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1.
Am J Physiol Cell Physiol ; 320(4): C635-C651, 2021 04 01.
Article in English | MEDLINE | ID: mdl-33356946

ABSTRACT

Disruption of copper homeostasis is closely involved in neurodegenerative disorders. This study examined whether a hybrid copper-binding compound, (E)-2-(4-(dimethylamino)phenylimino)methyl)quinolin-8-ol (DPMQ), is able to protect NG108-15 cells against oxidative stress. We found that treatment of cells with rotenone or hydrogen peroxide increased cellular oxidative stress and resulted in mitochondrial dysfunction and apoptosis. The cellular levels of Nrf2 and the Cu2+ chaperone DJ-1 were also decreased. These oxidative detrimental effects were all inhibited when cells were cotreated with DPMQ. DPMQ increased cellular Cu2+ content, DJ-1 protein level, superoxide dismutase (SOD) activity, and Nrf2 nuclear translocation under basal state. The activity of SOD decreased under redox imbalance and this decrease was blocked by DPMQ treatment, while the protein level of SOD1 remained unaltered regardless of the oxidative stress and DPMQ treatment. Using endogenous proteins, coimmunoprecipitation showed that DJ-1 bound with SOD1 and Nrf2 individually. The amount of Nrf2, bound to DJ-1, consistently reflected its cellular level, while the amount of SOD1, bound to DJ-1, was potentiated by DPMQ, being greater in the basal state than under redox imbalance. Simultaneous inclusion of nonpermeable Cu2+ chelator tetrathiomolybdate or triethylenetetramine during DPMQ treatment blocked all aforementioned effects of DPMQ, showing that the dependency of the effect of DPMQ on extracellular Cu2+. In addition, silencing of DJ-1 blocked the protection of DPMQ against oxidative stress. Taken all together, our results suggest that DPMQ stabilizes DJ-1 in a Cu2+-dependent manner, which then brings about SOD1 activation and Nrf2 nuclear translocation; these together alleviate cellular oxidative stress.


Subject(s)
Antioxidants/pharmacology , Chelating Agents/pharmacology , Copper/metabolism , Neurons/drug effects , Oxidative Stress/drug effects , Protein Deglycase DJ-1/metabolism , Animals , Apoptosis/drug effects , Cell Line, Tumor , Glioma/enzymology , Glioma/pathology , Humans , Hybridomas , Hydrogen Peroxide/toxicity , Mitochondria/drug effects , Mitochondria/enzymology , Mitochondria/pathology , NF-E2-Related Factor 2/metabolism , Neuroblastoma/enzymology , Neuroblastoma/pathology , Neurons/enzymology , Neurons/pathology , Protein Deglycase DJ-1/genetics , Rats , Rotenone/toxicity , Superoxide Dismutase-1/metabolism
2.
Proc Natl Acad Sci U S A ; 114(15): E3129-E3138, 2017 04 11.
Article in English | MEDLINE | ID: mdl-28351972

ABSTRACT

Proteolytic processing of amyloid precursor protein (APP) C-terminal fragments (CTFs) by γ-secretase underlies the pathogenesis of Alzheimer's disease (AD). An RNA interference screen using APP-CTF [99-residue CTF (C99)]- and Notch-specific γ-secretase interaction assays identified a unique ErbB2-centered signaling network that was predicted to preferentially govern the proteostasis of APP-C99. Consistently, significantly elevated levels of ErbB2 were confirmed in the hippocampus of human AD brains. We then found that ErbB2 effectively suppressed autophagic flux by physically dissociating Beclin-1 from the Vps34-Vps15 complex independent of its kinase activity. Down-regulation of ErbB2 by CL-387,785 decreased the levels of C99 and secreted amyloid-ß in cellular, zebrafish, and mouse models of AD, through the activation of autophagy. Oral administration of an ErbB2-targeted CL-387,785 for 3 wk significantly improves the cognitive functions of APP/presenilin-1 (PS1) transgenic mice. This work unveils a noncanonical function of ErbB2 in modulating autophagy and establishes ErbB2 as a therapeutic target for AD.


Subject(s)
Alzheimer Disease/pathology , Amyloid Precursor Protein Secretases/metabolism , Amyloid beta-Protein Precursor/metabolism , Autophagy , Brain/pathology , Presenilin-1/metabolism , Receptor, ErbB-2/metabolism , Alzheimer Disease/genetics , Alzheimer Disease/metabolism , Amyloid Precursor Protein Secretases/genetics , Amyloid beta-Peptides/genetics , Amyloid beta-Peptides/metabolism , Amyloid beta-Protein Precursor/genetics , Animals , Beclin-1/genetics , Beclin-1/metabolism , Brain/metabolism , Female , Humans , Male , Mice , Mice, Transgenic , Presenilin-1/genetics , Proteostasis , Receptor, ErbB-2/genetics , Zebrafish/genetics , Zebrafish/growth & development , Zebrafish/metabolism
3.
Int J Mol Sci ; 21(11)2020 Jun 05.
Article in English | MEDLINE | ID: mdl-32517029

ABSTRACT

Dengue virus (DENV) and Zika virus (ZIKV) are mosquito-borne flaviviruses that cause severe illness after infection. Currently, there are no specific or effective treatments against DENV and ZIKV. Previous studies have shown that tyrosine kinase activities and signal transduction are involved in flavivirus replication, suggesting a potential therapeutic strategy for DENV and ZIKV. In this study, we found that compound L3 can significantly reduce viral protein expression and viral titers in HEK-293, MCF-7, HepG2, and Huh-7 cells and exhibits superior therapeutic efficacy against flaviviral infection compared to other tyrosine kinase inhibitors. In addition, compound L3 can decrease endogenous HER2 activation and inhibit the phosphorylation of the HER2 downstream signaling molecules Src and ERK1/2, the levels of which have been associated with viral protein expression in MCF-7 cells. Moreover, silencing HER2 diminished DENV-2 and ZIKV expression in MCF-7 cells, which suggests that HER2 activity is involved in flavivirus replication. Furthermore, in DENV-2-infected AG129 mice, treatment with compound L3 increased the survival rates and reduced the viremia levels. Overall, compound L3 demonstrates therapeutic efficacy both in vitro and in vivo and could be developed as a promising antiviral drug against emerging flaviviruses or for concurrent DENV and ZIKV outbreaks.


Subject(s)
Antiviral Agents/pharmacology , Dengue Virus/drug effects , Zika Virus/drug effects , Afatinib/chemistry , Afatinib/pharmacology , Animals , Antiviral Agents/chemistry , Cells, Cultured , Dengue/virology , Dose-Response Relationship, Drug , ErbB Receptors/metabolism , HEK293 Cells , Humans , Inhibitory Concentration 50 , Mice , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacology , Signal Transduction , Virus Replication/drug effects , Zika Virus Infection/virology
4.
J Cell Physiol ; 233(12): 9594-9610, 2018 12.
Article in English | MEDLINE | ID: mdl-29943824

ABSTRACT

Copper is more likely than iron to generate reactive oxygen species (ROS) in a redox reaction due to its higher electrochemical reactivity. This study examined the effect of a newly synthesized Cu2+ binding compound, (E)-2-(4-(dimethylamino)phenylimino)methyl)quinolin-8-ol (DPMQ), on ultraviolet B (UVB) irradiation-induced cytotoxicity in human dermal fibroblasts. DPMQ induced Cu2+ influx as effectively as disulfiram, a Cu2+ ionophore anticancer drug. However, disulfiram induced ROS generation, mitochondrial dysfunction, and apoptosis in fibroblasts in a Cu2+ -dependent manner, whereas DPMQ was not only nontoxic, but protected cells against UVB irradiation-induced apoptosis in a Cu2+ -independent manner. UVB irradiation induced a Ca2+ -dependent increase in ROS generation, a decrease in Nrf2 levels, and activation of the mitochondrial apoptotic pathway, and these effects were prevented by DPMQ, which also increased Nrf2 nuclear translocation in a Cu2+ -independent manner. UVB irradiation activated 12-lipoxygenase and 12-hydroxyeicosatetraenoic acid (12-HETE), a product of 12-lipoxygenase, activated the TRPV1 channel. DMPQ did not act as a Ca2+ chelator, but inhibited the cytosolic Ca2+ increase induced by 12-HETE or capsaicin, but not that induced by bradykinin or ATP. Blockade of Ca2+ influx by pharmacological inhibition or silencing of the TRPV1 channel or chelation of cytosolic Ca2+ inhibited the UVB irradiation-induced Nrf2 reduction, ROS generation, mitochondrial dysfunction, and apoptosis. Taken together, our results suggest that Ca2+ influx via the TRPV1 channel is responsible for UVB irradiation-induced cytotoxicity and that DPMQ protects cells against UVB irradiation by inhibiting the TRPV1 channel and stabilizing Nrf2, and could thus be a potentially useful compound for the treatment of free radical-induced diseases.


Subject(s)
Copper/pharmacology , Cytoprotection , Ionophores/pharmacology , Quinolines/pharmacology , TRPV Cation Channels/metabolism , Ultraviolet Rays , Acetylcysteine/pharmacology , Apoptosis/drug effects , Apoptosis/radiation effects , Arachidonate 12-Lipoxygenase/metabolism , Caspase 3/metabolism , Cell Proliferation/drug effects , Cell Proliferation/radiation effects , Cytoprotection/drug effects , Cytoprotection/radiation effects , Dermis/cytology , Disulfiram/pharmacology , Enzyme Activation/drug effects , Enzyme Activation/radiation effects , Fibroblasts/cytology , Fibroblasts/drug effects , Fibroblasts/metabolism , Fibroblasts/radiation effects , Gene Silencing/drug effects , Gene Silencing/radiation effects , Humans , Ion Channel Gating/drug effects , Ion Channel Gating/radiation effects , Mitochondria/drug effects , Mitochondria/metabolism , Mitochondria/radiation effects , NF-E2-Related Factor 2/metabolism , Protective Agents/pharmacology , Reactive Oxygen Species/metabolism
5.
Biochem Biophys Res Commun ; 491(3): 595-602, 2017 09 23.
Article in English | MEDLINE | ID: mdl-28760340

ABSTRACT

Chikungunya is a severe disease that results from infection with the chikungunya virus (CHIKV), an arbovirus. Thus, we (1) explored a new approach to combining previously researched drugs that have shown the potential to inhibit CHIKV infection; and (2) demonstrated the antiviral effects of (-)-Epigallocatechin-3-gallate (EGCG) and the underlying mechanisms. Specifically, we used U2OS cells infected with CHIVK to assess the synergistic antiviral activities of EGCG and suramin. EGCG presented the ability to inhibit the viral RNA, progeny yield, and cytopathic effect (CPE) of CHIKV and also demonstrated the ability to protect against virus entry, replication, and release. Moreover, the results confirmed that EGCG and suramin can have synergistic effects against CHIKV strain S27 infection and two other clinical isolates of CHIKV. Our findings suggest that treatment with a combination of EGCG and suramin could provide a basis for the development of novel stretages against CHIKV infection.


Subject(s)
Catechin/analogs & derivatives , Chikungunya Fever/drug therapy , Chikungunya Fever/virology , Chikungunya virus/drug effects , Chikungunya virus/physiology , Suramin/administration & dosage , Antiviral Agents/administration & dosage , Catechin/administration & dosage , Dose-Response Relationship, Drug , Drug Combinations , Drug Synergism , Humans , Treatment Outcome
6.
Pharmacoepidemiol Drug Saf ; 26(1): 71-80, 2017 01.
Article in English | MEDLINE | ID: mdl-27730699

ABSTRACT

PURPOSE: To analyze and characterize data regarding the prevalence and types of outpatient drug-related problems (DRPs) found by clinical pharmacists after implementation of the Virtual Medicine Record in Cloud System (VMRCS). METHODS: A cross-sectional study regarding outpatient pharmaceutical care was conducted at a medical center in Taiwan. Patients aged >20 years old with multiple chronic diseases and polypharmacy were enrolled. In Stage I (1 October-31 December 2014), patients received pharmaceutical care according to prescription data accessed online in the VMRCS. In Stage II (1 June-31 August 2015), the VMRCS were pre-download and arranged to the institute's required format, facilitated DRP detection. Clinical pharmacists then reviewed and evaluated the prescription data through pre-downloaded VMRCS. Overall, 1539 and 1600 prescriptions were evaluated in these two stages, respectively. DRPs were recorded using the Pharmaceutical Care Network Europe (PCNE)-DRP. RESULTS: DRPs were found for 50.2% of patients in Stage I and 55.2% in Stage II (p < 0.05) and were most frequently encountered for "Drugs for the cardiovascular system" and caused by "Inappropriate duplication of therapeutic group or active ingredient." In terms of problems, incidence of "Unnecessary drug treatment" was highest. Duplicate medications were most frequently seen for "Drugs for acid-related disorders." The efficiency to identify DRPs was at least 2.4 times higher with pre-downloaded prescription data than with real-time online queries. CONCLUSIONS: With VMRCS, DRPs were more easily identified whether patients received medical care in the same hospital or not. DRPs could be efficiently prevented through the use of pre-downloaded patient prescription data. Copyright © 2016 John Wiley & Sons, Ltd.


Subject(s)
Drug-Related Side Effects and Adverse Reactions/epidemiology , Pharmaceutical Services/organization & administration , Pharmacists/organization & administration , Polypharmacy , Adult , Aged , Aged, 80 and over , Ambulatory Care/organization & administration , Cloud Computing , Cross-Sectional Studies , Electronic Health Records/statistics & numerical data , Female , Humans , Inappropriate Prescribing/statistics & numerical data , Male , Middle Aged , Practice Patterns, Physicians'/statistics & numerical data , Prevalence , Taiwan
7.
Arch Pharm (Weinheim) ; 349(5): 327-41, 2016 May.
Article in English | MEDLINE | ID: mdl-27027880

ABSTRACT

Copper and zinc have been found to contribute to the burden of amyloid-ß (Aß) aggregations in neurodegenerative Alzheimer's disease (AD). Dysregulation of these metals leads to the generation of reactive oxygen species (ROS) and eventually results in oxidative damage and accumulation of the Aß peptide, which are the key elements of the disease. Aiming to pursue the discovery of new modulators for the disease, we here rationally focused on conjugating the core hydroxyquinoline of the metal-protein attenuating compound PBT2 and the N-methylanilide analogous moiety of the Aß imaging agent to build a new type of multi-target modulators of Aß aggregations. We found that the N,N-dimethylanilinyl imines 7a, 8a, and the corresponding amines 7b, 8b exerted efficient inhibition of Cu(2+) - or Zn(2+) -induced Aß aggregations and significant disassembly of metal-mediated Aß aggregated fibrils. Further, 7a and 7b also exhibited significant ROC scavenging effects compared to PBT2. The results suggested that 7a and 7b are promising lead compounds for the development of a new therapy for AD.


Subject(s)
Amyloid beta-Peptides/drug effects , Amyloid beta-Peptides/metabolism , Hydroxyquinolines/chemistry , Hydroxyquinolines/therapeutic use , Protein Aggregation, Pathological/drug therapy , Amyloid beta-Peptides/chemistry , Amyloid beta-Peptides/ultrastructure , Chelating Agents/chemical synthesis , Chelating Agents/pharmacology , Chelating Agents/therapeutic use , Clioquinol/analogs & derivatives , Clioquinol/chemistry , Clioquinol/pharmacology , Clioquinol/therapeutic use , Copper/adverse effects , Hydroxyquinolines/chemical synthesis , Hydroxyquinolines/pharmacology , Structure-Activity Relationship , Zinc/adverse effects
8.
J Gastroenterol Hepatol ; 29(4): 769-74, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24325147

ABSTRACT

BACKGROUND: Simethicone and N-acetylcysteine have been widely used in improving endoscopic visibility. However, the optimal dose, volume, and dosing time for the premedication regimen are still unclear. AIM: Our aim was to assess the efficacy of premedication in improving endoscopic visibility and determine the contributions of dose, volume, and premedication time. METHODS: A total of 1849 patients were prospectively treated in three groups: group A: 100-mg simethicone suspension in 5 mL water; group B: 100-mg simethicone suspension in 100 mL water; and group C: 100-mg simethicone suspension in 100 mL water containing 200 mg N-acetylcysteine. Mucosa visibility was assessed at seven sites of upper gastrointestinal tract. The sum of scores was considered as total mucosal visibility score (TMVS). RESULTS: The upper body of stomach had the worst visibility score for all groups. TMVS of groups B and C were significantly lower than those of group A. Group C had a significantly fewer patients requiring endoscopic flushing than groups A and B. The TMVS for groups B and C were significantly lower than for group A within 30 min of beginning premedication. Beyond 30 min of premedication, there was no significant difference in the TMVS among groups. CONCLUSIONS: Premedication using 100 mg simethicone in 100 mL of water improves endoscopic visibility. Addition of N-acetylcysteine to simethicone in 100 mL of water reduces the need for endoscopic flushing. For patients unable to tolerate a large fluid volume, a 5-mL simethicone suspension administered more than 30 min prior to upper endoscopy is suggested.


Subject(s)
Acetylcysteine/administration & dosage , Endoscopy, Digestive System/methods , Image Enhancement/methods , Premedication/methods , Simethicone/administration & dosage , Adult , Aged , Female , Humans , Male , Middle Aged , Prospective Studies , Single-Blind Method , Suspensions , Time Factors , Water
9.
Arch Pharm (Weinheim) ; 347(3): 161-73, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24339192

ABSTRACT

Synthesis and evaluation of difluorophenylglycinols as new modulators of proteolytic processing of the amyloid-ß precursor proteins for Alzheimer's therapies were described. A range of N-substituted (R)- and (S)-difluorophenylglycinols, structured on the amino alcohol framework, were explored by incorporating the arylsulfonyl moieties and various N-substituents. Evans' chiral auxiliary strategy was employed for the asymmetric synthesis of these enantiomeric difluorophenylglycinols. Compounds with effects on the γ-secretase inhibition and ERK-mediated signaling pathways were evaluated on cell-based assays. Among them, N-cyclopropylmethyl derivatives R-12c and R-13c showed modest γ-secretase inhibition as well as ERK-dependent activation.


Subject(s)
Amyloid Precursor Protein Secretases/antagonists & inhibitors , Amyloid beta-Protein Precursor/metabolism , Ethanolamines/pharmacology , Protease Inhibitors/pharmacology , Alzheimer Disease/drug therapy , Alzheimer Disease/enzymology , Amyloid Precursor Protein Secretases/genetics , Amyloid Precursor Protein Secretases/metabolism , Enzyme Activation , Ethanolamines/chemical synthesis , Extracellular Signal-Regulated MAP Kinases/metabolism , HEK293 Cells , Humans , Molecular Structure , Protease Inhibitors/chemical synthesis , Proteolysis , Signal Transduction/drug effects , Structure-Activity Relationship , Transfection
10.
Molecules ; 18(7): 7557-69, 2013 Jun 27.
Article in English | MEDLINE | ID: mdl-23807580

ABSTRACT

Fluoroquinolones have been a class of important synthetic antimicrobial agents broadly and effectively used in clinic for infectious diseases. In this study, the synthesis of a range of fluoroquinolone derivatives with 4-(carbopiperazin-1-yl)piperazinyl moieties at the C7 position and their inhibition of bacterial pathogens commonly disseminated in hospital environment were described. The results indicated that a 7-[4-(4-(benzoyl)carbopiperazin-1-yl)]piperazinyl derivative 5h and two 7-[4-(4- (benzenesulfonyl)carbopiperazin-1-yl)]piperazinyl derivatives 5k and 5l showed more promising growth inhibition of ciprofloxacin-resistant P. aeruginosa (CRPA) with MIC values as low as 16 µg/mL which is 16-fold more potent than ciprofloxacin, while most of other derivatives maintained potency against methicillin-resistant Staphylococcus aureus (MRSA).


Subject(s)
Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Fluoroquinolones/chemistry , Fluoroquinolones/pharmacology , Methicillin-Resistant Staphylococcus aureus/drug effects , Pseudomonas aeruginosa/drug effects , Ciprofloxacin/pharmacology , Drug Resistance, Bacterial , Microbial Sensitivity Tests , Structure-Activity Relationship
11.
Microporous Mesoporous Mater ; 118(1): 467-472, 2009 Feb 01.
Article in English | MEDLINE | ID: mdl-32288626

ABSTRACT

Nanocomposites based on Keggin-type polyoxometalate H5PV2Mo10O40 (POM) and porous bamboo charcoal (BC) were prepared by activation and immobilization processes. The physical properties of the BC/POM composites were examined using FTIR, UV-Vis spectroscope, 31P MAS-NMR, SEM and TEM. These techniques indicated that the POM was intact on the surface of the BC matrix after impregnation. The POM particle size was found to be less than 150 nm based on TEM. The antibacterial effects of the BC/POM composites were assessed from the zone of inhibition, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and plate-counting method, and an excellent antibacterial performance was discovered.

12.
Neurosci Lett ; 440(1): 38-43, 2008 Jul 25.
Article in English | MEDLINE | ID: mdl-18547722

ABSTRACT

Previous studies have demonstrated that the ERK MAPK acts as a negative regulator of gamma-secretase. Here, we demonstrate that the activation of ERK MAPK pathway by sodium selenite can inhibit endogenous gamma-secretase activity. Consistently, the gamma-secretase-mediated production of amyloid-beta (Abeta) was dramatically attenuated by sodium selenite in a temporal manner. To substantiate the functional role of ERK MAPK in the regulation of gamma-secretase, we demonstrate that cells transfected with the wild-type MEK1 and a constitutively active mutant of MEK1 also displayed a significant attenuation of gamma-secretase activity. The active purified ERK1/2 can significantly reduce the gamma-secretase-mediated processing of C99, possibly through inducing alterations in the phosphorylation of both nicastrin and presenilin-1. Together, our data suggest that the selenite-elicited ERK activation could effectively reduce Abeta production, supporting that selenium compounds could represent a novel class of nutrient supplements to slow down the progression of Alzheimer's disease.


Subject(s)
Amyloid Precursor Protein Secretases/metabolism , Extracellular Signal-Regulated MAP Kinases/metabolism , Signal Transduction/drug effects , Sodium Selenite/pharmacology , Amyloid beta-Peptides/metabolism , Cell Line, Transformed , Dose-Response Relationship, Drug , Enzyme Activation/drug effects , Humans , Mutation/physiology , Peptide Fragments/metabolism , Time Factors
13.
Bioorg Med Chem ; 16(4): 1957-65, 2008 Feb 15.
Article in English | MEDLINE | ID: mdl-18024043

ABSTRACT

A type of new 1,2,3,4-tetrahydroisoquinoline derivatives was synthesized via concise procedure from commercially available tetrahydroisoquinoline. These derivatives were delicately designed to possess propargyl-related pharmacophores simulated with a monoamine oxidase inhibitor rasagiline. We investigated the effect of these synthetic tetrahydroisoquinoline derivatives on the regulation of proteolytic processing of amyloid precursor protein (APP) by an ERK-dependent signaling pathway. Additionally, these compounds were also evaluated on the prevention of the proteolytic processing of C99 as gamma-secretase inhibitors by using a highly efficient cell-based reporter gene assay for gamma-secretase. The results suggested that certain compounds might be explored to possess both sAPPalpha-releasing stimulation and gamma-secretase inhibitory potency, which may reflect the synergetic potential of neuroprotective activities for the treatment of Alzheimer's disease as they possessed both ERK activation and inhibition of amyloidogenic Abeta release.


Subject(s)
Amyloid beta-Protein Precursor/metabolism , Peptide Hydrolases/metabolism , Tetrahydroisoquinolines/pharmacology , Alzheimer Disease/drug therapy , Amyloid Precursor Protein Secretases/antagonists & inhibitors , Extracellular Signal-Regulated MAP Kinases/metabolism , Humans , Hydrolysis/drug effects , Neuroprotective Agents , Tetrahydroisoquinolines/chemistry
14.
Antiviral Res ; 159: 134-142, 2018 11.
Article in English | MEDLINE | ID: mdl-30300716

ABSTRACT

The chikungunya virus (CHIKV) is a mosquito-borne virus that belongs to the genus Alphavirus, family Togaviridae. It is the cause of chikungunya fever in humans, which presents a serious global threat due to its high rate of contagion. The clinical symptoms of CHIKV include fever and persistent, severe arthritis. Micafungin has broad-spectrum fungicidal activity against Candida spp. is a promising echinocandin that was recently approved by the U.S. Food and Drug Administration (FDA) and has demonstrated activity against Candida and Aspergillus. Recent studies have demonstrated the antiviral activity of micafungin; however, the inhibitory effects against CHIKV have yet to be investigated. Our objectives in this study were to explore the antiviral effects of micafungin on CHIKV infection and to elucidate the potential molecular mechanisms of inhibition. We determined that micafungin has the ability to counter CHIKV-induced cytopathic effects. We further discovered that micafungin limits virus replication, release, cell-to-cell transmission, and also slightly affected virus stability during high doses treatment. The efficacy of micafungin was further confirmed against two clinical isolates of CHIKV and two alphaviruses: Sindbis virus (SINV) and Semliki Forest virus (SFV). Our findings suggest that micafungin has considerable potential as a novel inhibitor against the viral replication, and intracellular and extracellular transmission of CHIKV, and has a little effect on virus stability. Our findings also suggest that micafungin could have curative effects on other alphavirus infections.


Subject(s)
Alphavirus/drug effects , Antiviral Agents/pharmacology , Chikungunya virus/drug effects , Micafungin/pharmacology , Alphavirus Infections/drug therapy , Chikungunya Fever/drug therapy , Chikungunya Fever/virology , Semliki forest virus/drug effects , Sindbis Virus/drug effects , Virus Replication/drug effects
15.
Med Chem ; 12(6): 544-52, 2016.
Article in English | MEDLINE | ID: mdl-26825066

ABSTRACT

BACKGROUND: The frequent use of antibacterial agents and the exposure of the patients to lifesaving intervention processes are consistently associated with the increased chance of nosocomial infections and the emergence of multidrug resistant microorganisms in the hospital environment. Thus, new antimicrobial agents are of unmet need to treat the severe nosocomial infections caused by these putative pathogens resistant to currently available agents. METHOD: Design, synthesis, and biological evaluation of analogues of nitazoxanide (NTZ), an FDA approved thiazolide antiparasitic, as new antimicrobial agents against nosocomial pathogens were described. The NTZ analogues were rationally explored on the basis of either increasing the electronic resonance effects at the nitrothiazolide moiety or improving the anionic form of the whole NTZ structure. RESULTS: The MICs and MBCs values of these NTZ analogues against prevalent nosocomial pathogens were measured. The benzologous analogues 3a and 4a and p-chlorobenzenesulfonamides 8d and 9d exhibited tremendous antimicrobial activities, which were 100- to 2000-fold more potent than NTZ and ciprofloxacin. CONCLUSION: The results demonstrated that delicate manipulation of the NTZ core structure could lead to promising antimicrobial agents against the nosocomial pathogens.


Subject(s)
Anti-Bacterial Agents/pharmacology , Thiazoles/pharmacology , Anti-Bacterial Agents/chemical synthesis , Ciprofloxacin/pharmacology , Cross Infection/microbiology , Gram-Negative Bacteria/drug effects , Gram-Positive Endospore-Forming Rods/drug effects , Microbial Sensitivity Tests , Nitro Compounds , Phthalimides/chemical synthesis , Phthalimides/pharmacology , Structure-Activity Relationship , Sulfonamides/chemical synthesis , Sulfonamides/pharmacology , Thiazoles/chemical synthesis
16.
J Med Chem ; 45(11): 2277-82, 2002 May 23.
Article in English | MEDLINE | ID: mdl-12014965

ABSTRACT

In the search for highly selective and potent derivatives of tacrine (1a), a number of homodimeric tacrine congeners were synthesized and conducted for their effects on rat acetylcholinesterase (AChE) and human butyrylcholinesterase (BChE) inhibitions. Heptylene-linked bis-(6-chloro)tacrine (3h) was found up to 3000- and 3-fold more potent in inhibiting rat AChE than tacrine and the unsubstituted bis-tacrine 3b, respectively. Changes in the size of the carbocyclic ring of the dimeric tacrine reduced both the selectivity and the potency of AChE inhibition as compared to 3b. Inserting an aza into the tacrine nucleus as the desired isosteres 3j-m resulted in moderate potency but tended to be detrimental to selectivity. The pronounced enhancement of AChE inhibition potency and AChE/BChE selectivity was achieved with incorporation of a halogen at the 6-position of homodimeric tacrines. The assay results of 3a-m also provided evidence that the 7-methylene tether tended to be optimal to AChE inhibition potency.


Subject(s)
Acetylcholinesterase/metabolism , Cholinesterase Inhibitors/chemical synthesis , Tacrine/chemical synthesis , Animals , Brain/enzymology , Butyrylcholinesterase/metabolism , Cholinesterase Inhibitors/chemistry , Cholinesterase Inhibitors/pharmacology , Dimerization , Humans , In Vitro Techniques , Rats , Structure-Activity Relationship , Tacrine/chemistry , Tacrine/pharmacology
17.
J Pharm Pharmacol ; 55(12): 1655-60, 2003 Dec.
Article in English | MEDLINE | ID: mdl-14738592

ABSTRACT

This article describes the synthesis and antioxidative properties of melatonin derivatives. Tryptamines and cysteinyl or mercaptopropionyl derivatives were deliberately condensed with coupling reagents to give melatonin derivatives 4a-d and 5a, b. The preliminary evaluation indicated that compound 4c showed improved scavenging activity compared with vitamin C (IC50 43 microM vs 65 microM, where IC50 is the concentration of the test compound that induced a change of 50% in absorbance during the 30 min observation) on diphenyl-p-picrylhydrazyl (DPPH) tests. Derivative 5b, which possesses the thiolactyl moiety, showed moderate potency compared with melatonin (IC50 235 microM vs 690 microM) in the H(2)O(2) scavenging test. Intriguingly, 4c displayed 2-fold more potency than melatonin (IC50 51 microM vs 125 microM) in scavenging NO in the macrophage model. These results suggested that the cysteinyl-conjugated derivative 4c may be a suitable lead to further optimize potent antioxidants for certain oxidative stress conditions.


Subject(s)
Antioxidants/pharmacology , Melatonin/pharmacology , Antioxidants/chemical synthesis , Antioxidants/chemistry , Cells, Cultured , Drug Interactions , Hydrogen Peroxide/chemistry , Melatonin/analogs & derivatives , Melatonin/chemistry , Structure-Activity Relationship
18.
J Pharm Pharmacol ; 54(12): 1697-703, 2002 Dec.
Article in English | MEDLINE | ID: mdl-12542902

ABSTRACT

We have investigated the developdment of potential antioxidants based on magnolol, a naturally occurring biphenolic obtained from the bark of Magnolia officinalis. A series of aminomethylated derivatives of magnolol were synthesized under the aromatic Mannich reaction. In-vitro testing for diphenyl-p-picrylhydrazyl (DPPH) scavenging and chemiluminescence assays in whole cell models revealed that the pyrrolidyl-containing magnolols (2b (5,5'-diallyl-3-(pyrrolidin-1-ylmethyl)-biphenyl-2,2'-diol), 3a (5,5'-diallyl-3,3'-bis-(pyrrolidin-1-ylmethyl)-biphenyl-2,2'-diol) and 4c (5,5'-diallyl-3-(morphorin-4-ylmethyl)-3'-(pyrrolidin-1-ylmethyl)-biphenyl-2,2'-diol)) displayed promising free radical scavenging effects as compared with magnolol. The results from compound 4c indicated that the naturally occurring component was suitable to be a lead compound toward promising antioxidants.


Subject(s)
Biphenyl Compounds/chemistry , Biphenyl Compounds/chemical synthesis , Free Radical Scavengers/chemical synthesis , Hydrazines/chemistry , Lignans , Biphenyl Compounds/isolation & purification , Free Radical Scavengers/chemistry , Luminescent Measurements , Magnolia/chemistry , Picrates , Plant Bark/chemistry , Plant Oils/chemistry
19.
Eur J Med Chem ; 79: 143-51, 2014 May 22.
Article in English | MEDLINE | ID: mdl-24732790

ABSTRACT

Structural optimization of the prior lead 3 led to the small molecular (D)-leucinamides with potent modulating activity and Notch-sparing selectivity on the proteolytic processing of amyloid-ß precursor proteins. The N-(R)-epoxypropyl analog 10c exhibited potent γ-secretase modulation compared to DAPT and showed substantial substrate selection for APP cleavage over Notch cleavage, while N-(2-fluoro)benzyl analog 10e showed the most potent γ-secretase inhibition with dull selectivity. The exceptional suppression of ERK-mediated activation suggested that these potent γ-secretase modulators may adapt an alternative pathway to prominently induce the differential inhibition of C99 cleavage by γ-secretase.


Subject(s)
Amyloid Precursor Protein Secretases/antagonists & inhibitors , Drug Discovery , Leucine/analogs & derivatives , Small Molecule Libraries/pharmacology , Amyloid Precursor Protein Secretases/metabolism , Cell Survival/drug effects , Cells, Cultured , Dose-Response Relationship, Drug , HEK293 Cells , Humans , Leucine/chemical synthesis , Leucine/chemistry , Leucine/pharmacology , Molecular Structure , Small Molecule Libraries/chemical synthesis , Small Molecule Libraries/chemistry , Stereoisomerism , Structure-Activity Relationship
20.
Appl Radiat Isot ; 94: 113-117, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25154567

ABSTRACT

N-Succinimidyl-4-[(18)F]fluorobenzoate ([(18)F]SFB) is a potential prosthetic agent for novel tracer development in positron emission tomography (PET). Previously, we reported a microwave-assisted one-pot synthesis of [(18)F]SFB with high efficacy. Herein, we reveal an improved and optimized approach based on this former model for producing [(18)F]SFB. With optimized approaches, the entire protocol can be completed within 25min, and [(18)F]SFB is generated in satisfactory quality for direct use without further purification via high-performance liquid chromatography.


Subject(s)
Benzoates/chemical synthesis , Benzoates/isolation & purification , Diathermy/methods , Isotope Labeling/methods , Microwaves , Radiopharmaceuticals/chemical synthesis , Radiopharmaceuticals/isolation & purification , Succinimides/chemical synthesis , Succinimides/isolation & purification , Materials Testing , Radiation Dosage , Radiopharmaceuticals/radiation effects
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