Saikokaryukotsuboreito, a herbal medicine, prevents chronic stress-induced anxiety in rats: comparison with diazepam.

Anxiety is frequently observed in several neuropsychiatric disorders, and stress is thought to precipitate or exacerbate anxiety. In this study, the anxiolytic action of a herbal medicine, saikokaryukotsuboreito, (SRBT) was examined in normal healthy rats using the elevated plus-maze test. Moreover, the improving effect of SRBT on chronic stress-induced anxiety was also examined. Single administration of SRBT did not have anxiolytic action in normal rats. Repeated administration of SRBT significantly improved chronic stress-induced anxiety. On the other hand, single administration of a typical anxiolytic, diazepam, had anxiolytic action in normal rats but repeated administration did not improve chronic stress-induced anxiety. These results suggest that SRBT does not have anxiolytic activity equivalent to that of diazepam but has potency for improving stress-related anxiety. This finding provides information important for the treatment of anxiety.