Parabens inhibit hNa_V 1.2 channels

Area of Science:

• Neuropharmacology
• Molecular Pharmacology

Background:

• Propylparaben, an antimicrobial preservative, exhibits anticonvulsant properties by targeting neuronal sodium channels (Na_V).
• The precise mechanism of Na_V channel inhibition by propylparaben and related compounds remains incompletely understood.

Purpose of the Study:

• To elucidate the mechanism of action of propylparaben and benzylparaben on human Na_V1.2 channels.
• To investigate the structure-activity relationship of parabens regarding Na_V channel inhibition.

Main Methods:

• Utilized patch-clamp whole-cell electrophysiology on HEK293 cells stably expressing hNa_V1.2.
• Recorded and analyzed hNa_V1.2 channel-mediated currents under various conditions.

Main Results:

• Propylparaben demonstrated state-dependent inhibition of hNa_V1.2, altering inactivation curves and recovery kinetics.
• Inhibition potency increased with the lipophilic ester group size, with benzylparaben and butylparaben showing stronger effects than propylparaben.
• Methylparaben, ethylparaben, and p-hydroxybenzoic acid exhibited diminished inhibitory effects.

Conclusions:

• Parabens act as blockers of hNa_V1.2 channels, sharing mechanisms with established antiseizure drugs.
• The lipophilicity of the ester group is a key determinant for the anticonvulsant potency of parabens.
• Findings support the rational design of novel anticonvulsant agents based on paraben structures.