Green Extraction and Molecular Docking-Guided Discovery of Asiaticoside as a Multi-Target Modulator of the SIRT1/HMGB1/p53-p21 Axis in H2O2-Induced Senescent Endothelial Cells

Endothelial cell senescence is a key contributor to vascular ageing and cardiovascular diseases. Asiaticoside, a pentacyclic triterpenoid saponin from Centella asiatica, exhibits anti-inflammatory and antioxidant activities, yet its potential to modulate endothelial senescence remains unexplored. Herein, we report the molecular docking-guided discovery of asiaticoside as a multi-target modulator of the SIRT1/HMGB1/p53–p21 senescence regulatory axis. Asiaticoside was isolated via a green acid-hydrolysis strategy using dilute HCl as the extraction solvent, followed by polyamide enrichment and C18 reversed-phase purification (purity > 98%). Molecular docking revealed that asiaticoside binds favourably to SIRT1 (−8.1 kcal mol−1), the HMGB1–DNA complex (−10.7 kcal mol−1), and several senescence-associated secretory phenotype (SASP)-related inflammatory cytokines. In H2O2-induced senescent human umbilical vein endothelial cells (HUVECs), asiaticoside at 100 μM significantly reduced senescence-associated β-galactosidase activity and alleviated G0/G1 cell cycle arrest without cytotoxicity. Mechanistically, asiaticoside restored SIRT1 expression, suppressed the secretion of IL-1β, IL-6, IL-8, TNF-α, and HMGB1, downregulated p21 at both mRNA and protein levels, reduced p53 protein expression, and suppressed p16 mRNA expression. These findings demonstrate that asiaticoside attenuates endothelial senescence and SASP-driven inflammation, an effect associated with restoration of SIRT1 expression and suppression of the HMGB1/p53–p21 pathway.