• 제목/요약/키워드: inhibition layer

검색결과 235건 처리시간 0.026초

Phytochemical analysis of the antioxidant properties of Silybum marianum L

  • Pendry Barbara;Busia Kofi;Bell Celia M
    • Advances in Traditional Medicine
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    • 제6권3호
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    • pp.167-173
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    • 2006
  • A growing body of evidence supports lipid peroxidation as having a role in the pathogenesis of liver disease. Although the probable cause of damage to human hepatocytes may be multifactorial, free radicals have been implicated in a variety of liver diseases, particularly in the presence of iron overload and toxic substances such as ethanol. Consequently, antioxidants, particularly those of plant origin such as flavonoids, may help to reduce the risk of developing these diseases. Silybum (S.) marianum, a medicinal plant widely used in traditional European medicine for the treatment of liver disorders, was evaluated for antioxidant activity. Thin layer chromatography and High Performance Liquid Chromatography analyses of crude extract of the plant confirmed the presence of a number of flavonoids reported in the literature. The antioxidant activity of these flavonoids was measured through inhibition of lipid peroxidation and 1, 1-diphenyl-2- picrylhydrazyl radical scavenging. The crude plant extract showed marked antioxidant activity in both assays. These results suggest that S. marianum contains flavonoids with antioxidant activity, capable of inhibiting or scavenging free radicals, thus supporting its traditional use as a hepatoprotective agent.

Studies on the Characteristics of Anti-Zona Antibody II. Effect of Anti-Zona Antibody on Fertilization of Porcine and Mouse Eggs In Vitro (항투명대 항체의 특성에 관한 연구 II. 항투명대 항체가 돼지난자와 생쥐난자의 체외수정에 미치는 영향)

  • 김은영;박세필;정형민;정길생;김종배
    • Korean Journal of Animal Reproduction
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    • 제14권2호
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    • pp.115-124
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    • 1990
  • These experiments were undertaken as a basic study to develop immunocontraceptive vaccine and to understand the role of zona pellucidae in early fertilization process by investigating the effect of monoclonal and polyclonal antibody to porcine zona pellucidae and polyclonal antibody to mouse zona pellucidae on the fertilization of porcine and mouse eggs in vitro. The results obtained in these experiments were summarized as follows : 1. Treatment of porcine and mouse eggs with undiluted anti-zona serum produced intense precipitation layer on the poricne and mouse zonae, respectively, thus resulting in the total inhibition of sperm adherence on surface of zona. 2. In vitro fertilization of eggs pre-treated with 0.3∼10% of various antibodies was examined, and resulting in that 5 and 10% of rabbit polyclonal antibodies to porcine zona inhibited completely both in vitro fertilization and polyspermy of porcine eggs while monoclonal to porcine zona and rabbit polyclonal antibody to mouse zona did not inhibit in vitro fertilization but monoclonal antibody reduced the rate of polyspermy compared to that of control group. Almost the same results were obtained in the study on the effect of anti-zona serum on in vitro fertilization of mouse eggs.

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Effects of Cyclic-AMP and Tannin on the Amylase Biosynthesis Induced by Gibberellin in Aleurone Layer I. Acid Phosphatase (Cyclic-AMP와 탄닌이 지베레린으로 유도되는 Amylase 생합성에 미치는 영향 I. Acid Phosphatase)

  • 권영명
    • Journal of Plant Biology
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    • 제21권1_4호
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    • pp.13-21
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    • 1978
  • The effect of cyclic-AMP on the induction of acid phosphatase activity in barley aleurone layers was examined. Tannic acid was used as a inhibitor. Decursinol and coumarin were also used as a comparison. Maxiumu promotion of the enzyme activity was obtained with 10-5M cyclic-AMP, but this promotion was lower than that of 10-5M GAS induced enzyme activity in incubation medium. The inhibition rate in the addition of tannic acid was shown 17% and 63% at a ratio to GAs (by weight) of 10 : 1, and 58% and 94% at a ratio of 100 : 1 treated with GAs, and cyclic-AMP, respectively. The most potentiation of 10-6M GAS effect was induced by the additiion of suboptimal concentration (10-6M) of cyclic-AMP. Additional GAs and cyclic-AMP were shown the recovery of the enzyme activity inhibited by tannic acid. The combination with cyclic-AMP and theophylline enhanced the enzyme activity, too. Any other nucleotides tested except cyclic-AMP didn't show the action. There were no differences in acid phosphatase isozyme patterns by polyacrylamide disc electrophoresis, in conjunction with the different additions but the size of bands showed great differences. Especially, the 3rd band and the 5th band group were remarkable.

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Antibacterial Activity of Powdered Spice against Escherichia coli and Staphylococcus aureus (향신료 분말의 Esdcherichia coli 와 Staphylococcus aureus 에 대한 항균작용)

  • 김미림;최경호;박찬성
    • Food Science and Preservation
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    • 제7권1호
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    • pp.124-131
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    • 2000
  • Antibacterial activities of powdered spices(garlic , ginger, cinnamon and clove) against pathogenic Escherichia coli )157:H7 and Staphyloccus auresus were investigated. Spice powder was added in was exponetial phase of each bacterial culture . Growth inhibition was determined by the absorbance at 660nm and morphological changes of the cells were observed by transmission electron microscope (TEM). Ginger powder has the highest antibacterial activity, following cinnamon , clove and garlic has the least activity.Growth of Escherichia coli O157:H7 and Staphyloccus aureus were completely inhibited within 5 hours after addition of 1 % of garlic , 0.3% of ginger or cinnamon , 0.5% of clove powder on the exponential phase of the cells. Spice untreated cells of E. coli and S. aureus, the cytoplasm was entirely surrounded by rigid cell wall and cell walls formed a smooth layer well attached to the plasma membrane. In the cells of E. coli and S. aureus treated with spice powder, cell wall and plasma membrane were lysed and severely damaged. E.coli cells growth in the presence of spice powder showed plammolysis, the loss of electron dense material, the formation of extra cellular blebs and cytoplasm burst out from the cell. S .sureus cells grown in the presence of spice powder showed swell of cell wall, the loss of electron dense material , coagulation of cell cytoplasm and formation of extra cellular blebs. Severely damaged cells of S. aureus lost whole cytoplasm and left as ghost of the cell. Spice powder stimulated autolyssi and induced cell death.

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Simple and Rapid Extraction of a Bacteriocin Produced by Streptococcus parauberis Z49 from Fermented Cultures (발효배양액에서 Streptococcus parauberis Z49균주가 생산하는 Bacteriocin의 간편한 추출)

  • Park, Hong-Je;Khang, Yong-Ho
    • Korean Journal of Microbiology
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    • 제46권3호
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    • pp.291-295
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    • 2010
  • A novel bacteriocin produced by Streptococcus parauberis Z49 strain was characterized and efficiently extracted from fermented cultures by use of aqueous two-phase systems. The nisin-like bacteriocin, which was active even after a heat treatment at $121^{\circ}C$ for 15 min and in the broad pH range from 2 to 12, showed inhibition of bacterial growth of Micrococcus luteus, Lactobacillus spp., Lactobacillus fermentum, Enterococcus faecium, Listereia monocytogenes, and Pseudomonas fluorescens. Optimal conditions of PEG 600/$Na_2SO_4$ aqueous two-phase systems for the simple and rapid extraction of a novel bacteriocin were determined to be PEG 600 15%, $Na_2SO_4$ 30%, and NaCl 8%, where the bacteriocin was concentrated in PEG layer.

Improvement of Oxidation-resisting Characteristic for SOFC Interconnect Material by Use of Thin Film Coating (박막 코팅을 이용한 SOFC 분리판 재료의 내산화성 향상)

  • Lee, Chang-Bo;Bae, Joong-Myeon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • 제30권12호
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    • pp.1211-1217
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    • 2006
  • This study is focused on oxidation prevention of STS430, which is generally used as solid oxide fuel cell(SOFC) interconnect at intermediate operating temperatures with oxidation-proof coatings. Inconel, $La_{0.6}Sr_{0.4}CoO_3(LSCo)$ and $La_{0.6}Sr_{0.4}CoO_3(LSCr)$ were chosen as coating materials. Using a radio frequency magnetron sputtering method, each target material was deposited as thin film on STS430 and was analyzed to find out favorable conditions. In this study, LSCr-coated STS430 can reduce electrical resistance to 1/3 level, compared with uncoated STS430. Also, long-term durability test at $700^{\circ}C$ for 1000 hours tells that LSCr thin layer performs an important role to prohibit serious degradations. Superior oxidation-resistant characteristic of LSCr-coated STS430 is attributed to the inhibition of spinel structure formation such as $MnCr_2O_4$.

Polymerized Organic Thin Films and Comparison on their Physical and Electrochemical Properties

  • Cho, S.H.;You, Y.J.;Kim, J.G.;Boo, J.H.
    • Journal of the Korean institute of surface engineering
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    • 제36권1호
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    • pp.9-13
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    • 2003
  • Plasma polymerized organic thin films were deposited on Si(100), glass and metal substrates at $25∼100 ^{\circ}C$ using thiophene and toluene precursors by PECVD method. In order to compare physical and electrochemical properties of the as-grown thin films, the effects of the RF plasma power in the range of 30∼100 W and deposition temperature on both corrosion protection efficiency and physical properties were studied. We found that the corrosion protection efficiency ($P_{k}$), which is one of the important factors for corrosion protection in the interlayer dielectrics of microelectronic devices application, was increased with increasing RF power. The highest $P_{k}$ value of plasma polymerized toluene film (85.27% at 70 W) was higher than that of the plasma polymerized thiophene film (65.17% at 100 W), indicating inhibition of oxygen reduction. The densely packed and tightly interconnected toluene film could act as an efficient barrier layer to the diffusion of molecular oxygen. The result of contact angle measurement showed that the plasma polymerized toluene films have more hydrophobic surface than those of the plasma polymerized thiophene films.

Functional Mechanism of Plant Growth Retardation by Bacillus subtilis IJ-31 and Its Allelochemicals

  • Kim, Won-Chan;Rhee, In-Koo
    • Journal of Microbiology and Biotechnology
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    • 제22권10호
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    • pp.1375-1380
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    • 2012
  • We previously isolated a rhizobacterium (Bacillus subtilis IJ-31) and demonstrated that its associated allelochemicals could indicate plant growth retardation. However, little is known about how the growth of plants is regulated by B. subtilis IJ-31 and its allelochemicals. In this study, we investigated whether plant growth retardation in this relationship occurred through the inhibition of gibberellin (GA) biosynthesis. GA $3{\beta}$-hydroxylase activity was found to be inhibited by B. subtilis IJ-31 and hydrocinnamic acid (HCA), which is one of the allelochemicals produced by B. subtilis IJ-31. Additionally, thin layer chromatography (TLC) demonstrated that B. subtilis IJ-31 culture broth and HCA both inhibit GA $3{\beta}$-hydroxylase (MBP-GA4) activity. The retardation of plants by HCA was then confirmed in vivo and in vitro using a Ryegrass and Arabidopsis growth retardation assay. Furthermore, treatment with either B. subtilis IJ-31 culture extract or its allelochemicals resulted in significant down-regulation of XTR9 gene expression in Arabidopsis. Overall, we identified the functional mechanism of plant growth retardation by B. subtilis IJ-31 and its allelochemicals.

Lamin A/C and Polymeric Actin in Genome Organization

  • Ondrej, Vladan;Lukasova, Emilie;Krejci, Jana;Matula, Pavel;Kozubek, Stanislav
    • Molecules and Cells
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    • 제26권4호
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    • pp.356-361
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    • 2008
  • In this work, we have studied the structural and functional linkage between lamin A/C, nuclear actin, and organization of chromosome territories (CTs) in mammary carcinoma MCF-7 cells. Selective down-regulation of lamin A/C expression led to disruption of the lamin A/C perinuclear layer and disorganization of lamin-bound emerin complexes at the inner nuclear membrane. The silencing of lamin A/C expression resulted in a decrease in the volume and surface area of chromosome territories, especially in chromosomes with high heterochromatin content. Inhibition of actin polymerization led to relaxation of the structure of chromosome territories, and an increase in the volumes and surface areas of the chromosome territories of human chromosomes 1, 2 and 13. The results show an important role of polymeric actin in the organization of the nuclei and the chromosome territories.

MUC1-C influences cell survival in lung adenocarcinoma Calu-3 cells after SARS-CoV-2 infection

  • Kim, Dongbum;Maharjan, Sony;Kim, Jinsoo;Park, Sangkyu;Park, Jeong-A;Park, Byoung Kwon;Lee, Younghee;Kwon, Hyung-Joo
    • BMB Reports
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    • 제54권8호
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    • pp.425-430
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    • 2021
  • Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces coronavirus disease 2019 (COVID-19) and may increase the risk of adverse outcomes in lung cancer patients. In this study, we investigated the expression and function of mucin 1 (MUC1) after SARS-CoV-2 infection in the lung epithelial cancer cell line Calu-3. MUC1 is a major constituent of the mucus layer in the respiratory tract and contributes to pathogen defense. SARS-CoV-2 infection induced MUC1 C-terminal subunit (MUC1-C) expression in a STAT3 activation-dependent manner. Inhibition of MUC1-C signaling increased apoptosis-related protein levels and reduced proliferation-related protein levels; however, SARS-CoV-2 replication was not affected. Together, these results suggest that increased MUC1-C expression in response to SARS-CoV-2 infection may trigger the growth of lung cancer cells, and COVID-19 may be a risk factor for lung cancer patients.