Computational studies reveal Fluorine based quinolines to be potent inhibitors for proteins involved in SARS-CoV-2 assembly

Lessons learned from the COVID-19 pandemic: the intranasal administration as a route for treatment - a patent review

The COVID-19 pandemic exposed the fragility of today's marketed treatments for respiratory infections. As a primary site of infection, the upper airways may represent a key access route for the control and treatment for these conditions. The present study aims to explore and identify, through a patent review, the novelty of therapies for COVID-19 that use the intranasal route for drug administration. A search was carried out in Wipo and Espacenet, using the descriptors 'COVID-19 OR SARS-CoV 2' AND 'treatment OR therapy' AND NOT 'vaccine OR immunizing' and the classification 'A61K9/0043'. Of the 151 patents identified, we excluded 73 duplicates, and 36 documents that meet the criteria adopted for exclusion (not nasally administered formulations, vaccines, post COVID-19 treatments, uncertain route of administration or form). We identified 78 unique patents on patent databases, of which 42 were selected for this review. The documents revealed the use of the intranasal pathway not only for drug repositioning but also for using plant-derived and biological molecules. Overall, the new formulations explore a variety of known drugs and natural products incorporated in drug carrier systems and devices for drug delivery and administration. Thus, the intranasal route remains a promising strategy for drug delivery, offering direct access to the primary infection site and warranting further exploration.

Structure-Activity Relationship of Ciprofloxacin towards S-Spike Protein of SARS-CoV-2: Synthesis and In-Silico Evaluation

The recent outbreak of the coronavirus (COVID-19) pandemic, caused by the SARS-CoV-2 virus, has posed serious threats to global health systems. Although several directions have been put by the WHO for effective treatment, use of antibiotics, particularly ciprofloxacin, in suspected and acquired Covid-19 patients has raised an even more serious concern of antibiotic resistance. Ciprofloxacin has been reported to inhibit entry of SARS-CoV-2 into the host cells via interacting with the spike (S) protein. However, a proper structure-activity relationship study of ciprofloxacin with the S-protein is lacking, which inhibits researchers from developing a more potent fluoroquinolone analogue, specific for inhibition of SARS-CoV-2 viral entry. Herein, in order to have a structure-activity relationship study, we have accomplished a short and convergent synthesis of different derivatives of ciprofloxacin and a detailed in-silico study using molecular docking to explore the interactions of the derivatives with S-protein. The ADMET studies also indicated the drug likeliness and nontoxicity of the derivatives. Furthermore, the molecular dynamics simulation approach was used to study the dynamical behavior after the best docked derivative binds to the protein, and the MM-PBSA approach was adopted to calculate the binding energies. This has led to a derivative that has higher interactions with the S-protein compared to ciprofloxacin, without hampering the dynamics of the interactions. The strong affinity of compound 5 with the SARS-CoV-2 spike RBD protein was further evaluated experimentally using biolayer interferometry (BLI). Furthermore, molecular docking and molecular dynamics simulation were extended to evaluate its binding with the mutated variants Delta and Omicron. We anticipate that the current study could lead to an alternative therapeutic viral inhibitor with a better efficacy than ciprofloxacin.

Methodology-Centered Review of Molecular Modeling, Simulation, and Prediction of SARS-CoV-2

Despite tremendous efforts in the past two years, our understanding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), virus-host interactions, immune response, virulence, transmission, and evolution is still very limited. This limitation calls for further in-depth investigation. Computational studies have become an indispensable component in combating coronavirus disease 2019 (COVID-19) due to their low cost, their efficiency, and the fact that they are free from safety and ethical constraints. Additionally, the mechanism that governs the global evolution and transmission of SARS-CoV-2 cannot be revealed from individual experiments and was discovered by integrating genotyping of massive viral sequences, biophysical modeling of protein-protein interactions, deep mutational data, deep learning, and advanced mathematics. There exists a tsunami of literature on the molecular modeling, simulations, and predictions of SARS-CoV-2 and related developments of drugs, vaccines, antibodies, and diagnostics. To provide readers with a quick update about this literature, we present a comprehensive and systematic methodology-centered review. Aspects such as molecular biophysics, bioinformatics, cheminformatics, machine learning, and mathematics are discussed. This review will be beneficial to researchers who are looking for ways to contribute to SARS-CoV-2 studies and those who are interested in the status of the field.

Antiviral Activity of Repurposing Ivermectin against a Panel of 30 Clinical SARS-CoV-2 Strains Belonging to 14 Variants

Over the past two years, several variants of SARS-CoV-2 have emerged and spread all over the world. However, infectivity, clinical severity, re-infection, virulence, transmissibility, vaccine responses and escape, and epidemiological aspects have differed between SARS-CoV-2 variants. Currently, very few treatments are recommended against SARS-CoV-2. Identification of effective drugs among repurposing FDA-approved drugs is a rapid, efficient and low-cost strategy against SARS-CoV-2. One of those drugs is ivermectin. Ivermectin is an antihelminthic agent that previously showed in vitro effects against a SARS-CoV-2 isolate (Australia/VI01/2020 isolate) with an IC50 of around 2 µM. We evaluated the in vitro activity of ivermectin on Vero E6 cells infected with 30 clinically isolated SARS-CoV-2 strains belonging to 14 different variants, and particularly 17 strains belonging to six variants of concern (VOC) (variants related to Wuhan, alpha, beta, gamma, delta and omicron). The in vitro activity of ivermectin was compared to those of chloroquine and remdesivir. Unlike chloroquine (EC50 from 4.3 ± 2.5 to 29.3 ± 5.2 µM) or remdesivir (EC50 from 0.4 ± 0.3 to 25.2 ± 9.4 µM), ivermectin showed a relatively homogeneous in vitro activity against SARS-CoV-2 regardless of the strains or variants (EC50 from 5.1 ± 0.5 to 6.7 ± 0.4 µM), except for one omicron strain (EC50 = 1.3 ± 0.5 µM). Ivermectin (No. EC50 = 219, mean EC50 = 5.7 ± 1.0 µM) was, overall, more potent in vitro than chloroquine (No. EC50 = 214, mean EC50 = 16.1 ± 9.0 µM) (p = 1.3 × 10-34) and remdesivir (No. EC50 = 201, mean EC50 = 11.9 ± 10.0 µM) (p = 1.6 × 10-13). These results should be interpreted with caution regarding the potential use of ivermectin in SARS-CoV-2-infected patients: it is difficult to translate in vitro study results into actual clinical treatment in patients.