Naoxintong capsules modulates tumor necrosis factor--induced endothelial senescence through silent information regulator 1 signaling.

Objective: To investigate the protective effects of Naoxintong capsules ( NXT)on tumor necrosis factor-α (TNF-α) -induced senescence inendothelial cells and its mechanism.
Methods: Human umbilical vascular endothelial cells (HUVECs) were treated with TNF-α ± NXT and assessed for silent information regulator 1 (SIRT1) expression and signaling. Cells were stained with beta-galactosidase to assess the levels of cellular senescence. SIRT1 was silenced through siRNA transfection.
Results: TNF-α treatment led to the downregulation of SIRT1, resulting in forkhead box O1 (FoxO-1) acetylation, p53 acetylation and enhanced p21 expression. Following TNF-α treatment, higher SA β-Gal activity improved. TNF-α enhanced the migration of HUVECs and increased SIRT1 expression, both of which were attenuated by NXT treatment. The downstream targets of SIRT1 including FoxO-1/p53/p21 were also modulated, and HUVECs were protected from TNF-α-induced senescence. In contrast, the NXT-mediated protection was prevented by SIRT1 silencing.
Conclusions: These findings suggest that sustained endothelial senescence can be induced by TNF-α stimulation via the SIRT1/FoxO-1/p53/p21 pathway. The protection of NXT against TNF- was partially mediated through its effects on SIRT1. This highlights the promise of NXT as a therapeutic for atherosclerosis.