• Title/Summary/Keyword: Preventive agents

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ROS Scavenger, Ebselen, Has No Preventive Effect in New Hearing Loss Model Using a Cholesterol-Chelating Agent

  • Lee, Min Young;Kabara, Lisa L.;Swiderski, Donald L.;Raphael, Yehoash;Duncan, R. Keith;Kim, Young Ho
    • Journal of Audiology & Otology
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    • v.23 no.2
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    • pp.69-75
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    • 2019
  • Background and Objectives: The antioxidant ebselen will be able to limit or prevent the ototoxicity arising from 2-hydroxypropyl-β-cyclodextrin (HPβCD). Niemann-Pick Type C (NPC) disease is a disorder of lysosomal storage manifested in sphingolipidosis. Recently, it was noted that experimental use of HPβCD could partially resolve the symptoms in both animals and human patients. Despite its desirable effect, HPβCD can induce hearing loss, which is the only major side effect noted to date. Understanding of the pathophysiology of hearing impairment after administration of HPβCD and further development of preventive methods are essential to reduce the ototoxic side effect. The mechanisms of HPβCD-induced ototoxicity remain unknown, but the resulting pathology bears some resemblance to other ototoxic agents, which involves oxidative stress pathways. To indirectly determine the involvement of oxidative stress in HPβCD-induced ototoxicity, we tested the efficacy of an antioxidant reagent, ebselen, on the extent of inner ear side effects caused by HPβCD. Materials and Methods: Ebselen was applied prior to administration of HPβCD in mice. Auditory brainstem response thresholds and otopathology were assessed one week later. Bilateral effects of the drug treatments also were examined. Results: HPβCD-alone resulted in bilateral, severe, and selective loss of outer hair cells from base to apex with an abrupt transition between lesions and intact areas. Ebselen co-treatment did not ameliorate HPβCD-induced hearing loss or alter the resulting histopathology. Conclusions: The results indirectly suggest that cochlear damage by HPβCD is unrelated to reactive oxygen species formation. However, further research into the mechanism(s) of HPβCD otopathology is necessary.

ROS Scavenger, Ebselen, Has No Preventive Effect in New Hearing Loss Model Using a Cholesterol-Chelating Agent

  • Lee, Min Young;Kabara, Lisa L.;Swiderski, Donald L.;Raphael, Yehoash;Duncan, R. Keith;Kim, Young Ho
    • Korean Journal of Audiology
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    • v.23 no.2
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    • pp.69-75
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    • 2019
  • Background and Objectives: The antioxidant ebselen will be able to limit or prevent the ototoxicity arising from 2-hydroxypropyl-β-cyclodextrin (HPβCD). Niemann-Pick Type C (NPC) disease is a disorder of lysosomal storage manifested in sphingolipidosis. Recently, it was noted that experimental use of HPβCD could partially resolve the symptoms in both animals and human patients. Despite its desirable effect, HPβCD can induce hearing loss, which is the only major side effect noted to date. Understanding of the pathophysiology of hearing impairment after administration of HPβCD and further development of preventive methods are essential to reduce the ototoxic side effect. The mechanisms of HPβCD-induced ototoxicity remain unknown, but the resulting pathology bears some resemblance to other ototoxic agents, which involves oxidative stress pathways. To indirectly determine the involvement of oxidative stress in HPβCD-induced ototoxicity, we tested the efficacy of an antioxidant reagent, ebselen, on the extent of inner ear side effects caused by HPβCD. Materials and Methods: Ebselen was applied prior to administration of HPβCD in mice. Auditory brainstem response thresholds and otopathology were assessed one week later. Bilateral effects of the drug treatments also were examined. Results: HPβCD-alone resulted in bilateral, severe, and selective loss of outer hair cells from base to apex with an abrupt transition between lesions and intact areas. Ebselen co-treatment did not ameliorate HPβCD-induced hearing loss or alter the resulting histopathology. Conclusions: The results indirectly suggest that cochlear damage by HPβCD is unrelated to reactive oxygen species formation. However, further research into the mechanism(s) of HPβCD otopathology is necessary.

Structure of SARS-CoV-2 Spike Glycoprotein for Therapeutic and Preventive Target

  • Jaewoo Hong;Hyunjhung Jhun;Yeo-Ok Choi;Afeisha S. Taitt;Suyoung Bae;Youngmin Lee;Chang-seon Song;Su Cheong Yeom;Soohyun Kim
    • IMMUNE NETWORK
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    • v.21 no.1
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    • pp.8.1-8.17
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    • 2021
  • The global crisis caused by the coronavirus disease 2019 (COVID-19) led to the most significant economic loss and human deaths after World War II. The pathogen causing this disease is a novel virus called the severe acute respiratory syndrome coronavirus 2 (SARSCoV-2). As of December 2020, there have been 80.2 million confirmed patients, and the mortality rate is known as 2.16% globally. A strategy to protect a host from SARS-CoV-2 is by suppressing intracellular viral replication or preventing viral entry. We focused on the spike glycoprotein that is responsible for the entry of SARS-CoV-2 into the host cell. Recently, the US Food and Drug Administration/EU Medicines Agency authorized a vaccine and antibody to treat COVID-19 patients by emergency use approval in the absence of long-term clinical trials. Both commercial and academic efforts to develop preventive and therapeutic agents continue all over the world. In this review, we present a perspective on current reports about the spike glycoprotein of SARS-CoV-2 as a therapeutic target.

Evaluation of Environment-friendly Control Agents for the Management of Powdery Mildew Infection during Seedling Stage of Three Cucurbitaceae Vegetables (친환경 육묘시 세 가지 박과채소의 흰가루병에 대한 친환경 제제의 방제효과)

  • Yeo, Kyung-Hwan;Jang, Yoon Ah;Kim, Su;Um, Young Chul;Lee, Sang Gyu;Rhee, Han Cheol
    • Journal of Bio-Environment Control
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    • v.22 no.4
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    • pp.413-420
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    • 2013
  • The purpose of this study was to evaluate the control efficacy of major environment-friendly control agents against powdery mildew, as affected by the application condition such as disease-developing stage and microclimate, as compared with the efficacy of pesticides in plug seedling of three Cucurbitaceae vegetables, including cucumber, melon, and oriental melon. Single or combined application of major six environment-friendly control agents was used in the experiment: two biofungicide (Ampelomyces quisqualis 94013 and Bacillus subtilis Y1336), two plant extracts (neem oil and extracts of Rheum undulatum), and two mineral materials (wettable sulfur powder and lime bordeaux mixture). These control agents were treated to the plug seedlings for preventing powdery mildew and curative applications for managing powdery mildew. In all treatments, the disease incidence declined as daily average temperatures increased to $30^{\circ}C$ for consecutive 6~8 days with maximum temperature over $40^{\circ}C$. In preventative application, the control efficacy against powdery mildew was the highest in the treatment of wettable sulfur powder, and lowest in the B. subtilis Y1336, with values of 20~40%. In cucumber seedlings, the preventive single application of neem oil or wettable sulfur powder was more effective than curative application of fungicides, while the control efficacy of these agents was similar to those of fungicides in melon seedlings. The single application of R. undulatum extracts was also effective in preventing the disease for both cucumber and melon seedlings, showing a higher control efficacy than those of biofungicides during seedling stage. The treatment of water spray was not effective and showed a higher disease incidence than the untreated control plot in the oriental melon and melon seedlings. The curative application with environment friendly control agents, after powdery mildew was first detected, could not successfully controlled the disease at the middle stage (5~10% of disease incidence) of disease development. The curative combined application of [R. undulatum extracts (1st application) + wettable sulfur powder (2nd) + neem oil (3rd)] showed the highest control efficacy among the other treatments, with control value over 80% at the early stage (less than 1% of disease incidence) of disease development.

Pharmacognosy for Korean Medical Food in the 21st Century

  • Kim, Dong-Myong;Cha, Eun-Chung;Chung, Ku-Jeum
    • Preventive Nutrition and Food Science
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    • v.10 no.1
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    • pp.95-102
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    • 2005
  • The term pharmacognosy as applied to a constituent scientific discipline of Korean Medical Food (KMF) has been in use for nearly several years, and it refers to studies on the pharmacological properties of natural products foods. During the last half of the 20th century, pharmacognosy for KMF evolved from being a descriptive botanical subject to one having a more chemical and biological focus. At the beginning of the 21st century, teaching pharmacognosy for KMF teaching in academic culinary arts and natural healing institutions has been given new relevance as a result of the explosive growth in the use of herbal foods (health foods) in modern KMF practice. In turn, pharmacognosy for KMF research areas are continuing to expand, and now include aspects of cellular and molecular biology in relation to natural products, ethnobotany and phytotherapy, in addition to the more traditional analytical method development and phytochemistry. Examples are provided in this review of promising bioactive compounds obtained in two multidisciplinary natural product KMF development and discovery projects, aimed at the elucidation of new plant-derived cancer chemotherapeutic agents and novel cancer chemopreventives, respectively. The systematic study of KMF offers pharmacognosy groups an attractive new area of research, ranging from investigating the biologically active principles of KMF and their mode of action and potential active substance interactions, to sanitary and quality control, and involvement in clinical trials.

Lipoxygenase Inhibition and Antioxidative Activity of Flavonoids from Paeonia moutan Seeds

  • Kim, Hyo-Jin;Chung, Shin-Kyo;Park, Sang-won
    • Preventive Nutrition and Food Science
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    • v.3 no.4
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    • pp.315-319
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    • 1998
  • Previously, the methanolic extract of Paeonia moutan seeds was found to potently inhibit soybean lipoxy-genase (SLO). Hence to isolate SLO inhibitor, the defattd methaniolic extract of the seeds was consecutively partitioned wiht ether, ethyl acetate,n-butanol ,adn water. The ether souble fraction showing strong inhibitory activity against SLO was further fractionated into a strongly acidic, a weakly acidic, and a neutral fractions. The strongly acidic components of the ether extract were successively subjected to chromatography on a silica gel, Sephadex LH-20, and preparative HPLC. Four phenolic compounds were isolated , and twio of them showing a strong SLO inhibition activity were identified as luteolin (IC50=2.32$\mu\textrm{g}$/ml) and 5,6,4'-trihydroxy-7,3'- dimethoxylflavone (IC50=0.31$\mu\textrm{g}$/ml) by UV, IR, 1H-& 13C-NMR, and MS spectroscopy. In addition, two flavonoids showed significantly antioxidative activity as strong as that of of $\alpha$-tocopherol (p<0.05) in the autoxidation system of linoleic acid. These results suggest that luteolin and 5,6,4'-trihydroxy-7,3'-dimethoxy-flavone may be used as a potential source of anti-inflammatory agents with antioxidative activity.

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Anticariogenic Properties of the Ethanol Extract of Pomegranate (Punica granatum) Husk (석류피 에탄올 추출물의 항치아우식 활성)

  • Yu, Yong-Ouk;Yu, Hyeon-Hee
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.21 no.1
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    • pp.199-203
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    • 2007
  • Dental caries is a major worldwide oral disease problem. Streptococcus mutans (S. mutans) plays an important role in the information of dental plaque and it is being noticed as major causative bacteria of dental caries. Therefore, the development of more effective, substantial and safe preventive agents against dental caries is strongly required. In the present study, inhibitory effects of the ethanol extract of the husk of pomegranate (Punica granatum L.) on the growth, acid production, adhesion and water-insoluble glucan synthesis of Streptococcus mutans (S. mutans) were examined. The ethanol extract of pomegranate husk (250 - 4000 ${\mu}$g/ml) significantly lowered the growth of S. mutans in a dose dependent manner. The acid production of S. mutans were inhibited by the presence of ethanol extract of pomegranate husk (500 - 4000 ${\mu}$g/ml) significantly. The ethanol extract of pomegranate husk (5000 - 4000 ${\mu}$g/ml) also significantly lowered the adherence of S. mutans. In water-insoluble glucan synthesis assay, 1000 - 4000 ${\mu}$g/ml of the ethanol extract of pomegranate husk significantly inhibited the formation of water-insoluble glucan. These results suggest that pomegranate husk may inhibit the caries-inducing properties of S. mutans. Further studies are necessary to clarify the active constituents of pomegranate husk responsible for such biomolecular activities.

Arthroscopic Treatment of Mixed Pyogenic and Tuberculous Arthritis of Shoulder Joint (견관절의 화농성 및 결핵성 복합 관절염의 관절경적 치료 - 증례보고 -)

  • Ko, Sang-Bong;Kim, Shin-Keun;Choi, Won-Kee;Park, Jae-Hyun;Choi, Chang-Hyuk
    • Journal of the Korean Arthroscopy Society
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    • v.12 no.2
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    • pp.129-133
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    • 2008
  • Although the incidence of tuberculosis has been decreased due to new anti-tuberculous agents, improved socioeconomic status and development of multimodal preventive methods, in recent that is increased due to low vaccination rate and appearance of multidrug resistence organism. And the incidence of pyogenic shoulder joint arthritis is increasing due to frequent injection therapy as primary treatment. We have managed the mixed shoulder joint arthritis-pyogenic and tuberculous-with arthroscopic debridement and antituberculous medication successfully and then we report this case with relevant literatures.

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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.

Anti-oxidant Activity of Saussurea lappa C.B. Clarke Roots

  • Chang, Kyung-Mi;Choi, Soo-Im;Kim, Gun-Hee
    • Preventive Nutrition and Food Science
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    • v.17 no.4
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    • pp.306-309
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    • 2012
  • This study was performed to investigate the potential use of Saussurea lappa C.B. Clarke as a source of antioxidant agents. Various solvent fractionates from S. lappa C.B. Clarke roots were investigated for their anti-oxidative effectiveness. The contents of total phenolics and flavonoids were determined by the Folin-Ciocalteu's colorimetric and the aluminum nitrate method, respectively. Total phenolic and flavonoid contents of n-butanol soluble fractionates from S. lappa C.B. Clarke, 44.43 ${\mu}g$ gallic acid equilibrium (GAE)/g extract and 92.15 ${\mu}g$ quercetin equilibrium (QE)/g extract, respectively, were higher than those of other solvent fractionates. The n-butanol soluble fractionates of S. lappa C.B. Clarke (1,000 ppm) showed the strongest inhibitory potential on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and reducing power at 92.98% and 0.38, respectively. Thus, our data shows that the S. lappa C.B. Clarke plant may help prevent antioxidative stress.