• BMB Reports
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• 제36권5호
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• pp.442-449
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• 2003

NAD(P)H quinone oxidoreductase is a ubiquitous enzyme that is known to directly reduce quinone substrates to hydroquinones by a two-electron reaction. We report the identification of NADPH quinone oxidoreductase from Kluyveromyces marxianus (KmQOR), which reduces quinone substrates directly to hydroquinones. The KmQOR gene was sequenced, expressed in Escherichia coli, purified, and characterized. The open-reading frame of the KmQOR gene consists of 1143 nucleotides, encoding a 380 amino acid polypeptide. The nucleotide sequence of the KmQOR gene was assigned to EMBL under accession number AY040868. The $M_r$ that was determined by SDS-PAGE for the protein subunit was about 42 kDa, and the molecular mass of the native KmQOR was 84 kDa, as determined by column calibration, indicating that the native protein is a homodimer. The KmQOR protein efficiently reduced 1,4-benzoquinone, whereas no activities were found for menadiones and methoxyquinones. These observations, and the result of an extended sequence analysis of known NADPH quinone oxidoreductase, suggest that KmQOR possesses a different action mechanism.

• Molecules and Cells
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• 제40권6호
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• pp.393-400
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• 2017

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease characterized by lack of insulin and high glucose levels. T2DM can cause bone loss and fracture, thus leading to diabetic osteoporosis. Promoting osteogenic differentiation of osteoblasts may effectively treat diabetic osteoporosis. We previously reported that Sirtuin 1 (Sirt1), a $NAD^+$-dependent deacetylase, promotes osteogenic differentiation through downregulation of peroxisome proliferator-activated receptor (PPAR) ${\gamma}$. We also found that miR-132 regulates osteogenic differentiation by downregulating Sirt1 in a $PPAR{\beta}/{\delta}$-dependent manner. The ligand-activated transcription factor, $PPAR{\alpha}$, is another isotype of the peroxisome proliferator-activated receptor family that helps maintain bone homeostasis and promot bone formation. Whether the regulatory role of $PPAR{\alpha}$ in osteogenic differentiation is mediated via Sirt1 remains unclear. In the present study, we aimed to determine this role and the underlying mechanism by using high glucose (HG) and free fatty acids (FFA) to mimic T2DM in MC3T3-E1 cells. The results showed that HG-FFA significantly inhibited expression of $PPAR{\alpha}$, Sirt1 and osteogenic differentiation, but these effects were markedly reversed by $PPAR{\alpha}$ overexpression. Moreover, siSirt1 attenuated the positive effects of $PPAR{\alpha}$ on osteogenic differentiation, suggesting that $PPAR{\alpha}$ promotes osteogenic differentiation in a Sirt1-dependent manner. Luciferase activity assay confirmed interactions between $PPAR{\alpha}$ and Sirt1. These findings indicate that $PPAR{\alpha}$ promotes osteogenic differentiation via the Sirt1-dependent signaling pathway.

• Parasites, Hosts and Diseases
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• 제58권4호
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• pp.431-443
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• 2020

Echinostoma mekongi n. sp. (Digenea: Echinostomatidae) is described based on adult flukes collected from humans residing along the Mekong River in Cambodia. Total 256 flukes were collected from the diarrheic stool of 6 echinostome egg positive villagers in Kratie and Takeo Province after praziquantel treatment and purging. Adults of the new species were 9.0-13.1 (av. 11.3) mm in length and 1.3-2.5 (1.9) mm in maximum width and characterized by having a head collar armed with 37 collar spines (dorsal spines arranged in 2 alternative rows), including 5 end group spines. The eggs in feces and worm uterus were 98-132 (117) ㎛ long and 62-90 (75) ㎛ wide. These morphological features closely resembled those of Echinostoma revolutum, E. miyagawai, and several other 37-collar-spined Echinostoma species. However, sequencing of the nuclear ITS (ITS1-5.8S rRNA-ITS2) and 2 mitochondrial genes, cox1 and nad1, revealed unique features distinct from E. revolutum and also from other 37-collar-spined Echinostoma group available in GenBank (E. bolschewense, E. caproni, E. cinetorchis, E. deserticum, E. miyagawai, E. nasincovae, E. novaezealandense, E. paraensei, E. paraulum, E. robustum, E. trivolvis, and Echinostoma sp. IG). Thus, we assigned our flukes as a new species, E. mekongi. The new species revealed marked variation in the morphology of testes (globular or lobulated), and smaller head collar, collar spines, oral and ventral suckers, and cirrus sac compared to E. revolutum and E. miyagawai. Epidemiological studies regarding the geographical distribution and its life history, including the source of human infections, remain to be performed.

• Archives of Pharmacal Research
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• 제22권2호
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• pp.219-224
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• 1999

In our search for the anticonvulsant consitutent of Gastrodia elata repeated column chromatographies guided by activity assay led to isolation of an active compound, which was identified as gastrodin on the basis of spectral data. Brain succinic semialdehyde dehydrogenase (SSADH) was inactivated by preincubation with gastrodin in a time-dependent manner and the reaction was monitored by absorption and fluorescene spectroscopic methods. The inactivation followed pseudo-first-order kinetics with the second-rate order constant of $1.2{\times}10^{3} M^{-1} min^{-1}$. The time course of the reaction was significantly affected by the coenzyme NAD^{+}$, which affected complete protection against the loss of the catalytic activity, whereas substrate succinic semialdehyde failed to prevent the inactivation of the enzyme. It is postulated that the gastrodin is able to elevate the neurotransmitter GABA levels in central nervous system by inhibitory action on one of the GABA degradative enzymes, SSADH.

• Parasites, Hosts and Diseases
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• 제57권4호
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• pp.423-427
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• 2019

Coenurosis is an important zoonotic helminthic disease caused by the larval stage of the tapeworm Taenia multiceps. This parasite typically infects the brain of the intermediate hosts, including sheep, goat, cattle and even humans. We report a case of T. multiceps infection in a yak confirmed by clinical symptoms, morphological characteristics, and molecular and phylogenetic analyses. The coenurus was thin-walled, whitish, and spherical in shape with a diameter of 10 cm. The parasite species was identified as T. multiceps by PCR amplification and sequencing of the 18S rRNA, cox1 and nad1 genes. Three gene sequences all showed high homology (all above 97%) with the reference sequences from different hosts. Moreover, phylogenetic reconstructions with the 3 published Taenia gene sequences confirmed that the Qinghai yak isolate was closely related to T. multiceps. Although there are advanced diagnosis and treatment methods for coenurosis, early infection is difficult to diagnose. Importantly, the findings of yak infection case should not be ignored due to its zoonotic potential.

• Nutrition Research and Practice
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• 제4권2호
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• pp.93-98
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• 2010

Our previous study demonstrated that methanolic extract of Chrysanthemum zawadskii Herbich var. latilobum Kitamura (Compositae) has the potential to induce detoxifying enzymes such as NAD(P)H:(quinone acceptor) oxidoreductase 1 (EC 1.6.99.2) (NQO1, QR) and glutathione S-transferase (GST). In this study we further fractionated methanolic extract of Chrysanthemum zawadskii and investigated the detoxifying enzyme-inducing potential of each fraction. The fraction (CZ-6) shown the highest QR-inducing activity was found to contain (+)-(3S,4S,5R,8S)-(E)-8-acetoxy-4-hydroxy-3-isovaleroyloxy-2-(hexa-2,4-diynyliden)-1,6-dioxaspiro [4,5] decane and increased QR enzyme activity in a dose-dependent manner. Furthermore, CZ-6 fraction caused a dose-dependent enhancement of luciferase activity in HepG2-C8 cells generated by stably transfecting antioxidant response element-luciferase gene construct, suggesting that it induces antioxidant/detoxifying enzymes through antioxidant response element (ARE)-mediated transcriptional activation of the relevant genes. Although CZ-6 fraction failed to induce hepatic QR in mice over the control, it restored QR activity suppressed by $CCl_4$ treatment to the control level. Hepatic injury induced by $CCl_4$ was also slightly protected by pretreatment with CZ-6. In conclusion, although CZ-6 fractionated from methanolic extract of Chrysanthemum zawadskii did not cause a significant QR induction in mice organs such as liver, kidney, and stomach, it showed protective effect from liver damage caused by $CCl_4$.

• Journal of Ginseng Research
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• 제40권4호
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• pp.423-430
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• 2016

Background: The induction of cellular defensive genes such as phase II detoxifying and antioxidant enzymes is a highly effective strategy for protection against carcinogenesis as well as slowing cancer development. Transcription factor Nrf2 (nuclear factor E2-related factor 2) is responsible for activation of phase II enzymes induced by natural chemopreventive compounds. Methods: Red ginseng oil (RGO) was extracted using a supercritical $CO_2$ extraction system and chemical profile of RGO was investigated by GC/MS. Effects of RGO on regulation of the Nrf2/antioxidant response element (ARE) pathway were determined by ARE-luciferase assay, western blotting, and confocal microscopy. Results: The predominant components of RGO were 9,12-octadecadienoic acid (31.48%), bicyclo[10.1.0] tridec-1-ene (22.54%), and 22,23-dihydrostigmasterol (16.90%). RGO treatment significantly increased nuclear translocation of Nrf2 as well as ARE reporter gene activity, leading to upregulation of heme oxygenase-1 and NAD(P)H:quinone oxidoreductase 1. Phosphorylation of the upstream kinases such as apoptosis signal-regulating kinase (ASK)1, mitogen-activated protein kinase (MAPK) kinase (MKK)4/7, c-Jun N-terminal kinase (JNK), and p38 MAPK were enhanced by treatment with RGO. In addition, RGO-mediated Nrf2 expression and nuclear translocation was attenuated by JNK inhibitor SP600125 and p38 MAPK inhibitor SB202190. Conclusion: RGO could be used as a potential chemopreventive agent, possibly by induction of Nrf2/ARE-mediated phase II enzymes via ASK1-MKK4/7-JNK and p38 MAPK signaling pathways.

• The Korean Journal of Physiology and Pharmacology
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• 제26권4호
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• pp.263-275
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• 2022

There is a paucity of detailed data related to the effect of senescence on the mitochondrial antioxidant capacity and redox state of senescent human cells. Activities of TCA cycle enzymes, respiratory chain complexes, hydrogen peroxide (H₂O₂), superoxide anions (SA), lipid peroxides (LPO), protein carbonyl content (PCC), thioredoxin reductase 2 (TrxR2), superoxide dismutase 2 (SOD2), glutathione peroxidase 1 (GPx1), glutathione reductase (GR), reduced glutathione (GSH), and oxidized glutathione (GSSG), along with levels of nicotinamide cofactors and ATP content were measured in young and senescent human foreskin fibroblasts. Primary and senescent cultures were biochemically identified by monitoring the augmented cellular activities of key glycolytic enzymes including phosphofructokinase, lactate dehydrogenase, and glycogen phosphorylase, and accumulation of H₂O₂, SA, LPO, PCC, and GSSG. Citrate synthase, aconitase, α-ketoglutarate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, isocitrate dehydrogenase, and complex I-III, II-III, and IV activities were significantly diminished in P25 and P35 cells compared to P5 cells. This was accompanied by significant accumulation of mitochondrial H₂O₂, SA, LPO, and PCC, along with increased transcriptional and enzymatic activities of TrxR2, SOD2, GPx1, and GR. Notably, the GSH/GSSG ratio was significantly reduced whereas NAD⁺/NADH and NADP⁺/NADPH ratios were significantly elevated. Metabolic exhaustion was also evident in senescent cells underscored by the severely diminished ATP/ADP ratio. Profound oxidative stress may contribute, at least in part, to senescence pointing at a potential protective role of antioxidants in aging-associated disease.

• 대한지역사회영양학회지
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• 제4권2호
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• pp.207-218
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• 1999

The increased number of elderly in Korea presents great challenges for community nutrition programs. Strategies to enhance elderly nutrition are needed, as well as dietary advice that are reality-based and tailored to the need of the elderly. The purpose of this study was to evaluate the overall effectiveness of an elderly nutrition improvement program(ENIP), by assessing changes in nutrition knowledge, attitudes, and behavior after program completion. ENIP was conducted in Suwon for 4 months in 1998 at 5 centers for the elderly. The program provided individual nutrition counseling and brief biweekly group education sessions. To stimulate participation and motivation, the elderly in two centers were served free milk packs(200ml) three time a week during the program(milk＋education group), and the elderly in 3 other centers were served yoghurt on the program day(education group). Altogether, 102 subjects finished the program(milk＋education group 67 ; education group 35). Data about nutrition knowledge, dietary attitudes, diet records(24 hour recall) and dietary habit was collected before(baseline) and after the program(follow-up). The Drop-out rate for the milk＋education group(2.9%) was significantly lower than that for the education group(30.0%)(p<.001). The Nutrition Knowledge fo females milk＋education group increased significantly after the program, but no significant differences were observed in other groups. Over 60% of all the elderly showed positive responses to the healthy eating attitudes. Energy, protein, vitamin A, riboflavin, Calcium and Potassium intakes improved in the male milk＋education group. The Vitamin C intake improved in the male education group. Energy and vitamin A intakes improved in the female milk＋education group and energy, vitamin A, thiamin, riboflavin, niacin, Ca nad P in the female education group. A stepwise multiple regression analysis was performed to examine the effects of food intake changes on overall nutrient quality. For all elderly, the fish intake explained 12.6% of the variance, followed by candy intake and vegetable intake(model $R^2$=19.6%). Dietary habits such as meal time regularity and salty food reduction were markedly improved in both groups. Sixty-one percent of the milk＋education subjects stated their participation was voluntary and active, while 51% of education subjects did. Sixty four percent of the subjects stated their interest on diet increased remarkably through program participation. Considering the results, it is conjectured that ENIP had a great impact on nutrient intake, dietary attitudes and habits. Milk supplement showed no direct effects on elderly nutrition improvement, but it encouraged the program by reducing drop-out rates and inducing voluntary participation. Therefore milk supplement could enhance the community nutrition education program. Moreover it is strongly suggested that the ENIP be expanded to other communities.

• 한국균학회지
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• 제30권2호
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• pp.124-130
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• 2002

본 연구에서는 버들송이(Agrocybe cylindracea)와 말똥진흙버섯(Phellinus igniarius)을 배양한 대두 추출물의 암예방 효과를 검토하기 위하여 in vitro상에서 암발생 억제물질 연구에 널리 이용되고 있는 기작 즉, Quinone reductase(QR), glutathione S-transerase(GST)의 활성 유도, glutathione(GSH)의 생성 촉진 그리고, polyamine 합성대사의 억제능을 측정하였다. 그 결과, 버들송이와 말똥진흙버섯를 배양한 대두 추출물이 마우스 hepatoma Hepa1c1c7 cell 배양에서 QR과 GST 유도활성이 있음이 확인되었다. 또한 GSH 생성량은 버들송이를 배양한 대두 추출물에서 20%, 말똥진흙버섯를 배양한 대두 추출물에서 40%로 증가하였다. 한편, 버들송이와 말똥진흙버섯을 배양한 대두 추출물의 polyamine 합성대사의 억제효과를 검토하기 위해 Acanthamoeba castellanii의 증식을 측정하였다. 그 결과, 버들송이와 말똥진흙버섯을 배양한 대두 추출물 20mg/3ml와 40mg/3ml를 처리할 경우 A. castellanii의 증식을 억제하는 것으로 나타났다. 이러한 결과 담자균을 배양한 대두 추출물은 in vitro상에서 나타난 암과 관련된 각종 활성으로부터 암예방 효과가 있는 것으로 나타나 기능성 식품으로서의 가능성을 보여주었다.