Ethaverine for COVID-19

Abstract To identify possible candidates for progression towards clinical studies against SARS-CoV-2, we screened a well-defined collection of 5632 compounds including 3488 compounds which have undergone clinical investigations (marketed drugs, phases 1 -3, and withdrawn) across 600 indications. Compounds were screened for their inhibition of viral induced cytotoxicity using the human epithelial colorectal adenocarcinoma cell line Caco-2 and a SARS-CoV-2 isolate. The primary screen of 5632 compounds gave 271 hits. A total of 64 compounds with IC50 <20 µM were identified, including 19 compounds with IC50 < 1 µM. Of this confirmed hit population, 90% have not yet been previously reported as active against SARS-CoV-2 in-vitro cell assays. Some 37 of the actives are launched drugs, 19 are in phases 1-3 and 10 pre-clinical. Several inhibitors were associated with modulation of host pathways including kinase signaling P53 activation, ubiquitin pathways and PDE activity modulation, with long chain acyl transferases were effective viral inhibitors.

AbstractSARS-CoV-2 is a novel coronavirus responsible for the COVID-19 pandemic, in which acute respiratory infections are associated with high socio-economic burden. We applied high-content screening to a well-defined collection of 5632 compounds including 3488 that have undergone previous clinical investigations across 600 indications. The compounds were screened by microscopy for their ability to inhibit SARS-CoV-2 cytopathicity in the human epithelial colorectal adenocarcinoma cell line, Caco-2. The primary screen identified 258 hits that inhibited cytopathicity by more than 75%, most of which were not previously known to be active against SARS-CoV-2 in vitro. These compounds were tested in an eight-point dose response screen using the same image-based cytopathicity readout. For the 67 most active molecules, cytotoxicity data were generated to confirm activity against SARS-CoV-2. We verified the ability of known inhibitors camostat, nafamostat, lopinavir, mefloquine, papaverine and cetylpyridinium to reduce the cytopathic effects of SARS-CoV-2, providing confidence in the validity of the assay. The high-content screening data are suitable for reanalysis across numerous drug classes and indications and may yield additional insights into SARS-CoV-2 mechanisms and potential therapeutic strategies.

The current pandemic caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) demands rapid identification of new antiviral molecules from the existing drugs. Drug repurposing is a significant alternative for pandemics and emerging diseases because of the availability of preclinical data, documented safety in clinic and possibility of immediate production and scalable capacity and supply. Several drugs such as ivermectin and hydroxy chloroquine have been repurposed as anti-SARS-CoV-2 agents, but the effect of these compounds in treating the COVID-19 patients remains sub-optimal. In the present study repurposed drug libraries consisting of 560 compounds from two different sources have been screened against SARS-CoV-2 isolate USA-WA1/2020 in Vero-E6 cell line and 24 compounds were found active. The SARS-CoV-2 virus propagated in Vero E6 cell line and used in screening the drug libraries was sequenced by Next Generation Sequencing to identify any mutations that may have accumulated in the virus genome. The whole genome sequencing data of SARS-CoV-2 showed 9 and 6 single nucleotide polymorphisms in spike protein with reference to Wuhan-Hu-1(NC045512.2) and USA/WA-CDC-WA1/2020 (MN985325.1) isolates respectively. The present study identified 24 compounds active against SARS-CoV-2 isolate USA-WA1/2020 out of 560 repurposed drugs from two libraries. The IC-50 values of the identified hits range from 0.4 µM to 16 µM. Further studies on the repurposed drugs identified in the present screen may be helpful in the rapid development of antiviral drugs against SARS-CoV-2.