Compound K, an intestinal metabolite of ginsenosides, inhibits PDGF-BB-induced VSMC proliferation and migration through G1 arrest and attenuates neointimal hyperplasia after arterial injury

Objective: Compound K (CK), an intestinal metabolite of ginsenosides, has pharmacological properties such as anti-angiogenesis, anti-inflammation, anti-platelet and anti-cancer activities. In the present study, we investigated the inhibitory effect of CK on vascular smooth muscle cell (VSMC) proliferation and migration in vitro and neointima formation in a rat carotid artery injury model. Results: CK significantly inhibited both the proliferation and migration of PDGF-BB-stimulated VSMCs in a concentration-dependent manner. In accordance with these findings, CK blocked the PDGF-BB-induced progression of synchronized cells through the G0/G1 phase of the cell cycle. CK also decreased the expressions of cell cycle-related proteins, including cyclin-dependent kinase (CDK) 2, cyclin E, CDK4, cyclin D1, and proliferative cell nuclear antigen (PCNA) in response to PDGF. However, CK did not affect early signal transduction through PDGF-R beta, Akt, ERK1/2 and PLC-gamma 1 phosphorylation. CK attenuated PDGF-BB-induced VSMC migration by inhibiting MMP-2 and MMP-9 expression. Furthermore, the CK-treated groups showed a significant reduction in neointima formation vs. the control group. Immunohistochemical staining demonstrated decreased expression of PCNA in the neointima of the CK-treated group. Conclusion: Our findings demonstrated that CK was capable of suppressing the abnormal VSMC proliferation and migration. It suggested that CK can be a therapeutic agent to control pathologic cardiovascular conditions such as restenosis and atherosclerosis. (c) 2013 Elsevier Ireland Ltd. All rights reserved.