The inhibitory effects of ginseng saponin on adrenal atrophy, thymus atrophy and the decrease of serum K+ concentration induced by cortisone acetate in unilateral adrenalectomized rats were studied. Ginseng saponin was isolated from the roots of Panax ginseng C. A. MEYER by using of Amberlite XAD-2 resin. Ginseng saponin (200 mg/kg, ×7 days, p. o.) was found to be antagonistic to the suppressive action of cortisone acetate (10 mg/kg, ×7 days, i. m.) on compensatory adrenal hypertrophy in rats after unilateral adrenalectomy and this finding was supported by histochemical studies. Ginseng saponin was also found to be antagonistic to the decrease of thymus weight and serum K+ concentration induced by cortisone acetate in these rats. On the other hand, the same dose of ginseng saponin alone had no effect on compensatory adrenal hypertrophy, thymus weight and serum K+ concentration in these rats. In histochemical studies, ginseng saponin showed no effect on the improvement of fatty metamorphosis induced by cortisone acetate in the liver of these rats. These actions of ginseng saponin, except for the effect on serum K+ concentration, were approximately the same as those of glycyrrhizin but different from those of saiko saponin isolated from the roots of Bupleurum falcatum LINNE.
