• Toxicological Research
• /
• v.34 no.4
• /
• pp.311-324
• /
• 2018

Arsenic is one of the most toxic environmental toxicants. More than 150 million people worldwide are exposed to arsenic through ground water contamination. It is an exclusive human carcinogen. Although the hallmarks of arsenic toxicity are skin lesions and skin cancers, arsenic can also induce cancers in the lung, liver, kidney, urinary bladder, and other internal organs. Arsenic is a non-mutagenic compound but can induce significant cytogenetic damage as measured by chromosomal aberrations, sister chromatid exchanges, and micronuclei formation in human systems. These genotoxic end points are extensively used to predict genotoxic potentials of different environmental chemicals, drugs, pesticides, and insecticides. These cytogenetic end points are also used for evaluating cancer risk. Here, by critically reviewing and analyzing the existing literature, we conclude that inorganic arsenic is a genotoxic carcinogen.

• Journal of applied mathematics & informatics
• /
• v.2 no.2
• /
• pp.53-62
• /
• 1995

If one is to estimate environmemtal risk based on data or predict risk based on expert opinion the parameter environmental risk musk be defined precisely so that when data becomes available the numerical values of the estimates and/or prediction can be evaluated. Also the definitionmust be precise so that it may be successfully used in regulatory and litigation activities. The presentation is a develop-ment of a definition which lends to statistical analysis and to inference in addition lends to ease of engineering interpretation. Various impli-cations and useful extensions in measuring numerically for two or more dimensional mixed effects of several toxicants could be developed in further research.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 2004.11a
• /
• pp.50-61
• /
• 2004

Lead and cadmium are potent environmental toxicants that affect populations living in Europe, Americas, and Asia. Identifying transporters for lead and cadmium could potentially 1 help us better understand possible risk factors. The iron transporter divalent metal transporter 1(DMT1) mediates intestinal transport of cadmium, and lead in yeast and fibroblasts overexpressing DMT1. In human intestinal cells knocking down expression of DMT1 attenuated uptake of cadmium and iron but not lead. A possible explanation is the expression of a second transporter for lead in intestine. In astrocytes, however, DMT1 appears to transport lead in an extracellular buffer at pH value. At neutral pH, transport was not mediated by DMT1 but rather by a transporter that is stimulated by bicarbonate and inhibited by 4,4'-diisothiocyanatodihydrostilbene-2,2'-disulfonic acid. The identity of this lead transporter is under study.

• Proceedings of the Korea Society of Environmental Toocicology Conference
• /
• 2003.05a
• /
• pp.146-147
• /
• 2003

The free-living nematode, Caenorhabditis elegans (C. elegans) has been adopted as a multicellular biosensor of biological toxicity for alkylphenol, organotin compounds and heavy metals. To adopt as a biosensor, suitability to assess must be fulfilledthrough several criteria; the organism must be sensitive to the testing toxicants, easy to manage in the laboratory and available throughout the year. C. elegans widely used as a simple multicellular organism in developmental biology studies and satisfies all these criteria, and its culture conditions, developmental staging, anatomy and genetic properties are well defined. In addition, researchers can take advantage of the worm's short life cycle, low cost and little individual variation. Moreover, genomic sequencing of C. elegans has recently been completed. With these aspectsof the organism, C. elegans become a more potent model organism for basic and applied bioassays.

• Journal of Microbiology and Biotechnology
• /
• v.25 no.11
• /
• pp.1773-1781
• /
• 2015

Environmental security is one of the major concerns for the safety of living organisms from a number of harmful pollutants in the atmosphere. Different initiatives, legislative actions, as well as scientific and social concerns have been discussed and adopted to control and regulate the threats of environmental pollution, but it still remains a worldwide challenge. Therefore, there is a need for developing certain sensitive, rapid, and selective techniques that can detect and screen the pollutants for effective bioremediation processes. In this perspective, isolated enzymes or biological systems producing enzymes, as whole cells or in immobilized state, can be used as a source for detection, quantification, and degradation or transformation of pollutants to non-polluting compounds to restore the ecological balance. Biosensors are ideal for the detection and measurement of environmental pollution in a reliable, specific, and sensitive way. In this review, the current status of different types of microbial biosensors and mechanisms of detection of various environmental toxicants are discussed.

• Proceedings of the PSK Conference
• /
• 2002.10a
• /
• pp.201-205
• /
• 2002

It is generally accepted that the immune system is one of the major target organs for many toxic chemicals. In addition, many toxic chemicals require metabolic activation by cytochrome P450s for their toxicity. Although the immune cells possess a limited amount of drug metabolizing capacity, metabolic activation of certain toxicants in liver and immune organs may have a significant role in immunosuppression. In the present studies, the possible role of metabolic activation by cytochrome P450s in chemical-induced immunosuppression was reviewed, with a particular emphasis on the methodological techniques to detect immunotoxicants requiring metabolic activation in vivo and in vitro. (omitted)

• Korean journal of applied entomology
• /
• v.31 no.3
• /
• pp.289-303
• /
• 1992

Investigation of the environmental impact of widespread pesticide use has revealed a virtue/vice relationship. Although many pesticides perform their function and disappear without harm to the environment, others persist beyond their useful purpose and cause direct of indirect hazard to man, domestic animals and wildlife. Concurrently, many pests have rapidly adjusted to chemical control practices through changes in behavior that avoid exposure to pesticides of throuth genetic selection for populations resistant to the toxicants. The prospect of losing control over insect herbivores and desease vectors and returning to the days of global hunger and disease is unthinkable. Fortunately, from basic studies of insect and plant biology many opportunities for the development of safe, selective and environmentally pacific strategies for insect pest management are being realized.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.23 no.4
• /
• pp.883-887
• /
• 2009

The effects of Sacchromyces cerevisiae-Fermented Artemisiae Argi Folium Water extract (AFS) on Nitric oxide production from mouse macrophage Raw 264.7 cells treated with EtOH, gallic acid, Nicotine, Acetaminophen, and Acetaldehyde were investigated through this study. AFS (0, 10, 50, 100, 200, 400 ug/mL) was simultaneously treated with EtOH (100 uM), gallic acid (100 uM), Nicotine (1 mM), Acetaminophen (2 mM), and Acetaldehyde (200 uM). And Nitric oxide production from Raw 264.7 cells was measured by Griess reagent method. AFS restorated the cellular production of Nitric oxide reduced by EtOH, gallic acid, Nicotine, and Acetaminophen in Raw 264.7 cells. AFS could be supposed to have the immuno-modulating activity concerned with macrophage's production of Nitric oxide.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.23 no.2
• /
• pp.438-442
• /
• 2009

The purpose of this study is to investigate the effect of water extract from Artemisiae Argi Folium Fermented with Lactobacillus pentosus (AFL) on hydrogen peroxide production within mouse macrophage Raw 264.7 Cells treated with gallic acid, EtOH, Nicotine, Acetaminophen, and Acetaldehyde. AFL (0${\sim}$400 ug/mL) was treated with gallic acid, EtOH, Nicotine, Acetaminophen, and Acetaldehyde. And the intracellular productions of hydrogen peroxide were measured by dihydrorhodamine 123 (DHR) assay. AFL showed the restoration of the intracellular productions of hydrogen peroxide which were reduced by gallic acid, EtOH, Nicotine, Acetaminophen in Raw 264.7 Cells. AFL could be supposed to have the immunological activity related with macrophage's oxidative burst.

• Natural Product Sciences
• /
• v.7 no.2
• /
• pp.38-44
• /
• 2001

NAD(P)H:quinone reductase (QR), known as DT-diaphorase, is a kind of detoxifying phase II metabolic enzyme catalyzing hydroquinone formation by two electron reduction pathway from quinone type compounds, and thus facilitating excretion of quinoids from human body. With the usefulness of QR induction activity assay system for the modulation of toxicants, in the course of searching for cancer chemopreventive agents from natural products, the methanolic extracts of approximately two hundreds of oriental medicines were primarily evaluated using the induction potential of quinone reductase (QR) activity in cultured murine Hepa1c1c7 cells. As a result, several extracts including Hordeum vulgare, Momordica cochinchinensis, Strychnos ignatii, Houttuynia cordata, and Polygala japonica were found to significantly induce QR activity. In addition, the methylene chloride fraction of H. vulgare, one major dietary food source, showed potent induction of QR activity $(CD=6.4{\mu}g/ml)$. Further study for isolation of active principles from these lead extracts is warranted for the discovery of novel cancer chemopreventive agents.