Bufalin, a bufanolide steroid from the parotoid glands of the Chinese toad, suppresses hERG K+ currents expressed in HEK293 cells.

In this study, we investigated the effect of bufalin on the human ether-à-go-go-related gene (hERG) K+ channels using the perforated patch recording technique. We measured a half-maximal inhibitory concentration (IC50 ) of 24.83 μM and maximal inhibitory effect of 39.45 ± 1.14% with bufalin. These findings suggest that bufalin is a potent hERG K+ channel blocker and may provide a new way for understanding Chan Su-induced arrhythmia.