Isolation, Identification, and in Vitro Antitumor Activity of Polyphenols From <i>Euryale ferox Salisb</i> . Shell

The shell of Euryale ferox Salisb., rich in polyphenols, has antitumor potential. We isolated and identified polyphenols from the shell and evaluated their in vitro antitumor activity. Compounds were extracted with 70% ethanol under ultrasound and purified by fractional extraction and silica gel chromatography, yielding three substances. Liquid chromatography-mass spectrometry (LC-MS) and nuclear magnetic resonance confirmed the three compounds as ellagic acid, corilagin, and geraniin. High-performance LC quantification showed corilagin and geraniin concentrations of 66.23 and 58.41 mg/g. In vitro experiments on cells showed the ethanol extract had strong inhibitory effects on cell proliferation (IC₅₀: 68.56 µg/mL for HeLa, 78.09 µg/mL for A2780), and cell proliferation, migration, and invasion were regulated by the three compounds, exhibiting time- and dose-dependent characteristics. Corilagin showed the strongest inhibitory effect on HeLa cell proliferation (74.61% at 48 h) and A2780 cell invasion (69.86%). Geraniin inhibited HeLa cell invasion (63.33%) and A2780 cell invasion (61.64%). This study determined the chemical structures of polyphenolic compounds from Euryale ferox Salisb. shell and their impact on tumor cell proliferation, migration, and invasion, offering evidence for developing antitumor drugs and insights for modernizing traditional Chinese medicinal resources.