Replicative senescence in endothelial cells is characterized by an irreversible cell cycle arrest and impaired endothelial function, contributing to vascular aging and cardiovascular disease. Natural compounds are being actively studied for their potential to delay cellular senescence and protect vascular health. Among them, rice bran has demonstrated several vascular benefits that are mainly attributed to gamma-oryzanol (γ-Orz), a major bioactive component in rice bran. However, its role in regulating endothelial replicative senescence and the underlying molecular mechanisms remain unclear. This study aimed to explore the protective effects of rice bran extract (RBE) and γ-Orz on replicative senescence in porcine coronary artery endothelial cells (PCAECs). Replicative senescence was modeled in PCAECs by serial passaging from P1 to P3 with varying concentrations of RBE and γ-Orz.Senescence was evaluated by measuring senescence-associated β-galactosidase (SA-β-gal) activity, cell proliferation, oxidative stress, and the expression of cell cycle regulatory proteins. RBE and γ-Orz significantly reduced SA-β-gal activity, improved proliferation, and decreased oxidative stress in P3 cells, along with downregulation of senescence-related proteins p53, p21, and p16. Additionally, γ-Orz suppressed sodium-glucose co-transporter 2 expression, reduced NADPH oxidase overexpression, and restored eNOS levels. These findings indicate that RBE and γ-Orz delay endothelial senescence by alleviating oxidative stress, highlighting their potential to reduce cardiovascular disease risk associated with endothelial senescence.

The most common heart valve disorder is calcific aortic valve stenosis (CAVS), which is characterized by a narrowing of the aortic valve. Treatment with the drug molecule, in addition to surgical and transcatheter valve replacement, is the primary focus of researchers in this field. The purpose of this study is to determine whether niclosamide can reduce calcification in aortic valve interstitial cells (VICs). To induce calcification, cells were treated with a pro-calcifying medium (PCM). Different concentrations of niclosamide were added to the PCM-treated cells, and the level of calcification, mRNA, and protein expression of calcification markers was measured. Niclosamide inhibited aortic valve calcification as observed from reduced alizarin red s staining in niclosamide treated VICs and also decreased the mRNA and protein expressions of calcification-specific markers: runt-related transcription factor 2 and osteopontin. Niclosamide also reduced the formation of reactive oxygen species, NADPH oxidase activity and the expression of Nox2 and p22 phox . Furthermore, in calcified VICs, niclosamide inhibited the expression of β-catenin and phosphorylated glycogen synthase kinase (GSK-3β), as well as the phosphorylation of AKT and ERK. Taken together, our findings suggest that niclosamide may alleviate PCM-induced calcification, at least in part, by targeting oxidative stress mediated GSK-3β/β-catenin signaling pathway via inhibiting activation of AKT and ERK, and may be a potential treatment for CAVS.