Discovery of Potential Antiviral Compounds against Hendra Virus by Targeting Its Receptor-Binding Protein (G) Using Computational Approaches

Hendra virus (HeV) belongs to the paramyxoviridae family of viruses which is associated with the respiratory distress, neurological illness, and potential fatality of the affected individuals. So far, no competitive approved therapeutic substance is available for HeV. For that reason, the current research work was conducted to propose some novel compounds, by adopting a Computer Aided Drug Discovery approach, which could be used to combat HeV. The G attachment Glycoprotein (Ggp) of HeV was selected to achieve the primary objective of this study, as this protein makes the entry of HeV possible in the host cells. Briefly, a library of 6000 antiviral compounds was screened for potential drug-like properties, followed by the molecular docking of short-listed compounds with the Protein Data Bank (PDB) structure of Ggp. Docked complexes of top two hits, having maximum binding affinities with the active sites of Ggp, were further considered for molecular dynamic simulations of 200 ns to elucidate the results of molecular docking analysis. MD simulations and Molecular Mechanics Energies combined with the Generalized Born and Surface Area (MMGBSA) or Poisson–Boltzmann and Surface Area (MMPBSA) revealed that both docked complexes are stable in nature. Furthermore, the same methodology was used between lead compounds and HeV Ggp in complex with its functional receptor in human, Ephrin-B2. Surprisingly, no major differences were found in the results, which demonstrates that our identified compounds can also perform their action even when the Ggp is attached to the Ephrin-B2 ligand. Therefore, in light of all of these results, we strongly suggest that compounds (S)-5-(benzylcarbamoyl)-1-(2-(4-methyl-2-phenylpiperazin-1-yl)-2-oxoethyl)-6-oxo-3,6-dihydropyridin-1-ium-3-ide and 5-(cyclohexylcarbamoyl)-1-(2-((2-(3-fluorophenyl)-2-methylpropyl)amino)-2-oxoethyl)-6-oxo-3,6-dihydropyridin-1-ium-3-ide could be considered as potential therapeutic agents against HeV; however, further in vitro and in vivo experiments are required to validate this study.

A Recombinant System and Reporter Viruses for Papiine Alphaherpesvirus 2

Primate simplex viruses, including Herpes simplex viruses 1 and 2, form a group of closely related herpesviruses, which establish latent infections in neurons of their respective host species. While neuropathogenic infections in their natural hosts are rare, zoonotic transmission of Macacine alphaherpesvirus 1 (McHV1) from macaques to humans is associated with severe disease. Human infections with baboon-derived Papiine alphaherpesvirus 2 (PaHV2) have not been reported, although PaHV2 and McHV1 share several biological properties, including neuropathogenicity in mice. The reasons for potential differences in PaHV2 and McHV1 pathogenicity are presently not understood, and answering these questions will require mutagenic analysis. Here, we report the development of a recombinant system, which allows rescue of recombinant PaHV2. In addition, we used recombineering to generate viruses carrying reporter genes (Gaussia luciferase or enhanced green fluorescent protein), which replicate with similar efficiency as wild-type PaHV2. We demonstrate that these viruses can be used to analyze susceptibility of cells to infection and inhibition of infection by neutralizing antibodies and antiviral compounds. In summary, we created a recombinant system for PaHV2, which in the future will be invaluable for molecular analyses of neuropathogenicity of PaHV2.

In-Utero Neurotoxicity of Nanoparticles

The unique physicochemical properties of nanoparticles (NPs) make them widely used in cosmetics, medicines, food additives, and antibacterial and antiviral compounds. NPs are also used in therapy and diagnostic applications. Depending on their origin, the NPs are commonly classified as naturally occurring and synthetic or anthropogenic NPs. Naturally occurring nanoparticles can be formed by many physical, chemical, and biological processes occurring in all spheres of the earth. However, synthetic NPs are specifically designed or unintentionally produced by different human activities. Owing to their nano size and special properties, the engineered NPs can enter the human body through different routes such as dermal penetration, intravenous injection and inhalation. NPs may accumulate in various tissues and organs including the brain. Indiscriminate use of NP is a matter concern due to the dangers of NP exposure to living organisms. It is possible for NPs to cross the placental barrier, and adversely affect the developing fetus, posing a health hazard in them by causing neurodevelopmental toxicity. Thus, NP-induced neurotoxicity is a topic that demands attention at the maternal-fetal interface. This chapter summarizes the routes by which NPs circumvent the blood-brain barrier, including recent investigations about NPs’ neurotoxicity as well as possible mechanisms involved in neural fetotoxicity.

Antiviral Effects of Plant Extracts Used in the Treatment of Important Animal Viral Diseases

The goal of this review was to highlight some plant species that have significant antiviral activity against DNA and RNA viruses in vitro and in vivo although more research is needed to address safety issues, drug interactions, and the possibility of using them in combination with other natural products. Viral infection plays an important role in human and animal diseases. Although there have been advances in immunization and antiviral drugs, there is still a lack of protective vaccines and effective antiviral drugs in human and veterinary medicine. The lack of effective antivirals necessitates the search for new effective antiviral compounds. Plants are naturally gifted at synthesizing antiviral compounds. They are rich sources of phytochemicals with different biological activities, including antiviral activities as a result of advanced analytical chemistry, standard virus assays, and development of standardization and extraction methods. Plant extracts have a wide variety of active compounds, including flavonoids, terpenoids, lignans, sulphides, polyphenolics, coumarins, saponins, furyl compounds, alkaloids, polyines, thiophenes, proteins, and peptides. Moreover, certain volatile oils have indicated a high level of antiviral activity. Replication, assembly, and release, as well as targeting virus host-specific interactions capable of inhibiting several viruses, could help the development of broad-spectrum antivirals for the prevention and control of viral pathogens. The in vitro antiviral activities of Erythroxylum deciduum, Lacistema hasslerianum (chodat), Xylopia aromatica, Heteropteris aphrodisiaca, Acacia nilotica (gum arabic tree), Lippia graveolens (Guettarda angelica (Velvetseed), Prunus myrtifolia, and Symphyopappus plant extracts can inhibite viral replication, and interfer with the early stages of viral adsorption of DNA viruses. However, Boesenbergia rotunda plant extracts have inhibited RNA viruses. A potent anti-SARS-CoV-2 inhibitor with B. rotunda extract and panduratin A after viral infection drastically suppresses SARS-CoV-2 infectivity in Vero E6 cells.

Bioinformatic Analysis of Antiviral Medicinal Compounds Against Sars Cov-2 Proteases

The world is under siege from a global pandemic caused by a novel class of coronaviruses called severe acute respiratory syndrome coronavirus-2 (SARS CoV-2). These viruses cause severe respiratory illness leading to death. Molecular studies reveal that SARS CoV-2 proteases are involved in the processing of viral polyproteins. This study was conducted to obtain antiviral agents for SARS CoV-2 proteases. An extensive library of antiviral medicinal compounds was scrutinized to determine the probable interaction with both main and 3-chymotrypsin like proteases. Six antiviral compounds (Abietic Acid, Gallic Acid, Piceatannol, Piperine, Sinomenine, and Triptolide) were capable of establishing hydrogen bonds with the active pocket residues of the viral proteases, with appreciable binding energy. These compounds were subjected to root mean square analysis and tested not only for acute toxicity, but also for absorption, distribution, metabolism, excretion, and toxicity properties. Results were favourable for use in the treatment of SARS COV-2 infection.

Rotten to the core: antivirals targeting the HIV-1 capsid core

The capsid core of HIV-1 is a large macromolecular assembly that surrounds the viral genome and is an essential component of the infectious virus. In addition to its multiple roles throughout the viral life cycle, the capsid interacts with multiple host factors. Owing to its indispensable nature, the HIV-1 capsid has been the target of numerous antiretrovirals, though most capsid-targeting molecules have not had clinical success until recently. Lenacapavir, a long-acting drug that targets the HIV-1 capsid, is currently undergoing phase 2/3 clinical trials, making it the most successful capsid inhibitor to-date. In this review, we detail the role of the HIV-1 capsid protein in the virus life cycle, categorize antiviral compounds based on their targeting of five sites within the HIV-1 capsid, and discuss their molecular interactions and mechanisms of action. The diverse range of inhibition mechanisms provides insight into possible new strategies for designing novel HIV-1 drugs and furthers our understanding of HIV-1 biology. Graphical Abstract

Current Trends in SPR Biosensing of SARS-CoV-2 Entry Inhibitors

The emerging risk of viral diseases has triggered the search for preventive and therapeutic agents. Since the beginning of the COVID-19 pandemic, greater efforts have been devoted to investigating virus entry mechanisms into host cells. The feasibility of plasmonic sensing technologies for screening interactions of small molecules in real time, while providing the pharmacokinetic drug profiling of potential antiviral compounds, offers an advantageous approach over other biophysical methods. This review summarizes recent advancements in the drug discovery process of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) inhibitors using Surface Plasmon Resonance (SPR) biosensors. A variety of SPR assay formats are discussed according to the binding kinetics and drug efficacies of both natural products and repurposed drugs. Special attention has been given to the targeting of antiviral agents that block the receptor binding domain of the spike protein (RBD-S) and the main protease (3CLpro) of SARS-CoV-2. The functionality of plasmonic biosensors for high-throughput screening of entry virus inhibitors was also reviewed taking into account experimental parameters (binding affinities, selectivity, stability), potential limitations and future applications.