scholarly journals Selective Mycobacterium tuberculosis Shikimate Kinase Inhibitors as Potential Antibacterials

2015 ◽  
Vol 7 ◽  
pp. PMC.S13212 ◽  
Author(s):  
Sara Gordon ◽  
Johayra Simithy ◽  
Douglas C. Goodwin ◽  
Angela I. Calderón
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Kinase Inhibitors ◽  
Shikimate Pathway ◽  
Multidrug Resistant ◽  
Antitubercular Agents ◽  
Shikimate Kinase ◽  
Antitubercular Drugs ◽  
Inhibitor Discovery

Owing to the persistence of tuberculosis (TB) as well as the emergence of multidrug-resistant and extensively drug-resistant (XDR) forms of the disease, the development of new antitubercular drugs is crucial. Developing inhibitors of shikimate kinase (SK) in the shikimate pathway will provide a selective target for antitubercular agents. Many studies have used in silico technology to identify compounds that are anticipated to interact with and inhibit SK. To a much more limited extent, SK inhibition has been evaluated by in vitro methods with purified enzyme. Currently, there are no data on in vivo activity of Mycobacterium tuberculosis shikimate kinase ( MtSK) inhibitors available in the literature. In this review, we present a summary of the progress of SK inhibitor discovery and evaluation with particular attention toward development of new antitubercular agents.

scholarly journals A New Strategy for Glioblastoma Treatment: In Vitro and In Vivo Preclinical Characterization of Si306, a Pyrazolo[3,4-d]Pyrimidine Dual Src/P-Glycoprotein Inhibitor

Cancers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 848 ◽  
Author(s):  
Anna Lucia Fallacara ◽  
Claudio Zamperini ◽  
Ana Podolski-Renić ◽  
Jelena Dinić ◽  
Tijana Stanković ◽  
...  
Keyword(s):  
Kinase Inhibitors ◽  
Multidrug Resistant ◽  
Cellular Level ◽  
Cns Tumors ◽  
Significant Activity ◽  
Src Tyrosine Kinase ◽  
P Glycoprotein ◽  
New Strategy

Overexpression of P-glycoprotein (P-gp) and other ATP-binding cassette (ABC) transporters in multidrug resistant (MDR) cancer cells is responsible for the reduction of intracellular drug accumulation, thus decreasing the efficacy of chemotherapeutics. P-gp is also found at endothelial cells’ membrane of the blood-brain barrier, where it limits drug delivery to central nervous system (CNS) tumors. We have previously developed a set of pyrazolo[3,4-d]pyrimidines and their prodrugs as novel Src tyrosine kinase inhibitors (TKIs), showing a significant activity against CNS tumors in in vivo. Here we investigated the interaction of the most promising pair of drug/prodrug with P-gp at the cellular level. The tested compounds were found to increase the intracellular accumulation of Rho 123, and to enhance the efficacy of paclitaxel in P-gp overexpressing cells. Encouraging pharmacokinetics properties and tolerability in vivo were also observed. Our findings revealed a novel role of pyrazolo[3,4-d]pyrimidines which may be useful for developing a new effective therapy in MDR cancer treatment, particularly against glioblastoma.

scholarly journals Mode of Action of Clofazimine and Combination Therapy with Benzothiazinones against Mycobacterium tuberculosis

2015 ◽  
Vol 59 (8) ◽  
pp. 4457-4463 ◽  
Author(s):  
Benoit Lechartier ◽  
Stewart T. Cole
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Bacterial Load ◽  
Multidrug Resistant ◽  
Content Type ◽  
Resistant Tuberculosis ◽  
Multidrug Resistant Tuberculosis ◽  
Drug Resistant Strains ◽  
Transfer Chain

ABSTRACTClofazimine (CZM) is an antileprosy drug that was recently repurposed for treatment of multidrug-resistant tuberculosis. InMycobacterium tuberculosis, CZM appears to act as a prodrug, which is reduced by NADH dehydrogenase (NDH-2), to release reactive oxygen species upon reoxidation by O2. CZM presumably competes with menaquinone (MK-4), a key cofactor in the mycobacterial electron transfer chain, for its reduction by NDH-2. We studied the effect of MK-4 supplementation on the activity of CZM againstM. tuberculosisand found direct competition between CZM and MK-4 for the cidal effect of CZM, against nonreplicating and actively growing bacteria, as MK-4 supplementation blocked the drug's activity against nonreplicating bacteria. We demonstrated that CZM, like bedaquiline, is synergisticin vitrowith benzothiazinones such as 2-piperazino-benzothiazinone 169 (PBTZ169), and this synergy also occurs against nonreplicating bacteria. The synergy between CZM and PBTZ169 was lost in an MK-4-rich medium, indicating that MK-4 is the probable link between their activities. The efficacy of the dual combination of CZM and PBTZ169 was testedin vivo, where a great reduction in bacterial load was obtained in a murine model of chronic tuberculosis. Taken together, these data confirm the potential of CZM in association with PBTZ169 as the basis for a new regimen against drug-resistant strains ofM. tuberculosis.

scholarly journals In VitroandIn VivoActivities of the Nitroimidazole TBA-354 against Mycobacterium tuberculosis

2014 ◽  
Vol 59 (1) ◽  
pp. 136-144 ◽  
Author(s):  
A. M. Upton ◽  
S. Cho ◽  
T. J. Yang ◽  
Y. Kim ◽  
Y. Wang ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Pharmacokinetic Profile ◽  
Multidrug Resistant ◽  
Phase Iii ◽  
Drug Resistant ◽  
Next Generation ◽  
Content Type ◽  
Resistant Tuberculosis

ABSTRACTNitroimidazoles are a promising new class of antitubercular agents. The nitroimidazo-oxazole delamanid (OPC-67683, Deltyba) is in phase III trials for the treatment of multidrug-resistant tuberculosis, while the nitroimidazo-oxazine PA-824 is entering phase III for drug-sensitive and drug-resistant tuberculosis. TBA-354 (SN31354[(S)-2-nitro-6-((6-(4-trifluoromethoxy)phenyl)pyridine-3-yl)methoxy)-6,7-dihydro-5H-imidazo[2,1-b][1,3]oxazine]) is a pyridine-containing biaryl compound with exceptional efficacy against chronic murine tuberculosis and favorable bioavailability in preliminary rodent studies. It was selected as a potential next-generation antituberculosis nitroimidazole following an extensive medicinal chemistry effort. Here, we further evaluate the pharmacokinetic properties and activity of TBA-354 againstMycobacterium tuberculosis. TBA-354 is narrow spectrum and bactericidalin vitroagainst replicating and nonreplicatingMycobacterium tuberculosis, with potency similar to that of delamanid and greater than that of PA-824. The addition of serum protein or albumin does not significantly alter this activity. TBA-354 maintains activity againstMycobacterium tuberculosisH37Rv isogenic monoresistant strains and clinical drug-sensitive and drug-resistant isolates. Spontaneous resistant mutants appear at a frequency of 3 × 10−7.In vitrostudies andin vivostudies in mice confirm that TBA-354 has high bioavailability and a long elimination half-life.In vitrostudies suggest a low risk of drug-drug interactions. Low-dose aerosol infection models of acute and chronic murine tuberculosis reveal time- and dose-dependentin vivobactericidal activity that is at least as potent as that of delamanid and more potent than that of PA-824. Its superior potency and pharmacokinetic profile that predicts suitability for once-daily oral dosing suggest that TBA-354 be studied further for its potential as a next-generation nitroimidazole.

scholarly journals Discovery of (3-Benzyl-5-hydroxyphenyl)carbamates as New Antitubercular Agents with Potent In Vitro and In Vivo Efficacy

Molecules ◽  
2019 ◽  
Vol 24 (10) ◽  
pp. 2021 ◽  
Author(s):  
Ya-Juan Cheng ◽  
Zhi-Yong Liu ◽  
Hua-Ju Liang ◽  
Cui-Ting Fang ◽  
Niu-Niu Zhang ◽  
...  
Keyword(s):  
Oral Administration ◽  
Inhibitory Activity ◽  
Multidrug Resistant ◽  
Infection Model ◽  
Antitubercular Agents ◽  
In Vivo Efficacy ◽  
Mouse Infection Model ◽  
Good Potential

A series of 3-amino-5-benzylphenol derivatives were designed and synthesized. Among them, (3-benzyl-5-hydroxyphenyl)carbamates were found to exert good inhibitory activity against M. tuberculosis H37Ra, H37Rv and clinically isolated multidrug-resistant M. tuberculosis strains (MIC = 0.625–6.25 μg/mL). The privileged compounds 3i and 3l showed moderate cytotoxicity against cell line A549. Compound 3l also exhibited potent in vivo inhibitory activity on a mouse infection model via the oral administration. The results demonstrated 3-hydroxyphenylcarbamates as a class of new antitubercular agents with good potential.

Structure of shikimate kinase, anin vivoessential metabolic enzyme in the nosocomial pathogenAcinetobacter baumannii, in complex with shikimate

2015 ◽  
Vol 71 (8) ◽  
pp. 1736-1744 ◽  
Author(s):  
Kristin A. Sutton ◽  
Jennifer Breen ◽  
Ulrike MacDonald ◽  
Janet M. Beanan ◽  
Ruth Olson ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Sequence Divergence ◽  
Shikimate Pathway ◽  
Multidrug Resistant ◽  
Metabolic Enzyme ◽  
Infection Model ◽  
Shikimate Kinase ◽  
Antibiotic Development ◽  
The Impact

Acinetobacter baumanniiis an opportunistic Gram-negative pathogen that is an important cause of healthcare-associated infections exhibiting high mortality rates. Clinical isolates of multidrug-resistant (MDR) and extremely drug-resistant (XDR)A. baumanniistrains are increasingly being observed. Compounding this concern is the dearth of new antibacterial agents in late-stage development that are effective against MDR and XDRA. baumannii. As part of an effort to address these concerns, two genes (aroAandaroC) of the shikimate pathway have previously been determined to be essential for the growth and survival ofA. baumanniiduring host infection (i.e.to be essentialin vivo). This study expands upon these results by demonstrating that theA. baumannii aroKgene, encoding shikimate kinase (SK), is also essentialin vivoin a rat soft-tissue infection model. The crystal structure ofA. baumanniiSK in complex with the substrate shikimate and a sulfate ion that mimics the binding interactions expected for the β-phosphate of ATP was then determined to 1.91 Å resolution and the enzyme kinetics were characterized. The flexible shikimate-binding domain and LID region are compared with the analogous regions in other SK crystal structures. The impact of structural differences and sequence divergence between SKs from pathogenic bacteria that may influence antibiotic-development efforts is discussed.

scholarly journals Preclinical Testing of the Nitroimidazopyran PA-824 for Activity against Mycobacterium tuberculosis in a Series of In Vitro and In Vivo Models

2005 ◽  
Vol 49 (6) ◽  
pp. 2294-2301 ◽  
Author(s):  
Anne J. Lenaerts ◽  
Veronica Gruppo ◽  
Karen S. Marietta ◽  
Christine M. Johnson ◽  
Diane K. Driscoll ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Bacterial Load ◽  
Multidrug Resistant ◽  
Infection Model ◽  
Significant Activity ◽  
Dependent Manner ◽  
In Vivo Models ◽  
Long Term Treatment

ABSTRACT This study extends earlier reports regarding the in vitro and in vivo efficacies of the nitroimidazopyran PA-824 against Mycobacterium tuberculosis. PA-824 was tested in vitro against a broad panel of multidrug-resistant clinical isolates and was found to be highly active against all isolates (MIC < 1 μg/ml). The activity of PA-824 against M. tuberculosis was also assessed grown under conditions of oxygen depletion. PA-824 showed significant activity at 2, 10, and 50 μg/ml, similar to that of metronidazole, in a dose-dependent manner. In a short-course mouse infection model, the efficacy of PA-824 at 50, 100, and 300 mg/kg of body weight formulated in methylcellulose or cyclodextrin/lecithin after nine oral treatments was compared with those of isoniazid, rifampin, and moxifloxacin. PA-824 at 100 mg/kg in cyclodextrin/lecithin was as active as moxifloxacin at 100 mg/kg and isoniazid at 25 mg/kg and was slightly more active than rifampin at 20 mg/kg. Long-term treatment with PA-824 at 100 mg/kg in cyclodextrin/lecithin reduced the bacterial load below 500 CFU in the lungs and spleen. No significant differences in activity between PA-824 and the other single drug treatments tested (isoniazid at 25 mg/kg, rifampin at 10 mg/kg, gatifloxacin at 100 mg/kg, and moxifloxacin at 100 mg/kg) could be observed. In summary, its good activity in in vivo models, as well as its activity against multidrug-resistant M. tuberculosis and against M. tuberculosis isolates in a potentially latent state, makes PA-824 an attractive drug candidate for the therapy of tuberculosis. These data indicate that there is significant potential for effective oral delivery of PA-824 for the treatment of tuberculosis.

scholarly journals Synergy between Circular Bacteriocin AS-48 and Ethambutol against Mycobacterium tuberculosis

2018 ◽  
Vol 62 (9) ◽  
Author(s):  
Clara Aguilar-Pérez ◽  
Begoña Gracia ◽  
Liliana Rodrigues ◽  
Asunción Vitoria ◽  
Rubén Cebrián ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Antimycobacterial Activity ◽  
Multidrug Resistant ◽  
Content Type ◽  
Gram Positive Bacteria ◽  
Antituberculosis Therapy ◽  
Circular Bacteriocin ◽  
Low Cytotoxicity

ABSTRACT The increasing incidence of multidrug-resistant Mycobacterium tuberculosis strains and the very few drugs available for treatment are promoting the discovery and development of new molecules that could help in the control of this disease. Bacteriocin AS-48 is an antibacterial peptide produced by Enterococcus faecalis and is active against several Gram-positive bacteria. We have found that AS-48 was active against Mycobacterium tuberculosis, including H37Rv and other reference and clinical strains, and also against some nontuberculous clinical mycobacterial species. The combination of AS-48 with either lysozyme or ethambutol (commonly used in the treatment of drug-susceptible tuberculosis) increased the antituberculosis action of AS-48, showing a synergic interaction. Under these conditions, AS-48 exhibits a MIC close to some MICs of the first-line antituberculosis agents. The inhibitory activity of AS-48 and its synergistic combination with ethambutol were also observed on M. tuberculosis-infected macrophages. Finally, AS-48 did not show any cytotoxicity against THP-1, MHS, and J774.2 macrophage cell lines at concentrations close to its MIC. In summary, bacteriocin AS-48 has interesting antimycobacterial activity in vitro and low cytotoxicity, so further studies in vivo will contribute to its development as a potential additional drug for antituberculosis therapy.

scholarly journals The Three RelE Homologs of Mycobacterium tuberculosis Have Individual, Drug-Specific Effects on Bacterial Antibiotic Tolerance

2010 ◽  
Vol 192 (5) ◽  
pp. 1279-1291 ◽  
Author(s):  
Ramandeep Singh ◽  
Clifton E. Barry ◽  
Helena I. M. Boshoff
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Survival Rates ◽  
Specific Effect ◽  
Multidrug Resistant ◽  
Cross Resistance ◽  
Bacterial Survival ◽  
E Coli ◽  
The Face

ABSTRACT In Escherichia coli, expression of the RelE and HipA toxins in the absence of their cognate antitoxins has been associated with generating multidrug-tolerant “persisters.” Here we show that unlike persisters of E. coli, persisters of Mycobacterium tuberculosis selected with one drug do not acquire cross-resistance to other classes of drugs. M. tuberculosis has three homologs of RelE arranged in operons with their apparent antitoxins. Each toxin individually arrests growth of both M. tuberculosis and E. coli, an effect that is neutralized by coexpression of the cognate antitoxin. Overexpression or deletion of each of the RelE toxins had a toxin- and drug-specific effect on the proportion of bacilli surviving antibiotic killing. All three toxins were upregulated in vivo, but none of the deletions affected survival during murine infection. RelE2 overexpression increased bacterial survival rates in the presence of rifampin in vitro, while deletion significantly decreased survival rates. Strikingly, deletion of this toxin had no discernible effect on the level of persisters seen in rifampin-treated mice. Our results suggest that, in vivo, RelE-generated persisters are unlikely to play a significant role in the generation of bacilli that survive in the face of multidrug therapy or in the generation of multidrug-resistant M. tuberculosis.

scholarly journals The Combination of Sulfamethoxazole, Trimethoprim, and Isoniazid or Rifampin Is Bactericidal and Prevents the Emergence of Drug Resistance in Mycobacterium tuberculosis

2012 ◽  
Vol 56 (10) ◽  
pp. 5142-5148 ◽  
Author(s):  
Catherine Vilchèze ◽  
William R. Jacobs
Keyword(s):  
Drug Resistance ◽  
Mycobacterium Tuberculosis ◽  
Multidrug Resistant ◽  
New Drugs ◽  
Drug Resistant ◽  
Content Type ◽  
The Past ◽  
Tb Treatment

ABSTRACTThe challenges of developing new drugs to treat tuberculosis (TB) are indicated by the relatively small number of candidates entering clinical trials in the past decade. To overcome these issues, we reexamined two FDA-approved antibacterial drugs, sulfamethoxazole (SMX) and trimethoprim (TMP), for use in TB treatment. SMX and TMP inhibit folic acid biosynthesis and are used in combination to treat infections of the respiratory, urinary, and gastrointestinal tracts. The MICs of SMX and TMP, alone and in combination, were determined for drug-susceptible, multidrug-resistant (MDR), and extensively drug-resistantMycobacterium tuberculosisstrains. While TMP alone was not effective againstM. tuberculosis, the combination of TMP and SMX was bacteriostatic againstM. tuberculosis. Surprisingly, the combination of SMX and TMP was also active against a subset of MDRM. tuberculosisstrains. Treatment ofM. tuberculosiswith TMP-SMX and a first-line anti-TB drug, either isoniazid or rifampin, was bactericidal, demonstrating that the combination of TMP and SMX with isoniazid or rifampin was not antagonistic. Moreover, the addition of SMX-TMP in combination with either isoniazid or rifampin also prevented the emergence of drug resistancein vitro. In conclusion, this study further illustrates the opportunity to reevaluate the activity of TMP-SMXin vivoto prevent the emergence of drug-resistantM. tuberculosis.

scholarly journals The promises and limitations of N-acetylcysteine as a potentiator of first-line and second-line tuberculosis drugs

2021 ◽  
Author(s):  
Catherine Vilchèze ◽  
William R. Jacobs
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Liver Injury ◽  
Multidrug Resistant ◽  
Human Macrophage ◽  
Second Line ◽  
Macrophage Cell ◽  
First Line ◽  
Host Infection

N-acetylcysteine (NAC) is most commonly used for the treatment of acetaminophen overdose and acetaminophen-induced liver injury. In patients infected with Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), NAC is given to treat hepatotoxicity induced by TB drugs. We had previously shown that cysteine, a derivative of NAC, potentiated the activity of isoniazid, a first-line TB drug, by preventing the emergence of INH resistance and persistence in M. tuberculosis in vitro. Herein, we demonstrate that in vitro, NAC has the same boosting activity with various combinations of first- and second-line TB drugs against drug-susceptible and multidrug-resistant M. tuberculosis strains. Similar to cysteine, NAC increased M. tuberculosis respiration. However, in M. tuberculosis-infected mice, the addition of NAC did not augment the activity of first- or second-line TB drugs. A comparison of the activity of NAC combined with TB drugs in murine and human macrophage cell lines revealed that studies in mice might not be recapitulated during host infection in vivo.

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