Candidate drugs against SARS-CoV-2 and COVID-19

Abstract

Outbreak and pandemic of coronavirus SARS-CoV-2 in 2019/2020 will challenge global health for the future. Because a vaccine against the virus will not be available in the near future, we herein try to offer a pharmacological strategy to combat the virus. There exists a number of candidate drugs that may inhibit infection with and replication of SARS-CoV-2. Such drugs comprise inhibitors of TMPRSS2 serine protease and inhibitors of angiotensin-converting enzyme 2 (ACE2). Blockade of ACE2, the host cell receptor for the S protein of SARS-CoV-2 and inhibition of TMPRSS2, which is required for S protein priming may prevent cell entry of SARS-CoV-2. Further, chloroquine and hydroxychloroquine, and off-label antiviral drugs, such as the nucleotide analogue remdesivir, HIV protease inhibitors lopinavir and ritonavir, broad-spectrum antiviral drugs arbidol and favipiravir as well as antiviral phytochemicals available to date may limit spread of SARS-CoV-2 and morbidity and mortality of COVID-19 pandemic. 1. Introduction The outbreak of coronavirus SARS-CoV-2 in Wuhan, China in December 2019, the cause of Corona Virus Disease of 2019 (COVID-19), represents a pandemic threat to global health [1,2]. The WHO declared COVID-19 as a pandemic on March 11th 2020. The outbreak has spread to more than 185 countries with more than 3,200,000 confirmed cases, more than 230,000 confirmed deaths and more than 1,000,000 total recoveries worldwide as of May 1st 2 2020 [3]. Hundreds of millions of lives have been affected as a result of mandatory isolations/quarantines. This pandemic has the potential to overwhelm national healthcare systems, and have major consequences on global economy if SARS-CoV-2 spread and virulence is not contained, or effective treatments are not developed.Coronaviruses are grouped into alpha, beta, gamma, and delta classes. Coronaviruses can infect both humans and animals. The source of the beta coronavirus SARS-CoV-2 is believed to be bats, which carry the virus with no signs of disease [4]. Beta coronaviruses caused earlier outbreaks of severe acute respiratory syndromes (SARS), including SARS-CoV (2002/2003 in Guangdong, China) and Middle East Respiratory Syndrome virus MERS-CoV (2012 in Saudi Arabia) [5]. Beta coronaviruses are pathogenic for humans and have a single stranded RNA genome, encapsulated by a membrane envelope [6]. The coronavirus crown-like ("corona") morphology is created by transmembrane spike glycoproteins (S proteins) that form homotrimers protruding from the viral surface [7]. The S proteins of SARS-CoV and SARS-CoV-2 display structural homology and conserved ectodomains, so earlier strategies employed to prevent binding of SARS-CoV to its host cell receptor angiotensin-converting enzyme 2 (ACE2) may be relevant, since SARS-CoV-2 also employs ACE2 for cell entry [8,9]. ACE2, an exopeptidase expressed on epithelial cells of the respiratory tract, may constitute a pharmacological target to limit cell entry of SARS-CoV-2. The established antimalarial drugs chloroquine and hydroxychloroquine ha...

Methylene Blue Inhibits In Vitro the SARS-CoV-2 Spike – ACE2 Protein-Protein Interaction – A Mechanism That Can Contribute to Its Antiviral Activity Against COVID-19

“…In fact, this assay setup is very similar to one recently shown to work as a specific and sensitive SARS-CoV-2 surrogate virus neutralization test based on antibody-mediated blockage of this same PPI (CoV-S-ACE2) (Tan et al, 2020). With this setup in our hands, we performed a preliminary screening of representative organic dyes from our in-house library plus a few compounds that are or have been considered of possible interest in inhibiting SAR-CoV-2 by different mechanisms of action, e.g., chloroquine, clemastine, and suramin (Colson et al, 2020;da Silva et al, 2020;Gordon et al, 2020;McKee et al, 2020;Xiu et al, 2020). Screening at 5 µM indicated that most have no activity and, hence, are unlikely to interfere with the S-protein -ACE2 binding needed for viral attachment.…”

Ivermectin as a promising RNA-dependent RNA polymerase inhibitor and a therapeutic drug against SARS-CoV2: Evidence from in silico studies

“…Currently, there is no clinically approved drug for SARS-CoV2. However, recent publications reveal that several medications such as ivermectin, hydroxychloroquine, and remdesivir are being used to reduce the virus load and improve disease symptoms (Caly et al 2020;McKee et al 2020;Wang et al 2020).…”

D936Y and Other Mutations in the Fusion Core of the SARS-Cov-2 Spike Protein Heptad Repeat 1 Undermine the Post-Fusion Assembly

“…Coronaviruses are named after the protruding spike (S) glycoproteins on their envelope, giving a crown (corona in latin) shape to the virions (4). Of the four structural proteins of coronavirues, S, envelope (E), membrane (M), and nucleocapsid (N), the S protein is the one playing a key role in mediating the viral entry into the host cells (5)(6)(7), making it one of the main targets for the development of therapeutic drugs and vaccines (8)(9)(10)(11)(12)(13)(14). Comprised of two functional subunits, S1 and S2, it first binds to a host receptor through the receptor-binding domain (RBD) in the S1 subunit and then fuses the viral and host membranes through the S2 subunit (7,15).…”