Glabrene, a natural product isolated and purified from the roots of Glycyrrhiza uralensis with estrogen-like activity, can stimulate DNA synthesis in human endothelial cells (ECV-304; E304) and has a bi-phasic effect on proliferation of human vascular smooth muscle cells (VSMC), exerts varying degrees of inhibition on tyrosinase-dependent melanin biosynthesis, suggesting that it may serve as candidates for skin-lightening agents.