• Toxicological Research
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• 제6권2호
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• pp.167-182
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• 1990

Dietary restriction (caloric restriction) is the only intervention which has been reliably shown to extend the maximum life span of warm-blooded animals and delay the many phenomena associated with aging. It is also one of the most effective modulators of toxicity, especially cancer endpoints. In spite of the known modulator effects of caloric restriction, the biological mechanisms responsible for these effects had not been in vestigated until recently. The National Center for Toxicological Research (NCTR), in a collaborative effort with the National Institute of Aging (NIA), initiated a project whereby nine (9) combinations of rodent species/strains and diets were fed both restricted and ad libitum. The NIA's initiative was to identify biomarkers of aging whereas NCTR's initiative was to identify the biological effects associated with the profound effects caloric restriction has in protecting against both spontaneous (age-related) and chemically-induced toxic endpoints. Independent of sex or species, caloric restriction has similar effects on body temperature, oxygen consumption and $CO_2$production. Caloric restriction also decreased lipid glycolysis and metabolism in rats and mice, which suggest decreased production of metabolites which could lead to fatty acid epoxide formation. The age-associated loss of ciradian regulation of intermediate enzymes is also significantly reduced. Moreover, caloric restriction reduced the age-associated feminization of sexually dimorphic liver isozymes, increased several glucocorticoid responsive isozymes, elevated glucagon/insulin ratios, produced less microsomal superoxide and enhanced the capacity for utilzing detoxicating metabolic pathways. Calorically restricted rats have less than half the number of aflatoxin ($AFB_1$)-DNA adducts than ad libitum animals and urinary excretion of $AFB_1$ was increased significantly. Finally, DNA repair mechanisms are enhanced and oncogene expression is decreased in calorically restricted animals.

• 한국초지조사료학회지
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• 제33권3호
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• pp.153-158
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• 2013

Molybdenum (Mo) in rhizosphere influences sulfate assimilation as well as a number of other physiological aspects. In this study, the activity of key enzymes in sulfate assimilatory pathways, such as ATP sulfurylase (ATPs), adenosine 5'-phosphosulphate reductase (APR), as well as the responses of reactive oxygen species (ROS), were analyzed to elucidate the metabolic and physiological effects of external Mo supply to detached leaves of Trifolium repens L. Mo supply with a range from 1 mM to 40 mM depressed the activity of ATPs throughout the entire time course. In the leaves exposed to 1 mM Mo, a continuous decrease in the activity of ATPs was confirmed by Native-PAGE. The APR activity was also declined by Mo treatment. The accumulation of $H_2O_2$ and ${O_2}^{{\cdot}-}$ were not significant up to 10 mM Mo, whereas a remarked accumulation was detected under 40 mM Mo supply. The data suggest that an external supply of Mo has an inhibitory effect on sulfate assimilation, and induces oxidative stress only at an extremely high concentration.

• 대한약침학회지
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• 제21권3호
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• pp.177-184
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• 2018

Objectives: Auraptene, a natural citrus coumarin, found in plants of Rutaceae and Apiaceae families. In this study, we investigated the effects of auraptene on tumor migration, invasion and matrix metalloproteinase (MMP)-2 and -9 enzymes activity. Methods: The effects of auraptene on the viability of A2780 and Hela cell lines was evaluated by MTT assay. Wound healing migration assay and Boyden chamber assay were determined the effect of auraptene on migration and cell invasion, respectively. MMP-2 and MMP-9 activities were analyzed by gelatin zymography assay. Results: Auraptene reduced A2780 cell viability. The results showed that auraptene inhibited in vitro migration and invasion of both cells. Furthermore, cell invasion ability suppressed at $100{\mu}M$ auraptene in Hela cells and at 25, $50{\mu}M$ in A2780 cell line. Gelatin zymography showed that for Hela cell line, auraptene suppressed MMP-2 enzymatic activity in all concentrations and for MMP-9 at a concentration between 12.5 to $100{\mu}M$ in A2780 cell line. Conclusion: Auraptene inhibited migration and invasion of human cervical and ovarian cancer cells in vitro by possibly inhibitory effects on MMP-2 and MMP-9 activity.

• Journal of Ginseng Research
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• 제40권4호
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• pp.375-381
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• 2016

Background: We evaluated the drug interaction profile of Red Ginseng (RG) with respect to the activities of major cytochrome P450 (CYP) enzymes and the drug transporter P-glycoprotein (P-gp) in healthy Korean volunteers. Methods: This article describes an open-label, crossover study. CYP probe cocktail drugs, caffeine, losartan, dextromethorphan, omeprazole, midazolam, and fexofenadine were administered before and after RG supplementation for 2 wk. Plasma samples were collected, and tolerability was assessed. Pharmacokinetic parameters were calculated, and 90% confidence intervals (CIs) of the geometric mean ratios of the parameters were determined from logarithmically transformed data using analysis of variance after RG administration versus before RG administration. Results: Fourteen healthy male participants were evaluated, none of whom were genetically defined as poor CYP2C9, 2C19, and CYP2D6 metabolizers based on genotyping. Before and after RG administration, the geometric least-square mean metabolic ratio (90% CI) was 0.870 (0.805-0.940) for caffeine to paraxanthine (CYP1A2), 0.871 (0.800-0.947) for losartan (CYP2C9) to EXP3174, 1.027 (0.938-1.123) for omeprazole (CYP2C19) to 5-hydroxyomeprazole, 1.373 (0.864-2.180) for dextromethorphan to dextrorphan (CYP2D6), and 0.824 (0.658-1.032) for midazolam (CYP3A4) to 1-hydroxymidazolam. The geometric mean ratio of the area under the curve of the last sampling time ($AUC_{last}$) for fexofenadine (P-gp) was 0.963 (0.845-1.098). Administration of concentrated RG for 2 wk weakly inhibited CYP2C9 and CYP3A4 and weakly induced CYP2D6. However, no clinically significant drug interactions were observed between RG and CYP and P-gp probe substrates. Conclusion: RG has no relevant potential to cause CYP enzyme- or P-gp-related interactions.

• Journal of Microbiology and Biotechnology
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• 제23권4호
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• pp.459-466
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• 2013

The lactic acid bacterium Streptococcus thermophilus is widely used as a starter culture for the production of dairy products. Whole-genome sequencing is expected to utilize the genetic basis behind the metabolic functioning of lactic acid bacterium (LAB), for development of their use in biotechnological and probiotic applications. We sequenced the whole genome of Streptococcus thermophilus MTCC 5461, the strain isolated from a curd source, by 454 GS-FLX titanium and Ion Torrent PGM. We performed comparative genome analysis using the local BLAST and RDP for 16S rDNA comparison and by the RAST server for functional comparison against the published genome sequence of Streptococcus thermophilus CNRZ 1066. The whole genome size of S. thermophilus MTCC 5461 is of 1.73Mb size with a GC content of 39.3%. Streptococcal virulence-related genes are either inactivated or absent in the strain. The genome possesses coding sequences for features important for a probiotic organism such as adhesion, acid tolerance, bacteriocin production, and lactose utilization, which was found to be conserved among the strains MTCC 5461 and CNRZ 1066. Biochemical analysis revealed the utilization of 17 sugars by the bacterium, where the presence of genes encoding enzymes involved in metabolism for 16 of these 17 sugars were confirmed in the genome. This study supports the facts that the strain MTCC 5461 is nonpathogenic and harbors essential features that can be exploited for its probiotic potential.

• Journal of Microbiology and Biotechnology
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• 제28권8호
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• pp.1293-1298
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• 2018

Phosphomannomutase (ManB) converts mannose-6-phosphate (M-6-P) to mannose-1-phosphate (M-1-P), which is a key metabolic precursor for the production of GDP-D-mannose used for production of glycoconjugates and post-translational modification of proteins. The aim of this study was to express the manB gene from Escherichia coli in Lactococcus lactis subsp. cremoris NZ9000 and to characterize the encoded enzyme. The manB gene from E. coli K12, of 1,371 bp and encoding 457 amino acids (52 kDa), was cloned and overexpressed in L. lactis NZ9000 using the nisin-controlled expression system. The enzyme was purified by Ni-NTA column chromatography and exhibited a specific activity of 5.34 units/mg, significantly higher than that of other previously reported ManB enzymes. The pH and temperature optima were 8.0 and $50^{\circ}C$, respectively. Interestingly, the ManB used in this study had two substrate specificity for both mannose-1-phosphate and glucose-1-phosphate, and the specific activity for glucose-1-phosphate was 3.76 units/mg showing 70% relative activity to that of mannose-1-phosphate. This is the first study on heterologous expression and characterization of ManB in lactic acid bacteria. The ManB expression system constructed in this study canbe used to synthesize rare sugars or glycoconjugates.

• Environmental Analysis Health and Toxicology
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• 제13권3_4호
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• pp.105-115
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• 1998

Reactive oxygen species (ROS) are highly reactive molecules due to their unpaired electron. They have been suspected as one of the major tissue damage inducers in biological metabolic systems. Antioxidant enzymes, such as catalase and superoxide dismutase, could not repair all the oxidative damages resulting from those excessive toxic ROS. It is, therefore, urgent to develop effective antioxidants to relieve from the oxidatire damages. In this study antioxidative effects were investigated by using two flavonoids such as quercetin and naringenin and a flavonoid-rich extract, Ginkgo biloba extract in combination with paraquat that is known as a strong generator of oxygen radicals. The results are summeringed as follows: 1. To assess radical scavenging ability reduction concentrations (IC$_{50}$) of 1,1-diphenyl-2-picrylhydrazine (DPPH) within 15 minutes were measured. The values of the IC$_{50}$ of quercetin and Ginkgo biloba extract were 15.4 $\mu$M and 13.2$\mu$g/ml, respectively. Their radical removing activities showed concentration-dependent manners. 2. In the hydrogen peroxide assay by using PMS-NADH system, quercetin, naringenin and Ginkgo biloba extract led to removing hydrogen peroxide in concentrationdependent manner whose removing abilities at 100$\mu$M or 100 $\mu$g/ml were 75.6, 25.8 and 26.0%, respectively. 3. In the hydrogen peroxide-induced rat blood hemolysis assay all three compounds led to similar effects whose hemolysis inhibition ratios at 100$\mu$M or 100$\mu$g/ml were 68.0, 5.14 and 55.8%, respectively. 4. In the xanthinee oxidase assay by measuring degree of NADH oxidation in the presence of hypoxanthine and xanthinee oxidase, both quercetin and Ginkgo biloba extract showed excellent activities showing 42.8 and 24.2% inhibiting xanthine oxidase activity at 100$\mu$M or 100$\mu$g/ml concentrations, respectively.

• 혜화의학회지
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• 제8권1호
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• pp.711-726
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• 1999

Aging in the life form occurs due to a gradual progression of the body growth and degeneration. Morphological and functional changes in the body decreases the adaptation and prevention capacity leading into the decline of a life force. Various studies have been released to examine the anti-aging effects of herbal prescriptions. This experiment has chosen Boganhwan which is used for the deficiency of the liver function and studied the anti-aging factors by examining the biotransformation enzymes. The following results were obtained in this study: 1. Hepatic lipid peroxide activity was significantly suppressed in the experimental group treated with Boganhwan for 2 weeks at the dosage of 350mg/kg, while other dosage groups did not present much changes. 2. Insignificant changes were shown for the cytochrome P-450 level, aminopyrine demethylase, and aniline hydroxylase (AH) activities. Cytochrome P-450 do not appears to be a part of the detoxification scheme. 3. Boganhwan decoction treated group showed most significant increase of superoxide dismutase (SOD), catalase, superoxide, and glutathione activities at the concentration of 350mg/kg and 500mg/kg. 4. Glutathione S-transferase and glutathione made most significant increase at the decoction concentration of 350mg/kg and 500mg/kg compared to the control group. 5. Hepatic glutathione concentration, protein bound-SH, and nonprotein bound-SH made most significant increase at the decoction concentration of 350mg/kg and 500mg/kg compared to the control group. From the above results, Boganhwan decoction played an important role in eliminating foreign substances in the body excluding cytochrome P-450 enzyme system. Thus, Boganhwan decoction can provide substantial aid in preventing and treating senile related illnesses.

• Archives of Pharmacal Research
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• 제27권2호
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• pp.239-245
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• 2004

KR-31543, (2S,3R,4S)-6-amino-4-[N-(4-chlorophenyl)-N-(2 -methyl-2H-tetrazol-5-ylmethyl) amino]-3,4-dihydro-2-dimethoxymethyl-3-hydroxy-2-methyl-2H-1-benzopyran, is a new neuroprotective agent for preventing ischemia-reperfusion damage. This study was performed to identify the metabolic pathway of KR-31543 in human liver microsomes and to characterize cytochrome P450 (CYP) enzymes that are involved in the metabolism of KR-31543. Human liver microsomal incubation of KR-31543 in the presence of NADPH resulted in the formation of two metabolites, M1 and M2. M1 was identified as N-(4-chlorophenyl)-N-(2-methyl-2H-tetrazol-5-ylmethyl)amine on the basis of LC/MS/MS analysis with a synthesized authentic standard, and M2 was suggested to be hydroxy-KR-31543. Correlation analysis between the known CYP enzyme activities and the rates of the formation of M 1 and M2 in the 12 human liver microsomes have showed significant correlations with testosterone 6$\beta$-hydroxylase activity (a marker of CYP3A4). Ketoconazole, a selective inhibitor of CYP3A4, and anti-CYP3A4 monoclonal antibodies potently inhibited both N-hydrolysis and hydroxylation of KR-31543 in human liver microsomes. These results provide evidence that CYP3A4 is the major isozyme responsible for the metabolism of KR-31543 to M1 and M2.

• 미생물학회지
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• 제25권4호
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• pp.353-359
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• 1987

균 성장속도가 tylosin 생합성에 미치는 영향을 조사하기 위하여, 여러 성장속도로 배양한 균체내에서 oxaloacetate 대사에 관여하는 효소들의 활성을 살펴보았다. 그 결과, 비 tylosin 생합성 속도($q_{p}$ )는 성장속도 $0.013h^{-1}$까지는 성장속도와 함께 증가하지만, 더 높은 성장속도에선 감소됨을 알 수 있었다. Citrate synthase, aspartate aminotransferase와 PEP carboxylase의 활성 및 합성은 $0.013h^{-1}$ 보다 낮은 성장속도에선 매우 낮게 나타났으며, 반면 methylmaionyl-CoA carboxyltransferase의 활성 및 합성은 tylosin 생합성과 마찬가지로 높은 성장속도에선 감소되었다. 따라서 tylosin 생합성은 균 성장속도에 의해 조절됨을 명백히 알 수 있었다.