• Title/Summary/Keyword: AMPK

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Adenine attenuates lipopolysaccharide-induced inflammatory reactions

  • Silwal, Prashanta;Lim, Kyu;Heo, Jun-Young;Park, Jong IL;Namgung, Uk;Park, Seung-Kiel
    • The Korean Journal of Physiology and Pharmacology
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    • v.22 no.4
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    • pp.379-389
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    • 2018
  • A nucleobase adenine is a fundamental component of nucleic acids and adenine nucleotides. Various biological roles of adenine have been discovered. It is not produced from degradation of adenine nucleotides in mammals but produced mainly during polyamine synthesis by dividing cells. Anti-inflammatory roles of adenine have been supported in IgE-mediated allergic reactions, immunological functions of lymphocytes and dextran sodium sulfate-induced colitis. However adenine effects on Toll-like receptor 4 (TLR4)-mediated inflammation by lipopolysaccharide (LPS), a cell wall component of Gram negative bacteria, is not examined. Here we investigated anti-inflammatory roles of adenine in LPS-stimulated immune cells, including a macrophage cell line RAW264.7 and bone marrow derived mast cells (BMMCs) and peritoneal cells in mice. In RAW264.7 cells stimulated with LPS, adenine inhibited production of pro-inflammatory cytokines $TNF-{\alpha}$ and IL-6 and inflammatory lipid mediators, prostaglandin $E_2$ and leukotriene $B_4$. Adenine impeded signaling pathways eliciting production of these inflammatory mediators. It suppressed $I{\kappa}B$ phosphorylation, nuclear translocation of nuclear factor ${\kappa}B$ ($NF-{\kappa}B$), phosphorylation of Akt and mitogen activated protein kinases (MAPKs) JNK and ERK. Although adenine raised cellular AMP which could activate AMP-dependent protein kinase (AMPK), the enzyme activity was not enhanced. In BMMCs, adenine inhibited the LPS-induced production of $TNF-{\alpha}$, IL-6 and IL-13 and also hindered phosphorylation of $NF-{\kappa}B$ and Akt. In peritoneal cavity, adenine suppressed the LPS-induced production of $TNF-{\alpha}$ and IL-6 by peritoneal cells in mice. These results show that adenine attenuates the LPS-induced inflammatory reactions.

α, γ-Mangostins Induce Autophagy and Show Synergistic Effect with Gemcitabine in Pancreatic Cancer Cell Lines

  • Kim, Myoungjae;Chin, Young-Won;Lee, Eun Joo
    • Biomolecules & Therapeutics
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    • v.25 no.6
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    • pp.609-617
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    • 2017
  • Pancreatic cancer is one of the most lethal and aggressive cancers in the world. However, no effective treatment is currently available for pancreatic cancer. The objective of this study was to determine the anti-pancreatic cancer effect of ${\alpha}$-mangostin (${\alpha}M$) and ${\gamma}$-mangostin (${\gamma}M$) extracted from the pericarp of Garcinia mangostana L.. Both ${\alpha}$M and ${\gamma}M$ reduced the viability of pancreatic cancer cells MIA PaCa-2 and PANC-1 in a dose-dependent manner. These compounds induced apoptosis by increasing c-PARP and c-Caspase 3 levels. They also induced autophagy by increasing levels of microtubule-associated protein 1A/1B light chain 3B (LC3II) in both cell lines while decreasing sequestosome 1 (p62) in MIA PaCa-2. Both ${\alpha}$M and ${\gamma}M$ induced autophagy through increasing phosphorylation levels of AMP-activated protein kinase (p-AMPK) and p38-mitogen activated protein kinase (p-p38) while decreasing phosphorylation level of mammalian target of rapamycin complex 1 (p-mTOR). Of various microRNAs (miRNA), miR-18a was found to be a putative regulatory miRNA for autophagy induced by ${\alpha}$M or ${\gamma}M$. In combination with gemcitabine, a compound frequently used in pancreatic cancer treatment, ${\alpha}$M and ${\gamma}M$ showed synergistic anti-cancer effects in MIA PaCa-2. Collectively, these results suggest that ${\alpha}$M and ${\gamma}M$ can induce apoptosis and autophagy in pancreatic cancer cells and that their anti-cancer effect is likely to be associated with miR-18a. In conclusion, ${\alpha}$M and ${\gamma}M$ might be used as a potential new therapy for pancreatic cancer.

Korean Red Ginseng attenuates ethanol-induced steatosis and oxidative stress via AMPK/Sirt1 activation

  • Han, Jae Yun;Lee, Sangkyu;Yang, Ji Hye;Kim, Sunju;Sim, Juhee;Kim, Mi Gwang;Jeong, Tae Cheon;Ku, Sae Kwang;Cho, Il Je;Ki, Sung Hwan
    • Journal of Ginseng Research
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    • v.39 no.2
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    • pp.105-115
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    • 2015
  • Background: Alcoholic steatosis is the earliest and most common liver disease, and may precede the onset of more severe forms of liver injury. Methods: The effect of Korean Red Ginseng extract (RGE) was tested in two murine models of ethanol (EtOH)-feeding and EtOH-treated hepatocytes. Results: Blood biochemistry analysis demonstrated that RGE treatment improved liver function. Histopathology and measurement of hepatic triglyceride content verified the ability of RGE to inhibit fat accumulation. Consistent with this, RGE administration downregulated hepatic lipogenic gene induction and restored hepatic lipolytic gene repression by EtOH. The role of oxidative stress in the pathogenesis of alcoholic liver diseases is well established. Treatment with RGE attenuated EtOH-induced cytochrome P450 2E1, 4-hydroxynonenal, and nitrotyrosine levels. Alcohol consumption also decreased phosphorylation of adenosine monophosphate-activated protein kinase, which was restored by RGE. Moreover, RGE markedly inhibited fat accumulation in EtOH-treated hepatocytes, which correlated with a decrease in sterol regulatory element-binding protein-1 and a commensurate increase in sirtuin 1 and peroxisome proliferator-activated receptor-a expression. Interestingly, the ginsenosides Rb2 and Rd, but not Rb1, significantly inhibited fat accumulation in hepatocytes. Conclusion: These results demonstrate that RGE and its ginsenoside components inhibit alcoholic steatosis and liver injury by adenosine monophosphate-activated protein kinase/sirtuin 1 activation both in vivo and in vitro, suggesting that RGE may have a potential to treat alcoholic liver disease.

The Gene Expression Level Differences associated with Exercise in the Mouse Brain exposed to Radiofrequency Radiation (전자파에 노출된 생쥐에서 운동량에 따른 뇌의 유전자 변화)

  • Lee, Min Sun
    • Journal of Digital Convergence
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    • v.18 no.1
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    • pp.241-247
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    • 2020
  • The effect of radiofrequency radiation (RF) exposure on mouse associated with the exercise was investigated in the brain at the molecular level. The expression of tyrosine hydroxylase(TH), FoxO3a, AMPKα and mRNA was investigated by real-time RT-PCR in striatum and the hypothalamus. In the striatum, TH mRNA expression was decreased in the exercise and RF exposure group. FoxO3a mRNA expression was significantly increased in the spontaneous exercise group and a significant decrease was observed in the RF exposure and spontaneous exercise group. In the hypothalamus, TH mRNA expression was significantly decreased in the RF exposure and spontaneous exercise group. But, FoxO3a mRNA expression was significantly increased in the RF exposure and spontaneous exercise group. We will further investigate the expression of protein molecules in the hippocampus of the brain to reveal the effects of RF radiation on memory.

Anti-Obese Effects of Ginseng/Ginsenosides : A Literature Review from 1983 to 2012 (인삼과 진세노사이드의 항비만 효과에 대한 문헌 고찰)

  • Choi, Munji;An, Jinpyo;Kim, Ae Jung;Lee, Myoungsook
    • Journal of the East Asian Society of Dietary Life
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    • v.24 no.3
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    • pp.335-350
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    • 2014
  • Compared to the large numbers of studies on the diabetes, hyperlipidemia and cancer therpeutic effects of ginseng, the anti-obese effect and mechanisms of ginsengs have not been studied as much. To determine the effects of ginseng on obesity, 14 keywords (ginseng, ginsenoside, obesity, weight, fat, diet, overeat, appetite, lipid, 3T3-L1, adipocyte, food intake, adipogenesis and lipolysis) were combined in searching a database. Fifty-six articles published from 1983 to 2012 as well as 656 patents registered until Aug $17^{th}$, 2012, were screened for anti-obese effects of ginseng. In the classification of experimental methods, 16 papers on 3T3-L1 cells, 38 papers on animals and three papers on human were reviewed. In terms of obese mechanisms of action, the most commonly used biomarkers were in order of lipid profiles > weight change > blood glucose > adipocytokine. Most ginseng studies on obesity focused on AMPK, $PPAR{\gamma}$, GLUT-4, PI3K and SREBP-1. Korean white ginseng extracts and Re repressed the lipogenesis genes such as PPARc2, SREBP-1c, LPL, FAS and DGAT1. However, ginseng or ginsenosides, PD (Rb1) and PT (Re), showed different or contradictory results. Water and ethanol extraction of ginseng showed contradictory effects on the secretion of inflammatory cytokines, wheras IL-6 was repressed by ethanol extracts and TNF-${\alpha}$ repressed by Re in vitro. Based on the literature, further studies on anti-obese mechanisms of ginseng, such as the inflammation-related obesity or cross signals between the adipocytes and the environments, are needed, instead of more studies on its hypolipidemic and hypoglycemic effects.

The Anti-obesity Effects of Younggyechulgam-tang-ga Hwanggi on Obesity in Mice Induced by High Fat Diet (고지방식이 유도 비만생쥐에 대한 영계출감탕(苓桂朮甘湯) 가(加) 황기(黃芪)의 항비만 효과)

  • Jeong, Man-Jin;Woo, Chang-Hoon;Ahn, Hee-Duk
    • Journal of Korean Medicine Rehabilitation
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    • v.28 no.2
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    • pp.1-20
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    • 2018
  • Objectives This study was conducted to experimentally evaluate the effects of Younggyechulgam-tang-ga Hwanggi(YGT) on obesity in mice induced by high fat diet. Methods The experiment was conducted with 4-week-old male mice divided into 5 groups. They were a normal diet group(Nor), a high fat diet group(Veh), a positive drug control group-orlistat 40 mg/kg(Oris), a 1.08 g/kg group(YGTL), and a 2.16 g/kg group(YGTH), and were tested for five weeks. Changes in antioxidant activity, body weight, organ weight, ROS, AST, ALT, TC, TG, HDL-C, LDL-C and lipid metabolism protein were checked. Results YGTL and YGTH group significantly reduced body weight compared to Veh group. YGTH group significantly reduced visceral fat weights compared to Veh group. In blood biochemistry analysis, ROS, AST, ALT, TC, TG and LDL-C in YGTL and YGTH group were significantly lower than Veh group. HDL-C increased significance in YGTL and YGTH group. In antioxidation protein analysis, Catalase, GPx and HO-1 have increased significantly in YGTL and YGTH group. YGTH group have increased $PPAR-{\alpha}$, p-AMPK compared to Veh group. but decreased FAS. SREBP-1, p-ACC levels in YGTL and YGTH group were decreased compared to Veh group, however CPT-1, UCP-2 levels in YGTL and YGTH group were increased compared to Veh group. Conclusions YGT has anti-obesity effects by regulating lipolysis and antioxidation in a diet-induced obesity model. Additional clinical studies are needed.

Capsanthin Inhibits both Adipogenesis in 3T3-L1 Preadipocytes and Weight Gain in High-Fat Diet-Induced Obese Mice

  • Jo, Sung Jun;Kim, Jeung Won;Choi, Hye Ok;Kim, Jung Hwan;Kim, Hyung Joong;Woo, Sun Hee;Han, Byung Hoon
    • Biomolecules & Therapeutics
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    • v.25 no.3
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    • pp.329-336
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    • 2017
  • Adipogenesis in murine preadipocyte 3T3L-1 has been used as a model system to study anti-obese bioactive molecules. During adipogenesis in 3T3-L1 preadipocytes, we found that capsanthin inhibited adipogenesis ($IC_{50}$; $2.5{\mu}M$) and also showed lipolytic activity in differentiated adipocytes from the preadipocytes ($ED_{50}$; 872 nM). We identified that the pharmacological activity of capsanthin on adipogenesis in 3T3-L1 was mainly due to its adrenoceptor-${\beta}_2$-agonistic activity. In high-fat diet animal model study, capsanthin significantly enhanced spontaneous locomotive activities together with progressive weight-loss. The capsanthin-induced activation of kinetic behavior in mice was associated with the excessive production of ATP initiated by both the enhanced lipolytic activity together with accelerated oxidation of fatty acids due to the adrenoceptor ${\beta}_2$-agonistic activity of capsanthin. Capsanthin also dose-dependently increased adiponectin and p-AMPK activity in high fat diet animals, suggesting that capsanthin has both anti-obesity and insulin sensitizing activities.

Arginase inhibition by rhaponticin increases L-arginine concentration that contributes to Ca2+-dependent eNOS activation

  • Koo, Bon-Hyeock;Lee, Jonghoon;Jin, Younghyun;Lim, Hyun Kyo;Ryoo, Sungwoo
    • BMB Reports
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    • v.54 no.10
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    • pp.516-521
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    • 2021
  • Although arginase primarily participates in the last reaction of the urea cycle, we have previously demonstrated that arginase II is an important cytosolic calcium regulator through spermine production in a p32-dependent manner. Here, we demonstrated that rhaponticin (RPT) is a novel medicinal-plant arginase inhibitor and investigated its mechanism of action on Ca2+-dependent endothelial nitric oxide synthase (eNOS) activation. RPT was uncompetitively inhibited for both arginases I and II prepared from mouse liver and kidney. It also inhibited arginase activity in both aorta and human umbilical vein endothelial cells (HUVECs). Using both microscope and FACS analyses, RPT treatments induced increases in cytosolic Ca2+ levels using Fluo-4 AM as a calcium indicator. Increased cytosolic Ca2+ elicited the phosphorylations of both CaMKII and eNOS Ser1177 in a time-dependent manner. RPT incubations also increased intracellular L-arginine (L-Arg) levels and activated the CaMKII/AMPK/Akt/eNOS signaling cascade in HUVECs. Treatment of L-Arg and ABH, arginase inhibitor, increased intracellular Ca2+ concentrations and activated CaMKII-dependent eNOS activation in ECs of WT mice, but, the effects were not observed in ECs of inositol triphosphate receptor type 1 knockout (IP3R1-/-) mice. In the aortic endothelium of WT mice, RPT also augmented nitric oxide (NO) production and attenuated reactive oxygen species (ROS) generation. In a vascular tension assay using RPT-treated aortic tissue, cumulative vasorelaxant responses to acetylcholine (Ach) were enhanced, and phenylephrine (PE)-dependent vasoconstrictive responses were retarded, although sodium nitroprusside and KCl responses were not different. In this study, we present a novel mechanism for RPT, as an arginase inhibitor, to increase cytosolic Ca2+ concentration in a L-Arg-dependent manner and enhance endothelial function through eNOS activation.

Inhibitory Effect of Cymbopogon Citratus Ethanol Extracts on Adipogenesis in 3T3-L1 Preadipocytes (레몬그라스 에탄올 추출물의 3T3-L1 지방세포 분화 억제효과)

  • Jo, Yong Seok;Ju, Sung Min;Hwang, Keum Hee;Kim, Min Sook;Kim, Kwang Sang;Jeon, Byung Hun
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.33 no.1
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    • pp.17-24
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    • 2019
  • Cymbopogon citratus, commonly know as lemongrass, prossesses strong antioxidant, anti-tumor and anti-inflammatory properties. Howerver, its anti-obesity activity remains to be elucidated. This study investigated the effect of ethanol extract of Cymbopogon citratus on adipogenesis, and its underlying mechanism, in 3T3-L1 preadipocytes. The results demonstrated that ethanol extracts of Cymbopogon citratus effectively suppressed intercellular lipid accumulation at non-toxic concentrations, and was associated with the down-regulation of adipocyte-specific transcription factors, including $C/EBP{\alpha}$ and $PPAR{\gamma}$, and phosphorylation of $AMPK{\alpha}$. Furthermore, ethanol extracts of Cymbopogon citratus increased p21 and p21 expression, while the expression of CDK2, cyclin A and cyclin B1 was reduced. As a result, ethanol extracts of Cymbopogon citratus seems to induce G0/G1 cell cycle arrest of 3T3-L1 cells. On the other hand, ERK and Akt signaling pathways were not involved in anti-adipogenesis by ethanol extracts of Cymbopogon citratus. Taken together, theses results suggest that ethanol extracts of Cymbopogon citratus inhibits adipocyte differentiation in 3T3-L1 cells and can be used as a safe and efficient natural substance to manage anti-obesity.

Purification of ginseng rare sapogenins 25-OH-PPT and its hypoglycemic, antiinflammatory and lipid-lowering mechanisms

  • Xu, Jing;Liu, Hairong;Su, Guangyue;Ding, Meng;Wang, Wei;Lu, Jincai;Bi, Xiuli;Zhao, Yuqing
    • Journal of Ginseng Research
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    • v.45 no.1
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    • pp.86-97
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    • 2021
  • Background: Panax ginseng Meyer has been used as a nourishing edible herb in East Asia for thousands of years. 25-OH-PPT was first discovered as a natural rare triterpenoid saponin in ginseng stems and leaves by our group. Research found that it showed strong inhibitory effects on α-glucosidase and protein tyrosine phosphatase 1B, and protected cardiocytes (H9c2) through PI3K/Akt pathway. Methods: In the research, in order to optimize the 25-OH-PPT enrichment process, optimal macroporous resins and optimal purification conditions were studied. Meanwhile, the hypoglycemic effect and mechanism of 25-OH-PPT were evaluated by using STZ to establish insulin-dependent diabetic mice and the spontaneous type 2 diabetes DB/DB mice. Results and Conclusion: Research found that 25-OH-PPT can reduce blood glucose and enhance glucose tolerance in STZ model mice. It increases insulin sensitivity by upregulating GLUT4 and AMPK in skeletal muscle, and activating insulin signaling pathways. In DB/DB mice, 25-OH-PPT achieves hypoglycemic effects mainly by activating the insulin signaling pathway. Meanwhile, through the influence of liver inflammatory factors and lipids in serum, it can be seen that 25-OH-PPT has obvious anti-inflammatory and lipid-lowering effects. These results provide new insights into the study of ginseng as a functional food.