Design and validation of neuronal exocytosis blocking peptides as potential novel antiperspirants.

Thermoregulation and heat dissipation by sweat production and evaporation are vital for human survival. However, hyperhidrosis or excessive perspiration might affect people's quality of life by causing discomfort and stress. The prolonged use of classical antiperspirants, anticholinergic medications or botulinum toxin injections for persistent hyperhidrosis might produce diverse side effects that limit their clinical use. Inspired by botox molecular mode of action, we used an in silico molecular modelling approach to design novel peptides to target neuronal acetylcholine exocytosis by interfering with the Snapin-SNARE complex formation. Our exhaustive design rendered the selection of 11 peptides that decreased calcium-dependent vesicle exocytosis in rat DRG neurons, reducing αCGRP release and TRPV1 inflammatory sensitization. The most potent peptides were palmitoylated peptides SPSR38-4.1 and SPSR98-9.1 that significantly suppressed acetylcholine release in vitro in human LAN-2 neuroblastoma cells. Noteworthy, local acute and chronic administration of SPSR38-4.1 peptide significantly decreased, in a dose-dependent manner, pilocarpine-induced sweating in an in vivo mouse model. Taken together, our in silico approach lead to the identification of active peptides able to attenuate excessive sweating by modulating neuronal acetylcholine exocytosis, and identified peptide SPSR38-4.1 as a promising new antihyperhidrosis candidate for clinical development.