Abstract:Angiotensin converting enzyme（ACE）-inhibitory peptides derived from pumpkin seed meal were evaluated for their effects on vascular endothelial dysfunction，focusing on the regulation of the ACE/angiotensin II type 1 receptor（AT1R） pathway in the renin-angiotensin-aldosterone system （RAAS），as well as the expression of vascular cell adhesion molecule 1（VCAM-1） and intercellular adhesion molecule 1（ICAM-1）. Results showed that pumpkin seed ACE-inhibitory peptides could enhance catalase （CAT），reduced glutathione（GSH），and nitric oxide （NO） levels in hydrogen peroxide （H2O2）-induced human umbilical vein endothelial cells （HUVEC），while reducing malondialdehyde （MDA） and endothelin-1（ET-1） levels. Additionally，they decreased tumor necrosis factor-alpha （TNF-α） levels in angiotensin II-induced HUVEC damage，suppressed mRNA expression of ACE，AT1R，ET-1，VCAM-1，and ICAM-1 in the RAAS，activated cellular mechanisms to alleviate endothelial injury，and thereby exerted protective effects against endothelial dysfunction. This study provides theoretical support for improving the comprehensive utilization of pumpkin seed byproducts and lays a foundation for the application of pumpkin seed ACE-inhibitory peptides in functional foods.