Virucidal, antiviral and immunomodulatory activities of β‐escin and Aesculus hippocastanum extract

Objectives β‐Escin, one of the constituents of Aesculus hippocastanum L. (Hippocastanaceae) seed extract (AH), inhibits NF‐κB activation, which plays an important role in HSV‐1 replication. The aim was to examine the antiherpetic activity of β‐escin and AH, as well as their effect on the activation of NF‐κB and AP‐1 and cytokine secretion in epithelial cells and macrophages. Methods Cell viability was evaluated using MTT assay, and antiviral and virucidal activity was determined by plaque assay. The effect on NF‐κB and AP‐1 signalling pathways activation was determined by a luciferase reporter assay, and cytokine production was measured by ELISA. Key findings β‐Escin and AH had virucidal and anti‐HSV‐1 activities, and the antiviral activity was discovered for other enveloped viruses (VSV and Dengue). Moreover, β‐escin and AH significantly reduced NF‐κB and AP‐1 activation and cytokine production in macrophages stimulated with HSV‐1 and TLRs ligands. However, an enhanced activation of these pathways and an increase in the levels of pro‐inflammatory cytokines in β‐escin and AH‐treated HSV‐1‐infected epithelial cells were found. Conclusions This study demonstrates virucidal and broad‐spectrum antiviral activities for β escin and AH. Besides, β‐escin and AH modulate cytokine production depending on the stimuli (viral or non‐viral) and the cell type under study.