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Effect of Daurisoline on HERG Channel Electrophysiological Function and Protein Expression

Qiangni Liu, Xiaofang Mao, Fandian Zeng, Si Jin, Xiaoyan Yang

J Nat Prod. 2012 Sep 28;75(9):1539-45.

PMID: 22974355

Abstract:

Daurisoline (1) is a bis-benzylisoquinoline alkaloid isolated from the rhizomes of Menispermum dauricum. The antiarrhythmic effect of 1 has been demonstrated in different experimental animals. In previous studies, daurisoline (1) prolonged action potential duration (APD) in a normal use-dependent manner. However, the electrophysiological mechanisms for 1-induced prolongation of APD have not been documented. In the present study, the direct effect of 1 was investigated on the hERG current and the expression of mRNA and protein in human embryonic kidney 293 (HEK293) cells stably expressing the hERG channel. It was shown that 1 inhibits hERG current in a concentration- and voltage-dependent manner. In the presence of 10 μM 1, steady-state inactivation of V(1/2) was shifted negatively by 15.9 mV, and 1 accelerated the onset of inactivation. Blockade of hERG channels was dependent on channel opening. The expression and function of hERG were unchanged by 1 at 1 and 10 μM, while hERG expression and the hERG current were decreased significantly by 1 at 30 μM. These results indicate that 1, at concentrations below 30 μM, exerts a blocking effect on hERG, but does not affect the expression and function of the hERG channel. This may explain the relatively lower risk of long QT syndrome after long-term usage.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
AP70553763 Daurisoline Daurisoline 70553-76-3 Price
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