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178 result(s) for "Nitro Compounds - therapeutic use"
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RRx-001 ameliorates inflammatory diseases by acting as a potent covalent NLRP3 inhibitor
The NLRP3 inflammasome plays a crucial role in innate immune-mediated inflammation and contributes to the pathogenesis of multiple autoinflammatory, metabolic and neurodegenerative diseases, but medications targeting the NLRP3 inflammasome are not available for clinical use. RRx-001 is a well-tolerated anticancer agent currently being investigated in phase III clinical trials, but its effects on inflammatory diseases are not known. Here, we show that RRx-001 is a highly selective and potent NLRP3 inhibitor that has strong beneficial effects on NLRP3-driven inflammatory diseases. RRx-001 inhibits the activation of the canonical, noncanonical, and alternative NLRP3 inflammasomes but not the AIM2, NLRC4 or Pyrin inflammasomes. Mechanistically, RRx-001 covalently binds to cysteine 409 of NLRP3 via its bromoacetyl group and therefore blocks the NLRP3-NEK7 interaction, which is critical for the assembly and activation of the NLRP3 inflammasome. More importantly, RRx-001 treatment attenuates the symptoms of lipopolysaccharide (LPS)-induced systemic inflammation, dextran sulfate sodium (DSS)-induced colitis and experimental autoimmune encephalomyelitis (EAE) in mice. Thus, our study identifies RRx-001 as a new potential therapeutic agent for NLRP3-driven diseases.
Exaggerated translation causes synaptic and behavioural aberrations associated with autism
Mice overexpressing eIF4E show autism-related behaviours and altered synaptic activity in the hippocampus, prefrontal cortex and striatum, and these phenotypes can be rescued with the cap-dependent translation inhibitor 4EGI-1. Targets for autism spectrum disorder treatment Aberrant protein synthesis has been hypothesized as one causal mechanism of autism spectrum disorders (ASDs), but the details of which pathways are disrupted remain unknown. Disruption of eIF4E, a key factor for translation initiation, has been associated with human autism, and now two independent papers implicate excessive cap-dependent translation in synaptic and ASD-related behavioural deficits in mice. Nahum Sonenberg and colleagues show that mice lacking 4E-BP2, an eIF4E repressor, display increased translation of neuroligins, synaptic proteins strongly implicated in autism. The mice also display ASD-related behaviors and alterations in hippocampal synaptic activity, which are reversed by normalization of eIF4E activity or neuroligin 1 levels. Eric Klann and colleagues show that mice overexpressing eIF4E also display ASD-related behaviours and altered synaptic activity in the hippocampus, prefrontal cortex and striatum, and that some phenotypes can be rescued with the cap-dependent translation inhibitor 4EGI-1. The converging results from these two studies implicate cap-dependent translation as a potential therapeutic target for treatment of ASD-related symptoms. Autism spectrum disorders (ASDs) are an early onset, heterogeneous group of heritable neuropsychiatric disorders with symptoms that include deficits in social interaction skills, impaired communication abilities, and ritualistic-like repetitive behaviours 1 , 2 . One of the hypotheses for a common molecular mechanism underlying ASDs is altered translational control resulting in exaggerated protein synthesis 3 . Genetic variants in chromosome 4q, which contains the EIF4E locus, have been described in patients with autism 4 , 5 . Importantly, a rare single nucleotide polymorphism has been identified in autism that is associated with increased promoter activity in the EIF4E gene 6 . Here we show that genetically increasing the levels of eukaryotic translation initiation factor 4E (eIF4E) in mice 7 results in exaggerated cap-dependent translation and aberrant behaviours reminiscent of autism, including repetitive and perseverative behaviours and social interaction deficits. Moreover, these autistic-like behaviours are accompanied by synaptic pathophysiology in the medial prefrontal cortex, striatum and hippocampus. The autistic-like behaviours displayed by the eIF4E-transgenic mice are corrected by intracerebroventricular infusions of the cap-dependent translation inhibitor 4EGI-1. Our findings demonstrate a causal relationship between exaggerated cap-dependent translation, synaptic dysfunction and aberrant behaviours associated with autism.
A novel hypoxia-selective epigenetic agent RRx-001 triggers apoptosis and overcomes drug resistance in multiple myeloma cells
The hypoxic bone marrow (BM) microenvironment confers growth/survival and drug resistance in multiple myeloma (MM) cells. Novel therapies targeting the MM cell in its hypoxic BM milieu may overcome drug resistance. Recent studies led to the development of a novel molecule RRx-001 with hypoxia-selective epigenetic and nitric oxide-donating properties. Here, we demonstrate that RRx-001 decreases the viability of MM cell lines and primary patient cells, as well as overcomes drug resistance. RRx-001 inhibits MM cell growth in the presence of BM stromal cells. RRx-001-induced apoptosis is associated with: (i) activation of caspases; (ii) release of ROS and nitrogen species; (iii) induction of DNA damage via ATM/γ-H2AX; and (iv) decrease in DNA methyltransferase (DNMT) and global methylation. RNA interference study shows a predominant role of DNMT1 in MM cell survival versus DNMT3a or DNMT3b. The deubiquitylating enzyme USP7 stimulates DNMT1 activity, and conversely, USP7-siRNA reduced DNMT1 activity and decreased MM cell viability. RRx-001 plus USP7 inhibitor P5091 triggered synergistic anti-MM activity. MM xenograft studies show that RRx-001 is well tolerated, inhibits tumor growth and enhances survival. Combining RRx-001 with pomalidomide, bortezomib or SAHA induces synergistic anti-MM activity. Our results provide the rationale for translation of RRx-001, either alone or in combination, to clinical evaluation in MM.
Combination therapy using nitro compounds improves the efficacy of experimental Chagas disease treatment
Drug combinations have been evaluated for Chagas disease in an attempt to improve efficacy and safety. In this line, the objective of this work is to assess the effects of treatment with nitro drugs combinations using benznidazole (BZ) or nifurtimox (NFX) plus the sulfone metabolite of fexinidazole (fex-SFN) in vitro and in vivo on Trypanosoma cruzi infection. The in vitro interaction of fex-SFN and BZ or NFX against infected H9c2 cells by the Y strain was classified as an additive (0.5⩾ΣFIC<4), suggesting the possibility of a dose reduction in the in vivo T. cruzi infection. Next, the effect of combining suboptimal doses was assessed in an acute model of murine T. cruzi infection. Drug combinations led to a faster suppression of parasitemia than monotherapies. Also, the associations led to higher cure levels than those in the reference treatment BZ 100 mg day−1 (57.1%) (i.e. 83.3% with BZ/fex-SFN and 75% with NFX/fex-SFN). Importantly, toxic effects resulting from the associations were not observed, according to weight gain and hepatic enzyme levels in the serum of experimental animals. Taken together, this study is a starting point to explore the potential effects of nitro drugs combinations in preclinical models of kinetoplastid-related infections.
Antiviral therapy for COVID-19 virus: A narrative review and bibliometric analysis
The COVID-19 epidemic has become a major international health emergency. Millions of people have died as a result of this phenomenon since it began. Has there been any successful pharmacological treatment for COVID-19 since the initial report on the virus? How many searches are undertaken to address the impact of the infection? What is the number of drugs that have undergone investigation? What are the mechanisms of action and adverse effects associated with the investigated pharmaceuticals used to treat COVID-19? Has the Food and Drug Administration (FDA) approved any medication to treat COVID-19? To date, our understanding is based on a restricted corpus of published investigations into the treatment of COVID-19. It is important to note that no single study comprehensively encompasses all pharmacological interventions for COVID-19. This paper provides an introductory summary of a bibliometric analysis conducted on the data about COVID-19, sourced explicitly from two platforms, namely PubMed and ScienceDirect. The analysis encompasses the period spanning from 2019 to 2022. Furthermore, this study examines the published literature about the pharmacological interventions for the novel coronavirus disease 2019 (COVID-19), explicitly focusing on the safety and effectiveness of different medications such as Remdesivir (marketed as Veklury®), Lopinavir/Ritonavir (commercially known as Kaletra® or Aluvia®), Ribavirin, Favipiravir (marketed as Avigan®), Ivermectin, Casirivimab and Imdevimab (branded as Ronapreve®), Sotrovimab (marketed as Xevudy®), Anakinra, Molnupiravir, Nirmatrelvir/Ritonavir (marketed as Paxlovid®), and Galidesivir. Findings indicate that while Remdesivir and Nirmatrelvir/Ritonavir show significant efficacy in reducing hospitalization and severe outcomes, drugs like Lopinavir/Ritonavir and Ivermectin have inconsistent results. Our insights suggest a multifaceted approach incorporating these therapies can significantly improve patient outcomes. Repurposing drugs has been critical in rapidly responding to COVID-19, allowing existing medications to be used in new ways to combat the virus. Combination therapies and further research are essential to optimize treatment strategies.
Feline Calicivirus Virulent Systemic Disease: Clinical Epidemiology, Analysis of Viral Isolates and In Vitro Efficacy of Novel Antivirals in Australian Outbreaks
Feline calicivirus (FCV) causes upper respiratory tract disease (URTD) and sporadic outbreaks of virulent systemic disease (FCV-VSD). The basis for the increased pathogenicity of FCV-VSD viruses is incompletely understood, and antivirals for FCV-VSD have yet to be developed. We investigated the clinicoepidemiology and viral features of three FCV-VSD outbreaks in Australia and evaluated the in vitro efficacy of nitazoxanide (NTZ), 2′-C-methylcytidine (2CMC) and NITD-008 against FCV-VSD viruses. Overall mortality among 23 cases of FCV-VSD was 39%. Metagenomic sequencing identified five genetically distinct FCV lineages within the three outbreaks, all seemingly evolving in situ in Australia. Notably, no mutations that clearly distinguished FCV-URTD from FCV-VSD phenotypes were identified. One FCV-URTD strain likely originated from a recombination event. Analysis of seven amino-acid residues from the hypervariable E region of the capsid in the cultured viruses did not support the contention that properties of these residues can reliably differentiate between the two pathotypes. On plaque reduction assays, dose–response inhibition of FCV-VSD was obtained with all antivirals at low micromolar concentrations; NTZ EC50, 0.4–0.6 µM, TI = 21; 2CMC EC50, 2.7–5.3 µM, TI > 18; NITD-008, 0.5 to 0.9 µM, TI > 111. Investigation of these antivirals for the treatment of FCV-VSD is warranted.
Phenotypic investigation of 4-nitrophenylacetyl- and 4-nitro-1 H -imidazoyl-based compounds as antileishmanial agents
Cutaneous leishmaniasis (CL) is a spectrum of clinical manifestations characterized by severe skin ulcerations that leads to social stigma. There are limited treatment options for CL, and the available drugs are becoming less efficacious due to drug resistance. More efficacious and safer antileishmanial drugs are needed. In this study, the biological effect of seven synthetically accessible nitroaromatic compounds was evaluated in vitro against amastigotes of Leishmania amazonensis , followed by in vivo evaluation using mouse models of CL. Two compounds ( 6 and 7 ) were active against amastigotes in vitro [half-maximal effective concentration (EC 50 ): 4.57 ± 0.08 and 9.19 ± 0.68 μ m , respectively], with selectivity indexes >50, and the other compounds were not selective. In vivo , compounds 6 and 7 (10 mg kg −1 , twice a day for 14 days) failed to reduce skin lesion sizes and parasite loads determined by light microscopy of lesion imprints and quantitative polymerase chain reaction. Nevertheless, the in vitro leishmanicidal efficacy sustained their use as templates for nitroimidazole-based antileishmanial drug discovery programmes focusing on analogues with more suitable properties.
Nitro-Oleic Acid (NO2-OA) Improves Systolic Function in Dilated Cardiomyopathy by Attenuating Myocardial Fibrosis
Nitro-oleic acid (NO2-OA), a nitric oxide (NO)- and nitrite (NO2−)-derived electrophilic fatty acid metabolite, displays anti-inflammatory and anti-fibrotic signaling actions and therapeutic benefit in murine models of ischemia-reperfusion, atrial fibrillation, and pulmonary hypertension. Muscle LIM protein-deficient mice (Mlp−/−) develop dilated cardiomyopathy (DCM), characterized by impaired left ventricular function and increased ventricular fibrosis at the age of 8 weeks. This study investigated the effects of NO2-OA on cardiac function in Mlp−/− mice both in vivo and in vitro. Mlp−/− mice were treated with NO2-OA or vehicle for 4 weeks via subcutaneous osmotic minipumps. Wildtype (WT) littermates treated with vehicle served as controls. Mlp−/− mice exhibited enhanced TGFβ signalling, fibrosis and severely reduced left ventricular systolic function. NO2-OA treatment attenuated interstitial myocardial fibrosis and substantially improved left ventricular systolic function in Mlp−/− mice. In vitro studies of TGFβ-stimulated primary cardiac fibroblasts further revealed that the anti-fibrotic effects of NO2-OA rely on its capability to attenuate fibroblast to myofibroblast transdifferentiation by inhibiting phosphorylation of TGFβ downstream targets. In conclusion, we demonstrate a substantial therapeutic benefit of NO2-OA in a murine model of DCM, mediated by interfering with endogenously activated TGFβ signaling.
Use-case scenarios for an anti-Cryptosporidium therapeutic
Cryptosporidium is a widely distributed enteric parasite that has an increasingly appreciated pathogenic role, particularly in pediatric diarrhea. While cryptosporidiosis has likely affected humanity for millennia, its recent “emergence” is largely the result of discoveries made through major epidemiologic studies in the past decade. There is no vaccine, and the only approved medicine, nitazoxanide, has been shown to have efficacy limitations in several patient groups known to be at elevated risk of disease. In order to help frontline health workers, policymakers, and other stakeholders translate our current understanding of cryptosporidiosis into actionable guidance to address the disease, we sought to assess salient issues relating to clinical management of cryptosporidiosis drawing from a review of the literature and our own field-based practice. This exercise is meant to help inform health system strategies for improving access to current treatments, to highlight recent achievements and outstanding knowledge and clinical practice gaps, and to help guide research activities for new anti- Cryptosporidium therapies.
Efficacy of orally administered fluralaner (BravectoTM) or topically applied imidacloprid/moxidectin (Advocate®) against generalized demodicosis in dogs
BACKGROUND : This laboratory study compared the efficacy of Bravecto™ (fluralaner), formulated as a chewable tablet, with the efficacy of Advocate® (imidacloprid/moxidectin), formulated for topical administration, against naturally acquired generalized demodicosis in dogs. METHODS : Sixteen dogs, all diagnosed with generalized demodectic mange, were randomly allocated to two equal groups. Bravecto™ chewable tablets were administered once orally at a minimum dose of 25 mg fluralaner/kg body weight to one group of dogs, while the second group was treated topically on three occasions at 28-day intervals with Advocate® at a minimum dose of 10 mg imidacloprid/kg body weight and 2.5 mg moxidectin/kg body weight. Mites were counted in skin scrapings and demodectic lesions were evaluated on each dog before treatment and at 28-day intervals thereafter over a 12 week study period. Deep skin scrapings (~4 cm2) were made from the same five sites on each dog at each subsequent examination. RESULTS : After single oral administration of Bravecto™ chewable tablets, mite numbers in skin scrapings were reduced by 99.8% on Day 28 and by 100% on Days 56 and 84. Mite numbers in the dogs treated topically on three occasions at 28-day intervals with Advocate® were reduced by 98.0% on Day 28, by 96.5% on Day 56 and by 94.7% on Day 84. Statistically significantly (P ≤ 0.05) fewer mites were found on Days 56 and 84 on the Bravecto™ treated dogs compared to Advocate® treated dogs. A marked decrease was observed in the occurrence of erythematous patches, crusts, casts and scales in the dogs treated with Bravecto™ and in the occurrence of erythematous patches in the dogs treated with Advocate®. With the exception of one dog in each treated group, all dogs exhibited hair regrowth ≥ 90% at the end of the study in comparison with their hair-coat at study start. CONCLUSIONS : Single oral administration of Bravecto™ chewable tablets is highly effective against generalized demodicosis, with no mites detectable at 56 and 84 days following treatment. In comparison, Advocate®, administered three times at 28-day intervals, is also highly effective against generalized demodicosis, but most dogs still harboured mites at all assessment time points. Both treatments resulted in a marked reduction of skin lesions and increase of hair re-growth 12 weeks after the initial treatment.