• Title/Summary/Keyword: Membrane permeability

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Condurango (Gonolobus condurango) Extract Activates Fas Receptor and Depolarizes Mitochondrial Membrane Potential to Induce ROS-dependent Apoptosis in Cancer Cells in vitro -CE-treatment on HeLa: a ROS-dependent mechanism-

  • Bishayee, Kausik;Mondal, Jesmin;Sikdar, Sourav;Khuda-Bukhsh, Anisur Rahman
    • Journal of Pharmacopuncture
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    • v.18 no.3
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    • pp.32-41
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    • 2015
  • Objectives: Condurango (Gonolobus condurango) extract is used by complementary and alternative medicine (CAM) practitioners as a traditional medicine, including homeopathy, mainly for the treatment of syphilis. Condurango bark extract is also known to reduce tumor volume, but the underlying molecular mechanisms still remain unclear. Methods: Using a cervical cancer cell line (HeLa) as our model, the molecular events behind condurango extract's (CE's) anticancer effect were investigated by using flow cytometry, immunoblotting and reverse transcriptase-polymerase chain reaction (RT-PCR). Other included cell types were prostate cancer cells (PC3), transformed liver cells (WRL-68), and peripheral blood mononuclear cells (PBMCs). Results: Condurango extract (CE) was found to be cytotoxic against target cells, and this was significantly deactivated in the presence of N-acetyl cysteine (NAC), a scavenger of reactive oxygen species (ROS), suggesting that its action could be mediated through ROS generation. CE caused an increase in the HeLa cell population containing deoxyribonucleic acid (DNA) damage at the G zero/Growth 1 (G0/G1) stage. Further, CE increased the tumor necrosis factor alpha ($TNF-{\alpha}$) and the fas receptor (FasR) levels both at the ribonucleic acid (RNA) and the protein levels, indicating that CE might have a cytotoxic mechanism of action. CE also triggered a sharp decrease in the expression of nuclear factor kappa-light-chain-enhancer of activated B cells ($NF-{\kappa}B$) both at the RNA and the protein levels, a possible route to attenuation of B-cell lymphoma 2 (Bcl-2), and caused an opening of the mitochondrial membrane's permeability transition (MPT) pores, thus enhancing caspase activities. Conclusion: Overall, our results suggest possible pathways for CE mediated cytotoxicity in model cancer cells.

Antibacterial Activity and Inhibition of Resistance in Methicillin-resistant Staphylococcus aureus by Maneung-hwan Ethanol Extract (만응환(萬應丸) 에탄올 추출물의 메티실린 내성 포도상구균에 대한 항균활성 및 내성억제 효과)

  • Na, Yong-su;Kim, Jong-gyu;Song, Yung-sun
    • Journal of Korean Medicine Rehabilitation
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    • v.30 no.1
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    • pp.31-45
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    • 2020
  • Objectives In this study, we investigated the antimicrobial activity of a 70% ethanol extract of Maneung-hwan (MEH), which is prescribed by practitioners of oriental medicine for use against methicillin-resistant Staphylococcus aureus (MRSA). Methods The antibacterial activity of MEH against MRSA strains was evaluated using the disc diffusion method, broth microdilution method (minimal inhibitory concentration, MIC), checkerboard dilution test, and time-kill test. The mechanism of action of MEH was investigated by bacteriolysis using detergents or ATPase inhibitors Additionally, mRNA and protein expression were investigated by quantitative reverse transcription-polymerase chain reaction and western blot assay, respectively. Results The MIC of MEH was 25~1,600 ㎍/mL against all the tested bacterial strains. We showed that MEH extract exerts strong antibacterial activity. In the checkerboard dilution test, the fractional inhibitory concentration index of MEH in combination with antibiotics indicated synergism or partial synergism against S. aureus. The time-kill study indicated that the growth of the tested bacteria was considerably inhibited after a 24-h treatment with MEH and selected antibiotics. To measure the cell membrane permeability, MEH (3.9 ㎍/mL) was combined with Triton X-100 (TX) at various concentrations N,N-dicyclohexylcarbodimide (DCCD) was also tested as an ATPase inhibitor. TX and DCCD cooperation against S. aureus exhibited synergistic action. Accordingly, the antimicrobial activity of MEH in the context of cell membrane rupture and ATPase inhibition was assessed. Additionally, the expression of genes and proteins associated with resistance was reduced after exposing MRSA to MEH. Conclusions These results suggest that MEH possesses antibacterial activity and acts as a potential natural antibiotic against MRSA.

Free Volume in Polyers Note II。: Positron Annihilation lifetime Spectroscopy and Applications

  • G. Consolati;M. Pegoraro;L. Zanderighi
    • Korean Membrane Journal
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    • v.1 no.1
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    • pp.25-37
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    • 1999
  • positron annihilation Lifetime Spectroscopy has been extensively applied in recent years to investigate the free volume in polymers owing to the capability of the electron-positron bound system (positronium) to probe the typical size of sub-nanometric cavities among the macromolecular chains. In this paper we show recent results obtained through this technique in some amorphous polymeric mem-branes(olyurethanes. PUs and polytrimethilsylilpropine PTMSP) after a brief survey of the general features of the annihilation process as well as of the experimental apparatus. Lifetime of o-ps decay({{{{ tau _3}}}}) in PUs increases going from sub {{{{ TAU _g}}}} to over {{{{ TAU _g}}}} temperatures following a sigmoid curve. The coefficient of dilatation of the free volume fraction is shown to be the sum of two contributes due to the variation with T of the number of holes and of their mean volume. PAL spectrum of PTMSP freshly prepared shows four lifetime components: {{{{ tau _3}}}} and {{{{ tau _4}}}}: only are useful for free volume study. Two kinds of holes of different equivalent radius are reported ({{{{ gamma _s}}}} 4.60 nm and {{{{ gamma _1}}}} 0.754) The equivalent volume does not change in a range of 100 K. however the physical aging increases density and decreases oxygen permeability while {{{{ gamma _s}}}} goes down to 0.374 and r1 to 0.735 The number of holes obtained from the intensities{{{{ IOTA _3}}}} and {{{{ IOTA _4}}}} of PAL spectra decreases with aging 21.7% and 3.5% for large and small holes respectively.

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The Protective Effects of Seokchangpowonji-san on $H_2O_2$-Mediated Cell Death of Neuro 2A as an Alzheimer Model System (산화적 손상에 의한 Neuro 2A 치매모델에서 석창포원지산의 방어효과)

  • Yim Jun-Mo;Lee Min-Goo;Yun Jong-Min;Lee In;Moon Byung-Soon
    • The Journal of Korean Medicine
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    • v.26 no.1 s.61
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    • pp.161-173
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    • 2005
  • Objective : The water extract of Seokchangpowonji-san (SWS) has traditionally been used for treatment of dementia in oriental medicine. However, little is known about the mechanism by which the water extract of SWS rescues cells from neurodegenerative disease such as Alzheimer's disease. Methods & Results: This study was designed to investigate the protective mechanisms of SWS on $\beta-amyloid$ or $H_2O_2$-induced$ cytotoxicity in neuro 2A cells. $H_2O_2$ markedly decreased the viability of neuro 2A cells, which was characterized by apparent apoptotic features such as membrane blebbing as well as fragmentation of genomic DNA and nuclei. However, the water extract of SWS significantly reduced $H_2O_2-induced$ cell death and apoptotic characteristics through reduction of intracellular peroxide generation. Also, the. extract prevented the mitochondrial dysfunction including the disruption of mitochondria membrane permeability transition (MPT) and the modulation in expression of Bcl-2 family proteins in $H_2O_2­treated$ neuro 2A cells. Furthermore, pretreatment with SWS inhibited the activation of caspase-3, and in turn, degradation of ICAD/DFF45 was completely abolished in $H_2O_2-treated$ cells. Conclusion: Taken together, the data suggest that the protective effects of the water extract of SWS against $\beta-amyloid$ induced oxidative injuries may be achieved through modulation of mitochondrial dysfunction.

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Effect of Dietary Xylooligosaccharide on Indigestion and Retarding Effect of Bile Acid Movement Across a Dialysis Membrane (식이 Xylooligo당의 난소화성과 담즙산 흡수 지연효과)

  • 이순재;주길재;이인구;김성옥
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.27 no.4
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    • pp.705-711
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    • 1998
  • The digestibility of xylooligosaccharide(XO) by juices of the digestive tract and retardation effect of XO on the adsorption of bile acids were compared with fructooligosaccharide(FO) and isomaltooligosaccharide(IO). In vitro digestion experiments showed that any hydrolyzed products of FO, IO and XO were not detected by HPLC after reaction with saliva, pancreatic, artifical intesteinal, and large intestinal luices, and artifical sera for 4 hours at 37$^{\circ}C$. However, IO were mostly digested by the small intestinal juice, and some quantity of FO were digested. XO were not digested at all by any enzyme of digestive tract. In order to investigate retardation effect of XO on the bile acid absorption. In vitro, permeability of bile acid against dialysis membrane was determined in the mixture which contained guar gum instead of XO was set 100%. The premeability of bile acid showed about 50% in the FO and IO mixture and 43% in the XO mixture. The activity of lactase in FO group and activity of sucrase and maltase in XO group in rat small intestinal mucosa were significantly decreased. Consequently, the present results indicate that XO is indigestible in digestive tract and has retarding effect of adsorption of bile acid compared with the other oligosaccharides. The disaccharidase activity of the XO dietary group was lower than that of the other oligosaccharides dietary group. Furthermore, it was suggested that hydrolysis of sugar may be retarded in digestive tract and glucose level in blood may be controlled effectively by the XO.

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Development Trend of Nanofiber Filter (나노섬유 필터의 개발 동향)

  • Kang Inn-Kyu;Kim Young-Jin;Byun Hong-Sik
    • Membrane Journal
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    • v.16 no.1
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    • pp.1-8
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    • 2006
  • Nanofiber is a broad phrase generally referring to a fiber with diameter less than 1 micron. Various polymers have been successfully electrospun into nanofibers in recent years. These nanofibers, due to their high surface area and porosity, have a great potential for use as filter medium, adsorption layers in protective clothing, etc. Nanofiber filters will enable new levels of filtration performance in the field of air filtration. In particular, nanofibers provide marked increases in filtration efficiency at relatively small pressure drop in permeability. Therefore, nanofiber filters could be substituted for conventional filter market due to the easy application of process and the possibility of coating to micron-sized non-woven sheets. This review is discussed on the trend of researche and development related to nanofiber filter including future marketability.

Oxygen Permeation and Hydrogen Production of BaCo1-x-yFexZryO3-δ by a Modified Glycine-nitrate Process (MGNP) (Modified glycine-nitrate process(MGNP)로 합성한 BaCo1-x-yFexZryO3-δ 산소투과도 및 수소생산성)

  • Yi, Eunjeong;Hwang, Haejin
    • Transactions of the Korean hydrogen and new energy society
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    • v.24 no.1
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    • pp.29-35
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    • 2013
  • A dense mixed ionic and electronic conducting ceramic membrane is one of the most promising materials because it can be used for separation of oxygen from the mixture gas. The $ABO_3$ perovskite structure shows high chemical stability at high temperatures under reduction and oxidation atmospheres. $BaCo_{1-x-y}Fe_xZr_yO_{3-{\delta}}$ (BCFZ) was well-known material as high mechanical strength, low thermal conductivity and stability in the high valence state. Glycine Nitrate Process (GNP) is rapid and effective method for powder synthesis using glycine as a fuel and show higher product crystallinity compared to solid state reaction and citrate-EDTA method. BCFZ was fabricated by modified glycine nitrate process. In order to control the burn-up reaction, $NH_4NO_3$ was used as extra nitrate. According to X-Ray Diffraction (XRD) results, BCFZ was single phase regardless of Zr dopants from y=0.1 to 0.3 on B sites. The green compacts were sintered at $1200^{\circ}C$ for 2 hours. Oxygen permeability, methane partial oxidation rate and hydrogen production ability of the membranes were characterized by using Micro Gas Chromatography (Micro GC) under various condition. The high oxygen permeation flux of BCFZ 1-451 was about $1ml{\cdot}cm^{-2}s^{-1}$. Using the humidified Argon gas, BCFZ 1-433 produced hydrogen about $1ml{\cdot}cm^{-2}s^{-1}$.

Influence of Heating, Cooling and Acidity on the Permeability of the Rabbit Erythrocyte Membrane (고온, 한냉 및 산도가 토끼 적혈구막 투과성에 미치는 영향)

  • Lee, D.S.;Shin, H.S.;Hwang, E.R.;Choi, D.K.
    • The Korean Journal of Physiology
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    • v.1 no.2
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    • pp.151-156
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    • 1967
  • Outward movement of hemoglobin and $K^+$ ion across rabbit erythrocyte membrane after heating, cooling and in acid medium was studied. One milliliter of rabbit blood was centrifuged and packed red cells were obtained. Packed red cells were resuspended by addition of 4 ml of 0.9% NaCl solution and were subjected to heating $(57^{\circ}C\;for\;5\;minutes)$ or cooling $(-4^{\circ}C{\sim}-8^{\circ}C\;of\;-10^{\circ}C{\sim}-11^{\circ}C\;for\;10\;minutes) $. For acid medium experiment packed ref cells were resuspended by addition of 4 ml of acid medium of PH 4.5 consisting of 0.01% glacial acetic acid in 0.85% NaCl solution and kept standing for 10 minutes. All red cell suspensions were centrifuged again and packed red cells were separated. This packed red cells were again suspended in 4 ml of NaCl solution of 0.8%, 0.7%, 0.6%, and 0.5% concentration respectively and kept standing for 20 minutes. The concentration of hemoglobin and $K^+$ in the supernatant of the above red cell suspensions were measured and the following results were obtained. 1. Outward movement of hemoglobin and $K^+$ was greatest in red cells subjected to heating. The movement paralled to the osmolal concentration gradient between extra- and intra-cellular phase of red cells. 2. In acid medium the outflux of hemoglobin and $K^+$ increased as compared to the control. 3. In red cells subjected to the cold of $-10^{\circ}C{\sim}-11^{\circ}C$ the outflux of hemoglobin and $K^+$ increased. Whereas in the environment of $-4^{\circ}C{\sim}-8^{\circ}C$ there was no change in the outflux of $K^+$. The he-moglobin outflux showed rather a decreased as compared to tile control.

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Danchunhwan Protects the Cytotoxicity of Beta-amyloid in SH-SY5Y Neuroblastoma Cells (베타아밀로이드 유도성 SH-SY5Y 세포독성에서 단천환(丹川丸)의 보호효과)

  • Yu, Bong-Sun;Kim, Jin-Kyung;;Park, Chan-Ny;So, Hong-Seob
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.20 no.6
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    • pp.1516-1523
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    • 2006
  • The water extract of Danchunhwan(DCH) has been traditionally used for treatment of dementia damage in oriental medicine. However, little is known about the mechanism by which the water extract of DCH rescues cells from neurodegenerative disease such as Alzheimer's disease. This study was designed to investigate the protective mechanisms of DCH on ${\beta}$-amyloid or $H_2O_2$-induced cytotoxicity in SH-SY5Y neuronblastoma cells. ${\beta}$-amyloid and $H_2O_2$ markedly decreased the viability of SH-SY5Y cells, which was characterized with apparent apoptotic features such as membrane blebbing as well as fragmentation of genomic DNA and nuclei. However, the water extract of DCH significantly reduced both ${\beta}$-amyloid or $H_2O_2$-induced cell death and apoptotic characteristics through reduction of intracellular peroxide generation. Also, the water extract of DCH prevented prevented the mitochondrial dysfunction including the disruption of mitochondria membrane permeability transition (MPT) and the perturbation in Bcl-2 family protein expressions in $H_2O_2$-treated SH-SY5Y cells.

Effect of Diet and Water Intake on Aquaporin 2 Function

  • Kim, Jun-Mo;Kim, Tae-Hee;Wang, Tong
    • Childhood Kidney Diseases
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    • v.20 no.1
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    • pp.11-17
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    • 2016
  • Appropriate control of diet and water intake is important for maintaining normal blood pressure, fluid and electrolyte homeostasis in the body. It is relatively understood that the amount of sodium and potassium intake directly affects blood pressure and regulates ion transporters; Na and K channel functions in the kidney. However, little is known about whether diet and water intake regulates Aquaporin (AQP) function. AQPs, a family of aquaporin proteins with different types being expressed in different tissues, are important for water absorption by the cell. Water reabsorption is a passive process driven by osmotic gradient and water permeability is critical for this process. In most of the nephron, however, water reabsorption is unregulated and coupled to solute reabsorption, such as AQP1 mediated water absorption in the proximal tubule. AQP2 is the only water channel founded so far that can be regulated by hormones in the kidney. AQP2 expressed in the apical membrane of the principal cells in the collecting tubule can be regulated by vasopressin (antidiuretic hormone) controlling the final volume of urine excretion. When vasopressin binds to its receptor on the collecting duct cells, it stimulates the translocation of AQP2 to the membrane, leading to increased water absorption via this AQP2 water channel. However, some studies also indicated that the AQP2 is also been regulated by vasopressin independent mechanism. This review is focused on the regulation of AQP2 by diet and the amount of water intake on salt and water homeostasis.