factor (TNF)-α, and the chemokine, thymus activation-regulated chemokine (TARC), by regulating the phosphorylation of IκBα and the translocation of cytoplasmic NF-κB into the nucleus. Furthermore, DHB attenuated the passive cutaneous anaphylactic (PCA) reaction reducing the exuded Evans blue amount in the mouse ear stimulated by IgE/BSA. These results suggest that DHB is a potential therapeutic candidate for the prevention and treatment of type I allergic disorders

    Tuberatolide B Suppresses Cancer Progression by Promoting ROS-Mediated Inhibition of STAT3 Signaling

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    Tuberatolide B (TTB, C27H34O4) is a diastereomeric meroterpenoid isolated from the Korean marine algae Sargassum macrocarpum. However, the anticancer effects of TTB remain unknown. In this study, we demonstrate that TTB inhibits tumor growth in breast, lung, colon, prostate, and cervical cancer cells. To examine the mechanism by which TTB suppresses cell growth, we determined the effect of TTB on apoptosis, ROS generation, DNA damage, and signal transduction. TTB induced ROS production in MDA-MB-231, A549, and HCT116 cells. Moreover, TTB enhanced DNA damage by inducing γH2AX foci formation and the phosphorylation of DNA damage-related proteins such as Chk2 and H2AX. Furthermore, TTB selectively inhibited STAT3 activation, which resulted in a reduction in cyclin D1, MMP-9, survivin, VEGF, and IL-6. In addition, TTB-induced ROS generation caused STAT3 inhibition, DNA damage, and apoptotic cell death. Therefore, TTB suppresses cancer progression by promoting ROS-mediated inhibition of STAT3 signaling, suggesting that TTB is useful for the treatment of cancer

    Potential Antioxidant Properties of Enzymatic Hydrolysates from <i>Stichopus</i> <i>japonicus</i> against Hydrogen Peroxide-Induced Oxidative Stress

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    A comprehensive antioxidant evaluation was performed on enzymatic hydrolysates of Stichopusjaponicus (S. japonicus) using Vero cells and zebrafish models for in vitro and in vivo studies, respectively. S. japonicus was hydrolyzed with food-grade enzymes (alcalase, α-chymotrypsin, flavourzyme, kojizyme, neutrase, papain, pepsin, protamex, and trypsin), and the free radical scavenging activities were screened via electron spin resonance (ESR) spectroscopy. According to the results, the enzymatic hydrolysates contained high protein and relatively low polysaccharide and sulfate contents. Among these hydrolysates, the α-chymotrypsin assisted hydrolysate from S. japonicus (α-chy) showed high yield and protein content, and strong hydroxyl radical scavenging activity. Therefore, α-chy was chosen for further purification. The α-chy was fractionated by ultrafiltration into three ultrafiltration (UF) fractions based on their molecular weight: >10 kDa (α-chy-I), 5–10 kDa (α-chy-II), and 2O2 exposed Vero cells. The α-chy and its UF fractions significantly decreased the intracellular reactive oxygen species (ROS) generation and increased cell viability in H2O2 exposed Vero cells. Among them, α-chy-III effectively declined the intracellular ROS levels and increased cell viability and exhibited protection against H2O2 induced apoptotic damage. Furthermore, α-chy-III remarkably attenuated the cell death, intracellular ROS and lipid peroxidation in H2O2 exposed zebrafish embryos. Altogether, our findings demonstrated that α-chy and its α-chy-III from S. japonicus possess strong antioxidant activities that could be utilized as a bioactive ingredient for functional food industries

    Potential Antioxidant Properties of Enzymatic Hydrolysates from Stichopus japonicus against Hydrogen Peroxide-Induced Oxidative Stress

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    A comprehensive antioxidant evaluation was performed on enzymatic hydrolysates of Stichopusjaponicus (S. japonicus) using Vero cells and zebrafish models for in vitro and in vivo studies, respectively. S. japonicus was hydrolyzed with food-grade enzymes (alcalase, &alpha;-chymotrypsin, flavourzyme, kojizyme, neutrase, papain, pepsin, protamex, and trypsin), and the free radical scavenging activities were screened via electron spin resonance (ESR) spectroscopy. According to the results, the enzymatic hydrolysates contained high protein and relatively low polysaccharide and sulfate contents. Among these hydrolysates, the &alpha;-chymotrypsin assisted hydrolysate from S. japonicus (&alpha;-chy) showed high yield and protein content, and strong hydroxyl radical scavenging activity. Therefore, &alpha;-chy was chosen for further purification. The &alpha;-chy was fractionated by ultrafiltration into three ultrafiltration (UF) fractions based on their molecular weight: &gt;10 kDa (&alpha;-chy-I), 5&ndash;10 kDa (&alpha;-chy-II), and &lt;5 kDa (&alpha;-chy-III), and we evaluated their antioxidant properties in H2O2 exposed Vero cells. The &alpha;-chy and its UF fractions significantly decreased the intracellular reactive oxygen species (ROS) generation and increased cell viability in H2O2 exposed Vero cells. Among them, &alpha;-chy-III effectively declined the intracellular ROS levels and increased cell viability and exhibited protection against H2O2 induced apoptotic damage. Furthermore, &alpha;-chy-III remarkably attenuated the cell death, intracellular ROS and lipid peroxidation in H2O2 exposed zebrafish embryos. Altogether, our findings demonstrated that &alpha;-chy and its &alpha;-chy-III from S. japonicus possess strong antioxidant activities that could be utilized as a bioactive ingredient for functional food industries
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