Il-Kwang Kim

In vitro anti-proliferative effect of 1,2,3,4,6-penta-O-galloyl-beta-D-glucose on human hepatocellular carcinoma cell line, SK-HEP-1 cells.

The root of Paeonia suffruticosa ANDREWS is an important Chinese crude drug used in many traditional prescriptions. 1,2,3,4,6-penta-O-galloyl-beta-D-glucose (PGG), a major component of this crude drug, was found to exhibit in vitro growth-inhibiting effect on human hepatocellular carcinoma cell line, SK-HEP-1 cells. The growth-inhibitory effect was related to the ability of PGG not only to cause a G(0)/G(1) phase arrest but also to suppress the activation of nuclear factor-kappa B. Neither apoptosis nor necrosis was observed in the cells treated with PGG. These findings suggest that PGG could be a candidate for developing a low-toxic anticancer agent.

Capsazepine, a vanilloid receptor antagonist, inhibits the expression of inducible nitric oxide synthase gene in lipopolysaccharide-stimulated RAW264.7 macrophages through the inactivation of nuclear transcription factor-kappa B

High amounts of nitric oxide (NO) production following the induction of inducible NO synthase (iNOS) gene expression has been implicated in the pathogenesis of inflammatory diseases. Capsaicin, a vanilloid receptor agonist, is known to have an inhibitory effect on NO production in macrophages. In the present study, we have found that capsazepine (CAPZ), a vanilloid receptor antagonist, also inhibited NO and iNOS protein syntheses induced by lipopolysaccharide in RAW264.7 macrophages via the suppression of iNOS mRNA. The mechanistic studies showed that CAPZ inhibited the expression of iNOS mRNA through the inactivation of nuclear transcription factor-kappa B (NF-kappa B). Thus, capsazepine may be a useful candidate for the development of a drug to treat inflammatory diseases related to iNOS gene overexpression.

Synthesis and characterization of copper(II) and nickel(II) complexes of a di-N-carboxymethylated tetraaza macrocycle

Abstract The reaction of 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0 1.18 ,0 7.12 ]docosane (L 1 ) with bromoacetic acid produced the macrocycle (L 2 =2,13-bis(2-carboxymethyl)-3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0 1.18 ,0 7.12 ]docosane) in which two carboxymethyl groups are appended. The complexes [NiL 2 ]·4H 2 O ( 2 ) and [CuL 2 ]·4H 2 O ( 3 ) have been prepared and characterized. The two pendant carboxymethyl groups of the macrocyclic ligand are trans to each other, and the absolute configuration is a trans -III in the solid state. The crystal structures of 2 and 3 revealed an axially elongated octahedral geometry with four nitrogen atoms of the macrocycle and two oxygen atoms of the pendant arms at the axial positions. The nickel(II) and copper(II) ions are located at an inversion center. Macrocycle L 2 reacts more rapidly with metal (II) ions than does L 1 . Spectra and electrochemical behaviors of the complexes are also discussed.

Scrophularia buergeriana regulates cytokine production in vitro

The Scrophularia buergeriana (SB) has long been used to treat various diseases an account of its antimicrobial and anti-virus activity. However, it is unclear how SB regulates the immune responses. This study investigated the effect of SB on the production of cytokines in a human T-cell line, MOLT-4 cells, and mouse peritoneal macrophages. The MOLT-4 cells were cultured for 24 h in the presence or absence of SB plus concanavalin (con) A. SB plus con A significantly increased the level of interleukin (IL)-2, IL-4 and interferon (IFN)-γ production compared with that of con A alone (approximately 1.79-fold for IL-2, 2-fold for IL-4, and 1.85-fold for IFN-γ, p < 0.05). SB plus recombinant IFN-γ (rIFN-γ) increased the level of IL-12 and NO production compared with rIFN-γ alone. In addition, SB plus rIFN-γ increased the level the iNOS expression on mouse peritoneal macrophages. Overall, SB may have an immune-enhancement effect through cytokine production.

Methallyl isothiocyanate inhibits the caspase-1 activity through the inhibition of intracellular calcium levels

Isothiocyanates (ITCs) play a major role in the potential chemopreventive effect. Cruciferous vegetables are a particularly abundant source of ITCs. Methallyl ITC (MAITC) belongs to ITCs as a synthesized compound. However, the effects of MATIC have never been elucidated. The aim of this work was to investigate the anti-inflammatory effects and mechanisms of methallyl isothiocyanate (MAITC) in mast cells. MAITC suppressed the intracellular calcium levels in phorbol myristate acetate (PMA) plus calcium ionophore A23187 (PMACI)-stimulated human mast cell line (HMC-1) cells. MAITC significantly inhibited the production and mRNA expression of interleukin (IL)-1β in PMACI-stimulated HMC-1 cells. The activities of caspase-1 and receptor interacting protein-2 were significantly inhibited by the treatment with MAITC in PMACI-stimulated HMC-1 cells. The activation of nuclear factor-κB and phosphorylation of extracellular signal-regulated kinase and IκBα were inhibited by the treatment with MAITC. In addition, MAITC significantly inhibited the production and mRNA expression of IL-6 and tumor necrosis factor-α in PMACI-stimulated HMC-1 cells. Furthermore, MAITC significantly inhibited caspase-1 enzymatic activity and reactive oxygen species generation in PMA-stimulated HMC-1 cells. Taken together, we can conclude that MAITC showed an anti-inflammatory effect on mast cell-mediated inflammatory reaction.

Electrochemical properties and synthesis of polyether tailed metallo porphyrin complex for coordinating species detection

The preparation and electrochemical characterization are described for a new class of metallo-porphyrins in which four oligomeric ethylene glycol chains are attached to each porphyrin structure. The resulting redox polyether hybrids are viscous liquids at room temperature, highly concentrated in porphyrin site (/spl sim/0.4 M), and dissolve large quantities of lithium salts. Microelectrode voltammetry and chronoamperometry have been used to assess the charge transport rates for various reactions in the undiluted melt state of the polyether-porphyrin. The apparent diffusion coefficients, D/sub APP/, vary over a wide range depending on the specific redox reaction and on the amount of added lithium electrolyte. The largest D/sub APP/ values are found for redox reactions centered on the porphyrin ring, while the smallest values are seen for the Fe III/II reaction. This difference is ascribed to enhanced charge transport by an electron hopping mechanism in the former cases. The temperature dependence for D/sub APP/ was used to examine activation parameters. The interaction of polyether-porphyrin melts with the axial ligand, CO, was also examined by voltammetry.

Photoelectrochemical characterization of GaAs and doped Fe/sub 2/O/sub 3/ semiconductive electrodes

The characterization for semiconductive electrodes of GaAs and Fe/sub 2/O/sub 3/ doped with MgO or CaO was investigated. The doped Fe/sub 2/O/sub 3/ semiconductive electrodes were prepared from thin films sintered at temperatures from 1100 to 1450/spl deg/C, and rapidly quenched in distilled water. The surfaces of the electrodes containing both corundum structure Fe/sub 2/O/sub 3/ and spinel structure Mg/sub x/Fe/sub 3-x/O/sub 4/ or Ca/sub x/Fe/sub 3-x/O/sub 4/ were analyzed by X-ray diffraction. The critical anodic and cathodic photocurrents on these electrodes were obtained at a doping amount of 5/spl sim/11 wt%. When the GaAs electrodes were treated with methylene violet, the anodic photocurrents were temporarily enhanced and inverted to the cathodic photocurrents after the treated surface was dried.