INVESTIGATIONS ON IN VITRO METABOLITES OF LINEZOLID IN VARIOUS SPECIES

INDIAN DRUGS ◽  
2019 ◽  
Vol 56 (05) ◽  
pp. 39-49
Author(s):  
S. L Kesana ◽  
◽  
H. B. Vamaraju ◽  
J. P. Dodle ◽  
P. C. Sastry
Keyword(s):  
Bacterial Infections ◽  
Liver Microsomes ◽  
Parent Drug ◽  
Analytical Techniques ◽  
Bacterial Protein ◽  
Acid Metabolite ◽  
Bacterial Protein Synthesis ◽  
Morpholine Ring ◽  
Modern Analytical

Linezolid is a potent synthetic oxazolidinone used for the treatment of bacterial infections with a new mechanism of action that involves early inhibition of bacterial protein synthesis. In humans, linezolid circulates mainly as parent drug and is excreted primarily as parent drug and a major inactive, morpholine ring-opened carboxylic acid metabolite. In vitro studies were conducted to identify the hepatic enzymes responsible for the oxidative metabolism of linezolid using human liver microsomes. However the specific enzyme responsible for the oxidation of linezolid was not identified. The present study is to check with and identify the probable metabolic pathways in various species like monkey, mouse, rat, dog and human livermicrosomes and put up the best model for the contingency studies using modern analytical techniques. The current investigation on the metabolites obtained after 60 minutes incubation revealed three additional metabolites, namely, M10, M11 and M12, adding on to the list of already reported metabolites.>

The effect of d,l-4-hydroxypropranolol on the thyroxine to 3,5,3'-triiodothyronine conversion in rat renal and liver microsomes

1984 ◽  
Vol 105 (2) ◽  
pp. 205-210 ◽  
Author(s):  
Preben Holme Jørgensen ◽  
lb Bo Lumholtz ◽  
Jens Faber ◽  
Carsten Kirkegaard ◽  
Kaj Siersbæk-Nielsen ◽  
...  
Keyword(s):  
Competitive Inhibition ◽  
Liver Microsomes ◽  
Parent Drug ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Beta Adrenoceptor ◽  
Adrenoceptor Agonist ◽  
Vitro Effect ◽  
Dose Dependent

Abstract. The in vitro effect of d,l-4-hydroxypropranolol, a major pharmacological active metabolite of the beta adrenoceptor blocking drug d,l-propranolol, on the thyroxine (T4) to 3,5,3'-triiodothyronine (T3) conversion has been studied using rat renal and liver microsomal fractions. The results showed, that primarily the metabolite, but also the parent drug inhibits the T3-production in a dose dependent manner. The potency, expressed as the 50% inhibition of the T3-production, was reached using 65 ± 12 (sd) μm d,l-4-OH-propranolol and 1000 ± 22 (sd) μm d,l-propranolol, respectively in both tissues. The efficacy of 4-OH-propranolol corresponded to a maximal inhibition of 86 ± 7% while it for d,l-propranolol corresponded to 58 ± 6% (P < 0.001). The beta adrenoceptor agonist isoprenaline itself did not effect the T4 to T3 conversion but considerably opposed the inhibitory effect of d,l-4-OH-propranolol but not of d,l-propranolol. The D-isomer form of propranolol, which is without beta receptor blocking activity inhibited the T3-production in the same degree as d,l-propranolol. Evaluation of the enzyme kinetic data suggested that 4-OH-propranolol caused a competitive inhibition of both T4 and DTT. It is concluded, that the metabolite d,l-4-OH-propranolol is a much more potent and efficacious inhibitor of the T4-5'-deiodination than d,l-propranolol.

scholarly journals Reduced Lytic Activity of Bacteriophages in Presence of Antibiotics Targeting Bacterial Protein Synthesis

2021 ◽  
Author(s):  
Medhavi Vashisth ◽  
Shikha Yashveer ◽  
Nitin Virmani ◽  
Bidhan Chandra Bera ◽  
Rajesh Kumar Vaid ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Bacterial Infections ◽  
Antagonistic Effect ◽  
Multiple Drug ◽  
Drug Resistant ◽  
Bacterial Protein ◽  
Protein Synthesis Machinery ◽  
Multiple Drug Resistant ◽  
Bacterial Protein Synthesis ◽  
Careful Assessment

Combination therapy of bacteriophage and antibiotics offers promise to treat multiple drug resistant bacterial infections through phage antibiotic synergy. However, its usage requires careful assessment as most antibiotics with mechanisms dependent upon inhibiting cell growth through interfering bacterial protein synthesis machinery were found to have an antagonistic effect on phage activity.

scholarly journals Synthesis and in vitro drug release studies on substituted polyphosphazene conjugates of lumefantrine.

2017 ◽  
Vol 9 (2) ◽  
pp. 36 ◽  
Author(s):  
Sahil Kumar ◽  
Alka Sharma ◽  
Rajesh K Singh ◽  
DN Prasad ◽  
TR Bhardwaj
Keyword(s):  
Drug Release ◽  
Analytical Techniques ◽  
In Vitro Drug Release ◽  
Drug Conjugate ◽  
Drug Conjugates ◽  
Release Studies ◽  
Effective Delivery ◽  
Glycine Methyl Ester ◽  
Modern Analytical

<p class="Default"><span>The present study pertains to the delivery of antimalarial drug (Lumifantrine). In this, polyphosphazene has been used in the synthesis of polyphosphazene-linked conjugates of Lumifantrine. These polymer-linked Conjugates have been synthesized and characterized by modern analytical techniques. The <em>in-vitro</em> drug release of Lumifantrine drug conjugates: <em>p</em>-Amino benzoic acid ester substituted polyphosphazene drug conjugate <strong>(15)</strong> and Glycine methyl ester substituted polyphosphazene drug conjugate <strong>(21) </strong>have been found to be 6.00 % and 5.96% (pH 1.2), 88.52% and 79.86% (pH 7.4), respectively. These drug conjugate may prove an effective delivery system for the treatment of malaria.</span></p>

scholarly journals In VitroandIn VivoActivities of Novel, Semisynthetic Thiopeptide Inhibitors of Bacterial Elongation Factor Tu

2011 ◽  
Vol 55 (11) ◽  
pp. 5277-5283 ◽  
Author(s):  
J. A. Leeds ◽  
M. J. LaMarche ◽  
J. T. Brewer ◽  
S. M. Bushell ◽  
G. Deng ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Elongation Factor ◽  
Infection Model ◽  
Elongation Factor Tu ◽  
Bacterial Protein ◽  
Preclinical Development ◽  
Gram Positive ◽  
Content Type

ABSTRACTRecently, we identified aminothiazole derivatives of GE2270 A. These novel semisynthetic congeners, like GE2270 A, target the essential bacterial protein elongation factor Tu (EF-Tu). Medicinal chemistry optimization of lead molecules led to the identification of preclinical development candidates 1 and 2. These cycloalklycarboxylic acid derivatives show activity against difficult to treat Gram-positive pathogens and demonstrate increased aqueous solubility compared to GE2270 A. We describe here thein vitroandin vivoactivities of compounds 1 and 2 compared to marketed antibiotics. Compounds 1 and 2 were potent against clinical isolates of methicillin-resistantStaphylococcus aureusand vancomycin-resistant enterococci (MIC90≤ 0.25 μg/ml) but weaker against the streptococci (MIC90≥ 4 μg/ml). Like GE2270 A, the derivatives inhibited bacterial protein synthesis and selected for spontaneous loss of susceptibility via mutations in thetufgene, encoding EF-Tu. The mutants were not cross-resistant to other antibiotic classes. In a mouse systemic infection model, compounds 1 and 2 protected mice from lethalS. aureusinfections with 50% effective doses (ED50) of 5.2 and 4.3 mg/kg, respectively. Similarly, compounds 1 and 2 protected mice from lethal systemicE. faecalisinfections with ED50of 0.56 and 0.23 mg/kg, respectively. In summary, compounds 1 and 2 are activein vitroandin vivoactivity against difficult-to-treat Gram-positive bacterial infections and represent a promising new class of antibacterials for use in human therapy.

scholarly journals Modulation of Release of Proinflammatory Bacterial Compounds by Antibacterials: Potential Impact on Course of Inflammation and Outcome in Sepsis and Meningitis

2002 ◽  
Vol 15 (1) ◽  
pp. 95-110 ◽  
Author(s):  
Roland Nau ◽  
Helmut Eiffert
Keyword(s):  
Protein Synthesis ◽  
Bacterial Load ◽  
Animal Experiments ◽  
Sufficient Evidence ◽  
Bacterial Protein ◽  
Protein Synthesis Inhibitors ◽  
Number Of Patients ◽  
Bacterial Protein Synthesis

SUMMARY Several bacterial components (endotoxin, teichoic and lipoteichoic acids, peptidoglycan, DNA, and others) can induce or enhance inflammation and may be directly toxic for eukaryotic cells. Bactericidal antibiotics which inhibit bacterial protein synthesis release smaller quantities of proinflammatory/toxic bacterial compounds than Β-lactams and other cell wall-active drugs. Among the Β-lactams, compounds binding to penicillin-binding protein 2 (PBP-2) release smaller amounts of bacterial substances than antibacterials inhibiting PBP-3. Generally, high antibiotic concentrations (more than 10 times the MIC) induce the release of fewer bacterial proinflammatory/toxic compounds than concentrations close to the MIC. In several in vitro and in vivo systems, bacteria treated with protein synthesis inhibitors or Β-lactams inhibiting PBP-2 induce less inflammation than bacteria treated with PBP-3-active Β-lactams. In mouse models of Escherichia coli peritonitis sepsis and of Streptococcus pneumoniae meningitis, lower release of proinflammatory bacterial compounds was associated with reduced mortality. In conclusion, sufficient evidence for the validity of the concept of modulating the release of proinflammatory bacterial compounds by antibacterials has been accumulated in vitro and in animal experiments to justify clinical trials in sepsis and meningitis. A properly conducted study addressing the potential benefit of bacterial protein synthesis inhibitors versus Β-lactam antibiotics will require both strict selection and inclusion of a large number of patients. The benefit of this approach should be greatest in patients with a high bacterial load.

Repurposing of auranofin against bacterial infections: An In silico and In vitro study

2020 ◽  
Vol 16 ◽  
Author(s):  
Nidhi Sharma ◽  
Arti Singh ◽  
Ruchika Sharma ◽  
Anoop Kumar
Keyword(s):  
Broad Spectrum ◽  
In Silico ◽  
Antibacterial Agent ◽  
Bacterial Infections ◽  
In Vitro Assays ◽  
Infection Model ◽  
Synergistic Activity ◽  
Bacterial Strains ◽  
Molecular Docking Study

Aim: The aim of the study was to find out the role of auranofin as a promising broad spectrum antibacterial agent. Methods: In-vitro assays (Percentage growth retardation, Bacterial growth kinetics, Biofilm formation assay) and In-silico study (Molegro virtual docker (MVD) version 6.0 and Molecular operating environment (MOE) version 2008.10 software). Results: The in vitro assays have shown that auranofin has good antibacterial activity against Gram positive and Gram negative bacterial strains. Further, auranofin has shown synergistic activity in combination with ampicillin against S. aureus and B. subtilis whereas in combination with neomycin has just shown additive effect against E. coli, P. aeruginosa and B. pumilus. In vivo results have revealed that auranofin alone and in combination with standard drugs significantly decreased the bioburden in zebrafish infection model as compared to control. The molecular docking study have shown good interaction of auranofin with penicillin binding protein (2Y2M), topoisomerase (3TTZ), UDP-3-O-[3- hydroxymyristoyl] N-acetylglucosaminedeacetylase (3UHM), cell adhesion protein (4QRK), β-lactamase (5CTN) and arylsulphatase (1HDH) enzyme as that of reference ligand which indicate multimodal mechanism of action of auranofin. Finally, MTT assay has shown non-cytotoxic effect of auranofin. Conclusion: In conclusion, auranofin in combination with existing antibiotics could be developed as a broad spectrum antibacterial agent; however, further studies are required to confirm its safety and efficacy. This study provides possibility of use of auranofin apart from its established therapeutic indication in combination with existing antibiotics to tackle the problem of resistance.

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