• Title/Summary/Keyword: Reductase

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Histone H3K4 Methyltransferase SET1A Stimulates the Adipogenesis of 3T3-L1 Preadipocytes (히스톤 H3K4 메칠화효소 SET1A에 의한 지방세포 분화 촉진)

  • Kim, Seon Hoo;Jung, Myeong Ho
    • Journal of Life Science
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    • v.27 no.10
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    • pp.1104-1110
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    • 2017
  • SET1A is a histone H3K4 methyltransferase that catalyzes di- and trimethylation of histone H3 at lysine 4 (H3K4). Mono-, di-, and trimethylations on H3K4 (H3K4me1, H3K4me2, and H3K4me3, respectively) are generally correlated with gene activation. Although H3K4 methylation is associated with the stimulation of adipogenesis of 3T3-L1 preadipocytes, it remains unknown whether SET1A plays a role in the regulation of adipogenesis of 3T3-L1 preadipocytes. Here, we investigated whether SET1A regulates 3T3-L1 preadipocytes' adipogenesis and characterized the mechanism involved in this regulation. SET1A expression increased during 3T3-L1 preadipocytes' adipogenesis. Consistent with the increased SET1A expression, the global H3K4me3 level had also increased on day 2 after the induction of adipogenesis in 3T3-L1 adipocytes. SET1A knockdown using siRNA in 3T3-L1 preadipocytes inhibited 3T3-L1 preadipocytes' adipogenesis, as assessed by Oil Red O staining and the expression of adipogenic genes, indicating that SET1A stimulates the adipogenesis of 3T3-L1 preadipocytes. SET1A knockdown inhibited the cell proliferation of 3T3-L1 cells during mitotic clonal expansion (MCE) via down-regulation of the cell cycle gene cyclin E1, as well as the DNA synthesis gene, dihydrofolate reductase. Furthermore, SET1A knockdown repressed peroxisome proliferator-activated receptor gamma ($PPAR{\gamma}$) expression during the late stage of adipogenesis. These results indicate that SET1A stimulates MCE and $PPAR{\gamma}$ expression, which leads to the promotion of 3T3-L1 preadipocytes' adipogenesis.

Enhanced PHB Accumulation in Photosystem- and Respiration-defective Mutants of a Cyanobacterium Synechocystis sp. PCC 6803 (Synechocystis sp. PCC 6803의 에너지 대사 결함 돌연변이 균주에서의 Poly(3-hydroxybutyrate) 축적량 증진)

  • Kim Soo-Youn;Choi Gang Guk;Park Youn Il;Park Young Mok;Yang Young Ki;Rhee Young Ha
    • Korean Journal of Microbiology
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    • v.41 no.1
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    • pp.67-73
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    • 2005
  • Photoautotrophic bacteria are promising candidates for the production of poly(3-hydroxybutyrate) (PHB) since they can address the critical problem of substrate costs. In this study, we isolated 25 Tn5-inserted mutants of the Synechocystis sp. PCC 6803 which showed enhanced PHB accumulation compared to the wild-type strain. After 5-days cultivation under nitrogen-limited mixotrophic conditions, the intracellular levels of PHB content in these mutants reached up to $10-30\%$ of dry cell weight (DCW) comparable to $4\%$ of DCW in the wild-type strain. Using the method of inverse PCR, the affected genes of the mutants were mapped on the completely known genome sequence of Synechocystis sp. PCC 6803. As a result, the increased PHB accumulation in 5 mutants were found to be resulted from defects of genes coding for NADH-ubiquinone oxidoreductase, O-succinylbenzoic-CoA ligase, photosystem II PsbT protein or histidine kinase, which are involved in photosystem in thylakoid inner membrane of the cell. The values of $NAD(P)H/NAD(P)^+$ ratio in the cells of these mutants were much higher than that of the wild-type strain as measured by using pulse-amplitude modulated fluorometer, suggesting that PHB synthesis could be enhanced by increasing the level of cellular NAD(P)H which is a limiting substrate for NADPH-dependent acetoacetyl-CoA reductase. From these results, it is likely that NAD(P)H would be a limiting factor for PHB synthesis in Synechocystis sp. PCC 6803.

Anti-atherogenic Effect of Green Tea Product through Hypolipidemic and Anti-oxidative Action in Ovariectomized Rats (난소절제 흰쥐에서 녹차가공품의 지질강하와 항산화 작용을 통한 항동맥경화 효과)

  • Cho, Mi-Kyung;Noh, Kyung-Hee;Kim, Jin-Ju;Song, Young-Sun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.36 no.10
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    • pp.1263-1270
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    • 2007
  • This study was carried out to investigate the effect of green tea product (GTP) on the risk factors of atherosclerosis in ovariectomized (OVX) rats. Sprague-Dewley female rats (10 weeks) weighing approximately $279{\pm}2g$ were divided into 4 groups: sham operated control group treated with high cholesterol diet (Sham-C), OVX control group treated with high cholesterol diet (OVX-C), OVX-G 5% group treated with high cholesterol containing 5% GTP and OVX-G 20% group treated with high cholesterol diet containing 20% GTP. Serum TG concentrations was lower in OVX-G 20% group than in the OVX-C group, whereas ratio of HDL-cholesterol to total cholesterol (%) was significantly (p<0.05) increased in the 20% GTP supplementation group than in the Sham-C and OVX-C groups. Tumor necrosis $factor-{\alpha}$ levels were significantly (p<0.05) decreased in the OVX-G 20% group. Hepatic TG levels were significantly (p<0.05) lowered in OVX-G 20% group than in the other groups. Glutathione levels and antioxidant enzyme activities including glutathione-reductase and Mn-superoxide dismutase in liver were significantly (p<0.05) higher in the OVX-G 20% group in the OVX-C group. Fecal total cholesterol concentrations were increased in the GTP supplementation groups than in the OVX-C group. From the above results, it is concluded that GTP may reduce the risk of atherosclerosis via hypolipidemic action. Therefore, it may be used to possibly improve the hyperlipemia in menopausal women.

Suppressive Effect of Green Tea Seed Coat Ethyl Acetate Fraction on Inflammation and Its Mechanism in RAW264.7 Macrophage Cell (RAW264.7 Macrophage Cell에서 녹차씨껍질 에틸아세테이트 분획의 염증억제 효과 및 기전 연구)

  • Noh, Kyung-Hee;Jang, Ji-Hyun;Min, Kwan-Hee;Chinzorig, Radnaabazar;Lee, Mi-Ock;Song, Young-Sun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.5
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    • pp.625-634
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    • 2011
  • Green tea seed coat (GTSC) was extracted with 100% ethanol for 4 hr and then fractionated with petroleum ether (PE), ethyl acetate (EtOAC) and butanol (BuOH). The EtOAC fraction showed the highest level in total phenol contents and the lowest level in nitric oxide (NO) production in LPS-stimulated RAW264.7 macrophage cell. Thus, this study was carried out to investigate the anti-inflammatory and its mechanisms of GTSC EtOAC fraction in LPS-stimulated RAW264.7 macrophage cell. GTSC EtOAC fraction contained EGC ($1146.48{\pm}11.01\;{\mu}g/g$), tannic acid ($966.99{\pm}32.24\;{\mu}g/g$), EC ($70.88{\pm}4.39\;{\mu}g/g$), gallic acid ($947.61{\pm}1.03\;{\mu}g/g$), caffeic acid ($37.69{\pm}1.46\;{\mu}g/g$), ECG ($35.46{\pm}3.19\;{\mu}g/g$), and EGCG ($15.53{\pm}0.09\;{\mu}g/g$) when analyzed by HPLC. NO production was significantly (p<0.05) suppressed in a dose-dependent manner with an $IC_{50}$ of $80.11\;{\mu}g$/mL. Also prostaglandin $E_2$ level was also inhibited in a dose-dependent manner. Moreover, iNOS protein expression was suppressed in dose-dependent manner but COX-2 gene expression was not affected. Total antioxidant capacity and glutathione (GSH) levels were enhanced more than the LPS-control. Expressions of antioxidative enzymes including catalase, GSH-reductase and Mn-SOD were elevated compared to LPS-control. Nuclear p65 level was decreased in the GTSC EtOAC fraction in a dose-dependent manner. These results indicate that GTSC EtOAC fraction inhibit oxidative stress and inflammatory responses through elevated GSH levels, antioxidative enzymes expressions and suppression of iNOS expression via NF-${\kappa}B$ down-regulation.

Effects of Extracts of Persimmon Leaf, Buckwheat Leaf, and Chinese Matrimony Vine Leaf on Body Fat and Lipid Metabolism in Rats (감잎, 메밀잎 및 구기자잎 추출물의 식이보충이 흰쥐의 체지방 감량과 지질대사 조절에 미치는 효과)

  • Jung, Un-Ju;Lee, Jeong-Sun;Bok, Song-Hae;Choi, Myung-Sook
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.9
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    • pp.1215-1226
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    • 2011
  • The objective of this study was to investigate the anti-obesity and lipid-lowering effects of extracts of persimmon leaf (PWE), buckwheat leaf (BWE), and chinese matrimony vine leaf (LWE) in rats fed a high-fat diet (HFD). Male Sprague-Dawley rats (n=40) were divided into four groups: HFD (35% fat, w/w), HFD (38.5% fat, w/w) supplemented with PWE (10%, w/w), BWE (10%, w/w), and LWE (10%, w/w) groups. The epididymal, perirenal, and interscapular white adipose tissue (WAT) weights as well as plasma leptin level were lowest in the LWE group. Supplementation with PWE and BWE also tended to lower the perirenal and retroperitonal WAT weights compared to the HFD control group, and there was a significant decrease in plasma leptin concentration. Furthermore, plasma triglyceride concentration, hepatic cholesterol content, and hepatic lipid droplet accumulation were significantly lower in the PWE, BWE, and LWE groups than in the HFD group. BWE supplementation markedly lowered plasma total cholesterol concentration, although there were no significant differences in plasma HDL-cholesterol concentration and ratio of HDL-cholesterol/total cholesterol among the groups. Hepatic HMG-CoA reductase activity was significantly higher in the PWE and LWE groups than in the HFD group, and hepatic ACAT was not changed by extract supplementation. However, supplementation with PWE, BWE, and LWE significantly increased fecal acidic sterol content in rats fed a HFD. These results suggest that supplementation with PWE, BWE, and LWE may be an effective anti-obesity strategy by lowering body fat weight and improving plasma and hepatic lipid profiles in HFD-fed rats.

A study on the Effects of Rehmannia Radix and Eukmigihwangtang (EMGHT) on Antioxidation Activity in Aging Rats (숙지황(熟地黃)과 육미지황탕(六味地黃湯)이 노화과정(老化過程) 흰쥐에서의 항산화(抗酸化) 기전(機轉)에 미치는 영향(影響))

  • Ahn, Sang-Won;Lee, Cheol-wan
    • Journal of Haehwa Medicine
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    • v.8 no.1
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    • pp.593-623
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    • 1999
  • This experimental study was designed to verify the anti-aging efficacy of Eukmigihwangtang (EMGHT) and Rehmannia Radix, and determine the specific role and actions of Rehmannia Radix. Normal rat (2 months old), aging rat (8 months old), and pathologically induced rat (2 months old, injected 30mg/kg of streptozotocin) are observed to study the aging eliciting factors such as peroxide contents and enzyme activities. The following results were obtained in this study: 1. For the body weight changes, normal group given Rehmannia Radix showed decrease in the body weight compared to the control group, aging group given EMGHT and Rehmannia Radix showed significant decrease in the body weight, and STZ injected group showed suppression to the body weight loss when given EMGHT and Rehmannia Radix. 2. For the content changes in serum lipid peroxide, normal group showed increasing level as the rat gets older. Aging group and STZ injected group given EMGHT and Rehmannia Radix showed significant decrease in the lipid peroxide level compared to the control group. Decrease was more prominant in the group given EMGHT. 3. For the changes in serum hydroxyl radical, normal group did not show significant changes, but aging group and STZ injected group given EMGHT and Rehmannia Radix showed significant decrease in the hydroxyl radical level compared to the control group. Decrease was more prominant in the group given EMGHT. 4. For the changes in serum superoxide dismutase (SOD) activity, normal group did not show significant changes, but aging group given EMGHT and Rehmannia Radix showed significant increase in the SOD activity compared to the control group. STZ injected group given EMGHT and Rehmannia Radix showed significant decrease in the SOD activity compared to the control group. 5. For the content changes in hepatic lipid peroxide, aging group and STZ injected group given EMGHT and Rehmannia Radix showed significant decrease in the lipid peroxide level compared to the control group. 6. For the changes in hepatic cytochrome P-450 activity, aging group and STZ injected group given EMGHT and Rehmannia Radix showed significant decrease compared to the control group. Cytochrome b5 activity was significantly decreased only in the STZ injected group given EMGHT and Rehmannia Radix. 7. For the changes in hepatic aminopyrine demethylase and aniline hydroxylase activity, aging group given EMGHT and Rehmannia Radix showed significant decrease compared to the control group. STZ injected group given EMGHT and Rehmannia Radix showed significant increase in the aminopyrine demethylase activity, and showed significant decrease in the aniline hydroxylase activity compared to the control group. 8. For the content changes in hepatic protein bound-SH and nonprotein bound-SH, againg group and STZ injected group given EMGHT and Rehmannia Radix showed significant increase compared to the control group. 9. For the content changes in hepatic glutathione level, aging group and STZ injected group given EMGHT and Rehmannia Radix showed significant increase compared to the control group. 10. For the changes in hepatic glutathione S-transferase activity, aging group and STZ injected group given EMGHT and Rehmannia Radix showed significant increase and decrease, respectively, compared to the control group. 11. For the changes in hepatic glutathione reductase activity, aging group and STZ injected group given EMGHT and Rehmannia Radix showed significant increase compared to the control group, while $\gamma$-Glutamylcystein synthetase activity did not show significant changes. 12. For the changes in hepatic superoxide dismutase activity, aging group and STZ injected group given EMGHT and Rehmannia Radix showed significant decrease compared to the control group. From the above results, the antioxidant effects of EMGHT and Rehmannia Radix were proved, as well as the role of Rehmannia Radix, a chief of EMGHT, was examined. In addition, since no change was reconized as the quantity of Rehmannia Radix and the order herbs increased, the reasonableness on EMGHT was proven with respect to its composition and quantity. Thus, the significance of EMGHT could be objectively exmined in terms of its composition and quantity. Considering animals used in the experiment, there were obvious changes in aging rats and pathologically induced rats than in normal rats. Consequently, it was noticeable that EMGHT and Rehmannia Radix were working selectively on the subjects.

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Antioxidant Effect of Hot water and Ethanol extracts from Cheonnyuncho (Opuntia humifusa) on Reactive Oxygen Species (ROS) Production in 3T3-L1 Adipocytes (3T3-L1 지방세포내 ROS 생성에 대한 천년초 열수 및 에탄올 추출물의 항산화 효과)

  • Yoon, Bo-Ra;Lee, Young-Jun;Kim, Sun-Gu;Jang, Jung-Young;Lee, Hyo-Ku;Rhee, Seong-Kap;Hong, Hee-Do;Choi, Hyeon-Son;Lee, Boo-Yong;Lee, Ok-Hwan
    • Food Science and Preservation
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    • v.19 no.3
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    • pp.443-450
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    • 2012
  • Recently, NADPH oxidase 4 (NOX4)-mediated generation of intracellular reactive oxygen species (ROS) was proposed to accelerate adipogenesis of 3T3-L1 cell. We have previously shown that Cheonnyuncho (Opuntia humifusa) extract significantly inhibited adipocyte differentiation via downregulation of $PPAR{\gamma}$ (peroxisome proliferator-activated receptor gamma) gene expression. In this study, we focused on the molecular mechanism(s) of NOX4, G6PDH (glucose-6-phosphate dehydrogenase) and antioxidant enzymes in anti-oxidative activities of 3T3-L1 adipocytes. Our results indicate that Cheonnyuncho extracts markedly inhibits ROS production during adipogenesis in 3T3-L1 cells. Cheonnyuncho extracts suppressed the mRNA expression of the pro-oxidant enzyme such as NOX4 and the NADPH-producing G6PDH enzyme. In addition, treatment with Cheonnyuncho extract was found to upregulate mRNA levels of antioxidant enzymes such as Mn-SOD (manganese-superoxide dismutase), Cu/Zn-SOD (copper/zinc-SOD), glutathione peroxidase (GPx), glutathion reductase (GR), and catalase, all of which are important for endogenous antioxidant responses. These data suggest that Cheonnyuncho extract may be effective in preventing the rise of oxidative stress during adipocyte differentiation through mechanism(s) that involves direct down regulation of NOX4 and G6PDH gene expression or via upregulation of endogenous antioxidant responses.

Contribution of Thymidylate Synthase Enhancer Region (TSER) Polymorphism to Total Plasma Homocysteine Levels in Korean Patients with Recurrent Spontaneous Abortion (한국인의 반복자연유산 환자에서 Thymidylate Synthase Enhancer Region (TSER) 돌연변이형의 혈중 호모시스테인 양과의 관련성)

  • Choi, Yoon-Kyung;Kang, Myung-Seo;Kim, Nam-Keun;Kim, Sun-Hee;Choi, Dong-Hee;An, Myung-Ok;Lee, Su-Man
    • Clinical and Experimental Reproductive Medicine
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    • v.31 no.3
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    • pp.183-190
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    • 2004
  • Objectives: Methylenetetrahydrofolate reductase (MTHFR) mutation are commonly associated with hyperhomocysteinemia, and through their defects in homocysteine metabolism, they have been implicated as a risk factor for recurrent spontaneous abortion. Recent report describe that 28-bp tandem repeat polymorphism in thymidylate synthase enhancer region (TSER) that influence enzyme activity would affect plasma homocysteine level. We have investigated the relationship between TSER genotype and plasma homocysteine level in 54 patients with recurrent spontaneous abortion. Methods: Plasma homocysteine level was measured by fluorescent polarizing immunoassay. MTHFR mutation (C677T and A1298C) was identified by PCR-restriction fragment length polymorphism assay and TSER mutation was analyzed by PCR method. The data were analyzed using the program SAS 8.2 for Windows. Results: Total homocysteine level was significantly higher in MTHFR 677TT genotype ($9.80{\pm}3.87{\mu}mol/L$) than MTHFR 677CC genotype ($8.14{\pm}1.74{\mu}mol/L$) in Korean patients with unexplained recurrent spontaneous abortion (p=0.0143). However, the plasma homocysteine level was not significantly different in the MTHFR 1298AA ($8.42{\pm}2.65{\mu}mol/L$) and 1298CC ($6.09{\pm}0.32{\mu}mol/L$; p=0.2058) and, TSER 2R2R ($8.61{\pm}1.68{\mu}mol/L$) and 3R3R ($8.05{\pm}2.81{\mu}mol/L$; p=0.9319) mutant genotypes, respectively. In this study, we found the combination effects of TSER and MTHFR C677T genotypes. Plasma homocysteine levels were the highest ($11.47{\pm}4.66{\mu}mol/L$) in individuals with TSER 3R3R ($8.05{\pm}2.81{\mu}mol/L$) and MTHFR 677TT ($9.80{\pm}3.87{\mu}mol/L$) genotypes. Individuals with a combination of both TSER 2R2R/2R3R and MTHFR 677CC/CT genotypes ($7.69{\pm}1.77{\mu}mol/L$) had lower plasma homocysteine levels than TSER 2R2R ($8.61{\pm}1.68{\mu}mol/L$) and MTHR 677CC ($8.14{\pm}1.74{\mu}mol/L$) genotypes, respectively. The effect of MTHFR polymorphism in the homocysteine metabolism appears to be stronger than that of TSER polymorphism. Conclusion: Although statistically not significant, we found the elevated level of plasma homocysteine in combined genotypes with TSER and MTHFR (C677T and A1298C) in Korean patients with unexplained habitual abortion. In this study, we reported the possibility that TSER polymorphism is a genetic determinant of plasma homocysteine levels in the Korean patients as well as MTHFR C677T polymorphism. A large prospective study is needed to verify our findings.

Processed Panax ginseng, sun ginseng, inhibits the differentiation and proliferation of 3T3-L1 preadipocytes and fat accumulation in Caenorhabditis elegans

  • Lee, Hyejin;Kim, Jinhee;Park, Jun Yeon;Kang, Ki Sung;Park, Joeng Hill;Hwang, Gwi Seo
    • Journal of Ginseng Research
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    • v.41 no.3
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    • pp.257-267
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    • 2017
  • Background: Heat-processed ginseng, sun ginseng (SG), has been reported to have improved therapeutic properties compared with raw forms, such as increased antidiabetic, anti-inflammatory, and antihyperglycemic effects. The aim of this study was to investigate the antiobesity effects of SG through the suppression of cell differentiation and proliferation of mouse 3T3-L1 preadipocyte cells and the lipid accumulation in Caenorhabditis elegans. Methods: To investigate the effect of SG on adipocyte differentiation, levels of stained intracellular lipid droplets were quantified by measuring the oil red O signal in the lipid extracts of cells on differentiation Day 7. To study the effect of SG on fat accumulation in C. elegans, L4 stage worms were cultured on an Escherichia coli OP50 diet supplemented with $10{\mu}g/mL$ of SG, followed by Nile red staining. To determine the effect of SG on gene expression of lipid and glucose metabolism-regulation molecules, messenger RNA (mRNA) levels of genes were analyzed by real-time reverse transcription-polymerase chain reaction analysis. In addition, the phosphorylation of Akt was examined by Western blotting. Results: SG suppressed the differentiation of 3T3-L1 cells stimulated by a mixture of 3-isobutyl-1-methylxanthine, dexamethasone, and insulin (MDI), and inhibited the proliferation of adipocytes during differentiation. Treatment of C. elegans with SG showed reductions in lipid accumulation by Nile red staining, thus directly demonstrating an antiobesity effect for SG. Furthermore, SG treatment down-regulated mRNA and protein expression levels of peroxisome proliferator-activated receptor subtype ${\gamma}$ ($PPAR{\gamma}$) and CCAAT/enhancer-binding protein-alpha ($C/EBP{\alpha}$) and decreased the mRNA level of sterol regulatory element-binding protein 1c in MDI-treated adipocytes in a dose-dependent manner. In differentiated 3T3-L1 cells, mRNA expression levels of lipid metabolism-regulating factors, such as amplifying mouse fatty acid-binding protein 2, leptin, lipoprotein lipase, fatty acid transporter protein 1, fatty acid synthase, and 3-hydroxy-3-methylglutaryl coenzyme A reductase, were increased, whereas that of the lipolytic enzyme carnitine palmitoyltransferase-1 was decreased. Our data demonstrate that SG inversely regulated the expression of these genes in differentiated adipocytes. SG induced increases in the mRNA expression of glycolytic enzymes such as glucokinase and pyruvate kinase, and a decrease in the mRNA level of the glycogenic enzyme phosphoenol pyruvate carboxylase. In addition, mRNA levels of the glucose transporters GLUT1, GLUT4, and insulin receptor substrate-1 were elevated by MDI stimulation, whereas SG dose-dependently inhibited the expression of these genes in differentiated adipocytes. SG also inhibited the phosphorylation of Akt (Ser473) at an early phase of MDI stimulation. Intracellular nitric oxide (NO) production and endothelial nitric oxide synthase mRNA levels were markedly decreased by MDI stimulation and recovered by SG treatment of adipocytes. Conclusion: Our results suggest that SG effectively inhibits adipocyte proliferation and differentiation through the downregulation of $PPAR{\gamma}$ and $C/EBP{\alpha}$, by suppressing Akt (Ser473) phosphorylation and enhancing NO production. These results provide strong evidence to support the development of SG for antiobesity treatment.

Effect of buchu (Allium tuberosum) on lipid peroxidation and antioxidative defense system in streptozotocin-induced diabetic rats (부추가 Streptozotocin 유발 당뇨쥐의 지질과산화와 항산화방어체계에 미치는 영향)

  • 송영선;정현실;노경희;조혜연;박지영;최춘연;권태완
    • Journal of Life Science
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    • v.13 no.3
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    • pp.333-342
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    • 2003
  • The pathogenic effort of high glucose, possibly in concert with fatty acids, is mediated to vascular complications of diabetes via increased production of reactive oxygen species(ROS), reactive nitrogen species(RNS), and subsequent oxidative stress. This study was carried out to investigate the suppressive effect of buchu(Allium tuberosum) on oxidative stress in streptozotocin(STZ)-induced diabetes in Sprague Dawley male rats. The effect of buchu supplementation (10%) on lipid peroxidation, and antioxidative defense system in blood and liver was compared among normal rats fed basal diet(normal) and diabetic rats fed basal diet(DM-control) or 10% buchu-supplemented diet(DM-buchu). Diabetes was experimentally induced by the femoral muscle injection of 50 mg STZ per kg of body weight. Animals were sacrificed after 4 wks of experimental diets feeding. The induction of diabetes by STZ elevated the level of lipid peroxidation represented by thiobarbituric acid-reactive substances(TBARS) and conjugated dienes in plasma, LDL, liver, and erythrocytes. 10% buchu-supplemented diet significantly reduced the levels of conjugated dienes in erythrocytes(p<0.05) and lowered TBARS in liver and LDL to the levels of control. Induction of diabetes by STZ elevated Mn-superoxide dismutase(Mn-SOD) activity and lowered activities of glutathionine reductase(GSH-red) and glutathionine peroxidase(GSH-px). Catalase activity was not affected by the induction of diabetes by STZ. However, buchu supplementation to diabetic rats significantly elevated catalase activity(p<0.05) and slightly elevated GSH-px and GSH-red activities in liver. GSH levels of blood and liver were lowered or not changed by induction of diabetes by STZ, respectively, while buchu supplementation to diabetic rats significantly elevated hepatic GSH level (p<0.05). In conclusion, it can be concluded that buchu might be a food source to attenuate oxidative stress in diabetic patients by inhibiting lipid peroxidation, by increasing hepatic GSH level, and by inducing anti-oxidative enzyme systems.