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1.
Fitoterapia ; 175: 105941, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38575089

ABSTRACT

Four undescribed compounds including three harzianic acids (1, 3 and 4) and one oxazolidinone (2), along with three known ones (5-7) were isolated from the solid fermented product of endophytic fungus Ilyonectria sp., their structures were elucidated as 1-amino-harzianic acid (1), ilyonectria-oxazolidinone (2),10'-nor- isoharzianic acid (3), isohomoharzianic acid (4), harzianic acid (5), isoharzianic acid (6), homoharzianic acid (7) by means of detailed chemical evidences and spectroscopic data analysis. All the compounds were evaluated for cytotoxicity against SMMC-7721 human cancer cell lines by MTS assay. Among the seven tested compounds, 1-amino-harzianic acid (1) demonstrated well cytotoxic activity against SMMC-7721 with IC50 value of 26.84 µM. The results of molecular docking indicated that compound exhibited moderate anti-tumor activity may through binding to apoptosis related proteins.


Subject(s)
Antineoplastic Agents , Molecular Docking Simulation , Oxazolidinones , Humans , Cell Line, Tumor , Molecular Structure , Antineoplastic Agents/pharmacology , Antineoplastic Agents/isolation & purification , Antineoplastic Agents/chemistry , Oxazolidinones/pharmacology , Oxazolidinones/isolation & purification , Endophytes/chemistry , China , Hypocreales/chemistry
2.
ACS Infect Dis ; 8(10): 2187-2197, 2022 10 14.
Article in English | MEDLINE | ID: mdl-36098580

ABSTRACT

Gram-negative bacteria are intrinsically resistant to a plethora of antibiotics that effectively inhibit the growth of Gram-positive bacteria. The intrinsic resistance of Gram-negative bacteria to classes of antibiotics, including rifamycins, aminocoumarins, macrolides, glycopeptides, and oxazolidinones, has largely been attributed to their lack of accumulation within cells due to poor permeability across the outer membrane, susceptibility to efflux pumps, or a combination of these factors. Due to the difficulty in discovering antibiotics that can bypass these barriers, finding targets and compounds that increase the activity of these ineffective antibiotics against Gram-negative bacteria has the potential to expand the antibiotic spectrum. In this study, we investigated the genetic determinants for resistance to rifampicin, novobiocin, erythromycin, vancomycin, and linezolid to determine potential targets of antibiotic-potentiating compounds. We subsequently performed a high-throughput screen of ∼50,000 diverse, synthetic compounds to uncover molecules that potentiate the activity of at least one of the five Gram-positive-targeting antibiotics. This led to the discovery of two membrane active compounds capable of potentiating linezolid and an inhibitor of lipid A biosynthesis capable of potentiating rifampicin and vancomycin. Furthermore, we characterized the ability of known inhibitors of lipid A biosynthesis to potentiate the activity of rifampicin against Gram-negative pathogens.


Subject(s)
Anti-Bacterial Agents , Oxazolidinones , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Erythromycin/pharmacology , Gram-Negative Bacteria/genetics , Linezolid , Lipid A , Novobiocin/pharmacology , Oxazolidinones/pharmacology , Rifampin/pharmacology , Vancomycin/pharmacology
3.
Bioorg Med Chem Lett ; 71: 128842, 2022 09 01.
Article in English | MEDLINE | ID: mdl-35680102

ABSTRACT

Increased resistance to gram positive infections have highlighted the limitations of currently available drug treatments including penicillins, macrolides and glycopeptides. As an alternative to address these challenges; Linezolid, the first antibiotic from oxazolidinone class, have shown the promising activities against such infections, although associated toxicological issues limiting the use of linezolid for prolonged treatments. In order to circumvent disadvantages allied with the marketed drugs, we herein reporting the synthesis of WCK 4034, an oxazolidinone antibiotic through our structure activity relationship (SAR) program. Through this exercise, WCK 4034, has shown competitive MIC values against Methicillin Sensitive S. aureus (MSSA, Sta-001), Methicillin Resistant S. aureus (MRSA, Sta-032), S. pneumoniae ATCC 49619 and H. influenza ATCC 35054 species as like linezolid. Although with an additional advantage; WCK 4034 has been found superior during dog PK studies as compare to Linezolid. With the preliminary studies in our hand, we herein assuming these improved pharmacokinetic values would be helpful. Moreover, WCK 4034 has successfully completed pre-clinical studies and ready to enter the clinical space, and paved the way for in house development of other oxazolidinone NCEs.


Subject(s)
Methicillin-Resistant Staphylococcus aureus , Oxazolidinones , Animals , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Dogs , Linezolid/pharmacology , Linezolid/therapeutic use , Microbial Sensitivity Tests , Oxazolidinones/chemistry , Oxazolidinones/pharmacology , Oxazolidinones/therapeutic use , Staphylococcus aureus , Streptococcus pneumoniae
4.
Fundam Clin Pharmacol ; 35(3): 595-619, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33290608

ABSTRACT

Cluster headache (CH) is the most common form of trigeminal autonomic cephalalgia. Current treatments have several limitations, and new drugs are required. This article first briefly reviews present acute and preventive treatments in CH, their mechanism of action and limitations, then describes the state of the art in recent clinical drug trials since 2015, and ends with a critique of trials in the CH field. Research is limited by lack of knowledge of pathophysiology and lack of animal models. In the past 5 years, no brand-new treatment has emerged, but promising drugs, such as CGRP(R) antibodies, are under study. According to the literature and guidelines, clinicians and researchers should be aware of many limitations in study protocols: concomitant medication, patient sample size, patients' protocol compliance, and study designs that tend to restrict patient recruitment.


Subject(s)
Cluster Headache/drug therapy , Cluster Headache/physiopathology , Antibodies, Monoclonal/pharmacology , Antibodies, Monoclonal/therapeutic use , Botulinum Toxins, Type A/pharmacology , Botulinum Toxins, Type A/therapeutic use , Capsaicin/analogs & derivatives , Capsaicin/pharmacology , Capsaicin/therapeutic use , Carbon Dioxide/pharmacology , Carbon Dioxide/therapeutic use , Clinical Trials as Topic , Cluster Headache/prevention & control , Humans , Ketamine/pharmacology , Ketamine/therapeutic use , Lysergic Acid Diethylamide/pharmacology , Lysergic Acid Diethylamide/therapeutic use , Oxazolidinones/pharmacology , Oxazolidinones/therapeutic use , Psilocybin/pharmacology , Psilocybin/therapeutic use , Receptors, Calcitonin Gene-Related Peptide/immunology , Somatostatin/analogs & derivatives , Somatostatin/pharmacology , Somatostatin/therapeutic use , Tryptamines/pharmacology , Tryptamines/therapeutic use
5.
J Med Chem ; 63(17): 9316-9339, 2020 09 10.
Article in English | MEDLINE | ID: mdl-32666789

ABSTRACT

Tuberculosis (TB) remains a serious public health challenge, and the research and development of new anti-TB drugs is an essential component of the global strategy to eradicate TB. In this work, we discovered a conformationally constrained oxazolidinone 19c with improved anti-TB activity and safety profile through a focused lead optimization effort. Compound 19c displayed superior in vivo efficacy in a mouse TB infection model compared to linezolid and sutezolid. The druggability of compound 19c was demonstrated in a panel of assays including microsomal stability, cytotoxicity, cytochrome P450 enzyme inhibition, and pharmacokinetics in animals. Compound 19c demonstrated an excellent safety profile in a battery of safety assays, including mitochondrial protein synthesis, hERG K+, hCav1.2, and Nav1.5 channels, monoamine oxidase, and genotoxicity. In a 4 week repeated dose toxicology study in rats, 19c appeared to have less bone marrow suppression than linezolid, which has been a major liability of the oxazolidinone class.


Subject(s)
Drug Design , Molecular Conformation , Oxazolidinones/chemistry , Oxazolidinones/pharmacology , Safety , Tuberculosis, Multidrug-Resistant/drug therapy , Animals , Chlorocebus aethiops , Female , Hep G2 Cells , Humans , Mice , Microbial Sensitivity Tests , Mycobacterium tuberculosis/drug effects , Mycobacterium tuberculosis/physiology , Oxazolidinones/adverse effects , Oxazolidinones/pharmacokinetics , Vero Cells
6.
Article in English | MEDLINE | ID: mdl-32122892

ABSTRACT

Tedizolid (TZD) and daptomycin (DAP) were assessed in a rat endocarditis model against Enterococcus faecalis, Enterococcus faecium (resistant to vancomycin and ampicillin), and Staphylococcus aureus As a monotherapy, TZD for 5 days was not effective in a comparison with no-treatment controls, while DAP for 5 days was significantly effective against these bacteria. Step-down therapy (DAP for 3 days followed by TZD for 2 days) was as effective as DAP for 5 days and was comparable to 3 days of DAP plus ceftriaxone against all bacteria and to 3 days of DAP plus gentamicin against E. faecalis OG1RF.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Daptomycin/therapeutic use , Endocarditis, Bacterial/drug therapy , Enterococcus , Gram-Positive Bacterial Infections/drug therapy , Methicillin-Resistant Staphylococcus aureus , Oxazolidinones/therapeutic use , Staphylococcal Infections/drug therapy , Tetrazoles/therapeutic use , Vancomycin Resistance , Vancomycin-Resistant Staphylococcus aureus , Animals , Anti-Bacterial Agents/pharmacology , Colony Count, Microbial , Daptomycin/pharmacology , Endocarditis, Bacterial/microbiology , Enterococcus/drug effects , Enterococcus faecalis/drug effects , Enterococcus faecium/drug effects , Gram-Positive Bacterial Infections/microbiology , Methicillin-Resistant Staphylococcus aureus/drug effects , Microbial Sensitivity Tests , Oxazolidinones/pharmacology , Rats , Staphylococcal Infections/microbiology , Tetrazoles/pharmacology
7.
J Ethnopharmacol ; 251: 112550, 2020 Apr 06.
Article in English | MEDLINE | ID: mdl-31918015

ABSTRACT

ETHNOPHARMACOLOGICAL RELEVANCE: Isatidis Radix, the sun-dried roots of Isatis indigotica Fortune ex Lindl., is one of the most usually used traditional Chinese medicines. For centuries, the herb has been employed in clinical practice for treatment of virus infection and inflammation. However, its active ingredients remain unclear. AIM OF THE STUDY: In the present study, the anti-influenza virus activity of epiprogoitrin, progoitrin, epigoitrin and goitrin, the Isatidis Radix derived glucosinolate isomers and their breakdown products, was firstly evaluated in vitro and in ovo and their mechanism of action was investigated. MATERIALS AND METHODS: Epiprogoitrin, progoitrin, epigoitrin and goitrin were isolated from Isatidis Radix by chiral separation. In vitro and in ovo evaluations were performed on Madin-Darby canine kidney (MDCK) cells and embryonated eggs respectively, both using protocols including prevention, treatment and virus neutralization. Hemagglutination (HA) and neuraminidase (NA) inhibition assays were performed for further understanding of the antiviral mechanism. RESULTS: Isatidis Radix derived glucosinolate isomers and their breakdown products all exhibited dose-dependent inhibition effect against influenza A virus (H1N1) without toxicity. The antiviral potency of the components was in the order of progoitrin > goitrin > epigoitrin > epiprogoitrin. The attachment of the constituents to the viral envelope conduced to the mechanism of their antiviral action without disturbing viral adsorption or budding. CONCLUSION: Taken together, these results are promising for further development of Isatidis Radix and may contribute an adjunct to pharmacotherapy for influenza virus infection.


Subject(s)
Antiviral Agents/pharmacology , Glucosinolates/pharmacology , Influenza A Virus, H1N1 Subtype/drug effects , Isatis , Oxazolidinones/pharmacology , Animals , Cell Survival/drug effects , Chick Embryo/virology , Dogs , Hemagglutination Tests , Madin Darby Canine Kidney Cells , Neuraminidase/antagonists & inhibitors , Plant Roots
8.
Chembiochem ; 21(7): 933-937, 2020 04 01.
Article in English | MEDLINE | ID: mdl-31688982

ABSTRACT

The failure of frontline antibiotics in the clinic is one of the most serious threats to human health and requires a multitude of novel therapeutics and innovative approaches to treatment so as to curtail the growing crisis. In addition to traditional resistance mechanisms resulting in the lack of efficacy of many antibiotics, most chronic and recurring infections are further made tolerant to antibiotic action by the presence of biofilms. Herein, we report an expanded set of 5-benzylidene-4-oxazolidinones that are able to inhibit the formation of Staphylococcus aureus biofilms, disperse preformed biofilms, and, in combination with common antibiotics, are able to significantly reduce the bacterial load in a robust collagen-matrix model of biofilm infection.


Subject(s)
Anti-Bacterial Agents/pharmacology , Benzylidene Compounds/pharmacology , Biofilms/drug effects , Oxazolidinones/pharmacology , Staphylococcus aureus/physiology , Acinetobacter baumannii/drug effects , Drug Synergism , Methicillin-Resistant Staphylococcus aureus/drug effects , Microbial Sensitivity Tests , Structure-Activity Relationship
9.
J Med Chem ; 61(20): 9360-9370, 2018 10 25.
Article in English | MEDLINE | ID: mdl-30226381

ABSTRACT

This report summarizes the identification and synthesis of novel LpxC inhibitors aided by computational methods that leveraged numerous crystal structures. This effort led to the identification of oxazolidinone and isoxazoline inhibitors with potent in vitro activity against P. aeruginosa and other Gram-negative bacteria. Representative compound 13f demonstrated efficacy against P. aeruginosa in a mouse neutropenic thigh infection model. The antibacterial activity against K. pneumoniae could be potentiated by Gram-positive antibiotics rifampicin (RIF) and vancomycin (VAN) in both in vitro and in vivo models.


Subject(s)
Amidohydrolases/antagonists & inhibitors , Isoxazoles/chemistry , Isoxazoles/pharmacology , Oxazolidinones/chemistry , Oxazolidinones/pharmacology , Animals , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Drug Evaluation, Preclinical , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Mice , Microbial Sensitivity Tests , Models, Molecular , Molecular Conformation
10.
Article in English | MEDLINE | ID: mdl-30126954

ABSTRACT

The efficacy of the standardized four-drug regimen (comprising isoniazid, rifampin, pyrazinamide, and ethambutol) for the treatment of tuberculosis (TB) is menaced by the emergence of multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains of Mycobacterium tuberculosis Intensive efforts have been made to develop new antibiotics or to repurpose old drugs, and several of these are currently being evaluated in clinical trials for their antitubercular activity. Among the new candidate drugs is macozinone (MCZ), the piperazine-containing benzothiazinone PBTZ169, which is currently being evaluated in phase I/II clinical trials. Here, we determined the in vitro and in vivo activity of MCZ in combination with a range of anti-TB drugs in order to design a new regimen against active TB. Two-drug combinations with MCZ were tested against M. tuberculosis using checkerboard and CFU enumeration after drug exposure assays. MCZ was observed to have no interactions with all first- and second-line anti-TB drugs. At the MIC of each drug, MCZ with either bedaquiline (BDQ), clofazimine (CLO), delamanid (DMD), or sutezolid (STZ) reduced the bacterial burden by 2 logs compared to that achieved with the drugs alone, indicating synergism. MCZ also displayed synergism with clomiphene (CLM), a potential inhibitor of the undecaprenyl pyrophosphate synthase (UppS) in mycobacteria. For all the other drugs tested in combination with MCZ, no synergistic activity was observed. Neither antagonism nor increased cytotoxicity was found for most combinations, suggesting that MCZ could be added to different TB treatment regimens without any significant adverse effects.


Subject(s)
Antitubercular Agents/pharmacology , Benzothiazoles/pharmacology , Piperazines/pharmacology , Thiazines/pharmacology , Tuberculosis/drug therapy , Animals , Cell Line, Tumor , Clofazimine/pharmacology , Clomiphene/pharmacology , Diarylquinolines/pharmacology , Drug Resistance, Multiple, Bacterial/drug effects , Ethambutol/pharmacology , Hep G2 Cells , Humans , Isoniazid/pharmacology , Mice , Mice, Inbred BALB C , Microbial Sensitivity Tests/methods , Mycobacterium tuberculosis/drug effects , Oxazolidinones/pharmacology , Pyrazinamide/pharmacology , Rifampin/pharmacology , Tuberculosis, Multidrug-Resistant/drug therapy
11.
J Glob Antimicrob Resist ; 14: 209-216, 2018 09.
Article in English | MEDLINE | ID: mdl-29753135

ABSTRACT

OBJECTIVES: Methicillin-resistant Staphylococcus aureus (MRSA) is a threat to the success of clinical treatment. Besides high antimicrobial resistance rates, the presence of heterogeneous vancomycin-intermediate S. aureus (hVISA) and heterogeneous daptomycin-non-susceptible S. aureus (hDNSSA) in the hospital environment is underestimated and is associated with treatment failure. The aim of this study was to investigate MRSA dissemination in a Brazilian hospital and to evaluate the efficacy of various treatment options in vitro. METHODS: MRSA strains were typed by MLST, PFGE and SCCmec typing. Minimum inhibitory concentrations (MICs) to daptomycin, linezolid, quinupristin/dalfopristin, teicoplanin, tetracycline, tigecycline, vancomycin and tedizolid were determined by broth microdilution. The presence of a heterogeneous population was detected by population analysis profile (PAP). Regarding hVISA and hDNSSA strains, the sequences and expression levels of genes involved in resistance to daptomycin and vancomycin were determined as well as cell wall thickness and autolysis. RESULTS: ST5/ST105-SCCmecII lineage was prevalent amongst 27 clinical MRSA characterised in this study. Two hDNSSA strains (one also hVISA) were detected and were confirmed by PAP. Isolate SCMSC29 (hVISA and hDNSSA) showed increased expression of genes involved in cell wall metabolism, slight cell wall thickening, reduction of autolysis, and single nucleotide polymorphisms (SNPs) in the rpoB and mprF genes compared with the susceptible strain SCMSC31. SCMSC35 (hDNSSA) presented SNPs in the rpoB and mprF genes as well as a thickened cell wall. CONCLUSIONS: Despite this worrying and hard to detect phenotype, treatment alternatives such as teicoplanin, linezolid, tetracycline, tigecycline, quinupristin/dalfopristin and tedizolid were all active against these isolates.


Subject(s)
Bacterial Proteins/genetics , Daptomycin/pharmacology , Methicillin-Resistant Staphylococcus aureus/genetics , Staphylococcal Infections/microbiology , Vancomycin/pharmacology , Bacteriolysis , Brazil , Cell Wall/genetics , Cell Wall/metabolism , Drug Resistance, Bacterial , Humans , Linezolid/pharmacology , Methicillin-Resistant Staphylococcus aureus/drug effects , Microbial Sensitivity Tests , Multilocus Sequence Typing , Oxazolidinones/pharmacology , Polymorphism, Single Nucleotide , Staphylococcal Infections/drug therapy , Tetrazoles/pharmacology
12.
Diagn Microbiol Infect Dis ; 91(1): 93-97, 2018 May.
Article in English | MEDLINE | ID: mdl-29452993

ABSTRACT

Skin and soft tissue infections (SSTI) are among the most commonly occurring infections and evidence suggests that these are increasing world-wide. The aetiology is diverse, but Staphylococcus aureus predominate and these are often resistant to antimicrobials that were previously effective. Tedizolid is a new oxazolidinone-class antibacterial indicated for the treatment of adults with SSTI caused by Gram-positive pathogens, including S. aureus. The aim of this study was to evaluate the in vitro efficacy of tedizolid in comparison to other clinically used antibacterials against antibiotic sensitive- and resistant-staphylococci, grown in planktonic cultures and as biofilms reflecting the growth of the microorganism during episodes of SSTI. Against a panel of 66 clinical staphylococci, sensitivity testing revealed that a lower concentration of tedizolid was required to inhibit the growth of staphylococci compared to linezolid, vancomycin and daptomycin; with the tedizolid MIC50 being 8-fold (S. aureus) or 4-fold (S. epidermidis) below that obtained for linezolid. In addition, cfr+ linezolid-resistant strains remained fully susceptible to tedizolid. Against S. aureus biofilms, 10×MIC tedizolid was superior or comparable with 10×MIC comparator agents in activity, and superior to 10×MIC linezolid against those formed by S. epidermidis (65 vs. 33% reduction, respectively). Under flow-conditions both oxazolidinones at 10×MIC statistically out-performed vancomycin in their ability to reduce the viable cell count within a S. aureus biofilm with fewer the 12% of cells surviving compared to 63% of cells. In conclusion, tedizolid offers a realistic lower-dose alternative agent to treat staphylococcal SSTI, including infections caused by multi-drug resistant strains.


Subject(s)
Anti-Bacterial Agents/pharmacology , Biofilms/drug effects , Oxazolidinones/pharmacology , Soft Tissue Infections/drug therapy , Staphylococcal Skin Infections/drug therapy , Staphylococcus/drug effects , Tetrazoles/pharmacology , Drug Resistance, Multiple, Bacterial , Humans , Linezolid/pharmacology , Microbial Sensitivity Tests , Soft Tissue Infections/microbiology , Staphylococcal Skin Infections/microbiology , Staphylococcus/growth & development , Staphylococcus/isolation & purification
13.
J Med Microbiol ; 67(2): 265-271, 2018 Feb.
Article in English | MEDLINE | ID: mdl-29300156

ABSTRACT

PURPOSE: Glycopeptides are widely used for the treatment of meticillin-resistant Staphylococcus aureus (MRSA) infections. Although difficult to detect, isolates with reduced (GISA), hetero (hGISA) or complete (GRSA) resistance to glycopeptides are increasingly reported. Optimal therapy for such strains is unknown. We compared the in vitro and in vivo activity of tedizolid (TED), a recently licensed oxazolidonone, with vancomycin (VAN) and teicoplanin (TEIC) combined with fusidic acid (FD) or rifampicin (RIF) against S. aureus (SA) with reduced susceptibility to glycopeptides. METHODS: Susceptibility was determined for six (GISA, hGISA and GRSA) reference strains and 72 clinical MRSA isolates screened for hGISA/GISA-like phenotypes. Synergy and bactericidal activity were assessed using chequerboard and time-kill assays. The G. mellonella wax moth caterpillar model was used to measure the activity of TED and the combinations in vivo. RESULTS: Glycopeptide MICs (VAN/TEIC) ranged from 0.5-8/4 and 0.125-1 for TED. No significant synergy was noted when VAN/TEIC were combined with either RIF or FD. Time-kill assays confirmed that TED was bacteriostatic but superior to VAN and TEIC against GISA strains. In G. mellonella TED was more effective than TEIC monotherapy versus GISA strains. The combination of TEIC with RIF was the most effective combination overall, both in vitro and in vivo. CONCLUSIONS: TED had good in vitro activity versus MRSA including those with reduced susceptibility to glycopeptides. Although bacteriostatic, it was effective in the G. mellonella model and superior to TEIC in the treatment of GISA. Although this supports the use of TED for MRSA and GISA, the TEIC/RIF combination also warrants further study.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Oxazolidinones/therapeutic use , Staphylococcal Infections/drug therapy , Staphylococcus aureus/drug effects , Teicoplanin/therapeutic use , Tetrazoles/therapeutic use , Vancomycin/therapeutic use , Animals , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/pharmacology , Drug Therapy, Combination , Humans , Larva/microbiology , Lepidoptera/microbiology , Methicillin-Resistant Staphylococcus aureus/drug effects , Microbial Sensitivity Tests , Oxazolidinones/administration & dosage , Oxazolidinones/pharmacology , Staphylococcal Infections/microbiology , Teicoplanin/administration & dosage , Teicoplanin/pharmacology , Tetrazoles/administration & dosage , Tetrazoles/pharmacology , Vancomycin/administration & dosage , Vancomycin/pharmacology
14.
Drug Des Devel Ther ; 11: 65-82, 2017.
Article in English | MEDLINE | ID: mdl-28053508

ABSTRACT

Tedizolid phosphate has high activity against the Gram-positive microorganisms mainly involved in acute bacterial skin and skin structure infections, such as strains of Staphylococcus aureus (including methicillin-resistant S. aureus strains and methicillin-sensitive S. aureus strains), Streptococcus pyogenes, Streptococcus agalactiae, the Streptococcus anginosus group, and Enterococcus faecalis, including those with some mechanism of resistance limiting the use of linezolid. The area under the curve for time 0-24 hours/minimum inhibitory concentration (MIC) pharmacodynamic ratio has shown the best correlation with the efficacy of tedizolid, versus the time above MIC ratio and the maximum drug concentration/minimum inhibitory concentration ratio. Administration of this antibiotic for 6 days has shown its noninferiority versus administration of linezolid for 10 days in patients with skin and skin structure infections enrolled in two Phase III studies (ESTABLISH-1 and ESTABLISH-2). Tedizolid's more favorable safety profile and dosage regimen, which allow once-daily administration, versus linezolid, position it as a good therapeutic alternative. However, whether or not the greater economic cost associated with this antibiotic is offset by its shorter treatment duration and possibility of oral administration in routine clinical practice has yet to be clarified.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Oxazolidinones/therapeutic use , Skin Diseases, Bacterial/drug therapy , Skin Diseases, Bacterial/microbiology , Tetrazoles/therapeutic use , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/pharmacology , Enterococcus faecalis/drug effects , Humans , Microbial Sensitivity Tests , Oxazolidinones/administration & dosage , Oxazolidinones/pharmacology , Streptococcus/drug effects , Tetrazoles/administration & dosage , Tetrazoles/pharmacology
15.
Int Immunopharmacol ; 42: 130-138, 2017 Jan.
Article in English | MEDLINE | ID: mdl-27912149

ABSTRACT

A flavone was isolated from Origanum vulgare and identified as didymin (O. vulgare didymin, OVD). The protective effect and mechanism of OVD on acute liver injury was then assessed in vivo and in vitro. Our results showed that OVD significantly alleviated CCl4-induced liver injury in mice and markedly decreased serum ALT and AST activities. OVD treatment significantly reduced CYP2E1 activity, lipid peroxidation level, ROS generation, NO production and pro-inflammatory cytokines (such as TNF-α, IL-6 and IL-1ß) in liver tissues and RAW 264.7 cells, but enhanced the hepatic antioxidative enzymes activities. Further study showed that OVD significantly inhibited the NF-κB and MAPK pathways. Interestingly, OVD notably enhanced Raf kinase inhibitor protein (RKIP) expression, and the effects of OVD on histological changes, oxidative stress and inflammation was largely abolished by the RKIP specific inhibitor locostatin. Our findings indicate that OVD can ameliorate CCl4-induced liver injury, which may be ascribed to its radical scavenging action, antioxidant activity, and modulation of MAPK and NF-κB signaling pathways.


Subject(s)
Anti-Inflammatory Agents/therapeutic use , Chemical and Drug Induced Liver Injury/drug therapy , Flavonoids/therapeutic use , Glycosides/therapeutic use , Origanum , Phosphatidylethanolamine Binding Protein/metabolism , Alanine Transaminase/blood , Animals , Aspartate Aminotransferases/blood , Carbon Tetrachloride , Cytochrome P-450 CYP2E1/metabolism , Cytokines/metabolism , Humans , Inflammation Mediators/metabolism , Lipid Peroxidation/drug effects , Male , Mice , Mice, Inbred ICR , Oxazolidinones/pharmacology , Phosphatidylethanolamine Binding Protein/antagonists & inhibitors , RAW 264.7 Cells , Reactive Oxygen Species/metabolism
16.
Antimicrob Agents Chemother ; 60(12): 7134-7145, 2016 12.
Article in English | MEDLINE | ID: mdl-27645240

ABSTRACT

RBx 11760, a bi-aryl oxazolidinone, was investigated for antibacterial activity against Gram-positive bacteria. The MIC90s of RBx 11760 and linezolid against Staphylococcus aureus were 2 and 4 mg/liter, against Staphylococcus epidermidis were 0.5 and 2 mg/liter, and against Enterococcus were 1 and 4 mg/liter, respectively. Similarly, against Streptococcus pneumoniae the MIC90s of RBx 11760 and linezolid were 0.5 and 2 mg/liter, respectively. In time-kill studies, RBx 11760, tedizolid, and linezolid exhibited bacteriostatic effect against all tested strains except S. pneumoniae RBx 11760 showed 2-log10 kill at 4× MIC while tedizolid and linezolid showed 2-log10 and 1.4-log10 kill at 16× MIC, respectively, against methicillin-resistant S. aureus (MRSA) H-29. Against S. pneumoniae 5051, RBx 11760 showed bactericidal activity, with 4.6-log10 kill at 4× MIC compared to 2.42-log10 and 1.95-log10 kill for tedizolid and linezolid, respectively, at 16× MIC. RBx 11760 showed postantibiotic effects (PAE) at 3 h at 4 mg/liter against MRSA H-29, and linezolid showed the same effect at 16 mg/liter. RBx 11760 inhibited biofilm production against methicillin-resistant S. epidermidis (MRSE) ATCC 35984 in a concentration-dependent manner. In a foreign-body model, linezolid and rifampin resulted in no advantage over stasis, while the same dose of RBx 11760 demonstrated a significant killing compared to the initial control against S. aureus (P < 0.05) and MRSE (P < 0.01). The difference in killing was statistically significant for the lower dose of RBx 11760 (P < 0.05) versus the higher dose of linezolid (P > 0.05 [not significant]) in a groin abscess model. In neutropenic mouse thigh infection, RBx 11760 showed stasis at 20 mg/kg of body weight, whereas tedizolid showed the same effect at 40 mg/kg. These data support RBx 11760 as a promising investigational candidate.


Subject(s)
Anti-Bacterial Agents/pharmacology , Gram-Positive Bacteria/drug effects , Oxazolidinones/pharmacology , Animals , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacokinetics , Biofilms , Disease Models, Animal , Drug Evaluation, Preclinical/methods , Drug Resistance, Bacterial/drug effects , Drug Resistance, Bacterial/genetics , Gram-Positive Bacterial Infections/drug therapy , Linezolid/pharmacology , Male , Mice , Microbial Sensitivity Tests , Neutropenia/drug therapy , Neutropenia/microbiology , Organophosphates/pharmacology , Oxazoles/pharmacology , Oxazolidinones/chemistry , Oxazolidinones/pharmacokinetics , Pyelonephritis/drug therapy , Pyelonephritis/microbiology , Rats, Wistar , Skin Diseases, Bacterial/drug therapy
17.
Expert Opin Ther Pat ; 26(5): 591-605, 2016 May.
Article in English | MEDLINE | ID: mdl-26998627

ABSTRACT

INTRODUCTION: Antimicrobial resistance in Gram-positive bacteria is a major health care issue. This review summarizes patent publications from 2012 to 2015 that divulged novel oxazolidinones as antibacterial agents. AREAS COVERED: A total of 25 patents obtained from Espacenet, WIPO Patentscope and FreePatentsOnline, and AcclaimIP search engines were reviewed. The patents were scrutinized based on the novelty of the compounds, their antibacterial activity (MIC, µg/mL), and the process of preparation. The oxazolidinones with promising antibacterial activity were classified according to the following structural diversities, as biaryl heterocyclic, fused heteroaryl rings containing oxazolidinones, and others. The biaryl heterocyclic, fused heteroaryl, benzoxazine, and the 1H-pyrazol-1-yl containing oxazolidinone derivatives demonstrated potent antibacterial activities superior to linezolid against Gram-positive bacteria. Some derivatives were effective against standard strains of Gram-negative bacteria, namely Moraxella catarrhalis ATCC A894, and Escherichia coli ATCC 25922. In addition, a patent disclosed a structural isomer of linezolid with marginal activity against the aerobic Gram-negative bacteria MDR Stenotrophomonas (Xanthomonas) maltophilia, while linezolid and vancomycin did not inhibit growth. Finally, some derivatives showed activity against respiratory infectious diseases' causative agents, such as B. anthracis, B. mallei, Y. pestis, and M. pneumoniae. EXPERT OPINION: Overall, there is limited in vivo data to support the potential clinical advancement of the currently reported novel derivatives.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Drug Design , Oxazolidinones/therapeutic use , Animals , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Drug Resistance, Multiple, Bacterial , Gram-Negative Bacteria/drug effects , Gram-Negative Bacterial Infections/drug therapy , Gram-Positive Bacteria/drug effects , Gram-Positive Bacterial Infections/drug therapy , Humans , Microbial Sensitivity Tests , Oxazolidinones/chemistry , Oxazolidinones/pharmacology , Patents as Topic
18.
J Lipid Res ; 56(11): 2085-93, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26342106

ABSTRACT

Recently, we showed in APOE*3-Leiden cholesteryl ester transfer protein (E3L.CETP) mice that anacetrapib attenuated atherosclerosis development by reducing (V)LDL cholesterol [(V)LDL-C] rather than by raising HDL cholesterol. Here, we investigated the mechanism by which anacetrapib reduces (V)LDL-C and whether this effect was dependent on the inhibition of CETP. E3L.CETP mice were fed a Western-type diet alone or supplemented with anacetrapib (30 mg/kg body weight per day). Microarray analyses of livers revealed downregulation of the cholesterol biosynthesis pathway (P < 0.001) and predicted downregulation of pathways controlled by sterol regulatory element-binding proteins 1 and 2 (z-scores -2.56 and -2.90, respectively; both P < 0.001). These data suggest increased supply of cholesterol to the liver. We found that hepatic proprotein convertase subtilisin/kexin type 9 (Pcsk9) expression was decreased (-28%, P < 0.01), accompanied by decreased plasma PCSK9 levels (-47%, P < 0.001) and increased hepatic LDL receptor (LDLr) content (+64%, P < 0.01). Consistent with this, anacetrapib increased the clearance and hepatic uptake (+25%, P < 0.001) of [(14)C]cholesteryl oleate-labeled VLDL-mimicking particles. In E3L mice that do not express CETP, anacetrapib still decreased (V)LDL-C and plasma PCSK9 levels, indicating that these effects were independent of CETP inhibition. We conclude that anacetrapib reduces (V)LDL-C by two mechanisms: 1) inhibition of CETP activity, resulting in remodeled VLDL particles that are more susceptible to hepatic uptake; and 2) a CETP-independent reduction of plasma PCSK9 levels that has the potential to increase LDLr-mediated hepatic remnant clearance.


Subject(s)
Cholesterol, VLDL/blood , Dyslipidemias/blood , Hypolipidemic Agents/pharmacology , Oxazolidinones/pharmacology , Proprotein Convertases/blood , Serine Endopeptidases/blood , Animals , Cardiovascular Diseases/prevention & control , Cholesterol Ester Transfer Proteins/antagonists & inhibitors , Cholesterol Ester Transfer Proteins/metabolism , Down-Regulation , Drug Evaluation, Preclinical , Dyslipidemias/drug therapy , Dyslipidemias/enzymology , Female , Gene Expression/drug effects , Gene Regulatory Networks , Hypolipidemic Agents/therapeutic use , Lipid Metabolism/drug effects , Metabolic Networks and Pathways , Mice, Transgenic , Oxazolidinones/therapeutic use , Proprotein Convertase 9
19.
Clin Infect Dis ; 61 Suppl 2: S69-78, 2015 Sep 15.
Article in English | MEDLINE | ID: mdl-26316560

ABSTRACT

Skin and soft-tissue infections (SSTIs) are an important cause of morbidity and mortality among hospitalized patients and a major therapeutic challenge for clinicians. Although uncomplicated SSTIs are managed successfully on an outpatient basis, more serious infections extending to the subcutaneous tissue, fascia, or muscle require complex management. Early diagnosis, selection of appropriate antimicrobials, and timely surgical intervention are key to successful treatment. Surgical-site infections, an important category of SSTI, occur in approximately half a million patients in North America annually. SSTIs are also a potential source for life-threatening bacteremia and metastatic abscesses. Gram-positive organisms, such as Staphylococcus aureus and Streptococcus pyogenes, are the dominant organisms isolated early in the infectious process, whereas gram-negative organisms are found in chronic wounds. Methicillin-resistant S. aureus (MRSA) is a potential bloodstream invader that requires aggressive antimicrobial treatment and surgery. Recent concerns regarding vancomycin activity include heteroresistance in MRSA and increase in the minimum inhibitory concentrations (>1 or 2 µg/mL); however, alternative agents, such as telavancin, daptomycin, linezolid, ceftaroline, dalbavancin, oritavancin, and tedizolid, are now available for the treatment of severe MRSA infections. Here, we present a review of the epidemiology, etiology, and available treatment options for the management of SSTIs.


Subject(s)
Aminoglycosides/therapeutic use , Anti-Bacterial Agents/therapeutic use , Skin Diseases, Bacterial/drug therapy , Soft Tissue Infections/drug therapy , Aminoglycosides/pharmacology , Anti-Bacterial Agents/pharmacology , Clinical Trials as Topic , Daptomycin/pharmacology , Daptomycin/therapeutic use , Gram-Negative Bacterial Infections/drug therapy , Gram-Negative Bacterial Infections/epidemiology , Gram-Negative Bacterial Infections/microbiology , Gram-Positive Bacterial Infections/drug therapy , Gram-Positive Bacterial Infections/epidemiology , Gram-Positive Bacterial Infections/microbiology , Humans , Lipoglycopeptides , Methicillin-Resistant Staphylococcus aureus/drug effects , Microbial Sensitivity Tests , North America/epidemiology , Oxazolidinones/pharmacology , Oxazolidinones/therapeutic use , Skin Diseases, Bacterial/epidemiology , Skin Diseases, Bacterial/microbiology , Soft Tissue Infections/epidemiology , Soft Tissue Infections/microbiology , Staphylococcal Infections/drug therapy , Staphylococcal Infections/epidemiology , Staphylococcal Infections/microbiology
20.
Pak J Pharm Sci ; 28(3): 997-1004, 2015 May.
Article in English | MEDLINE | ID: mdl-26004734

ABSTRACT

Vancomycin resistant Staphylococcus aureus (VRSA) has been reported from many parts of the world including Asian countries. Hence, main objective of study was to evaluate the possible occurrence of VRSA in hospitals of Lahore city and to ensure the effectiveness of various substitute therapeutic options. A total of 150 samples of pus/wounds were collected from three hospitals of the city and VRSA were isolated and confirmed through recommended method of Clinical and Laboratory Standards Institute. Out of 51 (49.04%) methicillin resistant S. aureus (MRSA) isolates, 5 (9.8%) were found resistant to vancomycin. Minimum inhibitory concentration (MIC) of Linezolid (LZD), Moxifloxacin (MFX) and Clindamycin (CD) were calculated against VRSA isolates by broth microdilution test. All 5 (100%) isolates were susceptible to Linezolid and Clindamycin, while 4 (80%) were susceptible to Moxifloxacin. Ethanolic extracts of Turmeric, Mint, Coriander, Garlic, Kalonji, Cinnamon and Cloves illustrate average MIC values of 140.8 µg/mL, 563.2 µg/mL, 486.4 µg/mL, 614.4 µg/mL, 409.6 µg/mL, 281.6 µg/mL and 64 µg/mL, respectively against 5 VRSA strains. Concentration dependent increase in growth inhibition zones of ethanolic plant extract was recorded by agar well diffusion test. This study was helpful to find out the effective antibiotic against VRSA. Plant extracts encompass anti-staphylococcal activity and this finding demands necessity of further exploration of potential found in these natural herb.


Subject(s)
Acetamides/pharmacology , Anti-Bacterial Agents/pharmacology , Clindamycin/pharmacology , Fluoroquinolones/pharmacology , Oxazolidinones/pharmacology , Plant Extracts/pharmacology , Staphylococcal Infections/microbiology , Staphylococcus aureus/drug effects , Surgical Wound Infection/microbiology , Vancomycin Resistance , Cinnamomum zeylanicum , Curcuma , Garlic , Humans , Linezolid , Mentha , Methicillin-Resistant Staphylococcus aureus/drug effects , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Microbial Sensitivity Tests , Moxifloxacin , Nigella sativa , Pakistan , Staphylococcus aureus/isolation & purification , Syzygium , Wound Infection/microbiology
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