Oxidative stress plays a crucial role in the development of neuronal disorders including brain ischemic injury. Thioredoxin 1 (Trx1), a 12 kDa oxidoreductase, has anti-oxidant and anti-apoptotic functions in various cells. It has been highly implicated in brain ischemic injury. However, the protective mechanism of Trx1 against hippocampal neuronal cell death is not identified yet. Using a cell permeable Tat-Trx1 protein, protective mechanism of Trx1 against hydrogen peroxide-induced cell death was examined using HT-22 cells and an ischemic animal model. Transduced Tat-Trx1 markedly inhibited intracellular ROS levels, DNA fragmentation, and cell death in H 2O 2-treatment HT-22 cells. Tat-Trx1 also significantly inhibited phosphorylation of ASK1 and MAPKs in signaling pathways of HT-22 cells. In addition, Tat-Trx1 regulated expression levels of Akt, NF-κB, and apoptosis related proteins. In an ischemia animal model, Tat-Trx1 markedly protected hippocampal neuronal cell death and reduced astrocytes and microglia activation. These findings indicate that transduced Tat-Trx1 might be a potential therapeutic agent for treating ischemic injury.

Oxidative stress plays a crucial role in the development of neuronal disorders including brain ischemic injury. Thioredoxin 1 (Trx1), a 12 kDa oxidoreductase, has anti-oxidant and anti-apoptotic functions in various cells. It has been highly implicated in brain ischemic injury. However, the protective mechanism of Trx1 against hippocampal neuronal cell death is not identified yet. Using a cell permeable Tat-Trx1 protein, protective mechanism of Trx1 against hydrogen peroxide-induced cell death was examined using HT-22 cells and an ischemic animal model. Transduced Tat-Trx1 markedly inhibited intracellular ROS levels, DNA fragmentation, and cell death in H 2O 2-treatment HT-22 cells. Tat-Trx1 also significantly inhibited phosphorylation of ASK1 and MAPKs in signaling pathways of HT-22 cells. In addition, Tat-Trx1 regulated expression levels of Akt, NF-κB, and apoptosis related proteins. In an ischemia animal model, Tat-Trx1 markedly protected hippocampal neuronal cell death and reduced astrocytes and microglia activation. These findings indicate that transduced Tat-Trx1 might be a potential therapeutic agent for treating ischemic injury.

In our ongoing search for new secondary metabolites from fungi, a basidiomycete fungus Irpex consors was selected for mycochemical investigation, and three new zwitterionic alkaloids (1-3) and five known compounds (4-8) were isolated from the culture broth (16 l) of I. consors. The culture filtrate was fractionated by a series of column chromatography including Diaion HP-20, silica gel, and Sephadex LH-20, Sep-Pak C18 cartridge, medium pressure liquid chromatography (MPLC), and high pressure liquid chromatography (HPLC) to yield eight compounds (1-8). The structures of the isolated compounds were elucidated by the interpretation of nuclear magnetic resonance (NMR) spectra and high-resolution mass spectrometry (HR-MS). Their antioxidant and antibacterial activities were examined. The zwitterionic structures of three new sesquiterpene alkaloids (1-3) were determined together with five known compounds identified as stereumamide E (4), stereumamide G (5), stereumamide H (6), stereumamide D (7), and sterostrein H (8). This is the first report of the zwitterionic alkaloids in the culture broth of I. consors. Three new zwitterionic alkaloids were named as consoramides A–C (1-3).

In our ongoing search for new secondary metabolites from fungi, a basidiomycete fungus Irpex consors was selected for mycochemical investigation, and three new zwitterionic alkaloids (1-3) and five known compounds (4-8) were isolated from the culture broth (16 l) of I. consors. The culture filtrate was fractionated by a series of column chromatography including Diaion HP-20, silica gel, and Sephadex LH-20, Sep-Pak C18 cartridge, medium pressure liquid chromatography (MPLC), and high pressure liquid chromatography (HPLC) to yield eight compounds (1-8). The structures of the isolated compounds were elucidated by the interpretation of nuclear magnetic resonance (NMR) spectra and high-resolution mass spectrometry (HR-MS). Their antioxidant and antibacterial activities were examined. The zwitterionic structures of three new sesquiterpene alkaloids (1-3) were determined together with five known compounds identified as stereumamide E (4), stereumamide G (5), stereumamide H (6), stereumamide D (7), and sterostrein H (8). This is the first report of the zwitterionic alkaloids in the culture broth of I. consors. Three new zwitterionic alkaloids were named as consoramides A–C (1-3).

Aldose reductase (AR) protein, a member of the NADPH-dependent aldo-keto reductase family, reduces a wide range of aldehydes and enhances cell survival by inhibition of oxidative stress. Oxidative stress is known as one of the major pathological factor in ischemia. Since the precise function of AR protein in ischemic injury is fully unclear, we examined the function of AR protein in hippocampal neuronal (HT-22) cells and in an animal model of ischemia in this study. Cell permeable Tat-AR protein was produced by fusion of protein transduction domain in Tat for delivery into the cells. Tat-AR protein transduced into HT-22 cells and significantly inhibited cell death and regulated the mitogen-activate protein kinases (MAPKs), Bcl-2, Bax, and Caspase-3 under oxidative stress condition. In an ischemic animal model, Tat-AR protein transduced into the brain tissues through the blood-brain barrier (BBB) and drastically decreased neuronal cell death in hippocampal CA1 region. These results indicate that transduced Tat-AR protein has protective effects against oxidative stress-induced neuronal cell death in vitro and in vivo, suggesting that Tat-AR protein could be used as potential therapeutic agent in ischemic injury.
Aldehyde Reductase ; Aldehydes ; Blood-Brain Barrier ; Brain ; CA1 Region, Hippocampal ; Caspase 3 ; Cell Death ; Cell Survival ; Humans ; In Vitro Techniques ; Ischemia ; Models, Animal ; Neurons ; Oxidative Stress ; Oxidoreductases ; Protein Kinases

Neuraminidase (NA) cleaves the glycosidic bond linkages of sialic acids to release the mature virions from infected cells and has been an attractive therapeutic target for anti-influenza agents. In our ongoing investigation of NA inhibitors in mushroom extracts, we found that the extract the fruiting body of Glaziella splendens potently inhibited neuraminidase. The fruiting bodies of G. splendens were extracted and partitioned successively with hexane, ethyl acetate, and butanol. The ethyl acetate soluble-layer was subjected to silica gel and Sephadex LH-20 column chromatographies, and MPLC to obtain five compounds (1–5). Their structures were determined by spectroscopic methods. NA inhibitory activity of these compounds was evaluated using NAs from recombinant rvH1N1, H3N2, and H5N1 influenza A viruses. One compound (1) was elucidated as a new azaphilone derivative, and four compounds (2–5) were identified as entonaemin A, comazaphilone D, rubiginosin A, and entonaemin B, respectively. Compounds 3 and 4 showed considerable inhibitory activity against three types of neuraminidases with the IC₅₀ values of 30.9, 41.8, and 35.7 µM for 3 and 46.5, 50.4, and 29.9 µM for 4, respectively. This study reveals that the fruiting bodies of G. splendens possess azaphilone derivatives with the NA inhibitory activity. This is the first report on the isolation of neuraminidase inhibitors from the fruiting bodies of G. splendens.
Agaricales ; Chromatography ; Fruit ; Influenza A virus ; N-Acetylneuraminic Acid ; Neuraminidase ; Sialic Acids ; Silica Gel ; Virion

Ginseng damping-off, caused by the fungal pathogens Rhizoctonia solani and Pythium sp., is a critical disease in ginseng seedling. In a continuing effort to find microorganisms with the potential of acting as a biocontrol agent against Rhizoctonia damping-off, we found that a Streptomyces sp. A501 showed significant antifungal activity against Rhizoctonia solani. In field experiment to test the efficacy of Streptomyces sp. A501 in controlling ginseng damping-off, the incidence of damping-off disease was meaningfully reduced when ginseng seeds were soaked in the culture broth of Streptomyces sp. A501 before sowing. To perform characterization of the antifungal compound, we isolated it from the culture broth of strain A501 through Diaion HP-20 and silica gel column chromatographies and preparative high-performance liquid chromatography. The structure of the antifungal compound was assigned as fungichromin by spectroscopic methods, mainly nuclear magnetic resonance and electrospray ionization-mass analysis.
Chromatography ; Chromatography, Liquid ; Incidence ; Magnetic Resonance Spectroscopy ; Panax* ; Pythium ; Rhizoctonia ; Seedlings ; Silica Gel ; Streptomyces*

During our ongoing investigation of neuraminidase inhibitors from medicinal fungi, we found that the fruiting bodies of Phellinus igniarius exhibited significant inhibitory activity against neuraminidase from recombinant H3N2 influenza viruses. Two active compounds were isolated from the methanolic extract of P. igniarius through solvent partitioning and Sephadex LH-20 column chromatography. The active compounds were identified as phelligridins E and G on proton nuclear magnetic resonance (¹H NMR) and electrospray ionization mass measurements. These compounds inhibited neuraminidases from recombinant rvH1N1, H3N2, and H5N1 influenza viruses, with IC₅₀ values in the range of 0.7~8.1 µM.
Chromatography ; Fruit* ; Fungi ; Magnetic Resonance Spectroscopy ; Methanol ; Neuraminidase* ; Orthomyxoviridae ; Protons

In a previous study, we identified a Streptomyces sp., A3265, as exhibiting potent antifungal activity against various plant pathogenic fungi, including Botrytis cinerea, Colletotrichum gloeosporioides, and Rhizoctonia solani. This strain also exhibited a biocontrolling effect against ginseng root rot and damping-off disease, common diseases of ginseng and other crops. In this study, we isolated two antifungal substances responsible for this biocontrolling effect via Diaion HP-20 and Sephadex LH-20 column chromatography, medium pressure liquid chromatography, and high-performance liquid chromatography. These compounds were identified as guanidylfungin A and methyl guanidylfungin A by spectroscopic methods. These compounds exhibited potent antimicrobial activity against various plant pathogenic fungi as well as against bacteria.
Bacteria ; Botrytis ; Chromatography ; Chromatography, Liquid ; Colletotrichum ; Fungi* ; Panax ; Plants* ; Rhizoctonia ; Streptomyces*

Essential fatty acid (EFA) is known to be required for the body to function normally and healthily. However, the effect of EFA on glucose uptake in skeletal muscle has not yet been fully investigated. In this study, we examined the effect of two EFAs, linoleic acid (LA) and alpha-linolenic acid (ALA), on glucose uptake of C2C12 skeletal muscle cells and investigated the mechanism underlying the stimulatory effect of polyunsaturated EFAs in comparison with monounsaturated oleic acid (OA). In palmitic acid (PA)-induced insulin resistant cells, the co-treatment of EFAs and OA with PA almost restored the PA-induced decrease in the basal and insulin-stimulated 2-NBDG (fluorescent D-glucose analogue) uptake, respectively. Two EFAs and OA significantly protected PA-induced suppression of insulin signaling, respectively, which was confirmed by the increased levels of Akt phosphorylation and serine/threonine kinases (PKCtheta and JNK) dephosphorylation in the western blot analysis. In PA-untreated, control cells, the treatment of 500 microM EFA significantly stimulated 2-NBDG uptake, whereas OA did not. Phosphorylation of AMP-activated protein kinase (AMPK) and one of its downstream molecules, acetyl-CoA carboxylase (ACC) was markedly induced by EFA, but not OA. In addition, EFA-stimulated 2-NBDG uptake was significantly inhibited by the pre-treatment of a specific AMPK inhibitor, adenine 9-beta-D-arabinofuranoside (araA). These data suggest that the restoration of suppressed insulin signaling at PA-induced insulin resistant condition and AMPK activation are involved at least in the stimulatory effect of EFA on glucose uptake in C2C12 skeletal muscle cells.
Acetyl-CoA Carboxylase ; Adenine ; alpha-Linolenic Acid ; AMP-Activated Protein Kinases* ; Blotting, Western ; Fatty Acids, Essential* ; Glucose* ; Insulin ; Linoleic Acid ; Muscle, Skeletal* ; Oleic Acid ; Palmitic Acid ; Phosphorylation ; Phosphotransferases