-
Biochimica Et Biophysica Acta.... Mar 2024Oseltamivir belongs to the neuraminidase inhibitors, developed against the influenza virus, and registered under the trademark Tamiflu. Despite its long-term...
Oseltamivir belongs to the neuraminidase inhibitors, developed against the influenza virus, and registered under the trademark Tamiflu. Despite its long-term acquaintance, there is limited information in the literature about its physicochemical and structural properties in a lipid-water system. We present an experimentally determined partition coefficient with structural information on the interaction of oseltamivir with the model membrane, its possible location, and its effect on the membrane thermodynamics. The hydrophobic part of the lipid bilayer is affected to a moderate extent, which was proved by slight changes in thermal and structural properties. Hereby, interaction of oseltamivir with the phospholipid bilayer induces concentration dependent decrease of lateral pressure in the bilayer acyl chain region. Oseltamivir charges the bilayer surface positively, which results in the zeta potential increase and changes in anisotropic properties studied by the polarised light microscopy. At the highest oseltamivir concentrations studied, the multilamellar structure is extensively disturbed, likely due to electrostatic repulsion between the adjacent bilayers.
Topics: Oseltamivir; Antiviral Agents; Lipid Bilayers; Phospholipids; Phosphates
PubMed: 38211646
DOI: 10.1016/j.bbamem.2024.184273 -
Foods (Basel, Switzerland) Dec 2023Our group previously demonstrated that Lamk exhibits many profound biological properties, including anticancer, antibacterial, and antioxidant activities. However, its...
Our group previously demonstrated that Lamk exhibits many profound biological properties, including anticancer, antibacterial, and antioxidant activities. However, its antiviral activity has not yet been investigated. Here, the aqueous extract of was prepared from the aerial parts (leaves, stalks, and trunks) to see whether it exerts anti-influenza (H1N1) effects and to reduce the organic solvents consumed during extraction, making it a desirable approach for the large-scale production for medical uses. Our plant extract was quantified to contain 7 g of gallic acid (GA) per 100 g of a dry sample, as determined using HPLC analysis. It also exerts potent antioxidant activities comparable to those of authentic GA. According to untargeted metabolomics (UPLC-ESI(-)-QTOF-MS/MS) with the aid of cheminformatics tools (MetFrag (version 2.1), SIRIUS (version 5.8.3), CSI:FingerID (version 4.8), and CANOPUS), the major metabolite was best annotated as "gallic acid", phenolics (e.g., quinic acid, shikimic acid, and protocatechuic acid), sugar derivatives, and dicarboxylic acids were deduced from this plant species for the first time. The aqueous plant extract efficiently inhibited an influenza A (H1N1) virus infection of MDCK cells with an IC of 5.14 µg/mL. Of equal importance, hemolytic activity was absent for this plant extract, signifying its applicability as a safe antiviral agent. Molecular docking suggested that GA interacts with conserved residues (e.g., Arg152 and Asp151) located in the catalytic inner shell of the viral neuraminidase (NA), sharing the same pocket as those of anti-neuraminidase drugs, such as laninamivir and oseltamivir. Additionally, other metabolites were also found to potentially interact with the active site and the hydrophobic 430-cavity of the viral surface protein, suggesting a possibly synergistic effect of various phytochemicals. Therefore, the aqueous extract may be a good candidate for coping with increasing influenza virus resistance to existing antivirals.
PubMed: 38201109
DOI: 10.3390/foods13010081 -
Biochemistry Feb 2024Vital to the treatment of influenza is the use of antivirals such as Oseltamivir (Tamiflu) and Zanamivir (Relenza); however, antiviral resistance is becoming an...
Vital to the treatment of influenza is the use of antivirals such as Oseltamivir (Tamiflu) and Zanamivir (Relenza); however, antiviral resistance is becoming an increasing problem for these therapeutics. The RNA-dependent RNA polymerase acidic N-terminal (PA) endonuclease, a critical component of influenza viral replication machinery, is an antiviral target that was recently validated with the approval of Baloxavir Marboxil (BXM). Despite its clinical success, BXM has demonstrated susceptibility to resistance mutations, specifically the I38T, E23K, and A36 V mutants of PA. To better understand the effects of these mutations on BXM resistance and improve the design of more robust therapeutics, this study examines key differences in protein-inhibitor interactions with two inhibitors and the I38T, E23K, and A36 V mutants. Differences in inhibitor binding were evaluated by measuring changes in binding to PA using two biophysical methods. The binding mode of two distinct inhibitors was determined crystallographically with both wild-type and mutant forms of PA. Collectively, these studies give some insight into the mechanism of antiviral resistance of these mutants.
Topics: Humans; Influenza, Human; Oxazines; Pyridines; Antiviral Agents; Endonucleases; Thiepins; Pyridones; Oseltamivir; Zanamivir; Triazines; Dibenzothiepins; Morpholines
PubMed: 38190441
DOI: 10.1021/acs.biochem.3c00536 -
The American Journal of the Medical... Apr 2024Influenza infection is rarely associated with cardiac conduction disorder. Cardiac arrhythmias due to such an infection have a full spectrum with ventricular arrythmias...
BACKGROUND
Influenza infection is rarely associated with cardiac conduction disorder. Cardiac arrhythmias due to such an infection have a full spectrum with ventricular arrythmias being the most common.
METHODS
In our systematic review from PubMed, OVID Medline and EMBASE we have identified 23 articles describing arrythmias associated with different influenza infection. Most of them were case reports where ventricular arrhythmias were the most common.
RESULTS
Complete heart block after influenza infection is usually temporary and a permanent pacemaker is rarely needed. There are reports of Influenza associated with arrhythmias in adults, neonates, and even fetuses in pregnant woman. Different mechanisms were described in literatures by which influenza causes arrhythmias such as interleukin 6 & tumor necrosis factor-alpha mediated inflammatory response, sympathetic overactivation, focal myocarditis and cleavage of angiotensin converting enzyme 2 protein which is cardioprotective.
CONCLUSIONS
ACE 2 binder influenza viruses have more prone to be associated with cardiac conduction disorder. Oseltamivir for influenza infection is also associated with bradycardia and can shorten or lengthen QT segment. Influenza vaccination has found to be protective from cardiac arrhythmia.
Topics: Adult; Infant, Newborn; Pregnancy; Female; Humans; Influenza, Human; Arrhythmias, Cardiac; Bradycardia; Oseltamivir; Myocarditis
PubMed: 38185405
DOI: 10.1016/j.amjms.2024.01.004 -
Virulence Dec 2024Influenza A virus (IAV) poses a threat to patients receiving immunosuppressive medications since they are more susceptible to infection with severe symptoms, and even...
Influenza A virus (IAV) poses a threat to patients receiving immunosuppressive medications since they are more susceptible to infection with severe symptoms, and even death. Understanding the direct effects of immunosuppressants on IAV infection is critical for optimizing immunosuppression in these patients who are infected or at risk of influenza virus infection. We profiled the effects of 10 immunosuppressants, explored the antiviral mechanisms of immunosuppressants, and demonstrated the combined effects of immunosuppressants with the antiviral drug oseltamivir in IAV-infected cell models. We found that mycophenolic acid (MPA) strongly inhibits viral RNA replication via depleting cellular guanosine pool. Treatment with 6-Thioguanine (6-TG) promoted viral protein degradation through a proteasomal pathway. Filgotinib blocked mRNA splicing of matrix protein 2, resulting in decreased viral particle assembly. Furthermore, combined treatment with immunosuppressants and oseltamivir inhibits IAV viral particle production in an additive or synergic manner. Our results suggest that MPA, 6-TG, and filgotinib could be the preferential choices for patients who must take immunosuppressants but are at risk of influenza virus infection.
Topics: Humans; Oseltamivir; Antiviral Agents; Influenza, Human; Influenza A Virus, H1N1 Subtype; Immunosuppressive Agents; Influenza A virus; Orthomyxoviridae Infections; Virus Replication; RNA, Messenger; Protein Stability
PubMed: 38170681
DOI: 10.1080/21505594.2023.2301242 -
Lung India : Official Organ of Indian... Jan 2024Antiviral combinations have been proposed as treatment for influenza in order to increase the antiviral activity by action at different sites of action as well as...
Antiviral combinations have been proposed as treatment for influenza in order to increase the antiviral activity by action at different sites of action as well as obviate the emergence of drug resistance to the commonly used antiviral agents like oseltamivir. Nitazoxanide has been found to exhibit anti-influenza viral activity with clinical benefit in a previous study. We recruited 242 cases of SARI, among whon 67 were confirmed to have influenza viral infection. In a randomized blinded fashion, 34 patients received a combination of nitazoxanide and oseltamivir whereas 33 cases received oseltamivir alone. Clinical parameters were followed in both groups and the nasal swabs were re-tested on day 6 for influenza positivity and the cycle threshold (CT) values. No significant differences were observed in terms of time for resolution of fever, other symptoms, and SOFA scores. Nine patients succumbed during the course of the illness that included three in the oseltamivir group and six in the combination group. All but one of those who expired had an underlying co-morbid illness. Our preliminary data suggest that the addition of nitazoxanide does not improve outcomes in hospitalized patients with influenza. Larger studies are recommended for statistically robust conclusions.
PubMed: 38160460
DOI: 10.4103/lungindia.lungindia_711_21 -
JAMA Pediatrics Feb 2024
Topics: Humans; Oseltamivir; Influenza, Human; Antiviral Agents; Enzyme Inhibitors; Neuraminidase
PubMed: 38147329
DOI: 10.1001/jamapediatrics.2023.5731 -
ACS Omega Dec 2023Influenza remains one of the most widespread infections, causing an annual illness in adults and children. Therefore, the search for new antiviral drugs is one of the...
Influenza remains one of the most widespread infections, causing an annual illness in adults and children. Therefore, the search for new antiviral drugs is one of the priorities of practical health care. Eight isorhamnetin glycosides were purified from Persicaria species, characterized by nuclear magnetic resonance spectroscopy and mass spectrometry and then evaluated as potential agents against influenza virus. A comprehensive in vitro and in vivo assessment of the compounds revealed that compound 5 displayed the most potent inhibitory activity with an EC value of 1.2-1.3 μM, better than standard drugs (isorhamnetin 28.0-56.0 μM and oseltamivir 1.3-9.1 μM). Molecular docking results also revealed that compound 5 has the lowest binding energy (-10.7 kcal/mol) among the tested compounds and isorhamnetin (-8.1 kcal/mol). The ability of the isorhamnetin glycosides to suppress the reproduction of the influenza virus was studied on a model of a cell culture and chicken embryos. The ability of active compounds to influence the structure of the virion, as well as the activity of hemagglutinin and neuraminidase, has been demonstrated. Compound 1, 5, and 6 demonstrated the most effective inhibition of virus replication for all tested viruses. Molecular dynamics simulation techniques were run for 100 ns for compound 5 with two protein receptors Hem (1RUY) and Neu (3BEQ). These results revealed that the Hem-complex system acquired a relatively more stable conformation and even better descriptors than the other Neu-complex studied systems, suggesting that it can be an effective inhibiting drug toward hemagglutinin than neuraminidase inhibition. Based on the reported results, compound 5 can be a good candidate to be evaluated for effectiveness in preclinical testing.
PubMed: 38144046
DOI: 10.1021/acsomega.3c08407 -
Viruses Dec 2023Influenza antiviral drugs are important tools in our fight against both annual influenza epidemics and pandemics. Polyphenols are a group of compounds found in plants,...
Influenza antiviral drugs are important tools in our fight against both annual influenza epidemics and pandemics. Polyphenols are a group of compounds found in plants, some of which have demonstrated promising antiviral activity. Previous in vitro and mouse studies have outlined the anti-influenza virus effectiveness of the polyphenol epigallocatechin-3-gallate (EGCG); however, no study has utilised the ferret model, which is considered the gold-standard for influenza antiviral studies. This study aimed to explore the antiviral efficacy of EGCG in vitro and in ferrets. We first performed studies in Madin-Darby Canine Kidney (MDCK) and human lung carcinoma (Calu-3) cells, which demonstrated antiviral activity. In MDCK cells, we observed a selective index (SI, CC50/IC50) of 77 (290 µM/3.8 µM) and 96 (290 µM/3.0 µM) against A/California/07/2009 and A/Victoria/2570/2019 (H1N1)pdm09 influenza virus, respectively. Calu-3 cells demonstrated a SI of 16 (420 µM/26 µM) and 18 (420 µM/24 µM). Ferrets infected with A/California/07/2009 influenza virus and treated with EGCG (500 mg/kg/day for 4 days) had no change in respiratory tissue viral titres, in contrast to oseltamivir treatment, which significantly reduced viral load in the lungs of treated animals. Therefore, we demonstrated that although EGCG showed antiviral activity in vitro against influenza viruses, the drug failed to impair viral replication in the respiratory tract of ferrets.
Topics: Animals; Dogs; Humans; Mice; Influenza, Human; Antiviral Agents; Influenza A Virus, H1N1 Subtype; Tea; Ferrets
PubMed: 38140688
DOI: 10.3390/v15122447 -
Viruses Nov 2023Influenza can cause respiratory infections, leading to significant morbidity and mortality in humans. While current influenza vaccines offer varying levels of...
Influenza can cause respiratory infections, leading to significant morbidity and mortality in humans. While current influenza vaccines offer varying levels of protection, there remains a pressing need for effective antiviral drugs to supplement vaccine efforts. Currently, the FDA-approved antiviral drugs for influenza include oseltamivir, zanamivir, peramivir, and baloxavir marboxil. These antivirals primarily target the virus, making them vulnerable to drug resistance. In this study, we evaluated the efficacy of the neuraminidase inhibitor, oseltamivir, against probenecid, which targets the host cells and is less likely to engender resistance. Our results show that probenecid has superior antiviral efficacy compared to oseltamivir in both in vitro replication assays and in vivo mouse models of influenza infection.
Topics: Humans; Animals; Mice; Oseltamivir; Influenza, Human; Probenecid; Influenza Vaccines; Antiviral Agents; Enzyme Inhibitors; Virus Replication; Neuraminidase; Drug Resistance, Viral
PubMed: 38140606
DOI: 10.3390/v15122366