Neutral Endopeptidase Inhibition Enhances Substance P Mediated Inflammation Due to Hypomagnesemia

PubMed Central

Weglicki, William B.; Chmielinska, Joanna J.; Tejero-Taldo, M. Isabel; Kramer, Jay H.; Spurney, Christopher; Viswalingham, Kandan; Lu, Bao; Mak, I. Tong

2013-01-01

During dietary deficiency of magnesium neurogenic inflammation is mediated, primarily, by elevated levels of substance P (SP). The enzyme most specific for degrading this neuropeptide is neutral endopeptidase (NEP). In recent studies we found that pharmacological inhibition of NEP by phosphoramidon resulted in elevated plasma levels of SP and greater oxidative stress. We also observed that hypomagnesemia reduced cardiac and intestinal expression of NEP. In these magnesium deficient rats increased intestinal permeability and impaired cardiac contractility occurred. In our colony of genetically-engineered NEP knockout mice that have reduced ability to degrade SP, we found increased oxidative stress that was prevented by SP (neurokinin-1) receptor blockade. Thus, we submit that inhibition of NEP by pharmacological, genetic and dietary approaches (magnesium restriction), causes greater neurogenic inflammation that may result in increased intestinal and cardiac dysfunction. PMID:19780404

Neutral endopeptidase inhibition enhances substance P mediated inflammation due to hypomagnesemia.

PubMed

Weglicki, William B; Chmielinska, Joanna J; Tejero-Taldo, Isabel; Kramer, Jay H; Spurney, Christopher F; Viswalingham, Kandan; Lu, Bao; Mak, I Tong

2009-09-01

During dietary deficiency of magnesium neurogenic inflammation is mediated, primarily, by elevated levels of substance P (SP). The enzyme most specific for degrading this neuropeptide is neutral endopeptidase (NEP). In recent studies we found that pharmacological inhibition of NEP by phosphoramidon resulted in elevated plasma levels of SP and greater oxidative stress. We also observed that hypomagnesemia reduced cardiac and intestinal expression of NEP. In these magnesium-deficient rats increased intestinal permeability and impaired cardiac contractility occurred. In our colony of genetically-engineered NEP knockout mice that have reduced ability to degrade SP, we found increased oxidative stress that was prevented by SP (neurokinin-1) receptor blockade. Thus, we submit that inhibition of NEP by pharmacological, genetic and dietary approaches (magnesium restriction), causes greater neurogenic inflammation that may result in increased intestinal and cardiac dysfunction.

Prospects for pharmacologic inhibition of hepatic glucose production.

PubMed

Kurukulasuriya, R; Link, J T; Madar, D J; Pei, Z; Rohde, J J; Richards, S J; Souers, A J; Szczepankiewicz, B G

2003-01-01

Type 2 diabetes is a widespread disease where effective pharmacologic therapies can have a profound beneficial public health impact. Increased hepatic glucose production (HGP) is observed in diabetics and its moderation by currently available agents provides therapeutic benefits. This review describes the challenges associated with the discovery of small molecules that inhibit HGP. Gluconeogenesis, glycogenolysis, liver architecture, and hepatocyte composition are described to provide background information on hepatic function. Current methods of target validation for drug discovery, HGP measurement, diabetes animal models, as well as current drug therapies are covered. In the accompanying review article the new drug targets being probed to produce the next generation of therapies are described. Significant pharmaceutical and academic efforts to pharmacologically inhibit HGP has the opportunity to provide new therapeutics for type 2 diabetics.

Heme Oxygenase Inhibition Sensitizes Neuroblastoma Cells to Carfilzomib.

PubMed

Barbagallo, Ignazio; Giallongo, Cesarina; Volti, Giovanni Li; Distefano, Alfio; Camiolo, Giuseppina; Raffaele, Marco; Salerno, Loredana; Pittalà, Valeria; Sorrenti, Valeria; Avola, Roberto; Di Rosa, Michelino; Vanella, Luca; Di Raimondo, Francesco; Tibullo, Daniele

2018-06-10

Neuroblastoma (NB) is an embryonic malignancy affecting the physiological development of adrenal medulla and paravertebral sympathetic ganglia in early infancy. Proteasome inhibitors (PIs) (i.e., carfilzomib (CFZ)) may represent a possible pharmacological treatment for solid tumors including NB. In the present study, we tested the effect of a novel non-competitive inhibitor of heme oxygenase-1 (HO-1), LS1/71, as a possible adjuvant therapy for the efficacy of CFZ in neuroblastoma cells. Our results showed that CFZ increased both HO-1 gene expression (about 18-fold) and HO activity (about 8-fold), following activation of the ER stress pathway. The involvement of HO-1 in CFZ-mediated cytotoxicity was further confirmed by the protective effect of pharmacological induction of HO-1, significantly attenuating cytotoxicity. In addition, HO-1 selective inhibition by a specific siRNA increased the cytotoxic effect following CFZ treatment in NB whereas SnMP, a competitive pharmacological inhibitor of HO, showed no changes in cytotoxicity. Our data suggest that treatment with CFZ produces ER stress in NB without activation of CHOP-mediated apoptosis, whereas co-treatment with CFZ and LS1/71 led to apoptosis activation and CHOP expression induction. In conclusion, our study showed that treatment with the non-competitive inhibitor of HO-1, LS1 / 71, increased cytotoxicity mediated by CFZ, triggering apoptosis following ER stress activation. These results suggest that PIs may represent a possible pharmacological treatment for solid tumors and that HO-1 inhibition may represent a possible strategy to overcome chemoresistance and increase the efficacy of chemotherapic regimens.

BACE1 inhibition more effectively suppresses initiation than progression of β-amyloid pathology.

PubMed

Peters, Finn; Salihoglu, Hazal; Rodrigues, Eva; Herzog, Etienne; Blume, Tanja; Filser, Severin; Dorostkar, Mario; Shimshek, Derya R; Brose, Nils; Neumann, Ulf; Herms, Jochen

2018-05-01

BACE1 is the rate-limiting protease in the production of synaptotoxic β-amyloid (Aβ) species and hence one of the prime drug targets for potential therapy of Alzheimer's disease (AD). However, so far pharmacological BACE1 inhibition failed to rescue the cognitive decline in mild-to-moderate AD patients, which indicates that treatment at the symptomatic stage might be too late. In the current study, chronic in vivo two-photon microscopy was performed in a transgenic AD model to monitor the impact of pharmacological BACE1 inhibition on early β-amyloid pathology. The longitudinal approach allowed to assess the kinetics of individual plaques and associated presynaptic pathology, before and throughout treatment. BACE1 inhibition could not halt but slow down progressive β-amyloid deposition and associated synaptic pathology. Notably, the data revealed that the initial process of plaque formation, rather than the subsequent phase of gradual plaque growth, is most sensitive to BACE1 inhibition. This finding of particular susceptibility of plaque formation has profound implications to achieve optimal therapeutic efficacy for the prospective treatment of AD.

All-trans retinoic acid inhibits craniopharyngioma cell growth: study on an explant cell model.

PubMed

Li, Qiang; You, Chao; Zhou, Liangxue; Sima, Xiutian; Liu, Zhiyong; Liu, Hao; Xu, Jianguo

2013-05-01

The ratio between FABP5 and CRABPII determines cellular response to physiological level of retinoic acid; tumor cells undergo proliferation with high level of FABP5 and apoptosis with high level of CRABPII. We intended to study FABP5 and CRABPII expression in craniopharyngiomas, to establish craniopharyngioma cell model using explants method, and to study the effect of pharmacological dose of retinoic acid on craniopharyngioma cells. Expression of FABP5 and CRABPII in craniopharyngioma tissue from 20 patients was studied using immunohistochemistry. Primary craniopharyngioma cell cultures were established using tissue explants method. Craniopharyngioma cells were treated using various concentrations of all-trans retinoic acid, and cell growth curve, apoptosis, expression of FABP5, CRABPII and NF-κB were assayed in different groups. FABP5/CRABPII ratio was significantly higher in adamatinomatous group than that in papillary group. Cell cultures were established in 19 cases (95 %). Pharmacological level retinoic acid inhibited cell growth and induced cellular apoptosis in dose dependent manner, and apoptosis rate cells treated with 30 μM retinoic acid for 24 h was 43 %. Also, retinoic acid increased CRABPII, and decreased FABP5 and NF-κB expression in craniopharyngioma cells. High FABP5/CRABPII ratio is observed in adamatinomatous craniopharyngioma. Retinoic acid at pharmacological level induced craniopharyngioma cell apoptosis via increasing FABP5/CRABPII ratio and inhibiting NF-κB signaling pathway. Our study demonstrated that all-trans retinoic acid might be a candidate for craniopharyngioma adjuvant chemotherapy in future.

The analgesic agent tapentadol inhibits calcitonin gene-related peptide release from isolated rat brainstem via a serotonergic mechanism.

PubMed

Greco, Maria Cristina; Navarra, Pierluigi; Tringali, Giuseppe

2016-01-15

In this study we tested the hypothesis that tapentadol inhibits GGRP release from the rat brainstem through a mechanism mediated by the inhibition of NA reuptake; as a second alternative hypothesis, we investigated whether tapentadol inhibits GGRP release via the inhibition of 5-HT reuptake. Rat brainstems were explanted and incubated in short-term experiments. CGRP released in the incubation medium was taken as a marker of CGRP release from the central terminals of trigeminal neurons within the brainstem. CGRP levels were measured by radioimmunoassay under basal conditions or in the presence of tapentadol; NA, 5-HT, clonidine, yohimbine and ondansetron were used as pharmacological tools to investigate the action mechanism of tapentadol. The α2-antagonist yohimbine failed to counteract the effects of tapentadol. Moreover, neither NA nor the α2-agonist clonidine per se inhibited K(+)-stimulated CGRP release, thereby indicating that the effects of tapentadol are nor mediated through the block of NA reuptake. Further experiments showed that 5-HT and tramadol, which inhibits both NA and 5-HT reuptake, significantly reduced K(+)-stimulated CGRP release. Moreover, the 5-HT3 antagonist ondansetron was able to counteract the effects of tapentadol in this system. This study provided pharmacological evidence that tapentadol inhibits stimulated CGRP release from the rat brainstem in vitro through a mechanism involving an increase in 5-HT levels in the system and the subsequent activation of 5-HT3 receptors. Copyright © 2015 Elsevier Inc. All rights reserved.

Discovery of PF-04620110, a Potent, Selective, and Orally Bioavailable Inhibitor of DGAT-1

PubMed Central

2011-01-01

Acyl-CoA:diacylglycerol acyltransferase-1 (DGAT-1) catalyzes the final committed step in the biosynthesis of triglycerides. DGAT-1 knockout mice have been shown to be resistant to diet-induced obesity and have increased insulin sensitivity. Thus, inhibition of DGAT-1 may represent an attractive target for the treatment of obesity or type II diabetes. Herein, we report the discovery and characterization of a potent and selective DGAT-1 inhibitor PF-04620110 (3). Compound 3 inhibits DGAT-1 with an IC50 of 19 nM and shows high selectivity versus a broad panel of off-target pharmacologic end points. In vivo DGAT-1 inhibition has been demonstrated through reduction of plasma triglyceride levels in rodents at doses of ≥0.1 mg/kg following a lipid challenge. On the basis of this pharmacologic and pharmacokinetic profile, compound 3 has been advanced to human clinical studies. PMID:24900321

Discovery of PF-04620110, a Potent, Selective, and Orally Bioavailable Inhibitor of DGAT-1.

PubMed

Dow, Robert L; Li, Jian-Cheng; Pence, Michael P; Gibbs, E Michael; LaPerle, Jennifer L; Litchfield, John; Piotrowski, David W; Munchhof, Michael J; Manion, Tara B; Zavadoski, William J; Walker, Gregory S; McPherson, R Kirk; Tapley, Susan; Sugarman, Eliot; Guzman-Perez, Angel; DaSilva-Jardine, Paul

2011-05-12

Acyl-CoA:diacylglycerol acyltransferase-1 (DGAT-1) catalyzes the final committed step in the biosynthesis of triglycerides. DGAT-1 knockout mice have been shown to be resistant to diet-induced obesity and have increased insulin sensitivity. Thus, inhibition of DGAT-1 may represent an attractive target for the treatment of obesity or type II diabetes. Herein, we report the discovery and characterization of a potent and selective DGAT-1 inhibitor PF-04620110 (3). Compound 3 inhibits DGAT-1 with an IC50 of 19 nM and shows high selectivity versus a broad panel of off-target pharmacologic end points. In vivo DGAT-1 inhibition has been demonstrated through reduction of plasma triglyceride levels in rodents at doses of ≥0.1 mg/kg following a lipid challenge. On the basis of this pharmacologic and pharmacokinetic profile, compound 3 has been advanced to human clinical studies.

Pharmacology of dextromethorphan: Relevance to dextromethorphan/quinidine (Nuedexta®) clinical use.

PubMed

Taylor, Charles P; Traynelis, Stephen F; Siffert, Joao; Pope, Laura E; Matsumoto, Rae R

2016-08-01

Dextromethorphan (DM) has been used for more than 50years as an over-the-counter antitussive. Studies have revealed a complex pharmacology of DM with mechanisms beyond blockade of N-methyl-d-aspartate (NMDA) receptors and inhibition of glutamate excitotoxicity, likely contributing to its pharmacological activity and clinical potential. DM is rapidly metabolized to dextrorphan, which has hampered the exploration of DM therapy separate from its metabolites. Coadministration of DM with a low dose of quinidine inhibits DM metabolism, yields greater bioavailability and enables more specific testing of the therapeutic properties of DM apart from its metabolites. The development of the drug combination DM hydrobromide and quinidine sulfate (DM/Q), with subsequent approval by the US Food and Drug Administration for pseudobulbar affect, led to renewed interest in understanding DM pharmacology. This review summarizes the interactions of DM with brain receptors and transporters and also considers its metabolic and pharmacokinetic properties. To assess the potential clinical relevance of these interactions, we provide an analysis comparing DM activity from in vitro functional assays with the estimated free drug DM concentrations in the brain following oral DM/Q administration. The findings suggest that DM/Q likely inhibits serotonin and norepinephrine reuptake and also blocks NMDA receptors with rapid kinetics. Use of DM/Q may also antagonize nicotinic acetylcholine receptors, particularly those composed of α3β4 subunits, and cause agonist activity at sigma-1 receptors. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

A network pharmacology-integrated metabolomics strategy for clarifying the difference between effective compounds of raw and processed Farfarae flos by ultra high-performance liquid chromatography-quadrupole-time of flight mass spectrometry.

PubMed

Ding, Mingya; Li, Zhen; Yu, Xie-An; Zhang, Dong; Li, Jin; Wang, Hui; He, Jun; Gao, Xiu-Mei; Chang, Yan-Xu

2018-07-15

This study aimed to clarify the difference between the effective compounds of raw and processed Farfarae flos using a network pharmacology-integrated metabolomics strategy. First, metabolomics data were obtained by ultra high-performance liquid chromatography-quadrupole-time of flight mass spectrometry (UHPLC-Q-TOF/MS). Then, metabolomics analysis was developed to screen for the influential compounds that were different between raw and processed Farfarae flos. Finally, a network pharmacology approach was applied to verify the activity of the screened compounds. As a result, 4 compounds (chlorogenic acid, caffeic acid, rutin and isoquercitrin) were successfully screened, identified, quantified and verified as the most influential effective compounds. They may synergistically inhibit the p38, JNK and ERK-mediated pathways, which would induce the inhibition of the expression of the IFA virus. The results revealed that the proposed network pharmacology-integrated metabolomics strategy was a powerful tool for discovering the effective compounds that were responsible for the difference between raw and processed Chinese herbs. Copyright © 2018 Elsevier B.V. All rights reserved.

A new agent developed by biotransformation of polyphyllin VII inhibits chemoresistance in breast cancer

PubMed Central

Zhang, Liang; Mao, Ai-Qin; Wei, Juan; Liu, De-Quan; Shi, Gui-Yang; Ma, Xin

2016-01-01

Biotransformation by the endophytes of certain plants changes various compounds, and this ‘green’ chemistry becomes increasingly important for finding new products with pharmacological activity. In this study, polyphyllin VII (PPL7) was biotransformed by endophytes from the medicinal plant Paris polyphylla Smith, var. yunnanensis. This produced a new compound, ZH-2, with pharmacological activity in vitro and in vivo. ZH-2 was more potent than PPL7 in selectively killing more chemoresistant than chemosensitive breast cancer cells. ZH-2 also re-sensitized chemoresistant breast cancer cells, as evidenced by the improved anti-cancer activity of commonly-used chemotherapeutic agent in vitro, in vivo, and in clinical samples. This anti-chemoresistance effect of ZH-2 was associated with inhibiting the epithelial-mesenchymal transition (EMT) pathway. Taken together, our findings are the first one to link biotransformation with a biomedicine. The results provide insights into developing new pharmacologically-active agents via biotransformation by endophytes. PMID:26701723

Loss of 5‐lipoxygenase activity protects mice against paracetamol‐induced liver toxicity

PubMed Central

Pu, Shiyun; Ren, Lin; Liu, Qinhui; Kuang, Jiangying; Shen, Jing; Cheng, Shihai; Zhang, Yuwei; Jiang, Wei; Zhang, Zhiyong; Jiang, Changtao

2015-01-01

Background and Purpose Paracetamol (acetaminophen) is the most widely used over‐the‐counter analgesic and overdosing with paracetamol is the leading cause of hospital admission for acute liver failure. 5‐Lipoxygenase (5‐LO) catalyses arachidonic acid to form LTs, which lead to inflammation and oxidative stress. In this study, we examined whether deletion or pharmacological inhibition of 5‐LO could protect mice against paracetamol‐induced hepatic toxicity. Experimental Approach Both genetic deletion and pharmacological inhibition of 5‐LO in C57BL/6J mice were used to study the role of this enzyme in paracetamol induced liver toxicity. Serum and tissue biochemistry, H&E staining, and real‐time PCR were used to assess liver toxicity. Key Results Deletion or pharmacological inhibition of 5‐LO in mice markedly ameliorated paracetamol‐induced hepatic injury, as shown by decreased serum alanine transaminase and aspartate aminotransferase levels and hepatic centrilobular necrosis. The hepatoprotective effect of 5‐LO inhibition was associated with induction of the antitoxic phase II conjugating enzyme, sulfotransferase2a1, suppression of the pro‐toxic phase I CYP3A11 and reduction of the hepatic transporter MRP3. In 5‐LO−/− mice, levels of GSH were increased, and oxidative stress decreased. In addition, PPAR α, a nuclear receptor that confers resistance to paracetamol toxicity, was activated in 5‐LO−/− mice. Conclusions and Implications The activity of 5‐LO may play a critical role in paracetamol‐induced hepatic toxicity by regulating paracetamol metabolism and oxidative stress. PMID:26398229

PARP activity and inhibition in fetal and adult oligodendrocyte precursor cells: Effect on cell survival and differentiation.

PubMed

Baldassarro, Vito A; Marchesini, Alessandra; Giardino, Luciana; Calzà, Laura

2017-07-01

Poly (ADP-ribose) polymerase (PARP) family members are ubiquitously expressed and play a key role in cellular processes, including DNA repair and cell death/survival balance. Accordingly, PARP inhibition is an emerging pharmacological strategy for cancer and neurodegenerative diseases. Consistent evidences support the critical involvement of PARP family members in cell differentiation and phenotype maturation. In this study we used an oligodendrocyte precursor cells (OPCs) enriched system derived from fetal and adult brain to investigate the role of PARP in OPCs proliferation, survival, and differentiation. The PARP inhibitors PJ34, TIQ-A and Olaparib were used as pharmacological tools. The main results of the study are: (i) PARP mRNA expression and PARP activity are much higher in fetal than in adult-derived OPCs; (ii) the culture treatment with PARP inhibitors is cytotoxic for OPCs derived from fetal, but not from adult, brain; (iii) PARP inhibition reduces cell number, according to the inhibitory potency of the compounds; (iv) PARP inhibition effect on fetal OPCs is a slow process; (v) PARP inhibition impairs OPCs maturation into myelinating OL in fetal, but not in adult cultures, according to the inhibitory potency of the compounds. These results have implications for PARP-inhibition therapies for diseases and lesions of the central nervous system, in particular for neonatal hypoxic/ischemic encephalopathy. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Recurrent angioedema associated with pharmacological inhibition of dipeptidyl peptidase IV.

PubMed

Hermanrud, Thorbjørn; Bygum, Anette; Rasmussen, Eva Rye

2017-01-10

Angioedema (AE) of the upper airways is a severe and potentially life-threatening condition. The incidence has been increasing in the past two decades, primarily due to increased use of medications inhibiting the degradation of vasoactive peptides. Acquired angioedema related to angiotensin-converting enzyme inhibitors (ACEI-AAE) is well known, but other pharmaceutical agents also affect the degradation of bradykinin and substance P. We present a middle-aged man with recurrent episodes of severe AE of the oral cavity, hypopharynx and larynx due to pharmacological inhibition of dipeptidyl peptidase IV. 2017 BMJ Publishing Group Ltd.

Treatment of Pancreatic Cancer with Pharmacological Ascorbate

PubMed Central

Cieslak, John A.; Cullen, Joseph J.

2016-01-01

The prognosis for patients diagnosed with pancreatic cancer remains dismal, with less than 3% survival at 5 years. Recent studies have demonstrated that high-dose, intravenous pharmacological ascorbate (ascorbic acid, vitamin C) induces cytotoxicity and oxidative stress selectively in pancreatic cancer cells vs. normal cells, suggesting a promising new role of ascorbate as a therapeutic agent. At physiologic concentrations, ascorbate functions as a reducing agent and antioxidant. However, when pharmacological ascorbate is given intravenously, it is possible to achieve millimolar plasma concentration. At these pharmacological levels, and in the presence of catalytic metal ions, ascorbate can induce oxidative stress through the generation of hydrogen peroxide (H2O2). Recent in vitro and in vivo studies have demonstrated ascorbate oxidation occurs extracellularly, generating H2O2 flux into cells resulting in oxidative stress. Pharmacologic ascorbate also inhibits the growth of pancreatic tumor xenografts and displays synergistic cytotoxic effects when combined with gemcitabine in pancreatic cancer. Phase I trials of pharmacological ascorbate in pancreatic cancer patients have demonstrated safety and potential efficacy. In this chapter, we will review the mechanism of ascorbate-induced cytotoxicity, examine the use of pharmacological ascorbate in treatment and assess the current data supporting its potential as an adjuvant in pancreatic cancer. PMID:26201606

Functional studies on the role of Notch signaling in Hydractinia development.

PubMed

Gahan, James M; Schnitzler, Christine E; DuBuc, Timothy Q; Doonan, Liam B; Kanska, Justyna; Gornik, Sebastian G; Barreira, Sofia; Thompson, Kerry; Schiffer, Philipp; Baxevanis, Andreas D; Frank, Uri

2017-08-01

The function of Notch signaling was previously studied in two cnidarians, Hydra and Nematostella, representing the lineages Hydrozoa and Anthozoa, respectively. Using pharmacological inhibition in Hydra and a combination of pharmacological and genetic approaches in Nematostella, it was shown in both animals that Notch is required for tentacle morphogenesis and for late stages of stinging cell maturation. Surprisingly, a role for Notch in neural development, which is well documented in bilaterians, was evident in embryonic Nematostella but not in adult Hydra. Adult neurogenesis in the latter seemed to be unaffected by DAPT, a drug that inhibits Notch signaling. To address this apparent discrepancy, we studied the role of Notch in Hydractinia echinata, an additional hydrozoan, in all life stages. Using CRISPR-Cas9 mediated mutagenesis, transgenesis, and pharmacological interference we show that Notch is dispensable for Hydractinia normal neurogenesis in all life stages but is required for the maturation of stinging cells and for tentacle morphogenesis. Our results are consistent with a conserved role for Notch in morphogenesis and nematogenesis across Cnidaria, and a lineage-specific loss of Notch dependence in neurogenesis in hydrozoans. Copyright © 2017 Elsevier Inc. All rights reserved.

Pharmacological and Toxicological Studies of Essential Oil of Lavandula stoechas subsp. luisieri.

PubMed

Arantes, Sílvia; Candeias, Fátima; Lopes, Orlando; Lima, Mónica; Pereira, Marízia; Tinoco, Teresa; Cruz-Morais, J; Martins, M Rosário

2016-09-01

The present study was carried out to evaluate the chemical and pharmacological properties of the essential oil of Lavandula stoechas subsp. luisieri, which is a spontaneous shrub widespread in Alentejo (Portugal). Oxygenated monoterpenes, such as 1,8-cineole, lavandulol, and necrodane derivatives, are the main components of essential oil. It revealed important antioxidant activity with a high ability to inhibit lipid peroxidation and showed an outstanding effect against a wide spectrum of microorganisms, such as gram-positive and gram-negative bacteria and pathogenic yeasts. The analgesic effect studied in rats was dose dependent, reaching a maximum of 67 % at 60 min with the dose of 200 mg/kg and the anti-inflammatory activity with this dose caused an inhibition in carrageenan-induced rat paw oedema (83 %) that is higher than dexamethasone 1 mg/Kg (69 %). Besides, animals exhibited normal behaviour after essential oil administration, revealing low toxicity. The essential oil of L. luisieri from Alentejo presents important pharmacological properties and low toxicity, and is a promised candidate to be used as a food supplement or in pharmaceutical applications. Georg Thieme Verlag KG Stuttgart · New York.

Clofilium inhibits Slick and Slack potassium channels.

PubMed

de Los Angeles Tejada, Maria; Stolpe, Kathleen; Meinild, Anne-Kristine; Klaerke, Dan A

2012-01-01

Slick and Slack high-conductance potassium channels have been recently discovered, and are found in the central nervous system and in the heart. Both channels are activated by Na(+) and Cl(-), and Slick channels are also inhibited by adenosine triphospate (ATP). An important role of setting the resting membrane potential and controlling the basal excitability of neurons has been suggested for these channels. In addition, no specific blockers for these channels are known up to the present. With the purpose of studying the pharmacological characteristics of Slick and Slack channels, the effects of exposure to the antiarrhythmic compound clofilium were evaluated. Clofilium was able to modulate the activity of Slick and Slack channels effectively, with a stronger effect on Slack than Slick channels. In order to evaluate the pharmacological behavior of Slick and Slack channels further, 38 commonly used potassium channel blockers were tested. Screening of these compounds did not reveal any modulators of Slick and Slack channels, except for clofilium. The present study provides a first approach towards elucidating the pharmacological characteristics of Slick and Slack channels and could be the basis for future studies aimed at developing potent and specific blockers and activators for these channels.

Studies on the pharmacological action of cactus: identification of its anti-inflammatory effect.

PubMed

Park, E H; Kahng, J H; Paek, E A

1998-02-01

The ethanol extracts of Opuntia ficus-indica fructus (EEOF) and Opuntia ficus-indica stem (EEOS) were prepared and used to evaluate the pharmacological effects of cactus. Both the extracts inhibited the writhing syndrome induced by acetic acid, indicating that they contains analgesic effect. The oral administrations of EEOF and EEOS suppressed carrageenan-induced rat paw edema and also showed potent inhibition in the leukocyte migration of CMC-pouch model in rats. Moreover, the extracts suppressed the release of beta-glucuronidase, a lysosomal enzyme in rat neutrophils. It was also noted that the extracts showed the protective effect on gastric mucosal layers. From the results it is suggested that the cactus extracts contain anti-inflammatory action having protective effect against gastric lesions.

Selective pharmacological inhibition of DDR1 prevents experimentally-induced glomerulonephritis in prevention and therapeutic regime.

PubMed

Moll, Solange; Yasui, Yukari; Abed, Ahmed; Murata, Takeshi; Shimada, Hideaki; Maeda, Akira; Fukushima, Naoshi; Kanamori, Masakazu; Uhles, Sabine; Badi, Laura; Cagarelli, Thomas; Formentini, Ivan; Drawnel, Faye; Georges, Guy; Bergauer, Tobias; Gasser, Rodolfo; Bonfil, R Daniel; Fridman, Rafael; Richter, Hans; Funk, Juergen; Moeller, Marcus J; Chatziantoniou, Christos; Prunotto, Marco

2018-06-01

Discoidin domain receptor 1 (DDR1) is a collagen-activated receptor tyrosine kinase extensively implicated in diseases such as cancer, atherosclerosis and fibrosis. Multiple preclinical studies, performed using either a gene deletion or a gene silencing approaches, have shown this receptor being a major driver target of fibrosis and glomerulosclerosis. The present study investigated the role and relevance of DDR1 in human crescentic glomerulonephritis (GN). Detailed DDR1 expression was first characterized in detail in human GN biopsies using a novel selective anti-DDR1 antibody using immunohistochemistry. Subsequently the protective role of DDR1 was investigated using a highly selective, novel, small molecule inhibitor in a nephrotoxic serum (NTS) GN model in a prophylactic regime and in the NEP25 GN mouse model using a therapeutic intervention regime. DDR1 expression was shown to be mainly limited to renal epithelium. In humans, DDR1 is highly induced in injured podocytes, in bridging cells expressing both parietal epithelial cell (PEC) and podocyte markers and in a subset of PECs forming the cellular crescents in human GN. Pharmacological inhibition of DDR1 in NTS improved both renal function and histological parameters. These results, obtained using a prophylactic regime, were confirmed in the NEP25 GN mouse model using a therapeutic intervention regime. Gene expression analysis of NTS showed that pharmacological blockade of DDR1 specifically reverted fibrotic and inflammatory gene networks and modulated expression of the glomerular cell gene signature, further validating DDR1 as a major mediator of cell fate in podocytes and PECs. Together, these results suggest that DDR1 inhibition might be an attractive and promising pharmacological intervention for the treatment of GN, predominantly by targeting the renal epithelium.

Pharmacologic inhibition of lactate production prevents myofibroblast differentiation.

PubMed

Kottmann, Robert Matthew; Trawick, Emma; Judge, Jennifer L; Wahl, Lindsay A; Epa, Amali P; Owens, Kristina M; Thatcher, Thomas H; Phipps, Richard P; Sime, Patricia J

2015-12-01

Myofibroblasts are one of the primary cell types responsible for the accumulation of extracellular matrix in fibrosing diseases, and targeting myofibroblast differentiation is an important therapeutic strategy for the treatment of pulmonary fibrosis. Transforming growth factor-β (TGF-β) has been shown to be an important inducer of myofibroblast differentiation. We previously demonstrated that lactate dehydrogenase and its metabolic product lactic acid are important mediators of myofibroblast differentiation, via acid-induced activation of latent TGF-β. Here we explore whether pharmacologic inhibition of LDH activity can prevent TGF-β-induced myofibroblast differentiation. Primary human lung fibroblasts from healthy patients and those with pulmonary fibrosis were treated with TGF-β and or gossypol, an LDH inhibitor. Protein and RNA were analyzed for markers of myofibroblast differentiation and extracellular matrix generation. Gossypol inhibited TGF-β-induced expression of the myofibroblast marker α-smooth muscle actin (α-SMA) in a dose-dependent manner in both healthy and fibrotic human lung fibroblasts. Gossypol also inhibited expression of collagen 1, collagen 3, and fibronectin. Gossypol inhibited LDH activity, the generation of extracellular lactic acid, and the rate of extracellular acidification in a dose-dependent manner. Furthermore, gossypol inhibited TGF-β bioactivity in a dose-dependent manner. Concurrent treatment with an LDH siRNA increased the ability of gossypol to inhibit TGF-β-induced myofibroblast differentiation. Gossypol inhibits TGF-β-induced myofibroblast differentiation through inhibition of LDH, inhibition of extracellular accumulation of lactic acid, and inhibition of TGF-β bioactivity. These data support the hypothesis that pharmacologic inhibition of LDH may play an important role in the treatment of pulmonary fibrosis. Copyright © 2015 the American Physiological Society.

Overexpression and knock-down studies highlight that a disintegrin and metalloproteinase 28 controls proliferation and migration in human prostate cancer.

PubMed

Rudnicka, Caroline; Mochizuki, Satsuki; Okada, Yasunori; McLaughlin, Claire; Leedman, Peter J; Stuart, Lisa; Epis, Michael; Hoyne, Gerard; Boulos, Sherif; Johnson, Liam; Schlaich, Markus; Matthews, Vance

2016-10-01

Prostate cancer is one of the most prevalent cancers in men. It is critical to identify and characterize oncogenes that drive the pathogenesis of human prostate cancer. The current study builds upon previous research showing that a disintegrin and metallproteinase (ADAM)28 is involved in the pathogenesis of numerous cancers. Our novel study used overexpression, pharmacological, and molecular approaches to investigate the biological function of ADAM28 in human prostate cancer cells, with a focus on cell proliferation and migration. The results of this study provide important insights into the role of metalloproteinases in human prostate cancer.The expression of ADAM28 protein levels was assessed within human prostate tumors and normal adjacent tissue by immunohistochemistry. Immunocytochemistry and western blotting were used to assess ADAM28 protein expression in human prostate cancer cell lines. Functional assays were conducted to assess proliferation and migration in human prostate cancer cells in which ADAM28 protein expression or activity had been altered by overexpression, pharmacological inhibition, or by siRNA gene knockdown.The membrane bound ADAM28 was increased in human tumor biopsies and prostate cancer cell lines. Pharmacological inhibition of ADAM28 activity and/or knockdown of ADAM28 significantly reduced proliferation and migration of human prostate cancer cells, while overexpression of ADAM28 significantly increased proliferation and migration.ADAM28 is overexpressed in primary human prostate tumor biopsies, and it promotes human prostate cancer cell proliferation and migration. This study supports the notion that inhibition of ADAM28 may be a potential novel therapeutic strategy for human prostate cancer.

How does curcumin work with poor bioavailability? Clues from experimental and theoretical studies

NASA Astrophysics Data System (ADS)

Shen, Liang; Liu, Cui-Cui; An, Chun-Yan; Ji, Hong-Fang

2016-02-01

Curcumin is a natural product with multiple biological activities and numerous potential therapeutic applications. However, its poor systemic bioavailability fails to explain the potent pharmacological effects and hinders its clinical application. Using experimental and theoretical approaches, we compared curcumin and its degradation products for its biological activities against Alzheimer’s disease (AD), including the superoxide anion radical (O2.-)-scavenging activity, Aβ fibrils (fAβ) formation-inhibiting activity, and enzymatic inhibition activity. We showed that compared to the parent compound curcumin, the degradation products mixture possessed higher O2.--scavenging activity and stronger inhibition against fAβ formation. The docking simulations revealed that the bioactive degradation products should make important contribution to the experimentally observed enzymatic inhibition activities of curcumin. Given that curcumin is readily degraded under physiological condition, our findings strongly suggested that the degradation products should make important contribution to the diverse biological activities of curcumin. Our novel findings not only provide novel insights into the complex pharmacology of curcumin due to its poor bioavailability, but also open new avenues for developing therapeutic applications of this natural product.

Pharmacological inhibition of NADPH oxidase protects against cisplatin induced nephrotoxicity in mice by two step mechanism.

PubMed

Wang, Yimin; Luo, Xiao; Pan, Hao; Huang, Wei; Wang, Xueping; Wen, Huali; Shen, Kezhen; Jin, Baiye

2015-09-01

Cisplatin induced nephrotoxicity is primarily caused by ROS (Reactive Oxygen Species) induced proximal tubular cell death. NADPH oxidase is major source of ROS production by cisplatin. Here, we reported that pharmacological inhibition of NADPH oxidase by acetovanillone (obtained from medicinal herb Picrorhiza kurroa) led to reduced cisplatin nephrotoxicity in mice. In this study we used various molecular biology and biochemistry methods a clinically relevant model of nephropathy, induced by an important chemotherapeutic drug cisplatin. Cisplatin-induced nephrotoxicity was evident by histological damage from loss of the tubular structure. The damage was also marked by the increase in blood urea nitrogen, creatinine, protein nitration as well as cell death markers such as caspase 3/7 activity and DNA fragmentation. Tubular cell death by cisplatin led to pro-inflammatory response by production of TNFα and IL1β followed by leukocyte/neutrophil infiltration which resulted in new wave of ROS involving more NADPH oxidases. Cisplatin-induced markers of kidney damage such as oxidative stress, cell death, inflammatory cytokine production and nephrotoxicity were attenuated by acetovanillone. In addition to that, acetovanillone enhanced cancer cell killing efficacy of cisplatin. Thus, pharmacological inhibition of NADPH oxidase can be protective for cisplatin-induced nephrotoxicity in mice. Copyright © 2015. Published by Elsevier Ltd.

5-Lipoxygenase as an endogenous modulator of amyloid beta formation in vivo

PubMed Central

Chu, Jin; Praticò, Domenico

2010-01-01

Objective The 5-lipoxygenase (5-LO) enzymatic pathway is widely distributed within the central nervous system, and is up-regulated in Alzheimer's disease. However, the mechanism whereby it may influence the disease pathogenesis remains elusive. Methods We evaluated the molecular mechanism by which 5-LO regulates Amyloid β (Aβ) formation in vitro and in vivo by pharmacological and genetic approaches. Results Here we show that 5-LO regulates the formation of Aβ by activating the cAMP-response element binding protein (CREB), which in turn increases transcription of the γ-secretase complex. Preventing CREB activation by pharmacologic inhibition or dominant negative mutants blocks the 5-LO-dependent elevation of Aβ formation and the increase of γ-secretase mRNA and protein levels. Moreover, 5-LO targeted gene disruption or its in vivo selective pharmacological inhibition results in a significant reduction of Aβ, CREB and γ-secretase levels. Interpretation These data establish a novel functional role for 5-LO in regulating endogenous formation of Aβ levels in the central nervous system. Thus, 5-LO pharmacological inhibition may be beneficial in the treatment and prevention of Alzheimer's disease. PMID:21280074

Salinomycin, A Polyether Ionophoric Antibiotic, Inhibits Adipogenesis

PubMed Central

Szkudlarek-Mikho, Maria; Saunders, Rudel A.; Yap, Sook Fan; Ngeow, Yun Fong; Chin, Khew-Voon

2012-01-01

The polyether ionophoric antibiotics including monensin, salinomycin, and narasin, are widely used in veterinary medicine and as food additives and growth promoters in animal husbandry including poultry farming. Their effects on human health, however, are not fully understood. Recent studies showed that salinomycin is a cancer stem cell inhibitor. Since poultry consumption has risen sharply in the last three decades, we asked whether the consumption of meat tainted with growth promoting antibiotics might have effects on adipose cells. We showed in this report that the ionophoric antibiotics inhibit the differentiation of preadipocytes into adipocytes. The block of differentiation is not due to the induction of apoptosis nor the inhibition of cell proliferation. In addition, salinomycin also suppresses the transcriptional activity of the CCAAT/enhancer binding proteins and the peroxisome proliferator-activated receptor γ. These results suggest that the ionophoric antibiotics can be exploited as novel anti-obesity therapeutics and as pharmacological probes for the study of adipose biology. Further, the pharmacological effects of salinomycin could be a harbinger of its toxicity on the adipose tissue and other susceptible target cells in cancer therapy. PMID:23123626

Inactivation by omeprazole of the carnitine transporter (OCTN2) reconstituted in liposomes.

PubMed

Pochini, Lorena; Scalise, Mariafrancesca; Indiveri, Cesare

2009-05-15

The effect of omeprazole on the carnitine (OCTN2) transporter reconstituted in liposomes has been studied. Omeprazole externally added to the proteoliposomes, inhibited the carnitine/carnitine antiport catalysed by the reconstituted transporter. The inhibition was partially reversed by DTE indicating that it was caused by the covalent reaction of omeprazole with Cys residue(s) of the transporter. Similar results were found with intact brush border vesicles. The residual inhibition of the transport in the presence of DTE, indicated the occurrence of an alternative inhibition mechanism of non-covalent nature. The IC(50) of the two inhibition modes derived from dose-response curves, were 5.7 microM and 20.4 microM, respectively. Kinetic studies of the inhibition showed that in the absence of DTE omeprazole behaved as non-competitive inhibitor. On the contrary, in the presence of DTE competitive inhibition was found. The K(i) of the transporter for the inhibitor was 5.2 microM or 14.6 microM in the absence or presence of DTE, i.e., under condition of covalent (non-competitive) or non-covalent (competitive) interaction of the inhibitor with the transporter. The presence of the substrate during the incubation of the omeprazole (in the absence of DTE) with the proteoliposomes facilitated the covalent reaction of the pharmacological compound with the transporter. Omeprazole did not inhibit when present in the internal proteoliposomal compartment, indicating that the inhibition was specifically due to interaction with external site(s) of the protein. The pharmacological compound was not transported by the reconstituted transporter. The possible in vivo implications of the interaction of omeprazole with the transporter are discussed.

Genetic ablation or pharmacologic inhibition of autophagy mitigated NSAID-associated gastric damages.

PubMed

Ock, Chan Young; Park, Jong-Min; Han, Young-Min; Jeong, Migyeong; Kim, Mi-Young; Lee, Ho Jae; Hahm, Ki Baik

2017-04-01

Non-steroidal anti-inflammatory drug (NSAID)-associated endoplasmic reticulum (ER) stress (a cyclooxygenase-2-independent mechanism) and consequent autophagic cell death are responsible for NSAID-associated gastric damage. Therefore, alleviating cytotoxicity executed via ER stress and autophagy can be a strategy to prevent NSAID-associated gastric damage. Here, we explored whether genetic or pharmacologic inhibition of autophagy can mitigate NSAID-associated gastric damage in in vitro and in vivo models. To examine the effects of genetic inhibition of NSAID-associated autophagy, we administered indomethacin to RGM1 gastric mucosal cells transfected with shPERK, siLC3B, or shATG5 and microtubule-associated protein light chain 3B knock-out (LC3B -/- ) mice. 3-Methyladenine (3-MA) or chloroquine (CQ) was used for pharmacologic inhibition of autophagy in both models. Indomethacin administration increased the expression of ER stress proteins including GRP78, ATF6, and CHOP. Indomethacin provoked the appearance of autophagic vesicles with the increased expression of ATG5 and LC3B-II. Genetic ablation of various ER stress genes significantly attenuated indomethacin-induced autophagy and apoptosis (p < 0.01), whereas knock-down of either ATG5 or LC3B significantly reduced indomethacin-induced cytotoxicity (p < 0.01). Testing each of the genes implicated in ER stress and autophagy showed that indomethacin leads to gastric cell apoptosis through autophagy induction consequent to ER stress. Pharmacological inhibition of autophagy with either 3-MA or CQ in rats or genetic ablation of LC3B in mice all had a significant rescuing effect against indomethacin-associated gastric damage (p < 0.01) and a decrease in molecular markers of autophagic and apoptotic gastric cells. In conclusion, preemptive autophagy inhibition can be a potential strategy to mitigate NSAID-associated gastric damage. NSAID administration triggered ER stress and subsequent autophagy. Inhibition of autophagy resulted in attenuated NSAID-associated cytotoxicity. Autophagy inhibitors represent a novel strategy to prevent NSAID-associated gastric damage.

Cannabidiol inhibits angiogenesis by multiple mechanisms.

PubMed

Solinas, M; Massi, P; Cantelmo, A R; Cattaneo, M G; Cammarota, R; Bartolini, D; Cinquina, V; Valenti, M; Vicentini, L M; Noonan, D M; Albini, A; Parolaro, D

2012-11-01

Several studies have demonstrated anti-proliferative and pro-apoptotic actions of cannabinoids on various tumours, together with their anti-angiogenic properties. The non-psychoactive cannabinoid cannabidiol (CBD) effectively inhibits the growth of different types of tumours in vitro and in vivo and down-regulates some pro-angiogenic signals produced by glioma cells. As its anti-angiogenic properties have not been thoroughly investigated to date, and given its very favourable pharmacological and toxicological profile, here, we evaluated the ability of CBD to modulate tumour angiogenesis. Firstly, we evaluated the effect of CBD on human umbilical vein endothelial cell (HUVEC) proliferation and viability - through [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay and FACS analysis - and in vitro motility - both in a classical Boyden chamber test and in a wound-healing assay. We next investigated CBD effects on different angiogenesis-related proteins released by HUVECs, using an angiogenesis array kit and an ELISA directed at MMP2. Then we evaluated its effects on in vitro angiogenesis in treated HUVECs invading a Matrigel layer and in HUVEC spheroids embedded into collagen gels, and further characterized its effects in vivo using a Matrigel sponge model of angiogenesis in C57/BL6 mice. CBD induced HUVEC cytostasis without inducing apoptosis, inhibited HUVEC migration, invasion and sprouting in vitro, and angiogenesis in vivo in Matrigel sponges. These effects were associated with the down-modulation of several angiogenesis-related molecules. This study reveals that CBD inhibits angiogenesis by multiple mechanisms. Its dual effect on both tumour and endothelial cells supports the hypothesis that CBD has potential as an effective agent in cancer therapy. © 2012 The Authors. British Journal of Pharmacology © 2012 The British Pharmacological Society.

INHIBITION OF INDOLEAMINE 2,3-DIOXYGENASE DOES NOT IMPEDE ORAL TOLERANCE

EPA Science Inventory

Rationale: Indoleamine 2,3-dioxygenase (IDO), a tryptophan catabolizing enzyme, regulates immune tolerance through inhibition of T-cell proliferation. Pharmacologic inhibition of IDO, which causes fetal rejection and increased tumor resistance in mice, may prove useful in cancer...

IP-FCM measures physiologic protein-protein interactions modulated by signal transduction and small-molecule drug inhibition.

PubMed

Smith, Stephen E P; Bida, Anya T; Davis, Tessa R; Sicotte, Hugues; Patterson, Steven E; Gil, Diana; Schrum, Adam G

2012-01-01

Protein-protein interactions (PPI) mediate the formation of intermolecular networks that control biological signaling. For this reason, PPIs are of outstanding interest in pharmacology, as they display high specificity and may represent a vast pool of potentially druggable targets. However, the study of physiologic PPIs can be limited by conventional assays that often have large sample requirements and relatively low sensitivity. Here, we build on a novel method, immunoprecipitation detected by flow cytometry (IP-FCM), to assess PPI modulation during either signal transduction or pharmacologic inhibition by two different classes of small-molecule compounds. First, we showed that IP-FCM can detect statistically significant differences in samples possessing a defined PPI change as low as 10%. This sensitivity allowed IP-FCM to detect a PPI that increases transiently during T cell signaling, the antigen-inducible interaction between ZAP70 and the T cell antigen receptor (TCR)/CD3 complex. In contrast, IP-FCM detected no ZAP70 recruitment when T cells were stimulated with antigen in the presence of the src-family kinase inhibitor, PP2. Further, we tested whether IP-FCM possessed sufficient sensitivity to detect the effect of a second, rare class of compounds called SMIPPI (small-molecule inhibitor of PPI). We found that the first-generation non-optimized SMIPPI, Ro-26-4550, inhibited the IL-2:CD25 interaction detected by IP-FCM. This inhibition was detectable using either a recombinant CD25-Fc chimera or physiologic full-length CD25 captured from T cell lysates. Thus, we demonstrate that IP-FCM is a sensitive tool for measuring physiologic PPIs that are modulated by signal transduction and pharmacologic inhibition.

Atorvastatin inhibits the apoptosis of human umbilical vein endothelial cells induced by angiotensin II via the lysosomal-mitochondrial axis.

PubMed

Chang, Ye; Li, Yuan; Ye, Ning; Guo, Xiaofan; Li, Zhao; Sun, Guozhe; Sun, Yingxian

2016-09-01

This study was aimed to evaluate lysosomes-mitochondria cross-signaling in angiotensin II (Ang II)-induced apoptosis of human umbilical vein endothelial cells (HUVECs) and whether atorvastatin played a protective role via lysosomal-mitochondrial axis. Apoptosis was detected by flow cytometry, Hoechst 33342 and AO/EB assay. The temporal relationship of lysosomal and mitochondrial permeabilization was established. Activity of Cathepsin D (CTSD) was suppressed by pharmacological and genetic approaches. Proteins production were measured by western blotting. Our study showed that Ang II could induce the apoptosis of HUVECs in a dose-depended and time-depended manner. Exposure to 1 μM Ang II for 24 h resulted in mitochondrial depolarization, cytochrome c release, and increased ROS production. Lysosomal permeabilization and CTSD redistribution into the cytoplasm occurred several hours prior to mitochondrial dysfunction. These effects were all suppressed by atorvastatin. Either pharmacological or genetic inhibition of CTSD preserved mitochondrial function and decreased apoptosis in HUVECs. Most importantly, we found that the protective effect of atorvastatin was significantly greater than pharmacological or genetic inhibition of CTSD. Finally, overexpression of CTSD without exposure to Ang II had no effect on mitochondrial function and apoptosis. Our data strongly suggested that Ang II induced apoptosis through the lysosomal-mitochondrial axis in HUVECs. Furthermore, atorvastatin played an important role in the regulation of lysosomes and mitochondria stability, resulting in an antagonistic role against Ang II on HUVECs.

Pharmacological Profile of BI 847325, an Orally Bioavailable, ATP-Competitive Inhibitor of MEK and Aurora Kinases.

PubMed

Sini, Patrizia; Gürtler, Ulrich; Zahn, Stephan K; Baumann, Christoph; Rudolph, Dorothea; Baumgartinger, Rosa; Strauss, Eva; Haslinger, Christian; Tontsch-Grunt, Ulrike; Waizenegger, Irene C; Solca, Flavio; Bader, Gerd; Zoephel, Andreas; Treu, Matthias; Reiser, Ulrich; Garin-Chesa, Pilar; Boehmelt, Guido; Kraut, Norbert; Quant, Jens; Adolf, Günther R

2016-10-01

Although the MAPK pathway is frequently deregulated in cancer, inhibitors targeting RAF or MEK have so far shown clinical activity only in BRAF- and NRAS-mutant melanoma. Improvements in efficacy may be possible by combining inhibition of mitogenic signal transduction with inhibition of cell-cycle progression. We have studied the preclinical pharmacology of BI 847325, an ATP-competitive dual inhibitor of MEK and Aurora kinases. Potent inhibition of MEK1/2 and Aurora A/B kinases by BI 847325 was demonstrated in enzymatic and cellular assays. Equipotent effects were observed in BRAF-mutant cells, whereas in KRAS-mutant cells, MEK inhibition required higher concentrations than Aurora kinase inhibition. Daily oral administration of BI 847325 at 10 mg/kg showed efficacy in both BRAF- and KRAS-mutant xenograft models. Biomarker analysis suggested that this effect was primarily due to inhibition of MEK in BRAF-mutant models but of Aurora kinase in KRAS-mutant models. Inhibition of both MEK and Aurora kinase in KRAS-mutant tumors was observed when BI 847325 was administered once weekly at 70 mg/kg. Our studies indicate that BI 847325 is effective in in vitro and in vivo models of cancers with BRAF and KRAS mutation. These preclinical data are discussed in the light of the results of a recently completed clinical phase I trial assessing safety, tolerability, pharmacokinetics, and efficacy of BI 847325 in patients with cancer. Mol Cancer Ther; 15(10); 2388-98. ©2016 AACR. ©2016 American Association for Cancer Research.

The interactions of azure B, a metabolite of methylene blue, with acetylcholinesterase and butyrylcholinesterase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Petzer, Anél, E-mail: 12264954@nwu.ac.za; Harvey, Brian H.; Petzer, Jacobus P.

Methylene blue (MB) is reported to possess diverse pharmacological actions and is attracting increasing attention for the treatment of neurodegenerative disorders such as Alzheimer's disease. Among the pharmacological actions of MB, is the significant inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). These activities may, at least in part, underlie MB's beneficial effects in Alzheimer's disease. MB is metabolized to yield N-demethylated products of which azure B, the monodemethyl metabolite, is the predominant species. Azure B has been shown to be pharmacologically active and also possesses a variety of biological actions. Azure B therefore may contribute to the pharmacological profile ofmore » MB. Based on these considerations, the present study investigates the possibility that azure B may, similar to MB, act as an inhibitor of human AChE and BuChE. The results document that azure B inhibits AChE and BuChE with IC{sub 50} values of 0.486 μM and 1.99 μM, respectively. The results further show that azure B inhibits AChE and BuChE reversibly, and that the modes of inhibition are most likely competitive. Although the AChE and BuChE inhibitory activities of azure B are twofold and fivefold, respectively, less potent than those recorded for MB [IC{sub 50}(AChE) = 0.214 μM; IC{sub 50}(BuChE) = 0.389 μM] under identical conditions, azure B may be a contributor to MB's in vivo activation of the cholinergic system and beneficial effects in Alzheimer's disease. - Highlights: • Methylene blue (MB) is a known inhibitor of AChE and BuChE. • Azure B, the major metabolite of MB, also is an inhibitor of AChE and BuChE. • Azure B may be a contributor to MB's in vivo activation of the cholinergic system. • Azure B may contribute to MB's potential in Alzheimer's disease therapy.« less

Effect of the wake-promoting agent modafinil on sleep-promoting neurons from the ventrolateral preoptic nucleus: an in vitro pharmacologic study.

PubMed

Gallopin, Thierry; Luppi, Pierre-Hervé; Rambert, Francis A; Frydman, Armand; Fort, Patrice

2004-02-01

The pharmacologic profile of modafinil, an increasingly popular wake-promoting drug for narcolepsy treatment, differs from those of classic psychostimulants such as amphetamine. However, its brain targets are still a matter of debate. We hypothesized that modafinil could increase waking by inhibiting the sleep-promoting neurons from the ventrolateral preoptic nucleus (VLPO). Such action could be direct or indirect via the potentiation of inhibition mediated by waking neurotransmitters. We thus studied the effect of modafinil on the membrane potential and firing rate of VLPO neurons recorded in rat-brain slices. We further determined whether pretreatment with modafinil modifies the effect of noradrenaline, carbachol, serotonin, histamine, dopamine, or clonidine. Pretreatment with modafinil specifically increased the inhibition of VLPO neurons induced by noradrenaline but had no effect when applied alone or in combination with other substances. Pretreatment with nisoxetine, a selective noradrenaline reuptake blocker, similarly increased the noradrenaline-induced inhibition of VLPO cells. Further, the potentiation by modafinil was minimized when modafinil and nisoxetine were applied together. These results suggest that modafinil blocks the reuptake of noradrenaline by the noradrenergic terminals on sleep-promoting neurons from the VLPO. Such a mechanism could be at least partially responsible for the wake-promoting effect of modafinil.

Pharmacological inhibition of fatty-acid oxidation synergistically enhances the effect of l-asparaginase in childhood ALL cells.

PubMed

Hermanova, I; Arruabarrena-Aristorena, A; Valis, K; Nuskova, H; Alberich-Jorda, M; Fiser, K; Fernandez-Ruiz, S; Kavan, D; Pecinova, A; Niso-Santano, M; Zaliova, M; Novak, P; Houstek, J; Mracek, T; Kroemer, G; Carracedo, A; Trka, J; Starkova, J

2016-01-01

l-asparaginase (ASNase), a key component in the treatment of childhood acute lymphoblastic leukemia (ALL), hydrolyzes plasma asparagine and glutamine and thereby disturbs metabolic homeostasis of leukemic cells. The efficacy of such therapeutic strategy will depend on the capacity of cancer cells to adapt to the metabolic challenge, which could relate to the activation of compensatory metabolic routes. Therefore, we studied the impact of ASNase on the main metabolic pathways in leukemic cells. Treating leukemic cells with ASNase increased fatty-acid oxidation (FAO) and cell respiration and inhibited glycolysis. FAO, together with the decrease in protein translation and pyrimidine synthesis, was positively regulated through inhibition of the RagB-mTORC1 pathway, whereas the effect on glycolysis was RagB-mTORC1 independent. As FAO has been suggested to have a pro-survival function in leukemic cells, we tested its contribution to cell survival following ASNase treatment. Pharmacological inhibition of FAO significantly increased the sensitivity of ALL cells to ASNase. Moreover, constitutive activation of the mammalian target of rapamycin pathway increased apoptosis in leukemic cells treated with ASNase, but did not increase FAO. Our study uncovers a novel therapeutic option based on the combination of ASNase and FAO inhibitors.

Identification of the anti-tumor activity and mechanisms of nuciferine through a network pharmacology approach

PubMed Central

Qi, Quan; Li, Rui; Li, Hui-ying; Cao, Yu-bing; Bai, Ming; Fan, Xiao-jing; Wang, Shu-yan; Zhang, Bo; Li, Shao

2016-01-01

Aim: Nuciferine is an aporphine alkaloid extracted from lotus leaves, which is a raw material in Chinese medicinal herb for weight loss. In this study we used a network pharmacology approach to identify the anti-tumor activity of nuciferine and the underlying mechanisms. Methods: The pharmacological activities and mechanisms of nuciferine were identified through target profile prediction, clustering analysis and functional enrichment analysis using our traditional Chinese medicine (TCM) network pharmacology platform. The anti-tumor activity of nuciferine was validated by in vitro and in vivo experiments. The anti-tumor mechanisms of nuciferine were predicted through network target analysis and verified by in vitro experiments. Results: The nuciferine target profile was enriched with signaling pathways and biological functions, including “regulation of lipase activity”, “response to nicotine” and “regulation of cell proliferation”. Target profile clustering results suggested that nuciferine to exert anti-tumor effect. In experimental validation, nuciferine (0.8 mg/mL) markedly inhibited the viability of human neuroblastoma SY5Y cells and mouse colorectal cancer CT26 cells in vitro, and nuciferine (0.05 mg/mL) significantly suppressed the invasion of 6 cancer cell lines in vitro. Intraperitoneal injection of nuciferine (9.5 mg/mL, ip, 3 times a week for 3 weeks) significantly decreased the weight of SY5Y and CT26 tumor xenografts in nude mice. Network target analysis and experimental validation in SY5Y and CT26 cells showed that the anti-tumor effect of nuciferine was mediated through inhibiting the PI3K-AKT signaling pathway and IL-1 levels in SY5Y and CT26 cells. Conclusion: By using a TCM network pharmacology method, nuciferine is identified as an anti-tumor agent against human neuroblastoma and mouse colorectal cancer in vitro and in vivo, through inhibiting the PI3K-AKT signaling pathways and IL-1 levels. PMID:27180984

The pharmacology of amphetamine and methylphenidate: Relevance to the neurobiology of attention-deficit/hyperactivity disorder and other psychiatric comorbidities.

PubMed

Faraone, Stephen V

2018-04-01

Psychostimulants, including amphetamines and methylphenidate, are first-line pharmacotherapies for individuals with attention-deficit/hyperactivity disorder (ADHD). This review aims to educate physicians regarding differences in pharmacology and mechanisms of action between amphetamine and methylphenidate, thus enhancing physician understanding of psychostimulants and their use in managing individuals with ADHD who may have comorbid psychiatric conditions. A systematic literature review of PubMed was conducted in April 2017, focusing on cellular- and brain system-level effects of amphetamine and methylphenidate. The primary pharmacologic effect of both amphetamine and methylphenidate is to increase central dopamine and norepinephrine activity, which impacts executive and attentional function. Amphetamine actions include dopamine and norepinephrine transporter inhibition, vesicular monoamine transporter 2 (VMAT-2) inhibition, and monoamine oxidase activity inhibition. Methylphenidate actions include dopamine and norepinephrine transporter inhibition, agonist activity at the serotonin type 1A receptor, and redistribution of the VMAT-2. There is also evidence for interactions with glutamate and opioid systems. Clinical implications of these actions in individuals with ADHD with comorbid depression, anxiety, substance use disorder, and sleep disturbances are discussed. Copyright © 2018 The Author. Published by Elsevier Ltd.. All rights reserved.

Study on extraction process and activity of plant polysaccharides

NASA Astrophysics Data System (ADS)

Ma, Xiaogen; Wang, Xiaojing; Fan, Shuangli; Chen, Jiezhong

2017-10-01

Recent studies have shown that plant polysaccharides have many pharmacological activities, such as hypoglycemic, anti-inflammatory and tumor inhibition. The pharmacological activities of plant polysaccharides were summarized. The extraction methods of plant polysaccharides were discussed. Finally, the extraction process of Herba Taraxaci polysaccharides was optimized by ultrasonic assisted extraction. Through single factor experiments and orthogonal experiment to optimize the optimum extraction process from dandelion polysaccharide, optimum conditions of dandelion root polysaccharide by ultrasonic assisted extraction method for ultrasonic power 320W, temperature 80°C, extraction time 40min, can get higher dandelion polysaccharide extract.

Pharmacological characterization and chemical fractionation of a liposterolic extract of saw palmetto (Serenoa repens): effects on rat prostate contractility.

PubMed

Chua, Thiam; Eise, Nicole T; Simpson, Jamie S; Ventura, Sabatino

2014-03-14

Saw palmetto (Serenoa repens) was first used medicinally by native American Indians to treat urological disorders. Nowadays, saw palmetto extracts are widely used in Europe and North America to treat the urinary symptoms associated with benign prostatic hyperplasia even though its mechanisms of action are poorly understood. This study aimed to characterize the bioactive constituents of a lipid extract of saw palmetto that are able to affect contractility of the rat prostate gland. The mechanism of action will also be investigated. A commercially available lipid extract of saw palmetto was subjected to fractionation using normal phase column chromatography. Composition of fractions was assessed by proton nuclear magnetic resonance spectroscopy ((1)H NMR) and mass spectrometry (MS). Contractile activities of these fractions were evaluated pharmacologically using isolated preparations of rat prostate gland and compared to the activity of the crude extract. Saw palmetto extract inhibited contractions of the rat prostate gland which were consistent with smooth muscle relaxant activity. Only the ethyl acetate fraction resulting from chromatography inhibited contractions of isolated rat prostates similarly to the inhibition produced by the crude lipid extract. Comparison with authentic samples and analysis of NMR data revealed that this bioactivity was due to the fatty acid components present in the ethyl acetate fraction. Bioassay using various pharmacological tools identified multiple contractile mechanisms which were affected by the bioactive constituents. A fatty acid component of saw palmetto extract causes inhibition of prostatic smooth muscle contractions via a non-specific mechanism. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

A highly soluble matrix metalloproteinase-9 inhibitor for potential treatment of dry eye syndrome.

PubMed

Mori, Mattia; De Lorenzo, Emanuele; Torre, Eugenio; Fragai, Marco; Nativi, Cristina; Luchinat, Claudio; Arcangeli, Annarosa

2012-11-01

Dry eye syndrome (DES) or keratoconjunctivitis sicca is an eye disease caused by the chronic lack of lubrication and moisture of the eye. The pathogenesis of DES involves the over-expression and over-activity of corneal Matrix Metalloproteinase 9 (MMP-9). We propose herein a new, non-symptomatic approach for the treatment of DES based on the inhibition of MMP-9 by a new highly soluble molecule, designed as PES_103 that has been shown to inhibit MMP-9 both in vitro and in vivo. The efficacy of PES_103 in vivo and the potential benefits of this treatment in restoring tear production were studied in this work using an animal model of reduced lacrimation. PES_103 did not show any significant corneal toxicity. © 2012 The Authors Basic & Clinical Pharmacology & Toxicology © 2012 Nordic Pharmacological Society.

Cholinesterases, a target of pharmacology and toxicology.

PubMed

Pohanka, Miroslav

2011-09-01

Cholinesterases are a group of serine hydrolases that split the neurotransmitter acetylcholine (ACh) and terminate its action. Of the two types, butyrylcholinesterase and acetylcholinesterase (AChE), AChE plays the key role in ending cholinergic neurotransmission. Cholinesterase inhibitors are substances, either natural or man-made that interfere with the break-down of ACh and prolong its action. Hence their relevance to toxicology and pharmacology. The present review summarizes current knowledge of the cholinesterases and their inhibition. Particular attention is paid to the toxicology and pharmacology of cholinesterase-related inhibitors such as nerve agents (e.g. sarin, soman, tabun, VX), pesticides (e.g. paraoxon, parathion, malathion, malaoxon, carbofuran), selected plants and fungal secondary metabolites (e.g. aflatoxins), drugs for Alzheimer's disease (e.g. huperzine, metrifonate, tacrine, donepezil) and Myasthenia gravis (e.g. pyridostigmine) treatment and other compounds (propidium, ethidium, decamethonium). The crucial role of the cholinesterases in neural transmission makes them a primary target of a large number of cholinesterase-inhibiting drugs and toxins. In pharmacology, this has relevance to the treatment of neurodegenerative disorders.

Coffee inhibition of CYP3A4 in vitro was not translated to a grapefruit-like pharmacokinetic interaction clinically.

PubMed

Dresser, George K; Urquhart, Brad L; Proniuk, Julianne; Tieu, Alvin; Freeman, David J; Arnold, John Malcolm; Bailey, David G

2017-10-01

Grapefruit can augment oral medication bioavailability through irreversible (mechanism-based) inhibition of intestinal CYP3A4. Supplementary data from our recent coffee-drug interaction clinical study showed some subjects had higher area under the plasma drug concentration - time curve (AUC) and plasma peak drug concentration (Cmax) of the CYP3A4 probe felodipine compared to aqueous control. It was hypothesized that coffee might interact like grapefruit in responsive individuals. Beans from six geographical locations were consistently brewed into coffee that was separated chromatographically to a methanolic fraction for in vitro inhibition testing of CYP3A4 metabolism of felodipine at 1% coffee strength. The effect of simultaneous incubation and 10-min preincubation with coffee fractions determined whether coffee had direct and mechanism-based inhibitory activity. A subsequent five-way randomized balanced controlled crossover clinical study evaluated the clinical pharmacokinetic interaction with single-dose felodipine. Grapefruit juice, water, or three of the in vitro tested coffees were ingested at 300 mL alone 1 h before and then with felodipine. In vitro, all six coffees decreased felodipine metabolism for both simultaneous and preincubation exposure compared to corresponding control. Five coffees demonstrated mechanism-based inhibition. Grapefruit increased felodipine AUC 0-8 (25 vs. 13 ng.h/mL, P < 0.001) and Cmax (5.8 vs. 2.7 ng/mL, P < 0.001) and decreased dehydrofelodipine/felodipine AUC 0-8 ratio (0.84 vs. 1.29, P < 0.001), while the three coffees caused no change in these parameters compared to water. Despite high in vitro potency of CYP3A4 inhibition, the coffees did not cause a clinical pharmacokinetic interaction possibly from insufficient amount of inhibitor(s) in coffee reaching intestinal CYP3A4 during the absorption phase of felodipine. The results of this study highlight the need for follow-up clinical testing when in vitro results indicate the possibility of an interaction. © 2017 The Authors. Pharmacology Research & Perspectives published by John Wiley & Sons Ltd, British Pharmacological Society and American Society for Pharmacology and Experimental Therapeutics.

PDE-4 Inhibition Rescues Aberrant Synaptic Plasticity in Drosophila and Mouse Models of Fragile X Syndrome

PubMed Central

Choi, Catherine H.; Schoenfeld, Brian P.; Weisz, Eliana D.; Bell, Aaron J.; Chambers, Daniel B.; Hinchey, Joseph; Choi, Richard J.; Hinchey, Paul; Kollaros, Maria; Gertner, Michael J.; Ferrick, Neal J.; Terlizzi, Allison M.; Yohn, Nicole; Koenigsberg, Eric; Liebelt, David A.; Zukin, R. Suzanne; Woo, Newton H.; Tranfaglia, Michael R.; Louneva, Natalia; Arnold, Steven E.; Siegel, Steven J.

2015-01-01

Fragile X syndrome (FXS) is the leading cause of both intellectual disability and autism resulting from a single gene mutation. Previously, we characterized cognitive impairments and brain structural defects in a Drosophila model of FXS and demonstrated that these impairments were rescued by treatment with metabotropic glutamate receptor (mGluR) antagonists or lithium. A well-documented biochemical defect observed in fly and mouse FXS models and FXS patients is low cAMP levels. cAMP levels can be regulated by mGluR signaling. Herein, we demonstrate PDE-4 inhibition as a therapeutic strategy to ameliorate memory impairments and brain structural defects in the Drosophila model of fragile X. Furthermore, we examine the effects of PDE-4 inhibition by pharmacologic treatment in the fragile X mouse model. We demonstrate that acute inhibition of PDE-4 by pharmacologic treatment in hippocampal slices rescues the enhanced mGluR-dependent LTD phenotype observed in FXS mice. Additionally, we find that chronic treatment of FXS model mice, in adulthood, also restores the level of mGluR-dependent LTD to that observed in wild-type animals. Translating the findings of successful pharmacologic intervention from the Drosophila model into the mouse model of FXS is an important advance, in that this identifies and validates PDE-4 inhibition as potential therapeutic intervention for the treatment of individuals afflicted with FXS. PMID:25568131

Glucose Transporter 1–Dependent Glycolysis Is Increased during Aging-Related Lung Fibrosis, and Phloretin Inhibits Lung Fibrosis

PubMed Central

Cho, Soo Jung; Moon, Jong-Seok; Lee, Chang-Min; Choi, Augustine M. K.

2017-01-01

Aging is associated with metabolic diseases such as type 2 diabetes mellitus, cardiovascular disease, cancer, and neurodegeneration. Aging contributes to common processes including metabolic dysfunction, DNA damage, and reactive oxygen species generation. Although glycolysis has been linked to cell growth and proliferation, the mechanisms by which the activation of glycolysis by aging regulates fibrogenesis in the lung remain unclear. The objective of this study was to determine if glucose transporter 1 (GLUT1)–induced glycolysis regulates age-dependent fibrogenesis of the lung. Mouse and human lung tissues were analyzed for GLUT1 and glycolytic markers using immunoblotting. Glycolytic function was measured using a Seahorse apparatus. To study the effect of GLUT1, genetic inhibition of GLUT1 was performed by short hairpin RNA transduction, and phloretin was used for pharmacologic inhibition of GLUT1. GLUT1-dependent glycolysis is activated in aged lung. Genetic and pharmacologic inhibition of GLUT1 suppressed the protein expression of α-smooth muscle actin, a key cytoskeletal component of activated fibroblasts, in mouse primary lung fibroblast cells. Moreover, we demonstrated that the activation of AMP-activated protein kinase, which is regulated by GLUT1-dependent glycolysis, represents a critical metabolic pathway for fibroblast activation. Furthermore, we demonstrated that phloretin, a potent inhibitor of GLUT1, significantly inhibited bleomycin-induced lung fibrosis in vivo. These results suggest that GLUT1-dependent glycolysis regulates fibrogenesis in aged lung and that inhibition of GLUT1 provides a potential target of therapy of age-related lung fibrosis. PMID:27997810

Glucose Transporter 1-Dependent Glycolysis Is Increased during Aging-Related Lung Fibrosis, and Phloretin Inhibits Lung Fibrosis.

PubMed

Cho, Soo Jung; Moon, Jong-Seok; Lee, Chang-Min; Choi, Augustine M K; Stout-Delgado, Heather W

2017-04-01

Aging is associated with metabolic diseases such as type 2 diabetes mellitus, cardiovascular disease, cancer, and neurodegeneration. Aging contributes to common processes including metabolic dysfunction, DNA damage, and reactive oxygen species generation. Although glycolysis has been linked to cell growth and proliferation, the mechanisms by which the activation of glycolysis by aging regulates fibrogenesis in the lung remain unclear. The objective of this study was to determine if glucose transporter 1 (GLUT1)-induced glycolysis regulates age-dependent fibrogenesis of the lung. Mouse and human lung tissues were analyzed for GLUT1 and glycolytic markers using immunoblotting. Glycolytic function was measured using a Seahorse apparatus. To study the effect of GLUT1, genetic inhibition of GLUT1 was performed by short hairpin RNA transduction, and phloretin was used for pharmacologic inhibition of GLUT1. GLUT1-dependent glycolysis is activated in aged lung. Genetic and pharmacologic inhibition of GLUT1 suppressed the protein expression of α-smooth muscle actin, a key cytoskeletal component of activated fibroblasts, in mouse primary lung fibroblast cells. Moreover, we demonstrated that the activation of AMP-activated protein kinase, which is regulated by GLUT1-dependent glycolysis, represents a critical metabolic pathway for fibroblast activation. Furthermore, we demonstrated that phloretin, a potent inhibitor of GLUT1, significantly inhibited bleomycin-induced lung fibrosis in vivo. These results suggest that GLUT1-dependent glycolysis regulates fibrogenesis in aged lung and that inhibition of GLUT1 provides a potential target of therapy of age-related lung fibrosis.

Novel pharmacological targets for the rhythm control management of atrial fibrillation.

PubMed

Burashnikov, Alexander; Antzelevitch, Charles

2011-12-01

Atrial fibrillation (AF) is a growing clinical problem associated with increased morbidity and mortality. Development of safe and effective pharmacological treatments for AF is one of the greatest unmet medical needs facing our society. In spite of significant progress in non-pharmacological AF treatments (largely due to the use of catheter ablation techniques), anti-arrhythmic agents (AADs) remain first line therapy for rhythm control management of AF for most AF patients. When considering efficacy, safety and tolerability, currently available AADs for rhythm control of AF are less than optimal. Ion channel inhibition remains the principal strategy for termination of AF and prevention of its recurrence. Practical clinical experience indicates that multi-ion channel blockers are generally more optimal for rhythm control of AF compared to ion channel-selective blockers. Recent studies suggest that atrial-selective sodium channel block can lead to safe and effective suppression of AF and that concurrent inhibition of potassium ion channels may potentiate this effect. An important limitation of the ion channel block approach for AF treatment is that non-electrical factors (largely structural remodeling) may importantly determine the generation of AF, so that "upstream therapy", aimed at preventing or reversing structural remodeling, may be required for effective rhythm control management. This review focuses on novel pharmacological targets for the rhythm control management of AF. Copyright © 2011 Elsevier Inc. All rights reserved.

Role of hyperforin in the pharmacological activities of St. John's Wort.

PubMed

Zanoli, Paola

2004-01-01

The phloroglucinol derivative hyperforin has been recently shown to be a major antidepressant component in the extract of Hypericum perforatum. Experimental studies clearly demonstrated its activity in different behavioral models of depression. Moreover clinical studies linked the therapeutic efficacy of Hypericum extracts to their hyperforin content, in a dose-dependent manner. The molecular mechanism of action of hyperforin is still under investigation. Hyperforin has been shown to inhibit, like conventional antidepressants, the neuronal uptake of serotonin, norepinephrine and dopamine. However, hyperforin inhibits also the uptake of gamma-aminobutyric acid (GABA) and L-glutamate. The uptake inhibition by hyperforin does not involve specific binding sites at the transporter molecules; its mechanism of action seems to be related to sodium conductive pathways, leading to an elevation in intracellular Na(+) concentration. Other additional mechanisms of action of hyperforin, involving ionic conductances as well synaptosomal and vesicular function, have been suggested. In addition to its antidepressant activity, hyperforin has many other pharmacological effects in vivo (anxiolytic-like, cognition-enhancing effects) and in vitro (antioxidant, anticyclooxygenase-1, and anticarcinogenic effects). These effects could be of clinical importance. On the other hand, the role of hyperforin in the pharmacological interactions occurring during Hypericum extract therapy must be fully investigated. Hyperforin seems to be responsible for the induction of liver cytochrome oxidase enzymes and intestinal P-glycoprotein. Several pharmacokinetic studies performed in rats and humans demonstrated oral bioavailability of hyperforin from Hypericum extract. Only recently a new chromatographic method for detection of hyperforin in the brain tissue has been developed and validated. Taking into account the chemical instability of hyperforin, current efforts are directed to the synthesis of new neuroactive derivatives.

Pharmacological inhibition of PI3K reduces adiposity and metabolic syndrome in obese mice and rhesus monkeys.

PubMed

Ortega-Molina, Ana; Lopez-Guadamillas, Elena; Mattison, Julie A; Mitchell, Sarah J; Muñoz-Martin, Maribel; Iglesias, Gema; Gutierrez, Vincent M; Vaughan, Kelli L; Szarowicz, Mark D; González-García, Ismael; López, Miguel; Cebrián, David; Martinez, Sonia; Pastor, Joaquin; de Cabo, Rafael; Serrano, Manuel

2015-04-07

Genetic inhibition of PI3K signaling increases energy expenditure, protects from obesity and metabolic syndrome, and extends longevity. Here, we show that two pharmacological inhibitors of PI3K, CNIO-PI3Ki and GDC-0941, decrease the adiposity of obese mice without affecting their lean mass. Long-term treatment of obese mice with low doses of CNIO-PI3Ki reduces body weight until reaching a balance that is stable for months as long as the treatment continues. CNIO-PI3Ki treatment also ameliorates liver steatosis and decreases glucose serum levels. The above observations have been recapitulated in independent laboratories and using different oral formulations of CNIO-PI3Ki. Finally, daily oral treatment of obese rhesus monkeys for 3 months with low doses of CNIO-PI3Ki decreased their adiposity and lowered their serum glucose levels, in the absence of detectable toxicities. Therefore, pharmacological inhibition of PI3K is an effective and safe anti-obesity intervention that could reverse the negative effects of metabolic syndrome in humans. Copyright © 2015 Elsevier Inc. All rights reserved.

Pharmacological inhibition of feline immunodeficiency virus (FIV).

PubMed

Mohammadi, Hakimeh; Bienzle, Dorothee

2012-05-01

Feline immunodeficiency virus (FIV) is a member of the retroviridae family of viruses and causes an acquired immunodeficiency syndrome (AIDS) in domestic and non-domestic cats worldwide. Genome organization of FIV and clinical characteristics of the disease caused by the virus are similar to those of human immunodeficiency virus (HIV). Both viruses infect T lymphocytes, monocytes and macrophages, and their replication cycle in infected cells is analogous. Due to marked similarity in genomic organization, virus structure, virus replication and disease pathogenesis of FIV and HIV, infection of cats with FIV is a useful tool to study and develop novel drugs and vaccines for HIV. Anti-retroviral drugs studied extensively in HIV infection have targeted different steps of the virus replication cycle: (1) inhibition of virus entry into susceptible cells at the level of attachment to host cell surface receptors and co-receptors; (2) inhibition of fusion of the virus membrane with the cell membrane; (3) blockade of reverse transcription of viral genomic RNA; (4) interruption of nuclear translocation and viral DNA integration into host genomes; (5) prevention of viral transcript processing and nuclear export; and (6) inhibition of virion assembly and maturation. Despite much success of anti-retroviral therapy slowing disease progression in people, similar therapy has not been thoroughly investigated in cats. In this article we review current pharmacological approaches and novel targets for anti-lentiviral therapy, and critically assess potentially suitable applications against FIV infection in cats.

Pharmacological inhibition of soluble epoxide hydrolase ameliorates diet-induced metabolic syndrome in rats.

PubMed

Iyer, Abishek; Kauter, Kathleen; Alam, Md Ashraful; Hwang, Sung Hee; Morisseau, Christophe; Hammock, Bruce D; Brown, Lindsay

2012-01-01

The signs of metabolic syndrome following chronic excessive macronutrient intake include body weight gain, excess visceral adipose deposition, hyperglycaemia, glucose and insulin intolerances, hypertension, dyslipidaemia, endothelial damage, cardiovascular hypertrophy, inflammation, ventricular contractile dysfunction, fibrosis, and fatty liver disease. Recent studies show increased activity of soluble epoxide hydrolase (sEH) during obesity and metabolic dysfunction. We have tested whether sEH inhibition has therapeutic potential in a rat model of diet-induced metabolic syndrome. In these high-carbohydrate, high-fat-fed rats, chronic oral treatment with trans-4-[4-(3-adamantan-1-ylureido)-cyclohexyloxy]-benzoic acid (t-AUCB), a potent sEH inhibitor, alleviated the signs of metabolic syndrome in vivo including glucose, insulin, and lipid abnormalities, changes in pancreatic structure, increased systolic blood pressure, cardiovascular structural and functional abnormalities, and structural and functional changes in the liver. The present study describes the pharmacological responses to this selective sEH inhibitor in rats with the signs of diet-induced metabolic syndrome.

In Vivo Selection of Transplanted Hepatocytes by Pharmacological Inhibition of Fumarylacetoacetate Hydrolase in Wild-type Mice

PubMed Central

Paulk, Nicole K; Wursthorn, Karsten; Haft, Annelise; Pelz, Carl; Clarke, Gregory; Newell, Amy H; Olson, Susan B; Harding, Cary O; Finegold, Milton J; Bateman, Raymond L; Witte, John F; McClard, Ronald; Grompe, Markus

2012-01-01

Genetic fumarylacetoacetate hydrolase (Fah) deficiency is unique in that healthy gene-corrected hepatocytes have a strong growth advantage and can repopulate the diseased liver. Unfortunately, similar positive selection of gene-corrected cells is absent in most inborn errors of liver metabolism and it is difficult to reach the cell replacement index required for therapeutic benefit. Therefore, methods to transiently create a growth advantage for genetically modified hepatocytes in any genetic background would be advantageous. To mimic the selective pressure of Fah deficiency in normal animals, an efficient in vivo small molecule inhibitor of FAH, 4-[(2-carboxyethyl)-hydroxyphosphinyl]-3-oxobutyrate (CEHPOBA) was developed. Microarray analysis demonstrated that pharmacological inhibition of FAH produced highly similar gene expression changes to genetic deficiency. As proof of principle, hepatocytes lacking homogentisic acid dioxygenase (Hgd) and hence resistant to FAH inhibition were transplanted into sex-mismatched wild-type recipients. Time course analyses of 4–6 weeks of CEHPOBA administration after transplantation showed a linear relationship between treatment length and replacement index. Compared to controls, recipients treated with the FAH-inhibitor had 20–100-fold increases in liver repopulation. We conclude that pharmacological inhibition of FAH is a promising approach to in vivo selection of hepatocytes. PMID:22871666

Experimental public speaking: contributions to the understanding of the serotonergic modulation of fear.

PubMed

Garcia-Leal, Cybele; Graeff, Frederico Guilherme; Del-Ben, Cristina Marta

2014-10-01

Public speaking is widely used as a model of experimental fear and anxiety. This review aimed to evaluate the effects of pharmacological challenges on public speaking responses and their implications for the understanding of the neurobiology of normal and pathological anxiety, specifically panic disorder. We also describe methodological features of experimental paradigms using public speaking as an inducer of fear and stress. Public speaking is a potent stressor that can provoke significant subjective and physiological responses. However, variations in the manners in which public speaking is modelled can lead to different responses that need to be considered when interpreting the results. Results from pharmacological studies with healthy volunteers submitted to simulated public speaking tests have similarities with the pharmacological responses of panic patients observed in clinical practice and panic patients differ from controls in the response to the public speaking test. These data are compatible with the Deakin and Graeff hypothesis that serotonin inhibits fear, as accessed by public speaking tasks, and that this inhibition is likely related to the actions of serotonin in the dorsal periaqueductal grey matter. Copyright © 2014 Elsevier Ltd. All rights reserved.

Regulation of the nitric oxide oxidase activity of myeloperoxidase by pharmacological agents.

PubMed

Maiocchi, Sophie L; Morris, Jonathan C; Rees, Martin D; Thomas, Shane R

2017-07-01

The leukocyte-derived heme enzyme myeloperoxidase (MPO) is released extracellularly during inflammation and impairs nitric oxide (NO) bioavailability by directly oxidizing NO or producing NO-consuming substrate radicals. Here, structurally diverse pharmacological agents with activities as MPO substrates/inhibitors or antioxidants were screened for their effects on MPO NO oxidase activity in human plasma and physiological model systems containing endogenous MPO substrates/antioxidants (tyrosine, urate, ascorbate). Hydrazide-based irreversible/reversible MPO inhibitors (4-ABAH, isoniazid) or the sickle cell anaemia drug, hydroxyurea, all promoted MPO NO oxidase activity. This involved the capacity of NO to antagonize MPO inhibition by hydrazide-derived radicals and/or the ability of drug-derived radicals to stimulate MPO turnover thereby increasing NO consumption by MPO redox intermediates or NO-consuming radicals. In contrast, the mechanism-based irreversible MPO inhibitor 2-thioxanthine, potently inhibited MPO turnover and NO consumption. Although the phenolics acetaminophen and resveratrol initially increased MPO turnover and NO consumption, they limited the overall extent of NO loss by rapidly depleting H 2 O 2 and promoting the formation of ascorbyl radicals, which inefficiently consume NO. The vitamin E analogue trolox inhibited MPO NO oxidase activity in ascorbate-depleted fluids by scavenging NO-consuming tyrosyl and urate radicals. Tempol and related nitroxides decreased NO consumption in ascorbate-replete fluids by scavenging MPO-derived ascorbyl radicals. Indoles or apocynin yielded marginal effects. Kinetic analyses rationalized differences in drug activities and identified criteria for the improved inhibition of MPO NO oxidase activity. This study reveals that widely used agents have important implications for MPO NO oxidase activity under physiological conditions, highlighting new pharmacological strategies for preserving NO bioavailability during inflammation. Copyright © 2017 Elsevier Inc. All rights reserved.

AMPK and SIRT1 activation contribute to inhibition of neuroinflammation by thymoquinone in BV2 microglia.

PubMed

Velagapudi, Ravikanth; El-Bakoush, Abdelmeneim; Lepiarz, Izabela; Ogunrinade, Folashade; Olajide, Olumayokun A

2017-11-01

Thymoquinone is a known inhibitor of neuroinflammation. However, the mechanism(s) involved in its action remain largely unknown. In this study, we investigated the roles of cellular reactive oxygen species (ROS), 5' AMP-activated protein kinase (AMPK) and sirtuin 1 (SIRT1) in the anti-neuroinflammatory activity of thymoquinone. We investigated effects of the compound on ROS generation in LPS-activated microglia using the fluorescent 2',7'-dichlorofluorescin diacetate (DCFDA)-cellular ROS detection. Immunoblotting was used to detect protein levels of p40 phox , gp91 phox , AMPK, LKB1 and SIRT1. Additionally, ELISA and immunofluorescence were used to detect nuclear accumulation of SIRT1. NAD + /NADH assay was also performed. The roles of AMPK and SIRT1 in anti-inflammatory activity of thymoquinone were investigated using RNAi and pharmacological inhibition. Our results show that thymoquinone reduced cellular ROS generation, possibly through inhibition of p40 phox and gp91 phox protein. Treatment of BV2 microglia with thymoquinone also resulted in elevation in the levels of LKB1 and phospho-AMPK proteins. We further observed that thymoquinone reduced cytoplasmic levels and increased nuclear accumulation of SIRT1 protein and increased levels of NAD + . Results also show that the anti-inflammatory activity of thymoquinone was abolished when the expressions of AMPK and SIRT1 were suppressed by RNAi or pharmacological antagonists. Pharmacological antagonism of AMPK reversed thymoquinone-induced increase in SIRT1. Taken together, we propose that thymoquinone inhibits cellular ROS generation in LPS-activated BV2 microglia. It is also suggested that activation of both AMPK and NAD + /SIRT1 may contribute to the anti-inflammatory, but not antioxidant activity of the compound in BV2 microglia.

Role of Spm-Cer-S1P signalling pathway in MMP-2 mediated U46619-induced proliferation of pulmonary artery smooth muscle cells: protective role of epigallocatechin-3-gallate.

PubMed

Chowdhury, Animesh; Sarkar, Jaganmay; Chakraborti, Tapati; Chakraborti, Sajal

2015-10-01

During remodelling of pulmonary artery, marked proliferation of pulmonary artery smooth muscle cells (PASMCs) occurs, which contributes to pulmonary hypertension. Thromboxane A2 (TxA2) has been shown to produce pulmonary hypertension. The present study investigates the inhibitory effect of epigallocatechin-3-gallate (EGCG) on the TxA2 mimetic, U46619-induced proliferation of PASMCs. U46619 at a concentration of 10 nM induces maximum proliferation of bovine PASMCs. Both pharmacological and genetic inhibitors of p(38)MAPK, NF-κB and MMP-2 significantly inhibit U46619-induced cell proliferation. EGCG markedly abrogate U46619-induced p(38)MAPK phosphorylation, NF-κB activation, proMMP-2 expression and activation, and also the cell proliferation. U46619 causes an increase in the activation of sphingomyelinase (SMase) and sphingosine kinase (SPHK) and also increase sphingosine 1 phosphate (S1P) level. U46619 also induces phosphorylation of ERK1/2, which phosphorylates SPHK leading to an increase in S1P level. Both pharmacological and genetic inhibitors of SMase and SPHK markedly inhibit U46619-induced cell proliferation. Additionally, pharmacological and genetic inhibitors of MMP-2 markedly abrogate U46619-induced SMase activity and S1P level. EGCG markedly inhibit U46619-induced SMase activity, ERK1/2 and SPHK phosphorylation and S1P level in the cells. Overall, Sphingomyeline-Ceramide-Sphingosine-1-phosphate (Spm-Cer-S1P) signalling axis plays an important role in MMP-2 mediated U46619-induced proliferation of PASMCs. Importantly, EGCG inhibits U46619 induced increase in MMP-2 activation by modulating p(38)MAPK-NFκB pathway and subsequently prevents the cell proliferation. Copyright © 2015 John Wiley & Sons, Ltd.

Arzanol, a Potent mPGES-1 Inhibitor: Novel Anti-Inflammatory Agent

PubMed Central

Kothavade, Pankaj S.; Nagmoti, Dnyaneshwar M.; Bulani, Vipin D.; Juvekar, Archana R.

2013-01-01

Arzanol is a novel phloroglucinol α-pyrone, isolated from a Mediterranean plant Helichrysum italicum (Roth) Don ssp. microphyllum which belongs to the family Asteraceae. Arzanol has been reported to possess a variety of pharmacological activities. However, anti-inflammatory, anti-HIV, and antioxidant activities have been studied in some detail. Arzanol has been reported to inhibit inflammatory transcription factor NFκB activation, HIV replication in T cells, releases of IL-1β, IL-6, IL-8, and TNF-α, and biosynthesis of PGE2 by potentially inhibiting mPGES-1 enzyme. Diversity of mechanisms of actions of arzanol may be useful in treatment of disease involving these inflammatory mediators such as autoimmune diseases and cancer. This review presents comprehensive information on the chemistry, structure-activity relationship, and pharmacological activities of arzanol. In addition this review discusses recent developments and the scope for future research in these aspects. PMID:24198734

Pharmacological cdk inhibitor R-Roscovitine suppresses JC virus proliferation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Orba, Yasuko; Laboratory of Molecular and Cellular Pathology, Hokkaido University Graduate School of Medicine, N15, W7, Kita-ku, 060-8638, Sapporo; Research Fellow of the Japan Society for the Promotion of Science

2008-01-05

The human Polyomavirus JC virus (JCV) utilizes cellular proteins for viral replication and transcription in the host cell nucleus. These cellular proteins represent potential targets for antiviral drugs against the JCV. In this study, we examined the antiviral effects of the pharmacological cyclin-dependent kinase (cdk) inhibitor R-Roscovitine, which has been shown to have antiviral activity against other viruses. We found that Roscovitine significantly inhibited the viral production and cytopathic effects of the JCV in a JCV-infected cell line. Roscovitine attenuated the transcriptional activity of JCV late genes, but not early genes, and also prevented viral replication via inhibiting phosphorylation ofmore » the viral early protein, large T antigen. These data suggest that the JCV requires cdks to transcribe late genes and to replicate its own DNA. That Roscovitine exhibited antiviral activity in JCV-infected cells suggests that Roscovitine might have therapeutic utility in the treatment of progressive multifocal leukoencephalopathy (PML)« less

Fetal muscle-type nicotinic acetylcholine receptor activation in TE-671 cells and inhibition of fetal movement in a day 40 pregnant goat model by optical isomers of the piperidine alkaloid coniine.

PubMed

Green, Benedict T; Lee, Stephen T; Welch, Kevin D; Pfister, James A; Panter, Kip E

2013-01-01

Coniine is an optically active toxic piperidine alkaloid and nicotinic acetylcholine receptor (nAChR) agonist found in poison hemlock (Conium maculatum L.). Coniine teratogenicity is hypothesized to be attributable to the binding, activation, and prolonged desensitization of fetal muscle-type nAChR, which results in the complete inhibition of fetal movement. However, pharmacological evidence of coniine actions at fetal muscle-type nAChR is lacking. The present study compared (-)-coniine, (+)-coniine, and nicotine for the ability to inhibit fetal movement in a day 40 pregnant goat model and in TE-671 cells that express fetal muscle-type nAChR. Furthermore, α-conotoxins (CTx) EI and GI were used to antagonize the actions of (+)- and (-)-coniine in TE-671 cells. (-)-Coniine was more effective at eliciting electrical changes in TE-671 cells and inhibiting fetal movement than was (+)-coniine, suggesting stereoselectivity by the receptor. The pyridine alkaloid nicotine did not inhibit fetal movement in a day 40 pregnant goat model, suggesting agonist specificity for the inhibition of fetal movement. Low concentrations of both CTxs potentiated the TE-671 cell response and higher concentrations of CTx EI, and GI antagonized the actions of both coniine enantiomers demonstrating concentration-dependent coagonism and selective antagonism. These results provide pharmacological evidence that the piperidine alkaloid coniine is acting at fetal muscle-type nAChR in a concentration-dependent manner.

Disposition, Metabolism and Histone Deacetylase and Acetyltransferase Inhibition Activity of Tetrahydrocurcumin and Other Curcuminoids

PubMed Central

Novaes, Júlia T.; Sayre, Casey L.; Majeed, Muhammed; Ho, Emmanuel A.; Oliveira, Ana Luísa de P.; Martinez, Stephanie E.; Davies, Neal M.; Lakowski, Ted M.

2017-01-01

Tetrahydrocurcumin (THC), curcumin and calebin-A are curcuminoids found in turmeric (Curcuma longa). Curcuminoids have been established to have a variety of pharmacological activities and are used as natural health supplements. The purpose of this study was to identify the metabolism, excretion, antioxidant, anti-inflammatory and anticancer properties of these curcuminoids and to determine disposition of THC in rats after oral administration. We developed a UHPLC–MS/MS assay for THC in rat serum and urine. THC shows multiple redistribution phases with corresponding increases in urinary excretion rate. In-vitro antioxidant activity, histone deacetylase (HDAC) activity, histone acetyltransferase (HAT) activity and anti-inflammatory inhibitory activity were examined using commercial assay kits. Anticancer activity was determined in Sup-T1 lymphoma cells. Our results indicate THC was poorly absorbed after oral administration and primarily excreted via non-renal routes. All curcuminoids exhibited multiple pharmacological effects in vitro, including potent antioxidant activity as well as inhibition of CYP2C9, CYP3A4 and lipoxygenase activity without affecting the release of TNF-α. Unlike curcumin and calebin-A, THC did not inhibit HDAC1 and PCAF and displayed a weaker growth inhibition activity against Sup-T1 cells. We show evidence for the first time that curcumin and calebin-A inhibit HAT and PCAF, possibly through a Michael-addition mechanism. PMID:29023392

STAT3 balances myocyte hypertrophy vis-à-vis autophagy in response to Angiotensin II by modulating the AMPKα/mTOR axis.

PubMed

Chen, Lei; Zhao, Lin; Samanta, Anweshan; Mahmoudi, Seyed Morteza; Buehler, Tanner; Cantilena, Amy; Vincent, Robert J; Girgis, Magdy; Breeden, Joshua; Asante, Samuel; Xuan, Yu-Ting; Dawn, Buddhadeb

2017-01-01

Signal transducers and activators of transcription 3 (STAT3) is known to participate in various cardiovascular signal transduction pathways, including those responsible for cardiac hypertrophy and cytoprotection. However, the role of STAT3 signaling in cardiomyocyte autophagy remains unclear. We tested the hypothesis that Angiotensin II (Ang II)-induced cardiomyocyte hypertrophy is effected, at least in part, through STAT3-mediated inhibition of cellular autophagy. In H9c2 cells, Ang II treatment resulted in STAT3 activation and cellular hypertrophy in a dose-dependent manner. Ang II enhanced autophagy, albeit without impacting AMPKα/mTOR signaling or cellular ADP/ATP ratio. Pharmacologic inhibition of STAT3 with WP1066 suppressed Ang II-induced myocyte hypertrophy and mRNA expression of hypertrophy-related genes ANP and β-MHC. These molecular events were recapitulated in cells with STAT3 knockdown. Genetic or pharmacologic inhibition of STAT3 significantly increased myocyte ADP/ATP ratio and enhanced autophagy through AMPKα/mTOR signaling. Pharmacologic activation and inhibition of AMPKα attenuated and exaggerated, respectively, the effects of Ang II on ANP and β-MHC gene expression, while concomitant inhibition of STAT3 accentuated the inhibition of hypertrophy. Together, these data indicate that novel nongenomic effects of STAT3 influence myocyte energy status and modulate AMPKα/mTOR signaling and autophagy to balance the transcriptional hypertrophic response to Ang II stimulation. These findings may have significant relevance for various cardiovascular pathological processes mediated by Ang II signaling.

STAT3 balances myocyte hypertrophy vis-à-vis autophagy in response to Angiotensin II by modulating the AMPKα/mTOR axis

PubMed Central

Samanta, Anweshan; Mahmoudi, Seyed Morteza; Buehler, Tanner; Cantilena, Amy; Vincent, Robert J.; Girgis, Magdy; Breeden, Joshua; Asante, Samuel; Xuan, Yu-Ting

2017-01-01

Signal transducers and activators of transcription 3 (STAT3) is known to participate in various cardiovascular signal transduction pathways, including those responsible for cardiac hypertrophy and cytoprotection. However, the role of STAT3 signaling in cardiomyocyte autophagy remains unclear. We tested the hypothesis that Angiotensin II (Ang II)-induced cardiomyocyte hypertrophy is effected, at least in part, through STAT3-mediated inhibition of cellular autophagy. In H9c2 cells, Ang II treatment resulted in STAT3 activation and cellular hypertrophy in a dose-dependent manner. Ang II enhanced autophagy, albeit without impacting AMPKα/mTOR signaling or cellular ADP/ATP ratio. Pharmacologic inhibition of STAT3 with WP1066 suppressed Ang II-induced myocyte hypertrophy and mRNA expression of hypertrophy-related genes ANP and β-MHC. These molecular events were recapitulated in cells with STAT3 knockdown. Genetic or pharmacologic inhibition of STAT3 significantly increased myocyte ADP/ATP ratio and enhanced autophagy through AMPKα/mTOR signaling. Pharmacologic activation and inhibition of AMPKα attenuated and exaggerated, respectively, the effects of Ang II on ANP and β-MHC gene expression, while concomitant inhibition of STAT3 accentuated the inhibition of hypertrophy. Together, these data indicate that novel nongenomic effects of STAT3 influence myocyte energy status and modulate AMPKα/mTOR signaling and autophagy to balance the transcriptional hypertrophic response to Ang II stimulation. These findings may have significant relevance for various cardiovascular pathological processes mediated by Ang II signaling. PMID:28686615

Determining the pharmacological activity of Physalis peruviana fruit juice on rabbit eyes and fibroblast primary cultures.

PubMed

Pardo, Juan Manuel; Fontanilla, Marta Raquel; Ospina, Luis Fernando; Espinosa, Lady

2008-07-01

The pharmacologic activity of compounds isolated from Physalis peruviana has been demonstrated. The use of this fruit juice for treating pterygium has been reported in Colombian traditional medicine. However, studies demonstrating the fruit juice's pharmacologic activity when used in this disease have not been published to date. In the present study the anti-inflammatory and cytostatic activities of P. peruviana fruit juice in a rabbit eye inflammatory model were investigated. A novel rabbit eye inflammation model was developed for studying the juice's anti-inflammatory activity (based on an adaptation of the Draize test). Cytostatic activity was evaluated by measuring and comparing growth rates of cultured fibroblasts exposed and not exposed to various fruit juice concentrations. P. peruviana fruit juice exhibited a mild anti-inflammatory activity compared with methylprednisolone, a known anti-inflammatory drug. An interesting dose-dependent cytostatic effect on cultured fibroblasts was also established. The data found suggest that the P. peruviana fruit juice anti-pterygium effect described in traditional medicine may be related to its inhibiting fibroblast growth. The present study contributes to the pharmacologic knowledge regarding a remedy commonly used in Colombian traditional medicine.

PDE-4 inhibition rescues aberrant synaptic plasticity in Drosophila and mouse models of fragile X syndrome.

PubMed

Choi, Catherine H; Schoenfeld, Brian P; Weisz, Eliana D; Bell, Aaron J; Chambers, Daniel B; Hinchey, Joseph; Choi, Richard J; Hinchey, Paul; Kollaros, Maria; Gertner, Michael J; Ferrick, Neal J; Terlizzi, Allison M; Yohn, Nicole; Koenigsberg, Eric; Liebelt, David A; Zukin, R Suzanne; Woo, Newton H; Tranfaglia, Michael R; Louneva, Natalia; Arnold, Steven E; Siegel, Steven J; Bolduc, Francois V; McDonald, Thomas V; Jongens, Thomas A; McBride, Sean M J

2015-01-07

Fragile X syndrome (FXS) is the leading cause of both intellectual disability and autism resulting from a single gene mutation. Previously, we characterized cognitive impairments and brain structural defects in a Drosophila model of FXS and demonstrated that these impairments were rescued by treatment with metabotropic glutamate receptor (mGluR) antagonists or lithium. A well-documented biochemical defect observed in fly and mouse FXS models and FXS patients is low cAMP levels. cAMP levels can be regulated by mGluR signaling. Herein, we demonstrate PDE-4 inhibition as a therapeutic strategy to ameliorate memory impairments and brain structural defects in the Drosophila model of fragile X. Furthermore, we examine the effects of PDE-4 inhibition by pharmacologic treatment in the fragile X mouse model. We demonstrate that acute inhibition of PDE-4 by pharmacologic treatment in hippocampal slices rescues the enhanced mGluR-dependent LTD phenotype observed in FXS mice. Additionally, we find that chronic treatment of FXS model mice, in adulthood, also restores the level of mGluR-dependent LTD to that observed in wild-type animals. Translating the findings of successful pharmacologic intervention from the Drosophila model into the mouse model of FXS is an important advance, in that this identifies and validates PDE-4 inhibition as potential therapeutic intervention for the treatment of individuals afflicted with FXS. Copyright © 2015 the authors 0270-6474/15/350396-13$15.00/0.

Cloning, characterization and anion inhibition study of a β-class carbonic anhydrase from the caries producing pathogen Streptococcus mutans.

PubMed

Dedeoglu, Nurcan; De Luca, Viviana; Isik, Semra; Yildirim, Hatice; Kockar, Feray; Capasso, Clemente; Supuran, Claudiu T

2015-07-01

The oral pathogenic bacterium involved in human dental caries formation Streptococcus mutans, encodes for two carbonic anhydrase (CA, EC 4.2.1.1) one belonging to the α- and the other one to the β-class. This last enzyme (SmuCA) has been cloned, characterized and investigated for its inhibition profile with a major class of CA inhibitors, the inorganic anions. Here we show that SmuCA has a good catalytic activity for the CO2 hydration reaction, with kcat 4.2×10(5)s(-1) and kcat/Km of 5.8×10(7)M(-1)×s(-1), being inhibited by cyanate, carbonate, stannate, divannadate and diethyldithiocarbamate in the submillimolar range (KIs of 0.30-0.64mM) and more efficiently by sulfamide, sulfamate, phenylboronic acid and phenylarsonic acid (KIs of 15-46μM). The anion inhibition profile of the S. mutans enzyme is very different from other α- and β-CAs investigated earlier. Identification of effective inhibitors of this new enzyme may lead to pharmacological tools useful for understanding the role of S. mutans CAs in dental caries formation, and eventually the development of pharmacological agents with a new mechanism of antibacterial action. Copyright © 2015 Elsevier Ltd. All rights reserved.

Neutral endopeptidase knockout induces hyperalgesia in a model of visceral pain, an effect related to bradykinin and nitric oxide.

PubMed

Fischer, Hanspeter S; Zernig, Gerald; Hauser, Kurt F; Gerard, Craig; Hersh, Louis B; Saria, Alois

2002-01-01

Neutral endopeptidase (EC3.4.24.11, NEP, enkephalinase) is a zinc-metalloendopeptidase, cleaving a variety of substrates like enkephalins, substance P, and bradykinin. In the brain, NEP is a key enzyme in the degradation of enkephalins. Pharmacological inhibition of NEP-activity causes analgesia resulting from enhanced extracellular enkephalin concentrations. Recently, transgenic mice lacking the enzyme NEP have been developed (Lu, 1995). The present study was designed to investigate the nociceptive behavior of these NEP-knockout mice. Interestingly, NEP-deficient mice did not respond with decreased pain perception, but exhibited hyperalgesia in the hot-plate jump, warm-water tail-withdrawal, and mostnotablyin theacetic-acid writhing test. Inhibition of aminopeptidase N by bestatin reduced writhing in both strains, whereas NEP-inhibition by thiorphan reduced writhing selectively in wild-type mice. Naloxone increased writhing in wild-type but not in knockouts, whereas the bradykinin B2-receptor antagonist HOE140 reduced writhing selectively in NEP-knockouts. Similarly, the nitric oxide synthase inhibitor L-NAME reduced writhing in NEP-knockouts. These results indicate that genetic elimination of NEP, in contrast to pharmacological inhibition, leads to bradykinin-induced hyperalgesia instead of enkephalin-mediated analgesia. Nitric oxide (NO) is suggested to be involved in this process.

[Pharmacodynamic evaluation and molecular mechanism research of Huanshao capsule on irregular menstruation].

PubMed

Sun, Jian-Hui; Huo, Hai-Ru; Li, Xiao-Qin; Li, Hong-Mei; Qin, De-Huai; Wu, Chun

2018-04-01

Huanshao capsule is widely used in irregular menstruation and has achieved a good effect. Huanshao capsule can promote gonad development in mice, significantly improve the ovarian index in mice, increase estrogen level and reduce FSH level in rats, inhibit the pain response induced by oxytocin and estrogen, inhibit writhing reaction induced by acetic acid pain in mice. Due to the complexity of traditional Chinese medical formula, the pharmacological mechanism of the treatment on the irregular menstruation of the Huanshao capsule is unclear. In this study, the internet-based computation platform (www.tcmip.cn）was used to explore the molecular mechanism of Huanshao capsule on the menstrual. The aim of this study was to find the molecular mechanism of Huanshao capsule in treating menstrual. In the study of the molecular mechanism of Huanshao capsule in the treatment of menstrual by using the internet-based computation platform, Huanshao capsule maybe treat the menstrual by the pathway of endocrine system, GnRH signal transduction pathway, estrogen signal transduction pathway, oxytocin signaling pathway, thyroid hormone signaling pathway, VEGF signaling pathway, FCεRI signaling pathway and purine metabolism and nucleotide metabolism. The early pharmacological study confirmed Huanshao capsule could increase the serum estradiol level and decrease follicle stimulating hormone level and the traditional Chinese medicine pharmacology coincide with the prediction result of internet-based computation platform which roles as the pathway of GnRH signaling pathway and estrogen signal transduction pathway. Other pathway needs further experimental verification. Copyright© by the Chinese Pharmaceutical Association.

Testing the Role of p21-Activated Kinases in Schwannoma Formation Using a Novel Genetically Engineered Murine Model that Closely Phenocopies Human NF2 Disease

DTIC Science & Technology

2016-06-01

control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. The major goal of this research project was to genetically and pharmacologically ...with three different pharmacologic PAK inhibitors to determine if targeted PAK inhibition in a preclinical model of schwannoma genesis rescues tumor...this research project was to genetically and pharmacologically test the requirement of Group A PAK signaling in Nf2 deficient schwannoma genesis. We

Pharmacological inhibition of myostatin suppresses systemic inflammation and muscle atrophy in mice with chronic kidney disease

PubMed Central

Zhang, Liping; Rajan, Vik; Lin, Eugene; Hu, Zhaoyong; Han, H. Q.; Zhou, Xiaolan; Song, Yanping; Min, Hosung; Wang, Xiaonan; Du, Jie; Mitch, William E.

2011-01-01

Chronic kidney disease (CKD) and several other catabolic conditions are characterized by increased circulating inflammatory cytokines, defects in IGF-1 signaling, abnormal muscle protein metabolism, and progressive muscle atrophy. In these conditions, no reliable treatments successfully block the development of muscle atrophy. In mice with CKD, we found a 2- to 3-fold increase in myostatin expression in muscle. Its pharmacological inhibition by subcutaneous injections of an anti-myostatin peptibody into CKD mice (IC50 ∼1.2 nM) reversed the loss of body weight (≈5–7% increase in body mass) and muscle mass (∼10% increase in muscle mass) and suppressed circulating inflammatory cytokines vs. results from CKD mice injected with PBS. Pharmacological myostatin inhibition also decreased the rate of protein degradation (16.38±1.29%; P<0.05), increased protein synthesis in extensor digitorum longus muscles (13.21±1.09%; P<0.05), markedly enhanced satellite cell function, and improved IGF-1 intracellular signaling. In cultured muscle cells, TNF-α increased myostatin expression via a NF-κB-dependent pathway, whereas muscle cells exposed to myostatin stimulated IL-6 production via p38 MAPK and MEK1 pathways. Because IL-6 stimulates muscle protein breakdown, we conclude that CKD increases myostatin through cytokine-activated pathways, leading to muscle atrophy. Myostatin antagonism might become a therapeutic strategy for improving muscle growth in CKD and other conditions with similar characteristics.—Zhang, L., Rajan, V., Lin, E., Hu, Z., Han, H.Q., Zhou, X., Song, Y., Min, H., Wang, X., Du, J., Mitch, W. E. Pharmacological inhibition of myostatin suppresses systemic inflammation and muscle atrophy in mice with chronic kidney disease. PMID:21282204

Thiopental Inhibits Global Protein Synthesis by Repression of Eukaryotic Elongation Factor 2 and Protects from Hypoxic Neuronal Cell Death

PubMed Central

Schwer, Christian I.; Lehane, Cornelius; Guelzow, Timo; Zenker, Simone; Strosing, Karl M.; Spassov, Sashko; Erxleben, Anika; Heimrich, Bernd; Buerkle, Hartmut; Humar, Matjaz

2013-01-01

Ischemic and traumatic brain injury is associated with increased risk for death and disability. The inhibition of penumbral tissue damage has been recognized as a target for therapeutic intervention, because cellular injury evolves progressively upon ATP-depletion and loss of ion homeostasis. In patients, thiopental is used to treat refractory intracranial hypertension by reducing intracranial pressure and cerebral metabolic demands; however, therapeutic benefits of thiopental-treatment are controversially discussed. In the present study we identified fundamental neuroprotective molecular mechanisms mediated by thiopental. Here we show that thiopental inhibits global protein synthesis, which preserves the intracellular energy metabolite content in oxygen-deprived human neuronal SK-N-SH cells or primary mouse cortical neurons and thus ameliorates hypoxic cell damage. Sensitivity to hypoxic damage was restored by pharmacologic repression of eukaryotic elongation factor 2 kinase. Translational inhibition was mediated by calcium influx, activation of the AMP-activated protein kinase, and inhibitory phosphorylation of eukaryotic elongation factor 2. Our results explain the reduction of cerebral metabolic demands during thiopental treatment. Cycloheximide also protected neurons from hypoxic cell death, indicating that translational inhibitors may generally reduce secondary brain injury. In conclusion our study demonstrates that therapeutic inhibition of global protein synthesis protects neurons from hypoxic damage by preserving energy balance in oxygen-deprived cells. Molecular evidence for thiopental-mediated neuroprotection favours a positive clinical evaluation of barbiturate treatment. The chemical structure of thiopental could represent a pharmacologically relevant scaffold for the development of new organ-protective compounds to ameliorate tissue damage when oxygen availability is limited. PMID:24167567

Hypoxia induces arginase II expression and increases viable human pulmonary artery smooth muscle cell numbers via AMPKα1 signaling

PubMed Central

Xue, Jianjing; Nelin, Leif D.

2017-01-01

Pulmonary artery smooth muscle cell (PASMC) proliferation is one of the hallmark features of hypoxia-induced pulmonary hypertension. With only supportive treatment options available for this life-threatening disease, treating and preventing the proliferation of PASMCs is a viable therapeutic option. A key promoter of hypoxia-induced increases in the number of viable human PASMCs is arginase II, with attenuation of viable cell numbers following pharmacologic inhibition or siRNA knockdown of the enzyme. Additionally, increased levels of arginase have been demonstrated in the pulmonary vasculature of patients with pulmonary hypertension. The signaling pathways responsible for the hypoxic induction of arginase II in PASMCs, however, remain unknown. Hypoxia is a recognized activator of AMPK, which is known to be expressed in human PASMCs (hPASMCs). Activation of AMPK by hypoxia has been shown to promote cell survival in PASMCs. In addition, pharmacologic agents targeting AMPK have been shown to attenuate chronic hypoxia-induced pulmonary hypertension in animal models. The present studies tested the hypothesis that hypoxia-induced arginase II expression in hPASMCs is mediated through AMPK signaling. We found that pharmacologic inhibitors of AMPK, as well as siRNA knockdown of AMPKα1, prevented hypoxia-induced arginase II. The hypoxia-induced increase in viable hPASMC numbers was also prevented following both pharmacologic inhibition and siRNA knockdown of AMPK. Furthermore, we demonstrate that overexpression of AMPK induced arginase II protein expression and viable cells numbers in hPASMCs. PMID:28213467

ROS-dependent activation of JNK converts p53 into an efficient inhibitor of oncogenes leading to robust apoptosis

PubMed Central

Shi, Y; Nikulenkov, F; Zawacka-Pankau, J; Li, H; Gabdoulline, R; Xu, J; Eriksson, S; Hedström, E; Issaeva, N; Kel, A; Arnér, E S J; Selivanova, G

2014-01-01

Rescue of the p53 tumor suppressor is an attractive cancer therapy approach. However, pharmacologically activated p53 can induce diverse responses ranging from cell death to growth arrest and DNA repair, which limits the efficient application of p53-reactivating drugs in clinic. Elucidation of the molecular mechanisms defining the biological outcome upon p53 activation remains a grand challenge in the p53 field. Here, we report that concurrent pharmacological activation of p53 and inhibition of thioredoxin reductase followed by generation of reactive oxygen species (ROS), result in the synthetic lethality in cancer cells. ROS promote the activation of c-Jun N-terminal kinase (JNK) and DNA damage response, which establishes a positive feedback loop with p53. This converts the p53-induced growth arrest/senescence to apoptosis. We identified several survival oncogenes inhibited by p53 in JNK-dependent manner, including Mcl1, PI3K, eIF4E, as well as p53 inhibitors Wip1 and MdmX. Further, we show that Wip1 is one of the crucial executors downstream of JNK whose ablation confers the enhanced and sustained p53 transcriptional response contributing to cell death. Our study provides novel insights for manipulating p53 response in a controlled way. Further, our results may enable new pharmacological strategy to exploit abnormally high ROS level, often linked with higher aggressiveness in cancer, to selectively kill cancer cells upon pharmacological reactivation of p53. PMID:24413150

Characterization of fibroblasts from hypertrophied right ventricle of pulmonary hypertensive rats.

PubMed

Imoto, Keisuke; Okada, Muneyoshi; Yamawaki, Hideyuki

2018-06-02

Pulmonary arterial hypertension (PAH), which is characterized by an elevation of pulmonary arterial resistance, leads to a lethal right heart failure. It is an urgent issue to clarify the pathogenesis of PAH-induced right heart failure. The present study aimed to elucidate the characteristics of cardiac fibroblasts (CFs) isolated from hypertrophied right ventricles of monocrotaline (MCT)-induced PAH model rats. CFs were isolated from the right ventricles of MCT-injected rats (MCT-CFs) and saline-injected control rats (CONT-CFs). Expression of α-smooth muscle actin and collagen type I in MCT-CFs was lower than that in CONT-CFs. On the other hand, proliferation, migration, and matrix metalloproteinase (MMP)-9 production were significantly enhanced in MCT-CFs. In MCT-CFs, phosphorylation of extracellular signal-regulated kinase (ERK) 1/2, c-Jun N-terminal kinase (JNK), and Ca 2+ /calmodulin-dependent protein kinase (CaMK) II was significantly enhanced. In addition to mRNA expression of Orai1, a Ca 2+ release-activated Ca 2+ channel, and stromal interaction molecules (STIM) 1, an endoplasmic reticulum Ca 2+ sensor, the associated store-operated Ca 2+ entry (SOCE) was significantly higher in MCT-CFs than CONT-CFs. Pharmacological inhibition of ERK1/2 pathway prevented the enhanced proliferation of MCT-CFs. The enhanced migration of MCT-CFs was prevented by a pharmacological inhibition of ERK1/2, JNK, CaMKII, or SOCE pathway. The enhanced MMP-9 production in MCT-CFs was prevented by a pharmacological inhibition of ERK1/2, CaMKII, or SOCE pathway but not JNK. The present results suggested that MCT-CFs exhibit proliferative and migratory phenotypes perhaps through multiple signaling pathways. This study for the first time determined the characteristics of CFs isolated from hypertrophied right ventricles of MCT-induced PAH model rats.

Neuromuscular activity of the venoms of the Colombian coral snakes Micrurus dissoleucus and Micrurus mipartitus: an evolutionary perspective.

PubMed

Renjifo, Camila; Smith, Eric N; Hodgson, Wayne C; Renjifo, Juan M; Sanchez, Armando; Acosta, Rodrigo; Maldonado, Jairo H; Riveros, Alain

2012-01-01

The venoms of coral snakes (genus Micrurus) are known to induce a broad spectrum of pharmacological activities. While some studies have investigated their potential human effects, little is known about their mechanism of action in terms of the ecological diversity and evolutionary relationships among the group. In the current study we investigated the neuromuscular blockade of the venom of two sister species Micrurus mipartitus and Micrurus dissoleucus, which exhibit divergent ecological characteristics in Colombia, by using the chick biventer cervicis nerve-muscle preparation. We also undertook a phylogenetic analysis of these species and their congeners, in order to provide an evolutionary framework for the American coral snakes. The venom of M. mipartitus caused a concentration-dependant inhibition (3-10 μg/ml) of nerve-mediated twitches and significantly inhibited contractile responses to exogenous ACh (1 mM), but not KCl (40 mM), indicating a postsynaptic mechanism of action. The inhibition of indirect twitches at the lower venom dose (3 μg/ml) showed to be triphasic and the effect was further attenuated when PLA2 was inhibited. M. dissoleucus venom (10-50 μg/ml) failed to produce a complete blockade of nerve-mediated twitches within a 3 h time period and significantly inhibited contractile responses to exogenous ACh (1 mM) and KCl (40 mM), indicating both postsynaptic and myotoxic mechanisms of action. Myotoxic activity was confirmed by morphological studies of the envenomed tissues. Our results demonstrate a hitherto unsuspected diversity of pharmacological actions in closely related species which exhibit divergent ecological characteristics; these results have important implications for both the clinical management of Coral snake envenomings and the design of Micrurus antivenom. Copyright © 2011 Elsevier Ltd. All rights reserved.

Novel application of complementary imaging techniques to examine in vivo glucose metabolism in the kidney

PubMed Central

Hato, Takashi; Friedman, Allon N.; Mang, Henry; Plotkin, Zoya; Dube, Shataakshi; Hutchins, Gary D.; Territo, Paul R.; McCarthy, Brian P.; Riley, Amanda A.; Pichumani, Kumar; Malloy, Craig R.; Harris, Robert A.; Dagher, Pierre C.

2016-01-01

The metabolic status of the kidney is a determinant of injury susceptibility and a measure of progression for many disease processes; however, noninvasive modalities to assess kidney metabolism are lacking. In this study, we employed positron emission tomography (PET) and intravital multiphoton microscopy (MPM) to assess cortical and proximal tubule glucose tracer uptake, respectively, following experimental perturbations of kidney metabolism. Applying dynamic image acquisition PET with 2-18fluoro-2-deoxyglucose (18F-FDG) and tracer kinetic modeling, we found that an intracellular compartment in the cortex of the kidney could be distinguished from the blood and urine compartments in animals. Given emerging literature that the tumor suppressor protein p53 is an important regulator of cellular metabolism, we demonstrated that PET imaging was able to discern a threefold increase in cortical 18F-FDG uptake following the pharmacological inhibition of p53 in animals. Intravital MPM with the fluorescent glucose analog 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxyglucose (2-NBDG) provided increased resolution and corroborated these findings at the level of the proximal tubule. Extending our observation of p53 inhibition on proximal tubule glucose tracer uptake, we demonstrated by intravital MPM that pharmacological inhibition of p53 diminishes mitochondrial potential difference. We provide additional evidence that inhibition of p53 alters key metabolic enzymes regulating glycolysis and increases intermediates of glycolysis. In summary, we provide evidence that PET is a valuable tool for examining kidney metabolism in preclinical and clinical studies, intravital MPM is a powerful adjunct to PET in preclinical studies of metabolism, and p53 inhibition alters basal kidney metabolism. PMID:26764206

Dual sphingosine kinase inhibitor SKI-II enhances sensitivity to 5-fluorouracil in hepatocellular carcinoma cells via suppression of osteopontin and FAK/IGF-1R signalling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grbčić, Petra; Tomljanović, Ivana; Klobučar, Marko

Hepatocellular carcinoma (HCC) represents the third leading cause of cancer-related deaths globally. Although 5-Fluorouracil (5-FU) is used as the first choice treatment for advanced HCC, it exerts poor efficacy and is associated with acquired and intrinsic resistance. Sphingosine kinases (Sphk) 1 and 2 play tumour-promoting roles in different cancer types including HCC and thus represent promising pharmacological targets. In the present study, we have investigated for the first time the anticancer efficacy and underlying molecular mechanisms of combined administration of 5-FU and dual Sphk1/Sphk2 inhibitor SKI-II (4-[[4-(4-chlorophenyl)-1,3-thiazol-2-yl]amino]phenol) in HepG2 hepatocellular carcinoma cells. Here, we report that co-administration of 5-FU andmore » SKI-II at low sub-toxic concentrations of 20 μM and 5 μM, respectively, synergistically inhibit cell proliferation, markedly reduce cell migration and the clonogenic survival, and increase apoptosis induction in HepG2 cells. Additional Western blot analyses have shown that possible mechanisms underlying enhanced sensitivity to 5-FU induced by dual Sphk 1/2 inhibition could include abrogation of FAK-regulated IGF-1R activity and down-regulation of osteopontin expression culminating in the inhibition of NF-κB activity and its downstream signalling mediated by sirtuin 1 and p38 MAPK. Our results clearly show that pharmacological blockade of both Sphk isoforms represents a promising strategy to boost the anti-tumour efficacy of 5-FU and provide a rationale for further in vivo studies into the possible use of SKI-II inhibitor as an adjunct to 5-FU treatment in HCC. - Highlights: • Pharmacological inhibition of sphingosine kinase 1/2 augments cytotoxic effects of 5-FU in HepG2 cells. • Co-administration of 5-FU and SKI-II synergistically inhibits cell proliferation, reduces cell migration and clonogenic survival and increases apoptosis induction in HepG2 cells. • The mechanism underlying chemosensitization effects includes attenuation of FAK/IGF-1R and osteopontin signaling leading to the inhibition of NF-κB activity and its downstream targets SIRT1 and p38 MAPK.« less

Is systems pharmacology ready to impact upon therapy development? A study on the cholesterol biosynthesis pathway

PubMed Central

Benson, Helen E; Sharman, Joanna L; Mpamhanga, Chido P; Parton, Andrew; Southan, Christopher; Harmar, Anthony J; Ghazal, Peter

2017-01-01

Background and Purpose An ever‐growing wealth of information on current drugs and their pharmacological effects is available from online databases. As our understanding of systems biology increases, we have the opportunity to predict, model and quantify how drug combinations can be introduced that outperform conventional single‐drug therapies. Here, we explore the feasibility of such systems pharmacology approaches with an analysis of the mevalonate branch of the cholesterol biosynthesis pathway. Experimental Approach Using open online resources, we assembled a computational model of the mevalonate pathway and compiled a set of inhibitors directed against targets in this pathway. We used computational optimization to identify combination and dose options that show not only maximal efficacy of inhibition on the cholesterol producing branch but also minimal impact on the geranylation branch, known to mediate the side effects of pharmaceutical treatment. Key Results We describe serious impediments to systems pharmacology studies arising from limitations in the data, incomplete coverage and inconsistent reporting. By curating a more complete dataset, we demonstrate the utility of computational optimization for identifying multi‐drug treatments with high efficacy and minimal off‐target effects. Conclusion and Implications We suggest solutions that facilitate systems pharmacology studies, based on the introduction of standards for data capture that increase the power of experimental data. We propose a systems pharmacology workflow for the refinement of data and the generation of future therapeutic hypotheses. PMID:28910500

Insig proteins mediate feedback inhibition of cholesterol synthesis in the intestine.

PubMed

McFarlane, Matthew R; Liang, Guosheng; Engelking, Luke J

2014-01-24

Enterocytes are the only cell type that must balance the de novo synthesis and absorption of cholesterol, although the coordinate regulation of these processes is not well understood. Our previous studies demonstrated that enterocytes respond to the pharmacological blockade of cholesterol absorption by ramping up de novo sterol synthesis through activation of sterol regulatory element-binding protein-2 (SREBP-2). Here, we genetically disrupt both Insig1 and Insig2 in the intestine, two closely related proteins that are required for the feedback inhibition of SREBP and HMG-CoA reductase (HMGR). This double knock-out was achieved by generating mice with an intestine-specific deletion of Insig1 using Villin-Cre in combination with a germ line deletion of Insig2. Deficiency of both Insigs in enterocytes resulted in constitutive activation of SREBP and HMGR, leading to an 11-fold increase in sterol synthesis in the small intestine and producing lipidosis of the intestinal crypts. The intestine-derived cholesterol accumulated in plasma and liver, leading to secondary feedback inhibition of hepatic SREBP2 activity. Pharmacological blockade of cholesterol absorption was unable to further induce the already elevated activities of SREBP-2 or HMGR in Insig-deficient enterocytes. These studies confirm the essential role of Insig proteins in the sterol homeostasis of enterocytes.

Insig Proteins Mediate Feedback Inhibition of Cholesterol Synthesis in the Intestine*

PubMed Central

McFarlane, Matthew R.; Liang, Guosheng; Engelking, Luke J.

2014-01-01

Enterocytes are the only cell type that must balance the de novo synthesis and absorption of cholesterol, although the coordinate regulation of these processes is not well understood. Our previous studies demonstrated that enterocytes respond to the pharmacological blockade of cholesterol absorption by ramping up de novo sterol synthesis through activation of sterol regulatory element-binding protein-2 (SREBP-2). Here, we genetically disrupt both Insig1 and Insig2 in the intestine, two closely related proteins that are required for the feedback inhibition of SREBP and HMG-CoA reductase (HMGR). This double knock-out was achieved by generating mice with an intestine-specific deletion of Insig1 using Villin-Cre in combination with a germ line deletion of Insig2. Deficiency of both Insigs in enterocytes resulted in constitutive activation of SREBP and HMGR, leading to an 11-fold increase in sterol synthesis in the small intestine and producing lipidosis of the intestinal crypts. The intestine-derived cholesterol accumulated in plasma and liver, leading to secondary feedback inhibition of hepatic SREBP2 activity. Pharmacological blockade of cholesterol absorption was unable to further induce the already elevated activities of SREBP-2 or HMGR in Insig-deficient enterocytes. These studies confirm the essential role of Insig proteins in the sterol homeostasis of enterocytes. PMID:24337570

mGluR antagonists and GABA agonists as novel pharmacological agents for the treatment of autism spectrum disorders.

PubMed

Oberman, Lindsay M

2012-12-01

The CDC currently estimates the prevalence of autism spectrum disorders (ASD) at 1 in 88 children. Though the exact etiology of ASD is unknown, recent studies implicate synaptic maturation and plasticity in the pathogenesis of ASD leading to an imbalance of excitation and inhibition, and specifically a disproportionately high level of excitation. Pharmacological agents that modulate excitation and inhibition are currently in clinical trials for treatment of ASD and show promising preliminary results. This paper reviews the literature implicating the role of glutamate and GABA pathways in the pathophysiology of ASD. It also provides a review of the current results from both animal models and human clinical trials of drugs aimed at normalizing the imbalance of excitation and inhibition through the use of metabotropic glutamate receptor (mGluR) antagonists and GABA agonists. Both mGluR antagonists and GABA agonists have promising preliminary data from animal model and small-scale Phase II human trials. They show significant efficacy in subpopulations and appear to have favorable side-effect profiles. Though preliminary data are extremely promising, results from ongoing larger, double-blind, placebo-controlled studies will give a more complete understanding of the efficacy and side-effect profile related to these drugs.

The study of chemical composition and pharmacological action of the alkaloid from plants of Lycoris Herb

NASA Astrophysics Data System (ADS)

Ji, Y. B.; Wei, C.; Xin, G. S.

2017-12-01

Recently, studies on Lycoris type alkaloids received the attention of scholars home and abroad. Lycoris type contains lots of alkaloids, it can be divided into seven types according to its molecular structure, including Lycorine, Crinine, Galanthamine, Tazettine, Narciclasine, Lycorenine, Homolycorine and Montanine. Researches have shown that Lycoris type possess multiple phamocology activity, such as strong anti-tumor activity of human breast cancer cell (MCF-7), human leukemia cell(HL-60); and strong inhibition effect of flu virus, measles virus, polio virus and SARS virus; Besides, Lycorine type has strong anti-Acetylcholinesterase effect. In a word, Lycorine type, Lycoris type alkaloids carries multiple pharmacology effect and is a promising substance.

Blue-Print Autophagy: Potential for Cancer Treatment

PubMed Central

Ruocco, Nadia; Costantini, Susan; Costantini, Maria

2016-01-01

The marine environment represents a very rich source of biologically active compounds with pharmacological applications. This is due to its chemical richness, which is claiming considerable attention from the health science communities. In this review we give a general overview on the marine natural products involved in stimulation and inhibition of autophagy (a type of programmed cell death) linked to pharmacological and pathological conditions. Autophagy represents a complex multistep cellular process, wherein a double membrane vesicle (the autophagosome) captures organelles and proteins and delivers them to the lysosome. This natural and destructive mechanism allows the cells to degrade and recycle its cellular components, such as amino acids, monosaccharides, and lipids. Autophagy is an important mechanism used by cells to clear pathogenic organism and deal with stresses. Therefore, it has also been implicated in several diseases, predominantly in cancer. In fact, pharmacological stimulation or inhibition of autophagy have been proposed as approaches to develop new therapeutic treatments of cancers. In conclusion, this blue-print autophagy (so defined because it is induced and/or inhibited by marine natural products) represents a new strategy for the future of biomedicine and of biotechnology in cancer treatment. PMID:27455284

Pharmacological inhibition of 2-arachidonoilglycerol hydrolysis enhances memory consolidation in rats through CB2 receptor activation and mTOR signaling modulation.

PubMed

Ratano, Patrizia; Petrella, Carla; Forti, Fabrizio; Passeri, Pamela Petrocchi; Morena, Maria; Palmery, Maura; Trezza, Viviana; Severini, Cinzia; Campolongo, Patrizia

2018-05-26

The endocannabinoid system is a key modulator of memory consolidation for aversive experiences. We recently found that the fatty acid amide hydrolase (FAAH) inhibitor URB597, which increases anandamide levels by inhibiting its hydrolysis, facilitates memory consolidation through a concurrent activation of both cannabinoid receptor type 1 (CB1) and 2 (CB2). Here, we investigated the role played on memory consolidation by the other major endocannabinoid, 2-arachidonoylglycerol (2-AG). To this aim, we tested the effects of pharmacological inhibition of monoacylglycerol lipase (MAGL) through systemic administration of the MAGL inhibitor JZL184 to rats immediately after training of the inhibitory avoidance task. Pharmacological enhancement of 2-AG tone facilitated memory consolidation through activation of CB2 receptor signaling. Moreover, we found that increased 2-AG signaling prevented the activation of the mammalian target of rapamycin (mTOR) signaling pathway in the hippocampus through a CB2-dependent mechanism. Our results identify a fundamental role for 2-AG and CB2 receptors in the modulation of memory consolidation for aversive experiences. Copyright © 2018 Elsevier Ltd. All rights reserved.

Comparative potency of obeticholic acid and natural bile acids on FXR in hepatic and intestinal in vitro cell models.

PubMed

Zhang, Yuanyuan; LaCerte, Carl; Kansra, Sanjay; Jackson, Jonathan P; Brouwer, Kenneth R; Edwards, Jeffrey E

2017-12-01

Obeticholic acid (OCA) is a semisynthetic farnesoid X receptor (FXR) agonist, an analogue of chenodeoxycholic acid (CDCA) which is indicated for the treatment of primary biliary cholangitis (PBC) in combination with ursodeoxycholic acid (UDCA). OCA efficiently inhibits bile acid synthesis and promotes bile acid efflux via activating FXR-mediated mechanisms in a physiologically relevant in vitro cell system, Sandwich-cultured Transporter Certified ™ human primary hepatocytes (SCHH). The study herein evaluated the effects of UDCA alone or in combination with OCA in SCHH. UDCA (≤100 μmol/L) alone did not inhibit CYP7A1 mRNA, and thus, no reduction in the endogenous bile acid pool observed. UDCA ≤100 μmol/L concomitantly administered with 0.1 μmol/L OCA had no effect on bile acid synthesis beyond what was observed with OCA alone. Furthermore, this study evaluated human Caco-2 cells (clone C2BBe1) as in vitro intestinal models. Glycine conjugate of OCA increased mRNA levels of FXR target genes in Caco-2 cells, FGF-19, SHP, OSTα/β, and IBABP, but not ASBT, in a concentration-dependent manner, while glycine conjugate of UDCA had no effect on the expression of these genes. The results suggested that UDCA ≤100 μmol/L did not activate FXR in human primary hepatocytes or intestinal cell line Caco-2. Thus, co-administration of UDCA with OCA did not affect OCA-dependent pharmacological effects. © 2017 The Authors. Pharmacology Research & Perspectives published by John Wiley & Sons Ltd, British Pharmacological Society and American Society for Pharmacology and Experimental Therapeutics.

Bilateral Cavernous Nerve Crush Injury in the Rat Model: A Comparative Review of Pharmacologic Interventions.

PubMed

Haney, Nora M; Nguyen, Hoang M T; Honda, Matthew; Abdel-Mageed, Asim B; Hellstrom, Wayne J G

2018-04-01

It is common for men to develop erectile dysfunction after radical prostatectomy. The anatomy of the rat allows the cavernous nerve (CN) to be identified, dissected, and injured in a controlled fashion. Therefore, bilateral CN injury (BCNI) in the rat model is routinely used to study post-prostatectomy erectile dysfunction. To compare and contrast the available literature on pharmacologic intervention after BCNI in the rat. A literature search was performed on PubMed for cavernous nerve and injury and erectile dysfunction and rat. Only articles with BCNI and pharmacologic intervention that could be grouped into categories of immune modulation, growth factor therapy, receptor kinase inhibition, phosphodiesterase type 5 inhibition, and anti-inflammatory and antifibrotic interventions were included. To assess outcomes of pharmaceutical intervention on erectile function recovery after BCNI in the rat model. The ratio of maximum intracavernous pressure to mean arterial pressure was the main outcome measure chosen for this analysis. All interventions improved erectile function recovery after BCNI based on the ratio of maximum intracavernous pressure to mean arterial pressure results. Additional end-point analysis examined the corpus cavernosa and/or the major pelvic ganglion and CN. There was extreme heterogeneity within the literature, making accurate comparisons between crush injury and therapeutic interventions difficult. BCNI in the rat is the accepted animal model used to study nerve-sparing post-prostatectomy erectile dysfunction. However, an important limitation is extreme variability. Efforts should be made to decrease this variability and increase the translational utility toward clinical trials in humans. Haney NM, Nguyen HMT, Honda M, et al. Bilateral Cavernous Nerve Crush Injury in the Rat Model: A Comparative Review of Pharmacologic Interventions. Sex Med Rev 2018;6:234-241. Copyright © 2017 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

Dual activation of CFTR and CLCN2 by lubiprostone in murine nasal epithelia.

PubMed

Schiffhauer, Eric S; Vij, Neeraj; Kovbasnjuk, Olga; Kang, Po Wei; Walker, Doug; Lee, Seakwoo; Zeitlin, Pamela L

2013-03-01

Multiple sodium and chloride channels on the apical surface of nasal epithelial cells contribute to periciliary fluid homeostasis, a function that is disrupted in patients with cystic fibrosis (CF). Among these channels is the chloride channel CLCN2, which has been studied as a potential alternative chloride efflux pathway in the absence of CFTR. The object of the present study was to use the nasal potential difference test (NPD) to quantify CLCN2 function in an epithelial-directed TetOn CLCN2 transgenic mouse model (TGN-K18rtTA-hCLCN2) by using the putative CLCN2 pharmacological agonist lubiprostone and peptide inhibitor GaTx2. Lubiprostone significantly increased chloride transport in the CLCN2-overexpressing mice following activation of the transgene by doxycycline. This response to lubiprostone was significantly inhibited by GaTx2 after CLCN2 activation in TGN-CLCN2 mice. Cftr(-/-) and Clc2(-/-) mice showed hyperpolarization indicative of chloride efflux in response to lubiprostone, which was fully inhibited by GaTx2 and CFTR inhibitor 172 + GlyH-101, respectively. Our study reveals lubiprostone as a pharmacological activator of both CFTR and CLCN2. Overexpression and activation of CLCN2 leads to improved mouse NPD readings, suggesting it is available as an alternative pathway for epithelial chloride secretion in murine airways. The utilization of CLCN2 as an alternative chloride efflux channel could provide clinical benefit to patients with CF, especially if the pharmacological activator is administered as an aerosol.

Inhibition of peroxynitrite-mediated DNA strand cleavage and hydroxyl radical formation by aspirin at pharmacologically relevant concentrations: implications for cancer intervention

PubMed Central

Chen, Wei; Zhu, Hong; Jia, Zhenquan; Li, Jianrong; Misra, Hara P.; Zhou, Kequan; Li, Yunbo

2009-01-01

Epidemiological studies have suggested that the long-term use of aspirin is associated with a decreased incidence of human malignancies, especially colorectal cancer. Since accumulating evidence indicates that peroxynitrite is critically involved in multistage carcinogenesis, this study was undertaken to investigate the ability of aspirin to inhibit peroxynitrite-mediated DNA damage. Peroxynitrite and its generator 3-morpholinosydnonimine (SIN-1) were used to cause DNA strand breaks in φX-174 plasmid DNA. We demonstrated that the presence of aspirin at concentrations (0.25 -2 mM) compatible with amounts in plasma during chronic anti-inflammatory therapy resulted in a significant inhibition of DNA cleavage induced by both peroxynitrite and SIN-1. Moreover, the consumption of oxygen caused by 250 µM SIN-1 was found to be decreased in the presence of aspirin, indicating that aspirin might affect the auto-oxidation of SIN-1. Furthermore, EPR spectroscopy using 5,5-dimethylpyrroline-N-oxide (DMPO) as a spin trap demonstrated the formation of DMPO-hydroxyl radical adduct (DMPO-OH) from authentic peroxynitrite, and that aspirin at 0.25 - 2 mM potently diminished the radical adduct formation in a concentration-dependent manner. Taken together, these results demonstrate for the first time that aspirin at pharmacologically relevant concentrations can inhibit peroxynitrite-mediated DNA strand breakage and hydroxyl radical formation. These results may have implications for cancer intervention by aspirin. PMID:19785994

Pharmacological Inhibition of Feline Immunodeficiency Virus (FIV)

PubMed Central

Mohammadi, Hakimeh; Bienzle, Dorothee

2012-01-01

Feline immunodeficiency virus (FIV) is a member of the retroviridae family of viruses and causes an acquired immunodeficiency syndrome (AIDS) in domestic and non-domestic cats worldwide. Genome organization of FIV and clinical characteristics of the disease caused by the virus are similar to those of human immunodeficiency virus (HIV). Both viruses infect T lymphocytes, monocytes and macrophages, and their replication cycle in infected cells is analogous. Due to marked similarity in genomic organization, virus structure, virus replication and disease pathogenesis of FIV and HIV, infection of cats with FIV is a useful tool to study and develop novel drugs and vaccines for HIV. Anti-retroviral drugs studied extensively in HIV infection have targeted different steps of the virus replication cycle: (1) inhibition of virus entry into susceptible cells at the level of attachment to host cell surface receptors and co-receptors; (2) inhibition of fusion of the virus membrane with the cell membrane; (3) blockade of reverse transcription of viral genomic RNA; (4) interruption of nuclear translocation and viral DNA integration into host genomes; (5) prevention of viral transcript processing and nuclear export; and (6) inhibition of virion assembly and maturation. Despite much success of anti-retroviral therapy slowing disease progression in people, similar therapy has not been thoroughly investigated in cats. In this article we review current pharmacological approaches and novel targets for anti-lentiviral therapy, and critically assess potentially suitable applications against FIV infection in cats. PMID:22754645

Inhibition of peroxynitrite-mediated DNA strand cleavage and hydroxyl radical formation by aspirin at pharmacologically relevant concentrations: Implications for cancer intervention

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Wei; College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310035; Department of Food Science and Technology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061

Epidemiological studies have suggested that the long-term use of aspirin is associated with a decreased incidence of human malignancies, especially colorectal cancer. Since accumulating evidence indicates that peroxynitrite is critically involved in multistage carcinogenesis, this study was undertaken to investigate the ability of aspirin to inhibit peroxynitrite-mediated DNA damage. Peroxynitrite and its generator 3-morpholinosydnonimine (SIN-1) were used to cause DNA strand breaks in {phi}X-174 plasmid DNA. We demonstrated that the presence of aspirin at concentrations (0.25-2 mM) compatible with amounts in plasma during chronic anti-inflammatory therapy resulted in a significant inhibition of DNA cleavage induced by both peroxynitrite and SIN-1.more » Moreover, the consumption of oxygen caused by 250 {mu}M SIN-1 was found to be decreased in the presence of aspirin, indicating that aspirin might affect the auto-oxidation of SIN-1. Furthermore, EPR spectroscopy using 5,5-dimethylpyrroline-N-oxide (DMPO) as a spin trap demonstrated the formation of DMPO-hydroxyl radical adduct (DMPO-OH) from authentic peroxynitrite, and that aspirin at 0.25-2 mM potently diminished the radical adduct formation in a concentration-dependent manner. Taken together, these results demonstrate for the first time that aspirin at pharmacologically relevant concentrations can inhibit peroxynitrite-mediated DNA strand breakage and hydroxyl radical formation. These results may have implications for cancer intervention by aspirin.« less

Modulation of Olfactory Bulb Network Activity by Serotonin: Synchronous Inhibition of Mitral Cells Mediated by Spatially Localized GABAergic Microcircuits

ERIC Educational Resources Information Center

Schmidt, Loren J.; Strowbridge, Ben W.

2014-01-01

Although inhibition has often been proposed as a central mechanism for coordinating activity in the olfactory system, relatively little is known about how activation of different inhibitory local circuit pathways can generate coincident inhibition of principal cells. We used serotonin (5-HT) as a pharmacological tool to induce spiking in ensembles…

A sea urchin Na(+)K(+)2Cl(-) cotransporter is involved in the maintenance of calcification-relevant cytoplasmic cords in Strongylocentrotus droebachiensis larvae.

PubMed

Basse, Wiebke C; Gutowska, Magdalena A; Findeisen, Ulrike; Stumpp, Meike; Dupont, Sam; Jackson, Daniel J; Himmerkus, Nina; Melzner, Frank; Bleich, Markus

2015-09-01

The cellular mechanisms of calcification in sea urchin larvae are still not well understood. Primary mesenchyme cells within the larval body cavity form a syncytium to secrete CaCO3 spicules from intracellular amorphous CaCO3 (ACC) stores. We studied the role of Na(+)K(+)2Cl(-) cotransporter (NKCC) in intracellular ACC accumulation and larval spicule formation of Strongylocentrotus droebachiensis. First, we incubated growing larvae with three different loop diuretics (azosemide, bumetanide, and furosemide) and established concentration-response curves. All loop diuretics were able to inhibit calcification already at concentrations that specifically inhibit NKCC. Calcification was most effectively inhibited by azosemide (IC50=6.5 μM), while larval mortality and swimming ability were not negatively impacted by the treatment. The inhibition by bumetanide (IC50=26.4 μM) and furosemide (IC50=315.4 μM) resembled the pharmacological fingerprint of the mammalian NKCC1 isoform. We further examined the effect of azosemide on the maintenance of cytoplasmic cords and on the occurrence of calcification vesicles using fluorescent dyes (calcein, FM1-43). Fifty micromolars of azosemide inhibited the maintenance of cytoplasmic cords and resulted in increased calcein fluorescence within calcification vesicles. The expression of NKCC in S. droebachiensis was verified by PCR and Western blot with a specific NKCC antibody. In summary, the pharmacological profile of loop diuretics and their specific effects on calcification in sea urchin larvae suggest that they act by inhibition of NKCC via repression of cytoplasmic cord formation and maintenance. Copyright © 2015 Elsevier Inc. All rights reserved.

Caspase Inhibition Prevents Tumor Necrosis Factor-α-Induced Apoptosis and Promotes Necrotic Cell Death in Mouse Hepatocytes in Vivo and in Vitro.

PubMed

Ni, Hong-Min; McGill, Mitchell R; Chao, Xiaojuan; Woolbright, Benjamin L; Jaeschke, Hartmut; Ding, Wen-Xing

2016-10-01

How different cell death modes and cell survival pathways cross talk remains elusive. We determined the interrelation of apoptosis, necrosis, and autophagy in tumor necrosis factor (TNF)-α/actinomycin D (ActD) and lipopolysaccharide/D-galactosamine (GalN)-induced hepatotoxicity in vitro and in vivo. We found that TNF-α/ActD-induced apoptosis was completely blocked by a general caspase inhibitor ZVAD-fmk at 24 hours but hepatocytes still died by necrosis at 48 hours. Inhibition of caspases also protected mice against lipopolysaccharide/GalN-induced apoptosis and liver injury at the early time point, but this protection was diminished after prolonged treatment by switching apoptosis to necrosis. Inhibition of receptor-interacting protein kinase (RIP)1 by necrostatin 1 partially inhibited TNF-α/ZVAD-induced necrosis in primary hepatocytes. Pharmacologic inhibition of autophagy or genetic deletion of Atg5 in hepatocytes did not protect against TNF-α/ActD/ZVAD-induced necrosis. Moreover, pharmacologic inhibition of RIP1 or genetic deletion of RIP3 failed to protect and even exacerbated liver injury after mice were treated with lipopolysaccharide/GalN and a pan-caspase inhibitor. In conclusion, our results suggest that different cell death mode and cell survival pathways are closely integrated during TNF-α-induced liver injury when both caspases and NF-κB are blocked. Moreover, results from our study also raised concerns about the safety of currently ongoing clinical trials that use caspase inhibitors. Copyright © 2016 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

[New pharmacological activities of garlic and its constituents].

PubMed

Sumiyoshi, H

1997-10-01

According to the recent pharmacological findings, garlic is a preventive rather than therapeutic. Epidemiological studies in China, Italy and USA showed the inverse relationship between stomach and colon cancer incidences and dietary garlic intake. Anti-carcinogenic activities of garlic and its constituents including sulfides and S-allyl cysteine, have been demonstrated using several animal models. Garlic preparations has been also shown to lower serum cholesterol and triglyceride levels, which are major risk factors of cardiovascular diseases, through inhibition of their bio-synthesis in the liver, and to inhibit oxidation of low density lipoprotein. Furthermore, in vitro and in vivo studies have revealed that aged garlic extract stimulated immune functions, such as proliferation of lymphocyte, cytokine release, NK activity and phagocytosis. More recently, aged garlic extract has been demonstrated to prolong life span of senescence accelerated mice and prevent brain atrophy. Manufacturing processes significantly affect chemical constituents in garlic preparations. Different forms contain different phytochemicals and may have different effects and toxicities. For example, aged garlic extract inhibited t-BuOOH-induced oxidation, whereas raw garlic stimulated the oxidation. Although garlic has been used as a condiment and folklore for a long time, it has been noted to cause adverse reactions, such as stomach ulcer and anemia. Among the garlic preparations, only aged garlic extract has been proven to be safe through toxicological studies. Thus, aged garlic extract could be the most promising garlic preparation for disease prevention.

The role of calcium signalling in the chondrogenic response of mesenchymal stem cells to hydrostatic pressure.

PubMed

Steward, A J; Kelly, D J; Wagner, D R

2014-10-28

The object of this study was to elucidate the role of Ca++ signalling in the chondrogenic response of mesenchymal stem cells (MSCs) to hydrostatic pressure (HP). MSCs were seeded into agarose hydrogels, subjected to HP or kept in free swelling conditions, and were cultured either with or without pharmacological inhibitors of Ca++ mobility and downstream targets. Chelating free Ca++, inhibiting voltage-gated calcium channels, and depleting intracellular calcium storessuppressed the beneficial effect of HP on chondrogenesis, indicating that Ca++ mobility may play an important role in the mechanotransduction of HP. However, inhibition of stretch-activated calcium channels in the current experiment yielded similar results to the control group, suggesting that mechanotransduction of HP is distinct from loads that generate cell deformations. Inhibition of the downstream targets calmodulin, calmodulin kinase II, and calcineurin all knocked down the effect of HP on chondrogenesis, implicating these targets in MSCs response to HP. All of the pharmacological inhibitors that abolished the chondrogenic response to HP also maintained a punctate vimentin organisation in the presence of HP, as opposed to the mechanoresponsive groups where the vimentin structure became more diffuse. These results suggest that Ca++ signalling may transduce HP via vimentin adaptation to loading.

Pharmacological identification of a novel Ca2+ channel in chicken brain synaptosomes.

PubMed

Lundy, P M; Hamilton, M G; Frew, R

1994-04-18

Ca2+ influx was measured in rat and chicken brain synaptosomes in the presence of a number of pharmacological tools which have recently been used to define voltage-sensitive Ca(2+)-channel (VSCC) types. In chicken brain synaptosomes. VSCCs which, because of their sensitivity to inhibition by omega-conotoxin (omega-CgTx), are thought to be exclusively N-type, the P-type VSCC polyamine inhibitor FTX (from Agelenopsis aperta venom; 1 microliters/ml), its synthetic analogue, sFTX (1-5 mM) and the polypeptides AgaIVA (IC50 0.29 microM) and omega-CgTx MVIIC (IC50 0.0022 microM) inhibited 70-100% of the measurable K+ stimulated Ca2+ influx. The prototypical N-channel VSCC inhibitor omega-CgTx GVIA (IC50 0.014 microM), Cd2+ (50 microM) and diluted venom from Hololena curta (1:2,500) also caused complete or almost complete, inhibition of Ca2+ influx. In comparable studies using rat brain synaptosomes, sFTX (1-10 mM) caused a dose-dependent reduction of Ca2+ influx, while FTX (1 microliters/ml) and AgaIVA (IC50 0.02 microM) completely inhibited Ca2+ influx. Similar to the findings in chicken synaptosomes, Cd2+ (50 microM) and H. curta (1:2,500 dilution) both inhibited K+ stimulated influx by > 80% whereas omega-CgTx (1 microM) only caused a maximum 25% inhibition. Both sFTX and its congener spermine, inhibited [125I]omega-CgTx binding to rat and chicken synaptosomal membranes. These results strongly implicate P-type channels as the major VSCC in rat brain. The results also clearly demonstrate a heretofore unrecognized, novel, FTX/AgaIVA/omega-CgTx GVIA/omega-CgTx MVIIC-sensitive VSCC in chicken brain.

Inhibition of Acid Sensing Ion Channel Currents by Lidocaine in Cultured Mouse Cortical Neurons

PubMed Central

Lin, Jun; Chu, Xiangping; Maysami, Samaneh; Li, Minghua; Si, Hongfang; Cottrell, James E.; Simon, Roger P.; Xiong, Zhigang

2012-01-01

BACKGROUND Lidocaine is a local anesthetic that has multiple pharmacological effects including antiarrhythmia, antinociception, and neuroprotection. Acid sensing ion channels (ASICs) are proton-gated cation channels that belong to the epithelial sodium channel/degenerin superfamily. Activation of ASICs by protons results in sodium and calcium influx. ASICs have been implicated in various physiological processes including learning/memory, nociception, and in acidosis-mediated neuron injury. In this study, we examined the effect of lidocaine on ASICs in cultured mouse cortical neurons. METHODS ASIC currents were activated and recorded using a whole-cell patch-clamp technique in cultured mouse cortical neurons. The effects of lidocaine at different concentrations were examined. To determine whether the inhibition of lidocaine on ASIC currents is subunit specific, we examined the effect of lidocaine on homomeric ASIC1a and ASIC2a currents expressed in Chinese hamster ovary cells. RESULTS Lidocaine significantly inhibits the ASIC currents in mouse cortical neurons. The inhibition was reversible and dose dependent. A detectable effect was noticed at a concentration of 0.3 mM lidocaine. At 30 mM, ASIC current was inhibited by approximately 90%. Analysis of the complete dose-response relationship yielded a half-maximal inhibitory concentration of 11.79 ± 1.74 mM and a Hill coefficient of 2.7 ± 0.5 (n = 10). The effect is rapid and does not depend on pH. In Chinese hamster ovary cells expressing different ASIC subunits, lidocaine inhibits the ASIC1a current without affecting the ASIC2a current. CONCLUSION ASIC currents are significantly inhibited by lidocaine. Our finding reveals a new pharmacological effect of lidocaine in neurons. PMID:21385979

Cyclophilin D-Sensitive Mitochondrial Permeability Transition in Adult Human Brain and Liver Mitochondria

PubMed Central

Morota, Saori; Chen, Li; Matsuyama, Nagahisa; Suzuki, Yoshiaki; Nakajima, Satoshi; Tanoue, Tadashi; Omi, Akibumi; Shibasaki, Futoshi; Shimazu, Motohide; Ikeda, Yukio; Uchino, Hiroyuki; Elmér, Eskil

2011-01-01

Abstract The mitochondrial permeability transition (mPT) is considered to be a major cause of cell death under a variety of pathophysiological conditions of the central nervous system (CNS) and other organs. Pharmacological inhibition or genetic knockout of the matrix protein cyclophilin D (CypD) prevents mPT and cell degeneration in several models of brain injury. If these findings in animal models are translatable to human disease, pharmacological inhibition of mPT offers a promising therapeutic target. The objective of this study was to validate the presence of a CypD-sensitive mPT in adult human brain and liver mitochondria. In order to perform functional characterization of human mitochondria, fresh tissue samples were obtained during hemorrhage or tumor surgery and mitochondria were rapidly isolated. Mitochondrial calcium retention capacity, a quantitative assay for mPT, was significantly increased by the CypD inhibitor cyclosporin A in both human brain and liver mitochondria, whereas thiol-reactive compounds and oxidants sensitized mitochondria to calcium-induced mPT. Brain mitochondria underwent swelling upon calcium overload, which was reversible upon calcium removal. To further explore mPT of human mitochondria, liver mitochondria were demonstrated to exhibit several classical features of the mPT phenomenon, such as calcium-induced loss of membrane potential and respiratory coupling, as well as release of the pro-apoptotic protein cytochrome c. We concluded that adult viable human brain and liver mitochondria possess an active CypD-sensitive mPT. Our findings support the rationale of CypD and mPT inhibition as pharmacological targets in acute and chronic neurodegeneration. PMID:21121808

Chemical Composition and Pharmacological Effects of Geopropolis Produced by Melipona quadrifasciata anthidioides.

PubMed

Dos Santos, Cintia Miranda; Campos, Jaqueline Ferreira; Dos Santos, Helder Freitas; Balestieri, José Benedito Perrella; Silva, Denise Brentan; de Picoli Souza, Kely; Carollo, Carlos Alexandre; Estevinho, Leticia M; Dos Santos, Edson Lucas

2017-01-01

Stingless bees produce geopropolis, which is popularly described for its medicinal properties, but for which few scientific studies have demonstrated pharmacological effects. The objective of this study was to investigate the chemical composition of the geopropolis of Melipona quadrifasciata anthidioides and to evaluate its antioxidant, antimutagenic, anti-inflammatory, and antimicrobial activities. The composition of the hydroethanolic extract of geopropolis (HEG) included di- and trigalloyl and phenylpropanyl heteroside derivatives, flavanones, diterpenes, and triterpenes. HEG showed antioxidant action via the direct capture of free radicals and by inhibiting the levels of oxidative hemolysis and malondialdehyde in human erythrocytes under oxidative stress. HEG also reduced the frequency of gene conversion and the number of mutant colonies of S. cerevisiae . The anti-inflammatory action of HEG was demonstrated by the inhibition of hyaluronidase enzyme activity. In addition, HEG induced cell death in all evaluated gram-positive bacteria, gram-negative bacteria, and yeasts, including clinical isolates with antimicrobial drug resistance. Collectively, these results demonstrate the potential of M. q. anthidioides geopropolis for the prevention and treatment of various diseases related to oxidative stress, mutagenesis, inflammatory processes, and microbial infections.

Chemical Composition and Pharmacological Effects of Geopropolis Produced by Melipona quadrifasciata anthidioides

PubMed Central

dos Santos, Cintia Miranda; Campos, Jaqueline Ferreira; dos Santos, Helder Freitas; Balestieri, José Benedito Perrella; Silva, Denise Brentan

2017-01-01

Stingless bees produce geopropolis, which is popularly described for its medicinal properties, but for which few scientific studies have demonstrated pharmacological effects. The objective of this study was to investigate the chemical composition of the geopropolis of Melipona quadrifasciata anthidioides and to evaluate its antioxidant, antimutagenic, anti-inflammatory, and antimicrobial activities. The composition of the hydroethanolic extract of geopropolis (HEG) included di- and trigalloyl and phenylpropanyl heteroside derivatives, flavanones, diterpenes, and triterpenes. HEG showed antioxidant action via the direct capture of free radicals and by inhibiting the levels of oxidative hemolysis and malondialdehyde in human erythrocytes under oxidative stress. HEG also reduced the frequency of gene conversion and the number of mutant colonies of S. cerevisiae. The anti-inflammatory action of HEG was demonstrated by the inhibition of hyaluronidase enzyme activity. In addition, HEG induced cell death in all evaluated gram-positive bacteria, gram-negative bacteria, and yeasts, including clinical isolates with antimicrobial drug resistance. Collectively, these results demonstrate the potential of M. q. anthidioides geopropolis for the prevention and treatment of various diseases related to oxidative stress, mutagenesis, inflammatory processes, and microbial infections. PMID:29213354

Cardiac ion channel modulation by the hypoglycaemic agent rosiglitazone.

PubMed

Hancox, J C

2011-06-01

The hypoglycaemic thiazolidinedione rosiglitazone is used clinically in the treatment of type 2 diabetes. However, in 2010, information relating to rosiglitazone-associated increased cardiovascular risk led the European Medicines Agency to recommend suspension of marketing authorizations for rosiglitazone-containing anti-diabetes drugs, while the US Food and Drug Administration recommended significant restriction on the agent's use. Two timely studies in this issue of the British Journal of Phrarmacology provide new information regarding modification of cardiac cellular electrophysiology by rosiglitazone. Szentandrássy et al. demonstrate canine ventricular action potential modification and concentration-dependent suppression of L-type Ca current and of transient outward and rapid delayed rectifier K currents. Jeong et al. demonstrate concentration-dependent inhibition of recombinant K(v) 4.3 channels, providing mechanistic insight into the likely molecular basis of transient outward K current inhibition by the compound. Further studies using diabetic models would be of value to determine whether, in a diabetic setting, rosiglitazone modification of these channels could affect the risk of arrhythmia at clinically relevant drug concentrations. © 2011 The Author. British Journal of Pharmacology © 2011 The British Pharmacological Society.

Mangiferin - a bioactive xanthonoid, not only from mango and not just antioxidant.

PubMed

Matkowski, Adam; Kuś, Piotr; Góralska, Edyta; Woźniak, Dorota

2013-03-01

Mangiferin is a plant natural polyphenol of C-glycosylxanthone structure and various pharmacological activities. It can be found in many plant species, among which the mango tree (Mangifera indica) is one of the primary sources. Mangiferin is also present in some medicinal herbs, influencing their therapeutic and preventive properties, and in honeybush (Cyclopia sp.), a popular South African herbal tea. Mangiferin dissolves well in water, so it can be easily extracted into infusions and decoctions. In the mangiferin molecule, four aromatic hydroxyl groups determine its strong antiradical and antioxidant properties. Mangiferin is also an efficient iron chelator, therefore preventing the generation of hydroxyl radical in Fenton-type reactions. Numerous published in vitro and in vivo pharmacological studies, demonstrated many other activities of mangiferin: analgesic, antidiabetic, antisclerotic, atimicrobial and antiviral, cardio-, hepato-, and neuroprotective, antiinflammatory, antiallergic, MAO inhibiting and memory improving, as well as radioprotective against X-ray, gamma, and UV radiation. Several studies indicated also its ability to inhibit cancerogenesis and cancer cells growth by apoptosis induction in vitro and in vivo. It is also used in cosmetics, due to antioxidant and UV-protecting properties.

A Systems Model for Ursodeoxycholic Acid Metabolism in Healthy and Patients With Primary Biliary Cirrhosis.

PubMed

Zuo, P; Dobbins, R L; O'Connor-Semmes, R L; Young, M A

2016-08-01

A systems model was developed to describe the metabolism and disposition of ursodeoxycholic acid (UDCA) and its conjugates in healthy subjects based on pharmacokinetic (PK) data from published studies in order to study the distribution of oral UDCA and potential interactions influencing therapeutic effects upon interruption of its enterohepatic recirculation. The base model was empirically adapted to patients with primary biliary cirrhosis (PBC) based on current understanding of disease pathophysiology and clinical measurements. Simulations were performed for patients with PBC under two competing hypotheses: one for inhibition of ileal absorption of both UDCA and conjugates and the other only of conjugates. The simulations predicted distinctly different bile acid distribution patterns in plasma and bile. The UDCA model adapted to patients with PBC provides a platform to investigate a complex therapeutic drug interaction among UDCA, UDCA conjugates, and inhibition of ileal bile acid transport in this rare disease population. © 2016 The Authors CPT: Pharmacometrics & Systems Pharmacology published by Wiley Periodicals, Inc. on behalf of American Society for Clinical Pharmacology and Therapeutics.

Cardioprotective effects of fatty acid amide hydrolase inhibitor URB694, in a rodent model of trait anxiety

PubMed Central

Carnevali, Luca; Vacondio, Federica; Rossi, Stefano; Macchi, Emilio; Spadoni, Gilberto; Bedini, Annalida; Neumann, Inga D.; Rivara, Silvia; Mor, Marco; Sgoifo, Andrea

2015-01-01

In humans, chronic anxiety represents an independent risk factor for cardiac arrhythmias and sudden death. Here we evaluate in male Wistar rats bred for high (HAB) and low (LAB) anxiety-related behavior, as well as non-selected (NAB) animals, the relationship between trait anxiety and cardiac electrical instability and investigate whether pharmacological augmentation of endocannabinoid anandamide-mediated signaling exerts anxiolytic-like and cardioprotective effects. HAB rats displayed (i) a higher incidence of ventricular tachyarrhythmias induced by isoproterenol, and (ii) a larger spatial dispersion of ventricular refractoriness assessed by means of an epicardial mapping protocol. In HAB rats, acute pharmacological inhibition of the anandamide-degrading enzyme, fatty acid amide hydrolase (FAAH), with URB694 (0.3 mg/kg), (i) decreased anxiety-like behavior in the elevated plus maze, (ii) increased anandamide levels in the heart, (iii) reduced isoproterenol-induced occurrence of ventricular tachyarrhythmias, and (iv) corrected alterations of ventricular refractoriness. The anti-arrhythmic effect of URB694 was prevented by pharmacological blockade of the cannabinoid type 1 (CB1), but not of the CB2, receptor. These findings suggest that URB694 exerts anxiolytic-like and cardioprotective effects in HAB rats, the latter via anandamide-mediated activation of CB1 receptors. Thus, pharmacological inhibition of FAAH might be a viable pharmacological strategy for the treatment of anxiety-related cardiac dysfunction. PMID:26656183

Modulation of Regulatory T Cell Activity by TNF Receptor Type II-Targeting Pharmacological Agents

PubMed Central

Zou, Huimin; Li, Ruixin; Hu, Hao; Hu, Yuanjia; Chen, Xin

2018-01-01

There is now compelling evidence that tumor necrosis factor (TNF)–TNF receptor type II (TNFR2) interaction plays a decisive role in the activation, expansion, and phenotypical stability of suppressive CD4+Foxp3+ regulatory T cells (Tregs). In an effort to translate this basic research finding into a therapeutic benefit, a number of agonistic or antagonistic TNFR2-targeting biological agents with the capacity to activate or inhibit Treg activity have been developed and studied. Recent studies also show that thalidomide analogs, cyclophosphamide, and other small molecules are able to act on TNFR2, resulting in the elimination of TNFR2-expressing Tregs. In contrast, pharmacological agents, such as vitamin D3 and adalimumab, were reported to induce the expansion of Tregs by promoting the interaction of transmembrane TNF (tmTNF) with TNFR2. These studies clearly show that TNFR2-targeting pharmacological agents represent an effective approach to modulating the function of Tregs and thus may be useful in the treatment of major human diseases such as autoimmune disorders, graft-versus-host disease (GVHD), and cancer. In this review, we will summarize and discuss the latest progress in the study of TNFR2-targeting pharmacological agents and their therapeutic potential based on upregulation or downregulation of Treg activity. PMID:29632537

Complement-induced histamine release from human basophils. III. Effect of pharmacologic agents.

PubMed

Hook, W A; Siraganian, R P

1977-02-01

Human serum activated with zymosan generates a factor (C5a) that releases histamine from autologous basophils. Previously we have presented evidence that this mechanism for C5a-induced release differs from IgE-mediated reactions. The effect of several pharmacologic agents known to alter IgE-mediated release was studied to determine whether they have a similar action on serum-induced release. Deuterium oxide (D2O), which enhances allergic release, inhibited in a concentration-dependent fashion the serum-induced reaction at incubation temperatures of 25 and 32 degrees C. The colchicine-induced inhibition was not reversed by D2O. Cytochalasin B, which gives a variable enhancement of IgE-mediated release, had a marked enhancing effect on the serum-induced reaction in all subjects tested. The following agents known to inhibit the IgE-mediated reaction also inhibited serum-induced release at 25 degrees C: colchicine, dibutyryl cyclic AMP, aminophylline, isoproterenol, cholera toxin, chlorphenesin, diethylcarbamazine, and 2-deoxy-D-glucose. These results suggest that the serum-induced release is modulated by intracellular cyclic AMP, requires energy, and is enhanced by the disruption of microfilaments. The lack of an effect by D2O would suggest that microtubular stabilization is not required. The data can be interpreted to indicate that IgE- and C5a-mediated reactions diverge at a late stage in the histamine release pathway.

A Review on the Pharmacological Activities and Phytochemicals of Alpinia officinarum (Galangal) Extracts Derived from Bioassay-Guided Fractionation and Isolation

PubMed Central

Basri, Aida Maryam; Taha, Hussein; Ahmad, Norhayati

2017-01-01

The rhizomes of Alpinia officinarum Hance have been used conventionally for the treatment of various ailments, triggering a wide interest from the scientific research community on this ethnomedicinal plant. This review summarizes the phytochemical and pharmacological properties of the extracts and fractions from A. officinarum, a plant species of the Zingiberaceae family. Different parts of the plant – leaves, roots, rhizomes, and aerial parts – have been extracted in various solvents – methanol, ethanol, ethyl acetate, hexane, dichloromethane, aqueous, chloroform, and petroleum ether, using various techniques – Soxhlet extraction, maceration, ultrasonication, and soaking, whereas fractionation of the plant extracts involves the solvent–solvent partition method. The extracts, fractions, and isolated compounds have been studied for their biological activities – antioxidant, antibacterial, anti-inflammatory, anticancer, antiproliferative, inhibition of enzymes, as well as the inhibition of nitric oxide production. More findings on A. officinarum are certainly important to further develop potential bioactive drug compounds. PMID:28503054

Extraction, Characterization, Stability and Biological Activity of Flavonoids Isolated from Chamomile Flowers

PubMed Central

Srivastava, Janmejai K; Gupta, Sanjay

2009-01-01

Dried flowers of Chamomile (Matricaria chamomilla) are largely used for their medicinal properties. In the present study, we examined the pharmacological properties of aqueous and methanolic fraction isolated from two varieties of German chamomile. HPLC-MS analysis of chamomile extract confirmed apigenin-7-O-glucoside as the major constituent of chamomile; some minor glycoside components were observed along with essential oils. These glucosides are highly stable in solution at different temperature range and their degradation occurs after long-term storage and extraction conditions at different pH and solvent. Methanolic fraction isolated from chamomile flowers demonstrated higher biologic response in inhibiting cell growth and causing induction of apoptosis in various human cancer cell lines compared to aqueous chamomile fraction. Apigenin glucosides inhibited cancer cell growth through deconjugation of glycosides that occurs in the cellular compartment to produce aglycone, apigenin. Taken together, the pharmacological profile of chamomile extract was dependent upon extraction process, storage conditions which affected the biological activity. PMID:20098626

Geraniol rescues inflammation in cellular and animal models of mevalonate kinase deficiency.

PubMed

Marcuzzi, Annalisa; Crovella, Sergio; Pontillo, Alessandra

2011-01-01

The inhibition of the mevalonate pathway through genetic defects such as mevalonate kinase deficiency (MKD) or pharmacological drugs such as aminobisphosphonates causes a shortage of intermediate compounds, in particular geranylgeranyl-pyrophosphate (GGPP), which is associated with the consequent augmented IL-1β release in monocytes. Considering that, due to its biochemical structure, isoprenoid geraniol enters the mevalonate pathway and may revert the genetic or pharmacological inhibition, the present study tested isoprenoid geraniol in cellular and animal MKD models obtained through the use of aminobisphosphonate pamidronate. The effect of natural isoprenoid geraniol on bacterial induced-inflammation was evaluated in a monocytic cell line (Raw 264.7) and in Balb/c mice treated with pamidronate. Geraniol diminished the levels of inflammatory markers induced by pamidronate stimuli in vitro and in vivo. Geraniol may be proposed as a novel therapeutic approach for the orphan disease MKD, and may also be considered for the evaluation of possible inflammatory side-effects of aminobisphosphonates.

Monoamine transporter and receptor interaction profiles in vitro predict reported human doses of novel psychoactive stimulants and psychedelics.

PubMed

Luethi, Dino; Liechti, Matthias E

2018-05-29

Pharmacological profiles of new psychoactive substances (NPSs) can be established rapidly in vitro and provide information on potential psychoactive effects in humans. The present study investigated whether specific in vitro monoamine transporter and receptor interactions can predict effective psychoactive doses in humans. We correlated previously assessed in vitro data of stimulants and psychedelics with human doses that are reported on the Internet and in books. For stimulants, dopamine and norepinephrine transporter inhibition potency was positively correlated with human doses, whereas serotonin transporter inhibition potency was inversely correlated with human doses. Serotonin 5-hydroxytryptamine-2A (5-HT2A) and 5-HT2C receptor affinity was significantly correlated with psychedelic doses, but 5-HT1A receptor affinity and 5-HT2A and 5-HT2B receptor activation potency were not. The rapid assessment of in vitro pharmacological profiles of NPSs can help to predict psychoactive doses and effects in humans and facilitate the appropriate scheduling of NPSs.

Cancer-selective death of human breast cancer cells by leelamine is mediated by bax and bak activation.

PubMed

Sehrawat, Anuradha; Kim, Su-Hyeong; Hahm, Eun-Ryeong; Arlotti, Julie A; Eiseman, Julie; Shiva, Sruti S; Rigatti, Lora H; Singh, Shivendra V

2017-02-01

The present study is the first to report inhibition of breast cancer cell growth in vitro and in vivo and suppression of self-renewal of breast cancer stem cells (bCSC) by a pine bark component (leelamine). Except for a few recent publications in melanoma, anticancer pharmacology of this interesting phytochemical is largely elusive. Leelamine (LLM) dose-dependently inhibited viability of MDA-MB-231 (triple-negative), MCF-7 (estrogen receptor-positive), and SUM159 (triple-negative) human breast cancer cells in association with apoptotic cell death induction. To the contrary, a normal mammary epithelial cell line derived from fibrocystic breast disease and spontaneously immortalized (MCF-10A) was fully resistant to LLM-mediated cell growth inhibition and apoptosis induction. LLM also inhibited self-renewal of breast cancer stem cells. Apoptosis induction by LLM in breast cancer cells was accompanied by a modest increase in reactive oxygen species production, which was not due to inhibition of mitochondrial electron transport chain complexes. Nevertheless, ectopic expression of manganese superoxide dismutase conferred partial protection against LLM-induced cell death but only at a lower yet pharmacologically relevant concentration. Exposure of breast cancer cells to LLM resulted in (a) induction and/or activation of multidomain proapoptotic proteins Bax and Bak, (b) caspase-9 activation, and (c) cytosolic release of cytochrome c. Bax and Bak deficiency in immortalized fibroblasts conferred significant protection against cell death by LLM. Intraperitoneal administration of LLM (7.5 mg/kg; 5 times/wk) suppressed the growth of orthotopic SUM159 xenografts in mice without any toxicity. In conclusion, the present study provides critical preclinical data to warrant further investigation of LLM. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Possible mechanism for inhibition of morphine formation from 6-acetylmorphine after intake of street heroin.

PubMed

Andersson, Maria; Björkhem-Bergman, Linda; Beck, Olof

2015-07-01

Heroin is de-acetylated in the body to morphine in two steps. The intermediate 6-acetylmorphine (6-AM) is formed rapidly and is considered important for the pharmacological effect of heroin. In urine drug testing, an atypical pattern of morphine and 6-AM is known to occur in low frequency. The aim of this study was to investigate this atypical pattern in more detail and to identify responsible substances for a possible inhibition of the conversion from 6-AM to morphine. Urine samples were selected from a routine flow of samples sent for drug testing. Out of 695 samples containing morphine and 6-acetylmorphine, 11.5% had the atypical pattern of a 6-AM to morphine ratio above 0.26 as derived from a bimodal frequency distribution. An in vitro study of the conversion of 6-acetylmorphine to morphine in human liver homogenates demonstrated that a number of known carboxylesterase inhibitors were able to inhibit the reaction mimicking the situation in vivo. Compound 3 (3,6-Dimethoxy-4-acetoxy-5-[2-(N-methylacetamido)ethyl]phenanthrene) a substance formed from thebaine during the production of heroin was found to be a strong inhibitor. Liquid chromatography-mass spectrometry was used to identify possible inhibitors present in vivo. This part of the investigation demonstrated that several components may contribute to the effect. It is concluded that inhibition of liver carboxylesterase activity is a possible mechanism causing the atypical pattern and that one candidate compound is the result of the heroin production process. An inhibition of 6-AM metabolism is likely to increase the pharmacological effect of heroin and may be related to a higher risk of lethal toxicity. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Inhibition of Glycoprotein VI Clustering by Collagen as a Mechanism of Inhibiting Collagen-Induced Platelet Responses: The Example of Losartan

PubMed Central

Jiang, Peng; Loyau, Stéphane; Tchitchinadze, Maria; Ropers, Jacques; Jondeau, Guillaume; Jandrot-Perrus, Martine

2015-01-01

Exposure of platelets to collagen triggers the formation of a platelet clot. Pharmacological agents capable of inhibiting platelet activation by collagen are thus of potential therapeutic interest. Thrombus formation is initiated by the interaction of the GPIb-V-IX complex with collagen-bound vWF, while GPVI interaction with collagen triggers platelet activation that is reinforced by ADP and thromboxane A2. Losartan is an angiotensin II (Ang II) type I receptor (AT1R) antagonist proposed to have an antiplatelet activity via the inhibition of both the thromboxane A2 (TXA2) receptor (TP) and the glycoprotein VI (GPVI). Here, we characterized in vitro the effects of losartan at different doses on platelet responses: losartan inhibited platelet aggregation and secretion induced by 1 μg.mL-1 and 10 μg.mL-1 of collagen with an IC50 of ~ 6 μM. Losartan inhibited platelet responses induced by the GPVI specific collagen related peptide but not by the α2β1 specific peptide. However, losartan did not inhibit the binding of recombinant GPVI to collagen, which is not in favor of a simple competition. Indeed, the clustering of GPVI observed in flow cytometry and using the Duolink methodology, was inhibited by losartan. The impact of a therapeutic dose of losartan (100 mg/day) on platelet responses was analyzed ex vivo in a double blind study. No statistically significant differences were observed between losartan-treated (n=25) and non-treated (n=30) patients in terms of collagen and U46619-induced platelet activation. These data indicate that in treated patients, losartan does not achieve a measurable antiplatelet effect but provide the proof of concept that inhibiting collagen-induced GPVI clustering is of pharmacological interest to obtain an antithrombotic efficacy. Trial Registration ClinicalTrials.gov NCT00763893 PMID:26052700

Network Architecture Predisposes an Enzyme to Either Pharmacologic or Genetic Targeting.

PubMed

Jensen, Karin J; Moyer, Christian B; Janes, Kevin A

2016-02-24

Chemical inhibition and genetic knockdown of enzymes are not equivalent in cells, but network-level mechanisms that cause discrepancies between knockdown and inhibitor perturbations are not understood. Here we report that enzymes regulated by negative feedback are robust to knockdown but susceptible to inhibition. Using the Raf-MEK-ERK kinase cascade as a model system, we find that ERK activation is resistant to genetic knockdown of MEK but susceptible to a comparable degree of chemical MEK inhibition. We demonstrate that negative feedback from ERK to Raf causes this knockdown-versus-inhibitor discrepancy in vivo. Exhaustive mathematical modeling of three-tiered enzyme cascades suggests that this result is general: negative autoregulation or feedback favors inhibitor potency, whereas positive autoregulation or feedback favors knockdown potency. Our findings provide a rationale for selecting pharmacologic versus genetic perturbations in vivo and point out the dangers of using knockdown approaches in search of drug targets.

Inhibition of P-glycoprotein enhances transport of imipramine across the blood-brain barrier: microdialysis studies in conscious freely moving rats.

PubMed

O'Brien, F E; Clarke, G; Fitzgerald, P; Dinan, T G; Griffin, B T; Cryan, J F

2012-06-01

Recent studies indicate that efflux of antidepressants by the multidrug resistance transporter P-glycoprotein (P-gp) at the blood-brain barrier (BBB) may contribute to treatment-resistant depression (TRD) by limiting intracerebral antidepressant concentrations. In addition, clinical experience shows that adjunctive treatment with the P-gp inhibitor verapamil may improve the clinical outcome in TRD. Therefore, the present study aimed to investigate the effect of P-gp inhibition on the transport of the tricyclic antidepressant imipramine and its active metabolite desipramine across the BBB. Intracerebral microdialysis in rats was used to monitor brain levels of imipramine and desipramine following i.v. imipramine administration, with or without pretreatment with one of the P-gp inhibitors verapamil or cyclosporin A (CsA). Plasma drug levels were also determined at regular intervals. Pretreatment with either verapamil or CsA resulted in significant increases in imipramine concentrations in the microdialysis samples, without altering imipramine plasma pharmacokinetics. Furthermore, pretreatment with verapamil, but not CsA, led to a significant elevation in plasma and brain levels of desipramine. The present study demonstrated that P-gp inhibition enhanced the intracerebral concentration of imipramine , thus supporting the hypothesis that P-gp activity restricts brain levels of certain antidepressants, including imipramine. These findings may help to explain reports of a beneficial response to adjunctive therapy with verapamil in TRD. © 2012 The Authors. British Journal of Pharmacology © 2012 The British Pharmacological Society.

In vitro growth inhibition of human cancer cells by novel honokiol analogs.

PubMed

Lin, Jyh Ming; Prakasha Gowda, A S; Sharma, Arun K; Amin, Shantu

2012-05-15

Honokiol possesses many pharmacological activities including anti-cancer properties. Here in, we designed and synthesized honokiol analogs that block major honokiol metabolic pathway which may enhance their effectiveness. We studied their cytotoxicity in human cancer cells and evaluated possible mechanism of cell cycle arrest. Two analogs, namely 2 and 4, showed much higher growth inhibitory activity in A549 human lung cancer cells and significant increase of cell population in the G0-G1 phase. Further elucidation of the inhibition mechanism on cell cycle showed that analogs 2 and 4 inhibit both CDK1 and cyclin B1 protien levels in A549 cells. Copyright © 2012 Elsevier Ltd. All rights reserved.

The membrane effects, and sensitivity to strychnine, of neural inhibition of the Mauthner cell, and its inhibition by glycine and GABA

PubMed Central

Diamond, J.; Roper, S.; Yasargil, G. M.

1973-01-01

1. Anionic conductance changes in Mauthner neurones of goldfish were measured during synaptically evoked inhibition and inhibition caused by iontophoretic application of the putative inhibitory transmitters glycine and γ-aminobutyric acid (GABA). 2. The effects of either amino acid were indistinguishable from those of the neural inhibitory transmitter(s). The membrane permeability during the neural or drug response was increased to Br-, Cl-, I-, SCN-, NO3-, ClO3-, and formate (HCOO-), but not to HCO3-, BrO3-, IO3-, SO4-, HPO4-, H2PO4-, acetate and citrate. 3. Strychnine was injected intramuscularly, iontophoretically, or applied topically to the exposed brain in order to compare quantitatively its ability to prevent inhibition evoked by synaptic activation and by pharmacological means. Inhibitions were measured by the increase in membrane conductance. 4. Strychnine, at concentrations just adequate to block completely the late collateral inhibition (LCI) and crossed VIII nerve inhibition, had little effect on the pharmacological inhibition caused by glycine, and sometimes there was no detectable effect at all. In one experiment even a local iontophoretic application of strychnine in a sufficient dose to diffuse over the cell and block the LCI almost completely, merely halved the effect of a small dose of glycine applied to the same localized region of the membrane. 5. Higher concentrations of strychnine than those necessary to block synaptically evoked inhibition would reduce the effect of glycine but not that of GABA. The evidence indicated that any apparent effect of strychnine upon GABA could be explained by displacement of the GABA-containing iontophoretic pipette. 6. The glycine-blocking action of iontophoretic pulses of strychnine was of relatively very slow onset and long duration compared to the effects of pulses of glycine and GABA. 7. These findings can be interpreted as either (1) strychnine has a presynaptic action, preventing the release of inhibitory neurotransmitter, in addition to its less potent post-synaptic one in blocking pharmacological inhibition, or (2) strychnine acts entirely post-synaptically, but the physiological transmitter action differs from that of glycine and GABA in being considerably more sensitive to strychnine antagonism. In either case, the use of strychnine as evidence for the claim that glycine is an inhibitory neurotransmitter at the Mauthner cell is questionable. PMID:4354770

Cocaine Inhibits Store-Operated Ca2+ Entry in Brain Microvascular Endothelial Cells: Critical Role for Sigma-1 Receptors

PubMed Central

Brailoiu, G. Cristina; Deliu, Elena; Console-Bram, Linda M; Soboloff, Jonathan; Abood, Mary E; Unterwald, Ellen M; Brailoiu, Eugen

2015-01-01

Sigma-1 receptor (Sig-1R) is an intracellular chaperone protein with many ligands, located at the endoplasmic reticulum. Binding of cocaine to Sig-1R has previously been found to modulate endothelial functions. In the present study, we show that cocaine dramatically inhibits store-operated Ca2+ entry (SOCE), a Ca2+ influx mechanism promoted by depletion of intracellular Ca2+ stores, in rat brain microvascular endothelial cells. Using either Sig-1R shRNA or pharmacological inhibition with the unrelated Sig-1R antagonists BD-1063 and NE-100, we show that cocaine-induced SOCE inhibition is dependent on Sig-1R. In addition to revealing new insight into fundamental mechanisms of cocaine-induced changes in endothelial function, these studies provide an unprecedented role for Sig-1R as a SOCE inhibitor. PMID:26467159

Advances in the development of AMPK-activating compounds.

PubMed

Sriwijitkamol, Apiradee; Musi, Nicolas

2008-10-01

AMP-activated protein kinase (AMPK) is an energy sensing enzyme that controls glucose and lipid metabolism. This review summarizes the present data on AMPK as a pharmacologic target for the treatment of metabolic disorders. The mechanisms governing AMPK activity and how this enzyme controls different metabolic pathways are reviewed briefly, and details about the effect that AMPK activators have on glucose metabolism are provided. Evidence obtained using the AMPK-activating compound 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside (AICAR) suggests that AMPK promotes glucose transport into skeletal muscles and that this enzyme inhibits hepatic glucose production. AICAR also induces fatty acid oxidation in muscle and inhibits cholesterol synthesis in the liver. The metabolic effects of AICAR on glucose and lipid metabolism indicate that AMPK may be a good pharmacologic target for the treatment of type 2 diabetes and hypercholesterolemia. Novel AMPK-specific compounds are allowing researchers to examine whether this enzyme is a useful pharmacologic target for the treatment of human disease and whether chronic activation of AMPK will be safe.

Potential Antileukemia Effect and Structural Analyses of SRPK Inhibition by N-(2-(Piperidin-1-yl)-5-(Trifluoromethyl)Phenyl)Isonicotinamide (SRPIN340)

PubMed Central

Siqueira, Raoni Pais; Righetto, Germanna Lima; Seraphim, Thiago Vargas; Salgado, Rafael Locatelli; Ferreira, Joana Gasperazzo; Barros, Marcus Vinícius de Andrade; de Oliveira, Leandro Licursi; Laranjeira, Angelo Brunelli Albertoni; Almeida, Márcia Rogéria; Júnior, Abelardo Silva; Fietto, Juliana Lopes Rangel; Kobarg, Jörg; de Oliveira, Eduardo Basílio; Teixeira, Robson Ricardo; Borges, Júlio César; Yunes, Jose Andrés; Bressan, Gustavo Costa

2015-01-01

Dysregulation of pre-mRNA splicing machinery activity has been related to the biogenesis of several diseases. The serine/arginine-rich protein kinase family (SRPKs) plays a critical role in regulating pre-mRNA splicing events through the extensive phosphorylation of splicing factors from the family of serine/arginine-rich proteins (SR proteins). Previous investigations have described the overexpression of SRPK1 and SRPK2 in leukemia and other cancer types, suggesting that they would be useful targets for developing novel antitumor strategies. Herein, we evaluated the effect of selective pharmacological SRPK inhibition by N-(2-(piperidin-1-yl)-5-(trifluoromethyl)phenyl)isonicotinamide (SRPIN340) on the viability of lymphoid and myeloid leukemia cell lines. Along with significant cytotoxic activity, the effect of treatments in regulating the phosphorylation of the SR protein family and in altering the expression of MAP2K1, MAP2K2, VEGF and FAS genes were also assessed. Furthermore, we found that pharmacological inhibition of SRPKs can trigger early and late events of apoptosis. Finally, intrinsic tryptophan fluorescence emission, molecular docking and molecular dynamics were analyzed to gain structural information on the SRPK/SRPIN340 complex. These data suggest that SRPK pharmacological inhibition should be considered as an alternative therapeutic strategy for fighting leukemias. Moreover, the obtained SRPK-ligand interaction data provide useful structural information to guide further medicinal chemistry efforts towards the development of novel drug candidates. PMID:26244849

Potential Antileukemia Effect and Structural Analyses of SRPK Inhibition by N-(2-(Piperidin-1-yl)-5-(Trifluoromethyl)Phenyl)Isonicotinamide (SRPIN340).

PubMed

Siqueira, Raoni Pais; Barbosa, Éverton de Almeida Alves; Polêto, Marcelo Depólo; Righetto, Germanna Lima; Seraphim, Thiago Vargas; Salgado, Rafael Locatelli; Ferreira, Joana Gasperazzo; Barros, Marcus Vinícius de Andrade; de Oliveira, Leandro Licursi; Laranjeira, Angelo Brunelli Albertoni; Almeida, Márcia Rogéria; Júnior, Abelardo Silva; Fietto, Juliana Lopes Rangel; Kobarg, Jörg; de Oliveira, Eduardo Basílio; Teixeira, Robson Ricardo; Borges, Júlio César; Yunes, Jose Andrés; Bressan, Gustavo Costa

2015-01-01

Dysregulation of pre-mRNA splicing machinery activity has been related to the biogenesis of several diseases. The serine/arginine-rich protein kinase family (SRPKs) plays a critical role in regulating pre-mRNA splicing events through the extensive phosphorylation of splicing factors from the family of serine/arginine-rich proteins (SR proteins). Previous investigations have described the overexpression of SRPK1 and SRPK2 in leukemia and other cancer types, suggesting that they would be useful targets for developing novel antitumor strategies. Herein, we evaluated the effect of selective pharmacological SRPK inhibition by N-(2-(piperidin-1-yl)-5-(trifluoromethyl)phenyl)isonicotinamide (SRPIN340) on the viability of lymphoid and myeloid leukemia cell lines. Along with significant cytotoxic activity, the effect of treatments in regulating the phosphorylation of the SR protein family and in altering the expression of MAP2K1, MAP2K2, VEGF and FAS genes were also assessed. Furthermore, we found that pharmacological inhibition of SRPKs can trigger early and late events of apoptosis. Finally, intrinsic tryptophan fluorescence emission, molecular docking and molecular dynamics were analyzed to gain structural information on the SRPK/SRPIN340 complex. These data suggest that SRPK pharmacological inhibition should be considered as an alternative therapeutic strategy for fighting leukemias. Moreover, the obtained SRPK-ligand interaction data provide useful structural information to guide further medicinal chemistry efforts towards the development of novel drug candidates.

MPX-004 and MPX-007: New Pharmacological Tools to Study the Physiology of NMDA Receptors Containing the GluN2A Subunit.

PubMed

Volkmann, Robert A; Fanger, Christopher M; Anderson, David R; Sirivolu, Venkata Ramana; Paschetto, Kathy; Gordon, Earl; Virginio, Caterina; Gleyzes, Melanie; Buisson, Bruno; Steidl, Esther; Mierau, Susanna B; Fagiolini, Michela; Menniti, Frank S

2016-01-01

GluN2A is the most abundant of the GluN2 NMDA receptor subunits in the mammalian CNS. Physiological and genetic evidence implicate GluN2A-containing receptors in susceptibility to autism, schizophrenia, childhood epilepsy and neurodevelopmental disorders such as Rett Syndrome. However, GluN2A-selective pharmacological probes to explore the therapeutic potential of targeting these receptors have been lacking. Here we disclose a novel series of pyrazine-containing GluN2A antagonists exemplified by MPX-004 (5-(((3-chloro-4-fluorophenyl)sulfonamido)methyl)-N-((2-methylthiazol-5-yl)methyl)pyrazine-2-carboxamide) and MPX-007 (5-(((3-fluoro-4-fluorophenyl)sulfonamido)methyl)-N-((2-methylthiazol-5-yl)methyl)methylpyrazine-2-carboxamide). MPX-004 and MPX-007 inhibit GluN2A-containing NMDA receptors expressed in HEK cells with IC50s of 79 nM and 27 nM, respectively. In contrast, at concentrations that completely inhibited GluN2A activity these compounds have no inhibitory effect on GluN2B or GluN2D receptor-mediated responses in similar HEK cell-based assays. Potency and selectivity were confirmed in electrophysiology assays in Xenopus oocytes expressing GluN2A-D receptor subtypes. Maximal concentrations of MPX-004 and MPX-007 inhibited ~30% of the whole-cell current in rat pyramidal neurons in primary culture and MPX-004 inhibited ~60% of the total NMDA receptor-mediated EPSP in rat hippocampal slices. GluN2A-selectivity at native receptors was confirmed by the finding that MPX-004 had no inhibitory effect on NMDA receptor mediated synaptic currents in cortical slices from GRIN2A knock out mice. Thus, MPX-004 and MPX-007 offer highly selective pharmacological tools to probe GluN2A physiology and involvement in neuropsychiatric and developmental disorders.

Recent advances in the study of (–)clausenamide: chemistry, biological activities and mechanism of action

PubMed Central

Chu, Shi-feng; Zhang, Jun-tian

2014-01-01

Clausenamide (clau) is one of seven novel compounds isolated from Clausena lansium (Lour) skeels. Clau is unusual in that it contains 4 chiral centers yielding 8 pairs of enantiomers. After identification of the configuration of these enantiomers, the synthesis of 16 enantiomers, including optically active clau and (+) and (–)clau was carried out. During this study, many stereochemical and synthetic difficulties were solved and the Baldwin principle was updated. Production scale is now sufficient to meet the needs of clinical practice. In a pharmacological study numerous models and indicators showed that (–)clau is the active enantiomer, while (+)clau is inactive and elicits greater toxicity than (–)clau. The principal pharmacological effects of (–)clau are to increase cognition, demonstrated in ten models of memory impairment, as well as to inhibit β-amyloid (Aβ) toxicity, blocking neurofibrillary tangle formation by inhibiting the phosphorylation of tau protein. This anti-dementia effect is characterized by increased synaptic plasticity both in efficacy and in structure and provides new support for the theory that synaptic loss is the main cause of dementia. (–)Clau is considered to be a promising drug candidate for treatment of Alzheimer׳s disease and other neurodegenerative disorders. PMID:26579412

Aerobic Exercise and Pharmacological Therapies for Skeletal Myopathy in Heart Failure: Similarities and Differences

PubMed Central

Bacurau, Aline V.; Cunha, Telma F.; Souza, Rodrigo W.; Voltarelli, Vanessa A.; Gabriel-Costa, Daniele; Brum, Patricia C.

2016-01-01

Skeletal myopathy has been identified as a major comorbidity of heart failure (HF) affecting up to 20% of ambulatory patients leading to shortness of breath, early fatigue, and exercise intolerance. Neurohumoral blockade, through the inhibition of renin angiotensin aldosterone system (RAS) and β-adrenergic receptor blockade (β-blockers), is a mandatory pharmacological therapy of HF since it reduces symptoms, mortality, and sudden death. However, the effect of these drugs on skeletal myopathy needs to be clarified, since exercise intolerance remains in HF patients optimized with β-blockers and inhibitors of RAS. Aerobic exercise training (AET) is efficient in counteracting skeletal myopathy and in improving functional capacity and quality of life. Indeed, AET has beneficial effects on failing heart itself despite being of less magnitude compared with neurohumoral blockade. In this way, AET should be implemented in the care standards, together with pharmacological therapies. Since both neurohumoral inhibition and AET have a direct and/or indirect impact on skeletal muscle, this review aims to provide an overview of the isolated effects of these therapeutic approaches in counteracting skeletal myopathy in HF. The similarities and dissimilarities of neurohumoral inhibition and AET therapies are also discussed to identify potential advantageous effects of these combined therapies for treating HF. PMID:26904163

Apigenin Restricts FMDV Infection and Inhibits Viral IRES Driven Translational Activity

PubMed Central

Qian, Suhong; Fan, Wenchun; Qian, Ping; Zhang, Dong; Wei, Yurong; Chen, Huanchun; Li, Xiangmin

2015-01-01

Foot-and-mouth disease (FMD) is a highly contagious disease of domestic and wild ruminants that is caused by FMD virus (FMDV). FMD outbreaks have occurred in livestock-containing regions worldwide. Apigenin, which is a flavonoid naturally existing in plant, possesses various pharmacological effects, including anti-inflammatory, anticancer, antioxidant and antiviral activities. Results show that apigenin can inhibit FMDV-mediated cytopathogenic effect and FMDV replication in vitro. Further studies demonstrate the following: (i) apigenin inhibits FMDV infection at the viral post-entry stage; (ii) apigenin does not exhibit direct extracellular virucidal activity; and (iii) apigenin interferes with the translational activity of FMDV driven by internal ribosome entry site. Studies on applying apigein in vivo are required for drug development and further identification of potential drug targets against FDMV infection. PMID:25835532

Apigenin restricts FMDV infection and inhibits viral IRES driven translational activity.

PubMed

Qian, Suhong; Fan, Wenchun; Qian, Ping; Zhang, Dong; Wei, Yurong; Chen, Huanchun; Li, Xiangmin

2015-03-31

Foot-and-mouth disease (FMD) is a highly contagious disease of domestic and wild ruminants that is caused by FMD virus (FMDV). FMD outbreaks have occurred in livestock-containing regions worldwide. Apigenin, which is a flavonoid naturally existing in plant, possesses various pharmacological effects, including anti-inflammatory, anticancer, antioxidant and antiviral activities. Results show that apigenin can inhibit FMDV-mediated cytopathogenic effect and FMDV replication in vitro. Further studies demonstrate the following: (i) apigenin inhibits FMDV infection at the viral post-entry stage; (ii) apigenin does not exhibit direct extracellular virucidal activity; and (iii) apigenin interferes with the translational activity of FMDV driven by internal ribosome entry site. Studies on applying apigein in vivo are required for drug development and further identification of potential drug targets against FDMV infection.

Reducing excessive GABAergic tonic inhibition promotes post-stroke functional recovery

PubMed Central

Clarkson, Andrew N.; Huang, Ben S.; MacIsaac, Sarah E.; Mody, Istvan; Carmichael, S. Thomas

2010-01-01

Stroke is a leading cause of disability; but no pharmacological therapy is currently available for promoting recovery. The brain region adjacent to stroke damage, the peri-infarct zone, is critical for rehabilitation, as it exhibits heightened neuroplasticity, allowing sensorimotor functions to re-map from damaged areas1–3. Thus, understanding the neuronal properties constraining this plasticity is important to developing new treatments. Here we show that after a stroke in mice, tonic neuronal inhibition is increased in the peri-infarct zone. This increased tonic inhibition is mediated by extrasynaptic GABAA receptors (GABAARs) and is caused by an impairment in GABA transporter (GAT-3/4) function. To counteract the heightened inhibition, we administered in vivo a benzodiazepine inverse agonist specific for the α5-subunit-containing extrasynaptic GABAARs at a delay after stroke. This treatment produced an early and sustained recovery of motor function. Genetically lowering the number of α5 or δ-subunit-containing GABAARs responsible for tonic inhibition also proved beneficial for post-stroke recovery, consistent with the therapeutic potential of diminishing extrasynaptic GABAAR function. Together, our results identify new pharmacological targets and provide the rationale for a novel strategy to promote recovery after stroke and possibly other brain injuries. PMID:21048709

A network pharmacology approach to discover active compounds and action mechanisms of San-Cao Granule for treatment of liver fibrosis

PubMed Central

Wei, Shizhang; Niu, Ming; Wang, Jian; Wang, Jiabo; Su, Haibin; Luo, Shengqiang; Zhang, Xiaomei; Guo, Yanlei; Liu, Liping; Liu, Fengqun; Zhao, Qingguo; Chen, Hongge; Xiao, Xiaohe; Zhao, Pan; Zhao, Yanling

2016-01-01

Ethnopharmacological relevance San-Cao Granule (SCG) has been used in patients with liver fibrosis for many years and has shown good effect. However, its mechanism of therapeutic action is not clear because of its complex chemical system. The purpose of our study is to establish a comprehensive and systemic method that can predict the mechanism of action of SCG in antihepatic fibrosis. Materials and methods In this study, a “compound–target–disease” network was constructed by combining the SCG-specific and liver fibrosis–specific target proteins with protein–protein interactions, and network pharmacology was used to screen out the underlying targets and mechanisms of SCG for treatment of liver fibrosis. Then, some key molecules of the enriched pathway were chosen to verify the effects of SCG on liver fibrosis induced by thioacetamide (TAA). Results This systematic approach had successfully revealed that 16 targets related to 11 SCG compounds were closely associated with liver fibrosis therapy. The pathway-enrichment analysis of them showed that the TGF-β1/Smad signaling pathway is relatively important. Animal experiments also proved that SCG could significantly ameliorate liver fibrosis by inhibiting the TGF-β1/Smad pathway. Conclusion SCG could alleviate liver fibrosis through the molecular mechanisms predicted by network pharmacology. Furthermore, network pharmacology could provide deep insight into the pharmacological mechanisms of Chinese herbal formulas. PMID:26929602

A network pharmacology approach to discover active compounds and action mechanisms of San-Cao Granule for treatment of liver fibrosis.

PubMed

Wei, Shizhang; Niu, Ming; Wang, Jian; Wang, Jiabo; Su, Haibin; Luo, Shengqiang; Zhang, Xiaomei; Guo, Yanlei; Liu, Liping; Liu, Fengqun; Zhao, Qingguo; Chen, Hongge; Xiao, Xiaohe; Zhao, Pan; Zhao, Yanling

2016-01-01

San-Cao Granule (SCG) has been used in patients with liver fibrosis for many years and has shown good effect. However, its mechanism of therapeutic action is not clear because of its complex chemical system. The purpose of our study is to establish a comprehensive and systemic method that can predict the mechanism of action of SCG in antihepatic fibrosis. In this study, a "compound-target-disease" network was constructed by combining the SCG-specific and liver fibrosis-specific target proteins with protein-protein interactions, and network pharmacology was used to screen out the underlying targets and mechanisms of SCG for treatment of liver fibrosis. Then, some key molecules of the enriched pathway were chosen to verify the effects of SCG on liver fibrosis induced by thioacetamide (TAA). This systematic approach had successfully revealed that 16 targets related to 11 SCG compounds were closely associated with liver fibrosis therapy. The pathway-enrichment analysis of them showed that the TGF-β1/Smad signaling pathway is relatively important. Animal experiments also proved that SCG could significantly ameliorate liver fibrosis by inhibiting the TGF-β1/Smad pathway. SCG could alleviate liver fibrosis through the molecular mechanisms predicted by network pharmacology. Furthermore, network pharmacology could provide deep insight into the pharmacological mechanisms of Chinese herbal formulas.

Repaglinide-gemfibrozil drug interaction: inhibition of repaglinide glucuronidation as a potential additional contributing mechanism.

PubMed

Gan, Jinping; Chen, Weiqi; Shen, Hong; Gao, Ling; Hong, Yang; Tian, Yuan; Li, Wenying; Zhang, Yueping; Tang, Yuwei; Zhang, Hongjian; Humphreys, William Griffith; Rodrigues, A David

2010-12-01

To further explore the mechanism underlying the interaction between repaglinide and gemfibrozil, alone or in combination with itraconazole. Repaglinide metabolism was assessed in vitro (human liver subcellular fractions, fresh human hepatocytes, and recombinant enzymes) and the resulting incubates were analyzed, by liquid chromatography-mass spectrometry (LC-MS) and radioactivity counting, to identify and quantify the different metabolites therein. Chemical inhibitors, in addition to a trapping agent, were also employed to elucidate the importance of each metabolic pathway. Finally, a panel of human liver microsomes (genotyped for UGT1A1*28 allele status) was used to determine the importance of UGT1A1 in the direct glucuronidation of repaglinide. The results of the present study demonstrate that repaglinide can undergo direct glucuronidation, a pathway that can possibly contribute to the interaction with gemfibrozil. For example, [³H]-repaglinide formed glucuronide and oxidative metabolites (M2 and M4) when incubated with primary human hepatocytes. Gemfibrozil effectively inhibited (∼78%) both glucuronide and M4 formation, but had a minor effect on M2 formation. Concomitantly, the overall turnover of repaglinide was also inhibited (∼80%), and was completely abolished when gemfibrozil was co-incubated with itraconazole. These observations are in qualitative agreement with the in vivo findings. UGT1A1 plays a significant role in the glucuronidation of repaglinide. In addition, gemfibrozil and its glucuronide inhibit repaglinide glucuronidation and the inhibition by gemfibrozil glucuronide is time-dependent. Inhibition of UGT enzymes, especially UGT1A1, by gemfibrozil and its glucuronide is an additional mechanism to consider when rationalizing the interaction between repaglinide and gemfibrozil. © 2010 The Authors. British Journal of Clinical Pharmacology © 2010 The British Pharmacological Society.

Role of ion channels and subcellular Ca2+ signaling in arachidonic acid-induced dilation of pressurized retinal arterioles.

PubMed

Kur, Joanna; McGahon, Mary K; Fernández, Jose A; Scholfield, C Norman; McGeown, J Graham; Curtis, Tim M

2014-05-02

To investigate the mechanisms responsible for the dilatation of rat retinal arterioles in response to arachidonic acid (AA). Changes in the diameter of isolated, pressurized rat retinal arterioles were measured in the presence of AA alone and following pre-incubation with pharmacologic agents inhibiting Ca(2+) sparks and oscillations and K(+) channels. Subcellular Ca(2+) signals were recorded in arteriolar myocytes using Fluo-4-based confocal imaging. The effects of AA on membrane currents of retinal arteriolar myocytes were studied using whole-cell perforated patch clamp recording. Arachidonic acid dilated pressurized retinal arterioles under conditions of myogenic tone. Eicosatetraynoic acid (ETYA) exerted a similar effect, but unlike AA, its effects were rapidly reversible. Arachidonic acid-induced dilation was associated with an inhibition of subcellular Ca(2+) signals. Interventions known to block Ca(2+) sparks and oscillations in retinal arterioles caused dilatation and inhibited AA-induced vasodilator responses. Arachidonic acid accelerated the rate of inactivation of the A-type Kv current and the voltage dependence of inactivation was shifted to more negative membrane potentials. It also enhanced voltage-activated and spontaneous large-conductance calcium-activated K(+) (BK) currents, but only at positive membrane potentials. Pharmacologic inhibition of A-type Kv and BK currents failed to block AA-induced vasodilator responses. Arachidonic acid suppressed L-type Ca(2+) currents. These results suggest that AA induces retinal arteriolar vasodilation by inhibiting subcellular Ca(2+)-signaling activity in retinal arteriolar myocytes, most likely through a mechanism involving the inhibition of L-type Ca(2+)-channel activity. Arachidonic acid actions on K(+) currents are inconsistent with a model in which K(+) channels contribute to the vasodilator effects of AA.

Dual activation of CFTR and CLCN2 by lubiprostone in murine nasal epithelia

PubMed Central

Schiffhauer, Eric S.; Vij, Neeraj; Kovbasnjuk, Olga; Kang, Po Wei; Walker, Doug; Lee, Seakwoo

2013-01-01

Multiple sodium and chloride channels on the apical surface of nasal epithelial cells contribute to periciliary fluid homeostasis, a function that is disrupted in patients with cystic fibrosis (CF). Among these channels is the chloride channel CLCN2, which has been studied as a potential alternative chloride efflux pathway in the absence of CFTR. The object of the present study was to use the nasal potential difference test (NPD) to quantify CLCN2 function in an epithelial-directed TetOn CLCN2 transgenic mouse model (TGN-K18rtTA-hCLCN2) by using the putative CLCN2 pharmacological agonist lubiprostone and peptide inhibitor GaTx2. Lubiprostone significantly increased chloride transport in the CLCN2-overexpressing mice following activation of the transgene by doxycycline. This response to lubiprostone was significantly inhibited by GaTx2 after CLCN2 activation in TGN-CLCN2 mice. Cftr−/− and Clc2−/− mice showed hyperpolarization indicative of chloride efflux in response to lubiprostone, which was fully inhibited by GaTx2 and CFTR inhibitor 172 + GlyH-101, respectively. Our study reveals lubiprostone as a pharmacological activator of both CFTR and CLCN2. Overexpression and activation of CLCN2 leads to improved mouse NPD readings, suggesting it is available as an alternative pathway for epithelial chloride secretion in murine airways. The utilization of CLCN2 as an alternative chloride efflux channel could provide clinical benefit to patients with CF, especially if the pharmacological activator is administered as an aerosol. PMID:23316067

The in vitro and in vivo pharmacological profiles of a platelet glycoprotein IIb/IIIa antagonist, NSL-9403.

PubMed

Katada, J; Takiguchi, Y; Muramatsu, M; Fujiyoshi, T; Uno, I

1997-10-01

The in vitro and in vivo pharmacological profiles of NSL-9403 [orotyl-serylarginyl-glycyl-asparatyl-tryptophane], a platelet glycoprotein IIb/IIIa (GpIIb/IIIa) antagonist, has been studied. NSL-9403 inhibited platelet aggregation of human platelet-rich plasma (PRP) with IC50 values of 4.3 +/- 0.4 microM (collagen) and 1.8 +/- 0.3 microM (ADP), which was about 100 times more potent than RGDS. It also inhibited the binding of fibrinogen to activated platelets. Ex vivo collagen and ADP-induced platelet aggregation in a guinea pig was inhibited after a bolus intravenous administration of NSL-9403 at 1.25 mg/kg and above. NSL-9403 had an anti-thrombotic effect in in vivo thrombosis models. In a platelet agonist-induced pulmonary embolic sudden death model, where a bolus injection of collagen and epinephrine induced sudden death in mice, intravenous administration of NSL-9403 before an injection of collagen and epinephrine inhibited this platelet-agonist induced death in a dose dependent manner. In an arterio-venous shunt, infusion of NSL-9403 at 3 mg/kg/hour prevented an increase in circulation pressure due to thrombus formation in the shunt circuit and platelet loss. Infusion of NSL-9403 at 1 to 10 mg/kg/hour produced a complete inhibition of platelet-dependent arterial thrombosis in a dog femoral arterial thrombosis model. Thus NSL-9403 is a potent inhibitor or platelet aggregation in vitro and a potent anti-thrombotic agent in vivo with a relatively short duration of action.

Agonist-induced CXCR4 and CB2 Heterodimerization Inhibits Gα13/RhoA-mediated Migration.

PubMed

Scarlett, Kisha A; White, El-Shaddai Z; Coke, Christopher J; Carter, Jada R; Bryant, Latoya K; Hinton, Cimona V

2018-04-01

G-protein-coupled receptor (GPCR) heterodimerization has emerged as a means by which alternative signaling entities can be created; yet, how receptor heterodimers affect receptor pharmacology remains unknown. Previous observations suggested a biochemical antagonism between GPCRs, CXCR4 and CB2 (CNR2), where agonist-bound CXCR4 and agonist-bound CB2 formed a physiologically nonfunctional heterodimer on the membrane of cancer cells, inhibiting their metastatic potential in vitro However, the reduced signaling entities responsible for the observed functional outputs remain elusive. This study now delineates the signaling mechanism whereby heterodimeric association between CXCR4 and CB2, induced by simultaneous agonist treatment, results in decreased CXCR4-mediated cell migration, invasion, and adhesion through inhibition of the Gα13/RhoA signaling axis. Activation of CXCR4 by its cognate ligand, CXCL12, stimulates Gα13 (GNA13), and subsequently, the small GTPase RhoA, which is required for directional cell migration and the metastatic potential of cancer cells. These studies in prostate cancer cells demonstrate decreased protein expression levels of Gα13 and RhoA upon simultaneous CXCR4/CB2 agonist stimulation. Furthermore, the agonist-induced heterodimer abrogated RhoA-mediated cytoskeletal rearrangement resulting in the attenuation of cell migration and invasion of an endothelial cell barrier. Finally, a reduction was observed in the expression of integrin α5 (ITGA5) upon heterodimerization, supported by decreased cell adhesion to extracellular matrices in vitro Taken together, the data identify a novel pharmacologic mechanism for the modulation of tumor cell migration and invasion in the context of metastatic disease. Implications: This study investigates a signaling mechanism by which GPCR heterodimerization inhibits cancer cell migration. Mol Cancer Res; 16(4); 728-39. ©2018 AACR . ©2018 American Association for Cancer Research.

Placental growth factor and its potential role in diabetic retinopathy and other ocular neovascular diseases.

PubMed

Nguyen, Quan Dong; De Falco, Sandro; Behar-Cohen, Francine; Lam, Wai-Ching; Li, Xuri; Reichhart, Nadine; Ricci, Federico; Pluim, Jennifer; Li, William W

2018-02-01

The role of vascular endothelial growth factor (VEGF), including in retinal vascular diseases, has been well studied, and pharmacological blockade of VEGF is the gold standard of treatment for neovascular age-related macular degeneration, retinal vein occlusion and diabetic macular oedema. Placental growth factor (PGF, previously known as PlGF), a homologue of VEGF, is a multifunctional peptide associated with angiogenesis-dependent pathologies in the eye and non-ocular conditions. Animal studies using genetic modification and pharmacological treatment have demonstrated a mechanistic role for PGF in pathological angiogenesis. Inhibition decreases neovascularization and microvascular abnormalities across different models, including oxygen-induced retinopathy, laser-induced choroidal neovascularization and in diabetic mice exhibiting retinopathies. High levels of PGF have been found in the vitreous of patients with diabetic retinopathy. Despite these strong animal data, the exact role of PGF in pathological angiogenesis in retinal vascular diseases remains to be defined, and the benefits of PGF-specific inhibition in humans with retinal neovascular diseases and macular oedema remain controversial. Comparative effectiveness research studies in patients with diabetic retinal disease have shown that treatment that inhibits both VEGF and PGF may provide superior outcomes in certain patients compared with treatment that inhibits only VEGF. This review summarizes current knowledge of PGF, including its relationship to VEGF and its role in pathological angiogenesis in retinal diseases, and identifies some key unanswered questions about PGF that can serve as a pathway for future basic, translational and clinical research. © 2016 The Authors. Acta Ophthalmologica published by John Wiley & Sons Ltd on behalf of Acta Ophthalmologica Scandinavica Foundation and European Association for Vision & Eye Research.

Pharmacological kynurenine 3-monooxygenase enzyme inhibition significantly reduces neuropathic pain in a rat model.

PubMed

Rojewska, Ewelina; Piotrowska, Anna; Makuch, Wioletta; Przewlocka, Barbara; Mika, Joanna

2016-03-01

Recent studies have highlighted the involvement of the kynurenine pathway in the pathology of neurodegenerative diseases, but the role of this system in neuropathic pain requires further extensive research. Therefore, the aim of our study was to examine the role of kynurenine 3-monooxygenase (Kmo), an enzyme that is important in this pathway, in a rat model of neuropathy after chronic constriction injury (CCI) to the sciatic nerve. For the first time, we demonstrated that the injury-induced increase in the Kmo mRNA levels in the spinal cord and the dorsal root ganglia (DRG) was reduced by chronic administration of the microglial inhibitor minocycline and that this effect paralleled a decrease in the intensity of neuropathy. Further, minocycline administration alleviated the lipopolysaccharide (LPS)-induced upregulation of Kmo mRNA expression in microglial cell cultures. Moreover, we demonstrated that not only indirect inhibition of Kmo using minocycline but also direct inhibition using Kmo inhibitors (Ro61-6048 and JM6) decreased neuropathic pain intensity on the third and the seventh days after CCI. Chronic Ro61-6048 administration diminished the protein levels of IBA-1, IL-6, IL-1beta and NOS2 in the spinal cord and/or the DRG. Both Kmo inhibitors potentiated the analgesic properties of morphine. In summary, our data suggest that in neuropathic pain model, inhibiting Kmo function significantly reduces pain symptoms and enhances the effectiveness of morphine. The results of our studies show that the kynurenine pathway is an important mediator of neuropathic pain pathology and indicate that Kmo represents a novel pharmacological target for the treatment of neuropathy. Copyright © 2015 Elsevier Ltd. All rights reserved.

Single dose pharmacokinetics, pharmacodynamics, tolerability and safety of BAY 60-5521, a potent inhibitor of cholesteryl ester transfer protein.

PubMed

Boettcher, Michael-Friedrich; Heinig, Roland; Schmeck, Carsten; Kohlsdorfer, Christian; Ludwig, Matthias; Schaefer, Anja; Gelfert-Peukert, Sabine; Wensing, Georg; Weber, Olaf

2012-02-01

To determine pharmacokinetics (PK), pharmacodynamics (PD), tolerability and safety of BAY 60-5521, a potent inhibitor of cholesteryl ester transfer protein (CETP). The first in man (FIM) study investigated the safety, tolerability, pharmacodynamics and pharmacokinetics in healthy male subjects following administration of single oral doses. The study was performed using a randomized, single-blind, placebo-controlled, single dose-escalation design. Thirty-eight young healthy male subjects (aged 20-45 years) received an oral dose of 5, 12.5, 25 or 50 mg BAY 60-5521 (n= 28) or were treated with a placebo (n= 10). In all four dose steps, only one adverse event (25 mg; mild skin rash) was considered drug related. Clinical laboratory parameters showed no clinically relevant changes. A clear dose-dependent CETP inhibition could be demonstrated starting at a dose of 5 mg. At a dose of 25 mg, a CETP inhibition >50% over 18 h was observed. After 50 mg, CETP inhibition >50% lasted more than 50 h. Twenty-four h after administration mean HDL-C-values showed a nearly dose-proportional increase. Following administration of 50 mg, a significant HDL-C increase of about 30% relative to baseline values was found. BAY 60-5521 was slowly absorbed reaching maximum concentrations in plasma after 4 to 6 h. The disposition in plasma was multi-exponential with an estimated mean terminal half-life of 76 to 144 h. BAY 60-5521 was clinically safe and well tolerated. No effects on heart rate, blood pressure and ECG recordings were observed during the study. A clear pharmacodynamic effect on CETP inhibition and HDL could be demonstrated. © 2011 The Authors. British Journal of Clinical Pharmacology © 2011 The British Pharmacological Society.

Inflammasome signaling affects anxiety- and depressive-like behavior and gut microbiome composition

PubMed Central

Wong, M-L; Inserra, A; Lewis, M D; Mastronardi, C A; Leong, L; Choo, J; Kentish, S; Xie, P; Morrison, M; Wesselingh, S L; Rogers, G B; Licinio, J

2016-01-01

The inflammasome is hypothesized to be a key mediator of the response to physiological and psychological stressors, and its dysregulation may be implicated in major depressive disorder. Inflammasome activation causes the maturation of caspase-1 and activation of interleukin (IL)-1β and IL-18, two proinflammatory cytokines involved in neuroimmunomodulation, neuroinflammation and neurodegeneration. In this study, C57BL/6 mice with genetic deficiency or pharmacological inhibition of caspase-1 were screened for anxiety- and depressive-like behaviors, and locomotion at baseline and after chronic stress. We found that genetic deficiency of caspase-1 decreased depressive- and anxiety-like behaviors, and conversely increased locomotor activity and skills. Caspase-1 deficiency also prevented the exacerbation of depressive-like behaviors following chronic stress. Furthermore, pharmacological caspase-1 antagonism with minocycline ameliorated stress-induced depressive-like behavior in wild-type mice. Interestingly, chronic stress or pharmacological inhibition of caspase-1 per se altered the fecal microbiome in a very similar manner. When stressed mice were treated with minocycline, the observed gut microbiota changes included increase in relative abundance of Akkermansia spp. and Blautia spp., which are compatible with beneficial effects of attenuated inflammation and rebalance of gut microbiota, respectively, and the increment in Lachnospiracea abundance was consistent with microbiota changes of caspase-1 deficiency. Our results suggest that the protective effect of caspase-1 inhibition involves the modulation of the relationship between stress and gut microbiota composition, and establishes the basis for a gut microbiota–inflammasome–brain axis, whereby the gut microbiota via inflammasome signaling modulate pathways that will alter brain function, and affect depressive- and anxiety-like behaviors. Our data also suggest that further elucidation of the gut microbiota–inflammasome–brain axis may offer novel therapeutic targets for psychiatric disorders. PMID:27090302

Inflammasome signaling affects anxiety- and depressive-like behavior and gut microbiome composition.

PubMed

Wong, M-L; Inserra, A; Lewis, M D; Mastronardi, C A; Leong, L; Choo, J; Kentish, S; Xie, P; Morrison, M; Wesselingh, S L; Rogers, G B; Licinio, J

2016-06-01

The inflammasome is hypothesized to be a key mediator of the response to physiological and psychological stressors, and its dysregulation may be implicated in major depressive disorder. Inflammasome activation causes the maturation of caspase-1 and activation of interleukin (IL)-1β and IL-18, two proinflammatory cytokines involved in neuroimmunomodulation, neuroinflammation and neurodegeneration. In this study, C57BL/6 mice with genetic deficiency or pharmacological inhibition of caspase-1 were screened for anxiety- and depressive-like behaviors, and locomotion at baseline and after chronic stress. We found that genetic deficiency of caspase-1 decreased depressive- and anxiety-like behaviors, and conversely increased locomotor activity and skills. Caspase-1 deficiency also prevented the exacerbation of depressive-like behaviors following chronic stress. Furthermore, pharmacological caspase-1 antagonism with minocycline ameliorated stress-induced depressive-like behavior in wild-type mice. Interestingly, chronic stress or pharmacological inhibition of caspase-1 per se altered the fecal microbiome in a very similar manner. When stressed mice were treated with minocycline, the observed gut microbiota changes included increase in relative abundance of Akkermansia spp. and Blautia spp., which are compatible with beneficial effects of attenuated inflammation and rebalance of gut microbiota, respectively, and the increment in Lachnospiracea abundance was consistent with microbiota changes of caspase-1 deficiency. Our results suggest that the protective effect of caspase-1 inhibition involves the modulation of the relationship between stress and gut microbiota composition, and establishes the basis for a gut microbiota-inflammasome-brain axis, whereby the gut microbiota via inflammasome signaling modulate pathways that will alter brain function, and affect depressive- and anxiety-like behaviors. Our data also suggest that further elucidation of the gut microbiota-inflammasome-brain axis may offer novel therapeutic targets for psychiatric disorders.

Pharmacological Effects of Active Components of Chinese Herbal Medicine in the Treatment of Alzheimer's Disease: A Review.

PubMed

Wang, Zhi-Yong; Liu, Jian-Gang; Li, Hao; Yang, Hui-Ming

2016-01-01

Alzheimer's disease (AD), the most common neurodegenerative disorder associated with dementia, not only severely decreases the quality of life for its victims, but also brings a heavy economic burden to the family and society. Unfortunately, few chemical drugs designed for clinical applications have reached the expected preventive or therapeutic effect so far, and combined with their significant side-effects, there is therefore an urgent need for new strategies to be developed for AD treatment. Traditional Chinese Medicine has accumulated many experiences in the treatment of dementia during thousands of years of practice; modern pharmacological studies have confirmed the therapeutic effects of many active components derived from Chinese herbal medicines (CHM). Ginsenoside Rg1, extracted from Radix Ginseng, exerts a [Formula: see text]-secretase inhibitor effect so as to decrease A[Formula: see text] aggregation. It can also inhibit the apoptosis of neuron cells. Tanshinone IIA, extracted from Radix Salviae miltiorrhizae, and baicalin, extracted from Radix Scutellariae[Formula: see text] can inhibit the oxidative stress injury in neuronal cells. Icariin, extracted from Epimedium brevicornum, can decrease A[Formula: see text] levels and the hyperphosphorylation of tau protein, and can also inhibit oxidative stress and apoptosis. Huperzine A, extracted from Huperzia serrata, exerts a cholinesterase inhibitor effect. Evodiamine, extracted from Fructus Evodiae, and curcumin, extracted from Rhizoma Curcumae Longae, exert anti-inflammatory actions. Curcumin can act on A[Formula: see text] and tau too. Due to the advantages of multi-target effects and fewer side effects, Chinese medicine is more appropriate for long-term use. In this present review, the pharmacological effects of commonly used active components derived from Chinese herbal medicines in the treatment of AD are discussed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Petzer, Anél, E-mail: 12264954@nwu.ac.za; Harvey, Brian H.; Wegener, Gregers

Methylene blue (MB) has been shown to act at multiple cellular and molecular targets and as a result possesses diverse medical applications. Among these is a high potency reversible inhibition of monoamine oxidase A (MAO-A) that may, at least in part, underlie its adverse effects but also its psycho- and neuromodulatory actions. MB is metabolized to yield N-demethylated products of which azure B, the monodemethyl species, is the major metabolite. Similar to MB, azure B also displays a variety of biological activities and may therefore contribute to the pharmacological profile of MB. Based on these observations, the present study examinesmore » the interactions of azure B with recombinant human MAO-A and -B. The results show that azure B is a potent MAO-A inhibitor (IC{sub 50} = 11 nM), approximately 6-fold more potent than is MB (IC{sub 50} = 70 nM) under identical conditions. Measurements of the time-dependency of inhibition suggest that the interaction of azure B with MAO-A is reversible. Azure B also reversibly inhibits the MAO-B isozyme with an IC{sub 50} value of 968 nM. These results suggest that azure B may be a hitherto under recognized contributor to the pharmacology and toxicology of MB by blocking central and peripheral MAO-A activity and as such needs to be considered during its use in humans and animals. Highlights: ► Methylene blue (MB) is a known potent MAO-A inhibitor. ► Azure B, the major metabolite of MB, is more potent as a MAO-A inhibitor. ► Azure B may be a contributor to the CNS pharmacology and toxicology of MB.« less

Effect of tyrphostin AG879 on Kv 4.2 and Kv 4.3 potassium channels.

PubMed

Yu, Haibo; Zou, Beiyan; Wang, Xiaoliang; Li, Min

2015-07-01

A-type potassium channels (IA) are important proteins for modulating neuronal membrane excitability. The expression and activity of Kv 4.2 channels are critical for neurological functions and pharmacological inhibitors of Kv 4.2 channels may have therapeutic potential for Fragile X syndrome. While screening various compounds, we identified tyrphostin AG879, a tyrosine kinase inhibitor, as a Kv 4.2 inhibitor from. In the present study we characterized the effect of AG879 on cloned Kv 4.2/Kv channel-interacting protein 2 (KChIP2) channels. To screen the library of pharmacologically active compounds, the thallium flux assay was performed on HEK-293 cells transiently-transfected with Kv 4.2 cDNA using the Maxcyte transfection system. The effects of AG879 were further examined on CHO-K1 cells expressing Kv 4.2/KChIP2 channels using a whole-cell patch-clamp technique. Tyrphostin AG879 selectively and dose-dependently inhibited Kv 4.2 and Kv 4.3 channels. In Kv 4.2/KChIP2 channels, AG879 induced prominent acceleration of the inactivation rate, use-dependent block and slowed the recovery from inactivation. AG879 induced a hyperpolarizing shift in the voltage-dependence of the steady-state inactivation of Kv 4.2 channels without apparent effect on the V1/2 of the voltage-dependent activation. The blocking effect of AG879 was enhanced as channel inactivation increased. Furthermore, AG879 significantly inhibited the A-type potassium currents in the cultured hippocampus neurons. AG879 was identified as a selective and potent inhibitor the Kv 4.2 channel. AG879 inhibited Kv 4.2 channels by preferentially interacting with the open state and further accelerating their inactivation. © 2015 The British Pharmacological Society.

Common theme for drugs effective in overactive bladder treatment: Inhibition of afferent signaling from the bladder

PubMed Central

Hood, Brandy; Andersson, Karl-Erik

2013-01-01

The overactive bladder syndrome and detrusor overactivity are conditions that can have major effects on quality of life and social functioning. Antimuscarinic drugs are still first-line treatment. These drugs often have good initial response rates, but adverse effects and decreasing efficacy cause long-term compliance problems, and alternatives are needed. The recognition of the functional contribution of the urothelium/suburothelium, the autonomous detrusor muscle activity during bladder filling and the diversity of nerve transmitters involved has sparked interest in both peripheral and central modulation of overactive bladder syndrome/detrusor overactivity pathophysiology. Three drugs recently approved for treatment of overactive bladder syndrome/detrusor overactivity (mirabegron, tadalafil and onabotulinum toxin A), representing different pharmacological mechanisms; that is, β-adrenoceptor agonism, phosphodiesterase type 5 inhibition, and inhibition of nerve release of efferent and afferent transmitters, all seem to have one effect in common: inhibition of the afferent nervous activity generated by the bladder during filling. In the present review, the different mechanisms forming the pharmacological basis for the use of these drugs are discussed. PMID:23072271

Characterization and Pharmacological Properties of a Novel Multifunctional Kunitz Inhibitor from Erythrina velutina Seeds

PubMed Central

Machado, Richele J. A.; Monteiro, Norberto K. V.; Migliolo, Ludovico; Silva, Osmar N.; Pinto, Michele F. S.; Oliveira, Adeliana S.; Franco, Octávio L.; Kiyota, Sumika; Bemquerer, Marcelo P.; Uchoa, Adriana F.; Morais, Ana H. A.; Santos, Elizeu A.

2013-01-01

Inhibitors of peptidases isolated from leguminous seeds have been studied for their pharmacological properties. The present study focused on purification, biochemical characterization and anti-inflammatory and anticoagulant evaluation of a novel Kunitz trypsin inhibitor from Erythrina velutina seeds (EvTI). Trypsin inhibitors were purified by ammonium sulfate (30–60%), fractionation followed by Trypsin-Sepharose affinity chromatography and reversed-phase high performance liquid chromatography. The purified inhibitor showed molecular mass of 19,210.48 Da. Furthermore, a second isoform with 19,228.16 Da was also observed. The inhibitor that showed highest trypsin specificity and enhanced recovery yield was named EvTI (P2) and was selected for further analysis. The EvTI peptide fragments, generated by trypsin and pepsin digestion, were further analyzed by MALDI-ToF-ToF mass spectrometry, allowing a partial primary structure elucidation. EvTI exhibited inhibitory activity against trypsin with IC50 of 2.2×10−8 mol.L−1 and constant inhibition (Ki) of 1.0×10−8 mol.L−1, by a non-competitive mechanism. In addition to inhibit the activity of trypsin, EvTI also inhibited factor Xa and neutrophil elastase, but do not inhibit thrombin, chymotrypsin or peptidase 3. EvTI was investigated for its anti-inflammatory and anti-coagulant properties. Firstly, EvTI showed no cytotoxic effect on human peripheral blood cells. Nevertheless, the inhibitor was able to prolong the clotting time in a dose-dependent manner by using in vitro and in vivo models. Due to anti-inflammatory and anticoagulant EvTI properties, two sepsis models were here challenged. EvTI inhibited leukocyte migration and specifically acted by inhibiting TNF-α release and stimulating IFN-α and IL-12 synthesis. The data presented clearly contribute to a better understanding of the use of Kunitz inhibitors in sepsis as a bioactive agent capable of interfering in blood coagulation and inflammation. PMID:23737945

mTOR Complex 1 Signaling Regulates the Generation and Function of Central and Effector Foxp3+ Regulatory T Cells.

PubMed

Sun, Im-Hong; Oh, Min-Hee; Zhao, Liang; Patel, Chirag H; Arwood, Matthew L; Xu, Wei; Tam, Ada J; Blosser, Richard L; Wen, Jiayu; Powell, Jonathan D

2018-06-08

The mechanistic/mammalian target of rapamycin (mTOR) has emerged as a critical integrator of signals from the immune microenvironment capable of regulating T cell activation, differentiation, and function. The precise role of mTOR in the control of regulatory T cell (Treg) differentiation and function is complex. Pharmacologic inhibition and genetic deletion of mTOR promotes the generation of Tregs even under conditions that would normally promote generation of effector T cells. Alternatively, mTOR activity has been observed to be increased in Tregs, and the genetic deletion of the mTOR complex 1 (mTORC1)-scaffold protein Raptor inhibits Treg function. In this study, by employing both pharmacologic inhibitors and genetically altered T cells, we seek to clarify the role of mTOR in Tregs. Our studies demonstrate that inhibition of mTOR during T cell activation promotes the generation of long-lived central Tregs with a memory-like phenotype in mice. Metabolically, these central memory Tregs possess enhanced spare respiratory capacity, similar to CD8 + memory cells. Alternatively, the generation of effector Tregs (eTregs) requires mTOR function. Indeed, genetic deletion of Rptor leads to the decreased expression of ICOS and PD-1 on the eTregs. Overall, our studies define a subset of mTORC1 hi eTregs and mTORC1 lo central Tregs. Copyright © 2018 by The American Association of Immunologists, Inc.

Pharmacologic effects of grain weevil extract on isolated guinea pig tracheal smooth muscle.

PubMed

Schachter, E Neil; Zuskin, Eugenija; Arumugam, Uma; Goswami, Satindra; Castranova, Vincent; Whitmer, Mike; Chiarelli, Angelo

2008-01-01

The grain weevil, an insect (pest) that infects grain, is a frequent contaminant of processed wheat, and its presence may contribute to respiratory abnormalities in grain workers. We studied the in vitro effects of an extract of grain weevil (GWE) on airway smooth muscle. Pharmacologic studies included in vitro challenge of guinea pig trachea with GWE, in parallel organ baths, pretreated with mediator-modifying agents or a control solution. Dose-related contractions of nonsensitized guinea pig trachea (GPT) were demonstrated using this extract. Pharmacologic studies were performed by pretreating guinea pig tracheal tissue with drugs known to modulate smooth muscle contraction: atropine, indomethacin, pyrilamine, acivicin, NDGA, BPB, TMB8, captopril, and capsaicin. Atropine, pyrilamine, BPB, and capsaicin significantly reduced the contractile effects of the extract at most of the challenge doses (p < 0.01 or p < 0.05). Inhibition of GWE-induced contraction by blocking of other mediators was less complete. We suggest that GWE causes dose-related airway smooth muscle constriction of the GPT by nonimmunologic mechanisms involving a variety of airway mediators and possibly cholinergic receptors.

Sensitization of Upper Airway Mechanoreceptors as a New Pharmacologic Principle to Treat Obstructive Sleep Apnea: Investigations with AVE0118 in Anesthetized Pigs

PubMed Central

Wirth, Klaus J.; Steinmeyer, Klaus; Ruetten, Hartmut

2013-01-01

Study Objectives: Drug treatment for obstructive sleep apnea (OSA) is desirable because at least 30% of patients do not tolerate continuous positive airway pressure (CPAP) treatment. The negative pressure reflex (NPR) involving superficially located mechanoreceptors in the upper airway (UA) is an important mechanism for UA patency inhibitable by topical UA anesthesia (lidocaine). The NPR may serve as a target for pharmacological intervention for a topical treatment of OSA. The objective was to determine the effect of pharmacological augmentation of the NPR on UA collapsibility. Design: We developed a model of UA collapsibility in which application of negative pressures caused UA collapses in spontaneously breathing α-chloralose-urethane anesthetized pigs as indicated by characteristic tracheal pressure and air flow changes. Setting: N/A. Patients or Participants: N/A. Interventions: N/A. Measurements and Results: The potassium channel blocker AVE0118 administered topically to the UA in doses of 1, 3, and 10 mg per nostril sensitized the NPR, shifting the mechanoreceptor response threshold for the genioglossus muscle to more positive pressures (P < 0.001; n = 6 per group) and dose-dependently inhibited UA collapsibility. Ten mg of AVE0118 prevented UA collapses against negative pressures of -150 mbar (P < 0.01) for > 4 h in all pigs, while in control pigs the UA collapsed at -50 mbar or less negative pressures. The effect of AVE0118 was abolished by UA lidocaine anesthesia. Acute intravenous administration of naloxone or acetazolamide was ineffective; paroxetine and mirtazepine were weakly effective and fluoxetine was moderately effective in line with reported clinical efficacy. Conclusion: Topical administration of AVE0118 to the UA is a promising pharmacologic approach for the treatment of OSA. Citation: Wirth KJ; Steinmeyer K; Ruetten H. Sensitization of upper airway mechanoreceptors as a new pharmacologic principle to treat obstructive sleep apnea: investigations with AVE0118 in anesthetized pigs. SLEEP 2013;36(5):699-708. PMID:23633752

Novel 16-substituted bifunctional derivatives of huperzine B: multifunctional cholinesterase inhibitors

PubMed Central

Shi, Yu-fang; Zhang, Hai-yan; Wang, Wei; Fu, Yan; Xia, Yu; Tang, Xi-can; Bai, Dong-lu; He, Xu-chang

2009-01-01

Aim: To design novel bifunctional derivatives of huperzine B (HupB) based on the concept of dual binding site of acetylcholinesterase (AChE) and evaluate their pharmacological activities for seeking new drug candidates against Alzheimer's disease (AD). Methods: Novel 16-substituted bifunctional derivatives of HupB were synthesized through chemical reactions. The inhibitory activities of the derivatives toward AChE and butyrylcholinesterase (BuChE) were determined in vitro by modified Ellman's method. Cell viability was quantified by the reduction of MTT. Results: A new preparative method was developed for the generation of 16-substituted derivatives of HupB, and pharmacological trials indicated that the derivatives were multifunctional cholinesterase inhibitors targeting both AChE and BuChE. Among the derivatives tested, 9c, 9e, 9f, and 9i were 480 to 1360 times more potent as AChE inhibitors and 370 to 1560 times more potent as BuChE inhibitors than the parent HupB. Further preliminary pharmacological trials of derivatives 9c and 9i were performed, including examining the mechanism of AChE inhibition, the substrate kinetics of the enzyme inhibition, and protection against hydrogen peroxide (H2O2)-induced cytotoxicity in PC12 cells. Conclusion: Preliminary pharmacological evaluation indicated that 16-substituted derivatives of HupB, particularly 9c and 9i, would be potentially valuable new drug candidates for AD therapy, and further exploration is needed to evaluate their pharmacological and clinical efficacies. PMID:19578388

Pharmacology of modality-specific transient receptor potential vanilloid-1 antagonists that do not alter body temperature.

PubMed

Reilly, Regina M; McDonald, Heath A; Puttfarcken, Pamela S; Joshi, Shailen K; Lewis, LaGeisha; Pai, Madhavi; Franklin, Pamela H; Segreti, Jason A; Neelands, Torben R; Han, Ping; Chen, Jun; Mantyh, Patrick W; Ghilardi, Joseph R; Turner, Teresa M; Voight, Eric A; Daanen, Jerome F; Schmidt, Robert G; Gomtsyan, Arthur; Kort, Michael E; Faltynek, Connie R; Kym, Philip R

2012-08-01

The transient receptor potential vanilloid-1 (TRPV1) channel is involved in the development and maintenance of pain and participates in the regulation of temperature. The channel is activated by diverse agents, including capsaicin, noxious heat (≥ 43°C), acidic pH (< 6), and endogenous lipids including N-arachidonoyl dopamine (NADA). Antagonists that block all modes of TRPV1 activation elicit hyperthermia. To identify efficacious TRPV1 antagonists that do not affect temperature antagonists representing multiple TRPV1 pharmacophores were evaluated at recombinant rat and human TRPV1 channels with Ca(2+) flux assays, and two classes of antagonists were identified based on their differential ability to inhibit acid activation. Although both classes of antagonists completely blocked capsaicin- and NADA-induced activation of TRPV1, select compounds only partially inhibited activation of the channel by protons. Electrophysiology and calcitonin gene-related peptide release studies confirmed the differential pharmacology of these antagonists at native TRPV1 channels in the rat. Comparison of the in vitro pharmacological properties of these TRPV1 antagonists with their in vivo effects on core body temperature confirms and expands earlier observations that acid-sparing TRPV1 antagonists do not significantly increase core body temperature. Although both classes of compounds elicit equivalent analgesia in a rat model of knee joint pain, the acid-sparing antagonist tested is not effective in a mouse model of bone cancer pain.

Modulation of the pharmacological effects of enzymatically-active PLA2 by BTL-2, an isolectin isolated from the Bryothamnion triquetrum red alga

PubMed Central

Oliveira, Simone CB; Fonseca, Fabiana V; Antunes, Edson; Camargo, Enilton A; Morganti, Rafael P; Aparício, Ricardo; Toyama, Daniela O; Beriam, Luís OS; Nunes, Eudismar V; Cavada, Benildo S; Nagano, Celso S; Sampaio, Alexandre H; Nascimento, Kyria S; Toyama, Marcos H

2008-01-01

Background An interaction between lectins from marine algae and PLA2 from rattlesnake was suggested some years ago. We, herein, studied the effects elicited by a small isolectin (BTL-2), isolated from Bryothamnion triquetrum, on the pharmacological and biological activities of a PLA2 isolated from rattlesnake venom (Crotalus durissus cascavella), to better understand the enzymatic and pharmacological mechanisms of the PLA2 and its complex. Results This PLA2 consisted of 122 amino acids (approximate molecular mass of 14 kDa), its pI was estimated to be 8.3, and its amino acid sequence shared a high degree of similarity with that of other neurotoxic and enzymatically-active PLA2s. BTL-2 had a molecular mass estimated in approximately 9 kDa and was characterized as a basic protein. In addition, BTL-2 did not exhibit any enzymatic activity. The PLA2 and BTL-2 formed a stable heterodimer with a molecular mass of approximately 24–26 kDa, estimated by molecular exclusion HPLC. In the presence of BTL-2, we observed a significant increase in PLA2 activity, 23% higher than that of PLA2 alone. BTL-2 demonstrated an inhibition of 98% in the growth of the Gram-positive bacterial strain, Clavibacter michiganensis michiganensis (Cmm), but only 9.8% inhibition of the Gram-negative bacterial strain, Xanthomonas axonopodis pv passiflorae (Xap). PLA2 decreased bacterial growth by 27.3% and 98.5% for Xap and Cmm, respectively, while incubating these two proteins with PLA2-BTL-2 inhibited their growths by 36.2% for Xap and 98.5% for Cmm. PLA2 significantly induced platelet aggregation in washed platelets, whereas BTL-2 did not induce significant platelet aggregation in any assay. However, BTL-2 significantly inhibited platelet aggregation induced by PLA2. In addition, PLA2 exhibited strong oedematogenic activity, which was decreased in the presence of BTL-2. BTL-2 alone did not induce oedema and did not decrease or abolish the oedema induced by the 48/80 compound. Conclusion The unexpected results observed for the PLA2-BTL-2 complex strongly suggest that the pharmacological activity of this PLA2 is not solely dependent on the presence of enzymatic activity, and that other pharmacological regions may also be involved. In addition, we describe for the first time an interaction between two different molecules, which form a stable complex with significant changes in their original biological action. This opens new possibilities for understanding the function and action of crude venom, an extremely complex mixture of different molecules. PMID:18534036

The N-terminal neurotensin fragment, NT1-11, inhibits cortisol secretion by human adrenocortical cells.

PubMed

Sicard, Flavie; Contesse, Vincent; Lefebvre, Hervé; Ait-Ali, Djida; Gras, Marjorie; Cartier, Dorthe; Decker, Annick; Chartrel, Nicolas; Anouar, Youssef; Vaudry, Hubert; Delarue, Catherine

2006-08-01

Neurotensin (NT) modulates corticosteroid secretion from the mammalian adrenal gland. The objective of this study was to investigate the possible involvement of NT in the control of cortisol secretion in the human adrenal gland. In vitro studies were conducted on cultured human adrenocortical cells. This study was conducted in a university research laboratory. Adrenal explants from patients undergoing expanded nephrectomy for kidney cancer were studied. Cortisol secretion from cultured adrenocortical cells was measured. NT1-11, the N-terminal fragment of NT, dose-dependently inhibited basal and ACTH-stimulated cortisol production by human adrenocortical cells in primary culture. In contrast, NT had no influence on cortisol output at concentrations up to 10(-6) m. HPLC and RT-PCR analyses failed to detect any significant amounts of NT and NT mRNA, respectively, in adrenal extracts. Molecular and pharmacological studies were performed to determine the type of NT receptor involved in the corticostatic effect of NT1-11. RT-PCR analysis revealed the expression of NT receptor type (NTR) 3 mRNA but not NTR1 and NTR2 mRNAs in the human adrenal tissue. However, the pharmacological profile of the adrenal NT1-11 receptor was different from that of NTR3, indicating that this receptor type is not involved in the action of NT1-11 on corticosteroidogenesis. Our results indicate that NT1-11 may act as an endocrine factor to inhibit cortisol secretion through activation of a receptor distinct from the classical NTR1, NTR2, and NTR3.

Pharmacological or genetic inhibition of LDHA reverses tumor progression of pediatric osteosarcoma.

PubMed

Gao, Shan; Tu, Dan-Na; Li, Heng; Jiang, Jian-Xin; Cao, Xin; You, Jin-Bin; Zhou, Xiao-Qin

2016-07-01

Reprogrammed energy metabolism is an emerging hallmark of cancer. Lactate dehydrogenase A (LDHA), a key enzyme involved in anaerobic glycolysis, is frequently deregulated in human malignancies. However, limited knowledge is known about its roles in the progression of osteosarcoma (OS). In this study, we found that LDHA is commonly upregulated in four OS cell lines compared with the normal osteoblast cells (hFOB1.19). Treatment with FX11, a specific inhibitor of LDHA, significantly reduced LDHA activity, and inhibited cell proliferation and invasive potential in a dose dependent manner. Genetic silencing of LDHA resulted in a decreased lactate level in the culture medium, reduced cell viability and decreased cell invasion ability. Meanwhile, silencing of LDHA also compromised tumorigenesis in vivo. Furthermore, knockdown of LDHA remarkably reduced extracellular acidification rate (ECAR) as well as glucose consumption. In the presence of 2-DG, a glycolysis inhibitor, LDHA-mediated cell proliferation and invasion were completely blocked, indicating the oncogenic activities of LDHA may dependent on Warburg effect. Finally, pharmacological inhibition of c-Myc or HIF1α significantly attenuated LDHA expression. Taken together, upregulated LDHA facilitates tumor progression of OS and might be a potential target for OS treatment. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Targeting Sphingosine Kinase-1 To Inhibit Melanoma

PubMed Central

Madhunapantula, SubbaRao V.; Hengst, Jeremy; Gowda, Raghavendra; Fox, Todd E.; Yun, Jong K; Robertson, Gavin P.

2012-01-01

SUMMARY Resistance to therapies develops rapidly for melanoma leading to more aggressive disease. Therefore, agents are needed that specifically inhibit proteins or pathways controlling the development of this disease, which can be combined, dependent on genes deregulated in a particular patient’s tumors. This study shows that elevated sphingosine-1-phosphate (S-1-P) levels resulting from increased activity of sphingosine kinase-1 (SPHK1) occur in advanced melanomas. Targeting SPHK1 using siRNA decreased anchorage dependent and independent growth as well as sensitized melanoma cells to apoptosis inducing agents. Pharmacological SPHK1 inhibitors SKI-I but not SKI-II decreased S-1-P content, elevated ceramide levels, caused a G2-M block and induced apoptotic cell death in melanomas. Targeting SPHK1 using siRNA or the pharmacological agent called SKI-I, decreased the levels of pAKT. Furthermore, SKI-I inhibited the expression of CYCLIN D1 protein and increased the activity of caspase-3/7, which in turn led to the degradation of PARP. In animals, SKI-I but not SKI-II retarded melanoma growth by 25-40%. Thus, targeting SPHK1 using siRNAs or SKI-I has therapeutic potential for melanoma treatment either alone or in combination with other targeted agents. PMID:22236408

Neuroprotection by stem cell factor in rat cortical neurons involves AKT and NFkappaB.

PubMed

Dhandapani, Krishnan M; Wade, F Marlene; Wakade, Chandramohan; Mahesh, Virendra B; Brann, Darrell W

2005-10-01

Stem cell factor (SCF) is a highly expressed cytokine in the central nervous system. In the present study, we demonstrate a neuroprotective role for SCF and its tyrosine kinase receptor, c-kit, against camptothecin-induced apoptosis and glutamate excitotoxicity in rat cortical neurons. This protection was blocked by pharmacological or molecular inhibition of either the MEK/ERK or PI3K/Akt signaling pathways. The importance of these pathways was further confirmed by the activation of both ERK, in a MEK-dependent manner, and Akt, via PI3K. Activation of Akt increased the binding of the p50 and p65 subunits of NFkappaB, which was also important for neuroprotection. Akt inhibition prevented NFkappaB binding, suggesting a role for Akt in SCF-induced NFkappaB. Pharmacological inhibition of NFkappaB or dominant negative IkappaB also prevented neuroprotection by SCF. SCF up-regulated the anti-apoptotic genes, bcl-2 and bcl-xL in an NFkappaB-dependent manner. Together, these findings demonstrate a neuroprotective role for SCF in cortical neurons, an effect that was mediated by Akt and ERK, as well as NFkappaB-mediated gene transcription. SCF represents a novel therapeutic target in the treatment of neurodegenerative disease.

Obatoclax induces Beclin 1- and ATG5-dependent apoptosis and autophagy in adenoid cystic carcinoma cells.

PubMed

Liang, L-Z; Ma, B; Liang, Y-J; Liu, H-C; Zhang, T-H; Zheng, G-S; Su, Y-X; Liao, G-Q

2015-05-01

Adenoid cystic carcinoma (ACC) is one of the most common salivary gland cancers. The prognosis of adenoid cystic carcinoma is poor for its high frequency of distant metastases and insensitivity to chemotherapy or molecular therapies. This study investigated the effect of Obatoclax on adenoid cystic carcinoma cells and its cytotoxic mechanism. Western blot, transmission electron microscopy, and pEGFP-LC3 plasmids transfection were carried out to detect autophagy in ACC cells treated with Obatoclax. 3-MA and RNA interference against Beclin 1 and ATG5 were used to inhibit autophagy. Then we used Western blot and Hochest 33342 staining for apoptosis assessment. Finally, cell viability was assessed by MTT assay. We found that Obatoclax induced cytoprotective autophagy which depended on ATG5 and partly on Beclin 1 in adenoid cystic carcinoma cells. Furthermore, pharmacologically inhibiting Obatoclax-induced autophagy promoted apoptosis. Downregulation of Beclin 1 or ATG5 attenuated the cytotoxicity of Obatoclax by suppressing both autophagy and apoptosis. Finally, when apoptosis was pharmacologically inhibited, autophagic cell death was initiated in adenoid cystic carcinoma cells treated with Obatoclax. In summary, Beclin 1 and ATG5 play important roles in regulating both Obatoclax-induced autophagy and apoptosis in adenoid cystic carcinoma. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Antiapoptotic and Trophic Effects of Dominant-Negative Forms of Dual Leucine Zipper Kinase in Dopamine Neurons of the Substantia Nigra In Vivo

PubMed Central

Chen, Xiqun; Rzhetskaya, Margarita; Kareva, Tatyana; Bland, Ross; During, Matthew J.; Tank, A. William; Kholodilov, Nikolai; Burke, Robert E.

2009-01-01

There is extensive evidence that the mitogen-activated protein kinase (MAPK) signaling cascade mediates programmed cell death in neurons. However, current evidence that the mixed linage kinases (MLKs), upstream in this cascade, mediate cell death is based, in the in vivo context, entirely on pharmacological approaches. The compounds used in these studies have neither complete specificity nor selectivity among these kinases. Therefore, to better address the molecular specificity of the MLKs in mediating neuron death, we used dominant-negative constructs delivered by AAV (adenoassociated virus) vector transfer. We assessed effects in a neurotoxin model of parkinsonism, in which neuroprotection by pharmacologic MLK inhibition has been reported. We find that two dominant-negative forms of dual leucine zipper kinase (DLK) inhibit apoptosis and enhance long-term survival of dopamine neurons, but a dominant negative of MLK3 does not. Interestingly, the kinase-dead form of DLK not only blocks apoptosis but also has trophic effects on dopamine neurons. Although the MAPK cascade activates a number of downstream cell death mediators, we find that inhibition of DLK correlates closely with blockade of phosphorylation of c-jun and prevention of cell death. We conclude that DLK acts primarily through c-jun phosphorylation to mediate cell death in this model. PMID:18199767

Emerging therapeutic targets in the short QT syndrome.

PubMed

Hancox, Jules C; Whittaker, Dominic G; Du, Chunyun; Stuart, A Graham; Zhang, Henggui

2018-05-01

Short QT Syndrome (SQTS) is a rare but dangerous condition characterised by abbreviated repolarisation, atrial and ventricular arrhythmias and risk of sudden death. Implantable cardioverter defibrillators (ICDs) are a first line protection against sudden death, but adjunct pharmacology is beneficial and desirable. Areas covered: The genetic basis for genotyped SQTS variants (SQT1-SQT8) and evidence for arrhythmia substrates from experimental and simulation studies are discussed. The main ion channel/transporter targets for antiarrhythmic pharmacology are considered in respect of potential genotype-specific and non-specific treatments for the syndrome. Expert opinion: Potassium channel blockade is valuable for restoring repolarisation and QT interval, though genotype-specific limitations exist in the use of some K + channel inhibitors. A combination of K + current inhibition during the action potential plateau, with sodium channel inhibition that collectively result in delaying repolarisation and post-repolarisation refractoriness is likely to be valuable in prolonging effective refractory period and wavelength for re-entry. Genotype-specific K + channel inhibition is limited by a lack of targeted inhibitors in clinical use, though experimentally available selective inhibitors now exist. The relatively low proportion of successfully genotyped cases justifies an exome or genome sequencing approach, to reveal new mediators and targets, as demonstrated recently for SLC4A3 in SQT8.

Reciprocal feedback regulation of PI3K and androgen receptor signaling in PTEN-deficient prostate cancer

PubMed Central

Carver, Brett S; Chapinski, Caren; Wongvipat, John; Hieronymus, Haley; Chen, Yu; Chandarlapaty, Sarat; Arora, Vivek K; Le, Carl; Koutcher, Jason; Scher, Howard; Scardino, Peter T; Rosen, Neal; Sawyers, Charles L

2011-01-01

Summary Prostate cancer is characterized by its dependence on androgen receptor and frequent activation of PI3K signaling. We find that AR transcriptional output is decreased in human and murine tumors with PTEN deletion and that PI3K pathway inhibition activates AR signaling by relieving feedback inhibition of HER kinases. Similarly, AR inhibition activates AKT signaling by reducing levels of the AKT phosphatase PHLPP. Thus, these two oncogenic pathways cross-regulate each other by reciprocal feedback. Inhibition of one activates the other, thereby maintaining tumor cell survival. However, combined pharmacologic inhibition of PI3K and AR signaling caused near complete prostate cancer regressions in a Pten-deficient murine prostate cancer model and in human prostate cancer xenografts, indicating that both pathways coordinately support survival. Significance The two most frequently activated signaling pathways in prostate cancer are driven by AR and PI3K. Inhibitors of the PI3K pathway are in early clinical trials and AR inhibitors confer clinical responses in most patients. However, these inhibitors rarely induce tumor regression in preclinical models. Here we show that these pathways regulate each other by reciprocal negative feedback, such that inhibition of one activates the other. Therefore, tumor cells can adapt and survive when either single pathway is inhibited pharmacologically. Our demonstration of profound tumor regressions with combined pathway inhibition in preclinical prostate tumor models provides rationale for combination therapy in patients. PMID:21575859

Acetylcholinesterase Inhibitors: Pharmacology and Toxicology

PubMed Central

Čolović, Mirjana B; Krstić, Danijela Z; Lazarević-Pašti, Tamara D; Bondžić, Aleksandra M; Vasić, Vesna M

2013-01-01

Acetylcholinesterase is involved in the termination of impulse transmission by rapid hydrolysis of the neurotransmitter acetylcholine in numerous cholinergic pathways in the central and peripheral nervous systems. The enzyme inactivation, induced by various inhibitors, leads to acetylcholine accumulation, hyperstimulation of nicotinic and muscarinic receptors, and disrupted neurotransmission. Hence, acetylcholinesterase inhibitors, interacting with the enzyme as their primary target, are applied as relevant drugs and toxins. This review presents an overview of toxicology and pharmacology of reversible and irreversible acetylcholinesterase inactivating compounds. In the case of reversible inhibitors being commonly applied in neurodegenerative disorders treatment, special attention is paid to currently approved drugs (donepezil, rivastigmine and galantamine) in the pharmacotherapy of Alzheimer’s disease, and toxic carbamates used as pesticides. Subsequently, mechanism of irreversible acetylcholinesterase inhibition induced by organophosphorus compounds (insecticides and nerve agents), and their specific and nonspecific toxic effects are described, as well as irreversible inhibitors having pharmacological implementation. In addition, the pharmacological treatment of intoxication caused by organophosphates is presented, with emphasis on oxime reactivators of the inhibited enzyme activity administering as causal drugs after the poisoning. Besides, organophosphorus and carbamate insecticides can be detoxified in mammals through enzymatic hydrolysis before they reach targets in the nervous system. Carboxylesterases most effectively decompose carbamates, whereas the most successful route of organophosphates detoxification is their degradation by corresponding phosphotriesterases. PMID:24179466

Pharmacological enhancement of fear reduction: preclinical models

PubMed Central

Graham, Bronwyn M; Langton, Julia M; Richardson, Rick

2011-01-01

Anxiety disorders have a high prevalence, and despite the substantial advances in the psychological treatment of anxiety, relapse is still a common problem. One approach to improving existing psychological treatments for anxiety has been to develop pharmacological agents that can be used to enhance the processes underlying exposure therapy, which is the most commonly used and empirically validated psychological treatment for anxiety during which individuals are taught to appropriately inhibit fear. Animal models of exposure therapy, particularly fear extinction, have proved to be a very useful way of examining the neural and molecular correlates of fear inhibition, which has in turn led to the identification of numerous drugs that enhance these processes in rats. Several of these drugs have subsequently been tested as novel pharmacological adjuncts to exposure therapy in humans with a range of anxiety disorders. The purpose of this review is to outline the key animal models of exposure therapy and to describe how these have been used to develop potential pharmacological adjuncts for anxiety disorders. Drugs that are currently in clinical use, as well as those currently in the preclinical stages of investigation, are described. LINKED ARTICLES This article is part of a themed issue on Translational Neuropharmacology. To view the other articles in this issue visit http://dx.doi.org/10.1111/bph.2011.164.issue-4 PMID:21175588

Pharmacology of 1-(3,4-dichlorobenzyl)-3,4,5,6-tetrahydro-2(1H)-pyrimidone, a novel antidepressant compound with antianxiety activity.

PubMed

Ellis, K O; Wessels, F L; Burns, R H; Pong, S F

1980-10-01

1-(3,4-dichlorobenzyl)-3,4,5,6-tetrahydro-2(1H)-pyrimidone (I) was evaluated in selected pharmacological tests, and its activity was compared to that of some clinically useful psychotropic drugs. Based on the results, it is evident that I has a unique profile of antidepressant and antianxiety activities that are evident in the same dose range. The mechanism of its antidepressant activity is proposed to be similar to the tricyclic antidepressants, that is, inhibition of norepinephrine uptake. Neither I nor the tricyclic antidepressants possess monoamine oxidase-inhibiting activity. However, unlike the tricyclic antidepressants, I is devoid of any significant anticholinergic activity and presumably is free of anticholinergic side effects.

Functional role of the Ca{sup 2+}-activated Cl{sup −} channel DOG1/TMEM16A in gastrointestinal stromal tumor cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berglund, Erik, E-mail: erik.berglund@ki.se; Department of Breast and Endocrine Surgery, Karolinska University Hospital, Stockholm; Akcakaya, Pinar

2014-08-15

DOG1, a Ca{sup 2+}-activated Cl{sup −} channel (CaCC), was identified in 2004 to be robustly expressed in gastrointestinal stromal tumors (GIST). It was rapidly included as a tumor marker in routine diagnostics, but the functional role remained unknown. CaCCs are important regulators of normal physiological functions, but also implicated in tumorigenesis, cancer progression, metastasis, cell migration, apoptosis, proliferation and viability in several malignancies. We therefore investigated whether DOG1 plays a role in the three latter in GIST by utilizing in vitro cell model systems. Confocal microscopy identified different subcellular localizations of DOG1 in imatinib-sensitive and imatinib-resistant cells. Electrophysiological studies confirmedmore » that DOG1-specific pharmacological agents possess potent activating and inhibiting properties. Proliferation assays showed small effects up to 72 h, and flow cytometric analysis of adherent cells with 7-AAD/Annexin V detected no pharmacological effects on viable GIST cells. However, inhibition of DOG1 conveyed pro-apoptotic effects among early apoptotic imatinib-resistant cells. In conclusion, DOG1 generates Cl{sup −} currents in GIST that can be regulated pharmacologically, with small effects on cell viability and proliferation in vitro. Inhibition of DOG1 might act pro-apoptotic on some early apoptotic GIST cell populations. Further studies are warranted to fully illuminate the function of DOG1 and its potential as therapeutic target. - Highlights: • Subcellular DOG1 localization varies between GIST cells. • DOG1 in GIST is voltage- and Ca{sup 2+}-activated. • Known TMEM16A modulators, like A01 and Eact, modulate DOG1. • DOG1 has small effects on cell viability and proliferation in vitro. • DOG1 impact early apoptotic GIST cells to undergo late apoptosis.« less

Mechanism of action of the insecticides, lindane and fipronil, on glycine receptor chloride channels.

PubMed

Islam, Robiul; Lynch, Joseph W

2012-04-01

Docking studies predict that the insecticides, lindane and fipronil, block GABA(A) receptors by binding to 6' pore-lining residues. However, this has never been tested at any Cys-loop receptor. The neurotoxic effects of these insecticides are also thought to be mediated by GABA(A) receptors, although a recent morphological study suggested glycine receptors mediated fipronil toxicity in zebrafish. Here we investigated whether human α1, α1β, α2 and α3 glycine receptors were sufficiently sensitive to block by either compound as to represent possible neurotoxicity targets. We also investigated the mechanisms by which lindane and fipronil inhibit α1 glycine receptors. Glycine receptors were recombinantly expressed in HEK293 cells and insecticide effects were studied using patch-clamp electrophysiology. Both compounds completely inhibited all tested glycine receptor subtypes with IC(50) values ranging from 0.2-2 µM, similar to their potencies at vertebrate GABA(A) receptors. Consistent with molecular docking predictions, both lindane and fipronil interacted with 6' threonine residues via hydrophobic interactions and hydrogen bonds. In contrast with predictions, we found no evidence for lindane interacting at the 2' level. We present evidence for fipronil binding in a non-blocking mode in the anaesthetic binding pocket, and for lindane as an excellent pharmacological tool for identifying the presence of β subunits in αβ heteromeric glycine receptors. This study implicates glycine receptors as novel vertebrate toxicity targets for fipronil and lindane. Furthermore, lindane interacted with pore-lining 6' threonine residues, whereas fipronil may have both pore and non-pore binding sites. © 2011 The Authors. British Journal of Pharmacology © 2011 The British Pharmacological Society.

Z-FL-COCHO, a cathepsin S inhibitor, enhances oxaliplatin-induced apoptosis through upregulation of Bim expression.

PubMed

Seo, Seung Un; Woo, Seon Min; Min, Kyoung-Jin; Kwon, Taeg Kyu

2018-04-15

Inhibition of cathespsin S not only inhibits invasion and angiogenesis, but also induces apoptosis and autophagy in cancer cells. In present study, we revealed that pharmacological inhibitor [Z-FL-COCHO (ZFL)] of cathepsin S up-regulates pro-apoptotic protein Bim expression at the posttranslational levels. These effects were not associated with MAPKs and AMPK signal pathways. Interestingly, pretreatment with the chemical chaperones (TUDCA and PBA) and knockdown of protein phosphatase 2A (PP2A) markedly inhibited ZFL-induced Bim upregulation. ZFL enhances oxaliplatin-mediated apoptosis through ER stress-induced Bim upregulation in cancer cells. Collectively, our results suggest that inhibition of cathepsin S-induced Bim upregulation contribute to anti-cancer drug-induced apoptotic cell death in renal carcinoma Caki cells. Copyright © 2018 Elsevier Inc. All rights reserved.

Discovery of Fragment-Derived Small Molecules for in Vivo Inhibition of Ketohexokinase (KHK)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huard, Kim; Ahn, Kay; Amor, Paul

Increased fructose consumption and its subsequent metabolism have been implicated in hepatic steatosis, dyslipidemia, obesity, and insulin resistance in humans. Since ketohexokinase (KHK) is the principal enzyme responsible for fructose metabolism, identification of a selective KHK inhibitor may help to further elucidate the effect of KHK inhibition on these metabolic disorders. Until now, studies on KHK inhibition with small molecules have been limited due to the lack of viable in vivo pharmacological tools. Herein we report the discovery of 12, a selective KHK inhibitor with potency and properties suitable for evaluating KHK inhibition in rat models. Key structural features interactingmore » with KHK were discovered through fragment-based screening and subsequent optimization using structure-based drug design, and parallel medicinal chemistry led to the identification of pyridine 12.« less

A pharmacologic increase in activity of plasma transaminase derived from small intestine in animals receiving an acyl CoA: diacylglycerol transferase (DGAT) 1 inhibitor.

PubMed

Yokoyama, Hideaki; Kobayashi, Akio; Kondo, Kazuma; Oshida, Shin-Ichi; Takahashi, Tadakazu; Masuyama, Taku; Shoda, Toshiyuki; Sugai, Shoichiro

2018-01-01

Acyl CoA: diacylglycerol acyltransferase (DGAT) 1 is an enzyme that catalyzes the re-synthesis of triglycerides (TG) from free fatty acids and diacylglycerol. JTT-553 is a DGAT1 inhibitor and exhibits its pharmacological action (inhibition of re-synthesis of TG) in the enterocytes of the small intestine leading to suppression of a postprandial elevation of plasma lipids. After repeated oral dosing JTT-553 in rats and monkeys, plasma transaminase levels were increased but there were neither changes in other hepatic function parameters nor histopathological findings suggestive of hepatotoxicity. Based on the results of exploratory studies for investigation of the mechanism of the increase in transaminase levels, plasma transaminase levels were increased after dosing JTT-553 only when animals were fed after dosing and a main factor in the diet contributing to the increase in plasma transaminase levels was lipids. After dosing JTT-553, transaminase levels were increased in the small intestine but not in the liver, indicating that the origin of transaminase increased in the plasma was not the liver but the small intestine where JTT-553 exhibits its pharmacological action. The increase in small intestinal transaminase levels was due to increased enzyme protein synthesis and was suppressed by inhibiting fatty acid-transport to the enterocytes. In conclusion, the JTT-553-related increase in plasma transaminase levels is considered not to be due to release of the enzymes from injured cells into the circulation but to be phenomena resulting from enhancement of enzyme protein synthesis in the small intestine due to the pharmacological action of JTT-553 in this organ.

An ionotropic but not a metabotropic glutamate agonist potentiates the pharmacological effects of olanzapine in the rat.

PubMed

Dall'Olio, Rossella; Rimondini, Roberto; Locchi, Federica; Voltattorni, Manuela; Gandolfi, Ottavio

2005-12-01

This study aimed to evaluate the possible potentiating action of ionotropic or metabotropic (metabotropic glutamate receptor type 5) glutamate agonists on pharmacological effects induced in rats by the atypical antipsychotic olanzapine. The administration of doses of olanzapine, which did not affect spontaneous motility, inhibited behaviors induced by the selective stimulation of 5HT(2A) and D(2) receptors. In particular, 0.03 or 0.06 mg/kg of olanzapine was sufficient to reduce, respectively, head shakes induced by the 5HT(2A) agonist 1-2,5-dimethoxy-4-iodophenyl-2-aminopropane (1 mg/kg) or hypermotility elicited by the D(2) stimulant quinpirole (0.15 mg/kg). Behavioral responses to a D(1)/D(2) agonist (apomorphine-induced stereotypies) were inhibited by doses of olanzapine that also influenced spontaneous behavior. The concomitant administration of D-cycloserine, an agonist at the glycine site on the N-methyl-D-aspartate receptor complex, given at a dose (3 mg/kg) that did not affect behavior, increased the inhibitory effect of olanzapine on the responses produced by 5HT2A, D(2) and D(1)/D(2) receptor stimulation. The concomitant administration of 2-chloro-5-hydroxyphenylglycine, an agonist of metabotropic glutamate receptor type 5, increased the inhibitory effect of olanzapine on the behaviors induced by the stimulation of D(2), but not 5HT2A or D(1)/D(2) receptors. As the effect on the serotonergic system seems important for the unusual pharmacological profile of atypical antipsychotics, the present results suggest that N-methyl-D-aspartate, but not metabotropic glutamate receptor type 5 agonists could be seen as promising therapeutic agents for increasing the pharmacological effects of olanzapine.

Pharmacological AMP Kinase Activators Target the Nucleolar Organization and Control Cell Proliferation

PubMed Central

Kodiha, Mohamed; Salimi, Ali; Wang, Yi Meng; Stochaj, Ursula

2014-01-01

Aims Phenformin, resveratrol and AICAR stimulate the energy sensor 5′-AMP activated kinase (AMPK) and inhibit the first step of ribosome biogenesis, de novo RNA synthesis in nucleoli. Nucleolar activities are relevant to human health, because ribosome production is crucial to the development of diabetic complications. Although the function of nucleoli relies on their organization, the impact of AMPK activators on nucleolar structures is not known. Here, we addressed this question by examining four nucleolar proteins that are essential for ribosome biogenesis. Methods Kidney cells were selected as model system, because diabetic nephropathy is one of the complications associated with diabetes mellitus. To determine the impact of pharmacological agents on nucleoli, we focused on the subcellular and subnuclear distribution of B23/nucleophosmin, fibrillarin, nucleolin and RPA194. This was achieved by quantitative confocal microscopy at the single-cell level in combination with cell fractionation and quantitative Western blotting. Results AMPK activators induced the re-organization of nucleoli, which was accompanied by changes in cell proliferation. Among the compounds tested, phenformin and resveratrol had the most pronounced impact on nucleolar organization. For B23, fibrillarin, nucleolin and RPA194, both agents (i) altered the nucleocytoplasmic distribution and nucleolar association and (ii) reduced significantly the retention in the nucleus. (iii) Phenformin and resveratrol also increased significantly the total concentration of B23 and nucleolin. Conclusions AMPK activators have unique effects on the subcellular localization, nuclear retention and abundance of nucleolar proteins. We propose that the combination of these events inhibits de novo ribosomal RNA synthesis and modulates cell proliferation. Our studies identified nucleolin as a target that is especially sensitive to pharmacological AMPK activators. Because of its response to pharmacological agents, nucleolin represents a potential biomarker for the development of drugs that diminish diabetic renal hypertrophy. PMID:24498249

Pharmacological AMP kinase activators target the nucleolar organization and control cell proliferation.

PubMed

Kodiha, Mohamed; Salimi, Ali; Wang, Yi Meng; Stochaj, Ursula

2014-01-01

Phenformin, resveratrol and AICAR stimulate the energy sensor 5'-AMP activated kinase (AMPK) and inhibit the first step of ribosome biogenesis, de novo RNA synthesis in nucleoli. Nucleolar activities are relevant to human health, because ribosome production is crucial to the development of diabetic complications. Although the function of nucleoli relies on their organization, the impact of AMPK activators on nucleolar structures is not known. Here, we addressed this question by examining four nucleolar proteins that are essential for ribosome biogenesis. Kidney cells were selected as model system, because diabetic nephropathy is one of the complications associated with diabetes mellitus. To determine the impact of pharmacological agents on nucleoli, we focused on the subcellular and subnuclear distribution of B23/nucleophosmin, fibrillarin, nucleolin and RPA194. This was achieved by quantitative confocal microscopy at the single-cell level in combination with cell fractionation and quantitative Western blotting. AMPK activators induced the re-organization of nucleoli, which was accompanied by changes in cell proliferation. Among the compounds tested, phenformin and resveratrol had the most pronounced impact on nucleolar organization. For B23, fibrillarin, nucleolin and RPA194, both agents (i) altered the nucleocytoplasmic distribution and nucleolar association and (ii) reduced significantly the retention in the nucleus. (iii) Phenformin and resveratrol also increased significantly the total concentration of B23 and nucleolin. AMPK activators have unique effects on the subcellular localization, nuclear retention and abundance of nucleolar proteins. We propose that the combination of these events inhibits de novo ribosomal RNA synthesis and modulates cell proliferation. Our studies identified nucleolin as a target that is especially sensitive to pharmacological AMPK activators. Because of its response to pharmacological agents, nucleolin represents a potential biomarker for the development of drugs that diminish diabetic renal hypertrophy.

ROCK inhibition in models of neurodegeneration and its potential for clinical translation.

PubMed

Koch, Jan Christoph; Tatenhorst, Lars; Roser, Anna-Elisa; Saal, Kim-Ann; Tönges, Lars; Lingor, Paul

2018-04-03

Neurodegenerative disorders like Parkinson's disease, Alzheimer's disease, or amyotrophic lateral sclerosis are affecting a rapidly increasing population worldwide. While common pathomechanisms such as protein aggregation, axonal degeneration, dysfunction of protein clearing and an altered immune response have been characterized, no disease-modifying therapies have been developed so far. Interestingly, a significant involvement of the Rho kinase (ROCK) signaling pathway has been described in all of these mechanisms making it a promising target for new therapeutic approaches. In this article, we first review current knowledge of the involvement of ROCK in neurodegenerative disorders and the utility of its inhibition as a disease-modifying therapy in different neurodegenerative disorders. After a detailed description of the biochemical characteristics of ROCK and its molecular interactors, differences of ROCK-expression under physiological and pathological conditions are compared. Next, different pharmacological and molecular-genetic strategies to inhibit ROCK-function are discussed, focusing on pharmacological ROCK-inhibitors. The role of the ROCK-pathway in cellular processes that are central in neurodegenerative disorders pathology like axonal degeneration, autophagy, synaptic and glial function is explained in detail. Finally, all available data on ROCK-inhibition in different animal models of neurodegenerative disorders is reviewed and first approaches for translation into human patients are discussed. Taken together, there is now extensive evidence from preclinical studies in several neurodegenerative disorders that characterize ROCK as a promising drug target for further translational research in neurodegenerative disorders. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Expression patterns and role of PTEN in rat peripheral nerve development and injury.

PubMed

Chen, Hui; Xiang, Jianping; Wu, Junxia; He, Bo; Lin, Tao; Zhu, Qingtang; Liu, Xiaolin; Zheng, Canbin

2018-05-29

Studies have suggested that phosphatase and tensin homolog (PTEN) plays an important role in neuroprotection and neuronal regeneration. To better understand the potential role of PTEN with respect to peripheral nerve development and injury, we investigated the expression pattern of PTEN at different stages of rat peripheral nerve development and injury and subsequently assessed the effect of pharmacological inhibition of PTEN using bpV(pic) on axonal regeneration in a rat sciatic nerve crush injury model. During the early stages of development, PTEN exhibits low expression in neuronal cell bodies and axons. From embryonic day (E) 18.5 and postnatal day (P)5 to adult, PTEN protein becomes more detectable, with high expression in the dorsal root ganglia (DRG) and axons. PTEN expression is inhibited in peripheral nerves, preceding myelination during neuronal development and remyelination after acute nerve injury. Low PTEN expression after nerve injury promotes Akt/mammalian target of rapamycin (mTOR) signaling pathway activity. In vivo pharmacological inhibition of PTEN using bpV(pic) promoted axonal regrowth, increased the number of myelinated nerve fibers, improved locomotive recovery and enhanced the amplitude response and nerve conduction velocity following stimulation in a rat sciatic nerve crush injury model. Thus, we suggest that PTEN may play potential roles in peripheral nerve development and regeneration and that inhibition of PTEN expression is beneficial for nerve regeneration and functional recovery after peripheral nerve injury. Copyright © 2018 Elsevier B.V. All rights reserved.

Anti-inflammatory activity of essential oils from Syzygium cumini and Psidium guajava.

PubMed

Siani, Antonio C; Souza, Mariana C; Henriques, Maria G M O; Ramos, Mônica F S

2013-07-01

Despite the many biological activities reported for essential oils, their anti-inflammatory ability is relatively underexplored considering the wide variation in plant sources and in their volatile composition. Oils from Syzygium cumini Skells (SC) and Psidium guajava L. (PG) (Myrtaceae) have been described as having diverse pharmacological activities. The current study seeks to evaluate the anti-inflammatory activity of the essential oils from the leaves of SC and PG, as well as some of their terpene-enriched fractions (+V = more volatile and -V = less volatile) obtained by vacuum distillation. Both the pharmacological responses and chemical compositions were correlated. The relative contents of the oils and their fractions were evaluated by gas chromatography. Individual constituents in the oils were characterized by gas chromatography coupled to mass spectrometry. Anti-inflammatory activity was accessed in the lipopolysaccharide-induced pleurisy model, by measuring the inhibition of total leukocyte, neutrophil and eosinophil migration in the mice pleural lavage, after oil treatment with the oils at 100 mg/kg. Eosinophil migration was inhibited by SC (67%), SC (+V) (63%), PG (76%), PG (+V) (67%) and PG (-V) (74%). This efficacy was correlated with the presence of β-pinene and β-caryophyllene in the oils, a result that was reinforced by evaluating both these pure components (38 and 50% inhibition, respectively). Synergistic effects associated with the presence of α-pinene were speculated. Essential oils from SC and PG may be useful to treat inflammatory diseases by mechanisms that include the inhibition of eosinophil migration.

Isolation and Characterization of a High Affinity Peptide Inhibitor of ClC-2 Chloride Channels*

PubMed Central

Thompson, Christopher H.; Olivetti, Pedro R.; Fuller, Matthew D.; Freeman, Cody S.; McMaster, Denis; French, Robert J.; Pohl, Jan; Kubanek, Julia; McCarty, Nael A.

2009-01-01

The ClC protein family includes voltage-gated chloride channels and chloride/proton exchangers. In eukaryotes, ClC proteins regulate membrane potential of excitable cells, contribute to epithelial transport, and aid in lysosomal acidification. Although structure/function studies of ClC proteins have been aided greatly by the available crystal structures of a bacterial ClC chloride/proton exchanger, the availability of useful pharmacological tools, such as peptide toxin inhibitors, has lagged far behind that of their cation channel counterparts. Here we report the isolation, from Leiurus quinquestriatus hebraeus venom, of a peptide toxin inhibitor of the ClC-2 chloride channel. This toxin, GaTx2, inhibits ClC-2 channels with a voltage-dependent apparent KD of ∼20 pm, making it the highest affinity inhibitor of any chloride channel. GaTx2 slows ClC-2 activation by increasing the latency to first opening by nearly 8-fold but is unable to inhibit open channels, suggesting that this toxin inhibits channel activation gating. Finally, GaTx2 specifically inhibits ClC-2 channels, showing no inhibitory effect on a battery of other major classes of chloride channels and voltage-gated potassium channels. GaTx2 is the first peptide toxin inhibitor of any ClC protein. The high affinity and specificity displayed by this toxin will make it a very powerful pharmacological tool to probe ClC-2 structure/function. PMID:19574231

Cathepsin G-Dependent Modulation of Platelet Thrombus Formation In Vivo by Blood Neutrophils

PubMed Central

Faraday, Nauder; Schunke, Kathryn; Saleem, Sofiyan; Fu, Juan; Wang, Bing; Zhang, Jian; Morrell, Craig; Dore, Sylvain

2013-01-01

Neutrophils are consistently associated with arterial thrombotic morbidity in human clinical studies but the causal basis for this association is unclear. We tested the hypothesis that neutrophils modulate platelet activation and thrombus formation in vivo in a cathepsin G-dependent manner. Neutrophils enhanced aggregation of human platelets in vitro in dose-dependent fashion and this effect was diminished by pharmacologic inhibition of cathepsin G activity and knockdown of cathepsin G expression. Tail bleeding time in the mouse was prolonged by a cathepsin G inhibitor and in cathepsin G knockout mice, and formation of neutrophil-platelet conjugates in blood that was shed from transected tails was reduced in the absence of cathepsin G. Bleeding time was highly correlated with blood neutrophil count in wildtype but not cathepsin G deficient mice. In the presence of elevated blood neutrophil counts, the anti-thrombotic effect of cathepsin G inhibition was greater than that of aspirin and additive to it when administered in combination. Both pharmacologic inhibition of cathepsin G and its congenital absence prolonged the time for platelet thrombus to form in ferric chloride-injured mouse mesenteric arterioles. In a vaso-occlusive model of ischemic stroke, inhibition of cathepsin G and its congenital absence improved cerebral blood flow, reduced histologic brain injury, and improved neurobehavioral outcome. These experiments demonstrate that neutrophil cathepsin G is a physiologic modulator of platelet thrombus formation in vivo and has potential as a target for novel anti-thrombotic therapies. PMID:23940756

Non-pharmacological treatment of Helicobacter pylori

PubMed Central

Shmuely, Haim; Domniz, Noam; Yahav, Jacob

2016-01-01

Many food and plant extracts have shown in vitro anti-Helicobacter pylori (H. pylori) activity, but are less effective in vivo. The anti-H. pylori effects of these extracts are mainly permeabilitization of the membrane, anti-adhesion, inhibition of bacterial enzymes and bacterial grown. We, herein, review treatment effects of cranberry, garlic, curcumin, ginger and pistacia gum against H. pylori in both in vitro, animal studies and in vivo studies. PMID:27158532

Study of in vitro antimicrobial and antiproliferative activities of selected Saharan plants.

PubMed

Palici, Ionut F; Liktor-Busa, Erika; Zupkó, István; Touzard, Blaise; Chaieb, Mohamed; Urbán, Edit; Hohmann, Judit

2015-12-01

The aim of the present study was the evaluation of the antimicrobial and antiproliferative activities of selected Saharan species, which are applied in the traditional medicine but not studied thoroughly from chemical and pharmacological point of view. The studied plants, namely Anthyllis henoniana, Centropodia forskalii, Cornulaca monacantha, Ephedra alata var. alenda, Euphorbia guyoniana, Helianthemum confertum, Henophyton deserti, Moltkiopsis ciliata and Spartidium saharae were collected from remote areas of North Africa, especially from the Tunisian region of Sahara. After drying and applying the appropriate extraction methods, the plant extracts were tested in antimicrobial screening assay, performed on 19 Gram-positive and -negative strains of microbes. The inhibition zones produced by plant extracts were determined by disc-diffusion method. Remarkable antibacterial activities were exhibited by extracts of Ephedra alata var. alenda and Helianthemum confertum against B. subtilis, M. catarrhalis and methicillin-resistant and non-resistant S. aureus. Minimum inhibitory concentrations of these two species were also determined. Antiproliferative effects of the extracts were evaluated against 4 human adherent cell lines (HeLa, A431, A2780 and MCF7). Notable cell growth inhibition was found for extract of Helianthemum confertum and Euphorbia guyoniana. Our results provided data for selection of some plant species for further detailed pharmacological and phytochemical examinations.

Plant-Derived Urease Inhibitors as Alternative Chemotherapeutic Agents.

PubMed

Hassan, Sherif T S; Žemlička, Milan

2016-07-01

Inhibition of the metalloenzyme urease has important pharmacologic applications in the field of antiulcer and antigastric cancer agents. Urease is involved in many serious infections caused by Helicobacter pylori in the gastric tract as well as by Proteus and related species in the urinary tract. Although numerous studies have described several novel urease inhibitors (UIs) used for the treatment of gastric and urinary infections, all these compounds have exhibited severe side effects, toxicity, and instability. Therefore, to overcome such problems, it is necessary to search for new sources of UIs, such as natural products, that provide reduced side effects, low toxicity, greater stability, and bioavailability. As limited studies have been conducted on plant-derived UIs, this paper aims to highlight and summarize the most promising compounds isolated and identified from plants, such as terpenoids, phenolic compounds, alkaloids, and other substances with inhibitory activities against plant and bacterial ureases; these are in vitro and in vivo studies with an emphasis on structure-activity relationship studies and types of inhibition that show high and promising levels of anti-urease activity. This will aid medicinal chemists in the design and synthesis of novel and pharmacologically potent UIs useful for the development of antiulcer drugs. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Canonical TGF-β Signaling Pathway Represses Human NK Cell Metabolism.

PubMed

Zaiatz-Bittencourt, Vanessa; Finlay, David K; Gardiner, Clair M

2018-06-15

Cytokines stimulate rapid metabolic changes in human NK cells, including increases in both glycolysis and oxidative phosphorylation pathways. However, how these are subsequently regulated is not known. In this study, we demonstrate that TGF-β can inhibit many of these metabolic changes, including oxidative phosphorylation, glycolytic capacity, and respiratory capacity. TGF-β also inhibited cytokine-induced expression of the transferrin nutrient receptor CD71. In contrast to a recent report on murine NK cells, TGF-β-mediated suppression of these metabolic responses did not involve the inhibition of the metabolic regulator mTORC1. Inhibition of the canonical TGF-β signaling pathway was able to restore almost all metabolic and functional responses that were inhibited by TGF-β. These data suggest that pharmacological inhibition of TGF-β could provide a metabolic advantage to NK cells that is likely to result in improved functional responses. This has important implications for NK cell-based cancer immunotherapies. Copyright © 2018 by The American Association of Immunologists, Inc.

Study on Transformation of Ginsenosides in Different Methods

PubMed Central

Zheng, Meng-meng; Xu, Fang-xue; Li, Yu-juan; Xi, Xiao-zhi; Cui, Xiao-wei

2017-01-01

Ginseng is a traditional Chinese medicine and has the extensive pharmacological activity. Ginsenosides are the major constituent in ginseng and have the unique biological activity and medicinal value. Ginsenosides have the good effects on antitumor, anti-inflammatory, antioxidative and inhibition of the cell apoptosis. Studies have showed that the major ginsenosides could be converted into rare ginsenosides, which played a significant role in exerting pharmacological activity. However, the contents of some rare ginsenosides are very little. So it is very important to find the effective way to translate the main ginsenosides to rare ginsenosides. In order to provide the theoretical foundation for the transformation of ginsenoside in vitro, in this paper, many methods of the transformation of ginsenoside were summarized, mainly including physical methods, chemical methods, and biotransformation methods. PMID:29387726

The role of FOXO and PPAR transcription factors in diet-mediated inhibition of PDC activation and carbohydrate oxidation during exercise in humans and the role of pharmacological activation of PDC in overriding these changes.

PubMed

Constantin-Teodosiu, Dumitru; Constantin, Despina; Stephens, Francis; Laithwaite, David; Greenhaff, Paul L

2012-05-01

High-fat feeding inhibits pyruvate dehydrogenase complex (PDC)-controlled carbohydrate (CHO) oxidation, which contributes to muscle insulin resistance. We aimed to reveal molecular changes underpinning this process in resting and exercising humans. We also tested whether pharmacological activation of PDC overrides these diet-induced changes. Healthy males consumed a control diet (CD) and on two further occasions an isocaloric high-fat diet (HFD). After each diet, subjects cycled for 60 min after intravenous infusion with saline (CD and HFD) or dichloroacetate (HFD+DCA). Quadriceps muscle biopsies obtained before and after 10 and 60 min of exercise were used to estimate CHO use, PDC activation, and mRNAs associated with insulin, fat, and CHO signaling. Compared with CD, HFD increased resting pyruvate dehydrogenase kinase 2 (PDK2), PDK4, forkhead box class O transcription factor 1 (FOXO1), and peroxisome proliferator-activated receptor transcription factor α (PPARα) mRNA and reduced PDC activation. Exercise increased PDC activation and whole-body CHO use in HFD, but to a lower extent than in CD. Meanwhile PDK4 and FOXO1, but not PPARα or PDK2, mRNA remained elevated. HFD+DCA activated PDC throughout and restored whole-body CHO use during exercise. FOXO1 appears to play a role in HFD-mediated muscle PDK4 upregulation and inhibition of PDC and CHO oxidation in humans. Also, pharmacological activation of PDC restores HFD-mediated inhibition of CHO oxidation during exercise.

Microwave-Assisted Synthesis of some Novel Azoles and Azolopyrimidines as Antimicrobial Agents.

PubMed

Gomha, Sobhi M; Farghaly, Thoraya A; Mabkhot, Yahia Nasser; Zayed, Mohie E M; Mohamed, Amany M G

2017-02-23

In this study, new derivatives of pyrazole, isoxazole, pyrazolylthiazole, and azolopyrimidine having a thiophene ring were synthesized under microwave irradiation. Their pharmacological activity toward bacteria and fungi inhibition was screened and compared to the references Chloramphenicol and Trimethoprim / sulphamethoxazole . The antimicrobial results of the investigated compounds revealed promising results and some derivatives have activities similar to the references used.

Cardiovascular Safety Pharmacology of Sibutramine.

PubMed

Yun, Jaesuk; Chung, Eunyong; Choi, Ki Hwan; Cho, Dae Hyun; Song, Yun Jeong; Han, Kyoung Moon; Cha, Hey Jin; Shin, Ji Soon; Seong, Won-Keun; Kim, Young-Hoon; Kim, Hyung Soo

2015-07-01

Sibutramine is an anorectic that has been banned since 2010 due to cardiovascular safety issues. However, counterfeit drugs or slimming products that include sibutramine are still available in the market. It has been reported that illegal sibutramine-contained pharmaceutical products induce cardiovascular crisis. However, the mechanism underlying sibutramine-induced cardiovascular adverse effect has not been fully evaluated yet. In this study, we performed cardiovascular safety pharmacology studies of sibutramine systemically using by hERG channel inhibition, action potential duration, and telemetry assays. Sibutramine inhibited hERG channel current of HEK293 cells with an IC50 of 3.92 μM in patch clamp assay and increased the heart rate and blood pressure (76 Δbpm in heart rate and 51 ΔmmHg in blood pressure) in beagle dogs at a dose of 30 mg/kg (per oral), while it shortened action potential duration (at 10 μM and 30 μM, resulted in 15% and 29% decreases in APD50, and 9% and 17% decreases in APD90, respectively) in the Purkinje fibers of rabbits and had no effects on the QTc interval in beagle dogs. These results suggest that sibutramine has a considerable adverse effect on the cardiovascular system and may contribute to accurate drug safety regulation.

Pharmacological endothelin receptor interaction does not occur in veins from ET(B) receptor deficient rats.

PubMed

Thakali, Keshari; Galligan, James J; Fink, Gregory D; Gariepy, Cheryl E; Watts, Stephanie W

2008-07-01

Heterodimerization of G-protein coupled receptors can alter receptor pharmacology. ET A and ET B receptors heterodimerize when co-expressed in heterologous expression lines. We hypothesized that ET A and ET B receptors heterodimerize and pharmacologically interact in vena cava from wild-type (WT) but not ET B receptor deficient (sl/sl) rats. Pharmacological endothelin receptor interaction was assessed by comparing ET-1-induced contraction in rings of rat thoracic aorta and thoracic vena cava from male Sprague Dawley rats under control conditions, ET A receptor blockade (atrasentan, 10 nM), ET B receptor blockade (BQ-788, 100 nM) or ET B receptor desensitization (Sarafotoxin 6c, 100 nM) and ET A plus ET B receptor blockade or ET A receptor blockade plus ET B receptor desensitization. In addition, similar pharmacological ET receptor antagonism experiments were performed in rat thoracic aorta and vena cava from WT and sl/sl rats. ET A but not ET B receptor blockade or ET B receptor desensitization inhibited aortic and venous ET-1-induced contraction. In vena cava but not aorta, when ET B receptors were blocked (BQ-788, 100 nM) or desensitized (S6c, 100 nM), atrasentan caused a greater inhibition of ET-1-induced contraction. Vena cava from WT but not sl/sl rats exhibited similar pharmacological ET receptor interaction. Immunocytochemistry was performed on freshly dissociated aortic and venous vascular smooth muscle cells to determine localization of ET A and ET B receptors. ET A and ET B receptors qualitatively co-localized more strongly to the plasma membrane of aortic compared to venous vascular smooth muscle cells. Our data suggest that pharmacological ET A and ET B receptor interaction may be dependent on the presence of functional ET B receptors and independent of receptor location.

THE INFLUENCE OF MAGNETIC FIELDS ON INHIBITION OF MCF-7 CELL GROWTH BY TAMOXIFEN

EPA Science Inventory

THE INFLUENCE OF MAGNETIC FIELDS ON INHIBITION OF MCF-7 CELL GROWTH BY TAMOXIFEN.
Harland and Liburdy (1) reported that 1.2-uT, 60-Hz magnetic fields could significantly block the inhibitory action of pharmacological levels of tamoxifen (10-7 M) on the growth of MCF-7 human br...

Combining systems pharmacology, transcriptomics, proteomics, and metabolomics to dissect the therapeutic mechanism of Chinese herbal Bufei Jianpi formula for application to COPD

PubMed Central

Zhao, Peng; Yang, Liping; Li, Jiansheng; Li, Ya; Tian, Yange; Li, Suyun

2016-01-01

Bufei Jianpi formula (BJF) has long been used as a therapeutic agent in the treatment of COPD. Systems pharmacology identified 145 active compounds and 175 potential targets of BJF in a previous study. Additionally, BJF was previously shown to effectively prevent COPD and its comorbidities, such as ventricular hypertrophy, by inhibition of inflammatory cytokine production, matrix metalloproteinases expression, and other cytokine production, in vivo. However, the system-level mechanism of BJF for the treatment of COPD is still unclear. The aim of this study was to gain insight into its system-level mechanisms by integrating transcriptomics, proteomics, and metabolomics together with systems pharmacology datasets. Using molecular function, pathway, and network analyses, the genes and proteins regulated in COPD rats and BJF-treated rats could be mainly attributed to oxidoreductase activity, antioxidant activity, focal adhesion, tight junction, or adherens junction. Furthermore, a comprehensive analysis of systems pharmacology, transcript, protein, and metabolite datasets is performed. The results showed that a number of genes, proteins, metabolites regulated in BJF-treated rats and potential target proteins of BJF were involved in lipid metabolism, cell junction, oxidative stress, and inflammatory response, which might be the system-level therapeutic mechanism of BJF treatment. PMID:27042044

Some indazoles reduced the activity of human serum paraoxonase 1, an antioxidant enzyme: in vitro inhibition and molecular modeling studies.

PubMed

Alım, Zuhal; Kılıç, Deryanur; Demir, Yeliz

2018-05-09

Paraoxonase 1 (PON1: EC 3.1.8.1) is a vital antioxidant enzyme against mainly atherosclerosis and many other diseases associated with oxidative stress. Thus, studies related to PON1 have an important place in the pharmacology. In this study, we aimed to evaluate the in vitro inhibition effects of some indazoles on the activity of human PON1. PON1 was purified from human serum with a specific activity of 5000 U/mg and 13.50% yield by using simple chromatographic methods. The indazoles showed K i values in a range of 26.0 ± 3.00-111 ± 31.0 μM against hPON1. All these indazoles exhibited competitive inhibition. In addition, molecular docking studies were performed in order to assess the probable binding mechanisms into the active site of hPON1. Molecular modeling studies confirmed our results. Inhibition of PON1 by indazoles supplies a verification to further consideration of limitation dosage of indazole molecule groups as drug.

Prejunctional Muscarinic Receptors in the Deep Muscular Plexus of Canine Ileum: Comparison with Smooth Muscle Receptors

DTIC Science & Technology

1992-01-01

oxotremorine . Based on thet pharmacological observations presented here, the pre;junctional muacarinic receptors in the axonal varicosities of deep muscular...and oxotremorine . Based on pirenzepine (5.60), methoctramine (5.65) and AF-DX 116 (5.21) the pharmacological observations presented here, the preiunc...be dis- carbachol and oxotremorine caused a concentration-dependent tinguished based on their affinities for ["H]NMS. inhibition of forskolin

Inhibition of in vivo histamine metabolism in rats by foodborne and pharmacologic inhibitors of diamine oxidase, histamine N-methyltransferase, and monoamine oxidase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hui, J.Y.; Taylor, S.L.

When (/sup 14/C)histamine was administered orally to rats, an average of 80% of the administered radioactivity was recovered in the urine at the end of 24 hr. About 10% of the total dose was excreted via the feces. Analysis of 4-hr urine samples found imidazoleacetic acid to be the predominant metabolite (60.6%), with N tau-methylimidazoleacetic acid (8.6%), N tau-methylhistamine (7.3%), and N-acetylhistamine (4.5%) to be the minor metabolites. Histamine metabolism was inhibited by simultaneous oral administration of aminoguanidine, isoniazid, quinacrine, cadaverine, putrescine, tyramine, and beta-phenylethylamine. The administration of inhibitors resulted in an increased amount of unmetabolized histamine and a decreasedmore » amount of metabolites reaching the urine. Pharmacologic inhibitors were found to be more potent and have a longer duration of action than foodborne ones. The inhibitors could potentiate food poisoning caused by histamine by inhibiting its metabolism.« less

Discovery of Imidazoquinolines as a Novel Class of Potent, Selective, and in Vivo Efficacious Cancer Osaka Thyroid (COT) Kinase Inhibitors.

PubMed

Glatthar, Ralf; Stojanovic, Aleksandar; Troxler, Thomas; Mattes, Henri; Möbitz, Henrik; Beerli, Rene; Blanz, Joachim; Gassmann, Ernst; Drückes, Peter; Fendrich, Gabriele; Gutmann, Sascha; Martiny-Baron, Georg; Spence, Fiona; Hornfeld, Jeff; Peel, John Edmonson; Sparrer, Helmut

2016-08-25

Cancer Osaka thyroid (COT) kinase is an important regulator of pro-inflammatory cytokines in macrophages. Thus, pharmacologic inhibition of COT should be a valid approach to therapeutically intervene in the pathogenesis of macrophage-driven inflammatory diseases such as rheumatoid arthritis. We report the discovery and chemical optimization of a novel series of COT kinase inhibitors, with unprecedented nanomolar potency for the inhibition of TNFα. Pharmacological profiling in vivo revealed a high metabolism of these compounds in rats which was demonstrated to be predominantly attributed to aldehyde oxidase. Due to the very low activity of hepatic AO in the dog, the selected candidate 32 displayed significant blood exposure in dogs which resulted in a clear prevention of inflammation-driven lameness. Taken together, the described compounds both potently and selectively inhibit COT kinase in primary human cells and ameliorate inflammatory pathologies in vivo, supporting the notion that COT is an appropriate therapeutic target for inflammatory diseases.

Pharmacological TLR4 Inhibition Protects against Acute and Chronic Fat-Induced Insulin Resistance in Rats.

PubMed

Zhang, Ning; Liang, Hanyu; Farese, Robert V; Li, Ji; Musi, Nicolas; Hussey, Sophie E

2015-01-01

To evaluate whether pharmacological TLR4 inhibition protects against acute and chronic fat-induced insulin resistance in rats. For the acute experiment, rats received a TLR4 inhibitor [TAK-242 or E5564 (2x5 mg/kg i.v. bolus)] or vehicle, and an 8-h Intralipid (20%, 8.5 mg/kg/min) or saline infusion, followed by a two-step hyperinsulinemic-euglycemic clamp. For the chronic experiment, rats were subcutaneously implanted with a slow-release pellet of TAK-242 (1.5 mg/d) or placebo. Rats then received a high fat diet (HFD) or a low fat control diet (LFD) for 10 weeks, followed by a two-step insulin clamp. Acute experiment; the lipid-induced reduction (18%) in insulin-stimulated glucose disposal (Rd) was attenuated by TAK-242 and E5564 (the effect of E5564 was more robust), suggesting improved peripheral insulin action. Insulin was able to suppress hepatic glucose production (HGP) in saline- but not lipid-treated rats. TAK-242, but not E5564, partially restored this effect, suggesting improved HGP. Chronic experiment; insulin-stimulated Rd was reduced ~30% by the HFD, but completely restored by TAK-242. Insulin could not suppress HGP in rats fed a HFD and TAK-242 had no effect on HGP. Pharmacological TLR4 inhibition provides partial protection against acute and chronic fat-induced insulin resistance in vivo.

State-dependent compound inhibition of Nav1.2 sodium channels using the FLIPR Vm dye: on-target and off-target effects of diverse pharmacological agents.

PubMed

Benjamin, Elfrida R; Pruthi, Farhana; Olanrewaju, Shakira; Ilyin, Victor I; Crumley, Gregg; Kutlina, Elena; Valenzano, Kenneth J; Woodward, Richard M

2006-02-01

Voltage-gated sodium channels (NaChs) are relevant targets for pain, epilepsy, and a variety of neurological and cardiac disorders. Traditionally, it has been difficult to develop structure-activity relationships for NaCh inhibitors due to rapid channel kinetics and state-dependent compound interactions. Membrane potential (Vm) dyes in conjunction with a high-throughput fluorescence imaging plate reader (FLIPR) offer a satisfactory 1st-tier solution. Thus, the authors have developed a FLIPR Vm assay of rat Nav1.2 NaCh. Channels were opened by addition of veratridine, and Vm dye responses were measured. The IC50 values from various structural classes of compounds were compared to the resting state binding constant (Kr)and inactivated state binding constant (Ki)obtained using patch-clamp electrophysiology (EP). The FLIPR values correlated with Ki but not Kr. FLIPRIC50 values fell within 0.1-to 1.5-fold of EP Ki values, indicating that the assay generally reports use-dependent inhibition rather than resting state block. The Library of Pharmacologically Active Compounds (LOPAC, Sigma) was screened. Confirmed hits arose from diverse classes such as dopamine receptor antagonists, serotonin transport inhibitors, and kinase inhibitors. These data suggest that NaCh inhibition is inherent in a diverse set of biologically active molecules and may warrant counterscreening NaChs to avoid unwanted secondary pharmacology.

On the Physiological Modulation and Potential Mechanisms Underlying Parieto-Occipital Alpha Oscillations

PubMed Central

Lozano-Soldevilla, Diego

2018-01-01

The parieto-occipital alpha (8–13 Hz) rhythm is by far the strongest spectral fingerprint in the human brain. Almost 90 years later, its physiological origin is still far from clear. In this Research Topic I review human pharmacological studies using electroencephalography (EEG) and magnetoencephalography (MEG) that investigated the physiological mechanisms behind posterior alpha. Based on results from classical and recent experimental studies, I find a wide spectrum of drugs that modulate parieto-occipital alpha power. Alpha frequency is rarely affected, but this might be due to the range of drug dosages employed. Animal and human pharmacological findings suggest that both GABA enhancers and NMDA blockers systematically decrease posterior alpha power. Surprisingly, most of the theoretical frameworks do not seem to embrace these empirical findings and the debate on the functional role of alpha oscillations has been polarized between the inhibition vs. active poles hypotheses. Here, I speculate that the functional role of alpha might depend on physiological excitation as much as on physiological inhibition. This is supported by animal and human pharmacological work showing that GABAergic, glutamatergic, cholinergic, and serotonergic receptors in the thalamus and the cortex play a key role in the regulation of alpha power and frequency. This myriad of physiological modulations fit with the view that the alpha rhythm is a complex rhythm with multiple sources supported by both thalamo-cortical and cortico-cortical loops. Finally, I briefly discuss how future research combining experimental measurements derived from theoretical predictions based of biophysically realistic computational models will be crucial to the reconciliation of these disparate findings. PMID:29670518

Pridopidine: Overview of Pharmacology and Rationale for its Use in Huntington's Disease.

PubMed

Waters, Susanna; Tedroff, Joakim; Ponten, Henrik; Klamer, Daniel; Sonesson, Clas; Waters, Nicholas

2018-01-01

Despite advances in understanding the pathophysiology of Huntington's disease (HD), there are currently no effective pharmacological agents available to treat core symptoms or to stop or prevent the progression of this hereditary neurodegenerative disorder. Pridopidine, a novel small molecule compound, has demonstrated potential for both symptomatic treatment and disease modifying effects in HD. While pridopidine failed to achieve its primary efficacy outcomes (Modified motor score) in two trials (MermaiHD and HART) there were consistent effects on secondary outcomes (TMS). In the most recent study (PrideHD) pridiopidine did not differ from placebo on TMS, possibly due to a large enduring placebo effect.This review describes the process, based on in vivo systems response profiling, by which pridopidine was discovered and discusses its pharmacological profile, aiming to provide a model for the system-level effects, and a rationale for the use of pridopidine in patients affected by HD. Considering the effects on brain neurochemistry, gene expression and behaviour in vivo, pridopidine displays a unique effect profile. A hallmark feature in the behavioural pharmacology of pridopidine is its state-dependent inhibition or activation of dopamine-dependent psychomotor functions. Such effects are paralleled by strengthening of synaptic connectivity in cortico-striatal pathways suggesting pridopidine has potential to modify phenotypic expression as well as progression of HD. The preclinical pharmacological profile is discussed with respect to the clinical results for pridopidine, and proposals are made for further investigation, including preclinical and clinical studies addressing disease progression and effects at different stages of HD.

Biochemical and Pharmacological Characterizations of ESI-09 Based EPAC Inhibitors: Defining the ESI-09 “Therapeutic Window”

PubMed Central

Zhu, Yingmin; Chen, Haijun; Boulton, Stephen; Mei, Fang; Ye, Na; Melacini, Giuseppe; Zhou, Jia; Cheng, Xiaodong

2015-01-01

The cAMP signaling cascade is one of the most frequently targeted pathways for the development of pharmaceutics. A plethora of recent genetic and pharmacological studies suggest that exchange proteins directly activated by cAMP (EPACs) are implicated in multiple pathologies. Selective EPAC inhibitors have been recently developed. One specific inhibitor, ESI-09, has been shown to block EPAC activity and functions, as well as to recapitulate genetic phenotypes of EPAC knockout mice when applied in vivo. However, a recent study raised concern that ESI-09 might act as a non-specific protein denaturant. Herein, we present a detailed biochemical and pharmacological characterization, as well as a structure-activity relationship (SAR) analysis of ESI-09. Our studies show that ESI-09 dose-dependently inhibits activity of both EPAC1 and EPAC2 with apparent IC50 values well below the concentrations shown to induce “protein denaturation”. Moreover, the ESI-09's action towards EPAC proteins is highly sensitive to minor modifications of the 3-chlorophenyl moiety. Taken together, these results demonstrate that ESI-09 indeed acts as an EPAC specific antagonist and does not significantly destabilize/denature proteins at pharmacological effective concentrations. This conclusion is further supported by NMR data showing that ESI-09 induces residue-dependent chemical shift changes at low concentrations, while preserving well dispersed peaks. PMID:25791905

Biochemical and pharmacological characterizations of ESI-09 based EPAC inhibitors: defining the ESI-09 "therapeutic window".

PubMed

Zhu, Yingmin; Chen, Haijun; Boulton, Stephen; Mei, Fang; Ye, Na; Melacini, Giuseppe; Zhou, Jia; Cheng, Xiaodong

2015-03-20

The cAMP signaling cascade is one of the most frequently targeted pathways for the development of pharmaceutics. A plethora of recent genetic and pharmacological studies suggest that exchange proteins directly activated by cAMP (EPACs) are implicated in multiple pathologies. Selective EPAC inhibitors have been recently developed. One specific inhibitor, ESI-09, has been shown to block EPAC activity and functions, as well as to recapitulate genetic phenotypes of EPAC knockout mice when applied in vivo. However, a recent study raised concern that ESI-09 might act as a non-specific protein denaturant. Herein, we present a detailed biochemical and pharmacological characterization, as well as a structure-activity relationship (SAR) analysis of ESI-09. Our studies show that ESI-09 dose-dependently inhibits activity of both EPAC1 and EPAC2 with apparent IC50 values well below the concentrations shown to induce "protein denaturation". Moreover, the ESI-09's action towards EPAC proteins is highly sensitive to minor modifications of the 3-chlorophenyl moiety. Taken together, these results demonstrate that ESI-09 indeed acts as an EPAC specific antagonist and does not significantly destabilize/denature proteins at pharmacological effective concentrations. This conclusion is further supported by NMR data showing that ESI-09 induces residue-dependent chemical shift changes at low concentrations, while preserving well dispersed peaks.

Inhibiting poly ADP-ribosylation increases fatty acid oxidation and protects against fatty liver disease.

PubMed

Gariani, Karim; Ryu, Dongryeol; Menzies, Keir J; Yi, Hyon-Seung; Stein, Sokrates; Zhang, Hongbo; Perino, Alessia; Lemos, Vera; Katsyuba, Elena; Jha, Pooja; Vijgen, Sandrine; Rubbia-Brandt, Laura; Kim, Yong Kyung; Kim, Jung Tae; Kim, Koon Soon; Shong, Minho; Schoonjans, Kristina; Auwerx, Johan

2017-01-01

To date, no pharmacological therapy has been approved for non-alcoholic fatty liver disease (NAFLD). The aim of the present study was to evaluate the therapeutic potential of poly ADP-ribose polymerase (PARP) inhibitors in mouse models of NAFLD. As poly ADP-ribosylation (PARylation) of proteins by PARPs consumes nicotinamide adenine dinucleotide (NAD + ), we hypothesized that overactivation of PARPs drives NAD + depletion in NAFLD. Therefore, we assessed the effectiveness of PARP inhibition to replenish NAD + and activate NAD + -dependent sirtuins, hence improving hepatic fatty acid oxidation. To do this, we examined the preventive and therapeutic benefits of the PARP inhibitor (PARPi), olaparib, in different models of NAFLD. The induction of NAFLD in C57BL/6J mice using a high-fat high-sucrose (HFHS)-diet increased PARylation of proteins by PARPs. As such, increased PARylation was associated with reduced NAD + levels and mitochondrial function and content, which was concurrent with elevated hepatic lipid content. HFHS diet supplemented with PARPi reversed NAFLD through repletion of NAD + , increasing mitochondrial biogenesis and β-oxidation in liver. Furthermore, PARPi reduced reactive oxygen species, endoplasmic reticulum stress and fibrosis. The benefits of PARPi treatment were confirmed in mice fed with a methionine- and choline-deficient diet and in mice with lipopolysaccharide-induced hepatitis; PARP activation was attenuated and the development of hepatic injury was delayed in both models. Using Sirt1 hep-/- mice, the beneficial effects of a PARPi-supplemented HFHS diet were found to be Sirt1-dependent. Our study provides a novel and practical pharmacological approach for treating NAFLD, fueling optimism for potential clinical studies. Non-alcoholic fatty liver disease (NAFLD) is now considered to be the most common liver disease in the Western world and has no approved pharmacological therapy. PARP inhibitors given as a treatment in two different mouse models of NAFLD confer a protection against its development. PARP inhibitors may therefore represent a novel and practical pharmacological approach for treating NAFLD. Copyright © 2016 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

TS-071 is a novel, potent and selective renal sodium-glucose cotransporter 2 (SGLT2) inhibitor with anti-hyperglycaemic activity.

PubMed

Yamamoto, K; Uchida, S; Kitano, K; Fukuhara, N; Okumura-Kitajima, L; Gunji, E; Kozakai, A; Tomoike, H; Kojima, N; Asami, J; Toyoda, H; Arai, M; Takahashi, T; Takahashi, K

2011-09-01

The renal sodium-glucose cotransporter 2 (SGLT2) plays an important role in the reuptake of filtered glucose in the proximal tubule and therefore may be an attractive target for the treatment of diabetes mellitus. This study characterizes the pharmacological profile of TS-071 ((1S)-1,5-anhydro-1-[5-(4-ethoxybenzyl)-2-methoxy-4-methylphenyl]-1-thio-D-glucitol hydrate), a novel SGLT2 inhibitor in vitro and in vivo. Inhibition of glucose uptake by TS-071 was studied in CHO-K1 cells stably expressing either human SGLT1 or SGLT2. Single oral dosing studies were performed in rats, mice and dogs to assess the abilities of TS-071 to increase urinary glucose excretion and to lower plasma glucose levels. TS-071 inhibited SGLT2 activity in a concentration-dependent manner and was a potent and highly selective inhibitor of SGLT2. Orally administered TS-071 increased urinary glucose excretion in Zucker fatty rats and beagle dogs at doses of 0.3 and 0.03 mg·kg(-1) respectively. TS-071 improved glucose tolerance in Zucker fatty rats without stimulating insulin secretion and reduced hyperglycaemia in streptozotocin (STZ)-induced diabetic rats and db/db mice at a dose of 0.3 mg·kg(-1). These data indicate that TS-071 is a potent and selective SGLT2 inhibitor that improves glucose levels in rodent models of type 1 and 2 diabetes and may be useful for the treatment for diabetes mellitus. © 2011 The Authors. British Journal of Pharmacology © 2011 The British Pharmacological Society.

Pharmacologic properties of brewery dust extracts in vitro.

PubMed

Schachter, E N; Zuskin, E; Rienzi, N; Goswami, S; Castranova, V; Whitmer, M; Siegel, P

2001-06-01

To study the effects of extracts of brewery dust on isolated guinea pig tracheal smooth muscle in vitro. Parallel pharmacologic intervention on guinea pig tracheal rings that were obtained from the same animal. Mount Sinai School of Medicine, Department of Pulmonary Medicine. The isolated guinea pig tracheal tissue of 18 guinea pigs. Pretreatment of guinea pig rings by mediator-modifying agents before challenge with the brewery dust extracts. The effect of brewery dust extracts on isolated guinea pig tracheal smooth muscle was studied using water-soluble extracts of dust obtained from brewery materials, including hops, barley, and brewery yeast. Dust extracts were prepared as a 1:10 (wt/vol) aqueous solution. Dose-related contractions of nonsensitized guinea pig tracheas were demonstrated using these extracts. The dust extracts contained significant quantities of bacterial components (eg, endotoxin and n-formyl-methionyl-leucyl-phenylalanine), but these agents were not thought to contribute directly to the constrictor effect of the dusts. Pharmacologic studies were performed by pretreating guinea pig tracheal tissue with the following drugs known to modulate smooth muscle contraction: atropine; indomethacin; pyrilamine; LY171883; nordihydroguaiaretic acid; captopril; thiorphan; verapamil; and TMB8. The constrictor effects of the dust extracts were inhibited by a wide variety of agents, the patterns of which depended on the dust extract. Atropine consistently and strikingly reduced the contractile effects of these extracts. These observations may suggest an interaction of the extracts with parasympathetic nerves or, more directly, with muscarinic receptors. The inhibition of contraction by the blocking of other mediators was less effective and varied with the dust extract. We suggest that brewery dust extracts cause a dose-related airway smooth muscle constriction by nonimmunologic mechanisms involving a variety of airway mediators and, possibly, cholinergic receptors. This effect is not dependent on presensitization of the guinea pigs.

Induction of oxidative DNA damage by mesalamine in the presence of copper: a potential mechanism for mesalamine anticancer activity.

PubMed

Zimmerman, Ryan P; Jia, Zhenquan; Zhu, Hong; Vandjelovic, Nathan; Misra, Hara P; Wang, Jianmin; Li, Yunbo

2011-02-27

Mesalamine is the first line pharmacologic intervention for patients with ulcerative colitis, and recent epidemiologic studies have demonstrated a protective association between therapeutic use of the drug and colorectal carcinoma. However, the mechanism by which this protection is afforded has yet to be elucidated. Because copper is found at higher than normal concentrations in neoplastic cell nuclei and is known to interact with phenolic compounds to generate reactive oxygen species, we investigated whether the reaction of mesalamine/copper was able to induce oxidative DNA strand breaks in φX-174 RF I plasmid DNA, and the various components of the mechanism by which the reaction occurred. Plasmid DNA strand breaks were induced by pharmacologically relevant concentrations of mesalamine in the presence of a micromolar concentration of Cu(II), and damage was inhibited by bathocuproinedisulfonic acid (BCS) and catalase. Further, we showed that the reaction of copper with mesalamine consumed molecular oxygen, which was inhibited by BCS. Electron paramagnetic resonance spectral analysis of the reaction of copper/mesalamine indicated the presence of the hydroxyl radical, which was inhibited by both BCS and catalase. This study demonstrates for the first time that through a copper-redox cycling mechanism, the copper-mediated oxidation of mesalamine is a pro-oxidant interaction that generates hydroxyl radicals which may participate in oxidative DNA damage. These results demonstrate a potential mechanism of the anticancer effects of mesalamine in patients with ulcerative colitis. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Inhibition of class IA PI3K enzymes in non-small cell lung cancer cells uncovers functional compensation among isoforms.

PubMed

Stamatkin, Christopher; Ratermann, Kelley L; Overley, Colleen W; Black, Esther P

2015-01-01

Deregulation of the phosphatidylinositol 3-kinase (PI3K) pathway is central to many human malignancies while normal cell proliferation requires pathway functionality. Although inhibitors of the PI3K pathway are in clinical trials or approved for therapy, an understanding of the functional activities of pathway members in specific malignancies is needed. In lung cancers, the PI3K pathway is often aberrantly activated by mutation of genes encoding EGFR, KRAS, and PIK3CA proteins. We sought to understand whether class IA PI3K enzymes represent rational therapeutic targets in cells of non-squamous lung cancers by exploring pharmacological and genetic inhibitors of PI3K enzymes in a non-small cell lung cancer (NSCLC) cell line system. We found that class IA PI3K enzymes were expressed in all cell lines tested, but treatment of NSCLC lines with isoform-selective inhibitors (A66, TGX-221, CAL-101 and IC488743) had little effect on cell proliferation or prolonged inhibition of AKT activity. Inhibitory pharmacokinetic and pharmacodynamic responses were observed using these agents at non-isoform selective concentrations and with the pan-class I (ZSTK474) agent. Response to pharmacological inhibition suggested that PI3K isoforms may functionally compensate for one another thus limiting efficacy of single agent treatment. However, combination of ZSTK474 and an EGFR inhibitor (erlotinib) in NSCLC resistant to each single agent reduced cellular proliferation. These studies uncovered unanticipated cellular responses to PI3K isoform inhibition in NSCLC that does not correlate with PI3K mutations, suggesting that patients bearing tumors with wildtype EGFR and KRAS are unlikely to benefit from inhibitors of single isoforms but may respond to pan-isoform inhibition.

Isoflavones isolated from red clover (Trifolium pratense) inhibit smooth muscle contraction of the isolated rat prostate gland.

PubMed

Brandli, A; Simpson, J S; Ventura, S

2010-09-01

This study investigated whether red clover contains any bioactive constituents which may affect contractility of rat prostatic smooth muscle in an attempt to determine whether its medicinal use in the treatment of benign prostatic hyperplasia is supported by pharmacological effects. A commercially available red clover extract was chemically fractionated and various isoflavones (genistein, formononetin and biochanin A) were isolated from these fractions and their effects on contractility were examined on preparations of the isolated rat prostate gland. Contractile effects of the isolated fractions were compared with commercially available isoflavones (genistein, formononetin and biochanin A). Pharmacological tools were used to investigate the mechanism of action modifying smooth muscle contraction. Crude red clover extract (Trinovin) inhibited electrical field stimulation induced contractions of the rat prostate across a range of frequencies with an IC(50) of approximately 68 microg/ml. Contractions of the rat prostate elicited by exogenous administration of acetylcholine, noradrenaline or adenosine 5'-triphosphate (ATP) were also inhibited. Chromatographic separation, and final purification by high performance liquid chromatography (HPLC) permitted the isolation of the isoflavones: daidzein, calycosin, formononetin, prunetin, pratensin, biochanin A and genistein. Genistein, formononetin and biochanin A (100 microM) from either commercial sources or isolated from red clover extract inhibited electrical field stimulation induced contractions of the isolated rat prostate. It is concluded that isoflavones contained in red clover are able to inhibit prostatic smooth muscle contractions in addition to their antiproliferative effects. However, the high concentrations required to observe these smooth muscle relaxant effects mean that a therapeutic benefit from this mechanism is unlikely at doses used clinically. Crown Copyright 2010. Published by Elsevier GmbH. All rights reserved.

A novel crosstalk between two major protein degradation systems: regulation of proteasomal activity by autophagy.

PubMed

Wang, Xiao J; Yu, Jun; Wong, Sunny H; Cheng, Alfred S L; Chan, Francis K L; Ng, Simon S M; Cho, Chi H; Sung, Joseph J Y; Wu, William K K

2013-10-01

Eukaryotes have two major intracellular protein degradation pathways, namely the ubiquitin-proteasome system (UPS) and autophagy. Inhibition of proteasomal activities has been previously shown to induce autophagy, indicating a coordinated and complementary relationship between these two systems. However, little is known about the regulation of the UPS by autophagy. In this study, we showed for the first time that proteasomes were activated in response to pharmacological inhibition of autophagy as well as disruption of autophagy-related genes by RNA interference under nutrient-deficient conditions in cultured human colon cancer cells. The induction was evidenced by the increased proteasomal activities and the upregulation of proteasomal subunits, including the proteasome β5 subunit, PSMB5. Co-inhibition of the proteasome and autophagy also synergistically increased the accumulation of polyubiquitinated proteins. Collectively, our findings suggest that proteasomes are activated in a compensatory manner for protein degradation upon autophagy inhibition. Our studies unveiled a novel regulatory mechanism between the two protein degradation pathways.

The enhancement of antiproliferative and proapoptotic activity of HDAC inhibitors by curcumin is mediated by Hsp90 inhibition.

PubMed

Giommarelli, Chiara; Zuco, Valentina; Favini, Enrica; Pisano, Claudio; Dal Piaz, Fabrizio; De Tommasi, Nunziatina; Zunino, Franco

2010-03-01

Curcumin, a natural polyphenol, has been described to exhibit effects on signaling pathways, leading to induction of apoptosis. In this study, we observed that curcumin inhibited Hsp90 activity causing depletion of client proteins implicated in survival pathways. Based on this observation, this study was designed to investigate the cellular effects of curcumin combination with the pan-HDAC inhibitors, vorinostat and panobinostat, which induce hyperacetylation of Hsp90, resulting in inhibition of its chaperone function. The results showed that, at subtoxic concentrations, curcumin markedly sensitized tumor cells to vorinostat- and panobinostat-induced growth inhibition and apoptosis. The sensitization was associated with persistent depletion of Hsp90 client proteins (EGFR, Raf-1, Akt, and survivin). In conclusion, our findings document a novel mechanism of action of curcumin and support the therapeutic potential of curcumin/HDAC inhibitors combination, because the synergistic interaction was observed at pharmacologically achievable concentrations, which were ineffective when each drug was used alone.

Osthole inhibits bone metastasis of breast cancer

PubMed Central

Guo, Baofeng; Ye, Yiyi; Han, Xianghui; Qin, Yuenong; Liu, Sheng

2017-01-01

Bone is one of the most common sites for breast cancer metastasis, which greatly contributes to patient morbidity and mortality. Osthole, a major extract from Cnidium monnieri (L.), exhibits many biological and pharmacological activities, however, its potential as a therapeutic agent in the treatment of breast cancer bone metastases remain poorly understood. In this study, we set out to investigate whether osthole could inhibit breast cancer metastasis to bone in mice and clarified the potential mechanism of this inhibition. In the murine model of breast cancer osseous metastasis, mice that received osthole developed significantly less bone metastases and displayed decreased tumor burden when compared with mice in the control group. Osthole inhibited breast cancer cell growth, migration, and invasion, and induced apoptosis of breast cancer cells. Additionally, it also regulated OPG/RANKL signals in the interactions between bone cells (osteoblasts and osteoclasts) and cancer cells. Besides, it also inhibited TGF-β/Smads signaling in breast cancer metastasis to bone in MDA-231BO cells. The results of this study suggest that osthole has real potential as a therapeutic candidate in the treatment of breast cancer patients with bone metastases. PMID:28938572

Costunolide inhibits proinflammatory cytokines and iNOS in activated murine BV2 microglia.

PubMed

Rayan, Nirmala Arul; Baby, Nimmi; Pitchai, Daisy; Indraswari, Fransisca; Ling, Eng-Ang; Lu, Jia; Dheen, Thameem

2011-06-01

Costunolide, a sesquiterpene lactone present in Costus speciosus root exerts a variety of pharmacological activity but its effects on neuroinflammation have not been studied. Microglia, the resident phagocytic cells in the central nervous system respond to neuroinflammation and their overwhelming response in turn aggravate brain damage during infection, ischemia and neurodegenerative diseases. In this study, we report the effect of Costunolide on the production of proinflammatory mediators and mechanisms involved in BV2 microglial cells stimulated with LPS. Costunolide attenuated the expression of tumour necrosis factor-alpha, interleukin-1,6, inducible nitric oxide synthase, monocyte chemotactic protein 1 and cyclooxygenase 2 in activated microglia. This Costunolide-mediated inhibition was correspondent with the inhibition of NFkappaB activation. It has been further shown that Costunolide suppressed MAPK pathway activation by inducing MKP-1 production. Collectively our results suggest that Costunolide shows an ability to inhibit expression of multiple neuroinflammatory mediators and this is attributable to the compounds inhibition of NFkappaB and MAPK activation. This novel role of Costunolide upon investigation may aid in developing better therapeutic strategies for treatment of neuroinflammatory diseases.

Pharmacological modulation of caspase-8 in thymus-related medical conditions.

PubMed

Pozzesi, Nicola; Fierabracci, Alessandra; Thuy, Trinh Thy; Martelli, Maria Paola; Liberati, Anna Marina; Ayroldi, Emira; Riccardi, Carlo; Delfino, Domenico V

2014-10-01

The thymus is a lymphoid organ that governs the development of a diverse T-cell repertoire capable of defending against nonself-antigens and avoiding autoimmunity. However, the thymus can also succumb to different diseases. Hypertrophic diseases, such as thymomas, are typically associated with impairment of negative selection, which leads to autoimmune disease, or disruption of positive selection, which results in immunodeficiency. Hypotrophic diseases of the thymus can manifest during acute infections, cancer, allogeneic bone marrow transplantation, or with aging. This condition leads to decreased immune function and can be treated by either replacing lost thymic tissue or by preventing thymic tissue death. Studies have demonstrated the critical role of caspase-8 in regulating apoptosis in the thymus. In this review, we discuss how pharmacological activation and inhibition of caspase-8 can be used to treat hypertrophic and hypotrophic diseases of the thymus, respectively, to improve its function. Copyright © 2014 by The American Society for Pharmacology and Experimental Therapeutics.

JAK/STAT1 signaling promotes HMGB1 hyperacetylation and nuclear translocation

PubMed Central

Lu, Ben; Antoine, Daniel J.; Kwan, Kevin; Lundbäck, Peter; Wähämaa, Heidi; Schierbeck, Hanna; Robinson, Melissa; Van Zoelen, Marieke A. D.; Yang, Huan; Li, Jianhua; Erlandsson-Harris, Helena; Chavan, Sangeeta S.; Wang, Haichao; Andersson, Ulf; Tracey, Kevin J.

2014-01-01

Extracellular high-mobility group box (HMGB)1 mediates inflammation during sterile and infectious injury and contributes importantly to disease pathogenesis. The first critical step in the release of HMGB1 from activated immune cells is mobilization from the nucleus to the cytoplasm, a process dependent upon hyperacetylation within two HMGB1 nuclear localization sequence (NLS) sites. The inflammasomes mediate the release of cytoplasmic HMGB1 in activated immune cells, but the mechanism of HMGB1 translocation from nucleus to cytoplasm was previously unknown. Here, we show that pharmacological inhibition of JAK/STAT1 inhibits LPS-induced HMGB1 nuclear translocation. Conversely, activation of JAK/STAT1 by type 1 interferon (IFN) stimulation induces HMGB1 translocation from nucleus to cytoplasm. Mass spectrometric analysis unequivocally revealed that pharmacological inhibition of the JAK/STAT1 pathway or genetic deletion of STAT1 abrogated LPS- or type 1 IFN-induced HMGB1 acetylation within the NLS sites. Together, these results identify a critical role of the JAK/STAT1 pathway in mediating HMGB1 cytoplasmic accumulation for subsequent release, suggesting that the JAK/STAT1 pathway is a potential drug target for inhibiting HMGB1 release. PMID:24469805

11β-HSD1 inhibition ameliorates metabolic syndrome and prevents progression of atherosclerosis in mice

PubMed Central

Hermanowski-Vosatka, Anne; Balkovec, James M.; Cheng, Kang; Chen, Howard Y.; Hernandez, Melba; Koo, Gloria C.; Le Grand, Cheryl B.; Li, Zhihua; Metzger, Joseph M.; Mundt, Steven S.; Noonan, Heather; Nunes, Christian N.; Olson, Steven H.; Pikounis, Bill; Ren, Ning; Robertson, Nancy; Schaeffer, James M.; Shah, Kashmira; Springer, Martin S.; Strack, Alison M.; Strowski, Matthias; Wu, Kenneth; Wu, TsueiJu; Xiao, Jianying; Zhang, Bei B.; Wright, Samuel D.; Thieringer, Rolf

2005-01-01

The enzyme 11β–hydroxysteroid dehydrogenase (HSD) type 1 converts inactive cortisone into active cortisol in cells, thereby raising the effective glucocorticoid (GC) tone above serum levels. We report that pharmacologic inhibition of 11β-HSD1 has a therapeutic effect in mouse models of metabolic syndrome. Administration of a selective, potent 11β-HSD1 inhibitor lowered body weight, insulin, fasting glucose, triglycerides, and cholesterol in diet-induced obese mice and lowered fasting glucose, insulin, glucagon, triglycerides, and free fatty acids, as well as improved glucose tolerance, in a mouse model of type 2 diabetes. Most importantly, inhibition of 11β-HSD1 slowed plaque progression in a murine model of atherosclerosis, the key clinical sequela of metabolic syndrome. Mice with a targeted deletion of apolipoprotein E exhibited 84% less accumulation of aortic total cholesterol, as well as lower serum cholesterol and triglycerides, when treated with an 11β-HSD1 inhibitor. These data provide the first evidence that pharmacologic inhibition of intracellular GC activation can effectively treat atherosclerosis, the key clinical consequence of metabolic syndrome, in addition to its salutary effect on multiple aspects of the metabolic syndrome itself. PMID:16103409

CD73 Protein as a Source of Extracellular Precursors for Sustained NAD+ Biosynthesis in FK866-treated Tumor Cells*

PubMed Central

Grozio, Alessia; Sociali, Giovanna; Sturla, Laura; Caffa, Irene; Soncini, Debora; Salis, Annalisa; Raffaelli, Nadia; De Flora, Antonio; Nencioni, Alessio; Bruzzone, Santina

2013-01-01

NAD+ is mainly synthesized in human cells via the “salvage” pathways starting from nicotinamide, nicotinic acid, or nicotinamide riboside (NR). The inhibition with FK866 of the enzyme nicotinamide phosphoribosyltransferase (NAMPT), catalyzing the first reaction in the “salvage” pathway from nicotinamide, showed potent antitumor activity in several preclinical models of solid and hematologic cancers. In the clinical studies performed with FK866, however, no tumor remission was observed. Here we demonstrate that low micromolar concentrations of extracellular NAD+ or NAD+ precursors, nicotinamide mononucleotide (NMN) and NR, can reverse the FK866-induced cell death, this representing a plausible explanation for the failure of NAMPT inhibition as an anti-cancer therapy. NMN is a substrate of both ectoenzymes CD38 and CD73, with generation of NAM and NR, respectively. In this study, we investigated the roles of CD38 and CD73 in providing ectocellular NAD+ precursors for NAD+ biosynthesis and in modulating cell susceptibility to FK866. By specifically silencing or overexpressing CD38 and CD73, we demonstrated that endogenous CD73 enables, whereas CD38 impairs, the conversion of extracellular NMN to NR as a precursor for intracellular NAD+ biosynthesis in human cells. Moreover, cell viability in FK866-treated cells supplemented with extracellular NMN was strongly reduced in tumor cells, upon pharmacological inhibition or specific down-regulation of CD73. Thus, our study suggests that genetic or pharmacologic interventions interfering with CD73 activity may prove useful to increase cancer cell sensitivity to NAMPT inhibitors. PMID:23880765

The Effects of Donepezil, an Acetylcholinesterase Inhibitor, on Impaired Learning and Memory in Rodents.

PubMed

Shin, Chang Yell; Kim, Hae-Sun; Cha, Kwang-Ho; Won, Dong Han; Lee, Ji-Yun; Jang, Sun Woo; Sohn, Uy Dong

2018-05-01

A previous study in humans demonstrated the sustained inhibitory effects of donepezil on acetylcholinesterase (AChE) activity; however, the effective concentration of donepezil in humans and animals is unclear. This study aimed to characterize the effective concentration of donepezil on AChE inhibition and impaired learning and memory in rodents. A pharmacokinetic study of donepezil showed a mean peak plasma concentration of donepezil after oral treatment (3 and 10 mg/kg) of approximately 1.2 ± 0.4 h and 1.4 ± 0.5 h, respectively; absolute bioavailability was calculated as 3.6%. Further, AChE activity was inhibited by increasing plasma concentrations of donepezil, and a maximum inhibition of 31.5 ± 5.7% was observed after donepezil treatment in hairless rats. Plasma AChE activity was negatively correlated with plasma donepezil concentration. The pharmacological effects of donepezil are dependent upon its concentration and AChE activity; therefore, we assessed the effects of donepezil on learning and memory using a Y-maze in mice. Donepezil treatment (3 mg/kg) significantly prevented the progression of scopolamine-induced memory impairment in mice. As the concentration of donepezil in the brain increased, the recovery of spontaneous alternations also improved; maximal improvement was observed at 46.5 ± 3.5 ng/g in the brain. In conclusion, our findings suggest that the AChE inhibitory activity and pharmacological effects of donepezil can be predicted by the concentration of donepezil. Further, 46.5 ± 3.5 ng/g donepezil is an efficacious target concentration in the brain for treating learning and memory impairment in rodents.

Mitigating hERG Inhibition: Design of Orally Bioavailable CCR5 Antagonists as Potent Inhibitors of R5 HIV-1 Replication

PubMed Central

2012-01-01

A series of CCR5 antagonists representing the thiophene-3-yl-methyl ureas were designed that met the pharmacological criteria for HIV-1 inhibition and mitigated a human ether-a-go-go related gene (hERG) inhibition liability. Reducing lipophilicity was the main design criteria used to identify compounds that did not inhibit the hERG channel, but subtle structural modifications were also important. Interestingly, within this series, compounds with low hERG inhibition prolonged the action potential duration (APD) in dog Purkinje fibers, suggesting a mixed effect on cardiac ion channels. PMID:24900457

Histaminergic and serotonergic receptor blocking substances from the medicinal plant Garcinia mangostana.

PubMed

Chairungsrilerd, N; Furukawa, K; Ohta, T; Nozoe, S; Ohizumi, Y

1996-10-01

A crude methanolic extract of the fruit hull of Mangosteen, Garcinia mangostana L. inhibited the contractions of isolated thoracic rabbit aorta induced by histamine and serotonin. The extract of the fruit hull has been fractionated by silica gel chromatography, monitoring the pharmacological activity to give alpha- and gamma-mangostin. On the basis of pharmacological data, it is suggested that alpha-mangostin and gamma-mangostin are a histaminergic and a serotonergic receptor blocking agent, respectively.

Studies of the pharmacology of 17α-ethynyl-androst-5-ene-3β,7β,17β-triol, a synthetic anti-inflammatory androstene

PubMed Central

Ahlem, Clarence N; Kennedy, Michael R; Page, Theodore M; Reading, Christopher L; White, Steven K; McKenzie, John J; Cole, Phaedra I; Stickney, Dwight R; Frincke, James M

2011-01-01

17α-Ethynyl-androst-5ene-3β, 7β, 17β-triol (HE3286) is an orally bioavailable analogue of androst-5-ene-3β,7β,17β-triol, a non-glucocorticoid anti-inflammatory metabolite of the adrenal steroid, dehydroepiandrosterone. The pharmacology of HE3286 was characterized in preparation for clinical trials in type 2 diabetes mellitus and other diseases of inflammation. Interactions with nuclear hormone receptors and P450 enzymes were measured in vitro. Drug metabolism was studied preclinically in mice, rats, dogs, and monkeys. Neurological and cardiopulmonary safety and dose-ranging and chronic toxicity studies were conducted in rats and dogs in accordance with FDA guidelines. Pharmacokinetics and metabolites were measured in Phase I clinical trials. HE3286 was differentially metabolized between species. HE3286 and metabolites did not bind or transactivate steroid binding nuclear hormone receptors or inhibit P450 enzymes. There were no adverse effects in safety pharmacology and canine toxicology studies. Although HE3286 did not elicit systemic toxicity in rats, mild estrogenic effects were observed, but without apparent association to hormonal changes. Safety margins were greater than 20-fold in rats and dogs with respect to the most commonly used clinical dose of 10 mg/day. The terminal half-life in humans was 8 hours in males and 5.5 hours in females. HE3286 is the first derivative of the DHEA metabolome to undergo a comprehensive pharmacological and safety evaluation. The results of these investigations have shown that HE3286 has a low potential for toxicity and possesses pharmacological properties generally suitable for use in human medicine. The favorable profile of HE3286 warrants further exploration of this new class of anti-inflammatory agents. PMID:21686136

Pharmacology of Bradykinin-Evoked Coughing in Guinea Pigs.

PubMed

Hewitt, Matthew M; Adams, Gregory; Mazzone, Stuart B; Mori, Nanako; Yu, Li; Canning, Brendan J

2016-06-01

Bradykinin has been implicated as a mediator of the acute pathophysiological and inflammatory consequences of respiratory tract infections and in exacerbations of chronic diseases such as asthma. Bradykinin may also be a trigger for the coughing associated with these and other conditions. We have thus set out to evaluate the pharmacology of bradykinin-evoked coughing in guinea pigs. When inhaled, bradykinin induced paroxysmal coughing that was abolished by the bradykinin B2 receptor antagonist HOE 140. These cough responses rapidly desensitized, consistent with reports of B2 receptor desensitization. Bradykinin-evoked cough was potentiated by inhibition of both neutral endopeptidase and angiotensin-converting enzyme (with thiorphan and captopril, respectively), but was largely unaffected by muscarinic or thromboxane receptor blockade (atropine and ICI 192605), cyclooxygenase, or nitric oxide synthase inhibition (meclofenamic acid and N(G)-nitro-L-arginine). Calcium influx studies in bronchopulmonary vagal afferent neurons dissociated from vagal sensory ganglia indicated that the tachykinin-containing C-fibers arising from the jugular ganglia mediate bradykinin-evoked coughing. Also implicating the jugular C-fibers was the observation that simultaneous blockade of neurokinin2 (NK2; SR48968) and NK3 (SR142801 or SB223412) receptors nearly abolished the bradykinin-evoked cough responses. The data suggest that bradykinin induces coughing in guinea pigs by activating B2 receptors on bronchopulmonary C-fibers. We speculate that therapeutics targeting the actions of bradykinin may prove useful in the treatment of cough. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

Pharmacologically inhibiting kinesin-5 activity with monastrol promotes axonal regeneration following spinal cord injury

PubMed Central

Xu, Chen; Klaw, Michelle C.; Lemay, Michel A.; Baas, Peter W.; Tom, Veronica J.

2014-01-01

While it is well established that the axons of adult neurons have a lower capacity for regrowth, some regeneration of certain CNS populations after spinal cord injury (SCI) is possible if their axons are provided with a permissive substrate, such as an injured peripheral nerve. While some axons readily regenerate into a peripheral nerve graft (PNG), these axons almost always stall at the distal interface and fail to re-innervate spinal cord tissue. Treatment of the glial scar at the distal graft interface with chondroitinase ABC (ChABC) can improve regeneration, but most regenerated axons need further stimulation to extend beyond the interface. Previous studies demonstrate that pharmacologically inhibiting kinesin-5, a motor protein best known for its essential role in mitosis but also expressed in neurons, with the pharmacological agent monastrol increases axon growth on inhibitory substrates in vitro. We sought to determine if monastrol treatment after a SCI improves functional axon regeneration. Animals received complete thoracic level 7 (T7) transections and PNGs and were treated intrathecally with ChABC and either monastrol or DMSO vehicle. We found that combining ChABC with monastrol significantly enhanced axon regeneration. However, there were no further improvements in function or enhanced c-Fos induction upon stimulation of spinal cord rostral to the transection. This indicates that monastrol improves ChABC-mediated axon regeneration but that further treatments are needed to enhance the integration of these regrown axons. PMID:25447935

Botany, Phytochemistry, Pharmacology and Toxicity of Strychnos nux-vomica L.: A Review.

PubMed

Guo, Rixin; Wang, Ting; Zhou, Guohong; Xu, Mengying; Yu, Xiankuo; Zhang, Xiao; Sui, Feng; Li, Chun; Tang, Liying; Wang, Zhuju

2018-01-01

Strychnos nux-vomica L. belongs to the genus Strychnos of the family Loganiaceae and grows in Sri Lanka, India and Australia. The traditional medicinal component is its seed, called Nux vomica. This study provides a relevant and comprehensive review of S. nux-vomica L., including its botany, ethnopharmacology, phytochemistry, pharmacology and toxicology, thus providing a foundation for future studies. Up to the present day, over 84 compounds, including alkaloids, iridoid glycosides, flavonoid glycosides, triterpenoids, steroids and organic acids, among others, have been isolated and identified from S. nux-vomica. These compounds possess an array of biological activities, including effects on the nervous system, analgesic and anti-inflammatory actions, antitumor effects, inhibition of the growth of pathogenic microorganisms and regulation of immune function. Furthermore, toxicity and detoxification methods are preliminarily discussed toward the end of this review. In further research on S. nux-vomica, bioactivity-guided isolation strategies should be emphasized. Its antitumor effects should be investigated further and in vivo animal experiments should be performed alongside in vitro testing. The pharmacological activity and toxicology of strychnine [Formula: see text]-oxide and brucine [Formula: see text]-oxide should be studied to explore the detoxification mechanism associated with processing more deeply.

Pharmacological correction of long QT-linked mutations in KCNH2 (hERG) increases the trafficking of Kv11.1 channels stored in the transitional endoplasmic reticulum.

PubMed

Smith, Jennifer L; Reloj, Allison R; Nataraj, Parvathi S; Bartos, Daniel C; Schroder, Elizabeth A; Moss, Arthur J; Ohno, Seiko; Horie, Minoru; Anderson, Corey L; January, Craig T; Delisle, Brian P

2013-11-01

KCNH2 encodes Kv11.1 and underlies the rapidly activating delayed rectifier K(+) current (IKr) in the heart. Loss-of-function KCNH2 mutations cause the type 2 long QT syndrome (LQT2), and most LQT2-linked missense mutations inhibit the trafficking of Kv11.1 channels. Drugs that bind to Kv11.1 and block IKr (e.g., E-4031) can act as pharmacological chaperones to increase the trafficking and functional expression for most LQT2 channels (pharmacological correction). We previously showed that LQT2 channels are selectively stored in a microtubule-dependent compartment within the endoplasmic reticulum (ER). We tested the hypothesis that pharmacological correction promotes the trafficking of LQT2 channels stored in this compartment. Confocal analyses of cells expressing the trafficking-deficient LQT2 channel G601S showed that the microtubule-dependent ER compartment is the transitional ER. Experiments with E-4031 and the protein synthesis inhibitor cycloheximide suggested that pharmacological correction promotes the trafficking of G601S stored in this compartment. Treating cells in E-4031 or ranolazine (a drug that blocks IKr and has a short half-life) for 30 min was sufficient to cause pharmacological correction. Moreover, the increased functional expression of G601S persisted 4-5 h after drug washout. Coexpression studies with a dominant-negative form of Rab11B, a small GTPase that regulates Kv11.1 trafficking, prevented the pharmacological correction of G601S trafficking from the transitional ER. These data suggest that pharmacological correction quickly increases the trafficking of LQT2 channels stored in the transitional ER via a Rab11B-dependent pathway, and we conclude that the pharmacological chaperone activity of drugs like ranolazine might have therapeutic potential.

Pharmacological correction of long QT-linked mutations in KCNH2 (hERG) increases the trafficking of Kv11.1 channels stored in the transitional endoplasmic reticulum

PubMed Central

Smith, Jennifer L.; Reloj, Allison R.; Nataraj, Parvathi S.; Bartos, Daniel C.; Schroder, Elizabeth A.; Moss, Arthur J.; Ohno, Seiko; Horie, Minoru; Anderson, Corey L.; January, Craig T.

2013-01-01

KCNH2 encodes Kv11.1 and underlies the rapidly activating delayed rectifier K+ current (IKr) in the heart. Loss-of-function KCNH2 mutations cause the type 2 long QT syndrome (LQT2), and most LQT2-linked missense mutations inhibit the trafficking of Kv11.1 channels. Drugs that bind to Kv11.1 and block IKr (e.g., E-4031) can act as pharmacological chaperones to increase the trafficking and functional expression for most LQT2 channels (pharmacological correction). We previously showed that LQT2 channels are selectively stored in a microtubule-dependent compartment within the endoplasmic reticulum (ER). We tested the hypothesis that pharmacological correction promotes the trafficking of LQT2 channels stored in this compartment. Confocal analyses of cells expressing the trafficking-deficient LQT2 channel G601S showed that the microtubule-dependent ER compartment is the transitional ER. Experiments with E-4031 and the protein synthesis inhibitor cycloheximide suggested that pharmacological correction promotes the trafficking of G601S stored in this compartment. Treating cells in E-4031 or ranolazine (a drug that blocks IKr and has a short half-life) for 30 min was sufficient to cause pharmacological correction. Moreover, the increased functional expression of G601S persisted 4–5 h after drug washout. Coexpression studies with a dominant-negative form of Rab11B, a small GTPase that regulates Kv11.1 trafficking, prevented the pharmacological correction of G601S trafficking from the transitional ER. These data suggest that pharmacological correction quickly increases the trafficking of LQT2 channels stored in the transitional ER via a Rab11B-dependent pathway, and we conclude that the pharmacological chaperone activity of drugs like ranolazine might have therapeutic potential. PMID:23864605

Aven-mediated checkpoint kinase control regulates proliferation and resistance to chemotherapy in conventional osteosarcoma.

PubMed

Baranski, Zuzanna; Booij, Tijmen H; Cleton-Jansen, Anne-Marie; Price, Leo S; van de Water, Bob; Bovée, Judith V M G; Hogendoorn, Pancras C W; Danen, Erik H J

2015-07-01

Conventional high-grade osteosarcoma is the most common primary bone sarcoma, with relatively high incidence in young people. In this study we found that expression of Aven correlates inversely with metastasis-free survival in osteosarcoma patients and is increased in metastases compared to primary tumours. Aven is an adaptor protein that has been implicated in anti-apoptotic signalling and serves as an oncoprotein in acute lymphoblastic leukaemia. In osteosarcoma cells, silencing Aven triggered G2 cell-cycle arrest; Chk1 protein levels were attenuated and ATR-Chk1 DNA damage response signalling in response to chemotherapy was abolished in Aven-depleted osteosarcoma cells, while ATM, Chk2 and p53 activation remained intact. Osteosarcoma is notoriously difficult to treat with standard chemotherapy, and we examined whether pharmacological inhibition of the Aven-controlled ATR-Chk1 response could sensitize osteosarcoma cells to genotoxic compounds. Indeed, pharmacological inhibitors targeting Chk1/Chk2 or those selective for Chk1 synergized with standard chemotherapy in 2D cultures. Likewise, in 3D extracellular matrix-embedded cultures, Chk1 inhibition led to effective sensitization to chemotherapy. Together, these findings implicate Aven in ATR-Chk1 signalling and point towards Chk1 inhibition as a strategy to sensitize human osteosarcomas to chemotherapy. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Targeted adenovirus mediated inhibition of NF-κB-dependent inflammatory gene expression in endothelial cells in vitro and in vivo.

PubMed

Kułdo, J M; Ásgeirsdóttir, S A; Zwiers, P J; Bellu, A R; Rots, M G; Schalk, J A C; Ogawara, K I; Trautwein, C; Banas, B; Haisma, H J; Molema, G; Kamps, J A A M

2013-02-28

In chronic inflammatory diseases the endothelium expresses mediators responsible for harmful leukocyte infiltration. We investigated whether targeted delivery of a therapeutic transgene that inhibits nuclear factor κB signal transduction could silence the proinflammatory activation status of endothelial cells. For this, an adenovirus encoding dominant-negative IκB (dnIκB) as a therapeutic transgene was employed. Selectivity for the endothelial cells was achieved by introduction of antibodies specific for inflammatory endothelial adhesion molecules E-selectin or VCAM-1 chemically linked to the virus via polyethylene glycol. In vitro, the retargeted adenoviruses selectively infected cytokine-activated endothelial cells to express functional transgene. The comparison of transductional capacity of both retargeted viruses revealed that E-selectin based transgene delivery exerted superior pharmacological effects. Targeted delivery mediated dnIκB transgene expression in endothelial cells inhibited the induced expression of several inflammatory genes, including adhesion molecules, cytokines, and chemokines. In vivo, in mice suffering from glomerulonephritis, E-selectin-retargeted adenovirus selectively homed in the kidney to microvascular glomerular endothelium. Subsequent downregulation of endothelial adhesion molecule expression 2 days after induction of inflammation demonstrated the pharmacological potential of this gene therapy approach. The data justify further studies towards therapeutic virus design and optimization of treatment schedules to investigate their capacity to interfere with inflammatory disease progression. Copyright © 2012 Elsevier B.V. All rights reserved.

Sirtuin inhibition attenuates the production of inflammatory cytokines in lipopolysaccharide-stimulated macrophages

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fernandes, Claudia A.; Fievez, Laurence; Neyrinck, Audrey M.

Highlights: Black-Right-Pointing-Pointer Lipopolysaccharide-stimulated macrophages were treated with cambinol and sirtinol. Black-Right-Pointing-Pointer Cambinol and sirtinol decreased lipopolysaccharide-induced cytokines. Black-Right-Pointing-Pointer Cambinol decreased NF-{kappa}B activity but had no impact on p38 MAPK activation. Black-Right-Pointing-Pointer Sirtuins are an interesting target for the treatment of inflammatory diseases. -- Abstract: In several inflammatory conditions such as rheumatoid arthritis or sepsis, the regulatory mechanisms of inflammation are inefficient and the excessive inflammatory response leads to damage to the host. Sirtuins are class III histone deacetylases that modulate the activity of several transcription factors that are implicated in immune responses. In this study, we evaluated the impact ofmore » sirtuin inhibition on the activation of lipopolysaccharide (LPS)-stimulated J774 macrophages by assessing the production of inflammatory cytokines. The pharmacologic inhibition of sirtuins decreased the production of tumour necrosis factor-alpha (TNF-{alpha}) interleukin 6 (IL-6) and Rantes. The reduction of cytokine production was associated with decreased nuclear factor kappa B (NF-{kappa}B) activity and inhibitor kappa B alpha (I{kappa}B{alpha}) phosphorylation while no impact was observed on the phosphorylation status of p38 mitogen-activated kinase (p38 MAPK). This work shows that sirtuin pharmacologic inhibitors are a promising tool for the treatment of inflammatory conditions.« less

Hydrophilic extract from Posidonia oceanica inhibits activity and expression of gelatinases and prevents HT1080 human fibrosarcoma cell line invasion

PubMed Central

Barletta, Emanuela; Ramazzotti, Matteo; Fratianni, Florinda; Pessani, Daniela; Degl'Innocenti, Donatella

2015-01-01

Posidonia oceanica (L.) Delile is an endemic Mediterranean sea-grass distributed in the infralittoral zones, where it forms meadows playing a recognized ecological role in the coastal marine habitat. Although its use as a traditional herbal remedy is poorly documented, recent literature reports interesting pharmacological activities as antidiabetic, antioxidant and vasoprotective. Differently from previous literature, this study presents a hydrophilic extraction method that recovers metabolites that may be tested in biological buffers. We showed for the first time in the highly invasive HT1080 human fibrosarcoma cell line that our hydrophilic extract from P. oceanica was able to strongly decrease gene and protein expression of gelatinases MMP-2 and MMP-9 and to directly inhibit in a dose-dependent manner gelatinolytic activity in vitro. Moreover, we have revealed that our extract strongly inhibited HT1080 cell migration and invasion. Biochemical analysis of the hydrophilic extract showed that catechins were the major constituents with minor contribution of gallic acid, ferulic acid and chlorogenic plus a fraction of uncharacterized phenols. However, if each individual compound was tested independently, none by itself was able to induce a direct inhibition of gelatinases as strong as that observed in total extract, opening up new routes to the identification of novel compounds. These results indicate that our hydrophilic extract from P. oceanica might be a source of new pharmacological natural products for treatment or prevention of several diseases related to an altered MMP-2 and MMP-9 expression. PMID:26176658

Cigarette smoke-induced alveolar epithelial-mesenchymal transition is mediated by Rac1 activation.

PubMed

Shen, Hui-juan; Sun, Yan-hong; Zhang, Shui-juan; Jiang, Jun-xia; Dong, Xin-wei; Jia, Yong-liang; Shen, Jian; Guan, Yan; Zhang, Lin-hui; Li, Fen-fen; Lin, Xi-xi; Wu, Xi-mei; Xie, Qiang-min; Yan, Xiao-feng

2014-06-01

Epithelial-mesenchymal transition (EMT) is the major pathophysiological process in lung fibrosis observed in chronic obstructive pulmonary disease (COPD) and lung cancer. Smoking is a risk factor for developing EMT, yet the mechanism remains largely unknown. In this study, we investigated the role of Rac1 in cigarette smoke (CS) induced EMT. EMT was induced in mice and pulmonary epithelial cells by exposure of CS and cigarette smoke extract (CSE) respectively. Treatment of pulmonary epithelial cells with CSE elevated Rac1 expression associated with increased TGF-β1 release. Blocking TGF-β pathway restrained CSE-induced changes in EMT-related markers. Pharmacological inhibition or knockdown of Rac1 decreased the CSE exposure induced TGF-β1 release and ameliorated CSE-induced EMT. In CS-exposed mice, pharmacological inhibition of Rac1 reduced TGF-β1 release and prevented aberrations in expression of EMT markers, suggesting that Rac1 is a critical signaling molecule for induction of CS-stimulated EMT. Furthermore, Rac1 inhibition or knockdown abrogated CSE-induced Smad2 and Akt (PKB, protein kinase B) activation in pulmonary epithelial cells. Inhibition of Smad2, PI3K (phosphatidylinositol 3-kinase) or Akt suppressed CSE-induced changes in epithelial and mesenchymal marker expression. Altogether, these data suggest that CS initiates EMT through Rac1/Smad2 and Rac1/PI3K/Akt signaling pathway. Our data provide new insights into the fundamental basis of EMT and suggest a possible new course of therapy for COPD and lung cancer. Copyright © 2014 Elsevier B.V. All rights reserved.

TLR3 dsRNA agonist inhibits growth and invasion of HepG2.2.15 HCC cells.

PubMed

Chen, Li; Xu, Yu-Yin; Zhou, Jia-Ming; Wu, Yuan-Yuan; E, Qun; Zhu, Yuan-Yuan

2012-07-01

Toll-like receptor 3 (TLR3) is a pattern-recognizing receptor that is involved in immune signaling and plays a crucial role in survival by being able to recognize various viral components including double-stranded RNA (dsRNA). TLR3 expression and function in cancer cells are not well understood. In this study, we investigated whether TLR3 agonist dsRNA (BM-06) can inhibit proliferation and invasion, and promote apoptosis in HepG2.2.15 cells. HepG2.2.15 cells secreting hepatitis B virus (HBV) were treated with BM-06 and poly(I:C). Western blot analysis and PCR were employed to determine pharmacodynamic changes in biomarkers relevant to TLR3 signaling. Cell proliferation, invasion and apoptosis were analyzed by CCK-8 assay, transwell assay and flow cytometry. The expression of HBsAg, and HBcAg was observed by immunohistochemistry. Compared with untreated cells, pharmacological NF-κB activity of the TLR3 pathway by BM-06 (1.734-fold) or poly(I:C) (1.377-fold) was induced. By western blot analysis, we found that dsRNA induced TLR3-activated HepG2.2.15 cells which expressed NF-κB levels predominantly in the cytoplasmic fraction but fewer signals in the nucleus. BM-06 inhibited the proliferation, invasion and secretion of HBV, and induced apoptosis in HepG2.2.15 cells. In addition, the antitumor effects of BM-06 were superior to poly(I:C). Pharmacological activation of the TLR3 pathway by BM-06 can inhibit HepG2.2.15 cell growth.

Inhibition of Mycobacterial Infection by the Tumor Suppressor PTEN*

PubMed Central

Huang, Guochang; Redelman-Sidi, Gil; Rosen, Neal; Glickman, Michael S.; Jiang, Xuejun

2012-01-01

The tumor suppressor PTEN is a lipid phosphatase that is frequently mutated in various human cancers. PTEN suppresses tumor cell proliferation, survival, and growth mainly by inhibiting the PI3K-Akt signaling pathway through dephosphorylation of phosphatidylinositol 3,4,5-triphosphate. In addition to it role in tumor suppression, the PTEN-PI3K pathway controls many cellular functions, some of which may be important for cellular resistance to infection. Currently, the intersection between tumorigenic signaling pathways and cellular susceptibility to infection is not well defined. In this study we report that PTEN signaling regulates infection of both noncancerous and cancerous cells by multiple intracellular mycobacterial pathogens and that pharmacological modulation of PTEN signaling can affect mycobacterial infection. We found that PTEN deficiency renders multiple types of cells hyper-susceptible to infection by Mycoplasma and Mycobacterium bovis Bacillus Calmette-Guérin (BCG). The lipid phosphatase activity of PTEN is required for attenuating infection. Furthermore, we found mycobacterial infection activates host cell Akt phosphorylation, and pharmacological inhibition of Akt or PI3K activity reduced levels of intracellular infection. Intriguingly, inhibition of mTOR, one of the downstream components of the Akt signaling and a promising cancer therapeutic target, also lowered intracellular Bacillus Calmette-Guérin levels in mammary epithelial cancer MCF-7 cells. These findings demonstrate a critical role of PTEN-regulated pathways in pathogen infection. The relationship of PTEN-PI3K-Akt mTOR status and susceptibility to mycobacterial infection suggests that the interaction of mycobacterial pathogens with cancer cells may be influenced by genetic alterations in the tumor cells. PMID:22613768

Pharmacologic inhibition of Pim kinases alters prostate cancer cell growth and resensitizes chemoresistant cells to taxanes.

PubMed

Mumenthaler, Shannon M; Ng, Patricia Y B; Hodge, Amanda; Bearss, David; Berk, Gregory; Kanekal, Sarath; Redkar, Sanjeev; Taverna, Pietro; Agus, David B; Jain, Anjali

2009-10-01

The serine/threonine family of Pim kinases function as oncogenes and have been implicated in prostate cancer progression, particularly in hormone-refractory prostate disease, as a result of their antiapoptotic function. In this study, we used a pharmacologic inhibitor targeting the Pim family members, SGI-1776, to determine whether modulation of Pim kinase activity could alter prostate cancer cell survival and modulate chemotherapy resistance. Extensive biochemical characterization of SGI-1776 confirmed its specificity for the three isoforms of the Pim family. Treatment of prostate cancer cells with SGI-1776 resulted in a dose-dependent reduction in phosphorylation of known Pim kinase substrates that are involved in cell cycle progression and apoptosis (p21(Cip1/WAF1) and Bad). Consequently, SGI-1776 compromised overall cell viability by inducing G(1) cell cycle arrest and triggering apoptosis. Overexpression of recombinant Pim-1 markedly increased sensitivity of SGI-1776-mediated prostate cancer cell apoptosis and p21(Cip1/WAF1) phosphorylation inhibition, reinforcing the specificity of SGI-1776. An additional cytotoxic effect was observed when SGI-1776 was combined with taxane-based chemotherapy agents. SGI-1776 was able to reduce cell viability in a multidrug resistance 1 protein-based taxane-refractory prostate cancer cell line. In addition, SGI-1776 treatment was able to resensitize chemoresistant cells to taxane-based therapies by inhibiting multidrug resistance 1 activity and inducing apoptosis. These findings support the idea that inhibiting Pim kinases, in combination with a chemotherapeutic agent, could play an important role in prostate cancer treatment by targeting the clinical problem of chemoresistance.

Antisense oligonucleotide inhibition of apolipoprotein C-III reduces plasma triglycerides in rodents, nonhuman primates, and humans.

PubMed

Graham, Mark J; Lee, Richard G; Bell, Thomas A; Fu, Wuxia; Mullick, Adam E; Alexander, Veronica J; Singleton, Walter; Viney, Nick; Geary, Richard; Su, John; Baker, Brenda F; Burkey, Jennifer; Crooke, Stanley T; Crooke, Rosanne M

2013-05-24

Elevated plasma triglyceride levels have been recognized as a risk factor for the development of coronary heart disease. Apolipoprotein C-III (apoC-III) represents both an independent risk factor and a key regulatory factor of plasma triglyceride concentrations. Furthermore, elevated apoC-III levels have been associated with metabolic syndrome and type 2 diabetes mellitus. To date, no selective apoC-III therapeutic agent has been evaluated in the clinic. To test the hypothesis that selective inhibition of apoC-III with antisense drugs in preclinical models and in healthy volunteers would reduce plasma apoC-III and triglyceride levels. Rodent- and human-specific second-generation antisense oligonucleotides were identified and evaluated in preclinical models, including rats, mice, human apoC-III transgenic mice, and nonhuman primates. We demonstrated the selective reduction of both apoC-III and triglyceride in all preclinical pharmacological evaluations. We also showed that inhibition of apoC-III was well tolerated and not associated with increased liver triglyceride deposition or hepatotoxicity. A double-blind, placebo-controlled, phase I clinical study was performed in healthy subjects. Administration of the human apoC-III antisense drug resulted in dose-dependent reductions in plasma apoC-III, concomitant lowering of triglyceride levels, and produced no clinically meaningful signals in the safety evaluations. Antisense inhibition of apoC-III in preclinical models and in a phase I clinical trial with healthy subjects produced potent, selective reductions in plasma apoC-III and triglyceride, 2 known risk factors for cardiovascular disease. This compelling pharmacological profile supports further clinical investigations in hypertriglyceridemic subjects.

Pharmacological inhibition of fibroblast growth factor (FGF) receptor signaling ameliorates FGF23-mediated hypophosphatemic rickets.

PubMed

Wöhrle, Simon; Henninger, Christine; Bonny, Olivier; Thuery, Anne; Beluch, Noemie; Hynes, Nancy E; Guagnano, Vito; Sellers, William R; Hofmann, Francesco; Kneissel, Michaela; Graus Porta, Diana

2013-04-01

Fibroblast growth factor 23 (FGF23) is a circulating factor secreted by osteocytes that is essential for phosphate homeostasis. In kidney proximal tubular cells FGF23 inhibits phosphate reabsorption and leads to decreased synthesis and enhanced catabolism of 1,25-dihydroxyvitamin D3 (1,25[OH]2 D3 ). Excess levels of FGF23 cause renal phosphate wasting and suppression of circulating 1,25(OH)2 D3 levels and are associated with several hereditary hypophosphatemic disorders with skeletal abnormalities, including X-linked hypophosphatemic rickets (XLH) and autosomal recessive hypophosphatemic rickets (ARHR). Currently, therapeutic approaches to these diseases are limited to treatment with activated vitamin D analogues and phosphate supplementation, often merely resulting in partial correction of the skeletal aberrations. In this study, we evaluate the use of FGFR inhibitors for the treatment of FGF23-mediated hypophosphatemic disorders using NVP-BGJ398, a novel selective, pan-specific FGFR inhibitor currently in Phase I clinical trials for cancer therapy. In two different hypophosphatemic mouse models, Hyp and Dmp1-null mice, resembling the human diseases XLH and ARHR, we find that pharmacological inhibition of FGFRs efficiently abrogates aberrant FGF23 signaling and normalizes the hypophosphatemic and hypocalcemic conditions of these mice. Correspondingly, long-term FGFR inhibition in Hyp mice leads to enhanced bone growth, increased mineralization, and reorganization of the disturbed growth plate structure. We therefore propose NVP-BGJ398 treatment as a novel approach for the therapy of FGF23-mediated hypophosphatemic diseases. Copyright © 2013 American Society for Bone and Mineral Research.

Metabolism and acetylation contribute to leucine-mediated inhibition of cardiac glucose uptake.

PubMed

Renguet, Edith; Ginion, Audrey; Gélinas, Roselle; Bultot, Laurent; Auquier, Julien; Robillard Frayne, Isabelle; Daneault, Caroline; Vanoverschelde, Jean-Louis; Des Rosiers, Christine; Hue, Louis; Horman, Sandrine; Beauloye, Christophe; Bertrand, Luc

2017-08-01

High plasma leucine levels strongly correlate with type 2 diabetes. Studies of muscle cells have suggested that leucine alters the insulin response for glucose transport by activating an insulin-negative feedback loop driven by the mammalian target of rapamycin/p70 ribosomal S6 kinase (mTOR/p70S6K) pathway. Here, we examined the molecular mechanism involved in leucine's action on cardiac glucose uptake. Leucine was indeed able to curb glucose uptake after insulin stimulation in both cultured cardiomyocytes and perfused hearts. Although leucine activated mTOR/p70S6K, the mTOR inhibitor rapamycin did not prevent leucine's inhibitory action on glucose uptake, ruling out the contribution of the insulin-negative feedback loop. α-Ketoisocaproate, the first metabolite of leucine catabolism, mimicked leucine's effect on glucose uptake. Incubation of cardiomyocytes with [ 13 C]leucine ascertained its metabolism to ketone bodies (KBs), which had a similar negative impact on insulin-stimulated glucose transport. Both leucine and KBs reduced glucose uptake by affecting translocation of glucose transporter 4 (GLUT4) to the plasma membrane. Finally, we found that leucine elevated the global protein acetylation level. Pharmacological inhibition of lysine acetyltransferases counteracted this increase in protein acetylation and prevented leucine's inhibitory action on both glucose uptake and GLUT4 translocation. Taken together, these results indicate that leucine metabolism into KBs contributes to inhibition of cardiac glucose uptake by hampering the translocation of GLUT4-containing vesicles via acetylation. They offer new insights into the establishment of insulin resistance in the heart. NEW & NOTEWORTHY Catabolism of the branched-chain amino acid leucine into ketone bodies efficiently inhibits cardiac glucose uptake through decreased translocation of glucose transporter 4 to the plasma membrane. Leucine increases protein acetylation. Pharmacological inhibition of acetylation reverses leucine's action, suggesting acetylation involvement in this phenomenon.Listen to this article's corresponding podcast at http://ajpheart.podbean.com/e/leucine-metabolism-inhibits-cardiac-glucose-uptake/. Copyright © 2017 the American Physiological Society.

Novel selective and potent 5-HT reuptake inhibitors with 5-HT1D antagonist activity: chemistry and pharmacological evaluation of a series of thienopyran derivatives.

PubMed

Torrado, Alicia; Lamas, Carlos; Agejas, Javier; Jiménez, Alma; Diaz, Nuria; Gilmore, Jeremy; Boot, John; Findlay, Jeremy; Hayhurst, Lorna; Wallace, Louise; Broadmore, Richard; Tomlinson, Rosemarie

2004-10-15

A series of compounds combining the naphthylpiperazine and thienopyran scaffolds has been prepared and evaluated for 5-HT reuptake inhibition with 5-HT1D antagonist activity. The design of these compounds has been based on the 'overlapping type' strategy where two pharmacophores are linked in a single molecule. The resultant dual pharmacological profile has the potential to deliver a more efficient treatment for depression.

Isolation of diacyl glycerol acyl transferase (DGAT) inhibitors from Pachydictyon coriaceum.

PubMed

Choi, Byoung Wook; Lee, Hyun Sun; Lee, Kyung Bok; Lee, Bong Ho

2011-07-01

The pharmacological inhibition of acyl CoA:diacylglycerol acyltransferase (DGAT, EC 2.3.1.20) has emerged as a target for the treatment of obesity and type 2 diabetes. Chromatographic analysis of the brown alga, Pachydictyon coriaceum, led to the isolation of diterpene dictyol E and hydroxyisocrenulatin. Pharmacological assay of these compounds demonstrated DGAT inhibitory activity with IC₅₀ values of 46.0 μM and 23.3 μM, respectively. Copyright © 2011 John Wiley & Sons, Ltd.

Pharmacological TLR4 Inhibition Protects against Acute and Chronic Fat-Induced Insulin Resistance in Rats

PubMed Central

Zhang, Ning; Liang, Hanyu; Farese, Robert V.; Li, Ji

2015-01-01

Aims To evaluate whether pharmacological TLR4 inhibition protects against acute and chronic fat-induced insulin resistance in rats. Materials and Methods For the acute experiment, rats received a TLR4 inhibitor [TAK-242 or E5564 (2x5 mg/kg i.v. bolus)] or vehicle, and an 8-h Intralipid (20%, 8.5 mg/kg/min) or saline infusion, followed by a two-step hyperinsulinemic-euglycemic clamp. For the chronic experiment, rats were subcutaneously implanted with a slow-release pellet of TAK-242 (1.5 mg/d) or placebo. Rats then received a high fat diet (HFD) or a low fat control diet (LFD) for 10 weeks, followed by a two-step insulin clamp. Results Acute experiment; the lipid-induced reduction (18%) in insulin-stimulated glucose disposal (Rd) was attenuated by TAK-242 and E5564 (the effect of E5564 was more robust), suggesting improved peripheral insulin action. Insulin was able to suppress hepatic glucose production (HGP) in saline- but not lipid-treated rats. TAK-242, but not E5564, partially restored this effect, suggesting improved HGP. Chronic experiment; insulin-stimulated Rd was reduced ~30% by the HFD, but completely restored by TAK-242. Insulin could not suppress HGP in rats fed a HFD and TAK-242 had no effect on HGP. Conclusions Pharmacological TLR4 inhibition provides partial protection against acute and chronic fat-induced insulin resistance in vivo. PMID:26196892

Pharmacological inhibition of myostatin suppresses systemic inflammation and muscle atrophy in mice with chronic kidney disease.

PubMed

Zhang, Liping; Rajan, Vik; Lin, Eugene; Hu, Zhaoyong; Han, H Q; Zhou, Xiaolan; Song, Yanping; Min, Hosung; Wang, Xiaonan; Du, Jie; Mitch, William E

2011-05-01

Chronic kidney disease (CKD) and several other catabolic conditions are characterized by increased circulating inflammatory cytokines, defects in IGF-1 signaling, abnormal muscle protein metabolism, and progressive muscle atrophy. In these conditions, no reliable treatments successfully block the development of muscle atrophy. In mice with CKD, we found a 2- to 3-fold increase in myostatin expression in muscle. Its pharmacological inhibition by subcutaneous injections of an anti-myostatin peptibody into CKD mice (IC(50) ∼1.2 nM) reversed the loss of body weight (≈5-7% increase in body mass) and muscle mass (∼10% increase in muscle mass) and suppressed circulating inflammatory cytokines vs. results from CKD mice injected with PBS. Pharmacological myostatin inhibition also decreased the rate of protein degradation (16.38 ± 1.29%; P<0.05), increased protein synthesis in extensor digitorum longus muscles (13.21 ± 1.09%; P<0.05), markedly enhanced satellite cell function, and improved IGF-1 intracellular signaling. In cultured muscle cells, TNF-α increased myostatin expression via a NF-κB-dependent pathway, whereas muscle cells exposed to myostatin stimulated IL-6 production via p38 MAPK and MEK1 pathways. Because IL-6 stimulates muscle protein breakdown, we conclude that CKD increases myostatin through cytokine-activated pathways, leading to muscle atrophy. Myostatin antagonism might become a therapeutic strategy for improving muscle growth in CKD and other conditions with similar characteristics.

NOS1 mediates AP1 nuclear translocation and inflammatory response.

PubMed

Srivastava, Mansi; Baig, Mirza S

2018-06-01

A hallmark of the AP1 functioning is its nuclear translocation, which induces proinflammatory cytokine expression and hence the inflammatory response. After endotoxin shock AP1 transcription factor, which comprises Jun, ATF2, and Fos family of proteins, translocates into the nucleus and induces proinflammatory cytokine expression. In the current study, we found, NOS1 inhibition prevents nuclear translocation of the AP1 transcription factor subunits. Pharmacological inhibition of NOS1 impedes translocation of subunits into the nucleus, suppressing the transcription of inflammatory genes causing a diminished inflammatory response. In conclusion, the study shows the novel mechanism of NOS1- mediated AP1 nuclear translocation, which needs to be further explored. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Inhibition of soluble epoxide hydrolase limits niacin-induced vasodilation in mice

PubMed Central

Inceoglu, A. B.; Clifton, H.L.; Yang, J.; Hegedus, C.; Hammock, B. D.; Schaefer, S.

2012-01-01

Background The use of niacin in the treatment of dyslipidemias is limited by the common side effect of cutaneous vasodilation, commonly termed flushing. Flushing is thought to be due to release of the vasodilatory prostanoids PGD2 and PGE2 from arachidonic acid metabolism through the cyclooxygenase (COX) pathway. Arachidonic acid is also metabolized by the cytochrome P450 system which is regulated, in part, by the enzyme soluble epoxide hydrolase (sEH). Methods: These experiments used an established murine model in which ear tissue perfusion was measured by laser Doppler to test the hypothesis that inhibition of sEH would limit niacin-induced flushing. Results: Niacin-induced flushing was reduced from 506 ± 126 to 213 ± 39 % in sEH knockout animals. Pharmacologic treatment with 3 structurally distinct sEH inhibitors similarly reduced flushing in a dose dependent manner, with maximal reduction to 143±15% of baseline flow using a concentration of 1 mg/kg TPAU (1-trifluoromethoxyphenyl-3-(1-acetylpiperidin-4-yl) urea). Systemically administered PGD2 caused ear vasodilation which was not changed by either pharmacologic sEH inhibition or by sEH gene deletion. Conclusions: Inhibition of sEH markedly reduces niacin-induced flushing in this model without an apparent effect on the response to PGD2. sEH inhibition may be a new therapeutic approach to limit flushing in humans. PMID:22526297

Doxycycline Inhibits Polarization of Macrophages to the Proangiogenic M2-type and Subsequent Neovascularization*

PubMed Central

He, Lizhi; Marneros, Alexander G.

2014-01-01

Macrophages occur along a continuum of functional states between M1-type polarized macrophages with antiangiogenic and antitumor activity and M2-type polarized macrophages, which have been implicated to promote angiogenesis and tumor growth. Proangiogenic M2-type macrophages promote various pathologic conditions, including choroidal neovascularization in models of neovascular age-related macular degeneration, or certain cancers, such as glioblastoma multiforme. Thus, a potential novel therapeutic approach to target pathological angiogenesis in these conditions would be to inhibit the polarization of macrophages toward the proangiogenic M2-type. However, no pharmacological inhibitors of M2-type macrophage polarization have been identified yet. Here we performed an unbiased pharmacological and small chemical screen to identify drugs that inhibit proangiogenic M2-type macrophage polarization and block pathologic macrophage-driven neovascularization. We identified the well tolerated and commonly used antibiotic doxycycline as a potent inhibitor of M2-type polarization of macrophages. Doxycycline inhibited, in a dose-dependent manner, M2-type polarization of human and bone marrow-derived mouse macrophages without affecting cell viability. Furthermore, doxycycline inhibited M2-type macrophage polarization and subsequent neovascularization in vivo in a laser injury model of choroidal neovascularization. Thus, doxycycline could be used to enhance current antiangiogenic treatment approaches in various conditions that are promoted by proangiogenic M2-type macrophages, including neovascular age-related macular degeneration and certain cancers. PMID:24505138

Effect of chronic pre-treatment with angiotensin converting enzyme inhibition on skeletal muscle mitochondrial recovery after ischemia/reperfusion.

PubMed

Thaveau, Fabien; Zoll, Joffrey; Bouitbir, Jamal; N'guessan, Benoît; Plobner, Philippe; Chakfe, Nabil; Kretz, Jean-Georges; Richard, Ruddy; Piquard, François; Geny, Bernard

2010-06-01

Impaired skeletal muscle energetic participates in peripheral arterial disease (PAD) patient's morbidity and mortality. Angiotensin converting enzyme inhibition (ACEi), cornerstone for pharmacologic risk factor management in PAD patients, might also be interesting by protecting skeletal muscle energetic. We therefore determined whether chronic ACEi might reduce ischemia-induced mitochondrial respiratory chain dysfunction in the frequent setting of hindlimb ischemia-reperfusion. Ischemic legs of rats submitted to 5 h ischemia induced by a rubber band tourniquet applied on the root of the hindlimb followed by reperfusion without (IR, n = 11) or after ACEi (n = 14; captopril 40 mg/kg per day during 28 days before surgery) were studied and compared to that of sham-operated animals (n = 11). The effect of ACEi on the non-ischemic contralateral leg was also determined in the ACEi group. Maximal oxidative capacities (V(max)) and complexes I, II and IV activities of the mitochondrial respiratory chain of the gastrocnemius muscle were determined using glutamate-malate, succinate and TMPD-ascorbate substrates. Arterial blood pressure was significantly decreased after ACEi (124 +/- 2.8 vs. 108 +/- 4.19 mmHg; P = 0.01). Ischemia-reperfusion reduced V(max) (4.4 +/- 0.4 vs. 8.7 +/- 0.5 micromol O2/min/g dry weight, -49%, P < 0.001), affecting mitochondrial complexes I, II and IV activities. ACEi failed to modulate ischemia-induced dysfunction (V(max) 5.1 +/- 0.7 micromol O2/min/g dry weight) or the non-ischemic contralateral muscle respiratory rate. Ischemia-reperfusion significantly impaired the mitochondrial respiratory chain I, II and IV complexes of skeletal muscle. Pharmacologic pre-treatment with ACEi did not prevent or increase such alterations. Further studies might be useful to improve the pharmacologic conditioning of PAD patients needing arterial revascularization.

Assessing and predicting drug-induced anticholinergic risks: an integrated computational approach.

PubMed

Xu, Dong; Anderson, Heather D; Tao, Aoxiang; Hannah, Katia L; Linnebur, Sunny A; Valuck, Robert J; Culbertson, Vaughn L

2017-11-01

Anticholinergic (AC) adverse drug events (ADEs) are caused by inhibition of muscarinic receptors as a result of designated or off-target drug-receptor interactions. In practice, AC toxicity is assessed primarily based on clinician experience. The goal of this study was to evaluate a novel concept of integrating big pharmacological and healthcare data to assess clinical AC toxicity risks. AC toxicity scores (ATSs) were computed using drug-receptor inhibitions identified through pharmacological data screening. A longitudinal retrospective cohort study using medical claims data was performed to quantify AC clinical risks. ATS was compared with two previously reported toxicity measures. A quantitative structure-activity relationship (QSAR) model was established for rapid assessment and prediction of AC clinical risks. A total of 25 common medications, and 575,228 exposed and unexposed patients were analyzed. Our data indicated that ATS is more consistent with the trend of AC outcomes than other toxicity methods. Incorporating drug pharmacokinetic parameters to ATS yielded a QSAR model with excellent correlation to AC incident rate ( R 2 = 0.83) and predictive performance (cross validation Q 2 = 0.64). Good correlation and predictive performance ( R 2 = 0.68/ Q 2 = 0.29) were also obtained for an M2 receptor-specific QSAR model and tachycardia, an M2 receptor-specific ADE. Albeit using a small medication sample size, our pilot data demonstrated the potential and feasibility of a new computational AC toxicity scoring approach driven by underlying pharmacology and big data analytics. Follow-up work is under way to further develop the ATS scoring approach and clinical toxicity predictive model using a large number of medications and clinical parameters.

Capsaicin-evoked iCGRP release from human dental pulp: a model system for the study of peripheral neuropeptide secretion in normal healthy tissue

PubMed Central

Fehrenbacher, Jill C.; Sun, Xiaoling X.; Locke, Erin E.; Henry, Michael A.; Hargreaves, Kenneth M.

2009-01-01

The mechanisms underlying trigeminal pain conditions are incompletely understood. In vitro animal studies have elucidated various targets for pharmacological intervention; however, a lack of clinical models that allow evaluation of viable innervated human tissue has impeded successful translation of many preclinical findings into clinical therapeutics. Therefore, we developed and characterized an in vitro method that evaluates the responsiveness of isolated human nociceptors by measuring basal and stimulated release of neuropeptides from collected dental pulp biopsies. Informed consent was obtained from patients presenting for extraction of normal wisdom teeth. Patients were anesthetized using nerve block injection, teeth were extracted and bisected, and pulp was removed and superfused in vitro. Basal and capsaicin-evoked peripheral release of immunoreactive calcitonin gene-related peptide (iCGRP) was analyzed by enzyme immunoassay. The presence of nociceptive markers within neurons of the dental pulp was characterized using confocal microscopy. Capsaicin increased the release of iCGRP from dental pulp biopsies in a concentration-dependent manner. Stimulated release was dependent on extracellular calcium, reversed by a TRPV1 receptor antagonist, and desensitized acutely (tachyphylaxis) and pharmacologically by pretreatment with capsaicin. Superfusion with phorbol 12-myristate 13-acetate (PMA) increased basal and stimulated release, whereas PGE2 augmented only basal release. Compared with vehicle treatment, pretreatment with PGE2 induced competence for DAMGO to inhibit capsaicin-stimulated iCGRP release, similar to observations in animal models where inflammatory mediators induce competence for opioid inhibition. These results indicate the release of iCGRP from human dental pulp provides a novel tool to determine the effects of pharmacological compounds on human nociceptor sensitivity. PMID:19428185

Pharmacological AMP-kinase activators have compartment-specific effects on cell physiology.

PubMed

Kodiha, Mohamed; Ho-Wo-Cheong, Dennis; Stochaj, Ursula

2011-12-01

5'-AMP-activated kinase (AMPK) regulates numerous biological events and is an essential target for the treatment of type 2 diabetes. The objectives of the present study were first to determine the compartment-specific effects of three established AMPK activators on Thr172 phosphorylation of the α-subunit, an indicator of AMPK activation. Second, we examined how cytoplasmic and nuclear processes are modulated by pharmacological AMPK activators. Specifically, the impact of phenformin, resveratrol, and 5-aminoimidazole-4-carboxamide riboside (AICAR) on Thr172 phosphorylation in the cytoplasm and nucleus was quantified by different methods. To analyze how these activators change cell physiology, we measured the inactivation of acetyl-CoA-carboxylase 1, a predominantly cytoplasmic enzyme that is crucial for lipid metabolism. As a criterion for activities associated with the nucleus, de novo RNA synthesis in nucleoli was quantified. Our studies demonstrate that pharmacological activators of AMPK can alter the balance between nuclear and cytoplasmic AMPK pools. Thus, phenformin and resveratrol caused a strong activation of AMPK in the cytoplasm, whereas the effect was less pronounced in nuclei. By contrast, AICAR elicited a comparable rise in Thr172 phosphorylation in both compartments. Notably, these activators differed drastically in their effects on physiological processes that are located in distinct subcellular compartments. All compounds led to a substantial inactivation of acetyl-CoA-carboxylase 1 in the cytoplasm, with only minor changes to the nuclear enzyme. In the nucleolus, transcription was strongly inhibited by resveratrol, while a moderate inhibition was observed with phenformin and AICAR. Taken together, the compartment-specific phosphorylation of AMPK and downstream events are determined by the activator.

Mechanism of inhibition of mouse Slo3 (KCa 5.1) potassium channels by quinine, quinidine and barium.

PubMed

Wrighton, David C; Muench, Stephen P; Lippiat, Jonathan D

2015-09-01

The Slo3 (KCa 5.1) channel is a major component of mammalian KSper (sperm potassium conductance) channels and inhibition of these channels by quinine and barium alters sperm motility. The aim of this investigation was to determine the mechanism by which these drugs inhibit Slo3 channels. Mouse (m) Slo3 (KCa 5.1) channels or mutant forms were expressed in Xenopus oocytes and currents recorded with 2-electrode voltage-clamp. Gain-of-function mSlo3 mutations were used to explore the state-dependence of the inhibition. The interaction between quinidine and mSlo3 channels was modelled by in silico docking. Several drugs known to block KSper also affected mSlo3 channels with similar levels of inhibition. The inhibition induced by extracellular barium was prevented by increasing the extracellular potassium concentration. R196Q and F304Y mutations in the mSlo3 voltage sensor and pore, respectively, both increased channel activity. The F304Y mutation did not alter the effects of barium, but increased the potency of inhibition by both quinine and quinidine approximately 10-fold; this effect was not observed with the R196Q mutation. Block of mSlo3 channels by quinine, quinidine and barium is not state-dependent. Barium inhibits mSlo3 outside the cell by interacting with the selectivity filter, whereas quinine and quinidine act from the inside, by binding in a hydrophobic pocket formed by the S6 segment of each subunit. Furthermore, we propose that the Slo3 channel activation gate lies deep within the pore between F304 in the S6 segment and the selectivity filter. © 2015 The Authors. British Journal of Pharmacology published by John Wiley & Sons Ltd on behalf of The British Pharmacological Society.

Pharmacological Studies on Clostridial Neurotoxins.

DTIC Science & Technology

1982-08-01

1974). The entire (e.g., dichain) molecule is needed to poison intact cells, but only the light chain polypeptide is needed to inhibit protein...synthesis in broken cell preparations. The sequence of events that underlies the ability of diphtheria toxin to poison eukaryotic cells is not unique to...may belong to a novel class of internalized poisons . In at least one respect the latter possibility is true. Most toxins that are internalized act in

Pharmacology for sleep disturbance in PTSD.

PubMed

Lipinska, Gosia; Baldwin, David S; Thomas, Kevin G F

2016-03-01

Symptoms of sleep disturbance, particularly nightmares and insomnia, are a central feature of post-traumatic stress disorder (PTSD). Emerging evidence suggests that specific treatment of PTSD-related sleep disturbance improves other symptoms of the disorder, which in turn suggests that such disturbance may be fundamental to development and maintenance of the disorder. This mini-review focuses on pharmacological treatment of sleep disturbance in adult PTSD (specifically, studies testing the efficacy of antidepressants, adrenergic inhibiting agents, antipsychotics and benzodiazepine and non-benzodiazepine hypnotics). We conclude that only prazosin, an adrenergic inhibiting agent, has had its efficacy established by multiple randomised controlled trials. There is also high-level evidence supporting use of eszopiclone, as well as risperidone and olanzapine as adjunct therapy. Antidepressants such as sertraline, venlafaxine and mirtazapine, benzodiazepines such as alprazolam and clonazepam and non-benzodiazepine hypnotics such as zolpidem appear ineffective in treating PTSD-related sleep disturbance. Most studies that report reduced frequency of nightmares and insomnia also report decreases in overall symptom severity. Such findings suggest that (i) sleep disruption is central to PTSD; (ii) treating sleep disruption may be an effective way to address other symptoms of the disorder and (iii) PTSD symptoms tend to cluster together in predictable ways. Copyright © 2016 John Wiley & Sons, Ltd.

In vitro metabolism and drug-drug interaction potential of UTL-5g, a novel chemo- and radioprotective agent.

PubMed

Wu, Jianmei; Shaw, Jiajiu; Dubaisi, Sarah; Valeriote, Frederick; Li, Jing

2014-12-01

N-(2,4-dichlorophenyl)-5-methyl-1,2-oxazole-3-carboxamide (UTL-5g), a potential chemo- and radioprotective agent, acts as a prodrug requiring bioactivation to the active metabolite 5-methylisoxazole-3-carboxylic acid (ISOX). UTL-5g hydrolysis to ISOX and 2,4-dichloroaniline (DCA) has been identified in porcine and rabbit liver esterases. The purpose of this study was to provide insights on the metabolism and drug interaction potential of UTL-5g in humans. The kinetics of UTL-5g hydrolysis was determined in human liver microsomes (HLM) and recombinant human carboxylesterases (hCE1b and hCE2). The potential of UTL-5g and its metabolites for competitive inhibition and time-dependent inhibition of microsomal cytochrome P450 (P450) was examined in HLM. UTL-5g hydrolysis to ISOX and DCA in HLM were NADPH-independent, with a maximum rate of reaction (Vmax) of 11.1 nmol/min per mg and substrate affinity (Km) of 41.6 µM. Both hCE1b and hCE2 effectively catalyzed UTL-5g hydrolysis, but hCE2 exhibited ∼30-fold higher catalytic efficiency (Vmax/Km) than hCE1b. UTL-5g and DCA competitively inhibited microsomal CYP1A2, CYP2B6, and CYP2C19 (IC50 values <50 µM), and exhibited time-dependent inhibition of microsomal CYP1A2 with the inactivation efficiency (kinact/KI) of 0.68 and 0.51 minute(-1)·mM(-1), respectively. ISOX did not inhibit or inactivate any tested microsomal P450. In conclusion, hCE1b and hCE2 play a key role in the bioactivation of UTL-5g. Factors influencing carboxylesterase activities may have a significant impact on the pharmacological and therapeutic effects of UTL-5g. UTL-5g has the potential to inhibit P450-mediated metabolism through competitive inhibition or time-dependent inhibition. Caution is particularly needed for potential drug interactions involving competitive inhibition or time-dependent inhibition of CYP1A2 in the future clinical development of UTL-5g. Copyright © 2014 by The American Society for Pharmacology and Experimental Therapeutics.

Foxp3+ T cells inhibit antitumor immune memory modulated by mTOR inhibition.

PubMed

Wang, Yanping; Sparwasser, Tim; Figlin, Robert; Kim, Hyung L

2014-04-15

Inhibition of mTOR signaling enhances antitumor memory lymphocytes. However, pharmacologic mTOR inhibition also enhances regulatory T-cell (Treg) activity. To counter this effect, Treg control was added to mTOR inhibition in preclinical models. Tregs were controlled with CD4-depleting antibodies because CD4 depletion has high translational potential and already has a well-established safety profile in patients. The antitumor activity of the combination therapy was CD8 dependent and controlled growth of syngeneic tumors even when an adoptive immunotherapy was not used. Lymphocytes resulting from the combination therapy could be transferred into naïve mice to inhibit aggressive growth of lung metastases. The combination therapy enhanced CD8 memory formation as determined by memory markers and functional studies of immune recall. Removal of FoxP3-expressing T lymphocytes was the mechanism underlying immunologic memory formation following CD4 depletion. This was confirmed using transgenic DEREG (depletion of regulatory T cells) mice to specifically remove Foxp3(+) T cells. It was further confirmed with reciprocal studies where stimulation of immunologic memory because of CD4 depletion was completely neutralized by adoptively transferring tumor-specific Foxp3(+) T cells. Also contributing to tumor control, Tregs that eventually recovered following CD4 depletion were less immunosuppressive. These results provide a rationale for further study of mTOR inhibition and CD4 depletion in patients. ©2014 AACR.

Inhibition of poly (ADP-ribose) Synthetase Attenuates Neutrophil Recruitment and Exerts Antiinflammatory Effects

PubMed Central

Szabó, Csaba; Lim, Lina H.K.; Cuzzocrea, Salvatore; Getting, Stephen J.; Zingarelli, Basilia; Flower, Roderick J.; Salzman, Andrew L.; Perretti, Mauro

1997-01-01

A cytotoxic cycle triggered by DNA single-strand breakage and poly (ADP-ribose) synthetase activation has been shown to contribute to the cellular injury during various forms of oxidant stress in vitro. The aim of this study was to investigate the role of poly (ADP-ribose) synthetase (PARS) in the process of neutrophil recruitment and in development of local and systemic inflammation. In pharmacological studies, PARS was inhibited by 3-aminobenzamide (10–20 mg/kg) in rats and mice. In other sets of studies, inflammatory responses in PARS−/− mice were compared with the responses in corresponding wild-type controls. Inhibition of PARS reduced neutrophil recruitment and reduced the extent of edema in zymosan- and carrageenan-triggered models of local inflammation. Moreover, inhibition of PARS prevented neutrophil recruitment, and reduced organ injury in rodent models of inflammation and multiple organ failure elicited by intraperitoneal injection of zymosan. Inhibition of PARS also reduced the extent of neutrophil emigration across murine mesenteric postcapillary venules. This reduction was due to an increased rate of adherent neutrophil detachment from the endothelium, promoting their reentry into the circulation. Taken together, our results demonstrate that PARS inhibition reduces local and systemic inflammation. Part of the antiinflammatory effects of PARS inhibition is due to reduced neutrophil recruitment, which may be related to maintained endothelial integrity. PMID:9314553

Head-to-head comparison of structurally unrelated dipeptidyl peptidase 4 inhibitors in the setting of renal ischemia reperfusion injury.

PubMed

Reichetzeder, Christoph; von Websky, Karoline; Tsuprykov, Oleg; Mohagheghi Samarin, Azadeh; Falke, Luise Gabriele; Dwi Putra, Sulistyo Emantoko; Hasan, Ahmed Abdallah; Antonenko, Viktoriia; Curato, Caterina; Rippmann, Jörg; Klein, Thomas; Hocher, Berthold

2017-07-01

Results regarding protective effects of dipeptidyl peptidase 4 (DPP4) inhibitors in renal ischaemia-reperfusion injury (IRI) are conflicting. Here we have compared structurally unrelated DPP4 inhibitors in a model of renal IRI. IRI was induced in uninephrectomized male rats by renal artery clamping for 30 min. The sham group was uninephrectomized but not subjected to IRI. DPP4 inhibitors or vehicle were given p.o. once daily on three consecutive days prior to IRI: linagliptin (1.5 mg·kg -1 ·day -1 ), vildagliptin (8 mg·kg -1 ·day -1 ) and sitagliptin (30 mg·kg -1 ·day -1 ). An additional group received sitagliptin until study end (before IRI: 30 mg·kg -1 ·day -1 ; after IRI: 15 mg·kg -1 ·day -1 ). Plasma-active glucagon-like peptide type 1 (GLP-1) increased threefold to fourfold in all DPP4 inhibitor groups 24 h after IRI. Plasma cystatin C, a marker of GFR, peaked 48 h after IRI. Compared with the placebo group, DPP4 inhibition did not reduce increased plasma cystatin C levels. DPP4 inhibitors ameliorated histopathologically assessed tubular damage with varying degrees of drug-specific efficacies. Renal osteopontin expression was uniformly reduced by all DPP4 inhibitors. IRI-related increased renal cytokine expression was not decreased by DPP4 inhibition. Renal DPP4 activity at study end was significantly inhibited in the linagliptin group, but only numerically reduced in the prolonged/dose-adjusted sitagliptin group. Active GLP-1 plasma levels at study end were increased only in the prolonged/dose-adjusted sitagliptin treatment group. In rats with renal IRI, DPP4 inhibition did not alter plasma cystatin C, a marker of glomerular function, but may protect against tubular damage. © 2017 The Authors. British Journal of Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.

Genetic and Pharmacological Inhibition of TREM-1 Limits the Development of Experimental Atherosclerosis.

PubMed

Joffre, Jeremie; Potteaux, Stephane; Zeboudj, Lynda; Loyer, Xavier; Boufenzer, Amir; Laurans, Ludivine; Esposito, Bruno; Vandestienne, Marie; de Jager, Saskia C A; Hénique, Carole; Zlatanova, Ivana; Taleb, Soraya; Bruneval, Patrick; Tedgui, Alain; Mallat, Ziad; Gibot, Sebastien; Ait-Oufella, Hafid

2016-12-27

Innate immune responses activated through myeloid cells contribute to the initiation, progression, and complications of atherosclerosis in experimental models. However, the critical upstream pathways that link innate immune activation to foam cell formation are still poorly identified. This study sought to investigate the hypothesis that activation of the triggering receptor expressed on myeloid cells (TREM-1) plays a determinant role in macrophage atherogenic responses. After genetically invalidating Trem-1 in chimeric Ldlr -/- Trem-1 -/- mice and double knockout ApoE -/- Trem-1 -/- mice, we pharmacologically inhibited Trem-1 using LR12 peptide. Ldlr -/- mice reconstituted with bone marrow deficient for Trem-1 (Trem-1 -/- ) showed a strong reduction of atherosclerotic plaque size in both the aortic sinus and the thoracoabdominal aorta, and were less inflammatory compared to plaques of Trem-1 +/+ chimeric mice. Genetic invalidation of Trem-1 led to alteration of monocyte recruitment into atherosclerotic lesions and inhibited toll-like receptor 4 (TLR 4)-initiated proinflammatory macrophage responses. We identified a critical role for Trem-1 in the upregulation of cluster of differentiation 36 (CD36), thereby promoting the formation of inflammatory foam cells. Genetic invalidation of Trem-1 in ApoE -/- /Trem-1 -/- mice or pharmacological blockade of Trem-1 in ApoE -/- mice using LR-12 peptide also significantly reduced the development of atherosclerosis throughout the vascular tree, and lessened plaque inflammation. TREM-1 was expressed in human atherosclerotic lesions, mainly in lipid-rich areas with significantly higher levels of expression in atheromatous than in fibrous plaques. We identified TREM-1 as a major upstream proatherogenic receptor. We propose that TREM-1 activation orchestrates monocyte/macrophage proinflammatory responses and foam cell formation through coordinated and combined activation of CD36 and TLR4. Blockade of TREM-1 signaling may constitute an attractive novel and double-hit approach for the treatment of atherosclerosis. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

The protective effect of Nigella sativa against liver injury: a review.

PubMed

Mollazadeh, Hamid; Hosseinzadeh, Hossein

2014-12-01

Nigella sativa (Family Ranunculaceae) is a widely used medicinal plant throughout the world. N. sativa is referred in the Middle East as a part of an overall holistic approach to health. Pharmacological properties of N. sativa including immune stimulant, hypotensive, anti-inflammatory, anti-cancer, antioxidant, hypoglycemic, spasmolytic and bronchodilator have been shown. Reactive oxygen species (ROS) and oxidative stress are known as the major causes of many diseases such as liver injury and many substances and drugs can induce oxidative damage by generation of ROS in the body. Many pharmacological properties of N. sativa are known to be attributed to the presence of thymoquinone and its antioxidant effects. Thymoquinone protects liver from injury via different mechanisms including inhibition of iron-dependent lipid peroxidation, elevation in total thiol content and glutathione level, radical scavengering, increasing the activity of quinone reductase, catalase, superoxide dismutase and glutathione transferase, inhibition of NF-κB activity and inhibition of both cyclooxygenase and lipoxygenase. Therefore, this review aimed to highlight the roles of ROS in liver diseases and the mechanisms of N. sativa in prevention of liver injury.

Design, Synthesis, and Pharmacological Evaluation of Novel Multisubstituted Pyridin-3-amine Derivatives as Multitargeted Protein Kinase Inhibitors for the Treatment of Non-Small Cell Lung Cancer.

PubMed

Zhu, Wei; Chen, Hui; Wang, Yulan; Wang, Jiang; Peng, Xia; Chen, Xianjie; Gao, Yinglei; Li, Chunpu; He, Yulong; Ai, Jing; Geng, Meiyu; Zheng, Mingyue; Liu, Hong

2017-07-27

A novel series of pyridin-3-amine derivatives were designed, synthesized, and evaluated as multitargeted protein kinase inhibitors for the treatment of non-small cell lung cancer (NSCLC). Hit 1 was first disclosed by in silico screening against fibroblast growth factor receptors (FGFR), which was subsequently validated by in vitro experiments. The structure-activity relationship (SAR) of its analogues was then explored to afford novel FGFR inhibitors 2a-2p and 3a-3q. Among them, 3m showed potent inhibition against FGFR1, 2, and 3. Interestingly, compound 3m not only inhibited various phosphorylation and downstream signaling across different oncogenic forms in FGFR-overactivated cancer cells but also showed nanomolar level inhibition against several other NSCLC-related oncogene kinases, including RET, EGFR, EGFR/T790M/L858R, DDR2, and ALK. Finally, in vivo pharmacology evaluations of 3m showed significant antitumor activity (TGI = 66.1%) in NCI-H1581 NSCLC xenografts with a good pharmacokinetic profile.

Calcium channel blockers and transmitter release at the normal human neuromuscular junction.

PubMed

Protti, D A; Reisin, R; Mackinley, T A; Uchitel, O D

1996-05-01

Transmitter release evoked by nerve stimulation is highly dependent on Ca2+ entry through voltage-activated plasma membrane channels. Calcium influx may be modified in some neuromuscular diseases like Lambert-Eaton syndrome and amyotrophic lateral sclerosis. We studied the pharmacologic sensitivity of the transmitter release process to different calcium channel blockers in normal human muscles and found that funnel web toxin and omega-Agatoxin-IVA, both P-type calcium channel blockers, blocked nerve-elicited muscle action potentials and inhibited evoked synaptic transmission. The transmitter release was not affected either by nitrendipine, an L-type channel blocker, or omega-Conotoxin-GVIA, an N-type channel blocker. The pharmacologic profile of neuromuscular transmission observed in normal human muscles indicates that P-like channels mediate transmitter release at the motor nerve terminals.

The interferon-induced antiviral protein PML (TRIM19) promotes the restriction and transcriptional silencing of lentiviruses in a context-specific, isoform-specific fashion.

PubMed

Masroori, Nasser; Merindol, Natacha; Berthoux, Lionel

2016-03-22

The promyelocytic leukemia (PML) protein, a type I interferon (IFN-I)-induced gene product and a member of the tripartite motif (TRIM) family, modulates the transcriptional activity of viruses belonging to various families. Whether PML has an impact on the replication of HIV-1 has not been fully addressed, but recent studies point to its possible involvement in the restriction of HIV-1 in human cells and in the maintenance of transcriptional latency in human cell lines in which HIV-1 is constitutively repressed. We investigated further the restriction of HIV-1 and a related lentivirus, SIVmac, by PML in murine cells and in a lymphocytic human cell line. In particular, we studied the relevance of PML to IFN-I-mediated inhibition and the role of individual human isoforms. We demonstrate that both human PML (hPML) and murine PML (mPML) inhibit the early post-entry stages of the replication of HIV-1 and a related lentivirus, SIVmac. In addition, HIV-1 was transcriptionally silenced by mPML and by hPML isoforms I, II, IV and VI in MEFs. This PML-mediated transcriptional repression was attenuated in presence of the histone deacetylase inhibitor SAHA. In contrast, depletion of PML had no effect on HIV-1 gene expression in a human T cell line. PML was found to contribute to the inhibition of HIV-1 by IFN-I. Specifically, IFN-α and IFN-β treatments of MEFs enhanced the PML-dependent inhibition of HIV-1 early replication stages. We show that PML can inhibit HIV-1 and other lentiviruses as part of the IFN-I-mediated response. The restriction takes place at two distinct steps, i.e. reverse transcription and transcription, and in an isoform-specific, cellular context-specific fashion. Our results support a model in which PML activates innate immune antilentiviral effectors. These data are relevant to the development of latency reversal-inducing pharmacological agents, since PML was previously proposed as a pharmacological target for such inhibitors. This study also has implications for the development of murine models of HIV-1.

Monocarboxylate Transporter MCT1 Promotes Tumor Metastasis Independently of Its Activity as a Lactate Transporter.

PubMed

Payen, Valéry L; Hsu, Myriam Y; Rädecke, Kristin S; Wyart, Elisabeth; Vazeille, Thibaut; Bouzin, Caroline; Porporato, Paolo E; Sonveaux, Pierre

2017-10-15

Extracellular acidosis resulting from intense metabolic activities in tumors promotes cancer cell migration, invasion, and metastasis. Although host cells die at low extracellular pH, cancer cells resist, as they are well equipped with transporters and enzymes to regulate intracellular pH homeostasis. A low extracellular pH further activates proteolytic enzymes that remodel the extracellular matrix to facilitate cell migration and invasion. Monocarboxylate transporter MCT1 is a passive transporter of lactic acid that has attracted interest as a target for small-molecule drugs to prevent metastasis. In this study, we present evidence of a function for MCT1 in metastasis beyond its role as a transporter of lactic acid. MCT1 activates transcription factor NF-κB to promote cancer cell migration independently of MCT1 transporter activity. Although pharmacologic MCT1 inhibition did not modulate MCT1-dependent cancer cell migration, silencing or genetic deletion of MCT1 in vivo inhibited migration, invasion, and spontaneous metastasis. Our findings raise the possibility that pharmacologic inhibitors of MCT1-mediated lactic acid transport may not effectively prevent metastatic dissemination of cancer cells. Cancer Res; 77(20); 5591-601. ©2017 AACR . ©2017 American Association for Cancer Research.

Substituent effect of N-benzylated gramine derivatives that prevent the PP2A inhibition and dissipate the neuronal Ca2+ overload, as a multitarget strategy for the treatment of Alzheimer's disease.

PubMed

Gonzalez, Dorleta; Arribas, Raquel L; Viejo, Lucia; Lajarin-Cuesta, Rocio; de Los Rios, Cristobal

2018-05-15

Following the premises of the multitarget-directed ligands approach for the drug R&D against neurodegenerative diseases, where Alzheimer's disease (AD) outstands, we have synthesized and evaluated analogues of the gramine derivative ITH12657 (1-benzyl-5-methyl-3-(piperidin-1-ylmethyl-1H-indole, 2), which had shown important neuroprotective properties, such as blocking effect of voltage-gated Ca 2+ channels (VGCC), and prevention of phosphoprotein phosphatase 2A (PP2A) inhibition. The new analogues present different substitutions at the pending phenyl ring, what slightly modified their pharmacological characteristics. The VGCC blockade was enhanced in derivatives possessing nitro groups, while the pro-PP2A feature was ameliorated by the presence of fluorine. Chlorine atoms supplied good activities over the two biological targets aimed; nevertheless that substitution provoked loss of viability at 100-fold higher concentrations (10 μM), what discards them for a deeper pharmacological study. Overall, the para-fluorine derivative of ITH12657 was the most promising candidate for further preclinical assays. Copyright © 2018 Elsevier Ltd. All rights reserved.

[Design, synthesis and evaluation of bis-nicotine derivatives as inhibitors of cholinesterases and beta-amyloid aggregation].

PubMed

Luo, Wen; Zhao, Yong-mei; Tian, Run-guo; Su, Ya-bin; Hong, Chen

2013-11-01

A novel series of bis-nicotine derivatives (3a-3i) were designed, synthesized and evaluated as bivalent anti-Alzheimer's disease agents. The pharmacological results indicated that compounds 3e-3i inhibited both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) in the micromolar range (IC50, 2.28-117.86 micromol x L(-1) for AChE and 1.67-125 micromol x L(-1) for BChE), which was at the same potency as rivastigmine. A Lineweaver-Burk plot and molecular modeling study showed that these derivatives targeted both the catalytic active site (CAS) and the peripheral anionic site (PAS) of AChE. Besides, these compounds could significantly inhibit the self-induced Abeta aggregation with inhibition activity (11.85%-62.14%) at the concentration of 20 micromol x L(-1).

Naringin Alleviates Diabetic Kidney Disease through Inhibiting Oxidative Stress and Inflammatory Reaction.

PubMed

Chen, Fenqin; Zhang, Ning; Ma, Xiaoyu; Huang, Ting; Shao, Ying; Wu, Can; Wang, Qiuyue

2015-01-01

Naringin, a flavanone glycoside extracted from Citrus grandis Osbeck, has a wide range of pharmacological effects. In the present study we aimed at demonstrating the protective effect of naringin against diabetic kidney disease (DKD) and elucidating its possible molecular mechanism underlying. The beneficial effect of naringin was assessed in rats with streptozotocin (STZ)-induced diabetes and high glucose-induced HBZY-1 cells. According to our results, first we found that naringin relieved kidney injury, improved renal function and inhibited collagen formation and renal interstitial fibrosis. Second, we confirmed that naringin restrained oxidative stress by activating Nrf2 antioxidant pathway. Moreover, the results suggested that naringin significantly resisted inflammatory reaction by inhibiting NF- κ B signaling pathway. Taken together, our results demonstrate that naringin effectively alleviates DKD, which provide theoretical basis for naringin clinically used to treatment of DKD.

A Pharmacological Screening Approach for Discovery of Neuroprotective Compounds in Ischemic Stroke

PubMed Central

Beraki, Simret; Litrus, Lily; Soriano, Liza; Monbureau, Marie; To, Lillian K.; Braithwaite, Steven P.; Nikolich, Karoly; Urfer, Roman; Oksenberg, Donna; Shamloo, Mehrdad

2013-01-01

With the availability and ease of small molecule production and design continuing to improve, robust, high-throughput methods for screening are increasingly necessary to find pharmacologically relevant compounds amongst the masses of potential candidates. Here, we demonstrate that a primary oxygen glucose deprivation assay in primary cortical neurons followed by secondary assays (i.e. post-treatment protocol in organotypic hippocampal slice cultures and cortical neurons) can be used as a robust screen to identify neuroprotective compounds with potential therapeutic efficacy. In our screen about 50% of the compounds in a library of pharmacologically active compounds displayed some degree of neuroprotective activity if tested in a pre-treatment toxicity assay but just a few of these compounds, including Carbenoxolone, remained active when tested in a post-treatment protocol. When further examined, Carbenoxolone also led to a significant reduction in infarction size and neuronal damage in the ischemic penumbra when administered six hours post middle cerebral artery occlusion in rats. Pharmacological testing of Carbenoxolone-related compounds, acting by inhibition of 11-β-hydroxysteroid dehydrogenase-1 (11β-HSD1), gave rise to similarly potent in vivo neuroprotection. This indicates that the increase of intracellular glucocorticoid levels mediated by 11β-HSD1 may be involved in the mechanism that exacerbates ischemic neuronal cell death, and inhibiting this enzyme could have potential therapeutic value for neuroprotective therapies in ischemic stroke and other neurodegenerative disorders associated with neuronal injury. PMID:23874920

Monoamine oxidase: isoforms and inhibitors in Parkinson's disease and depressive illness

PubMed Central

Youdim, Moussa B H; Bakhle, Y S

2006-01-01

A few years after the foundation of the British Pharmacological Society, monoamine oxidase (MAO) was recognized as an enzyme of crucial interest to pharmacologists because it catalyzed the major inactivation pathway for the catecholamine neurotransmitters, noradrenaline, adrenaline and dopamine (and, later, 5-hydroxytryptamine, as well). Within the next decade, the therapeutic value of inhibitors of MAO in the treatment of depressive illness was established. Although this first clinical use exposed serious side effects, pharmacological interest in, and investigation of, MAO continued, resulting in the characterization of two isoforms, MAO-A and -B, and isoform-selective inhibitors. Selective inhibitors of MAO-B have found a therapeutic role in the treatment of Parkinson's disease and further developments have provided reversible inhibitors of MAO-A, which offer antidepressant activity without the serious side effects of the earlier inhibitors. Clinical observation and subsequent pharmacological analysis have also generated the concept of neuroprotection, reflecting the possibility of slowing, halting and maybe reversing, neurodegeneration in Parkinson's or Alzheimer's diseases. Increased levels of oxidative stress in the brain may be critical for the initiation and progress of neurodegeneration and selective inhibition of brain MAO could contribute importantly to lowering such stress. There are complex interactions between free iron levels in brain and MAO, which may have practical outcomes for depressive disorders. These aspects of MAO and its inhibition and some indication of how this important area of pharmacology and therapeutics might develop in the future are summarized in this review. PMID:16402116

Effect of Militarily-Relevant Metals on Muscle Wound Repair

DTIC Science & Technology

2010-12-01

patients with myelodysplastic syndromes and transfusional overload . Leukemia Res 2007; 31 (Suppl 3): S10-S15. 16. Graeme KA, Pollack CV Jr: Heavy...lead, and antimony inhibit wound repair. Soluble forms of iron , as well as insoluble forms of cobalt, also inhibited repair. In many cases, repair...antimony, tungsten, nickel, cobalt, iron , tin, and copper. Aim 3: Assess the effect of pharmacological intervention on the mitigation of

Targeting Protein O-GlcNAc Modifications In Breast Cancer

DTIC Science & Technology

2010-09-30

O-GlcNAcation and elevated expression of O-GlcNAc transferase (OGT), the enzyme catalyzing addition of O-GlcNAc to proteins. Reduction of O...regulatory switch mechanism analogous to phosphorylation (28). Cytosolic and nuclear enzymes dynamically catalyze addition (O-GlcNAc transferase or OGT) and...levels, through pharmacological inhibition or genetic knock-down of enzymes that add or remove O-GlcNAc, can inhibit ErbB2-mediated oncogenic

Polysaccharide enhances Radix Saposhnikoviae efficacy through inhibiting chromones decomposition in intestinal tract.

PubMed

Yang, Jing-Ming; Jiang, Hua; Dai, Hong-Liang; Wang, Zi-Wei; Jia, Gui-Zhi; Meng, Xiang-Cai

2016-09-06

Vegetative but not reproductive stage of Saposhnikovia divaricate (Turxz.) schischk possesses pharmacological activities. However, our recent study showed that reproductive S. divaricate supplemented with polysaccharide showed evidently elevated pharmacological activities and increased cimifugin content in rat serum. The aims of present study were to assess the influence of polysaccharides on the chromones pharmacological activities in Radix Saposhnikoviae (RS), the dried root of vegetative stage of S. divaricate, and to explore the underlying mechanisms. Only cimifugin was detected in the plasma of chromone treated animals and RS polysaccharide significantly increased the plasma content of cimifugin. It was shown that neither cimifugin absorption nor glycoside components transformation in simulated digestive fluid was affected by RS polysaccharide. However, a significant promotion of transformation of cimifugin to more stable prime-O-glucosylcimifugin (PGCN) by RS polysaccharide, and a protective effect of polysaccharide on chromone components were observed in small intestine solutions. Meanwhile, RS polysaccharide produced a significant elevation of cimifugin and PGCN concentration in vivo. Based on these findings, we concluded that RS polysaccharide could greatly increase the content of cimifugin, which might be related to its degradation-proof effect on cimifugin, via transforming cimifugin to comparatively more stable PGCN and spatial structure protection.

Optimising the combination dosing strategy of abemaciclib and vemurafenib in BRAF-mutated melanoma xenograft tumours.

PubMed

Tate, Sonya C; Burke, Teresa F; Hartman, Daisy; Kulanthaivel, Palaniappan; Beckmann, Richard P; Cronier, Damien M

2016-03-15

Resistance to BRAF inhibition is a major cause of treatment failure for BRAF-mutated metastatic melanoma patients. Abemaciclib, a cyclin-dependent kinase 4 and 6 inhibitor, overcomes this resistance in xenograft tumours and offers a promising drug combination. The present work aims to characterise the quantitative pharmacology of the abemaciclib/vemurafenib combination using a semimechanistic pharmacokinetic/pharmacodynamic modelling approach and to identify an optimum dosing regimen for potential clinical evaluation. A PK/biomarker model was developed to connect abemaciclib/vemurafenib concentrations to changes in MAPK and cell cycle pathway biomarkers in A375 BRAF-mutated melanoma xenografts. Resultant tumour growth inhibition was described by relating (i) MAPK pathway inhibition to apoptosis, (ii) mitotic cell density to tumour growth and, under resistant conditions, (iii) retinoblastoma protein inhibition to cell survival. The model successfully described vemurafenib/abemaciclib-mediated changes in MAPK pathway and cell cycle biomarkers. Initial tumour shrinkage by vemurafenib, acquisition of resistance and subsequent abemaciclib-mediated efficacy were successfully captured and externally validated. Model simulations illustrate the benefit of intermittent vemurafenib therapy over continuous treatment, and indicate that continuous abemaciclib in combination with intermittent vemurafenib offers the potential for considerable tumour regression. The quantitative pharmacology of the abemaciclib/vemurafenib combination was successfully characterised and an optimised, clinically-relevant dosing strategy was identified.

Botany, ethnomedicines, phytochemistry and pharmacology of Himalayan paeony (Paeonia emodi Royle.).

PubMed

Ahmad, Mushtaq; Malik, Khafsa; Tariq, Akash; Zhang, Guolin; Yaseen, Ghulam; Rashid, Neelam; Sultana, Shazia; Zafar, Muhammad; Ullah, Kifayat; Khan, Muhammad Pukhtoon Zada

2018-06-28

Himalayan paeony (Paeonia emodi Royle.) is an important species used to treat various diseases. This study aimed to compile the detailed traditional medicinal uses, phytochemistry, pharmacology and toxicological investigations on P. emodi. This study also highlights taxonomic validity, quality of experimental designs and shortcomings in previously reported information on Himalayan paeony. The data was extracted from unpublished theses (Pakistan, China, India and Nepal), and different published research articles confined to pharmacology, phytochemistry and antimicrobial activities using different databases through specific keywords. The relevant information regarding medicinal uses, taxonomic/common names, part used, collection and identification source, authentication, voucher specimen number, plant extracts and their characterization, isolation and identification of phytochemicals, methods of study in silico, in vivo or in vitro, model organism used, dose and duration, minimal active concentration, zone of inhibition (antimicrobial study), bioactive compound(s), mechanism of action on single or multiple targets, and toxicological information. P. emodi is reported for diverse medicinal uses with pharmacological properties like antioxidant, nephroprotective, lipoxygenase inhibitory, cognition and oxidative stress release, cytotoxic, anti-inflammatory, antiepileptic, anticonvulsant, haemaglutination, alpha-chymotrypsin inhibitory, hepatoprotective, hepatic chromes and pharmacokinetics of carbamazepine expression, β-glucuronidase inhibitory, spasmolytic and spasmogenic, and airway relaxant. Data confined to its taxonomic validity, shows 10% studies with correct taxonomic name while 90% studies with incorrect taxonomic, pharmacopeial and common names. The literature reviewed, shows lack of collection source (11 reports), without proper source of identification (15 reports), 33 studies without voucher specimen number, 26 reports lack information on authentic herbarium submission and most of the studies (90%) without validation of taxonomic names using recognized databases. In reported methods, 67% studies without characterization of extracts, 25% lack proper dose, 40% without duration and 31% reports lack information on proper controls. Similarly, only 18% studies reports active compound(s) responsible for pharmacological activities, 14% studies show minimal active concentration, only 2.5% studies report mechanism of action on target while none of the reports mentioned in silico approach. P. emodi is endemic to Himalayan region (Pakistan, China, India and Nepal) with diverse traditional therapeutic uses. Majority of reviewed studies showed confusion in its taxonomic validity, incomplete methodologies and ambiguous findings. Keeping in view the immense uses of P. emodi in various traditional medicinal systems, holistic pharmacological approaches in combination with reverse pharmacology, system biology, and "omics" technologies are recommended to improve the quality of research which leads to natural drug discovery development at global perspectives. Copyright © 2018 Elsevier B.V. All rights reserved.

The Chick Embryo Chorioallantoic Membrane as an In Vivo Assay to Study Antiangiogenesis

PubMed Central

Ribatti, Domenico

2010-01-01

Antiangiogenesis, e.g., inhibition of blood vessel growth, is being investigated as a way to prevent the growth of tumors and other angiogenesis-dependent diseases. Pharmacological inhibition interferes with the angiogenic cascade or the immature neovasculature with synthetic or semi-synthetic substances, endogenous inhibitors or biological antagonists. The chick embryo chorioallantoic membrane (CAM) is an extraembryonic membrane, which serves as a gas exchange surface and its function is supported by a dense capillary network. Because its extensive vascularization and easy accessibility, CAM has been used to study morphofunctional aspects of the angiogenesis process in vivo and to study the efficacy and mechanism of action of pro- and anti-angiogenic molecules. The fields of application of CAM in the study of antiangiogenesis, including our personal experience, are illustrated in this review article. PMID:27713265

Pharmacological interference with 123I-metaiodobenzylguanidine: a limitation to developing cardiac innervation imaging in clinical practice?

PubMed

Stefanelli, A; Treglia, G; Bruno, I; Rufini, V; Giordano, A

2013-05-01

(123)I-metaiodo-benzylguanidine (MIBG) scintigraphy is considered a valid imaging test to evaluate the cardiac sympathetic nervous system. However, scientific literature showed that some drugs are able to or are expected to interfere with MIBG uptake. Thirty years after introduction of the method and over 15 years since the appearance of the first document on pharmacological interference with MIBG, an update on this issue has become necessary. The aims of this review paper are: (1) to identify the pharmacological basis of interference of a variety of substances with MIBG uptake; and (2) to update the list of drugs that definitely interfere with MIBG on the grounds of evidence in the literature. A MEDLINE search was conducted. Scientific studies, case report and review articles were collected. Papers published demonstrating drugs interfering with MIBG uptake were evaluated. Drugs may interact with MIBG uptake by 5 mechanism: (1) type-1 uptake inhibition; (2) inhibition of active transport to vesicles; (3) competition in transport to vesicles; (4) depletion of neurosecretory vesicle content; (5) calcium-mediated mechanism. We find that drugs like cocaine, antidepressants, some antipsychotic, tramadol, labetalol, sympatho-mimetics, reserpine and some calcium antagonists (as diltiazem, verapamil and nifedipine) do interfere with MIBG uptake. On the other hand, we find that controversial data are available on scientific literature regarding digoxin and amiodarone. A compiled statement of MIBG interfering medicines is now recommended to help nuclear medicine physicians in clinical practice to avoid potential pitfalls and improve the efficacy of (123)I-MIBG scintigraphy as a diagnostic tool.

Neuregulin 1-ErbB4-PI3K signaling in schizophrenia and phosphoinositide 3-kinase-p110δ inhibition as a potential therapeutic strategy.

PubMed

Law, Amanda J; Wang, Yanhong; Sei, Yoshitatsu; O'Donnell, Patricio; Piantadosi, Patrick; Papaleo, Francesco; Straub, Richard E; Huang, Wenwei; Thomas, Craig J; Vakkalanka, Radhakrishna; Besterman, Aaron D; Lipska, Barbara K; Hyde, Thomas M; Harrison, Paul J; Kleinman, Joel E; Weinberger, Daniel R

2012-07-24

Neuregulin 1 (NRG1) and ErbB4, critical neurodevelopmental genes, are implicated in schizophrenia, but the mediating mechanisms are unknown. Here we identify a genetically regulated, pharmacologically targetable, risk pathway associated with schizophrenia and with ErbB4 genetic variation involving increased expression of a PI3K-linked ErbB4 receptor (CYT-1) and the phosphoinositide 3-kinase subunit, p110δ (PIK3CD). In human lymphoblasts, NRG1-mediated phosphatidyl-inositol,3,4,5 triphosphate [PI(3,4,5)P3] signaling is predicted by schizophrenia-associated ErbB4 genotype and PIK3CD levels and is impaired in patients with schizophrenia. In human brain, the same ErbB4 genotype again predicts increased PIK3CD expression. Pharmacological inhibition of p110δ using the small molecule inhibitor, IC87114, blocks the effects of amphetamine in a mouse pharmacological model of psychosis and reverses schizophrenia-related phenotypes in a rat neonatal ventral hippocampal lesion model. Consistent with these antipsychotic-like properties, IC87114 increases AKT phosphorylation in brains of treated mice, implicating a mechanism of action. Finally, in two family-based genetic studies, PIK3CD shows evidence of association with schizophrenia. Our data provide insight into a mechanism of ErbB4 association with schizophrenia; reveal a previously unidentified biological and disease link between NRG1-ErbB4, p110δ, and AKT; and suggest that p110δ is a previously undescribed therapeutic target for the treatment of psychiatric disorders.

Anti-inflammatory therapies in myocardial infarction: failures, hopes and challenges.

PubMed

Huang, Shuaibo; Frangogiannis, Nikolaos G

2018-05-01

In the infarcted heart, the damage-associated molecular pattern proteins released by necrotic cells trigger both myocardial and systemic inflammatory responses. Induction of chemokines and cytokines and up-regulation of endothelial adhesion molecules mediate leukocyte recruitment in the infarcted myocardium. Inflammatory cells clear the infarct of dead cells and matrix debris and activate repair by myofibroblasts and vascular cells, but may also contribute to adverse fibrotic remodelling of viable segments, accentuate cardiomyocyte apoptosis and exert arrhythmogenic actions. Excessive, prolonged and dysregulated inflammation has been implicated in the pathogenesis of complications and may be involved in the development of heart failure following infarction. Studies in animal models of myocardial infarction (MI) have suggested the effectiveness of pharmacological interventions targeting the inflammatory response. This article provides a brief overview of the cell biology of the post-infarction inflammatory response and discusses the use of pharmacological interventions targeting inflammation following infarction. Therapy with broad anti-inflammatory and immunomodulatory agents may also inhibit important repair pathways, thus exerting detrimental actions in patients with MI. Extensive experimental evidence suggests that targeting specific inflammatory signals, such as the complement cascade, chemokines, cytokines, proteases, selectins and leukocyte integrins, may hold promise. However, clinical translation has proved challenging. Targeting IL-1 may benefit patients with exaggerated post-MI inflammatory responses following infarction, not only by attenuating adverse remodelling but also by stabilizing the atherosclerotic plaque and by inhibiting arrhythmia generation. Identification of the therapeutic window for specific interventions and pathophysiological stratification of MI patients using inflammatory biomarkers and imaging strategies are critical for optimal therapeutic design. © 2018 The British Pharmacological Society.

New approaches to pharmacological treatment of osteoporosis.

PubMed Central

Akesson, Kristina

2003-01-01

Osteoporosis has been recognized as a major public health problem for less than two decades. The increasing incidence of fragility fractures, such as vertebral, hip, and wrist fractures, first became apparent from epidemiological studies in the early and mid-1980s, when effective treatment was virtually unavailable. Pharmacological therapies that effectively reduce the number of fractures by improving bone mass are now available widely in countries around the world. Most current agents inhibit bone loss by reducing bone resorption, but emerging therapies may increase bone mass by directly promoting bone formation--as is the case with parathyroid hormone. Current treatment alternatives include bisphosphonates, calcitonin, and selective estrogen receptor modulators, but sufficient calcium and vitamin D are a prerequisite. The availability of evidence-based data that show reductions in the incidence of fractures of 30-50% during treatment has been a major step forward in the pharmacological prevention of fractures. With all agents, fracture reduction is most pronounced for vertebral fracture in high-risk individuals; alendronate and risedronate also may protect against hip fracture in the elderly. New approaches to pharmacological treatment will include further development of existing drugs, especially with regard to tolerance and frequency of dosing. New avenues for targeting the condition will emerge as our knowledge of the regulatory mechanisms of bone remodelling increases, although issues of tissue specificity may be difficult to solve. In the long term, information gained through knowledge of bone genetics may be used to adapt pharmacological treatments more precisely to each individual. PMID:14710507

Clinical pharmacology review of safinamide for the treatment of Parkinson's disease.

PubMed

Fabbri, Margherita; Rosa, Mario M; Abreu, Daisy; Ferreira, Joaquim J

2015-12-01

Safinamide (Xadago™) is an oral α-aminoamide derivative marketed for the treatment of Parkinson's disease (PD). The drug has both dopaminergic properties, namely highly selective and reversible inhibition of monoamine oxidase B, and nondopamimetic properties, namely selective sodium channel blockade and calcium channel modulation, with consequent inhibition of excessive glutamate release. In 2014, safinamide was approved in the European Economic Area, as "an add-on therapy to stable dose levodopa, alone or in combination with other PD therapies in mid- to late-stage-fluctuating PD patients." In addition, evidence has been provided for safinamide in the treatment of motor symptoms in early PD patients. This article summarizes the pharmacological properties, development program, clinical indications for PD treatment, stratified according to several disease's stages and the safety profile of safinamide. A meta-analysis of the most frequent adverse events among Phase III trials has been also performed.

Hypothalamic κ-Opioid Receptor Modulates the Orexigenic Effect of Ghrelin

PubMed Central

Romero-Picó, Amparo; Vázquez, Maria J; González-Touceda, David; Folgueira, Cintia; Skibicka, Karolina P; Alvarez-Crespo, Mayte; Van Gestel, Margriet A; Velásquez, Douglas A; Schwarzer, Christoph; Herzog, Herbert; López, Miguel; Adan, Roger A; Dickson, Suzanne L; Diéguez, Carlos; Nogueiras, Rubén

2013-01-01

The opioid system is well recognized as an important regulator of appetite and energy balance. We now hypothesized that the hypothalamic opioid system might modulate the orexigenic effect of ghrelin. Using pharmacological and gene silencing approaches, we demonstrate that ghrelin utilizes a hypothalamic κ-opioid receptor (KOR) pathway to increase food intake in rats. Pharmacological blockade of KOR decreases the acute orexigenic effect of ghrelin. Inhibition of KOR expression in the hypothalamic arcuate nucleus is sufficient to blunt ghrelin-induced food intake. By contrast, the specific inhibition of KOR expression in the ventral tegmental area does not affect central ghrelin-induced feeding. This new pathway is independent of ghrelin-induced AMP-activated protein kinase activation, but modulates the levels of the transcription factors and orexigenic neuropeptides triggered by ghrelin to finally stimulate feeding. Our novel data implicate hypothalamic KOR signaling in the orexigenic action of ghrelin. PMID:23348063

Pharmacological discrimination of plasmalemmal and mitochondrial sodium-calcium exchanger in cardiomyocyte-derived H9c2 cells.

PubMed

Namekata, Iyuki; Hamaguchi, Shogo; Tanaka, Hikaru

2015-01-01

We examined the effects of SEA0400 and CGP-37157 on the plasmalemmal Na(+)-Ca(2+) exchanger (NCX) and mitochondrial NCX using H9c2 cardiomyocytes loaded with Ca(2+)-sensitive fluorescent probes. The plasmalemmal NCX activity, which was measured as the increase in cytoplasmic Ca(2+) concentration after application of low Na(+) extracellular solution, was inhibited by SEA0400 but not by CGP-37157. The mitochondrial NCX activity, which was measured in permeabilized H9c2 cells as the decrease in mitochondrial Ca(2+) concentration after application of Ca(2+)-free extramitochondrial solution, was inhibited by CGP-37157 but not by SEA0400. These results indicate that SEA0400 and CGP-37157 act as selective inhibitors towards plasmalemmal and mitochondrial NCX, respectively, and provide pharmacological evidence that the plasmalemmal and mitochondrial NCX are distinct molecular entities.

Pharmacological Inhibition of PKCθ Counteracts Muscle Disease in a Mouse Model of Duchenne Muscular Dystrophy.

PubMed

Marrocco, V; Fiore, P; Benedetti, A; Pisu, S; Rizzuto, E; Musarò, A; Madaro, L; Lozanoska-Ochser, B; Bouché, M

2017-02-01

Inflammation plays a considerable role in the progression of Duchenne Muscular Dystrophy (DMD), a severe muscle disease caused by a mutation in the dystrophin gene. We previously showed that genetic ablation of Protein Kinase C θ (PKCθ) in mdx, the mouse model of DMD, improves muscle healing and regeneration, preventing massive inflammation. To establish whether pharmacological targeting of PKCθ in DMD can be proposed as a therapeutic option, in this study we treated young mdx mice with the PKCθ inhibitor Compound 20 (C20). We show that C20 treatment led to a significant reduction in muscle damage associated with reduced immune cells infiltration, reduced inflammatory pathways activation, and maintained muscle regeneration. Importantly, C20 treatment is efficient in recovering muscle performance in mdx mice, by preserving muscle integrity. Together, these results provide proof of principle that pharmacological inhibition of PKCθ in DMD can be considered an attractive strategy to modulate immune response and prevent the progression of the disease. Duchenne muscular dystrophy (DMD) is a severe muscle disease affecting 1:3500 male births. DMD is caused by a mutation in dystrophin gene, coding for a protein required for skeletal and cardiac muscle integrity. Lack of a functional dystrophin is primarily responsible for the muscle eccentric contraction-induced muscle damage, observed in dystrophic muscle. However, inflammation plays a considerable role in the progression of DMD. Glucocorticoids, which have anti-inflammatory properties, are being used to treat DMD with some success; however, long term treatment with these drugs induces muscle atrophy and wasting, outweighing their benefit. The identification of specific targets for anti-inflammatory therapies is one of the ongoing therapeutic options. Although blunting inflammation would not be a "cure" for the disease, the emerging clue is that multiple strategies, addressing different aspects of the pathology, which may eventually converge, may be successful. In this context, we previously showed that genetic ablation of Protein Kinase C θ (PKCθ), an enzyme known to be involved in immune response, in mdx, the mouse model of DMD, improves muscle healing and regeneration, preventing massive inflammation. To establish whether pharmacological targeting of PKCθ in DMD can be proposed as a therapeutic option, in this study we treated young mdx mice with the PKCθ inhibitor Compound 20 (C20). We show that C20 treatment led to a significant reduction in muscle damage associated with reduced immune cells infiltration, reduced inflammatory pathways activation, and maintained muscle regeneration. Importantly, C20 treatment is efficient in recovering muscle performance in mdx mice, by preserving muscle integrity. Together, these results provide proof of principle that pharmacological inhibition of PKCθ in DMD can be considered an attractive strategy to modulate immune response and prevent the progression of the disease. Copyright © 2017 3-V Biosciences. Published by Elsevier B.V. All rights reserved.

Effects of Pharmacologic and Genetic Inhibition of Alk on Cognitive Impairments in NF1 Mutant Mice

DTIC Science & Technology

2014-06-01

approximately 90% of patients with neurofibromatosis , are associated with cognitive impairment. Impaired academic performance is common and often requires...associated with neurofibromatosis is hard to study in humans. The phenotypes observed in mice indicate a specific function for Neurofibromin in the...year of the project. References 1 Acosta, M. T., Gioia, G. A. & Silva, A. J. Neurofibromatosis type 1: new insights into neurocognitive issues

Beta Catenin in Prostate Cancer Apoptosis

DTIC Science & Technology

2011-04-03

understand their role in apoptosis. TRAIL-TZD studies also revealed that pretreatment with a pharmacological inhibitor of GSK3B (AR-A014418) can sensitize...cells potently to TRAIL-induced apoptosis in the absence of TZD. These suggested that the inhibition of GSK3B activity might be the major mechanism by...which TZD sensitizes prostate cancer cells towards TRAIL. GSK3B might thus represent a novel target for developing prostate cancer therapeutics. The in

Calcitonin controls bone formation by inhibiting the release of sphingosine 1-phosphate from osteoclasts

PubMed Central

Keller, Johannes; Catala-Lehnen, Philip; Huebner, Antje K.; Jeschke, Anke; Heckt, Timo; Lueth, Anja; Krause, Matthias; Koehne, Till; Albers, Joachim; Schulze, Jochen; Schilling, Sarah; Haberland, Michael; Denninger, Hannah; Neven, Mona; Hermans-Borgmeyer, Irm; Streichert, Thomas; Breer, Stefan; Barvencik, Florian; Levkau, Bodo; Rathkolb, Birgit; Wolf, Eckhard; Calzada-Wack, Julia; Neff, Frauke; Gailus-Durner, Valerie; Fuchs, Helmut; de Angelis, Martin Hrabĕ; Klutmann, Susanne; Tsourdi, Elena; Hofbauer, Lorenz C.; Kleuser, Burkhard; Chun, Jerold; Schinke, Thorsten; Amling, Michael

2014-01-01

The hormone calcitonin (CT) is primarily known for its pharmacologic action as an inhibitor of bone resorption, yet CT-deficient mice display increased bone formation. These findings raised the question about the underlying cellular and molecular mechanism of CT action. Here we show that either ubiquitous or osteoclast-specific inactivation of the murine CT receptor (CTR) causes increased bone formation. CT negatively regulates the osteoclast expression of Spns2 gene, which encodes a transporter for the signalling lipid sphingosine 1-phosphate (S1P). CTR-deficient mice show increased S1P levels, and their skeletal phenotype is normalized by deletion of the S1P receptor S1P3. Finally, pharmacologic treatment with the nonselective S1P receptor agonist FTY720 causes increased bone formation in wild-type, but not in S1P3-deficient mice. This study redefines the role of CT in skeletal biology, confirms that S1P acts as an osteoanabolic molecule in vivo and provides evidence for a pharmacologically exploitable crosstalk between osteoclasts and osteoblasts. PMID:25333900

Obligatory role for GPER in cardiovascular aging and disease^

PubMed Central

Daniel, Christoph; Sharma, Geetanjali; Amann, Kerstin; Arterburn, Jeffrey B.; Barton, Matthias; Prossnitz, Eric R.

2016-01-01

Pharmacological activation of the heptahelical G protein-coupled receptor GPER by selective ligands counteracts multiple aspects of cardiovascular disease. We thus expected that genetic deletion or pharmacological inhibition of GPER would further aggravate such disease states, particularly with age. To the contrary, we found that genetic ablation of Gper in mice prevented cardiovascular pathologies associated with aging by reducing superoxide (.O2−) formation by NADPH oxidase (Nox) and reduced expression the Nox isoform Nox1. Blocking GPER activity pharmacologically with G36, a synthetic, small molecule, GPER-selective blocker (GRB), decreased Nox1 abundance and .O2− production to basal amounts in cells exposed to angiotensin II and in mice chronically infused with angiotensin II. Thus, this study revealed a role for GPER activity in regulating Nox1 abundance and associated .O2−-mediated structural and functional damage that contributes to disease pathology. Our results indicated that GRBs represent a new class of drugs that can indirectly reduce Nox activity and could be used for the treatment of chronic disease processes involving excessive .O2− formation, including arterial hypertension and diastolic heart failure. PMID:27803283

Autophagy mediates pharmacological lifespan extension by spermidine and resveratrol.

PubMed

Morselli, Eugenia; Galluzzi, Lorenzo; Kepp, Oliver; Criollo, Alfredo; Maiuri, Maria Chiara; Tavernarakis, Nektarios; Madeo, Frank; Kroemer, Guido

2009-12-23

Although autophagy has widely been conceived as a self-destructive mechanism that causes cell death, accumulating evidence suggests that autophagy usually mediates cytoprotection, thereby avoiding the apoptotic or necrotic demise of stressed cells. Recent evidence produced by our groups demonstrates that autophagy is also involved in pharmacological manipulations that increase longevity. Exogenous supply of the polyamine spermidine can prolong the lifespan of (while inducing autophagy in) yeast, nematodes and flies. Similarly, resveratrol can trigger autophagy in cells from different organisms, extend lifespan in nematodes, and ameliorate the fitness of human cells undergoing metabolic stress. These beneficial effects are lost when essential autophagy modulators are genetically or pharmacologically inactivated, indicating that autophagy is required for the cytoprotective and/or anti-aging effects of spermidine and resveratrol. Genetic and functional studies indicate that spermidine inhibits histone acetylases, while resveratrol activates the histone deacetylase Sirtuin 1 to confer cytoprotection/longevity. Although it remains elusive whether the same histones (or perhaps other nuclear or cytoplasmic proteins) act as the downstream targets of spermidine and resveratrol, these results point to an essential role of protein hypoacetylation in autophagy control and in the regulation of longevity.

Novel, broad-spectrum anticonvulsants containing a sulfamide group: pharmacological properties of (S)-N-[(6-chloro-2,3-dihydrobenzo[1,4]dioxin-2-yl)methyl]sulfamide (JNJ-26489112).

PubMed

McComsey, David F; Smith-Swintosky, Virginia L; Parker, Michael H; Brenneman, Douglas E; Malatynska, Ewa; White, H Steve; Klein, Brian D; Wilcox, Karen S; Milewski, Michael E; Herb, Mark; Finley, Michael F A; Liu, Yi; Lubin, Mary Lou; Qin, Ning; Reitz, Allen B; Maryanoff, Bruce E

2013-11-27

Broad-spectrum anticonvulsants are of considerable interest as antiepileptic drugs, especially because of their potential for treating refractory patients. Such "neurostabilizers" have also been used to treat other neurological disorders, including migraine, bipolar disorder, and neuropathic pain. We synthesized a series of sulfamide derivatives (4-9, 10a-i, 11a, 11b, 12) and evaluated their anticonvulsant activity. Thus, we identified promising sulfamide 4 (JNJ-26489112) and explored its pharmacological properties. Compound 4 exhibited excellent anticonvulsant activity in rodents against audiogenic, electrically induced, and chemically induced seizures. Mechanistically, 4 inhibited voltage-gated Na(+) channels and N-type Ca(2+) channels and was effective as a K(+) channel opener. The anticonvulsant profile of 4 suggests that it may be useful for treating multiple forms of epilepsy (generalized tonic-clonic, complex partial, absence seizures), including refractory (or pharmacoresistant) epilepsy, at dose levels that confer a good safety margin. On the basis of its pharmacology and other favorable characteristics, 4 was advanced into human clinical studies.

Novel, Broad-Spectrum Anticonvulsants Containing a Sulfamide Group: Pharmacological Properties of (S)-N-[(6-Chloro-2,3-dihydrobenzo[1,4]dioxin-2-yl)methyl]sulfamide (JNJ-26489112)

PubMed Central

McComsey, David F.; Smith-Swintosky, Virginia L.; Parker, Michael H.; Brenneman, Douglas E.; Malatynska, Ewa; White, H. Steve; Klein, Brian D.; Wilcox, Karen S.; Milewski, Michael E.; Herb, Mark; Finley, Michael F. A.; Liu, Yi; Lubin, Mary Lou; Qin, Ning; Reitz, Allen B.; Maryanoff, Bruce E.

2014-01-01

Broad-spectrum anticonvulsants are of considerable interest as antiepileptic drugs, especially because of their potential for treating refractory patients. Such “neurostabilizers” have also been used to treat other neurological disorders, including migraine, bipolar disorder, and neuropathic pain. We synthesized a series of sulfamide derivatives (4–9, 10a–i, 11a, 11b, 12) and evaluated their anticonvulsant activity. Thus, we identified promising sulfamide 4 (JNJ-26489112) and explored its pharmacological properties. Compound 4 exhibited excellent anticonvulsant activity in rodents against audiogenic, electrically-induced, and chemically-induced seizures. Mechanistically, 4 inhibited voltage-gated Na+ channels and N-type Ca2+ channels, and was effective as a K+ channel opener. The anticonvulsant profile of 4 suggests that it may be useful for treating multiple forms of epilepsy (generalized tonic-clonic, complex partial, absence seizures), including refractory (or pharmacoresistant) epilepsy, at dose levels that confer a good safety margin. On the basis of its pharmacology and other favorable characteristics, 4 was advanced into human clinical studies. PMID:24205976

New orally active DNA minor groove binding small molecule CT-1 acts against breast cancer by targeting tumor DNA damage leading to p53-dependent apoptosis.

PubMed

Saini, Karan Singh; Hamidullah; Ashraf, Raghib; Mandalapu, Dhanaraju; Das, Sharmistha; Siddiqui, Mohd Quadir; Dwivedi, Sonam; Sarkar, Jayanta; Sharma, Vishnu Lal; Konwar, Rituraj

2017-04-01

Targeting tumor DNA damage and p53 pathway is a clinically established strategy in the development of cancer chemotherapeutics. Majority of anti-cancer drugs are delivered through parenteral route for reasons like severe toxicity, lack of stability, and poor enteral absorption. Current DNA targeting drugs in clinical like anthracycline suffers from major drawbacks like cardiotoxicity. Here, we report identification of a new orally active small molecule curcumin-triazole conjugate (CT-1) with significant anti-breast cancer activity in vitro and in vivo. CT-1 selectively and significantly inhibits viability of breast cancer cell lines; retards cells cycle progression at S phase and induce mitochondrial-mediated cell apoptosis. CT-1 selectively binds to minor groove of DNA and induces DNA damage leading to increase in p53 along with decrease in its ubiquitination. Inhibition of p53 with pharmacological inhibitor as well as siRNA revealed the necessity of p53 in CT-1-mediated anti-cancer effects in breast cancer cells. Studies using several other intact p53 and deficient p53 cancer cell lines further confirmed necessity of p53 in CT-1-mediated anti-cancer response. Pharmacological inhibition of pan-caspase showed CT-1 induces caspase-dependent cell death in breast cancer cells. Most interestingly, oral administration of CT-1 induces significant inhibition of tumor growth in LA-7 syngeneic orthotropic rat mammary tumor model. CT-1 treated mammary tumor shows enhancement in DNA damage, p53 upregulation, and apoptosis. Collectively, CT-1 exhibits potent anti-cancer effect both in vitro and in vivo and could serve as a safe orally active lead for anti-cancer drug development. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Autophagy inhibition synergistically enhances anti-cancer efficacy of RAMBA, VN/12-1 in SKBR-3 cells and tumor xenografts

PubMed Central

Godbole, Abhijit M.; Purushottamachar, Puranik; Martin, Marlena S.; Daskalakis, Constantine; Njar, Vincent C. O.

2012-01-01

VN/12-1 is a novel retinoic acid metabolism blocking agent (RAMBA) discovered in our laboratory. The purpose of the study was to elucidate the molecular mechanism of VN/12-1’s anticancer activity in breast cancer cell lines and in tumor xenografts. We investigated the effects of VN/12-1 on induction of autophagy andapoptosis in SKBR-3 cells. Further, we also examined the impact of pharmacological and genomic inhibition of autophagy on VN/12-1’s anti-cancer activity. Finally, the anti-tumor activity of VN/12-1 was evaluated as a single agent and in combination with autophagy inhibitor chloroquine (CHL) in an SKBR-3 mouse xenograft model. Short exposure of low dose (< 10 µM) of VN/12-1 induced endoplasmic reticulum stress (ERS), autophagy and inhibits G1-S phase transition and caused a protective response. However, higher dose of VN/12-1 initiates apoptosis in vitro. Inhibition of autophagy using either pharmacological inhibitors or RNA interference of Beclin-1 enhanced anti-cancer activity induced by VN/12-1 in SKBR-3 cells by triggering apoptosis. Importantly, VN/12-1 (5 mg/kg twice weekly) and the combination of VN/12-1 (5 mg/kg twice weekly) + chloroquine (50 mg/kg twice weekly) significantly suppressed established SKBR-3 tumor growth by 81.4% (p < 0.001 vs. control) and 96.2% (p < 0.001 vs. control), respectively. Our novel findings suggest that VN/12-1 may be useful as a single agent or in combination with autophagy inhibitors for treating human breast cancers. Our data provides a strong rationale for clinical evaluation of VN/12-1 as single agent or in combination with autophagy inhibitors. PMID:22334589

Depressant effects of hypoxia and hypoglycaemia on neuro-effector transmission of guinea-pig intestine studied in vitro with a pharmacological model

PubMed Central

Corbett, A D; Lees, G M

1996-01-01

Since intermittent ischaemia may play an important role in the ætiology of Inflammatory Bowel Disease, particularly Crohn's Disease, a pharmacological model of neuronal ischaemia was applied to guinea-pig isolated intestinal preparations to mimic the acute effects of reduced blood flow on intestinal motility.Neuro-effector transmission and smooth muscle performance were examined in myenteric plexus-longitudinal muscle preparations of guinea-pig ileum exposed to sodium cyanide (NaCN), in order to inhibit oxidative phosphorylation, or to iodoacetic acid (IAA), to block glycolysis. Comparisons were made with the effects due to simple deprivation of oxygen or glucose.Depressions of cholinergic neuro-effector transmission induced by hypoxia or NaCN (effective concentration range 0.1–3 mM), given as separate treatments, singly or repetitively over 60–90 min, were apparent within 30 s and were reversible. The maximum inhibition was 90% and the IC50 for NaCN was 0.3 mM. A conspicuous component of these inhibitions was prejunctional.Non-cholinergic neuro-effector contractions were inhibited by up to 90% by anoxia or NaCN but recovery was incomplete and slower than with cholinergic contractions.Glucose-free solutions also caused a reversible failure of cholinergic neuro-effector transmission but of slower onset. In contrast, IAA (0.06–1 mM) abolished contractions irreversibly, apparently by a direct depressant effect on smooth muscle contraction. Unlike NaCN, IAA caused an initial potentiation of electrically-induced contractions, partly by a prejunctional potentiation of cholinergic neuro-effector transmission.It is concluded that a disruption of intestinal activity in pathological conditions associated with intestinal ischaemia may result from disturbances in the function of enteric neurones. PMID:9117084

Inhibition of human Na(v)1.5 sodium channels by strychnine and its analogs.

PubMed

Yuan, Chunhua; Sun, Lirong; Zhang, Meng; Li, Shuji; Wang, Xuemin; Gao, Tianming; Zhu, Xinhong

2011-08-15

Strychnine and brucine from the seeds of the plant Strychnos nux vomica have been shown to have interesting pharmacological effects on several neurotransmitter receptors. In this study, we have characterized the pharmacological properties of strychnine and its analogs on human Na(v)1.5 channels to assess their potential therapeutic advantage in certain arrhythmias. Among the eight alkaloids, only strychnine and icajine exhibited inhibition potency on the Na(v)1.5 channel with the half-maximum inhibition (IC(50)) values of 83.1μM and 104.6μM, respectively. Structure-function analysis indicated that the increased bulky methoxy groups on the phenyl ring or the negatively charged oxygen atom may account for this lack of inhibition on the Na(v)1.5 channel. Strychnine and icajine may bind to the channel by cation-π interactions. The substitution with a large side chain on the phenyl ring or the increased molecular volume may alter the optimized position for the compound close to the binding sites of the channel. Strychnine and icajine bind to the Na(v)1.5 channel with a new mechanism that is different from TTX and local anesthetics. They bind to the outer vestibule of the channel pore with fast association and dissociation rates at resting state. Strychnine and icajine had little effect on steady-state fast inactivation but markedly shifted the slow inactivation of Na(v)1.5 currents toward more hyperpolarized potentials. The property of icajine influencing slow-inactivated state of Na(v)1.5 channel would be potential therapeutic advantages in certain arrhythmias. Copyright © 2011 Elsevier Inc. All rights reserved.

Enhancement of mitomycin C-induced cytotoxicity by curcumin results from down-regulation of MKK1/2-ERK1/2-mediated thymidine phosphorylase expression.

PubMed

Weng, Shao-Hsing; Tsai, Min-Shao; Chiu, Yu-Fan; Kuo, Ya-Hsun; Chen, Huang-Jen; Lin, Yun-Wei

2012-03-01

Curcumin (diferuloylmethane), a phenolic compound obtained from the rhizome of Curcuma longa, has been found to inhibit cell proliferation in various human cancer cell lines, including non-small cell lung cancer (NSCLC). Thymidine phosphorylase (TP) is considered an attractive therapeutic target, because increased TP expression can suppress cancer cell death induced by DNA-damaging agents. Mitomycin C (MMC), a chemotherapeutic agent used to treat NSCLC, inhibits tumour growth through DNA cross-linking and breaking. Whether MMC can affect TP expression in NSCLC is unknown. Therefore, in this study, we suggested that curcumin enhances the effects of MMC-mediated cytotoxicity by decreasing TP expression and ERK1/2 activation. Exposure of human NSCLC cell lines H1975 and H1650 to curcumin decreased MMC-elicited phosphorylated MKK1/2-ERK1/2 protein levels. Moreover, curcumin significantly decreased MMC-induced TP protein levels by increasing TP mRNA and protein instability. Enhancement of ERK1/2 activation by constitutively active MKK1/2 (MKK1/2-CA) increased TP protein levels and cell viability in curcumin- and MMC-co-treated cells. In contrast, U0126, a MKK1/2 inhibitor, augmented the cytotoxic effect and the down-regulation of TP by curcumin and MMC. Specific inhibition of TP by siRNA significantly enhanced MMC-induced cell death and cell growth inhibition. Our results suggest that suppression of TP expression or administration of curcumin along with MMC may be a novel lung cancer therapeutic modality in the future. © 2011 The Authors. Basic & Clinical Pharmacology & Toxicology © 2011 Nordic Pharmacological Society.

Inhibition of IKKβ Reduces Ethanol Consumption in C57BL/6J Mice.

PubMed

Truitt, Jay M; Blednov, Yuri A; Benavidez, Jillian M; Black, Mendy; Ponomareva, Olga; Law, Jade; Merriman, Morgan; Horani, Sami; Jameson, Kelly; Lasek, Amy W; Harris, R Adron; Mayfield, R Dayne

2016-01-01

Proinflammatory pathways in neuronal and non-neuronal cells are implicated in the acute and chronic effects of alcohol exposure in animal models and humans. The nuclear factor-κB (NF-κB) family of DNA transcription factors plays important roles in inflammatory diseases. The kinase IKKβ mediates the phosphorylation and subsequent proteasomal degradation of cytosolic protein inhibitors of NF-κB, leading to activation of NF-κB. The role of IKKβ as a potential regulator of excessive alcohol drinking had not previously been investigated. Based on previous findings that the overactivation of innate immune/inflammatory signaling promotes ethanol consumption, we hypothesized that inhibiting IKKβ would limit/decrease drinking by preventing the activation of NF-κB. We studied the systemic effects of two pharmacological inhibitors of IKKβ, TPCA-1 and sulfasalazine, on ethanol intake using continuous- and limited-access, two-bottle choice drinking tests in C57BL/6J mice. In both tests, TPCA-1 and sulfasalazine reduced ethanol intake and preference without changing total fluid intake or sweet taste preference. A virus expressing Cre recombinase was injected into the nucleus accumbens and central amygdala to selectively knock down IKKβ in mice genetically engineered with a conditional Ikkb deletion ( Ikkb F/F ). Although IKKβ was inhibited to some extent in astrocytes and microglia, neurons were a primary cellular target. Deletion of IKKβ in either brain region reduced ethanol intake and preference in the continuous access two-bottle choice test without altering the preference for sucrose. Pharmacological and genetic inhibition of IKKβ decreased voluntary ethanol consumption, providing initial support for IKKβ as a potential therapeutic target for alcohol abuse.

Effects of alcohol on histone deacetylase 2 (HDAC2) and the neuroprotective role of trichostatin A (TSA).

PubMed

Agudelo, Marisela; Gandhi, Nimisha; Saiyed, Zainulabedin; Pichili, Vijaya; Thangavel, Samikkannu; Khatavkar, Pradnya; Yndart-Arias, Adriana; Nair, Madhavan

2011-08-01

Previous studies have implicated histone deacetylases (HDACs) and HDAC inhibitors (HDIs) such as trichostatin A (TSA) in the regulation of gene expression during drug addiction. Furthermore, an increase in HDAC activity has been linked to neurodegeneration. Alcohol has also been shown to promote abundant generation of reactive oxygen species (ROS) resulting in oxidative stress. TSA inhibits HDACs and has been shown to be neuroprotective in other neurodegenerative disease models. Although HDACs and HDIs have been associated with drug addiction, there is no evidence of the neurodegenerative role of HDAC2 and neuroprotective role of TSA in alcohol addiction. Therefore, we hypothesize that alcohol modulates HDAC2 through mechanisms involving oxidative stress. To test our hypothesis, the human neuronal cell line, SK-N-MC, was treated with different concentrations of ethanol (EtOH); HDAC2 gene and protein expression were assessed at different time points. Pharmacological inhibition of HDAC2 with TSA was evaluated at the gene level using qRT-PCR and at the protein level using Western blot and flow cytometry. ROS production was measured with a fluorescence microplate reader and fluorescence microscopy. Our results showed a dose-dependent increase in HDAC2 expression with EtOH treatment. Additionally, alcohol significantly induced ROS, and pharmacological inhibition of HDAC2 with TSA was shown to be neuroprotective by significantly inhibiting HDAC2 and ROS. These results suggest that EtOH can upregulate HDAC2 through mechanisms involving oxidative stress and HDACs may play an important role in alcohol use disorders (AUDs). Moreover, the use of HDIs may be of therapeutic significance for the treatment of neurodegenerative disorders including AUDs. Copyright © 2011 by the Research Society on Alcoholism.

Pharmacological Inhibition of O-GlcNAcase Enhances Autophagy in Brain through an mTOR-Independent Pathway.

PubMed

Zhu, Yanping; Shan, Xiaoyang; Safarpour, Farzaneh; Erro Go, Nancy; Li, Nancy; Shan, Alice; Huang, Mina C; Deen, Matthew; Holicek, Viktor; Ashmus, Roger; Madden, Zarina; Gorski, Sharon; Silverman, Michael A; Vocadlo, David J

2018-03-05

The glycosylation of nucleocytoplasmic proteins with O-linked N-acetylglucosamine residues (O-GlcNAc) is conserved among metazoans and is particularly abundant within brain. O-GlcNAc is involved in diverse cellular processes ranging from the regulation of gene expression to stress response. Moreover, O-GlcNAc is implicated in various diseases including cancers, diabetes, cardiac dysfunction, and neurodegenerative diseases. Pharmacological inhibition of O-GlcNAcase (OGA), the sole enzyme that removes O-GlcNAc, reproducibly slows neurodegeneration in various Alzheimer's disease (AD) mouse models manifesting either tau or amyloid pathology. These data have stimulated interest in the possibility of using OGA-selective inhibitors as pharmaceuticals to alter the progression of AD. The mechanisms mediating the neuroprotective effects of OGA inhibitors, however, remain poorly understood. Here we show, using a range of methods in neuroblastoma N2a cells, in primary rat neurons, and in mouse brain, that selective OGA inhibitors stimulate autophagy through an mTOR-independent pathway without obvious toxicity. Additionally, OGA inhibition significantly decreased the levels of toxic protein species associated with AD pathogenesis in the JNPL3 tauopathy mouse model as well as the 3×Tg-AD mouse model. These results strongly suggest that OGA inhibitors act within brain through a mechanism involving enhancement of autophagy, which aids the brain in combatting the accumulation of toxic protein species. Our study supports OGA inhibition being a feasible therapeutic strategy for hindering the progression of AD and other neurodegenerative diseases. Moreover, these data suggest more targeted strategies to stimulate autophagy in an mTOR-independent manner may be found within the O-GlcNAc pathway. These findings should aid the advancement of OGA inhibitors within the clinic.

Differential involvement of ipsilateral and contralateral spinal cord astrocyte D-serine in carrageenan-induced mirror-image pain: role of σ1 receptors and astrocyte gap junctions.

PubMed

Choi, Hoon-Seong; Roh, Dae-Hyun; Yoon, Seo-Yeon; Choi, Sheu-Ran; Kwon, Soon-Gu; Kang, Suk-Yun; Moon, Ji-Young; Han, Ho-Jae; Beitz, Alvin J; Lee, Jang-Hern

2018-02-01

Although we have recently demonstrated that spinal astrocyte gap junctions mediate the development of mirror-image pain (MIP), it is still unclear which astrocyte-derived factor is responsible for the development of MIP and how its production is controlled. In the present study, we focused on the role of ipsilateral versus contralateral D-serine in the development of MIP and investigated the possible involvement of σ1 receptors and gap junctions in astrocyte D-serine production. Following carrageenan injection, mechanical allodynia was tested at various time points to examine the effect of individual drugs. Immunohistochemistry and Western blot analyses were performed to clarify the expression levels of spinal D-serine, serine racemase, σ1 receptors and connexin 43. The expression of ipsilateral D-serine was up-regulated during the early phase of inflammation, while contralateral D-serine increased during the later phase of inflammation. The pharmacological inhibition of D-serine during the early phase blocked the development of both ipsilateral and contralateral mechanical allodynia. However, the inhibition of D-serine during the later phase of inflammation blocked contralateral, but not ipsilateral mechanical allodynia. Furthermore, the inhibition of σ1 receptors during the earlier phase of inflammation inhibited the increase in ipsilateral D-serine. Conversely, the blockade of astrocyte gap junctions suppressed the up-regulation of contralateral D-serine during the later phase of inflammation. Spinal astrocyte D-serine plays an important role in the development of mirror-image pain. Furthermore, σ1 receptors and astrocyte gap junction signalling mediate ipsilateral and contralateral D-serine production respectively. © 2017 The British Pharmacological Society.

Pharmacologic properties of KT2-962 (6-isopropyl-3-[4-(p- chlorobenzenesulfonylamino)-butyl]-azulene-1-sulfonic acid sodium salt); a new TXA2/prostaglandin endoperoxide receptor antagonist.

PubMed

Kosakai, K; Wakabayashi, S; Sato, T; Mochizuki, S; Tomiyama, A; Zhou, Q; Satake, N; Shibata, S

1993-03-01

Pharmacologic properties of KT2-962 (6-isopropyl-3-[4-(p-chlorobenzenesulfonylamino)butyl]-azulene+ ++-1-sulfonic acid sodium salt, KT) were studied in isolated rat aorta, rat tail artery, rabbit aorta, rabbit renal artery, and pig coronary artery. KT competitively inhibited the contractions induced by thromboxane A2 (TXA2) mimetic, U46619 (pA2 values 9.95, 8.85, 7.87, 8.49, and 9.12, respectively). KT also inhibited the contraction of rabbit aorta induced by prostaglandin2 alpha (PGF2 alpha, pA2 value 7.85) and the contraction of guinea pig ileum induced by LTD4 (pA2 value 5.48) but did not alter the contractions induced by norepinephrine (NE), Ca2+, serotonin, and histamine. KT did not alter the contractions of guinea pig ileum, which did not contract with U46619, induced by PGE2 and PGF2 alpha. KT inhibited the aggregations of rabbit platelets induced by U46619, arachidonic acid, and collagen (IC50 values 7.9, 140, and 16 microM, respectively) but not those induced by ADP. It also inhibited the specific binding of TXA2/PGH2 receptor antagonist, [3H]SQ29,548, to rabbit gel-filtered platelets with an IC50 value of 1.5 x 10(-8) M. In in vivo experiments with mice, oral administration of KT protected the U46619-induced sudden death with the minimum effective dose of 0.3 mg/kg and provided such protection for > 8 h at 1.0 mg/kg. These results indicate that KT is a new nonprostanoid type TXA2/PGH2 receptor antagonist that is orally effective and long acting.

Activation of muscarinic M3 receptors inhibits large-conductance voltage- and Ca2+-activated K+ channels in rat urinary bladder smooth muscle cells

PubMed Central

Parajuli, Shankar P.

2013-01-01

Large conductance voltage- and Ca2+-activated K+ (BK) channels are key regulators of detrusor smooth muscle (DSM) contraction and relaxation during urine voiding and storage. Here, we explored whether BK channels are regulated by muscarinic receptors (M-Rs) in native freshly isolated rat DSM cells under physiological conditions using the perforated whole cell patch-clamp technique and pharmacological inhibitors. M-R activation with carbachol (1 μM) initially evoked large transient outward BK currents, followed by inhibition of the spontaneous transient outward BK currents (STBKCs) in DSM cells. Carbachol (1 μM) also inhibited the amplitude and frequency of spontaneous transient hyperpolarizations (STHs) and depolarized the DSM cell membrane potential. Selective inhibition of the muscarinic M3 receptors (M3-Rs) with 4-diphenylacetoxy-N-methylpiperidine (4-DAMP; 0.1 μM), but not muscarinic M2 receptors with methoctramine (1 μM), blocked the carbachol inhibitory effects on STBKCs. Furthermore, blocking the inositol 1,4,5-triphosphate (IP3) receptors with xestospongin-C (1 μM) inhibited the carbachol-induced large transient outward BK currents without affecting carbachol inhibitory effects on STBKCs. Upon pharmacological inhibition of all known cellular sources of Ca2+ for BK channel activation, carbachol (1 μM) did not affect the voltage-step-induced steady-state BK currents, suggesting that the muscarinic effects in DSM cells are mediated by mobilization of intracellular Ca2+. In conclusion, our findings provide strong evidence that activation of M3-Rs leads to inhibition of the STBKCs, STHs, and depolarization of DSM cells. Collectively, the data suggest the existence of functional interactions between BK channels and M3-Rs at a cellular level in DSM. PMID:23703523

Characterization of glioma stem cells through multiple stem cell markers and their specific sensitization to double-strand break-inducing agents by pharmacological inhibition of ataxia telangiectasia mutated protein.

PubMed

Raso, Alessandro; Vecchio, Donatella; Cappelli, Enrico; Ropolo, Monica; Poggi, Alessandro; Nozza, Paolo; Biassoni, Roberto; Mascelli, Samantha; Capra, Valeria; Kalfas, Fotios; Severi, Paolo; Frosina, Guido

2012-09-01

Previous studies have shown that tumor-driving glioma stem cells (GSC) may promote radio-resistance by constitutive activation of the DNA damage response started by the ataxia telangiectasia mutated (ATM) protein. We have investigated whether GSC may be specifically sensitized to ionizing radiation by inhibiting the DNA damage response. Two grade IV glioma cell lines (BORRU and DR177) were characterized for a number of immunocytochemical, karyotypic, proliferative and differentiative parameters. In particular, the expression of a panel of nine stem cell markers was quantified by reverse transcription-polymerase chain reaction (RT-PCR) and flow cytometry. Overall, BORRU and DR177 displayed pronounced and poor stem phenotypes, respectively. In order to improve the therapeutic efficacy of radiation on GSC, the cells were preincubated with a nontoxic concentration of the ATM inhibitors KU-55933 and KU-60019 and then irradiated. BORRU cells were sensitized to radiation and radio-mimetic chemicals by ATM inhibitors whereas DR177 were protected under the same conditions. No sensitization was observed after cell differentiation or to drugs unable to induce double-strand breaks (DSB), indicating that ATM inhibitors specifically sensitize glioma cells possessing stem phenotype to DSB-inducing agents. In conclusion, pharmacological inhibition of ATM may specifically sensitize GSC to DSB-inducing agents while sparing nonstem cells. © 2012 The Authors; Brain Pathology © 2012 International Society of Neuropathology.

Activation of AMPK Inhibits Cholera Toxin Stimulated Chloride Secretion in Human and Murine Intestine

PubMed Central

Hoekstra, Nadia; Collins, Danielle; Collaco, Anne; Baird, Alan W.; Winter, Desmond C.; Ameen, Nadia; Geibel, John P.; Kopic, Sascha

2013-01-01

Increased intestinal chloride secretion through chloride channels, such as the cystic fibrosis transmembrane conductance regulator (CFTR), is one of the major molecular mechanisms underlying enterotoxigenic diarrhea. It has been demonstrated in the past that the intracellular energy sensing kinase, the AMP-activated protein kinase (AMPK), can inhibit CFTR opening. We hypothesized that pharmacological activation of AMPK can abrogate the increased chloride flux through CFTR occurring during cholera toxin (CTX) mediated diarrhea. Chloride efflux was measured in isolated rat colonic crypts using real-time fluorescence imaging. AICAR and metformin were used to activate AMPK in the presence of the secretagogues CTX or forskolin (FSK). In order to substantiate our findings on the whole tissue level, short-circuit current (SCC) was monitored in human and murine colonic mucosa using Ussing chambers. Furthermore, fluid accumulation was measured in excised intestinal loops. CTX and forskolin (FSK) significantly increased chloride efflux in isolated colonic crypts. The increase in chloride efflux could be offset by using the AMPK activators AICAR and metformin. In human and mouse mucosal sheets, CTX and FSK increased SCC. AICAR and metformin inhibited the secretagogue induced rise in SCC, thereby confirming the findings made in isolated crypts. Moreover, AICAR decreased CTX stimulated fluid accumulation in excised intestinal segments. The present study suggests that pharmacological activation of AMPK effectively reduces CTX mediated increases in intestinal chloride secretion, which is a key factor for intestinal water accumulation. AMPK activators may therefore represent a supplemental treatment strategy for acute diarrheal illness. PMID:23935921

Pharmacological modulation of the voltage-gated neuronal Kv7/KCNQ/M-channel alters the intrinsic excitability and synaptic responses of pyramidal neurons in rat prefrontal cortex slices.

PubMed

Peng, Hui; Bian, Xi-Ling; Ma, Fu-Cui; Wang, Ke-Wei

2017-09-01

The prefrontal cortex (PFC) critical for higher cognition is implicated in neuropsychiatric diseases, such as Alzheimer's disease, depression and schizophrenia. The voltage-activated Kv7/KCNQ/M-channel or M-current modulates the neuronal excitability that defines the fundamental mechanism of brain function. However, whether M-current functions to regulate the excitability of PFC neurons remains elusive. In this study, we recorded the native M-current from PFC layer V pyramidal neurons in rat brain slices and showed that it modulated the intrinsic excitability and synaptic responses of PFC pyramidal neurons. Application of a specific M-channel blocker XE991 (40 μmol/L) or opener retigabine (10 μmol/L) resulted in inhibition or activation of M-current, respectively. In the current-clamp recordings, inhibition of M-current was evidenced by the increased average spike frequency and the reduced first inter-spike interval (ISI), spike onset latency and fast afterhyperpolarization (fAHP), whereas activation of M-current caused opposite responses. Furthermore, inhibition of M-current significantly increased the amplitude of excitatory postsynaptic potentials (EPSPs) and depolarized the resting membrane potential (RMP) without affecting the miniature EPSC (mEPSC) frequency. These data demonstrate that voltage-gated neuronal Kv7/KCNQ/M-current modulates the excitability and synaptic transmission of PFC neurons, suggesting that pharmacological modulation of M-current in the PFC may exert beneficial effects on cognitive deficits implicated in the pathophysiology of neuropsychiatric disorders.

Inhibition of LSD1 sensitizes glioblastoma cells to histone deacetylase inhibitors

PubMed Central

Singh, Melissa M.; Manton, Christa A.; Bhat, Krishna P.; Tsai, Wen-Wei; Aldape, Kenneth; Barton, Michelle C.; Chandra, Joya

2011-01-01

Glioblastoma multiforme (GBM) is a particularly aggressive brain tumor and remains a clinically devastating disease. Despite innovative therapies for the treatment of GBM, there has been no significant increase in patient survival over the past decade. Enzymes that control epigenetic alterations are of considerable interest as targets for cancer therapy because of their critical roles in cellular processes that lead to oncogenesis. Several inhibitors of histone deacetylases (HDACs) have been developed and tested in GBM with moderate success. We found that treatment of GBM cells with HDAC inhibitors caused the accumulation of histone methylation, a modification removed by the lysine specific demethylase 1 (LSD1). This led us to examine the effects of simultaneously inhibiting HDACs and LSD1 as a potential combination therapy. We evaluated induction of apoptosis in GBM cell lines after combined inhibition of LSD1 and HDACs. LSD1 was inhibited by targeted short hairpin RNA or pharmacological means and inhibition of HDACs was achieved by treatment with either vorinostat or PCI-24781. Caspase-dependent apoptosis was significantly increased (>2-fold) in LSD1-knockdown GBM cells treated with HDAC inhibitors. Moreover, pharmacologically inhibiting LSD1 with the monoamine oxidase inhibitor tranylcypromine, in combination with HDAC inhibitors, led to synergistic apoptotic cell death in GBM cells; this did not occur in normal human astrocytes. Taken together, these results indicate that LSD1 and HDACs cooperate to regulate key pathways of cell death in GBM cell lines but not in normal counterparts, and they validate the combined use of LSD1 and HDAC inhibitors as a therapeutic approach for GBM. PMID:21653597

Blockade of store-operated calcium entry alleviates high glucose-induced neurotoxicity via inhibiting apoptosis in rat neurons.

PubMed

Xu, Zhenkuan; Xu, Wenzhe; Song, Yan; Zhang, Bin; Li, Feng; Liu, Yuguang

2016-07-25

Altered store-operated calcium entry (SOCE) has been suggested to be involved in many diabetic complications. However, the association of altered SOCE and diabetic neuronal damage remains unclear. This study aimed to investigate the effects of altered SOCE on primary cultured rat neuron injury induced by high glucose. Our data demonstrated that high glucose increased rat neuron injury and upregulated the expression of store-operated calcium channel (SOC). Inhibition of SOCE by a pharmacological inhibitor and siRNA knockdown of stromal interaction molecule 1 weakened the intracellular calcium overload, restored mitochondrial membrane potential, downregulated cytochrome C release and inhibited cell apoptosis. As well, treatment with the calcium chelator BAPTA-AM prevented cell apoptosis by ameliorating the high glucose-increased intracellular calcium level. These findings suggest that SOCE blockade may alleviate high glucose-induced neuronal damage by inhibiting apoptosis. SOCE might be a promising therapeutic target in diabetic neurotoxicity. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Daphnetin inhibits invasion and migration of LM8 murine osteosarcoma cells by decreasing RhoA and Cdc42 expression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fukuda, Hiroki; Nakamura, Seikou; Chisaki, Yugo

2016-02-26

Daphnetin, 7,8-dihydroxycoumarin, present in main constituents of Daphne odora var. marginatai, has multiple pharmacological activities including anti-proliferative effects in cancer cells. In this study, using a Transwell system, we showed that daphnetin inhibited invasion and migration of highly metastatic murine osteosarcoma LM8 cells in a dose-dependent manner. Following treatment by daphnetin, cells that penetrated the Transwell membrane were rounder than non-treated cells. Immunofluorescence analysis revealed that daphnetin decreased the numbers of intracellular stress fibers and filopodia. Moreover, daphnetin treatment dramatically decreased the expression levels of RhoA and Cdc42. In summary, the dihydroxycoumarin derivative daphnetin inhibits the invasion and migration ofmore » LM8 cells, and therefore represents a promising agent for use against metastatic cancer. - Highlights: • Daphnetin, a coumarin-derivative, inhibited invasion and migration of LM8 cells. • Stress fibers and filopodia were decreased by daphnetin treatment. • Daphnetin decreased RhoA and Cdc42 protein expression.« less

Inhibition of SLC1A5 sensitizes colorectal cancer to cetuximab.

PubMed

Ma, Huanrong; Wu, Zhenzhen; Peng, Jianjun; Li, Yang; Huang, Hongxiang; Liao, Yi; Zhou, Minyu; Sun, Li; Huang, Na; Shi, Min; Bin, Jianping; Liao, Yulin; Rao, Jinjun; Wang, Lin; Liao, Wangjun

2018-06-15

Cetuximab resistance is a key barrier in treating metastatic colorectal cancer (mCRC). Targeting of metabolic resources import could resensitize drug-resistant cancer cells to anticancer treatments. Here we showed that the expression of the glutamine transporter solute carrier 1 family member 5 (SLC1A5) in clinical CRC samples of patients resisted to cetuximab was significantly higher than in those of patients responded to cetuximab. Inhibition of SLC1A5 by shRNA-mediated gene silencing or pharmacological inhibitor significantly suppressed the growth of CRC. Moreover, inhibition of SLC1A5 significantly enhanced the inhibitory efficacy of cetuximab on CRC proliferation both in vitro and in vivo. Mechanistically, SLC1A5 inhibition facilitated EGFR degradation through the ubiquitin-proteasome pathway, and decreased the expression of nuclear EGFR, both of which might have contribution to the improved response to cetuximab. This study provides the metabolic molecule SLC1A5 as a potential therapeutic target to increase the efficacy of cetuximab on CRC. © 2018 UICC.

Effects of resveratrol on rat neurosteroid synthetic enzymes.

PubMed

Wang, Yiluan; Sun, Jianliang; Chen, Ling; Zhou, Songyi; Lin, Han; Wang, Yiyan; Lin, Nengming; Ge, Ren-Shan

2017-10-01

Resveratrol, a common polyphenol, has extensive pharmacological activities. Resveratrol inhibits some steroid biosynthetic enzymes, indicating that it may block neurosteroid synthesis. The objective of the present study is to investigate the inhibition of resveratrol on neurosteroidogenic enzymes rat 5α-reductase 1 (SRD5A1), 3α-hydroxysteroid dehydrogenase (AKR1C9), and retinol dehydrogenase 2 (RDH2). The IC 50 values of resveratrol on SRD5A1, AKR1C9, and RDH2 were >100μM, 0.436±0.070μM, and 4.889±0.062μM, respectively. Resveratrol competitively inhibited rat AKR1C9 and RDH2 against steroid substrates. Docking showed that resveratrol bound to the steroid binding pocket of AKR1C9. It exerted a mixed mode on these AKR1C9 and RDH2 against cofactors. In conclusion, resveratrol potently inhibited rat AKR1C9 and RDH2 to regulate local neurosteroid levels. Copyright © 2017. Published by Elsevier B.V.

Cyclooxygenase Inhibition in Sepsis: Is There Life after Death?

PubMed Central

Aronoff, David M.

2012-01-01

Prostaglandins are important mediators and modulators of the inflammatory response to infection. The prostaglandins participate in the pathogenesis of hemodynamic collapse, organ failure, and overwhelming inflammation that characterize severe sepsis and shock. In light of this, cyclooxygenase (COX) inhibiting pharmacological agents have been extensively studied for their capacity to ameliorate the aberrant physiological and immune responses during severe sepsis. Animal models of sepsis, using the systemic administration of pathogen-associated molecular patterns (PAMPs) or live pathogens, have been used to examine the effectiveness of COX inhibition as a treatment for severe sepsis. These studies have largely shown beneficial effects on mortality. However, human studies have failed to show clinical utility of COX inhibitor treatment in severely septic patients. Why this approach “worked” in animals but not in humans might reflect differences in the controlled nature of animal investigations compared to human studies. This paper contrasts the impact of COX inhibitors on mortality in animal models of sepsis and human studies of sepsis and examines potential reasons for differences between these two settings. PMID:22665954

YFa and analogs: investigation of opioid receptors in smooth muscle contraction.

PubMed

Kumar, Krishan; Goyal, Ritika; Mudgal, Annu; Mohan, Anita; Pasha, Santosh

2011-10-28

To study the pharmacological profile and inhibition of smooth muscle contraction by YFa and its analogs in conjunction with their receptor selectivity. The effects of YFa and its analogs (D-Ala2) YFa, Y (D-Ala2) GFMKKKFMRF amide and Des-Phe-YGGFMKKKFMR amide in guinea pig ileum (GPI) and mouse vas deferens (MVD) motility were studied using an isolated tissue organ bath system, and morphine and DynA (1-13) served as controls. Acetylcholine was used for muscle stimulation. The observations were validated by specific antagonist pretreatment experiments using naloxonazine, naltrindole and norbinaltorphimine norBNI. YFa did not demonstrate significant inhibition of GPI muscle contraction as compared with morphine (15% vs 62%, P = 0.0002), but moderate inhibition of MVD muscle contraction, indicating the role of κ opioid receptors in the contraction. A moderate inhibition of GPI muscles by (Des-Phe) YFa revealed the role of anti-opiate receptors in the smooth muscle contraction. (D-Ala-2) YFa showed significant inhibition of smooth muscle contraction, indicating the involvement of mainly δ receptors in MVD contraction. These results were supported by specific antagonist pretreatment assays. YFa revealed its side-effect-free analgesic properties with regard to arrest of gastrointestinal transit. The study provides evidences for the involvement of κ and anti-opioid receptors in smooth muscle contraction.

In vitro pharmacological characterization of CJ-042794, a novel, potent, and selective prostaglandin EP(4) receptor antagonist.

PubMed

Murase, Akio; Taniguchi, Yasuhito; Tonai-Kachi, Hiroko; Nakao, Kazunari; Takada, Junji

2008-01-16

Activation of the prostaglandin E(2) (PGE(2)) EP(4) receptor, a G-protein-coupled receptor (GPCR), results in increases in intracellular cyclic AMP (cAMP) levels via stimulation of adenylate cyclase. Here we describe the in vitro pharmacological characterization of a novel EP(4) receptor antagonist, CJ-042794 (4-{(1S)-1-[({5-chloro-2-[(4-fluorophenyl)oxy]phenyl}carbonyl)amino]ethyl}benzoic acid). CJ-042794 inhibited [(3)H]-PGE(2) binding to the human EP(4) receptor with a mean pK(i) of 8.5, a binding affinity that was at least 200-fold more selective for the human EP(4) receptor than other human EP receptor subtypes (EP(1), EP(2), and EP(3)). CJ-042794 did not exhibit any remarkable binding to 65 additional proteins, including GPCRs, enzymes, and ion channels, suggesting that CJ-042794 is highly selective for the EP(4) receptor. CJ-042794 competitively inhibited PGE(2)-evoked elevations of intracellular cAMP levels in HEK293 cells overexpressing human EP(4) receptor with a mean pA(2) value of 8.6. PGE(2) inhibited the lipopolysaccharide (LPS)-induced production of tumor necrosis factor alpha (TNFalpha) in human whole blood (HWB); CJ-042794 reversed the inhibitory effects of PGE(2) on LPS-induced TNFalpha production in a concentration-dependent manner. These results suggest that CJ-042794, a novel, potent, and selective EP(4) receptor antagonist, has excellent pharmacological properties that make it a useful tool for exploring the physiological role of EP(4) receptors.

Receptors and aging: dedicated to the memory of Paul Ehrlich for the 100th anniversary of his Nobel Prize.

PubMed

Robert, L; Labat-Robert, J; Robert, A M

2010-01-01

The initiation and evolution of the receptor concept and its application in pharmacology can be traced back to Paul Ehrlich's original experiments. Since several decades the receptor concept is in the foreground of cell biology and pharmacology. We present here a short reminder of Ehrlich's concepts on receptor action, its evolution and modifications as a result of increasing life expectancy of human societies. Results obtained by several teams on the age-dependent modifications of receptor function are reviewed with special emphasis on the age-dependent loss of receptors and of uncoupling of receptors from their intracellular transmission pathway. As a special example we summarize our results on the elastin receptor and its age-dependent modifications. These modifications result in the loss of the physiologically helpful functions mediated by this receptor, such as vasodilation by coupling with the inducible nitric oxide synthase (iNOS)-inhibition of cellular cholesterol synthesis and modulation of free radical production by inhibition of the guanine nucleotide binding protein (Gi protein)-mediated transmission pathway. Only the harmful effects such as free radical release and up-regulation of elastase production remain in "old" cells. The age-dependent modifications of receptor function play an important role in the increasing frequency and severity of age-related diseases such as athero-arteriosclerosis and emphysema as well as the loss of hormone- and drug actions. These processes and their inhibition or correction represent a new challenge for cellular pharmacology. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

Histone deacetylase inhibition reduces hypothyroidism-induced neurodevelopmental defects in rats.

PubMed

Kumar, Praveen; Mohan, Vishwa; Sinha, Rohit Anthony; Chagtoo, Megha; Godbole, Madan M

2015-11-01

Thyroid hormone (TH) through its receptor (TRα/β) influences spatio-temporal regulation of its target gene repertoire during brain development. Though hypothyroidism in WT rodent models of perinatal hypothyroidism severely impairs neurodevelopment, its effect on TRα/β knockout mice is less severe. An explanation to this paradox is attributed to a possible repressive action of unliganded TRs during development. Since unliganded TRs suppress gene expression through the recruitment of histone deacetylase (HDACs) via co-repressor complexes, we tested whether pharmacological inhibition of HDACs may prevent the effects of hypothyroidism on brain development. Using valproate, an HDAC inhibitor, we show that HDAC inhibition significantly blocks the deleterious effects of hypothyroidism on rat cerebellum, evident by recovery of TH target genes like Bdnf, Pcp2 and Mbp as well as improved dendritic structure of cerebellar Purkinje neurons. Together with this, HDAC inhibition also rescues hypothyroidism-induced motor and cognitive defects. This study therefore provides an insight into the role of HDACs in TH insufficiency during neurodevelopment and their inhibition as a possible therapeutics for treatment. © 2015 Society for Endocrinology.

Valerian extract Ze 911 inhibits postsynaptic potentials by activation of adenosine A1 receptors in rat cortical neurons.

PubMed

Vissiennon, Z; Sichardt, K; Koetter, U; Brattström, A; Nieber, K

2006-06-01

In this study we evaluated the adenosine A1 receptor-mediated effect of valerian extract (Ze 911) on postsynaptic potentials (PSPs) in pyramidal cells of the rat cingulate cortex in a slice preparation. We first observed that N6-cyclopentyladenosine (CPA, 0.01 - 10 microM), an adenosine A1 receptor agonist, inhibited PSPs in a concentration-dependent manner. The CPA (10 microM)-induced inhibition was antagonized by 1,3-dipropyl-8-cyclopentylxanthine (DPCPX, 0.1 microM), an adenosine A1 receptor antagonist. Ze 911 concentration dependently (0.1 - 15 mg/mL) inhibited PSPs in the presence of the adenosine A2A receptor antagonist 1,3,7-trimethyl-8-(3-chlorostyryl)xanthine (CSC, 0.2 microM) and adenosine deaminase (1 U/mL). The maximal inhibition induced by 10 mg/mL was completely antagonised by DPCPX (0.1 microM), an A1 receptor blocker. The data suggest that activation of adenosine A1 receptors is involved in the pharmacological effects of the valerian extract Ze 911.

Inhibiting Myosin Light Chain Kinase Induces Apoptosis In Vitro and In Vivo

PubMed Central

Fazal, Fabeha; Gu, Lianzhi; Ihnatovych, Ivanna; Han, YooJeong; Hu, WenYang; Antic, Nenad; Carreira, Fernando; Blomquist, James F.; Hope, Thomas J.; Ucker, David S.; de Lanerolle, Primal

2005-01-01

Previous short-term studies have correlated an increase in the phosphorylation of the 20-kDa light chain of myosin II (MLC20) with blebbing in apoptotic cells. We have found that this increase in MLC20 phosphorylation is rapidly followed by MLC20 dephosphorylation when cells are stimulated with various apoptotic agents. MLC20 dephosphorylation is not a consequence of apoptosis because MLC20 dephosphorylation precedes caspase activation when cells are stimulated with a proapoptotic agent or when myosin light chain kinase (MLCK) is inhibited pharmacologically or by microinjecting an inhibitory antibody to MLCK. Moreover, blocking caspase activation increased cell survival when MLCK is inhibited or when cells are treated with tumor necrosis factor alpha. Depolymerizing actin filaments or detaching cells, processes that destabilize the cytoskeleton, or inhibiting myosin ATPase activity also resulted in MLC20 dephosphorylation and cell death. In vivo experiments showed that inhibiting MLCK increased the number of apoptotic cells and retarded the growth of mammary cancer cells in mice. Thus, MLC20 dephosphorylation occurs during physiological cell death and prolonged MLC20 dephosphorylation can trigger apoptosis. PMID:15988034

Terbinafine inhibits gap junctional intercellular communication

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Ju Yeun, E-mail: whitewndus@naver.com

Terbinafine is an antifungal agent that selectively inhibits fungal sterol synthesis by blocking squalene epoxidase. We evaluated the effect of terbinafine on gap junctional intercellular communication (GJIC). Fluorescence recovery after photobleaching (FRAP) and I-YFP GJIC assays revealed that terbinafine inhibits GJIC in a reversible and dose-dependent manner in FRT-Cx43 and LN215 cells. Treatment with terbinafine did not affect Cx43 phosphorylation status or intracellular Ca{sup 2+} concentration, well-known action mechanisms of various GJIC blockers. While a structurally related chemical, naftifine, attenuated GJIC, epigallocatechin gallate, another potent squalene epoxidase inhibitor with a different structure, did not. These results suggest that terbinafine inhibitsmore » GJIC with a so far unknown mechanism of action. - Highlights: • In vitro pharmacological studies were performed on FRT-Cx43 and LN215 cells. • Terbinafine inhibits gap junctional intercellular communication in both cell lines. • The inhibitory effect of terbinafine is reversible and dose-dependent. • Treatment of terbinafine does not alter Cx43 phosphorylation or cytosolic Ca{sup 2+} concentration. • Inhibition of squalene epoxidase is not involved in this new effect of terbinafine.« less

Preserved pharmacological activity of hepatocytes-treated extracts of valerian and St. John's wort.

PubMed

Simmen, Urs; Saladin, Caroline; Kaufmann, Priska; Poddar, Manisha; Wallimann, Christine; Schaffner, Willi

2005-07-01

The two herbal extracts valerian (Valeriana officinalis L.) and St. John's wort (Hypericum perforatum L.) were studied for their metabolic changes upon incubation with freshly prepared rat hepatocytes and subsequently analysed phytochemically as well as pharmacologically in vitro. Quantitative HPLC analysis of valerian extracts revealed considerable metabolic activities with regard to sesquiterpenes and iridoids. The amount of acetoxyvalerenic acid decreased 9-fold, while that of hydroxyvalerenic acid correspondingly increased 9-fold due to O-deacetylation. The valepotriates didrovaltrate, isovaltrate and valtrate decreased 2-, 18- and 16-fold, respectively. However, the binding affinities of the incubated extracts to the benzodiazepine and picrotoxin binding site of the GABA (A) receptor were quite similar to those of the non-incubated extracts. Neither valerenic acids nor valepotriates exhibited any significant effect on the two binding sites when tested as single compounds. Therefore, either other constituents represent the active ones or multiple compounds are necessary for the observed inhibitory and allosteric effects at the GABA (A) receptor. Extracts of St. John's wort were less potently metabolised than valerian. The amount of pseudohypericin and the main flavonoids (hyperoside, rutin, isoquercitrin, quercitrin, quercetin and I3,II8-biapigenin) slightly decreased during the 4-h incubation period. Both the antagonist effect at the corticotropin-releasing factor (CRF) type 1 receptor and the binding inhibition at the 5-HT transporter were attenuated during the metabolic treatment. The reduced antagonist effect correlates with the decreasing amount of pseudohypericin known to be a CRF (1) receptor antagonist. In conclusion, the incubation of plant extracts with freshly prepared rat hepatocytes represents a useful approach to study the pharmacological action of metabolised plant extracts. The consistent pharmacological activity of both valerian and St. John's wort is concordant with the known clinical efficacy of pharmacological activities.

Molecular Docking and Pharmacological Investigations of Rivastigmine-Fluoxetine and Coumarin-Tacrine hybrids against Acetyl Choline Esterase.

PubMed

Babitha, Pallikkara Pulikkal; Sahila, Mohammed Marunnan; Bandaru, Srinivas; Nayarisseri, Anuraj; Sureshkumar, Sivanpillai

2015-01-01

The present AChE inhibitors have been successful in the treatment of Alzheimer׳s Diseases however suffers serious side effects. Therefore in this view, the present study was sought to identify compounds with appreciable pharmacological profile targeting AChE. Analogue of Rivastigmine and Fluoxetine hybrid synthesized by Toda et al, 2003 (dataset1), and Coumarin-Tacrine hybrids synthesized by Qi Sun et al (dataset2) formed the test compounds for the present pharmacological evaluation. p-cholorophenyl substituted Rivastigmine and Fluoxetine hybrid compound (26d) from dataset 1 and -OCH3 substitute Coumarin-Tacrine hybrids (1h) from dataset 2 demonstrated superior pharmacological profile. 26 d showed superior pharmacological profile comparison to the entire compounds in either dataset owing to its better electrostatic interactions and hydrogen bonding patterns. In order to identify still better compound with pharmacological profile than 26 d and 1h, virtual screening was performed. The best docked compound (PubCId: PubCid: 68874404) showed better affinity than its parent 26 d, however showed poor ADME profile and AMES toxicity. CHEMBL2391475 (PubCid: 71699632) similar to 1h had reduced affinity in comparison to its parent compound 1h. From, our extensive analysis involving binding affinity analysis, ADMET properties predictions and pharmacophoric mappings, we report p-cholorophenyl substituted rivastigmine and fluoxetine hybrid (26d) to be a potential candidate for AcHE inhibition which in addition can overcome narrow therapeutic window of present AChE inhibitors in clinical treatment of Alzheimer׳s disease. AD - Alzheimer׳s Disease, AChE - Acetyl Choline Estarase, OPLS - Optimized Potentials for Liquid Simulations, PDB - Protein Data Bank.

Novel Method of Preparation and Activity Research on Arctigenin from Fructus Arctii.

PubMed

Cai, Enbo; Han, Jiahong; Yang, Limin; Zhang, Weiyuan; Zhao, Yan; Chen, Qiulian; Guo, Meng; He, Xinhong

2018-01-01

Arctigenin has many pharmacological activities with clinical significance and is derived from Arctium lappa L. However, the present extraction method is inefficient and does not have meaningful industrial production. A new method to directly prepare arctigenin was established by combining enzyme-assisted extraction and central composite design. Arctigenin's further pharmacological activity was also surveyed in vitro . β-D-Glucosidase, a food-grade enzyme, was added directly to the fruits of A. lappa L. to hydrolyze the arctiin to arctigenin, and the obtained samples were subsequently subjected to ethanol (30%, v/v) extraction. The pharmacological activity of the extraction and arctigenin was determined by inhibiting acetylcholinesterase (AChE) and scavenging nitrite. The factors investigated include the enzyme concentration (0.5%-2.5%), ultrasound time (10 min -3 0 min), and extraction temperature (30°C-50°C). From the analysis of the results by Design-Expert (V8.0.6), the optimal extraction conditions were obtained: enzyme concentration (1.4%), ultrasound time (25 min), and extraction temperature (45°C). The highest yield of arctigenin, obtained under the optimal conditions was 6.39%, representing an increase of 28.15% compared to the reference extraction without enzyme processing. The IC 50 values of the extraction and arctigenin, respectively, for inhibiting AChE were 0.572 mg/ml and 0.462 mg/ml, and those for nitrite-scavenging were 34.571 mg/ml and 17.49 mg/ml. The results demonstrate that using an enzyme directly in the production is an effective means for extracting arctigenin from Fructus arctii. The extraction has the activities of inhibiting AChE and scavenging nitrite, probably because there has arctigenin in it. It is implied that the extraction and arctigenin could contribute to human health in clinical applications. The new method of adding enzyme directly to the preparation of arctigenin was carried out instead of preparing arctigenin by two-step methodThree factors affecting the efficiency of preparation were analyzed and discussed include the enzyme concentration, ultrasound time, and extraction temperature by central composite designThis new method of preparing arctigenin improved the yield significantly than other methodsArctigenin has remarkable pharmacological activities of inhibiting acetylcholinesterase and scavenging nitrite. Abbreviations used: AChE: Acetylcholinesterase, CCD: Central composite design, TCM: Traditional Chinese medicines, AD.

Novel Method of Preparation and Activity Research on Arctigenin from Fructus Arctii

PubMed Central

Cai, Enbo; Han, Jiahong; Yang, Limin; Zhang, Weiyuan; Zhao, Yan; Chen, Qiulian; Guo, Meng; He, Xinhong

2018-01-01

Background: Arctigenin has many pharmacological activities with clinical significance and is derived from Arctium lappa L. However, the present extraction method is inefficient and does not have meaningful industrial production. Objective: A new method to directly prepare arctigenin was established by combining enzyme-assisted extraction and central composite design. Arctigenin's further pharmacological activity was also surveyed in vitro. Materials and Methods: β-D-Glucosidase, a food-grade enzyme, was added directly to the fruits of A. lappa L. to hydrolyze the arctiin to arctigenin, and the obtained samples were subsequently subjected to ethanol (30%, v/v) extraction. The pharmacological activity of the extraction and arctigenin was determined by inhibiting acetylcholinesterase (AChE) and scavenging nitrite. Results: The factors investigated include the enzyme concentration (0.5%–2.5%), ultrasound time (10 min−3 0 min), and extraction temperature (30°C–50°C). From the analysis of the results by Design-Expert (V8.0.6), the optimal extraction conditions were obtained: enzyme concentration (1.4%), ultrasound time (25 min), and extraction temperature (45°C). The highest yield of arctigenin, obtained under the optimal conditions was 6.39%, representing an increase of 28.15% compared to the reference extraction without enzyme processing. The IC50 values of the extraction and arctigenin, respectively, for inhibiting AChE were 0.572 mg/ml and 0.462 mg/ml, and those for nitrite-scavenging were 34.571 mg/ml and 17.49 mg/ml. Conclusions: The results demonstrate that using an enzyme directly in the production is an effective means for extracting arctigenin from Fructus arctii. The extraction has the activities of inhibiting AChE and scavenging nitrite, probably because there has arctigenin in it. It is implied that the extraction and arctigenin could contribute to human health in clinical applications. SUMMARY The new method of adding enzyme directly to the preparation of arctigenin was carried out instead of preparing arctigenin by two-step methodThree factors affecting the efficiency of preparation were analyzed and discussed include the enzyme concentration, ultrasound time, and extraction temperature by central composite designThis new method of preparing arctigenin improved the yield significantly than other methodsArctigenin has remarkable pharmacological activities of inhibiting acetylcholinesterase and scavenging nitrite. Abbreviations used: AChE: Acetylcholinesterase, CCD: Central composite design, TCM: Traditional Chinese medicines, AD: PMID:29576707

Protective effect of caspase inhibition on compression-induced muscle damage

PubMed Central

Teng, Bee T; Tam, Eric W; Benzie, Iris F; Siu, Parco M

2011-01-01

Abstract There are currently no effective therapies for treating pressure-induced deep tissue injury. This study tested the efficacy of pharmacological inhibition of caspase in preventing muscle damage following sustained moderate compression. Adult Sprague–Dawley rats were subjected to prolonged moderate compression. Static pressure of 100 mmHg compression was applied to an area of 1.5 cm2 in the tibialis region of the right limb of the rats for 6 h each day for two consecutive days. The left uncompressed limb served as intra-animal control. Rats were randomized to receive either vehicle (DMSO) as control treatment (n = 8) or 6 mg kg−1 of caspase inhibitor (z-VAD-fmk; n = 8) prior to the 6 h compression on the two consecutive days. Muscle tissues directly underneath the compression region of the compressed limb and the same region of control limb were harvested after the compression procedure. Histological examination and biochemical/molecular measurement of apoptosis and autophagy were performed. Caspase inhibition was effective in alleviating the compression-induced pathohistology of muscle. The increases in caspase-3 protease activity, TUNEL index, apoptotic DNA fragmentation and pro-apoptotic factors (Bax, p53 and EndoG) and the decreases in anti-apoptotic factors (XIAP and HSP70) observed in compressed muscle of DMSO-treated animals were not found in animals treated with caspase inhibitor. The mRNA content of autophagic factors (Beclin-1, Atg5 and Atg12) and the protein content of LC3, FoxO3 and phospho-FoxO3 that were down-regulated in compressed muscle of DMSO-treated animals were all maintained at their basal level in the caspase inhibitor treated animals. Our data provide evidence that caspase inhibition attenuates compression-induced muscle apoptosis and maintains the basal autophagy level. These findings demonstrate that pharmacological inhibition of caspase/apoptosis is effective in alleviating muscle damage as induced by prolonged compression. PMID:21540338

Sphingosine and FTY720 are potent inhibitors of the transient receptor potential melastatin 7 (TRPM7) channels.

PubMed

Qin, Xin; Yue, Zhichao; Sun, Baonan; Yang, Wenzhong; Xie, Jia; Ni, Eric; Feng, Yi; Mahmood, Rafat; Zhang, Yanhui; Yue, Lixia

2013-03-01

Transient receptor potential melastatin 7 (TRPM7) is a unique channel kinase which is crucial for various physiological functions. However, the mechanism by which TRPM7 is gated and modulated is not fully understood. To better understand how modulation of TRPM7 may impact biological processes, we investigated if TRPM7 can be regulated by the phospholipids sphingosine (SPH) and sphingosine-1-phosphate (S1P), two potent bioactive sphingolipids that mediate a variety of physiological functions. Moreover, we also tested the effects of the structural analogues of SPH, N,N-dimethyl-D-erythro-sphingosine (DMS), ceramides and FTY720 on TRPM7. HEK293 cells stably expressing TRPM7 were used for whole-cell, single-channel and macropatch current recordings. Cardiac fibroblasts were used for native TRPM7 current recording. SPH potently inhibited TRPM7 in a concentration-dependent manner, whereas S1P and other ceramides did not produce noticeable effects. DMS also markedly inhibited TRPM7. Moreover, FTY720, an immunosuppressant and the first oral drug for treatment of multiple sclerosis, inhibited TRPM7 with a similar potency to that of SPH. In contrast, FTY720-P has no effect on TRPM7. It appears that SPH and FTY720 inhibit TRPM7 by reducing channel open probability. Furthermore, endogenous TRPM7 in cardiac fibroblasts was markedly inhibited by SPH, DMS and FTY720. This is the first study demonstrating that SPH and FTY720 are potent inhibitors of TRPM7. Our results not only provide a new modulation mechanism of TRPM7, but also suggest that TRPM7 may serve as a direct target of SPH and FTY720, thereby mediating S1P-independent physiological/pathological functions of SPH and FTY720. © 2012 The Authors. British Journal of Pharmacology © 2012 The British Pharmacological Society.

Multipotent MAO and cholinesterase inhibitors for the treatment of Alzheimer's disease: synthesis, pharmacological analysis and molecular modeling of heterocyclic substituted alkyl and cycloalkyl propargyl amine.

PubMed

Samadi, Abdelouahid; de los Ríos, Cristóbal; Bolea, Irene; Chioua, Mourad; Iriepa, Isabel; Moraleda, Ignacio; Bartolini, Manuela; Andrisano, Vincenza; Gálvez, Enrique; Valderas, Carolina; Unzeta, Mercedes; Marco-Contelles, José

2012-06-01

The synthesis, pharmacological evaluation and molecular modeling of heterocyclic substituted alkyl and cycloalkyl propargyl amines 1-7 of type I, and 9-12 of type II, designed as multipotent inhibitors able to simultaneously inhibit monoamine oxidases (MAO-A/B) as well as cholinesterase (AChE/BuChE) enzymes, as potential drugs for the treatment of Alzheimer's disease, are described. Indole derivatives 1-7 of type I are well known MAO inhibitors whose capacity to inhibit AChE and BuChE was here investigated for the first time. As a result, compound 7 was identified as a MAO-B inhibitor (IC(50) = 31 ± 2 nM) and a moderately selective eqBuChE inhibitor (IC(50) = 4.7 ± 0.2 μM). Conversely, the new and readily available 5-amino-7-(prop-2-yn-1-yl)-6,7,8,9-tetrahydropyrido[2,3-b][1,6]naphthyridine derivatives 9-13 of type II are poor MAO inhibitors, but showed AChE selective inhibition, compound 12 being the most attractive as it acts as a non-competitive inhibitor on EeAChE (IC(50) = 25 ± 3 nM, K(i) = 65 nM). The ability of this compound to interact with the AChE peripheral binding site was confirmed by kinetic studies and by molecular modeling investigation. Studies on human ChEs confirmed that 12 is a selective AChE inhibitor with inhibitory potency in the submicromolar range. Moreover, in agreement with its mode of action, 12 was shown to be able to inhibit Aβ aggregation induced by hAChE by 30.6%. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Monoamine Oxidase-A Inhibition and Associated Antioxidant Activity in Plant Extracts with Potential Antidepressant Actions

PubMed Central

Guillén, Hugo

2018-01-01

Monoamine oxidase (MAO) catalyzes the oxidative deamination of amines and neurotransmitters and is involved in mood disorders, depression, oxidative stress, and adverse pharmacological reactions. This work studies the inhibition of human MAO-A by Hypericum perforatum, Peganum harmala, and Lepidium meyenii, which are reported to improve and affect mood and mental conditions. Subsequently, the antioxidant activity associated with the inhibition of MAO is determined in plant extracts for the first time. H. perforatum inhibited human MAO-A, and extracts from flowers gave the highest inhibition (IC50 of 63.6 μg/mL). Plant extracts were analyzed by HPLC-DAD-MS and contained pseudohypericin, hypericin, hyperforin, adhyperforin, hyperfirin, and flavonoids. Hyperforin did not inhibit human MAO-A and hypericin was a poor inhibitor of this isoenzyme. Quercetin and flavonoids significantly contributed to MAO-A inhibition. P. harmala seed extracts highly inhibited MAO-A (IC50 of 49.9 μg/L), being a thousand times more potent than H. perforatum extracts owing to its content of β-carboline alkaloids (harmaline and harmine). L. meyenii root (maca) extracts did not inhibit MAO-A. These plants may exert protective actions related to antioxidant effects. Results in this work show that P. harmala and H. perforatum extracts exhibit antioxidant activity associated with the inhibition of MAO (i.e., lower production of H2O2). PMID:29568754

Gasotransmitters in cancer: from pathophysiology to experimental therapy

PubMed Central

Szabo, Csaba

2017-01-01

The three endogenous gaseous transmitters — nitric oxide (NO), carbon monoxide (CO) and hydrogen sulfide (H2S) — regulate a number of key biological functions. Emerging data identify several new mechanisms of each of these three gasotransmitters in tumour biology. It is now appreciated that they show bimodal pharmacological character in cancer, in that not only the inhibition of their biosynthesis, but also elevation of the concentration of each gasotransmitter beyond a certain threshold can exert anticancer effects. This Review discusses the role of each gasotransmitter in cancer and the effects of compounds — some of which are in early-stage clinical studies — that modulate the levels of each gasotransmitter. A clearer understanding of the pharmacological character of these three gases and their underlying biological mechanisms is expected to guide further clinical translation. PMID:26678620

Design, synthesis, and antihypertensive activity of curcumin-inspired compounds via ACE inhibition and vasodilation, along with a bioavailability study for possible benefit in cardiovascular diseases.

PubMed

Zhuang, Xiao-Dong; Liao, Li-Zhen; Dong, Xiao-Bian; Hu, Xun; Guo, Yue; Du, Zhi-Min; Liao, Xin-Xue; Wang, Li-Chun

2016-01-01

This study describes the synthesis of a novel series of curcumin-inspired compounds via a facile synthetic route. The structures of these derivatives were ascertained using various spectroscopic and analytic techniques. The pharmacological effects of the target analogs were assessed by assaying their inhibition of angiotensin-converting enzyme (ACE). All of the synthesized derivatives exhibited considerable inhibition of ACE, with half-maximal inhibitory concentrations ranging from 1.23 to 120.32 μM. In a docking analysis with testicular ACE (tACE), the most promising inhibitor (4j) was efficiently accommodated in the deep cleft of the protein cavity, making close interatomic contacts with Glu162, His353, and Ala356, comparable with lisinopril. Compounds 4i, 4j, 4k, and 4l were further selected for determination of their vasodilator activity (cardiac output and stroke volume) on isolated rat hearts using the Langendorff technique. The bioavailability of compound 4j was determined in experimental mice.

The effect of mangiferin on skin: Penetration, permeation and inhibition of ECM enzymes.

PubMed

Ochocka, Renata; Hering, Anna; Stefanowicz-Hajduk, Justyna; Cal, Krzysztof; Barańska, Helena

2017-01-01

Mangiferin (2-C-β-D-glucopyranosyl-1,3,6,7-tetrahydroxyxanthone) is a polyphenol with strong antioxidant properties. Mangiferin is obtained from the mango tree (Mangifera indica L., Anacardiaceae). It has been proven that mangiferin exhibits many pharmacological activities. The aim of this study was to analyze the penetration of mangiferin into the human skin and through the skin. According to our knowledge, skin penetration and permeation studies of mangiferin have not been analyzed so far. Additionally, the influence of mangiferin on two Extracellular Matrix Enzymes (ECM): collagenase and elastase, was evaluated for the first time. It has been indicated that mangiferin is able to permeate the stratum corneum and penetrate into the epidermis and dermis in comparable amounts. For confirmation of the obtained results, fluorescence microscopy was successfully utilized. The analysis revealed the capability of mangiferin to reversibly inhibit elastase and collagenase activity. The mechanism of mangiferin interaction with both enzymes was estimated as a noncompetitive inhibition.

The effect of mangiferin on skin: Penetration, permeation and inhibition of ECM enzymes

PubMed Central

Hering, Anna; Stefanowicz–Hajduk, Justyna; Cal, Krzysztof; Barańska, Helena

2017-01-01

Mangiferin (2-C-β-D-glucopyranosyl-1,3,6,7-tetrahydroxyxanthone) is a polyphenol with strong antioxidant properties. Mangiferin is obtained from the mango tree (Mangifera indica L., Anacardiaceae). It has been proven that mangiferin exhibits many pharmacological activities. The aim of this study was to analyze the penetration of mangiferin into the human skin and through the skin. According to our knowledge, skin penetration and permeation studies of mangiferin have not been analyzed so far. Additionally, the influence of mangiferin on two Extracellular Matrix Enzymes (ECM): collagenase and elastase, was evaluated for the first time. It has been indicated that mangiferin is able to permeate the stratum corneum and penetrate into the epidermis and dermis in comparable amounts. For confirmation of the obtained results, fluorescence microscopy was successfully utilized. The analysis revealed the capability of mangiferin to reversibly inhibit elastase and collagenase activity. The mechanism of mangiferin interaction with both enzymes was estimated as a noncompetitive inhibition. PMID:28750062

Pharmacologic Characterization of Valbenazine (NBI-98854) and Its Metabolites.

PubMed

Grigoriadis, Dimitri E; Smith, Evan; Hoare, Sam R J; Madan, Ajay; Bozigian, Haig

2017-06-01

The vesicular monoamine transporter 2 (VMAT2) is an integral presynaptic protein that regulates the packaging and subsequent release of dopamine and other monoamines from neuronal vesicles into the synapse. Valbenazine (NBI-98854), a novel compound that selectively inhibits VMAT2, is approved for the treatment of tardive dyskinesia. Valbenazine is converted to two significant circulating metabolites in vivo, namely, (+)- α -dihydrotetrabenazine (R,R,R-HTBZ) and a mono-oxy metabolite, NBI-136110. Radioligand-binding studies were conducted to assess and compare valbenazine, tetrabenazine, and their respective metabolites in their abilities to selectively and potently inhibit [ 3 H]-HTBZ binding to VMAT2 in rat striatal, rat forebrain, and human platelet homogenates. A broad panel screen was conducted to evaluate possible off-target interactions of valbenazine, R,R,R-HTBZ, and NBI-136110 at >80 receptor, transporter, and ion channel sites. Radioligand binding showed R,R,R-HTBZ to be a potent VMAT2 inhibitor in homogenates of rat striatum (K i = 1.0-2.8 nM), rat forebrain (K i = 4.2 nM), and human platelets (K i = 2.6-3.3 nM). Valbenazine (K i = 110-190 nM) and NBI-136110 (K i = 160-220 nM) also exhibited inhibitory effects on VMAT2, but with lower potency than R,R,R-HTBZ. Neither valbenazine, R,R,R-HTBZ, nor NBI-136110 had significant off-target interactions at serotonin (5-HT 1A , 5-HT 2A , 5-HT 2B ) or dopamine (D 1 or D 2 ) receptor sites. In vivo studies measuring ptosis and prolactin secretion in the rat confirmed the specific and dose-dependent interactions of tetrabenazine and R,R,R-HTBZ with VMAT2. Evaluations of potency and selectivity of tetrabenazine and its pharmacologically active metabolites were also performed. Overall, the pharmacologic characteristics of valbenazine appear consistent with the favorable efficacy and tolerability findings of recent clinical studies [KINECT 2 (NCT01733121), KINECT 3 (NCT02274558)]. Copyright © 2017 by The Author(s).

The pharmacological effects of Salvia species on the central nervous system.

PubMed

Imanshahidi, Mohsen; Hosseinzadeh, Hossein

2006-06-01

Salvia is an important genus consisting of about 900 species in the family Lamiaceae. Some species of Salvia have been cultivated world wide for use in folk medicine and for culinary purposes. The dried root of Salvia miltiorrhiza, for example, has been used extensively for the treatment of coronary and cerebrovascular disease, sleep disorders, hepatitis, hepatocirrhosis, chronic renal failure, dysmenorrhea, amenorrhea, carbuncles and ulcers. S. officinalis, S. leriifolia, S. haematodes, S. triloba and S. divinorum are other species with important pharmacological effects. In this review, the pharmacological effects of Salvia species on the central nervous system will be reviewed. These include sedative and hypnotic, hallucinogenic, skeletal muscle relaxant, analgesic, memory enhancing, anticonvulsant, neuroprotective and antiparkinsonian activity, as well as the inhibition of ethanol and morphine withdrawal syndrome.

Sigma-1 receptor and inflammatory pain.

PubMed

Gris, Georgia; Cobos, Enrique José; Zamanillo, Daniel; Portillo-Salido, Enrique

2015-06-01

The sigma-1 receptor (Sig-1R) is a unique ligand-regulated molecular chaperone that interacts with several protein targets such as G protein-coupled receptors and ion channels to modulate their activity. Sig-1R is located in areas of the central and peripheral nervous system that are key to pain control. Previous preclinical studies have suggested a potential therapeutic use of Sig-1R antagonists for the management of neuropathic pain. Recent studies using pharmacological and genetic tools have explored the role of Sig-1R in inflammatory pain conditions. Mice lacking the Sig-1R have shown different patterns of phenotypic responses to inflammatory injury. Systemic or peripheral administration of several Sig-1R antagonists, including the selective Sig-1R antagonist S1RA, inhibited both mechanical and thermal hypersensitivity in several preclinical models of inflammatory pain. These recent studies are summarized in the present commentary. Central and peripheral pharmacological blockade of Sig-1R could be an effective option to treat inflammatory pain.

The biochemical characterization, stabilization studies and the antiproliferative effect of bromelain against B16F10 murine melanoma cells.

PubMed

São Paulo Barretto Miranda, Íngara Keisle; Fontes Suzart Miranda, Anderson; Souza, Fernanda Vidigal Duarte; Vannier-Santos, Marcos André; Pirovani, Carlos Priminho; Pepe, Iuri Muniz; Rodowanski, Ivanoé João; Ferreira, Katiúcia Tícila de Souza Eduvirgens; Mendes Souza Vaz, Luciano; de Assis, Sandra Aparecida

2017-06-01

The current study aims to extract bromelain from different parts (stem, crown, peels, pulp and leaves) of Ananas comosus var. comosus AGB 772; to determine of optimum pH and temperature; to test bromelain stability in disodium EDTA and sodium benzoate, and to investigate its pharmacological activity on B16F10 murine melanoma cells in vitro. The highest enzymatic activity was found in bromelain extracted from the pulp and peel. The optimum bromelain pH among all studied pineapple parts was 6.0. The optimum temperature was above 50 °C in all bromelain extracts. The fluorescence analysis confirmed the stability of bromelain in the presence of EDTA and sodium benzoate. Bromelain was pharmacologically active against B16F10 melanoma cells and it was possible verifying approximately 100% inhibition of tumor cell proliferation in vitro. Since bromelain activity was found in different parts of pineapple plants, pineapple residues from the food industry may be used for bromelain extraction.

Sodium orthovanadate associated with pharmacological doses of ascorbate causes an increased generation of ROS in tumor cells that inhibits proliferation and triggers apoptosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Günther, T-hat nia Mara Fischer; Kviecinski, Maicon Roberto; Baron, Carla Cristine

2013-01-18

Graphical abstract: -- Abstract: Pharmacological doses of ascorbate were evaluated for its ability to potentiate the toxicity of sodium orthovanadate (Na{sub 3}VO{sub 4}) in tumor cells. Cytotoxicity, inhibition of cell proliferation, generation of ROS and DNA fragmentation were assessed in T24 cells. Na{sub 3}VO{sub 4} was cytotoxic against T24 cells (EC{sub 50} = 5.8 μM at 24 h), but in the presence of ascorbate (100 μM) the EC{sub 50} fell to 3.3 μM. Na{sub 3}VO{sub 4} plus ascorbate caused a strong inhibition of cell proliferation (up to 20%) and increased the generation of ROS (4-fold). Na{sub 3}VO{sub 4} did notmore » directly cleave plasmid DNA, at this aspect no synergism was found occurring between Na{sub 3}VO{sub 4} and ascorbate once the resulting action of the combination was no greater than that of both substances administered separately. Cells from Ehrlich ascites carcinoma-bearing mice were used to determine the activity of antioxidant enzymes, the extent of the oxidative damage and the type of cell death. Na{sub 3}VO{sub 4} alone, or combined with ascorbate, increased catalase activity, but only Na{sub 3}VO{sub 4} plus ascorbate increased superoxide dismutase activity (up to 4-fold). Oxidative damage on proteins and lipids was higher due to the treatment done with Na{sub 3}VO{sub 4} plus ascorbate (2–3-fold). Ascorbate potentiated apoptosis in tumor cells from mice treated with Na{sub 3}VO{sub 4}. The results indicate that pharmacological doses of ascorbate enhance the generation of ROS induced by Na{sub 3}VO{sub 4} in tumor cells causing inhibition of proliferation and apoptosis. Apoptosis induced by orthovanadate and ascorbate is closer related to inhibition on Bcl-xL and activation of Bax. Our data apparently rule out a mechanism of cell demise p53-dependent or related to Cdk2 impairment.« less

The antifungal caspofungin increases fluoroquinolone activity against Staphylococcus aureus biofilms by inhibiting N-acetylglucosamine transferase.

PubMed

Siala, Wafi; Kucharíková, Soňa; Braem, Annabel; Vleugels, Jef; Tulkens, Paul M; Mingeot-Leclercq, Marie-Paule; Van Dijck, Patrick; Van Bambeke, Françoise

2016-11-03

Biofilms play a major role in Staphylococcus aureus pathogenicity but respond poorly to antibiotics. Here, we show that the antifungal caspofungin improves the activity of fluoroquinolones (moxifloxacin, delafloxacin) against S. aureus biofilms grown in vitro (96-well plates or catheters) and in vivo (murine model of implanted catheters). The degree of synergy among different clinical isolates is inversely proportional to the expression level of ica operon, the products of which synthesize poly-N-acetyl-glucosamine polymers, a major constituent of biofilm matrix. In vitro, caspofungin inhibits the activity of IcaA, which shares homology with β-1-3-glucan synthase (caspofungin's pharmacological target in fungi). This inhibition destructures the matrix, reduces the concentration and polymerization of exopolysaccharides in biofilms, and increases fluoroquinolone penetration inside biofilms. Our study identifies a bacterial target for caspofungin and indicates that IcaA inhibitors could potentially be useful in the treatment of biofilm-related infections.

Inhibition of the mitochondrial pyruvate carrier protects from excitotoxic neuronal death.

PubMed

Divakaruni, Ajit S; Wallace, Martina; Buren, Caodu; Martyniuk, Kelly; Andreyev, Alexander Y; Li, Edward; Fields, Jerel A; Cordes, Thekla; Reynolds, Ian J; Bloodgood, Brenda L; Raymond, Lynn A; Metallo, Christian M; Murphy, Anne N

2017-04-03

Glutamate is the dominant excitatory neurotransmitter in the brain, but under conditions of metabolic stress it can accumulate to excitotoxic levels. Although pharmacologic modulation of excitatory amino acid receptors is well studied, minimal consideration has been given to targeting mitochondrial glutamate metabolism to control neurotransmitter levels. Here we demonstrate that chemical inhibition of the mitochondrial pyruvate carrier (MPC) protects primary cortical neurons from excitotoxic death. Reductions in mitochondrial pyruvate uptake do not compromise cellular energy metabolism, suggesting neuronal metabolic flexibility. Rather, MPC inhibition rewires mitochondrial substrate metabolism to preferentially increase reliance on glutamate to fuel energetics and anaplerosis. Mobilizing the neuronal glutamate pool for oxidation decreases the quantity of glutamate released upon depolarization and, in turn, limits the positive-feedback cascade of excitotoxic neuronal injury. The finding links mitochondrial pyruvate metabolism to glutamatergic neurotransmission and establishes the MPC as a therapeutic target to treat neurodegenerative diseases characterized by excitotoxicity. © 2017 Divakaruni et al.

Inhibition of the mitochondrial pyruvate carrier protects from excitotoxic neuronal death

PubMed Central

Wallace, Martina; Buren, Caodu; Martyniuk, Kelly; Andreyev, Alexander Y.; Li, Edward; Fields, Jerel A.; Cordes, Thekla; Reynolds, Ian J.; Bloodgood, Brenda L.; Metallo, Christian M.

2017-01-01

Glutamate is the dominant excitatory neurotransmitter in the brain, but under conditions of metabolic stress it can accumulate to excitotoxic levels. Although pharmacologic modulation of excitatory amino acid receptors is well studied, minimal consideration has been given to targeting mitochondrial glutamate metabolism to control neurotransmitter levels. Here we demonstrate that chemical inhibition of the mitochondrial pyruvate carrier (MPC) protects primary cortical neurons from excitotoxic death. Reductions in mitochondrial pyruvate uptake do not compromise cellular energy metabolism, suggesting neuronal metabolic flexibility. Rather, MPC inhibition rewires mitochondrial substrate metabolism to preferentially increase reliance on glutamate to fuel energetics and anaplerosis. Mobilizing the neuronal glutamate pool for oxidation decreases the quantity of glutamate released upon depolarization and, in turn, limits the positive-feedback cascade of excitotoxic neuronal injury. The finding links mitochondrial pyruvate metabolism to glutamatergic neurotransmission and establishes the MPC as a therapeutic target to treat neurodegenerative diseases characterized by excitotoxicity. PMID:28254829

The antifungal caspofungin increases fluoroquinolone activity against Staphylococcus aureus biofilms by inhibiting N-acetylglucosamine transferase

PubMed Central

Siala, Wafi; Kucharíková, Soňa; Braem, Annabel; Vleugels, Jef; Tulkens, Paul M; Mingeot-Leclercq, Marie-Paule; Van Dijck, Patrick; Van Bambeke, Françoise

2016-01-01

Biofilms play a major role in Staphylococcus aureus pathogenicity but respond poorly to antibiotics. Here, we show that the antifungal caspofungin improves the activity of fluoroquinolones (moxifloxacin, delafloxacin) against S. aureus biofilms grown in vitro (96-well plates or catheters) and in vivo (murine model of implanted catheters). The degree of synergy among different clinical isolates is inversely proportional to the expression level of ica operon, the products of which synthesize poly-N-acetyl-glucosamine polymers, a major constituent of biofilm matrix. In vitro, caspofungin inhibits the activity of IcaA, which shares homology with β-1-3-glucan synthase (caspofungin's pharmacological target in fungi). This inhibition destructures the matrix, reduces the concentration and polymerization of exopolysaccharides in biofilms, and increases fluoroquinolone penetration inside biofilms. Our study identifies a bacterial target for caspofungin and indicates that IcaA inhibitors could potentially be useful in the treatment of biofilm-related infections. PMID:27808087

Naringin Alleviates Diabetic Kidney Disease through Inhibiting Oxidative Stress and Inflammatory Reaction

PubMed Central

Chen, Fenqin; Zhang, Ning; Ma, Xiaoyu; Huang, Ting; Shao, Ying; Wu, Can; Wang, Qiuyue

2015-01-01

Naringin, a flavanone glycoside extracted from Citrus grandis Osbeck, has a wide range of pharmacological effects. In the present study we aimed at demonstrating the protective effect of naringin against diabetic kidney disease (DKD) and elucidating its possible molecular mechanism underlying. The beneficial effect of naringin was assessed in rats with streptozotocin (STZ)-induced diabetes and high glucose-induced HBZY-1 cells. According to our results, first we found that naringin relieved kidney injury, improved renal function and inhibited collagen formation and renal interstitial fibrosis. Second, we confirmed that naringin restrained oxidative stress by activating Nrf2 antioxidant pathway. Moreover, the results suggested that naringin significantly resisted inflammatory reaction by inhibiting NF- κ B signaling pathway. Taken together, our results demonstrate that naringin effectively alleviates DKD, which provide theoretical basis for naringin clinically used to treatment of DKD. PMID:26619044

Allosteric Inhibition of Bcr-Abl Kinase by High Affinity Monobody Inhibitors Directed to the Src Homology 2 (SH2)-Kinase Interface*

PubMed Central

Wojcik, John; Lamontanara, Allan Joaquim; Grabe, Grzegorz; Koide, Akiko; Akin, Louesa; Gerig, Barbara; Hantschel, Oliver; Koide, Shohei

2016-01-01

Bcr-Abl is a constitutively active kinase that causes chronic myelogenous leukemia. We have shown that a tandem fusion of two designed binding proteins, termed monobodies, directed to the interaction interface between the Src homology 2 (SH2) and kinase domains and to the phosphotyrosine-binding site of the SH2 domain, respectively, inhibits the Bcr-Abl kinase activity. Because the latter monobody inhibits processive phosphorylation by Bcr-Abl and the SH2-kinase interface is occluded in the active kinase, it remained undetermined whether targeting the SH2-kinase interface alone was sufficient for Bcr-Abl inhibition. To address this question, we generated new, higher affinity monobodies with single nanomolar KD values targeting the kinase-binding surface of SH2. Structural and mutagenesis studies revealed the molecular underpinnings of the monobody-SH2 interactions. Importantly, the new monobodies inhibited Bcr-Abl kinase activity in vitro and in cells, and they potently induced cell death in chronic myelogenous leukemia cell lines. This work provides strong evidence for the SH2-kinase interface as a pharmacologically tractable site for allosteric inhibition of Bcr-Abl. PMID:26912659

7-MEOTA-donepezil like compounds as cholinesterase inhibitors: Synthesis, pharmacological evaluation, molecular modeling and QSAR studies.

PubMed

Korabecny, Jan; Dolezal, Rafael; Cabelova, Pavla; Horova, Anna; Hruba, Eva; Ricny, Jan; Sedlacek, Lukas; Nepovimova, Eugenie; Spilovska, Katarina; Andrs, Martin; Musilek, Kamil; Opletalova, Veronika; Sepsova, Vendula; Ripova, Daniela; Kuca, Kamil

2014-07-23

A novel series of 7-methoxytacrine (7-MEOTA)-donepezil like compounds was synthesized and tested for their ability to inhibit electric eel acetylcholinesterase (EeAChE), human recombinant AChE (hAChE), equine serum butyrylcholinesterase (eqBChE) and human plasmatic BChE (hBChE). New hybrids consist of a 7-MEOTA unit, representing less toxic tacrine (THA) derivative, connected with analogues of N-benzylpiperazine moieties mimicking N-benzylpiperidine fragment from donepezil. 7-MEOTA-donepezil like compounds exerted mostly non-selective profile in inhibiting cholinesterases of different origin with IC50 ranging from micromolar to sub-micromolar concentration scale. Kinetic analysis confirmed mixed-type inhibition presuming that these inhibitors are capable to simultaneously bind peripheral anionic site (PAS) as well as catalytic anionic site (CAS) of AChE. Molecular modeling studies and QSAR studies were performed to rationalize studies from in vitro. Overall, 7-MEOTA-donepezil like derivatives can be considered as interesting candidates for Alzheimer's disease treatment. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

A Phenotypic Screen in Zebrafish Identifies a Novel Small-Molecule Inducer of Ectopic Tail Formation Suggestive of Alterations in Non-Canonical Wnt/PCP Signaling

PubMed Central

Gebruers, Evelien; Cordero-Maldonado, María Lorena; Gray, Alexander I.; Clements, Carol; Harvey, Alan L.; Edrada-Ebel, Ruangelie; de Witte, Peter A. M.; Crawford, Alexander D.; Esguerra, Camila V.

2013-01-01

Zebrafish have recently emerged as an attractive model for the in vivo bioassay-guided isolation and characterization of pharmacologically active small molecules of natural origin. We carried out a zebrafish-based phenotypic screen of over 3000 plant-derived secondary metabolite extracts with the goal of identifying novel small-molecule modulators of the BMP and Wnt signaling pathways. One of the bioactive plant extracts identified in this screen – Jasminum gilgianum, an Oleaceae species native to Papua New Guinea – induced ectopic tails during zebrafish embryonic development. As ectopic tail formation occurs when BMP or non-canonical Wnt signaling is inhibited during the tail protrusion process, we suspected a constituent of this extract to act as a modulator of these pathways. A bioassay-guided isolation was carried out on the basis of this zebrafish phenotype, identifying para-coumaric acid methyl ester (pCAME) as the active compound. We then performed an in-depth phenotypic analysis of pCAME-treated zebrafish embryos, including a tissue-specific marker analysis of the secondary tails. We found pCAME to synergize with the BMP-inhibitors dorsomorphin and LDN-193189 in inducing ectopic tails, and causing convergence-extension defects in compound-treated embryos. These results indicate that pCAME may interfere with non-canonical Wnt signaling. Inhibition of Jnk, a downstream target of Wnt/PCP signaling (via morpholino antisense knockdown and pharmacological inhibition with the kinase inhibitor SP600125) phenocopied pCAME-treated embryos. However, immunoblotting experiments revealed pCAME to not directly inhibit Jnk-mediated phosphorylation of c-Jun, suggesting additional targets of SP600125, and/or other pathways, as possibly being involved in the ectopic tail formation activity of pCAME. Further investigation of pCAME’s mechanism of action will help determine this compound’s pharmacological utility. PMID:24349481

Effects of Pharmacological Inhibition and Genetic Deficiency of Plasminogen Activator Inhibitor-1 in Radiation-Induced Intestinal Injury

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abderrahmani, Rym; Francois, Agnes; Buard, Valerie

2009-07-01

Purpose: To investigate effects of plasminogen activator inhibitor 1 (PAI-1) genetic deficiency and pharmacological PAI-1 inhibition with PAI-039 in a mouse model of radiation-induced enteropathy. Methods and Materials: Wild-type (Wt) and PAI-1{sup -/-} knockout mice received a single dose of 19 Gy to an exteriorized localized intestinal segment. Sham and irradiated Wt mice were treated orally with 1 mg/g of PAI-039. Histological modifications were quantified using a radiation injury score. Moreover, intestinal gene expression was monitored by real-time PCR. Results: At 3 days after irradiation, PAI-039 abolished the radiation-induced increase in the plasma active form of PAI-1 and limited themore » radiation-induced gene expression of transforming growth factor {beta}1 (TGF-{beta}1), CTGF, PAI-1, and COL1A2. Moreover, PAI-039 conferred temporary protection against early lethality. PAI-039 treatment limited the radiation-induced increase of CTGF and PAI-1 at 2 weeks after irradiation but had no effect at 6 weeks. Radiation injuries were less severe in PAI-1{sup -/-} mice than in Wt mice, and despite the beneficial effect, 3 days after irradiation, PAI-039 had no effects on microscopic radiation injuries compared to untreated Wt mice. Conclusions: A genetic deficiency of PAI-1 is associated with amelioration of late radiation enteropathy. Pharmacological inhibition of PAI-1 by PAI-039 positively impacts the early, acute phase increase in plasma PAI-1 and the associated radiation-induced gene expression of inflammatory/extracellular matrix proteins. Since PAI-039 has been shown to inhibit the active form of PAI-1, as opposed to the complete loss of PAI-1 in the knockout animals, these data suggest that a PAI-1 inhibitor could be beneficial in treating radiation-induced tissue injury in acute settings where PAI-1 is elevated.« less

The Autophagy-Senescence Connection in Chemotherapy: Must Tumor Cells (Self) Eat Before They Sleep?

PubMed Central

Goehe, Rachel W.; Di, Xu; Sharma, Khushboo; Bristol, Molly L.; Henderson, Scott C.; Valerie, Kristoffer; Rodier, Francis; Davalos, Albert R.

2012-01-01

Exposure of MCF-7 breast tumor cells or HCT-116 colon carcinoma cells to clinically relevant concentrations of doxorubicin (Adriamycin; Farmitalia Research Laboratories, Milan, Italy) or camptothecin results in both autophagy and senescence. To determine whether autophagy is required for chemotherapy-induced senescence, reactive oxygen generation induced by Adriamycin was suppressed by N-acetyl cysteine and glutathione, and the induction of ataxia telangiectasia mutated, p53, and p21 was modulated pharmacologically and/or genetically. In all cases, autophagy and senescence were collaterally suppressed. The close association between autophagy and senescence indicated by these experiments reflects their collateral regulation via common signaling pathways. The potential relationship between autophagy and senescence was further examined through pharmacologic inhibition of autophagy with chloroquine and 3-methyl-adenine and genetic ablation of the autophagy-related genes ATG5 and ATG7. However, inhibition of autophagy by pharmacological and genetic approaches could not entirely abrogate the senescence response, which was only reduced and/or delayed. Taken together, our findings suggest that autophagy and senescence tend to occur in parallel, and furthermore that autophagy accelerates the development of the senescent phenotype. However, these responses are not inexorably linked or interdependent, as senescence can occur when autophagy is abrogated. PMID:22927544

Nitroglycerin drives endothelial nitric oxide synthase activation via the phosphatidylinositol 3-kinase/protein kinase B pathway

PubMed Central

Mao, Mao; Sudhahar, Varadarajan; Ansenberger-Fricano, Kristine; Fernandes, Denise C.; Tanaka, Leonardo Y.; Fukai, Tohru; Laurindo, Francisco R.M.; Mason, Ronald P.; Vasquez-Vivar, Jeannette; Minshall, Richard D.; Stadler, Krisztian; Bonini, Marcelo G.

2012-01-01

Nitroglycerin (GTN) has been clinically used to treat angina pectoris and acute heart episodes for over 100 years. The effects of GTN have long been recognized and active research has contributed to the unraveling of numerous metabolic routes capable of converting GTN to the potent vasoactive messenger nitric oxide. Recently, the mechanism by which minute doses of GTN elicit robust pharmacological responses was revisited and eNOS activation was implicated as an important route mediating vasodilation induced by low GTN doses (1–50 nM). Here, we demonstrate that at such concentrations the pharmacologic effects of nitroglycerin are largely dependent on the phosphatidylinositol 3-kinase, Akt/PKB, and phosphatase and tensin homolog deleted on chromosome 10 (PTEN) signal transduction axis. Furthermore, we demonstrate that nitroglycerin-dependent accumulation of 3,4,5-InsP3, probably because of inhibition of PTEN, is important for eNOS activation, conferring a mechanistic basis for GTN pharmacological action at pharmacologically relevant doses. PMID:22037515

Development of Personalized Cancer Therapy for Men with AdvancedProstate Cancer

DTIC Science & Technology

2016-10-01

propose to study the mechanism of pharmacologic inhibition of the MLL complex in prostate cancer cells 3) we will assess the in vivo efficacy of the...Project Goals: 1) Enroll patients with known or suspicious for prostate cancer in the NIH MRI /metabolic imaging program, 2) Whole exome and...Henderson 02/11/2014-01/31/2017 Project Goals: 1) Enroll patients with known or suspicious for prostate cancer in the NIH MRI /metabolic imaging program

Drug design strategies focusing on the CXCR4/CXCR7/CXCL12 pathway in leukemia and lymphoma.

PubMed

Barbieri, Federica; Bajetto, Adriana; Thellung, Stefano; Würth, Roberto; Florio, Tullio

2016-11-01

Chemokines control homing and trafficking of leukocytes in bone marrow and lymphoid organs. In particular, CXCL12 and its receptors CXCR4/CXCR7 control the homeostasis of multiple organs and systems. Their overexpression is linked to tumor development, both through a direct modulation of neoplastic cell proliferation, survival, and migration, and, indirectly, acting on the tumor microenvironment which sustains drug resistant tumor stem-like cells. Leukemia and lymphomas frequently display upregulation of CXCL12/CXCR4 in bone marrow that nurtures tumor cells, and confers resistance to conventional chemotherapy, increasing disease relapse. Areas covered: The authors review the molecular and cellular mechanisms by which the CXCL12/CXCR4-7 system supports leukemic bone marrow and how it contributes to leukemia development, and their potential pharmacological targeting. Besides receptor antagonists that directly inhibit leukemic cell proliferation, preclinical and clinical studies demonstrate that CXCR4 inhibition mobilizes leukemic-lymphoma cells from their niches, improving conventional chemotherapy efficacy. Clinically available and experimental pharmacological tools targeting CXCR4/CXCR7 are also described. Expert opinion: Studies have revealed the therapeutic efficacy of combining CXCR4 inhibitors and cytotoxic agents to sensitize leukemic cells, and overcome natural or acquired resistance. However, several issues are still to be unveiled (for example the role of CXCR7) to maximize therapeutic response and reduce potential toxicities.

AMP-activated protein kinase and adenosine are both metabolic modulators that regulate chloride secretion in the shark rectal gland ( Squalus acanthias).

PubMed

Neuman, Rugina I; van Kalmthout, Juliette A M; Pfau, Daniel J; Menendez, Dhariyat M; Young, Lawrence H; Forrest, John N

2018-04-01

The production of endogenous adenosine during secretagogue stimulation of CFTR leads to feedback inhibition limiting further chloride secretion in the rectal gland of the dogfish shark (Squalus acanthias). In the present study, we examined the role of AMP-kinase (AMPK) as an energy sensor also modulating chloride secretion through CFTR. We found that glands perfused with forskolin and isobutylmethylxanthine (F + I), potent stimulators of chloride secretion in this ancient model, caused significant phosphorylation of the catalytic subunit Thr 172 of AMPK. These findings indicate that AMPK is activated during energy-requiring stimulated chloride secretion. In molecular studies, we confirmed that the activating Thr 172 site is indeed present in the α-catalytic subunit of AMPK in this ancient gland, which reveals striking homology to AMPKα subunits sequenced in other vertebrates. When perfused rectal glands stimulated with F + I were subjected to severe hypoxic stress or perfused with pharmacologic inhibitors of metabolism (FCCP or oligomycin), phosphorylation of AMPK Thr 172 was further increased and chloride secretion was dramatically diminished. The pharmacologic activation of AMPK with AICAR-inhibited chloride secretion, as measured by short-circuit current, when applied to the apical side of shark rectal gland monolayers in primary culture. These results indicate that that activated AMPK, similar to adenosine, transmits an inhibitory signal from metabolism, that limits chloride secretion in the shark rectal gland.

Phenotypic assessment of THC discriminative stimulus properties in fatty acid amide hydrolase knockout and wildtype mice.

PubMed

Walentiny, D Matthew; Vann, Robert E; Wiley, Jenny L

2015-06-01

A number of studies have examined the ability of the endogenous cannabinoid anandamide to elicit Δ(9)-tetrahydrocannabinol (THC)-like subjective effects, as modeled through the THC discrimination paradigm. In the present study, we compared transgenic mice lacking fatty acid amide hydrolase (FAAH), the enzyme primarily responsible for anandamide catabolism, to wildtype counterparts in a THC discrimination procedure. THC (5.6 mg/kg) served as a discriminative stimulus in both genotypes, with similar THC dose-response curves between groups. Anandamide fully substituted for THC in FAAH knockout, but not wildtype, mice. Conversely, the metabolically stable anandamide analog O-1812 fully substituted in both groups, but was more potent in knockouts. The CB1 receptor antagonist rimonabant dose-dependently attenuated THC generalization in both groups and anandamide substitution in FAAH knockouts. Pharmacological inhibition of monoacylglycerol lipase (MAGL), the primary catabolic enzyme for the endocannabinoid 2-arachidonoylglycerol (2-AG), with JZL184 resulted in full substitution for THC in FAAH knockout mice and nearly full substitution in wildtypes. Quantification of brain endocannabinoid levels revealed expected elevations in anandamide in FAAH knockout mice compared to wildtypes and equipotent dose-dependent elevations in 2-AG following JZL184 administration. Dual inhibition of FAAH and MAGL with JZL195 resulted in roughly equipotent increases in THC-appropriate responding in both groups. While the notable similarity in THC's discriminative stimulus effects across genotype suggests that the increased baseline brain anandamide levels (as seen in FAAH knockout mice) do not alter THC's subjective effects, FAAH knockout mice are more sensitive to the THC-like effects of pharmacologically induced increases in anandamide and MAGL inhibition (e.g., JZL184). Copyright © 2015 Elsevier Ltd. All rights reserved.

A Novel Pharmacologic Activity of Ketorolac for Therapeutic Benefit in Ovarian Cancer Patients.

PubMed

Guo, Yuna; Kenney, S Ray; Cook, Linda; Adams, Sarah F; Rutledge, Teresa; Romero, Elsa; Oprea, Tudor I; Sklar, Larry A; Bedrick, Edward; Wiggins, Charles L; Kang, Huining; Lomo, Lesley; Muller, Carolyn Y; Wandinger-Ness, Angela; Hudson, Laurie G

2015-11-15

We previously identified the R-enantiomer of ketorolac as an inhibitor of the Rho-family GTPases Rac1 and Cdc42. Rac1 and Cdc42 regulate cancer-relevant functions, including cytoskeleton remodeling necessary for tumor cell adhesion and migration. This study investigated whether administration of racemic (R,S) ketorolac after ovarian cancer surgery leads to peritoneal distribution of R-ketorolac, target GTPase inhibition in cells retrieved from the peritoneal cavity, and measureable impact on patient outcomes. Eligible patients had suspected advanced-stage ovarian, fallopian tube or primary peritoneal cancer. Secondary eligibility was met when ovarian cancer was confirmed and optimally debulked, an intraperitoneal port was placed, and there were no contraindications for ketorolac administration. R- and S-ketorolac were measured in serum and peritoneal fluid, and GTPase activity was measured in peritoneal cells. A retrospective study correlated perioperative ketorolac and ovarian cancer-specific survival in ovarian cancer cases. Elevated expression and activity of Rac1 and Cdc42 was detected in ovarian cancer patient tissues, confirming target relevance. Ketorolac in peritoneal fluids was enriched in the R-enantiomer and peritoneal cell GTPase activity was inhibited after ketorolac administration when R-ketorolac was at peak levels. After adjusting for age, AJCC stage, completion of chemotherapy, and neoadjuvant therapy, women given perioperative ketorolac had a lower hazard of death (HR, 0.30; 95% confidence interval, 0.11-0.88). Ketorolac has a novel pharmacologic activity conferred by the R-enantiomer and R-ketorolac achieves sufficient levels in the peritoneal cavity to inhibit Rac1 and Cdc42, potentially contributing to the observed survival benefit in women who received ketorolac. ©2015 American Association for Cancer Research.

A novel pharmacologic activity of ketorolac for therapeutic benefit in ovarian cancer patients

PubMed Central

Guo, Yuna; Kenney, S. Ray; Cook, Linda; Adams, Sarah F.; Rutledge, Teresa; Romero, Elsa; Oprea, Tudor I.; Sklar, Larry A.; Bedrick, Edward; Wiggins, Charles L.; Kang, Huining; Lomo, Lesley; Muller, Carolyn Y.; Wandinger-Ness, Angela; Hudson, Laurie G.

2015-01-01

PURPOSE We previously identified the R-enantiomer of ketorolac as an inhibitor of the Rho-family GTPases Rac1 and Cdc42. Rac1 and Cdc42 regulate cancer-relevant functions including cytoskeleton remodeling necessary for tumor cell adhesion and migration. This study investigated whether administration of racemic (R,S) ketorolac after ovarian cancer surgery leads to peritoneal distribution of R-ketorolac, target GTPase inhibition in cells retrieved from the peritoneal cavity, and measureable impact on patient outcomes. EXPERIMENTAL DESIGN Eligible patients had suspected advanced stage ovarian, fallopian tube or primary peritoneal cancer. Secondary eligibility was met when ovarian cancer was confirmed and optimally debulked, an intraperitoneal port was placed, and there were no contraindications for ketorolac administration. R- and S-ketorolac were measured in serum and peritoneal fluid, and GTPase activity was measured in peritoneal cells. A retrospective study correlated peri-operative ketorolac and ovarian cancer-specific survival in ovarian cancer cases. RESULTS Elevated expression and activity of Rac1 and Cdc42 was detected in ovarian cancer patient tissues, confirming target relevance. Ketorolac in peritoneal fluids was enriched in the R-enantiomer and peritoneal cell GTPase activity was inhibited after ketorolac administration when R-ketorolac was at peak levels. After adjusting for age, AJCC stage, completion of chemotherapy, and neo-adjuvant therapy, women given peri-operative ketorolac had a lower hazard of death (Hazard Ratio=0.30 [95%CI 0.11–0.88]). CONCLUSION Ketorolac has a novel pharmacologic activity conferred by the R-enantiomer and R-ketorolac achieves sufficient levels in the peritoneal cavity to inhibit Rac1 and Cdc42, potentially contributing to the observed survival benefit in women who received ketorolac. PMID:26071482

The Canonical Wnt Pathway Drives Macropinocytosis in Cancer.

PubMed

Redelman-Sidi, Gil; Binyamin, Anna; Gaeta, Isabella; Palm, Wilhelm; Thompson, Craig B; Romesser, Paul B; Lowe, Scott W; Bagul, Mukta; Doench, John G; Root, David E; Glickman, Michael S

2018-06-05

Macropinocytosis has emerged as an important pathway of protein acquisition in cancer cells, particularly in tumors with activated Ras such as pancreatic and colon cancer. Macropinocytosis is also the route of entry of Bacillus Calmette-Guerin (BCG) and other microbial therapies of cancer. Despite this important role in tumor biology and therapy, the full mechanisms by which cancer cells can activate macropinocytosis remain incompletely defined. Using BCG uptake to assay macropinocytosis, we executed a genome-wide shRNA screen for macropinocytosis activators and identified Wnt pathway activation as a strong driver of macropinocytosis. Wnt-driven macropinocytosis was downstream of the beta catenin-dependent canonical Wnt pathway, was Pak1 dependent, and supported albumin-dependent growth in Ras-WT cells. In cells with activated Ras-dependent macropinocytosis, pharmacologic or genetic inhibition of Wnt signaling suppressed macropinocytosis. In a mouse model of Wnt-driven colonic hyperplasia via APC silencing, Wnt-activated macropinocytosis stimulated uptake of luminal microbiota, a process reversed by topical pharmacologic inhibition of macropinocytosis. Our findings indicate that Wnt pathway activation drives macropinocytosis in cancer, and its inhibition could provide a therapeutic vulnerability in Wnt-driven intestinal polyposis and cancers with Wnt activation. Copyright ©2018, American Association for Cancer Research.

Physico-chemical characterization and pharmacological activities of sulfated polysaccharide from sea urchin, Paracentrotus lividus.

PubMed

Salem, Yosra Ben; Amri, Safa; Hammi, Khaoula Mkadmini; Abdelhamid, Amal; Cerf, Didier Le; Bouraoui, Abderrahman; Majdoub, Hatem

2017-04-01

Sulfated polysaccharide (SP) from the eggs of sea urchin Paracentrotus lividus, extracted by papain digestion, was characterized by size exclusion chromatography coupling on-line with light scattering and viscosity detectors (SEC/MALS/VD/DRI), gas chromatography coupled to mass spectrometer (GC-MS), and Fourier transform infrared spectroscopy (FTIR) analysis. The native molecular mass of the extracted polysaccharide is high (≥22 000 KDa) and it is composed mainly of arabinose, accompanied by other monosaccharides (mostly galactose, glucose and fucose), significant amounts of uronic acids (18.4%) and relatively high proportions of sulfate (22.4%). The pharmacological evaluation of SP showed a significant in vivo anti-inflammatory activity (p<0.001), 3h after injection, the edema inhibition was 75.8% at the dose of 100mg/Kg; a significant peripheral analgesic activity (p<0.001), with 64.9% of writhing inhibition, and a significant increase in the hot plate reaction time in mice indicating central analgesic activity. In addition, an interesting gastroprotective effect was observed with this polysaccharide; the gastric ulcer inhibition was 69.7%, at the dose of 100mg/Kg. Copyright © 2017 Elsevier B.V. All rights reserved.

ATG7 regulates energy metabolism, differentiation and survival of Philadelphia-chromosome-positive cells

PubMed Central

Karvela, Maria; Baquero, Pablo; Kuntz, Elodie M.; Mukhopadhyay, Arunima; Mitchell, Rebecca; Allan, Elaine K.; Chan, Edmond; Kranc, Kamil R.; Calabretta, Bruno; Salomoni, Paolo; Gottlieb, Eyal; Holyoake, Tessa L.; Helgason, G. Vignir

2016-01-01

ABSTRACT A major drawback of tyrosine kinase inhibitor (TKI) treatment in chronic myeloid leukemia (CML) is that primitive CML cells are able to survive TKI-mediated BCR-ABL inhibition, leading to disease persistence in patients. Investigation of strategies aiming to inhibit alternative survival pathways in CML is therefore critical. We have previously shown that a nonspecific pharmacological inhibition of autophagy potentiates TKI-induced death in Philadelphia chromosome-positive cells. Here we provide further understanding of how specific and pharmacological autophagy inhibition affects nonmitochondrial and mitochondrial energy metabolism and reactive oxygen species (ROS)-mediated differentiation of CML cells and highlight ATG7 (a critical component of the LC3 conjugation system) as a potential specific therapeutic target. By combining extra- and intracellular steady state metabolite measurements by liquid chromatography-mass spectrometry with metabolic flux assays using labeled glucose and functional assays, we demonstrate that knockdown of ATG7 results in decreased glycolysis and increased flux of labeled carbons through the mitochondrial tricarboxylic acid cycle. This leads to increased oxidative phosphorylation and mitochondrial ROS accumulation. Furthermore, following ROS accumulation, CML cells, including primary CML CD34+ progenitor cells, differentiate toward the erythroid lineage. Finally, ATG7 knockdown sensitizes CML progenitor cells to TKI-induced death, without affecting survival of normal cells, suggesting that specific inhibitors of ATG7 in combination with TKI would provide a novel therapeutic approach for CML patients exhibiting persistent disease. PMID:27168493

Inhibition of the TGF-β receptor I kinase promotes hematopoiesis in MDS

PubMed Central

Zhou, Li; Nguyen, Aaron N.; Sohal, Davendra; Ying Ma, Jing; Pahanish, Perry; Gundabolu, Krishna; Hayman, Josh; Chubak, Adam; Mo, Yongkai; Bhagat, Tushar D.; Das, Bhaskar; Kapoun, Ann M.; Navas, Tony A.; Parmar, Simrit; Kambhampati, Suman; Pellagatti, Andrea; Braunchweig, Ira; Zhang, Ying; Wickrema, Amittha; Medicherla, Satyanarayana; Boultwood, Jacqueline; Platanias, Leonidas C.; Higgins, Linda S.; List, Alan F.; Bitzer, Markus

2008-01-01

MDS is characterized by ineffective hematopoiesis that leads to peripheral cytopenias. Development of effective treatments has been impeded by limited insight into pathogenic pathways governing dysplastic growth of hematopoietic progenitors. We demonstrate that smad2, a downstream mediator of transforming growth factor–β (TGF-β) receptor I kinase (TBRI) activation, is constitutively activated in MDS bone marrow (BM) precursors and is overexpressed in gene expression profiles of MDS CD34+ cells, providing direct evidence of overactivation of TGF-β pathway in this disease. Suppression of the TGF-β signaling by lentiviral shRNA-mediated down-regulation of TBRI leads to in vitro enhancement of hematopoiesis in MDS progenitors. Pharmacologic inhibition of TBRI (alk5) kinase by a small molecule inhibitor, SD-208, inhibits smad2 activation in hematopoietic progenitors, suppresses TGF-β–mediated gene activation in BM stromal cells, and reverses TGF-β–mediated cell-cycle arrest in BM CD34+ cells. Furthermore, SD-208 treatment alleviates anemia and stimulates hematopoiesis in vivo in a novel murine model of bone marrow failure generated by constitutive hepatic expression of TGF-β1. Moreover, in vitro pharmacologic inhibition of TBRI kinase leads to enhancement of hematopoiesis in varied morphologic MDS subtypes. These data directly implicate TGF-β signaling in the pathobiology of ineffective hematopoiesis and identify TBRI as a potential therapeutic target in low-risk MDS. PMID:18474728

Functional and physical interaction between Bcl-XL and a BH3-like domain in Beclin-1

PubMed Central

Maiuri, M Chiara; Le Toumelin, Gaëtane; Criollo, Alfredo; Rain, Jean-Christophe; Gautier, Fabien; Juin, Philippe; Tasdemir, Ezgi; Pierron, Gérard; Troulinaki, Kostoula; Tavernarakis, Nektarios; Hickman, John A; Geneste, Olivier; Kroemer, Guido

2007-01-01

The anti-apoptotic proteins Bcl-2 and Bcl-XL bind and inhibit Beclin-1, an essential mediator of autophagy. Here, we demonstrate that this interaction involves a BH3 domain within Beclin-1 (residues 114–123). The physical interaction between Beclin-1 and Bcl-XL is lost when the BH3 domain of Beclin-1 or the BH3 receptor domain of Bcl-XL is mutated. Mutation of the BH3 domain of Beclin-1 or of the BH3 receptor domain of Bcl-XL abolishes the Bcl-XL-mediated inhibition of autophagy triggered by Beclin-1. The pharmacological BH3 mimetic ABT737 competitively inhibits the interaction between Beclin-1 and Bcl-2/Bcl-XL, antagonizes autophagy inhibition by Bcl-2/Bcl-XL and hence stimulates autophagy. Knockout or knockdown of the BH3-only protein Bad reduces starvation-induced autophagy, whereas Bad overexpression induces autophagy in human cells. Gain-of-function mutation of the sole BH3-only protein from Caenorhabditis elegans, EGL-1, induces autophagy, while deletion of EGL-1 compromises starvation-induced autophagy. These results reveal a novel autophagy-stimulatory function of BH3-only proteins beyond their established role as apoptosis inducers. BH3-only proteins and pharmacological BH3 mimetics induce autophagy by competitively disrupting the interaction between Beclin-1 and Bcl-2 or Bcl-XL. PMID:17446862

Building muscle, browning fat and preventing obesity by inhibiting myostatin.

PubMed

Lebrasseur, N K

2012-01-01

The obesity epidemic is an overwhelming global health concern. Interventions to improve body weight and composition aim to restore balance between nutrient intake and energy expenditure. Myostatin, a powerful negative regulator of skeletal muscle mass, has emerged as a potential therapeutic target for obesity and type 2 diabetes mellitus because of the prominent role skeletal muscle plays in metabolic rate and insulin-mediated glucose disposal. In fact, inhibition of myostatin by genetic manipulation or pharmacological means leads to a hypermuscular and very lean build in mice. The resistance of myostatin-null mice to diet-induced obesity, fat mass accumulation and metabolic dysfunction has been presumed to be a result of their large skeletal muscle mass; however, in this issue of Diabetologia, Zhang et al. (doi: 10.1007/s00125-011-2304-4 ) provide evidence that myostatin inhibition also significantly impacts the phenotype of white adipose tissue (WAT). The authors reveal elevated expression of key metabolic genes of fatty acid transport and oxidation and, intriguingly, the presence of brown adipose tissue-like cells in WAT of myostatin-null mice. They also show that pharmacological inhibition of myostatin replicates several of the protective benefits conveyed by its genetic inactivation. Herein, these data, areas in need of further investigation and the evidence that implicates myostatin as a target for obesity and type 2 diabetes mellitus are discussed.

Pharmacology and toxicology of pahayokolide A, a bioactive metabolite from a freshwater species of Lyngbya isolated from the Florida Everglades

PubMed Central

Berry, John P.; Gantar, Miroslav; Gawley, Robert E.; Wang, Minglei; Rein, Kathleen S.

2008-01-01

The genus of filamentous cyanobacteria, Lyngbya, has been found to be a rich source of bioactive metabolites. However, identification of such compounds from Lyngbya has largely focused on a few marine representatives. Here, we report on the pharmacology and toxicology of pahayokolide A from a freshwater isolate, Lyngbya sp. strain 15−2, from the Florida Everglades. Specifically, we investigated inhibition of microbial representatives and mammalian cell lines, as well as toxicity of the compound to both invertebrate and vertebrate models. Pahayokolide A inhibited representatives of Bacillus, as well as the yeast, Saccharomyces cerevisiae. Interestingly, the compound also inhibited several representatives of green algae that were also isolated from the Everglades. Pahayokolide A was shown to inhibit a number of cancer cell lines over a range of concentrations (IC50 varied from 2.13 to 44.57 μM) depending on the cell-type. When tested against brine shrimp, pahayokolide was only marginally toxic at the highest concentrations tested (1 mg/mL). The compound was, however, acutely toxic to zebrafish embryos (LC50=2.15 μM). Possible biomedical and environmental health aspects of the pahayokolides remain to be investigated; however, the identification of bioactive metabolites such as these demonstrates the potential of the Florida Everglades as source of new toxins and drugs. PMID:15683832

Optimising the combination dosing strategy of abemaciclib and vemurafenib in BRAF-mutated melanoma xenograft tumours

PubMed Central

Tate, Sonya C; Burke, Teresa F; Hartman, Daisy; Kulanthaivel, Palaniappan; Beckmann, Richard P; Cronier, Damien M

2016-01-01

Background: Resistance to BRAF inhibition is a major cause of treatment failure for BRAF-mutated metastatic melanoma patients. Abemaciclib, a cyclin-dependent kinase 4 and 6 inhibitor, overcomes this resistance in xenograft tumours and offers a promising drug combination. The present work aims to characterise the quantitative pharmacology of the abemaciclib/vemurafenib combination using a semimechanistic pharmacokinetic/pharmacodynamic modelling approach and to identify an optimum dosing regimen for potential clinical evaluation. Methods: A PK/biomarker model was developed to connect abemaciclib/vemurafenib concentrations to changes in MAPK and cell cycle pathway biomarkers in A375 BRAF-mutated melanoma xenografts. Resultant tumour growth inhibition was described by relating (i) MAPK pathway inhibition to apoptosis, (ii) mitotic cell density to tumour growth and, under resistant conditions, (iii) retinoblastoma protein inhibition to cell survival. Results: The model successfully described vemurafenib/abemaciclib-mediated changes in MAPK pathway and cell cycle biomarkers. Initial tumour shrinkage by vemurafenib, acquisition of resistance and subsequent abemaciclib-mediated efficacy were successfully captured and externally validated. Model simulations illustrate the benefit of intermittent vemurafenib therapy over continuous treatment, and indicate that continuous abemaciclib in combination with intermittent vemurafenib offers the potential for considerable tumour regression. Conclusions: The quantitative pharmacology of the abemaciclib/vemurafenib combination was successfully characterised and an optimised, clinically-relevant dosing strategy was identified. PMID:26978007

Involvement of PPAR-γ in the neuroprotective and anti-inflammatory effects of angiotensin type 1 receptor inhibition: effects of the receptor antagonist telmisartan and receptor deletion in a mouse MPTP model of Parkinson's disease.

PubMed

Garrido-Gil, Pablo; Joglar, Belen; Rodriguez-Perez, Ana I; Guerra, Maria J; Labandeira-Garcia, Jose L

2012-02-22

Several recent studies have shown that angiotensin type 1 receptor (AT1) antagonists such as candesartan inhibit the microglial inflammatory response and dopaminergic cell loss in animal models of Parkinson's disease. However, the mechanisms involved in the neuroprotective and anti-inflammatory effects of AT1 blockers in the brain have not been clarified. A number of studies have reported that AT1 blockers activate peroxisome proliferator-activated receptor gamma (PPAR γ). PPAR-γ activation inhibits inflammation, and may be responsible for neuroprotective effects, independently of AT1 blocking actions. We have investigated whether oral treatment with telmisartan (the most potent PPAR-γ activator among AT1 blockers) provides neuroprotection against dopaminergic cell death and neuroinflammation, and the possible role of PPAR-γ activation in any such neuroprotection. We used a mouse model of parkinsonism induced by the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and co-administration of the PPAR-γ antagonist GW9662 to study the role of PPAR-γ activation. In addition, we used AT1a-null mice lesioned with MPTP to study whether deletion of AT1 in the absence of any pharmacological effect of AT1 blockers provides neuroprotection, and investigated whether PPAR-γ activation may also be involved in any such effect of AT1 deletion by co-administration of the PPAR-γ antagonist GW9662. We observed that telmisartan protects mouse dopaminergic neurons and inhibits the microglial response induced by administration of MPTP. The protective effects of telmisartan on dopaminergic cell death and microglial activation were inhibited by co-administration of GW9662. Dopaminergic cell death and microglial activation were significantly lower in AT1a-null mice treated with MPTP than in mice not subjected to AT1a deletion. Interestingly, the protective effects of AT1 deletion were also inhibited by co-administration of GW9662. The results suggest that telmisartan provides effective neuroprotection against dopaminergic cell death and that the neuroprotective effect is mediated by PPAR-γ activation. However, the results in AT1-deficient mice show that blockage of AT1, unrelated to the pharmacological properties of AT1 blockers, also protects against dopaminergic cell death and neuroinflammation. Furthermore, the results show that PPAR-γ activation is involved in the anti-inflammatory and neuroprotective effects of AT1 deletion.

Oridonin Suppresses Proliferation of Human Ovarian Cancer Cells via Blockage of mTOR Signaling.

PubMed

Xia, Rong; Chen, Sun-Xiao; Qin, Qin; Chen, Yan; Zhang, Wei-Wei; Zhu, Rong-Rong; Deng, An-Mei

2016-01-01

Oridonin, an ent-kaurane diterpenoid compound isolated from the traditional Chinese herb Rabdosia rubescens, has shown various pharmacological and physiological effects such as anti-tumor, anti-bacterial, and anti-inflammatory properties. However, the effect of oridonin on human ovarian cancer cell lines has not been determined. In this study, we demonstrated that oridonin inhibited ovarian cancer cell proliferation, migration and invasion in a dose-dependent manner. Furthermore, we showed oridonin inhibited tumor growth of ovarian cancer cells (SKOV3) in vivo. We then assessed mechanisms and found that oridonin specifically abrogated the phosphorylation/activation of mTOR signaling. In summary, our results indicate that oridonin is a potential inhibitor of ovarian cancer by blocking the mTOR signaling pathway.

Use of systems pharmacology modeling to elucidate the operating characteristics of SGLT1 and SGLT2 in renal glucose reabsorption in humans

PubMed Central

Lu, Yasong; Griffen, Steven C.; Boulton, David W.; Leil, Tarek A.

2014-01-01

In the kidney, glucose in glomerular filtrate is reabsorbed primarily by sodium-glucose cotransporters 1 (SGLT1) and 2 (SGLT2) along the proximal tubules. SGLT2 has been characterized as a high capacity, low affinity pathway responsible for reabsorption of the majority of filtered glucose in the early part of proximal tubules, and SGLT1 reabsorbs the residual glucose in the distal part. Inhibition of SGLT2 is a viable mechanism for removing glucose from the body and improving glycemic control in patients with diabetes. Despite demonstrating high levels (in excess of 80%) of inhibition of glucose transport by SGLT2 in vitro, potent SGLT2 inhibitors, e.g., dapagliflozin and canagliflozin, inhibit renal glucose reabsorption by only 30–50% in clinical studies. Hypotheses for this apparent paradox are mostly focused on the compensatory effect of SGLT1. The paradox has been explained and the role of SGLT1 demonstrated in the mouse, but direct data in humans are lacking. To further explore the roles of SGLT1/2 in renal glucose reabsorption in humans, we developed a systems pharmacology model with emphasis on SGLT1/2 mediated glucose reabsorption and the effects of SGLT2 inhibition. The model was calibrated using robust clinical data in the absence or presence of dapagliflozin (DeFronzo et al., 2013), and evaluated against clinical data from the literature (Mogensen, 1971; Wolf et al., 2009; Polidori et al., 2013). The model adequately described all four data sets. Simulations using the model clarified the operating characteristics of SGLT1/2 in humans in the healthy and diabetic state with or without SGLT2 inhibition. The modeling and simulations support our proposition that the apparent moderate, 30–50% inhibition of renal glucose reabsorption observed with potent SGLT2 inhibitors is a combined result of two physiological determinants: SGLT1 compensation and residual SGLT2 activity. This model will enable in silico inferences and predictions related to SGLT1/2 modulation. PMID:25540623

Use of systems pharmacology modeling to elucidate the operating characteristics of SGLT1 and SGLT2 in renal glucose reabsorption in humans.

PubMed

Lu, Yasong; Griffen, Steven C; Boulton, David W; Leil, Tarek A

2014-01-01

In the kidney, glucose in glomerular filtrate is reabsorbed primarily by sodium-glucose cotransporters 1 (SGLT1) and 2 (SGLT2) along the proximal tubules. SGLT2 has been characterized as a high capacity, low affinity pathway responsible for reabsorption of the majority of filtered glucose in the early part of proximal tubules, and SGLT1 reabsorbs the residual glucose in the distal part. Inhibition of SGLT2 is a viable mechanism for removing glucose from the body and improving glycemic control in patients with diabetes. Despite demonstrating high levels (in excess of 80%) of inhibition of glucose transport by SGLT2 in vitro, potent SGLT2 inhibitors, e.g., dapagliflozin and canagliflozin, inhibit renal glucose reabsorption by only 30-50% in clinical studies. Hypotheses for this apparent paradox are mostly focused on the compensatory effect of SGLT1. The paradox has been explained and the role of SGLT1 demonstrated in the mouse, but direct data in humans are lacking. To further explore the roles of SGLT1/2 in renal glucose reabsorption in humans, we developed a systems pharmacology model with emphasis on SGLT1/2 mediated glucose reabsorption and the effects of SGLT2 inhibition. The model was calibrated using robust clinical data in the absence or presence of dapagliflozin (DeFronzo et al., 2013), and evaluated against clinical data from the literature (Mogensen, 1971; Wolf et al., 2009; Polidori et al., 2013). The model adequately described all four data sets. Simulations using the model clarified the operating characteristics of SGLT1/2 in humans in the healthy and diabetic state with or without SGLT2 inhibition. The modeling and simulations support our proposition that the apparent moderate, 30-50% inhibition of renal glucose reabsorption observed with potent SGLT2 inhibitors is a combined result of two physiological determinants: SGLT1 compensation and residual SGLT2 activity. This model will enable in silico inferences and predictions related to SGLT1/2 modulation.

Tangeretin and its metabolite 4'-hydroxytetramethoxyflavone attenuate EGF-stimulated cell cycle progression in hepatocytes; role of inhibition at the level of mTOR/p70S6K.

PubMed

Cheng, Z; Surichan, S; Ruparelia, K; Arroo, R; Boarder, M R

2011-04-01

The mechanisms by which the dietary compound tangeretin has anticancer effects may include acting as a prodrug, forming an antiproliferative product in cancer cells. Here we show that tangeretin also inhibits cell cycle progression in hepatocytes and investigate the role of its primary metabolite 4'-hydroxy-5,6,7,8-tetramethoxyflavone (4'-OH-TMF) in this effect. We used epidermal growth factor (EGF)-stimulated rat hepatocytes, with [(3)H]-thymidine incorporation into DNA as an index of progression to S-phase of the cell cycle, and Western blots for phospho-proteins involved in the cell signalling cascade. Incubation of tangeretin with microsomes expressing CYP1A, or with hepatocytes, generated a primary product we identified as 4'-OH-TMF. Low micromolar concentrations of tangeretin or 4'-OH-TMF gave a concentration-dependent inhibition of EGF-stimulated progression to S-phase while having little effect on cell viability. To determine whether time for conversion of tangeretin to an active metabolite would enhance the inhibitory effect we used long pre-incubations; this reduced the inhibitory effect, in parallel with a reduction in the concentration of tangeretin. The EGF-stimulation of hepatocyte cell cycle progression requires signalling through Akt/mTOR/p70S6K kinase cascades. The tangeretin metabolite 4'-OH-TMF selectively inhibited S6K phosphorylation in the absence of significant inhibition of upstream Akt activity, suggesting an effect at the level of mTOR. Tangeretin and 4'-OH-TMF both inhibit cell cycle progression in primary hepatocytes. The inhibition of p70S6K phosphorylation by 4'-OH-TMF raises the possibility that inhibition of the mTOR pathway may contribute to the anticancer influence of a flavonoid-rich diet. © 2011 The Authors. British Journal of Pharmacology © 2011 The British Pharmacological Society.

Pre-clinical pharmacology of ICI D2138, a potent orally-active non-redox inhibitor of 5-lipoxygenase.

PubMed Central

McMillan, R. M.; Spruce, K. E.; Crawley, G. C.; Walker, E. R.; Foster, S. J.

1992-01-01

1. This paper describes the pre-clinical pharmacology of ICI D2138, a potent orally-active non-redox inhibitor of 5-lipoxygenase which is undergoing clinical evaluation. 2. ICI D2138 potently inhibited leukotriene synthesis in murine peritoneal macrophages (IC50 = 3 nM) and human blood (IC50 = 20 nM). In human and dog blood, ICI D2138 did not inhibit thromboxane B2 synthesis at a concentration of 500 microM, thus the selectivity ratio (cyclo-oxygenase: 5-lipoxygenase) was greater than 20,000. In contrast, zileuton (a 5-lipoxygenase inhibitor also undergoing clinical evaluation) exhibited a selectivity ratio of 15-100. 3. ICI D2138 potently and dose-dependently inhibited ex vivo leukotriene B4 (LTB4) synthesis by rat blood with ED50 values of 0.9, 4.0 and 80.0 mg kg-1 p.o. at 3, 10 and 20 h respectively after dosing. Similar activity was observed for inhibition of LTB4 production in a zymosan-inflamed rat air pouch model. Zileuton produced ED50 values of 5 and 20 mg kg-1 at 3 and 10 h respectively. 4. Oral administration of 1, 3 or 10 mg kg-1 ICI D2138 to dogs produced maximal inhibition of ex vivo LTB4 synthesis by blood for 5, 9 and 31 h respectively. A dose of 5 mg kg-1 p.o. of zileuton caused maximal inhibition of LTB4 for 24 h. 5. Oral administration of 10 mg kg-1 ICI D2138 caused total inhibition of LTB4 production in zymosan-inflamed rabbit knee joint. 6. Topical administration of ICI D2138 to rabbit skin caused a dose-related inhibition of arachidonic acid-induced plasma extravasation with an ID30 of 1.08 nmol per site.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1334748

Pharmacological and neuroprotective profile of an essential oil derived from leaves of Aloysia citrodora Palau.

PubMed

Abuhamdah, Sawsan; Abuhamdah, Rushdie; Howes, Melanie-Jayne R; Al-Olimat, Suleiman; Ennaceur, Abdel; Chazot, Paul L

2015-09-01

The Jordanian 'Melissa', (Aloysia citrodora) has been poorly studied both pharmacologically and in the clinic. Essential oils (EO) derived from leaves of A. citrodora were obtained by hydrodistillation, analysed by gas chromatography-mass spectrometry (GC-MS) and were investigated for a range of neurobiological and pharmacological properties, as a basis for potential future use in drug discovery. A selection of central nervous system (CNS) receptor-binding profiles was carried out. Antioxidant activity and ferrous iron-chelating assays were adopted, and the neuroprotective properties of A. citrodora EO assessed using hydrogen peroxide-induced and β-amyloid-induced neurotoxicity with the CAD (Cath.-a-differentiated) neuroblastoma cell line. The major chemical components detected in the A. citrodora EOs, derived from dried and fresh leaves, included limonene, geranial, neral, 1, 8-cineole, curcumene, spathulenol and caryophyllene oxide, respectively. A. citrodora leaf EO inhibited [(3) H] nicotine binding to well washed rat forebrain membranes, and increased iron-chelation in vitro. A. citrodora EO displays effective antioxidant, radical-scavenging activities and significant protective properties vs both hydrogen peroxide- and β-amyloid-induced neurotoxicity. A. citrodora EO displays a range of pharmacological properties worthy of further investigation to isolate the compounds responsible for the observed neuroactivities, to further analyse their mode of action and determine their clinical potential in neurodegenerative diseases. © 2015 Royal Pharmaceutical Society.

The Vesicular Monoamine Transporter-2: An Important Pharmacological Target for the Discovery of Novel Therapeutics to Treat Methamphetamine Abuse

PubMed Central

Nickell, Justin R.; Siripurapu, Kiran B.; Vartak, Ashish; Crooks, Peter A.; Dwoskin, Linda P.

2014-01-01

Methamphetamine abuse escalates, but no approved therapeutics are available to treat addicted individuals. Methamphetamine increases extracellular dopamine in reward-relevant pathways by interacting at vesicular monoamine transporter-2 (VMAT2) to inhibit dopamine uptake and promote dopamine release from synaptic vesicles, increasing cytosolic dopamine available for reverse transport by the dopamine transporter (DAT). VMAT2 is the target of our iterative drug discovery efforts to identify pharmacotherapeutics for methamphetamine addiction. Lobeline, the major alkaloid in Lobelia inflata, potently inhibited VMAT2, methamphetamine-evoked striatal dopamine release, and methamphetamine self-administration in rats but exhibited high affinity for nicotinic acetylcholine receptors (nAChRs). Defunctionalized, unsaturated lobeline analog, meso-transdiene (MTD), exhibited lobeline-like in vitro pharmacology, lacked nAChR affinity, but exhibited high affinity for DAT, suggesting potential abuse liability. The 2,4-dicholorophenyl MTD analog, UKMH-106, exhibited selectivity for VMAT2 over DAT, inhibited methamphetamine-evoked dopamine release, but required a difficult synthetic approach. Lobelane, a saturated, defunctionalized lobeline analog, inhibited the neurochemical and behavioral effects of methamphetamine; tolerance developed to the lobelane-induced decrease in methamphetamine self-administration. Improved drug-likeness was afforded by the incorporation of a chiral N-1,2-dihydroxypropyl moiety into lobelane to afford GZ-793A, which inhibited the neurochemical and behavioral effects of methamphetamine, without tolerance. From a series of 2,5-disubstituted pyrrolidine analogs, AV-2-192 emerged as a lead, exhibiting high affinity for VMAT2 and inhibiting methamphetamine-evoked dopamine release. Current results support the hypothesis that potent, selective VMAT2 inhibitors provide the requisite preclinical behavioral profile for evaluation as pharmacotherapeutics for methamphetamine abuse and emphasize selectivity for VMAT2 relative to DAT as a criterion for reducing abuse liability of the therapeutic. PMID:24484975

Disruption of mitochondrial electron transport chain function potentiates the pro-apoptotic effects of MAPK inhibition.

PubMed

Trotta, Andrew P; Gelles, Jesse D; Serasinghe, Madhavika N; Loi, Patrick; Arbiser, Jack L; Chipuk, Jerry E

2017-07-14

The mitochondrial network is a major site of ATP production through the coupled integration of the electron transport chain (ETC) with oxidative phosphorylation. In melanoma arising from the V600E mutation in the kinase v-RAF murine sarcoma viral oncogene homolog B (BRAF V600E ), oncogenic signaling enhances glucose-dependent metabolism while reducing mitochondrial ATP production. Likewise, when BRAF V600E is pharmacologically inhibited by targeted therapies ( e.g. PLX-4032/vemurafenib), glucose metabolism is reduced, and cells increase mitochondrial ATP production to sustain survival. Therefore, collateral inhibition of oncogenic signaling and mitochondrial respiration may help enhance the therapeutic benefit of targeted therapies. Honokiol (HKL) is a well tolerated small molecule that disrupts mitochondrial function; however, its underlying mechanisms and potential utility with targeted anticancer therapies remain unknown. Using wild-type BRAF and BRAF V600E melanoma model systems, we demonstrate here that HKL administration rapidly reduces mitochondrial respiration by broadly inhibiting ETC complexes I, II, and V, resulting in decreased ATP levels. The subsequent energetic crisis induced two cellular responses involving cyclin-dependent kinases (CDKs). First, loss of CDK1-mediated phosphorylation of the mitochondrial division GTPase dynamin-related protein 1 promoted mitochondrial fusion, thus coupling mitochondrial energetic status and morphology. Second, HKL decreased CDK2 activity, leading to G 1 cell cycle arrest. Importantly, although pharmacological inhibition of oncogenic MAPK signaling increased ETC activity, co-treatment with HKL ablated this response and vastly enhanced the rate of apoptosis. Collectively, these findings integrate HKL action with mitochondrial respiration and shape and substantiate a pro-survival role of mitochondrial function in melanoma cells after oncogenic MAPK inhibition.

Mitochondrial metabolism of pyruvate is essential for regulating glucose-stimulated insulin secretion.

PubMed

Patterson, Jessica N; Cousteils, Katelyn; Lou, Jennifer W; Manning Fox, Jocelyn E; MacDonald, Patrick E; Joseph, Jamie W

2014-05-09

It is well known that mitochondrial metabolism of pyruvate is critical for insulin secretion; however, we know little about how pyruvate is transported into mitochondria in β-cells. Part of the reason for this lack of knowledge is that the carrier gene was only discovered in 2012. In the current study, we assess the role of the recently identified carrier in the regulation of insulin secretion. Our studies show that β-cells express both mitochondrial pyruvate carriers (Mpc1 and Mpc2). Using both pharmacological inhibitors and siRNA-mediated knockdown of the MPCs we show that this carrier plays a key role in regulating insulin secretion in clonal 832/13 β-cells as well as rat and human islets. We also show that the MPC is an essential regulator of both the ATP-regulated potassium (KATP) channel-dependent and -independent pathways of insulin secretion. Inhibition of the MPC blocks the glucose-stimulated increase in two key signaling molecules involved in regulating insulin secretion, the ATP/ADP ratio and NADPH/NADP(+) ratio. The MPC also plays a role in in vivo glucose homeostasis as inhibition of MPC by the pharmacological inhibitor α-cyano-β-(1-phenylindol-3-yl)-acrylate (UK5099) resulted in impaired glucose tolerance. These studies clearly show that the newly identified mitochondrial pyruvate carrier sits at an important branching point in nutrient metabolism and that it is an essential regulator of insulin secretion.

Inhibition of endothelial cell expression of plasminogen activator inhibitor type-1 by gemfibrozil.

PubMed

Fujii, S; Sawa, H; Sobel, B E

1993-10-18

Increased concentrations of plasminogen activator inhibitor type-1 (PAI-1) in plasma are associated with impaired fibrinolysis and venous and arterial thrombo-embolic disease. In pilot studies designed to identify pharmacologic approaches capable of diminishing such increases, we found that gemfibrozil attenuated the stimulation of synthesis of PAI-1 in a human, immortal, hepatoma cell line (Hep G2) induced by platelets. The present study was performed to determine whether it exerts analogous effects in non-immortal endothelial cells and whether it may therefore facilitate fibrinolysis locally in vivo. Human umbilical vein endothelial cells were incubated with pharmacologic concentrations of gemfibrozil. Gemfibrozil, 100 microM, suppressed basal PAI-1 production by 15% and attenuated the augmentation of synthesis of PAI-1 induced by lysates from platelets (4 x 10(7)/ml) by 36% over 24 h without inhibiting overall protein synthesis. In addition, the increases in PAI-1 mRNA otherwise induced by platelet lysates over 6 h were suppressed by 49% (Northern blots) without any demonstrable change in the intracellular half-life of PAI-1 mRNA. Pulse-chase experiments demonstrated diminution of PAI-1 protein synthesis in parallel with the changes observed in PAI-1 mRNA. To determine whether these effects of gemfibrozil on endothelial cells in vitro were paralleled by consistent changes in the concentrations of PAI-1 in plasma in vivo, we studied rabbits with induced carotid artery thrombosis and thrombolysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluating the microbicidal, antiparasitic and antitumor effects of CR-LAAO from Calloselasma rhodostoma venom.

PubMed

Costa, Tássia R; Menaldo, Danilo L; Prinholato da Silva, Cássio; Sorrechia, Rodrigo; de Albuquerque, Sérgio; Pietro, Rosemeire C L R; Ghisla, Sandro; Antunes, Lusânia M Greggi; Sampaio, Suely V

2015-09-01

CR-LAAO is an L-amino acid oxidase from Calloselasma rhodostoma snake venom that has been broadly studied regarding its structural and biochemical characteristics, however, few studies have investigated its pharmacological effects. The present study aimed at the evaluation of the biotechnological potential of CR-LAAO by determining its bactericidal, antifungal, leishmanicidal and trypanocidal activity, as well as its cytotoxicity on human tumor and non-tumor cell lines. After 24 h of preincubation, CR-LAAO showed bactericidal effects against both Staphylococcus aureus (MIC 0.78 μg/mL) and Escherichia coli (MIC 31.25 μg/mL) strains, inducing dismantle of bacterial cell walls. After 6 h of preincubation with Candida albicans, CR-LAAO was able to inhibit 80% of the yeast growth, and it also showed cytotoxic activity on Leishmania species and Trypanosoma cruzi. Additionally, CR-LAAO showed high cytotoxicity on HepG2 and HL-60 tumor cells (IC50 10.78 and 1.7 μg/mL), with lower effects on human mononuclear cells (PBMC). The cytotoxic effects of CR-LAAO were significantly inhibited in the presence of catalase, which suggests the involvement of hydrogen peroxide in its mechanisms of toxicity. Therefore, CR-LAAO showed promising pharmacological effects, and these results provide important information for the development of therapeutic strategies with directed action, such as more effective antimicrobial agents. Copyright © 2015 Elsevier B.V. All rights reserved.

Inhibition of the Autophagy Pathway Synergistically Potentiates the Cytotoxic Activity of Givinostat (ITF2357) on Human Glioblastoma Cancer Stem Cells.

PubMed

Angeletti, Francesca; Fossati, Gianluca; Pattarozzi, Alessandra; Würth, Roberto; Solari, Agnese; Daga, Antonio; Masiello, Irene; Barbieri, Federica; Florio, Tullio; Comincini, Sergio

2016-01-01

Increasing evidence highlighted the role of cancer stem cells (CSCs) in the development of tumor resistance to therapy, particularly in glioblastoma (GBM). Therefore, the development of new therapies, specifically directed against GBM CSCs, constitutes an important research avenue. Considering the extended range of cancer-related pathways modulated by histone acetylation/deacetylation processes, we studied the anti-proliferative and pro-apoptotic efficacy of givinostat (GVS), a pan-histone deacetylase inhibitor, on cell cultures enriched in CSCs, isolated from nine human GBMs. We report that GVS induced a significant reduction of viability and self-renewal ability in all GBM CSC cultures; conversely, GVS exposure did not cause a significant cytotoxic activity toward differentiated GBM cells and normal mesenchymal human stem cells. Analyzing the cellular and molecular mechanisms involved, we demonstrated that GVS affected CSC viability through the activation of programmed cell death pathways. In particular, a marked stimulation of macroautophagy was observed after GVS treatment. To understand the functional link between GVS treatment and autophagy activation, different genetic and pharmacological interfering strategies were used. We show that the up-regulation of the autophagy process, obtained by deprivation of growth factors, induced a reduction of CSC sensitivity to GVS, while the pharmacological inhibition of the autophagy pathway and the silencing of the key autophagy gene ATG7 , increased the cell death rate induced by GVS. Altogether these findings suggest that autophagy represents a pro-survival mechanism activated by GBM CSCs to counteract the efficacy of the anti-proliferative activity of GVS. In conclusion, we demonstrate that GVS is a novel pharmacological tool able to target GBM CSC viability and its efficacy can be enhanced by autophagy inhibitory strategies.

Pharmacological NAD-Boosting Strategies Improve Mitochondrial Homeostasis in Human Complex I-Mutant Fibroblasts.

PubMed

Felici, Roberta; Lapucci, Andrea; Cavone, Leonardo; Pratesi, Sara; Berlinguer-Palmini, Rolando; Chiarugi, Alberto

2015-06-01

Mitochondrial disorders are devastating genetic diseases for which efficacious therapies are still an unmet need. Recent studies report that increased availability of intracellular NAD obtained by inhibition of the NAD-consuming enzyme poly(ADP-ribose) polymerase (PARP)-1 or supplementation with the NAD-precursor nicotinamide riboside (NR) ameliorates energetic derangement and symptoms in mouse models of mitochondrial disorders. Whether these pharmacological approaches also improve bioenergetics of human cells harboring mitochondrial defects is unknown. It is also unclear whether the same signaling cascade is prompted by PARP-1 inhibitors and NR supplementation to improve mitochondrial homeostasis. Here, we show that human fibroblasts mutant for the NADH dehydrogenase (ubiquinone) Fe-S protein 1 (NDUFS1) subunit of respiratory complex I have similar ATP, NAD, and mitochondrial content compared with control cells, but show reduced mitochondrial membrane potential. Interestingly, mutant cells also show increased transcript levels of mitochondrial DNA but not nuclear DNA respiratory complex subunits, suggesting activation of a compensatory response. At variance with prior work in mice, however, NR supplementation, but not PARP-1 inhibition, increased intracellular NAD content in NDUFS1 mutant human fibroblasts. Conversely, PARP-1 inhibitors, but not NR supplementation, increased transcription of mitochondrial transcription factor A and mitochondrial DNA-encoded respiratory complexes constitutively induced in mutant cells. Still, both NR and PARP-1 inhibitors restored mitochondrial membrane potential and increased organelle content as well as oxidative activity of NDUFS1-deficient fibroblasts. Overall, data provide the first evidence that in human cells harboring a mitochondrial respiratory defect exposure to NR or PARP-1, inhibitors activate different signaling pathways that are not invariantly prompted by NAD increases, but equally able to improve energetic derangement. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.

Inhibition of the Autophagy Pathway Synergistically Potentiates the Cytotoxic Activity of Givinostat (ITF2357) on Human Glioblastoma Cancer Stem Cells

PubMed Central

Angeletti, Francesca; Fossati, Gianluca; Pattarozzi, Alessandra; Würth, Roberto; Solari, Agnese; Daga, Antonio; Masiello, Irene; Barbieri, Federica; Florio, Tullio; Comincini, Sergio

2016-01-01

Increasing evidence highlighted the role of cancer stem cells (CSCs) in the development of tumor resistance to therapy, particularly in glioblastoma (GBM). Therefore, the development of new therapies, specifically directed against GBM CSCs, constitutes an important research avenue. Considering the extended range of cancer-related pathways modulated by histone acetylation/deacetylation processes, we studied the anti-proliferative and pro-apoptotic efficacy of givinostat (GVS), a pan-histone deacetylase inhibitor, on cell cultures enriched in CSCs, isolated from nine human GBMs. We report that GVS induced a significant reduction of viability and self-renewal ability in all GBM CSC cultures; conversely, GVS exposure did not cause a significant cytotoxic activity toward differentiated GBM cells and normal mesenchymal human stem cells. Analyzing the cellular and molecular mechanisms involved, we demonstrated that GVS affected CSC viability through the activation of programmed cell death pathways. In particular, a marked stimulation of macroautophagy was observed after GVS treatment. To understand the functional link between GVS treatment and autophagy activation, different genetic and pharmacological interfering strategies were used. We show that the up-regulation of the autophagy process, obtained by deprivation of growth factors, induced a reduction of CSC sensitivity to GVS, while the pharmacological inhibition of the autophagy pathway and the silencing of the key autophagy gene ATG7, increased the cell death rate induced by GVS. Altogether these findings suggest that autophagy represents a pro-survival mechanism activated by GBM CSCs to counteract the efficacy of the anti-proliferative activity of GVS. In conclusion, we demonstrate that GVS is a novel pharmacological tool able to target GBM CSC viability and its efficacy can be enhanced by autophagy inhibitory strategies. PMID:27833530

Medicinal Plants for the Treatment of Local Tissue Damage Induced by Snake Venoms: An Overview from Traditional Use to Pharmacological Evidence

PubMed Central

Félix-Silva, Juliana; Silva-Junior, Arnóbio Antônio; Zucolotto, Silvana Maria

2017-01-01

Snakebites are a serious problem in public health due to their high morbimortality. Most of snake venoms produce intense local tissue damage, which could lead to temporary or permanent disability in victims. The available specific treatment is the antivenom serum therapy, whose effectiveness is reduced against these effects. Thus, the search for complementary alternatives for snakebite treatment is relevant. There are several reports of the popular use of medicinal plants against snakebites worldwide. In recent years, many studies have been published giving pharmacological evidence of benefits of several vegetal species against local effects induced by a broad range of snake venoms, including inhibitory potential against hyaluronidase, phospholipase, proteolytic, hemorrhagic, myotoxic, and edematogenic activities. In this context, this review aimed to provide an updated overview of medicinal plants used popularly as antiophidic agents and discuss the main species with pharmacological studies supporting the uses, with emphasis on plants inhibiting local effects of snake envenomation. The present review provides an updated scenario and insights into future research aiming at validation of medicinal plants as antiophidic agents and strengthens the potentiality of ethnopharmacology as a tool for design of potent inhibitors and/or development of herbal medicines against venom toxins, especially local tissue damage. PMID:28904556

Medicinal Plants for the Treatment of Local Tissue Damage Induced by Snake Venoms: An Overview from Traditional Use to Pharmacological Evidence.

PubMed

Félix-Silva, Juliana; Silva-Junior, Arnóbio Antônio; Zucolotto, Silvana Maria; Fernandes-Pedrosa, Matheus de Freitas

2017-01-01

Snakebites are a serious problem in public health due to their high morbimortality. Most of snake venoms produce intense local tissue damage, which could lead to temporary or permanent disability in victims. The available specific treatment is the antivenom serum therapy, whose effectiveness is reduced against these effects. Thus, the search for complementary alternatives for snakebite treatment is relevant. There are several reports of the popular use of medicinal plants against snakebites worldwide. In recent years, many studies have been published giving pharmacological evidence of benefits of several vegetal species against local effects induced by a broad range of snake venoms, including inhibitory potential against hyaluronidase, phospholipase, proteolytic, hemorrhagic, myotoxic, and edematogenic activities. In this context, this review aimed to provide an updated overview of medicinal plants used popularly as antiophidic agents and discuss the main species with pharmacological studies supporting the uses, with emphasis on plants inhibiting local effects of snake envenomation. The present review provides an updated scenario and insights into future research aiming at validation of medicinal plants as antiophidic agents and strengthens the potentiality of ethnopharmacology as a tool for design of potent inhibitors and/or development of herbal medicines against venom toxins, especially local tissue damage.

PARADIGM - HF: The Rise of the Arnis.

PubMed

Guha, Kaushik; Varkey, Sneha; Sharma, Rakesh

2016-01-01

Heart failure remains a widespread commonly encountered clinical condition. It is responsible for increased healthcare expenditure, driven by frequent and often prolonged hospital admissions associated with an increased mortality. A clinically useful classification of the syndrome is, patients with left ventricular systolic impairment (Heart Failure and reduced ejection fraction, HFREF) and patients with preserved left ventricular systolic function (HFPEF). The pharmacological treatment for patients with HFREF has evolved over the last twenty five years, focusing on modulation of the neurohormonal activation which represents a hallmark of this condition. This has led to the development of a stepwise treatment algorithm predominately based on inhibition of the renin angiotensin aldosterone pathway and counteracting sympathetic over-activation. In particular since the early trials in chronic heart failure (CHF) demonstrated a significant mortality benefit with ACE-inhibitors, subsequent studies have been conducted in conjunction with these drugs. The rationale being that it would be unethical to trial any new agent without the concomitant use of ACE-inhibitors. The recent publication of the PARADIGM -HF study has challenged this convention by trialling a novel pharmacological agent against an ACE-inhibitor in a landmark trial. The review sets out the current pharmacological treatment for patients with heart failure and discusses the recent findings with this novel class of medication.

[Pharmacological studies on ginger. V. Pharmacological comparison between (6)-shogaol and capsaicin].

PubMed

Suekawa, M; Sone, H; Sakakibara, I; Ikeya, Y; Aburada, M; Hosoya, E

1986-11-01

Pharmacological actions of (6)-shogaol and capsaicin were studied. Both (6)-shogaol (0.5 mg/kg, i.v.) and capsaicin (0.1 mg/kg, i.v.) caused a triad such as a rapid fall in blood pressure, bradycardia and aponea in rats. Both drugs-induced marked pressor responses in blood pressure, which occurred after the rapid fall, were markedly reduced by a spinal destruction. In pithed rats, both drugs-induced peripheral pressor responses were markedly reduced with the combined treatment of [D-Arg1, D-Pro2, D-Trp7,9, Leu11]-substance P (0.5 mg/kg, i.v.), phentolamine (10 mg/kg, i.v.) and the section of sciatic nerves. In isolated guinea-pig trachea, (6)-shogaol (100 microM) and capsaicin (10 microM) induced contractile responses which were slightly inhibited by substance P antagonist (10 microM), but exhibited also a tachyphylaxis. Furthermore, although (6)-shogaol (3.6 microM) showed positive inotropic and chronotropic actions on isolated atria in rats, this effect of (6)-shogaol disappeared by repeated injections or pretreatment (100 mg/kg, s.c.) of (6)-shogaol. These results suggest that (6)-shogaol and capsaicin have similar actions, and that both drugs may cause a peripheral action by releasing an unknown active substance from nerve ends.

Targeting Notch pathway induces growth inhibition and differentiation of neuroblastoma cells.

PubMed

Ferrari-Toninelli, Giulia; Bonini, Sara Anna; Uberti, Daniela; Buizza, Laura; Bettinsoli, Paola; Poliani, Pietro Luigi; Facchetti, Fabio; Memo, Maurizio

2010-12-01

High-risk neuroblastoma is a severe pediatric tumor characterized by poor prognosis. Understanding the molecular mechanisms involved in tumor development and progression is strategic for the improvement of pharmacological therapies. Notch was recently proposed as a pharmacological target for the therapy of several cancers and is emerging as a new neuroblastoma-related molecular pathway. However, the precise role played by Notch in this cancer remains to be studied extensively. Here, we show that Notch activation by the Jagged1 ligand enhances the proliferation of neuroblastoma cells, and we propose the possible use of Notch-blocking γ-secretase inhibitors (GSIs) in neuroblastoma therapy. Two different GSIs, Compound E and DAPT, were tested alone or in combination with 13-cis retinoic acid (RA) on neuroblastoma cell lines. SH-SY5Y and IMR-32 cells were chosen as paradigms of lower and higher malignancy, respectively. Used alone, GSIs induced complete cell growth arrest, promoted neuronal differentiation, and significantly reduced cell motility. The combination of GSIs and 13-cis RA resulted in the enhanced growth inhibition, differentiation, and migration of neuroblastoma cells. In summary, our data suggest that a combination of GSIs with 13-cis RA offers a therapeutic advantage over a single agent, indicating a potential novel therapy for neuroblastoma.

Repurposing ebselen for treatment of multidrug-resistant staphylococcal infections.

PubMed

Thangamani, Shankar; Younis, Waleed; Seleem, Mohamed N

2015-06-26

Novel antimicrobials and new approaches to developing them are urgently needed. Repurposing already-approved drugs with well-characterized toxicology and pharmacology is a novel way to reduce the time, cost, and risk associated with antibiotic innovation. Ebselen, an organoselenium compound, is known to be clinically safe and has a well-known pharmacology profile. It has shown potent bactericidal activity against multidrug-resistant clinical isolates of staphylococcus aureus, including methicillin- and vancomycin-resistant S. aureus (MRSA and VRSA). We demonstrated that ebselen acts through inhibition of protein synthesis and subsequently inhibited toxin production in MRSA. Additionally, ebselen was remarkably active and significantly reduced established staphylococcal biofilms. The therapeutic efficacy of ebselen was evaluated in a mouse model of staphylococcal skin infections. Ebselen 1% and 2% significantly reduced the bacterial load and the levels of the pro-inflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1 beta (IL-1β), and monocyte chemo attractant protein-1 (MCP-1) in MRSA USA300 skin lesions. Furthermore, it acts synergistically with traditional antimicrobials. This study provides evidence that ebselen has great potential for topical treatment of MRSA skin infections and lays the foundation for further analysis and development of ebselen as a potential treatment for multidrug-resistant staphylococcal infections.

Regulation and signaling of human bombesin receptors and their biological effects.

PubMed

Weber, H Christian

2009-02-01

This review will highlight recent advances in the understanding of molecular mechanisms by which mammalian bombesin receptors are regulated and which intracellular signaling pathways have been characterized to mediate agonist-dependent receptor biological effects. Mammalian bombesin receptors have been demonstrated to be involved in a larger array of physiological and pathophysiological conditions than previously reported. Pharmacological experiments in vitro and in vivo as well as utilization of animals genetically deficient of the gastrin-releasing peptide receptor demonstrated roles in memory and fear behavior, lung development and injury, small intestinal cell repair, autocrine tumor growth, and mediating signals for pruritus and penile reflexes. Intracellular signaling studies predominantly of the gastrin-releasing peptide receptor owing to its frequent overexpression in some human malignancies showed that PI3 kinase activation is an important mechanism of cell proliferation. Tumor cell treatment including gastrin-releasing peptide receptor antagonists combined with inhibition of epidermal growth factor receptor resulted in an additive effect on blocking cell proliferation. Novel molecular mechanisms of the orphan bombesin receptor subtype-3 and gastrin-releasing peptide receptor gene regulation have been elucidated. Inhibition of gastrin-releasing peptide receptor signaling in human malignancies represents an attractive target for pharmacological treatment. Novel functions of bombesin related peptides have been identified including processes in the central nervous system, lung and intestinal tract.

Study of pharmacological activities of methanol extract of Jatropha gossypifolia fruits.

PubMed

Apu, Apurba Sarker; Hossain, Faruq; Rizwan, Farhana; Bhuyan, Shakhawat Hossan; Matin, Maima; Jamaluddin, A T M

2012-12-01

The present study was carried out to investigate the possible in vivo analgesic, neuropharmacological and anti-diarrheal activities of the methanol extract of Jatropha gossypifolia fruits. The analgesic activity was measured by acetic acid induced writhing inhibition test. The neuropharmacological activities were evaluated by hole cross, hole-board, and elevated plus-maze (EPM) tests and the anti-diarrheal activity was assessed by castor oil induced diarrhea inhibition method. The extract showed highly significant (P < 0.001) analgesic activity with % inhibitions of writhing response at doses 200 and 400 mg/kg body weight were 77.86% and 71.25%, respectively. The extract at both doses showed significant (P < 0.05) sedative effect in-hole cross test. In-hole board test, the extract showed highly significant (P < 0.001) anxiolytic activity at lower dose whereas this activity was observed at higher dose in EPM test. The extract also showed highly significant (P < 0.001) anti-diarrheal activity. The findings of the study clearly indicate the presence of significant analgesic, neuropharmacological and anti-diarrheal properties of the plant, which demands further investigation including, compound isolation.

18β-glycyrrhetinic acid inhibits migration and invasion of human gastric cancer cells via the ROS/PKC-α/ERK pathway.

PubMed

Cai, Hongke; Chen, Xi; Zhang, Jianbo; Wang, Jijian

2018-01-01

18β-glycyrrhetinic acid (18β-GA) is a bioactive component of licorice root which exerts pharmacological activities including anti-inflammatory, antiviral, anti-oxidative and anti-cancer effects. The current study further investigated the molecular mechanisms associated with the inhibitory effects of 18β-GA on tumor metastasis in human gastric cancer cells. The results indicated that 18β-GA significantly reduced invasion and migration activities and suppressed MMP-2 and 9 activities on SGC-7901cells in a dose-dependent manner. Further study showed 18β-GA upregulated E-cadherin expression but downregulated vimentin expression. The results also showed that 18β-GA inhibited ROS formation, PKC-α expression and the phosphorylation of ERK in a dose-dependent manner. In conclusion, this study revealed that 18β-GA inhibits migration and invasion via the ROS/PKC-α/ERK signaling pathway in gastric cancer cells. This suggests that 18β-GA has the potential to be used as an effective chemopreventive agent for the prevention of gastric cancer metastasis.

Calcineurin inhibition enhances motor neuron survival following injury

PubMed Central

Hui, Kelvin KW; Liadis, Nicole; Robertson, Jennifer; Kanungo, Anish; Henderson, Jeffrey T

2010-01-01

Abstract The immunosuppressive agents cyclosporin A (CsA) and FK-506 have previously been shown to exhibit neurotrophic and neuroprotective properties in vivo. Given that significant clinical expertise exists for both drugs, they represent an attractive starting point for treatment of acute neural injuries. One putative mechanism for neuroprotection by these drugs relates to inhibition of calcineurin activity. However each drug–immunophilin complex can potentially influence additional signal transduction pathways. Furthermore, several non-immunosuppressive immunophilin ligands have been described as possessing neuroprotective properties, suggesting that neuroprotection may be separable from calcineurin inhibition. In the present study, we examined the mechanism of this neuroprotection in facial motor neurons following axotomy-induced injury. Similar to previous studies in rats, CsA and FK-506 enhanced motor neuron survival in mice following acute injury. To examine the mechanism responsible for neuroprotection by these agents, pharmacologic inhibitors of several potential alternate signalling pathways (17-(allylamino)-17-demethoxygeldanamycin, rapamycin, cypermethrin) were evaluated with respect to neuroprotection. Of these, only cypermethrin, a direct calcineurin inhibitor not previously associated with neuronal survival properties, was observed to significantly enhance motor neuron survival following injury. The results demonstrate for the first time that direct inhibition of calcineurin is neuroprotective in vivo. These data support a model in which calcineurin inhibition promotes neuronal survival, distinct from effects upon neurite outgrowth. PMID:19243469

Secreted Isoform of Human Lynx1 (SLURP-2): Spatial Structure and Pharmacology of Interactions with Different Types of Acetylcholine Receptors

NASA Astrophysics Data System (ADS)

Lyukmanova, E. N.; Shulepko, M. A.; Shenkarev, Z. O.; Bychkov, M. L.; Paramonov, A. S.; Chugunov, A. O.; Kulbatskii, D. S.; Arvaniti, M.; Dolejsi, Eva; Schaer, T.; Arseniev, A. S.; Efremov, R. G.; Thomsen, M. S.; Dolezal, V.; Bertrand, D.; Dolgikh, D. A.; Kirpichnikov, M. P.

2016-08-01

Human-secreted Ly-6/uPAR-related protein-2 (SLURP-2) regulates the growth and differentiation of epithelial cells. Previously, the auto/paracrine activity of SLURP-2 was considered to be mediated via its interaction with the α3β2 subtype of the nicotinic acetylcholine receptors (nAChRs). Here, we describe the structure and pharmacology of a recombinant analogue of SLURP-2. Nuclear magnetic resonance spectroscopy revealed a ‘three-finger’ fold of SLURP-2 with a conserved β-structural core and three protruding loops. Affinity purification using cortical extracts revealed that SLURP-2 could interact with the α3, α4, α5, α7, β2, and β4 nAChR subunits, revealing its broader pharmacological profile. SLURP-2 inhibits acetylcholine-evoked currents at α4β2 and α3β2-nAChRs (IC50 ~0.17 and >3 μM, respectively) expressed in Xenopus oocytes. In contrast, at α7-nAChRs, SLURP-2 significantly enhances acetylcholine-evoked currents at concentrations <1 μM but induces inhibition at higher concentrations. SLURP-2 allosterically interacts with human M1 and M3 muscarinic acetylcholine receptors (mAChRs) that are overexpressed in CHO cells. SLURP-2 was found to promote the proliferation of human oral keratinocytes via interactions with α3β2-nAChRs, while it inhibited cell growth via α7-nAChRs. SLURP-2/mAChRs interactions are also probably involved in the control of keratinocyte growth. Computer modeling revealed possible SLURP-2 binding to the ‘classical’ orthosteric agonist/antagonist binding sites at α7 and α3β2-nAChRs.

AMP-activated protein kinase (AMPK)-dependent and -independent pathways regulate hypoxic inhibition of transepithelial Na+ transport across human airway epithelial cells.

PubMed

Tan, C D; Smolenski, R T; Harhun, M I; Patel, H K; Ahmed, S G; Wanisch, K; Yáñez-Muñoz, R J; Baines, D L

2012-09-01

Pulmonary transepithelial Na(+) transport is reduced by hypoxia, but in the airway the regulatory mechanisms remain unclear. We investigated the role of AMPK and ROS in the hypoxic regulation of apical amiloride-sensitive Na(+) channels and basolateral Na(+) K(+) ATPase activity. H441 human airway epithelial cells were used to examine the effects of hypoxia on Na(+) transport, AMP : ATP ratio and AMPK activity. Lentiviral constructs were used to modify cellular AMPK abundance and activity; pharmacological agents were used to modify cellular ROS. AMPK was activated by exposure to 3% or 0.2% O(2) for 60 min in cells grown in submerged culture or when fluid (0.1 mL·cm(-2) ) was added to the apical surface of cells grown at the air-liquid interface. Only 0.2% O(2) activated AMPK in cells grown at the air-liquid interface. AMPK activation was associated with elevation of cellular AMP:ATP ratio and activity of the upstream kinase LKB1. Hypoxia inhibited basolateral ouabain-sensitive I(sc) (I(ouabain) ) and apical amiloride-sensitive Na(+) conductance (G(Na+) ). Modification of AMPK activity prevented the effect of hypoxia on I(ouabain) (Na(+) K(+) ATPase) but not apical G(Na+) . Scavenging of superoxide and inhibition of NADPH oxidase prevented the effect of hypoxia on apical G(Na+) (epithelial Na(+) channels). Hypoxia activates AMPK-dependent and -independent pathways in airway epithelial cells. Importantly, these pathways differentially regulate apical Na(+) channels and basolateral Na(+) K(+) ATPase activity to decrease transepithelial Na(+) transport. Luminal fluid potentiated the effect of hypoxia and activated AMPK, which could have important consequences in lung disease conditions. © 2012 The Authors. British Journal of Pharmacology © 2012 The British Pharmacological Society.

The Nucleotide Synthesis Enzyme CAD Inhibits NOD2 Antibacterial Function in Human Intestinal Epithelial Cells

PubMed Central

Richmond, Amy L.; Kabi, Amrita; Homer, Craig R.; García, Noemí Marina; Nickerson, Kourtney P.; NesvizhskiI, Alexey I.; Sreekumar, Arun; Chinnaiyan, Arul M.; Nuñez, Gabriel; McDonald, Christine

2013-01-01

BACKGROUND & AIMS Polymorphisms that reduce the function of nucleotide-binding oligomerization domain (NOD)2, a bacterial sensor, have been associated with Crohn’s disease (CD). No proteins that regulate NOD2 activity have been identified as selective pharmacologic targets. We sought to discover regulators of NOD2 that might be pharmacologic targets for CD therapies. METHODS Carbamoyl phosphate synthetase/ aspartate transcarbamylase/dihydroorotase (CAD) is an enzyme required for de novo pyrimidine nucleotide synthesis; it was identified as a NOD2-interacting protein by immunoprecipitation-coupled mass spectrometry. CAD expression was assessed in colon tissues from individuals with and without inflammatory bowel disease by immunohistochemistry. The interaction between CAD and NOD2 was assessed in human HCT116 intestinal epithelial cells by immunoprecipitation, immunoblot, reporter gene, and gentamicin protection assays. We also analyzed human cell lines that express variants of NOD2 and the effects of RNA interference, overexpression and CAD inhibitors. RESULTS CAD was identified as a NOD2-interacting protein expressed at increased levels in the intestinal epithelium of patients with CD compared with controls. Overexpression of CAD inhibited NOD2-dependent activation of nuclear factor κB and p38 mitogen-activated protein kinase, as well as intracellular killing of Salmonella. Reduction of CAD expression or administration of CAD inhibitors increased NOD2-dependent signaling and antibacterial functions of NOD2 variants that are and are not associated with CD. CONCLUSIONS The nucleotide synthesis enzyme CAD is a negative regulator of NOD2. The antibacterial function of NOD2 variants that have been associated with CD increased in response to pharmacologic inhibition of CAD. CAD is a potential therapeutic target for CD. PMID:22387394

Pharmacological interactions of anti-inflammatory-analgesics in odontology.

PubMed

Gómez-Moreno, Gerardo; Guardia, Javier; Cutando, Antonio; Calvo-Guirado, José Luis

2009-02-01

In this second article we describe the more interesting pharmacological interactions in dental practice based on the prescription of analgesic narcotics, paracetamol and non-selective non-steroid anti-inflammatory drugs (NSAI) (which inhibit cyclooxigenase 1 -COX 1- and cyclooxigenase 2 -COX 2-) and selective NSAIs (COX 2 inhibitors). The importance of preventing the appearance of these pharmacological interactions is because these are medicaments prescribed daily in odontology for moderate pain treatment and inflammation in the oral cavity. Paracetamol can interact with warfarin and therefore care should be taken with chronic alcoholic patients. All NSAIs reduce renal blood flow and consequently are capable of reducing the efficacy of medicaments used for treating arterial hypertension, which act via a renal mechanism. Especial attention should be taken considering the risk of interaction between the antagonists of AT1 receptors of angiostensin II (ARAII) and the NSAIs.

The Alkylating-HDAC Inhibition Fusion Principle: Taking Chemotherapy to the Next Level with the First in Class Molecule EDO-S101.

PubMed

Mehrling, Thomas; Chen, Yi

2016-01-01

Chemotherapy may still be an essential component to treat cancer in combination with new targeted therapies. But chemotherapy needs to get smarter in order to make those combination regimens more effective and also more tolerable, particularly for an aging population. We describe the first time the synthesis and pharmacological testing of a fusion molecule comprising of the alkylator bendamustine and the HDAC-inhibitor vorinostat. The drug was designed to allow for the exploitation of both mechanisms of action simultaneously with the goal to provide a molecule with superior efficacy over the single agents. The pharmacological testing confirms the full functional capacity of both moieties and encouraging pharmacological data raises the hope that the drug may turn out to be a great addition to the armentarium of anticancer agents.

TC Mps1 12, a novel Mps1 inhibitor, suppresses the growth of hepatocellular carcinoma cells via the accumulation of chromosomal instability.

PubMed

Choi, Minji; Min, Yoo Hong; Pyo, Jaehyuk; Lee, Chang-Woo; Jang, Chang-Young; Kim, Ja-Eun

2017-06-01

Chromosomal instability is not only a hallmark of cancer but also an attractive therapeutic target. A diverse set of mitotic kinases maintains chromosomal stability. One of these is monopolar spindle 1 (Mps1, also known as TTK), which is essential for chromosome alignment and for the spindle assembly checkpoint (SAC). Pharmacological inhibition of Mps1 has been suggested as a cancer therapeutic; however, despite the existence of a novel Mps1 inhibitor, TC Mps1 12, no such studies have been performed. The effects of TC Mps1 12 on cell viability, chromosome alignment, centrosome number, mitotic duration, apoptosis and SAC were determined in hepatocellular carcinoma (HCC) cells. In addition, the association of Mps1 expression with the overall survival of HCC patients was analysed. Treatment of human HCC cells with TC Mps1 12 led to chromosome misalignment and missegregation, and disorganization of centrosomes. Even in the presence of these errors, TC Mps1 12-treated cells overrode the SAC, resulting in a shortened mitotic duration and mitotic slippage. This mitotic catastrophe triggered apoptosis and, finally, inhibited the growth of HCC cells. In addition, the expression of the Mps1-encoding TTK gene was associated with poor overall survival of HCC patients. TC Mps1 12 results in the accumulation of chromosomal instabilities and mitotic catastrophe in HCC cells. Overall, these data demonstrate that the inhibition of Mps1 kinase using TC Mps1 12 is a promising therapeutic approach for liver cancer. © 2017 The British Pharmacological Society.

Lubiprostone targets prostanoid EP₄ receptors in ovine airways.

PubMed

Cuthbert, A W

2011-01-01

Lubiprostone, a prostaglandin E₁ derivative, is reported to activate ClC-2 chloride channels located in the apical membranes of a number of transporting epithelia. Lack of functioning CFTR chloride channels in epithelia is responsible for the genetic disease cystic fibrosis, therefore, surrogate channels that can operate independently of CFTR are of interest. This study explores the target receptor(s) for lubiprostone in airway epithelium. All experiments were performed on the ventral tracheal epithelium of sheep. Epithelia were used to measure anion secretion from the apical surface as short circuit current or as fluid secretion from individual airway submucosal glands, using an optical method. The EP₄ antagonists L-161982 and GW627368 inhibited short circuit current responses to lubiprostone, while EP₁(,)₂(&)₃ receptor antagonists were without effect. Similarly, lubiprostone induced secretion in airway submucosal glands was inhibited by L-161982. L-161982 effectively competed with lubiprostone with a K(d) value of 0.058 µM, close to its value for binding to human EP₄ receptors (0.024 µM). The selective EP₄ agonist L-902688 and lubiprostone behaved similarly with respect to EP₄ receptor antagonists. Results of experiments with H89, a protein kinase A inhibitor, were consistent with lubiprostone acting through a G(s) -protein coupled EP₄ receptor/cAMP cascade. Lubiprostone-induced short-circuit currents and submucosal gland secretions were inhibited by selective EP₄ receptor antagonists. The results suggest EP₄ receptor activation by lubiprostone triggers cAMP production necessary for CFTR activation and the secretory responses, a possibility precluded in CF tissues. © 2010 The Author. British Journal of Pharmacology © 2010 The British Pharmacological Society.

Perinatal asphyxia: CNS development and deficits with delayed onset

PubMed Central

Herrera-Marschitz, Mario; Neira-Pena, Tanya; Rojas-Mancilla, Edgardo; Espina-Marchant, Pablo; Esmar, Daniela; Perez, Ronald; Muñoz, Valentina; Gutierrez-Hernandez, Manuel; Rivera, Benjamin; Simola, Nicola; Bustamante, Diego; Morales, Paola; Gebicke-Haerter, Peter J.

2013-01-01

Perinatal asphyxia constitutes a prototype of obstetric complications occurring when pulmonary oxygenation is delayed or interrupted. The primary insult relates to the duration of the period lacking oxygenation, leading to death if not re-established. Re-oxygenation leads to a secondary insult, related to a cascade of biochemical events required for restoring proper function. Perinatal asphyxia interferes with neonatal development, resulting in long-term deficits associated to mental and neurological diseases with delayed clinical onset, by mechanisms not yet clarified. In the experimental scenario, the effects observed long after perinatal asphyxia have been explained by overexpression of sentinel proteins, such as poly(ADP-ribose) polymerase-1 (PARP-1), competing for NAD+ during re-oxygenation, leading to the idea that sentinel protein inhibition constitutes a suitable therapeutic strategy. Asphyxia induces transcriptional activation of pro-inflammatory factors, in tandem with PARP-1 overactivation, and pharmacologically induced PARP-1 inhibition also down-regulates the expression of proinflammatory cytokines. Nicotinamide has been proposed as a suitable PARP-1 inhibitor. Its effect has been studied in an experimental model of global hypoxia in rats. In that model, the insult is induced by immersing rat fetus into a water bath for various periods of time. Following asphyxia, the pups are delivered, treated, and nursed by surrogate dams, pending further experiments. Nicotinamide rapidly distributes into the brain following systemic administration, reaching steady state concentrations sufficient to inhibit PARP-1 activity for several hours, preventing several of the long-term consequences of perinatal asphyxia, supporting the idea that nicotinamide constitutes a lead for exploring compounds with similar or better pharmacological profiles. PMID:24723845

Fibroblast activation protein (FAP) as a novel metabolic target.

PubMed

Sánchez-Garrido, Miguel Angel; Habegger, Kirk M; Clemmensen, Christoffer; Holleman, Cassie; Müller, Timo D; Perez-Tilve, Diego; Li, Pengyun; Agrawal, Archita S; Finan, Brian; Drucker, Daniel J; Tschöp, Matthias H; DiMarchi, Richard D; Kharitonenkov, Alexei

2016-10-01

Fibroblast activation protein (FAP) is a serine protease belonging to a S9B prolyl oligopeptidase subfamily. This enzyme has been implicated in cancer development and recently reported to regulate degradation of FGF21, a potent metabolic hormone. Using a known FAP inhibitor, talabostat (TB), we explored the impact of FAP inhibition on metabolic regulation in mice. To address this question we evaluated the pharmacology of TB in various mouse models including those deficient in FGF21, GLP1 and GIP signaling. We also studied the ability of FAP to process FGF21 in vitro and TB to block FAP enzymatic activity. TB administration to diet-induced obese (DIO) animals led to profound decreases in body weight, reduced food consumption and adiposity, increased energy expenditure, improved glucose tolerance and insulin sensitivity, and lowered cholesterol levels. Total and intact plasma FGF21 were observed to be elevated in TB-treated DIO mice but not lean animals where the metabolic impact of TB was significantly attenuated. Furthermore, and in stark contrast to naïve DIO mice, the administration of TB to obese FGF21 knockout animals demonstrated no appreciable effect on body weight or any other measures of metabolism. In support of these results we observed no enzymatic degradation of human FGF21 at either end of the protein when FAP was inhibited in vitro by TB. We conclude that pharmacological inhibition of FAP enhances levels of FGF21 in obese mice to provide robust metabolic benefits not observed in lean animals, thus validating this enzyme as a novel drug target for the treatment of obesity and diabetes.

Pharmacological profile and efficiency in vivo of diflapolin, the first dual inhibitor of 5-lipoxygenase-activating protein and soluble epoxide hydrolase.

PubMed

Garscha, Ulrike; Romp, Erik; Pace, Simona; Rossi, Antonietta; Temml, Veronika; Schuster, Daniela; König, Stefanie; Gerstmeier, Jana; Liening, Stefanie; Werner, Markus; Atze, Heiner; Wittmann, Sandra; Weinigel, Christina; Rummler, Silke; Scriba, Gerhard K; Sautebin, Lidia; Werz, Oliver

2017-08-24

Arachidonic acid (AA) is metabolized to diverse bioactive lipid mediators. Whereas the 5-lipoxygenase-activating protein (FLAP) facilitates AA conversion by 5-lipoxygenase (5-LOX) to pro-inflammatory leukotrienes (LTs), the soluble epoxide hydrolase (sEH) degrades anti-inflammatory epoxyeicosatrienoic acids (EETs). Accordingly, dual FLAP/sEH inhibition might be advantageous drugs for intervention of inflammation. We present the in vivo pharmacological profile and efficiency of N-[4-(benzothiazol-2-ylmethoxy)-2-methylphenyl]-N'-(3,4-dichlorophenyl)urea (diflapolin) that dually targets FLAP and sEH. Diflapolin inhibited 5-LOX product formation in intact human monocytes and neutrophils with IC 50  = 30 and 170 nM, respectively, and suppressed the activity of isolated sEH (IC 50  = 20 nM). Characteristic for FLAP inhibitors, diflapolin (I) failed to inhibit isolated 5-LOX, (II) blocked 5-LOX product formation in HEK cells only when 5-LOX/FLAP was co-expressed, (III) lost potency in intact cells when exogenous AA was supplied, and (IV) prevented 5-LOX/FLAP complex assembly in leukocytes. Diflapolin showed target specificity, as other enzymes related to AA metabolism (i.e., COX1/2, 12/15-LOX, LTA 4 H, LTC 4 S, mPGES 1 , and cPLA 2 ) were not inhibited. In the zymosan-induced mouse peritonitis model, diflapolin impaired vascular permeability, inhibited cysteinyl-LTs and LTB 4 formation, and suppressed neutrophil infiltration. Diflapolin is a highly active dual FLAP/sEH inhibitor in vitro and in vivo with target specificity to treat inflammation-related diseases.

Green tea polyphenols and tannic acid act as potent inhibitors of phorbol ester-induced nitric oxide generation in rat hepatocytes independent of their antioxidant properties.

PubMed

Srivastava, R C; Husain, M M; Hasan, S K; Athar, M

2000-05-29

The deleterious effects of excessive release of nitric oxide (NO) have been implicated in the tissue damage and inflammation. In this study, the effect of various flavonoids and other oxidant scavenging chemical agents have been studied for their ability to inhibit 12-O-tetradecanoyl phorbol 13-acetate (TPA)-induced NO generation in rat hepatocyte. Hepatocytes activated with TPA (25-200 nM) released NO in a concentration- and time-dependent manner. Green tea polyphenols (GTP) and tannic acid (TA) were most effective in inhibiting TPA-induced NO generation (90%). These agents were also effective in inhibiting NO formation when added 2 h following TPA addition. The other oxidant scavengers, such as L-histidine, sodium azide, vitamin E and sodium benzoate, were not found to be effective even up to 1.0 mM concentration. These results suggest that TA and GTP are potent inhibitors of NOS activity and the inhibition of TPA-induced NO generation by these polyphenols is independent of their antioxidant activity. It is tempting to speculate that these agents could be utilized in the pharmacological manipulations of NO-dependent pathophysiological responses.

Gustatory detection of tetrodotoxin and saxitoxin, and its competitive inhibition by quinine and strychnine in freshwater fishes.

PubMed

Hara, Toshiaki J

2011-01-01

Fish detect extremely low levels of marine toxins tetrodotoxin (TTX) and saxitoxin (STX) via the specialized gustatory receptor(s). Physiological and pharmacological studies show that receptor(s) for TTX and STX are distinct from those which detect feeding stimulant amino acids and bile acids, and that TTX and STX do not share the same receptor populations, while interacting with quinine and strychnine in a competitive fashion suggestive of an antidotal relationship.

Gustatory Detection of Tetrodotoxin and Saxitoxin, and Its Competitive Inhibition by Quinine and Strychnine in Freshwater Fishes

PubMed Central

Hara, Toshiaki J.

2011-01-01

Fish detect extremely low levels of marine toxins tetrodotoxin (TTX) and saxitoxin (STX) via the specialized gustatory receptor(s). Physiological and pharmacological studies show that receptor(s) for TTX and STX are distinct from those which detect feeding stimulant amino acids and bile acids, and that TTX and STX do not share the same receptor populations, while interacting with quinine and strychnine in a competitive fashion suggestive of an antidotal relationship. PMID:22163186

[Evaluation of anti-inflammatory activity of extracts from Siberian plants].

PubMed

Nesterova, Iu V; Povet'eva, T N; Aksinenko, S G; Suslov, N I; Gaĭdamovich, N N; Nagorniak, Iu G; Popova, E V; Kravtsova, S S; Andreeva, T I

2009-01-01

Experimental investigations have shown that water-alcohol extracts from plants containing alkaloids (Aconitum baikalense, Aconitum septentrionale, Delphinium elatum L., Conium maculatum) and salicylic acid (Filipendula ulmaria, Salix viminalis, Fragaria vesca, Rubus idaeus) inhibited the development of main symptoms of inflammation, viz. exudation, pain, fever, to the same extent as non-steroidal anti-inflammatory agents. The substances studied in this work may be used to develop new efficient pharmacological preparations for the treatment of different inflammatory conditions associated with severe pain syndrome.

Biological properties of 6-gingerol: a brief review.

PubMed

Wang, Shaopeng; Zhang, Caihua; Yang, Guang; Yang, Yanzong

2014-07-01

Numerous studies have revealed that regular consumption of certain fruits and vegetables can reduce the risk of many diseases. The rhizome of Zingiber officinale (ginger) is consumed worldwide as a spice and herbal medicine. It contains pungent phenolic substances collectively known as gingerols. 6-Gingerol is the major pharmacologically-active component of ginger. It is known to exhibit a variety of biological activities including anticancer, anti-inflammation, and anti-oxidation. 6-Gingerol has been found to possess anticancer activities via its effect on a variety of biological pathways involved in apoptosis, cell cycle regulation, cytotoxic activity, and inhibition of angiogenesis. Thus, due to its efficacy and regulation of multiple targets, as well as its safety for human use, 6-gingerol has received considerable interest as a potential therapeutic agent for the prevention and/or treatment of various diseases. Taken together, this review summarizes the various in vitro and in vivo pharmacological aspects of 6-gingerol and the underlying mechanisms.

Characterization of rodent liver and kidney AVP receptors: pharmacologic evidence for species differences.

PubMed

Tahara, A; Tsukada, J; Ishii, N; Tomura, Y; Wada, K; Kusayama, T; Yatsu, T; Uchida, W; Tanaka, A

1999-10-22

Radioligand binding studies with [3H]vasopressin (AVP) were used to determine the affinities of AVP receptor agonists and antagonists for mouse liver and kidney plasma membrane preparations. Both membrane preparations exhibited one class of high-affinity binding site. AVP ligand binding inhibition studies confirmed that mouse liver binding sites belong to the V1A subtype while kidney binding sites belong to the V2 receptor subtype. The affinity of each ligand for mouse V1A receptors was very similar to that for rat V1A receptors, showing differences in Ki values of less than 3-fold. In contrast, several peptide (d(CH2)5Tyr(Me)AVP) and nonpeptide (OPC-21268 and SR 49059) ligands had different affinities for mouse and rat kidney V2 receptors, with differences in Ki values ranging from 14- to 17-fold. These results indicate that mouse and rat kidney V2 receptors show significant pharmacologic differences.

An integrated bioinformatics analysis to dissect kinase dependency in triple negative breast cancer.

PubMed

Ryall, Karen A; Kim, Jihye; Klauck, Peter J; Shin, Jimin; Yoo, Minjae; Ionkina, Anastasia; Pitts, Todd M; Tentler, John J; Diamond, Jennifer R; Eckhardt, S Gail; Heasley, Lynn E; Kang, Jaewoo; Tan, Aik Choon

2015-01-01

Triple-Negative Breast Cancer (TNBC) is an aggressive disease with a poor prognosis. Clinically, TNBC patients have limited treatment options besides chemotherapy. The goal of this study was to determine the kinase dependency in TNBC cell lines and to predict compounds that could inhibit these kinases using integrative bioinformatics analysis. We integrated publicly available gene expression data, high-throughput pharmacological profiling data, and quantitative in vitro kinase binding data to determine the kinase dependency in 12 TNBC cell lines. We employed Kinase Addiction Ranker (KAR), a novel bioinformatics approach, which integrated these data sources to dissect kinase dependency in TNBC cell lines. We then used the kinase dependency predicted by KAR for each TNBC cell line to query K-Map for compounds targeting these kinases. We validated our predictions using published and new experimental data. In summary, we implemented an integrative bioinformatics analysis that determines kinase dependency in TNBC. Our analysis revealed candidate kinases as potential targets in TNBC for further pharmacological and biological studies.

[Pharmacological study on hemostasis, analgesic and anti inflammation effects of the alcohol extract of Hibiscus tiliaceus].

PubMed

Qiu, Fen; Tian, Hui; Zhang, Zhi; Yuan, Xian-Ling; Tan, Yuan-Feng; Ning, Xiao-Qing

2013-10-01

To study the effects of hemostasis, analgesic and anti inflammation of the alcohol extract of Hibiscus tiliaceus and offer pharmacological and experimental basis for its safe and effective use in clinic. The effects of hemostasist were observed with tail breaking method, capillary tube method and slide method; Hot board and body distortion induced by acetic acid methods were applied in mice analgesia experiment, the mice model of acute auricle swelling induced by dmi ethylbenzene and capillary permeability induced by acetic acid were applied to observe the anti inflammatory effects. The alcohol extract of Hibiscus tiliaceus could significantly reduce the bleeding time and the clotting time, delay the plant reaction time and reduce the writhing times of the mice, and it also had effect on inhibiting swelling of mice ear and the permeability of the capillary. These results suggest that the alcohol extract of Hibiscus tiliaceus has the effects of hemostasis, analgesic and anti inflammation.

YFa and analogs: Investigation of opioid receptors in smooth muscle contraction

PubMed Central

Kumar, Krishan; Goyal, Ritika; Mudgal, Annu; Mohan, Anita; Pasha, Santosh

2011-01-01

AIM: To study the pharmacological profile and inhibition of smooth muscle contraction by YFa and its analogs in conjunction with their receptor selectivity. METHODS: The effects of YFa and its analogs (D-Ala2) YFa, Y (D-Ala2) GFMKKKFMRF amide and Des-Phe-YGGFMKKKFMR amide in guinea pig ileum (GPI) and mouse vas deferens (MVD) motility were studied using an isolated tissue organ bath system, and morphine and DynA (1-13) served as controls. Acetylcholine was used for muscle stimulation. The observations were validated by specific antagonist pretreatment experiments using naloxonazine, naltrindole and norbinaltorphimine norBNI. RESULTS: YFa did not demonstrate significant inhibition of GPI muscle contraction as compared with morphine (15% vs 62%, P = 0.0002), but moderate inhibition of MVD muscle contraction, indicating the role of κ opioid receptors in the contraction. A moderate inhibition of GPI muscles by (Des-Phe) YFa revealed the role of anti-opiate receptors in the smooth muscle contraction. (D-Ala-2) YFa showed significant inhibition of smooth muscle contraction, indicating the involvement of mainly δ receptors in MVD contraction. These results were supported by specific antagonist pretreatment assays. CONCLUSION: YFa revealed its side-effect-free analgesic properties with regard to arrest of gastrointestinal transit. The study provides evidences for the involvement of κ and anti-opioid receptors in smooth muscle contraction. PMID:22110284

The separate and combined effects of monoamine oxidase inhibition and nicotine on P50 sensory gating.

PubMed

Smith, Dylan M; Fisher, Derek; Blier, Pierre; Illivitsky, Vadim; Knott, Verner

2015-06-01

The cognitive effects of nicotine in humans remain a topic of great interest, due to the continued prevalence of cigarette smoking in society as well as the hypothesis that cognitively impaired populations such as schizophrenia patients use nicotine as a means of self-medicating against deficits of sensory gating. However, chronic smoking can predispose individuals to robust monoamine oxidase (MAO) inhibition, and thus far, the effect of MAO inhibition on human sensory gating is unknown. In this study, we investigated the effects of both nicotine (6-mg gum) and pharmacologically induced MAO-A inhibition via moclobemide (75 mg) on P50 event-related potential-indexed sensory gating in a sample of 24 healthy non-smoking males. Ratio score (rP50) measured gating revealed significant improvement in auditory stimulus suppression after combined nicotine and MAO-A inhibition compared to placebo and to the nicotine-alone condition. This nicotine + MAO-A inhibition-induced efficient gating was consistent regardless of participants' baseline (placebo) gating efficiency, despite the observation that nicotine in the absence of MAO-A inhibition exhibited a detrimental effect on gating in participants with high baseline suppression ratios. Nicotine and monoamine oxidase-inhibiting agents in tobacco smoke appear to exert a synergistic effect on sensory gating, which may contribute to the elevated dependence rates seen in populations with cognitive deficits such as schizophrenia.

Differential inhibition of macrophage foam-cell formation and atherosclerosis in mice by PPARα, β/δ, and γ

PubMed Central

Li, Andrew C.; Binder, Christoph J.; Gutierrez, Alejandra; Brown, Kathleen K.; Plotkin, Christine R.; Pattison, Jennifer W.; Valledor, Annabel F.; Davis, Roger A.; Willson, Timothy M.; Witztum, Joseph L.; Palinski, Wulf; Glass, Christopher K.

2004-01-01

PPARα, β/δ, and γ regulate genes involved in the control of lipid metabolism and inflammation and are expressed in all major cell types of atherosclerotic lesions. In vitro studies have suggested that PPARs exert antiatherogenic effects by inhibiting the expression of proinflammatory genes and enhancing cholesterol efflux via activation of the liver X receptor–ABCA1 (LXR-ABCA1) pathway. To investigate the potential importance of these activities in vivo, we performed a systematic analysis of the effects of PPARα, β, and γ agonists on foam-cell formation and atherosclerosis in male LDL receptor–deficient (LDLR–/–) mice. Like the PPARγ agonist, a PPARα-specific agonist strongly inhibited atherosclerosis, whereas a PPARβ-specific agonist failed to inhibit lesion formation. In concert with their effects on atherosclerosis, PPARα and PPARγ agonists, but not the PPARβ agonist, inhibited the formation of macrophage foam cells in the peritoneal cavity. Unexpectedly, PPARα and PPARγ agonists inhibited foam-cell formation in vivo through distinct ABCA1-independent pathways. While inhibition of foam-cell formation by PPARα required LXRs, activation of PPARγ reduced cholesterol esterification, induced expression of ABCG1, and stimulated HDL-dependent cholesterol efflux in an LXR-independent manner. In concert, these findings reveal receptor-specific mechanisms by which PPARs influence macrophage cholesterol homeostasis. In the future, these mechanisms may be exploited pharmacologically to inhibit the development of atherosclerosis. PMID:15578089

ACUTE PHARMACOLOGICAL INHIBITION OF CHOLINESTERASE RESULTS IN MINIMAL NEUROMUSCULAR JITTER CHANGES.

EPA Science Inventory

Concern over the lack of available endpoints to assess peripheral nervous system dysfunction after pesticide exposure has led to the search for new laboratory models. Recently our lab adapted the in vivo clinical practice of stimulation single fiber electromyography (SFEMG) for u...

Kinetics and Mechanism Study of Competitive Inhibition of Jack-Bean Urease by Baicalin

PubMed Central

Tan, Lirong; Su, Jiyan; Wu, Dianwei; Yu, Xiaodan; Su, Zuqing; Wu, Xiaoli; Kong, Songzhi; Lai, Xiaoping; Lin, Ji; Su, Ziren

2013-01-01

Baicalin (BA) is the principal component of Radix Scutellariae responsible for its pharmacological activity. In this study, kinetics and mechanism of inhibition by BA against jack-bean urease were investigated for its therapeutic potential. It was revealed that the IC50 of BA against jack-bean urease was 2.74 ± 0.51 mM, which was proved to be a competitive and concentration-dependent inhibition with slow-binding progress curves. The rapid formation of initial BA-urease complex with an inhibition constant of K i = 3.89 × 10−3 mM was followed by a slow isomerization into the final complex with an overall inhibition constant of K i* = 1.47 × 10−4 mM. High effectiveness of thiol protectors against BA inhibition indicated that the strategic role of the active-site sulfhydryl group of the urease was involved in the blocking process. Moreover, the inhibition of BA was proved to be reversible due to the fact that urease could be reactivated by dithiothreitol but not reactant dilution. Molecular docking assay suggested that BA made contacts with the important activating sulfhydryl group Cys-592 residues and restricted the mobility of the active-site flap. Taken together, it could be deduced that BA was a competitive inhibitor targeting thiol groups of urease in a slow-binding manner both reversibly and concentration-dependently, serving as a promising urease inhibitor for treatments on urease-related diseases. PMID:24198731

Pharmacological Inhibition of Poly(ADP-Ribose) Polymerases Improves Fitness and Mitochondrial Function in Skeletal Muscle

PubMed Central

Pirinen, Eija; Canto, Carles; Jo, Young-Suk; Morato, Laia; Zhang, Hongbo; Menzies, Keir; Williams, Evan G.; Mouchiroud, Laurent; Moullan, Norman; Hagberg, Carolina; Li, Wei; Timmers, Silvie; Imhof, Ralph; Verbeek, Jef; Pujol, Aurora; van Loon, Barbara; Viscomi, Carlo; Zeviani, Massimo; Schrauwen, Patrick; Sauve, Anthony; Schoonjans, Kristina; Auwerx, Johan

2014-01-01

SUMMARY We previously demonstrated that the deletion of the poly(ADP-ribose)polymerase (Parp)-1 gene in mice enhances oxidative metabolism, thereby protecting against diet-induced obesity. However, the therapeutic use of PARP inhibitors to enhance mitochondrial function remains to be explored. Here, we show tight negative correlation between Parp-1 expression and energy expenditure in heterogeneous mouse populations, indicating that variations in PARP-1 activity have an impact on metabolic homeostasis. Notably, these genetic correlations can be translated into pharmacological applications. Long-term treatment with PARP inhibitors enhances fitness in mice by increasing the abundance of mitochondrial respiratory complexes and boosting mitochondrial respiratory capacity. Furthermore, PARP inhibitors reverse mitochondrial defects in primary myotubes of obese humans and attenuate genetic defects of mitochondrial metabolism in human fibroblasts and C. elegans. Overall, our work validates in worm, mouse and human models that PARP inhibition may be used to treat both genetic and acquired muscle dysfunction linked to defective mitochondrial function. PMID:24814482

Celecoxib: a potent cyclooxygenase-2 inhibitor in cancer prevention.

PubMed

Kismet, Kemal; Akay, M Turan; Abbasoglu, Osman; Ercan, Aygün

2004-01-01

Non-steroidal anti-inflammatory drugs (NSAIDs) are the most widely used therapeutic agents in the treatment of pain, inflammation and fever. They may also have a role in the management of cancer prevention, Alzheimer's disease and prophylaxis against cardiovascular disease. These drugs act primarily by inhibiting cyclooxygenase enzyme, which has two isoforms, cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2). Selective COX-2 inhibitors provide potent anti-inflammatory and analgesic effects without the side effects of gastric and renal toxicity and inhibition of platelet function. Celecoxib is a potent COX-2 inhibitor being developed for the treatment of rheumatoid arthritis and osteoarthritis. Chemoprevention is the use of pharmacological or natural agents to prevent, suppress, interrupt or reverse the process of carcinogenesis. For this purpose, celecoxib is being used for different cancer types. The effects of NSAIDs on tumor growth remain unclear, but are most likely to be multifocal. In this article, we reviewed COX-2 selectivity, the pharmacological properties of celecoxib, the use of celecoxib for cancer prevention and the mechanisms of chemoprevention.

Feedback regulation on PTEN/AKT pathway by the ER stress kinase PERK mediated by interaction with the Vault complex.

PubMed

Zhang, Wei; Neo, Suat Peng; Gunaratne, Jayantha; Poulsen, Anders; Boping, Liu; Ong, Esther Hongqian; Sangthongpitag, Kanda; Pendharkar, Vishal; Hill, Jeffrey; Cohen, Stephen M

2015-03-01

The high proliferation rate of cancer cells, together with environmental factors such as hypoxia and nutrient deprivation can cause Endoplasmic Reticulum (ER) stress. The protein kinase PERK is an essential mediator in one of the three ER stress response pathways. Genetic and pharmacological inhibition of PERK has been reported to limit tumor growth in xenograft models. Here we provide evidence that inactive PERK interacts with the nuclear pore-associated Vault complex protein and that this compromises Vault-mediated nuclear transport of PTEN. Pharmacological inhibition of PERK under ER stress results is abnormal sequestration of the Vault complex, leading to increased cytoplasmic PTEN activity and lower AKT activation. As the PI3K/PTEN/AKT pathway is crucial for many aspects of cell growth and survival, this unexpected effect of PERK inhibitors on AKT activity may have implications for their potential use as therapeutic agents. Copyright © 2014. Published by Elsevier Inc.

Microwave-assisted extraction and pharmacological evaluation of polysaccharides from Posidonia oceanica.

PubMed

Ben Salem, Yosra; Abdelhamid, Amal; Mkadmini Hammi, Khaoula; Le Cerf, Didier; Bouraoui, Abderrahman; Majdoub, Hatem

2017-10-01

Microwave-assisted extraction was employed for the isolation of polysaccharides from Posidonia oceanica (PPO). The extracting parameters were optimized adopting response surface methodology. The highest polysaccharide yield (2.55 ± 0.09%), which is in concordance with the predicted value (2.76%), was obtained under the following conditions: extraction time 60 s, liquid-solid ratio of 50:1 (mL/g) and power of 800 W. This polysaccharide, with molecular weight of 524 KDa, characterized by gas chromatography-mass spectrometry showed that PPO was mainly composed of galactose, glucose, and arabinose with molar percentages 25.38, 24.37, and 21.64%, respectively. The pharmacological evaluation of PPO using animal models at the dose of 100 mg/kg indicated a significant anti-inflammatory activity with a percentage of inhibition of edema of 54.65% and a significant antinociceptive activity with 78.91% inhibition of writhing for peripheral analgesic activity and an increase in the hot plate reaction time for central analgesic activity.

Legumain Regulates Differentiation Fate of Human Bone Marrow Stromal Cells and Is Altered in Postmenopausal Osteoporosis.

PubMed

Jafari, Abbas; Qanie, Diyako; Andersen, Thomas L; Zhang, Yuxi; Chen, Li; Postert, Benno; Parsons, Stuart; Ditzel, Nicholas; Khosla, Sundeep; Johansen, Harald Thidemann; Kjærsgaard-Andersen, Per; Delaisse, Jean-Marie; Abdallah, Basem M; Hesselson, Daniel; Solberg, Rigmor; Kassem, Moustapha

2017-02-14

Secreted factors are a key component of stem cell niche and their dysregulation compromises stem cell function. Legumain is a secreted cysteine protease involved in diverse biological processes. Here, we demonstrate that legumain regulates lineage commitment of human bone marrow stromal cells and that its expression level and cellular localization are altered in postmenopausal osteoporotic patients. As shown by genetic and pharmacological manipulation, legumain inhibited osteoblast (OB) differentiation and in vivo bone formation through degradation of the bone matrix protein fibronectin. In addition, genetic ablation or pharmacological inhibition of legumain activity led to precocious OB differentiation and increased vertebral mineralization in zebrafish. Finally, we show that localized increased expression of legumain in bone marrow adipocytes was inversely correlated with adjacent trabecular bone mass in a cohort of patients with postmenopausal osteoporosis. Our data suggest that altered proteolytic activity of legumain in the bone microenvironment contributes to decreased bone mass in postmenopausal osteoporosis. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

[STUDYING THE ROLE OF BRAIN MELANOCORTIN RECEPTORS IN THE SUPPRESSING OF FOOD INTAKE UNDER ETHER STRESS IN MICE].

PubMed

Bazhan, N M; Kulikova, E V; Makarova, E N; Yakovleva, T V; Kazantseva, A Yu

2015-12-01

Melanocortin (MC) system regulates food intake under the rest conditions. Stress inhibits food intake. It is not clear whether brain MC system is involved in stress-induced anorexia in mice. The aim of the work was to investigate the effect of pharmacological blockade and activation of brain MC receptors on food intake under stress. C57B1/6J male mice were subjected to ether stress (0.5 minute ether anesthesia) before the administration of saline solution or synthetic non-selective blocker (SHU9119) or agonist (Melanotan II) of MC receptors into the lateral brain ventricle. Food intake was pre-stimulated with 17 hours of fasting in all mice. Ether stress decreased food intake, increased the plasma corticosterone level and hypothalamic mRNA AgRP (natural MC receptor antagonist) level at 1 hour after the stress. Pharmacological blockade of the MC receptors weakened stress-induced anorexia and decreased mRNA AgRP level in the hypothalamus. Pharmacological stimulation of the MC receptors enhanced ether stress-induced anorexia and hypercortisolism. Thus, our data demonstrated that the central MC system was involved in the development of stress-induced anorexia in mice.

Obligatory role for GPER in cardiovascular aging and disease.

PubMed

Meyer, Matthias R; Fredette, Natalie C; Daniel, Christoph; Sharma, Geetanjali; Amann, Kerstin; Arterburn, Jeffrey B; Barton, Matthias; Prossnitz, Eric R

2016-11-01

Pharmacological activation of the heptahelical G protein-coupled estrogen receptor (GPER) by selective ligands counteracts multiple aspects of cardiovascular disease. We thus expected that genetic deletion or pharmacological inhibition of GPER would further aggravate such disease states, particularly with age. To the contrary, we found that genetic ablation of Gper in mice prevented cardiovascular pathologies associated with aging by reducing superoxide (⋅O 2 - ) formation by NADPH oxidase (Nox) specifically through reducing the expression of the Nox isoform Nox1 Blocking GPER activity pharmacologically with G36, a synthetic, small-molecule, GPER-selective blocker (GRB), decreased Nox1 abundance and ⋅O 2 - production to basal amounts in cells exposed to angiotensin II and in mice chronically infused with angiotensin II, reducing arterial hypertension. Thus, this study revealed a role for GPER activity in regulating Nox1 abundance and associated ⋅O 2 - -mediated structural and functional damage that contributes to disease pathology. Our results indicated that GRBs represent a new class of drugs that can reduce Nox abundance and activity and could be used for the treatment of chronic disease processes involving excessive ⋅O 2 - formation, including arterial hypertension and heart failure. Copyright © 2016, American Association for the Advancement of Science.

Autophagy mediates pharmacological lifespan extension by spermidine and resveratrol

PubMed Central

Morselli, Eugenia; Galluzzi, Lorenzo; Kepp, Oliver; Criollo, Alfredo; Maiuri, Maria Chiara; Tavernarakis, Nektarios; Madeo, Frank; Kroemer, Guido

2009-01-01

Although autophagy has widely been conceived as a self-destructive mechanism that causes cell death, accumulating evidence suggests that autophagy usually mediates cytoprotection, thereby avoiding the apoptotic or necrotic demise of stressed cells. Recent evidence produced by our groups demonstrates that autophagy is also involved in pharmacological manipulations that increase longevity. Exogenous supply of the polyamine spermidine can prolong the lifespan of (while inducing autophagy in) yeast, nematodes and flies. Similarly, resveratrol can trigger autophagy in cells from different organisms, extend lifespan in nematodes, and ameliorate the fitness of human cells undergoing metabolic stress. These beneficial effects are lost when essential autophagy modulators are genetically or pharmacologically inactivated, indicating that autophagy is required for the cytoprotective and/or anti-aging effects of spermidine and resveratrol. Genetic and functional studies indicate that spermidine inhibits histone acetylases, while resveratrol activates the histone deacetylase Sirtuin 1 to confer cytoprotection/longevity. Although it remains elusive whether the same histones (or perhaps other nuclear or cytoplasmic proteins) act as the downstream targets of spermidine and resveratrol, these results point to an essential role of protein hypoacetylation in autophagy control and in the regulation of longevity. PMID:20157579

Pharmacology of the human red cell voltage-dependent cation channel; Part I. Activation by clotrimazole and analogues.

PubMed

Barksmann, Trine L; Kristensen, Berit I; Christophersen, Palle; Bennekou, Poul

2004-01-01

The activation and pharmacological modulation of the nonselective voltage-dependent cation (NSVDC) channel from human erythrocytes were studied. Basic channel activation was achieved by suspending red cells in a low Cl(-) Ringer (2 mM), where a positive membrane potential (V(m) = E(Cl)) immediately developed. Voltage- and time-dependent activation of the NSVDC channel occurred, reaching a cation conductance (g+) of 1.5-2.0 microS cm(-2). In the presence of the classical Gárdos channel blocker clotrimazole (0-50 microM), activation occurred faster, and g+ saturated dose-dependently (EC50 = 14 microM) at a value of about 4 microS cm(-2). The clotrimazole analogues TRAM-34, econazole, and miconazole also stimulated the channel, whereas the chemically more distant Gárdos channel inhibitors nitrendipine and cetiedil had no effects. Although the potency for modulation of the NSVDC channel is much lower than the IC50 value for Gárdos channel inhibition, clotrimazole (and its analogues) constitutes the first chemical class of positive modulators of the NSVDC channel. This may be an important pharmacological "fingerprint" in the identification of the cloned equivalent of the erythrocyte channel.

Action of bradykinin potentiating factor (BPF) and dimercaprol (BAL) on the responses to bradykinin of isolated preparations of rat intestines.

PubMed

Camargo, A; Ferreira, S H

1971-06-01

BPF and BAL inhibited kininase activity of homogenates of rat intestine. However, BFP potentiated and BAL inhibited the contractions induced by bradykinin on rat isolated duodenum (low calcium solution) and terminal ileum (normal calcium solution). Neither BPF nor BAL affects the relaxation induced by bradykinin of rat duodenum bathed in normal Tyrode. These results suggest that two different types of pharmacological receptor are involved in the action of bradykinin on rat intestine, and that other factors besides the inhibition of agonist destruction participate in the mechanism of potentiation of kinin action by BPF.

Action of bradykinin potentiating factor (BPF) and dimercaprol (BAL) on the responses to bradykinin of isolated preparations of rat intestines

PubMed Central

Camargo, A.; Ferreira, S. H.

1971-01-01

BPF and BAL inhibited kininase activity of homogenates of rat intestine. However, BFP potentiated and BAL inhibited the contractions induced by bradykinin on rat isolated duodenum (low calcium solution) and terminal ileum (normal calcium solution). Neither BPF nor BAL affects the relaxation induced by bradykinin of rat duodenum bathed in normal Tyrode. These results suggest that two different types of pharmacological receptor are involved in the action of bradykinin on rat intestine, and that other factors besides the inhibition of agonist destruction participate in the mechanism of potentiation of kinin action by BPF. PMID:5091164

Paeoniflorin protects against ischemia-induced brain damages in rats via inhibiting MAPKs/NF-κB-mediated inflammatory responses.

PubMed

Guo, Ruo-Bing; Wang, Guo-Feng; Zhao, An-Peng; Gu, Jun; Sun, Xiu-Lan; Hu, Gang

2012-01-01

Paeoniflorin (PF), the principal component of Paeoniae Radix prescribed in traditional Chinese medicine, has been reported to exhibit many pharmacological effects including protection against ischemic injury. However, the mechanisms underlying the protective effects of PF on cerebral ischemia are still under investigation. The present study showed that PF treatment for 14 days could significantly inhibit transient middle cerebral artery occlusion (MCAO)-induced over-activation of astrocytes and microglia, and prevented up-regulations of pro-inflamamtory mediators (TNFα, IL-1β, iNOS, COX(2) and 5-LOX) in plasma and brain. Further study demonstrated that chronic treatment with PF suppressed the activations of JNK and p38 MAPK, but enhanced ERK activation. And PF could reverse ischemia-induced activation of NF-κB signaling pathway. Moreover, our in vitro study revealed that PF treatment protected against TNFα-induced cell apoptosis and neuronal loss. Taken together, the present study demonstrates that PF produces a delayed protection in the ischemia-injured rats via inhibiting MAPKs/NF-κB mediated peripheral and cerebral inflammatory response. Our study reveals that PF might be a potential neuroprotective agent for stroke.

Phosphoinositide-3-Kinase Is the Primary Mediator of Phosphoinositide-Dependent Inhibition in Mammalian Olfactory Receptor Neurons

PubMed Central

Ukhanov, Kirill; Corey, Elizabeth; Ache, Barry W.

2016-01-01

Odorants inhibit as well as excite primary olfactory receptor neurons (ORNs) in many animal species. Growing evidence suggests that inhibition of mammalian ORNs is mediated by phosphoinositide (PI) signaling through activation of phosphoinositide 3-kinase (PI3K), and that canonical adenylyl cyclase III signaling and PI3K signaling interact to provide the basis for ligand-induced selective signaling. As PI3K is known to act in concert with phospholipase C (PLC) in some cellular systems, the question arises as to whether they work together to mediate inhibitory transduction in mammalian ORNs. The present study is designed to test this hypothesis. While we establish that multiple PLC isoforms are expressed in the transduction zone of rat ORNs, that odorants can activate PLC in ORNs in situ, and that pharmacological blockade of PLC enhances the excitatory response to an odorant mixture in some ORNs in conjunction with PI3K blockade, we find that by itself PLC does not account for an inhibitory response. We conclude that PLC does not make a measurable independent contribution to odor-evoked inhibition, and that PI3K is the primary mediator of PI-dependent inhibition in mammalian ORNs. PMID:27147969

Malonyl-coenzyme-A is a potential mediator of cytotoxicity induced by fatty-acid synthase inhibition in human breast cancer cells and xenografts.

PubMed

Pizer, E S; Thupari, J; Han, W F; Pinn, M L; Chrest, F J; Frehywot, G L; Townsend, C A; Kuhajda, F P

2000-01-15

A biologically aggressive subset of human breast cancers and other malignancies is characterized by elevated fatty-acid synthase (FAS) enzyme expression, elevated fatty acid (FA) synthesis, and selective sensitivity to pharmacological inhibition of FAS activity by cerulenin or the novel compound C75. In this study, inhibition of FA synthesis at the physiologically regulated step of carboxylation of acetyl-CoA to malonyl-CoA by 5-(tetradecyloxy)-2-furoic acid (TOFA) was not cytotoxic to breast cancer cells in clonogenic assays. FAS inhibitors induced a rapid increase in intracellular malonyl-CoA to several fold above control levels, whereas TOFA reduced intracellular malonyl-CoA by 60%. Simultaneous exposure of breast cancer cells to TOFA and an FAS inhibitor resulted in significantly reduced cytotoxicity and apoptosis. Subcutaneous xenografts of MCF7 breast cancer cells in nude mice treated with C75 showed FA synthesis inhibition, apoptosis, and inhibition of tumor growth to less than 1/8 of control volumes, without comparable toxicity in normal tissues. The data suggest that differences in intermediary metabolism render tumor cells susceptible to toxic fluxes in malonyl-CoA, both in vitro and in vivo.

Antiophidian properties of the aqueous extract of Mikania glomerata.

PubMed

Maiorano, Victor A; Marcussi, Silvana; Daher, Maristela A F; Oliveira, Clayton Z; Couto, Lucélio B; Gomes, Odair A; França, Suzelei C; Soares, Andreimar M; Pereira, Paulo S

2005-12-01

Aqueous extracts, prepared from dried or fresh roots, stems or leaves of Mikania glomerata, a plant found in Mata Atlântica in Southeastern Brazil, were able to efficiently neutralize different toxic, pharmacological, and enzymatic effects induced by venoms from Bothrops and Crotalus snakes. Phospholipase A(2) activity and the edema induced by Crotalus durissus terrificus venom were inhibited around 100 and approximately 40%, respectively, although this inhibition was only partial for Bothrops venoms. The hemorrhagic activity of Bothrops venoms (Bothrops altenatus, Bothrops moojeni, Bothrops neuwiedi, and Bothrops jararacussu) was significantly inhibited by this vegetal species, while the clotting activity of Crotalus durissus terrificus, Bothrops jararacussu, and Bothrops neuwiedi venoms was totally inhibited. Although, the mechanism of action of Mikania glomerata extract is still unknown, the finding that no visible change was detected in the electrophoretic pattern of snake venom after incubation with the extract excludes proteolytic degradation as a potential mechanism. Since the extract of Mikania glomerata significantly inhibited the studied snake venoms, it may be used as an alternative treatment to serumtherapy and, in addition, as a rich source of potential inhibitors of PLA(2)s, metalloproteases and serineproteases, enzymes involved in several physiopathological human and animal diseases.

Inhibition of Ubiquitin-specific Peptidase 8 Suppresses Adrenocorticotropic Hormone Production and Tumorous Corticotroph Cell Growth in AtT20 Cells

PubMed Central

Jian, Fang-Fang; Li, Yun-Feng; Chen, Yu-Fan; Jiang, Hong; Chen, Xiao; Zheng, Li-Li; Zhao, Yao; Wang, Wei-Qing; Ning, Guang; Bian, Liu-Guan; Sun, Qing-Fang

2016-01-01

Background: Two recent whole-exome sequencing researches identifying somatic mutations in the ubiquitin-specific protease 8 (USP8) gene in pituitary corticotroph adenomas provide exciting advances in this field. These mutations drive increased epidermal growth factor receptor (EGFR) signaling and promote adrenocorticotropic hormone (ACTH) production. This study was to investigate whether the inhibition of USP8 activity could be a strategy for the treatment of Cushing's disease (CD). Methods: The anticancer effect of USP8 inhibitor was determined by testing cell viability, colony formation, apoptosis, and ACTH secretion. The immunoblotting and quantitative reverse transcription polymerase chain reaction were conducted to explore the signaling pathway by USP8 inhibition. Results: Inhibition of USP8-induced degradation of receptor tyrosine kinases including EGFR, EGFR-2 (ERBB2), and Met leading to a suppression of AtT20 cell growth and ACTH secretion. Moreover, treatment with USP8 inhibitor markedly induced AtT20 cells apoptosis. Conclusions: Inhibition of USP8 activity could be an effective strategy for CD. It might provide a novel pharmacological approach for the treatment of CD. PMID:27569239

Gremlin inhibits UV-induced skin cell damages via activating VEGFR2-Nrf2 signaling

PubMed Central

Xu, Qiu-yun; Zhang, Jing; Lin, Meng-ting; Tu, Ying; He, Li; Bi, Zhi-gang; Cheng, Bo

2016-01-01

Ultra Violet (UV) radiation induces reactive oxygen species (ROS) production, DNA oxidation and single strand breaks (SSBs), which will eventually lead to skin cell damages or even skin cancer. Here, we tested the potential activity of gremlin, a novel vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2) agonist, against UV-induced skin cell damages. We show that gremlin activated VEGFR2 and significantly inhibited UV-induced death and apoptosis of skin keratinocytes and fibroblasts. Pharmacological inhibition or shRNA-mediated knockdown of VEGFR2 almost abolished gremlin-mediated cytoprotection against UV in the skin cells. Further studies showed that gremlin activated VEGFR2 downstream NF-E2-related factor 2 (Nrf2) signaling, which appeared required for subsequent skin cell protection. Nrf2 shRNA knockdown or S40T dominant negative mutation largely inhibited gremlin-mediated skin cell protection against UV. At last, we show that gremlin dramatically inhibited UV-induced ROS production and DNA SSB formation in skin keratinocytes and fibroblasts. We conclude that gremlin protects skin cells from UV damages via activating VEGFR2-Nrf2 signaling. Gremlin could be further tested as a novel anti-UV skin protectant. PMID:27713170

Gremlin inhibits UV-induced skin cell damages via activating VEGFR2-Nrf2 signaling.

PubMed

Ji, Chao; Huang, Jin-Wen; Xu, Qiu-Yun; Zhang, Jing; Lin, Meng-Ting; Tu, Ying; He, Li; Bi, Zhi-Gang; Cheng, Bo

2016-12-20

Ultra Violet (UV) radiation induces reactive oxygen species (ROS) production, DNA oxidation and single strand breaks (SSBs), which will eventually lead to skin cell damages or even skin cancer. Here, we tested the potential activity of gremlin, a novel vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2) agonist, against UV-induced skin cell damages. We show that gremlin activated VEGFR2 and significantly inhibited UV-induced death and apoptosis of skin keratinocytes and fibroblasts. Pharmacological inhibition or shRNA-mediated knockdown of VEGFR2 almost abolished gremlin-mediated cytoprotection against UV in the skin cells. Further studies showed that gremlin activated VEGFR2 downstream NF-E2-related factor 2 (Nrf2) signaling, which appeared required for subsequent skin cell protection. Nrf2 shRNA knockdown or S40T dominant negative mutation largely inhibited gremlin-mediated skin cell protection against UV. At last, we show that gremlin dramatically inhibited UV-induced ROS production and DNA SSB formation in skin keratinocytes and fibroblasts. We conclude that gremlin protects skin cells from UV damages via activating VEGFR2-Nrf2 signaling. Gremlin could be further tested as a novel anti-UV skin protectant.

Mitochondrial Probe Methyltriphenylphosphonium (TPMP) Inhibits the Krebs Cycle Enzyme 2-Oxoglutarate Dehydrogenase.

PubMed

Elkalaf, Moustafa; Tůma, Petr; Weiszenstein, Martin; Polák, Jan; Trnka, Jan

2016-01-01

Methyltriphenylphosphonium (TPMP) salts have been widely used to measure the mitochondrial membrane potential and the triphenylphosphonium (TPP+) moiety has been attached to many bioactive compounds including antioxidants to target them into mitochondria thanks to their high affinity to accumulate in the mitochondrial matrix. The adverse effects of these compounds on cellular metabolism have been insufficiently studied and are still poorly understood. Micromolar concentrations of TPMP cause a progressive inhibition of cellular respiration in adherent cells without a marked effect on mitochondrial coupling. In permeabilized cells the inhibition was limited to NADH-linked respiration. We found a mixed inhibition of the Krebs cycle enzyme 2-oxoglutarate dehydrogenase complex (OGDHC) with an estimated IC50 3.93 [3.70-4.17] mM, which is pharmacologically plausible since it corresponds to micromolar extracellular concentrations. Increasing the lipophilic character of the used TPP+ compound further potentiates the inhibition of OGDHC activity. This effect of TPMP on the Krebs cycle ought to be taken into account when interpreting observations on cells and mitochondria in the presence of TPP+ derivatives. Compounds based on or similar to TPP+ derivatives may also be used to alter OGDHC activity for experimental or therapeutic purposes.

Mitochondrial Probe Methyltriphenylphosphonium (TPMP) Inhibits the Krebs Cycle Enzyme 2-Oxoglutarate Dehydrogenase

PubMed Central

Elkalaf, Moustafa; Tůma, Petr; Weiszenstein, Martin; Polák, Jan

2016-01-01

Methyltriphenylphosphonium (TPMP) salts have been widely used to measure the mitochondrial membrane potential and the triphenylphosphonium (TPP+) moiety has been attached to many bioactive compounds including antioxidants to target them into mitochondria thanks to their high affinity to accumulate in the mitochondrial matrix. The adverse effects of these compounds on cellular metabolism have been insufficiently studied and are still poorly understood. Micromolar concentrations of TPMP cause a progressive inhibition of cellular respiration in adherent cells without a marked effect on mitochondrial coupling. In permeabilized cells the inhibition was limited to NADH-linked respiration. We found a mixed inhibition of the Krebs cycle enzyme 2-oxoglutarate dehydrogenase complex (OGDHC) with an estimated IC50 3.93 [3.70–4.17] mM, which is pharmacologically plausible since it corresponds to micromolar extracellular concentrations. Increasing the lipophilic character of the used TPP+ compound further potentiates the inhibition of OGDHC activity. This effect of TPMP on the Krebs cycle ought to be taken into account when interpreting observations on cells and mitochondria in the presence of TPP+ derivatives. Compounds based on or similar to TPP+ derivatives may also be used to alter OGDHC activity for experimental or therapeutic purposes. PMID:27537184

Apigenin inhibits rat neurosteroidogenic 5α-reductase 1 and 3α-hydroxysteroid dehydrogenase.

PubMed

Wu, Ying; Li, Lili; Zhou, Songyi; Shen, Qiuxia; Lin, Han; Zhu, Qiqi; Sun, Jianliang; Ge, Ren-Shan

2017-11-01

Apigenin, a common flavonoid, has extensive pharmacological activities. Apigenin inhibits some steroid biosynthetic enzymes, suggesting that it may block neurosteroid synthesis. Neurosteroids play many important roles in neurological functions. The objective of the present study is to investigate effects of apigenin on neurosteroidogenic enzymes, 5α-reductase 1 (SRD5A1), 3α-hydroxysteroid dehydrogenase (AKR1C9), and retinol dehydrogenase 2 (RoDH2), in rats. SRD5A1, AKR1C9, and RoDH2 were expressed in COS-1 cells and the effects of apigenin on these enzymes and modes of action were explored using radiolabeled substrates and thin-layer chromatographic separation coupled with radiometry. Apigenin inhibited SRD5A1, AKR1C9, and RoDH2 activities with IC 50 values of 100, 0.891 ± 0.065, and >100 μM, respectively. Apigenin competitively inhibited rat AKR1C9 when its substrate 5α-dihydrotestosterone was used and uncompetitively inhibited the enzyme when cofactor NADPH was used. In conclusion, apigenin is a potent inhibitor of rat AKR1C9, thereby controlling the rate of neurosteroid biosynthesis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Assessment of Enzyme Inhibition: A Review with Examples from the Development of Monoamine Oxidase and Cholinesterase Inhibitory Drugs.

PubMed

Ramsay, Rona R; Tipton, Keith F

2017-07-15

The actions of many drugs involve enzyme inhibition. This is exemplified by the inhibitors of monoamine oxidases (MAO) and the cholinsterases (ChE) that have been used for several pharmacological purposes. This review describes key principles and approaches for the reliable determination of enzyme activities and inhibition as well as some of the methods that are in current use for such studies with these two enzymes. Their applicability and potential pitfalls arising from their inappropriate use are discussed. Since inhibitor potency is frequently assessed in terms of the quantity necessary to give 50% inhibition (the IC 50 value), the relationships between this and the mode of inhibition is also considered, in terms of the misleading information that it may provide. Incorporation of more than one functionality into the same molecule to give a multi-target-directed ligands (MTDLs) requires careful assessment to ensure that the specific target effects are not significantly altered and that the kinetic behavior remains as favourable with the MTDL as it does with the individual components. Such factors will be considered in terms of recently developed MTDLs that combine MAO and ChE inhibitory functions.

Elucidation of flow-mediated tumour cell-induced platelet aggregation using an ultrasound standing wave trap.

PubMed

Bazou, D; Santos-Martinez, M J; Medina, C; Radomski, M W

2011-04-01

Tumour cells activate and aggregate platelets [tumour cell-induced platelet aggregation (TCIPA)] and this process plays an important role in the successful metastasis of cancer cells. To date, most studies on TCIPA have been conducted under no-flow conditions. In this study, we have investigated TCIPA in real time under flow conditions, using an ultrasound standing wave trap that allows formation and levitation of cancer cell clusters in suspension, thus mimicking the conditions generated by flowing blood. Using 59M adenocarcinoma and HT1080 fibrosarcoma cells and human platelets, cancer cell cluster-platelet aggregates were imaged in real time using epi-fluorescence microscopy (F-actin) and investigated in detail using confocal microscopy (matrix metalloproteinase-2-GPIIb/IIIa co-localization) and scanning electron and helium-ion microscopy (<1 nm resolution). The release of gelatinases from aggregates was studied using zymography. We found that platelet activation and aggregation takes place on the surface of cancer cells (TCIPA), leading to time-dependent disruption of cancer cell clusters. Pharmacological modulation of TCIPA revealed that EDTA, prostacyclin, o-phenanthroline and apyrase significantly down-regulated TCIPA and, in turn, delayed cell cluster disruption, However, EGTA and aspirin were ineffective. Pharmacological inhibition of TCIPA correlated with the down-regulation of platelet activation as shown by flow-cytometry assay of platelet P-selectin. Our results show for the first time, that during TCIPA, platelet activation disrupts cancer cell clusters and this can contribute to metastasis. Thus, selective targeting of platelet aggregate-cancer cell clusters may be an important strategy to control metastasis. © 2011 The Authors. British Journal of Pharmacology © 2011 The British Pharmacological Society.

Reciprocal feedback regulation of PI3K and androgen receptor signaling in PTEN-deficient prostate cancer.

PubMed

Carver, Brett S; Chapinski, Caren; Wongvipat, John; Hieronymus, Haley; Chen, Yu; Chandarlapaty, Sarat; Arora, Vivek K; Le, Carl; Koutcher, Jason; Scher, Howard; Scardino, Peter T; Rosen, Neal; Sawyers, Charles L

2011-05-17

Prostate cancer is characterized by its dependence on androgen receptor (AR) and frequent activation of PI3K signaling. We find that AR transcriptional output is decreased in human and murine tumors with PTEN deletion and that PI3K pathway inhibition activates AR signaling by relieving feedback inhibition of HER kinases. Similarly, AR inhibition activates AKT signaling by reducing levels of the AKT phosphatase PHLPP. Thus, these two oncogenic pathways cross-regulate each other by reciprocal feedback. Inhibition of one activates the other, thereby maintaining tumor cell survival. However, combined pharmacologic inhibition of PI3K and AR signaling caused near-complete prostate cancer regressions in a Pten-deficient murine prostate cancer model and in human prostate cancer xenografts, indicating that both pathways coordinately support survival. Copyright © 2011 Elsevier Inc. All rights reserved.

Buprenorphine metabolites, buprenorphine-3-glucuronide and norbuprenorphine-3-glucuronide, are biologically active

PubMed Central

Brown, Sarah M.; Holtzman, Michael; Kim, Thomas; Kharasch, Evan D.

2012-01-01

Background The long-lasting high affinity opioid buprenorphine has complex pharmacology including ceiling effects with respect to analgesia and respiratory depression. Plasma concentrations of the major buprenorphine metabolites norbuprenorphine, buprenorphine-3-glucuronide, and norbuprenorphine-3-glucuronide approximate or exceed those of the parent drug. Buprenorphine glucuronide metabolites pharmacology is undefined. This investigation determined binding and pharmacological activity of the two glucuronide metabolites, and in comparison with buprenorphine and norbuprenorphine. Methods Competitive inhibition of radioligand binding to human mu, kappa, delta opioid and nociceptin receptors was used to determine glucuronide binding affinities for these receptors. Common opiate effects were assessed in vivo in Swiss Webster mice. Antinociception was assessed using a tail-flick assay, respiratory effects were measured using unrestrained whole-body plethysmography, and sedation was assessed by inhibition of locomotion measured by open-field testing. Results Buprenorphine-3-glucuronide had high affinity for human mu (Ki = 4.9±2.7 pM), delta (Ki = 270±0.4 nM), and nociceptin (Ki = 36±0.3 μM) but not kappa receptors. Norbuprenorphine-3-glucuronide had affinity for human kappa (Ki = 300±0.5 nM) and nociceptin (Ki= 18±0.2 μM) but not mu or delta receptors. At the dose tested, buprenorphine-3-glucuronide had a small antinociceptive effect. Neither glucuronide had significant effects on respiratory rate, but norbuprenorphine-3-glucuronide decreased tidal volume. Norbuprenorphine-3-glucuronide also caused sedation. Conclusions Both glucuronide metabolites of buprenorphine are biologically active at doses relevant to metabolite exposures which occur after buprenorphine. Activity of the glucuronides may contribute to the overall pharmacology of buprenorphine. PMID:22037640

Grape seed and tea extracts and catechin 3-gallates are potent inhibitors of α-amylase and α-glucosidase activity.

PubMed

Yilmazer-Musa, Meltem; Griffith, Anneke M; Michels, Alexander J; Schneider, Erik; Frei, Balz

2012-09-12

This study evaluated the inhibitory effects of plant-based extracts (grape seed, green tea, and white tea) and their constituent flavan-3-ol monomers (catechins) on α-amylase and α-glucosidase activity, two key glucosidases required for starch digestion in humans. To evaluate the relative potency of extracts and catechins, their concentrations required for 50 and 90% inhibition of enzyme activity were determined and compared to the widely used pharmacological glucosidase inhibitor, acarbose. Maximum enzyme inhibition was used to assess relative inhibitory efficacy. Results showed that grape seed extract strongly inhibited both α-amylase and α-glucosidase activity, with equal and much higher potency, respectively, than acarbose. Whereas tea extracts and catechin 3-gallates were less effective inhibitors of α-amylase, they were potent inhibitors of α-glucosidase. Nongallated catechins were ineffective. The data show that plant extracts containing catechin 3-gallates, in particular epigallocatechin gallate, are potent inhibitors of α-glucosidase activity and suggest that procyanidins in grape seed extract strongly inhibit α-amylase activity.

Osthole inhibits the tumorigenesis of hepatocellular carcinoma cells.

PubMed

Lin, Zhi-Kun; Liu, Jia; Jiang, Guo-Qiang; Tan, Guang; Gong, Peng; Luo, Hai-Feng; Li, Hui-Min; Du, Jian; Ning, Zhen; Xin, Yi; Wang, Zhong-Yu

2017-03-01

Hepatocellular carcinoma (HCC) accounts for approximately 90% of all cases of primary liver cancer, and the majority of patients with HCC are deprived of effective curative methods. Osthole is a Chinese herbal medicine which has been reported to possess various pharmacological functions, including hepatocellular protection. In the present study, we investigated the anticancer activity of osthole using HCC cell lines. We found that osthole inhibited HCC cell proliferation, induced cell cycle arrest, triggered DNA damage and suppressed migration in HCC cell lines. Furthermore, we demonstrated that osthole not only contributed to cell cycle G2/M phase arrest via downregulation of Cdc2 and cyclin B1 levels, but also induced DNA damage via an increase in ERCC1 expression. In addition, osthole inhibited the migration of HCC cell lines by significantly downregulating MMP-2 and MMP-9 levels. Finally, we demonstrated that osthole inhibited epithelial-mesenchymal transition (EMT) via increasing the expression of epithelial biomarkers E-cadherin and β-catenin, and significantly decreasing mesenchymal N-cadherin and vimentin protein expression. These results suggest that osthole may have potential chemotherapeutic activity against HCC.

Antioxidative effects of cinnamomi cortex: A potential role of iNOS and COX-II

PubMed Central

Chung, Jin-Won; Kim, Jeong-Jun; Kim, Sung-Jin

2011-01-01

Background: Cinnamomi cortex has wide varieties of pharmacological actions such as anti-inflammatory action, anti-platelet aggregation, and improving blood circulation. In this study, we tested to determine whether the Cinnamomi cortex extract has antioxidant activities. Materials and Methods: Antioxidative actions were explored by measuring free radical scavenging activity, NO levels, and reducing power. The mechanism of antioxidative action of Cinnamomi cortex was determined by measuring iNOS and COX-II expression in lipopolysaccharide (LPS) stimulated Raw cells. Results: Seventy percent methanolic extract of Cinnamomi cortex exerted significant 1,1-diphenyl--2--picrylhydrazyl (DPPH) free radicals and NO scavenging activities in a dose-dependent manner. More strikingly, the Cinnamomi cortex extract exerted dramatic reducing power activity (13-fold over control). Production of iNOS induced by LPS was significantly inhibited by the Cinnamomi cortex extract, suggesting that it inhibits NO production by suppressing iNOS expression. Additionally, COX-2 induced by LPS was dramatically inhibited by the Cinnamomi cortex extract. Conclusion: These results suggest that 70% methanolic extract of Cinnamomi cortex exerts significant antioxidant activity via inhibiting iNOS and COX-II induction. PMID:22262934

Rift valley fever virus infection of human cells and insect hosts is promoted by protein kinase C epsilon.

PubMed

Filone, Claire Marie; Hanna, Sheri L; Caino, M Cecilia; Bambina, Shelly; Doms, Robert W; Cherry, Sara

2010-11-24

As an arthropod-borne human pathogen, Rift Valley fever virus (RVFV) cycles between an insect vector and mammalian hosts. Little is known about the cellular requirements for infection in either host. Here we developed a tissue culture model for RVFV infection of human and insect cells that is amenable to high-throughput screening. Using this approach we screened a library of 1280 small molecules with pharmacologically defined activities and identified 59 drugs that inhibited RVFV infection with 15 inhibiting RVFV replication in both human and insect cells. Amongst the 15 inhibitors that blocked infection in both hosts was a subset that inhibits protein kinase C. Further studies found that infection is dependent upon the novel protein kinase C isozyme epsilon (PKCε) in both human and insect cells as well as in adult flies. Altogether, these data show that inhibition of cellular factors required for early steps in the infection cycle including PKCε can block RVFV infection, and may represent a starting point for the development of anti-RVFV therapeutics.

mTORC1-Mediated Inhibition of 4EBP1 Is Essential for Hedgehog Signaling-Driven Translation and Medulloblastoma.

PubMed

Wu, Chang-Chih; Hou, Shirui; Orr, Brent A; Kuo, Bryan R; Youn, Yong Ha; Ong, Taren; Roth, Fanny; Eberhart, Charles G; Robinson, Giles W; Solecki, David J; Taketo, Makoto M; Gilbertson, Richard J; Roussel, Martine F; Han, Young-Goo

2017-12-18

Mechanistic target of rapamycin (MTOR) cooperates with Hedgehog (HH) signaling, but the underlying mechanisms are incompletely understood. Here we provide genetic, biochemical, and pharmacologic evidence that MTOR complex 1 (mTORC1)-dependent translation is a prerequisite for HH signaling. The genetic loss of mTORC1 function inhibited HH signaling-driven growth of the cerebellum and medulloblastoma. Inhibiting translation or mTORC1 blocked HH signaling. Depleting 4EBP1, an mTORC1 target that inhibits translation, alleviated the dependence of HH signaling on mTORC1. Consistent with this, phosphorylated 4EBP1 levels were elevated in HH signaling-driven medulloblastomas in mice and humans. In mice, an mTORC1 inhibitor suppressed medulloblastoma driven by a mutant SMO that is inherently resistant to existing SMO inhibitors, prolonging the survival of the mice. Our study reveals that mTORC1-mediated translation is a key component of HH signaling and an important target for treating medulloblastoma and other cancers driven by HH signaling. Copyright © 2017 Elsevier Inc. All rights reserved.

4‑Phenylbutyrate protects rat skin flaps against ischemia‑reperfusion injury and apoptosis by inhibiting endoplasmic reticulum stress.

PubMed

Yue, Zhen-Shuang; Zeng, Lin-Ru; Quan, Ren-Fu; Tang, Yang-Hua; Zheng, Wen-Jie; Qu, Gang; Xu, Can-Da; Zhu, Fang-Bing; Huang, Zhong-Ming

2016-02-01

4‑phenylbutyrate (4‑PBA) is a low molecular weight fatty acid, which has been demonstrated to regulate endoplasmic reticulum (ER) stress. ER stress‑induced cell apoptosis has an important role in skin flap ischemia; however, a pharmacological approach for treating ischemia‑induced ER dysfunction has yet to be reported. In the present study, the effects of 4‑PBA‑induced ER stress inhibition on ischemia‑reperfusion injury were investigated in the skin flap of rats, and transcriptional regulation was examined. 4‑PBA attenuated ischemia‑reperfusion injury and inhibited cell apoptosis in the skin flap. Furthermore, 4‑PBA reversed the increased expression levels of two ER stress markers: CCAAT/enhancer-binding protein‑homologous protein and glucose‑regulated protein 78. These results suggested that 4‑PBA was able to protect rat skin flaps against ischemia‑reperfusion injury and apoptosis by inhibiting ER stress marker expression and ER stress‑mediated apoptosis. The beneficial effects of 4‑PBA may prove useful in the treatment of skin flap ischemia‑reperfusion injury.

4-Phenylbutyrate protects rat skin flaps against ischemia-reperfusion injury and apoptosis by inhibiting endoplasmic reticulum stress

PubMed Central

YUE, ZHEN-SHUANG; ZENG, LIN-RU; QUAN, REN-FU; TANG, YANG-HUA; ZHENG, WEN-JIE; QU, GANG; XU, CAN-DA; ZHU, FANG-BING; HUANG, ZHONG-MING

2016-01-01

4-phenylbutyrate (4-PBA) is a low molecular weight fatty acid, which has been demonstrated to regulate endoplasmic reticulum (ER) stress. ER stress-induced cell apoptosis has an important role in skin flap ischemia; however, a pharmacological approach for treating ischemia-induced ER dysfunction has yet to be reported. In the present study, the effects of 4-PBA-induced ER stress inhibition on ischemia-reperfusion injury were investigated in the skin flap of rats, and transcriptional regulation was examined. 4-PBA attenuated ischemia-reperfusion injury and inhibited cell apoptosis in the skin flap. Furthermore, 4-PBA reversed the increased expression levels of two ER stress markers: CCAAT/enhancer-binding protein-homologous protein and glucose-regulated protein 78. These results suggested that 4-PBA was able to protect rat skin flaps against ischemia-reperfusion injury and apoptosis by inhibiting ER stress marker expression and ER stress-mediated apoptosis. The beneficial effects of 4-PBA may prove useful in the treatment of skin flap ischemia-reperfusion injury. PMID:26648447

Inhibition of Wnt/beta-catenin signaling downregulates expression of aldehyde dehydrogenase isoform 3A1 (ALDH3A1) to reduce resistance against temozolomide in glioblastoma in vitro.

PubMed

Suwala, Abigail Kora; Koch, Katharina; Rios, Dayana Herrera; Aretz, Philippe; Uhlmann, Constanze; Ogorek, Isabella; Felsberg, Jörg; Reifenberger, Guido; Köhrer, Karl; Deenen, René; Steiger, Hans-Jakob; Kahlert, Ulf D; Maciaczyk, Jaroslaw

2018-04-27

Glioblastoma is the most aggressive type of glioma. The Wingless (Wnt) signaling pathway has been shown to promote stem cell properties and resistance to radio- and chemotherapy in glioblastoma. Here, we demonstrate that pharmacological Wnt pathway inhibition using the porcupine inhibitor LGK974 acts synergistically with temozolomide (TMZ), the chemotherapeutic drug currently used as standard treatment for glioblastoma, to suppress in vitro growth of glioma cells. Synergistic growth inhibition was independent of the O 6 -alkylguanine DNA alkyltransferase ( MGMT ) promoter methylation status. Transcriptomic analysis revealed that expression of aldehyde dehydrogenase 3A1 ( ALDH3A1 ) was significantly down-regulated when cells were treated with LGK974 and TMZ. Suppressing ALDH3A1 expression increased the efficacy of TMZ and reduced clonogenic potential accompanied by decreased expression of stem cell markers CD133, Nestin and Sox2. Taken together, our study suggests that previous observations concerning Wnt signaling blockade to reduce chemoresistance in glioblastoma is at least in part mediated by inhibition of ALDH3A1.

Inhibition of lysophosphatidic acid receptors 1 and 3 attenuates atherosclerosis development in LDL-receptor deficient mice.

PubMed

Kritikou, Eva; van Puijvelde, Gijs H M; van der Heijden, Thomas; van Santbrink, Peter J; Swart, Maarten; Schaftenaar, Frank H; Kröner, Mara J; Kuiper, Johan; Bot, Ilze

2016-11-24

Lysophosphatidic acid (LPA) is a natural lysophospholipid present at high concentrations within lipid-rich atherosclerotic plaques. Upon local accumulation in the damaged vessels, LPA can act as a potent activator for various types of immune cells through its specific membrane receptors LPA 1/3. LPA elicits chemotactic, pro-inflammatory and apoptotic effects that lead to atherosclerotic plaque progression. In this study we aimed to inhibit LPA signaling by means of LPA 1/3 antagonism using the small molecule Ki16425. We show that LPA 1/3 inhibition significantly impaired atherosclerosis progression. Treatment with Ki16425 also resulted in reduced CCL2 production and secretion, which led to less monocyte and neutrophil infiltration. Furthermore, we provide evidence that LPA 1/3 blockade enhanced the percentage of non-inflammatory, Ly6C low monocytes and CD4 + CD25 + FoxP3 + T-regulatory cells. Finally, we demonstrate that LPA 1/3 antagonism mildly reduced plasma LDL cholesterol levels. Therefore, pharmacological inhibition of LPA 1/3 receptors may prove a promising approach to diminish atherosclerosis development.

Rebamipide, an Amino Acid Analog of 2(1H)-Quinolinone, Inhibits the Formation of Human Osteoclasts

PubMed Central

Kobashigawa, Tsuyoshi

2016-01-01

Objectives. Drug repositioning or drug reprofiling (DR) has recently been growing in importance. DR has a significant advantage over traditional drug development because the repositioned drug has already passed toxicity tests; its safety is known, and the risk of adverse toxicology is reduced. In the current study, we investigated the role of rebamipide, a mucosa-protecting agent, with recently reported anti-inflammatory function, in human osteoclastogenesis. Methods. Peripheral blood mononuclear cells (PBMCs) were cultured in the presence of M-CSF and sRANKL. Osteoclast formation was evaluated by immunohistological staining for CD51/61 (vitronectin receptors). Osteoclast formation, in the presence or absence of rebamipide (0, 1, and 3 mM), was observed by time-lapse photography and actin ring formation. The number of absorption sites and area of absorption were calculated using Osteologic™ plates. Pit formation was studied by 3D-SEM. Results. Rebamipide inhibited human osteoclast formation at 3 mM, a pharmacological concentration, and inhibited resorbing activity dose-dependently. Rebamipide induced the degradation of actin rings in mature osteoclasts. This mechanism may involve inhibiting the osteoclast fusion pathway through reducing the expression of DC-specific transmembrane protein (DC-STAMP). Conclusions. The present study suggests that rebamipide would be useful as a novel agent for osteoporosis and rheumatoid arthritis. PMID:27965978

Rebamipide, an Amino Acid Analog of 2(1H)-Quinolinone, Inhibits the Formation of Human Osteoclasts.

PubMed

Nanke, Yuki; Kobashigawa, Tsuyoshi; Yago, Toru; Kawamoto, Manabu; Yamanaka, Hisashi; Kotake, Shigeru

2016-01-01

Objectives . Drug repositioning or drug reprofiling (DR) has recently been growing in importance. DR has a significant advantage over traditional drug development because the repositioned drug has already passed toxicity tests; its safety is known, and the risk of adverse toxicology is reduced. In the current study, we investigated the role of rebamipide, a mucosa-protecting agent, with recently reported anti-inflammatory function, in human osteoclastogenesis. Methods. Peripheral blood mononuclear cells (PBMCs) were cultured in the presence of M-CSF and sRANKL. Osteoclast formation was evaluated by immunohistological staining for CD51/61 (vitronectin receptors). Osteoclast formation, in the presence or absence of rebamipide (0, 1, and 3 mM), was observed by time-lapse photography and actin ring formation. The number of absorption sites and area of absorption were calculated using Osteologic™ plates. Pit formation was studied by 3D-SEM. Results . Rebamipide inhibited human osteoclast formation at 3 mM, a pharmacological concentration, and inhibited resorbing activity dose-dependently. Rebamipide induced the degradation of actin rings in mature osteoclasts. This mechanism may involve inhibiting the osteoclast fusion pathway through reducing the expression of DC-specific transmembrane protein (DC-STAMP). Conclusions . The present study suggests that rebamipide would be useful as a novel agent for osteoporosis and rheumatoid arthritis.

Interactions of the hepatitis C virus protease inhibitor faldaprevir with cytochrome P450 enzymes: in vitro and in vivo correlation.

PubMed

Sabo, John P; Kort, Jens; Ballow, Charles; Kashuba, Angela D M; Haschke, Manuel; Battegay, Manuel; Girlich, Birgit; Ting, Naitee; Lang, Benjamin; Zhang, Wei; Cooper, Curtis; O'Brien, Drané; Seibert, Eleanore; Chan, Tom S; Tweedie, Donald; Li, Yongmei

2015-04-01

The potential inhibition of the major human cytochrome P450 (CYP) enzymes by faldaprevir was evaluated both in vitro and in clinical studies (healthy volunteers and hepatitis C virus [HCV] genotype 1-infected patients). In vitro studies indicated that faldaprevir inhibited CYP2B6, CYP2C9, and CYP3A, and was a weak-to-moderate inactivator of CYP3A4. Faldaprevir 240 mg twice daily in healthy volunteers demonstrated moderate inhibition of hepatic and intestinal CYP3A (oral midazolam: 2.96-fold increase in AUC(0-24 h)), weak inhibition of hepatic CYP3A (intravenous midazolam: 1.56-fold increase in AUC(0-24 h)), weak inhibition of CYP2C9 ([S]-warfarin: 1.29-fold increase in AUC(0-120 h)), and had no relevant effects on CYP1A2, CYP2B6, or CYP2D6. Faldaprevir 120 mg once daily in HCV-infected patients demonstrated weak inhibition of hepatic and intestinal CYP3A (oral midazolam: 1.52-fold increase in AUC(0-∞)), and had no relevant effects on CYP2C9 or CYP1A2. In vitro drug-drug interaction predictions based on inhibitor concentration ([I])/inhibition constant (Ki) ratios tended to overestimate clinical effects and a net-effect model provided a more accurate approach. These studies suggest that faldaprevir shows a dose-dependent inhibition of CYP3A and CYP2C9, and does not induce CYP isoforms. © 2015, The American College of Clinical Pharmacology.

Effects of pharmacological and genetic disruption of CXCR4 chemokine receptor function in B-cell acute lymphoblastic leukaemia.

PubMed

Randhawa, Shubhchintan; Cho, Byung S; Ghosh, Dipanjan; Sivina, Mariela; Koehrer, Stefan; Müschen, Markus; Peled, Amnon; Davis, Richard E; Konopleva, Marina; Burger, Jan A

2016-08-01

B cell acute lymphoblastic leukaemia (B-ALL) cells express high levels of CXCR4 chemokine receptors for homing and retention within the marrow microenvironment. Bone marrow stromal cells (BMSC) secrete CXCL12, the ligand for CXCR4, and protect B-ALL cells from cytotoxic drugs. Therefore, the therapeutic use of CXCR4 antagonists has been proposed to disrupt cross talk between B-ALL cells and the protective stroma. Because CXCR4 antagonists can have activating agonistic function, we compared the genetic and pharmacological deletion of CXCR4 in B-ALL cells, using CRISPR-Cas9 gene editing and CXCR4 antagonists that are in clinical use (plerixafor, BKT140). Both genetic and pharmacological CXCR4 inhibition significantly reduced B-ALL cell migration to CXCL12 gradients and beneath BMSC, and restored drug sensitivity to dexamethasone, vincristine and cyclophosphamide. NOD/SCID/IL-2rγnull mice injected with CXCR4 gene-deleted B-ALL cells had significant delay in disease progression and superior survival when compared to control mice injected with CXCR4 wild-type B-ALL cells. These findings indicate that anti-leukaemia activity of CXCR4 antagonists is primarily due to CXCR4 inhibition, rather than agonistic activity, and corroborate that CXCR4 is an important target to overcome stroma-mediated drug resistance in B-ALL. © 2016 John Wiley & Sons Ltd.

A small-molecule compound inhibits a collagen-specific molecular chaperone and could represent a potential remedy for fibrosis.

PubMed

Ito, Shinya; Ogawa, Koji; Takeuchi, Koh; Takagi, Motoki; Yoshida, Masahito; Hirokawa, Takatsugu; Hirayama, Shoshiro; Shin-Ya, Kazuo; Shimada, Ichio; Doi, Takayuki; Goshima, Naoki; Natsume, Tohru; Nagata, Kazuhiro

2017-12-08

Fibrosis can disrupt tissue structure and integrity and impair organ function. Fibrosis is characterized by abnormal collagen accumulation in the extracellular matrix. Pharmacological inhibition of collagen secretion therefore represents a promising strategy for the management of fibrotic disorders, such as liver and lung fibrosis. Hsp47 is an endoplasmic reticulum (ER)-resident collagen-specific molecular chaperone essential for correct folding of procollagen in the ER. Genetic deletion of Hsp47 or inhibition of its interaction with procollagen interferes with procollagen triple helix production, which vastly reduces procollagen secretion from fibroblasts. Thus, Hsp47 could be a potential and promising target for the management of fibrosis. In this study, we screened small-molecule compounds that inhibit the interaction of Hsp47 with collagen from chemical libraries using surface plasmon resonance (BIAcore), and we found a molecule AK778 and its cleavage product Col003 competitively inhibited the interaction and caused the inhibition of collagen secretion by destabilizing the collagen triple helix. Structural information obtained with NMR analysis revealed that Col003 competitively binds to the collagen-binding site on Hsp47. We propose that these structural insights could provide a basis for designing more effective therapeutic drugs for managing fibrosis. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Allosteric Inhibition of Bcr-Abl Kinase by High Affinity Monobody Inhibitors Directed to the Src Homology 2 (SH2)-Kinase Interface.

PubMed

Wojcik, John; Lamontanara, Allan Joaquim; Grabe, Grzegorz; Koide, Akiko; Akin, Louesa; Gerig, Barbara; Hantschel, Oliver; Koide, Shohei

2016-04-15

Bcr-Abl is a constitutively active kinase that causes chronic myelogenous leukemia. We have shown that a tandem fusion of two designed binding proteins, termed monobodies, directed to the interaction interface between the Src homology 2 (SH2) and kinase domains and to the phosphotyrosine-binding site of the SH2 domain, respectively, inhibits the Bcr-Abl kinase activity. Because the latter monobody inhibits processive phosphorylation by Bcr-Abl and the SH2-kinase interface is occluded in the active kinase, it remained undetermined whether targeting the SH2-kinase interface alone was sufficient for Bcr-Abl inhibition. To address this question, we generated new, higher affinity monobodies with single nanomolar KD values targeting the kinase-binding surface of SH2. Structural and mutagenesis studies revealed the molecular underpinnings of the monobody-SH2 interactions. Importantly, the new monobodies inhibited Bcr-Abl kinase activity in vitro and in cells, and they potently induced cell death in chronic myelogenous leukemia cell lines. This work provides strong evidence for the SH2-kinase interface as a pharmacologically tractable site for allosteric inhibition of Bcr-Abl. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

CDC42 inhibition suppresses progression of incipient intestinal tumors

USDA-ARS?s Scientific Manuscript database

Mutations in the APC or Beta-catenin genes are well-established initiators of colorectal cancer, yet modifiers that facilitate the survival and progression of nascent tumor cells are not well defined. Using genetic and pharmacologic approaches in mouse colorectal cancer and human colorectal cancer x...

Inhibition of glutathione synthesis eliminates the adaptive response of ascitic hepatoma 22 cells to nedaplatin that targets thioredoxin reductase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Yijun; Lu, Hongjuan; Wang, Dongxu

2012-12-15

Thioredoxin reductase (TrxR) is a target for cancer therapy and the anticancer mechanism of cisplatin involves TrxR inhibition. We hypothesize that the anticancer drug nedaplatin (NDP), an analogue of cisplatin and a second-generation platinum complex, also targets TrxR. Furthermore, we investigate whether the therapeutic efficacy of NDP can be enhanced by simultaneous modulation of 1) TrxR, via NDP, and 2) glutathione (GSH), via the GSH synthesis inhibitor buthionine sulfoximine (BSO). Mice bearing ascitic hepatoma 22 (H22) cells were treated with NDP alone or NDP plus BSO. TrxR activity of H22 cells was inhibited by NDP in a dose-dependent manner. Amore » high correlation between the inhibition of TrxR activity at 6 h and the inhibition of ascitic fluid volume at 72 h was established (r = 0.978, p < 0.01). As an adaptive response, the viable ascitic cancer cells after NDP treatment displayed an enlarged cell phenotype, assembled with several-fold more antioxidant enzymes and GSH-predominant non-protein free thiols. This adaptive response was largely eliminated when BSO was co-administered with NDP, leading to the decimation of the H22 cell population without enhancing renal toxicity, since at this dose, NDP did not inhibit renal TrxR activity. In conclusion, the pharmacological effect of NDP involves TrxR inhibition, and the adaptive response of NDP-treated ascitic H22 cells can be efficiently counteracted by BSO. Simultaneous modulation of TrxR and GSH on ascitic H22 cells using NDP plus BSO greatly enhances therapeutic efficacy as compared with the single modulation of TrxR using NDP alone. -- Highlights: ► Nedaplatin at a pharmacological dose inhibits TrxR in cancer cells but not in kidney. ► The nedaplatin-treated cancer cells exhibit adaptive response. ► Buthionine sulfoximine inhibits glutathione in both cancer cells and kidney. ► Buthionine sulfoximine counteracts the adaptive response to the nedaplatin treatment. ► Buthionine sulfoximine does not aggravate renal toxicity of the nedaplatin treatment.« less

Role of exchange protein directly activated by cAMP (EPAC1) in breast cancer cell migration and apoptosis.

PubMed

Kumar, Naveen; Gupta, Sonal; Dabral, Surbhi; Singh, Shailja; Sehrawat, Seema

2017-06-01

Despite the current progress in cancer research and therapy, breast cancer remains the leading cause of mortality among half a million women worldwide. Migration and invasion of cancer cells are associated with prevalent tumor metastasis as well as high mortality. Extensive studies have powerfully established the role of prototypic second messenger cAMP and its two ubiquitously expressed intracellular cAMP receptors namely the classic protein kinaseA/cAMP-dependent protein kinase (PKA) and the more recently discovered exchange protein directly activated by cAMP/cAMP-regulated guanine nucleotide exchange factor (EPAC/cAMP-GEF) in cell migration, cell cycle regulation, and cell death. Herein, we performed the analysis of the Cancer Genome Atlas (TCGA) dataset to evaluate the essential role of cAMP molecular network in breast cancer. We report that EPAC1, PKA, and AKAP9 along with other molecular partners are amplified in breast cancer patients, indicating the importance of this signaling network. To evaluate the functional role of few of these proteins, we used pharmacological modulators and analyzed their effect on cell migration and cell death in breast cancer cells. Hence, we report that inhibition of EPAC1 activity using pharmacological modulators leads to inhibition of cell migration and induces cell death. Additionally, we also observed that the inhibition of EPAC1 resulted in disruption of its association with the microtubule cytoskeleton and delocalization of AKAP9 from the centrosome as analyzed by in vitro imaging. Finally, this study suggests for the first time the mechanistic insights of mode of action of a primary cAMP-dependent sensor, Exchange protein activated by cAMP 1 (EPAC1), via its interaction with A-kinase anchoring protein 9 (AKAP9). This study provides a new cell signaling cAMP-EPAC1-AKAP9 direction to the development of additional biotherapeutics for breast cancer.

Pharmacological Inhibition of Macrophage Toll-like Receptor 4/Nuclear Factor-kappa B Alleviates Rhabdomyolysis-induced Acute Kidney Injury.

PubMed

Huang, Rong-Shuang; Zhou, Jiao-Jiao; Feng, Yu-Ying; Shi, Min; Guo, Fan; Gou, Shen-Ju; Salerno, Stephen; Ma, Liang; Fu, Ping

2017-09-20

Acute kidney injury (AKI) is the most common and life-threatening systemic complication of rhabdomyolysis. Inflammation plays an important role in the development of rhabdomyolysis-induced AKI. This study aimed to investigate the kidney model of AKI caused by rhabdomyolysis to verify the role of macrophage Toll-like receptor 4/nuclear factor-kappa B (TLR4/NF-κB) signaling pathway. C57BL/6 mice were injected with a 50% glycerin solution at bilateral back limbs to induce rhabdomyolysis, and CLI-095 or pyrrolidine dithiocarbamate (PDTC) was intraperitoneally injected at 0.5 h before molding. Serum creatinine levels, creatine kinase, the expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6, and hematoxylin and eosin stainings of kidney tissues were tested. The infiltration of macrophage, mRNA levels, and protein expression of TLR4 and NF-κB were investigated by immunofluorescence double-staining techniques, reverse transcriptase-quantitative polymerase chain reaction, and Western blotting, respectively. In vitro, macrophage RAW264.7 was stimulated by ferrous myoglobin; the cytokines, TLR4 and NF-κB expressions were also detected. In an in vivo study, using CLI-095 or PDTC to block TLR4/NF-κB, functional and histologic results showed that the inhibition of TLR4 or NF-κB alleviated glycerol-induced renal damages (P < 0.01). CLI-095 or PDTC administration suppressed proinflammatory cytokine (TNF-α, IL-6, and IL-1β) production and macrophage infiltration into the kidney (P < 0.01). Moreover, in an in vitro study, CLI-095 or PDTC suppressed myoglobin-induced expression of TLR4, NF-κB, and proinflammatory cytokine levels in macrophage RAW264.7 cells (P < 0.01). The pharmacological inhibition of TLR4/NF-κB exhibited protective effects on rhabdomyolysis-induced AKI by the regulation of proinflammatory cytokine production and macrophage infiltration.

Mutationally activated BRAF(V600E) elicits papillary thyroid cancer in the adult mouse.

PubMed

Charles, Roch-Philippe; Iezza, Gioia; Amendola, Elena; Dankort, David; McMahon, Martin

2011-06-01

Mutated BRAF is detected in approximately 45% of papillary thyroid carcinomas (PTC). To model PTC, we bred mice with adult-onset, thyrocyte-specific expression of BRAF(V600E). One month following BRAF(V600E) expression, mice displayed increased thyroid size, widespread alterations in thyroid architecture, and dramatic hypothyroidism. Over 1 year, without any deliberate manipulation of tumor suppressor genes, all mice developed PTC displaying nuclear atypia and marker expression characteristic of the human disease. Pharmacologic inhibition of MEK1/2 led to decreased thyroid size, restoration of thyroid form and function, and inhibition of tumorigenesis. Mice with BRAF(V600E)-induced PTC will provide an excellent system to study thyroid tumor initiation and progression and the evaluation of inhibitors of oncogenic BRAF signaling.

Synthesis and pharmacological evaluation of N-substituted 2-(2-oxo-2H-chromen-4-yloxy)propanamide as cyclooxygenase inhibitors.

PubMed

Rambabu, D; Mulakayala, Naveen; Ismail; Kumar, K Ravi; Kumar, G Pavan; Mulakayala, Chaitanya; Kumar, Chitta Suresh; Kalle, Arunasree M; Rao, M V Basaveswara; Oruganti, Srinivas; Pal, Manojit

2012-11-01

A series of novel N-substituted 2-(2-oxo-2H-chromen-4-yloxy)propanamide derivatives were synthesized via converting the readily available 4-hydroxy coumarin to the corresponding ethyl 2-(2-oxo-2H-chromen-4-yloxy)propanoate followed by hydrolysis and then reacting with different substituted amines. The molecular structures of two representative compounds, that is, 3 and 5l were confirmed by single crystal X-ray diffraction study. All the compounds synthesized were evaluated for their cyclooxygenase (COX) inhibiting properties in vitro. The compound 5i showed balanced selectivity towards COX-2 over COX-1 inhibition and good docking scores when docked into the COX-2 protein. Copyright © 2012 Elsevier Ltd. All rights reserved.

[Effects of lysine clonixinate on platelet function. Comparison with other non-steroidal anti-inflammatory agents].

PubMed

Kramer, E H; Sassetti, B; Kaminker, A J; De Los Santos, A R; Martí, M L; Di Girolamo, G

2001-01-01

One of the mechanisms of action of non steroid antiinflammatory drugs (NSAIDs) consists of inhibition of prostaglandin synthesis. This explains many of the pharmacological effects and adverse events observed in medical practice. Administration of NSAIDs to patients with hemostatic disorders or perioperative conditions entails the risk of bleeding due to inhibition of platelet function. This study deals with platelet changes induced by lysine clonixinate vs diclofenac, ibuprofen and aspirin in classical tests such as platelet count, platelet factor 3 (PF3) activity and platelet aggregation with various inductors and more recent procedures such as P-selectin measurement by flow cytometry. Unlike control drugs, lysine clonixinate did not induce changes in platelet count or function when administered to healthy volunteers at the commonly used therapeutic doses.

Novel, broad-spectrum anticonvulsants containing a sulfamide group: advancement of N-((benzo[b]thien-3-yl)methyl)sulfamide (JNJ-26990990) into human clinical studies.

PubMed

Parker, Michael H; Smith-Swintosky, Virginia L; McComsey, David F; Huang, Yifang; Brenneman, Douglas; Klein, Brian; Malatynska, Ewa; White, H Steve; Milewski, Michael E; Herb, Mark; Finley, Michael F A; Liu, Yi; Lubin, Mary Lou; Qin, Ning; Iannucci, Robert; Leclercq, Laurent; Cuyckens, Filip; Reitz, Allen B; Maryanoff, Bruce E

2009-12-10

In seeking broad-spectrum anticonvulsants to treat epilepsy and other neurological disorders, we synthesized and tested a group of sulfamide derivatives (4a-k, 5), which led to the clinical development of 4a (JNJ-26990990). This compound exhibited excellent anticonvulsant activity in rodents against audiogenic, electrically induced, and chemically induced seizures, with very weak inhibition of human carbonic anhydrase-II (IC(50) = 110 microM). The pharmacological profile for 4a supports its potential in the treatment of multiple forms of epilepsy, including pharmacoresistant variants. Mechanistically, 4a inhibited voltage-gated Na(+) channels and N-type Ca(2+) channels but was not effective as a K(+) channel opener. The pharmacokinetics and metabolic properties of 4a are discussed.

Involvement of a Gardos-type potassium channel in head activator-induced mitosis of BON cells.

PubMed

Kayser, S T; Ulrich, H; Schaller, H C

1998-06-01

The human neuroendocrine cell line BON was used to study second messengers involved in signal transduction for entry into mitosis. BON cells produce the neuropeptide head activator (HA) and use it as autocrine growth factor. HA stimulates BON cell proliferation by triggering entry into mitosis. HA-induced mitosis is mediated by an inhibitory G protein, the action of which is blocked by pertussis toxin. HA signaling requires inhibition of the cAMP pathway, calcium influx, and hyperpolarization of cells. The latter is a very important and sensitive step involving a calcium-activated potassium channel. Cell cycle progression and proliferation of BON cells are most efficiently inhibited with specific inhibitors of this potassium channel. Pharmacology and RNA analysis suggest identity with the recently cloned Gardos-type potassium channel.

Inhibition of CatA: an emerging strategy for the treatment of heart failure.

PubMed

Ruf, Sven; Buning, Christian; Schreuder, Herman; Linz, Wolfgang; Hübschle, Thomas; Linz, Dominik; Ruetten, Hartmut; Wirth, Klaus; Sadowski, Thorsten

2013-03-01

The lysosomal serine carboxypeptidase CatA has a very important and well-known structural function as well as a, so far, less explored catalytic function. A complete loss of the CatA protein results in the lysosomal storage disease galactosialidosis caused by intralysosomal degradation of β-galactosidase and neuraminidase 1. However, mice with a catalytically inactive CatA enzyme show no signs of this disease. This observation establishes a clear distinction between structural and catalytic functions of the CatA enzyme. Recently, several classes of orally bioavailable synthetic inhibitors of CatA have been identified. Pharmacological studies in rodents indicate a remarkable influence of CatA inhibition on cardiovascular disease progression and identify CatA as a promising novel target for the treatment of heart failure.

GSK-3beta inhibition enhances sorafenib-induced apoptosis in melanoma cell lines.

PubMed

Panka, David J; Cho, Daniel C; Atkins, Michael B; Mier, James W

2008-01-11

Glycogen synthase kinase-3beta (GSK-3beta) can participate in the induction of apoptosis or, alternatively, provide a survival signal that minimizes cellular injury. We previously demonstrated that the multikinase inhibitor sorafenib induces apoptosis in melanoma cell lines. In this report, we show that sorafenib activates GSK-3beta in multiple subcellular compartments and that this activation undermines the lethality of the drug. Pharmacologic inhibition and/or down-modulation of the kinase enhances sorafenib-induced apoptosis as determined by propidium iodide staining and by assessing the mitochondrial release of apoptosis-inducing factor and Smac/DIABLO. Conversely, the forced expression of a constitutively active form of the enzyme (GSK-3beta(S9A)) protects the cells from the apoptotic effects of the drug. This protective effect is associated with a marked increase in basal levels of Bcl-2, Bcl-x(L), and survivin and a diminution in the degree to which these anti-apoptotic proteins are down-modulated by sorafenib exposure. Sorafenib down-modulates the pro-apoptotic Bcl-2 family member Noxa in cells with high constitutive GSK-3beta activity. Pharmacologic inhibition of GSK-3beta prevents the disappearance of Noxa induced by sorafenib and enhances the down-modulation of Mcl-1. Down-modulation of Noxa largely eliminates the enhancing effect of GSK-3 inhibition on sorafenib-induced apoptosis. These data provide a strong rationale for the use of GSK-3beta inhibitors as adjuncts to sorafenib treatment and suggest that preservation of Noxa may contribute to their efficacy.

Mechanism of mitochondrial permeability transition pore induction and damage in the pancreas: inhibition prevents acute pancreatitis by protecting production of ATP

PubMed Central

Mukherjee, Rajarshi; Mareninova, Olga A; Odinokova, Irina V; Huang, Wei; Murphy, John; Chvanov, Michael; Javed, Muhammad A; Wen, Li; Booth, David M; Cane, Matthew C; Awais, Muhammad; Gavillet, Bruno; Pruss, Rebecca M; Schaller, Sophie; Molkentin, Jeffery D; Tepikin, Alexei V; Petersen, Ole H; Pandol, Stephen J; Gukovsky, Ilya; Criddle, David N; Gukovskaya, Anna S

2016-01-01

Objective Acute pancreatitis is caused by toxins that induce acinar cell calcium overload, zymogen activation, cytokine release and cell death, yet is without specific drug therapy. Mitochondrial dysfunction has been implicated but the mechanism not established. Design We investigated the mechanism of induction and consequences of the mitochondrial permeability transition pore (MPTP) in the pancreas using cell biological methods including confocal microscopy, patch clamp technology and multiple clinically representative disease models. Effects of genetic and pharmacological inhibition of the MPTP were examined in isolated murine and human pancreatic acinar cells, and in hyperstimulation, bile acid, alcoholic and choline-deficient, ethionine-supplemented acute pancreatitis. Results MPTP opening was mediated by toxin-induced inositol trisphosphate and ryanodine receptor calcium channel release, and resulted in diminished ATP production, leading to impaired calcium clearance, defective autophagy, zymogen activation, cytokine production, phosphoglycerate mutase 5 activation and necrosis, which was prevented by intracellular ATP supplementation. When MPTP opening was inhibited genetically or pharmacologically, all biochemical, immunological and histopathological responses of acute pancreatitis in all four models were reduced or abolished. Conclusions This work demonstrates the mechanism and consequences of MPTP opening to be fundamental to multiple forms of acute pancreatitis and validates the MPTP as a drug target for this disease. PMID:26071131

Inhibitory effect of 2,4-dichlorophenoxyacetic acid on ROS, autophagy formation, and mRNA replication for influenza virus infection.

PubMed

Enkhtaivan, Gansukh; Muthuraman, Pandurangan; Kim, Doo Hwan

2017-08-01

Influenza virus has had a high rate of antigenic shift and drift that causes significant morbidity and mortality in humans and animals. The lack of excellent pharmacological treatment underlines the importance of the development of the novel antiviral drugs. We investigated the anti-influenza A and B viruses of 2,4-dichlorophenoxyacetic acid (2,4-D), which is the synthetic analog to auxin and is used as a popular herbicide in the agricultural practices. 2,4-D was evaluated using a cytopathic effect reduction method; assay results showed that 2,4-D possessed strong anti-influenza A and B viruses inhibiting the formation of a visible cytopathic effect. Influenza viral RNA expression was performed by quantitative real-time polymerase chain reaction. 2,4-D also inhibited virus replication in the early stage of influenza virus infection without direct interaction with virus particles. Additionally, 2,4-D significantly inhibited various factors occur during influenza virus infection as the acidic vesicular formation and reactive oxygen species production. Moreover, 2,4-D represented no cytotoxicity in normal kidney cell. Therefore, these findings provide an understanding of the mechanism and efficient use of 2,4-D in pharmacological applications against influenza virus infection. Copyright © 2017 John Wiley & Sons, Ltd.

Synthesis of Pyridine and Spiropyridine Derivatives Derived from 2-aminoprop- 1-ene-1,1,3-tricarbonitrile Together with their c-Met Kinase and Antiproliferative Evaluations.

PubMed

Mohareb, Rafat M; Abouzied, Amr S; Abbas, Nermeen S

2018-02-07

Among a wide range of pyridines, 3-cyanopyridines acquired a special attention due to their wide range of pharmacological activities especially the therapeutic activities. Many pharmacological drugs containing the pyridine nucleus were known in the market. The aim of this work was to synthesize target molecules not only possess anti-tumor activities but also kinase inhibitors. To achieve this goal, our strategy was to synthesize a series of 3-cyanopyridine derivatives using 2-aminoprop-1-ene-1,1,3-tricarbonitrile (1) as the key starting material for many heterocyclization reactions. Muticoponent reactions were adopted using compound 1 to get different pyridine derivatives that were capable for different heterocyclization reactions. Antiproliferative evaluations and c-Met kinase, Pim-1 kinse inhibitions were perform where some compounds gave high activities. Compounds that showed high antiprolifeative activity were tested gor c-Met-independent and the results showed that compounds 5c, 5e, 5f, 7c, 7f and 16d were more active than foretinib. The Pim-1 kinase inhibition activity of some selected compounds showed that compounds 5e and 16c were high potent to inhibit Pim-1 activity. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

The extracellular matrix metalloproteinase inducer EMMPRIN is a target of nitric oxide in myocardial ischemia/reperfusion.

PubMed

Tarin, Carlos; Lavin, Begoña; Gomez, Monica; Saura, Marta; Diez-Juan, Antonio; Zaragoza, Carlos

2011-07-15

Nitric oxide (NO) is an important defense against myocardial ischemia/reperfusion (I/R) injury. Although matrix metalloproteinase (MMP)-mediated necrosis of cardiac myocytes is well characterized, the role of inducible NO synthase (iNOS)-derived NO in this process is poorly understood. I/R injury was increased in iNOS-deficient mice and in mice treated with 1400 W (a pharmacological iNOS inhibitor) and was associated with significantly increased expression of extracellular matrix metalloproteinase inducer (EMMPRIN) and EMMPRIN-associated MMPs. Transcriptional activity of an EMMPRIN luciferase promoter reporter expressed in cardiac myocytes was inhibited by NO in a cGMP-dependent manner, and this transcriptional inhibition was abolished by mutation of a putative E2F site. Consistent with these findings, EMMPRIN null mice, in which iNOS is normally induced, are partially protected against I/R injury. Pharmacological inhibition of iNOS in EMMPRIN null mice had no additional protective effect, suggesting that EMMPRIN is a downstream target of NO. Administration of anti-EMMPRIN neutralizing antibodies partly reduced the excess heart damage and MMP-9 expression induced by I/R in iNOS null mice, indicating that regulation of EMMPRIN is an important mechanism of NO-mediated cardioprotection. Copyright © 2011 Elsevier Inc. All rights reserved.

Protonophore properties of hyperforin are essential for its pharmacological activity.

PubMed

Sell, Thomas S; Belkacemi, Thabet; Flockerzi, Veit; Beck, Andreas

2014-12-16

Hyperforin is a pharmacologically active component of the medicinal plant Hypericum perforatum (St. John's wort), recommended as a treatment for a range of ailments including mild to moderate depression. Part of its action has been attributed to TRPC6 channel activation. We found that hyperforin induces TRPC6-independent H(+) currents in HEK-293 cells, cortical microglia, chromaffin cells and lipid bilayers. The latter demonstrates that hyperforin itself acts as a protonophore. The protonophore activity of hyperforin causes cytosolic acidification, which strongly depends on the holding potential, and which fuels the plasma membrane sodium-proton exchanger. Thereby the free intracellular sodium concentration increases and the neurotransmitter uptake by Na(+) cotransport is inhibited. Additionally, hyperforin depletes and reduces loading of large dense core vesicles in chromaffin cells, which requires a pH gradient in order to accumulate monoamines. In summary the pharmacological actions of the "herbal Prozac" hyperforin are essentially determined by its protonophore properties shown here.

Monoacylglycerol lipase – a target for drug development?

PubMed Central

Fowler, CJ

2012-01-01

The endocannabinoid (eCB) system is involved in processes as diverse as control of appetite, perception of pain and the limitation of cancer cell growth and invasion. The enzymes responsible for eCB breakdown are attractive pharmacological targets, and fatty acid amide hydrolase inhibitors, which potentiate the levels of the eCB anandamide, are now undergoing pharmaceutical development. ‘Drugable’ selective inhibitors of monoacylglycerol lipase, a key enzyme regulating the levels of the other main eCB, 2-arachidonoylglycerol, were however not identified until very recently. Their availability has resulted in a large expansion of our knowledge concerning the pharmacological consequences of monoacylglycerol lipase inhibition and hence the role(s) played by the enzyme in the body. In this review, the pharmacology of monoacylglycerol lipase will be discussed, together with an analysis of the therapeutic potential of monoacylglycerol lipase inhibitors as analgesics and anticancer agents. PMID:22428756

Evidence for strychnine-sensitive glycine receptors in human amygdala.

PubMed

Dudeck, O; Lübben, S; Eipper, S; Knörle, R; Kirsch, M; Honegger, J; Zentner, J; Feuerstein, T J

2003-09-01

Recent studies suggested the existence of strychnine-sensitive glycine-receptors in mammalian amygdala. In the present study, we investigated the amino acid concentrations as well as immunocytochemical and pharmacological properties of glycine-receptors in fresh human amygdala tissue obtained from epilepsy surgery. High pressure liquid chromatography revealed a considerable amount of glycine and its precursors and glycine-receptors agonists L-serine and taurine in this tissue. Immunohistochemistry using the monoclonal antibody mAb4a, recognizing an epitope common to all alpha-subunit variants of glycine receptors, displayed a specific labeling at the soma and on proximal dendrites of mostly tripolar, large-sized neurons of irregular distribution and arrangement. To elucidate the pharmacological properties of the glycine-receptors found slices of human amygdala were preloaded with [(3)H]-choline and superfused. Glycine induced an overflow of [(3)H]-acetylcholine, which was inhibited by strychnine in a concentration-dependent manner. Furthermore, the glycine-induced release of [(3)H]-acetylcholine was significantly inhibited by furosemide, indicating glycine-induced actions to be attributed to chloride channels. These actions of glycine were not influenced by MK-801, D-CP-Pene or bicuculline. Thus, the effects of glycine did not seem to be mediated through NMDA or GABA receptors. These observations indicate that strychnine-sensitive, chloride-conducting glycine receptors, which elicit the release of [(3)H]-acetylcholine, are present at the soma and on proximal dendrites of neurons in human amygdala. It is hypothesized that glycine may display a regulatory role in amygdaloid functions, probably via cholinergic interneurons.

A herbal formula consisting of Rosae Multiflorae Fructus and Lonicerae Japonicae Flos inhibits inflammatory mediators in LPS-stimulated RAW 264.7 macrophages.

PubMed

Cheng, Brian Chi-Yan; Ma, Xiao-Qing; Kwan, Hiu-Yee; Tse, Kai-Wing; Cao, Hui-Hui; Su, Tao; Shu, Xin; Wu, Zheng-zhi; Yu, Zhi-ling

2014-05-14

A herbal formula (RL) consisting of Rosae Multiflorae Fructus (Yingshi) and Lonicerae Japonicae Flos (Jinyinhua) has been traditionally used to treat inflammatory disorders. This study aims to investigate the anti-inflammatory mode and mechanism of action of the ethanol extract of RL so as to provide a pharmacological basis for the use of RL in treating inflammatory diseases. RL consisting of Yingshi and Jinyinhua (in 5:3 ratio) was extracted using absolute ethanol. We investigated its effects on nitric oxide (NO), interleukin-6 (IL-6), tumour necrosis factor (TNF)-α, inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), mitogen-activated protein kinases (MAPKs) and nuclear factor κB (NFκB) in mouse RAW 264.7 macrophages activated with lipopolysaccharide (LPS). RL could decrease the secretion of NO, IL-6 and TNF-α into the culture medium and the cellular protein levels of iNOS and COX-2, which were associated with the reduction of the phosphorylation/activation of JNK and p38, and the inhibition of the transcriptional activity of NF-κB. The present study demonstrated an inhibitory effect of RL on the inflammatory mediators regulated by the NF-κB and MAPK signalling pathways in LPS-stimulated RAW 264.7 macrophages, providing a pharmacological basis for RL in the control of inflammatory disorders. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Protective mechanism of Korean Red Ginseng in cisplatin-induced ototoxicity through attenuation of nuclear factor-κB and caspase-1 activation.

PubMed

Kim, Su-Jin; Kwak, Hyun Jeong; Kim, Dae-Seung; Choi, Hyun-Myung; Sim, Jung-Eun; Kim, Sung-Hoon; Um, Jae-Young; Hong, Seung-Heon

2015-07-01

Cisplatin is an effective anti-cancer drug; however, one of its side effects is irreversible sensorineural hearing damage. Korean Red Ginseng (KRG) has been used clinically for the treatment of various diseases; however, the underlying mechanism of KRG treatment of ototoxicity has not been studied extensively. The present study aimed to further investigate the mechanism of KRG on cisplatin-induced toxicity in auditory HEI-OC1 cells in vitro, as well as in vivo. The pharmacological effects of KRG on cisplatin-induced changes in the hearing threshold of mice were determined, as well as the effect on the impairment of hair cell arrays. In addition, in order to elucidate the protective mechanisms of KRG, the regulatory effects of KRG on cisplatin-induced apoptosis-associated gene levels and nuclear factor-κB (NF-κB) activation were investigated in auditory cells. The results revealed that KRG prevented cisplatin-induced alterations in the hearing threshold of mice as well as the destruction of hair cell arrays in rat organ of Corti primary explants. In addition, KRG inhibited cisplatin-mediated cell toxicity, reactive oxygen species generation, interleukin-6 production, cytochrome c release and activation of caspases-3 in the HEI-OC1 auditory cell line. Furthermore, the results demonstrated that KRG inhibited the activation of NF-κB and caspase-1. In conclusion, these results provided a model for the pharmacological mechanism of KRG and provided evidence for potential therapies against ototoxicity.

Design, synthesis, and antihypertensive activity of curcumin-inspired compounds via ACE inhibition and vasodilation, along with a bioavailability study for possible benefit in cardiovascular diseases

PubMed Central

Zhuang, Xiao-dong; Liao, Li-zhen; Dong, Xiao-bian; Hu, Xun; Guo, Yue; Du, Zhi-min; Liao, Xin-xue; Wang, Li-chun

2016-01-01

This study describes the synthesis of a novel series of curcumin-inspired compounds via a facile synthetic route. The structures of these derivatives were ascertained using various spectroscopic and analytic techniques. The pharmacological effects of the target analogs were assessed by assaying their inhibition of angiotensin-converting enzyme (ACE). All of the synthesized derivatives exhibited considerable inhibition of ACE, with half-maximal inhibitory concentrations ranging from 1.23 to 120.32 μM. In a docking analysis with testicular ACE (tACE), the most promising inhibitor (4j) was efficiently accommodated in the deep cleft of the protein cavity, making close interatomic contacts with Glu162, His353, and Ala356, comparable with lisinopril. Compounds 4i, 4j, 4k, and 4l were further selected for determination of their vasodilator activity (cardiac output and stroke volume) on isolated rat hearts using the Langendorff technique. The bioavailability of compound 4j was determined in experimental mice. PMID:26792980

[The medical treatment of attention deficit hyperactivity disorder (ADHD) with amphetamines in children and adolescents].

PubMed

Frölich, Jan; Banaschewski, Tobias; Spanagel, Rainer; Döpfner, Manfred; Lehmkuhl, Gerd

2012-09-01

Psychostimulants (methylphenidate and amphetamines) are the drugs of first choice in the pharmacological treatment of children and adolescents with attention deficit hyperactivity disorder (ADHD). We summarize the pharmacological characteristics of amphetamines and compare them with methylphenidate, special emphasis being given to a comparison of effects and side effects of the two substances. Finally, we analyze the abuse and addiction risks. Publications were chosen based on a Medline analysis for controlled studies and meta-analyses published between 1980 and 2011; keywords were amphetamine, amphetamine salts, lisdexamphetamine, controlled studies, and metaanalyses. Amphetamines generally exhibit some pharmacologic similarities with methylphenidate. However, besides inhibiting dopamine reuptake amphetamines also cause the release of monoamines. Moreover, plasma half-life is significantly prolonged. The clinical efficacy and tolerability of amphetamines is comparable to methylphenidate. Amphetamines can therefore be used if the individual response to methylphenidate or tolerability is insufficient before switching to a nonstimulant substance, thus improving the total response rate to psychostimulant treatment. Because of the high abuse potential of amphetamines, especially in adults, the prodrug lisdexamphetamine (Vyvanse) could become an effective treatment alternative. Available study data suggest a combination of high clinical effect size with a beneficial pharmacokinetic profile and a reduced abuse risk. In addition to methylphenidate, amphetamines serve as important complements in the psychostimulant treatment of ADHD. Future studies should focus on a differential comparison of the two substances with regard to their effects on different core symptom constellations and the presence of various comorbidities.

Osthole attenuates the development of carrageenan-induced lung inflammation in rats.

PubMed

Li, Zhipeng; Ji, Haijie; Song, Xiuyun; Hu, Jinfeng; Han, Ning; Chen, Naihong

2014-05-01

Osthole has been reported to possess a variety of pharmacological activities, such as antiinflammatory effect. In the present study, we have investigated the effect of osthole on lung inflammation associated with carrageenan-induced pleurisy in rats. The result showed that osthole could inhibit significantly pleural exudates formation and PMNs infiltration. Histological examination revealed osthole could reduce lung inflammation in rats treated with carrageenan. The myeloperoxidase (MPO) level was examined in pleural exudates. The result showed that osthole could attenuate MPO level in pleural exudates. Further studies showed osthole could decrease tumor necrosis factor alpha (TNF-α) and interleukin 1beta (IL-1β) levels in the lungs. Taken together, the present results suggested that osthole could inhibit lung inflammation on carrageenan-induced pleurisy in rats and that could be related to a reduction of PMNs infiltration and release of inflammatory factors. Copyright © 2014 Elsevier B.V. All rights reserved.

Lactate rescues neuronal sodium homeostasis during impaired energy metabolism.

PubMed

Karus, Claudia; Ziemens, Daniel; Rose, Christine R

2015-01-01

Recently, we established that recurrent activity evokes network sodium oscillations in neurons and astrocytes in hippocampal tissue slices. Interestingly, metabolic integrity of astrocytes was essential for the neurons' capacity to maintain low sodium and to recover from sodium loads, indicating an intimate metabolic coupling between the 2 cell types. Here, we studied if lactate can support neuronal sodium homeostasis during impaired energy metabolism by analyzing whether glucose removal, pharmacological inhibition of glycolysis and/or addition of lactate affect cellular sodium regulation. Furthermore, we studied the effect of lactate on sodium regulation during recurrent network activity and upon inhibition of the glial Krebs cycle by sodium-fluoroacetate. Our results indicate that lactate is preferentially used by neurons. They demonstrate that lactate supports neuronal sodium homeostasis and rescues the effects of glial poisoning by sodium-fluoroacetate. Altogether, they are in line with the proposed transfer of lactate from astrocytes to neurons, the so-called astrocyte-neuron-lactate shuttle.

MmPPOX inhibits Mycobacterium tuberculosis lipolytic enzymes belonging to the hormone-sensitive lipase family and alters mycobacterial growth.

PubMed

Delorme, Vincent; Diomandé, Sadia V; Dedieu, Luc; Cavalier, Jean-François; Carrière, Frédéric; Kremer, Laurent; Leclaire, Julien; Fotiadu, Frédéric; Canaan, Stéphane

2012-01-01

Lipid metabolism plays an important role during the lifetime of Mycobacterium tuberculosis, the causative agent of tuberculosis. Although M. tuberculosis possesses numerous lipolytic enzymes, very few have been characterized yet at a biochemical/pharmacological level. This study was devoted to the M. tuberculosis lipolytic enzymes belonging to the Hormone-Sensitive Lipase (HSL) family, which encompasses twelve serine hydrolases closely related to the human HSL. Among them, nine were expressed, purified and biochemically characterized using a broad range of substrates. In vitro enzymatic inhibition studies using the recombinant HSL proteins, combined with mass spectrometry analyses, revealed the potent inhibitory activity of an oxadiazolone compound, named MmPPOX. In addition, we provide evidence that MmPPOX alters mycobacterial growth. Overall, these findings suggest that the M. tuberculosis HSL family displays important metabolic functions, thus opening the way to further investigations linking the involvement of these enzymes in mycobacterial growth.

MmPPOX Inhibits Mycobacterium tuberculosis Lipolytic Enzymes Belonging to the Hormone-Sensitive Lipase Family and Alters Mycobacterial Growth

PubMed Central

Delorme, Vincent; Diomandé, Sadia V.; Dedieu, Luc; Cavalier, Jean-François; Carrière, Frédéric; Kremer, Laurent; Leclaire, Julien; Fotiadu, Frédéric; Canaan, Stéphane

2012-01-01

Lipid metabolism plays an important role during the lifetime of Mycobacterium tuberculosis, the causative agent of tuberculosis. Although M. tuberculosis possesses numerous lipolytic enzymes, very few have been characterized yet at a biochemical/pharmacological level. This study was devoted to the M. tuberculosis lipolytic enzymes belonging to the Hormone-Sensitive Lipase (HSL) family, which encompasses twelve serine hydrolases closely related to the human HSL. Among them, nine were expressed, purified and biochemically characterized using a broad range of substrates. In vitro enzymatic inhibition studies using the recombinant HSL proteins, combined with mass spectrometry analyses, revealed the potent inhibitory activity of an oxadiazolone compound, named MmPPOX. In addition, we provide evidence that MmPPOX alters mycobacterial growth. Overall, these findings suggest that the M. tuberculosis HSL family displays important metabolic functions, thus opening the way to further investigations linking the involvement of these enzymes in mycobacterial growth. PMID:23029536

Study of analgesic effect of earthworm extract

PubMed Central

Luo, Wei; Deng, Zhen-han; Li, Rui; Cheng, Guo; Kotian, Ronak Naveenchandra

2017-01-01

Pain represents a major clinical problem and one which has exercised generations of healthcare professionals. Earthworms are used as a traditional Chinese medicine, and have been applied pharmacologically and clinically since a long time in China. However, the analgesic effects of earthworm extract (EE) are seldom studied. Hence, we evaluated the analgesic effects of EE in mice. The obtained data showed that EE increased pain threshold and exhibited peripheral but not central analgesic effects in mice; evidenced by increased inhibition ratio in acetic acid writhing test and formalin test, whereas only slight increase in inhibition ratio in hot plate test and tail immersion test. In addition, EE decreased serum norepinephrine (NE), 5-hydroxytryptamine (5-HT), and nitric oxide (NO) synthase (NOS) concentration, similar to other analgesic drugs like morphine and aspirin. In a nutshell, the obtained data have demonstrated that EE has peripheral analgesic properties and could be used as a promising analgesic drug. PMID:29273677

Lactate rescues neuronal sodium homeostasis during impaired energy metabolism

PubMed Central

Karus, Claudia; Ziemens, Daniel; Rose, Christine R

2015-01-01

Recently, we established that recurrent activity evokes network sodium oscillations in neurons and astrocytes in hippocampal tissue slices. Interestingly, metabolic integrity of astrocytes was essential for the neurons' capacity to maintain low sodium and to recover from sodium loads, indicating an intimate metabolic coupling between the 2 cell types. Here, we studied if lactate can support neuronal sodium homeostasis during impaired energy metabolism by analyzing whether glucose removal, pharmacological inhibition of glycolysis and/or addition of lactate affect cellular sodium regulation. Furthermore, we studied the effect of lactate on sodium regulation during recurrent network activity and upon inhibition of the glial Krebs cycle by sodium-fluoroacetate. Our results indicate that lactate is preferentially used by neurons. They demonstrate that lactate supports neuronal sodium homeostasis and rescues the effects of glial poisoning by sodium-fluoroacetate. Altogether, they are in line with the proposed transfer of lactate from astrocytes to neurons, the so-called astrocyte-neuron-lactate shuttle. PMID:26039160

In vitro pharmacological activity of the tetrahydroisoquinoline salsolinol present in products from Theobroma cacao L. like cocoa and chocolate.

PubMed

Melzig, M F; Putscher, I; Henklein, P; Haber, H

2000-11-01

Cocoa and chocolate contain the tetrahydroisoquinoline alkaloid salsolinol up to a concentration of 25 microg/g. Salsolinol is a dopaminergic active compound which binds to the D(2) receptor family, especially to the D(3) receptor with a K(i) of 0.48+/-0.021 micromol/l. It inhibits the formation of cyclic AMP and the release of beta-endorphin and ACTH in a pituitary cell system. Taking the detected concentration and the pharmacological properties into account, salsolinol seems to be one of the main psychoactive compounds present in cocoa and chocolate and might be included in chocolate addiction.

Functional screening of pharmacological chaperones via restoration of enzyme activity upon denaturation.

PubMed

Shanmuganathan, Meera; Britz-McKibbin, Philip

2012-10-02

Pharmacological chaperones (PCs) are small molecules that stabilize and promote protein folding. Enzyme inhibition is widely used for PC selection; however, it does not accurately reflect chaperone activity. We introduce a functional assay for characterization of PCs based on their capacity to restore enzyme activity that is abolished upon chemical denaturation. Dose-dependent activity curves were performed as a function of urea to assess the chaperone potency of various ligands to β-glucocerebrosidase as a model system. Restoration of enzyme activity upon denaturation allows direct screening of PCs for treatment of genetic disorders associated with protein deficiency, such as Gaucher disease.

Efficiency and specificity of RAAS inhibitors in cardiovascular diseases: how to achieve better end-organ protection?

PubMed

Nehme, Ali; Zibara, Kazem

2017-11-01

RAAS, a major pharmacological target in cardiovascular medicine, is inhibited by pharmacological classes including angiotensin converting enzyme (ACE) inhibitors (ACEIs), angiotensin-II type 1 blockers (ARBs) and aldosterone receptors antagonists, in addition to the recently introduced direct renin inhibitors (DRIs). However, currently used RAAS inhibitors still cannot achieve their desired effects and are associated with certain drawbacks, such as adverse side effects, incomplete blockage of the system and poor end-organ protection. In this review, we discuss the efficiency and specificity of the current RAAS inhibitors and propose some recommendations for achieving better treatments with better end-organ protection.

The role of JAK-3 in regulating TLR-mediated inflammatory cytokine production in innate immune cells.

PubMed

Wang, Huizhi; Brown, Jonathan; Gao, Shegan; Liang, Shuang; Jotwani, Ravi; Zhou, Huaxin; Suttles, Jill; Scott, David A; Lamont, Richard J

2013-08-01

The role of JAK-3 in TLR-mediated innate immune responses is poorly understood, although the suppressive function of JAK3 inhibition in adaptive immune response has been well studied. In this study, we found that JAK3 inhibition enhanced TLR-mediated immune responses by differentially regulating pro- and anti- inflammatory cytokine production in innate immune cells. Specifically, JAK3 inhibition by pharmacological inhibitors or specific small interfering RNA or JAK3 gene knockout resulted in an increase in TLR-mediated production of proinflammatory cytokines while concurrently decreasing the production of IL-10. Inhibition of JAK3 suppressed phosphorylation of PI3K downstream effectors including Akt, mammalian target of rapamycin complex 1, glycogen synthase kinase 3β (GSK3β), and CREB. Constitutive activation of Akt or inhibition of GSK3β abrogated the capability of JAK3 inhibition to enhance proinflammatory cytokines and suppress IL-10 production. In contrast, inhibition of PI3K enhanced this regulatory ability of JAK3 in LPS-stimulated monocytes. At the transcriptional level, JAK3 knockout lead to the increased phosphorylation of STATs that could be attenuated by neutralization of de novo inflammatory cytokines. JAK3 inhibition exhibited a GSK3 activity-dependent ability to enhance phosphorylation levels and DNA binding of NF-κB p65. Moreover, JAK3 inhibition correlated with an increased CD4(+) T cell response. Additionally, higher neutrophil infiltration, IL-17 expression, and intestinal epithelium erosion were observed in JAK3 knockout mice. These findings demonstrate the negative regulatory function of JAK3 and elucidate the signaling pathway by which JAK3 differentially regulates TLR-mediated inflammatory cytokine production in innate immune cells.

Melatonin inhibits AP-2β/hTERT, NF-κB/COX-2 and Akt/ERK and activates caspase/Cyto C signaling to enhance the antitumor activity of berberine in lung cancer cells

PubMed Central

Zhang, Changlin; Qin, Lijun; Wang, Jingshu; Yu, Zhenlong; Shi, Dingbo; Xiao, Xiangsheng; Xie, Fangyun; Huang, Wenlin; Deng, Wuguo

2016-01-01

Melatonin, a molecule produced throughout the animal and plant kingdoms, and berberine, a plant derived agent, both exhibit antitumor and multiple biological and pharmacological effects, but they have never been combined altogether for the inhibition of human lung cancers. In this study, we investigated the role and underlying mechanisms of melatonin in the regulation of antitumor activity of berberine in lung cancer cells. Treatment with melatonin effectively increased the berberine-mediated inhibitions of cell proliferation, colony formation and cell migration, thereby enhancing the sensitivities of lung cancer cells to berberine. Melatonin also markedly increased apoptosis induced by berberine. Further mechanism study showed that melatonin promoted the cleavage of caspse-9 and PARP, enhanced the inhibition of Bcl2, and triggered the releasing of cytochrome C (Cyto C), thereby increasing the berberine-induced apoptosis. Melatonin also enhanced the berberine-mediated inhibition of telomerase reverses transcriptase (hTERT) by down-regulating the expression of AP-2β and its binding on hTERT promoter. Moreover, melatonin enhanced the berberine-mediated inhibition of cyclooxygenase 2 (COX-2) by inhibiting the nuclear translocation of NF-κB and its binding on COX-2 promoter. Melatonin also increased the berberine-mediated inhibition of the phosphorylated Akt and ERK. Collectively, our results demonstrated that melatonin enhanced the antitumor activity of berberine by activating caspase/Cyto C and inhibiting AP-2β/hTERT, NF-κB/COX-2 and Akt/ERK signaling pathways. Our findings provide new insights in exploring the potential therapeutic strategies and novel targets for lung cancer treatment. PMID:26672764

Current status and future directions of pharmacological therapy for acromegaly.

PubMed

Mercado, Moisés; Espinosa, Etual; Ramírez, Claudia

2016-09-01

Acromegaly is a chronic systemic disorder caused in the vast majority of cases by a GH-secreting pituitary adenoma and resulting in significant morbidity and mortality if left untreated. The treatment of choice is the trans-sphenoidal resection of the adenoma, and although 80% of patients with microadenomas or confined macroadenomas achieve biochemical remission, the surgical success rate for patients harboring tumors with extrasellar extension is below 50%. Thus, a considerable proportion of patients will require some form of adjuvant treatment. Acromegaly can be approached pharmacologically by inhibiting GH secretion by the tumor (somatostatin analogues, dopamine agonists) or by antagonizing GH actions at its target tissues (GH receptor antagonists). The primary pharmacological treatment of acromegaly is increasingly gaining acceptance by both physicians and patients. The decision to use primary pharmacological treatment has to take into account the clinical characteristics of the patient (presence of comorbidities that significantly increase the surgical risk) and the biological nature of the adenoma (tumor size and location), as well as other aspects such as the availability of a pituitary surgeon and the cost of medications. This review provides a critical summary and update of the pharmacological treatment of acromegaly focusing both, on well-established agents and strategies as well as on novel compounds that are currently being developed.

Cato Guldberg and Peter Waage, the history of the Law of Mass Action, and its relevance to clinical pharmacology.

PubMed

Ferner, Robin E; Aronson, Jeffrey K

2016-01-01

We have traced the historical link between the Law of Mass Action and clinical pharmacology. The Law evolved from the work of the French chemist Claude Louis Berthollet, was first formulated by Cato Guldberg and Peter Waage in 1864 and later clarified by the Dutch chemist Jacobus van 't Hoff in 1877. It has profoundly influenced our qualitative and quantitative understanding of a number of physiological and pharmacological phenomena. According to the Law of Mass Action, the velocity of a chemical reaction depends on the concentrations of the reactants. At equilibrium the concentrations of the chemicals involved bear a constant relation to each other, described by the equilibrium constant, K. The Law of Mass Action is relevant to various physiological and pharmacological concepts, including concentration-effect curves, dose-response curves, and ligand-receptor binding curves, all of which are important in describing the pharmacological actions of medications, the Langmuir adsorption isotherm, which describes the binding of medications to proteins, activation curves for transmembrane ion transport, enzyme inhibition and the Henderson-Hasselbalch equation, which describes the relation between pH, as a measure of acidity and the concentrations of the contributory acids and bases. Guldberg and Waage recognized the importance of dynamic equilibrium, while others failed to do so. Their ideas, over 150 years old, are embedded in and still relevant to clinical pharmacology. Here we explain the ideas and in a subsequent paper show how they are relevant to understanding adverse drug reactions. © 2015 The British Pharmacological Society.

Design, synthesis, pharmacological evaluation, QSAR analysis, molecular modeling and ADMET of novel donepezil-indolyl hybrids as multipotent cholinesterase/monoamine oxidase inhibitors for the potential treatment of Alzheimer's disease.

PubMed

Bautista-Aguilera, Oscar M; Esteban, Gerard; Bolea, Irene; Nikolic, Katarina; Agbaba, Danica; Moraleda, Ignacio; Iriepa, Isabel; Samadi, Abdelouahid; Soriano, Elena; Unzeta, Mercedes; Marco-Contelles, José

2014-03-21

The design, synthesis, and pharmacological evaluation of donepezil-indolyl based amines 7-10, amides 12-16, and carboxylic acid derivatives 5 and 11, as multipotent ASS234 analogs, able to inhibit simultaneously cholinesterase (ChE) and monoamine oxidase (MAO) enzymes for the potential treatment of Alzheimer's disease (AD), is reported. Theoretical studies using 3D-Quantitative Structure-Activity Relationship (3D-QSAR) was used to define 3D-pharmacophores for inhibition of MAO A/B, AChE, and BuChE enzymes. We found that, in general, and for the same substituent, amines are more potent ChE inhibitors (see compounds 12, 13 versus 7 and 8) or equipotent (see compounds 14, 15 versus 9 and 10) than the corresponding amides, showing a clear EeAChE inhibition selectivity. For the MAO inhibition, amides were not active, and among the amines, compound 14 was totally MAO A selective, while amines 15 and 16 were quite MAO A selective. Carboxylic acid derivatives 5 and 11 showed a multipotent moderate selective profile as EeACE and MAO A inhibitors. Propargylamine 15 [N-((5-(3-(1-benzylpiperidin-4-yl)propoxy)-1-methyl-1H-indol-2-yl)methyl)prop-2-yn-1-amine] resulted in the most potent hMAO A (IC50 = 5.5 ± 1.4 nM) and moderately potent hMAO B (IC50 = 150 ± 31 nM), EeAChE (IC50 = 190 ± 10 nM), and eqBuChE (IC50 = 830 ± 160 nM) inhibitor. However, the analogous N-allyl and the N-morpholine derivatives 16 and 14 deserve also attention as they show an attractive multipotent profile. To sum up, donepezil-indolyl hybrid 15 is a promising drug for further development for the potential prevention and treatment of AD. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Concurrent Autophagy Inhibition Overcomes the Resistance of Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors in Human Bladder Cancer Cells.

PubMed

Kang, Minyong; Lee, Kyoung-Hwa; Lee, Hye Sun; Jeong, Chang Wook; Kwak, Cheol; Kim, Hyeon Hoe; Ku, Ja Hyeon

2017-02-04

Despite the potential therapeutic efficacy of epithelial growth factor receptor (EGFR) inhibitors in the treatment of advanced stage bladder cancer, there currently is no clear evidence to support this hypothesis. In this study, we investigate whether the concurrent treatment of autophagy-blocking agents with EGFR inhibitors exerts synergistic anti-cancer effects in T24 and J82 human bladder cancer cells. Lapatinib and gefitinib were used as EGFR inhibitors, and bafilomycin A1 (BFA1), chloroquine (CQ) and 3-methyladenine (3-MA) were used as the pharmacologic inhibitors of autophagy activities. To assess the proliferative and self-renewal capabilities, the Cell Counting Kit-8 (CCK-8) assay and a clonogenic assay were performed, respectively. To examine apoptotic cell death, flow cytometry using annexin-V/propidium iodide (PI) was used. To measure the autophagy activities, the expression levels of LC3I and II was determined by Western blot analysis. To validate the synergistic effects of autophagy inhibition with EGFR inhibitors, we specifically blocked key autophagy regulatory gene ATG12 by transfection of small interference RNA and examined the phenotypic changes. Of note, lapatinib and gefitinib triggered autophagy activities in T24 and J82 human bladder cancer cells, as indicated by upregulation of LC3II. More importantly, inhibiting autophagy activities with pharmacologic inhibitors (BFA1, CQ or 3-MA) remarkably reduced the cell viabilities and clonal proliferation of T24 and J82 cells, compared to those treated with either of the agents alone. We also obtained similar results of the enhanced anti-cancer effects of EGFR inhibitors by suppressing the expression of ATG12. Notably, the apoptotic assay showed that synergistic anti-cancer effects were induced via the increase of apoptotic cell death. In summary, concomitant inhibition of autophagy activities potentiated the anti-cancer effects of EGFR inhibitors in human bladder cancer cells, indicating a novel therapeutic strategy to treat advanced bladder cancer.

Protein kinase Cε regulates nuclear translocation of extracellular signal-regulated kinase, which contributes to bradykinin-induced cyclooxygenase-2 expression.

PubMed

Nakano, Rei; Kitanaka, Taku; Namba, Shinichi; Kitanaka, Nanako; Sugiya, Hiroshi

2018-06-04

The proinflammatory mediator bradykinin stimulated cyclooxygenase-2 (COX-2) expression and subsequently prostaglandin E 2 synthesis in dermal fibroblasts. The involvement of B2 receptors and Gαq in the role of bradykinin was suggested by using pharmacological inhibitors. The PKC activator PMA stimulated COX-2 mRNA expression. Bradykinin failed to induce COX-2 mRNA expression in the presence of PKC inhibitors, whereas the effect of bradykinin was observed in the absence of extracellular Ca 2+ . Bradykinin-induced COX-2 mRNA expression was inhibited in cells transfected with PKCε siRNA. These observations suggest that the novel PKCε is concerned with bradykinin-induced COX-2 expression. Bradykinin-induced PKCε phosphorylation and COX-2 mRNA expression were inhibited by an inhibitor of 3-phosphoinositide-dependent protein kinase-1 (PDK-1), and bradykinin-induced PDK-1 phosphorylation was inhibited by phospholipase D (PLD) inhibitors, suggesting that PLD/PDK-1 pathway contributes to bradykinin-induced PKCε activation. Pharmacological and knockdown studies suggest that the extracellular signal-regulated kinase 1 (ERK1) MAPK signaling is involved in bradykinin-induced COX-2 expression. Bradykinin-induced ERK phosphorylation was attenuated in the cells pretreated with PKC inhibitors or transfected with PKCε siRNA. We observed the interaction between PKCε and ERK by co-immunoprecipitation experiments. These observations suggest that PKCε activation contributes to the regulation of ERK1 activation. Bradykinin stimulated the accumulation of phosphorylated ERK in the nuclear fraction, that was inhibited in the cells treated with PKC inhibitors or transfected with PKCε siRNA. Consequently, we concluded that bradykinin activates PKCε via the PLD/PDK-1 pathway, which subsequently induces activation and translocation of ERK1 into the nucleus, and contributes to COX-2 expression for prostaglandin E 2 synthesis in dermal fibroblasts.

6-Shogaol, an active constituent of ginger, inhibits breast cancer cell invasion by reducing matrix metalloproteinase-9 expression via blockade of nuclear factor-κB activation.

PubMed

Ling, H; Yang, H; Tan, S-H; Chui, W-K; Chew, E-H

2010-12-01

Shogaols are reported to possess anti-inflammatory and anticancer activities. However, the antimetastatic potential of shogaols remains unexplored. This study was performed to assess the effects of shogaols against breast cancer cell invasion and to investigate the underlying mechanisms. The anti-invasive effect of a series of shogaols was initially evaluated on MDA-MB-231 breast cancer cells using the matrigel invasion assay. The suppressive effects of 6-shogaol on phorbol 12-myristate 13-acetate (PMA)-induced matrix metalloproteinase-9 (MMP-9) gelatinolytic activity and nuclear factor-κB (NF-κB) activation were further determined. Shogaols (6-, 8- and 10-shogaol) inhibited PMA-stimulated MDA-MB-231 cell invasion with an accompanying decrease in MMP-9 secretion. 6-Shogaol was identified to display the greatest anti-invasive effect in association with a dose-dependent reduction in MMP-9 gene activation, protein expression and secretion. The NF-κB transcriptional activity was decreased by 6-shogaol; an effect mediated by inhibition of IκB phosphorylation and degradation that subsequently led to suppression of NF-κB p65 phosphorylation and nuclear translocation. In addition, 6-shogaol was found to inhibit JNK activation with no resulting reduction in activator protein-1 transcriptional activity. By using specific inhibitors, it was demonstrated that ERK and NF-κB signalling, but not JNK and p38 signalling, were involved in PMA-stimulated MMP-9 activation. 6-Shogaol is a potent inhibitor of MDA-MB-231 cell invasion, and the molecular mechanism involves at least in part the down-regulation of MMP-9 transcription by targeting the NF-κB activation cascade. This class of naturally occurring small molecules thus have potential for clinical use as antimetastatic treatments. © 2010 The Authors. British Journal of Pharmacology © 2010 The British Pharmacological Society.

Activation of serotonin 2C receptors in dopamine neurons inhibits binge-like eating in mice

USDA-ARS?s Scientific Manuscript database

Neural networks that regulate binge eating remain to be identified, and effective treatments for binge eating are limited. We combined neuroanatomic, pharmacologic, electrophysiological, Cre-lox, and chemogenetic approaches to investigate the functions of 5-hydroxytryptamine (5-HT) 2C receptor (5-HT...

Maintenance pharmacological immunosuppressive strategies in renal transplantation.

PubMed Central

Vella, J. P.; Sayegh, M. H.

1997-01-01

Current maintenance immunosuppressive regimens for transplantation are based on three classes of drugs: corticosteroids, immunophilin-binding agents (eg, cyclosporin and tacrolimus), and antimetabolites (eg, azathioprine and mycophenolate). Drugs from the various classes inhibit the immune system at different points and are thus synergistic when used in combination. PMID:9338020

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pemble,C.; Johnson, L.; Kridel, S.

Human fatty acid synthase (FAS) is uniquely expressed at high levels in many tumor types. Pharmacological inhibition of FAS therefore represents an important therapeutic opportunity. The drug Orlistat, which has been approved by the US Food and Drug Administration, inhibits FAS, induces tumor cell-specific apoptosis and inhibits the growth of prostate tumor xenografts. We determined the 2.3-{angstrom}-resolution crystal structure of the thioesterase domain of FAS inhibited by Orlistat. Orlistat was captured in the active sites of two thioesterase molecules as a stable acyl-enzyme intermediate and as the hydrolyzed product. The details of these interactions reveal the molecular basis for inhibitionmore » and suggest a mechanism for acyl-chain length discrimination during the FAS catalytic cycle. Our findings provide a foundation for the development of new cancer drugs that target FAS.« less

Pharmacologically active phenylpropanoids from Senra incana.

PubMed

Farah, M H; Samuelsson, G

1992-02-01

Coniferaldehyde, scopoletin, sinapaldehyde, and syringaldehyde were isolated from an aqueous extract of Senra incana. All four compounds inhibited prostaglandin synthetase in a dose-dependent way. Compared to aspirin, the potency of coniferaldehyde and scopoletin was about five times higher, whereas syringaldehyde and sinapaldehyde had about half the potency of this reference compound. On topical application, sinapaldehyde and scopoletin dose-dependently inhibited ethyl phenylpropiolate-induced edema of the rat ear. The active dose range was 1-10 micrograms/ear. Higher doses had a lower effect. Syringaldehyde was active in the range 20-100 micrograms/ear, whereas the effect of coniferaldehyde was inconclusive. Coniferaldehyde and sinapaldehyde inhibited electrically induced contractions of the guinea pig ileum in a dose-dependent way. Syringaldehyde showed a weak inhibition at a concentration of 550 microM.

Ibogaine and the inhibition of acetylcholinesterase.

PubMed

Alper, Kenneth; Reith, Maarten E A; Sershen, Henry

2012-02-15

Ibogaine is a psychoactive monoterpine indole alkaloid extracted from the root bark of Tabernanthe iboga Baill. that is used globally in medical and nonmedical settings to treat drug and alcohol addiction, and is of interest as an ethnopharmacological prototype for experimental investigation and pharmaceutical development. The question of whether ibogaine inhibits acetylcholinesterase (AChE) is of pharmacological and toxicological significance. AChE activity was evaluated utilizing reaction with Ellman's reagent with physostigmine as a control. Ibogaine inhibited AChE with an IC(50) of 520±40 μM. Ibogaine's inhibition of AChE is physiologically negligible, and does not appear to account for observations of functional effects in animals and humans that might otherwise suggest the possible involvement of pathways linked to muscarinic acetylcholine transmission. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.