• KOREAN JOURNAL OF CROP SCIENCE
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• v.48
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• pp.13-23
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• 2003

The trace mineral, selenium (Se), is an essential nutrient of fundamental importance to human health. It is also very toxic and can cause Se poisoning (selenosis) in human and animals when its intake exceeds a suitable amount. Se functions within mammalian systems primarily in the form of solenoprotein. About 35 selenoproteins have been identified, though many have not yet been fully elucidated. Selenoproteins contain Se as selenocyseine (Sec) and perform variety of structural and enzymic roles; the enzymic roles are best-known as the antioxidants for hydrogen peroxides and lipid peroxides, and the catalysts for production of activity thyroid hormone. Glutathione peroxidases ($\textrm{GP}_X$) among the selenoproteins prevent the generation of free radicals and decrease the risk of oxidative damage to tissues, as does thioredoxin reductase (TR). TR also provides reducing power for several biochemical processes. Selenoproteins P and W are involved with oxidant defense in plasma and muscle, respectively, A selenoprotein is also required for sperm motility and may reduce the risk of miscarriage. Some epidemiological studies have revealed an inverse correlation between Se status and cardiovascular disease, and there is considerable evidence 1mm population com-parison data and animal studies that Se is anticarcinogenic. It is also suggested that Se should be needed for the proper functioning of the immune system, and appear to be a key nutrient in counteracting the development of virulence and inhibiting HIV progression to AIDS. As research continues, the role of selenium in the etiology of chronic diseases like appropriate medical nutrition therapy can be delivered and its effectiveness assessed. Se status in individuals is affected by diet and the availability of the Se. The Se content of plants is affected by the content and availability of the element in the soil in which they are grown, and so greatly varies from country to country, while the Se composition of meat reflects the feeding patterns of livestock. This paper provides an overview on Se as an essential trace mineral for human.

• Journal of Embryo Transfer
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• v.26 no.2
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• pp.135-140
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• 2011

Genistein is a product of naturally occurring isoflavones at relatively high levels in soybeans. The harmful effects of ethanol are attributed to the induction of biological processes which lead to an increase in the generation of reactive oxygen species in fetuses. In this study, we investigated the effects of genistein ($1{\times}10^{-8}$ and $1{\times}10^{-7}\;{\mu}g$/ml) on gene expressions of the representative cellular antioxidative enzymes in ethanol (1 ${\mu}l$/ml)-treated mouse fetuses during the critical period (embryonic days 8.5~10.5) of organogenesis using a semi-quantitative RT-PCR analysis. The mRNA levels of cytosolic glutathione peroxidase (GPx), phospholipid hydroperoxide GPx, cytosolic CU,Zn-superoxide dismutase (SOD), and mitochondrial SOD were significantly decreased in ethanol-treated fetuses. However, the mRNA levels of ethanol plus genistein-treated fetuses were significantly higher than those of ethanol alone fetuses. These results indicate that genistein can up-regulate the expressions of GPx and SOD mRNAs reduced by the ethanol treatment in fetuses.

• Journal of Aquaculture
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• v.19 no.3
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• pp.157-165
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• 2006

Expression of major antioxidant enzyme (AOE) including Cu/Zn superoxide dismutase (Cu/Zn-SOD), catalase (CAT), glutathione-S-transferase (GST) and 3 glutathione peroxidase isotypes (GPXs) at mRNA levels during heat stress was examined in mud loach (Misgurnus mizolepis) liver. Based on the semi-quantitative RT-PCR, real-time RT-PCR and/or northern dot blot hybridization, the antioxidant enzyme genes were generally up-regulated during elevation of water temperature from $23^{\circ}C$ up to $32^{\circ}C$. GPXs and SOD displayed the most significant elevation of mRNA levels (up to 3 and 2 folds, respectively) while CAT showed the steady-state expression irrespective of thermal conditions. GST represented the relatively moderate response (1.3-fold increase) in its transcription to thermal stress. The transcriptional activation of AOE genes was not significant at the treatment temperature lower than $29^{\circ}C$. Increased mRNA levels of GPX (extracellular form) and SOD genes in the fish exposed to $32^{\circ}C$ was readily detectable 1 day after exposure to heat stress.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.5
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• pp.661-670
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• 2006

Selenium (Se) obtained from dietary sources including cereals, grains and vegetables is an essential micronutrient for normal function of the body. Plants convert Se into selenomethionine and incorporate it into proteins in place of methionine, while higher animals synthesize selenoproteins containing selenocysteine. Excessive Se in the body is methylated stepwise to methylated selenium metabolites from selenide. Both inorganic and organic forms of selenium can be the nutritional sources in human, and they are transformed to selenide and then the amino acid selenocysteine attached to a specific $tRNA^{ser(sec)}$. The selenocysteine (Sec) is incorporated into selenoprotein sequences by the UGA codon. The decoding of UGA as Sec requires specific mechanisms because UGA is normally read as a stop codon: cis-acting sequences in the mRNA (the selenocysteine insertion sequence, SECIS, within the 3'untranslated region) and trans -acting factors dedicated to Sec incorporation are required for incorporation of Sec during translation of selenoprotein mRNAs. Approximately 25 selenoproteins have been identified in mammals. Several of these, including glutathione peroxidases, thioredoxin reductases and selenoprotein P, have been purified or cloned, allowing further characterization of their biological function. The antioxidant properties of selenoproteins help prevent cellular damage from free radicals which may contribute to the development of chronic disease such as cancer and heart disease. Other selenoproteins have important roles in regulation of thyroid function and play a role in the immune system. Daily selenium iatake was reported to be $42.0{\pm}16.9{\mu}g/day$ in Korean adult women. This review focuses on the metabolism and biological functions of selenium, and the nutritional status of selenium in the Korean population.

• The Plant Pathology Journal
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• v.24 no.4
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• pp.375-383
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• 2008

It is well known that NtMEK2, a tobacco MAPK kinase, is the upstream kinase of both salicylic acid-induced protein kinase and wound-induced protein kinase. In addition, expression of $NtMEK2^{DD}$, a constitutively active mutant of NtMEK2, is known to induce multiple defense responses in tobacco. In this study, transgenic rice plants that contained an active or inactive mutant of NtMEK2 under the control of a steroid inducible promoter were generated and used to determine if a similar MAPK cascade is involved in disease resistance in rice. The expression of $NtMEK2^{DD}$ in transgenic rice plants resulted in HR-like cell death. The observed cell death was preceded by the activation of endogenous rice 48-kDa MBP kinase, which is also activated by Xanthomonas oryzae pv. oryzae, the bacterial blight pathogen of rice. In addition, prolonged activation of the MAPK induced the generation of hydrogen peroxide and up-regulated the expression of defense-related genes including the pathogenesis-related genes, peroxidases and glutathione S-transferases. These results demonstrate that NtMEK2 is functionally replaceable with rice MAPK kinase in inducing the activation of the downstream MAPK, which in turn induces multiple defense responses in rice.

• Journal of Microbiology and Biotechnology
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• v.26 no.2
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• pp.277-286
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• 2016

Makgeolli lees (ML) has several physiological effects such as antioxidant, antidiabetic, and anticancer properties, but its biological functions have not been determined definitively. Here, we tested whether ML has a cytoprotective effect on paraquat (PQ)-induced oxidative stress in the human lung carcinoma cell line A549. At 0.1 mg/ml ML, viability of PQ-exposed A549 cells was restored by 12.4%, 18.5%, and 48.6% after 24, 48, and 72 h, respectively. ML also reduced production of the intracellular reactive oxygen species (ROS) that were generated by PQ treatment. Further experiments revealed that ML treatment enhanced the expression and nuclear translocation of nuclear factor erythroid 2-related factor 2 (NRF2) as well as ARE-GFP reporter activity. ML treatment also effectively increased the expression of NRF2's target genes NAD(P)H dehydrogenase quinone 1 (NQO1) and heme oxygenase 1 (HO-1). Moreover, we found that expression of cytoprotective genes, including glutathione peroxidases (GPXs), superoxide dismutase (SOD1), catalase (CAT), peroxiredoxin 3 (PRDX3), and peroxiredoxin 4 (PRDX4), was greatly enhanced by treatment with ML during PQ exposure. Taken together, the data suggest that treatment of PQ-exposed A549 cells with ML ameliorates cytotoxicity through induction of NRF2 expression and its target genes HO-1, NQO1, and other antioxidant genes. Thus, ML may serve as a functional food applicable to ROS-mediated human diseases.

• Food Science of Animal Resources
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• v.43 no.6
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• pp.1111-1127
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• 2023

Health-promoting preparations of inanimate microorganisms or their components are postbiotics. Since probiotics are sensitive to heat and oxygen, postbiotics are stable during industrial processing and storage. Postbiotics boost poultry growth, feed efficiency, intestinal pathogen reduction, and health, making them acceptable drivers of sustainable poultry production. It contains many important biological properties, such as immunomodulatory, antioxidant, and anti-inflammatory responses. Postbiotics revealed promising antioxidant effects due to higher concentrations of uronic acid and due to some enzyme's production of antioxidants, e.g., superoxide dismutase, glutathione peroxidase, and nicotinamide adenine dinucleotide oxidases and peroxidases. Postbiotics improve intestinal villi, increase lactic acid production, and reduce Enterobacteriaceae and fecal pH, all of which lead to a better immune reaction and health of the gut, as well as better growth performance. P13K/AKT as a potential target pathway for postbiotics-improved intestinal barrier functions. Similarly, postbiotics reduce yolk and plasma cholesterol levels in layers and improve egg quality. It was revealed that favorable outcomes were obtained with various inclusion levels at 1 kg and 0.5 kg. According to several studies, postbiotic compounds significantly increased poultry performance. This review article presents the most recent research investigating the beneficial results of postbiotics in poultry.

• Korean journal of applied entomology
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• v.61 no.1
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• pp.155-163
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• 2022

The application of fungicides is indispensable to global food security, and their use has increased in recent times. Fungicides, directly or indirectly, have impacted insects, leading to genetic and molecular-level changes. Various detoxification mechanisms allow insects to eliminate reactive oxygen species (ROS) toxicity induced by agrochemicals including fungicides. In the present study, we analyzed the mRNA expression levels of detoxifying enzymes in Tenebrio molitor larvae following exposure to non-lethal doses (0.2, 2, and 20 ㎍/µL) of a fungicide captan. Transcripts of peroxidases (POXs), catalases (CATs), superoxide dismutases (SODs), and glutathione-s-transferases (GSTs) were screened from the T. molitor transcriptome database. RT-qPCR analysis showed that TmPOX5 mRNA increased significantly 24 h post-captan exposure. A similar increase was noticed for TmSOD4 mRNA 3 h post-captan exposure. Moreover, the expression of TmCAT2 mRNA increased significantly 24 h post-treatment with 2 ㎍/µL captan. TmGST1 and TmGST3 mRNA expression also increased noticeably after captan exposure. Taken together, these results suggest that TmPOX5 and TmSOD4 mRNA can be used as biomarkers or xenobiotics sensors for captan exposure in T. molitor, while other detoxifying enzymes showed differential expression.