Chemical Composition and Bioactivity of Nelumbo nucifera Gaertn. Flower Extract Fractions: In Vitro Antioxidant and Anti-Inflammatory Properties

With the aging global population, interest in skin aging and skin health products is increasing. <i>Nelumbo nucifera</i> Gaertn. (lotus) has been widely used for its pharmacological benefits, including antioxidant, anti-inflammatory, skin-whitening, and anti-aging properties. In this study, we aimed to develop a safe and biologically active extract by extracting lotus flowers with hot water, followed by sequential fractionation using porous resin chromatography with stepwise ethanol elution (100% water and 30%, 70%, and 100% ethanol). The 30% and 70% ethanol fractions showed the highest total polyphenol and flavonoid contents. Liquid chromatography-electrospray ionization-mass spectrometry analysis identified major flavonoids, including myricetin and quercetin derivatives, in these fractions. These fractions were combined to formulate a novel <i>Nelumbo nucifera</i> flower extract (NFE), which exhibited potent antioxidant activity confirmed by 2,2-diphenyl-1-picrylhydrazyl, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) and ferric reducing antioxidant power assays. NFE significantly inhibited nitric oxide and prostaglandin E₂ secretion in lipopolysaccharide-activated murine RAW264.7 macrophages. In human keratinocytes HaCaT cells, NFE reduced tumor necrosis factor-α-induced expression and secretion of the pro-inflammatory cytokines interleukin (IL)-6 and IL-8 without cytotoxicity. These findings demonstrate that NFE has strong in vitro antioxidant and anti-inflammatory activities, supporting its potential as a bioactive ingredient for application in improving skin health preparations.