Common Antiviral Drugs May be Effective Against COVID-19

Tilorone, quinacrine and pyronaridines effectiveness depended on whether they were used in human-derived cell lines or monkey derived cell lines.

A recent study conducted by investigators from North Carolina State University and Collaborations Pharmaceuticals has found that 3 common antiviral and antimalarial drugs were effective in vitro at preventing the SARS-CoV-2 virus from replicating. Results from the study were published in the journal ACS Omega.

"We were looking for compounds that could block the entry of the virus into the cell," Ana Puhl, a co-corresponding author on the study said. "We chose these compounds because we know that other antivirals which successfully act against Ebola are also effective inhibitors of SARS-CoV-2."

For the study, the investigators analyzed 3 antiviral drugs, tilorone, quinacrine and pyronaridine, which have been shown to be effective against Ebola and the Marburg virus. They tested the compounds in vitro against COVID-19 as well as against a common cold virus (HCoV 229E) and murine hepatitis virus (MHV).

Infecting cell lines that represent potential targets for the SARS-CoV-2 virus, the investigators looked at how well the therapies prevented viral replication within cells.

"In the human-derived cell lines, we found that all three compounds worked similarly to remdesivir, which is currently being used to treat COVID-19," Frank Scholle, associate professor of biology at NC State and co-author of the research said. "However, they were not at all effective in the Vero cells."

The team behind the study plans for future research that include testing the 3 compounds in a mouse model, to further understand how they can inhibit the virus from replicating within cells.

"One of the more interesting findings here is that these compounds don't just prevent the virus from potentially binding to the cells, but that they may also inhibit viral activity because these compounds are acting on the lysosomes," Puhl said. "Lysosomes, which are important for normal cell function, are hijacked by the virus for entry and exit out of the cell. So, if that mechanism is disrupted, it cannot infect other cells.”