• Biomolecules & Therapeutics
• /
• v.17 no.3
• /
• pp.263-269
• /
• 2009

4-Hydroxybenzaldehyde, a phenolic compound found in a variety of natural sources, was previously shown to contain anti-inflammatory and related anti-angiogenic and anti-nociceptive activities. The present work was designed to assess some pharmacological activities of 2,4-dihydroxybenzaldehyde (DHD), an analogue of 4-hydroxybenzaldehyde. DHD exhibited a significant inhibition in the chick chorioallantoic membrane (CAM) angiogenesis, and its $IC_{50}$ value was $2.4\;{\mu}g/egg$. DHD also contained in vivo anti-inflammatory activity using acetic acid-induced permeability and carrageenan-induced air pouch models in mice. In the air pouch model, DHD showed significant suppression in exudate volume, number of polymorphonuclear leukocytes and nitrite content. DHD showed an anti-nociceptive activity in the acetic acid-induced writhing test in mice. It also suppressed enhanced production of nitric oxide (NO) and elevated expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells. It was able to slightly decrease the level of reactive oxygen species in the stimulated macrophages. DHD at the used concentrations couldn't modulate the viabilities of RAW264.7 cells. Taken together, like 4-hydroxybenzaldehyde, DHD contains anti-angiogenic, anti-inflammatory and anti-nociceptive activities.

• Macromolecular Research
• /
• v.12 no.2
• /
• pp.156-171
• /
• 2004

We describe the precision synthesis schemes of siloxane-containing polymers, i.e., the control of their molecular weight, stereoregularity, and higher-order structures. First, we found a new catalytic dehydrocoupling reaction of water with bis(dimethylsilyl)benzene to give poly(phenylene-disiloxane). Together with this reaction, we applied hetero-condensations to the synthesis of thermally stable poly(arylene-siloxane)s. The dehydrocoupling reaction was applied to the synthesis of syndiotactic poly(methylphenylsiloxane) and poly(silsesquioxane)s, which we also prepared by hydrolysis and deaminative condensation reactions. We discuss the tendency for loop formation to occur in the synthesis of poly(silsesquioxane) by hydrolysis, and provide comments on the design of functionality of the polymers produced. By taking advantage of the low energy barrier to rotation in the silicon-oxygen bond, we designed selective oxygen-permeable membrane materials and liquid crystalline materials. The low surface free energy of siloxane-containing systems allows surface modification of a blend film and the design of holographic grating materials.

• Ocean and Polar Research
• /
• v.38 no.3
• /
• pp.185-193
• /
• 2016

In this study, antioxidative potentials of the crude extract and its four solvent fractions from the Arctic terrestrial plant Ranunculus heperporeus were evaluated by using four different activity tests, including the inhibition of intracellular reactive oxygen species (ROS) and lipid peroxidation in Raw 264.7 cells as well as determining the extent of both the scavenging of peroxynitrite ($ONOO^-$) and the oxidative damage of genomic DNA purified from Raw 264.7 cells. Based on a comparative analysis, n-BuOH, and 85% aq.MeOH solvent fractions showed good scavenging effects on the production of intracellcular ROS and inhibited membrane lipid peroxidation and DNA oxidation. In addition, n-BuOH and 85% aq.MeOH fractions exhibited good scavenging effects on both authentic peroxynitrite and one generated from SIN-1. Among the samples tested, the n-BuOH fraction revealed the strongest antioxidant effect.

• Environmental Analysis Health and Toxicology
• /
• v.21 no.2 s.53
• /
• pp.165-172
• /
• 2006

The backs with a hair cut of 6-week-old healthy ICR male mice were once exposed to a dose of $400mJ/cm^2$ UVB. An acute dermal inflammation was observed, and the inflamed skins were almost completely cured after 6 days of the exposure. At 24 hours after exposure, the epidermal keratinocytes showed a cell-membrane damage with the destruction of intercellular junctions, agglutination of tonofilaments within the cytoplasm and nucleus damage. The activity of XO showed a significant increase (p<0.05) in up to 144 hours. The activities of CAT and SOD showed a significant decrease (p<0.05) in up to 96 hours, but they were not significantly different from the normal value at 144 hours. The GST activity was significantly decreased (p<0.01) in up to 96 hours, not so at 24 hours. However, that was not significantly different from the normal value at 144 hours. There was a significant decrease (p<0.01) in the contents of TBARS at 48 and 96 hours, without any significant difference at 144 hours. While the content of GSH was significantly lower (p<0.05) at 24 hours, that was not significantly different thereafter up to 144 hours from the normal value. Therefore, it is assumed that skin damage with a dose of $400mJ/cm^2$ UVB irradiation might be caused by the oxidative stress which was resulted from the unbalance of oxygen fret radical generating and scavenging enzymes.

• Korean Journal of Optics and Photonics
• /
• v.15 no.1
• /
• pp.1-5
• /
• 2004

Tunable diode laser absorption spectroscopy was performed for analysis of the H$_2$$^{18}$ O/H$_2$$^{16}$ O isotope ratio of a water sample which was enriched by the membrane distillation method. In order to improve the signal-to-noise ratio, the wavelength modulation spectroscopic method was used with a lock-in amplifier. The fringe noise could be suppressed by using the FFT (Fast Fourier Transform) lowpass filter and the optimization of the modulation depth of the laser frequency. The maximum deviation of $\delta$-value was measured to be$\pm$4$\textperthousand$.

• Proceedings of the Korean Magnestics Society Conference
• /
• 2011.06a
• /
• pp.129-129
• /
• 2011

The limited understanding of the surface properties of $Pt_3Ni$ for the oxygen reduction reaction (ORR) in polymer electrolyte membrane fuel cell (PEMFC) has motivated the study of properties and electronic structures of seven layered $Pt_3Ni$ (001), (110), and (111) surfaces. The first principle method based on density functional theory (DFT) is carried out. It is found that the bulk $Pt_3Ni$ has a ferromagnetic ground state with the ordered fcc type L12 structure, which is in good agreement with other results. Non magnetic Pt has the induced magnetic moment due to the strong hybridization between 3d Ni and 5d Pt. The magnetic moment of Pt and Ni enhanced on the surface of each due to surface effect however the magnetic moment of surface Pt in the Pt-segregated Pt3Ni (111) decreased and the magnetic moment of Ni in Ni rich subsurface increased significantly. The calculated d band centers of Pt explain the possibilities for oxygen absorption and play the important roles in altering the catalytic properties. The spin polarized densities of states are presented in order to understand physical properties of Pt in different surfaces in detail.

• Ocean and Polar Research
• /
• v.31 no.2
• /
• pp.213-218
• /
• 2009

We examined the intracellular antioxidative effects of 20 Arctic seaweed extracts in Raw 264.7 cells. Each seaweed species was subjected to extraction using acetone/dichloromethane and methanol, respectively, after which the extracts were combined and used as the test sample. The antioxidant ability of all 20 seaweeds extracts was evaluated using four different activity tests, including the degree of occurrence of intracellular reactive oxygen species (ROS), $ONOO^-$, and lipid peroxidation in Raw 264.7 cells, as well as the extent of oxidative damage of genomic DNA purified from Raw 264.7 cells. Crude extracts from Monostroma obscurum, Alaria esculnta, Laminaria digitata, Desmarestia aculeata, Chorda filum, Ptilota seriata, Phycidrys rubens, Devaleraea ramentacea and Palmaria palmata exhibited significant scavenging effects on the generation of intracellular ROS. Among them, Monostroma obscurum and Phycidrys rubens significantly inhibited membrane lipid peroxidation and DNA oxidation. Moreover, Phycidrys rubens exhibited scavenging effects on peroxynitrite generated from SIN-1.

• Biomolecules & Therapeutics
• /
• v.25 no.4
• /
• pp.404-410
• /
• 2017

Benzylideneacetophenone derivative (1E)-1-(4-hydroxy-3-methoxyphenyl) hept-1-en-3-one (JC3) elicited cytotoxic effects on MDA-MB 231 human breast cancer cells-radiation resistant cells (MDA-MB 231-RR), in a dose-dependent manner, with an $IC_{50}$ value of $6{\mu}M$ JC3. JC3-mediated apoptosis was confirmed by increase in sub-G1 cell population. JC3 disrupted the mitochondrial membrane potential, and reduced expression of anti-apoptotic B cell lymphoma-2 protein, whereas it increased expression of pro-apoptotic Bcl-2-associated X protein, leading to the cleavage of caspase-9, caspase-3 and poly (ADP-ribose) polymerase. In addition, JC3 activated mitogen-activated protein kinases, and specific inhibitors of these kinases abrogated the JC3-induced increase in apoptotic bodies. JC3 increased the level of intracellular reactive oxygen species and enhanced oxidative macromolecular damage via lipid peroxidation, protein carbonylation, and DNA strand breakage. Considering these findings, JC3 is an effective therapy against radiation-resistant human breast cancer cells.

• Molecules and Cells
• /
• v.38 no.7
• /
• pp.630-637
• /
• 2015

Morus alba root extract (MARE) has been used to treat hyperglycaemic conditions in oriental medicine. Here, we studied whether MARE possesses a cytotoxic effect on neuroblastoma. To check the cytotoxicity generated by MARE was whether relatively higher against the cancer cells rather than normal cells, we chose a neuroblastoma cell line (B103) and a normal cell line (Rat-2). A CCK assay revealed that MARE ($10{\mu}g/ml$) reduced cell viability to approximately 60% compared to an untreated control in B103 cells. But in Rat-2 cells, MARE induced relatively lower cytotoxicity. To investigate the mechanisms underlying the cytotoxic effect of MARE, we used flow cytometry combined with immunoblot analyses. We found that MARE-treatment could accumulate ROS and depolarize mitochondria membrane potential of B103 cells. Further treatment with MARE in B103 cells also could damage DNA and induce apoptosis. An expression study of p-Akt also suggested that there was a reduction in cellular proliferation and transcription along with the process of apoptosis, which was further evidenced by an increase in Bax and cleaved-caspase 3 activity. Together, our findings suggest that MARE produces more cytotoxicity in cancer cells while having a relatively attenuated effect on normal cells. As such, MARE may be a safer option in cancer therapeutics, and it also shows potential for the patients with symptoms of hyperglycemia and cancer.

• Korean Journal of Food Science and Technology
• /
• v.28 no.5
• /
• pp.974-980
• /
• 1996

A biosensor was prepared with dual cathode electrode and immobilized enzyme membrane. A nylon net was used for the immobilization of glucose oxidase and alcohol oxidase. The immobilized enzymes were placed on the surface of the electrode which was prepared with one anode and two cathodes as an oxygen electrode. The determination of components by the biosensor was based on the consumption of dissolved oxygen. The optimum condition of this system was 0.1 M potassium phosphate buffer solution, pH 7.5 at $35^{\circ}C$. Glucose and ethanol in takju were simultaneously determined by the biosensor. Comparing with UV-spectrophotometer and gas chromatograph for cross checking, there was a good correlation between the biosensor and the conventional methods. Biosensor with dual cathode electrode required no clarification or pretreatments. It was used for simultaneous determination of glucose and ethanol during the fermentation of takju.