• Title/Summary/Keyword: human toxicity

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In vitro biological evaluation of 100 selected methanol extracts from the traditional medicinal plants of Asia

  • Li, Chunmei;Wang, Myeong-Hyeon
    • Nutrition Research and Practice
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    • v.8 no.2
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    • pp.151-157
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    • 2014
  • BACKGROUND/OBJECTIVES: In Asia, various medicinal plants have been used as the primary sources in the health care regimen for thousands of years. In recent decades, various studies have investigated the biological activity and potential medicinal value of the medicinal plants. In this study, 100 methanol extracts from 98 plant species were evaluated for their biological activities. MATERIALS/METHODS: The research properties, including 1,1-diphenyl-2-pic-rylhydrazyl (DPPH) radical scavenging activity, ${\alpha}$-glucosidase and ${\alpha}$-tyrosinase inhibitory effects, anti-inflammatory activity, and anticancer activity were evaluated for the selected extracts. RESULTS: Fifteen of the extracts scavenged more than 90% of the DPPH radical. Among the extracts, approximately 20 extracts showed a strong inhibitory effect on ${\alpha}$-glucosidase, while most had no effect on ${\alpha}$-tyrosinase. In addition, 52% of the extracts showed low toxicity to normal cells, and parts of the extracts exhibited high anti-inflammatory and anticancer activities on the murine macrophage cell (RAW 264.7) and human colon cancer cell (HT-29) lines, respectively. CONCLUSIONS: Our findings may contribute to further nutrition and pharmacological studies. Detailed investigations of the outstanding samples are currently underway.

Uncertainty Minimization in Quantitative Electron Spin Resonance Measurement: Considerations on Sampling Geometry and Signal Processing

  • Park, Sangeon;Shim, Jeong Hyun;Kim, Kiwoong;Jeong, Keunhong;Song, Nam Woong
    • Journal of the Korean Magnetic Resonance Society
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    • v.24 no.2
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    • pp.53-58
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    • 2020
  • Free radicals including reactive oxygen species (ROS) are important chemicals in the research area of biology, pharmaceutical, medical, and environmental science as well as human health risk assessment as they are highly involved in diverse metabolism and toxicity mechanisms through chemical reactions with various components of living bodies. Electron spin resonance (ESR) spectroscopy is a powerful tool for detecting and quantifying those radicals in biological environments. In this work we observed the ESR signal of 2,2,6,6-Tetra-methyl piperidine 1-oxyl (TEMPO) in aqueous solution at various concentrations to estimate the uncertainty factors arising from the experimental conditions and signal treatment methods. As the sample position highly influences the signal intensity, dual ESR tube geometry (consists of a detachable sample tube and a position fixed external tube) was adopted. This type of measurement geometry allowed to get the relative uncertainty of signal intensity lower than 1% when triple measurements are averaged. Linear dependence of signal intensity on the TEMPO concentration, which is required for the quantification of unknown sample, could be obtained over a concentration range of ~103 by optimizing the signal treatment method depending on the concentration range.

Di-acetyl-nor-aporphines: Novel molecules and a novel mechanism to inhibit melanogenesis

  • Lintner, Karl;Peschard, Olivier;Leroux, Richard;Mondon, Philippe;Lamy, Francois
    • Proceedings of the SCSK Conference
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    • 2003.09a
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    • pp.268-284
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    • 2003
  • Nor-aporphine derivatives have been discovered which interfere with the flux of Calcium into and out of the cell interior. It has been shown that adrenergic antagonists that block the Calcium exchange lead to an inhibition of Protein kinase C activity, thus blocking tyrosinase activation. Di-acetyl-dimethoxy-methyl-nor-aporphine is a semi-synthetic molecule of natural origin with very high potency. On B16 melanocytes as well as in normal human melanocytes the decrease in melanin synthesis reaches -50% at a level of 40 ppm in the culture medium. On a molar concentration basis, this is 50 to 70 times stronger than Kojic acid inhibition. Yet, the cell viability is not affected. Reversibility studies show that after washing out of the active compound, melanogenesis returns to normal levels. Possible mechanisms of the activity are discussed. Tests carried out on SkinEthic(R) three-dimensional models of the epidermis and in vivo clinical studies on Asian population confirm the strong inhibition of melanogenesis. Safety evaluation of these molecules, on the other hand, demonstrates good skin tolerance and absence of toxicity.

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Environmental Impact Evaluation of Virgin Pulp Using Life Cycle Assessment Methodology (LCA기법을 이용한 천연펄프의 환경 영향 평가)

  • 김형진;조병묵;황용우;박광호
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.36 no.1
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    • pp.49-60
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    • 2004
  • Life Cycle Assessment for the pulp, which is mainly used as the raw material of fine paper, base paper for food packaging and paper cup, has been carried out in this study to consider environmental aspects by quantifying the environmental emission and to evaluate its environmental impact potential. The system boundary was selected from cradle to gate stage(raw material acquisition, transportation of raw material and product manufacturing) of the product. Environmental impact was divided into 8 categories considering Korean situation: abiotic resource depletion, global warming, ozone depletion, acidification, eutrophication, photochemical oxidant creation, ecotoxicity and human toxicity. In Life Cycle Impact Assessment(LCIA) methodology phase, Ecopoint, Eco-indicator 95 and Korean eco-indicator were used and the results carried out by each methodology were compared. The results from this study were also compared with those of foreign study to verify the reliability of the results. The results of the study could be utilized as the basic data for Environmental Management System(EMS), Design for Environment(DfE) and Type III eco-labeling in the paper and paper-related industry.

Controllable Movement of the Azobenzene Linked Crown Ether Conjugated Liposome

  • Seo, Eun-Seok;Kim, Soo-Hyun;Kim, Jin-Seok;Kim, Byung-Kyu
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.1158-1162
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    • 2005
  • Drug delivery systems have been developed to reduce the side toxicity of drugs by localizing them in the site of action. But it depends on the circulation of the blood and it doesn't have the function of locomotive mechanism of itself for searching for the region of disease. However, this problem could be solved by nanobot which have the locomotive function. So, we mimic the movement of cell that can move in a human body. In this paper, to polymerize the encapsulated actin within the liposome, electroporation technique is employed. In order to optimize polymerization and depolymerization of the liposome, we compare the time of polymerization and depolymerization by concentration of crown ether. we synthesis the liposome which contain azobenzene Linked crown Ether conjugated Actin protein. Azobenze linked crown ether holds the K+ ion by exposure of UV light and this disturbs the actin polymerization. In result, UV light could control the liposome growth. Finally, we could develop the liposome robot and control the growth and degeneration of the liposome by external stimuli such s UV light. The merit of the controlling by UV light doesn't need to inject proteins which induce polymerization and depolymerization of actin protein.

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Inhibitory Effects of Dunning Rat Prostate Tumor Fluid on Proliferation of the Metastatic MAT-LyLu Cell Line

  • Bugan, Ilknur;Altun, Seyhan
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.2
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    • pp.831-836
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    • 2015
  • Tumor fluid accumulation occurs in both human cancer and experimental tumor models. Solid tumors show a tendency to tumor fluid accumulation because of their anatomical and physiological features and this may be influenced by molecular factors. Fluid accumulation in the peri-tumor area also occurs in the Dunning model of rat prostate cancer as the tumor grows. In this study, the effects of tumor fluids that were obtained from Dunning prostate tumor-bearing Copenhagen rats on the strongly metastatic MAT-LyLu cell line were investigatedby examining the cell's migration and tumor fluid's toxicity and the kinetic parameters such as cell proliferation, mitotic index, and labelling index. In this research, tumor fluids were obtained from rats injected with $2{\times}10^5$ MAT-LyLu cells and treated with saline solution, and 200 nM tetrodotoxin (TTX), highly specific sodium channel blocker was used. Sterilized tumor fluids were added to medium of MAT-LyLu cells with the proportion of 20% in vitro. Consequently, it was demonstrated that Dunning rat prostate tumor fluid significantly inhibited proliferation (up to 50%), mitotic index, and labeling index of MAT-LyLu cells (up to 75%) (p<0.05) but stimulated the motility of the cells in vitro.

Pesticide Exposure and Health (농약 노출과 건강)

  • Lee, Won-Jin
    • Journal of Environmental Health Sciences
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    • v.37 no.2
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    • pp.81-93
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    • 2011
  • Although pesticides have increased crop production and controlled disease, they have produced a number of adverse health effects. Pesticides have potential human toxicity and a variety of groups, such as farmers or industrial workers, as well as the general population, are exposed to pesticides. The purpose of this article, therefore, is to provide an overview of pesticide exposure and health through a literature review, focusing on exposure assessment, acute poisoning, chronic health effects, and future research needs. The exposure types and levels of pesticides vary by study subjects and need to be assessed by integrating several methods focused on the epidemiological purpose. Acute pesticide poisoning is a major public health problem in the world. Paraquat is the main causative pesticide for acute poisoning in Korea and should be banned in order to save several thousands of lives every year. Occupational pesticide exposure also causes numerous chronic diseases among farmers and industrial workers, including cancers, respiratory diseases, depression, retinal degeneration, diabetes, and abnormal menstrual cycle. However, controversy exists regarding the long-term effects of low-dose environmental pesticide exposure. The area of pesticide study is relatively new with broad study populations and it has received little academic and policy attention, particularly in Korea. More detailed studies investigating the risk of pesticide-related health effects and intervention efforts to reduce the problems are needed in Korea.

Recombinant Azurin from Pseudomonas aeruginosa Induces Apoptotic Cell Death in Oral Squamous Carcinoma Cells

  • Kim, Uk-Kyu;Jeon, Hyun-Jun;Lee, Moo-Hyung;Kim, Gyoo-Cheon
    • International Journal of Oral Biology
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    • v.35 no.2
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    • pp.35-42
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    • 2010
  • The use of bacteria in the treatment of cancer has a long and interesting history. The use of live bacteria in this way however has a number of potential problems including toxicity. Purified low molecular weight bacterial proteins have therefore been tested as anticancer agents to avoid such complications. Oral cancer is a widely occurring disease around the world and these lesions are typically very resistant to anticancer agents. In our present study we investigated the effects of purified recombinant azurin from Pseudomonas (P.) aeruginosa against YD-9 (p53-positive) human oral squamous carcinoma cells. Azurin showed cytotoxic effects against these cells in a dose dependent manner. The cell death accompanied by this treatment was found to be characterized by chromatin condensation and apoptotic bodies. Azurin treatment was further found to increase the expression of p53 The stabilization of p53 and induction of apoptosis in YD-9 cells by azurin suggests that it has potentially very strong anticancer properties in oral squamous carcinoma.

The Recommended Approaches and Recent Trends in Reproductive and Developmental Toxicology (생식 · 발생독성시험의 방법적 고찰과 최신 연구 동향)

  • Kwack, Seung-Jun;Cho, Dae-Hyun
    • Toxicological Research
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    • v.21 no.4
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    • pp.271-278
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    • 2005
  • Reproductive and developmental toxicology is concerned with various physical or chemical agents interfering with fertility in both gender or normal growth of offsprings. Reproductive and developmental toxicology is rather a complex science, with many fields, i.e., various endpoints are involved and many different mechanisms of action. For that reason, diverse aspects must be considered when attempting to assess possible adverse health effects in the area of reproductive and developmental toxicology. The thalidomide tragedy made it clear to regulatory authorities around the world that systematic, comprehensive evaluation of the reproductive cycle was needed to adequately evaluate the potential of medicinal drugs to impair the process of reproduction or the development of embryos, fetuses, and children. International Conference on Harmonization of Technical Requirements for the Registration of Pharmaceuticals for Human Use (ICH) and U.S. Food and Drug Administration (FDA) developed a guideline to assess the reproductive and developmental toxicity. Also these guidelines have since been applied to the detection and regulation of environmental toxicants, food additives, and so on. Although it was hoped that testing procedures of guideline would be updated constantly to reflect the current state of the science in reproductive and developmental toxicology, it was not until this decade that regulatory guidelines and testing methods have been altered in a significant way. In this paper, we would like to present the recommended approaches and recent trends for improvement of testing guidelines or experimental methods in reproductive and developmental toxicology.

Alteration in Response to Chemicals Induced by Physical Exercise (육체운동에 의해 유발되는 화학물질에 대한 반응성의 변화)

  • 김영철
    • Toxicological Research
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    • v.18 no.3
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    • pp.215-226
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    • 2002
  • Acute or repeated physical exercise affects a large number of physiological parameters including hemodynamics, respiration, pH, temperature, gastrointestinal function and biotransformation, which determine the pharmacokinetics of drugs and chemicals. The rate and the amount of a chemical reaching the active site are altered by physical exercise, which results in significant changes in pharmacolosical/toxicological activity of the chemical. This aspect of physical exercise has vast implication in therapeutics and in safety evaluation, particularly for chemicals that have a low margin of safety. However there appears to be a wide inter- and intraindividual variation in the effects of physical exercise depend-ing on the duration, intensity and type of exercise, and also on the properties of each chemical. It is suggested that more studies need to be done to determine which factor(s) plays a major role in the disposition of chemicals in human/animals performing physical exercise. Certain chemicals induce severe toxicity due to metabolic conversion to reactive intermediate metabolites. it is suggested that repeated exercise may enhance the free radical scavenging system by increasing the activity of antioxidant enzymes. This area of research remain to be explored to elucidate the interaction of exercise and chemical on the antioxidant system.