Repurposed Drugs Offer Hope for Preventing/Treating COVID

A new approach to the war on COVID has potential according to a study published in the June 30^th issue of Science Advances. The University of Cambridge is investigating the possibility that a host of drugs, already approved for other uses, may uncover new weapons against this pandemic.  Historically, many drugs originally developed to favorably outwit one disease have proven useful in other ways.  For instance, zidovudine, now known as azidothymidine (AZT), did not work as a cancer drug but 20 years later proved to work well for the prevention and treatment of HIV.

Cambridge researchers used computer models to screen some 2,000 drugs as potential anti-viral treatments.  The researchers narrowed the field down to 200, then chose a subset of 40 to test in the lab using cell lines cultivated from humans and non-human primates; all cell lines were infected with SARS-CoV-2.  Two drugs in particular—proguanil, an anti-malaria drug, and sulfasalazine, a medication for rheumatoid arthritis and ulcerative colitis—successfully stopped COVID viral replication in the cells.

Another study, this one from the Tokyo University of Science, has also come up with a duo of drugs with great promise, perhaps even better than the Cambridge findings. These researchers also tested a panel of already approved drugs in similarly infected cell model cultures. They found a different duo of drugs that effectively blocked the virus: the anti-inflammatory drug cepharanthine and the HIV viral protease* inhibitor nelfinavir. Cepharanthine inhibited SARS-CoV-2 entry into host cells by blocking viral entrance into target cells while nelfinavir suppressed viral replication through protease inhibition.

This picture shows that cepharanthine in the upper left-hand corner sporting fashionable pale turquoise and grey blocks the ugly brown COVID spike from entering the cell. In the lower left-hand corner, a lump of lovely lime green nelfinavir enters the cell and rips apart the protease which stops viral reproduction. The color choices are for artistic purposes and do not represent the actual cells, virions, or drugs.

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*Protease is an enzyme that breaks down proteins into shorter molecules called peptides which allows the virus to construct new proteins in order to replicate new virions inside the host cell.

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