Anxiolytic-like Effects of Sanjoin-Tang Extracts and its Ingredients in the Elevated Plus-Maze in Mice

This study was carried out to evaluate the putative anxiolytic-1ike effects of the aqueous extracts of Sanjoin-tang (SJIT) and its ingredients using the elevated plus maze (EPM) test in mice. SJIT consists of five herbs, namely, Zizyphi Spinosi Semen (roasted), Glycyrrhizae Radix, Cnidii Rhizoma, Anemarrhenae Rhizoma, and Hoelen. The aqueous extracts of SJIT and each herbal drug were orally administered to ICR mice, 1 hr before evaluating behavioral activity in the EPM test, respectively. Repeated treatments (for 3 days) of the aqueous extract of SJIT (400 mg/kg) significantly increased time-spend in the open arms and arms entries into the open arms in the EPM test. Zizyphi Spinosi Semen (400 mg/kg), an ingredient of SJIT, significantly increased timespent in the open arms and arm entries into the open arms (P < 0.05). However, the other ingredient of SJIT did not show any anxiolytic-like behaviors. In addition, the anxiolytic-like effects of Zizyphi Spinosi Semen were blocked by pindolol (lO mg/kg), a $5-HT_{1A}$ receptor antagonist. These results suggest that Zizyphi Spinosi Semen (roasted) as an ingredient of SJIT plays a crucial anxiolytic role, and it acts via the serotonergic nervous system.