Oligomeric peptides from blue mussel protect endothelial cells from oxLDL-induced oxidative stress and apoptosis

In this work, the protective effects of PIISVYWK (P1) and FSVVPSPK (P2) were examined against oxLDL-induced endothelial dysfunction in human umbilical vein endothelial cells. Both peptides significantly improved cell viability, enhanced nitric oxide production, and upregulated endothelial nitric oxide synthase expression while suppressing oxLDL-induced lectin-like oxidized low-density lipoprotein receptor-1 expression. Moreover, P1 and P2 exhibited strong antioxidant activity by reducing reactive oxygen species, enhancing the expression of antioxidant enzymes including superoxide dismutase, catalase, and glutathione peroxidase, and inhibiting lipid peroxidation. They also mitigated oxLDL-induced apoptosis by preserving mitochondrial membrane potential and regulating apoptosis-related gene expression. Additionally, both peptides exerted anti-inflammatory effects by downregulating intercellular adhesion molecule-1 and vascular cell adhesion molecule-1. These findings indicate that P1 and P2 may serve as natural agents with protective effects against oxLDL-induced endothelial dysfunction, warranting further studies to evaluate their in vivo relevance and potential applicability in cardiovascular health.