The immune enhancement effect of Nelumbo nucifera Gaertner Seed Extract (NSE) in murine macrophage RAW 264.7 cells

Since the global shock caused by COVID-19, interest in immune-enhancing materials is rapidly increasing, therefore, the development of novel materials is necessary from the industrial and health perspectives. In this study, we selected Nelumbo nucifera Gaertner Seed Extract (NSE) and evaluated immune enhancement effect by using RAW 264.7 murine macrophage cells. NSE significantly up-regulated production of nitric oxide and reactive oxygen species without affecting cell viability in RAW 264.7 cells. Additionally, NSE exhibited an increase of inducible nitric oxide synthase and cyclooxygenase-2 expression in RAW 264.7 cells. The enzyme-linked immuno-sorbent assay results showed that NSE-treatment significantly enhanced production of interleukin 6 and tumor necrosis factor-α in RAW 264.7 cells. Furthermore, we observed that NSE significantly up-regulated phosphorylation of p65, I kappa B kinase α/β, and I kappa B (IκB) α as well as down-regulation of IκB α expression in RAW 264.7 cells. Our findings indicate that NSE could be the potential health-functional food material with capacity of improving immunity via Nuclear factor-kappa B signaling pathway.