• International Journal of Industrial Entomology and Biomaterials
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• v.14 no.1
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• pp.9-13
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• 2007

Hexane extract of Porteresia coarctata (Roxb.) exhibits a toxic effect on the tissues of Spodoptera litura (F) while fed at the dose of 1000 and 2000 ppm thoroughly mixing with castor leaves (Ricinus communis L) after dissolving in DMSO at late fourth instar whereas only DMSO treated castor leaves were fed to control group. The larvae were put to rear at $28^{\circ}C{\pm}1^{\circ}C$, $76{\pm}4%$ R.H. under 12 L + 12 D photoperiodic regime. In test group insects substantial reduction of protein and DNA content was marked in fat body and midgut tissues compared to DMSO treated control group. The significant biochemical alterations in the midgut tissues and fat body of test group insects indicate the insecticidal property of the said plant extract that could be tested in facilitating the phenomenal stride in Integrated Pest Management.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.155-158
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• 2000

Production of decursinol angelate, a new potential anticancer agent, in Angelica gigas Nakai root culture was increased by treatment of $H_2O_2$, and various polysaccharides such as $CM-\;{\beta}\;-cyclodextrin$, glucan, $CM-\;{\beta}\;-chitin$, yeast extract and pectin. One mmole $H_2O_2$ enhanced the production of decursinol angelate. However, higher concentrations of $H_2O_2$ were founded to be toxic for root growth whereas specific productivity of decursinol angelate was increased at high concentrations of $H_2O_2$. In the case of polysaccharide elicitors, $CM-\;{\beta}\;-chitin$ was the most effective for enhanced production of secondary metabolite in A. gigas Nakai root culture.

• Biomolecules & Therapeutics
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• v.21 no.1
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• pp.1-9
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• 2013

Polyamines, putrescine, spermidine and spermine, are ubiquitous in living cells and are essential for eukaryotic cell growth. These polycations interact with negatively charged molecules such as DNA, RNA, acidic proteins and phospholipids and modulate various cellular functions including macromolecular synthesis. Dysregulation of the polyamine pathway leads to pathological conditions including cancer, inflammation, stroke, renal failure and diabetes. Increase in polyamines and polyamine synthesis enzymes is often associated with tumor growth, and urinary and plasma contents of polyamines and their metabolites have been investigated as diagnostic markers for cancers. Of these, diacetylated derivatives of spermidine and spermine are elevated in the urine of cancer patients and present potential markers for early detection. Enhanced catabolism of cellular polyamines by polyamine oxidases (PAO), spermine oxidase (SMO) or acetylpolyamine oxidase (AcPAO), increases cellular oxidative stress and generates hydrogen peroxide and a reactive toxic metabolite, acrolein, which covalently incorporates into lysine residues of cellular proteins. Levels of protein-conjuagated acrolein (PC-Acro) and polyamine oxidizing enzymes were increased in the locus of brain infarction and in plasma in a mouse model of stroke and also in the plasma of stroke patients. When the combined measurements of PC-Acro, interleukin 6 (IL-6), and C-reactive protein (CRP) were evaluated, even silent brain infarction (SBI) was detected with high sensitivity and specificity. Considering that there are no reliable biochemical markers for early stage of stroke, PC-Acro and PAOs present promising markers. Thus the polyamine metabolites in plasma or urine provide useful tools in early diagnosis of cancer and stroke.

• 한국균학회소식:학술대회논문집
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• 2016.05a
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• pp.35-35
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• 2016

A mycotoxin is a toxic secondary metabolite produced by organisms of the fungus kingdom, commonly known as molds and has been widely contaminated in agricultural products such as grains and cereals. Many methods including high performance liquid chromatography (HPLC) and gas chromatography (GC) have already been proposed and reviewed for mycotoxins. These methods are either expensive or time-consuming due to the complication of sample preparation and pre-concentration before determination. In addition, both methods are unsuitable for the routine screening of large sample numbers. A biosensor is a fictive analytical device that combines a biological component with a physicochemical detector for the detection of an analyte. Biosensors represent a rapidly expanding field, at the present time, with an estimated 60% annual growth rate; the major impetus coming from the health-care industry but with some pressure from other areas, such as food safety and environmental monitoring. Antibodies and aptamers are bioreceptors which have been used in the development of biosensors. There are many kinds of antibodies and aptamers specific to mycotoxin, and antibody (or aptamer)-based biosensors have been successfully developed for the detection of mycotoxin. The biosensors permit the rapid, sensitive, simple, and on-site detection of a range of mycotoxins and can be an alternative method to traditional methods such as HPLC and GC. This presentation provides the development trends of biosensors to mycotoxins and their application to food and agricultural products.

• Korean Journal of Food Science and Technology
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• v.38 no.2
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• pp.256-261
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• 2006

Soybeans were fermented with Monascus sp. to select strain with highest mevinolin production through solidstate fermentation. Monascus pilosus IFO 480 showed highest yield of 2.2 mg mevinolin per g dry weight without citrinin, toxic fungal secondary metabolite, as byproduct. Nutrient broth used for soybean fermentation with Monascus sp. was composed of 3.4 rice powder, 1.1 peptone, 2.6 glycine, 12.9 glucose, initial pH 6.0 (%, w/v). Mevinolin was present in fermentation substrate largely as hydroxy carboxylate form (open lactone, 91.8-96.8%), which is used as hypocholesterolemic agent. Production of mevinolin continued up to 50 days fermentation time at $30^{\circ}C$.

• The Korean Journal of Pesticide Science
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• v.7 no.1
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• pp.45-50
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• 2003

This study was conducted to understand the role of oxidative enzyme cytochrome $P_{450}$ in the bioactivation of benfuracarb and to know metabolites of benfuracarb by cytochrome $P_{450}$. The bimolecular imhibition rate constant $(k_i)$ of benfuracarb on acetylcholinesterase (AChE) was as low as $1.1{\times}10^3\;M^{-1}\;min^{-1}$, suggesting that benfuracarb should be activated for its toxic action. The potency of benfuracarb on AChE in the oxidase system (cytochrome $P_{450}$ + NADPH) in vitro was 10-fold higher than that of control (cytochrome $P_{450}$). Such a similar result was also found in the oxidase + PBO system. In vivo the $I_{50}$ of benfuracarb was 22.7mg $kg^{-1}$, but pie-treatment of piperonyl butoxide (PBO) reduced the $I_{50}$ by >100mg $kg^{-1}$. This result suggests that cytochrome $P_{450}$ was involved in the activation of benfuracarb. Using microsomal oxidase system, metabolites of benfuracarb were elucidated. Fifty-eight percent of benfuracarb was converted to carbofuran, a major toxic metabolite, in the oxidase system, while only less than two percent of benfuracarb was converted to carbofuran in the oxidase + PBO system. These results also suggest that cytochrome $P_{450}$ was involved in the activation of benfuracarb. Overall results indicate that cytochrome $P_{450}$ could be involved in the bioactivation of benfuracarb to carbofuran.

• 한국균학회소식:학술대회논문집
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• 2018.05a
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• pp.13-13
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• 2018

Alternaria is a ubiquitous fungal genus, widely distributed in the environment and a range of different habitats. It includes both plant pathogenic and saprophytic species, which can affect crops in the field or cause post-harvest spoilage of plant fruits and kernels. Numerous Alternaria species cause damage to agricultural products including cereal grains, fruits and vegetables, and are responsible for severe economic losses worldwide. Most Alternaria species have the ability to produce a variety of secondary metabolites, which may play important roles in plant pathology as well as food quality and safety. Alternariol (AOH), alternariol monomethyl ether (AME), tenuazonic acid (TeA), tentoxin (TEN) and altenuene (ALT) are considered the main Alternaria compounds thought to pose a risk to human health. However, food-borne Alternaria species are able to produce many additional metabolites, whose toxicity has been tested incompletely or not tested at all. Both alternariols are mutagenic and their presence in cereal grain has been associated with high levels of human esophageal cancer in China. TeA exerts cytotoxic and phytotoxic properties, and is acutely toxic in different animal species, causing hemorrhages in several organs. The possible involvement of TA in the etiology of onyalai, a human hematological disorder occurring in Africa, has been suggested. Altertoxins (ALXs) have been found to be more potent mutagens and acutely toxic to mice than AOH and AME. Other metabolites, such as TEN, are reported to be phytotoxins, and their toxicity on animals has not been demonstrated up to now. Vegetable foods infected by Alternaria rot are obviously not suitable for consumption. Thus, whole fresh fruits are not believed to contribute significantly with Alternaria toxins to human exposure. However, processed vegetable products may introduce considerable amounts of these toxins to the human diet if decayed or moldy fruit is not removed before processing. The taxonomy of the genus is not well defined yet, which makes it difficult to establish an accurate relationship between the contaminant species and their associated mycotoxins. Great efforts have been made to organize taxa into subgeneric taxonomic levels, especially for the small-spored, food associated species, which are closely related and constitute the most relevant food pathogens from this genus. Several crops of agricultural value are susceptible to infection by different Alternaria species and can contribute to the entry of Alternaria mycotoxins in the food chain. The distribution of Alternaria species was studied in different commodities grown in Argentina. These food populations were characterized through a polyphasic approach, with special interest in their secondary metabolite profiles, to understand their full chemical potential. Alternaria species associated with tomato, bell pepper, blueberry, apples and wheat cultivated in Argentina showed a surprisingly high metabolomic and mycotoxigenic potential. The natural occurrence of Alternaria toxins in these foods was also investigated. The results here presented will provide background for discussion on regulations for Alternaria toxins in foods.

• Biomolecules & Therapeutics
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• v.22 no.2
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• pp.149-154
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• 2014

Effects of diallyl sulfide (DAS) on thioacetamide-induced hepatotoxicity and immunotoxicity were investigated. When male Sprague-Dawley rats were treated orally with 100, 200 and 400 mg/kg of DAS in corn oil for three consecutive days, the activity of cytochrome P450 (CYP) 2E1-selective p-nitrophenol hydroxylase was dose-dependently suppressed. In addition, the activities of CYP 2B-selective benzyloxyresorufin O-debenzylase and pentoxyresorufin O-depentylase were significantly induced by the treatment with DAS. Western immunoblotting analyses also indicated the suppression of CYP 2E1 protein and/or the induction of CYP 2B protein by DAS. To investigate a possible role of metabolic activation by CYP enzymes in thioacetamide-induced hepatotoxicity, rats were pre-treated with 400 mg/kg of DAS for 3 days, followed by a single intraperitoneal treatment with 100 and 200 mg/kg of thioacetamide in saline for 24 hr. The activities of serum alanine aminotransferase and aspartate aminotransferase significantly elevated by thioacetamide were protected in DAS-pretreated animals. Likewise, the suppressed antibody response to sheep erythrocytes by thioacetamide was protected by DAS pretreatment in female BALB/c mice. Taken together, our present results indicated that thioacetamide might be activated to its toxic metabolite(s) by CYP 2E1, not by CYP 2B, in rats and mice.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.2
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• pp.201-208
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• 1997

It is becoming increasingly clear that the inflammatory reaction can be ascribed to a complex array of mediators generated and released from activated phagocytes. In this study, the effect of PAF on interleukin-1(IL-1) activity by rat alveolar macrophages(AM) was examined using thymocyte proliferation assay in the supernate of sample obtained after 24 hr culture. When AM were cultured with PAF alone, no change in IL-1 activity was observed. However, the combined addition of PAF and muramyl dipeptide(MDP) or lipopolysaccharide(LPS) to AM cultures markedly enhanced IL-1 activity by 2-3 fold compared with AM cultures with the stimulant alone in a concentration dependent fashion. The peack effect was found at $10^{-8}$ M PAF with MDP and $10^{-14}$ M PAF with LPS. the effect of PAF was also tested in silica, toxic respirable dust, -added AM cultures as well as in the cultures containing bacterial compounds. Although silica did not stimulate the IL-1 activity, PAF could enhance IL-1 activity by 2 fold above the value of the silica-treated AM cultures with the peak response at $10^{-12}$ M PAF. Optimal enhancement of IL-1 activity occured when MDP and PAF were present together at the initiation of the 24 hr AM cultures. Additionaly, the biologically inactive precursor/metabolite of PAF, lyso-PAF failed to induce enhancement of IL-1 activity. When the specific, but structurally different PAF receptor antagonists, BN 52021($10^{-5}$ M) and CV 3988($10^{-5}$ M) was treated 15 min before addition of PAF($10^{-8}$ M) and MDP$(10\;{\mu}g/ml)$ to the AM cultures, it markedly inhibited the enhancement of IL-1 activity induced by PAF. The effects of these PAF antagonists were also observed in LPS$(10\;{\mu}g/ml)$-stimulated cells. Collectively, these data suggest that PAF enhances IL-1 activity by interaction with a specific receptor.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.6
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• pp.564-570
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• 2005

In the present study, the protective effects of Bcl-2 over-expression in a suspension culture (without any adaptation) and spent medium (low nutrient and high toxic metabolite conditions) were investigated. In the suspension culture without prior adaptation, the viability of the control cell line fall to 0% by day 7, whereas the Bcl-2 cell line had a viability of 65%. The difference in the viability and viable cell density between the Bcl-2 and control cell lines was more apparent in the suspension culture than the static culture, and became even more apparent on day 6. Fluorescence microscopic counting revealed that the major mechanism of cell death in the control cell line in both the static and suspension cultures was apoptosis. For the Bcl-2 cell lines, necrosis was the major mode of cell death in the static culture, but apoptosis became equally important in the suspension culture. When the NS0 6A1 cell line was cultured in spent medium taken from a 14 day batch culture, the control cell line almost completely lost its viability by day 5, whereas, the Bcl-2 still had a viability of 73%. The viable cell density and viability of the Bcl-2 cell line cultivated in fresh medium were 2.2 and 2.7 fold higher, respectively, than those of the control cultures. However, the viable cell density and viability of the Bcl-2 cultivated in the spent medium were 8.7 and 7.8 fold higher, respectively, than those of the control cultures. Most of the dead cells in the control cell line were apoptotic; whereas, the major cell death mechanisms in the Bcl-2 cell line were necrotic.