Eugenol Inhibits Ox-LDL-Induced Proliferation and Migration of Human Vascular Smooth Muscle Cells by Inhibiting the Ang II/MFG-E8/MCP-1 Signaling Cascade.

OBJECTIVE: In this study, we investigated the effect and mechanism of action of eugenol on oxidized low-density lipoprotein (ox-LDL)-induced abnormal proliferation and migration of human vascular smooth muscle cells (HVSMCs).

METHODS: HVSMCs were treated with 100 ug/mL ox-LDL for 24 hours to establish a cell model. After 1-hour pretreatment, eugenol at concentrations of 5, 25, and 50 uM was added. Cell viability was assessed using an MTT assay, PCNA expression was detected using Western blot, cell cycle distribution was analyzed using flow cytometry, and cell migration ability was evaluated using wound healing and Transwell migration assays. To investigate the mechanisms, Ang II receptors were inhibited by 1000 nM valsartan, MFG-E8 was knocked down by shRNA, MCP-1 was inhibited by siRNA, and MFG-E8 was overexpressed using plasmids.

RESULTS: The findings from this study elucidated the stimulatory impact of ox-LDL on the proliferation and functionality of HVSMCs. Different concentrations of eugenol effectively mitigated the enhanced activity of HVSMCs induced by ox-LDL, with 50 uM eugenol exhibiting the most pronounced inhibitory effect. Flow cytometry and Western blot results showed ox-LDL reduced G1 phase cells and increased PCNA expression, while 50 uM eugenol inhibited ox-LDL-induced HVSMC proliferation. In wound healing and Transwell migration experiments, the ox-LDL group showed larger cell scratch filling and migration than the control group, both of which were inhibited by 50 uM eugenol. Inhibiting the Ang II/MFG-E8/MCP-1 signaling cascade mimicked eugenol's effects, while MFG-E8 overexpression reversed eugenol's inhibitory effect.

CONCLUSION: Eugenol can inhibit the proliferation and migration of ox-LDL-induced HVSMCs by inhibiting Ang II/MFG-E8/MCP-1 signaling cascade, making it a potential therapeutic drug for atherosclerosis.