PurposesWe have previously reported that Ginsenoside Rb1 may effectively prevent HUVECs from senescence, however, the detailed mechanism has not demonstrated up to now. Recent studies have shown that sirtuin-1 (Sirt1) plays an important role in the development of endothelial senescence. The purpose of this study was to explore whether Sirt1 is involved in the action of Ginsenoside Rb1 regarding protection against H2O2-induced HUVEC Senescence.Methods and ResultsSenescence induced by hydrogen peroxide (H2O2) in human umbilical vein endothelial cells (HUVECs) was examined by analyzing plasminogen activator inhibitor-1 (PAI-1) expression, cell morphology, and senescence-associated beta-galactosidase (SA-β-gal) activity. The results revealed that 42% of control-treated HUVECs were SA-β-gal positive after treatment by 60 µmol/L H2O2, however, this particular effect of H2O2 was decreased more than 2-fold (19%) in the HUVECs when pretreated with Rb1 (20 µmol/L) for 30 min. Additionally, Rb1 decreased eNOS acetylation, as well as promoted more NO production that was accompanied by an increase in Sirt1 expression. Furthermore, upon knocking down Sirt1, the effect of Rb1 on HUVEC senescence was blunted.ConclusionsThe present study indicated that Ginsenoside Rb1 acts through stimulating Sirt1 in order to protect against endothelial senescence and dysfunction. As such, Sirt1 appears to be of particular importance in maintaining endothelial functions and delaying vascular aging.

No abstract

We showed that Rb1 effectively protects HUVECs from senescence through eNOS modulation.

Oxidative low-density lipoprotein (ox-LDL) induces endothelium senescence and promotes atherosclerosis. Ginsenoside Rb1 (gRb1) has been proved to protect human umbilical vein cells (HUVECs), but its effect on ox-LDL–induced endothelium senescence and the underlying mechanism remains unknown. This study is to explore the involvement of the SIRT1/Beclin-1/autophagy axis in the effect of gRb1 on protecting endothelium against ox-LDL–induced senescence. Hyperlipidemia of Sprague Dawley rats was induced by high-fat diet, and gRb1 was intraperitoneal injected. A senescence model of HUVECs induced by ox-LDL was also established. The results showed that gRb1 alleviated hyperlipidemia-induced endothelium senescence and ox-LDL-induced HUVECs senescence. GRb1 also restored the reductions in SIRT1 and autophagy, which were involved in the anti-senescence effects. Beclin-1 acetylation was reduced, and the correlation between SIRT1 and Beclin-1 was increased by gRb1. Results of our study demonstrated the anti-senescence function of gRb1 against hyperlipidemia in the endothelium, and the underlying mechanism involves the SIRT1/Beclin-1/autophagy axis.

Age-related myocardial dysfunction is a very large healthcare burden. Here, we aimed to investigate whether ginsenoside Rb1 (Rb1) improves age-related myocardial dysfunction and to identify the relevant molecular mechanism. Young mice and aged mice were injected with Rb1 or vehicle for 3 months. Then, their cardiac function was inspected by transthoracic echocardiography. Serum and myocardium tissue were collected from all mice for histological or molecular expression analyses, including aging-related proteins, markers relevant to fibrosis and inflammation, and markers indicating the activation of the nuclear factor-kappa B (NF-[Formula: see text]B) pathway. Compared with the control condition, Rb1 treatment significantly increased the ejection fraction percentage and significantly decreased the internal diameter and volume of the left ventricle at the end-systolic and end-diastolic phases in aged mice. Rb1 treatment reduced collagen deposition and collagen I, collagen III, and transforming growth factor-[Formula: see text]1 protein expression levels in aged hearts. Rb1 also decreased the aging-induced myocardial inflammatory response, as measured by serum or myocardial interleukin-6 and tumor necrosis factor-[Formula: see text] levels. Furthermore, Rb1 treatment in aged mice increased cytoplasmic NF-[Formula: see text]B but decreased nuclear NF-[Formula: see text]B, which indicated the suppression of the NF-[Formula: see text]B signaling pathway by regulating the translocation of NF-[Formula: see text]B. Rb1 could alleviate aging-related myocardial dysfunction by suppressing fibrosis and inflammation, which is potentially associated with regulation of the NF-[Formula: see text]B signaling pathway.