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

Eugenol inhibited Ang II-induced premature senescence in both vascular tissues and HVSMCs.

• 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 eugenol intervention.
• Valsartan, an Ang II receptor antagonist, served as a positive control drug.
• Senescence was assessed using SA-β-gal staining and detection of senescence marker molecules p21 and p53.
• Eugenol significantly enhanced arterial stiffness and structural changes in aged vessels.

Eugenol attenuated the senescence-associated secretory phenotype (SASP) and enhanced the proliferative activity of senescent VSMCs.

• Both SASP attenuation and restoration of proliferative activity were observed following eugenol treatment in Ang II-induced senescent HVSMCs.
• These effects were assessed in the context of Ang II-induced premature senescence models.
• The findings were evaluated alongside SA-β-gal staining and senescence marker molecule detection.

Ang II exposure led to increased MFG-E8 expression in cells and vascular tissues, a change that eugenol was able to reverse.

• MFG-E8 expression was detected using immunohistochemistry, reverse transcription-quantitative PCR, and western blot analysis.
• Eugenol downregulated MFG-E8 expression in both Ang II-treated HVSMCs and vascular tissues.
• MFG-E8 upregulation was identified as a consequence of Ang II-induced senescence in the experimental models.

Knockdown of MFG-E8 suppressed the Ang II-induced senescence phenotype in HVSMCs.

• HVSMC cell lines with MFG-E8 knockdown were generated using short hairpin RNA methods.
• MFG-E8 knockdown recapitulated the anti-senescence effects observed with eugenol treatment.
• This finding establishes MFG-E8 as a mediator of Ang II-induced VSMC senescence.

Overexpression of MFG-E8 directly induced HVSMC senescence and counteracted the anti-aging effects of eugenol.

• HVSMC cell lines with MFG-E8 overexpression were generated using plasmid overexpression methods.
• MFG-E8 overexpression was sufficient to directly induce a senescence phenotype in HVSMCs.
• MFG-E8 overexpression counteracted the anti-aging effects of eugenol, confirming MFG-E8 as a functional target of eugenol's mechanism of action.