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Recent Developments in Therapies and Strategies Against COVID-19
Published in Hanadi Talal Ahmedah, Muhammad Riaz, Sagheer Ahmed, Marius Alexandru Moga, The Covid-19 Pandemic, 2023
Misbah Hameed, M. Zia-Ul-Haq, Marius Moga
Oseltamivir is a viral neuraminidase enzyme blocker. The inhibition of the enzyme restricts the progeny influenza virus release from the infected cells and inhibits new viral cycles. Progeny virions bind to the cell surface glycoproteins through sialic acid. Neuraminidase removes this sialic acid resulting in the release of progeny virions. The neuraminidase inhibitors hinder the final stage of release of new virion [29].
Infections
Published in Evelyne Jacqz-Aigrain, Imti Choonara, Paediatric Clinical Pharmacology, 2021
Evelyne Jacqz-Aigrain, Imti Choonara
The first molecules used in the treatment for flu, amantadine and rimantadine, were confirmed to have had a limiting effect on the A virus, but their effectiveness was limited because of the emergence of resistant strains. The design of a new class of inhibitors for viral neuraminidase has resulted in the creation of effective antiviral compounds free of toxicity [4]. Neuraminidase is an enzyme present in the envelope of the virus that facilitates its liberation after its budding. It does this by cleaving the residues of sialic acid (Neu5 Ac) that are present in the glucoconjugates of the viral receptor at the surface of the respiratory epithelium. Neuraminidase also facilitates the diffusion of the virus through the bronchial tree by modifying the structure of the mucus, rich in muccoploysaccharides. The blocking of this enzymatique activity leads to the inhibition of the formation of lysis zones and reduces the titre of viral particles in the animal and in humans. Two of these compounds have received market authorisation in several countries: zanamivir (Relenza®) and oseltamivir (Tamiflu®) [5].
Antiviral therapeutics for viral infections of the central nervous system
Published in Avindra Nath, Joseph R. Berger, Clinical Neurovirology, 2020
Influenza A and B virus isolates with reduced susceptibility to peramivir have been observed in cell culture and in vivo. Reduced susceptibility may be conferred by amino acid substitutions (including H275Y in influenza A/H1N1 as well as R292K and N294S in influenza A/H3N2) in viral neuraminidase. These isolates with reduced susceptibility have been identified in community surveillance studies, including patients who have not been exposed to peramivir. In 2014, a community cluster of influenza A (H1N1) pdm9 with an H275Y substitution was found to exhibit cross resistance among oseltamivir and peramivir in six-patients [87]. This resistance substitution has also emerged during IV peramivir use in immunocompromised hosts.
Exploring the biomedical potential of a novel modified glass ionomer cement against the pandrug-resistant oral pathogen Candida albicans SYN-01
Published in Journal of Oral Microbiology, 2023
Nessma A. El Zawawy, Samy El-Safty, El-Refaie Kenawy, Sara Ibrahim Salem, Sameh S. Ali, Yehia A.-G. Mahmoud
In a trial to explain the ability of CS-MC-GICs to control dental caries, we observed that CS-MC-GICs have strong anti-neuraminidase activity, so this will diminish the ability of the selected strain to invade the dental/oral tissues. Similarly, Rajasekaran et al. [92] reported that Mussaenda elmeri, Santiria apiculata and Anisophyllea disticha inhibited viral neuraminidase enzymatic activity as there is not any study on inhibition of Candida neuraminidase enzyme. Our study also determined that CS-MC-GIC acted as a reversible non-competitive inhibitor for neuraminidase enzyme in PDR-CA-SYN-01. In accordance with our results, Chintakrindi et al. [93] showed that certain flavones and chalcones inhibited the activity of the viral neuraminidase enzyme in a non-competitive manner. Moreover, Silveria et al. [94] recorded that an alkaloidal extract from the stems of T. divaricata inhibited acetylcholinesterase activity in a reversible non-competitive manner. In addition, Kong et al. [95] stated that grape seed extract inhibited both α-amylase and α-glucosidase enzymes in a reversible competitive manner. To the best of our knowledge, this study might be the first to evaluate the activity of CS-MC-GICs against PDR-CA-SYN-01, biofilm formation, and neuraminidase activity. Thus, a new avenue for further research and development on this newly discovered CS-MC-GIC for translation into therapeutic strategies has been opened.
What are the considerations when selecting a model for influenza drug discovery?
Published in Expert Opinion on Drug Discovery, 2023
Woo-Jin Shin, Seongil Choi, Baik-Lin Seong
The discovery and development of antiviral drugs begins with knowledge in virology, and in particular, how the virus infects the host cells and how the virus interacts/utilizes the host protein within the cells [7]. In the case of segmented negative-stranded RNA viruses (sNSVs), viral RNA forms a complex with viral polymerase and nucleoprotein to form a viral ribonucleoprotein (vRNP) complex. Influenza viruses utilize viral neuraminidase, the prime antiviral target for NAIs, that cleaves the host receptor sialic acid to release the newly assembled virions from the infected cells at the later stage of infection [8]. To determine whether the target of interest can be interfered with to cripple viral replication, methods such as reverse genetics [9] or CRISPR screening [10] can be implemented. When selecting a model that is efficient for antiviral drug discovery, several considerations must be made. These considerations, in combination with a knowledge of chemical biology, will accelerate future drug design and discovery. We list below some of the important points that must be considered.
Possible therapeutic agents for COVID-19: a comprehensive review
Published in Expert Review of Anti-infective Therapy, 2020
Khaled Mosaad Elhusseiny, Fatma Abd-Elshahed Abd-Elhay, Mohamed Gomaa Kamel
Hesperidin is a natural derivative of citrus fruits. It has shown a protective effect against influenza A virus at the early stage of infection through inhibition of viral neuraminidase (sialidase) enzyme, important for the virions release from infected cells [176]. A group of researchers investigated its efficacy against SARS-CoV-2. Interestingly, hesperidin bound to RBD of SARS-CoV-2 spike protein, and therefore inhibited the interaction between ACE-II receptor and spike protein. This step, subsequently, inhibited viral entry inside host cells. This finding encourages conducting more trials on hesperidin, because it is cheap, available, with no adverse effects, except for the low incidence of nausea and vomiting [177].