RESUMEN
ß-Escin is a mixture of triterpenoid saponins extracted from horse chestnut seeds that have diverse pharmacological activities, including anti-inflammation, anti-edematous, venotonic, and antiviral effects. In the clinical setting, ß-escin is primarily used to treat venous insufficiency and blunt trauma injuries. The anti-Zika virus (ZIKV) activity of ß-escin has not been explored. This study investigated the antiviral efficacy of ß-escin on ZIKV and dengue virus (DENV) in vitro and then elucidated the underlying mechanism. The inhibitory effects of ß-escin on viral RNA synthesis, protein levels, and infection ability were determined using qRT-PCR, Western blotting, and immunofluorescence assays, respectively. To further characterize how ß-escin interferes with the viral life cycle, the time-of-addition experiment was performed. An inactivation assay was performed to determine whether ß-escin affects ZIKV virion stability. To broaden these findings, the antiviral effects of ß-escin on different DENV serotypes were assessed using dose-inhibition and time-of-addition assays. The results showed that ß-escin exhibits anti-ZIKV activity by decreasing viral RNA levels, protein expression, progeny yield, and virion stability. ß-Escin inhibited ZIKV infection by disrupting viral binding and replication. Furthermore, ß-escin demonstrated antiviral activities against four DENV serotypes in a Vero cell model and prophylactic protection against ZIKV and DENV infections.