• Title/Summary/Keyword: $IC_{50}$ values

Search Result 1,075, Processing Time 0.03 seconds

형상에 따른 초전도 튜브의 전기적 특성변화

  • Jang, G.E.;Park, C.W.;Ha, D.W.;Seung, T.H.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2004.07a
    • /
    • pp.527-530
    • /
    • 2004
  • High-temperature Superconductor(HTS) tubes were fabricated in term of different diameter, length and thickness by centrigugal forming method. For powder melting by induction the optimum range of melting temperatures and preheating temperature were $1050^{\circ}C{\sim}1100^{\circ}C\;amd\;550^{\circ}C$ for 30min, respectively. The mould renting speed was 1000rpm. A tube was annealed at $840^{\circ}C$ for 72hours in oxygen atmosphere. The plate-like grains were well developed along the renting direction and typical grain size was about more than $40{\mu}m$. It was found that Ic values increased with increasing the tube diameter while the Ic decreased with increasing tube thickness. Also Ic decreased with increasing the tube length. The measured Ic in $50mm{\times}70mm{\times}25mm$ tube was about 896Amp.

  • PDF

Enzymatic Assessment of $2-Hydroxyethyl-{\beta}-undecenate$ Purified from Cumin (Cuminum cymium L.) Seed for Anti-periodontitis (Cumin(Cuminum cymium L.) seed로부터 정제한 $2-hydroxyethyl-{\beta}-undecenate$의 항치주염 효과의 효소학적 평가)

  • Ryu, Il-Hwan;Kang, Eun-Ju;Lee, Kap-Sang;Park, Chung-Soon
    • Korean Journal of Food Science and Technology
    • /
    • v.39 no.6
    • /
    • pp.669-675
    • /
    • 2007
  • The present study was conducted to explore the anti-inflammatory action of $2-hydroxyethyl-{\beta}-undecenate$ (HPS) purified from Cumin (Cuminum cymium L.) seed against periodontitis. From the study in which human leukocyte was employed to detect the inhibiting effects of 5-lipokygenase and cyclooxygenase, enzymes generating carriers of infection like $LTB_4$ and PGs, as well as of collagenase and elastase, organ-destroying enzymes, following conclusions could be drawn: HPS was found to inhibit leukotrien $B_4$ biosynthesis by stimulating more than 97% of human polymorphonuclear leukocyte (PMNL) with addition of $5\;{\times}\;10^{-2}\;M$ when $IC_{50}$ was set at $2\;{\times}\;10^{-4}\;M$. Ninety-two percent of enzyme activation turned out to be inhibited when $5\;{\times}\;10^{-2}\;M$ was added in a test to prove inhibiting effects of HPS against activation of PMNL 5-lipoxygenase from homogeneous humans and purified 5-lipoxygenase on the market. Besides, $IC_{50}$ for enzyme activation was valued at $2.5\;{\times}\;10^{-4}\;M$, while the value of $IC_{50}$ for purified 5-lipoxygenase was $2.3\;{\times}\;10^{-4}\;M$. The $IC_{50}$ values of COX-activated leukocyte and purified collagenase were $5.1\;{\times}\;10^{-4}\;M$ and $2.3\;{\times}\;10^{-4}\;M$, respectively. Moreover, the value of $IC_{50}$ for activation of leukocyte collagenase was $2\;{\times}\;10^{-3}\;M$, whereas that for purified collagenase was $5\;{\times}\;10^{-2}\;M$. In case of leukocyte elastase, addition of $5\;{\times}\;10^{-2}\;M$ inhibited its activation by 66%. In case of purified one, however, activation of enzyme was inhibited by 25% with addition of $5\;{\times}\;10^{-2}\;M$. Furthermore, the $IC_{50}$ value for activation of leukocyte elastase was revealed to be $7.5\;{\times}\;10^{-3}\;M$. From the virulence test with human gingiva cell, it was shown that, on the second day of cultivation, 47.83% of the cell had been activated when HPS was added by $5\;{\times}\;10^{-2}\;M$. Even the addition of HPS by $1\;{\times}\;10^{-2}\;M$ featured 68.53% of cell activation, suggesting relatively strong toxicity of the substance against gingiva cell.

The Inhibitory Effects of Poria cocos Bark Extract on Melanogenesis (복령피 추출물의 멜라닌 생성 저해 효과)

  • Lee, Eung-Ji;Bae, Seong-Yun;Son, Rak-Ho;Lee, Yong-Hwa
    • Journal of the Society of Cosmetic Scientists of Korea
    • /
    • v.35 no.3
    • /
    • pp.243-250
    • /
    • 2009
  • To develop a new natural whitening agent for cosmetics, we investigated the inhibitory effects of Poria cocos Bark extracts (PCBE) and its active compound on melanogenesis. PCBE showed ROS scavenging activities in 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and xanthine/xanthine oxidase system with the $IC_{50}$ values of $19.4{\pm}2.21{\mu}g$/mL and $IC_{50}=103{\pm}3.33{\mu}g$/mL, respectively. PCBE reduced intracellular tyrosinase activity about 34 % at concentration of $50{\mu}g$/mL. And PCBE reduced melanin contents of B16 melanoma cells about 51 % at concentration of $50{\mu}g$/mL without cell cytotoxicity (below $100{\mu}g$/mL). We purified one active compound from PCBE and identified its structure. It was identified as 3-$\beta$-hydroxylanosta-7,9(11),24-trien-4-oic acid, triterpene family, by $^1H$-NMR, $^{13}C$-NMR and Mass analysis. 3-$\beta$-hydroxylanosta-7,9(11),24-trien-4-oic acid showed ROS scavenging activities in DPPH radical and xanthine/xanthine oxidase system with the $IC_{50}$ values of $4.3{\pm}0.15{\mu}g$/mL and $54{\pm}1.67{\mu}g$/mL, respectively. Also, it was shown that 3-$\beta$-hydroxylanosta-7,9(11),24-trien-4-oic acid reduced intracellular tyrosinase activity about 43 % at concentration of $10{\mu}g$/mL. And it inhibited melanin synthesis in a dose dependent manner ($IC_{50}=3.6{\mu}g$/mL) without cell cytotoxicity (below $100{\mu}g$/mL). 3-$\beta$-hydroxylanosta-7,9(11),24-trien-4-oic acid inhibited tyrosinase, TRP-1 and TRP-2 expression at protein level. These results suggest that PCBE and 3-$\beta$-hydroxylanosta-7,9(11),24-trien-4-oic acid reduced melanin formation by the inhibition of tyrosinase activity and expression in B16 melanoma cells. Therefore, we suggest that PCBE could be used as a useful whitening agent.

Antioxidative and Neuroprotective Effects of Enzymatic Extracts from Leaves of Perilla frutescens var.japonica

  • Kim, Eun-Kyung;Lee, Seung-Jae;Lim, Beong-Ou;Jeon, You-Jin;Song, Min-Dong;Park, Tae-Kyu;Lee, Kwang-Ho;Kim, Bo-Kyung;Lee, Sang-Rak;Moon, Sang-Ho;Jeon, Byong-Tae;Park, Pyo-Jam
    • Food Science and Biotechnology
    • /
    • v.17 no.2
    • /
    • pp.279-286
    • /
    • 2008
  • The antioxidative activity of various enzymatic extracts from leaves of Perilla frutescens var. japonica was evaluated by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl, and alkyl radical scavenging activity using an electron spin resonance (ESR) spectrometer. For this study, the leaves were enzymatically hydrolyzed by 8 carbohydrases (Dextrozyme, AMG, Promozyme, Maltogenase, Termamyl, Viscozyme, Celluclast, and BAN) and 9 proteases [Flavourzyme, Neutrase, Protamex, Alcalase, PP-trypsin (trypsin from porcine pancreas), papain, pepsin, $\alpha$-chymotrypsin, and BP-trypsin (trypsin from bovine pancreas)]. The DPPH radical scavenging activities of Promozyme and Alcalase extracts were the highest, and the $IC_{50}$ values were 77.25 and $109.66\;{\mu}g/mL$, respectively. All enzymatic extracts of the leaves scavenged hydroxyl radical, and the $IC_{50}$ values of Celluclast and pepsin extracts which were the highest activity were 243.34 and $241.86\;{\mu}g/mL$, respectively. The BAN and $\alpha$-chymotrypsin extracts showed the highest scavenging activities, and the $IC_{50}$ values were 21.13 and $33.23\;{\mu}g/mL$, respectively. The pepsin extracts from the leaves showed protective effect on $H_2O_2$-induced DNA damage. In addition, the pepsin extracts decreased cell death in PC-12 cells against $H_2O_2$-induced oxidative damage. The findings of the present study suggest that enzymatic extracts of the leaves possess antioxidative activity.

Antioxidant Constituents from the Leaves of Cedrela sinensis A. Juss

  • Lee, Ik-Soo;Wei, Chun-Hua;Thoung, Phuong Thien;Song, Kyung-Sik;Seong, Yeon-Hee;Bae, Ki-Hwan
    • Korean Journal of Medicinal Crop Science
    • /
    • v.14 no.5
    • /
    • pp.267-272
    • /
    • 2006
  • Phytochemical study on the EtOAc fraction from the MeOH extract of the leaves of Cedrela sinensis led to the isolation of five known phenolic compounds (1-5), whose structures were identified as (+)-catechin (1), $kaempferol-3-0-{\alpha}- L-rhamnopyranoside$ (2), quercetin (3), $quercetin-3-O-{\alpha}-L-rhamnopyranoside$ (4), and $quercetin-3-O-{\beta}-D-glucopyranoside$ (5), respectively, by comparing their spectral $(uv,\;JR,\;IH\;and\;^{13}C-NMR,\;and\;ESI-MS)$ and physicochemical data with those reported in the literature. Among the isolated compounds (1-5), compounds 1 and 3-5 exhibited significant DPPH radical scavenging effects with $IC{_50}$ values ranging from $21.3{\pm}1.4\;to\;38.1{\pm}3.2 {\mu}M$ as well as superoxide anion radical scavenging effects with $IC{_50}$ values ranging from $9.4{\pm}0.7\;to\;21.2{\pm}3.6 {\mu}M$. Furthermore, compounds 1 and 3-5 also exhibited considerable inhibitory effects on LDL peroxidation induced by either $CU^{2+}$ or AAPH with $IC{_50}$ values ranging from $1.4{\pm}0.4\;to\;11.9{\pm}1.4\;{\mu}M$. These results indicated that flavonoids are the major constituents of C. sinensis and considered to be antioxidant principles of this plant.

Apoptotic Potential and Chemical Composition of Jordanian Propolis Extract against Different Cancer Cell Lines

  • Abutaha, Nael
    • Journal of Microbiology and Biotechnology
    • /
    • v.30 no.6
    • /
    • pp.893-902
    • /
    • 2020
  • Propolis is a resinous substance that is collected by Apis mellifera from plant sources and is used in traditional medicine. To study the phytochemical constituents and apoptotic potential of Jordanian propolis extract against different cancer cell lines, propolis was extracted using methanol, hexane, and ethyl acetate and was fractionated using chromatographic methods. Cytotoxicity was assessed using MTT and LDH assays. The apoptotic potential was investigated using florescence microscopy, multicaspase assay, Annexin-V and dead cell assay, and cell cycle assay. The phytochemical constituents were analyzed using GC-MS. The methanol extract of propolis exhibited cytotoxic potential against all cell lines tested. The IC50 values of the methanol extract were 47.4, 77.8, 91.2, and 145.0 ㎍/ml for HepG2, LoVo, MDAMB231, and MCF7 cell lines, respectively. The IC50 values of the F1 fraction were 31.6 (MDAMB231), 38.9 (HepG2), 36.7 (LoVo) and 75.5 (MCF7) ㎍/ml. On further purification using thin-layer chromatography, the IC50 values of the F1-3 fraction were found to be 84.31(HepG2), 79.2 (MCF7), 70.4 (LoVo), and 68.9 (MDAMB231) ㎍/ml, respectively. The anticancer potential of the F1 fraction was confirmed through the induction of apoptosis and cell cycle arrest at the G0/G1 phase. The GC-MS analysis of the F1 fraction revealed the presence of 3-methyl-4-isopropylphenol (29.44%) as a major constituent. These findings indicate the potential of propolis extract as a cancer therapy. However, further investigation is required to assess the acute and subacute toxicity of the most active fraction.

Antioxidant Activity of Anthraquinones and Flavonoids from Flower of Reynoutria sachalinensis

  • Zhang Xinfeng;Thuong Phuong Thien;Jin WenYi;Su Nguyen Duy;Sok Dai Eun;Bae KiHwan;Kang Sam Sik
    • Archives of Pharmacal Research
    • /
    • v.28 no.1
    • /
    • pp.22-27
    • /
    • 2005
  • Bioassay-guided fractionation of methanol extract of Reynoutria sachalinensis flower using DPPH assay has led to the isolation of three anthraquinones and three flavonoids. Their structures were identified as emodin (1), emodin-8-O-$\beta$-D-glucopyranoside (2), physcion-8-O-$\beta$-D­glucopyranoside (3), quercetin-3-O-$\alpha$-L-arabinofuranoside (4), quercetin-3-O-$\beta$-D-galactopyra­noside (5), and quercetin-3-O-$\beta$-D-glucuronopyranoside (6) by comparing their physicochemical and spectral data with those published in literatures. All isolated compounds were evaluated for antioxidant activities with free radical 1, 1-diphenyl-2-picrylhydrazyl (DPPH) scavenging, superoxide radical scavenging and $Cu^{2+}$-mediated low density lipoprotein (LDL) oxidation assay. The results demonstrated that three flavonoids, 4, 5, and 6 had remarkable antioxidant activities with the $IC_{50}$ values of 64.3, 54.7, and 46.2${\mu}M$ (DPPH scavenging), the $IC_{50}$ values of 6.0, 6.7, and $4.4{\mu}M$ (superoxide radical scavenging) and the $IC_{50}$ values of 3.8, 3.2, and 5.4${\mu}M$ against LDL oxidation, respectively.

Formulation and Cytotoxicity of Ribosome-Inactivating Protein Mirabilis Jalapa L. Nanoparticles Using Alginate-Low Viscosity Chitosan Conjugated with Anti-Epcam Antibodies in the T47D Breast Cancer Cell Line

  • Wicaksono, Psycha Anindya;Sismindari, Sismindari;Martien, Ronny;Ismail, Hilda
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.17 no.4
    • /
    • pp.2277-2284
    • /
    • 2016
  • Ribosome-inactivating protein (RIP) from Mirabilis jalapa L. leaves has cytotoxic effects on breast cancer cell lines but is less toxic towards normal cells. However, it can easily be degraded after administration so it needs to be formulated into nanoparticles to increase its resistance to enzymatic degradation. The objectives of this study were to develop a protein extract of M. jalapa L. leaves (RIP-MJ) incorporated into nanoparticles conjugated with Anti-EpCAM antibodies, and to determine its cytotoxicity and selectivity in the T47D breast cancer cell line. RIP-MJ was extracted from red-flowered M. jalapa L. leaves. Nanoparticles were formulated based on polyelectrolyte complexation using low viscosity chitosan and alginate, then chemically conjugated with anti-EpCAM antibody using EDAC based on carbodiimide reaction. RIP-MJ nanoparticles were characterised for the particle size, polydispersity index, zeta potential, particle morphology, and entrapment efficiency. The cytotoxicity of RIP-MJ nanoparticles against T47D and Vero cells was then determined with MTT assay. The optimal formula of RIP-MJ nanoparticles was obtained at the concentration of RIP-MJ, low viscosity chitosan and alginate respectively 0.05%, 1%, and 0.4% (m/v). RIP-MJ nanoparticles are hexagonal with high entrapment efficiency of 98.6%, average size of 130.7 nm, polydispersity index of 0.380 and zeta potential +26.33 mV. The $IC_{50}$ values of both anti-EpCAM-conjugated and non-conjugated RIP-MJ nanoparticles for T47D cells (13.3 and $14.9{\mu}g/mL$) were lower than for Vero cells (27.8 and $33.6{\mu}g/mL$). The $IC_{50}$ values of conjugated and non-conjugated RIP-MJ for both cells were much lower than $IC_{50}$ values of non-formulated RIP-MJ (>$500{\mu}g/mL$).

In vitro Assessment of Cytochrome P450 Inhibition by Red Ginseng Ginsenosides (홍삼 Ginsenoside의 Cytochrome P450 저해 활성 평가)

  • Ryu, Chang Seon;Shin, Jang Hyun;Shin, Byoung Chan;Sim, Jae Han;Yang, Hyeon Dong;Lee, Sung Woo;Kim, Bong-Hee
    • YAKHAK HOEJI
    • /
    • v.59 no.2
    • /
    • pp.49-54
    • /
    • 2015
  • In the present study we evaluated comparative herb-drug interaction potential of red ginseng total powder, ginsenoside Rg1, and Rb1 by inhibition of CYP isoforms including CYP1A2, CYP2A6, CYP2B6, CYP2C9, CYP2C19, CYP2D6, CYP2E1 and CYP3A4 using pooled human liver microsomes (HLMs). As measured by liquid chromatography-electrospray ionization tandem mass spectrometry, red ginseng total powder inhibited significantly activities of CYP1A2, CYP2A6, CYP2B6, CYP2C9, CYP2C19, CYP2D6, CYP2E1 and testosterone 6-beta hydroxylation by CYP3A4, but the $IC_{50}$ values were higher than $556{\mu}g/ml$. Activities of CYP2B6, CYP2C9, CYP2D6 and CYP3A4 were inhibited by ginsenoside Rb1. Also, activities of CYP1A2, CYP2A6, CYP2B6, CYP2C9, CYP2C19, CYP2D6 and testosterone 6-beta hydroxylation by CYP3A4 were inhibited by ginsenoside Rg1. The $IC_{50}$ values of ginsenoside Rb1 and Rg1 were higher than $200{\mu}g/ml$. Based on $IC_{50}$ values against CYP isoforms, ginsenosides-drug interactions by CYP inhibition may be very low in clinical situations.

Potential Role of $Ca^{++}$ on the Differentiation of Erythroid Progenitor Cells

  • Cho, In-Koo;Huh, In-Hoe;Lee, Sang-Jun;Kim, Dong-Seop;Ann, Hyung-Soo
    • Archives of Pharmacal Research
    • /
    • v.18 no.2
    • /
    • pp.105-112
    • /
    • 1995
  • In ordedr to gain insight into the mechanisms byl which erythropoietin promotes erythropoiesis, effects of various inhibitors on the erythropoietin-propmoted differentiation of erythroid progenitor cells and on the erythroid progenitor cells and on the erythropoietin-promoted $Ca^{++}$ uptake in the progenitor cells were determined, and the relationship between the inhibitory activity of each inhibitor cells were determined, and he relationship between the inhibitory activity of each inhibitor toward the differentiation and channel blocker (varapamil), a $Ca^{++}$ chelator (EDTA) and a protein kinase C inhibitor (stauroporine). All of these agents inhibited both the erythropoietin-mediated differentiation of the erythroid progenitor cells, as determined by the incroporation of $^{59}Fe$ into heme, and $Ca^{++}$ uptake in a concentrtion dependent manner. In the cases of varapamil and EDTA, the half-miximal inhibitory concentration $(IC_{50})$ values for differentiation of the progenitor cells may be theconsequence of the inhibition of the $Ca^{++}$ uptake in a concentration dependent manner. In the cases of varapamil and EDTA, the half-miximal inhibitory concentration dependent manner. In the cases of verapamil and EDTA, the half-miximal inhibitory concentration $(IC_{50})$ values for differentiation of the progenitor cells may be the consequence of the inhibition of the $Ca^{++}$ uptake by the inhibitor. On the other hand, in the cases of genistein and stauroporine, the $IC_{50}$ values for inhibition of differentitation were significantly different from that for inhibition of $Ca^{++}$uptake. These results suggest that the mechanism of inhibition of differentiation by these two inhibitors in complex. However, taken all together, the above results support the proposition that $Ca^{++}$ uptake may play a role in the erythropoietin-mediated differentiation of erythoid progenitor cells.

  • PDF