Suppressive effect of formononetin on platelet-derived growth factor-BB-stimulated proliferation and migration of vascular smooth muscle cells.

Abnormal proliferation and migration of vascular smooth muscle cells (VSMCs) has been implicated in intimal hyperplasia, atherosclerosis and restenosis following percutaneous coronary intervention. Formononetin, a phytoestrogen extracted from the root of Astragalus membranaceus, has been widely used in Chinese tradition medicine due to its protective effects against certain symptoms of cancer, hypertension, inflammation, hypoxia-induced cytotoxicity and ovariectomy-induced bone loss. However, the effect of formononetin on platelet-derived growth factor (PDGF)-BB-induced proliferation and migration of VSMCs, as well as the underlying molecular mechanism, remains largely unclear. In the present study, treatment with formononetin significantly inhibited PDGF-BB-induced proliferation and migration of human VSMCs. Investigation into the underlying molecular mechanism revealed that the administration of formononetin suppressed PDGF-BB-stimulated switch of VSMCs to a proliferative phenotype. Furthermore, treatment with formononetin inhibited the PDGF-BB-induced upregulation of cell cycle-related proteins, matrix metalloproteinase (MMP2) and MMP9. In addition, the that administration of formononetin inhibited the phosphorylation of AKT induced by PDGF-BB in VSMCs. The present results suggest that formononetin has a suppressive effect on PDGF-BB-stimulated VSMCs proliferation and migration, which may occur partly via the inhibition of AKT signaling pathway. Therefore, formononetin may be useful for the treatment of intimal hyperplasia, atherosclerosis and restenosis.