Enhancement of the immune response in mice by Astragalus membranaceus extracts.

Astragalus membranaceus extracts injected into normal mice or mice immunodepressed by cyclophosphamide or radiation treatment or by aging are able to enhance the antibody response to a T-dependent antigen. Optimal conditions for maximum effect have been established in normal C3H/HeJ and (C57B1/10 x DBA/2)F1 mice. Enhancement of the antibody response was associated with increase of Th cell activity in normal and immunodepressed mice. The biological activity of endotoxin-free extracts is dependent on the carbohydrate content.