Inhibition by plant herb extracts of steroid bindings in uterus, liver and serum of the rabbit.

To assess the action of herb extracts, glycyrrhizin and paeoniflorin, upon steroids, their binding to several classes of intracellular and serum steroid-binding proteins was studied in the rabbit. Glycyrrhizin and paeoniflorin exhibited similar binding behaviors. They bound minimally to estrogen and androgen receptors, but not to the progesterone receptor in uterine cytosol, and exhibited a moderate binding activity to glucocorticoid receptors in liver cytosol. They also exhibited weak binding activity to both cortico-steroid-binding globulin and sex-hormone-binding globulin.