Antiproliferative effects of the traditional Chinese medicine shimotsu-to, its component cnidium rhizome and derived compounds on primary cultures of mouse aorta smooth muscle cells.

Antiproliferative effects of the Japanese-Sino medicine Shimotsu-to (a combined prescription of cnidium rhizome, angelica root, peony root and rehmannia root) were investigated in the primary culture of smooth muscle cells (SMC) of mouse aorta. Fetal bovine serum (10%)-induced proliferation of primary cultured SMC was inhibited by Shimotsu-to at 4, 20, 100 or 500 micrograms/ml. The inhibitory effect was selective on SMC and due to cnidium rhizome or angelica root. The IC50 values of senkyunolide H, senkyunolide A, ligustilide and butylidenephthalide derived from cnidium were below 0.1, 1.52, 1.68 and 3.25 micrograms/ml, respectively. These results indicate that the antiproliferative effect of Shimotsu-to may depend on these cnidium-derived phthalides.