Byoung-Soo Kim

Immune-suppressive activity of punicalagin via inhibition of NFAT activation.

Since T cell activation is central to the development of autoimmune diseases, we screened a natural product library comprising 1400 samples of medicinal herbal extracts, to identify compounds that suppress T cell activity. Punicalagin (PCG) isolated from the fruit of Punica granatum was identified as a potent immune suppressant, based on its inhibitory action on the activation of the nuclear factor of activated T cells (NFAT). PCG downregulated the mRNA and soluble protein expression of interleukin-2 from anti-CD3/anti-CD28-stimulated murine splenic CD4+ T cells and suppressed mixed leukocytes reaction (MLR) without exhibiting cytotoxicity to the cells. In vivo, the PCG treatment inhibited phorbol 12-myristate 13-acetate (PMA)-induced chronic ear edema in mice and decreased CD3+ T cell infiltration of the inflamed tissue. These results suggest that PCG could be a potential candidate for the therapeutics of various immune pathologies.

Growth phase-dependent roles of Sir2 in oxidative stress resistance and chronological lifespan in yeast

Silent Information Regulator 2 (Sir2), a conserved NAD+-dependent histone deacetylase, has been implicated as one of the key factors in regulating stress response and longevity. Here, we report that the role of Sir2 in oxidative stress resistance and chronological lifespan is dependent on growth phase in yeast. In exponential phase, sir2Δ cells were more resistant to H2O2 stress and had a longer chronological lifespan than wild type. By contrast, in post-diauxic phase, sir2Δ cells were less resistant to H2O2 stress and had a shorter chronological lifespan than wild type cells. Similarly, the expression of antioxidant genes, which are essential to cope with oxidative stress, was regulated by Sir2 in a growth phasedependent manner. Collectively, our findings highlight the importance of the metabolic state of the cell in determining whether Sir2 can protect against or accelerate cellular aging of yeast.

Suppression of influenza B virus replication by sakuranetin and mode of its action: Anti-influenza B virus activity of sakuranetin

This study aimed to investigate in vitro the anti‐influenza B/Lee/40 virus effect of sakuranetin and mode of its action. The sakuranetin exhibited potent antiviral activity against influenza B/Lee/40 virus, reducing the formation of a visible cytopathic effect, with a 50% inhibitory concentration (IC50) of 7.21 μg/ml and no cytotoxicity at a concentration of 100 μg/ml, and the derived therapeutic index (TI) was >13.87. Oseltamivir showed weak anti‐influenza B/Lee/40 virus activity with IC50 of 80.74 μg/ml, 50% cytotoxicity concentration of >100 μg/ml, and TI of >1.24. Sakuranetin also showed effective inhibitory effects when added at the viral attachment, entry, and postentry steps. Moreover, sakuranetin effectively inactivated influenza B/Lee/40 virus infection in dose‐ and temperature‐dependent manners. Sakuranetin indicated an inhibitory effect in viral RNA synthesis in the presence of 100 μg/ml of sakuranetin. Overall, this research revealed that sakuranetin could inhibit influenza B/Lee/40 virus replication and that sakuranetin may be involved in the virus attachment, entry, and postentry. Therefore, sakuranetin is a good candidate for a chemopreventive agent for influenza virus‐related diseases.

A Study on Effects of incense smokes of `Cheung-Woon` on Concentration

Objectives : This study aimed to assess the effects of incense smokes of `Cheung-Woon` on the concentration and EEG in healthy individuals. Methods : A total of 48 healthy volunteers participated in this study. The volunteers were examined with K-MAS, CBT(Corsi block tapping task), and EEG before and after smelling the incense smokes of `Cheung-Woon`. K-MAS measured the recalled words, and CBT measured the recalled positions and orders of the color boxes. EEG measured the relative power of wave, wave, SMR wave, mid- wave, high- wave, wave and T(concentraion index T