• 제목/요약/키워드: Biological Agents

검색결과 901건 처리시간 0.027초

DIFFERENT EFFECTS OF QUERCETIN ON MATRIX METALLOPROTEINASES EXPRESSION IN EARLY AND LATE PASSAGE HUMAN FIBROBLASTS

  • Eum, Sung-Yong;Oh, Jang-Hee;Park, Jong-Min;Chung, An-Sik
    • 한국독성학회:학술대회논문집
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    • 한국독성학회 2001년도 International Symposium on Dietary and Medicinal Antimutgens and Anticarcinogens
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    • pp.158-158
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    • 2001
  • Bioflavonoids have been regarded as therapeutic agents for a wide range of disease including cancer. The increase of matrix metalloproteinases expression is a key event in several pathological conditions, e.g., dermal photocarcinogenesis, tumor initiation, invasion and metastasis. In this study, we investigated effects of quercetin, a major bioflavonoid in human diet, on matrix metalloproteinase (MMR)-1, MMP-2, MMP-3, MMP-9 mRNA expression during cellular aging in cultured human foreskin fibroblast. (omitted)

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Sulforaphane Inhibits Osteoclastogenesis by Inhibiting Nuclear Factor-κB

  • Kim, Soo-Jin;Kang, So-Young;Shin, Hyun-Hee;Choi, Hye-Seon
    • Molecules and Cells
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    • 제20권3호
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    • pp.364-370
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    • 2005
  • We show that sulforaphane inhibits osteoclastogenesis in the presence of macrophage colony-stimulating factor (M-CSF) and receptor for activation of nuclear factor-${\kappa}B$ ligand (RANKL) in osteoclast (OC) precursors. Sulforaphane, an aliphatic isothiocyanate, is a known cancer chemo-preventative agent with anti-oxidative properties. Nuclear factor-${\kappa}B$ (NF-${\kappa}B$) is a critical transcription factor in RANKL-induced osteoclastogenesis, and electrophoretic mobility shift assays (EMSAs) and assay of NF-${\kappa}B$-mediated secreted alkaline phosphatase (SEAP) revealed that sulforaphane selectively inhibited NF-${\kappa}B$ activation induced by RANKL. Inhibition may involve interaction of sulforaphane with thiol groups, since it was prevented by reducing agents.

Characterization of Protein Factor Regulating the Superoxide-Sensor SoxR in Escherichia coli

  • Koo, Mi-Sun;Rah, So-Yeon;Lee, Kang-Lok;Roe, Jung-Hye
    • 한국생물물리학회:학술대회논문집
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    • 한국생물물리학회 2001년도 학술 발표회 진행표 및 논문초록
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    • pp.64-64
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    • 2001
  • Escherichia coli has developed soxRS regulon to defend against toxicity of superoxide radical. SoxR, superoxide sensor, is oxidized by superoxide-generating agents or nitric oxide and oxidized SoxR activates the transcription of soxS gene. In order to find out the trans-acting factors regulating SoxR activity in vivo, soxS::lacZ single copy operon fusion construct was prepared and random Tn10 insertional mutatons were performed.(omitted)

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생물테러리즘의 위기관리방안 (The Countermeasure to the Stages of Crisis Management in the Bioterrorism)

  • 이광렬
    • 한국콘텐츠학회:학술대회논문집
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    • 한국콘텐츠학회 2009년도 춘계 종합학술대회 논문집
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    • pp.608-613
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    • 2009
  • 이 연구는 생물테러리즘을 위기로 인식하고 생물테러리즘을 위기관리별로 어떻게 관리할 것인가에 대한 관리방안을 연구하는데 그 목적이 있다. 9.11 테러 이후 발생한 탄저균 테러는 전 세계에 생물병원체에 의한 공포감을 인식시켜 주었으며, 그 위험성이 강조된 사례이다. 본 연구결과 생물테러리즘 위기는 4단계로 구분하여 관리할 때 완화 및 예방단계에서는 테러리즘의 기준을 정하고, 대비를 하기 위하여 테러관련 법을 제정하고, 조기발견을 위한 감시체계를 확보해야 한다. 대비단계에서는 초동조치팀을 편성하고 교육훈련을 통해 대응하는 요령을 숙달시켜야 하며, 각종 자원을 확보해야 한다. 대응단계에서는 숙달된 초동조치팀이 즉각 투입되어 현장 정리 및 확산을 방지해야 하며, 복구단계에서는 평가체제를 구축하여 조기에 정상적인 생활로 복귀할 수 있도록 조치해야 한다.

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Antimicrobial and Anti-Biofilm Activities of the Methanol Extracts of Medicinal Plants against Dental Pathogens Streptococcus mutans and Candida albicans

  • Choi, Hyoung-An;Cheong, Dae-Eun;Lim, Ho-Dong;Kim, Won-Ho;Ham, Mi-Hyoun;Oh, Myung-Hwan;Wu, Yuanzheng;Shin, Hyun-Jae;Kim, Geun-Joong
    • Journal of Microbiology and Biotechnology
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    • 제27권7호
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    • pp.1242-1248
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    • 2017
  • Several medicinal plants are ethnomedically used in Korea as agents for treating infection, anti-inflammation, and pain relief. However, beyond typical inhibitory effects on cell growth, little is known about the potential anti-biofilm activity of these herbs, which may help to prevent cavities and maintain good oral health. This study aimed to investigate the antimicrobial and anti-biofilm activities of the methanol extracts of 37 Korean medicinal plants against dental pathogens Streptococcus mutans and Candida albicans, which synergize their virulence so as to induce the formation of plaque biofilms in the oral cavity. The antimicrobial activities were investigated by broth dilution and disk diffusion assay. The anti-biofilm and antioxidant activities were evaluated based on the inhibitory effect against glucosyltransferase (GTase) and the DPPH assay, respectively. Among 37 herbs, eight plant extracts presented growth and biofilm inhibitory activities against both etiologic bacteria. Among them, the methanol extracts (1.0 mg/ml) from Camellia japonica and Thuja orientalis significantly inhibited the growth of both bacteria by over 76% and over 83% in liquid media, respectively. Minimum inhibitory concentration (MIC) values of these methanol extracts were determined to be 0.5 mg/ml using a disk diffusion assay on solid agar media. Biofilm formation was inhibited by more than 92.4% and 98.0%, respectively, using the same concentration of each extract. The present results demonstrate that the medicinal plants C. japonica and T. orientalis are potentially useful as antimicrobial and anti-biofilm agents in preventing dental diseases.

Efficacy of Chaetomium Species as Biological Control Agents against Phytophthora nicotianae Root Rot in Citrus

  • Phung, Manh Hung;Wattanachai, Pongnak;Kasem, Soytong;Poeaim, Supattra
    • Mycobiology
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    • 제43권3호
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    • pp.288-296
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    • 2015
  • Thailand is one of the largest citrus producers in Southeast Asia. Pathogenic infection by Phytophthora, however, has become one of major impediments to production. This study identified a pathogenic oomycete isolated from rotted roots of pomelo (Citrus maxima) in Thailand as Phytophthora nicotianae by the internal transcribed spacer ribosomal DNA sequence analysis. Then, we examined the in vitro and in vivo effects of Chaetomium globosum, Chaetomium lucknowense, Chaetomium cupreum and their crude extracts as biological control agents in controlling this P. nicotianae strain. Represent as antagonists in biculture test, the tested Chaetomium species inhibited mycelial growth by 50~56% and parasitized the hyphae, resulting in degradation of P. nicotianae mycelia after 30 days. The crude extracts of these Chaetomium species exhibited antifungal activities against mycelial growth of P. nicotianae, with effective doses of $2.6{\sim}101.4{\mu}g/mL$. Under greenhouse conditions, application of spores and methanol extracts of these Chaetomium species to pomelo seedlings inoculated with P. nicotianae reduced root rot by 66~71% and increased plant weight by 72~85% compared to that in the control. The method of application of antagonistic spores to control the disease was simple and economical, and it may thus be applicable for large-scale, highly effective biological control of this pathogen.

Biologic response of local hemostatic agents used in endodontic microsurgery

  • Jang, Youngjune;Kim, Hyeon;Roh, Byoung-Duck;Kim, Euiseong
    • Restorative Dentistry and Endodontics
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    • 제39권2호
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    • pp.79-88
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    • 2014
  • Appropriate use of local hemostatic agent is one of the important factors on the prognosis of endodontic microsurgery. However, most investigations to date focus on the hemostatic efficacy of the agents, whereas their biologic characteristics have not received enough attention. The purpose of this paper was to review the biologic response of local hemostatic agents, and to provide clinical guidelines on their use during endodontic microsurgery. Electronic database (PUBMED) was screened to search related studies from 1980 to 2013, and 8 clinical studies and 18 animal studies were identified. Among the materials used in these studies, most widely-investigated and used materials, epinephrine, ferric sulfate (FS) and calcium sulfate (CS), were thoroughly discussed. Influence of these materials on local tissue and systemic condition, such as inflammatory and foreign body reaction, local ischemia, dyspigmentation, delayed or enhanced bone and soft tissue healing, and potential cardiovascular complications were assessed. Additionally, biological property of their carrier materials, cotton pellet and absorbable collagen, were also discussed. Clinicians should be aware of the biologic properties of local hemostatic agents and their carrier materials, and should pay attention to the potential complications when using them in endodontic microsurgery.

Novel Approaches for Efficient Antifungal Drug Action

  • Lee, Heejeong;Lee, Dong Gun
    • Journal of Microbiology and Biotechnology
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    • 제28권11호
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    • pp.1771-1781
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    • 2018
  • The emergence of multidrug-resistant microorganisms, as well as fungal infectious diseases that further threaten health, especially in immunodeficient populations, is a major global problem. The development of new antifungal agents in clinical trials is inferior to the incidence of drug resistance, and the available antifungal agents are restricted. Their mechanisms aim at certain characteristics of the fungus in order to avoid biological similarities with the host. Synthesis of the cell wall and ergosterol are mainly targeted in clinical use. The need for new approaches to antifungal therapeutic agents or development alternatives has increased. This review explores new perspectives on mechanisms to effectively combat fungal infections and effective antifungal activity. The clinical drug have a common feature that ultimately causes caspase-dependent cell death. The drugs-induced cell death pathway is associated with mitochondrial dysfunction, including mitochondrial membrane depolarization and cytochrome c release. This mechanism of action also reveals antimicrobial peptides, the primary effector molecules of innate systems, to highlight new alternatives. Furthermore, drug combination therapy is suggested as another strategy to combat fungal infection. The proposal for a new approach to antifungal agents is not only important from a basic scientific point of view, but will also assist in the selection of molecules for combination therapy.

Terpenes from Forests and Human Health

  • Cho, Kyoung Sang;Lim, Young-ran;Lee, Kyungho;Lee, Jaeseok;Lee, Jang Ho;Lee, Im-Soon
    • Toxicological Research
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    • 제33권2호
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    • pp.97-106
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    • 2017
  • Forest bathing has beneficial effects on human health via showering of forest aerosols as well as physical relaxation. Terpenes that consist of multiple isoprene units are the largest class of organic compounds produced by various plants, and one of the major components of forest aerosols. Traditionally, terpene-containing plant oil has been used to treat various diseases without knowing the exact functions or the mechanisms of action of the individual bioactive compounds. This review categorizes various terpenes easily obtained from forests according to their anti-inflammatory, anti-tumorigenic, or neuroprotective activities. Moreover, potential action mechanisms of the individual terpenes and their effects on such processes, which are described in various in vivo and in vitro systems, are discussed. In conclusion, the studies that show the biological effectiveness of terpenes support the benefits of forest bathing and propose a potential use of terpenes as chemotherapeutic agents for treating various human diseases.