Background:

Daurisoline is a hERG inhibitor and also an autophagy blocker.

Daurisoline (compound 1) shows a maximal inhibitory effect on the end of depolarization (IhERG-step) at +20 mV and on the peak tail current (IhERG-tail) at +60 mV. At concentrations of 1, 3, 10, and 30 μM, the inhibition ratios for current amplitude at the end of depolarization (IhERG-step) are 32.2±4.2%, 41.6±2.6%, 62.1±5.9%, and 74.8±6.8%, respectively; the IC50 is 9.1 μM. In turn, the inhibition ratios for IhERG-tail are 16.7±5.8%, 31.1±4.5%, 55.1±7.2%, and 81.2±7.0%, respectively; the IC50 is 9.6 μM[1]. Daurisoline (DAS) inhibits the CPT-induced autophagy in different cancer cell lines, with IC50s of 74.75±1.03, 50.54±1.02 and 80.81±1.10 μM in HeLa, A549 and HCT-116 cells, respectively. DAC and Daurisoline also impair lysosomal function and lysosomal acidification, via inhibiting the lysosome V-type ATPase acitivity in DAC and Daurisoline treated cells[2].

The results show that plasma concentration exists a biexponential decline following iv administration of Daurisoline (DS) or dauricine (Dau) 6 mg/kg. After iv Daurisoline and Dau 6 mg/kg in beagle dogs, HR, LVSP, dp/dtmax, and SBP are decreased. But the maximum pharmacological effects of both drugs peak at 10 to15 min later than the maximum plasma concentration is observed[3].

[1]. Liu Q, et al. Effect of daurisoline on HERG channel electrophysiological function and protein expression. J Nat Prod. 2012 Sep 28;75(9):1539-45. [2]. Wu MY, et al. Natural autophagy blockers, dauricine (DAC) and daurisoline (DAS), sensitize cancer cells tocamptothecin-induced toxicity. Oncotarget. 2017 Sep 8;8(44):77673-77684. [3]. Shi SJ, et al. Pharmacokinetic-pharmacodynamic modeling of daurisoline and dauricine in beagle dogs. Acta Pharmacol Sin. 2003 Oct;24(10):1011-5.