• Title/Summary/Keyword: screening of natural products

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Practices of Antitumor Screening Tests for Natural Products (천연항종양성자원 とスクリニングの 실제)

  • 코이치
    • Korean Journal of Plant Resources
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    • v.5 no.2
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    • pp.95-103
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    • 1992
  • Present anticancer drugs in the clinical side have not showed a conclusive effect of the chemotherapy for cancer patients. In order to find much more efficient antitumor agents fromnatural resources, various screening methods vivo and in vitro have been developed by manyresearchers. The intention of this paper is to provide an outline of some background on the tumorsystem in drug development of natural products, to review some screening programs for theevaluation of antitumor activity and to introduce the practical procedures of some antitumorscreening methods in vivo and in vitro. At the end of this paper, the current literatures related toantitumor natural products from higher plants at our laboratory are described.Key words'anticancer drugs, screening methods.

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A DNA Strand-Nicking Principle of a Higher Plant, Caesalpinia sappan

  • Mar, Woongchon;Lee, Hyun-Tai;Je, Kang-Hoon;Choi, Hye-Young;Seo, Eun-Kyoung
    • Archives of Pharmacal Research
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    • v.26 no.2
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    • pp.147-150
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    • 2003
  • To find anticancer agents from higher plants, DNA strand-scission assay method was employed for bioassay-guided fractionation as well as for screening the crude extracts. During the screening, an ethyl acetate extracts of the heartwood of Caesalpinia sappan L. (Leguminosae) exhibited potent DNA strand-scission activity. Therefore, the ethyl acetate extracts of the dried heartwood of C. sappan was subjected to the bioassay-guided fractionation, which led to the isolation of a known compound, brazilin (1) as the active constituent. In addition, caesalpine J (2) was also isolated as an inactive constituent.

Evaluation of Telomerase Inhibitors Using DE81 Filter Spotting Method from Natural Products

  • Lee, Sung-Jin;Woongchon Mar
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1998.11a
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    • pp.183-183
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    • 1998
  • Telomerase synthesizes telomeric DNA repeats onto chromosome ends de novo. Telomerase activation and telomere shortening in human somatic cells have been implicated in cell tumorigenesis and immortalization. In order to find the potential inhibitors against telomerase activitiy which can be used as potential anticancer agents, we screened about 100 kinds of natural products after partition into n-hexane, ethyl acetate and aqueous layers from methanol extracts. The inhibitory effects of these materials against telomerase enzyme activity were tested in 293T cell culture using telomeric repeat amplification protocol(TRAP). The incorporation of $\^$32/P-dGTP into amplified DNA was measured by adsorption to Whatman DE81 paper instead of using TRAP assay for screening the extracts of natural products. Strong effective compounds were not found in this study but DE81 filter spotting method may be a useful model for the screening. Some of the compounds which showed somewhat inhibitory effects had cytotoxic effects also.

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Screening of $5{\alpha}-Reductase$ Inhibition and Comedolytic Effects from Natural Products (천연물로부터 $5{\alpha}-Reductase$ 활성억제 및 면포용해효과의 검색)

  • 최승만;김창덕;이민호;최영호;랑문정;안호정;윤여표
    • YAKHAK HOEJI
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    • v.43 no.3
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    • pp.342-350
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    • 1999
  • The antibacterial activity against Propionibacterium acnes (P. acnes), $5{\alpha}-reductase$ inhibition and comedolytic effects are the important pharmacological target sites of antiacne drughs. We previously reported on the antibacterial activities against P. acnes by natural products. In the present study the screening of $5{\alpha}-reductase$ inhibition and comedolytic effects from natural products were performed. Seven natural products such as Angelica koreana, Sophora flavescens, Prunus persica, Bombyx mori, Areca catechu, Galla rhois and Gleditschia koraiensis perfectly inhibited the activity of $5{\alpha}-reductase$ at the concentration of 0.01% (w/v). Sixteen natural products which were shown to have the potent antibacterial activities against P.acnes or $5{\alpha}-reductase$ inhibition activities were assayed for the comedolytic test. In the results of comedolytic effects on experimentally-induced comedones (EIC), Sophora flavescens showed the strongest comedolytic effect on EIC, and Polygonum cuspidatum and Angelica koreana showed stronger comedolytic effects on EIC than azelaic acid used for a positive control at the concentration of 3% (w/v). These results suggest that several natural products including Sophora flavescens can be developed as noble antiacne agents.

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Development of New Antitumor Drugs from Natural Sources , with Guida (항종양활성 Screening을 지표로 한 천연물의약품의 개발연구와 그 생약소재의 품질평가에 대하여(抗腫瘍活性スクリ-ニングを指標とした天然物醫藥品の開發硏究とその生約素材の品質評價について))

  • Takeya, Koichi
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 1993.08a
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    • pp.14-20
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    • 1993
  • We in anticancer drug development from natural resources have conceived and used a wide variety of experimental screening systems to support our efforts during the past 20 tears. Screens have been devided to address targets at the molecular, biochemical and cellular levels, both in vivo and in vitro. Screens have been essential for the experimental evaluation of the products from natural sources. In this congress, antitumor screening methods for deveol[ment of new drugs from natural sources and evaluation of their crude drugs are discussed.

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