Some natural flavonoids are competitive inhibitors of caspase-1, -3, and -7 despite their cellular toxicity

► Flavonoids induce cytotoxicity and apoptosis in cancer. ► Flavonoids inhibit caspase activity in vitro and in vivo. ► Flavonoids are selective inhibitors of specific caspases. ► Flavonoids may be used to development specific small molecule caspase inhibitors. ► Caspase inhibitors can be used as novel therapeutic strategies.