Kaempferol inhibits atherosclerotic plaque development via dual-targeting of p53-p21-p16 senescence pathway and Nrf2/HO-1/NQO1 antioxidant mechanism: Insights from combined in vivo and in vitro research

Atherosclerosis, a leading cause of cardiovascular disease, is driven by aging-related endothelial cell senescence, oxidative stress, and inflammation. Kaempferol, a dietary flavonoid, exerts potent antioxidant and anti-senescence effects on the vasculature. We investigated whether kaempferol mitigates atherosclerosis through dual suppression of vascular oxidative damage and endothelial senescence. Male ApoE-/- mice on a high-fat diet were treated with kaempferol or vehicle. Atherosclerotic lesions were quantified in the aorta (Oil Red O staining), and endothelial function was assessed by vasodilation assays. Aortic tissues were analyzed for oxidative stress markers (ROS, MDA, SOD) and inflammatory cytokines (TNF-α, IL-6). Endothelial senescence in the vasculature was evaluated by γ-H2A.X staining and expression of p53, p16INK4a and p21. Separately, human endothelial cells were exposed to H₂O₂ to induce oxidative stress and senescence, with or without kaempferol; ROS levels and markers of cellular senescence (SA-β-gal, p53, p16INK4a, p21) were then measured. Kaempferol-treated mice exhibited markedly smaller aortic plaque areas than controls. Endothelium-dependent vasorelaxation improved, and oxidative stress in the aorta was attenuated (reduced ROS/MDA, increased SOD activity). Pro-inflammatory TNF-α and IL-6 levels were suppressed, while antioxidant Nrf2 and HO-1 expression was elevated. In vitro, kaempferol significantly reduced H₂O₂-induced endothelial senescence: treated cells showed fewer SA-β-gal-positive cells and decreased expression of p16INK4a and p21, indicating reduced cellular aging. Kaempferol significantly ameliorates experimental atherosclerosis via simultaneous antioxidative and anti-senescent actions, highlighting its potential as a therapeutic agent for vascular disease.