Emerging antiviral resistance

Inhibition of influenza A virus replication by a marine derived quinolone alkaloid targeting virus nucleoprotein

Owing to the emergence of drug resistance and high morbidity and mortality, the need for novel anti-influenza A virus (IAV) drugs with divergent targets is highly sought after. Herein, a novel quinolone alkaloid (QLA) derived from marine fungus was discovered with broad-spectrum anti-IAV activities with low toxicity. Distinct from current anti-IAV drugs, QLA may block virus replication and viral RNA (vRNA) export from the nucleus by targeting virus nucleoprotein (NP). QLA can block the binding of chromosome region maintenance 1 to nuclear export signal 3 of NP to inhibit the nuclear export of NP and vRNP. QLA may also affect vRNP assembly by interfering with the binding of NP to RNA rather than NP oligomerization. Arg305 and Phe488-Gly490 may be required for the interaction between QLA and NP, and the binding pocket around these amino acids may be a promising target for anti-IAV drugs. Importantly, oral administration of QLA can protect the mice against IAV-induced death and weight loss, superior to the effects of the clinical drug oseltamivir. In summary, the marine derived compound QLA has the potential to be developed into a novel anti-IAV agent targeting virus NP protein in the future.

Searching glycolate oxidase inhibitors based on QSAR, molecular docking, and molecular dynamic simulation approaches

Primary hyperoxaluria type 1 (PHT1) treatment is mainly focused on inhibiting the enzyme glycolate oxidase, which plays a pivotal role in the production of glyoxylate, which undergoes oxidation to produce oxalate. When the renal secretion capacity exceeds, calcium oxalate forms stones that accumulate in the kidneys. In this respect, detailed QSAR analysis, molecular docking, and dynamics simulations of a series of inhibitors containing glycolic, glyoxylic, and salicylic acid groups have been performed employing different regression machine learning techniques. Three robust models with less than 9 descriptors-based on a tenfold cross (Q² _CV) and external (Q² _EXT) validation-were found i.e., MLR1 (Q² _CV = 0.893, Q² _EXT = 0.897), RF1 (Q² _CV = 0.889, Q² _EXT = 0.907), and IBK1 (Q² _CV = 0.891, Q² _EXT = 0.907). An ensemble model was built by averaging the predicted pIC₅₀ of the three models, obtaining a Q² _EXT = 0.933. Physicochemical properties such as charge, electronegativity, hardness, softness, van der Waals volume, and polarizability were considered as attributes to build the models. To get more insight into the potential biological activity of the compouds studied herein, docking and dynamic analysis were carried out, finding the hydrophobic and polar residues show important interactions with the ligands. A screening of the DrugBank database V.5.1.7 was performed, leading to the proposal of seven commercial drugs within the applicability domain of the models, that can be suggested as possible PHT1 treatment.

Evaluation of cytotoxicity and antiviral activity of Rhazya stricta Decne leaves extract against influenza A/PR/8/34 (H1N1)

Influenza viruses have developed resistance to the current classes of drugs, which means they could eventually become more virulent and cause more mortality and hospitalization. Our study aims to investigate the antiviral activity of Rhazya stricta Decne leaves extract in vitro and search for new promising drugs from R. stricta identified compounds in silico. The study was performed in vitro by utilizing Madin-Darby Canine Kidney cell line (MDCK) as a substrate for the influenza virus and estimating the inhibition performance of the plant leaves extract. Additionally, in silico screening was conducted to explore the antiviral activity of R. stricta phytochemicals. We investigated the cytotoxicity of R. stricta leaves extract and its antiviral activity against influenza virus (A/Puerto Rico/8/34 (H1N1)) using the MTT assay. The mode of action of the plant leaves extract during the viral life cycle was tested using time-of-addition assay. In silico analyses were performed, including molecular docking, drug-likeness analysis, and toxicity risk assessment, to state the leading compounds to be developed into an anti-influenza virus drug. The 50% cytotoxicity concentration of the leaves extract was CC50: 184.6 µg/mL, and the 50% inhibition concentration was CI50: 19.71 µg\mL. The time of addition assay revealed that R. stricta leaves extract exerted its activity in the late step of the influenza virus replication cycle. In comparison to Oseltamivir, the leading compounds showed better binding affinity and can be developed into oral drugs with low toxicity risk. Isolation and purification of the leading compounds and testing their antiviral activity in vitro and in vivo are required.

An Overview of Antiviral Peptides and Rational Biodesign Considerations

Viral diseases have contributed significantly to worldwide morbidity and mortality throughout history. Despite the existence of therapeutic treatments for many viral infections, antiviral resistance and the threat posed by novel viruses highlight the need for an increased number of effective therapeutics. In addition to small molecule drugs and biologics, antimicrobial peptides (AMPs) represent an emerging class of potential antiviral therapeutics. While AMPs have traditionally been regarded in the context of their antibacterial activities, many AMPs are now known to be antiviral. These antiviral peptides (AVPs) have been shown to target and perturb viral membrane envelopes and inhibit various stages of the viral life cycle, from preattachment inhibition through viral release from infected host cells. Rational design of AMPs has also proven effective in identifying highly active and specific peptides and can aid in the discovery of lead peptides with high therapeutic selectivity. In this review, we highlight AVPs with strong antiviral activity largely curated from a publicly available AMP database. We then compile the sequences present in our AVP database to generate structural predictions of generic AVP motifs. Finally, we cover the rational design approaches available for AVPs taking into account approaches currently used for the rational design of AMPs.

Design, synthesis, and biological activity of a novel series of 2-ureidonicotinamide derivatives against influenza A virus

BACKGROUND

Viral resistance to existing inhibitors and the time-dependent effectiveness of neuraminidase inhibitors have limited the number of antivirals that can be used for prophylaxis and therapeutic treatment of severe influenza infection. Thus, there is an urgent need to develop new drugs to prevent and treat influenza infection.

OBJECTIVE

The aim of this study was to design and synthesize a novel series of 2-ureidonicotinamide derivatives, and evaluate their anti-IAV activities. Furthermore, we predicted the abilities of these compounds inhibiting PA-PB1 subunit and forecasted the docking poses of these compounds with RNA polymerase protein (PDB ID 3CM8).

METHOD

The novel designed compounds were synthesized using classical methods of organic chemistry and tested in vitro for their abilities inhibiting RNP and against influenza A virus. In addition, the 23 synthesized molecules were subjected to the generated pharmacophore Hypo1 to forecast the activity target PA-PB1 subunit of RNA polymerase. The ADMET pharmacokinetic parameters were calculated by the ADMET modules in Discovery Studio 2016. The docking results helped us to demonstrate the possible interactions between these compounds with 3CM8.

RESULTS

The synthesized 2-ureidonicotinamide derivatives were characterized as potent anti-influenza inhibitors. The target compounds 7b and 7c demonstrated significant antiviral activities, and could be considered as novel lead compounds of antiviral inhibitors. In addition, compound 7b revealed suitable ADME properties expressed, and might be a significant RNA polymerase inhibitor targeting PA-PB1 subunit based on the predictable results and the docking results.

CONCLUSION

This study revealed a novel series of compounds that might be useful in the search for an effective drug against influenza virus.

Facial Synthesis and Bioevaluation of Well-Defined OEGylated Betulinic Acid-Cyclodextrin Conjugates for Inhibition of Influenza Infection

Betulinic acid (BA) and its derivatives exhibit a variety of biological activities, especially their anti-HIV-1 activity, but generally have only modest inhibitory potency against influenza virus. The entry of influenza virus into host cells can be competitively inhibited by multivalent derivatives targeting hemagglutinin. In this study, a series of hexa-, hepta- and octavalent BA derivatives based on α-, β- and γ-cyclodextrin scaffolds, respectively, with varying lengths of flexible oligo(ethylene glycol) linkers was designed and synthesized using a microwave-assisted copper-catalyzed 1,3-dipolar cycloaddition reaction. The generated BA-cyclodextrin conjugates were tested for their in vitro activity against influenza A/WSN/33 (H1N1) virus and cytotoxicity. Among the tested compounds, 58, 80 and 82 showed slight cytotoxicity to Madin-Darby canine kidney cells with viabilities ranging from 64 to 68% at a high concentration of 100 μM. Four conjugates 51 and 69–71 showed significant inhibitory effects on influenza infection with half maximal inhibitory concentration values of 5.20, 9.82, 7.48 and 7.59 μM, respectively. The structure-activity relationships of multivalent BA-cyclodextrin conjugates were discussed, highlighting that multivalent BA derivatives may be potential antiviral agents against influenza infection.

Nanobioengineering: A promising approach for early detection of COVID-19

Unique pneumonia due to an unknown source emerged in December 2019 in the city of Wuhan, China. Consequently, the World Health Organization (WHO) declared this condition as a new coronavirus disease-19 also known as COVID-19 on February 11, 2020, which on March 13, 2020 was declared as a pandemic. The virus that causes COVID-19 was found to have a similar genome (80% similarity) with the previously known acute respiratory syndrome also known as SARS-CoV. The novel virus was later named Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2 falls in the family of Coronaviridae which is further divided into Nidovirales and another subfamily called Orthocoronavirinae. The four generations of the coronaviruses belongs to the Orthocoronavirinae family that consists of alpha, beta, gamma and delta coronavirus which are denoted as α-CoV, β-CoV, γ-CoV, δ-CoV respectively. The α-CoV and β-CoVs are mainly known to infect mammals whereas γ-CoV and δ-CoV are generally found in birds. The β-CoVs also comprise of SARS-CoV and also include another virus that was found in the Middle East called the Middle East respiratory syndrome virus (MERS-CoV) and the cause of current pandemic SARS-CoV-2. These viruses initially cause the development of pneumonia in the patients and further development of a severe case of acute respiratory distress syndrome (ARDS) and other related symptoms that can be fatal leading to death.

Edible Plant Sprouts: Health Benefits, Trends, and Opportunities for Novel Exploration

The consumption of plant sprouts as part of human day-to-day diets is gradually increasing, and their health benefit is attracting interest across multiple disciplines. The purpose of this review was to (a) critically evaluate the phytochemicals in selected sprouts (alfalfa, buckwheat, broccoli, and red cabbage), (b) describe the health benefits of sprouts, (c) assess the recent advances in sprout production, (d) rigorously evaluate their safety, and (e) suggest directions that merit special consideration for further novel research on sprouts. Young shoots are characterized by high levels of health-benefitting phytochemicals. Their utility as functional ingredients have been extensively described. Tremendous advances in the production and safety of sprouts have been made over the recent past and numerous reports have appeared in mainstream scientific journals describing their nutritional and medicinal properties. However, subjects such as application of sprouted seed flours in processed products, utilizing sprouts as leads in the synthesis of nanoparticles, and assessing the dynamics of a relationship between sprouts and gut health require special attention for future clinical exploration. Sprouting is an effective strategy allowing manipulation of phytochemicals in seeds to improve their health benefits.

Optimization and SAR research at the piperazine and phenyl rings of JNJ4796 as new anti-influenza A virus agents, part 1

JNJ4796, a small molecule fuse inhibitor targeting the conserved stem region of hemagglutinin, effectively neutralized a broad spectrum of group 1 influenza A virus (IAV), and protected mice against lethal and sublethal influenza challenge after oral administration. In this study, we reported the modification and structure-activity relationship (SAR) of C (piperazine ring) and E (phenyl ring) rings of JNJ4796. Compound (R)-2c was identified to show excellent in vitro activity against IAV H1N1 and Oseltamivir-resistant IAV H1N1 stains (IC₅₀: 0.03-0.06 μM), low cytotoxicity (CC₅₀ > 200 μM), accepted oral PK profiles and low inhibition rate of hERG (13.2%, at 10 μM). Evaluation for the in vivo anti-IAV efficacy of (R)-2c will begin soon.

Nanoparticle composite TPNT1 is effective against SARS-CoV-2 and influenza viruses

A metal nanoparticle composite, namely TPNT1, which contains Au-NP (1 ppm), Ag-NP (5 ppm), ZnO-NP (60 ppm) and ClO₂ (42.5 ppm) in aqueous solution was prepared and characterized by spectroscopy, transmission electron microscopy, dynamic light scattering analysis and potentiometric titration. Based on the in vitro cell-based assay, TPNT1 inhibited six major clades of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with effective concentration within the range to be used as food additives. TPNT1 was shown to block viral entry by inhibiting the binding of SARS-CoV-2 spike proteins to the angiotensin-converting enzyme 2 (ACE2) receptor and to interfere with the syncytium formation. In addition, TPNT1 also effectively reduced the cytopathic effects induced by human (H1N1) and avian (H5N1) influenza viruses, including the wild-type and oseltamivir-resistant virus isolates. Together with previously demonstrated efficacy as antimicrobials, TPNT1 can block viral entry and inhibit or prevent viral infection to provide prophylactic effects against both SARS-CoV-2 and opportunistic infections.

Antimicrobial resistance of ocular microbes and the role of antimicrobial peptides

Isolation of antimicrobial-resistant microbes from ocular infections may be becoming more frequent. Infections caused by these microbes can be difficult to treat and lead to poor outcomes. However, new therapies are being developed which may help improve clinical outcomes. This review examines recent reports on the isolation of antibiotic-resistant microbes from ocular infections. In addition, an overview of the development of some new antibiotic therapies is given. The recent literature regarding antibiotic use and resistance, isolation of antibiotic-resistant microbes from ocular infections and the development of potential new antibiotics that can be used to treat these infections was reviewed. Ocular microbial infections are a global public health issue as they can result in vision loss which compromises quality of life. Approximately 70 per cent of ocular infections are caused by bacteria including Chlamydia trachomatis, Staphylococcus aureus, and Pseudomonas aeruginosa and fungi such as Candida albicans, Aspergillus spp. and Fusarium spp. Resistance to first-line antibiotics such as fluoroquinolones and azoles has increased, with resistance of S. aureus isolates from the USA to fluoroquinolones reaching 32 per cent of isolates and 35 per cent being methicillin-resistant (MRSA). Lower levels of MRSA (seven per cent) were isolated by an Australian study. Antimicrobial peptides, which are broad-spectrum alternatives to antibiotics, have been tested as possible new drugs. Several have shown promise in animal models of keratitis, especially treating P. aeruginosa, S. aureus or C. albicans infections. Reports of increasing resistance of ocular isolates to mainstay antibiotics are a concern, and there is evidence that for ocular surface disease this resistance translates into worse clinical outcomes. New antibiotics are being developed, but not by large pharmaceutical companies and mostly in university research laboratories and smaller biotech companies. Antimicrobial peptides show promise in treating keratitis.

In silico molecular docking and molecular dynamics examination of Andrographis paniculata compounds of Andrographolide, Neoandrographolide, and 5-hydroxy-7,8,2’,3’-tetramethoxyflavone inhibition activity to SARS-CoV-2 main protease

In this work, Andrographis paniculata compounds of Andrographolide, Neoandrographolide, and 5-hydroxy-7,8,2’,3’-tetramethoxyflavone inhibition activity to SARS CoV-2 main protease were examined through in silico molecular docking and molecular dynamics simulation, with Remdesivir as control ligand. Docking score and MMGBSA were examined as well as molecular dynamics parameters: RMSD, RMSF and Protein ligand contact fraction. Our study found that Andrographis paniculata compounds of Andrographolide, Neoandrographolide, and 5-hydroxy-7,8,2’,3’-tetramethoxyflavone have comparable inhibition activity to SARS CoV-2 main protease in comparison to Remdesivir. 5-hydroxy7,8,2’,3’-tetramethoxyflavone has the lowest docking score, which was further validated by protein ligand contact fraction examination, although MMGBSA score is lowest for Remdesivir.

Advances in the development of entry inhibitors for sialic-acid-targeting viruses

Over the past decades, several antiviral drugs have been developed to treat a range of infections. Yet the number of treatable viral infections is still limited, and resistance to current drug regimens is an ever-growing problem. Therefore, additional strategies are needed to provide a rapid cure for infected individuals. An interesting target for antiviral drugs is the process of viral attachment and entry into the cell. Although most viruses use distinct host receptors for attachment to the target cell, some viruses share receptors, of which sialic acids are a common example. This review aims to give an update on entry inhibitors for a range of sialic-acid-targeting viruses and provides insight into the prospects for those with broad-spectrum potential.