Antidepressive‐like effect of volatile components of kososan in a mouse model of stress‐induced depression

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