Schizandra chinensis and Scutellaria baicalensis counter stress behaviors in mice

The individual and combined antistress effects of the fruit of Schizandra chinensis and the radix of Scutellaria baicalensis were evaluated using a mouse acute stress model. Stress consisted of immobilization and electric foot shocks over 5 days. Mice were treated with herbal extracts for 7 days before exposing the animals to stress. Before each stressor presentation, the mice were treated with each herbal extract. Reduced locomotor activity and the percentage of time spent in the open arms of an elevated plus-maze under stress were recovered by treatment with the extract containing equal amounts of S. chinensis and S. baicalensis (CB11) at 200 and 400 mg/kg (p < 0.05). The effects of CB11 were greater than the effects of S. chinensis or S. baicalensis alone. CB11 treatment (100, 200 and 400 mg/kg) significantly reduced serum corticosterone levels (p < 0.05). Spleen size and the serum interleukin-2 level decreases induced by stress were prevented by CB11 (200 mg/kg) (p < 0.05). Taken together, these results suggest that S. chinensis and S. baicalensis in equal amounts could be used to treat stress disorders, in part, by preventing corticosterone and IL-2 level changes and ameliorating stress-related behavior parameters. Copyright (C) 2007 John Wiley & Sons, Ltd.