Licorice infusion (LI) and its constituents - liquiritin (1) and glycyrrhizin (2) were investigated for their capacity to stimulate the activation and the cell cycle progression of human lymphycytes, measured as the CD69 expression and DNA content. LI (100-800 microg/ml) stimulated the expression of CD69 on lymphocyte. (1) and (2) did not stimulate the CD69 expression of lymphocytes.