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bioRxiv · 10.1101/2020.12.13.420406

Identification of bis-benzylisoquinoline alkaloids as SARS-CoV-2 entry inhibitors from a library of natural products in vitro

He, C.-L.·Huang, L.-Y.·Wang, K.·Gu, C.-J.·Hu, J.·Zhang, G.-J.·Xu, W.·Xie, Y.-H.·Tang, N.·Huang, A.-L.
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Abstract

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a major public health issue. To screen for antiviral drugs for COVID-19 treatment, we constructed a SARS-CoV-2 spike (S) pseudovirus system using an HIV-1-based lentiviral vector with a luciferase reporter gene to screen 188 small potential antiviral compounds. Using this system, we identified nine compounds, specifically, bis-benzylisoquinoline alkaloids, that potently inhibited SARS-CoV-2 pseudovirus entry, with EC50 values of 0.1-10 M. Mechanistic studies showed that these compounds, reported as calcium channel blockers (CCBs), inhibited Ca2+-mediated membrane fusion and consequently suppressed coronavirus entry. These candidate drugs showed broad-spectrum efficacy against the entry of several coronavirus pseudotypes (SARS-CoV, MERS-CoV, SARS-CoV-2 [S-D614, S-G614, N501Y.V1 and N501Y.V2]) in different cell lines (293T, Calu-3, and A549). Antiviral tests using native SARS-CoV-2 in Vero E6 cells confirmed that four of the drugs (SC9/cepharanthine, SC161/hernandezine, SC171, and SC185/neferine) reduced cytopathic effect and supernatant viral RNA load. Among them, cepharanthine showed the strongest anti-SARS-CoV-2 activity. Collectively, this study offers new lead compounds for coronavirus antiviral drug discovery.

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He, C.-L., Huang, L.-Y., Wang, K., Gu, C.-J., Hu, J., Zhang, G.-J., Xu, W., Xie, Y.-H., Tang, N., Huang, A.-L.. 2020-12-14. Identification of bis-benzylisoquinoline alkaloids as SARS-CoV-2 entry inhibitors from a library of natural products in vitro. https://doi.org/10.1101/2020.12.13.420406

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