The Inhibitory Effects of Bee Venom and Melittin on the Proliferation of Vascular Smooth Muscle Cells

In the present study, I have investigated the bee venom (BV) and melittin (a major component of BV) -mediated anti-proliferative effects, and defined its mechanisms of action in cultured rat aortic vascular smooth muscle cells (VSMCs). BV and melittin $(0.4{\sim}0.8\;{\mu}g/ml)$ effectively inhibited 50 ng/ml platelet derived growth factor BB (PDGF-BB)-induced VSMCs proliferations. The regulation of apoptosis has attracted much attention as a possible means of eliminating excessively proliferating VSMCs. In the present study, the treatment of BV and melittin strongly induced apoptosis of VSMCs. I examined the effects on $NF-{\kappa}B$ activation to investigate a possible mechanism for anti-proliferative effects of BV and melittin, the PDGF-BB-induced $I{\kappa}B{\alpha}$ phosphorylation and its degradation were potently inhibited by melittin, and DNA binding activity and nuclear translocation of $NF-{\kappa}B$ p50 subunit in response to the action of PDGF-BB were potently attenuated by melittin. In further investigations, melittin markedly inhibited the PDGF-BB-induced phosphorylation of Akt but not ERK1/2, upstream signals of $NF-{\kappa}B$. Treatment of melittin also potently induced pro-apoptotic protein p53, Bax, and caspase-3 expression, but decreased anti-apoptotic protein Bcl-2 expression. These results suggest that the anti-proliferative effects of BV and melittin in VSMCs through induction of apoptosis via suppressions of $NF-{\kappa}B$ and Akt activation, and enhancement of apoptotic signal pathway. Based on these results, BV acupuncture can be a candidate as a therapeutic method for restenosis and atherosclerosis.