• Molecules and Cells
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• v.19 no.2
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• pp.279-282
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• 2005

In mammals, 7-dehydrocholesterol reductase (Dhcr7) is the terminal enzyme in cholesterol biosynthesis. We previously reported that the Dhcr7 proximal promoter (-179 to +1), which contains CpG islands, is responsible for sterol-mediated expression of the rat gene. In the present study, we examined whether methylation of this region affects the transcriptional activity of the Dhcr7 gene. In vitro DNA methylation of the Dhcr7 promoter and luciferase-reporter assays showed that DNA methylation of the CpG islands suppressed transcription. Furthermore, treatment of the methylated Dhcr7 promoter with the demethylating agent, 5-aza-2'-deoxycytidine (5-Aza-CdR), reversed the suppression of promoter activity. These results indicate that methylation of the CpG islands is an important transcriptional regulatory mechanism in the Dhcr7 promoter.

• Journal of Microbiology and Biotechnology
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• v.6 no.6
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• pp.425-431
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• 1996

The enzymatic characteristics of Alcaligenes latus were investigated by measuring the variations of various enzyme activities related to biosynthesis and degradation of poly-${\beta}$-hydroxybutyrate (PHB) during cultivation. All PHB biosynthetic enzymes, ${\beta}$-ketothiolase, acetoacetyl-CoA reductase, and PHB synthase, were activated gradually at the PHB accumulation stage, and the PHB synthase showed the highest value among three enzymes. This indicates that the rate of PHB biosynthesis is mainly controlled by either ${\beta}$-ketothiolase or acetoacetyl-CoA reductase rather than PHB synthase. The enzymatic activities related to the degradation of PHB were also measured, and the degradation of PHB was controlled by the activity of PHB depolymerase. The effect of supplements of metabolic regulators, citrate and tyrosine, was also investigated, and the activity of glucose-6-phosphate dehydrogenase was increased by metabolic regulators, especially by tyrosine. The activities of ${\beta}$-ketothiolase and acetoacetyl-CoA reductase were also activated by citrate and tyrosine, while the activity of PHB depolymerase was depressed. The increased rate and yield of PHB biosynthesis by metabolic regulators may be due to the increment of acetyl-CoA concentration either by the repression of the TCA cycle by citrate through product inhibition or by the activation of sucrose metabolism by the supplemented tyrosine.

• Korean Journal of Pharmacognosy
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• v.42 no.4
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• pp.371-378
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• 2011

Aldose reductase (AR) has been implicated in the development of the diabetic complications. To discover novel treatments for diabetic complications from natural sources, 65 Korean herbal medicines have been investigated for inhibitory activities on AR. Of these, 23 herbal medicines exhibited a significant inhibitory activity compared with 3,3-tetramethyleneglutaric acid (TMG). Particularly, 8 herbal medicines, Acer tataricum (twig, stem and leaf), Acer tataricum (fruit), Rhododendron schlippenbachii (twig, stem and leaf), Weigela subsessilis (twig, stem and leaf), Acer mono (branch and leaf), Ailanthus altissima (twig, stem and leaf), Lindera obtusiloba (branch and leaf), Solidago serotina (whole plant) showed three times more potent inhibitory activity than the positive control, TMG.

• Korean Journal of Pharmacognosy
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• v.45 no.4
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• pp.366-375
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• 2014

Aldose reductase (AR) has been indicated the critical enzyme of the polyol pathway in the development of the diabetic complications. In this study, 119 Vietnamese herbal medicines have been investigated for inhibitory activities on AR. Among them, 7 herbal medicines, Synedrella nodiflora (stems and leaves), Combretum sundaicum (stems and leaves), Argyreia acuta (stems and leaves), Platea latifolia (whole plants), Linociera sangda (whole plants), Rhaphiolepis indica (whole plants), Harrisonia perforata (stems and leaves) and 2 fractions from Harrisonia perforata (stems and leaves) with EtOAc and BuOH, exhibited a significant inhibitory activity against AR. Particularly, S. nodiflora, A. acuta and H. perforata (stems and leaves) showed 1.0-1.8 times more potent inhibitory activity than the positive control, 3,3-tetramethyleneglutaric acid (TMG).

• BMB Reports
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• v.32 no.6
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• pp.605-609
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• 1999

Thioltransferase, also called glutaredoxin, is a general GSH-disulfide reductase of importance for redox regulation. Previously, the protein thioltransferase, now called S-type thioltransferase, was purified and characterized from Arabidopsis thaliana seed. In the present study, a second thioltransferase, called L-type thioltransferase, was purified to homogeneity from Arabidopsis thaliana leaves. The purification procedures included DEAE-cellulose ion-exchange chromatography, Sephadex G-50 gel filtration, and glutathione-agarose affinity chromatography. The purified enzyme was confirmed to show a unique band on SDS-PAGE and its molecular weight was estimated to be 26.6 kDa, which appeared to be atypical compared with those of most other thioltransferase. It could utilize 2-hydroxyethyl disulfide, S-sulfocysteine, and insulin as substrates, and also contained dehydroascorbate reductase activity. Its optimum pH was 8.5 and its activity was greatly activated by L-cysteine. When it was kept for 30 min, it appeared to be very stable up to $70^{\circ}C$. It was activated by $MgCl_2$ and, on the contrary, inhibited by $ZnCl_2$, $MnCl_2$, and $AlCl_3$.

• Journal of Applied Biological Chemistry
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• v.51 no.1
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• pp.13-16
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• 2008

Five anthraquinones, emodin (1), ${\omega}$-hydroxyemodin (2), chrysophanol-8-O-${\beta}$-D-glucoside (3), emodin-8-O-${\beta}$-D-glucoside (4), and physcion-8-O-${\beta}$-D-glucoside (5), and five flavonoids, kaempferol-3-O-${\beta}$-D-glucoside (6), quercetin (7), quercitrin (8), isoquercitrin (9), and (+)-catechin (10), were isolated from the EtOAc-soluble extract of the fruits of Rumex japonicus. The structures of 1-10 were identified by spectroscopic methods including NMR studies. This is the first report on the isolation of compounds 3-5 from this plant. The isolates were subjected to in vitro bioassays to evaluate their inhibitory activities on the rat lens aldose reductase (RLAR), among which two anthraquinones (1 and 4), and five flavonols (5-9) showed significant activities on RLAR.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.269-269
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• 1994

GABA shunt에 관여하는 두 가지 효소인, GABA transminase와 Succinic semialdehyde reductase에 대한 단일 클론 항체를 생산하고 이들 항체의 특성을 살펴보았다. 소의 뇌에서 순수 정제된 효소를 동물에 주사한 후 immunodot-blot 분석법에 의하여 일차적으로 항체를 분비하는 hybridoma를 골라낸 후 생산된 단일 클론 항체가 특이적으로 이들 효소와 반응하는 가를 알아보기 위하여 Western blot 분석을 실시하였다. 뇌조직에서 추출한 총단백질을 SDS 전기영동법에 의하여 분리한 후 이들 항체를 처리한 결과, GABA-T에 대한 항체는 특이적으로 분자량이 50kDa에 해당하는 단백질 밴드만을 인지하였고 SSA reductase에 대한 항체의 경우 분자량이 34kDa 크기의 단백질 밴드와 반응하였다. 이들 분자량은 순수 정제된 소뇌의 효소 단백질의 크기에 해당하는 것을 확인하였다. 이들 소뇌의 효소에 대한 항체를 추적물체로 사용하여 다른 포유동물자 조류의 효소와 비교하는 cross-reactivity 연구를 수행하였다. 소, 돼지, 토끼, 쥐 (rat), 개, 고양이 그리고 닭의 뇌를 제거한 후 총단백질을 추출하고 Western blot을 해본 결과 GABA transaminase의 경우 조류를 제외하고 다른 포유동물에서는 같은 분자량의 단일 단백질 밴드를 확인하였고 SSA reductase의 경우 조류를 포함하는 모든 동물에서 같은 분자량의 밴드를 확인하였다 이상의 결과로 미루어 보아 포유류 뇌에 있는 이들 효소들은 변역학적으로 아주 유사하다고 사료된다.

• Journal of Nutrition and Health
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• v.32 no.6
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• pp.637-643
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• 1999

The effects of yam(Dioscorea) on lowering cholesterol level and its mechanism were investigated. The concentrations of plasma and liver lipids, and the excretions of fecal neutral sterol and bile acid were measured in male Sprague-Dawley rats. Five Groups of 8 rats were fed hypercholesterolemic diet(1% cholesterol, 10% lard ; control), hypercholesterolemic diet plus 15% or 30% dried yam powder prepared by either hot-air(15HY, 30HY) or freeze dry(15FY, 30FY) for 4wk. Plasma total lipid, total cholesterol and cholesterol level was also significantly lower(28%, p<0.05), buy HMG-CoA reductase activity was higher in 30FY(230%, p<0.05) than in control. Although no significant differences in fecal neutral sterols were observed among groups, the yam-fed rats apparently had less bacterial degradation of cholesterol as indicated by a significantly greater of fecal cholesterol to coprostanol than in controls. Total fecal bile acids were significantly greater in rats fed yam(15HY : 5 folds, 15FY ; 12,30HY ; 12, 20FY ; 22) than in controls. The ratio of secondary to primary bile acids was almost 8 times lower in 30FY than in control. These data indicate that yam lowers cholesterol both in plasma and in liver through increasing fecal bile acid excretion as well as HMG-CoA reductase activity. Freeze-dried yam, which possesses viscosity, was more effective in cholesterol-lowering action than hot-air dried one.

• Korean Journal of Pharmacognosy
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• v.48 no.3
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• pp.195-201
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• 2017

To develop new therapy for prevention and treatment of hair loss is very important according to increase of the number of hair loss people. The aim of this study was to investigate the hair growth promoting effects of pectin lyase-modified red ginseng extract (GS-E3D). We examined antioxidant and anti-inflammatory effects, human hair dermal papilla cells (HHDPC) proliferation, and testoterone-induced $5{\alpha}$-reductase inhibitory effects. GS-E3D show not only 1,1-diphenyl-2-picryhydrazyl (DPPH) radical scavenging activity and xanthine oxidase inhibitory effects as an anti-oxidant property, but also lip-oxygenase and hyaluronidase inhibitory effects as an anti-inflammatory property. Human hair dermal papilla cells proliferation by GS-E3D was higher than those of minoxidil or finasteride, using the positive controls. Moreover, GS-E3D exhibited $5{\alpha}$-reductase inhibitory activities after stimulating by testoterone. The present results indicate that GS-E3D has a potential to be as an hair growth promoting agent for cosmetic materials.

• Journal of Pharmacopuncture
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• v.10 no.1 s.22
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• pp.121-135
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• 2007

Objectives : This study was carried out to examine protective effect of wild ginseng extract on HepG2 human hepatoma cell line against tert-Butyl hydroperoxide (t-BHP)-induced oxidative damage. Methods : To evaluate protective effect of wild ginseng extract against t-BHP induced cytotoxicity, LDH level and activity of glutathione peroxidase and reductase were measured. Gene expression was also measured using DNA microarray. Results : Wild ginseng extract showed a significant protective effect against t-BHP-induced cytotoxicity in HepG2 cell line. It is not, however, related with the activities of glutathione peroxidase and glutathione reductase. Analysis of gene expression using DNA chip, demonstrated that 28 genes were up-regulated in t-BHP only group. Five genes - selenoprotein P, glutathione peroxidase 3, sirtuin 2, peroxiredoxin 2, serfiredoxin 1 homolog - may be related with the protective effect of wild ginseng extract. Conclusions : Based on the results, a protective effect of wild ginseng extract against t-BHP-induced oxidative damage in HepG2 cell line is not associated with the activities of glutathione peroxidase and glutathione reductase, but with the expression of selenoprotein P, glutathione peroxidase 3, sirtuin 2, peroxiredoxin 2, and serfiredoxin 1 homolog.