• Title/Summary/Keyword: therapeutic agents

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Inhibition Effect of Gleditsia Sinensis Lam on T tyrosinase Activity and Reactive Oxygen Species related to Melanin Biosynthesis

  • Kim, Yeon-Zu;Kim, Jin;Park, Hee-Jung;Lee, Chang-Moon;Lee, Ki-Young
    • 한국생물공학회:학술대회논문집
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    • 2005.04a
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    • pp.541-543
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    • 2005
  • Recently many efforts have been made to develop new therapeutic agents against skin pigmentation abnormalities. The aim of this study is to investigate the skin-whitening effect of Gleditsia Sinensis Lam and to develop new drug delivery carrier. Inhibitory effaces of Gleditsia Sinensis Lam extracts on melanin synthesis were studied. Namely, UV-absorbing ability, free radical scavenging activity and tyrosinase inhibitory of Gleditsia Sinensis Lam extracts were investigated As a result, the extracts of Gleditsia Sinensis Lam were found to inhibit the activity of tyrosinase. Moreover they absorbed wavelength in the UV-B and UV-C region, and extracts of Gleditsia Sinensis Lam had free radical scavenging activity. In this study, in order to administer these ingredient effectively, the shape of liposome observed by TEM was spherical and uniform.

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Natural Product Research in Dental Caries Prevention (임상가를 위한 특집 1 - 충치예방과 관련된 천연물(natural products) 연구의 현황)

  • Jeon, Jae-Gyu
    • The Journal of the Korean dental association
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    • v.50 no.9
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    • pp.544-551
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    • 2012
  • Dental caries is a biofilm-related oral disease, and continues to afflict the majority of the world's population. Although fluoride, delivered in various modalities, remains the mainstay for the prevention of caries, additional approaches are required to enhance its effectiveness. Natural products have been used as a major source of innovative and effective therapeutic agents throughout human history, and have shown promise as a source of components for the development of new drugs. In addition. studies using natural products to prevent or treat oral diseases such as dental caries have received a great deal of attention. A number of compounds, such as epicatechin, allicin and sanguinarine, isolated from natural products, have also been investigated for their efficacy against oral microbial pathogens. However, the use of natural products as an anti-caries agent in clinical practice was controversial because of inadequate knowledge concerning their mechanisms of action and chemical characterization. This study focuses on the current knowledge of natural products in dental caries prevention and suggests natural products are importance sources for the prevention of dental caries.

Transcranial Doppler Ultrasonography in Vascular Headaches (혈관성 두통환자에서의 Transcranial Doppler이용)

  • Chung, Chin-Sang;Lee, Hye-Seung
    • Annals of Clinical Neurophysiology
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    • v.1 no.1
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    • pp.76-79
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    • 1999
  • The most significant factor in pathogenesis of vascular headaches like migraine and cluster headache is dynamic changes of diameters of the cerebral arteries. TCD is a valuable noninvasive tool to assess the cerebral hemodynamic status by measuring the flow velocities of the intracranial cerebral arteries around the circle of Willis. TCD can evaluate flow velocities and vasoreactivity of the patients with a vascular headache during the ictal phase as well as during intericatal phase. Distribution of the changes recorded differ between types of headaches and also between the major ictal symptoms. The changes suggest the presence of prolonged vasospasm interictally and more marked relaxation of the cerebral arteries. TCD can be used to monitor the long-term clinical course of patients with vascular headache by correlation the symptomatic improvement and TCD data before and after long-term pharmacological prophylactic treatments. During the ictal phases large intervention. The results may be used in selecting and evaluating the agents for abortive therapy for acute attacks. In conclusion TCD can quantitatively evaluate vascular headaches when making diagnosis and classification and can provide guidelines to choose more individualized therapeutic options for both acute and long-term treatment.

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Radiotracer Methods for Targeted Imaging of the Epidermal Growth Factor Receptor (Epidermal Growth factor 수용체 영상을 위한 방사성추적자 기술)

  • Jung, Kyung-Ho;Lee, Kyung-Han
    • Nuclear Medicine and Molecular Imaging
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    • v.42 no.3
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    • pp.185-191
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    • 2008
  • While indirect targeting strategies using reporter-genes are taking center stage in current molecular imaging research, another vital strategy has long involved direct imaging of specific receptors using radiolabeled ligands. Recently, there is renewal of immense interest in this area with particular attention to the epidermal growth factor receptor (EGFR), a transmembrane glycoprotein critically involved in the regulation of many cellular functions and malignancies. Recently, two novel classes of EGFR-targeting anticancer drugs have entered clinical trials with great expectations. These are monoclonal antibodies such as cetuximab that target the extracellular domain, and small molecule tyrosine kinase inhibitors such as gefitinib (lressa) and erlotinib (Tarceva) that target the catalytic domain of the receptor. However, early results have showed disappointing survival benefits, disclosing a major challenge for this therapeutic strategy; namely, the need to identify tumors that are most likely to respond to the agents. To address this important clinical issue, several noninvasive imaging techniques are under investigation including radiolabeled probes based on small molecule tyrosine kinase inhibitors, anti-EGFR antibodies, and EGF peptides. This review describes the current status, limitations, and future prospects in the development of radiotracer methods for EGFR imaging.

Mercury Contents in Normal Blood of Koreans (우리나라 정상인의 혈중 수은량)

  • Kim, Yong-Sun;Chung, Kyou-Chull
    • Journal of Preventive Medicine and Public Health
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    • v.15 no.1
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    • pp.75-82
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    • 1982
  • Normal range of mercury contents in blood and its relationship with urinary mercury excretion were studies with 68 healthy male adults living in Seoul city, who had no obvious evidence of .either occupational exposure to mercury or therapeutic use of mercurial agents. Mercury analysis was made by means of dithizone colorimetric method with coefficient of variation of 10.9% in .an average ranging from 5.1% to 18.0%. 1. Mercury contents in normal human blood were both normally and log-normally distributed, and better fitted to the latter. 2. Geometric mean and standard deviation of the mercury contents were $24.0(log^{-1}1.38){\pm}1.66{\mu}g/100ml(log^{-1}0.22{\mu}g/100ml)$ ranging from 7.2 to 79.7 ${\mu}g/100ml$ with 95% confidence interval. 3. Mercury contents in normal human blood differed from person to person (p<0.01), and the variability of the measurements was negligible (p>0.05). 4. Mercury in the blood was contained much higher in erythrocytes than in plasma (p<0.01), showing the geometric means of $21.0{\pm}1.25{\mu}g/100ml$ in red blood cells and $14.3{\pm}1.62{\mu}g/100ml$ in plasma, respectively. 5. Mercury contents in normal human blood had a relationship of power function with mercury excretion in urine corrected with a gram of creatinine excretion per liter of urine (p<0.10).

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Development of Macrocyclic Ligands for Stable Radiometal Complexes (안정한 방사금속 착물을 위한 거대고리 리간드 개발)

  • Yoo, Jeong-Soo;Lee, Jae-Tae
    • The Korean Journal of Nuclear Medicine
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    • v.39 no.4
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    • pp.215-223
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    • 2005
  • Current interest in the regioselective N-functionalization of tetraazacycloalkanes (cyclen and cyclam) stems mainly from their complexes with radioactive metals for applications in diagnostic ($^{64}Cu,\;^{111}In,\;^{67}Ga$) and therapeutic ($^{90}Y$) medicine, and with paramagnetic ions for magnetic resonance imaging ($Gd^{+3}$). Selective methods for the N-substitution of cyclen and cyclam is a crucial step in most syntheses of cyclen and cyclam-based radiometal complexes and bifunctional chelating agents. In addition, mixing different pendent groups to give hetero-substituted cyclen derivatives would be advantageous in many applications for fine-tuning the compound's physical properties. So far, numerous approaches for the regioselective N-substitution of tetraazacycloalkanes and more specifically cyclen and cyclam are reported. Unfortunately, none of them are general and every strategy has its own strong points and drawbacks. Herein, we categorize numerous regioselective N-alkylation methods into three strategies, such as 1) direct substitution of the macrocycle, 2) introductiou of the functional groups prior to cyclization, and 3) protection/iunclionallrationideproteclion. Our discussion is also split into the methods of mono- and tri-functionalization and di-functionalizataion based on number of substituents. At the end, we describe new trials for the new macrocycles which iorm more stable metal complexes with various radiometals, and briefly mention the commercially available tetraazacycloalkanes which are used for the biconjugation of biomolecules.

Isolation and Characterization of Psacotheasin, a Novel Knottin-Type Antimicrobial Peptide, from Psacothea hilaris

  • Hwang, Jae-Sam;Lee, June-Young;Hwang, Bo-Mi;Nam, Sung-Hee;Yun, Eun-Young;Kim, Seong-Ryul;Lee, Dong-Gun
    • Journal of Microbiology and Biotechnology
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    • v.20 no.4
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    • pp.708-711
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    • 2010
  • We report the isolation and characterization of a novel knottin-type antimicrobial peptide from the yellow-spotted long-horned beetle Psacothea hilaris. A cDNA encoding a 56-mer knottin-type propeptide was identified and its predicted molecular mass and pI were 5.92 kDa and 8.28, respectively. A 34-mer mature peptide was also selected and named herein as psacotheasin. The antimicrobial activity of chemically synthesized psacotheasin against human bacterial pathogens was subsequently investigated. The results showed that psacotheasin exerted potent activities against both Gram-positive and Gram-negative bacterial strains. The present study suggests that psacotheasin can be applied to develop novel therapeutic agents.

Anti-inflammatory Effect of Indirubin-3'-Monoxime-5-Sulphonic Acid on Lipopolysaccharide-stimulated Murine Macrophage

  • Park, Gang-Baek;Kim, Hyun-Jin;Heo, Hye-Seon;Park, Geun-Mook;Park, Kyung-Woo;Kim, Jin-Kyung
    • Biomedical Science Letters
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    • v.17 no.3
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    • pp.225-230
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    • 2011
  • Indirubin is the active ingredient of Danggui Longhui Wan, a mixture of plants that is used in traditional Chinese medicine to treat chronic diseases. In this study we investigated the anti-inflammatory effects of an indirubin derivative, indirubin-3’-monoxime-5-sulphonic acid (I3M-5S, $C_{16}H_{11}N_3O_5S$). We found that I3M-5S inhibits the production of various inflammatory mediators such as nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$) as well as inflammatory cytokines, tumor necrosis factor-${\alpha}$ and interleukin-6 in lipopolysaccharide (LPS) stimulated murine macrophage, RAW264.7 cells. In addition, the expression of inducible nitric oxide synthase and cyclooxygenase-2, which are essential enzymes to produce NO and $PGE_2$, respectively, was blocked by I3M-5S treatment in LPS-stimulated RAW264.7 cells. Present data suggest that I3M-5S exhibits potent anti-inflammatory activity in cultured macrophages and merit further study as potential therapeutic agents for inflammatory disorders.

Antioxidant Effect of Alisma plantago-aquatica var. orientale and Its Main Component (택사 메탄올 추출물과 주성분의 항산화작용)

  • Kim, Se-Eun;Rhyu, Dong-Young;Yokozawa, Takako;Park, Jong-Cheol
    • Korean Journal of Pharmacognosy
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    • v.38 no.4
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    • pp.372-375
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    • 2007
  • Reactive oxygen species(ROS) or free radicals are produced in the pathogenesis of human diseases including atherosclerosis, diabetes, cancer, and aging. Antioxidants are associated with the prevention of ROS-induced tissue and cellular damage in the various diseases. This study investigated the antioxidative activities of the methanol extract of Alisma plantagoaquatica var. orientale and its main component under conditions of radical generation using allophycocyanin and ferric-thiocyanate assay. Alisol B 23-acetate as a main component was isolated from the methanol extract of Alisma plantago-aquatica var. orientale. In results, the extract of Alisma plantago-aquatica var. orientale showed inhibitory activity on AAPH [2,2'-azobis(2-amidinopropane)dihydrochloride]-induced protein oxidation. Also, the extract of Alisma plantago-aquatica var. orientale and alisol B 23-acetate inhibited lipid peroxidation. These results indicate that Alisma plantago-aquatica var. orientale and alisol B 23-acetate show promise as therapeutic agents for various damages involving free radical reactions.

Inhibition of Melanogenesis by Abietatriene from Vitex Trifolia Leaf Oil

  • Lee, Hong Gu;Kim, Tae Yoon;Jeon, Jung Hoon;Lee, Sang Hwa;Hong, Yoon Ki;Jin, Mu Hyun
    • Natural Product Sciences
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    • v.22 no.4
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    • pp.252-258
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    • 2016
  • Vitex trifolia L. has been used traditionally to treat various illnesses, such as inflammation, headache, migraine, and gastrointestinal infections. We analyzed and evaluated the composition of V. trifolia leaf oil. Based on the results, we isolated abietatriene from V. trifolia leaf oil and investigated the effect of V. trifolia leaf oil and its active compound abietatriene on melanogenesis in B16F10 melanoma cells. They significantly decreased melanin contents and melanogenic factors, such as tyrosinase, TRP-1, TRP-2, and MITF dose-dependently in both protein and mRNA levels. Protein and mRNA expressions were determined by Western blot analysis and quantitative real time RT-PCR. Findings indicate that V. trifolia leaf oil and abietatriene reduce melanogenesis by regulating the expression of melanogenic factors. These results suggest that V. trifolia leaf oil and abietatriene could comprise a useful therapeutic agent for treating hyperpigmentation and used as effective skin-whitening agents.