Abstract
The ethnopharmacological relevance of the Millingtonia hortensis (M. hortensis) flower's aqueous extract lies in its traditional use as a herbal remedy in Southeast Asia. With a rich history in folk medicine, this aqueous has been esteemed for its purported sedative and anxiolytic properties. Our research delves into the scientific basis of these traditional claims, exploring the potential mechanisms underlying the observed effects of M. hortensis flower's aqueous extract on sleep promotion and mood regulation. This study aimed to explore the sleep-promoting effects of M. hortensis dried flower in mice, using an aqueous concentration equivalent to a human concentration of 2.7 mg/mL. Anxiolytic and antidepressant properties were evaluated using behavioural tests, while electroencephalography (EEG) analysis probed the neural mechanisms underlying sleep promotion post-consumption. The aqueous extract of M. hortensis dried flower administered to mice showed a decrease in immobility in the forced swimming test, demonstrating antidepressant-like effects. Moreover, mice treated with M. hortensis aqueous exhibited increased non-rapid eye movement (NREM) sleep duration, corroborating sleep-promoting potential. EEG analysis of mice treated with M. hortensis aqueous revealed heightened beta oscillations in the frontal and parietal cortex, while pre-treatment with M. hortensis aqueous or diazepam enhanced rapid eye movement (REM) sleep after thiopental administration. Interestingly, M. hortensis aqueous pre-treatment augmented delta frequency ranges in the frontal cortex. Overall, these findings indicate that M. hortensis dried flower's aqueous extract, at a human-equivalent dosage, exerts significant behavioural and neural effects specifically, sedative and hypnotic aspects in mice, corroborating its potential as a natural remedy to promote sleep and regulate mood.