Cardiotonic steroids are steroid-like natural compounds known to inhibit Na + /K + -ATPase pumps. To develop a broad-spectrum antiviral drug against the emerging coronavirus infection, this study assessed the antiviral properties of these compounds. The activity of seven types of cardiotonic steroids against the MERS-CoV, SARS-CoV, and SARS-CoV-2 coronavirus varieties was analyzed using immunofluorescence antiviral assay in virus-infected cells. Bufalin, cinobufagin, and telocinobufagin showed high anti-MERS-CoV activities (IC 50 , 0.017~0.027 μM); bufalin showed the most potent anti-SARS-CoV and SARS-CoV-2 activity (IC 50 , 0.016~0.019 μM); cinobufotalin and resibufogenin showed comparatively low anti-coronavirus activity (IC 50 , 0.231~1.612 μM). Differentially expressed genes in Calu3 cells treated with cinobufagin, telocinobufagin, or bufalin, which had high antiviral activity during MERS-CoV infection were analyzed using QuantSeq 3′ mRNA-Seq analysis and data showed similar gene expression patterns. Furthermore, the intraperitoneal administration of 10 mg/kg/day bufalin, cinobufagin, or digitoxin induced 100% death after 1, 2, and 4 days in 5-day repeated dose toxicity studies and it indicated that bufalin had the strongest toxicity. Pharmacokinetic studies suggested that telocinobufagin, which had high anti-coronavirus activity and low toxicity, had better microsomal stability, lower CYP inhibition, and better oral bioavailability than cinobufagin. Therefore, telocinobufagin might be the most promising cardiotonic steroid as a therapeutic for emerging coronavirus infections, including COVID-19.
【저자키워드】 COVID-19, coronavirus, Antiviral, pharmacokinetics, MERS, cardiotonic steroid, 【초록키워드】 SARS-CoV-2, Coronavirus infection, SARS-CoV, SARS-CoV-2 coronavirus, Toxicity, antiviral activity, MERS-CoV, antiviral drug, activity, Coronavirus infections, stability, therapeutic, death, immunofluorescence, differentially expressed gene, administration, Analysis, dose, antiviral property, steroid, digitoxin, virus-infected cells, Compound, these compounds, MERS-CoV infection, gene expression patterns, oral bioavailability, repeated, anti-coronavirus activity, Seven, analyzed, develop, indicated, inhibit, treated, variety, suggested, Calu3 cell, Cardiotonic, 【제목키워드】 Therapeutics, Spectrum, steroid, property, Potential, Cardiotonic,