Cordycepin Attenuates Neointimal Formation by Inhibiting Reactive Oxygen Species–Mediated Responses in Vascular Smooth Muscle Cells in Rats

Abstract

We determined the action mechanism of cordycepin, a major bioactive component of Cordyceps militaris, on responses of rat aortic smooth muscle cells (RASMCs) and on vascular disorders, especially neointimal formation. Cordycepin inhibited platelet-derived growth factor-BB (PDGF-BB)-induced RASMCs migration and proliferation in a dose-dependent manner. However, pre-treatment with N^ω-nitro-L-arginine methyl ester, a nitric oxide synthase (NOS) inhibitor, and 1,3-dipropyl-8-sulphophenylxanthine (DPSPX), an A₁/A₂ adenosine–receptor antagonist, abolished the inhibitory role of cordycepin. Cordycepin suppressed the phosphorylation of p38 mitogen–activated protein kinase (p38 MAPK) and heat shock protein 27 (Hsp27), but not that of extracellular signal-regulated kinase (ERK) 1/2 in RASMCs stimulated by PDGF-BB. The production of reactive oxygen species (ROS), O₂⁻ and H₂O₂, induced by PDGF-BB was abolished by the treatment of cordycepin. Moreover, the sprout outgrowth of aortic rings by PDGF-BB was inhibited by cordycepin. In vivo neointimal formation evoked by balloon-injury was significantly attenuated by the administration of cordycepin. These results demonstrate that cordycepin may exert inhibitory effects on PDGF-BB–induced migration and proliferation via interfering with adenosine receptor–mediated NOS pathways, thus resulting in the attenuation of neointima formation. In conclusion, cordycepin may be a potent, promising anti-atherosclerosis agent.