Bufalin, a bufanolide steroid from the parotoid glands of the Chinese toad, inhibits L‐type Ca²⁺ channels and contractility in rat ventricular myocytes

Abstract

Bufalin is a bufanolide steroid compound in Chan Su. Chan Su is a traditional Chinese medicine prepared from the dried white secretion of the auricular and skin glands of toads and has been used as an oriental drug. However, the effect of bufalin on cardiac function and its underlying cellular mechanisms remain unclear. Here, we explore the cellular mechanisms of bufalin on myocardial protection via the whole-cell patch-clamp recording and video-based edge detection system. Exposure to bufalin resulted in a concentration-dependent blockade of I , with the half-maximal inhibitory concentration (IC ) of 60 μm and the maximal inhibitory effect of 71.50 ± 2.67%. Bufalin at 100 μm reduced cell shortening by 33.83 ± 4.01%. Bufalin restrained L-type Ca channels conductance, and contractility in rat ventricular myocytes. Thus, the protective effects of bufalin on the heart may be determined by the inhibitory effect on I and the negative inotropic action caused by the decrease of intracellular Ca in rat myocardial cells.

Anti-tumor Activity of Bufalin by Inhibiting c-MET Mediated MEK/ERK and PI3K/AKT Signaling Pathways in Gallbladder Cancer

“…Bufalin is a kind of cardiac glycosides which is derived from the serous fluid secreted by the parotid venom glands and skin of Bufo melanostictus and Bufo bufo gargarizans [20]. Researches have showed that Bufalin has many pharmacological activities, including anti-inflammatory, anti-tumor, antiviral, cardiotonic and narcotic effects [21][22][23][24]. Among these effects, the anti-tumor activity of Bufalin has caught the attention of many researchers.…”

6‐Gingerol, an active pungent component of ginger, inhibits L‐type Ca2+ current, contractility, and Ca2+ transients in isolated rat ventricular myocytes

“…Therefore, LTCCs blockers generally protect against myocardial ischemic injury via the inhibition of calcium channels. Previous studies have emphasized the inhibitory effect of verapamil (VER) on myocardial contraction and the protective effect on excess calcium overload (Song et al, ). Hence, drugs that can weaken I Ca‐L are promising for myocardial protection (Song et al, ).…”

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

“…Bufalin (C 24 H 34 O 4 ) is one of the main active components of Chan Su . In our previous study, we have found that bufalin can inhibit the L‐type Ca 2+ channels and contractility in rat ventricular myocytes . However, some studies have also shown that bufalin has cardiotoxic effects and can increase the risk of cardiac arrhythmia , but studies that have demonstrated cellular mechanisms of arrhythmia caused by bufalin are limited.…”