Identification of anti-severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) oxysterol derivatives in vitro

ABSTRACT

Development of effective antiviral drugs targeting the severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) are urgently needed to combat the coronavirus disease 2019 (COVID-19). Oxysterols, defined as oxidized derivatives of cholesterol, include endogenous (naturally occurring) cholesterol metabolites as well as semi-synthetic oxysterol derivatives. We have previously studied the use of semi-synthetic oxysterol derivatives as drug candidates for inhibition of cancer, fibrosis, and bone regeneration. In this study, we have screened a panel of naturally occurring and semi-synthetic oxysterol derivatives for anti-SARS-CoV-2 activity, using a cell culture infection assay. We show that the natural oxysterols, 7-ketocholesterol, 22(R)-hydroxycholesterol, 24(S)-hydroxycholesterol, and 27-hydroxycholesterol, substantially inhibited SARS-CoV-2 propagation in cultured cells. Among semi-synthetic oxysterols, Oxy186 displayed antiviral activity comparable to natural oxysterols. In addition, related oxysterol analogues Oxy210 and Oxy232 displayed more robust anti-SARS-CoV-2 activities, reducing viral replication more than 90% at 10 M and 99% at 15 M, respectively. When orally administered in mice, peak plasma concentrations of Oxy210 fall into a therapeutically relevant range (19 M), based on the dose-dependent curve for antiviral activity in our cell culture infection assay. Mechanistic studies suggest that Oxy210 reduced replication of SARS-CoV-2 with disrupting the formation of double membrane vesicles (DMVs), intracellular membrane compartments associated with viral replication. Oxy210 also inhibited the replication of hepatitis C virus, another RNA virus whose replication is associated with DMVs, but not the replication of the DMV-independent hepatitis D virus. Our study warrants further evaluation of Oxy210 and Oxy232 as a safe and reliable oral medication, which could help protect vulnerable populations with increased risk developing COVID-19.