Escin induces cell death in human skin melanoma cells through apoptotic mechanisms

Natural products based on their significant anti-cancer potencies have been used in cancer treatment. A natural blend of triterpenoid saponins derived from the horse chestnut (Aesculus hippocastanum L.), has been investigated in various diseases based on its main active ingredient escin. Herein, we examined the potential antiproliferative, proapoptotic, and cytotoxic activities of escin on human skin melanoma (CHL-1) cells. Cytotoxicity of escin was determined by MTT assay. Morphological changes were detected by confocal microscopy and ultrastructural changes by transmission electron microscopy studies. Phosphatidylserine translocation assay, Bcl-2 activation assessment, and oxidative stress analysis were used to determine the cell death mode of the cells. The results showed that escin reduced cell viability in a dose-dependent manner within 24 h of exposure and was highly cytotoxic at lower concentrations (IC₅₀ value 6 μg/mL). Escin inactivated Bcl-2 signaling and triggered apoptosis by increasing the reactive oxygen species and by causing morphological and ultrastructural changes that implicate to the proapoptotic activity. Escin has been found to exert high potential for an anti-cancer drug following further in vitro and in vivo investigations.