Search

There is merit in investigating novel therapeutic molecules that hit vital targets during the viral infection cycle i.e. disrupting the interaction between SARS-CoV-2's spike glycoprotein and the host's angiotensin converting enzyme 2 (ACE2) receptor, potentially offering new avenues for treatment. Accordingly, lipid-based vesicular systems like liposomes or niosomes are frequently utilized to overcome these hurdles. Thus, chemically synthesized compounds were encapsulated within PEGylated bilosomes (PBs) to improve their solubility and intestinal permeability, thereby enhancing their anti-SARS-CoV-2 effectiveness. The formulae were prepared according to 2 3 full factorial design which was also used to explore the impact of the change in predetermined formulation variables on the properties of the prepared vesicles (entrapment efficiency EE%, particle size PS, and zeta potential ZP). Additionally, the optimized formula (F4) which is composed of 3% bile salt (BS), 40 mg 1,2-distearoyl- sn -glycero-3-phosphoethanolamine- N -[amino(polyethylene glycol)-2000] (DSPE) and sodium deoxycholate (SDC) as a bile salt, was selected as an optimum formula with desirability value 0.674 using Design Expert® software. Both the in vitro release and ex vivo experiments results confirmed the significant superiority of the F4 over the drug dispersion. Both cytotoxicity and anti-SARS-CoV-2 activity of all examined compound-loaded PBs (PB3a-PB3g) were assessed in Vero E6 cells via MTT assay. Both compounds PB3c and PB3g displayed the highest IC 50 values (0.71 and 1.25 μg mL -1 , respectively) ensuring their superior antiviral potential. Moreover, it was revealed that PB3c demonstrated more than 80% virucidal activity and over 80% inhibition of viral adsorption with little effect on the viral replication ∼(5-10%). Moreover, molecular docking and dynamic studies were conducted to pursue the binding affinities of the investigated compounds towards the ACE2 target of the SARS-CoV-2 spike protein, assuring their feasible inhibitory potential. Collectively, the investigated compound-loaded PBs can be treated as promising lead drug delivery panels for COVID-19 management., Competing Interests: The authors declared no conflict of interest., (This journal is © The Royal Society of Chemistry.)

We detected highly pathogenic avian influenza A(H5N1) virus in wild rats collected from a rural area in Giza, Egypt, near poultry farms, markets, and backyard flocks. Sequence and phylogenetic analyses indicated that the virus from the rats belonged to clade 2.3.4.4b, which has been the predominant virus genotype circulating in Egypt and worldwide since 2021-2022. Active surveillance of avian influenza viruses in wild and domestic mammals is recommended to prevent further spread to mammals and humans.

WHO declared severe acute respiratory syndrome coronavirus-2' (SARS-CoV-2) was global health emergency since 2020. In our study eighteen natural compounds were investigated for possible anti-SARS-CoV-2 potential, where the most potent natural compounds were ursolic acid and dioscin with IC 50 value of 4.49 µg/mL and 7.11 µg/mL, respectively. Hesperidin, catechin, diosmin, isorhamnetin-3- O -glucoside and hyperoside showed medium antiviral activity with IC 50 value of 20.87, 22.57, 38.92, 39.62 and 47.10 µg/mL, respectively. Molecular modelling studies including docking study and predictive ADME study were performed on all tested molecules. Their binding energies after docking were calculated and their orientations at the active sites of both SARS-CoV-2 main protease (Mpro) and spike (S) receptors were visualised and compared to the downloaded ligands. Also, the predictive ADME studies showed good pharmacokinetic properties of most of the tested compounds. The obtained in silico results obtained confirmed that many of the tested compounds are promising SARS-CoV-2 inhibitors.

Since its first isolation from migratory birds in Egypt in 2016, highly pathogenic avian influenza (HPAI) H5N8 has caused several outbreaks among domestic poultry in various areas of the country affecting poultry health and production systems. However, the genetic and biological properties of the H5N8 HPAI viruses have not been fully elucidated yet. In this study, we aimed to monitor the evolution of circulating H5N8 viruses and identify the pathogenicity and mammalian adaptation in vitro and in vivo. Three H5N8 HPAI viruses were used in this study and were isolated in 2021-2022 from poultry and wild birds during our routine surveillance. RNA extracts were subjected to full genome sequencing. Genetic, phylogenetic, and antigenic analyses were performed to assess viral characteristics and similarities to previously isolated viruses. Phylogenetic analysis showed that the hemagglutinin genes of the three isolates belonged to clade 2.3.4.4b and grouped with the 2019 viruses from G3 with high similarity to Russian and European lineages. Multiple basic amino acids were observed at cleavage sites in the hemagglutinin proteins of the H5N8 isolates, indicating high pathogenicity. In addition, several mutations associated with increased virulence and polymerase activity in mammals were observed. Growth kinetics assays showed that the H5N8 isolate is capable of replicating efficiently in mammalian cells lines. In vivo studies were conducted in SPF chickens (White Leghorn), mice, and hamsters to compare the virological characteristics of the 2022 H5N8 isolates with previous H5N8 viruses isolated in 2016 from the first introduction. The H5N8 viruses caused lethal infection in all tested chickens and transmitted by direct contact. However, we showed that the 2016 H5N8 virus causes a higher mortality in chickens compared to 2022 H5N8 virus. Moreover, the 2022 virus can replicate efficiently in hamsters and mice without preadaptation causing systemic infection. These findings underscore the need for continued surveillance of H5 viruses to identify circulating strains, determine the commercial vaccine's effectiveness, and identify zoonotic potential., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Moatasim et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The ongoing threat of Middle East respiratory syndrome coronavirus (MERS-CoV) underscores the importance of developing effective antiviral treatments. Current research was conducted to identify potential antiviral compounds from soft corals: Sinularia leptoclados , Sarcophyton ehrenbergi , Nephthea sp., Sarcophyton glaucum and Sarcophyton regulare . The antiviral activities of soft corals extracts were evaluated against MERS-CoV. Gas chromatography-mass spectrometry (GC-MS) was used to identify bioactive compounds. The molecular docking was performed to examine the identified compounds for their binding potentials towards three pathogenic factors of MERS-CoV: main protease, spike and non-structural protein 16/10 complex. The methanolic extract of soft coral Sarcophyton regulare exhibited the most promising activity with 50% inhibitory concentration (IC 50 ) of 4.29 µg/ml and selective index (SI) of 112.2. Among the identified compounds in the active fraction, the molecular docking showed that two fatty acid esters: hexadecanoic acid, 2-hydroxy-1-(hydroxymethyl) ethyl ester and octadecanoic acid, 2-hydroxy-1 (hydroxymethyl) ethyl ester had promising docking scores.

The search for new molecules targeting SARS-CoV-2 has been a priority since 2020. The continuous evolution of new mutants increases the need for more research in the area. One way to find new leads is to repurpose existing drugs and molecules against the required target. Here, we present the in vitro and in silico screening of ten previously synthesized and reported compounds as anti-COVID 19 agents. The compounds were screened in vitro against VERO-E6 cells to find their Cytotoxic Concentration (CC 50 ) and their Inhibitory Concentration (IC 50 ). Compounds 1, 2, and 5 revealed a promising anti-SARS-CoV-2 of (IC 50  = 2.4, 11.2 and 2.8 µM), respectively while compounds 3 and 7 showed moderate activity of (IC 50  = 17.8 and 26.1 µM) compared to Chloroquine which showed an IC 50 of 24.9 µM. Among tested compounds, 1 showed the highest selectivity (CC 50 /IC 50 ) of 192.8. Docking, molecular dynamics and ADME studies were done to investigate potential interactions between compounds and SARS-CoV-2 targets as well as to study the possibility of using them as lead compounds., (© 2024. The Author(s).)

A comprehensive study of fruits and leaves extracts of Citrus medica var. sarcodactylis Swingle and Limonia acidissima L. family Rutaceae was accomplished to investigate their antiviral activity along with their zinc oxide nanoparticles formulation (ZnONPs) against the avian influenza H5N1 virus. A thorough comparative phytochemical investigation of C. medica and L.acidissima leaves and fruits was performed using UPLC-QTOF-MS-MS. Antiviral effects further aided by molecular docking proved the highly significant potential of using C. medica and L.acidissima extracts as medicinal agents. Antiviral potency is ascendingly arranged as L. acidissima leaves (LAL) >  L. acidissima fruits (LAF) >  C. medica leaves (CML) at 160 μg. Nano formulation of LAF has the most splendid antiviral upshot. The metabolomic profiling of CMF and LAL revealed the detection of 48 & 74 chromatographic peaks respectively. Docking simulation against five essential proteins in survival and replication of the influenza virus revealed that flavonoid di-glycosides (hesperidin, kaempferol-3- O -rutinoside, and kaempferol-7-neohesperidoside) have shown great affinity toward the five investigated proteins and achieved docking scores which approached or even exceeded that achieved by the native ligands. Hesperidin has demonstrated the best binding affinity toward neuraminidase (NA), haemagglutinin (HA), and polymerase protein PB2 (-10.675, -8.131, and -10.046 kcal/mol respectively. We propose using prepared crude methanol extracts of both plants as an antiviral agent., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 Published by Elsevier Ltd.)

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the latest arisen contagious respiratory pathogen related to the global outbreak of atypical pneumonia pandemic (COVID-19). The essential oils (EOs) of Eucalyptus camaldulensis, E. ficifolia F. Muell., E. citriodora Hook, E. globulus Labill, E. sideroxylon Cunn. ex Woolls, and E. torquata Luehm. were investigated for its antiviral activity against SARS-CoV-2. The EOs phytochemical composition was determined using GC/MS analysis. Correlation with the explored antiviral activity was also studied using multi-variate data analysis and Pearson's correlation. The antiviral MTT and cytopathic effect inhibition assays revealed very potent and promising anti SARS-CoV-2 potential for E. citriodora EO (IC 50  = 0.00019 µg/mL and SI = 26.27). The multivariate analysis revealed α-pinene, α-terpinyl acetate, globulol, γ -terpinene, and pinocarvone were the main biomarkers for E. citriodora oil. Pearson's correlation revealed that globulol is the top positively correlated compound in E. citriodora oil to its newly explored potent anti SARS-CoV-2 potential. A molecular simulation was performed on globulol via docking in the main active sites of both SARS-CoV-2 viral main protease (Mpro) and spike protein (S). In silico predictive ADMET study was also developed to investigate the pharmacokinetic profile and predict globulol toxicity. The obtained in silico, in vitro and Pearson's correlation results were aligned showing promising SARS-CoV-2 inhibitory activity of E. citriodora and globulol. This study is a first record for E. citriodora EO as a novel lead exhibiting potent in vitro, and in silico anti SARS-CoV-2 potential and suggesting its component globulol as a promising candidate for further extensive in silico, in vitro and in vivo anti-COVID studies., (© 2024. The Author(s).)

The first detection of a human infection with avian influenza A/H6N1 virus in Taiwan in 2013 has raised concerns about this virus. During our routine surveillance of avian influenza viruses (AIVs) in live-bird markets in Egypt, an H6N1 virus was isolated from a garganey duck and was characterized. Phylogenetic analysis indicated that the Egyptian H6N1 strain A/Garganey/Egypt/20869C/2022(H6N1) has a unique genomic constellation, with gene segments inherited from different subtypes (H5N1, H3N8, H7N3, H6N1, and H10N1) that have been detected previously in AIVs from Egypt and some Eurasian countries. We examined the replication of kinetics of this virus in different mammalian cell lines (A549, MDCK, and Vero cells) and compared its pathogenicity to that of the ancestral H6N1 virus A/Quail/HK/421/2002(H6N1). The Egyptian H6N1 virus replicated efficiently in C57BL/6 mice without prior adaptation and grew faster and reached higher titers than in A549 cells than the ancestral strain. These results show that reassortant H6 AIVs might pose a potential threat to human health and highlight the need to continue surveillance of H6 AIVs circulating in nature., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

SARS-CoV-2 caused pandemic represented a major risk for the worldwide human health, animal health and economy, forcing extraordinary efforts to discover drugs for its prevention and cure. Considering the extensive interest in the pregnane glycosides because of their diverse structures and excellent biological activities, we investigated them as antiviral agents against SARS-COV-2. We selected 21 pregnane glycosides previously isolated from the genus Caralluma from Asclepiadaceae family to be tested through virtual screening molecular docking simulations for their potential inhibition of SARS-CoV-2 M pro . Almost all target compounds showed a more or equally negative docking energy score relative to the co-crystallized inhibitor X77 (S=-12.53 kcal/mol) with docking score range of (-12.55 to -19.76 kcal/mol) and so with a potent predicted binding affinity to the target enzyme. The activity of the most promising candidates was validated by in vitro testing. Arabincoside C showed the highest activity (IC 50 =35.42 μg/ml) and the highest selectivity index (SI=9.9) followed by Russelioside B (IC 50 =50.80 μg/ml), and Arabincoside B (IC 50 =53.31 μg/ml)., (© 2024 Wiley‐VHCA AG, Zurich, Switzerland.)

In this article, emulsomes (EMLs) were fabricated to encapsulate the N -(5-nitrothiazol-2-yl)-carboxamido derivatives ( 3a - 3g ) in an attempt to improve their biological availability and antiviral activity. Next, both cytotoxicity and anti-SARS-CoV-2 activities of the examined compounds loaded EMLs ( F3a - g ) were assessed in Vero E6 cells via MTT assay to calculate the CC 50 and inhibitory concentration 50 (IC 50 ) values. The most potent 3e -loaded EMLs ( F3e ) elicited a selectivity index of 18 with an IC 50 value of 0.73 μg/mL. Moreover, F3e was selected for further elucidation of a possible mode of action where the results showed that it exhibited a combination of virucidal (>90%), viral adsorption (>80%), and viral replication (>60%) inhibition. Besides, molecular docking and MD simulations towards the SARS-CoV-2 Mpro were performed. Finally, a structure-activity relationship (SAR) study focussed on studying the influence of altering the size, type, and flexibility of the α-substituent to the carboxamide in addition to compound contraction on SARS-CoV-2 activity.HighlightsEmulsomes (EMLs) were fabricated to encapsulate the N -(5-nitrothiazol-2-yl)-carboxamido derivatives ( 3a - 3g ).The most potent 3e -loaded EMLs ( F3e ) showed an IC 50 value of 0.73 μg/mL against SARS-CoV-2.F3e exhibited a combination of virucidal (>90%), viral adsorption (>80%), and viral replication (>60%) inhibition.Molecular docking, molecular dynamics (MD) simulations, and MM-GBSA calculations were performed.Structure-activity relationship (SAR) study was discussed to study the influence of altering the size, type, and flexibility of the α-substituent to the carboxamide on the anti-SARS-CoV-2 activity.

Repurposing vitamins as antiviral supporting agents is a rapid approach used to control emerging viral infections. Although there is considerable evidence supporting the use of vitamin supplementation in viral infections, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the specific role of each vitamin in defending against coronaviruses remains unclear. Antiviral activities of available vitamins on the infectivity and replication of human coronaviruses, namely, SARS-CoV-2, Middle East respiratory syndrome coronavirus (MERS-CoV), and human coronavirus 229E (HCoV-229E), were investigated using in silico and in vitro studies. We identified potential broad-spectrum inhibitor effects of Hydroxocobalamin and Methylcobalamin against the three tested CoVs. Cyanocobalamin could selectively affect SARS-CoV-2 but not MERS-CoV and HCoV-229E. Methylcobalamin showed significantly higher inhibition values on SARS-CoV-2 compared with Hydroxocobalamin and Cyanocobalamin, while Hydroxocobalamin showed the highest potent antiviral activity against MERS-CoV and Cyanocobalamin against HCoV-229E. Furthermore, in silico studies were performed for these promising vitamins to investigate their interaction with SARS-CoV-2, MERS-CoV, and HCoV-229E viral-specific cell receptors (ACE2, DPP4, and hAPN protein, respectively) and viral proteins (S-RBD, 3CL pro, RdRp), suggesting that Hydroxocobalamin, Methylcobalamin, and Cyanocobalamin may have significant binding affinity to these proteins. These results show that Methylcobalamin may have potential benefits for coronavirus-infected patients.

The evolution of a safe and effective therapeutic system to conquer SAR-CoV-2 infection deemed to be a crucial worldwide demand. Curcumin (CUR) is a phytomedicinal polyphenolic drug that exhibited a well-reported anti-SAR-CoV-2. However, the therapeutic activity of CUR is hindered by its poor intestinal permeability and diminished aqueous solubility. Therefore, this study strived to develop D-alpha-tocopheryl polyethylene glycol succinate (TPGS) bilosomes (TPGS-Bs) adopting 2 3 full factorial designs to improve solubility and intestinal permeability of CUR, hence boosting its anti-SARS-CoV-2 activity. Eight experimental runs were attained considering three independent variables: soybean phosphatidylcholine amount (mg) (SPC amount), bile salt amount (mg) (BS amount), and TPGS amount (mg). The optimum formula (F4) exhibited EE % (88.5 ± 2.4 %), PS (181.5 ± 21.6 nm), and ZP (-34.5 ± 3.7 mV) with desirability value = 0.739 was picked as an optimum formula. Furthermore, the optimum formula (F4) was extra coated with chitosan (CS) to improve permeability and anti-SAR-CoV-2 activity. Caco-2 cell uptake after 2 hr revealed the superiority of CS-F4 and F4 by 6 and 5 folds relative to CUR dispersion, respectively. Furthermore, CS-F4 exhibited a significantly higher anti-SARS-CoV-2 activity with IC 50 (0.24 µg/ml) by 8.3 times than F4 (1.99 µg/ml). Besides, the mechanistic study demonstrated that the two formulae imparted antiviral activity by inhibiting the spike protein by virucidal potentialities. In addition, the conducted molecular docking and MD simulations towards the SARS-CoV-2 M pro enzyme confirmed the interaction of CUR with key residues of the virus enzymes. Based on the preceded, CS-F4 could be assumed to be used to effectively eradicate SARS-CoV-2 infection., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Ricinus communis L. is a medicinal plant that displays valuable pharmacological properties, including antioxidant, antimicrobial, analgesic, antibacterial, antiviral and anti-inflammatory properties. This study targeted to isolate and identify some constituents of R. communis leaves using ultra-performance liquid chromatography coupled with mass spectroscopy (UPLC-MS/MS) and different chromatographic techniques. In vitro anti-MERS and anti-SARS-CoV-2 activity for different fractions and for two pure isolated compounds, lupeol (RS) and ricinine (RS1) were evaluated using a plaque reduction assay with three different mechanisms and IC 50 based on their cytotoxic concentration (CC 50 ) from an MTT assay using Vero E6 cell line. Isolated phytoconstituents and remdesivir are assessed for in-silico anti-COVID-19 activity using molecular docking tools. The methylene chloride extract showed pronounced virucidal activity against SARS-CoV-2 (IC 50  = 1.76 μg/ml). It was also shown that ricinine had superior potential activity against SARS-CoV-2, (IC 50  = 2.5 μg/ml). Lupeol displayed the most potency against MERS, (IC 50  = 5.28 μg/ml). Ricinine appeared to be the most biologically active compound. The study showed that R. communis and its isolated compounds have potential natural virucidal activity against SARS-COV-2; however, additional exploration is necessary and study for their in vivo activity., (© 2023 Walter de Gruyter GmbH, Berlin/Boston.)

The recent pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has opened the door to potential threats of the respiratory system. The discovery of drugs from natural sources is one of the most important strategies for treating the upper respiratory tract. In this study, we investigated the selected formulated EOs activities against Gram-negative (E. coli, K. pneumonia, and P. aeruginosa ) and Gram-positive ( S. aureus, E. fecalis ) bacteria and against the SARS-CoV-2 virus, with the mode of action investigated as anti-SARS-CoV-2. Cinnamomum zeylanicum and Syzygium aromaticum EOs were the most promising antibacterial oils. C. zeylanicum EO showed MIC values of 1, 1, 2, ≤0.5, and 8 µg/mL against E. coli , K. pneumoniae, P. aeruginosa, S. aureus, and E. fecalis , respectively, while S. aromaticum EO showed MIC values of 8, 4, 32, 8, 32 µg/mL against the same organisms. The cytotoxic activity of the oil samples was tested in VERO-E6 cells using (MTT) assay and showed that the safest oil was F. vulgare , then L. nobilis , C. carvi , S. aromaticum , and E. globulus . The most potent antiviral EOs were C. zeylanicum oil and S. aromaticum , with IC 50 value of 15.16 and 96.5 µg/mL, respectively. Moreover, the safety index of S. aromaticum EO (26.3) was greater than the oil of C. zeylanicum (7.25). The mechanism by which C. zeylanicum oil exerts its antiviral activity may involve both the virucidal effect and its impact on viral reproduction. The nano-emulsion dosage form of the potent EOs was prepared and re-examined against the same bacterial and viral strains. Finally, the chemical characterization of these promising essential oils was analyzed and identified using the GC-MS approach. To the best of our knowledge, this is the first report concerning the in vitro investigation of anti-SARS-CoV-2 activity of these selected essential oils, along with a proposed mechanism for the potent oil's activity., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Author(s).)

In the current investigation, two novel series of (tetrahydro)thioquinazoline- N -arylacetamides and (tetrahydro)thioquinazoline- N -arylacetohydrazides were designed, synthesized and investigated for their antiviral activity against SARS-CoV-2. The thioquinazoline- N -arylacetamide 17g as well as the tetrahydrothioquinazoline- N -arylacetohydrazides 18c and 18f showed potent antiviral activity with IC 50 of 21.4, 38.45 and 26.4 µM, respectively. In addition, 18c and 18f demonstrated potential selectivity toward the SARS-CoV-2 over the host cells with SI of 10.67 and 16.04, respectively. Further evaluation of the mechanism of action of the three derivatives 17g, 18c , and 18f displayed that they can inhibit the virus at the adsorption as well as at the replication stages, in addition to their virucidal properties. In addition, 17g, 18c , and 18f demonstrated satisfactory physicochemical properties as well as drug-likeness properties to be further optimized for the discovery of novel antiviral agents. The docking simulation on M pro binding site predicted the binding pattern of the target compounds rationalizing their differential activity based on their hydrophobic interaction and fitting in the hydrophobic S2 subsite of the binding site., Competing Interests: The authors have no conflict of interest to declare., (© 2022 Elsevier B.V. All rights reserved.)

Active surveillance and studying the virological features of avian-origin influenza viruses are essential for early warning and preparedness for the next potential pandemic. During our active surveillance of avian influenza viruses in wild birds in Egypt in the period 2014-2017, multiple reassortant low-pathogenic avian influenza H7N3 viruses were isolated. In this study, we investigated and compared the infectivity, pathogenicity, and transmission of four different constellation forms of Egyptian H7N3 viruses in chickens and mice and assessed the sensitivity of these viruses to different commercial antiviral drugs in vitro. Considerable variation in virus pathogenicity was observed in mice infected with different H7N3 viruses. The mortality rate ranged from 20 to 100% in infected mice. Infected chickens showed only ocular clinical signs at three days postinfection as well as systemic viral infection in different organs. Efficient virus replication and transmission in chickens was observed within each group, indicating that these subtypes can spread easily from wild birds to poultry without prior adaptation. Mutations in the viral proteins associated with antiviral drug resistance were not detected, and all strains were sensitive to the antiviral drugs tested. In conclusion, all of the viruses studied had the ability to infect mice and chickens. H7N3 viruses circulating among wild birds in Egypt could threaten poultry production and public health., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Multiple incursions of different subtypes of highly pathogenic avian influenza (HPAI) A/H5NX viruses have caused widely considerable outbreaks in poultry and hundreds of human infections. Extensive reassortment events associated with currently circulating clade 2.3.4.4b of A/H5NX viruses have been widely recorded. Wild migratory birds contribute to the spillover of diverse viruses throughout their migration flyways. During our active surveillance of avian influenza in Egypt, we successfully isolated and fully characterized HPAI A/H5N5 virus of clade 2.3.4.4b that was detected in a healthy purple heron. The Egyptian H5N5 virus is genotypically similar with the same subtype that was detected in the far east of Russia and several European countries. The antigenic analysis showed that the Egyptian H5N5 virus is distinct from HPAI A(H5N8) viruses in Egypt. The virus preferentially binds to avian-like receptors rather than human-like receptors. Our results showed that the virus caused 100% and 60% lethality in chicken and mice respectively. Increasing active surveillance efforts, monitoring the dynamics of emerging AIVs, and risk assessment implementation should be globally applied especially in hot spot regions like Egypt., Competing Interests: Declaration of competing interest The authors declare no competing interest., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The COVID-19 pandemic caused a huge health crisis all over the globe. SARS-CoV-2 is the virus responsible for the disease and it is highly contagious leaving millions of confirmed infected cases and a dangerous death toll. Carica papaya is a tropical plant known for its antiviral activity since it possesses different classes of compounds that are believed to combat various viral classes. In this study, the extracts prepared from C. papaya leaves cultivated in Egypt were evaluated for their anti-SARS-CoV-2 activity using crystal violet assay and for their cytotoxicity through MTT assay. The total methanolic extract, n -hexane, ethyl acetate, and n -butanol fractions of papaya leaves were used in the study and the results revealed that the n -hexane fraction has a high anti-SARS-CoV-2 activity with an IC 50 value = 1.98 μg mL -1 . Moreover, it also showed a high selectivity index value = 104.7. Dereplication of the secondary metabolites in the crude methanolic extract of C. papaya leaves revealed the presence of different classes of compounds including sterols, terpenes, fatty acid, alkaloids and flavonoids that are known to possess antiviral activities against various classes of viruses. The current study was assisted by molecular docking, molecular dynamics simulation and MM-PBSA calculations for the annotated compounds against 6 SARS-CoV-2 target proteins. The results of these in silico -based investigations showed high to moderate binding on the targeted proteins. This postulation may instigate further research studies concerning the compounds responsible for this high anti-SARS-CoV-2 activity of the n -hexane fraction of C. papaya leaves., Competing Interests: The authors declare that they have no conflicts of interests., (This journal is © The Royal Society of Chemistry.)

The anti-MERS-CoV activities of three medicinal plants (Azadirachta indica, Artemisia judaica, and Sophora tomentosa) were evaluated. The highest viral inhibition percentage (96%) was recorded for S. tomentosa. Moreover, the mode of action for both S. tomentosa and A. judaica showed 99.5% and 92% inhibition, respectively, with virucidal as the main mode of action. Furthermore, the anti-MERS-CoV and anti-SARS-CoV-2 activities of S. tomentosa were measured. Notably, the anti-SARS-CoV-2 activity of S. tomentosa was very high (100%) and anti-MERS-CoV inhibition was slightly lower (96%). Therefore, the phytochemical investigation of the very promising S. tomentosa L. led to the isolation and structural identification of nine compounds (1−9). Then, both the CC50 and IC50 values for the isolated compounds against SARS-CoV-2 were measured. Compound 4 (genistein 4’-methyl ether) achieved superior anti-SARS-CoV-2 activity with an IC50 value of 2.13 µm. Interestingly, the mode of action of S. tomentosa against SARS-CoV-2 showed that both virucidal and adsorption mechanisms were very effective. Additionally, the IC50 values of S. tomentosa against SARS-CoV-2 and MERS-CoV were found to be 1.01 and 3.11 µg/mL, respectively. In addition, all the isolated compounds were subjected to two separate molecular docking studies against the spike (S) and main protease (Mpr°) receptors of SARS-CoV-2.

In this article, 34 anticoagulant drugs were screened in silico against the main protease (M pro ) of SARS-CoV-2 using molecular docking tools. Idraparinux, fondaparinux, eptifibatide, heparin, and ticagrelor demonstrated the highest binding affinities towards SARS-CoV-2 M pro . A molecular dynamics study at 200 ns was also carried out for the most promising anticoagulants to provide insights into the dynamic and thermodynamic properties of promising compounds. Moreover, a quantum mechanical study was also conducted which helped us to attest to some of the molecular docking and dynamics findings. A biological evaluation (in vitro) of the most promising compounds was also performed by carrying out the MTT cytotoxicity assay and the crystal violet assay in order to assess inhibitory concentration 50 (IC 50 ). It is worth noting that ticagrelor displayed the highest intrinsic potential for the inhibition of SARS-CoV-2 with an IC 50 value of 5.60 µM and a safety index of 25.33. In addition, fondaparinux sodium and dabigatran showed promising inhibitory activities with IC 50 values of 8.60 and 9.40 µM, respectively, and demonstrated safety indexes of 17.60 and 15.10, respectively. Moreover, the inhibitory potential of the SARS-CoV-2 M pro enzyme was investigated by utilizing the SARS-CoV-2 M pro assay and using tipranavir as a reference standard. Interestingly, promising SARS-CoV-2 M pro inhibitory potential was attained for fondaparinux sodium with an IC 50 value of 2.36 µM, surpassing the reference tipranavir (IC 50 = 7.38 µM) by more than three-fold. Furthermore, highly eligible SARS-CoV-2 M pro inhibitory potential was attained for dabigatran with an IC 50 value of 10.59 µM. Finally, an SAR was discussed, counting on the findings of both in vitro and in silico approaches.

The search for an effective anti-viral to inhibit COVID-19 is a challenge for the specialized scientific research community. This work investigated the anti-coronavirus activity for spirooxindole-based phenylsulfone cycloadducts in a single and combination protocols. The newly designed anti-SARS-CoV-2 therapeutics spirooxindoles synthesized by [3 + 2] cycloaddition reactions represent an efficient approach. One-pot multicomponent reactions between phenyl vinyl sulfone, substituted isatins, and amines afforded highly stereoselective anti-SARS-CoV-2 therapeutics spirooxindoles with three stereogenic centers. Herein, the newly synthesized spirooxindoles were assessed individually against the highly pathogenic human coronaviruses and proved to be highly potent and safer. Interestingly, the synergistic effect by combining the potent, tested spirooxindoles resulted in an improved antiviral activity as well as better host-cell safety. Compounds 4i and 4d represented the most potent activity against MERS-CoV with IC 50 values of 11 and 23 µM, respectively. Both compounds 4c and 4e showed equipotent activity with the best IC 50 against SARS-CoV-2 with values of 17 and 18 µM, respectively, then compounds 4d and 4k with IC 50 values of 24 and 27 µM, respectively. Then, our attention oriented to perform a combination protocol as anti-SARS-CoV-2 for the best compounds with a different binding mode and accompanied with different pharmacophores. Combination of compound 4k with 4c and combination of compounds 4k with 4i proved to be more active and safer. Compounds 4k with 4i displayed IC 50 = 3.275 µM and half maximal cytotoxic-concentration CC 50 = 11832 µM. MD simulation of the most potential compounds as well as in silico ADMET properties were investigated. This study highlights the potential drug-like properties of spirooxindoles as a cocktail anti-coronavirus protocol.

A series of 1″-(alkylsulfonyl)-dispiro[indoline-3,2'-pyrrolidine-3',3″-piperidine]-2,4″-diones 6a‒o has been synthesized through regioselective multi-component azomethine dipolar cycloaddition reaction of 1-(alkylsulfonyl)-3,5-bis(ylidene)-piperidin-4-ones 3a‒h. X-ray diffraction studies (6b‒d,h) confirmed the structures. The majority of the synthesized analogs reveal promising antiproliferation properties against a variety of human cancer cell lines (MCF7, HCT116, A431 and PaCa2) with good selectivity index towards normal cell (RPE1). Some of the synthesized agents exhibit potent inhibitory properties against the tested cell lines with higher efficacies than the standard references (sunitinib and 5-fluorouracil). Compound 6m is the most potent. Multi-targeted inhibitory properties against EGFR and VEGFR-2 have been observed for the synthesized agents. Flow cytometry supports the antiproliferation properties and shows the tested agents as apoptosis and necrosis forming. Vero cell viral infection model demonstrates the anti-SARS-CoV-2 properties of the synthesized agents. Compound 6f is the most promising (about 3.3 and 4.8 times the potency of the standard references, chloroquine and hydroxychloroquine). QSAR models explain and support the observed biological properties., (© 2022. The Author(s).)

During the current coronavirus disease 2019 (COVID-19) pandemic, symptoms of depression are commonly documented among both symptomatic and asymptomatic quarantined COVID-19 patients. Despite that many of the FDA-approved drugs have been showed anti-SARS-CoV-2 activity in vitro and remarkable efficacy against COVID-19 in clinical trials, no pharmaceutical products have yet been declared to be fully effective for treating COVID-19. Antidepressants comprise five major drug classes for the treatment of depression, neuralgia, migraine prophylaxis, and eating disorders which are frequently reported symptoms in COVID-19 patients. Herein, the efficacy of eight frequently prescribed FDA-approved antidepressants on the inhibition of both SARS-CoV-2 and MERS-CoV was assessed. Additionally, the in vitro anti-SARS-CoV-2 and anti-MERS-CoV activities were evaluated. Furthermore, molecular docking studies have been performed for these drugs against the spike (S) and main protease (M pro ) pockets of both SARS-CoV-2 and MERS-CoV. Results showed that Amitriptyline, Imipramine, Paroxetine, and Sertraline had potential anti-viral activities. Our findings suggested that the aforementioned drugs deserve more in vitro and in vivo studies targeting COVID-19 especially for those patients suffering from depression., (© 2022. The Author(s).)

From 2010 to 2013, genotype I avian influenza A(H9N2) viruses of the G1-lineage were isolated from several poultry species in Egypt. In 2014, novel reassortant H9N2 viruses were detected in pigeons designated as genotype II. To monitor the subsequent genetic evolution of Egyptian A(H9N2) viruses, we characterized the full genomes of 173 viruses isolated through active surveillance from 2017 to 2022. In addition, we compared the virological characteristics and pathogenicity of representative viruses. Phylogenetic analysis of the HA indicated that all studied sequences from 2017-2021 were grouped into G1-like H9N2 viruses previously detected in Egypt. Phylogenetic analysis indicated that the Egyptian A(H9N2) viruses had undergone further reassortment, inheriting four genes (PB2, PB1, PA, NS) from genotype II, with their remaining segments deriving from genotype I viruses (these viruses designated as genotype III). Studying the virological features of the two most dominant genotypes (I and III) of Egyptian H9N2 viruses in vitro and in vivo indicated that both replicated well in mammalian cells, but did not show any clinical signs in chickens, ducks, and mice. Monitoring avian influenza viruses through surveillance programs and understanding the genetic and antigenic characteristics of circulating H9N2 viruses are essential for risk assessment and influenza pandemic preparedness.

There is an urgent need to develop and synthesize new anti-influenza drugs with activity against different strains, resistance to mutations, and suitability for various populations. Herein, we tested in vitro and in vivo the antiviral activity of new 1,2,3-triazole glycosides incorporating benzimidazole, benzooxazole, or benzotriazole cores synthesized by using a click approach. The Cu-catalyzation strategy consisted of 1,3-dipolar cycloaddition of the azidoalkyl derivative of the respective heterocyclic and different glycosyl acetylenes with five or six carbon sugar moieties. The antiviral activity of the synthesized glycosides against wild-type and neuraminidase inhibitor resistant strains of the avian influenza H5N1 and human influenza H1N1 viruses was high in vitro and in mice. Structure-activity relationship studies showed that varying the glycosyl moiety in the synthesized glycosides enhanced antiviral activity. The compound (2 R ,3 R ,4 S ,5 R )-2-((1-(Benzo[d]thiazol-2-ylmethyl)-1 H -1,2,3-triazol-4-yl)methoxy)tetrahydro-2 H -pyran-3,4,5-triyl triacetate (Compound 9c ) had a 50% inhibitory concentration (IC 50 ) = 2.280 µM and a ligand lipophilic efficiency (LLE) of 6.84. The compound (2 R ,3 R ,4 S ,5 R )-2-((1-((1 H -Benzo[d]imidazol-2-yl)methyl)-1 H -1,2,3-triazol-4-yl)methoxy)tetrahydro-2 H -pyran-3,4,5-triyl triacetate had IC 50 = 2.75 µM and LLE = 7.3 after docking analysis with the H5N1 virus neuraminidase. Compound 9c achieved full protection from H1N1 infection and 80% protection from H5N1 in addition to a high binding energy with neuraminidase and was safe in vitro and in vivo. This compound is suitable for further clinical studies as a new neuraminidase inhibitor.

Several natural products recovered from a marine-derived Aspergillus niger were tested for their inhibitory activity against SARS CoV-2 in vitro. Aurasperone A ( 3 ) was found to inhibit SARS CoV-2 efficiently (IC 50 = 12.25 µM) with comparable activity with the positive control remdesivir (IC 50 = 10.11 µM). Aurasperone A exerted minimal cytotoxicity on Vero E6 cells (CC 50 = 32.36 mM, SI = 2641.5) and it was found to be much safer than remdesivir (CC 50 = 415.22 µM, SI = 41.07). To putatively highlight its molecular target, aurasperone A was subjected to molecular docking against several key-viral protein targets followed by a series of molecular dynamics-based in silico experiments that suggested M pro to be its primary viral protein target. More potent anti-SARS CoV-2 M pro inhibitors can be developed according to our findings presented in the present investigation.

Seasonal human influenza is a serious respiratory infection caused by influenza viruses that can be found all over the world. Type A influenza is a contagious viral infection that, if left untreated, can lead to life-threatening consequences. Fortunately, the plant kingdom has many potent medicines with broad-spectrum antiviral activity. Herein, six plant constituents, namely Tanshinone IIA 1, Carnosic acid 2, Rosmarinic acid 3, Glycyrrhetinic acid 4, Baicalein 5, and Salvianolic acid B 6, were screened for their antiviral activities against H1N1 virus using in vitro and in silico approaches. Hence, their anti-influenza activities were tested in vitro to determine inhibitory concentration 50 (IC 50 ) values after measuring their CC 50 values using MTT assay on MDCK cells. Interestingly, Tanshinone IIA (TAN) 1 was the most promising member with CC 50  = 9.678 μg/ml. Moreover, the plaque reduction assay carried on TAN 1 revealed promising viral inhibition percentages of 97.9%, 95.8%, 94.4%, and 91.7% using concentrations 0.05 μg/μl, 0.025 μg/μl, 0.0125 μg/μl, and 0.006 μg/μl, respectively. Furthermore, in silico molecular docking disclosed the superior affinities of Salvianolic acid B (SAL) 6 towards both surface glycoproteins of influenza A virus (namely, hemagglutinin (HA) and neuraminidase (NA)). The docked complexes of both SAL and TAN inside HA and NA receptor pockets were selected for 100 ns MD simulations followed by MM-GBSA binding free energy calculation to confirm the docking results and give more insights regarding the stability of both compounds inside influenza mentioned receptors, respectively. The selection criteria of the previously mentioned complexes were based on the fact that SAL showed the highest docking scores on both viral HA and NA glycoproteins whereas TAN achieved the best inhibitory activity on the other hand. Finally, we urge more advanced preclinical and clinical research, particularly for TAN, which could be used to treat the human influenza A virus effectively., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The outbreak of coronavirus disease-2019, caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a worldwide emerging crisis. Polyphenols are a class of herbal metabolites with a broad-spectrum antiviral activity. However, most polyphenols encounter limited efficacy due to their poor solubility and degradation in neutral and basic environments. Thus, the effectiveness of their pharmaceutical application is critically dependent on the delivery systems to overcome the aforementioned drawbacks. Herein, Polyphenols-rich Cuphea ignea extract was prepared and its constituents were identified and quantified. Molecular docking was conducted for 15 compounds in the extract against SARS-CoV-2 main protease, among which rutin, myricetin-3- O -rhamnoside and rosmarinic acid depicted the most promising antiviral activity. Further, a self-nanoemulsifying formulation, composed of 10% oleic acid, 40% tween 20 and propylene glycol 50%, was prepared to improve the solubility of the extract components and enable its concurrent delivery permitting combined potency. Upon dilution with aqueous phases, the formulation rapidly Formsnanoemulsion of good stability and excellent dissolution profile in acidic pH when compared to the crude extract. It inhibited SARS-CoV-2 completely in vitro at a concentration as low as 5.87 μg/mL presenting a promising antiviral remedy for SARS-CoV-2, which may be attributed to the possible synergism between the extract components., Competing Interests: This work has been submitted for patent application to patent office Academy of Scientific Research and Technology, Egypt under number 2020/1698., (© 2021 Elsevier B.V. All rights reserved.)

We have discovered a family of synthetic oxazole-based macrocycles to be active against SARS-CoV-2. The synthesis, pharmacological properties, and docking studies of the compounds are reported in this study. The structure of the new macrocycles was confirmed by NMR spectroscopy and mass spectrometry. Compounds 13, 14, and 15a-c were evaluated for their anti-SARS-CoV-2 activity on SARS-COV-2 (NRC-03-nhCoV) virus in Vero-E6 cells. Isopropyl triester 13 and triacid 14 demonstrated superior inhibitory activities against SARS-CoV-2 compared to carboxamides 15a-c. MTT cytotoxicity assays showed that the CC 50 (50% cytotoxicity concentration) of 13, 14, and 15a-c ranged from 159.1 to 741.8 μM and their safety indices ranged from 2.50 to 39.1. Study of the viral inhibition via different mechanisms of action (viral adsorption, replication, or virucidal property) showed that 14 had mild virucidal (60%) and inhibitory effects on virus adsorption (66%) at 20 μM concentrations. Compound 13 displayed several inhibitory effects at three levels, but the potency of its action is primarily virucidal. The inhibitory activity of compounds 13, 14, and 15a-c against the enzyme SARS-CoV-2 M pro was evaluated. Isopropyl triester 13 had a significant inhibition activity against SARS-CoV-2 M pro with an IC 50 of 2.58 µM. Large substituents on the macrocyclic template significantly reduced the inhibitory effects of the compounds. Study of the docking of the compounds in the SARS CoV-2-M pro active site showed that the most potent macrocycles 13 and 14 exhibited the best fit and highest affinity for the active site binding pocket. Taken together, the present study shows that the new macrocyclic compounds constitute a new family of SARS CoV-2-M pro inhibitors that are worth being further optimized and developed., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Sets of 3-alkenyl-2-oxindoles (6,10,13) were synthesized in a facile synthetic pathway through acid dehydration (EtOH/HCl) of the corresponding 3-hydroxy-2-oxoindolines (5,9,12). Single crystal (10a,c) and powder (12a,26f) X-ray studies supported the structures. Compounds 6c and 10b are the most effective agents synthesized (about 3.4, 3.3 folds, respectively) against PaCa2 (pancreatic) cancer cell line relative to the standard reference used (Sunitinib). Additionally, compound 10b reveals antiproliferative properties against MCF7 (breast) cancer cell with IC 50 close to that of Sunitinib. CAM testing reveals that compounds 6 and 10 demonstrated qualitative and quantitative decreases in blood vessel count and diameter with efficacy comparable to that of Sunitinib, supporting their anti-angiogenic properties. Kinase inhibitory properties support their multi-targeted inhibitory activities against VEGFR-2 and c-kit in similar behavior to that of Sunitinib. Cell cycle analysis studies utilizing MCF7 exhibit that compound 6b arrests the cell cycle at G1/S phase while, 10b reveals accumulation of the tested cell at S phase. Compounds 6a and 10b reveal potent antiviral properties against SARS-CoV-2 with high selectivity index relative to the standards (hydroxychloroquine, chloroquine). Safe profile of the potent synthesized agents, against normal cells (VERO-E6, RPE1), support the possible development of better hits based on the attained observations., (Copyright © 2021. Published by Elsevier Inc.)

Six compounds namely, tanshinone IIA (1), carnosic acid (2), rosmarinic acid (3), salvianolic acid B (4), baicalein (5), and glycyrrhetinic acid (6) were screened for their anti-SARS-CoV-2 activities against both the spike (S) and main protease (Mpro) receptors using molecular docking studies. Molecular docking recommended the superior affinities of both salvianolic acid B (4) and glycyrrhetinic acid (6) as the common results from the previously published computational articles. On the other hand, their actual anti-SARS-CoV-2 activities were tested in vitro using plaque reduction assay to calculate their IC 50 values after measuring their CC 50 values using MTT assay on Vero E6 cells. Surprisingly, tanshinone IIA (1) was the most promising member with IC 50 equals 4.08 ng μl -1 . Also, both carnosic acid (2) and rosmarinic acid (3) showed promising IC 50 values of 15.37 and 25.47 ng μl -1 , respectively. However, salvianolic acid (4) showed a weak anti-SARS-CoV-2 activity with an IC 50 value equals 58.29 ng μl -1 . Furthermore, molecular dynamics simulations for 100 ns were performed for the most active compound from the computational point of view (salvianolic acid 4), besides, the most active one biologically (tanshinone IIA 1) on both the S and Mpro complexes of them (four different molecular dynamics processes) to confirm the docking results and give more insights regarding the stability of both compounds inside the SARS-CoV-2 mentioned receptors, respectively. Also, to understand the mechanism of action for the tested compounds towards SARS-CoV-2 inhibition it was necessary to examine the mode of action for the most two promising compounds, tanshinone IIA (1) and carnosic acid (2). Both compounds (1 and 2) showed very promising virucidal activity with a most prominent inhibitory effect on viral adsorption rather than its replication. This recommended the predicted activity of the two compounds against the S protein of SARS-CoV-2 rather than its Mpro protein. Our results could be very promising to rearrange the previously mentioned compounds based on their actual inhibitory activities towards SARS-CoV-2 and to search for the reasons behind the great differences between their in silico and in vitro results against SARS-CoV-2. Finally, we recommend further advanced preclinical and clinical studies especially for tanshinone IIA (1) to be rapidly applied in COVID-19 management either alone or in combination with carnosic acid (2), rosmarinic acid (3), and/or salvianolic acid (4)., Competing Interests: The authors declare no conflict of interest., (This journal is © The Royal Society of Chemistry.)

Until now, there has been no direct evidence of the effectiveness of repurposed FDA-approved drugs against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infections. Although curcumin, hesperidin, and quercetin have broad spectra of pharmacological properties, their antiviral activities against SARS-CoV-2 remain unclear. Our study aimed to assess the in vitro antiviral activities of curcumin, hesperidin, and quercetin against SARS-CoV-2 compared to hydroxychloroquine and determine their mode of action. In Vero E6 cells, these compounds significantly inhibited virus replication, mainly as virucidal agents primarily indicating their potential activity at the early stage of viral infection. To investigate the mechanism of action of the tested compounds, molecular docking studies were carried out against both SARS-CoV-2 spike (S) and main protease (Mpro) receptors. Collectively, the obtained in silico and in vitro findings suggest that the compounds could be promising SARS-CoV-2 Mpro inhibitors. We recommend further preclinical and clinical studies on the studied compounds to find a potential therapeutic targeting COVID-19 in the near future.

In late December 2019, a novel coronavirus, namely severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), escaped the animal-human interface and emerged as an ongoing global pandemic with severe flu-like illness, commonly known as coronavirus disease 2019 (COVID-19). In this study, a molecular docking study was carried out for seventeen ( 17 ) structural analogues prepared from natural maslinic and oleanolic acids, screened against SARS-CoV-2 main protease. Furthermore, we experimentally validated the virtual data by measuring the half-maximal cytotoxic and inhibitory concentrations of each compound. Interestingly, the chlorinated isoxazole linked maslinic acid (compound 17 ) showed promising antiviral activity at micromolar non-toxic concentrations. Thoughtfully, we showed that compound 17 mainly impairs the viral replication of SARS-CoV-2. Furthermore, a very promising SAR study for the examined compounds was concluded, which could be used by medicinal chemists in the near future for the design and synthesis of potential anti-SARS-CoV-2 candidates. Our results could be very promising for performing further additional in vitro and in vivo studies on the tested compound ( 17 ) before further licensing for COVID-19 treatment.

Since the emergence of the SARS-CoV-2 pandemic in 2019, it has remained a significant global threat, especially with the newly evolved variants. Despite the presence of different COVID-19 vaccines, the discovery of proper antiviral therapeutics is an urgent necessity. Nature is considered as a historical trove for drug discovery, especially in global crises. During our efforts to discover potential anti-SARS CoV-2 natural therapeutics, screening our in-house natural products and plant crude extracts library led to the identification of C. benedictus extract as a promising candidate. To find out the main chemical constituents responsible for the extract's antiviral activity, we utilized recently reported SARS CoV-2 structural information in comprehensive in silico investigations (e.g., ensemble docking and physics-based molecular modeling). As a result, we constructed protein-protein and protein-compound interaction networks that suggest cnicin as the most promising anti-SARS CoV-2 hit that might inhibit viral multi-targets. The subsequent in vitro validation confirmed that cnicin could impede the viral replication of SARS CoV-2 in a dose-dependent manner, with an IC 50 value of 1.18 µg/mL. Furthermore, drug-like property calculations strongly recommended cnicin for further in vivo and clinical experiments. The present investigation highlighted natural products as crucial and readily available sources for developing antiviral therapeutics. Additionally, it revealed the key contributions of bioinformatics and computer-aided modeling tools in accelerating the discovery rate of potential therapeutics, particularly in emergency times like the current COVID-19 pandemic.

Since its emergence in 2014, the highly pathogenic avian influenza H5N8 virus has continuously and rapidly spread worldwide in the poultry sector resulting in huge economic losses. A typical inactivated H5N8 vaccine is prepared using the six internal genes from A/PR8/1934 (H1N1) and the two major antigenic proteins (HA and NA) from the circulating H5N8 strain with the HA modified to a low pathogenic form (PR8 HA/NA-H5N8 ). The contribution of the other internal proteins from H5N8, either individually or in combination, to the overall protective efficacy of PR8-based H5N8 vaccine has not been investigated. Using reverse genetics, a set of PR8-based vaccines expressing the individual proteins from an H5N8 strain were rescued and compared to the parent PR8 and low pathogenic H5N8 strains and the commonly used PR8 HA/NA-H5N8 . Except for the PR8-based vaccine strains expressing the HA of H5N8, none of the rescued combinations could efficiently elicit virus-neutralizing antibodies. Compared to PR8, the non-HA viral proteins provided some protection to infected chickens six days post infection. We assume that this late protection was related to cell-based immunity rather than antibody-mediated immunity. This may explain the slight advantage of using full low pathogenic H5N8 instead of PR8 HA/NA-H5N8 to improve protection by both the innate and the humoral arms of the immune system.

SARS-CoV-2 virus is transmitted in closed settings to people in contact with COVID-19 patients such as healthcare workers and household contacts. However, household person-to-person transmission studies are limited. Households participating in an ongoing cohort study of influenza incidence and prevalence in rural Egypt were followed. Baseline enrollment was done from August 2015 to March 2017. The study protocol was amended in April 2020 to allow COVID-19 incidence and seroprevalence studies. A total of 290 households including 1598 participants were enrolled and followed from April to October 2020 in four study sites. When a participant showed respiratory illness symptoms, a serum sample and a nasal and an oropharyngeal swab were obtained. Swabs were tested by RT-PCR for SARS-CoV-2 infection. If positive, the subject was followed and swabs collected on days three, six, nine, and 14 after the first swab day and a serum sample obtained on day 14. All subjects residing with the index case were swabbed following the same sampling schedule. Sera were collected from cohort participants in October 2020 to assess seroprevalence. Swabs were tested by RT-PCR. Sera were tested by Microneutralization Assay to measure the neutralizing antibody titer. Incidence of COVID-19, household secondary attack rate, and seroprevalence in the cohort were determined. The incidence of COVID-19 was 6.9% and the household secondary attack rate was 89.8%. Transmission within households occurred within two-days of confirming the index case. Infections were asymptomatic or mild with symptoms resolving within 10 days. The majority developed a neutralizing antibody titer by day 14 post onset. The overall seroprevalence among cohort participants was 34.8%. These results suggest that within-household transmission is high in Egypt. Asymptomatic or mild illness is common. Most infections seroconvert and have a durable neutralizing antibody titer., Competing Interests: The authors have declared that no competing interests exist.

Since the emergence of SARS-CoV-2 at the end of 2019, 64 candidate vaccines are in clinical development and 173 are in the pre-clinical phase. Five types of vaccines are currently approved for emergency use in many countries (Inactivated, Sinopharm; Viral-vector, Astrazeneca, and Gamaleya Research Institute; mRNA, Moderna, and BioNTech/Pfizer). The main challenge in this pandemic was the availability to produce an effective vaccine to be distributed to the world's population in a short time. Herein, we developed a whole virus NRC-VACC-01 inactivated candidate SARS-CoV-2 vaccine and tested its safety and immunogenicity in laboratory animals. In the preclinical studies, we used four experimental animals (mice, rats, guinea pigs, and hamsters). Antibodies were detected as of week three post vaccination and continued up to week ten in the four experimental models. Safety evaluation of NRC-VACC-01 inactivated candidate vaccine in rats revealed that the vaccine was highly tolerable. By studying the effect of booster dose in the immunological profile of vaccinated mice, we observed an increase in neutralizing antibody titers after the booster shot, thus a booster dose was highly recommended after week three or four. Challenge infection of hamsters showed that the vaccinated group had lower morbidity and shedding than the control group. A phase I clinical trial will be performed to assess safety in human subjects.

(1) Background: Drug repositioning is an unconventional drug discovery approach to explore new therapeutic benefits of existing drugs. Currently, it emerges as a rapid avenue to alleviate the COVID-19 pandemic disease. (2) Methods: Herein, we tested the antiviral activity of anti-microbial and anti-inflammatory Food and Drug Administration (FDA)-approved drugs, commonly prescribed to relieve respiratory symptoms, against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the viral causative agent of the COVID-19 pandemic. (3) Results: Of these FDA-approved antimicrobial drugs, Azithromycin, Niclosamide, and Nitazoxanide showed a promising ability to hinder the replication of a SARS-CoV-2 isolate, with IC 50 of 0.32, 0.16, and 1.29 µM, respectively. We provided evidence that several antihistamine and anti-inflammatory drugs could partially reduce SARS-CoV-2 replication in vitro. Furthermore, this study showed that Azithromycin can selectively impair SARS-CoV-2 replication, but not the Middle East Respiratory Syndrome Coronavirus (MERS-CoV). A virtual screening study illustrated that Azithromycin, Niclosamide, and Nitazoxanide bind to the main protease of SARS-CoV-2 (Protein data bank (PDB) ID: 6lu7) in binding mode similar to the reported co-crystalized ligand. Also, Niclosamide displayed hydrogen bond (HB) interaction with the key peptide moiety GLN: 493A of the spike glycoprotein active site. (4) Conclusions: The results suggest that Piroxicam should be prescribed in combination with Azithromycin for COVID-19 patients.

Using convalescent plasma as immunotherapy is an old method for treatment of infectious diseases. Several countries have recently allowed the use of such therapy for the treatment of COVID-19 patients especially those who are critically ill. A similar program is currently being tested in Egypt. Here, we tested 227 plasma samples from convalescent donors in Egypt for neutralizing antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using a microneutralization (MN) assay. A third of the tested samples did not have antibody titers and 58% had titers between 1:10 and 1:80. Only 12% had titers >1:160. We also compared MN assays using different virus concentrations, plaque reduction neutralization (PRNT) assays, and a chemiluminescence assay that measures immunoglobulin G (IgG) binding to N and S proteins of SARS-CoV-2. Our results indicated that a MN assay using 100 TCID50/ml provides comparable results to PRNT and allows for high throughput testing., (Copyright © 2020 Gomaa, Kandeil, Mostafa, Roshdy, Kayed, Shehata, Kutkat, Moatasim, El Taweel, Mahmoud, Kamel, Abo Shama, El Sayes, El-Shesheny, Bakheet, Elgohary, Elbadry, Nassif, Ahmed, Abdel Messih, Kayali and Ali.)

Due to the challenges for developing vaccines in devastating pandemic situations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), developing and screening of novel antiviral agents are peremptorily demanded. Herein, we developed EGYVIR as a potent immunomodulatory herbal extract with promising antiviral activity against SARS-CoV-2. It constitutes of a combination of black pepper extract with curcumin extract. The antiviral effect of EGYVIR extract is attributed to the two key phases of the disease in severe cases. First, the inhibition of the nuclear translocation of NF-kβ p50, attenuating the SARS-CoV-2 infection-associated cytokine storm. Additionally, the EGYVIR extract has an in vitro virucidal effect for SARS-CoV-2. The in vitro study of EGYVIR extract against SARS-CoV-2 on Huh-7 cell lines, revealed the potential role of NF-kβ/TNFα/IL-6 during the infection process. EGYVIR antagonizes the NF-kβ pathway in-silico and in-vitro studies. Consequently, it has the potential to hinder the release of IL-6 and TNFα, decreasing the production of essential cytokines storm elements., Competing Interests: The authors have declared that no competing interests exist.

Anecdotal evidence showed a negative correlation between Bacille Calmette-Guérin (BCG) vaccination and incidence of COVID-19. Incidence of the disease in children is much lower than in adults. It is hypothesized that BCG and other childhood vaccinations may provide some protection against SARS-CoV-2 infection through trained or adaptive immune responses. Here, we tested whether BCG, Pneumococcal, Rotavirus, Diphtheria, Tetanus, Pertussis, Hepatitis B, Haemophilus influenzae, Hepatitis B, Meningococcal, Measles, Mumps, and Rubella vaccines provide cross-reactive neutralizing antibodies against SARS-CoV-2 in BALB/c mice. Results indicated that none of these vaccines provided antibodies capable of neutralizing SARS-CoV-2 up to seven weeks post vaccination. We conclude that if such vaccines have any role in COVID-19 immunity, this role is not antibody-mediated., Competing Interests: The authors have declared that no competing interests exist.

This report announces the complete genome sequences of two severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) isolates detected in Egypt. The isolates were obtained from oropharyngeal swab specimens from two Egyptians in Upper and Lower Egypt. Sequence analysis showed mutations that differentiate Egyptian strains from the reference strain 2019-nCoV WHU01., (Copyright © 2020 Kandeil et al.)

The surveillance and virological characterization of H5N8 avian influenza viruses are important in order to assess their zoonotic potential. The genetic analyses of the Egyptian H5N8 viruses isolated through active surveillance in wild birds and domestic poultry in the winter of 2016/2017 showed multiple introductions of reassortant viruses. In this study, we investigated and compared the growth kinetics, infectivity, and pathogenicity of the three reassortant forms of H5N8 viruses detected in wild birds and domestic poultry in Egypt during the first introduction wave in the winter of 2016/2017. Three representative H5N8 viruses (abbreviated as 813, 871, and 13666) were selected. The 871/H5N8 virus showed enhanced growth properties in vitro in Madin Darby canine kidney (MDCK) and A549 cells. Interestingly, all viruses replicated well in mice without prior adaptation. Infected C57BL/6 mice showed 20% mortality for 813/H5N8 and 60% mortality for 871/H5N8 and 13666/H5N8, which could be attributed to the genetic differences among the viruses. Studies on the pathogenicity in experimentally infected ducks revealed a range of pathogenic effects, with mortality rate ranging from 0% for 813/H5N8 and 13666/H5N8 to 28% for 871/H5N8. No significant differences were observed among the three compared viruses in infected chickens. Overall, different H5N8 viruses had variable biological characteristics, indicating a continuous need for surveillance and virus characterization efforts.

: Dromedary camels are the natural reservoirs of the Middle East respiratory syndrome coronavirus (MERS-CoV). Camels are mostly bred in East African countries then exported into Africa and Middle East for consumption. To understand the distribution of MERS-CoV among camels in North Africa and the Middle East, we conducted surveillance in Egypt, Senegal, Tunisia, Uganda, Jordan, Saudi Arabia, and Iraq. We also performed longitudinal studies of three camel herds in Egypt and Jordan to elucidate MERS-CoV infection and transmission. Between 2016 and 2018, a total of 4027 nasal swabs and 3267 serum samples were collected from all countries. Real- time PCR revealed that MERS-CoV RNA was detected in nasal swab samples from Egypt, Senegal, Tunisia, and Saudi Arabia. Microneutralization assay showed that antibodies were detected in all countries. Positive PCR samples were partially sequenced, and a phylogenetic tree was built. The tree suggested that all sequences are of clade C and sequences from camels in Egypt formed a separate group from previously published sequences. Longitudinal studies showed high seroprevalence in adult camels. These results indicate the widespread distribution of the virus in camels. A systematic active surveillance and longitudinal studies for MERS-CoV are needed to understand the epidemiology of the disease and dynamics of viral infection., Competing Interests: The authors declare no conflict of interest.

Recently, two genetically distinct influenza viruses were detected in bats in Guatemala and Peru. We conducted influenza A virus surveillance among four bat species in Egypt. Out of 1,202 swab specimens, 105 were positive by real-time PCR. A virus was successfully isolated in eggs and propagated in MDCK cells in the presence of N -tosyl-l-phenylalanine chloromethyl ketone-treated trypsin. Genomic analysis revealed that the virus was phylogenetically distinct from all other influenza A viruses. Analysis of the hemagglutinin gene suggested a common ancestry with other H9 viruses, and the virus showed a low level of cross-reactivity with serum raised against H9N2 viruses. Bats were seropositive for the isolated viruses. The virus replicated in the lungs of experimentally infected mice. While it is genetically distinct, this virus shares several avian influenza virus characteristics suggesting a more recent avian host origin. IMPORTANCE Through surveillance, we isolated and characterized an influenza A virus from Egyptian fruit bats. This virus had an affinity to avian-like receptors but was also able to infect mice. Our findings indicate that bats may harbor a diversity of influenza A viruses. Such viruses may have the potential to cross the species barrier to infect other species, including domestic birds, mammals, and, possibly, humans., (Copyright © 2019 American Society for Microbiology.)