Zinc pyrithione is a potent inhibitor of PLPro and cathepsin L enzymes with ex vivo inhibition of SARS-CoV-2 entry and replication

As SARS-CoV-2 triggered a global health crisis, there is an urgent need to provide patients with safe, effective, accessible, and preferably oral therapeutics for COVID-19 that complement mRNA vaccines. Zinc compounds are widely known for their antiviral properties. Therefore, we have prepared a library of zinc complexes with pyrithione (1-hydroxy-2(1H)-pyridinethione) and its analogues, all of which showed promising in vitro inhibition of cathepsin L, an enzyme involved in SARS-CoV-2 entry, and PLPro, an enzyme involved in SARS-CoV-2 replication both in (sub)micromolar range. Zinc pyrithione 1a is a well-established, commercially available antimicrobial agent and was therefore selected for further evaluation of its SARS-CoV-2 entry and replication inhibition in an ex vivo system derived from primary human lung tissue. Our results suggest that zinc pyrithione complex 1a provides a multitarget approach to combat SARS-CoV-2 and should be considered for repurposing as a potential therapeutic against the insidious COVID-19 disease. Featured imageIn our study, we show that zinc pyrithione holds immense potential for the development of a possible out-patient treatment for SARS-CoV-2 due to its inhibition of viral entry and replication. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=167 SRC="FIGDIR/small/482819v1_ufig1.gif" ALT="Figure 1"> View larger version (111K): org.highwire.dtl.DTLVardef@2da94corg.highwire.dtl.DTLVardef@1c5da6borg.highwire.dtl.DTLVardef@86acd6org.highwire.dtl.DTLVardef@1bd4c3d_HPS_FORMAT_FIGEXP M_FIG C_FIG