• 제목/요약/키워드: Xenobiotics

검색결과 155건 처리시간 0.029초

Free radical scavenging phenolic compounds of the leaves of Juglans sinensis

  • Kim, Mi-Hee;Ko, Eun-Kyung;Jun, Jung-Yang;Li-Xun;Oh, Myung-Hun;An, Nyeon-Hyoung;Kim, Youn-Chul
    • 대한약학회:학술대회논문집
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    • 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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    • pp.381.3-382
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    • 2002
  • Free radical-mediated cell damage and free radical attack on polyunsaturated fatty acids result in the formation of lipid radicals. These lipid radicals react readily with molecular oxygen to produce peroxy radicals responsible for initiating lipid peroxidation. The peroxidation of cellular membrane lipid can lead to cell necrosis and considered to be implicated in a number of pathophysiological conditions as well as in the toxicity of many xenobiotics. DPPH is known to abstract labile hydrogen and the ability to scavenge the DPPH radical is related to the inhibition of lipid peroxidation. (omitted)

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Does Agitation Condition Affect the Correlation Between in vitro Permeability of Xenobiotics across Caco-2 Cells and in vivo Bioavailability of the Compounds\ulcorner

  • Yoo, Ho-Jung;Kim, In-Wha;Hong, Soon-Sun;Chung, Suk-Jae;Shim, Chang-Koo
    • 대한약학회:학술대회논문집
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    • 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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    • pp.419.2-420
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    • 2002
  • Caco-2 is a cell line derived from the human colon adenocarcinoma and often used as a model for studying intestinal drug absorption. It has been well-known that a strong correlation holds between in vitro permeability across Caco-2 cell monolayers and in vivo bioavailability for various drugs. but the correlation curves varied depending on laboratories. The permeabilities of drugs across Caco-2 cell monolayers have been measured under different agitation conditions. (omitted)

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Environmental Factors and Bioremediation of Xenobiotics Using White Rot Fungi

  • Magan, Naresh;Fragoeiro, Silvia;Bastos, Catarina
    • Mycobiology
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    • 제38권4호
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    • pp.238-248
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    • 2010
  • This review provides background information on the importance of bioremediation approaches. It describes the roles of fungi, specifically white rot fungi, and their extracellular enzymes, laccases, ligninases, and peroxidises, in the degradation of xenobiotic compounds such as single and mixtures of pesticides. We discuss the importance of abiotic factors such as water potential, temperature, and pH stress when considering an environmental screening approach, and examples are provided of the differential effect of white rot fungi on the degradation of single and mixtures of pesticides using fungi such as Trametes versicolor and Phanerochaete chrysosporium. We also explore the formulation and delivery of fungal bioremedial inoculants to terrestrial ecosystems as well as the use of spent mushroom compost as an approach. Future areas for research and potential exploitation of new techniques are also considered.

생강 뿌리썩음증상의 병징학, 기생체간 상호작용 및 약제방제 (Symptomatology, Interacton and Management of Rhizome Rot of Ginger by Xenobiotics)

  • 도쉬;마투르
    • 한국응용곤충학회지
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    • 제26권4호
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    • pp.261-265
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    • 1987
  • 뿌리썩음증상은 병징에 따라 3가지로 대별되었다. 뿌리썩음증상은 Pythium aphanidermatum을 선접종 후 Fusarium solani를 후접종 하였을 때 가장 심하였다. 뿌리혹선충과 Phthium aphanidermatum과의 상호작용은 없었다. 근경 발아는 각 처리에서 현저히 증가하였고 Alliette 0.25% 처리에서 가장 높았다. 토양관주에 의한 치료 및 예방효과는 Alliette, Burgandy mixture, 다이센 M-45, 디포라탄이 우수하였으며, 수량도 증가하였다.

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Molecular targets of pepper as bioavailability enhancer

  • Gohil, Priyanshee;Mehta, Anita
    • Advances in Traditional Medicine
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    • 제9권4호
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    • pp.269-276
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    • 2009
  • Black pepper (family Piperaceae), is called king of spices because it is one of the oldest spice and alone accounts for about 35% of the world's total spice trade. The pepper is used in Ayurvedic medicine for the treatment of various ailments particularly neurological, broncho-pulmonary and gastrointestinal disorders. Pepper has also been reported to have various pharmacological actions but recently, it is highlighted as a bioavailability enhancer. This results in higher plasma concentration of drugs, nutrients, ions and other xenobiotics, rendering them more bioavailable for physiological as well as pharmacological actions in the body. Numerous scientific studies reported that piperine; a main bioactive compound of pepper, is responsible for its bioavailability enhancing property. It's a well known fact that pepper enhances bioavailability by inhibition of microsomal enzyme system but other mechanisms are also responsible to acts as a bioavailability enhancer. The brief overview of the mechanism of action of pepper as well as its applications as bioavailability enhancer is given in the present article.

INDUCTION OF MICROSOMAL EPOXIDE HYDROLASE BY SULFUR AMINO ACID-DEPRIVATION VIA THE PATHWAY OF C-JUN N-TERMINAL KINASE AND ITS EXTRACELLULAR EXPOSURE DURING CELL DEATH

  • Kang, Keon-Wook;Lee, Chang-Ho;Kim, Sang-Geon
    • 한국독성학회:학술대회논문집
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    • 한국독성학회 2002년도 Current Trends in Toxicological Sciences
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    • pp.78-78
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    • 2002
  • Microsomal epoxide hydrolase (mEH), an epoxide detoxifying enzyme and putative cell surface autoantigen, is inducible by xenobiotics and by certain pathophysiological conditions. The present study was designed to determine mEH expression in H4IIE cells during cell death initiated by sulfur amino acid deprivation (SAAD) and to identify the signaling pathway for the enzyme induction.(omitted)

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Establishment of New Method for the Assay of Glutamate-cysteine Ligase Activity in Crude Liver Extracts

  • Kwon Young-Hye;Stipanuk Martha H.
    • Toxicological Research
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    • 제22권1호
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    • pp.39-45
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    • 2006
  • As the antioxidant and free radical scavenger, glutathione (GSH) participates in the preservation of cellular redox status and defense against reactive oxygen species and xenobiotics. Glutamate-cysteine ligase (GCL; also known as ${\gamma}$-glutamylcysteine synthetase, EC 6.3.2.2) is the rate limiting enzyme in GSH synthesis. In the present study, the accurate method for determination of GCL activity in crude liver extracts was developed by measuring both ${\gamma}$-glutamylcysteine and GSH from cysteine in the presence of glutamate, glycine and an ATP-generating system. We added glycine to promote the conversion of ${\gamma}$-glutamylcysteine to GSH, and to minimize the possibility of ${\gamma}$-glutamylcysteine metabolism to cysteine and oxoproline by ${\gamma}$-glutamylcyclotransferase. We established optimal conditions and substrate concentrations for the enzyme assay, and verified that inhibition of GCL by GSH did not interfere with this assay. Therefore, this assay of hepatic GCL under optimal conditions could provide a more accurate measurement of this enzyme activity in the crude liver extracts.

OXIDATIVE DAMAGE, DNA REPAIR AND SIGNAL TRANSDUCTION IN CHEMICAL TERATOGENESIS.

  • Peter G Wells;Yadvinder Bhuller;Connie S Chen;Jeffrey T Henderson;Winnie Jeng;Sonja Kasapinovic;Julia C Kennedy;Rebecca R Laposa;Christopher J Nicol;Toufan Parman;Michael J Wiley;Louise M Winn;Andrea W Wong
    • 한국독성학회:학술대회논문집
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    • 한국독성학회 2002년도 Current Trends in Toxicological Sciences
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    • pp.44-64
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    • 2002
  • Embryonic prostaglandin H synthases (PHSs) and lipoxygenases bioactivate xenobiotics (phenytoin, thalidomide, benzo[a]pyrene) to free radical intermediates that initiate reactive oxygen species (ROS) formation, which oxidatively damage cellular macromolecules and/or alter signal transduction.(omitted)

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Toxicological Studies on the Essential Oil of Eugenia caryophyllata Buds

  • Park, Hee-Juhn
    • Natural Product Sciences
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    • 제12권2호
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    • pp.94-100
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    • 2006
  • The essential oil (EC-oil) obtained from the buds of Eugenia caryophyllata (Myrtaceae) was examined for its free radical-scavenging activity, cytotoxicity, and in vivo toxicity. To find the xenobiotic properties of EC-oil, serum thiobarbituric acid reactive substances (TBARS) level and hepatic drug-metabolizing enzyme activities were measured. It was found that EC-oil displayed xenobiotic properties like bromobenzene. The cytotoxicities of eugenol and of the EC-oil were greatly attenuated by the sulfhydryl-containing N-acetyl-L-cysteine (NAC), suggesting that eugenol was susceptible to nucleophilic sulfhydryl. In addition, eugenol also showed potent free radical-scavenging activity in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Moreover, methyleugenol considerably exhibited less cytotoxicity and less potent free radical-scavenging activity than eugenol, and the cell viability of the methyleugenol was more increased with NAC treatment than the eugenol. These results indicate that the phenolic OH in eugenol may play a crucial role in both cytotoxicity and free radical-scavenging activity. The fashion on oxidative stress and hepatic drug-metabolizing enzyme activities of eugenol resembled those of bromobenznene.

MUTAGENICITY AND ANTIMUTAGENICITY OF CATECHIN AND TANNINS FROM THE BARK OF HAMAMELIS VIRGINIANA L. IN HUMAN Hep G2 CELLS

  • Sundermann, Volker-Mersch;Andreas Dauer;Evelyne Lhoste;Siegfried Knasmuller
    • 한국독성학회:학술대회논문집
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    • 한국독성학회 2001년도 International Symposium on Dietary and Medicinal Antimutgens and Anticarcinogens
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    • pp.95-96
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    • 2001
  • The mutagenic and antimutagenic activities of catechin, hamamelitannin and two proanthocyanidin fractions prepared from the bark of Hamamelis virginia L. - a commonly used medicinal herb - were investigated in a human derived hepatoma (Hep G2) cell line using the single cell gel electrophoresis (SCGE, syn. Comet assay) for the detection of DNA-migration. The cells possess different phase I and phase II enzymes involved in the biotransformation of xenobiotics.(omitted)

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