Figure 9.

Synergisms and antagonisms between herbs. (a) Examples of synergism or antagonism with respect to anxiolytic effects measured based on time spent in open arms in elevated plus-maze test. The paired columns for herbal combinations BA and BYPA show in each instance that the anxiolytic effect induced by the combination (red column on the right) exceeded the sum of effects induced by the individual component herbs (composite column on the left: B in green, Y in light blue, P in dark blue, and A in yellow); in contrast, the paired columns for YP show that the anxiolytic effects induced by its component herbs Y and P were abolished by antagonisms within the YP combination. (b) Examples of antagonism with respect to sedative effects measured based on number of head-dips in the hole-board test. The paired columns for herbal combinations BP, BA, and BYPA show that the sedative effects induced by the component herbs in each instance (composite column on the left) were completely abolished by antagonisms within each combination. Sedative effects were estimated based on head-dips in the hole-board test. The anxiolytic or sedative effects represented by the combination columns were those indicated in Figures 4 and 5 for a dosage of 120 mg/kg. The individual effects of single herbs represented in the composite column were derived from the dose-response relationships for the single-herb data in Figures 4 and 5: the total dosage in each composite column was 120 mg/kg, and the contributions of individual herbs were estimated based on their weight ratios in the combination and interpolations of their individual dose-response curves.