Figure 2 (IMAGE) Institute for Basic Science Caption Astersaponin I prevents COVID-19 infection in a dose-dependent manner, with an IC50 value of 2 μM. The saponin worked equally as well against all variants of SARS-CoV-2, due to its ability to block membrane fusion. Credit Institute for Basic Science Usage Restrictions Attribution Required License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.