• Title/Summary/Keyword: $NO_2$ inhibition

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Inhibition of Nitric Oxide Production, iNOS and COX-2 Expression of Ergosterol Derivatives from Phellinus pini

  • Hong, Yun-Jung;Jang, A-Reum;Jang, Hyun-Jin;Yang, Ki-Sook
    • Natural Product Sciences
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    • v.18 no.3
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    • pp.147-152
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    • 2012
  • Ergosta-4,6,8(14),22-tetraen-3-one (1), ergosta-7,24(28)-dien-3-ol (2), and 5,8-epidioxyergosta-6,22-dien-3-ol(3) were isolated from the fruit body of Phellinus pini. Their structures were based on spectroscopic methods including IR, MS, and NMR (1D and 2D). These compounds were screened for their ability to inhibit nitric oxide (NO) production in LPS-activated RAW 264.7 cells. Compounds 1, 2, and 3 reduced NO production in the assay with $IC_50$ values of 29.7 ${\mu}M$ (1), 15.1 ${\mu}M$ (2), and 18.4 ${\mu}M$ (3) respectively. They also suppressed the expression of protein and m-RNA of iNOS and COX-2 in a dose dependent manner by western blot analysis and RT-PCR experiment in LPS-activated microglial cells.

Inhibition of Cyclooxygenase and Prostaglandin E2 Synthesis by Crude Methanolic Extract from Euonymus Alatus (Thunb.) Sieb in SKBR3 Human Breast Cancer Cell Line

  • Kim Joong-Oh;Jang Tae-Hyun;Kim Min-Sung;Kim Dong-Il;Lee Tae-Kyun
    • The Journal of Korean Medicine
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    • v.26 no.1 s.61
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    • pp.37-45
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    • 2005
  • In the present study, we examined the effect of crude methanolic extract (CME) from Euonymus alatus (Thunb.) Sieb on arachidonic acid (AA) cascade in SKBR3 human breast cancer cell line. CME had a potent inhibitory activity of prostaglandin E2 (PGE2) release induced by A23187, a $Ca^{2+}$ ionophore. The inhibition was concentration-dependent, with the 50 value of about 5 M. CME had no inhibitory effect on A23187-induced phosphorylation of p42/p44 extracellular signal regulated kinase/mitogen-activated protein kinase or on the liberation of [14C]-AA from the cells labeled with [14C]-AA. However, CME concentration-dependently inhibited the conversion of AA to $PGE_2$ in microsomal preparations, showing its possible inhibition of cyclooxygenase (COX). In enzyme assay in vitro, CME inhibited the activities of both constitutive COX (COX­I) and inducible COX (COX-2) in a concentration-dependent manner, with the 50 values of about 0.8 and 2M, respectively. Lineweaver-Burk plot analysis indicated that CME competitively inhibited the activities of both COX-l and -2. This study is a first demonstration that CME directly inhibits COX activity.

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Catalase protects cardiomyocytes via its inhibition of nitric oxide synthesis

  • Chae, Han-Jung;Chae, Soo-Wan;Kim, Hyung-Ryong
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.80.3-81
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    • 2003
  • Nitric oxide (NO) has been reported to play an important role as an effector molecule in cytokine signal transduction in cardiomyocytes. The treatment of IL-1b/ TNF-a (2 ng/ml)/ IFN-g (50 U/ml) induced apoptosis in neonatal rat ventricular cardiomyocytes via NO-dependent pathway. When cardiomyocytes were treated with IL-1b (20 ng/ml)/TNF-a (2 ng/ml)/ IFN-g(50 U/ml) in the presence of catalase, the cells were much more resisant to the cell death as well as NO synthesis. However, catalase significantly enhanced the expression of iNOS protein in cardiomyocytes. (omitted)

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Enhancement of Anti-inflammatory Activity of Lactobacillus plantarum Fermented by Achyranthes japonica on Extraction Solvents (추출 용매에 따른 Lactobacillus plantarum 발효 우슬의 항염증 효과 증진)

  • Jo, Eun Sol;Woo, Young Min;Kim, Ok Ju;Jo, Min Young;Ahn, Mee Young;Lee, Jae-Hwa;Ha, Jong-Myung;Kim, Andre
    • Applied Chemistry for Engineering
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    • v.30 no.2
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    • pp.145-150
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    • 2019
  • In this study, we used extracts obtained from five different solvents (water, ethanol, hexane, ethyl acetate, butanol) of Achyranthes japonica (AJ) and also AJ fermented with Lactobacillus plantarum (LP) to confirm effects on the anti-inflammatory activity in RAW264.7 cells. Experiments of measuring nitric oxide (NO) and cytokine production were performed in lipopolysaccharide (LPS)-induced RAW264.7 cells, and the expression of both cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) was observed by a western blot method. The cytotoxicity of RAW264.7 was confirmed by the cell counting kit (CCK) assay at a concentration of $100{\mu}g/mL$, which has no toxicity. As a result of the inhibition of NO production, the inhibition rate of AJ-LP extracted with ethanol samples was about 74% higher than that of using the control group. Interleukin-6 (IL-6), tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), and Interleukin-$1{\beta}$ (IL-$1{\beta}$), which are inflammatory cytokines, also showed an excellent efficacy with inhibition rates of about 57, 70, and 74%, respectively. Comparing to the results of COX-2 and iNOS expression in the AJ group, the inhibition rate of 20-hydroxyecdysone was the highest than others. On the other hand, the COX-2 expression level of AJ-LP group decreased about 16% compared to that of the control group, and the iNOS expression level was also decreased about 7%. These results suggest that the extract of AJ fermented from L. plantarum can be used as an anti-inflammatory natural material.

Inhibitory Effect of Licorice Ethanol Extracts and Glycyrrhizin on Cytochrome P450 Drug-Metabolizing Enzymes in Human Liver Microsomes (감초 물 추출물 및 Glycyrrhizin이 인체 간 Microsome에서 Cytochrome P450 약물대사효소에 미치는 영향)

  • Park Jong-Hoon;Park Ji-Young;Ju Young-Sung
    • Journal of Society of Preventive Korean Medicine
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    • v.7 no.2
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    • pp.65-74
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    • 2003
  • Objective : The aim of present study is to evaluate the inhibitory potential of licorice extract and glycyrrhizin on cytochrome P450(CYP) in human liver microsomes. Methods : Using human liver microsomes, water extract of licorice and glycyrrhizin as an inhibitor were co-incubated with each probe drug representing selective CYP isoform activity. We measured relative metabolic activity in incubation condition compared to that with no extract of licorice using HPLC system. Results : Both water extracts of licorice and glycyrrhizin showed inhibitory effect on CYP-catalyzed reactions. CYP2C19 $(IC_{50}=126.7{\mu}g/ml)$ is most potently inhibited by water extract than other tested CYP isoforms$(IC_{50}>450{\mu}g/ml)$, but glycyrrhizin exhibited potent inhibition on CYP1A2$(IC_{50}=106.9{\mu}g/ml)$ followed by CYP2C9 and CYP2D6. Conclusion: These results indicate that water extract of licorice and glycyrrhizin have inhibitory potential on CYP-catalyzed reaction in human liver microsomes. But the mechanism of inhibition was slightly different between them Water extract of licorice mainly inhibited CYP2C19, and glycyrrhizin primarily inhibited CYP1A2. The inhibition by water extract of licorice and glycyrrhizin on CYP isoforms may cause drug interaction with co-administered drug leading to toxicity or treatment failure.

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Eupafolin Suppresses P/Q-Type Ca2+ Channels to Inhibit Ca2+/Calmodulin-Dependent Protein Kinase II and Glutamate Release at Rat Cerebrocortical Nerve Terminals

  • Chang, Anna;Hung, Chi-Feng;Hsieh, Pei-Wen;Ko, Horng-Huey;Wang, Su-Jane
    • Biomolecules & Therapeutics
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    • v.29 no.6
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    • pp.630-636
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    • 2021
  • Eupafolin, a constituent of the aerial parts of Phyla nodiflora, has neuroprotective property. Because reducing the synaptic release of glutamate is crucial to achieving pharmacotherapeutic effects of neuroprotectants, we investigated the effect of eupafolin on glutamate release in rat cerebrocortical synaptosomes and explored the possible mechanism. We discovered that eupafolin depressed 4-aminopyridine (4-AP)-induced glutamate release, and this phenomenon was prevented in the absence of extracellular calcium. Eupafolin inhibition of glutamate release from synaptic vesicles was confirmed through measurement of the release of the fluorescent dye FM 1-43. Eupafolin decreased 4-AP-induced [Ca2+]i elevation and had no effect on synaptosomal membrane potential. The inhibition of P/Q-type Ca2+ channels reduced the decrease in glutamate release that was caused by eupafolin, and docking data revealed that eupafolin interacted with P/Q-type Ca2+ channels. Additionally, the inhibition of calcium/calmodulin-dependent protein kinase II (CaMKII) prevented the effect of eupafolin on evoked glutamate release. Eupafolin also reduced the 4-AP-induced activation of CaMK II and the subsequent phosphorylation of synapsin I, which is the main presynaptic target of CaMKII. Therefore, eupafolin suppresses P/Q-type Ca2+ channels and thereby inhibits CaMKII/synapsin I pathways and the release of glutamate from rat cerebrocortical synaptosomes.

Comparative Study of Bang-poong (root of Saposhnikovia divaricata Schischkin) and Related Species on Neuroprotective and Acetylcholinesterase Inhibitory Effects (방풍류(防風類) 약재(藥材)의 신경세포보호효과 및 아세틸콜린에스터라제 저해 효과 비교)

  • Ju, In Gyoung;Lee, Seungmin;Choi, Jin Gyu;Oh, Myung Sook
    • The Korea Journal of Herbology
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    • v.34 no.5
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    • pp.29-37
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    • 2019
  • Objectives : Bang-poong (Saposhnikovia divaricata; SD) was traditionally used to treat inflammatory disorders. In this study, we aimed to investigate whether Bang-poong and related species including SD, Glehnia littoralis (GL), and Peucedanum japonicum (PJ) possess neuroprotective effects and acetylcholinesterase (AChE) inhibitory activities. Methods : Roots of SD, GL and PJ were extracted with distilled water (DW) or 70% ethanol (EtOH). We assessed 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activities of the extracts. To examine neuroprotective effects, we measured cell viability in PC12 or HT22 cells after treatment of the extracts with $H_2O_2$ or amyloid-beta ($A{\beta}$). To assess anti-neuroinflammatory effects, we measured the nitric oxide (NO) levels after treatment with the extracts and lipopolysaccharide (LPS) in BV2 microglial cells. In addition, we performed AChE inhibition assay to explore effects of the extracts on the cholinergic system. Results : DW and EtOH extracts of SD, GL and PJ showed mild DPPH free radical scavenging activities. Also, DW extracts of GL and PJ showed protective effects against $H_2O_2$-induced toxicity in PC12 cells. In LPS-activated BV2 cells, EtOH extracts of SD, GL and PJ exerted inhibitory effects on NO production. Meanwhile, DW extracts of SD, GL and PJ inhibited the $A{\beta}$-induced cell death in HT22 cells. In addition, DW and EtOH extracts of GL exhibited remarkable inhibitory activities on AChE. Conclusions : We demonstrated that SD, GL and PJ exert anti-oxidative, anti-neuroinflammatory and AChE inhibitory activities. These results indicate that SD, GL and PJ could be potential candidates for neurological disorders.

Inhibition of DNA Methylation Is Involved in Transdifferentiation of Myoblasts into Smooth Muscle Cells

  • Lee, Won Jun;Kim, Hye Jin
    • Molecules and Cells
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    • v.24 no.3
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    • pp.441-444
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    • 2007
  • Despite the importance of cell fate decisions regulated by epigenetic programming, no experimental model has been available to study transdifferentiation from myoblasts to smooth muscle cells. In the present study, we show that myoblast cells can be induced to transdifferentiate into smooth muscle cells by modulating their epigenetic programming. The DNA methylation inhibitor, zubularine, induced the morphological transformation of C2C12 myoblasts into smooth muscle cells accompanied by de novo synthesis of smooth muscle markers such as smooth muscle ${\alpha}$-actin and transgelin. Furthermore, an increase of p21 and decrease of cyclinD1 mRNA were observed following zebularine treatment, pointing to inhibition of cell cycle progression. This system may provide a useful model for studying the early stages of smooth muscle cell differentiation.

A Study on the Boilogical Activity of Taxus spp. (주목류의 생물활성 연구)

  • Kim, Tae-Hee
    • Korean Journal of Pharmacognosy
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    • v.21 no.2
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    • pp.142-147
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    • 1990
  • Yew cortex, twigs and leaves(Florida yew, Taxus floridana Nutt et Champ; Pacific, yew Taxus brevifolia Nutt(Taxaceae)) were extracted with MeOH and $CHCI_3$, respectively, and then the chloroform extract was fractionated by silica column chromatography. As biologically active substances, taxol derivatives were identified and several biological activity tests were followed. The results showed that it bad no antimosquito activity and inhibited the growth of root meristem of cress seeds. The chloroform ext. of Florida yew showed 91%, inhibition rate at 400 ppm and the taxol fractions of Pacific yew did 91% at 200 ppm, 94% at 100 ppm. In the antitumor activity tests in vitro against a cultured cell line of L1210 mouse leukemia, Pacific yew showed 99% inhibition rate at 1.0 ppm and Florida yew did 97% at 10 ppm.

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Production of Antibody against Saikosaponin a, an Active Component of Bupleuri Radix

  • Jung, Da-Woon;Sung, Chung-Ki
    • Archives of Pharmacal Research
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    • v.21 no.2
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    • pp.135-139
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    • 1998
  • High titer rabbit polyclonal antibodies (pAbs) which show a specificity for saikosaponin a (SSA), have been generated. The immunogen used was a conjugate of SSA linked through its glucose moiety to bovine serum albumin by periodate oxidation method. The antibody titers obtained from two rabbits, innoculated with the immunogen, reached a plateau after the fourth and third booster injection, respectively. The specificity of the pAbs was determined by hapten inhibition assays using several SSA-like structures. SSA competitively inhibited the binding of the rabbit anti-SSA pAbs to SSA-ovalbumin on solid phase, a coated antigen on the well. The antibodies showed high specificity to SSA, exhibiting no significant cross-reactivity with any of SSA analogues tested.

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