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

With the aging global population, interest in skin aging and skin health products is increasing. Nelumbo nucifera 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 Nelumbo nucifera 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.