RESUMEN
As overproduction of reactive oxygen species (ROS) causes various diseases, antioxidants that scavenge ROS, or inhibitors that suppress excessive ROS generation, can be used as therapeutic agents. From a library of approved drugs, we screened compounds that reduced superoxide anions produced by pyocyanin-stimulated leukemia cells and identified benzbromarone. Further investigation of several of its analogues showed that benziodarone possessed the highest activity in reducing superoxide anions without causing cytotoxicity. In contrast, in a cell-free assay, benziodarone induced only a minimal decrease in superoxide anion levels generated by xanthine oxidase. These results suggest that benziodarone is an inhibitor of NADPH oxidases in the plasma membrane but is not a superoxide anion scavenger. We investigated the preventive effect of benziodarone on lipopolysaccharide (LPS)-induced murine lung injury as a model of acute respiratory distress syndrome (ARDS). Intratracheal administration of benziodarone attenuated tissue damage and inflammation via its ROS-reducing activity. These results indicate the potential application of benziodarone as a therapeutic agent against diseases caused by ROS overproduction.
Asunto(s)
Lesión Pulmonar , Ratones , Animales , Humanos , Especies Reactivas de Oxígeno/metabolismo , Superóxidos , Lipopolisacáridos/toxicidad , NADPH Oxidasas/metabolismoRESUMEN
Although the exact pathogenesis of idiopathic pulmonary fibrosis (IPF) is still unknown, the transdifferentiation of fibroblasts into myofibroblasts and the production of extracellular matrix components such as collagen, triggered by alveolar epithelial cell injury, are important mechanisms of IPF development. In the lungs of IPF patients, apoptosis is less likely to be induced in fibroblasts than in alveolar epithelial cells, and this process is involved in the pathogenesis of IPF. We used a library containing approved drugs to screen for drugs that preferentially reduce cell viability in LL29 cells (lung fibroblasts from an IPF patient) compared with A549 cells (human alveolar epithelial cell line). After screening, we selected eperisone, a central muscle relaxant used in clinical practice. Eperisone showed little toxicity in A549 cells and preferentially reduced the percentage of viable LL29 cells, while pirfenidone and nintedanib did not have this effect. Eperisone also significantly inhibited transforming growth factor-ß1-dependent transdifferentiation of LL29 cells into myofibroblasts. In an in vivo study using ICR mice, eperisone inhibited bleomycin (BLM)-induced pulmonary fibrosis, respiratory dysfunction, and fibroblast activation. In contrast, pirfenidone and nintedanib were less effective than eperisone in inhibiting BLM-induced pulmonary fibrosis under this experimental condition. Finally, we showed that eperisone did not induce adverse effects in the liver and gastrointestinal tract in the BLM-induced pulmonary fibrosis model. Considering these results, we propose that eperisone may be safer and more therapeutically beneficial for IPF patients than current therapies.
RESUMEN
Renal ischemia/reperfusion (I/R) injury is a major clinical problem because it can cause acute kidney injury (AKI) or lead to the transition from AKI to chronic kidney disease (CKD). Oxidative stress, which involves the production of reactive oxygen species (ROS), plays an important role in the development and exacerbation of I/R-induced kidney injury. However, we have previously reported that lecithinized superoxide dismutase (PC-SOD), a SOD derivative with high tissue affinity and high stability in plasma, has beneficial effects in various disease models because of its inhibitory effect on ROS production. Therefore, we aimed to determine the effects of intravenous PC-SOD administration in a mouse model of renal injury induced by I/R. PC-SOD markedly ameliorated the I/R-induced increases in markers of renal damage (urea nitrogen, creatinine, neutrophil gelatinase-associated lipocalin, and interleukin-6) and tubular necrosis 48 h after the intervention. We also found that PC-SOD significantly ameliorated the I/R-induced increase in ROS production, using an ex vivo imaging system. Furthermore, PC-SOD inhibited the increases in expression of markers of fibrosis (α-smooth muscle actin and collagen 1A1) 96 h after, and renal fibrosis 25 days after I/R was induced. Finally, we found that PC-SOD ameliorated the I/R-induced AKI in mice with high-fat diet-induced prediabetes. These results suggest that PC-SOD inhibits AKI and the transition from AKI to CKD through the inhibition of ROS production. Therefore, we believe that PC-SOD may represent an effective therapeutic agent for I/R-induced renal injury.
Asunto(s)
Lesión Renal Aguda/prevención & control , Modelos Animales de Enfermedad , Fibrosis/prevención & control , Estrés Oxidativo , Fosfatidilcolinas/administración & dosificación , Especies Reactivas de Oxígeno/metabolismo , Daño por Reperfusión/complicaciones , Superóxido Dismutasa/administración & dosificación , Lesión Renal Aguda/etiología , Lesión Renal Aguda/metabolismo , Lesión Renal Aguda/patología , Animales , Dieta Alta en Grasa , Fibrosis/etiología , Fibrosis/metabolismo , Fibrosis/patología , Masculino , Ratones , Ratones Endogámicos ICRRESUMEN
A total of 1253 compounds approved as therapeutic drugs in Japan (Pharmaceuticals and Medical Devices Agency (PMDA)-approved compounds) were screened for their therapeutic effects against Staphylococcus aureus infection using the silkworm infection model. In the first stage of screening with an index of prolonged survival, 80 compounds were identified as hits. Of these, 64 compounds were clinically used as antimicrobial agents, and the remaining 16 compounds were not. The 16 compounds were examined for their dose-dependent therapeutic effects on the silkworm model as a second screening step, and we obtained five compounds as a result. One of the compounds (capecitabine) had no documented in vitro minimum inhibitory concentration (MIC) value against S. aureus. The MIC value of capecitabine against S. aureus strains ranged from 125 to 250 µg/ml, and capecitabine was therapeutically effective at a dose of 200 mg/kg in a murine model of S. aureus infection. These results suggest that silkworm-based drug repositioning studies are of potential value. Furthermore, the therapeutic effects of capecitabine demonstrated in this study provide an important scientific rationale for clinical observational studies examining the association between staphylococcal infection events and capecitabine administration in cancer chemotherapy patients.
RESUMEN
The adenosine A2B receptor is a critical protein in intestinal water secretion. In the present study, we screened compound libraries to identify inhibitors of the A2B receptor and evaluated their effect on adenosine-induced intestinal fluid secretion. The screening identified the dihydropyridine calcium antagonists nifedipine and nisoldipine. Their respective affinities for the A2B receptor (Ki value) were 886 and 1,399 nM. Nifedipine and nisoldipine, but not amlodipine or nitrendipine, inhibited both calcium mobilization and adenosine-induced cAMP accumulation in cell lines. Moreover, adenosine injection into the lumen significantly increased fluid volume in the colonic loop of wild-type mice but not A2B receptor-deficient mice. PSB-1115, a selective A2B receptor antagonist, and nifedipine prevented elevated adenosine-stimulated fluid secretion in mice. Our results may provide useful insights into the structure-activity relationship of dihydropyridines for A2B receptor. As colonic fluid secretion by adenosine seems to rely predominantly on the A2B receptor, nifedipine could be a therapeutic candidate for diarrhoea-related diseases.
Asunto(s)
Antagonistas del Receptor de Adenosina A2/farmacología , Bloqueadores de los Canales de Calcio/farmacología , Colon/metabolismo , Mucosa Intestinal/efectos de los fármacos , Mucosa Intestinal/metabolismo , Nifedipino/farmacología , Receptor de Adenosina A2B/metabolismo , Adenosina/metabolismo , Antagonistas del Receptor de Adenosina A2/química , Animales , Bloqueadores de los Canales de Calcio/química , AMP Cíclico/metabolismo , Ratones , Estructura Molecular , Nifedipino/químicaRESUMEN
Alveolar epithelial injury induced by reactive oxygen species (ROS) and abnormal collagen production by activated fibroblasts (myofibroblasts) is involved in the onset and exacerbation of idiopathic pulmonary fibrosis (IPF). Compared with alveolar epithelial cells, lung fibroblasts, especially myofibroblasts, exhibit an apoptosis-resistance phenotype (apoptosis paradox) that appears to be involved in IPF pathogenesis. Thus, we screened for chemicals eliciting preferential cytotoxicity of LL29 cells (lung fibroblasts from an IPF patient) compared with A549 cells (human lung alveolar epithelial cell line) from medicines already in clinical use. We identified idebenone, a synthetic analogue of coenzyme Q10 (CoQ10, an antioxidant) that has been used clinically as a brain metabolic stimulant. Idebenone induced cell growth inhibition and cell death in LL29 cells at a lower concentration than in A549 cells, a feature that was not observed for other antioxidant molecules (such as CoQ10) and two IPF drugs (pirfenidone and nintedanib). Administration of idebenone prevented bleomycin-induced pulmonary fibrosis and increased pulmonary ROS levels. Importantly, idebenone also improved pulmonary fibrosis and lung function when administered after the development of fibrosis, whereas administration of CoQ10 similarly prevented bleomycin-induced pulmonary fibrosis, but had no effect after its development. Administration of idebenone, but not CoQ10, suppressed bleomycin-induced increases in lung myofibroblasts. In vitro, treatment of LL29 cells with idebenone, but not CoQ10, suppressed TGF-ß-induced collagen production. These results suggest that in addition to antioxidant activity, idebenone exerts inhibitory activity on the function of lung fibroblasts, with the former activity being preventative and the latter therapeutic for bleomycin-induced fibrosis. Thus, we propose that idebenone may be more therapeutically beneficial for IPF patients than current treatments.
RESUMEN
The treatment for patients with chronic obstructive pulmonary disease (COPD) usually involves a combination of anti-inflammatory and bronchodilatory drugs. We recently found that mepenzolate bromide (1) and its derivative, 3-(2-hydroxy-2, 2-diphenylacetoxy)-1-(3-phenoxypropyl)-1-azoniabicyclo[2.2.2]octane bromide (5), have both anti-inflammatory and bronchodilatory activities. We chemically modified 5 with a view to obtain derivatives with both anti-inflammatory and longer-lasting bronchodilatory activities. Among the synthesized compounds, (R)-(-)-12 ((R)-3-(2-hydroxy-2,2-diphenylacetoxy)-1-(3-phenylpropyl)-1-azoniabicyclo[2.2.2]octane bromide) showed the highest affinity in vitro for the human muscarinic M3 receptor (hM3R). Compared to 1 and 5, (R)-(-)-12 exhibited longer-lasting bronchodilatory activity and equivalent anti-inflammatory effect in mice. The long-term intratracheal administration of (R)-(-)-12 suppressed porcine pancreatic elastase-induced pulmonary emphysema in mice, whereas the same procedure with a long-acting muscarinic antagonist used clinically (tiotropium bromide) did not. These results suggest that (R)-(-)-12 might be therapeutically beneficial for use with COPD patients given the improved effects seen against both inflammatory pulmonary emphysema and airflow limitation in this animal model.
Asunto(s)
Antiinflamatorios no Esteroideos/farmacología , Bencilatos/farmacología , Broncodilatadores/farmacología , Piperidinas/farmacología , Enfisema Pulmonar/tratamiento farmacológico , Receptor Muscarínico M3/antagonistas & inhibidores , Administración por Inhalación , Animales , Antiinflamatorios no Esteroideos/administración & dosificación , Antiinflamatorios no Esteroideos/química , Bencilatos/administración & dosificación , Bencilatos/química , Broncodilatadores/administración & dosificación , Broncodilatadores/química , Relación Dosis-Respuesta a Droga , Ratones , Estructura Molecular , Elastasa Pancreática/metabolismo , Piperidinas/administración & dosificación , Piperidinas/química , Enfisema Pulmonar/metabolismo , Receptor Muscarínico M3/metabolismo , Relación Estructura-Actividad , PorcinosRESUMEN
The use of non-steroidal anti-inflammatory drugs (NSAIDs) for the treatment of inflammatory pain is limited by gastrointestinal complications. The rapid action of NSAIDs is associated with better pain relief. Previously, we demonstrated that fluoro-loxoprofen, a novel NSAID, has less ulcerogenic potential than other NSAIDs, attributable to its gastroprotective properties. The aim of this study was to investigate and compare the effects of fluoro-loxoprofen on inflammatory pain in rats with those of other NSAIDs. Oral administration of fluoro-loxoprofen, loxoprofen, and celecoxib resulted in equivalent analgesic action against yeast-induced inflammatory pain. The antinociceptive effect of fluoro-loxoprofen was maximized within 1â¯h after administration, which is less time than that observed for loxoprofen (2â¯h) and celecoxib (3â¯h). We confirmed that both fluoro-loxoprofen and loxoprofen suppressed the increases in prostaglandin E2 in inflamed paws. In addition to yeast-induced pain, fluoro-loxoprofen produced a similar effect against adjuvant-induced inflammatory pain, with faster peak analgesic effects than those observed for loxoprofen and celecoxib. Taken together, these results suggest that the analgesic effect of fluoro-loxoprofen is equivalent to that of loxoprofen and celecoxib. Moreover, the analgesic effect of fluoro-loxoprofen against inflammatory pain was more rapid than that of other NSAIDs, and this may be associated with its rapid absorption property.
Asunto(s)
Dolor Agudo/tratamiento farmacológico , Analgésicos/uso terapéutico , Antiinflamatorios no Esteroideos/uso terapéutico , Dolor Crónico/tratamiento farmacológico , Fenilpropionatos/uso terapéutico , Dolor Agudo/metabolismo , Animales , Dolor Crónico/metabolismo , Dinoprostona/metabolismo , Femenino , Pie , Masculino , Ratas Endogámicas Lew , Ratas WistarRESUMEN
The standard treatment for chronic obstructive pulmonary disease is a combination of anti-inflammatory drugs and bronchodilators. We recently found that mepenzolate bromide (MP), an antagonist for human muscarinic M3 receptor (hM3R), has both anti-inflammatory and short-acting bronchodilatory activities. To obtain MP derivatives with longer-lasting bronchodilatory activity, we synthesized hybrid compounds based on MP and two other muscarinic antagonists with long-acting bronchodilatory activity glycopyrronium bromide (GC) and aclidinium bromide (AD). Of these three synthesized hybrid compounds (MP-GC, GC-MP, MP-AD) and MP, MP-AD showed the highest affinity for hM3R and had the longest lasting bronchodilatory activity, which was equivalent to that of GC and AD. Both MP-GC and MP-AD exhibited an anti-inflammatory effect equivalent to that of MP, whereas, in line with GC and AD, GC-MP did not show this effect. We also confirmed that administration of MP-AD suppressed elastase-induced pulmonary emphysema in a mouse model. These findings provide important information about the structure-activity relationship of MP for both bronchodilatory and anti-inflammatory activities.
RESUMEN
BACKGROUND AND PURPOSE: Visceral hypersensitivity is responsible for pathogenesis of irritable bowel syndrome (IBS). Therefore, its prevention can help avoid abdominal pain and discomfort in IBS. To find candidate drugs for visceral hypersensitivity, we screened existing medicines for their ability to prevent visceral sensitivity induced by colorectal distension (CRD) in rats and identified chlorpromazine, a typical antipsychotic drug, as a candidate compound. In this study, we investigated the effect of chlorpromazine on visceral hypersensitivity. EXPERIMENTAL APPROACH: Visceral sensitivity (visceromotor response) was monitored by measuring the electrical activity of the abdominal external oblique muscle contraction in response to CRD using a barostat apparatus. Visceral hypersensitivity was induced by a colonic instillation of sodium butyrate or acetic acid in neonates. KEY RESULTS: Oral administration of chlorpromazine suppressed butyrate-induced visceral hypersensitivity to CRD. Interestingly, atypical antipsychotic drugs, quetiapine and risperidone, ameliorated butyrate-induced visceral hypersensitivity, whereas the typical antipsychotic drugs, haloperidol and sulpiride, did not. Pharmacological analysis using specific inhibitors showed that a selective 5-HT2A receptor antagonist, ketanserin, suppressed butyrate-induced visceral hypersensitivity, whereas a selective dopamine D2 receptor antagonist, L-741626, did not. Furthermore, the 5-HT2A receptor agonist AL-34662 stimulated visceral sensitivity to CRD in healthy control rats but not in butyrate-treated rats. These findings suggest that increased 5-HT levels in the colon contribute to the induction of visceral hypersensitivity. CONCLUSIONS AND IMPLICATIONS: Our results indicate that chlorpromazine ameliorates visceral hypersensitivity and that the 5-HT2A receptor is a potential therapeutic target for treating abdominal pain and discomfort in IBS.
Asunto(s)
Antipsicóticos/uso terapéutico , Clorpromazina/uso terapéutico , Antagonistas del Receptor de Serotonina 5-HT2/uso terapéutico , Dolor Visceral/tratamiento farmacológico , Ácido Acético , Animales , Antipsicóticos/farmacología , Ácido Butírico , Clorpromazina/farmacología , Colon/efectos de los fármacos , Colon/metabolismo , Ganglios Espinales/efectos de los fármacos , Ganglios Espinales/metabolismo , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Masculino , Ratas Wistar , Receptor de Serotonina 5-HT2A/metabolismo , Serotonina/metabolismo , Antagonistas del Receptor de Serotonina 5-HT2/farmacología , Dolor Visceral/inducido químicamente , Dolor Visceral/metabolismoRESUMEN
Idiopathic pulmonary fibrosis (IPF) involves alveolar epithelial injury and abnormal collagen production caused by activated fibroblasts; transforming growth factor (TGF)-ß1 is implicated in this activation. In this study, we screened for chemicals capable of inhibiting TGF-ß1-induced collagen production in cultured fibroblasts from medicines already in clinical use. We selected felodipine based on its extent of collagen production inhibition, clinical safety profile, and other pharmacological activity. Felodipine is a dihydropyridine Ca2+ channel blocker that has been used clinically to treat patients with high blood pressure. Felodipine suppressed collagen production within LL29 cells in the presence of TGF-ß1, but not in its absence. Intratracheal administration of felodipine prevented bleomycin-induced pulmonary fibrosis, alteration of lung mechanics and respiratory dysfunction. Felodipine also improved pulmonary fibrosis, as well as lung and respiratory function when administered after fibrosis development. Furthermore, administration of felodipine suppressed a bleomycin-induced increase in activated fibroblasts in the lung. We also found other dihydropyridine Ca2+ channel blockers (nifedipine and benidipine) inhibited collagen production in vitro and partially prevented bleomycin-induced pulmonary fibrosis, alteration of lung mechanics and respiratory dysfunction in vivo. We propose that these Ca2+ channel blockers may be therapeutically beneficial for IPF patients.
Asunto(s)
Bloqueadores de los Canales de Calcio/uso terapéutico , Felodipino/uso terapéutico , Fibrosis Pulmonar/tratamiento farmacológico , Animales , Bleomicina/toxicidad , Línea Celular , Humanos , Masculino , Ratones , Ratones Endogámicos ICR , Fibrosis Pulmonar/etiologíaRESUMEN
Pharmacological therapy for irritable bowel syndrome (IBS) has not been established. In order to find candidate drugs for IBS with diarrhea (IBS-D), we screened a compound library of drugs clinically used for their ability to prevent stress-induced defecation and visceral hypersensitivity in rats. We selected the bronchodilator aminophylline from this library. Using a specific inhibitor for each subtype of adenosine receptors (ARs) and phosphodiesterases (PDEs), we found that both A2BARs and PDE4 are probably mediated the inhibitory effect of aminophylline on wrap restraint stress (WRS)-induced defecation. Aminophylline suppressed maternal separation- and acetic acid administration-induced visceral hypersensitivity to colorectal distension (CRD), which was mediated by both A2AARs and A2BARs. We propose that aminophylline is a candidate drug for IBS-D because of its efficacy in both of stress-induced defecation and visceral hypersensitivity, as we observed here, and because it is clinically safe.
Asunto(s)
Aminofilina/administración & dosificación , Broncodilatadores/administración & dosificación , Diarrea/tratamiento farmacológico , Fármacos Gastrointestinales/administración & dosificación , Síndrome del Colon Irritable/tratamiento farmacológico , Animales , Modelos Animales de Enfermedad , Evaluación Preclínica de Medicamentos , Ratas , Resultado del TratamientoRESUMEN
For acute respiratory distress syndrome (ARDS), mechanical ventilation (MV) is a life-saving intervention without alternative; however, MV can cause ventilator-induced lung injury. Reactive oxygen species (ROS) play important roles in the pathogenesis of both ARDS and ventilator-induced lung injury. Lecithinized superoxide dismutase (PC-SOD) overcomes the limitations of superoxide dismutase such as low tissue affinity and low stability in plasma. In this study, we examined the effect of PC-SOD on tissue injury, edema, and inflammation in the lung and other organs of mice subjected to cecal ligation and puncture (CLP), LPS administration, or MV. The severity of the lung injury was assessed on the basis of vascular permeability, histopathologic evaluation, and lung mechanics. Intravenous PC-SOD administration (the first administered just before CLP) increased the survival rate and decreased vascular permeability in mice subjected to CLP. PC-SOD, but not dexamethasone or sivelestat sodium hydrate (sivelestat), suppressed CLP-induced kidney injury and systemic inflammation. PC-SOD also suppressed vascular permeability, tissue injury, and inflammation in the lung induced by LPS administration. Moreover, PC-SOD, but not dexamethasone or sivelestat, suppressed vascular permeability, edema, tissue injury, and mechanical alterations in the lung induced by MV. In vivo imaging analysis of ROS revealed that CLP, LPS administration, and MV increased the level of ROS and that this increase was suppressed by PC-SOD. The results of this study thus suggest that, on the basis of its ROS-reducing properties, intravenous administration of PC-SOD may be beneficial for patients at high risk of developing ARDS.
Asunto(s)
Fosfatidilcolinas/uso terapéutico , Síndrome de Dificultad Respiratoria/tratamiento farmacológico , Síndrome de Dificultad Respiratoria/prevención & control , Superóxido Dismutasa/uso terapéutico , Animales , Ciego/patología , Dexametasona/farmacología , Modelos Animales de Enfermedad , Glicina/análogos & derivados , Glicina/farmacología , Glicina/uso terapéutico , Ligadura , Lipopolisacáridos , Lesión Pulmonar/complicaciones , Lesión Pulmonar/tratamiento farmacológico , Lesión Pulmonar/patología , Masculino , Ratones , Ratones Endogámicos ICR , Insuficiencia Multiorgánica/complicaciones , Insuficiencia Multiorgánica/patología , Fosfatidilcolinas/farmacología , Punciones , Especies Reactivas de Oxígeno/metabolismo , Respiración Artificial , Sulfonamidas/farmacología , Sulfonamidas/uso terapéutico , Superóxido Dismutasa/farmacologíaRESUMEN
Macroautophagy is an intracellular degradation system that utilizes the autophagosome to deliver cytoplasmic components to the lysosome. Measuring autophagic activity is critically important but remains complicated and challenging. Here, we have developed GFP-LC3-RFP-LC3ΔG, a fluorescent probe to evaluate autophagic flux. This probe is cleaved by endogenous ATG4 proteases into equimolar amounts of GFP-LC3 and RFP-LC3ΔG. GFP-LC3 is degraded by autophagy, while RFP-LC3ΔG remains in the cytosol, serving as an internal control. Thus, autophagic flux can be estimated by calculating the GFP/RFP signal ratio. Using this probe, we re-evaluated previously reported autophagy-modulating compounds, performed a high-throughput screen of an approved drug library, and identified autophagy modulators. Furthermore, we succeeded in measuring both induced and basal autophagic flux in embryos and tissues of zebrafish and mice. The GFP-LC3-RFP-LC3ΔG probe is a simple and quantitative method to evaluate autophagic flux in cultured cells and whole organisms.
Asunto(s)
Autofagia/efectos de los fármacos , Ensayos Analíticos de Alto Rendimiento , Lisosomas/efectos de los fármacos , Sondas Moleculares/genética , Fagosomas/efectos de los fármacos , Bibliotecas de Moléculas Pequeñas/farmacología , Animales , Autofagia/genética , Cisteína Endopeptidasas/genética , Cisteína Endopeptidasas/metabolismo , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Embrión no Mamífero , Regulación de la Expresión Génica , Genes Reporteros , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Células HeLa , Humanos , Lisosomas/metabolismo , Ratones , Proteínas Asociadas a Microtúbulos/genética , Proteínas Asociadas a Microtúbulos/metabolismo , Sondas Moleculares/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Fagosomas/metabolismo , Espectrometría de Fluorescencia , Ubiquitina-Proteína Ligasas , Pez CebraRESUMEN
Ephrin type-B receptor 2 (EphB2) is a member of the receptor tyrosine kinase family and plays an important role in learning and memory functions. In patients with Alzheimer's disease (AD) and in mouse models of AD, a reduction in the hippocampal EphB2 level is observed. It was recently reported that normalization of the EphB2 level in the dentate gyrus rescues memory function in a mouse model of AD, suggesting that drugs that restore EphB2 levels may be beneficial in the treatment of AD. Amyloid ß (Aß) oligomers, which are believed to be key molecules involved in the pathogenesis of AD, induce EphB2 degradation through their direct binding to EphB2. Thus, compounds that inhibit the binding of Aß oligomers to EphB2 may be beneficial. Here, we screened for such compounds from drugs already approved for clinical use in humans. Utilizing a cell-free screening assay, we determined that dihydroergotamine mesilate, bromocriptine mesilate, cepharanthine, and levonorgestrel inhibited the binding of Aß oligomers to EphB2 but not to cellular prion protein, another endogenous receptor for Aß oligomers. Additionally, these four compounds did not affect the binding between EphB2 and ephrinB2, an endogenous ligand for EphB2, suggesting that the compounds selectively inhibited the binding of Aß oligomers to EphB2. This is the first identification of compounds that selectively inhibit the binding of Aß oligomers to EphB2. These results suggest that these four compounds may be safe and effective drugs for treatment of AD.
RESUMEN
Functional dyspepsia (FD), a functional gastrointestinal disorder, is characterized by persistent or recurrent postprandial upper abdominal discomfort and epigastric pain. The high prevalence of FD and associated healthcare costs suggests that treatment of this condition by methods other than prescribed medicines, such as natural products, could be beneficial. Delayed gastric emptying and impaired gastric accommodation play important roles in the development of FD. Anethole (1-methoxy-4-((E)-propenyl)-benzene), a major component of essential fennel oil, has been used as a flavoring, in alcoholic beverage production and in pharmaceutical formulations for many years. In this study, we examined the effects of anethole on delayed gastric emptying and impaired gastric accommodation in rodents. Oral administration of anethole improved clonidine-induced delayed gastric emptying but did not affect normal gastric emptying in mice. Fennel oil and Anchu-san (a Japanese herbal medicine containing anethole) also restored delayed gastric emptying. Furthermore, oral administration of anethole stimulated gastric accommodation in rats. These results suggest that anethole could be beneficial for the treatment of FD.
Asunto(s)
Anisoles/farmacología , Dispepsia/tratamiento farmacológico , Vaciamiento Gástrico/efectos de los fármacos , Gastroparesia/tratamiento farmacológico , Acetilcolinesterasa/metabolismo , Administración Oral , Derivados de Alilbenceno , Animales , Anisoles/administración & dosificación , Inhibidores de la Colinesterasa/administración & dosificación , Inhibidores de la Colinesterasa/farmacología , Modelos Animales de Enfermedad , Dispepsia/fisiopatología , Vaciamiento Gástrico/fisiología , Gastroparesia/fisiopatología , Masculino , Ratones , Ratones Endogámicos ICR , Ratas , Ratas Sprague-DawleyRESUMEN
In the stress response, activation of the hypothalamic-pituitary-adrenal axis, and particularly the release of glucocorticoids, plays a critical role. However, dysregulation of this system and sustained high plasma levels of glucocorticoids can result in depression. Recent studies have suggested the involvement of reactive oxygen species (ROS), such as superoxide anion, in depression. However, direct evidence for a role of ROS in the pathogenesis of this disorder is lacking. In this study, using transgenic mice expressing human Cu/Zn-superoxide dismutase (SOD1), an enzyme that catalyzes the dismutation of superoxide anions, we examined the effect of SOD1 overexpression on depressive-like behavioral phenotypes in mice. Depressive-like behaviors were induced by daily subcutaneous administration of the glucocorticoid corticosterone for 4 weeks, and was monitored with the social interaction test, the sucrose preference test and the forced swim test. These tests revealed that transgenic mice overexpressing SOD1 are more resistant to glucocorticoid-induced depressive-like behavioral disorders than wild-type animals. Furthermore, compared with wild-type mice, transgenic mice showed a reduction in the number of 8-hydroxy-2'-deoxyguanosine (a marker of oxidative stress)-positive cells in the hippocampal CA3 region following corticosterone administration. These results suggest that overexpression of SOD1 protects mice against glucocorticoid-induced depressive-like behaviors by decreasing cellular ROS levels.
Asunto(s)
Trastorno Depresivo/metabolismo , Trastorno Depresivo/prevención & control , Trastornos Mentales/metabolismo , Trastornos Mentales/prevención & control , Especies Reactivas de Oxígeno/metabolismo , Superóxido Dismutasa/metabolismo , Animales , Conducta Animal , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Trastorno Depresivo/inducido químicamente , Glucocorticoides , Masculino , Trastornos Mentales/inducido químicamente , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Estrés Oxidativo/efectos de los fármacos , Fenotipo , Regulación hacia ArribaRESUMEN
Superoxide dismutase covalently bound to four lecithin molecules (PC-SOD) has been found to have beneficial therapeutic effects in animal models of various diseases. However, the mechanism underlying these improved therapeutic effects has not yet been elucidated. It has previously been shown that PC-SOD localizes on the plasma membrane and in the lysosomes of cells. In this study, we evaluated the superoxide anion-scavenging activity of PC-SOD in HL-60 human promyelocytic leukemia cells. Compared to SOD, PC-SOD had only 17% scavenging activity in cell-free systems. Nevertheless, by analyzing enzyme activities in cell suspensions containing PC-SOD or SOD, PC-SOD and SOD showed almost equal activity for scavenging extracellular superoxide anions produced by HL-60 cells. Furthermore, the activity for scavenging extracellular superoxide anions increased with increased amount of PC-SOD on the plasma membrane. Moreover, PC-SOD exhibited no obvious inhibitory effect on the scavenging of intracellular superoxide anions. These results suggested that the association of PC-SOD with the plasma membrane plays a key role in its beneficial therapeutic effects. Thus, this finding may provide a rationale for selecting target diseases for PC-SOD treatment.
Asunto(s)
Aniones/metabolismo , Fosfatidilcolinas/metabolismo , Superóxido Dismutasa/metabolismo , Superóxidos/metabolismo , Membrana Celular/metabolismo , Células HL-60 , Células HeLa , Humanos , Espacio Intracelular/metabolismo , Lisosomas/metabolismo , Oxidación-Reducción , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Delayed gastric emptying and impaired gastric accommodation (decreased gastric compliance) play important roles in functional dyspepsia (FD). Here we screen for a clinically used drug with an ability to improve delayed gastric emptying in rats. Oral administration of aldioxa (dihydroxyaluminum allantoinate) partially improved clonidine- or restraint stress-induced delayed gastric emptying. Administration of allantoin, but not aluminium hydroxide, restored the gastric emptying. Both aldioxa and allantoin inhibited clonidine binding to the α-2 adrenergic receptor, suggesting that antagonistic activity of the allantoin moiety of aldioxa on this receptor is involved in the restoration of gastric emptying activity. Aldioxa or aluminium hydroxide but not allantoin restored gastric compliance with restraint stress, suggesting that aluminium hydroxide moiety is involved in this restoration. We propose that aldioxa is a candidate drug for FD, because its safety in humans has already been confirmed and its ameliorating effect on both of delayed gastric emptying and impaired gastric compliance are confirmed here.
Asunto(s)
Alantoína/análogos & derivados , Hidróxido de Aluminio/farmacología , Dispepsia/tratamiento farmacológico , Dispepsia/fisiopatología , Vaciamiento Gástrico/efectos de los fármacos , Alantoína/farmacología , Animales , Masculino , Ratones , Ratones Endogámicos ICR , Ratas , Ratas Sprague-Dawley , Receptores Adrenérgicos alfa 2/metabolismoRESUMEN
Amyloid-ß peptide (Aß), especially its oligomeric form, is believed to play an important role in the pathogenesis of Alzheimer's disease (AD). To this end, the binding of Aß oligomer to cellular prion protein (PrP(C)) plays an important role in synaptic dysfunction in a mouse model of AD. Here, we have screened for compounds that inhibit Aß oligomer binding to PrP(C) from medicines already used clinically (Mizushima Approved Medicine Library 1), and identified dextran sulfate sodium (DSS) as a candidate. In a cell-free assay, DSS inhibited Aß oligomer binding to PrP(C) but not to ephrin receptor B2, another endogenous receptor for Aß oligomers, suggesting that the drug's action is specific to the binding of Aß oligomer to PrP(C) . Dextran on the other hand did not affect this binding. DSS also suppressed Aß oligomer binding to cells expressing PrP(C) but not to control cells. Furthermore, while incubation of mouse hippocampal slices with Aß oligomers inhibited the induction of long-term potentiation, simultaneous treatment with DSS restored the long-term potentiation. As DSS has already been approved for use in patients with hypertriglyceridemia, and its safety in humans has been confirmed, we propose further analysis of this drug as a candidate for AD treatment. Amyloid-ß peptide (Aß) oligomer-binding to cellular prion protein (PrP(C) ) is important in synaptic dysfunction in Alzheimer's disease (AD). We found here that dextran sulfate sodium (DSS) inhibits Aß oligomer binding to PrP(C) . Simultaneous treatment of hippocampal slices with DSS restored long-term potentiation (LTP) in the presence of Aß oligomers. Since DSS has already been approved for clinical use, we propose this drug is a candidate drug for AD treatment.