LAUSR

The current COVID‐19 pandemic caused by SARS‐Cov‐2 is responsible for more than 6 million deaths globally. The development of broad‐spectrum and cost‐effective antivirals is urgently needed. Medicinal plants are renowned as a complementary approach in which antiviral natural products have been established as safe and effective drugs. Here, we report that the percolation extract of Spatholobus suberectus Dunn (SSP) is a broad‐spectrum viral entry inhibitor against SARS‐CoV‐1/2 and other enveloped viruses. The viral inhibitory activities of the SSP were evaluated by using pseudotyped SARS‐CoV‐1 and 2, HIV‐1ADA and HXB2, and H5N1. SSP effectively inhibited viral entry and with EC50 values ranging from 3.6 to 5.1 μg/ml. Pre‐treatment of pseudovirus or target cells with SSP showed consistent inhibitory activities with the respective EC50 value of 2.3 or 2.1 μg/ml. SSP blocked both SARS‐CoV‐2 spike glycoprotein and the host ACE2 receptor. In vivo studies indicated that there was no abnormal toxicity and behavior in long‐term SSP treatment. Based on these findings, we concluded that SSP has the potential to be developed as a drug candidate for preventing and treating COVID‐19 and other emerging enveloped viruses.