Salvia miltiorrhiza (Danshen) inhibits L-type calcium current and attenuates calcium transient and contractility in rat ventricular myocytes

Abstract Ethnopharmacological relevance Salvia miltiorrhiza (SM, Danshen), a traditional Chinese herbal drug, has been widely used for hundreds of years to treat coronary artery disease. Materials and methods We studied the effects of SM on the L-type Ca 2+ current ( I Ca-L ) with whole-cell patch-clamp technique in rat ventricular myocytes, and its influence on Ca 2+ transient and contractility using video-based edge detection and dual excitation fluorescence photomultiplier systems as well. Results Exposure to SM solution caused a concentration- and voltage-dependent blockade of I Ca-L , and the dose of SM solution (10 g/l) decreased the maximal inhibitory effect of 35.2±1.2%. However, SM solution did not significantly change the current–voltage relationship or reversal potential of I Ca-L , nor did it altered the activation and inactivation gating properties of cardiac Ca 2+ channels. Meanwhile, SM decreased the amplitude of myocyte shortening and the peak value of Ca 2+ transient with a significant decrease in the time to 90% of the baseline ( T r ), but the time to 10% of the peak ( T p ) was not dramatically prolonged. Conclusions The results indicated that SM significantly inhibited L-type Ca 2+ channels, decreased [Ca 2+ ] i and contractility in adult rat cardiac myocytes. These findings may be relevant to the cardioprotective efficacy of SM.