Exploring the impact of a naturally occurring sapogenin diosgenin on underlying mechanisms of Ca2+ movement and cytotoxicity in human prostate cancer cells

Literature has shown that diosgenin, a naturally occurring sapogenin, inducedcytotoxic effects in many cancer models. This study investigated the effect of diosgenin on intracellular Ca2+ concentration ([Ca2+]i) and cytotoxicity in PC3 human prostate cancer cells. Diosgenin (250‐1000 μM) caused [Ca2+]i rises which was reduced by Ca2+ removal. Treatment with thapsigargin eliminated diosgenin‐induced [Ca2+]i increases. In contrast, incubation with diosgeninabolished thapsigargin‐caused [Ca2+]i increases. Suppression of phospholipase C with U73122 eliminated diosgenin‐caused [Ca2+]i increases. Diosgenin evoked Mn2+ influx suggesting that diosgenin induced Ca2+ entry. Diosgenin‐induced Ca2+influx was suppressed by PMA, GF109203X, and nifedipine, econazole, or SKF96365. Diosgenin (250‐600 μM) concentration‐dependently decreased cell viability. However, diosgenin‐induced cytotoxicity was not reversed by chelation of cytosolic Ca2+ with BAPTA/AM. Together, diosgenin evoked [Ca2+]i increases via Ca2+ release and Ca2+ influx, and caused Ca2+‐non‐associated deathin PC3 cells. These findings reveal a newtherapeutic potential of diosgenin for human prostate cancer.