Eugenol Attenuates Angiotensin II-Induced Vascular Smooth Muscle Cell Senescence via Downregulation of Milk Fat Globule-EGF Factor 8

The biological aging of vascular smooth muscle cells (VSMCs) is a critical event contributing to vascular aging and age-related diseases. The objective of this study is to assess the potential mechanism by which eugenol inhibits vascular senescence by downregulating milk fat globule-EGF factor 8 (MFG-E8) expression in VSMCs and vascular tissues. A model of angiotensin II (Ang II)-induced vascular aging in mice and a premature aging model in human vascular smooth muscle cells (HVSMCs) were established to assess the efficacy of eugenol intervention, with valsartan, an Ang II receptor antagonist, serving as a positive control drug. Senescence-associated-β-galactosidase (SA-β-gal) staining, along with the detection of senescence marker molecules p21 and p53, were used to assess the senescence status of cells and vascular tissues. The expression level of MFG-E8 was detected using immunohistochemistry, reverse transcription-quantitative PCR, and western blot analysis. HVSMC cell lines with MFG-E8 knockdown and overexpression were generated using short hairpin RNA and plasmid overexpression methods, respectively, to assess the role of MFG-E8 in the anti-senescence effects of eugenol on VSMCs. Eugenol inhibited Ang II-induced premature senescence in both vascular tissues and HVSMCs, significantly enhancing arterial stiffness and structural changes in aged vessels. It also attenuated the senescence-associated secretory phenotype (SASP) and enhanced the proliferative activity of senescent VSMCs. Ang II exposure led to increased MFG-E8 expression in cells and vascular tissues, a change that eugenol was able to reverse. Knockdown of MFG-E8 suppressed the Ang II-induced senescence phenotype in HVSMCs, whereas overexpression of MFG-E8 directly induced HVSMC senescence and counteracted the anti-aging effects of eugenol. Eugenol prevents Ang II-induced aging in VSMCs and vascular tissues by downregulating MFG-E8 expression, underscoring its potential as an antiaging drug.