The Protective Efficacy of Total Alkaloids from Nelumbinis Plumula on Irradiation-Induced Oxidative Stress Damage in Human Umbilical Vein Endothelial Cells

A high-purity alkaloid-enriched extract (NPAE) was developed from Nelumbinis Plumula. Beyond quantifying its representative alkaloids and total alkaloid content, this study revealed the novel radioprotective role of NPAE against radiation-induced oxidative stress in human umbilical vein endothelial cells (HUVECs). Pretreatment with NPAE significantly attenuated H₂O₂-induced oxidative stress and suppressed irradiation-induced pyroptosis, primarily through restoration of redox homeostasis and inhibition of inflammasome activation. Mechanistic investigations showed that NPAE downregulated the expression of GSDMD-N and cleaved caspase-1, while reducing the secretion of proinflammatory cytokines (IL-18 and IL-1β). These results demonstrate that NPAE effectively alleviates oxidative damage and prevents pyroptosis in endothelial cells, highlighting its potential as a promising phytotherapeutic agent for protection against ionizing radiation injury.