VGSC blocker-1 is a powerful small molecule that serves as a blocker for the neonatal isoform of the VGSC subtype known as Nav1.5 (nNav1.5). It effectively blocks INa peak currents by 34.9% at a concentration of 1 μM, and demonstrates a 0.3% inhibition of cell invasion at the same concentration in the MDA-MB-231 human breast cancer cell line, without compromising cell viability.

VGSC blocker 1 (compound 1), at concentrations ranging from 1.0 to 10 μM, effectively inhibits the human breast cancer cell line MDA-MB-231[1]. Specifically, this compound reduces cell viability and impacts cell invasion within this cell line. Experimental results demonstrate that VGSC blocker 1 decreases INa peak currents by 34.9% at a concentration of 1 µM, alongside a marginal 0.3% inhibition of cell invasion at the same concentration. These effects surpass the efficacy thresholds previously established at 0.1 µM for significant nNav1.5 current blockade and 1 µM for cell invasion inhibition, underscoring the compound's potent biological activity against MDA-MB-231 cells.