Endocrine-Disrupting Effects of Salicylate Preservatives on Neurosteroidogenesis: Targeting 5α-Reductase Type 1

Salicylate preservatives are widely used in consumer products and pharmaceuticals. This study investigates their potential endocrine-disrupting effects on neurosteroidogenesis, focusing on 5α-reductase type 1 (SRD5A1). We evaluated the effects of 13 salicylates on human SRD5A1 using SF126 glioblastoma cell microsomes and rat brain microsomes, examining dihydrotestosterone production in SF126 cells. Results revealed a hierarchy of inhibitory potency against human SRD5A1, with methyl salicylate (IC₅₀, 71.93 μM) to menthyl salicylate (2.41 μM), indicating increasing potency. Kinetic analysis indicates their mixed/noncompetitive inhibitions. In SF126 cells, all salicylates at 100 μM significantly reduced dihydrotestosterone production. Rat SRD5A1 showed reduced sensitivity, with menthyl salicylate as the most potent inhibitor (IC₅₀, 17.12 μM). Docking analysis suggests salicylates bind to the reduced nicotinamide adenine dinucleotide phosphate site of both human and rat SRD5A1. Bivariate correlation analysis highlights the influence of LogP, molecular weight, carbon number in the alcohol moiety, and pK_a on inhibitory potency. 3D-QSAR revealed the importance of hydrophobic aromatic regions in SRD5A1 binding. This study delineates the inhibitory effects of salicylates and binding mechanisms on human and rat SRD5A1, providing insights into their impact on neurosteroid production.