Nature's Brewery to Bedtime: The Role of Hops in GABAA Receptor Modulation and Sleep Promotion

Doctoral Dissertation University of Turku. ISBN: 978-951-29-9577-6 (2023) Insomnia often requires pharmacological interventions, with benzodiazepines and Z-drugs enhancing GABA's inhibitory effects by stabilizing GABAA receptor chloride ion channels. Prolonged use, however, raises dependency and cognitive concerns. Humulus lupulus (hops) is gaining attention as a natural relaxant and sleep aid, potentially modulating GABAA receptors differently. This study explores hops' neuroactive phytochemicals and their therapeutic mechanisms. The alpha-acid humulone and hop prenylflavonoids affect GABA-induced displacement of [3H]EBOB in the GABAA receptor, showing flumazenil-insensitive and subtype-selective effects. Molecular docking identifies binding sites, with humulone's activity confirmed electrophysiologically and in mouse studies, impacting sleep onset and duration. These findings suggest hops as positive modulators of GABAA receptors, offering insights for sleep aid optimization.