• Title/Summary/Keyword: Research Activity

Search Result 21,839, Processing Time 0.044 seconds

Anti-complement Activity of Flavonoids from Litsea japonica

  • Lee, Sun-Young;Min , Byung-Sun;Kim, Jung-Hee;Moon, Hyung-In;Lee, Joong-Ku;Kim, Tae-Jin;Kim, Young-Ho;Lee, Hyeong-Kyu
    • Proceedings of the PSK Conference
    • /
    • 2002.10a
    • /
    • pp.372.1-372.1
    • /
    • 2002
  • AIzelin (1) and quercitrin (2) isolated from the EtOAc-soluble fraction of the leaves of Litsea japonica Jussieu (Lauraceae) showed inhibitory activity against classical pathway complement system with 50% inhibitory concentration ($IC_{50}$/) values of 112.2 and 198.2 $\mu\textrm{g}$/$m\ell$. respectively. For the structure-activity relationship of flavonoids on anti-complement system. myricitrin (3) from JUQ/ans mandshurica Maximowicz (Juglandaceae) also tested anti-complement activity. while this was devoid of any significant activity. (omitted)

  • PDF

Long term activity measurement of the primary circuit water on the LVR-15 research reactor

  • Ladislav Viererbl;Vit Klupak;Hana Assmann Vratislavska
    • Nuclear Engineering and Technology
    • /
    • v.56 no.4
    • /
    • pp.1250-1253
    • /
    • 2024
  • Activity measurement of the primary circuit water of fission reactors is one method that can provide early detection of a damaged fuel assembly in the reactor core. This is an important aspect in the safe operation of the reactor and for radiation protection of staff. Radionuclides in the primary circuit water are produced by the activation of stable nuclides and the fission of fissile nuclides, mainly the isotope 235U. In the LVR-15 research reactor, measurement of the activity of the primary circuit water has been regularly undertaken since 1996. A water sample is taken from the primary circuit every week and the activities are measured four days later using gamma spectrometry. The results of these long-term measurements from 1996 to 2022 are presented. The activity time dependences of the individual radionuclides are discussed in relation to fuel assembly damage and for events connected to contamination of the water by objects inserted into the primary circuit during experiments carried out near the reactor core.

Antifungal Activities of Magainin-2 Hybrid Peptides against Trichosporon beigelii

  • LEE, DONG GUN;SONG YUB SHIN;SUNG GU LEE;KIL LYONG KIM;MYUNG KYU LEE;KYUNG SOO HAHM
    • Journal of Microbiology and Biotechnology
    • /
    • v.7 no.1
    • /
    • pp.49-51
    • /
    • 1997
  • In order to obtain a hybrid synthetic peptide with a more potent antifungal activity than magainin-2 but without hemolytic activity, four hybrid peptides were designed from the sequences of magainin 2 and cecropin A and their antifungal activities against Trichosporon beigelii were investigated. The result showed that analogue 2 and 4 exhibited better antifungal activity against T. beigelii than magainin-2 but no hemolytic activities. The peptides, therefore, could be used as models for the development of potent antifungal peptides.

  • PDF

STUDIES OF ACNE TREATMENT USING ORIENTAL HERBS(New Approach to select anti-acne agents)

  • Nam, Chun-Ja;Han, Y.G.;Kim, S.J.;Kim, J.H.;Oh, J.Y.;Park, J.W.;Lee, H.
    • Journal of the Society of Cosmetic Scientists of Korea
    • /
    • v.25 no.4 s.34
    • /
    • pp.111-121
    • /
    • 1999
  • Acne vulgaris, the most common skin disease. can be formed as only a few comedons or severe inflammatory lesions. The pathogenesis of acne involves various factors; excessive androgen, excessive sebum production, abnormal alteration of follicular epithelium, proliferation of Propionibacterium acnes, and inflammation. We investigated acne therapy using oriental herbs described in the Korean traditional medical book(Dong-ui-bo-gam). Oriental herbs(Angelica daurica, Arctium lappa, Coptidis rhizoma, and Glycyrrhiza glabra) were chosen based on their respective property of sebum control, anti-inflammatory activity, and anti-bacterial activity. We examined the effect of acne treatment, in terms of chemotactic inhibition, lipogenesis inhibition, and anti-bacterial activity for P. acnes. 1. Neutrophil chemotaxis assay; P. acnes secrete chemotactic factors and other pro-inflammatory extracellular products. Neutrophil chemotactic activity of P. acnes was measured by 48-well chemotaxis method. Angelica daurica clearly suppressed chemotactic activity of P. acnes. 2. Using sebaceous gland of hamster ear lipogenesis assay; Sebaceous lipogenesis was measured using ear biopsies by incubation or $C^{14}$-acetate in culture media. The $C^{14}$-labeled lipids were extracted and determined by liquid scintilation counting. Coptidis rhizoma markedly inhibited sebum production. 3. Anti-bacterial assay for P. acnes(MIC test); Glycyrrhiza glabra showed anti-bacterial activity. P. acnes did not develop resistance against Glycyrrhiza glabra. Retinoids are effectively to inhibit sebum production and regulate follicular keratinization process, with little anti-inflammatory activity. Angelica daurica suppressed neutrophil chemotaxis, Coptidis rhizoma inhibited sebum production, and Glycyrrhiza glabra showed anti-bacterial activity against P. acnes. A combined formulation of Angelica daurica, Coptidis rhizoma. and Glycyrrhiza glabra is expected to provide effective acne treatment.

  • PDF

Reduced Anti-inflammatory Activity of Acetylsalicylic Acid Maltol Ester, Aspalatone

  • Han, Byung-Hoon;Suh, Dae-Yeon;Yang, Hyun-Ok;Lee, Song-Jin;Kim, Hyun-Pyo
    • Archives of Pharmacal Research
    • /
    • v.17 no.3
    • /
    • pp.166-169
    • /
    • 1994
  • The anti-inflammatory activity of acetylsalicylic acid maltol ester (aspalatone), a potential anti-thombotic agent, was studied using the several experimental animal models of inflammation. By oral administration, aspalatone was found to possess the weak anti-inflammatory activity in models of an acute inflammation, in which aspalatone showed approximately one-third to one-fourth of the anti-inflammatory activity of aspirin. Aspalatone (200 mg/kg/day) and aspirin (50 mg/kg/day), however, did not show the inhibitory activity against granuloma fomation and adjuvant-induced arthritis.

  • PDF

Synthesis and In Vitro Antibacterial Activity of Quaternary Ammonium Cephalosporin Derivatives Bearing Oxazolidinone Moiety

  • Chung, In-Hwa;Kim, Choong-Sup;Seo , Jae-Hong;Chung, Bong-Young
    • Archives of Pharmacal Research
    • /
    • v.22 no.6
    • /
    • pp.579-584
    • /
    • 1999
  • Several oxazolidinones having amine moiety were prepared to form a quaternay ammonium salt with cephalosporin nucleus, and antibacterial activity of the quaternary ammonium cephalosporin derivatives bearing oxazolidinone moiety were examined particularly with expectation of dual activity. However, the cephalosporin-oxazolidinone compounds revealed rather weaker antibacterial activity in vitro than their parent oxazolidinone and cephalosporin without showing any characteristic activity as expected.

  • PDF

Studies on Biological Activity of Wood Extractives(XIV) - Antifungal activity of isoflavonoids -

  • Park, Youngki;Lee, Sung-Suk;Lee, Hak-Ju;Choi, Don-Ha
    • Journal of the Korean Wood Science and Technology
    • /
    • v.31 no.3
    • /
    • pp.70-76
    • /
    • 2003
  • Five isoflavonoids, biochanin A-7-O-β-D-xylopyranosyl-(1⟶6)-β-D-gluco- pyranoside (1), (-)-maackiain (2), calycosin (3), trifolirhizin (4) and genistein (5), were tested for antifungal activity against nine fungi. These compounds were isolated from the wood (compound 1 and 2) and from the bark (compound 3, 4 and 5) of S. japonica. According to the results of antifungal activity test, (-)-maackiain was evaluated as the best antifungal compound among the isolated compounds. In this regard, it could be mentioned that high antifungal activity of S. japonica wood extracts was originated from (-)-maackiain.

Differential Effects of Tautomycetin and Its Derivatives on Protein Phosphatase Inhibition, Immunosuppressive Function and Antitumor Activity

  • Niu, Mingshan;Sun, Yan;Liu, Bo;Tang, Li;Qiu, Rongguo
    • The Korean Journal of Physiology and Pharmacology
    • /
    • v.16 no.2
    • /
    • pp.145-151
    • /
    • 2012
  • In the present work, we studied the structure-activity relationship (SAR) of tautomycetin (TMC) and its derivatives. Further, we demonstrated the correlation between the immunosuppressive fuction, anticancer activity and protein phosphatase type 1 (PP1) inhibition of TMC and its derivatives. We have prepared some TMC derivatives via combinatorial biosynthesis, isolation from fermentation broth or chemical degradation of TMC. We found that the immunosuppressive activity was correlated with anticancer activity for TMC and its analog compounds, indicating that TMC may home at the same targets for its immunosuppressive and anticancer activities. Interestingly, TMC-F1, TMC-D1 and TMC-D2 all retained significant, albeit reduced PP1 inhibitory activity compared to TMC. However, only TMC-D2 showed immunosuppressive and anticancer activities in studies carried out in cell lines. Moreover, TMC-Chain did not show any significant inhibitory activity towards PP1 but showed strong growth inhibitory effect. This observation implicates that the maleic anhydride moiety of TMC is critical for its phosphatase inhibitory activity whereas the C1-C18 moiety of TMC is essential for the inhibition of tumor cell proliferation. Furthermore, we measured $in$ $vivo$ phosphatase activities of PP1 in MCF-7 cell extracts treated with TMC and its related compounds, and the results indicate that the cytotoxicity of TMC doesn't correlate with its $in$ $vivo$ PP1 inhibition activity. Taken together, our study suggests that the immunosuppressive and anticancer activities of TMC are not due to the inhibition of PP1. Our results provide a novel insight for the elucidation of the underlying molecular mechanisms of TMC's important biological functions.

In vitro Antioxidative Properties of Lactobacilli

  • Kim, H.S.;Chae, H.S.;Jeong, S.G.;Ham, J.S.;Im, S.K.;Ahn, C.N.;Lee, J.M.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.19 no.2
    • /
    • pp.262-265
    • /
    • 2006
  • The antioxidative properties of lactobacilli originating from humans (Lactobacillus acidophilus KCTC 3111, Lactobacillus jonsonii KCTC 3141, Lactobacillus acidophilus KCTC 3151, and Lactobacillus brevis KCTC 3498) were investigated using in vitro methods, including inhibition of lipid peroxidation, resistance to hydrogen peroxide and hydroxyl radical, hydroxyl radical scavenging activity, and glutathione peroxidase (GPX) activity. L. acidophilus KCTC 3111 showed the highest inhibition of lipid peroxidation in both intact cells (49.7%) and cell lysate (65.2%). This strain exhibited resistance to hydrogen peroxide and hydroxyl radical, which was viable for 7 h in the concentration of 1.0 mM hydrogen peroxide. In addition, this strain showed high hydroxyl radical scavenging activity. In the GPX activity assay, the highest activity was measured in L. brevis 3498. GPX activity of L acidophilus 3111 was lower than that of L. brevis 3498.

Anti-melanogenesis Effects of Schizophragma hydrangeoides Leaf Ethanol Extracts via Downregulation of Tyrosinase Activity

  • Hyun, Ho Bong;Hyeon, Hye Jin;Kim, Sung Chun;Go, Boram;Yoon, Seon-A;Jung, Yong-Hwan;Ham, Young-Min
    • Korean Journal of Plant Resources
    • /
    • v.34 no.6
    • /
    • pp.510-516
    • /
    • 2021
  • Whitening agents derived from natural sources which do not have side effects are sought after. Schizophragma hydrangeoides is an edible plant that grows wild on Jeju Island. We aimed to determine whether S. hydrangeoides extracts show anti-melanogenic activity. Here, we found that 70% ethanol extracts of S. hydrangeoides leaf suppressed α-melanocyte-stimulating hormone-induced melanogenesis in B16F10 mouse melanoma cells. This activity of anti-melanogenesis in B16F10 cells were investigated by determining melanin content and tyrosinase activity, and by performing western blotting. The 70% ethanol extract downregulated tyrosinase and tyrosinase-related protein 1. In addition, the n-hexane fraction of S. hydrangeoides leaf (HFSH) exhibited significant anti-melanogenic activity among the various solvent fractions tested without reducing the viability of B16F10 cells. Taken together, these results indicate that extracts from S. hydrangeoides leaf can influence cellular processes via modulation of tyrosinase activity. Hence, S. hydrangeoides can be used as a whitening agent in the cosmetic industry and as a therapeutic agent for treating hyperpigmentation disorders in the clinic.