• Title/Summary/Keyword: Selective inhibitor

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Anti-oxidative Activity of Lycopene Via the Induction of HO-1 Expression by MAPK/Nrf2 Signaling Pathway in RAW 264.7 Cells (RAW 264.7 세포에서 Lycopene의 MAPK/Nrf2/HO-1 신호 전달 체계를 통한 항산화 효과)

  • Chung-Mu Park;Hyun An;Hyun-Seo Yoon
    • Journal of The Korean Society of Integrative Medicine
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    • v.12 no.1
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    • pp.1-10
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    • 2024
  • Purpose: Lycopene is abundantly contained in Tomatoes and is known for diverse biological activities such as antioxidant, anti-inflammatory, and anticancer effects. In this study, the antioxidative potential of lycopene was investigated through the induction of hemeoxygenase (HO)-1 by nuclear factor-erythroid 2 p45-related factor2 (Nrf2) and upstream signaling molecules, mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K)/Aktin RAW 264.7 cells. Methods: The antioxidative potential of lycopene against oxidative stress and its molecular mechanisms were determined by the cell viability assay, intracellular reactive oxygen species (ROS) formation assay, and Western blot analysis in RAW 264.7 cells. Results: Lycopene treatment significantly attenuated tert-butyl hydroperoxide (t-BHP) induced intracellular ROS formation in a dose-dependent manner without any cytotoxicity. In addition, 50 µM of lycopene for 6 h treatment induced potent HO-1 expression and its transcription factor, Nrf2. MAPK and PI3K/Aktwere also analyzed due to their critical roles in the regulation of cellular redox homeostasis against oxidative damage. As a result, phosphorylation of extracellular regulated kinase (ERK) was significantly induced by lycopene treatment while the activated status of c-Jun NH2-terminal kinase (JNK), p38, and Akt, were not given any effect. To confirm the antioxidative mechanism of HO-1 mediated by ERK activation, each selective inhibitor was employed in a protection assay, in which oxidative damage occurred by t-BHP. Lycopene, SnPP, and CoPP treatments reflected accelerated HO-1 expression could be a protective role against oxidative damage-initiated cell death. A selective inhibitor for ERK significantly inhibited the lycopene-induced cytoprotective effect but selective inhibitors for other signaling molecules did not attenuate the rate of t-BHP-induced cell death. Conclusion: In conclusion, lycopene potently scavenged intracellular ROS formation and enhanced the HO-1 mediated antioxidative potential through the modulation of Nrf2, MAPK signaling pathway in RAW 264.7 cells.

Phorbol 12-Myristate 13-Acetate Enhances Long-Term Potentiation in the Hippocampus through Activation of Protein Kinase $C{\delta}$ and ${\varepsilon}$

  • Kim, Eung Chang;Lee, Myeong Jong;Shin, Sang Yep;Seol, Geun Hee;Han, Seung Ho;Yee, Jaeyong;Kim, Chan;Min, Sun Seek
    • The Korean Journal of Physiology and Pharmacology
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    • v.17 no.1
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    • pp.51-56
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    • 2013
  • Many intracellular proteins and signaling cascades contribute to the sensitivity of N-methyl-D-aspartate receptors (NMDARs). One such putative contributor is the serine/threonine kinase, protein kinase C (PKC). Activation of PKC by phorbol 12-myristate 13-acetate (PMA) causes activation of extracellular signal-regulated kinase (ERK) and promotes the formation of new spines in cultured hippocampal neurons. The purpose of this study was to examine which PKC isoforms are responsible for the PMA-induced augmentation of long-term potentiation (LTP) in the CA1 stratum radiatum of the hippocampus in vitro and verify that this facilitation requires NMDAR activation. We found that PMA enhanced the induction of LTP by a single episode of theta-burst stimulation in a concentration-dependent manner without affecting to magnitude of baseline field excitatory postsynaptic potentials. Facilitation of LTP by PMA (200 nM) was blocked by the nonspecific PKC inhibitor, Ro 31-8220 ($10{\mu}M$); the selective $PKC{\delta}$ inhibitor, rottlerin ($1{\mu}M$); and the $PKC{\varepsilon}$ inhibitor, TAT-${\varepsilon}V1$-2 peptide (500 nM). Moreover, the NMDAR blocker DL-APV ($50{\mu}M$) prevented enhancement of LTP by PMA. Our results suggest that PMA contributes to synaptic plasticity in the nervous system via activation of $PKC{\delta}$ and/or $PKC{\varepsilon}$, and confirm that NMDAR activity is required for this effect.

Mechanism of the relaxant action of imipramine in isolated rat aorta (흰쥐 대동맥에서 imipramine의 혈관이완 작용기전)

  • Kang, Hyung-sub;Lee, Sang-woo;Baek, Sung-su;Joe, Sung-gun;Kim, Jin-shang
    • Korean Journal of Veterinary Research
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    • v.43 no.4
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    • pp.597-606
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    • 2003
  • Although the antidepressant effects of imipramine (IMI) have been well known in several studies, the effects on cardiovascular system, particularly the vasorelaxant effects, have not known clearly. We hypothesis that IMI-induced vasorelaxation involves NO (nitrie oxide), activation of guanylate cyclase (GC) and $Ca^{2+}$ channel. The possible roles of the endothelium and $Ca^{2+}$ in IMI-induced responses were investigated using isolated rings of rat thoracic aorta and anesthesized rats. In KCl-precontracted rings. IMI produces endothelium-dependent and endothelium-independent relaxations in intact (+E) as well as endothelium-denuded (-E) rat aorta in a concentration-dependent manner. In phenylephrine (PE)-precontracted rings, the IMI-induced relaxation was significantly greater in +E rings. The IMI-induced relaxations were suppressed by nitric oxide synthase (NOS) inhibitors, N(G)-nitro-L-arginine (L-NNA), N(omega)-nitro-L-arginine methyl ester (L-NAME) and aminoguanidine, a non-selective GC inhibitor, methylene blue, $Na^+$ channel blockers, lidocaine and procaine, or $Ca^{2+}$ channel blockers, nifedipine and verapamil, in PE-precontracted +E rings, but not in PE-precontracted -E rings. These relaxations were also suppressed by lidocaine or procaine in -E aortic rings. However, IMI-induced relaxations were not inhibited by a PLC inhibitor 2-nitro-4-carboxyphenyl-n,n-diphenylcarbamate (NCDC), an inositol monophosphatase inhibitor, lithium, indomethacin and dexamethasone in +E and -E rings. In vivo, infusion of IMI elicited significant decrease in arterial blood pressure. After intravenous injection of saponin, NOS inhibitors. MB and nifedipine, infusion of IMI inhibited the IMI-lowered blood pressure markedly. These findings suggest that the endothelium-dependent relaxation induced by IMI is mediated by activation of NO/cGMP signaling cascade or inhibition of $Ca^{2+}$ entry through voltage-gated channel, and this mechanism may contribute to the hypotensive effects of IMI in rats.

Kojic Acid, a Potential Inhibitor of NF-$textsc{k}$B Activation in Transfectant Human HaCaT and SCC-13 Cells

  • Moon, Ki-Young;Ahn, Kwang-Seok;Lee, Jin-seon;Kim, Yeong-Shik
    • Archives of Pharmacal Research
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    • v.24 no.4
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    • pp.307-311
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    • 2001
  • The activation of NF-$\kappa$B induced by kojic Acid, an inhibitor of tyrosinase for biosynthesis of melanin in melanocytes, was investigated in human transfectant HaCaT and SCC-13 cells. These two keratinocyte cell lines transfected with pNF-$\kappa$B-SEAP-NPT plasmid were used to determine the activation of NF-$\kappa$B. Transfectant cells release the secretory alkaline phosphatase (SEAP) as a transcription reporter in response to the NF-$\kappa$B activity and contain the neomycin phosphotransferase (NPT) gene for the dominant selective marker of geneticin resistance. NF-$\kappa$B activation was measured in the SEAP reporter gene assay using a fluorescence detection method. Kojic Acid showed the inhibition of cellular NF-$\kappa$B activity in both human keratinocyte transfectants. It could also downregulate the ultraviolet ray (UVR)-induced activation of NF-$\kappa$B expression in transfectant HaCaT cells. Moreover, the inhibitory activity of kojic Acid in transfectant HaCaT cells was found to be more potent than known antioxidants, e.g., vitamin C and N~acetyl-L-cysteine. These results indicate that kojic Acid is a potential inhibitor of NF-$\kappa$B activation in human keratinocytes, and suggest the hypothesis that NF-$\kappa$B activation may be involved in kojic Acid induced anti-melanogenic effect.

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Src Family Kinase Inhibitor PP2 Induces LC3 Conversion in a Manner That is Uncoupled from Autophagy and Increases Apoptosis in Multidrug-Resistant Cells

  • Kim, Yun-Ki;Ahn, Jun-Ho;Lee, Mi-Chael
    • Biomolecules & Therapeutics
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    • v.20 no.4
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    • pp.393-398
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    • 2012
  • Recently, we reported that defective autophagy may contribute to the inhibition of the growth in response to PP2 (4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine), a selective SFK inhibitor, in multidrug-resistant v-Ha-ras-transformed NIH 3T3 cells (Ras-NIH 3T3/Mdr). In this study, we demonstrated that PP2 induces LC3 conversion via a mechanism that is uncoupled from autophagy and increases apoptosis in Ras-NIH 3T3/Mdr cells. PP2 preferentially induced autophagy in Ras-NIH 3T3 cells rather than in Ras-NIH 3T3/Mdr cells as determined by LC3-I to LC3-II conversion and GFP-LC3 fluorescence microscopy. Beclin 1 knockdown experiments showed that, regardless of drug resistance, PP2 induces autophagy via a Beclin 1-dependent mechanism. PP2 induced a conformational change in Beclin 1, resulting in the enhancement of the pro-autophagic activity of Beclin 1, in Ras-NIH 3T3 cells. Further, PI3K inhibition induced by wortmannin caused a significant increase in apoptosis in Ras-NIH 3T3 cells, as demonstrated by flow cytometric analysis of Annexin V staining, implying that autophagy inhibition through PI3K increases apoptosis in response to PP2 in Ras-NIH 3T3 cells. However, despite the fact that wortmannin abrogates PP2-induced GFP-LC3 punctae formation, some LC3 conversion remains in Ras-NIH 3T3/Mdr cells, suggesting that LC3 conversion may occur in an autophagy-independent manner. Taken together, these results suggest that PP2 induces LC3 conversion independent of PI3K, concomitant with the uncoupling of LC3 conversion from autophagy, in multidrug-resistant cells.

Abuse Liability Assessment of l-Deprenyl by Testing Methamphetamine-like Discriminative Effects (메탐페타민 유사 분별능 시험을 통한 l-디프레닐의 약물남용가능성 평가)

  • Lee, Sun-Hee;Kim, Pu-Young
    • YAKHAK HOEJI
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    • v.42 no.1
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    • pp.101-107
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    • 1998
  • The antiparkinsonian agent l-deprenyl, a selective monoamine oxidase (MAO)-B inhibitor, is metabolized in part to l-methamphetamine and l-amphetamine. l< /I>-Deprenyl was evaluated for amphetamine and methamphetamine-like discriminative stimulus effects in rats and its mechanism of action was investigated. Rats were trained under a 5-response, fixed ratio schedule of stimulus-shock termination or a 10-response. Fixed-ratio schedule of food-presentation which discriminate between d-amphetamine (1mg/kg, i.p.) and saline or d-methamphetamine (1mg/kg, i.p.) and saline in a two-lever, operant conditioning procedure. Full generalization was obtained to d-amphetamine (1~3mg/kg). d-methamphetamine (1~3mg/kg) and l-deprenyl (17~30mg/kg) under both the food presentation and stimulus shock termination schedule. l-Deprenyl has dose-dependent amphetamine-and methamphetamine-like discriminative stimulus properties in rats only at doses of 17 and 30mg/kg. Reversible MAO-B inhibitor, RO 16-6491 didn`t show any amphetamine-like discriminative properties. Aromatic amino acid decarboxylase inhibitor, NSD 1015 decreased % responding of l-deprenyl in the methamphetamine-trained rats under the stimulus-shock termination schedule. SKF-525A produced partial inhibition of methamphetamine-like discriminative effects of l-deprenyl under the food presentation schedule. These results suggest that l-deprenyl has no abuse liability at the therapeutic range but there needs some caution at high doses and furthermore, drug discrimination studies under the food presentation and shock termination schedule are useful for the assessment of abuse liability of psychostimulants.

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A Study on the Prescription Patterns of Gastrointestinal Protective Agent with Non-Steroidal Anti-Inflammatory Drugs in Korean Elderly Patients with Osteoarthritis (골관절염을 진단받고 비스테로이드성 항염제 복용 중인 65세 이상 환자의 위장관보호제 처방양상 연구)

  • Chun, Seongmin;Choi, Yoonhee
    • Journal of The Korean Society of Integrative Medicine
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    • v.8 no.4
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    • pp.79-92
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    • 2020
  • Purpose : The purpose of this study was to evaluate the prescription pattern of NSAIDs and GPAs in the arthritis patients over 65 years old to prevent the GI adverse events. Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most commonly used agents to treat arthritis, can cause gastrointestinal (GI) adverse effects. Recent guidelines recommend that moderate risk patients who have one or two risk factors, should be prescribed either combination of non-selective NSAID (nsNSAIDs) and gastroprotective agent (GPAs) or selective NSAID alone. Methods : Study population was National Patient Sample of 2011. Number of drugs used were 138 for NSAIDs and 21 for GPAs. Chi-square test was used to compare prescribing patterns. Results : The appropriate prescription rate follows the guideline was 11.2%: co-prescription with nsNSAID and proton pump inhibitor (PPI) or misoprostol was 1.6% and selective NSAID alone was 9.6%. Inappropriate prescription rates were as follows: co-prescription with nsNSAID and Histamine-2 receptor antagonist (H2RA) or antiacid was 53.8% and nsNSAID alone was 35.0%. The appropriate prescription rate among the types of medical institute was 54.4% in tertiary hospital, 31.2% in secondary hospital, and 6.0% in primary hospital. The appropriate prescription rate among the regions was 19.4%, highest in Seoul and 4.2%, lowest in Jeju. The appropriate prescription rate among the medical departments was as follow: 12.2% in orthopaedic surgery, 11.0% in internal medicine, and 7.7% in other departments. Conclusion : This finding suggests the needs to revise the national medical insurance imbursement policy, provide continuing medical education about the guideline of medical doctors.

Comparison of Bleeding Tendency Between Selective Serotonin Reuptake Inhibitors and Serotonin Norepinephrine Reuptake Inhibitors Using Platelet Function Analyzer (혈소판기능분석기를 이용한 선택적 세로토닌 재흡수 억제제와 세로토닌 노르에피네프린 재흡수 억제제의 출혈 경향성 비교)

  • Koo, Seung Mo;Kim, Hyun;Lee, Kang Joon
    • Korean Journal of Psychosomatic Medicine
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    • v.29 no.2
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    • pp.153-161
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    • 2021
  • Objectives : The purpose of this study is to compare bleeding tendency of selective serotonin reuptake inhibitor (SSRI) and serotonin norepinephrine reuptake inhibitors (SNRI) using platelet function analyzer (PFA-100) in patients with major depressive disorder. Methods : This study is a prospective open-label study conducted by a single institution. A total of 41 subjects diagnosed with major depressive disorder under the DSM-5 diagnostic criteria participated in this study. The subjects were classified into SSRI (escitalopram) groups and SNRI (duloxetine) groups, respectively, according to random assignments. The closure time (CT) was measured using a platelet function analyzer (PFA-100) before each antidepressant was administered and after 6 weeks. Paired-sample t-test was conducted within each group to determine whether a specific antidepressant had an effect on closure time. In order to confirm the relative change in platelet function between the two groups, an independent sample t-test was conducted to compare and analyze the change in closure time between the two groups. Results : There was no significant changes in closure time (CEPI-CT, CADP-CT) before and 6 weeks after drug administration in the SSRI and SNRI groups, and there was no difference in the amount of changes in closure time between the two groups. Conclusions : Our results showed no difference in bleeding tendency between SSRI and SNRI. This study suggests that further large-scale studies on bleeding tendency for various antidepressants are needed in the future.

Quantitative Study of the Reformation of Excess Sludge by Intense Aeration Under Nutrient-poor Conditions

  • L Guang Wei;Chen Liming;Toda Kiyoshi;Zhang Shuting
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.9 no.6
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    • pp.519-522
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    • 2004
  • In the course of anaerobic storage of excess sludge, odors due to chemicals such as hydrogen sulfide are produced. These odors cause many problems. Many methods have been developed to eliminate odors, but all current methods are not only costly, but also largely inef­fective. In this paper, we investigate the process of transformation of sludge microorganism cul­tures through intense aeration under nutrient-poor conditions, in terms of the selective adjust­ment and control of microorganism culture. The aerated sludge is subsequently returned to the adjusting pool, where the microorganisms inhibit odors, thus the excess sludge itself will act as an odor inhibitor. The process can be verified in terms of viability, in that the degradation capac­ity of the sludge was maintained after the intensely-aerated sludge was returned to the treat­ment system.

Allyl Alcohol Found in Heated Garlic is a Potent Selective Inhibitor of Yeasts

  • Lee Se-Hi;Woo Yong-Ho;Kyung Kyu-Hang
    • Journal of Microbiology and Biotechnology
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    • v.16 no.8
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    • pp.1236-1239
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    • 2006
  • Allyl alcohol (2-propen-l-ol), found in considerable amounts in heated garlic, was able to discriminate yeasts from bacteria and was approximately three orders of magnitude more inhibitory towards yeasts than bacteria. The average minimum inhibitory concentration (MIC) of allyl alcohol for bacteria and yeasts was 5.0% and 0.0056%, respectively. The unsaturated primary alcohols, including allyl alcohol and 2-buten-l-ol, seemed to work differently from all the other saturated alcohols and unsaturated secondary alcohols in inhibiting various yeasts. An alcohol dehydrogenase-negative (ADH$^-$) strain of Saccharomyces cerevisiae was as resistant to allyl alcohol as various bacteria, exhibiting an MIC of 5.0%. The unsaturated primary alcohols were apparently oxidized into the corresponding unsaturated aldehydes before they inhibited the yeasts.