Antitumor activity in vitro of glycyrrhetinic acid and its combinations with calcium signaling modulators

The antitumor activity in vitro of glycyrrhetinic acid and its combinations with modulators of cellular calcium metabolism and inhibitors of calcium-binding proteins was studied. It was shown that glycyrrhetinic acid dose-dependently suppresses the growth of glioma C6 and HeLa. Enhancement of the inhibitory effect can be achieved by combining glycyrrhetinic acid with A23187 (calcium ionophore), chlorpromazine (calmodulin inhibitor), cyclosporine (calcineurin inhibitor), U73122 (phospholipase C inhibitor), ruthenium red (inhibitor of vanilloid channels of transient receptor potential and mitochondrial Ca 2+ -uniporter), which provides a more pronounced effect than the use of glycyrrhetinic acid and the above compounds separately. Tumor cells of glioma C6 and HeLa were more sensitive to glycyrrhetinnic acid, the studied modulators of cellular calcium metabolism and combinations of glycyrrhetinic acid with these modulators than normal cells of primary rat brain culture.