Antidepressive‐like effect of volatile components of kososan in a mouse model of stress‐induced depression. Issue 2 (October 2016) - Ito, Naoki
ABSTRACT: Aim: Kososan (Xiang‐Su‐San in Chinese), a kampo (traditional Japanese herbal) medicine, contains large amounts of unique volatile components (termed KSv). This study evaluated the antidepressive‐like effects of KSv alone or in combination with the water‐soluble extracts of kososan (termed KSw), neither of which is fully known, in a mouse model of stress‐induced depression. Methods: KSv, KSw + KSv (in toto or with a specific component herb removed), or KSw + perillaldehyde (a major volatile component of perillae herba) was given to stress‐induced depression‐like model mice for 9 days, followed by measurement of immobility time in forced swimming test (FST). KSv was also analyzed on gas chromatography–mass spectroscopy. Results: KSv (100%, inhaled) significantly reduced FST immobility time. KSw (0.5 g/kg, oral) + KSv (50%, inhaled) reduced immobility time to a significantly greater extent than did either alone, whereas KSw + KSv with perillae herba removed (50%, inhaled) did not. Likewise, KSw + 0.5% (v/v) perillaldehyde significantly had less immobility time than did either alone. Conclusion: Inhaled KSv has antidepressive‐like activity in a mouse model of stress‐induced depression and enhances the antidepressive‐like activity of KSw. Perillaldehyde in perillae herba may account in part for the enhancing effects of KSv. Copyright © 2016 John Wiley & Sons, Ltd.