• Title/Summary/Keyword: blocking effect

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Anti-inflammatory Effect of Leaves Extracts from Aralia cordata through Inhibition of NF-κB and MAPKs Signaling in LPS-stimulated RAW264.7 Cells

  • Ji, Eo Hyun;Kim, Da Som;Sim, Su Jin;Park, Gwang Hun;Song, Jeong Ho;Jeong, Jin Boo;Kim, Nahyun
    • Korean Journal of Plant Resources
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    • v.31 no.6
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    • pp.634-640
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    • 2018
  • Aralia cordata (A. cordata), which belongs to Araliaceae, is a perennial herb widely distributed in East Asia. We evaluated the anti-inflammatory effect of stems (AC-S), roots (AC-R) and leaves (AC-L) extracted with 100% methanol of A. cordata and elucidated the potential signaling pathway in LPS-stimulated RAW264.7 cells. The AC-L showed a strong anti-inflammatory activity through inhibition of NO production. AC-L dose-dependently inhibited NO production by suppressing iNOS, COX-2 and $IL-{\beta}$ expression in LPS-stimulated RAW264.7 cells. AC-L inhibited the degradation and phosphorylation of $I{\kappa}B-{\alpha}$, which donated to the inhibition of p65 nuclear accumulation and $NF-{\kappa}B$ activation. Furthermore, AC-L suppressed the phosphorylation of ERK1/2 and p38. These results suggested that AC-L may utilize anti-inflammatory activity by blocking $NF-{\kappa}B$ and MAPK signaling pathway and indicated that the AC-L can be used as a natural anti-inflammatory drugs.

Ecklonia cava (Laminariales) and Sargassum horneri (Fucales) synergistically inhibit the lipopolysaccharide-induced inflammation via blocking NF-κB and MAPK pathways

  • Asanka Sanjeewa, K.K.;Fernando, I.P.S.;Kim, Seo-Young;Kim, Won-Suck;Ahn, Ginnae;Jee, Youngheun;Jeon, You-Jin
    • ALGAE
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    • v.34 no.1
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    • pp.45-56
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    • 2019
  • Ecklonia cava (EC) has been widely utilized as an ingredient in commercial products such as functional foods and cosmeceuticals. Recently it has been found that Sargassum horneri (SH) has been invading on Jeju Island coast area by its huge blooming. Moreover, both seaweeds are considering as important ingredients in traditional medicine specifically in East-Asian countries (China, Japan, and Korea). In the present study, we attempted to compare anti-inflammatory properties of 70% ethanolic extracts of EC (ECE), SH (SHE), and their different combinations on lipopolysaccharide (LPS)-activated RAW 264.7 cells. Results indicated that 8 : 2 combinations of ECE : SHE significantly inhibited LPS-activated inflammatory responses (cytokines, protein, and gene expression) in RAW 264.7 macrophage cells compared to the respective extracts and other combinations. The synergistic effect of ECE and SHE was found to be prominent than the effects of ECE or SHE alone. These observations provide useful information for the industrial formulation of functional materials (functional foods and cosmeceuticals) using these two particular seaweeds in Jeju Island of South Korea.

The Effect of Honokiol on Ergosterol Biosynthesis and Vacuole Function in Candida albicans

  • Sun, Lingmei;Liao, Kai
    • Journal of Microbiology and Biotechnology
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    • v.30 no.12
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    • pp.1835-1842
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    • 2020
  • Ergosterol, an essential constituent of membrane lipids of yeast, is distributed in both the cell membrane and intracellular endomembrane components such as vacuoles. Honokiol, a major polyphenol isolated from Magnolia officinalis, has been shown to inhibit the growth of Candida albicans. Here, we assessed the effect of honokiol on ergosterol biosynthesis and vacuole function in C. albicans. Honokiol could decrease the ergosterol content and upregulate the expression of genes related with the ergosterol biosynthesis pathway. The exogenous supply of ergosterol attenuated the toxicity of honokiol against C. albicans. Honokiol treatment could induce cytosolic acidification by blocking the activity of the plasma membrane Pma1p H+-ATPase. Furthermore, honokiol caused abnormalities in vacuole morphology and function. Concomitant ergosterol feeding to some extent restored the vacuolar morphology and the function of acidification in cells treated by honokiol. Honokiol also disrupted the intracellular calcium homeostasis. Amiodarone attenuated the antifungal effects of honokiol against C. albicans, probably due to the activation of the calcineurin signaling pathway which is involved in honokiol tolerance. In conclusion, this study demonstrated that honokiol could inhibit ergosterol biosynthesis and decrease Pma 1p H+-ATPase activity, which resulted in the abnormal pH in vacuole and cytosol.

The influence of air gaps on buffer temperature within an engineered barrier system

  • Seok Yoon;Gi-Jun Lee
    • Nuclear Engineering and Technology
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    • v.55 no.11
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    • pp.4120-4124
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    • 2023
  • High-level radioactive waste produced by nuclear power plants are disposed subterraneously utilizing an engineered barrier system (EBS). A gap inevitably exists between the disposal canisters and buffer materials, which may have a negative effect on the thermal transfer and water-blocking efficiency of the system. As few previous experimental works have quantified this effect, this study aimed to create an experimental model for investigating differences in the temperature changes of bentonite buffer in the presence and absence of air gaps between it and a surrounding stainless steel cell. Three test scenarios comprised an empty cell and cells partially or completely filled with bentonite. The temperature was measured inside the buffers and on the inner surface of their surrounding cells, which were artificially heated. The time required for the entire system to reach 100℃ was approximately 40% faster with no gap between the inner cell surface and the bentonite. This suggests that rock-buffer spaces should be filled in practice to ensure the rapid dissipation of heat from the buffer materials to their surroundings. However, it can be advantageous to retain buffer-canister gaps to lower the peak buffer temperature.

Myocardial Preserving Effect of Fructose-1, 6-diphosphate in Isolated Rat Heart (적출된 쥐심장을 이용한 Fructose-1, 6 diphosphate의 심근보호 효과에 관한 실험)

  • 이철주;조수신;류재온;김문환;김세환;이익호;박소라;서창국
    • Journal of Chest Surgery
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    • v.26 no.2
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    • pp.75-79
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    • 1993
  • Myocardial protection against ischemic and reperfusion injuries is still in troublesome eventhough couples of the way of myocardial protection have been applied since 1970's. One of the possibility in myocardial protection is adding Fructose-l,6-diphosphate(FDP) in cardioplegic solution. It is assumed that FDP can promote ATP production under anaerobic condition as well as inhibiting the supressing effect of lactate on phosphofructokinase. We compared the myocardial protecting effects of FDP in crystalloid cardioplegic solution (St. Thomas formula, 10$^{\circ}C$, pH = 7.4) and reperfusate using isolated rat hearts in modified Langendorf apparatus by the parameters of preischemic and post reperfusing heart rate, time to first beat, occurance of arrhythmia, time to stabilization, and the rate of left ventricular pressure developing. Group A (n = 10), containing no FDP in cardioplegic and reperfusing solutions was control. Group B (n = 5), containing FDP in cardioplegic solution, showed statistically significant superiority of postischemic left ventricular pressure development than the control group. Group C (n = 5), containing FDP in reperfusate, showed statistically significant myocardial depressing effect than the controls. Other parameters were unremarkable. The cause is uncertain, but it is assumed that the negative feedback inhibition of FDP in energy metabolism or unknown blocking effect of FDP on certain transmembrane ionic currents is present. In conclusion, 1) FDP in cardioplegic solution has beneficial effect on postischemic left ventricular preservation. 2) FDP is strong acid when is hydrolyzed, so precise acid titration is neccessary. 3) FDP in reperfusate has negative left ventricular preservation, otherwise the mechanism is still uncertain.

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Effects of Ginsenosides on Acid Secretion in Gastric Cells Isolated from Human and Rabbit Gastric Mucosa (인체 및 토끼 위선세포에서 인삼사포닌의 위산분비 매개 신호전달체계에 미치는 영향)

  • Kim, Hye-Yeong;Kim, Sin-Il;Kim, Gyeong-Hwan
    • Journal of Ginseng Research
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    • v.22 no.1
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    • pp.22-31
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    • 1998
  • Antiulcer effects of ginseng saponin, acidic polysaccharide and methanol extract of Panax ginseng in the patients and experimental animals were reported. Postulated action mechanisms of ginseng were histamine-Ht receptor blocking and increasing gastric blood flow In the present study, the effect of ginsenosides, the biologically active glycosides of ginseng, on gastric acid secretion was examined using gastric cells isolated from human and rabbit gastric mucosa. Ginseng saponin, ginsenoside $Rb_1$, $Rb_2$, $Rg_1$ and $Rh_2$ were tested in unstimulated as well as stimulated gastric cells. Histamine ($10^4$M) and 3-isobutyl-1-methylxanthine ($10^4$M) were used as secretagogues. To investigate the mechanism of ginsenosides on acid secretion, the levels of cAMP and cGMP were monitored in gastric cells. As a result, high concerltration(1mg/ml) of ginseng saponin showed 73-75% of stimulated acid secretion in control gastric cells. However, ginseng saponin had no effect on unstimulated acid secretion and the levels of cGMP and cAMP in gastric cells. Ginsenoside $Rb_1$, $Rb_2$ and $Rh_2$ significantly inhibited stimulated acid secretion. Gastric cGMP levels were increased by all ginsenosides tested while cAMP levels were increased by all ginsenosides in unstimulated state of gastric cells, but increased by ginsenosides ginsenoside $Rg_1$ and $Rh_2$in stimulated state of gastric cells. The results suggest that inhibition of ginseng saponin on gastric acid secretion represents a complex effect of individual ginsenosides, which produce a range of effect on acid secretion. The inhibition site of ginseng saponin on stimulated acid secretion is postulated as post cAMP levels in acid secretary pathway such as protein phosphorylation or proton pump. Nitric oxide may not be involved in the inhibitory effect of ginseng saponin on stimulated acid secretion.

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Telmisartan Inhibits TNFα-Induced Leukocyte Adhesion by Blocking ICAM-1 Expression in Astroglial Cells but Not in Endothelial Cells

  • Jang, Changhwan;Kim, Jungjin;Kwon, Youngsun;Jo, Sangmee A.
    • Biomolecules & Therapeutics
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    • v.28 no.5
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    • pp.423-430
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    • 2020
  • Telmisartan is an angiotensin-II receptor blocker and acts as a selective modulator of peroxisome proliferator-activated receptor gamma (PPARγ). Several studies have demonstrated that telmisartan ameliorates depression and memory dysfunction and reduces brain inflammation. We hypothesized that the beneficial effects of telmisartan on brain could be due to modulation of the blood-brain barrier (BBB) function. Here, we examined the effect of telmisartan on tumor necrosis factor alpha (TNF-α)-induced expression of intercellular adhesion molecule 1 (ICAM-1) which plays an important role in leukocyte transcytosis through the BBB. Telmisartan blocked TNF-α-induced ICAM-1 expression and leukocyte adhesion in U87MG human glioma cells but showed no effect on human brain microvascular endothelial cells. In U87MG cells, a PPAR antagonist, GW9662 did not block the effect of telmisartan on ICAM1 expression but rather potentiated. Moreover, GW9662 caused no change in TNF-α-induced ICAM-1 expression, suggesting no implication of PPARγ in the telmisartan effect. Further studies showed that telmisartan blocked TNF-α-induced activation of c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase 1/2 (ERK1/2), p38, and nuclear factorkappa B (NF-κB). In contrast, inhibitors of JNK, ERK1/2 and NF-κB but not p38, blocked ICAM-1 expression induced by TNF-α. Thus, our findings suggest that the beneficial effect of telmisartan is likely due to the reduction of astrocytic ICAM1 expression and leukocytes adhesion to astrocytes, and that this response was mediated by the inhibition of JNK/ERK1/2/NF-κB activation and in the PPAR-independent manner. In conclusion, this study enhances our understanding of the mechanism by which telmisartan exerts the beneficial brain function.

Antimutagenic Mechanism of Water Extract from Rehmannia glutinosa Liboshitz on 4-nitroquinoline 1-oxide Induced Mutagenesis n E. coli B.r (대장균에서 4-nitroquinoline 1-oride의 변이원성에 대한 숙지황 물추출물의 항돌연변이 작용특성)

  • 안병용;한종현;최동성
    • KSBB Journal
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    • v.16 no.5
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    • pp.486-492
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    • 2001
  • The antimutagenic mechanism of the fraction III(RG III)separated from the water extract of Rehmannia glutionosa was investigated by Escherichia. coli GW and B/r strains. RG-III treatment did not affect the ${\beta}$-galactosidase activity E. coli GW-1060, 1106, 1107 and 1105. These results indicated that RG-III did not induce RecA protein amplification and did not also prevent the proteolytic cleavage of LexA. The bio-antimutagenicity and survival effect of RG-III on 4-nitroquinoline 1-oxide(4NQO), N-methyl-N-nitor-N\`-nitrosoguanidine(MNING) were investigate by E. coli B/r strains with have different pathway of DNA repai. RG-III slightly increased the survival of 4NQO-treated WP2, WP2s, WP67, CM561, CM611 cells, but the reactivation of survival cannot ve explained by the repair mode. RG-III caused the decrease of mutagenicity and lethality treated with MNNG in ZA159 despite of the increase in WP2, WP2s, WP67, CW561, CM611. Compared with bio-antimutagenic effects of RG-III on 4NQO, greatly increased antimutagenic effects of RG-III were observed with all the E. coli B/r strains tested, but less active in ZA159. These results suggest that RG-III was identified as a blocking agent for preventing the 4NQO induced mutagenesis, and may act as chl-products.

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Study on Preventing Copyrights Infringement through Blocking Advertisements of Illegal Copyrighted Websites (불법 저작물 사이트의 광고 차단을 통한 저작권 침해 방지 연구 - 자금 추적 기반 방식을 중심으로)

  • Shin, Myeong-Seob;Yong, Mi-Ran;Lee, Yeong-Ju
    • The Journal of the Korea Contents Association
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    • v.20 no.7
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    • pp.331-341
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    • 2020
  • Recently the government has succeeded in shutting down the Illegal Copyrighted Websites by cracking down on the operators of the websites. But this only caused 'the Balloon Effect', similar websites were created and users shifted to the new websites. 'Follow the money' is drawing attention as a way to complement the effect of policies. It tracks the commercialization scheme and fund flows of the Illegal Copyrighted Websites and blocks the supply and publication of advertisements, which are the main source of revenue. This approach aims at self-closure of Illegal websites by blocking the revenue source. In this study, we have selected and analyzed overseas cases that adopted these measures. Many countries had different policies and campaigns, but three things are common: non-punishment measures, partnership based on voluntary participation, pursuing a variety of purposes other than protecting the copyright industry. In Korea, the reason public-private Partnerships was not properly established had been caused by the difference of views between them. Advertisers and agencies need to expand their awareness that illegal advertisements can have adverse effects such as brand image damage and enormous economic losses. Also campaigns and conferences related with the policy should be held to prevent copyright infringement through mutual understanding and cooperation.

Pharmacological Studies on Human Vas Deferens -Coexistence of Adrenergic and Cholinergic Receptors, and Effect of Diazepam- (인체 정관의 약리학적 검색 -아드레날린성 및 콜린성 수용체의 공존과 Diazepam의 작용-)

  • Kim, Won-Joon;Lee, Kwang-Youn;Ha, Jeoung-Hee;Park, Tong-Choon
    • The Korean Journal of Pharmacology
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    • v.24 no.2
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    • pp.189-195
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    • 1988
  • This study aimed to investigate the autonomic innervations of human vas deferens and the effect of diazepam, a benzodiazepine sedative antianxiety drug, on the smooth muscle contractility of vas deferens. The specimens were obtained from healthy volunteers undergoing elective vasectomy with local anesthesia. The muscle preparation did not show any spontaneous contraction, but showed a good contraction induced by norepinephrine exerting the strongest response at $33^{\circ}C$. Phentolamine inhibited the norepinephrine-induced contraction concentration-dependently. Isoproterenol, a beta-adrenergic agonist evoked a considerable extent of contraction, and this contractile activity was antagonized by propranolol, a beta-adrenergic blocking agent. Acetylcholine induced a dashing contraction of the human vas deferens, and atropine, a muscarinic receptor blocking agent abolished the acetylcholine-induced contraction. Diazepam inhibited the norepinephrine-induced contraction in a concentration dependent manner. These results suggest that the smooth muscle of human vas deferens has cholinergic muscarinic and beta adrenergic receptors as well as the predominant alpha adrepergic receptor. Diazepam inhibits the motility, especially norepinephrine-induced contraction of human vas deferens.

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