Ginsenoside Rb1 prevents age-related endothelial senescence by modulating SIRT1/caveolin-1/enos signaling pathway

Background: , a classic book on traditional Chinese medicine, states that ginseng "harmonizes the five internal organs, calming the spirit and prolonging the years of life." Considered one of the primary bioactive compounds derived from Panax ginseng, ginsenoside Rb1 (g-Rb1) has been scientifically suggested to possess anti-senescence efficacy. More research is needed to explore the vascular pharmacological activity and potential clinical application value of g-Rb1. Aims of the study: Our previous study demonstrated that g-Rb1 could mitigate cellular senescence via the SIRT1/eNOS pathway. This study was performed to explore the exact mechanisms by which g-Rb1 modulates the SIRT1/eNOS pathway. Materials and methods: We used human primary umbilical vein endothelial cells (HUVECs) to establish a replicative ageing model. Real-time (RT‒PCR), western blotting, small interfering RNA (siRNA), and immunoprecipitation were conducted to detect the effect of g-Rb1 on the SIRT1/caveolin-1/eNOS axis. Results: G-Rb1 increased NO production and alleviated replicative senescence of HUVECs. The application of g-Rb1 elevated the mRNA and protein abundance of both SIRT1 and eNOS while concomitantly suppressing the expression of caveolin-1. Inhibition of SIRT1 and eNOS by siRNAs suppressed the anti-senescence function of g-Rb1, while caveolin-1 siRNA could enhance it. G-Rb1 decreased the acetylation level of caveolin-1 and increased NO production, which was suppressed by SIRT1 siRNA. Both g-Rb1 and caveolin-1 siRNA could reduce the acetylation level of eNOS and increase NO production. Conclusion: G-Rb1 prevents age-related endothelial senescence by modulating the SIRT1/caveolin-1/eNOS signaling pathway.