Proceedings of the Korean Society of Applied Pharmacology (한국응용약물학회:학술대회논문집)
The Korean Society of Applied Pharmacology
- Semi Annual
Domain
- Health Sciences > Biomedical Sciences
2003.11a
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Body weight is maintained at a relatively constant level over days and months despite variability in food intake and physical activity. To achieve energy homeostasis, the hypothalamus receives information related to energy surplus or shortage from the periphery and controls food intake and energy expenditure. Leptin, an adipocyte derived hormone, is a principal mediator that signals the brain about the stored energy status. Increased leptin signaling in the brain prevents excess energy stores by suppressing food intake and increasing energy expenditure. In addition, insulin and nutrients themselves, such as glucose and free fatty acids, also regulate food intake.
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NADPH is an essential co-factor for fat and cholesterol biosynthesis. However, the role of cytosolic NADP
$\^$ +/-dependent isocitrate dehydrogenase (IDPc), a putative NADPH producer, in the control of the fat and cholesterol metabolism has not been assessed. Here we report that increased or decreased IDPc expression in 3T3-Ll fat cells promoted or retarded adipogenesis, respectively. Furthermore, overexpression of IDPc in transgenic mice exhibited fatty liver, hypertriglyceridemia, hypercholesterolemia and obesity by increasing NADPH production leading to subsequent stimulation of acetyl-coenzyme A and malonyl-coenzyme A consumption. In contrast, administrations of a synthetic IDPc inhibitor, DAl1004, to ob/ob mice effectively reduced body weight with lowering cholesterol and triglyceride levels. In addition, a positive relationship (${\gamma}$ = 0.69,$\rho$ <0.0l) between plasma IDPc activity and body mass indexes was observed in 98 randomly-selected human volunteers. Our findings strongly indicate that NADPH produced by IDPc plays an important role in controlling body fat and lipid biosynthesis. -
Adipocyte development has an impact on human health issues mainly through the association of obesity with Type II diabetes, hyperlipidemia, hypertension and cardiovascular disorders. Obesity results from excessive food intake and reduced energy expenditure, and such surplus energy is stored in adipose tissue.
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Interest in the regulation of body weight and the pathological physiology of obesity has been rekindled by the cloning of the obese(ob) gene and identification of its product, leptin, in 1994. The first publication appeared in Nature and is a milestone of obesity research. The remarkable metabolic effects of leptin in rodents are: a) inhibition of food intake, b) stimulation of energy expenditure, and c) reversal of obesity. These effects, though mostly desirable, have not been fully demonstrated in humans. The central action of leptin in the regulation of body weight includes two pathways in rodents: a) When the body weight increasing, more leptin is secreted from adipose tissue, which acts on hypothalamus, probably through a POMC or MSH pathway via M4 receptor, initiates a series of response to obesity, i.e. sympathetic tone increased, energy expenditure enhanced and food intake reduced. b) When body weight reduced, leptin concentration decreased with the shrinkage of fat mass, which may also act on the hypothalamus, probably through a NPY-Y5 receptor pathway. Then a cascade of response to hungry was induced, i.e. increase of parasympathetic tone and food intake, decrease of energy expenditure and body temperature, as well as shut-down of the reproductive function.
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Obesity is one of the most serious problems in human life which may cause various diseases, i.e., cancer, hypertension and diabetes. The biochemical and clinical researches on this issue have been widely studied worldwide, and the mechanism and improvement of obesity have been gradually clarified. In this workshop, three distinguished speakers from clinical, biochemical and pharmaceutical development fields have been invited. Professor Yasushi Saito is a high prestigious worldwide in terms of the study of obesity.
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Visceral fat accumulation is known to be an evident clinical index for the insulin resistance related with obesity. Patients with excessive accumulation of visceral fat frequently suffered from metabolic disorder, such as hyperlipidemia, hypertension, and glucose intolerance. However, molecular mechanism for the pathogenesis of obesity-accompanied metabolic disorders has not been fully elucidated. It has been clarified that adipocytes in visceral fat area have different functions from subcutaneous fat area, and these differences might contribute the pathological significance of excessive accumulation of visceral fat for the accompanied insulin resistance and hyperinsulinemia.
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Engorgement of macrophages with cholesterol is the defining pathological characteristic of atherosclerotic plaques, the cause of most heart attacks and strokes. Activated human macrophages uptake low density lipoprotein (LDL) by the bulk-phase fluid, and aggregated LDL by patocytosis. After incorporation of LDL and aggregated LDL into macrophages, neutral cholesterol esterase is decreased and cholesterol efflux is also deceased, resulting that macrophages become foam cells.
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The ethanol extract of peony root (Paeonia Lactiflora Pall, Paeoniaceae) and its major active components including gallic acid and methyl gallate were evaluated for their protective effects against free radical generation and lipid peroxidation. And protective effects against hydrogen peroxide-induced oxidative DNA damage in a mammalian cell line were performed. The ethanol extract of peony root (PRE), gallic acid and methyl gallate were shown to possess the significant free radical scavenging effect against 1,1-diphenyl-2-picryl hydrazine (DPPH) radical generation and were revealed the inhibitory effect of lipid peroxidation as expressed by malondialdehyde (MDA) formation. They were also found to strongly inhibit hydrogen peroxide-induced DNA damage from NIH/3T3 fibroblasts, assessed by single cell gel electrophoresis. Furthermore, oral administration of 50% PRE (50% ethanol extract), gallic acid and methyl gallate potently inhibited micronucleated reticulocyte (MNRET) formation of mouse peripheral blood induced by KBrO3 treatment in vivo. Therefore, PRE containing gallic acid and methyl gallate may be a useful natural antioxidant by scavenging free radicals, inhibition of lipid peroxidation and protecting oxidative DNA damage.
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It is now convincing that free radical generation is involved in the pathophy siological mechanisms of ischemic stroke, particularly in ischemia-reperfusion injury. The present study, therefore, examined neuroprotective effect of aloesin isolated from Aloe vera, which was known to have antioxidative activity, in a rat model of transient focal cerebral ischemia. Transient focal cerebral ischemia was induced by occlusion of middle cerebral artery for 2 hr with a silicone-coated 4-0 nylon monofilament in male Sprague-Dawley rats under isoflurane anesthesia Aloesin (1, 3, 10, 30 and 50 mg/kg/injection) was administered intravenously 3 times at 0.5, 2 and 4 hr after onset of ischemia. Neurological score was measured 24 hr after onset of ischemia immediately before sacrifice. Seven serial coronal slices of the brain were stained with 2,3,5-triphenyltetrazolium chloride and infarct size was measured using a computerized image analyzer. Treatment with the close of 1 or 50 mg/kg did not significantly reduce infarct volume compared with the saline vehicle-treated control group. However, treatments with the closes of 3 and 10 mg/kg significantly reduced both infarct volume and edema by approximately 47% compared with the control group, producing remarkable behavioral recovery effect. Treatment with the close of 30 mg/kg also significantly reduced infarct volume to a lesser extent by approximately 33% compared with the control group, but produced similar degree of behavioral recovery effect. In addition, general pharmacological studies showed that aloesin was a quite safe compound. The results suggest that aloesin can serve as a lead chemical for the development of neuroprotective agents by providing neuroprotection against focal ischemic neuronal injury.
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Opuntia ficus-indicavar. saboten Makino (Cactaceae) is a tropical or subtropical plant that has been widely used as folk medicine for the treatment of diabetes, asthma, burn, edema and gastritis. The purposes of the present study were to identify antioxidant constituents from fruits and stems of the plant cultivated in Cheju island, Korea, and examine their in vitro neuroprotective activities. Using a chromatographic fractionation method, ten chemical constituents were isolated from ethyl acetate extracts. By means of chemical and spectroscopic methods, those were identified as eight flavonoids such as kaempherol (a), quercetin (b), kaempferol 3-methyl ether (c), quercetin 3-methyl ether (d), narcissin (e), dihydrokaernpferol (f), dihydroquercetin (g) and erioclictyol (h), and two terpenoids such as 3-oxo-
${\alpha}$ -ionol-${\beta}$ -d-glucopyranoside (i) and roseoside (j). Among the isolated compounds, comrounds c~e and h~j were those reported for the first titre from the plant. Compounds b, d and g showed DPPH free radical scavenging activities with IC$\sub$ 50/ values of 28, 19 and 31,${\mu}$ M respectively. Compounds d and g also inhibited iron-dependent lipid peroxidation with IC$\sub$ 50/ values of 2.4 and 3.5${\mu}$ M. In a primary rat cortical neuronal cell culture system, compounds b, d and g inhibited xanthine/xanthine oxidase-induced (IC$\sub$ 50/ values of 18.2, 2.1 and 54.6${\mu}$ M) and H$_2$ O$_2$ -induced (IC$\sub$ 50/ values of 13.6, 1.9 and 25.7${\mu}$ M) cytotoxicities. In addition, compounds d and g inhibited NMDA-induced excitotoxicity by 21 and 33%, and only compound d inhibited growth factor withdrawal-induced apoptosis by 31% at a tested concentration of 3${\mu}$ M. The results suggest that the antioxidant constituents with in vitroneuroprotective activities may serve as lead chemicals for the development of neuroprotective agent. -
It is thought that highly reactive oxygen radicals generated at the ischemia-reperfusion in case of strokes play an important role in damaging the brain. We examined the neuroprotective effects from the several medicinal herbs in the transient ischemic rat model and compared their effects with the free radical scavenging activities. Transient ischemia was induced by intraluminal occusion of the right middle cerebral artety for 120 min and reperfusion was continued for 22 h in rats. The free radical scavenging properties of medicinal herbs were examined in vitro by determination of the interaction with the 1,l-diphenyl-2-picrylhydrazyl (DPPH) stable free radical. Aqueous extracts of 11 medicinal herbs (200 mg/kg) were orally administered, promptly prior to reperfusion and 2 h after reperfusion. Total infarction volume in the ipsilateral hemisphere of ischemia reperfusion rats was significantly lowered by the treatment of 7 medicinal herbs (Sophora flavescens, Lycopus lucidus, Sanguisorba officinalis, Caesalpinia sappan, Albizia julibrissin, Rubia akane, Psoralea corylifolia, Prunella vulgaris). However, all of these medicinal herbs did not show antioxidative activities. These results suggest that neuroprotective effects of several drugs are not always correlated with their antioxidative properties.
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The aim of this study was to investigate the effect of resveratrol on the oxidative stress-induced inhibition of gap junctional intercellular communication (GJIC) in HaCaT keratinocyte. Anti-oxidative activity of resveratrol was measured by a,a-diphenyl-b-picrylhydrazyl (DPPH) assay and dichlorodihydrofluorescein diacetate oxidation assay. GJIC of HaCaT keratinocyte was assessed using the scrape loading/dye transfer technique. Western blots and reverse transcription-polymerase chain reaction were also analyzed for Connexin 43 protein and mRNA expression, respectively. Resveratrol scavenged directly the stable DPPH radical over a concentration range of 4 mg/
$\mell$ (78.2$\pm$ 2.7% of control) to 500 mg/$\mell$ (29.9$\pm$ 4.2% of control) and prevent to increase the intracellular fluorescence induced by oxidative stress significantly. Ultraviolet A irradiation (UVA) and 12-O-tetradecanoylphorbol-13-acetate markedly reduced GJIC, which was restored by resveratrol. There were no significant differences in the level of Connexin 43 protein and mRNA expression among any of the experimental groups. Our data suggests that resveratrol has the protective effect on the oxidative stress-induced inhibition of gap junctional intercellular communication in HaCaT keratinocyte and this protection is likely due to the scavenging of reactive oxygen species. -
Flavonoids are phenolic compounds widely distributed in wide variety of edible plants including leafy vegetables, fruits, beverages. Quercetin is one of bioflavonoid compounds and has anti-tumor effect by suppressing tumor growth in vitro and in vivo, including multiple biological effects by antioxidant and effective anti-inflammatory agent. The present study investigated whether quercetin can enhance antioxidant enzyme activities (glutathione peroxidase: GPX, superoxide dismutase : SOD, catalase: CAT) and intracellular reactive oxygen intermediate (ROI) levels in the presence of taurine on B16F10 murine melanoma cells. From this result, the antioxidant enzyme activities of quercetin in the presence of taurine was enhanced. In addition, the same treatments decreased intracellular reactive oxygen intermediate levels on B16F10 murine melanoma cells. Taken together, these results demonstrate that the antioxidant effect of quercetin can enhance in the presence of taurine and it might play an important role in anti-tumor effect.
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Minocycline is known to protect neurons from microglia-mediated cell death in many experimental models of brain diseases including ischemic stroke, Huntingtons disease (HD), amyotrophic lateral sclerosis (ALS), traumatic brain injury, multiple sclerosis, and Parkinsons disease. When the activity of caspases was assessed using their fluorescent peptide substrates, activation of caspase-2, 3, 8, and 9 was evident within 2 8 hr following oxidative insult with 0.5 mM hydrogen peroxide in PC12 cells. Minocycline significantly attenuated activation of these caspases up to 18 hr, resulting a significant increase in the cell viability as assessed by MTT assay as well as trypan blue staining. However, cleavage of alpha-spectrin and a cdk5 activator p35, which are known to be substrates for calpain, remained unchanged in the presence of minocycline, suggesting that minocycline did not block caspase-3-independent cell death or necrosis. Moreover, co-treatment with minocycline and a calpain inhibitor calpeptin synergistically inhibited hydrogen peroxide-induced cell death. These data suggest that minocycline directly inhibited apoptosis, but not necrosis, after oxidative insult in PC12 cells.
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Herbchoke solution produced by Choa pharmaceutical company contained pyroligneous liquid and extracts from artichoke leaves. Pyroligneous liquid is produced by process carbonizing Oak in 350∼400
$^{\circ}C$ . It contain water 96%, acetic acid 3% and organic compound 1%. There are 200 kinds of constituents including minerals, vitamin B-complex and organic acids in it. The organic acids of them were presumed as active materials. It is traditionally used for treatment of stress related disorder, hepatic disease, immune disorder, G-I disorder and inflammatory disease. Extracts from artichoke leaves are traditionally used for treatment of stress related disorder, that is, hepatic disease, dyspeptic disorder, hyperlipidemic disorder and diuretic disorder. The aim of this study was to investigate anti-stress effects of Hervchoke juice produced from Choa pharmaceutical company. -
There are now increasing evidences that free radicals and reactive oxygen species are involved in a variety of pathological events. Reactive Oxygen Species (ROS) are produced during normal cellular function. ROS lead to lipid peroxidation, massive protein oxdiation and degradation. Under normal conditions, antioxidant are substnaces that either directly or indirectly protect cell against adverse effect of ROS. several biologically important compound include
${\beta}$ -carotene, taruine and flavonoids reported have antioxidant function. The various antioxidant either scavange superoxide and free radicals or stimulate the detoxification mechanisms within cells resulting in increased detoxification of free radicals formation and thus in prevention of many pathophysiologic processes. This study carried out to investigate the antioxidant activity of flavonoids, myricetin with other antioxidants,${\beta}$ -carotene and taurine on B16Fl0. In order to investigate the efficacy of antioxidant activity, we measured cell viability, antioxidant enzyme activity (SOD, GPX, CAT) and intracellular reactive oxygen intermediate (ROI). In this results, we show that these flavonoids with other antioxidant substrates are increased antioxidant activity level. -
Estrogen receptor is a ligand-activated transcription factor. Its action depends on the receptor, its ligand, and its coactivator proteins. As a consequence, the concentration of the receptor is a major component that governs the magnitude of the estrogen response. Despite the extensive knowledge on mechanism of estrogen receptor action, regulation of estrogen receptor itself is not very well understood. Estrogen receptor is known to be downregulated under hypoxia leading to inhibition of estrogen receptor mediated transcription activation. We have studied mechanism of loss of estrogen responsiveness under hypoxia. We found that Hif-l
${\alpha}$ , a major transcription factor regulating hypoxic response, inhibited transcription of estrogen response element driven luciferase gene by expression of HIF-l${\alpha}$ /vp16 construct designed to contain transcription activity under normoxia. This loss of estrogen responsiveness appears to be the result of ER${\alpha}$ downregulation. ER${\alpha}$ was downregulated at the levels of ligand-biding and protein within l2-24h, and the response was blocked by the proteasome inhibitor MG132, protein synthesis inhibitor cyclohexamide, and tyrosine kinase inhibitor Genistein. These results demonstrate that Hif-l${\alpha}$ downregulates ER${\alpha}$ by proteasome dependent pathway. -
Methanol extract of Loranthus yadoriki showed the prolongation effect of bleeding time in vivo using mice in dose dependent manner. From the MeOH extract of Loranthus yadoriki, compound-A was isolated by the activity guided isolation method using silicagel column chromatography. The anti-coagulant activity was evaluated by the bleeding time test in vivo and plasma recalcification time test in vitro. Compound A showed moderate anti -coagulant activity on plasma recalcification time in vitro.
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We report upon the cytotoxic activity of the ginseng saponin metabolite, Compound K (20-O-D-glucopyranosyl-20(S)-protopanaxadiol, IH90l) on various human leukemia cell lines. Compound K had most effect on U937, a human monocytic leukemia cell line, which on treatment showed; a exposure of phosphatidylserine from the inner cell membrane to the outer cell membrane, the formation of apoptotic bodies and DNA fragmentation, - characteristics of apoptosis. Compound K induced apoptosis by up-regulating Bax, disrupting the mitochondria membrane potential, and by activating caspase 9 and caspase 3. Therefore, we suggest that Compound K inhibit U937 cell growth by inducing apoptosis through the up-regulation of Bax and caspase activation.
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Mast cells accumulation can be causally related with several allergic inflammations. Previous work has demonstrated that glucocorticoids decreased tissue mast cell number and stem cell factor (SCF)-induced migration of mast cells required p38 mitogen-activated protein kinase (MAPK) activation. In the present study, we investigated the effects of dexamethasone on SCF-induced migration of rat peritoneal mast cells (RPMCs). SCF significantly induced migration of RPMCs at 4 h. Dexamethasone dose-dependently inhibited SCF-induced migration of RPMCs (about 90.1% at 100 nM, P<0.05). MAPK p38 inhibitor, SB203580 (20
${\mu}$ M) also inhibited the SCF-induced migration. The ability of SCF to enhance morphological alteration and F -actin formation was also abolished by treatment of dexamethasone. Dexamethasone inhibited SCF-induced p38 MAPK activation to near basal level and induced the MKP-1 expression. In addition, SCF-induced inflammatory cytokine production was significantly inhibited by treatment of dexamethasone or SB203580 (p<0.01). Our results show that dexamethasone potently regulates SCF -induced migration, p38 MAPK activation and inflammatory cytokine production through expression of MKP-l protein in RPMCs. Such modulation may have functional consequences during dexamethasone treatment, especially mast cell-mediated allergic inflammation disorders. -
Sepsis remains common surgical problems with high morbidity and mortality despite improvement in the management for septic patient. Although hepatocellular dysfunction occurs during sepsis, the mechanism responsible for this remains unclear. In sepsis, a state of severe oxidative stress is encountered, with host endogenous antioxidant defenses overcome. Therefore, the aim of this study was to determine the effect of a-tocopherol (AT) vasoregulatory gene expression during polymicrobial sepsis. Rats were subjected to polymicrobial sepsis by cecal ligation and puncture (CLP). AT (15 mg/kg) was intraperitonealy injected for 3 days prior to CLP. Blood samples were taken 24 h after CLP for measurement of the extent of hepatocellular damage. Liver samples were taken for RT-PCR analysis of mRNA for genes of interest: endothelin-l (ET-l), its receptors
$ET_{A}$ and$ET_{B}$ , nitric oxide synthases (iNOS and eNOS), cyclooxygenase-2 (COX -2), heme oxygenase-l (HO-l), and tumor necrosis factor-$\alpha$ (TNF-$\alpha$ ). The activities of serum alanine aminotransferase and lipid peroxidation level were significantly increased; an increase which was prevented by AT pretreatment. CLP significantly increased the mRNA levels of ET-1 and$ET_{B}$ ; an increase that was prevented by AT pretreatment. However, the level of$ET_{A}$ mRNA significantly decreased after CLP; a decrease that was not prevented by AT pretreatment. There were significant increases in the mRNA expression of iNOS, HO-l and COX -2 in CLP groups. This increase was prevented by AT pretreatment. The expression of eNOS and TNF-$\alpha$ mRNA significantly increased in CLP, which was not prevented by AT pretreatment. Our findings suggest that there was an imbalanced vasoregulatory gene expression in sepsis, and AT ameliorates this change through its free radical scavenging activity. -
Inulin, an active component of Chicorium intybus root, has been shown to stimulate the growth of bifidobacteria, and inhibit colon carcinogenesis. NO mediates a number of the host-defense functions of activated macrophages, including antimicrobial and tumoricidal activity. We examined the effect of inulin on the synthesis of NO in RAW 264.7 cells. Inulin alone had no effect, whereas inulin with IFN-ν synergistically increased the NO production and inducible NO synthase (iNOS) expression in RAW 264.7 cells. Synergy between IFN-ν and inulin was mainly dependent on inulin-induced TNF-
${\alpha}$ secretion. Also, protein kinase C (PKC)-${\alpha}$ was involved in the inulin-induced NO production. Inulin-mediated NO production was inhibited by the protein tyrosine kinase (PTK) inhibitor, tyrphostin AG126. Since iNOS gene transcriptions have been shown to be under the control of the NF -$\kappa$ B/Rel family of transcription factors, we assessed the effect of inulin on NF -$\kappa$ B/Rel using an EMSA. Inulin produced strong induction of NF-$\kappa$ B/Rel binding, whereas AP-l binding was slightly induced in RAW 264.7 cells. Inulin stimulated phosphorylation and degradation of I$\kappa$ B-${\alpha}$ . These results suggest that in IFN-ν-primed RAW 264.7 cells inulin might stimulate NO synthesis via activation of PKC-${\alpha}$ and PTK, resulting in the activation of NF-$\kappa$ B. -
Recently diabetes has been found to be associated with metabolic bone diseases such as osteoporosis. In the present study, attempts have been made-to explore the effect of high glucose in bone formation. Osteoblast-like UMR 106 cells were treated with high glucose (22mM, 33mM, 44mM) for 1 or 2 days. High glucose significantly inhibited proliferation of UMR106 cells in a time- and dose- dependent manner as evidenced by MTT assay. For the evaluation of collagen synthesis, UMR 106 cells were cultured in high glucose media (44mM) for 24 h and the ratio of collagen content to total protein was measured. In addition, gene expression pattern of type I collagen was assessed by RT-PCR. The high concentration of glucose inhibited a collagen synthesis, a marker of bone formation activity. JNK, c- Jun N-terminal Kinase, is known to play an important role in stress-associated cell death. In this regard, we tested to determine whether high glucose has any effect on JNK activity. It has been found that treatment of high glucose induced phosphorylation of JNK. On the other hand, ERK phosphorylation was inhibited by high glucose in a dose-dependent manner. Taken together, Therefore these results indicate that inhibition of proliferation in UMR 106 cells following high glucose is related to JNK/ERK containing signal pathways. This study showed high glucose concentration could alter the bone metabolism leading to defective bone formation, suggesting that high glucose due to diabetes may playa significant role in the development of metabolic bone disease.
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Insulin-dependent or Type 1 diabetes mellitus (IDDM) has been associated with an increased severity of periodontal disease. Since periodontal ligament (PDL) cells play a significant role in maintenance and regeneration of mineralized tissue, the success of procedures, such as guided tissue regeneration, is directly related to the ability of these cells to augment mineralized tissue. In this study, we investigated the time- and dose-dependent effect of high glucose on the proliferation and collagen synthesis of human periodontal ligament (PDL) cells. PDL cells were treated with high glucose (22mM, 33mM, 44mM) for 1 or 2 days. High glucose significantly inhibited proliferation of PDL cells as a time- and dose-dependent manner as evidenced by MTT assay. PDL cells were cultured in high glucose media (22mM, 33mM, 44mM) for 24 h. The ratio of collagen content to total protein was evaluated, and the gene expression of type I collagen was assessed by RT - PCR. The high concentration of glucose inhibited collagen synthesis, a marker of bone formation activity. This study indicated high glucose concentration could alter the metabolism of periodontal ligament cell, leading to alveolar bone destruction.
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Kim, Sang-Chul;Park, Soo-Young;Hyoun, Jae-Hee;Kang, Ji-Hoon;Lee, Young-Ki;Park, Deok-Bae;Yoo, Eun-Sook;Kang, Hee-Kyoung 81
The present study was taken to examine the inhibitory effect of extracts of Scytosiphon lomentaria, a marine alga growing in Jeju Island, on the growth of cancer cells and to develop an anti-cancer agent using components of S. lomemtaria. The effect was observed by the measurement of metabolic activity using colorimetric 3-(4,5-dimethylthiazol)-2,5-diphenyltetrazolium bromide (MTT) assay. In results, crude extract of this alga markedly inhibited the growth of leukemia cell lines such as HL-60 and KG-1, but could scarcely inhibit the growth of normal cells (HEL299) and adenocarcinoma cells (SNU-16 and HCT-I5). When HL-60 cells were treated with the extract, DNA fragmentation and the increase of proportion of sub-G1 hypodiploid cells were observed. Therefore, the inhibitory effect of S. lomemtaria on the growth of HL-60 cells seems to arise from the induction of apoptosis. In order to understand the mechanism of apoptosis inducton by S. lomemtaria, we examined the changes of Bcl-2 and Bax expression. The extract reduced Bcl-2, an anti-apoptotic protein, but increased Bax, a pro-apoptotic protein in a dose-dependent manner. When we examined the activation of caspase-3, an effector of apoptosis, the expression of active form(19 kDa) of caspase-3 was increased and the increase of their activities was demonstrated by the cleavage of poly(ADP-ribose)polymerase, a substrate of caspase-3, to 85 kDa. The results indicate that extract of S. lomentaria induces the apoptosis of HL-60 cells via the down-regulation of Bc1-2 and the activation of caspases. -
Park, Soo-Young;Kim, Sang-Chul;Hyoun, Jae-Hee;Lee, Nam-Ho;Kim, Se-Jae;Lee, Young-Ki;Park, Deok-Bae;Yoo, Eun-Sook;Kang, Hee-Kyoung 82
The present study was undertaken to examine the cytotoxic effect of extract of Eurya emarginata against cancer cells and to develop an anti-cancer agent using components of its leaves. The crude extract of its leaves markedly inhibited the growth of leukemia cells including HL-60. When the HL-60 cells were treated with the extract, DNA fragmentation, morphologic changes and sub-Gl hypodiploid cells were observed. Therefore, the inhibitory effect of E. emarginata on the growth of the HL-60 cells appears to arise from the induction of apoptosis. Moreover, the extract markedly reduced c-Myc expression in a time-dependent manner. Eutigoside C showing the cytotoxic effect was isolated from the leaves of E. emarginata. Eutigoside C reduced the Bcl-2 protein and mRNA levels in a time-dependent manner, whereas the Bax protein and mRNA expression levels were slightly increased. When HL-60 cells were treated with eutigoside C, the release of cytochrome C from mitochondria into the cytosol was observed. Also, the expressions of the active forms of caspase 9 and 3 were increased and the activation of caspase 3 was demonstrated by the cleavage of Poly(ADP-ribose) polymerase, a vital substrate of effector caspase. The results indicate that the eutigoside C from E. emarginata induce apoptosis of HL-60 cells via the down-regulation of Bcl-2 expression and activation of caspases. -
Yoo, Byoung-Kwon;Park, Ji-Woong;Yoon, Seo-Young;Jeon, Mi-Jin;Park, Gyu-Hwan;Chun, Hyun-Joo;Ko, Kwang-Ho 83
In our previous study, glucose deprivation was reported to induce the potentiated death and ATP loss in immunostimulated astroglia. And this vulnerability to glucose deprivation was due to overproduction of nitric oxide (NO) and hydrogen peroxide (H$_2$ O$_2$ ). In the present study, the role of extracellular signal-regulated kinase 1/2 (ERK1/2) in the glucose deprivation-induced death of immunostimulated astroglia was examined. We showed that immunostimulation with LPS+IFN-ν activated the ERKl/2 signal pathway and produced a large amount of NO and H$_2$ O$_2$ . Generation of NO and H$_2$ O$_2$ in immunostimulated astroglia was mediated via ERK1/2 signal pathways, since addition of the ERK kinase (MEKl) inhibitor PD98059 reduced NO and H$_2$ O$_2$ production. ERK1/2 activation-mediated NO and H$_2$ O$_2$ production is due to an activation of iNOS and NADPH oxidase, respectively. Finally, we found that glucose deprivation caused ATP depletion and the augmented death in immunostimulated astroglia, which was also prevented by PD98059 treatment. These results demonstrate that the ERK1/2 signal pathways play an important role in glucose deprivation induced the death in immunostimulated astroglia by regulating the generation of NO and H$_2$ O$_2$ . -
Lead has long been considered as a toxic environmental pollutant, which severely damages central nervous system. Lead can cause hypo- and de-myelination, and glial cells are closely related with myelination or demyelination. Matrix metalloproteinases (MMPs) are proteolytic enzymes that are involved in the remodelling of the extracellular matrix in a variety of physiological and pathological processes. MMPs also seem to be important in the pathogenesis of inflammatory demyelinating diseases of the central and peripheral nervous system. In this study, we investigated whether lead affects MMP-9 expression in rat primary glial cells. Treatment of 0.1-5
${\mu}$ M lead dose- and time-dependently increased MMP-9 expression in rat primary glial cells. The activity of MMPs was determined using zymography. Lead activated Erk(1/2) but neither of the other endogenous MAP kinases, p38 or JNK. Inhibition of Erk(1/2) activation by PD98059, a MEK inihibitor, prevented lead-induced expression of MMP-9. The results of the present study suggest that lead intoxication may adversely affect brain function at least in part by inducing MMP-9 expression through Erk(1/2) activation in primary glial cells. -
This study has been undertaken to increase availability of native camellia in Jeonnam as a medicinal resource and to isolate the effective components from them. Multidrug resistance(MDR) by tumor cells is a major obstacle to successful cancer chemotherapy. We report that the crude extracts of camellia flowers, leaves has a chemosensitizing effect that can reverse Pgp-mediated MDR by increasing the intracellular accumulation of drugs. The cytotoxic and chemosensitizing effects of MeOH extract from 12 spp. citrus fruits on the AML-2/D100 were determined using MTT assay. Chemosensitizing effects was screened in the presence of vincristine, a good substrate of Pgp. IC
$\sub$ 50/ for extracts in AML-2/WT was found to be 65∼350$\mu\textrm{g}$ /$m\ell$ whereas the range of its mean IC$\sub$ 50/ value in Pgp-overexpressing cells (AML-2/Dl00) in the presence of vincristine was 90∼400$\mu\textrm{g}$ /$m\ell$ . Of the extracts tested, mature leaf extract displayed the most potent chemosensitizing effect[IC$\sub$ 50/;100$\mu\textrm{g}$ /$m\ell$ , CR;1.06, RF;2.97 in the presence of VCR]. This indicates that the toxicity (IC$\sub$ 50/;288.89$\mu\textrm{g}$ /$m\ell$ ) of mature leaf extract is minimal at concentrations required for a complete reversal of the drug resistance. Also, this result indicates that crude extracts of camellia mature leaves would contain some principles which have chemosensitizing activity. -
In a continuous effort to develop novel anticancer agents we newly synthesized and evaluated the antitumor activity of nucleoside analogues. One analogue, 4 - [2-Chlor-6- (3-iodo- benzy lamino) -purin -9-yl]- 2,3-dihydroxy-cyclopentanecarbo xylic acid methylamide (LJ-331), has been shown to exert a potent inhibition of human cancer cell growth in vitro including human lung (A549), stomach (SNU-638) and leukemia (HL-60) cancer cells. Following mechanism of action study revealed that LJ - 331induces cell cycle arrest at the G1 phase in HL-60 cells and evokes apoptotic phenomena such as an increase in DNA ladder intensity and chromatin condensation by a dose- and time-dependent manner. LJ-331 also activated the caspase-3 activity in HL-60. This result suggests that the growth inhibition of human cancer cells by LJ-331 might be related to the cell cycle arrest and induction of apoptosis.
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Taurine (2-aminoethanesulfonic acid,
$^{+}NH_3CH_2CH_2{SO_3}^{-}$ ) is endogenous$\beta$ -amino acid which is essential in fetal nutrition and development and is present in abundant quantities in several tissues of fetus. In utero, taurine deficiency causes abnormal development and abnormal function of brain, retina, kidney and myocardium. Thus, transfer of taurine into fetus is important during embryonic development. Taurine transporter (TauT) has 12 hydrophobic membrane -spanning domains, which is typical of the$Na^{+}$ - and$Cl^{-}$ -dependent transporter gene family. Among the various biosynthetic enzymes of taurine, cysteine sulfinic acid decarboxylase (CSD) is the rate-limiting enzyme for biosynthesis of taurine. However, the enzyme activities of taurine biosynthesis are limited in early stage of embryonic development. To analyze the expression period of TauT and CSD during embryonic development, we have investigated the gene expression of TauT and CSD using reverse transcriptase polymerase chain reaction (RT-PCR) in mouse and chicken embryos. RT-PCR anaylsis revealed that both TauT and CSD mRNAs were already expressed at Day-4.5 in mouse embryo. In chicken whole embryo, TauT and CSD mRNAs began to appear on developing times of 48 hrs and 12 hrs, respectively. TauT mRNA was detected in the organs of heart, brain and eye of the day-3 chicken embryo. Our data show that TauT and CSD mRNAs were expressed in early stage of embryonic development. -
Cytochrome P-450 3A4 (CYP3A4) is major enzyme in human liver, the role of this is detoxification and metabolizing more than 50% clinical drugs in use. Expression of CYP3A4 is transciptionally regulated by the Pregnenolone X receptor (PXR), of which human form is Steroid and Xenobiotics receptor (SXR). SXR is activated by wide range of endogenous and exogenous compounds, and then induces CYP3A4 gene expression. In the previous study, it has been known that proximal promoter (-864 to +64) does not response to chemical inducers such as pregnenolone 16a-carbonitrile (PCN), Rifampicin, Estrogen in terms of transcription of CYP 3A4 in cultured cells. Here, we developed luciferase reporter gene assay system to detect SXR-based CYP 3A4 transcriptional activity. We have used CYP3A4-Luc plasmid that contains proximal promoter of human CYP3A4 gene upstream of the luciferase gene. We did transient transfection of 3A4-luciferase gene and SXR. In the HepG2 cells transfected with CYP3A4-Luc, when rifampicin treatment was combined with histone deacetylase inhibitor (HDAC Inhibitor), such as Trichostatin A, Hc-toxin and IN 2001 of the luciferase activity was induced 10-20 fold over control.
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Exposure of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) causes a variety of biological and toxicology effects, most of which are mediated by aryl hydrocarbon receptor (AhR). The ligand-bound AhR as a heterodimer with AhR nuclear translocator (ARNT) binds to its specific DNA recognition site, the dioxin-responsive element (DRE), and it results in increased transcription of CYP1A1 gene. Retinoic acid (RA) regulates the transcription of various genes for several essential functions through binding to two classes of nuclear receptors, the retinoic acid receptor (RAR) and retinoid X receptor (RXR). Constitutive androstane receptor (CAR) also regulates the transcription of gene. In this study, we have examined how RAR, RXR and CAR regulated CYP1A1 in rainbow trout hepatoma cell (RTH 149) using luciferase reporter gene assay system. We did transient transfection with CYP1A1 luciferase reporter gene and treated with TCDD, all-trans RA, 9-cis RA and phenobarbital. Treatment of all-trans RA, 9-cis RA or phenobarbital decreased the TCDD induced transcription of CYP1Al. When we did transient cotransfection with CYP1A1 luciferase reporter gene and RXR, as increase of RXR concentration, the TCDD induced transcription of CYP1A1 was decreased. Transfection with CAR also decreased the TCDD induced transcription of CYP1A1 in RTH 149 cells.
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The acetylation of histone is one of the mechanisms involved in the regulation of gene expression and is tightly controlled by two core enzymes, histone acetyltransferase (HAT) and deacetylase (HDAC). There are several reports that imbalance of HAT and HDAC activity is associated with abnormal behavior of the cells in morphology, cell cycle, differentiation, and carcinogenesis. Recently, an increasing number of structurally diverse HDAC inhibitors have been identified that inhibit proliferation and induce differentiation and/or apoptosis of tumor cells in vivo and in vitro. In this study, we have investigated the effects of novel HDAC inhibitors, IN2001 on ER positive and ER negative human breast cancer cell lines. The growth inhibition, cell cycle arrest and apoptosis of cells by HDAC inhibitors were determined using SRB assay, DNA fragmentation, and flow cytometry. We found that IN 2001 as well as Trichostatin A inhibited cell growth dose-dependently in both ER positive and ER negative human breast cancer cell lines. The growth inhibition with HDAC inhibitors was associated with profound morphological change. The result of cell cycle analysis after 24 h exposure of IN2001 showed G2-M cell cycle arrest in MCF-7 cell and apoptosis in T47D and MDA-MB-231 cell. In summary, IN2001 has antiproliferative effect on human breast cancer cells regardless of the expression of estrogen receptor. These findings heights the possibility of developing HDAC inhibitors as potential anticancer therapeutic agents for the treatment of breast cancer.
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We have studied the mechanism of action of TCDD on CYP1A1 promoter activity in both Hepa I and MCF-7 cells using transient transfection system with plAl-Luc reporter gene. When HDAC inhibitors, such as trichostatin A, HC toxin and a novel HDAC inhibitor, IN2001 were cotreated with TCDD to the cells transfected with plAl-Luc reporter gene, the basal promoter activity of CYP1A1 was increased by HDAC inhibitors. Also, in MCF-7 human breast cancer cells, HDAC inhibitors, such as IN2001 and trichostatin A increased the basal activity of CYP1A1 promoter but TCDD stimulated CYP1A1 promoter activity was not changed by HDAC inhibitors. And, in stably-transfected Hepa I cells with plAl-Luc, HDAC inhibitors increased the basal promoter activity only.
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Mycoplasmas resemble H. pylori in production of ammonia and induction of inflammatory cytokines from immune and non-immne cells. In Republic of Korea infection rate of H. pylori is relatively high but only a proportion of them invite additional inflammation and progress into gastric cancers. Therefore, additional risk factors cannot be excluded. The presence and identification of mycoplasma were confirmed by semi -nested PCR and sequencing and the results were compared with pathological data. Fifty-six samples collected from Korean chronic gastritis patients were used for the study. Twenty-three (41.1%) were positive to mycoplasmas and all of them were identified as human mycoplasmas, M. faucium, M. fermentans, M. orale, M. salivarium and M. spermatophilum. Mycoplasma-infected chronic gastritis samples showed more severe, additional infiltration of neutrophils than non-infected samples and the difference was significant (P < 0.05). In conclusion human mycoplasma infection may playa role in progression of chronic gastritis to metaplasia by inducing additional inflammation.
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Previously, wogonin (5,7-dihydroxy-8-methoxyflavone) was found to suppress proinflammatory enzyme expression including cyclooxygenase-2 (COX-2), contributing to in vivo anti-inflammatory activity against skin inflammation. However, the detailed effect on each skin cell type has not been understood. Therefore, present investigation was carried out to find the effect of wogonin on inflammation-associated gene expression from skin fibroblasts in culture using reverse transcriptase-polymerase chain reaction. As a result, it was found that wogonin (10 - 100
${\mu}$ M) clearly down-regulated COX -2 expression from NIH/3T3 cells treated with 12-O-tetradecanoylphorbol 13-acetate, interleukin-1${\beta}$ or tumor necrosis factor-a. But, the expression levels of COX-1, interleukin-1${\beta}$ and fibronectin were not significantly affected. This finding was well correlated with significant reduction of prostaglandin E$_2$ (PGE$_2$ ) production by wogonin. As a comparison, NS-398 (selective cyclooxygenase-2 inhibitor) did not suppress COX -2 expression and other gene levels, while PGE$_2$ production was potently reduced at 0.1 - 10${\mu}$ M. All these results suggest that COX -2 down-regulation of skin fibroblasts may be, at least in part, one of anti-inflammatory mechanisms of wogonin against skin inflammation. -
This study is investigated the effect of Rubus coreanus MIQ. against nephrotoxicity induced by cisplatin in rat. We examined the potency of the extract of R. coreanus fruits by the activity-guided fractionation. The EtOAc- and BuOH fraction, niga-ichigoside F
$_1$ and 23-hydroxytormentic acid showed significant protective effects as lipid peroxidation in renal tissue and was was not affect the activity of xanthine oxidase and aldehyde oxidase by cisplatin-induced nephrotoxicity. The concentration of glutathione in renal tissue was decreased by cisplatin-induced nephrotoxicity, but was improved by pretreatment of R. coreanus compounds especially in butanol, ethylacetate fraction and 23-hydroxytormentic acid. -
${\beta}$ -(1,3)-D-Glucans have been known to exhibit antitumor and antimicrobial activities. The presence of dectin-1,${\alpha}$ ,${\beta}$ -glucan receptor of dendritic cell, on macrophage has been controvertial. RT-PCR analysis led to the detection of dectin-1${\alpha}$ and${\beta}$ in murine macrophage Raw264.7 cell line. Among the various organs of mouse, dectin-1${\alpha}$ and${\beta}$ were detected in the thymus, lung, spleen, stomach and intestine. To analyze gene expression modulated by${\beta}$ -glucan treated murine Raw264.7 macrophage, total mRNA was applied to cDNA microarray to interrogate the expression of 7,000 known genes. cDNA chip analysis showed that${\beta}$ -glucan of P. osteatus increased gene expressions of immunomodulating genes, membrane antigenic proteins, chemokine ligands, complements, cytokines, various kinases, lectin associated genes and oncogenes in Raw 264.7 cell line. When treated with${\beta}$ -glucan of P. osteatus and LPS, induction of gene expression of TNF-${\alpha}$ and IFN-R1 was confirmed by RT-PCR analysis. Induction of TNF-R type II expression was confirmed by FACS analysis. IL-6 expression was abolished by EDTA in${\beta}$ -glucan and LPS treated Raw264.7 cell line, indicating that${\beta}$ -glucan binds to dectin-l in a Ca$\^$ ++/ -dependent manner. To increase antitumor efficacy of${\beta}$ -glucan, ginsenoside Rh2 (GRh2) was co-treated with${\beta}$ -glucan in vivo and in vitro tests. IC$\sub$ 50/ values of GRh2 were 20 and 25$\mu\textrm{g}$ /$m\ell$ in SNU-1 and B16 melanoma F10 cell line, respectively. Co-treatment with${\beta}$ -glucan and GRh2 showed synergistic antitumor activity with cisplatin and mitomycin C both in vitro and in vivo. Single or co-treatment with${\beta}$ -glucan and GRh2 increased tumor bearing mouse life span. Co-treatment with${\beta}$ -glucan and GRh2 showed more increased life span with mitomycin C than that with cisplatin. Antitumor activities were 67% and 72 % by co-injection with${\beta}$ -glucan and GRh2 in the absence or presence of mitomycin C, respectively. -
We studied the effect of Rubus croceacanthus Leveille (RCL) on mast cell-mediated anaphylactic reactions. RCL inhibited compound 48/80-induced systemic anaphylactic shock. When RCL was given at concentrations ranging from 0.01 to 1 mg/
$m\ell$ , the histamine release from rat peritoneal mast cells induced by compound 48/80 was reduced in a dose-dependent manner. RCL also inhibited passive cutaneous anaphylaxis activated by anti-dinitrophenyl IgE. In addition, RCL inhibited phorbol 12-myristate 13-acetate and A23187-induced tumor necrosis factor-${\alpha}$ secretion from human mast cell line HMC-1 cells. These results indicate that RCL may possess a strong anti-anaphylactic activity. -
We have reported that oral administration of Saiko-Ka-Ryukotsu-Borei-To (SRB), a traditional Chinese formulation, inhibited the intimal thickening in carotid artery after balloon injury in cholesterol-fed rats. To elucidate its mechanism, the effects of SRB on migration and proliferation of vascular smooth muscle cell (VSMC) were examined in vivo and in vitro. We have reported that oral administration of Saiko-ka-Ryukotsu-Borei-To (SRB), a traditional Chinese formulation, inhibited the intimal thickening in carotid artery after balloon injury in cholesterol-fed rats. To elucidate its mechanism, the effects of SRB on migration and proliferation of vascular smooth muscle cell (VSMC) were examined in vivo and in vitro.
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Prostaglandins (PGs) and nitric oxide (NO) produced by inducible cyclooygenase (COX-2) and nitric oxide synthase (iNOS), respectively, have been implicated as important mediators in the process of inflammation and carcinogenesis. On this line, the potential COX-2 or iNOS inhibitors have been considered as anti-inflammatory and cancer chemopreventive agents. In our continuing efforts of searching for novel cancer chemopreventive agents from natural products, we isolated natural sesquiterpenoids as potential COX-2 and iNOS inhibitors in cultured lipopolysaccharide (LPS)-activated mouse macrophage RAW 264.7 cells. Alantolactone, a natural eudesmane-type sesquiterpenoid, exhibited a potent inhibition of COX-2 (IC50 = 0.4
$\mu\textrm{g}$ /$m\ell$ ) and iNOS activity (IC50 = 0.08$\mu\textrm{g}$ /$m\ell$ ) in the assay system determined by PGE2 and NO accumulation, respectively. The inhibitory potential of alantolactone on the PGE2 and NO production was well coincided with the suppression of COX-2 and iNOS protein and mRNA expression in LPS-induced macrophages. Furthermore, alantolactone inhibited NF-kB but not AP-l binding activity on nuclear extracts evoked by LPS-stimulated macrophage cells, suggesting the possible involvement of NF-kB in the regulation of COX-2 and iNOS expression. In further study with COX-2-expressing human colon HT-29 cells, alantolactone inhibited the cell proliferation, down-regulated COX-2, and inhibited the ERK phosphorylation in the early time. These results suggest that a natural sesquiterpenoid alantolactone might be a potential lead candidate for further developing COX-2 or iNOS inhibitor possessing cancer chemopreventive or anti-inflammatory activity -
The inhibitors of prostaglandin biosynthesis and nitric oxide production by corresponding inducible isozyme have been considered as potential anti-inflammatory and cancer chemopreventive agents. In our continuous search for cancer chemopreventive agents from natural products, we have evaluated the inhibitory potential of PGE
$_2$ and NO production in lipopolysaccharide (LPS)-induced mouse macrophage RAW264.7 cells. As a result, pinosylvin (3,5-dihydroxy-trans-stilbene), a stilbenoid, mainly found from the heartwood and leaves of the Pinus sylvestris, showed potential inhibitory activity of LPS-induced PGE$_2$ and NO production in a dose-dependent manner. Pinosylvin also suppressed the LPS-induced iNOS protein expression. Further study revealed that pinosylvin exhibited antioxidant activity by the DPPH free radical scavenging potential and inhibitory effect of xanthine oxidase activity. In addition, pinosylvin inhibited COX -2 overexpressed human colon cancer cell (HT-29) growth in a time- and dose-dependent manner. These findings suggest that pinosylvin might be a promising candidate for developing cancer chemopreventive agent. -
A rapid and reproducible high performance liquid chromatographic assay of prazosin in human plasma was developed. After addition of internal standard (IS, terazosin hydrochloride) and alkalization of the plasma, the drug and IS were extracted into t-butylmethylether. The organic phase was back-extracted into 0.05% phosphoric acid and 50
${\mu}\ell$ of the acid solution was injected into a reverse-phase C18 column with a mobile phase consisting of water : acetonitrile : triethylamine = 75 : 25 : 0.1 (pH 5.0). The samples were detected utilizing a fluorescence detector. A -
Choline serves critical roles in the CNS both as a precursor of neurotransmitter and as an essential component of membrane phospholipids. The long-term maintenance of brain choline concentration is dependent on choline transport across the blood-brain barrier (BBB), And, we examined to elucidate the characteristics of transport of choline across the BBB using conditionally immortalized rat brain capillary endothelial cell line (TR-BBB) in vitro. The [
$^3$ H]choline in TR - BBB was increased by time dependently, but independent on Na$\^$ +/, and the transport process is saturable with Michaelis-Menten constrant, Km of about 26${\mu}$ M. The uptake of [$^3$ H]choline is susceptible for inhibition by various organic cationic compounds including hemicholinium-3, tetraethylammonium chloride (TEA) and$\ell$ -carnitine. Also, we investigated the relationship of transport of choline and cationic drugs. The uptake of [$^3$ H]choline is inhibited by antioxidant, a-phenyl-n-tert-butyl nitrone (PBN) with IC$\sub$ 50/ of 1.2 mM. and by Alzheimer's disease therapeutics, such as acetyl$\ell$ -carnitine, tacrine and donepezil. Also, choline uptake presented competitive inhibition with PBN, donepezil and acetyl$\ell$ -carnitine in Lineweaver-Burk plot. In conclusion, TR-BBB cells express a saturable transport system for uptake of choline, and several cationic drugs may be transported into the brain by BBB choline transporter. -
The purpose of this study is to examine that the efflux transport system for choline from brain to blood is present at the blood-brain barrier (BBB) using brain efflux index (BEI) method. [
$^3$ H]Choline was microinjected into parietal cortex area 2 (Par2) region of rat brain, and was eliminated from the brain with an apparent elimination half life of 45 min. The BBB efflux clearance of [$^3$ H]choline was 0.12$m\ell$ /min/g brain, which was calculated from the efflux rate constant (1.5${\times}$ 10$\^$ -2/ min$\^$ -1/) and the distribution volume in the brain slice (8.1$m\ell$ /g brain). This process was saturable and significantly inhibited by various organic cationic compounds including hemicholinium-3, tetraethylammonium chloride (TEA) and verapamil, by antioxidant,${\alpha}$ -phenyl-n-tert-butyl nitrone (PBN), and by Alzheimer's disease therapeutics, such as acetyl$\ell$ -carnitine and tacrine. In conclusion, this finding is the first direct in vivo evidence that choline is transported from brain to the blood across the BBB via a carrier-mediated efflux transport process. -
Lee, Jee-Hwan;Cho, Jung-Ah;Ki, Chan-Young;Son, Yeon-Kyoung;Park, Jeong-Hill;Park, Man-Ki;Han, Yong-Nam 108
The current study was performed to observe the effects of Panax ginseng (PG) and P. quinquefolia (PQ) on hemodynamics such as blood flow rate (BF), blood flow velocity (BV), heart rate (HR), systolic blood pressure (SBP) and diastolic blood pressure (DBP, and body temperature (BT) in healthy young men. After testing equality of variance, Student's t-test using PROC TTEST was examined to. prove statistical differences between control and ginseng conditions at each time point. It was found that the BF data were fluctuated by personal deviation. In order to minimize the deviation, the results obtained for 6 hrs were reconstituted after dividing them into two periods of the first half from 1 to 3 hrs and of the latter half from 3.5 to 6 hrs. And then the reconstitution data and dose-response curves were obtained. Blood flow such as BF and BV shows significant increases both two periods in the dose of PG 2.25 and PG 9.0, whereas significant decrease in the dose of PG 4.5. However, in the PQ groups, the middle dose PQ 4.5 shows the highest significant increase among the three doses. Except for PG 2.25 in HR, other doses show significant decreases both in the first half and latter half. SBP of PQ 9.0 shows only a significant decrease in the first half; on the other hand, in the latter half, PG 4.5, PG 9.0 and PQ 9.0 significantly increase SBP. In addition, DBP of PG 2.25 and PG 4.5 show significant increase in the both periods. In the BT, PQ groups show gradual decrease from PQ 2.25 to PQ 9.0; however, PG groups show differently. PG 4.5 shows significant decrease, but PG 9.0 shows a increase without statistical meanings. In summary, PG is more effective in respect to keeping homeostasis of hemodynamics. -
Taurine is present in a variety of tissue and exhibits many important physiological functions in many tissues. Although it is known that many tissues mediate taurine transport, its functions of taurine transport in bone have not been identified yet. In the present study, we investigated the expression of taurine transporter (TauT) and taurine uptake using mouse stromal ST2 cells and osteoblast-like MC3T3-El cells, which is bone related cells. Detection of TauT mRNA expression in these cells were performed by reverse transcription polymerase chain reaction (RT-PCR). The activity of TauT was assessed by measuring the uptake of [
$^3$ H]taurine in the presence or absence of inhibitors. TauT mRNA was detected in these cells. [$^3$ H]Taurine uptake was dependent upon the presence of extracellular sodium, chloride and calcium ions, and inhibited by cold-taurine and${\beta}$ -alanine. These results suggest that taurine has biological functions in bone and some effect on the bone cells. -
It is well-documented that decreased antioxidant defense system by ultraviolet(UV) irradiation is the most important reason to induce the skin aging, especially photoaging. Chlorogenic acid(CA), a nonflavonoid catecholic compound, is present in the diet as part of fruits, tea, coffee and wine and has been reported to have anti-inflammatory, antimutagenic and anticarcinogenic activities. In this study, we examined the effects of CA on the UV -induced photoaging. Firstly, we investigated the protective effect of CA on antioxidant defense system in HaCaT human keratinocytes after UV irradiation treatment. UV irradiation decreased antioxidant defence enzyme activities of superoxide dismutase, catalase and GSH contents, which were restored by CA. To elucidate the effect of CA, 1% of CA and vehicle were applied to human buttock skin before and after UV irradiation (2MED). CA prevented UV -induced matrix metalloproteinase-1 mRNA expression and procollagen mRNA depression. And CA also increased CD1a(Langerhans cell) expression significantly. Our results suggest that CA has protective effects on UV -induced photoaging by increasing cellular antioxidant defense system. Therefore, CA may be a useful anti-aging agent for cosmetic purpose.
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Green tea have been widely reported as functional foods because of their various bioactivities. In the present study, we used 3T3-Ll cells model of white adipocytes to clarify whether green tea and its main pharmaceutically effective compounds (EGCG, caffeine and theanine) prevent obesity. Cellular viability, glycerol-3-phosphate dehydrogenase activity, glycerol release and HSL mRNA levels were checked. Glycerol release into the medium was significantly increased by the cells treated with green tea extract. Glycerol release into the medium was significantly increased by the cells treated with green tea extract. Caffeine and theanine from green tea showed some level of lipolytic activity, and glycerol-3-phosphate dehydrogenase activity was remarkably decreased by EGCG. These results suggest that green tea has anti-obesity effect through inhibition of adipogenesis and stimulation of lipolysis. Catechins and theanine of green tea might be the factors responsible for the modulation of lipid metabolism and adipocyte differentiation.
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Voltage-gated
$K^{+}$ (Kv) channels represent a structurally and functionally diverse group of membrane proteins. These channels play an important role in determining the length of the cardiac action potential and are the targets for antiarrhythmic drugs. Many$K^{+}$ channel genes have been cloned from human myocardium and functionally contribute to its electrical activity. One of these channels, Kv1.5, is one of the more cardiovascular-specific$K^{+}$ channel isoforms identified to date and forms the molecular basis for an ultra-rapid delayed rectifier$K^{+}$ current found in human atrium. Thus, the blocker of hKv1.5 is expected to be an ideal antiarrhythmic drug for atrial fibrillation. Chelidonine was isolated from Chelidonium majus L. We examined the effect of chelidonine on the hKv1.5 current expressed in Ltk-cells using whole cell mode of patch clamp techniques. Chelidonine selectively inhibited the hKv1.5 current expressed in Ltk-cells in a concentration-dependent manner, whereas did not affect the HERG current expressed in HEK-293 cells. Additionally, chelidonine reduced the tail current amplitude recorded at -50 mV after 250 ms depolarizing pulses to +60 mV, and slowed the deactivation time course resulting in a 'crossover' phenomenon when the tail currents recorded under control conditions and in the presence of chelidonine were superimposed. We found that chelidonine also inhibited the$K^{+}$ current in isolated human atrial myocytes where hKv1.5 channels were predominantly expressed. Furthermore, we examined the effects of chelidonine on the action potentials in rabbit hearts using conventional microelectrode technique. Chelidonine prolonged the action potential durations (APD) of atrial, ventricular myocytes and Purkinje fibers in a dose-dependent manner. However, the effect of chelidonine on atrial APD was frequency-dependent whereas the effect of chelidonine on the APDs of ventricular myocytes and Purkinje fibers was not frequency- dependent. Also, the selective action of chelidonine on heart was more potent than dofetilide,$K^{+}$ channel blocker. -
Proteomic analysis of murine peritoneal macrophages after in vitro exposure to static magnetic fieldA number of studies have demonstrated recently nonthermal interactions of extremely low frequency electromagnetic fields with cellular systems, such as the cells of the immune system. Particular concern came from epidemiological findings, which correlated environmental exposure of human body to weak electromagnetic fields with an elevated risk for developing certain type of leukemias and cancers. Several home/environmental sources generating extremely low frequency electromagnetic fields, such as 50 - 60 Hz high-voltage transmission lines, video display terminals, electric blankets, clinical nuclear magnetic resonance imaging procedures, etc., may interact with the human body. In this study we examined the effects of static magnetic fields (SMF) on the phagocytosis of the murine peritoneal macrophages (C57BL/6). The cells were exposed in vitro for 24 h at 37
$^{\circ}C$ to 400 G SMF. The phagocytic activity of peritoneal macrophages was determined with a luminometer. Exposure to the SMF decreased phagocytic activity of murine peritoneal macrophages. In order to provide a more exact mechanism of the phenomenon, we analyzed peritoneal macrophages for alteration in their proteomes. The expression levels of these 5 proteins were increased in the SMF. In total 5 proteins which were differentially expressed in the SMF compared with control group were identified. The expression levels of these 5 proteins were increased in the SMF. -
Ginseng is a medicinal herb widely used in Asian countries, and its pharmacological effects has been demonstrated in various systems such as cardiovascular, central nervous, and endocrine systems. Its effects are mainly attributed to the ginsenosides. We hypothesize that a component of Panax ginseng, ginsenoside-Rbl, acts by binding to estrogen receptor. We have investigated the estrogenic activity of ginsenoside-Rbl in a transient transfection system using estrogen receptors
${\alpha}$ or${\beta}$ with estrogen -responsive luciferase plasmids in COS monkey kidney cells. Ginsenoside-Rbl activated both estrogen receptors${\alpha}$ and${\beta}$ in a dose-dependent manner (0.5 -100 M ). Activation was inhibited by the specific estrogen receptor antagonist ICI 182,780, indicating that the estrogenic effect of ginsenoside-Rbl is estrogen receptor dependent. Next, we evaluated the ability of ginsenoside-Rbl to induce estrogen-responsive progesterone receptor gene by semi-quantitative RT-PCR assays. MCF-7 cells treated with l7${\beta}$ -estradiol or ginsenoside- Rb1 exhibited an increased expression of progesterone receptor mRNA. However, ginsenoside-Rbl failed to displace the specific binding of [3H]17${\beta}$ -estradiol to estrogen receptor in MCF-7 cells as examined by whole cell ligand binding assays, suggesting that there is no direct interaction of ginsenoside-Rbl with estrogen receptor. Our results indicate that estrogen-like activity of ginsenoside-Rbl is independent of direct estrogen receptor association. -
Naturally occurring sugar mimics with a nitrogen in the ring are classified into five structural classes: polyhydroxylated pyrrolidines, piperidines, indolizidines. pyrrolizidine, and nortropanes. Glycosidase are involved in a wide range of important biological processes, such as intestinal digestion, post-translational processing of glycoproteins and the lysosomal catabolism of glycoconjugate. The realization that alkaloidal sugar mimics might have enormous therapeutic potential in many diseases such as viral infection, cancer and diabetes has led to increasing interest and demand for these compounds. Most of these effects can be shown to result from the direct or indrect inhibition of glycosidases.
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In 1998, Osada and co-workers isolated 140 mg of a novel cytokine modulator from 18 L of the culture broth of Streptomyces RK95- 31 isolated from a soil sample in Hiroshima Prefecture. This new immunosuppressant was named (-)-cytoxazone and its absolute configuration was determined on the basis of its NMR, CD and X -ray analysis. It interferes with cytokine IL4, IL10 and IgG production by selective inhibition of the signaling pathway of Th2 cells, but not Thl cells. Inhibitors of Th2-dependent cytokine production have potential as potent chemotherapeutic agents in the field of immunotherapy. The (-)-cytoxazone is different from known immunomodulators such as FK 506 and rapamycin in respect of structure and biological activity. As such cytoxazone should be a useful tool for understanding signaling pathways in Th2 cells, the synthesis of (-)-cytoxazone is of interest for the development of new cytokine modulators.
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PPARs (peroxisome proliferator activated receptors) are member of nuclear hormone receptors superfamily. Activations of PPARs upon binding with ligands modulate glucose metabolite, differentiation of adipocyte, inflammation response, and so on. Thiazolidinedione analog is one of potential antidiabetic drug that binds and activates PPARν selectively and enhances insulin sensitivity. In an effort to develop novel and effective antidiabetic thiazolidindione analogs, syntheses of benzoxazole and benzothiazole-linked thiazolidinedione analogs were performed via coupling reaction of benzoxazolylalkylaminoethanol with hydroxybenzylthiazolidinedione to develop novel and effective antidiabetic thiazolidindiones. All compounds were evaluated their biological potency by PPARν transactivation assay and revealed the similar potency with Troglitazone. However, lengthening of N-alkyl substituent did not seem to be beneficial for the activity.
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The use of PPARν (peroxisome proliferator activated receptor ν) activators in the treatment of type 2 diabetes is well established due to their ability to lower blood glucose and insulin levels and omprove insulin sensitivity. Thiazolidinedione analog is one of the potential antidiabetic drug that binds and activates PPARν selectively. In an effort to develop novel and effective antidiabetic thiazolidindione analogs, synthesis of tetrahydroquinoline and para-substituted benzene-linked thiazolidinedione analogs were carried out via coupling reaction of the hydrophobic segments with hydroxybenzylthiazolidinedione.